Feasibility study of integral heat sink space suit concepts

Integral heat sink material space suit for body temperature contro

Quantum Monte Carlo Study of Disordered Fermions

We study a strongly correlated fermionic model with attractive interactions in the presence of disorder in two spatial dimensions. Our model has been designed so that it can be solved using the recently discovered meron-cluster approach. Although the model is unconventional it has the same symmetries of the Hubbard model. Since the naive algorithm is inefficient, we develop a new algorithm by combining the meron-cluster technique with the directed-loop update. This combination allows us to compute the pair susceptibility and the winding number susceptibility accurately. We find that the s-wave superconductivity, present in the clean model, does not disappear until the disorder reaches a temperature dependent critical strength. The critical behavior as a function of disorder close to the phase transition belongs to the Berezinsky-Kosterlitz-Thouless universality class as expected. The fermionic degrees of freedom, although present, do not appear to play an important role near the phase transition.Comment: published version, more data added to Fig 5 and clarifications in text, 8 page

Near-deterministic quantum teleportation and resource-efficient quantum computation using linear optics and hybrid qubits

We propose a scheme to realize deterministic quantum teleportation using linear optics and hybrid qubits. It enables one to efficiently perform teleportation and universal linear-optical gate operations in a simple and near-deterministic manner using all-optical hybrid entanglement as off-line resources. Our analysis shows that our new approach can outperforms major previous ones when considering both the resource requirements and fault tolerance limits.Comment: 10 pages, 5 figures; extended version, title, abstract and figures changed, details added, to be published in Phys. Rev.

Development of resins for composites by resin transfer molding

Designed to cover a wide range of resin technology and to meet the near-term and long-term needs of the aircraft industry, this research has three objectives: to produce resin transfer molding (RES) resins with improved processability, to produce prepreg systems with high toughness and service temperature, and to produce new resin systems. Progress on reaching the objectives is reported

Technology study of passive control of humidity in space suits

Water vapor condensation and adsorption techniques for passive humidity control in space suit

Part I. Conformational analysis of 1,4-disubstituted cyclohexanes. Part II. Synthesis and conformational analysis of two bicyclic analogues of cyclohexane-1,4-dione

Part I. The conformational equilibria of cis-1,4-bromochloro-cyclohexane, trans-1,4-dibromo-, trans-1,4-dichloro-, and trans-1,4-bromochlorocyclohexane were measured by integration of the separate axial and equatorial proton signals at low temperature. The two possible chair forms of the cis compound were shown to exist in equal amounts, contrary to the result of Atkinson and Lunde. The free energy difference between the diaxial form and the diequatorial form of each of the trans compounds was shown to be roughly one-fifth of what one would expect if additivity of conformational energies was assumed. This was attributed to the greater electrostatic attraction in the di-axial form. Related cases from the literature were also discussed. Part II. The two bicyclic analogues of cyclohexane-1,4-dione studied were bicyclo[3.2.2] nonan-6,8-dione (11) and bicyclo-[3.3.1] nonan-3,9-dione (28). The first diketone was prepared by the thermal decarboxylation of 1,5-dicarboxybicyclo[3.2.2] nonan-6,8-dione. A discussion of this decarboxylation in relation to Bredt\u27s Rule was presented. The principal mass spectral feature of two derivatives of 11 was presented. The diketone 11 has two possible conformations each of which has a cyclohexane-1,4-dione ring locked in a flexible form by a trimethylene bridge. The conformational composition of 11 was determined by dipole moment measurement. The conformations of the diketone 28 and its 9-ethylene ketal were determined by infrared and nmr spectroscopy, and dipole moment measurements. The ethylene ketal was tentatively assigned a non-flattened twin-chair conformation, while 28 was shown to be an equilibrium mixture of 90% of twin-chair and 10% of chair-boat, with the cyclohexane-1,4-dione moiety in the boat form