3,249 research outputs found
Folly to the Greeks: Good Reasons to Give up Reason
A discussion of why a strong doctrine of 'reason' may not be worth sustaining in the face of modern scientific speculation, and the difficulties this poses for scientific rationality, together with comments on the social understanding of religion, and why we might wish to transcend common sense
Impedance Controlled Connector Interface
A connector interface for electrically mating a multi-row connector with a printed circuit board is defined by a flex circuit in the form of laminated polyimide layers having conductive traces for each interconnect pair with connection fields at the opposite ends of the traces for electrical connection to the terminal pins on the connector and the conductive pads or pins on the circuit board. The conductive traces are all of equal length to provide equal resistance and impedance paths for each of the circuit interconnects
On Self-Adjoint and J-Self-Adjoint Dirac-Type Operators: A Case Study
We provide a comparative treatment of some aspects of spectral theory for self-adjoint and non-self-adjoint (but J-self-adjoint) Dirac-type operators connected with the defocusing and focusing nonlinear Schrödinger equation, of relevance to nonlinear optics. In addition to a study of Dirac and Hamiltonian systems, we also introduce the concept of Weyl-Titchmarsh half-line m-coefficients (and 2 × 2 matrix-valued M-matrices) in the non-self-adjoint context and derive some of their basic properties. We conclude with an illustrative example showing that crossing spectral arcs in the non-self-adjoint context imply the blowup of the norm of spectral projections in the limit where the crossing point is approached
Right Angle Electrical Connector and Insertion Tool Therefor
Disclosed is a multi-row right angle connector and a press block for installing the connector on a mounting substrate without soldering the contact pins. The connector legs comprise eye of the needle compliant interfaces that make electrical contact with the interior surfaces of the substrate\u27s plated through holes. The press block is designed for use with a four-row right angle receptacle and locates rows 2, 3, and 4 on respective true grid positions and serves as a means for transmitting force from an external press to the contact pin tails. The contact tails in rows 2, 3, and 4 have a T-shaped shoulder that is pressed into a pocket in the press block. The insertion force is applied to the pins in row 1 by a corner having a radius matching the radius of the row 1 tails
Elimination of Supply Harmonics: An Evolution of Current Compensation and Active Filtering Methods
The price of the extensive use of power electronic devices is becoming clear: increasing harmonic pollution. This survey takes a brief look at background information related to harmonics, including their sources, effects, and characteristics. Then, the evolution of the harmonics elimination approaches of current compensation and active filtering, which are becoming more feasible due to research and technological improvements, are discussed in order to give some insight into the directions that research is taking
Elimination of Supply Harmonics
The price of the extensive use of power electronic devices is becoming clear: increasing harmonic pollution. The greater amount of harmonics being introduced into power distribution systems is of concern to both power consumers and power companies. First, a brief look is taken at background information which describes harmonic sources, effects, and characteristics. Then the evolution of the harmonics elimination approaches of current compensation and active filtering are discussed to give some insight into the directions that research is taking
Thermal Tolerance in Tropical Versus Subtropical Pacific Reef Corals
Upper lethal temperature tolerances of reef corals in Hawaii and at
Enewetak, Marshall Islands, were determined in the field and under controlled
laboratory conditions. Enewetak corals survived in situ temperatures of nearly
34° C, whereas 32° C was lethal to Hawaiian corals for similar short-term exposures.
Laboratory determinations indicate that the upper thermal limits of Hawaiian corals
are approximately 2° C less than congeners from the tropical Pacific. Differences in
coral thermal tolerances correspond to differences in the ambient temperature
patterns between geographic areas
TID and SEE Testing Results of Altera Cyclone Field Programmable Gate Array
Total ionizing dose (TID) and single event effects testing was performed on Altera Cyclone FPGAs. The devices exhibit slight performance degradation to a TID of 1 Mrad (Si), but also exhibited single event latchup at a low LET
Completing the Square to Find the Supersymmetric Matter Effective Action Induced by Coupling to Linearized N=1 Supergravity
We consider generic N=1 supersymmetric matter coupled to linearized N=1
supergravity through the multiplet of currents. By completing the square, we
find the effective action giving the leading supergravity induced correction to
the matter dynamics, expressed explicitly as a quadratic form in the components
of the current multiplet. The effective action is supersymmetry invariant
through an interplay of the local terms arising from the auxiliary field
couplings, and the nonlocal terms arising from graviton and gravitino exchange,
neither of which is separately invariant. Having an explicit form for the
supergravity induced effective action is a first step in studying whether
supergravity corrections can lead to dynamical supersymmetry breaking in
supersymmetric matter dynamics. In Appendices we give explicit expressions for
the currents, in our notational conventions, in the Wess-Zumino and
supersymmetric Yang Mills models.Comment: TEX; to be submitted to Annals of Physic
Effects of human recombinant growth hormone on exercise capacity, cardiac structure, and cardiac function in patients with adult-onset growth hormone deficiency
Objective Epidemiological studies suggest that adult-onset growth hormone deficiency (AGHD) might increase the risk of death from cardiovascular causes. Methods This was a 6-month double-blind, placebo-controlled, randomised, cross-over trial followed by a 6-month open-label phase. Seventeen patients with AGHD received either recombinant human growth hormone (rGH) (0.4 mg injection daily) or placebo for 12 weeks, underwent washout for 2 weeks, and were then crossed over to the alternative treatment for a further 12 weeks. Cardiac magnetic resonance imaging, echocardiography, and cardiopulmonary exercise testing were performed at baseline, 12 weeks, 26 weeks, and the end of the open phase (12 months). The results were compared with those of 16 age- and sex-matched control subjects. Results At baseline, patients with AGHD had a significantly higher systolic blood pressure, ejection fraction, and left ventricular mass than the control group, even when corrected for body surface area. Treatment with rGH normalised the insulin-like growth factor 1 concentration without an effect on exercise capacity, cardiac structure, or cardiac function. Conclusion Administration of rGH therapy for 6 to 9 months failed to normalise the functional and structural cardiac differences observed in patients with AGHD when compared with a control group
- …