Research study of structural damage produced in silicon semiconductors by neutron irradiation Final report, Jun. 1969 - Jul. 1970

Characteristics of damage produced in silicon semiconductors by neutron irradiatio

The Investment Comparison Tool (ICT): A Method to Assess Research and Development Investments

This paper presents a software tool (the Investment Comparison Tool), a methodology (the Investment Comparison Methodology), and a decision support system (the Investment Comparison System) to aid decision makers with Research and Development Investment allocations. The Investment Comparison System (ICS) can be used vertically within an organization and horizontally across organizations at multiple portfolio investment levels. The ICS is applicable to any R&D environment ranging from Industry Research Environments to Federal Agencies. The ICS described in this paper is comprised of a system architecture, databases, Group Decision Making (GDM) methods, an Investment Comparison Tool (ICT) that includes various algorithms, and reporting tools. To aid in the usage of the ICS, an Assessment and Evaluation Framework, a detailed methodology with its technical foundation, and a corresponding example are also presented. The decision making process used in the methodology is the Analytical Hierarchy Process combined with methods for GDM. ICS is unique because of how it uses a combination of algorithms for assessing R&D Investments and the wide flexibility of its use

Research study of structural damage produced in silicon semiconductors by neutron irradiation Semiannual report

Etching techniques for undoped and lithium doped silicon solar cells and observation by surface replication and thin film transmission electron microscop

IRAS 16293-2422: A very young binary system?

We present 4".5 x 2".5 resolution millimeter wavelength observations of the young far-infrared source IRAS 16293-2422 which resolve the continuum emission into two sources, MM 1 and MM 2. These sources coincide with known radio continuum sources and may constitute a very young binary system with a projected separation of 840 AU. Flux measurements from 18 cm to 25 μm show that the majority of the millimeter wavelength emission arises from dust within 300 AU of the individual central objects. The total dynamical mass of 1.1-1.3 M_⊙, coupled with our mass estimates for MM 1 and MM 2, suggests that the mass in circumstellar material is comparable to that of the central stellar cores. Since the stellar masses are constrained to be ≤ 0.5 M_⊙ each, it is likely that the bolometric luminosity of 30-40 L_⊙ is derived mainly from accretion of the observed circumstellar material. Maps of the J = 2, 3-1, 2 transition of SO obtained simultaneously show that this emission is centered on MM 1, with weaker emission in a clumpy distribution to the east and west. No SO emission is detected toward MM 2, indicating an upper limit to the fractional abundance which is a factor of 10 below that toward MM 1. We propose that the SO emission toward MM 1 is a result of the outflow activity associated with this source and that the outlying emission clumps trace regions of mild interaction between the outflow and the ambient cloud

Baseline tests of the EPC Hummingbird electric passenger vehicle

The rear-mounted internal combustion engine in a four-passenger Volkswagen Thing was replaced with an electric motor made by modifying an aircraft generator and powered by 12 heavy-duty, lead-acid battery modules. Vehicle performance tests were conducted to measure vehicle maximum speed, range at constant speed, range over stop-and-go driving schedules, maximum acceleration, gradeability limit, road energy consumption, road power, indicated energy consumption, braking capability, battery charger efficiency, and battery characteristics. Test results are presented in tables and charts

The circumbinary disk of HD 98800B: Evidence for disk warping

The quadruple young stellar system HD 98800 consists of two spectroscopic binary pairs with a circumbinary disk around the B component. Recent work by Boden and collaborators using infrared interferometry and radial velocity data resulted in a determination of the physical orbit for HD 98800B. We use the resulting inclination of the binary and the measured extinction toward the B component stars to constrain the distribution of circumbinary material. Although a standard optically and geometrically thick disk model can reproduce the spectral energy distribution, it cannot account for the observed extinction if the binary and the disk are coplanar. We next constructed a dynamical model to investigate the influence of the A component, which is not in the Ba‐Bb orbital plane, on the B disk. We find that these interactions have a substantial impact on the inclination of the B circumbinary disk with respect to the Ba‐Bb orbital plane. The resulting warp would be sufficient to place material into the line of sight and the noncoplanar disk orientation may also cause the upper layers of the disk to intersect the line of sight if the disk is geometrically thick. These simulations also support that the dynamics of the Ba‐Bb orbit clear the inner region to a radius of~3 AU. We then discuss whether the somewhat unusual properties of the HD 98800B disk are consistent with material remnant from the star formation process or with more recent creation by collisions from larger bodies

Ultraslow light in inhomogeneously broadened media

We calculate the characteristics of ultraslow light in an inhomogeneously broadened medium. We present analytical and numerical results for the group delay as a function of power of the propagating pulse. We apply these results to explain the recently reported saturation behavior [Baldit {\it et al.}, \prl {\bf 95}, 143601 (2005)] of ultraslow light in rare earth ion doped crystal.Comment: 4 pages, 5 figure

One dimensional chain of quantum molecule motors as a mathematical physics model for muscle fibre

A quantum chain model of many molecule motors is proposed as a mathematical physics theory on the microscopic modeling of classical force-velocity relation and tension transients of muscle fibre. We proposed quantum many-particle Hamiltonian to predict the force-velocity relation for the slow release of muscle fibre which has no empirical relation yet, it is much more complicate than hyperbolic relation. Using the same Hamiltonian, we predicted the mathematical force-velocity relation when the muscle is stimulated by alternative electric current. The discrepancy between input electric frequency and the muscle oscillation frequency has a physical understanding by Doppler effect in this quantum chain model. Further more, we apply quantum physics phenomena to explore the tension time course of cardiac muscle and insect flight muscle. Most of the experimental tension transients curves found their correspondence in the theoretical output of quantum two-level and three-level model. Mathematically modeling electric stimulus as photons exciting a quantum three-level particle reproduced most tension transient curves of water bug Lethocerus Maximus.Comment: 16 pages, 12 figures, Arguments are adde

Expansion and Collapse in the Cosmic Web

We study the kinematics of the gaseous cosmic web at high redshift with Lyman alpha forest absorption in multiple QSO sightlines. Using a simple analytic model and a cosmological hydrodynamic simulation we constrain the underlying three-dimensional distribution of velocities from the observed line-of-sight distribution of velocity shear across the plane of the sky. The distribution is found to be in good agreement with the intergalactic medium (IGM) undergoing large scale motions dominated by the Hubble flow. Modeling the Lyman alpha clouds analytically and with a hydrodynamics simulation, the average expansion velocity of the gaseous structures causing the Lyman alpha forest in the lower redshift (z = 2) sample appears about 20 percent lower than the local Hubble expansion velocity. We interpret this as tentative evidence for some clouds undergoing gravitational collapse. However, the distribution of velocities is highly skewed, and the majority of clouds at redshifts from 2 to 3.8 expand typically about 5 - 20 percent faster than the Hubble flow. This behavior is explained if most absorbers in the column density range typically detectable are expanding filaments that stretch and drain into more massive nodes. We find no evidence for the observed distribution of velocity shear being significantly influenced by processes other than Hubble expansion and gravitational instability, like galactic winds. To avoid overly disturbing the IGM, winds may be old and/or limp by the time we observe them in the Lyman alpha forest, or they may occupy only an insignificant volume fraction of the IGM. (abridged)Comment: 63 pages, 26 figures, AAS Latex; ApJ, in pres