Computer program for network synthesis by frequency response fit

Computer program synthesizes a passive network by minimizing the difference in desired and actual frequency response. The program solves for the critical points of the error function /weighted least squares fit between calculated and desired frequency response/ by the multivariable Newton-Raphson method with components constrained to an admissible region

Impact of shuttle environment on prelaunch handling of nickel-hydrogen batteries

Deployment of the American Satellite Company 1 spacecraft for the Space Shuttle Discovery in August 1985 set a new milestone in nickel-hydrogen battery technology. This communications satellite is equipped with two 35 Ah nickel-hydrogen batteries and it is the first such satellite launched into orbit via the Space Shuttle. The prelaunch activities, combined with the environmental constraints onboard the Shuttle, led to the development of a new battery handling procedure. An outline of the prelaunch activities, with particular attention to battery charging, is presented

Collisional excitation of intersteller molecules: Ammonia

Theoretical rate constants are presented for excitation of NH3 by collisions with He. The lowest 22 levels of ortho-NH3 and the lowest 16 levels of para-NH3 are considered at kinetic temperatures of 15 to 300 K

Performative regulation: a case study in how powerful people avoid criminal labels

This paper explores the role of invested powerful business actors in the criminalisation process as applied to the illicit antiquities market. We present a case study of the precise mechanics of the role played by trade interests in the formation of the Dealing in Cultural Objects (Offences) Act 2003. This process involved the trade’s entering appearance in the legislative process and neutralising the possible constraining effects on its members of the new criminal offence which was to be created. We begin by exploring the political, historical and economic context in which discussion of the terms of the 2003 Act first began. We then follow the Act from its genesis through its various stages of drafting and re-drafting, to its enactment. This case study of a single piece of legislation provides further data to add to the line of prior research that illustrates that powerful white-collar criminals, as well as sometimes preventing criminal legislation entering the statute books, can also influence the design of criminal legislation that does enter the statute books in order to protect themselves and their own business interests. We also use this case study of a process of contemporary law-making to outline the concept of performative regulation: broadly, that which in appearance serves political ends but in practice effects an inconsequential level of control

Rotational excitation of symmetric top molecules by collisions with atoms: Close coupling, coupled states, and effective potential calculations for NH3-He

The formalism for describing rotational excitation in collisions between symmetric top rigid rotors and spherical atoms is presented both within the accurate quantum close coupling framework and also the coupled states approximation of McGuire and Kouri and the effective potential approximation of Rabitz. Calculations are reported for thermal energy NH3-He collisions, treating NH3 as a rigid rotor and employing a uniform electron gas (Gordon-Kim) approximation for the intermolecular potential. Coupled states are found to be in nearly quantitative agreement with close coupling results while the effective potential method is found to be at least qualitatively correct. Modifications necessary to treat the inversion motion in NH3 are discussed

Are flexible contracts bad for workers? Evidence from job satisfaction data

If workers can choose between permanent and flexible contracts, compensating wage differentials should arise to equalize on-the-job utility in the two types of contracts. Estimating job satisfaction using the British Household Panel Survey shows that agency and casual contracts are associated with routinely lower satisfaction. This results because the low job satisfaction associated with less job security is not offset by higher compensation or other job characteristics. Job security is sufficiently important that holding constant this one facet of satisfaction eliminates the overall gap in job satisfaction between flexible and permanent contracts

An Analysis of Four-quark Energies in SU(2) Lattice Monte Carlo using the Flux-tube Symmetry:

Energies of four-quark systems calculated by the static quenched SU(2) lattice Monte Carlo method are analyzed in $2\times 2$ bases for square, rectangle, tilted rectangle, linear and quadrilateral geometry configurations and in $3\times 3$ bases for a non-planar geometry configuration. For small interquark distances, a lattice effect is taken into account by considering perimeter dependent terms which are characterized by the cubic symmetry. It is then found that a parameter $f$ - that can be identified as a gluon field overlap factor - is rather well described by the form $exp(-[b_sE{\cal A}+\sqrt{b_s}F{\cal P}])$, where ${\cal A}$ and ${\cal P}$ are the area and perimeter mainly defined by the positions of the four quarks, $b_s$ is the string constant in the 2-quark potentials and $E,F$ are constants.Comment: (19 pages of Latex - 1 page of figures not included - sent on request). Preprint HU-TFT-94-2

Design concepts for the ASTROMAG cryogenic system

Described is a proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper presents a liquid helium storage concept which would permit cryogenic lifetimes of up to 3 years between refills. It is proposed that the superconducting coil be cooled using superfluid helium pumped by the thermomechanical effect. It is also proposed that the storage tank be resupplied with helium in orbit. A method for charging and discharging the magnet with minimum helium loss using split gas-cooled leads is discussed. A proposal to use a Stirling cycle cryocooler to extend the storage life of the cryostat will also be presented