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Charles E. Swenberg

Bio: Charles E. Swenberg is an academic researcher from Armed Forces Radiobiology Research Institute. The author has contributed to research in topics: DNA supercoil & DNA. The author has an hindex of 11, co-authored 40 publications receiving 3236 citations.

Papers
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Book
02 Dec 1999
TL;DR: The first edition of the Electronic Processes of Organic Crystals, published in 1982, became the classic reference in the field and has been expanded to cover the major theoretical and experimental advances over the last fifteen years.
Abstract: The first edition of Pope and Swenberg's Electronic Processes of Organic Crystals, published in 1982, became the classic reference in the field. It provides a tutorial on the experimental and related theoretical properties of aromatic hydrocarbon crystals and includes emerging work on polymers and superconductivity. This new edition has been expanded to cover the major theoretical and experimental advances over the last fifteen years. It contains a unified description of what is known in almost every aspect of the field. The basic phenomena covered in the first edition included fluorescence, exciton and charge carrier generation, transport, recombination, and photoemission; the new edition adds solitons, polarons, bipolarons, spin waves, and charge density waves. It provides in-depth coverage of such model polymers such as polyacetylene, polydiacetylene, poly (phenylene-vinylene), polyanilines, polysilanes, and fullerenes. It also provides detailed treatments of the expanding areas of electroluminescence, non-linear optics, organic magnets, organic superconductors, and Langmuir-Blodgett films. In addition, it contains a chapter on major applications, including LED's, photocopiers, photoconductors, batteries, transistors, liquid crystals, photorefractive devices, and sensors. As in the first volume, the authors take informed positions in controversial areas. This book will be an essential reference for organic material scientists, whether they are experienced researchers or just entering the field. It will also be a reliable guide to anyone interested in this rapidly growing field

1,733 citations

Journal ArticleDOI
TL;DR: In recent years, the number of studies of electronic processes in organic solids has assumed explosive proportions, and the increasing ability of organic chemists to design and synthesize molecules and structures almost to order has made it possible to provide an experimental testing ground for what were once figments of the imagi-nation of theorists.
Abstract: In recent years, the number of studies of electronic processes in organic solids has assumed explosive proportions. In retrospect, it was inevitable. The increasing ability of organic chemists to design and synthesize molecules and structures almost to order has made it possible to provide an experimental testing ground for what were once figments of the imagi­ nations of theorists. Thus excellent approximations of ideal oneand two­ dimensional solids can be prepared with electrical properties varying from those of an insulator, to those of a superconductor. Disordered systems can be prepared with a large range of nearest-neighbor interaction energies, with and without additional trapping sites, making it possible to test almost any conceivable theory of energy or charge migration in a random or regular network. Increasingly sophisticated computer simulations are providing unusual insights into the microscopic details of dynamical processes, such as carrier or energy transport. These serve as a check on analytical theories and even a guide to indicate which assumptions are likely to be reasonable. The simulations can probe situations that are as yet not readily accessible to experiment, such as time domains in the femtosecond range. All of this ncw interest has been superimposed on what has been an orderly growth in a relatively isolated field, the study of the electrical and optical properties of polycyclic aromatic hydrocarbons

71 citations

Book
11 Mar 1989
TL;DR: In this paper, the effects of low and high LET radiation on Neoplastic Transformation in cells and the importance of single track effects in space were investigated in the context of human spaceflight.
Abstract: Radiation Environment in Space.- The Earth's Trapped and Transient Space Radiation Environment.- Ambient Electron Density Distribution at About 500 km Altitude at the Earth's Ionosphere.- The Space Radiation Environment at 840 km.- Solar Proton Event Forecasts.- Radiation Hazards in Low Earth Orbit, Polar Orbit, Geosynchronous Orbit, and Deep Space.- Analysis of the Radiative Risk During Hermes Mission.- Biological Effects of Space Radiation.- Heavy Ion Effects.- Heavy Ion Effects on Cells: An Approach to Theoretical Understanding.- Cosmic Ray HZE Particle Effects in Biological Systems: Results of Experiments in Space.- Effects of Low and High LET Radiation on Neoplastic Transformation in Cells and the Importance of Single Track Effects in Space.- Effects of LET, Fluence and Particle Energy on Inactivation, Chromosomal Aberrations and DNA Strand Breaks.- Induction of Chromosome Aberrations in Chinese Hamster Cells After Heavy Ion Irradiation.- Heavy Ion Radiation Effects on Single Spores of Bacillus Subtilis.- Biological Action of Heavy Ion Irradiation on Individual Yeast Cells.- Delta-Electron Emission in Heavy Ion Collisions.- Genetic Effects.- The Role of Repair Processes in Cellular and Genetical Response to Radiation.- Reactions of Genetic Systems to Heavy Ions: Acute and Late Effects.- Nature of Radiation Induced Mutations. Experimental Approaches on the Question of Intragenic Events.- Genetic and Developmental Responses of Radiation Sensitive Mutants of the Nematode, C. elegans, to Ultraviolet, High and Low LET Radiation.- Ionizing Radiation Induced Mutagenesis: Molecular Genetic Changes and Role of DNA Lesions and Repair.- Cellular Effects.- Radiation Physics Related to Biology.- Biochemistry of Subcellular and Cellular Radiation Effects.- High Energy Proton Induced Mutations in Cultured Chinese Hamster Cells.- Cultures of Erythroleukemic Cells (K-562) on a Stratospheric Balloon Flight.- Transposition of Retrotransposons After Gamma and UV Irradiation.- Flow Cytometry Techniques for the Study of Irradiated Hematopoietic Stem Cells.- The Kinetics of UV-Induced Thymine Dimerization.- Effects of Ultrahigh Vacuum and UV Irradiation on Transforming DNA of Haemophilus Influenzae.- Effect of High-Vacuum, Deep Temperatures and VUV Irradiation on Bacterial Spores.- Physiology Radiobiology.- Selected Examples of Degenerative Late Effects Caused by Particulate Radiations in Normal Tissues.- Delayed Effects of Proton Irradiation in the Lens and Integument: A Primate Model.- Life Shortening and Causes of Death in Experimental Animals Following Whole-Body Exposure to Ionizing Radiation.- Acute Radiation Syndromes in Man.- Extrapolation of Animal Data to Man.- Radiation Induced Damage to the Regenerative Capacity of Surgically Traumatized Rat Femur After Single Doses of X-Rays.- Cardiopulmonary Effects Following Local Irradiation of the Heart in Adult Male Wistar/Neuherberg Rats.- Post-Irradiation Alterations in Cerebral Blood Flow.- Analysis of the Involvement of the Terrestrial Space Radiation in the Microgravity Effects on DrosophilaMelanogaster Development and Aging.- Behavioral and Neurobiological Aspects.- Current Trends in Behavioral Radiobiology.- Effects of Iron Particles on Behavior and Brain Function: Initial Studies.- Correlative Motor Behavioral and Striatal Dopaminergic Alterations Induced by 56Fe Radiation.- Protection From Space Radiation.- Variation of Galactic Cosmic Radiation by Solar Modulation, Geomagnetic Shielding and Shielding by Material.- Radiation Problems in Manned Spaceflight - European Efforts.- Space Radiation Exposures for Manned Polar Missions: A Parametric Study.- Protection of Polar Platforms from Penetrating Radiation.- Galactic Cosmic Radiation Doses to Astronauts Outside the Magnetosphere.- DNA and Radioprotection.- Excision Repair is Enhanced by WR-2721 Radioprotection.- Impact of Spaceflight Environment on Radiation Response.- Radiation Protection Guidelines for Space Missions.- Dosimetry.- Space Radiation Dosimetry on U.S. and Soviet Manned Missions.- Measurements of Cosmic Ray LET-Spectra for the D1 Mission Using Plastic Nuclear Track Detectors.- Cosmic Ray LET-Spectrum Measured in the Spacelab 2 Mission.- New Directions in Space Dosimetry.- Summary.- Participants.

69 citations

Journal ArticleDOI
TL;DR: Research on intracellular signaling in the context of neural network learning is reviewed and many experimental results suggest a link between the cytoskeleton and cognitive processing.
Abstract: This paper introduces the ideas of neural networks in the context of currently recognized cellular structures within neurons. Neural network models and paradigms require adaptation of synapses for learning to occur in the network. Some models of learning paradigms require information to move from axon to dendrite. This motivated us to examine the possibility of intracellular signaling to mediate such signals. The cytoskeleton forms a substrate for intracellular signaling via material transport and other putative mechanisms. Furthermore, many experimental results suggest a link between the cytoskeleton and cognitive processing. In this paper we review research on intracellular signaling in the context of neural network learning.

39 citations


Cited by
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Journal ArticleDOI
29 Apr 2004-Nature
TL;DR: The future holds even greater promise for this technology, with an entirely new generation of ultralow-cost, lightweight and even flexible electronic devices in the offing, which will perform functions traditionally accomplished using much more expensive components based on conventional semiconductor materials such as silicon.
Abstract: Organic electronics are beginning to make significant inroads into the commercial world, and if the field continues to progress at its current, rapid pace, electronics based on organic thin-film materials will soon become a mainstay of our technological existence. Already products based on active thin-film organic devices are in the market place, most notably the displays of several mobile electronic appliances. Yet the future holds even greater promise for this technology, with an entirely new generation of ultralow-cost, lightweight and even flexible electronic devices in the offing, which will perform functions traditionally accomplished using much more expensive components based on conventional semiconductor materials such as silicon.

4,967 citations

Journal ArticleDOI
TL;DR: In this article, the authors present new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of organic thin-film transistors (OTFTs) and discuss progress in the growing field of n-type OTFTs.
Abstract: Organic thin-film transistors (OTFTs) have lived to see great improvements in recent years. This review presents new insight into conduction mechanisms and performance characteristics, as well as opportunities for modeling properties of OTFTs. The shifted focus in research from novel chemical structures to fabrication technologies that optimize morphology and structural order is underscored by chapters on vacuum-deposited and solution-processed organic semiconducting films. Finally, progress in the growing field of the n-type OTFTs is discussed in ample detail. The Figure, showing a pentacene film edge on SiO2, illustrates the morphology issue.

4,804 citations

Journal ArticleDOI
TL;DR: In this article, a review summarizes recent progress in the development of polymer solar cells and provides a synopsis of major achievements in the field over the past few years, while potential future developments and the applications of this technology are also briefly discussed.
Abstract: This Review summarizes recent progress in the development of polymer solar cells. It covers the scientific origins and basic properties of polymer solar cell technology, material requirements and device operation mechanisms, while also providing a synopsis of major achievements in the field over the past few years. Potential future developments and the applications of this technology are also briefly discussed.

3,832 citations

Journal ArticleDOI
10 Aug 1995-Nature
TL;DR: In this paper, the interpenetrating network formed from a phase-segregated mixture of two semiconducting polymers is shown to provide both the spatially distributed interfaces necessary for efficient charge photo-generation, and the means for separately collecting the electrons and holes.
Abstract: THE photovoltaic effect involves the production of electrons and holes in a semiconductor device under illumination, and their subsequent collection at opposite electrodes. In many inorganic semiconductors, photon absorption produces free electrons and holes directly1. But in molecular semiconductors, absorption creates electrona¤-hole pairs (excitons) which are bound at room temperature2, so that charge collection requires their dissociation. Exciton dissociation is known to be efficient at interfaces between materials with different electron affinities and ionization potentials, where the electron is accepted by the material with larger electron affinity and the hole by the material with lower ionization potential3. A two-layer diode structure can thus be used, in which excitons generated in either layer diffuse towards the interface between the layers. However, the exciton diffusion range is typically at least a factor of 10 smaller than the optical absorption depth, thus limiting the efficiency of charge collection3. Here we show that the interpenetrating network formed from a phase-segregated mixture of two semiconducting polymers provides both the spatially distributed interfaces necessary for efficient charge photo-generation, and the means for separately collecting the electrons and holes. Devices using thin films of these polymer mixtures show promise for large-area photodetectors.

3,165 citations

Journal ArticleDOI
TL;DR: Organolead trihalide perovskites are shown to exhibit the best of both worlds: charge-carrier mobilities around 10 cm2 V−1 s−1 and low bi-molecular charge-recombination constants.
Abstract: Organolead trihalide perovskites are shown to exhibit the best of both worlds: charge-carrier mobilities around 10 cm2 V−1 s−1 and low bi-molecular charge-recombination constants. The ratio of the two is found to defy the Langevin limit of kinetic charge capture by over four orders of magnitude. This mechanism causes long (micrometer) charge-pair diffusion lengths crucial for flat-heterojunction photovoltaics.

2,712 citations