3,063 research outputs found
Vitamin E as a Treatment for Nonalcoholic Fatty Liver Disease: Reality or Myth?
Obesity is one of the major epidemics of this millennium, and its incidence is growing worldwide. Following the epidemics of obesity, nonalcoholic fatty liver disease (NAFLD) has become a disease of increasing prevalence and a leading cause of morbidity and mortality closely related to cardiovascular disease, malignancies, and cirrhosis. It is believed that oxidative stress is a main player in the development and progression of NAFLD. Currently, a pharmacological approach has become necessary in NAFLD because of a failure to modify lifestyle and dietary habits in most patients. Vitamin E is a potent antioxidant that has been shown to reduce oxidative stress in NAFLD. This review summarizes the biological activities of vitamin E, with a primary focus on its therapeutic efficacy in NAFLD
Nonlinear normal modes of a two degree of freedom oscillator with a bilateral elastic stop
A study of the non linear modes of a two degree of freedom mechanical system
with bilateral elastic stop is considered. The issue related to the
non-smoothness of the impact force is handled through a regularization
technique. In order to obtain the Nonlinear Normal Mode (NNM), the harmonic
balance method with a large number of harmonics, combined with the asymptotic
numerical method, is used to solve the regularized problem. These methods are
present in the software "package" MANLAB. The results are validated from
periodic orbits obtained analytically in the time domain by direct integration
of the non regular problem. The two NNMs starting respectively from the two
linear normal modes of the associated underlying linear system are discussed.
The energy-frequency plot is used to present a global vision of the behavior of
the modes. The dynamics of the modes are also analyzed comparing each periodic
orbits and modal lines. The first NNM shows an elaborate dynamics with the
occurrence of multiple impacts per period. On the other hand, the second NNM
presents a more simple dynamics with a localization of the displacement on the
first mass
K-harmonic manifolds
The present work is aimed toward the study of manifolds which admit k-harmonic metrics. These generalize the "classical" harmonic manifolds and in their definition, the k-th elementary symmetric polynomials of a certain endomorphism Φ of the fibres in the tangent bundle play a role similar to that of Ruse's invariant in classical harmonic spaces. We investigate some properties of k-harmonic manifolds analogous to those enjoyed by harmonic manifolds and obtain some results relating k-harmonic manifolds to harmonic ones. For instance we prove: (a) a k-harmonic manifold is necessarily Einstein, (b) a manifold is simply 1-harmonic iff it is simply n-harmonic. We also work out a general formulation of k-harmonic manifolds in terms of the Jacobi fields on the manifold. This enables us, in particular, to generalize the equations of Walker, and obtain in the case of symmetric spaces, a finite set of necessary conditions for k-harmonicity. As an application of this we are able to show that if a locally symmetric space is n-harmonic then it is k-harmonic for all k. Under the further assumption of compactness we prove that an irreducible k-harmonic manifold is necessarily a symmetric space of rank one. Consequently:(1) a compact simply connected riemannian symmetric manifold, k-harmonic for one k is k-harmonic for all k; and(2) by a theorem of Avez we can drop the assumption of symmetry in (l) but assume instead that the manifold is n-harmonic
The New ADE-TLM Algorithm for Modeling Debye Medium
In this paper, we present a novel approach to simulating the interaction between electromagnetic waves and a Debye medium utilizing a Transmission Line Matrix (TLM) algorithm with the symmetrical condensed node (SCN-TLM) technique. The proposed method utilizes the polarization current within the media and incorporates the auxiliary differential equation (ADE) technique to handle scattering following the conventional discretization process. The averaged approximation is employed to utilize the polarization current density J and the electric voltage. By reducing the number of operations required per iteration, the New ADE- TLM method has successfully decreased the computational time compared to time convolution techniques. Despite this reduction in computational time, the New ADE-TLM method maintains a numerical accuracy that is comparable to that of time convolution techniques. The efficiency and precision of this approach are confirmed by the agreement between the results obtained and those predicted by the analytic model
Lebanon’s Democracy: Prospects and Pitfalls
ABSTRACT
In Lebanon, there is a common understanding and belief among many politicians and citizens, in equal measure, that Lebanon is a democratic country. This belief is not only restricted to those inside Lebanon, but also to be found in neighbouring Arab countries and among their people. In other words, Lebanon is believed to be a country that enjoys a relatively democratic political system, rule of law, and a vibrant civil society, compared to the rest of the region. However, this is for the most part a misunderstanding, and originates from most Lebanese people’s view that a modest level of freedom should be considered democracy, and that a relatively unconstrained civil society means an effective civil society.
The main purpose of this thesis is to analyse Lebanon’s political system and establish a clearer picture about whether the democratic claim is real or just an illusion. In order to build this picture, I have concentrated on the internal and external obstacles that have impeded the evolution of the Lebanese political system. The first part of the thesis discusses whether or not the Lebanese political system shares any of the features of functioning democratic political systems and whether or not it is running in a modus which reflects democratic values. In later chapters, the thesis moves on to examine the internal and external factors that have hindered the state from becoming a sovereign, authoritative state and thus without the necessary foundations for becoming a democratic state.
The study will demonstrate that Lebanon suffers from the domination of a militant organisation within its borders which violates the country’s sovereignty and disrupts the government and its institutions from functioning properly and being authoritative. Moreover, it will reveal that most citizens - a key element in any democracy - continue to feel subjugated, unable to make their voices heard, and without a say in the decision making process.
Moreover, it will be demonstrated that Lebanon suffers from several problems. Firstly and most importantly, it suffers from the lack of an effective state that imposes the rule of law on all of Lebanon’s territory. Secondly and equally important, Lebanon suffers from missing a major component that constitutes an essential pillar for the state, and that is sovereignty. Thirdly, election results are not taken into consideration as the public’s electoral choices are not respected, while instead powerful elite continues to rule the country illegally. These impediments and many others lead the study to conclude that the Lebanese political system currently remains far from being considered a democracy
Numerical Study of the Combustion of CH4-C3H8/ Air: Application to a Combustion Chamber with Two Coaxial Jets
In this study, we studied numerically the non-premixed combustion provided by two coaxial methane-propane/air jets in a 3D cylindrical combustion chamber. To study this kind of phenomenon we used a special treatment of the mathematical model and we chose two models of computation PDF and LES. In order to find the aero-thermo-chemical characteristics in the burner, namely: axial velocity, temperature and mass fraction of carbon monoxide CO. Using commercial calculation software CFD Fluent The objective of this work is to research the fuel that reduces the emission of carbon monoxide CO, which is considered a gas toxic to the environment, by comparing the two fuels CH4 and C3H8. The results give methane fuel reduces carbon monoxide as a pollutant chemical species in combustion products compared to propane fuel.
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