Solidification mechanism of highly undercooled metal alloys

Experiments were conducted on metal droplet undercooling, using Sn-25wt%Pb and Ni-34wt%Sn alloys. To achieve the high degree of undercooling, emulsification treatments were employed. Results show the fraction of supersaturated primary phase is a function of the amount of undercooling, as is the fineness of the structures. The solidification behavior of the tin-lead droplets during recalescence was analyzed using three different hypotheses; (1) solid forming throughout recalescence is of the maximum thermodynamically stable composition; (2) partitionless solidification below the T sub o temperature, and solid forming thereafter is of the maximum thermodynamically stable composition; and (3) partitionless solidification below the T sub o temperature with solid forming thereafter that is of the maximum thermodynamically metastable composition that is possible. The T sub o temperature is calculated from the equal molar free energies of the liquid solid using the regular solution approximation

On Proclus as a Platonic Exegete

A response to John Finamore, “The Divided Line and the Cave in Proclus' Republic Commentary.

Development of Data Processing Skills of Physics Students in Intermediate Laboratory Course

Peer reviewe

Geometrical First Principles in Proclus’ Commentary on the First Book of Euclid’s Elements

In his commentary on Euclid, Proclus says both that the first principle of geometry are self-evident and that they are hypotheses received from the single, highest, unhypo- thetical science, which is probably dialectic. The implication of this seems to be that a geometer both does and does not know geometrical truths. This dilemma only exists if we assume that Proclus follows Aristotle in his understanding of these terms. This paper shows that this is not the case, and explains what Proclus himself means by definition, hypothesis, axiom, postulate, and the self-evident, and how geometry is a science that receives its principles from dialectic

The Deficiencies of the Presocratic Material Elements and the Dream Theory in Theaetetus

The Dream Theory in Theaetetus is Plato's generalised account of Presocratic elements. Evidence for this given from Laws, Phaedo, Timaeus, and through a comparison with Aristotle's account

Non enim ab hiis que sensus est iudicare sensum. Sensation and Thought in Theaetetus, Plotinus and Proclus

I examine the relation between sensation and discursive thought (dianoia) in Plato, Plotinus, and Proclus. In Theaetetus, a soul whose highest faculty was sensation would have no unified experience of the sensible world, lacking universal ideas to give order to the sensible flux. It is implied that such universals are grasped by the soul’s thinking. In Plotinus the soul is not passive when it senses the world, but as the logos of all things it thinks the world through its own forms. Proclus argues against the derivation of universal logoi from the senses, which alone can’t make the sensible world comprehensible. At most they give a record of the original sense-impression in its particularity. The soul’s own projected logoi give the sensible world stability. For Proclus, bare sensation does not depend on thought, but a unified experience of the sense-world depends on its paradigmatic logoi in our souls

The Role of the Digression on the Man of the Law Courts and the Philosopher (172b-177c) in the Argument of Theaetetus

Interpretations of the Theaetetus digression fail to see how it functions in Plato’s argument because they have taken its praise of the philosopher at face value. But this is not the philosopher from Republic. His otherworldliness reflects both Theodorus’ mathematical understanding of philosophy as the study of ‘divine’ objects and the judgement of the man of the law courts that philosophy renders a man useless for the city’s business. In spite of how appealing interpreters have found it, Socrates’ mythological language shows that the philosopher is an enigma to the practical man. That is why Socrates must appeal to the practical knowledge of the crafts to refute the relativism of opinion that he had to put forward in Protagoras’ defence

The Soul and the Virtues in Proclus’ Commentary on the Republic of Plato

Dans la septième dissertation de son Commentaire sur la République de Platon, Proclus fournit les éléments d’une philosophie politique néoplatonicienne très structurée. Fidèle, de façon générale, à la description platonicienne de l’âme tripartite et des quatre vertus cardinales, il introduit cependant d’importantes nuances dans cette théorie. L’idée de la prédominance d’une partie de l’âme sur une autre et l’idée de « vies mixtes » où deux parties de l’âme prédominent en même temps élargissent la description platonicienne des différents types poli­tiques. En outre, en s’efforçant de donner diverses explications métaphysiques de la nature et du nombre des parties de l’âme et des vertus, Proclus inscrit la philosophie politique platonicienne plus ou moins tout d’une pièce dans une hiérarchie cosmique néoplatonicienne.In the 7th essay of his Commentary on the Republic of Plato, Proclus sup­plies the elements of a fairly robust Neoplatonic political philosophy. In general he agrees with Plato’s account of the tripartite soul and the four cardinal virtues, while introducing important nuances into the theory. The idea of the dominance of one part of the soul over another, and the idea of ‘mixed lives’, where two parts dominate at once, extend Plato’s account of the various political types. Further, in his attempt to give various metaphysical explanations for the nature and number of the parts of the soul and the virtues, Proclus inserts Platonic political philosophy more or less whole-cloth into a Neoplatonic cosmic hierarch

Neoplatonism and the Hegelianism of James Doull

In this study I will show how Neoplatonism is not properly understood as a moment within the Hegelian dialectic. The Hegelian analysis obscures both the true character of the Neoplatonic One, and the Neoplatonic account of the relation between thought and its object, because it treats these positions as deficient versions of itself. We must remember that the Neoplatonists had before them the long tradition of Aristotelianism and Middle Platonism, in which the first principle was a self-consciousness. They did not elevate the One beyond Nous simply because of the precedence of Plato's Parmenides; rather they interpreted that text from what they considered to be philosophical necessity. They thought that it was philosophically superior to conceive of the First as One rather than Nous/Being. And just as in Hegel, I think, the decision of this school as a whole to write of the First in this manner has its origin in their analysis of human consciousness