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Application of Dvoretzky’s Theorem of Measure Concentration in Physics and Cosmology

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Open Journal of Microphysics 2015年第2期5卷 11-15页

作者： Mohamed s. El Naschie Department of Physics University of Alexandria Alexandria Egypt

Using Dvoretzky’s theorem in conjunction with Bohm’s picture of a quantum particle inside a guiding quantum wave akin to De Broglie-Bohm pilot wave we derive Einstein’s famous formula E = mc2 as the sum of two parts E(O) = mc2/22 of the quantum particle and E(D) = m c2 (21/22) of the quantum wave where m is the mass, c is the speed of light and E is the energy. In addition we look at the problem of black holes information in the presence of extra dimensions where it seems initially that extra dimensions would logically lead to a hyper-surface for a black hole and consequently a reduction of the corresponding information density due to the dilution effect of these additional dimensions. The present paper argues that the counterintuitive opposite of the above is what should be expected. Again this surprising result is a consequence of the same well known theorem on measure concentration due to I. Dvoretzky. We conclude that there are only two real applications of the theorem and we expect that many more applications in physics and cosmology will be found in due course.

关键词： spacetime Extra Dimensions Dvoretzky’s Theorem Information Paradox E-Infinity Theory Counterintuitive Geometry Dark Energy of the Quantum Wave 'tHooft-susskind Black Holes Wave-Particle Duality De Broglie-Bohm Pilot Wave

Corrosion Penetration and Crystal structure of AA5022 in HCl solution and Rare Earth Elements

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Journal of Materials science & Technology 2005年第3期21卷 324-330页

作者： A.A.El-Meligi s.H.sanad A.A.Ismail A.M.Barakat Electrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypElectrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypElectrochem. and Corrosion Lab. Physical Chemistry Dept. National Research Centre Dokki Cairo EgypChemistry Dept. Faculty of Science Cairo University Cairo Egypt

Al-alloy (AA5022) corrosion penetration (CP) and crystal structure were investigated after running static immersion corrosion tests in 1 mol/L HCl solution and different concentrations of rare earth elements (La3+), (Ce3+) and their combination, at different temperatures. X-ray diffraction (XRD) was used to examine the surface structure before and after immersion, and secondary electron detector (sED) was operated to study surface morphology. In 1 mol/L HCI solution the corrosion penetration increased with increasing temperature and immersion time. The increase of La3+ concentrations up to 1000×10-6 g/L led to the decrease in the corrosion penetration, and the decrease in Ce3+ concentrations up to 50×10-6 g/L decreases the corrosion penetration of the alloy. Mix3 (combination of La3+ and Ce3+) dramatically reduced the corrosion penetration. This suggests that a synergistic effect exists between La3+ and Ce3+. The reaction kinetics both in absence and presence of La3+ and Ce3+ and their combination would follow a parabolic rate law. The XRD patterns revealed that the intensities of certain hkl phases are affected. The crystalline structure has not been deformed either before or after testing and there are no additional peaks except that of the as-received alloy. In the case of accelerating CP, the surface morphology shows that the roughness and voids of surface are increased.

关键词： Al-alloy Corrosion penetration Crystal structure XRD

Reflection and refraction of plane waves at the boundary of an elastic solid and double-porosity dual-permeability materials

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Petroleum science 2019年第2期16卷 298-317页

作者： M.Kumar M.s.Barak M.Kumari Department of Mathematics B R Ambedkar Govt. College Department of Mathematics Indira Gandhi University

Phenomena of reflection and refraction of plane harmonic waves at a plane interface between an elastic solid and doubleporosity dual-permeability material are investigated. The elastic solid behaves non-dissipatively, while double-porosity dual-permeability materials behave dissipatively to wave propagation due to the presence of viscosity in pore fluids. All the waves(i.e., incident and reflected) in an elastic medium are considered as homogeneous(i.e., having the same directions of propagation and attenuation), while all the refracted waves in double-porosity dual-permeability materials are inhomogeneous(i.e., having different directions of propagation and attenuation). The coefficients of reflection and refraction for a given incident wave are obtained as a non-singular system of linear equations. The energy shares of reflected and refracted waves are obtained in the form of an energy matrix. A numerical example is considered to calculate the partition of incident energy among various reflected and refracted waves. The effect of incident direction on the partition of the incident energy is analyzed with a change in wave frequency, wave-induced fluid-flow, pore-fluid viscosity and double-porosity *** has been confirmed from numerical interpretation that during the reflection/refraction process, conservation of incident energy is obtained at each angle of incidence.

关键词： Plane harmonic wave Double-porosity dual-permeability Reflection/refraction coefficients Energy share Elastic solid

Thermal-hydraulic and stress analysis of AP1000 reactor containment during LOCA in dry cooling mode

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Nuclear science and Techniques 2017年第6期28卷 73-85页

作者： sh.sheykhi s.Talebi M.soroush E.Masoumi Department of Energy Engineering and Physics Amirkabir University of Technology(Tehran Polytechnic) Young Researchers and Elite Club Islamic Azad UniversitySouth Tehran Branch

some kinds of break in the reactor coolant system may cause the coolant to exit rapidly from the failure site,which leads to the loss of coolant accident(LOCA).In this paper,a stress analysis of an AP1000 reactor containment is performed in an LOCA,with the passive containment cooling system(PCCs) being available and not available for cooling the wall's *** variations in the mechanical properties of the wall's containment,including elastic modulus,strength,and stress,are analyzed using the ABAQUs code.A general two-phase model is applied for modeling thermal-hydraulic behavior inside the *** pressure and temperature from thermal-hydraulic models are considered as boundary conditions of the ABAQUs code to obtain distributions of temperature and stress across steel shell of the containment in the *** results indicate that if the PCCs fails,the peak pressure inside the containment exceeds the design ***,the stress would still be lower than the yield stress value,and no risk would threaten the integrity of the containment.

关键词： Two-phase flow LOCA Containment integrity AP1000 reactor

Influence of alkali metal doping on surface properties and catalytic activity/selectivity of CaO catalysts in oxidative coupling of methane

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Journal of Natural Gas Chemistry 2008年第4期17卷 313-320页

作者： V.H.Rane s.T.Chaudhari V.R.Choudhary Chemical Engineering and Process Development Division National Chemical Laboratory

surface properties （viz. surface area, basicity/base strength distribution, and crystal phases） of alkali metal doped CaO （alkali metal/Ca= 0.1 and 0.4） catalysts and their catalytic activity/selectivity in oxidative coupling of methane （OCM） to higher hydrocarbons at different reaction conditions （viz. temperature, 700 and 750 ℃; CH4/O2 ratio, 4.0 and 8.0 and space velocity, 5140-20550 cm^3 ·g^-1·h^-1） have been investigated. The influence of catalyst calcination temperature on the activity/selectivity has also been investigated. The surface properties （viz. surface area, basicity/base strength distribution） and catalytic activity/selectivity of the alkali metal doped CaO catalysts are strongly influenced by the alkali metal promoter and its concentration in the alkali metal doped CaO catalysts. An addition of alkali metal promoter to CaO results in a large decrease in the surface area but a large increase in the surface basicity （strong basic sites） and the C2＋ selectivity and yield of the catalysts in the OCM process. The activity and selectivity are strongly influenced by the catalyst calcination temperature. No direct relationship between surface basicity and catalytic activity/selectivity has been observed. Among the alkali metal doped CaO catalysts, Na-CaO （Na/Ca = 0.1, before calcination） catalyst （calcined at 750 ℃）, showed best performance （C2＋ selectivity of 68.8% with 24.7% methane conversion）, whereas the poorest performance was shown by the Rb-CaO catalyst in the OCM process.

关键词： oxidative coupling of methane alkali metal doped CaO catalysts basicity/base strength distribution catalytic activity/selectivity

Analysis of the Biotribological Behavior for the stainless steel/Polyethylene Contact Using a Knee Prosthesis simulator

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Journal of Bionic Engineering 2012年第1期9卷 59-65页

作者： M. Boujelbene s. Dhouibi M. Kharrat M. Dammak Laboratoire des systkmes Electromeeaniques Ecole Nationale d＇Ingenieurs de Sfax Route de Soukra km 35 B.P. 1173 3038 Sfax Tunisia Institut superieur de Gestion Industrielle de sfax Route de Mharza Km 15 B.P. 954 3018 Sfax Tunisia Faeulte des sciences de Gafsa Campus Universitaire Sidi Ahmed Zarrouk 2112 Gafsa Tunisia Institut Preparatoire aux Etudes d＇Ingenieurs de sfax Route de Menzel Chaker Km 05 B.P. 1172 3018 Sfax Tunisia

In this work, a friction and wear simulator was used to reproduce the Anterior-Posterior （AP） sliding and the Flex- ion-Extension （FE） rotation generated in the knee joint during human gait cycle. We chose to simplify the contact geometry between the Total Knee Arthroplasty （TKA） femoral component and tibial insert. A 304L stainless steel cylinder which replaces the femoral component was loaded onto a flat High Density Polyethylene （HDPE） block which replaces the tibial insert. The tribological behavior of the considered contact was analyzed by tracking the number of cycles, the friction coefficient, the roughness of the wear track on HDPE, the HDPE weight loss and the damage mechanisms. The friction coefficient shows a gradual increase with the number of cycles for both AP and FE kinematics. The evolution of friction coefficient with the number of cycles is not affected by the value of the imposed normal load in the case of AP sliding. For the FE rotation, decreased friction coefficient is obtained when the imposed normal load increases. For both considered AP and FE kinematics, the roughness of the wear track on the HDPE is not affected by the imposed normal load. It shows a progressive decrease when the number of cycles increases. The wear of HDPE obeys the Archard law and the wear coefficient increases with the normal force. For a given value of normal load, the obtained wear coefficient for the AP sliding is larger than that obtained for FE rotation. A predominant adhesive wear mechanism was identified for both AP and FE kinematics. Under the same normal load, damage development in terms of plastic deformation, micro-cracking and debonding is more pronounced for the AP sliding if compared with the FE rotation. For a given kinematics, the damage severity increases with the normal load. This finding is in good agreement with the predicted values of the wear coefficient according to the Archard law.

关键词： knee prosthesis polyethylene friction wear gait cycle

Intranasal administration of tetrabromobisphenol A bis(2-hydroxyethyl ether) induces neurobehavioral changes in neonatal sprague Dawley rats

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Journal of Environmental sciences 2018年第1期30卷 76-86页

作者： Qian s.Liu Na Liu Zhendong sun Qunfang Zhou Guibin Jiang state Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences school of Life science Shanxi University

Tetrabromobisphenol A（TBBPA） and its derivatives are now being highly concerned due to their emerging environmental occurrence and deleterious effects on non-target *** the potential neurotoxicity of TBBPA derivatives which has been demonstrated in vitro, what could happen in vivo is worthy of being studied. Tetrabromobisphenol A bis（2-hydroxyethyl ether）（TBBPA-BHEE）, a representative TBBPA derivative, was selected for a21-day exposure experiment on neonatal sprague Dawley（sD） rats through intranasal administration. The neurobehavioral, histopathological changes, and differentially expressed genes based on RNA microarray were investigated to evaluate the neurological effects of this chemical. The results indicated that TBBPA-BHEE exposure significantly compromised the motor co-ordination performance and the locomotor activities（p 〈 0.05）. The neurobehavioral phenotype could be attributed to the obvious histopathological changes in both cerebrum and cerebellum, such as neural cell swelling, microglial activation and proliferation. A total of 911 genes were up-regulated, whereas 433 genes were down-regulated. Gene set enrichment analysis showed multiple signaling pathways, including ubiquitin-mediated proteolysis and wingless-int（Wnt） signaling pathway etc. were involved due to TBBPA-BHEE exposure. The gene ontology enrichment analysis showed the basic cellular function and the neurological processes like synaptic transmission were influenced. The toxicological effects of TBBPA-BHEE observed in this study suggested the potential neuronal threaten from unintended exposure,which would be of great value in the biosafety evaluation of TBBPA derivatives.

关键词： TBBPA derivatives Intranasal administration Neurobehavorial test Histopathological observation Microarray analysis

Tekcrete Fast~: Fiber-reinforced, rapid-setting sprayed concrete for rib and surface control

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International Journal of Mining science and Technology 2018年第1期28卷 29-34页

作者： stephen C.Tadolini Peter s.Mills David R.Burkhard Minova UsA IncGeorgetownKYUSA san Juan Coal Company WaterflowNMUSA

Fiber-reinforced spayed concrete has been used for several years in civil and tunneling *** conducted to reduce cure times and increase compressive and flexural strengths resulted in the development of Tekcrete Fast~, a cementitious product capable of obtaining 41 MPa compressive strength and 8 MPa flexural strength in only 3 h and reaching 7 d strengths of 62 and 11.7 MPa, respectively.A single bag product that uses conventional shotcrete and gunite application systems makes it a natural crossover product for mining *** discovery of incredible adhesion properties and high resistance to chloride permeability helps ensure long-term stability and increases the ease of *** results from Disaster City~ in Texas and the application for rehabilitating a coal mine belt entry are *** case study illustrates the effectiveness of the product in stabilizing a coal mine beltway and adjacent cross-cuts that were subjected to progressive sloughage due to humidity and cyclical loading.

关键词： sprayed concrete Coal mine High strength concrete Polypropylene fiber

Constitutive model for methane desorption and diffusion based on pore structure differences between soft and hard coal

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International Journal of Mining science and Technology 2017年第6期27卷 937-944页

作者： Liu Yanwei Wang Dandan Hao Fuchang Liu Mingju Mitri Hani s. school of safety science and Engineering Henan Polytechnic University Jiaozuo 454000 China The Collaborative Innovation Center of Coal safety Production of Henan Province Jiaozuo 454000 China Department of Mining and Materials Engineering McGill University Montreal H3A0E8 Canada school of Civil Engineering Henan Polytechnic University Jiaozuo 454000 China

This paper aims to improve the accuracy and applicability of gas diffusion mathematical models from coal particles. Firstly, a new constitutive model for gas diffusion from coal particles with tri-disperse pore structure is constructed by considering the difference in characteristics between soft coal and hard *** analytical solution is then derived, that is, the quantitative relationship between gas diffusion rate(Qt/Q_∞) and diffusion time(t), The pore structure parameters of soft coal and hard coal from Juji coal mine are determined. Gas diffusion rules are numerically calculated and investigated by physical simulation methods. Lastly, the applicability of this model is verified. The results show that the homogeneous model only applies to the gas diffusion process of hard coal during the initial 10 min. The calculation results from this model and the physical experimental results of soft coal and hard coal are nearly identical during the initial 30 min.

关键词： soft and hard coal Gas diffusion Pore structure Constitutive models Physical simulation