| 1. |
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| 2. |
- Glasbey, JC, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 3. |
- Thomas, HS, et al.
(författare)
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- 2019
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swepub:Mat__t
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| 4. |
- Tabiri, S, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 5. |
- Bravo, L, et al.
(författare)
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- 2021
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swepub:Mat__t
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| 6. |
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| 8. |
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| 9. |
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| 10. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 11. |
- Moussas, X., et al.
(författare)
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The gears of the Antikythera Mechanism : an educational pathfinder to the solar system
- 2011
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Ingår i: IAU Symposium.
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Konferensbidrag (refereegranskat)abstract
- The Antikythera Mechanism is the most sophisticated extant ancient astronomical instrument and analogue computer known and was assembled sometime between 150 and 100 BCE, almost a century after the death of Archimedes. The mechanism has a great educational potential as it appeals to inquiring minds as an astonishing artefact of science and technology. The latest research findings reveal significant cultural and social functions in its operations. This astonishing astronomical instrument has a clear interdisciplinary valueand it has that it may be used as an educational medium, to engage the general public, and especially to attract students both to/from exact sciences and to/from the humanities. The astronomical and technical knowledge embedded in the mechanism can also be used to introduce some aspects of modern science through the unknown technological achievements of Hellenic antiquity.
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| 12. |
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| 14. |
- Yosri, Nermeen, et al.
(författare)
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Anti-Viral and Immunomodulatory Properties of Propolis : Chemical Diversity, Pharmacological Properties, Preclinical and Clinical Applications, and In Silico Potential against SARS-CoV-2
- 2021
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Ingår i: Foods. - : MDPI AG. - 2304-8158. ; 10:8
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Forskningsöversikt (refereegranskat)abstract
- Propolis, a resin produced by honeybees, has long been used as a dietary supplement and folk remedy, and more recent preclinical investigations have demonstrated a large spectrum of potential therapeutic bioactivities, including antioxidant, antibacterial, anti-inflammatory, neuroprotective, immunomodulatory, anticancer, and antiviral properties. As an antiviral agent, propolis and various constituents have shown promising preclinical efficacy against adenoviruses, influenza viruses, respiratory tract viruses, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), human immunodeficiency virus (HIV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Over 300 chemical components have been identified in propolis, including terpenes, flavonoids, and phenolic acids, with the specific constituent profile varying widely according to geographic origin and regional flora. Propolis and its constituents have demonstrated potential efficacy against SARS-CoV-2 by modulating multiple pathogenic and antiviral pathways. Molecular docking studies have demonstrated high binding affinities of propolis derivatives to multiple SARS-CoV-2 proteins, including 3C-like protease (3CL(pro)), papain-like protease (PLpro), RNA-dependent RNA polymerase (RdRp), the receptor-binding domain (RBD) of the spike protein (S-protein), and helicase (NSP13), as well as to the viral target angiotensin-converting enzyme 2 (ACE2). Among these compounds, retusapurpurin A has shown high affinity to 3CL(pro) (Delta G = -9.4 kcal/mol), RdRp (-7.5), RBD (-7.2), NSP13 (-9.4), and ACE2 (-10.4) and potent inhibition of viral entry by forming hydrogen bonds with amino acid residues within viral and human target proteins. In addition, propolis-derived baccharin demonstrated even higher binding affinity towards PLpro (-8.2 kcal/mol). Measures of drug-likeness parameters, including metabolism, distribution, absorption, excretion, and toxicity (ADMET) characteristics, also support the potential of propolis as an effective agent to combat COVID-19.
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| 15. |
- Moslem, W. M., et al.
(författare)
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Electrostatic structures associated with dusty electronegative magnetoplasmas
- 2010
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Ingår i: New Journal of Physics. - [Moslem, W. M.] Port Said Univ, Fac Sci, Dept Phys, Port Said, Egypt. [Abdelsalam, U. M.] Fayoum Univ, Fac Sci, Dept Math, Al Fayyum, Egypt. [Sabry, R.] Mansoura Univ, Fac Sci, Dept Phys, Theoret Phys Grp,Damietta Branch, New Damietta 34517, Egypt. [Shukla, P. K.] Ruhr Univ Bochum, Inst Theoret Phys 4, Fak Phys & Astron, D-44780 Bochum, Germany. [Shukla, P. K.] Umea Univ, Dept Phys, SE-90187 Umea, Sweden. [Moslem, W. M.] Suez Canal Univ, Fac Sci Port Said, Dept Phys, Ismailia, Egypt. [Shukla, P. K.] Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. [Shukla, P. K.] Inst Super Tecn, GoLP, P-1049001 Lisbon, Portugal. [Shukla, P. K.] Rutherford Appleton Lab, CCLRC Ctr Fundamental Phys, Didcot 0X11 0QX, Oxon, England. [Shukla, P. K.] Univ Strathclyde, SUPA Dept Phys, Glasgow G4 0NG, Lanark, Scotland. [Shukla, P. K.] Univ Kwazulu Natal, Fac Sci & Agr, Sch Phys, ZA-4000 Durban, South Africa. : IOP Publishing. - 1367-2630. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- By using the hydrodynamic equations of positive and negative ions, the Boltzmann electron density distribution and the Poisson equation with stationary dust, a three-dimensional (3D) Zakharov-Kuznetsov (ZK) equation is derived for small but finite amplitude ion-acoustic waves. However, the ZK equation is not appropriate to describe the system either at critical plasma compositions or in the vicinity of the critical plasma compositions. Therefore, the modified ZK (MZK) and extended ZK (EZK) equations are derived. The generalized expansion method is used to analytically solve the ZK, MZK and EZK equations. A new class of solutions that admits a train of well-separated bell-shaped periodic pulses is obtained. In certain conditions, the latter degenerates to either solitary or shock wave solutions. The effects of the physical parameters on the nonlinear structures are examined in many plasma environments having different negative ion species, such as D- and F-regions of the Earth's ionosphere, as well as in laboratory plasma experiments. Numerical analysis of the solutions revealed that the profile of the nonlinear pulses suffers amplitude and width modifications due to enhancement of the dust practices, negative ions, positive-to-negative ion mass ratio and positive/negative ion cyclotron frequency. Furthermore, the necessary conditions for both solitons and shocks propagation as well as their polarity are examined.
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| 16. |
- Allam, Sabry, et al.
(författare)
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Development of acoustic models for high frequency resonators for turbocharged IC-engines
- 2012
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Ingår i: SAE Technical Paper 2012-01-1559, 2012. - 400 Commonwealth Drive, Warrendale, PA, United States : SAE International.
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Konferensbidrag (refereegranskat)abstract
- Automotive turbo compressors generate high frequency noise in the air intake system. This sound generation is of importance for the perceived sound quality of luxury cars and may need to be controlled by the use of silencers. The silencers usually contain resonators with slits, perforates and cavities. The purpose of the present work is to develop acoustic models for these resonators where relevant effects such as the effect of a realistic mean flow on losses and 3D effects are considered. An experimental campaign has been performed where the two-port matrices and transmission loss of sample resonators have been measured without flow and for two different mean flow speeds. Models for two resonators have been developed using 1D linear acoustic theory and a FEM code (COMSOL Multi-physics). For some resonators a separate linear 1D Matlab code has also been developed. Different models, from the literature, for including the effect of mean flow on the acoustic losses at slits and perforates have been implemented in the codes and compared to the experimental data. Correct modeling of acoustic losses for resonators with complicated geometry is important for the simulation and development of new and improved silencers, and the present work contributes to this understanding. The developed models give acceptable agreement with the measured results even with flow but can be improved for 3D FEM if correct CAD data is available. The 1D linear theory can be used for simple geometries and to get a general overview related to the resonance frequencies and damping level.
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| 17. |
- El-Shamy, E. F., et al.
(författare)
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Head-on collision of ion-acoustic solitary waves in multicomponent plasmas with positrons
- 2010
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 17:8
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Tidskriftsartikel (refereegranskat)abstract
- The head-on collision between two ion-acoustic solitary waves in an unmagnetized multicomponent plasma consisting of hot ions, hot positrons, and two-electron temperature distributions is investigated using the extended Poincare-Lighthill-Kuo method. The Kortwege-de Vries equations and the analytical phase shifts after the head-on collision of two solitary waves in this multicomponent plasma are obtained. The effects of two different types of isothermal electrons, the ratio of the hot ion temperature to the effective temperature, the ratio of the effective temperature to the positron temperature, the ratio of the number density of positrons to that of electrons species, and the physical processes (either isothermal or adiabatic) on the phase shifts are studied. It is found that these parameters can significantly influence the phase shifts of the solitons. The relevance of this investigation to space and laboratory plasmas is pointed out.
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| 18. |
- Hussein, Mohammad H., et al.
(författare)
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Beta 2 -adrenergic receptor gene haplotypes and bronchodilator response in Egyptian patients with chronic obstructive pulmonary disease
- 2017
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Ingår i: Advances in Medical Sciences. - Warsaw, Poland : Elsevier. - 1896-1126 .- 1898-4002. ; 62:1, s. 193-201
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Chronic obstructive pulmonary disease (COPD) is a multi-factorial disorder caused by environmental determinants and genetic risk factors. Understanding the genetic predisposition of COPD is essential to develop personalized treatment regimens. Beta2-adrenergic receptor (ADRB2) gene polymorphisms have been implicated in the pathogenesis of obstructive pulmonary diseases. This study was conducted to assess the genetic association between Arg16Gly and Gln27Glu polymorphisms and COPD in the Egyptian patients, and to analyze their impact on the clinical outcome and therapeutic response.Patients/methods: The study population included 115 participants (61 COPD patients and 54 healthy controls) were genotyped for the Arg16Gly (rs1042713) and Gln27Glu (rs1042714) polymorphisms. Pulmonary function test was done and repeated in patients after salbutamol inhalation.Results: The Gly16 and Gln27 alleles represented 57% and 70% of the whole study population, and only 3 haplotypes were detected; Arg16/Gln27, Gly16/Gln27, and Gly16/Glu27. Genotypes and haplotypes homozygous for Arg16 and Gln27 were more likely to develop COPD (p<0.05). However, individuals carrying Glu27 allele conferred protection against COPD development (p=0.002). Furthermore, Arg16 genotypes and haplotypes were significantly associated with higher grades of dyspnea, more COPD symptoms and frequent exacerbations. In contrast, patients carrying Glu27 allele had better bronchial airway responsiveness to β2-agonists.Conclusions: Our findings suggested that the ADRB2 gene polymorphisms may have vital role in COPD risk, severity, and bronchodilator response among Egyptian population. Larger epidemiological studies are needed for results validation.
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| 19. |
- Khan, Ramsha, et al.
(författare)
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Appraisal of water quality and ecological sensitivity with reference to riverfront development along the River Gomti, India
- 2022
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Ingår i: Applied water science. - : Springer Nature. - 2190-5487 .- 2190-5495. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- The conflict between the vitality of natural ecosystem versus artificially developed systems has existed since decades. The ecological sensitivity and socio-economic aspects associated with riverfront development along rivers have attracted the attention of environmentalists and ecologists across the globe. The present study evaluates the impacts of channelization and riverfront development on the water quality of river Gomti through Water Pollution Index (WPI) and other statistical tools. Of the total studied sites, 75% were found to be in the 'highly polluted' category even after the development of riverfront. An approximate increase of 274.5% and 171.76% was witnessed in the WPI values at the midstream sites of Kudiaghat and Daliganj, respectively. This increase in the WPI values clearly stated the deteriorated water quality of river Gomti after the channelization. The major issue of domestic sewage discharge with partial or no treatment into the river seems to be unresolved even after a considerable period of riverfront development. This study can provide a reference database toward development of such projects across the globe.
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| 20. |
- Madenci, Emrah, et al.
(författare)
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Behavior of functionally graded carbon nanotube reinforced composite sandwich beams with pultruded GFRP core under bending effect
- 2024
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Ingår i: Frontiers in Materials. - : Frontiers. - 2296-8016. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- A novel generation of composite sandwich beams with laminated carbon fiber-reinforced polymer skins and pultruded glass fiber-reinforced polymer core materials was examined for their flexural behavior. The strength and failure mechanisms of the composite sandwich beams in flatwise and edgewise configurations were investigated using three-point static bending tests. These sophisticated composite structures must be designed and used in a variety of sectors, and our research provides vital insights into their performance and failure patterns. In comparison to the reference specimens (FGM-1), the carbon nanotube-reinforced specimens’ bending capacity was affected and ranged from −2.5% to 7.75%. The amount of the carbon nanotube addition had a substantial impact on the beams’ application level and load-carrying capacity. Particularly, the application of 0.5 wt% additive in the outermost fiber region of the beams, such as in FGM-4, led to an increase in the bending capacity. However, the stiffness values at the maximum load were decreased by 0.3%–18.6% compared to FGM-1, with the minimum level of the decrease in FGM-4. The experimental results were compared with the theoretical calculations based on the high-order shear deformation theory, which yielded an approximation between 11.99% and 12.98% by applying the Navier’s solution.
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| 21. |
- Madenci, Emrah, et al.
(författare)
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Experimental investigation and analytical verification of buckling of functionally graded carbon nanotube-reinforced sandwich beams
- 2024
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Ingår i: Heliyon. - : Elsevier. - 2405-8440. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- Carbon nanotube (CNT) reinforcement can lead to a new way to enhance the properties of composites by transforming the reinforcement phases into nanoscale fillers. In this study, the buckling response of functionally graded CNT-reinforced composite (FG-CNTRC) sandwich beams was investigated experimentally and analytically. The top and bottom plates of the sandwich beams were composed of carbon fiber laminated composite layers and hard core. The hard core was made of a pultruded glass fiber-reinforced polymer (GFRP) profile. The layers of FG-CNTRC surfaces were reinforced with different proportions of CNT. The reference sample was made of only a pultruded GFRP profile. In the study, the reference sample and four samples with CNT were tested under compression. The largest buckling load difference between the reference sample and the sample with CNT was 37.7%. The difference between the analytical calculation results and experimental results was obtained with an approximation of 0.49%–4.92%. Finally, the buckling, debonding, interlaminar cracks, and fiber breakage were observed in the samples.
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| 22. |
- Moslem, W M, et al.
(författare)
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Three dimensional cylindrical Kadomtsev-Petviashvili equation in a very dense electron-positron-ion plasma
- 2010
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Ingår i: Physics of Plasmas. - : American Institute of Physics (AIP). - 1070-664X .- 1089-7674. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- By using the hydrodynamic equations of ions, Thomas-Fermi electron/positron density distribution, and Poisson equation, a three-dimensional cylindrical Kadomtsev-Petviashvili (CKP) equation is derived for small but finite amplitude ion-acoustic waves. The generalized expansion method is used to analytically solve the CKP equation. New class of solutions admits a train of well-separated bell-shaped periodic pulses is obtained. At certain condition, the latter degenerates to solitary wave solution. The effects of physical parameters on the solitary pulse structures are examined. Furthermore, the energy integral equation is used to study the existence regions of the localized pulses. The present study might be helpful to understand the excitation of nonlinear ion-acoustic waves in a very dense astrophysical objects such as white dwarfs.
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| 23. |
- Sabry, R., et al.
(författare)
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On the generation of envelope solitons in the presence of excess superthermal electrons and positrons
- 2011
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Ingår i: Astrophysics and Space Science. - : Springer Science and Business Media LLC. - 0004-640X .- 1572-946X. ; 333:1, s. 203-208
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Tidskriftsartikel (refereegranskat)abstract
- A theoretical model is presented to investigate the existence, formation, and possible realization of nonlinear envelope ion acoustic solitary waves which accompany collisionless electron-positron-ion plasmas with high-energy electrons and positrons (represented by kappa distribution). By employing the reductive perturbation method, the hydrodynamic model and the Poisson equation are reduced to nonlinear Schrodinger equation. The effects of the superthermal parameters, as well as ion-to-electron temperature ratio on the propagation and stability of the envelope solitary waves are examined. The superthermal parameters (ion-to-electron temperature ratio) give rise to instability (stability) of the solitary excitations, since the instability window is strongly modified. Finally, the present results should elucidate the excitation of the nonlinear ion-acoustic solitary wave packets in superthermal electron-positron-ion plasmas, particularly in interstellar medium.
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| 24. |
- Sabry, R., et al.
(författare)
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Three-dimensional nonlinear Schrodinger equation in electron-positron-ion magnetoplasmas
- 2011
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 18:3
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional ion-acoustic envelope soliton excitations in electron-positron-ion magnetoplasmas are interpreted. This is accomplished through the derivation of three-dimensional nonlinear Schrodinger equation, where the nonlinearity is balancing with the dispersive terms. The latter contains both an external magnetic field besides the usual plasma parameter effects. Based on the balance between the nonlinearity and the dispersion terms, the regions for possible envelope solitons are investigated indicating that new regimes for modulational instability of envelope ion-acoustic waves could be obtained, which cannot exist in the unmagnetized case. This will allow us to establish additional new regimes, different from the usual unmagnetized plasma, for envelope ion-acoustic waves to propagate in multicomponent plasma that may be observed in space or astrophysics.
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| 25. |
- Sabry, R. Z., et al.
(författare)
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Frequency Dependent Permittivity of Soil and Bentonite : For Lightning Protection and High Frequency Earthing Systems
- 2019
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Ingår i: 2019 International Symposium on Lightning Protection (XV SIPDA). - : IEEE. - 9781728118918
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Konferensbidrag (refereegranskat)abstract
- This paper presents the frequency dependent permittivity of a selected type of soil, bentonite and four of their mixes by weight. The permittivity at a low frequencies, vary significantly with moisture content in the cases of both sand and bentonite. For dry sand, bentonite and all bentonite mixes, the permittivity shows a rapid drop with the increment of frequency from near 0 Hz to 0.6 kHz, followed by a moderate decrement up to about 10-20 kHz. All parameters have rather insignificant variation after about 50 kHz and level of around 1MHz. These outcomes provide some key information to analyze the behavior of bentonite based backfill materials that are widely used in electrical earthing networks, especially in the case of high frequency earthing and lightning protection systems.
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