964 research outputs found

    Critical analysis of the thermodynamics of reaction kinetics

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    Our objective is to show the weakness of the recent thermodynamics of chemical reactions. We show that such a thermodynamic theory of chemical reactions, which could be similar to the generalized Onsagers theory in thermodynamics, is not reality at the moment

    Rosen-Chambers Variation Theory of Linearly-Damped Classic and Quantum Oscillator

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    Phenomena of damped harmonic oscillator is important in the description of the elementary dissipative processes of linear responses in our physical world. Its classical description is clear and understood, however it is not so in the quantum physics, where it also has a basic role. Starting from the Rosen-Chambers restricted variation principle a Hamilton like variation approach to the damped harmonic oscillator will be given. The usual formalisms of classical mechanics, as Lagrangian, Hamiltonian, Poisson brackets, will be covered too. We shall introduce two Poisson brackets. The first one has only mathematical meaning and for the second, the so-called constitutive Poisson brackets, a physical interpretation will be presented. We shall show that only the fundamental constitutive Poisson brackets are not invariant throughout the motion of the damped oscillator, but these show a kind of universal time dependence in the universal time scale of the damped oscillator. The quantum mechanical Poisson brackets and commutation relations belonging to these fundamental time dependent classical brackets will be described. Our objective in this work is giving clearer view to the challenge of the dissipative quantum oscillator

    Onsagerian Quantum Mechanics

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    We describe the basic quantum-mechanical categories and properties of the thermodynamical basis of Onsagers theorem. 3 basic principles are used: 1. energy dissipation; 2. Hamiltonian formalism; 3. Onsagers linearity. We obtain the 2 characteristic values of the observables, their main-value and the deviation, the first and second momentums of the probability distribution function, which we also derived also from the same principles

    A study and experiment plan for digital mobile communication via satellite

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    The viability of mobile communications is examined within the context of a frequency division multiple access, single channel per carrier satellite system emphasizing digital techniques to serve a large population of users. The intent is to provide the mobile users with a grade of service consistant with the requirements for remote, rural (perhaps emergency) voice communications, but which approaches toll quality speech. A traffic model is derived on which to base the determination of the required maximum number of satellite channels to provide the anticipated level of service. Various voice digitalization and digital modulation schemes are reviewed along with a general link analysis of the mobile system. Demand assignment multiple access considerations and analysis tradeoffs are presented. Finally, a completed configuration is described

    The third transitional Identity of migrant adolescents. The case of Hotel House an Italian multi-ethnic skyscraper-ghetto

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    The adolescent\u2019s identity achievement is a complex task, even more so if they are migrants living in a particular context of ethnic ghettoization. Hotel House is an enormous, isolated condominium situated on the outskirts of Porto Recanati, a small Italian town. It is a unique reality poorly studied from a social psychological perspective. The present paper aims to measure the perceived levels of self-concept clarity, self-determination, ethnic group identification, relationship with parents, depression and life satisfaction in a group of 91 adolescents (11\u201319 years; 30% females; 1.5 immigrant\u2019s generation) living in this context. The analysis shows low levels of self-concept clarity and self-determination, especially in female adolescents, quite satisfactory relationships with their parents and medium levels of group identification and life satisfaction. The identification with their ethnic subgroups seems to provide a third transitional identity which works as a temporary link between native country values and host country values. The regression analysis shows significant associations: self-determination is negatively associated with depression and positively associated with the perception of life satisfaction; the father\u2019s closeness is a negative predictor for depression and a positive predictor for life satisfaction; mother\u2019s closeness is negatively associated with depression

    Strain path changes in aluminum

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    Sheet metal forming processes involve large plastic deformation and changes in strain path. In this work, a detailed analysis of a commercially pure aluminum sheet subjected to tension-tension sequences with pre-strain in the rolling direction (RD) and reloads along different directions is presented, taking into consideration the mechanical behavior and texture evolution. Two main hardening behavior tendencies are observed, depending whether the reloading direction occurs for an angle smaller or larger than 45º.publishe
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