Effect of layer thickness on the high temperature mechanical properties of Al/SiC nanolaminates

Composite laminates on the nanoscale have shown superior hardness and toughness, but little is known about their high temperature behavior. The mechanical properties (elastic modulus and hardness) were measured as a function of temperature by means of nanoindentation in Al/SiC nanolaminates, a model metal–ceramic nanolaminate fabricated by physical vapor deposition. The influence of the Al and SiC volume fraction and layer thicknesses was determined between room temperature and 150 °C and, the deformation modes were analyzed by transmission electron microscopy, using a focused ion beam to prepare cross-sections through selected indents. It was found that ambient temperature deformation was controlled by the plastic flow of the Al layers, constrained by the SiC, and the elastic bending of the SiC layers. The reduction in hardness with temperature showed evidence of the development of interface-mediated deformation mechanisms, which led to a clear influence of layer thickness on the hardness.

A plastic analysis of nonprismatic folded plate structures

A computer method for the plastic analysis of folded plate structures is presented. The method considers the specific characteristics of the folded plate structural model using a simplified one-dimensional theory. and it can be applied to the analysis of any type of folded pIates, either prismatic or nonprismatic, with arbitrary cross-section. A simple example is analyzed in order to show the possibilities of the procedure and some results of interest are presented

Written on the threshold

One of the most productive discoveries of art and architectural criticism is the comparative reading between different situations. It is an approach that does away with all conventions and destroys any attempt to codifing the future. It also reveals the futility of established styles or movements. In the early 20th century, the Russian Formalists spoke of the dissimilarity of the similar in literature and more than a few studies on the visual arts have used the comparative method, from Heinrich Wolfflin to Robert Venturi. But something more has to be added, personal biography. The involvement of the individual, their name and their life, in the history of art bursts in with all the force of what is real, with no need for credibility, because it merely is what it is. The histories of architecture and art tell things in a believable, perfectly connected manner, without the fits and starts of personal biography - when this appears we find ourselves in a different sort of situation.

Long-term plasticity in interneurons of the dentate gyrus

Single interneurons influence thousands of postsynaptic principal cells, and the control of interneuronal excitability is an important regulator of the computational properties of the hippocampus. However, the mechanisms underlying long-term alterations in the input–output functions of interneurons are not fully understood. We report a mechanism of interneuronal plasticity that leads to the functional enhancement of the gain of glutamatergic inputs in the absence of long-term potentiation of the excitatory synaptic currents. Interneurons in the dentate gyrus exhibit a characteristic, limited (≈8 mV) depolarization of their resting membrane potential after high-frequency stimulation of the perforant path. The depolarization can be observed with either whole-cell or perforated patch electrodes, and it lasts in excess of 3 h. The long-term depolarization is specific to interneurons, because granule cells do not show it. The depolarization requires the activation of Ca2+-permeable α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and the rise of intracellular Ca2+, but not N-methyl-d-aspartate (NMDA) receptor activation. Data on the maintenance of the depolarization point to a major role for a long-term change in the rate of electrogenic Na+/K+-ATPase pump function in interneurons. As a result of the depolarization, interneurons after the tetanus respond with action potential discharges to previously subthreshold excitatory postsynaptic potentials (EPSPs), even though the EPSPs are not potentiated. These results demonstrate that the plastic nature of the interneuronal resting membrane potential underlies a unique form of long-term regulation of the gain of excitatory inputs to γ-aminobutyric acid (GABA)ergic neurons.

A criatividade como competência essencial no desenvolvimento progressivo do aluno em artes visuais

Relatório da Prática de Ensino Supervisionada, Mestrado em Ensino das Artes Visuais, Universidade de Lisboa, Instituto de Educação, 2016

Certain letters of James Howell : selected from the Familiar letters as first published between 1645 & 1655.

Text within double red lines.

Teaching and scholarship & the res publica,

The liberal arts college and the course of human affairs.--The modern languages and our melting pot.--The college teacher and his high school colleague.--The scientist and our social problems.--The business man and better education.--The twentieth century and the United States.

Two medieval satires on the University of Paris: La bataille des vii ars of Henri d'Andeli, and the Morale scolarium of John of Garland.

Series note varies: At head of title of v. 1 and on verso of t.-p of v. 2, Memoirs of the University of California. v. 4, no. 1, 2. History, v. 1, no. 1, 2.

The art of landscape architecture /

"March 1990."

The History of ancient Greece, its colonies, and conquests.

Pt. 1. From the earliest accounts till the division of the Macedonian empire in the East; including the history of literature, philosophy, and the fine arts. 6th ed. 4 v. -- Pt. 2. Embracing the history of the ancient world from the dominion of Alexander to that of Augustus, with a survey of preceding periods, and a continuation of the history of arts and letters. A new ed., with corrections and additions. v. 1.

Proceedings of the National Association of Elocutionists.

Mode of access: Internet.

Funding for the John F. Kennedy Center [microform] : hearing before the Committee on Environment and Public Works, United States Senate, Ninety-sixth Congress, first session, on S. 1532 ... July 20, 1979.

Reuse of record except for individual research requires license from Congressional Information Service, Inc.

American journal of archaeology : the journal of the Archaeological Institute of America.

Imprint varies: Boston, MA : Archaeological Institute of America,

Etching and other graphic arts;

Includes index.

Industrial arts in our elementary schools,

Mode of access: Internet.