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Understanding roof deformation mechanics and parametric sensitivities of coal mine entries using the discrete element method

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International Journal of Mining Science and Technology 2020年第1期30卷 123-129页

作者： rami Abousleiman Gabriel Walton Sankhaneel Sinha Department of Geology and Geological Engineering Colorado School of MinesGoldenCO 80218USA

Although conventional coal mine designs are conservative regarding pillar strength,local failures such as roof-falls and pillar bursts still affect mine safety and *** studies have identified that discontinuous,layered roof materials have some self-supporting *** research is a preliminary step towards understanding these mechanics in coal-measure *** others have considered broad conceptual models and simplified analogs for mine roof behavior,this study presents a unique numerical model that more completely represents in-situ roof *** discrete element method(DEM)is utilized to conduct a parametric analysis considering a range of in-situ stress ratios,material properties,and joint networks to determine the parameters controlling the stability of single-entries modeled in *** results are compared to empirical observations of roof-support effectiveness(ARBS)in the context of the coal mine roof rating(CMRR)*** such as immediate roof displacement,overall stability,and statistical relationships between model parameters and outcomes are presented *** practical applications of this line of research include:(1)roof-support optimization for a range of coal-measure rocks,(2)establishment of a relationship between roof stability and pillar stress,and(3)determination of which parameters are most critical to roof stability and therefore require concentrated evaluation.

关键词： Numerical modeling Discrete element method Coal mine roof rating Analysis of roof bolt systems Sensitivity analysis Strain softening ubiquitous joints Discrete fracture network

Gravitational Field as a Pressure Force from Logarithmic Lagrangians and Non-Standard Hamiltonians：The Case of Stellar Halo of Milky Way

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Communications in Theoretical Physics 2018年第3期69卷 233-240页

作者： rami Ahmad El-Nabulsi Athens Institute for Education and Research Mathematics and Physics Divisions 8 Valaoritou Street Kolonaki 10671 Athens Greece

Recently,the notion of non-standard Lagrangians was discussed widely in literature in an attempt to explore the inverse variational problem of nonlinear differential *** forms of non-standard Lagrangians were introduced in literature and have revealed nice mathematical and physical *** interesting form related to the inverse variational problem is the logarithmic Lagrangian,which has a number of motivating features related to the Li′enard-type and Emden nonlinear differential *** types of Lagrangians lead to nonlinear dynamics based on non-standard *** this communication,we show that some new dynamical properties are obtained in stellar dynamics if standard Lagrangians are replaced by Logarithmic Lagrangians and their corresponding non-standard *** interesting consequence concerns the emergence of an extra pressure term,which is related to the gravitational field suggesting that gravitation may act as a pressure in a strong gravitational *** case of the stellar halo of the Milky Way is considered.

关键词：非标准对数 Lagrangian 重力压力盒子光圈银河

Accelerated Dilatonic-Brans-Dicke cyclic and non-singular universe from string theory

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Research in Astronomy and Astrophysics 2011年第11期11卷 1249-1256页

作者： Ahmad rami El-Nabulsi Department of Nuclear Engineering Cheju National UniversityAra-dong 1Jeju 690-756South Korea Key Laboratory of Numerical Simulation of Sichuan Province College of Mathematics and Information Science Neijiang Normal University

We discuss the late-time dynamics of a particular four-dimensional Brans-Dicke cosmology with a dilaton field motivated by string theories （solitonic p-branes or D-branes） in which the dilaton field and the scale factor of the fiat, homogeneous spacetime are correlated. We examine the late-time-evolution of the equations of motion where various attractive consequences are revealed artd discussed in some detail.

关键词： cosmology: theory-cosmological parameters

Dark energy in five-dimensional Brans-Dicke cosmology with dimensional reduction

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Research in Astronomy and Astrophysics 2011年第8期11卷 888-894页

作者： Ahmad rami El-Nabulsi Department of Nuclear Engineering Cheju National University South Korea College of Mathematics and Information Sciences Neijiang Normal University

We explore a 5D Brans-Dicke scalar cosmology by conjecturing that the four-dimensional Hubble parameter varies as H = εФ^s, ε ∈ R and s is some unknown power index and that the extra-dimensions compactify as the visible dimensions expand as b（t） ≈ a^x （t）, x ∈R^-. We mainly discuss the case x = - 1. For critical values of e close to unity, it was observed that the acceleration of the universe occurs at red- shift close to z = 0.8 which indicates that in our model, accelerated expansion of the universe began only recently. Several interesting points are revealed and discussed in some detail.

关键词： Brans-Dicke cosmology -- dark energy

Mild hypothermia as a treatment for central nervous system injuries Positive or negative effects?

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Neural Regeneration Research 2013年第28期8卷 2677-2686页

作者： rami Darwazeh Yi Yan Department of Neurosurgery the First Affiliated Hospital of Chongqing Medical University

Besides local neuronal damage caused by the primary insult, central nervous system injuries may secondarily cause a progressive cascade of related events including brain edema, ischemia, oxida- tive stress, excitotoxicity, and dysregulation of calcium homeostasis. Hypothermia is a beneficial strategy in a variety of acute central nervous system injuries. Mild hypothermia can treat high in- tracranial pressure following traumatic brain injuries in adults. It is a new treatment that increases survival and quality of life for patients suffering from ischemic insults such as cardiac arrest, stroke, and neurogenic fever following brain trauma. Therapeutic hypothermia decreases free radical pro- duction, inflammation, excitotoxicity and intracranial pressure, and improves cerebral metabolism after traumatic brain injury and cerebral ischemia, thus protecting against central nervous system damage. Although a series of pathological and physiological changes as well as potential side ef- fects are observed during hypothermia treatment, it remains a potential therapeutic strategy for central nervous system injuries and deserves further study.

关键词： neural regeneration reviews brain injury spinal cord injury central nervous system injury mildhypothermia therapeutic hypothermia traumatic brain injury neuroregeneration

Charged Randall-Sundrum Braneworld Type Ⅱ with Higher Order Curvature Corrections from Superstring Arguments and Dominated by Quintessence

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Communications in Theoretical Physics 2010年第5期53卷 869-881页

作者： EL-NABULSI Ahmad rami Department of Nuclear and Energy Engineering Cheju National University

We discuss a new class of RSH braneworld cosmology exhibiting accelerated expansion and dominated byquintessence. It is explicitly demonstrated that the universe expansion history (transition from inflation to decelerationepoch to acceleration and effective quintessence era) may naturally occur in such unified theory for some classes of inversescalar potentials. Besides a decaying effective cosmological constant, the model incorporates an increasing black holemass, an increasing Maxwellian electrical charge with cosmic time and a time-dependent brane tension. The cosmologicalmodel exhibits several features of cosmological and astrophysical interest for both the early and late universe consistentwith recent observations, in particular the ones concerned with the gravitational constants, black holes masses andcharges and variation of the gauge coupling parameters with cosmic time. One interesting mark of the constructedmodel concerns the fact that a black hole mass surrounded by quintessence energy may increase with time even if thehorizon disappears.

关键词：宇宙加速膨胀时间依赖性更正超弦曲率高阶世界黑洞质量

Scalar Tensor Cosmology With Kinetic, Gauss-Bonnet and Nonminimal Derivative Couplings and Supersymmetric Loop Corrected Potential

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Communications in Theoretical Physics 2019年第7期71卷 831-836页

作者： rami Ahmad El-Nabulsi Athens Institute for Education and Research Mathematics and Physics Divisions8 Valaoritou StreetKolonaki 10671 AthensGreece

We discuss a particular four-dimensional cosmology based on non-minimal scalar tensor theories characterized by a supersymmetric loop corrected potential and a Hubble parameter defined as a function of the scalar ***-law solutions are obtained in the FRW background giving rise to acceleratedly expanding universe characterized by a scale factor and a scalar field depending both on the non-minimal coupling parameterξ.Based on SNeIa data and on Hubble data X-ray gas mass fraction measurements,we find 0.116<ξ<0.225 which results on a universe dominated by vacuum energy.

关键词： scalar tensor cosmology Gauss-Bonnet coupling non-minimal derivative coupling vacuum energy

Tellurium intervened Fe-N codoped carbon for improved oxygen reduction reaction and high-performance Zn-air batteries

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Journal of Materials Science & Technology 2023年第6期137卷 215-222页

作者： Rui Wang Zihan Meng Xuemin Yan Tian Tian Ming Lei rami Adel Pashameah Hala MAbo-Dief Hassan Algadi Nina Huang Zhanhu Guo Haolin Tang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan 528200China College of Chemistry and Environmental Engineering Yangtze UniversityJingzhou 434023China State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China Department of Chemistry Faculty of Applied ScienceUmm Al-Qura UniversityMakkah 24230Saudi Arabia Department of Science and Technology University College-RanyahTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia Department of Electrical Engineering Faculty of EngineeringNajran UniversityP.O.Box 1988Najran 11001Saudi Arabia College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Chemical and Bimolecular Engineering Integrated Composites Laboratory(ICL)University of TennesseeKnoxvilleTN 37996USA Guangdong Hydrogen Energy Institute of WHUT Xianhu Hydrogen ValleyFoshan 528200China

Pyrolysis-acquired iron and nitrogen codoped carbon(Fe-N-C)has been comprehensively investigated for its promising oxygen reduction reaction(ORR)catalytic performance and structural *** modification of non-metal elements with larger atomic radius and the corresponding intrinsic microstructure-property relations are rarely *** this study,tellurium(Te)intervened Fe-N-C was prepared by micelles-induced polymerization with Te nanowires as an in-situ intervening *** out-plane bonding of Te with Fe induced the increase of both N content and proportion of pyridinic N on the material surface,thus improving the ORR catalytic *** assembled Zn-air battery demonstrated a maximum power density of 250 mW/cm^(2)and excellent rate capability under various discharge current densities,which was much better than the Pt/***,the current work demonstrates a novel Te/Fe-N-C material and reveals an original Te intervened Fe-N-C strategy and N reconfiguration mechanism,which is of great significance for the design of key materials in energy-related fields.

关键词： Te/Fe-N-C Assembly ORR Electrocatalysis Zn-air battery

Oscillating Flat FRW Dark Energy Dominated Cosmology from Periodic Functional Approach

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Communications in Theoretical Physics 2010年第7期54卷 16-20页

作者： EL-NABULSI Ahmad rami Department of Nuclear and Energy Engineering Cheju National University

我基于一条周期的功能的途径讨论爱因斯坦一般相关性的理论的修正。在这条新途径，一改正的周期的重力的联合常数产生并且起术语对理论起作用的周期的抑制的作用。把震荡的宇宙被黑暗精力统治了是可完成的并且及时 acceleratedly 膨胀... 详细信息

我基于一条周期的功能的途径讨论爱因斯坦一般相关性的理论的修正。在这条新途径，一改正的周期的重力的联合常数产生并且起术语对理论起作用的周期的抑制的作用。把震荡的宇宙被黑暗精力统治了是可完成的并且及时 acceleratedly 膨胀，这被发现。

关键词：宇宙学暗能量主导功能 FRW 周期平面摆动广义相对论