Aerobraking characteristics for several potential manned Mars entry vehicles

While a reduction in weight is always desirable for any space vehicle, it is crucial for vehicles to be used in the proposed Manned Mars Mission (MMM). One such way to reduce a spacecraft's weight is through aeroassist braking which is an alternative to retro-rockets, the traditional method of slowing a craft approaching from a high energy orbit. In this paper aeroassist braking was examined for two blunt vehicle configurations and one streamlined configuration. For each vehicle type, a range of lift-to-drag ratios was examined and the entry angle windows, bank profiles, and trajectory parameters were recorded here. In addition, the sensitivities of velocity and acceleration with respect to the entry angle and bank angles were included. Also, the effect of using different atmosphere models was tested by incorporating several models into the simulation program

Balancing Justice Needs and Private Property in Constitutional Takings Provisions: A Comparative Assessment of India, Australia, and the United States

This Article explores the relationship between justice needs and private property in the constitutional takings provisions of the Indian, Australian, and American constitutions. Building upon established scholarship, it develops a theoretical framework within which to consider the way in which a state balances the requirement to provide minimal levels of justice for its citizens through the re-distribution of goods and resources with the need to protect the private property of individuals. We summarize this framework in what we refer to as the “Justice Needs-Protection of Private Property Continuum.” Using the framework developed, the Article provides an outline of the takings provisions found in the Indian, Australian, and American constitutions. Part I examines Article 300A of the Constitution of India, which contains the scope of the power of compulsory acquisition exercised by the Indian state. Part II assesses Section 51(xxxi) of the Australian Constitution which, unlike its American and Indian counterparts, operates as both a grant of power to the federal government, as well as a limitation imposed upon that power, which may, it seems, operate so as to provide some minimal protection for individual private property interests. Part III considers the Takings Clause of the Fifth Amendment to the United States Constitution which, as interpreted by the Supreme Court, provides perhaps the most robust means among the three jurisdictions considered for protecting the individual private property interests as against state takings. The Conclusion offers comparative reflections on the nature of the takings provision found in each jurisdiction.Krithika Ashok, Paul T. Babie, & John V. Ort

Odd Triplet Pairing in clean Superconductor/Ferromagnet heterostructures

We study triplet pairing correlations in clean Ferromagnet (F)/Superconductor (S) nanojunctions, via fully self consistent solution of the Bogoliubov-de Gennes equations. We consider FSF trilayers, with S being an s-wave superconductor, and an arbitrary angle $\alpha$ between the magnetizations of the two F layers. We find that contrary to some previous expectations, triplet correlations, odd in time, are induced in both the S and F layers in the clean limit. We investigate their behavior as a function of time, position, and $\alpha$. The triplet amplitudes are largest at times on the order of the inverse ``Debye'' frequency, and at that time scale they are long ranged in both S and F. The zero temperature condensation energy is found to be lowest when the magnetizations are antiparallel.Comment: Four pages, including four figure

THE VALUE OF PUBLIC INFORMATION FOR MICROECONOMIC PRODUCTION DECISIONS

Procedures are needed to evaluate the benefits of the provision of information. This paper shows how to apply a money metric definition of the value of information for this purpose. The application is to microeconomic input choices for agricultural production, and the information to be valued concerns the effect of fertilization on sorghum yield. In this paper application both output price and output level are stochastic, and the probability distribution of output is affected by the chosen level of fertilizer.Crop Production/Industries,

Three-dimensional Binary Superlattices of Oppositely-charged Colloids

We report the equilibrium self-assembly of binary crystals of oppositely-charged colloidal microspheres at high density. By varying the magnitude of the charge on near equal-sized spheres we show that the structure of the binary crystal may be switched between face-centered cubic, cesium chloride and sodium chloride. We interpret these transformations in terms of a competition between entropic and Coulombic forces

Millimeter-wave surface impedance of optimally-doped Ba(Fe1-xCox)2As2 single crystals

Precision measurements of active and reactive components of in-plane microwave surface impedance were performed in single crystals of optimally-doped Fe-based superconductor Ba(Fe1-xCox)2As2 (x = 0.074, Tc = 22.8 K). Measurements in a millimeter wavelength range (Ka band, 35-40 GHz) were performed using whispering gallery mode excitations in the ultrahigh quality factor quasioptical sapphire disk resonator with YBa2Cu2O7 superconducting (Tc = 90 K) end plates. The temperature variation of the London penetration depth is best described by a power-law function, delta {\lambda}(T) is proportional to T with the exponent n, n = 2.8, in reasonable agreement with radio-frequency measurements on crystals of the same batch. This power-law dependence is characteristic of a nodeless superconducting gap in the extended s-wave pairing scenario with a strong pair-breaking scattering. The quasiparticle conductivity of the samples, {\sigma}1(T), gradually increases with the decrease of temperature, showing no peak below or at Tc, in notable contrast with the behavior found in the cuprates. The temperature-dependent quasiparticle scattering rate was analyzed in a two-fluid model, assuming the validity of the Drude description of conductivity and generalized expression for the scattering rate. This analysis allows us to estimate the range of the values of a residual surface resistance from 3 to 6 mOhm.Comment: 7 pages, 7 figure

Probability for Primordial Black Holes in Multidimensional Universe with Nonlinear Scalar Curvature Terms

We investigate multi-dimensional universe with nonlinear scalar curvature terms to evaluate the probability of creation of primordial black holes. For this we obtain Euclidean instanton solution in two different topologies: (a) $S^{D-1}$ - topology which does not accommodate primordial black holes and (b) $S^1\times S^{D-2}$-topology which accommodates a pair of black holes. The probability for quantum creation of an inflationary universe with a pair of black holes has been evaluated assuming a gravitational action which is described by a polynomial function of scalar curvature with or without a cosmological constant ($\Lambda$) using the framework of semiclassical approximation of Hartle-Hawking boundary conditions. We discuss here a class of new gravitational instantons solution in the $R^4$-theory which are relevant for cosmological model building.Comment: 18 pages, no figure. accepted in Phys. Rev.