Insulating structure Patent

Insulating system for receptacles of liquefied gases using wire cloth for forming frost laye

Design reliability goal developed from small sample

Sampling distributions, constructed by Monte Carlo simulation are used in hardware development to establish a design reliability goal, to place a confidence coefficient on reliability estimates, and to determine whether sample stress/strength data demonstrate a specified reliability at a specified confidence level

QCD: Challenges for the Future

Despite many experimental verifications of the correctness of our basic understanding of QCD, there remain numerous open questions in strong interaction physics and we focus on the role of future colliders in addressing these questions. We discuss possible advances in the measurement of $\alpha_s$, in the study of parton distribution functions, and in the understanding of low $x$ physics at present colliders and potential new facilities. We also touch briefly on the role of spin physics in advancing our understanding of QCD.Comment: 12 pages, LATEX2e with snow2e, epsfig and 2 figures. Also available at http://penguin.phy.bnl.gov/~dawson/qcdsnow.ps . QCD working group summary at DPF/DPB Summer Study on New Directions for High Energy Physics, Snowmass, CO, June 25- July 12, 199

Mu and Tau Neutrino Thermalization and Production in Supernovae: Processes and Timescales

We investigate the rates of production and thermalization of $\nu_\mu$ and $\nu_\tau$ neutrinos at temperatures and densities relevant to core-collapse supernovae and protoneutron stars. Included are contributions from electron scattering, electron-positron annihilation, nucleon-nucleon bremsstrahlung, and nucleon scattering. For the scattering processes, in order to incorporate the full scattering kinematics at arbitrary degeneracy, the structure function formalism developed by Reddy et al. (1998) and Burrows and Sawyer (1998) is employed. Furthermore, we derive formulae for the total and differential rates of nucleon-nucleon bremsstrahlung for arbitrary nucleon degeneracy in asymmetric matter. We find that electron scattering dominates nucleon scattering as a thermalization process at low neutrino energies ($\epsilon_\nu\lesssim 10$ MeV), but that nucleon scattering is always faster than or comparable to electron scattering above $\epsilon_\nu\simeq10$ MeV. In addition, for $\rho\gtrsim 10^{13}$ g cm$^{-3}$, $T\lesssim14$ MeV, and neutrino energies $\lesssim60$ MeV, nucleon-nucleon bremsstrahlung always dominates electron-positron annihilation as a production mechanism for $\nu_\mu$ and $\nu_\tau$ neutrinos.Comment: 29 pages, LaTeX (RevTeX), 13 figures, submitted to Phys. Rev. C. Also to be found at anonymous ftp site http://www.astrophysics.arizona.edu; cd to pub/thompso

Many-Body Corrections to Charged-Current Neutrino Absorption Rates in Nuclear Matter

Including nucleon--nucleon correlations due to both Fermi statistics and nuclear forces, we have developed a general formalism for calculating the charged--current neutrino--nucleon absorption rates in nuclear matter. We find that at one half nuclear density many--body effects alone suppress the rates by a factor of two and that the suppression factors increase to $\sim$5 at $4\times10^{14}$ g cm$^{-3}$. The associated increase in the neutrino--matter mean--free--paths parallels that found for neutral--current interactions and opens up interesting possibilities in the context of the delayed supernova mechanism and protoneutron star cooling.Comment: 11 pages, APS REVTeX format, 1 PostScript figure, uuencoded compressed, and tarred, submitted to Physical Review Letter

Optical Albedo Theory of Strongly-Irradiated Giant Planets: The Case of HD 209458b

We calculate a new suite of albedo models for close-in extrasolar giant planets and compare with the recent stringent upper limit for HD 209458b of Rowe et al. using MOST. We find that all models without scattering clouds are consistent with this optical limit. We explore the dependence on wavelength and waveband, metallicity, the degree of heat redistribution, and the possible presence of thermal inversions and find a rich diversity of behaviors. Measurements of transiting extrasolar giant planets (EGPs) at short wavelengths by MOST, Kepler, and CoRoT, as well as by proposed dedicated multi-band missions, can complement measurements in the near- and mid-IR using {\it Spitzer} and JWST. Collectively, such measurements can help determine metallicity, compositions, atmospheric temperatures, and the cause of thermal inversions (when they arise) for EGPs with a broad range of radii, masses, degrees of stellar insolation, and ages. With this paper, we reappraise and highlight the diagnostic potential of albedo measurements of hot EGPs shortward of $\sim$1.3 $\mu$m.Comment: 6 pages, 1 table, 1 color figure; accepted to the Astrophysical Journa

Solutions of some Schrodinger equations

Two types of non-Hermitian systems are considered. One of them is both non-Hermitian and non-Linear and an iterative process is used to obtain excited state solutions; the ground state may be solved exactly. The model has been used in many physical systems and the method of calculation uses a simple Hilbert space with a generalised inner product. The second type has a complex term in the Hamiltonian and is a well studied problem in the infinite interval. Here a finite interval is considered and a complete set of eigenfunctions for this interval is used.The relationship between the finite interval states and the infinite interval states is discussed

Assessing Organic Chemistry Students? Understanding Of Chemical Bonding Concepts and their Perception of a Project-based Lab

Organic Chemistry students’ understanding of Organic Chemistry is shaped by their prior experiences, in-class experiences, and laboratory experiences. One essential prior General Chemistry experience that affects Organic Chemistry students is the understanding of chemical structures and bonding. This fundamental topic is the basis of the structure-function relationship and it highlights the numerous conceptual interconnections present in chemistry. However, many students possess incoherent knowledge structures regarding this topic. Therefore, more effective assessments are needed to identify these interconnected misconceptions. The use of concept-mapping and think-aloud interviews were used to investigate the knowledge structures of undergraduate Organic Chemistry students’ understanding of bonding concepts, resonance and Lewis structures for the first chapter of this dissertation. The study found that understanding of electronegativity was weak among students with low concept map scores (LS students) in comparison to students with high concept map scores (HS students). Additionally, several common misconceptions over the three topics were revealed through student interviews. An examination of LS student interviews further revealed that a lack of understanding of electronegativity led to a misunderstanding of polar covalent bonding. The think-aloud interviews reflected the connections students made with the concepts of electronegativity and polar covalent bonding in their concept maps. Chemistry labs are also considered a critical component of Organic Chemistry education. Laboratory instruction is presented in a variety of styles such as traditional or “cookbook”, project-based, open inquiry, and guided inquiry. Students can experience these laboratory environments in a variety of ways which directly affects how they learn or what they take away from the laboratory experience. The second half of this dissertation characterizes undergraduate students’ perspectives of a project-based Organic Chemistry laboratory and their perceptions of success and purpose in that laboratory using the theoretical framework of phenomenography. Eighteen participants were interviewed in a semi-structured interview format to collect their perspectives. A situated cognition framework was also used to design an outcome space that describes students’ engagement in the laboratory environment and its relationship to learning

The Third Plague Pandemic and British India: A Transformation of Science, Policy, and Indian Society

This paper seeks to understand the role of the Third Plague Pandemic\u27s overwhelming devastation in colonial India, specifically through the new advancements in scientific understanding, unheard of proactive prevention measures, and increased separation between the colonial powers of Great Britain and the common people of India