اسماعیل قائدی

In this paper natural convection heat transfer of nanofluid simulated in a box with square and circular blocks. Governing equations is solved using finite volume method by Fluent software and Nusselt number near the hot wall at different Darcy numbers, is obtained for box with square or circular blocks. Results show that when there is a few blocks, temperature contour and streamlines depend on blocks geometry while increasing the number of blocks decrease this dependency. For box containing heater element in square arrangement, conduction heat transfer is dominant while in horizontal arrangement convection is dominant. By growth of Rayleigh number and consequently increasing of rotational flow convection portion in heat transfer increases. Although most portion of heat transfer is by conduction and convection has little effect. In the next part of research effect of nanoparticle concentration in heat transfer is studied. Results show an increase in average Nusselt number and heat transfer coefficient for higher volumetric concentrations of nanoparticles. Time taken to reach steady state for water based nanofluid is less than time for water/ Copper oxide, ethylene glycol, and water/ Copper oxide, propylene glycol. Variation of heat transfer coefficient in term of Nusselt number for Copper oxide, ethylene glycol, and Copper oxide, propylene glycol nanofluids with increase of nanoparticle concentration is independent of Rayligh number

The hermeneutic circle articulated by different hermeneuticans in various versions is one of the basic problems in modern hermeneutics. Romanic hermeneutics introduced the circle as a methodological principle، but in philosophical hermeneutics the circle has ontological dimensions and regards as a process of understanding. Heidegger believes that hermeneutic circle reflects Dasein’s existential constitution and Gadamer sees it as a description of mechanism of understanding. Each of these conceptions require entering specific factors in to the circle and expects special functions from it. In this article different narratives and conceptions of circle is discussed then we use an analytic approach to study functions and elements of circle in four levels: We attempted to articulate function and elements of the circle in discriminative levels. The first level consists in understanding and interpretation of text، which is based on philological function of the circle. The second level includes a process of revision and review of pre-understanding and prejudice. Self-understanding another function of the circle is inspected in the third level. The fourth level scrutinized effecting in effective history that is another function of hermeneutic circle.

The modern hermeneutics era began with Schleiermacher's attempts to expand the scope of hermeneutics. He declared misunderstanding natural. While admitting its being customary and inevitable, he concluded that understanding is always an act of interpretation. In his view, every act of understanding involves two modes of interpretation, i.e. grammatical interpretation and technical (also called psychological) interpretation. The former addresses the linguistic functions and features of text while the latter views the text as the realization of author's individuality, and studies it according to his/her dealing with the language. In Schleiermacher's belief, in each mode of interpretation, understanding and interpretation take place in a circular process known as hermeneutic circle. The grammatical interpretation focuses on physical aspects of text, i.e. the whole text and its individual parts. On the contrary, technical interpretation addresses the author's individuality. Understanding of author's individuality is made possible only when the interpreter makes guesses and comparisons with himself in order to find a way to the author's mental world.

The dialectic of familiarity and strangeness was introduced by Romantic hermeneuticians who aimed to depict the process of understanding by elaborating components of it. Schleiermacher referenced familiarity and strangeness to language and its functions in grammatical interpretation. However, in technical or psychological interpretation his approaches are a kind of metaphysics of individuality and he mentions it as the base of strangeness. He believes this strangeness can be overcome by approaching the author’s mind, then the text can be understood from his point of view, an approach that takes place based on intuition. Therefore divination is the element of familiarity. But Gadamer, who on one hand is not satisfied with his psychological account and considers understanding necessity to require familiarity and strangeness, on the other hand, regards temporal distance and hermeneutic horizon as the elements of strangeness and tradition as the element of familiarity. He considers that understanding is realized only thorough dialectical process in the base of the dialectics of familiarity and strangeness.