Nanostructured materials: basic concepts and microstructure☆

Beyond molecular chemistry based on the covalent bond, supramolecular chemistry aims at developing highly complex chemical systems from components interacting through noncovalent intermolecular forces. Over the past quarter century, supramolecular chemistry has grown into a major field and has fueled numerous developments at the interfaces with biology and physics. Some of the conceptual advances and future challenges are profiled here.

https://science.sciencemag.org/content/sci/295/5564/2400.full.pdf

Toward Self-Organization and Complex Matter

There has been increased research interest in systems composed of multiple autonomous mobile robots exhibiting cooperative behavior. Groups of mobile robots are constructed, with an aim to studying such issues as group architecture, resource conflict, origin of cooperation, learning, and geometric problems. As yet, few applications of cooperative robotics have been reported, and supporting theory is still in its formative stages. In this paper, we give a critical survey of existing works and discuss open problems in this field, emphasizing the various theoretical issues that arise in the study of cooperative robotics. We describe the intellectual heritages that have guided early research, as well as possible additions to the set of existing motivations.

Cooperative mobile robotics: antecedents and directions

As the wind of time blows into the sails of space, the unfolding of the universe nurtures the evolution of matter under the pressure of information From divided to condensed and on to organized, living, and thinking matter, the path is toward an increase in complexity through self-organization

/pdf/toward-complex-matter-supramolecular-chemistry-and-self-54zcdo8k02.pdf

Toward complex matter: supramolecular chemistry and self-organization.

Computers are physical systems: the laws of physics dictate what they can and cannot do. In particular, the speed with which a physical device can process information is limited by its energy and the amount of information that it can process is limited by the number of degrees of freedom it possesses. Here I explore the physical limits of computation as determined by the speed of light c, the quantum scale h and the gravitational constant G. As an example, I put quantitative bounds to the computational power of an 'ultimate laptop' with a mass of one kilogram confined to a volume of one litre.

Ultimate physical limits to computation

1 This chapter shows application of a consistent set of clear physical principles to describe the beginnings of the universe by the (hot) Big Bang model. The ultimate beginning presents difficulties for the physicist, particularly when it comes to explaining why we find a very inhomogeneous cosmos, instead of a uniform, radiating gas. Stars, globular clusters, galaxies, and clusters of galaxies dot space, but we cannot at present explain their presence without invoking a "deus ex machina." We expect ultimately to rationalize the existence of these local inhomogeneities through gravitational contractions of regions of higher than average mass density that in tum arise out of fluctuations, but the case cannot yet be made completely. Meanwhile, the Big Bang (incomplete) model deals with cosmic evolution in the large, as a balance between gravitational attraction and cosmic expansion. Its relationships are described by two simple equations derived from Einstein's theory of general relativity via local conservations of mass-energy and of momentum. Unfortunately, this model does not by itself produce the observed inhomogeneities. Neither the assumption of thermodynamic fluctuations following a "smooth" beginning nor that ofa chaotic beginning can itself account for stars and galaxies. A mystery remains. -THE EDITOR This chapter describes the efforts of cosmologists (and nature?) to form galactic and stellar structures, comments on them from the viewpoint of the homeokinetic principles (Soodak and Iberall, 1978) discussed elsewhere in this volume, and pursues some parallels in the origin of life. It appears that there are no serious problems in understanding the origin of stars, given the previous formation of a galactic gas mass. A number of reasonable, even likely, paths lead to star formation. On the other hand, the origin of inhomogeneities required to initiate galaxy formation is not yet known. Appendix 1 remarks on some advances in observational and theoretical cosmology made since the original writing of this chapter HARRY SOODAK • Department of Physics, The City College of New York, New York, New York

/pdf/self-organizing-systems-iqagjbi8lb.pdf

Self-Organizing Systems

Self-organizing systems : the emergence of order

The present invention is directed to the transdermal administration of melatonin together with a suitable permeation enhancer. The invention includes a transdermal drug delivery device (10) comprising a matrix (12) adapted to be placed in melatonin- and permeation enhancer-transmitting relation with the skin site (18). The matrix (12) contains sufficient amounts of a permeation enhancer and of melatonin, in combination, to continuously administer to the skin (18) for a predetermined period of time the melatonin to provide an effective therapeutic result. The invention is also directed to a method for the transdermal administration of a therapeutically effective amount of melatonin together with a skin permeation-enhancing amount of a suitable permeation enhancer. The invention further includes methods for time- and rate-patterned transdermal delivery of melatonin to simulate the natural circadian rhythmic profile of melatonin in mammals.

F. Eugene Yates

Papers

Self-Organizing Systems

Self-organizing systems : the emergence of order

Device for the transdermal administration of melatonin

Physiological Integrations in Action

Controlled transdermal administration of melatonin