The density functional definition of exchange and correlation differs from the traditional one. In order to calculate the density functional theory ~DFT!, quantities accurately, molecular Kohn–Sham ~KS! solutions have been obtained from ab initio wave functions for the homonuclear diatomic molecules Li2, N2, F2. These afford the construction of the KS determinant Cs and the calculation of its t...

General Dynamics C4 Systems extends the Digital Modular Radio (DMR) system to the High Frequency (HF) domain. Base-band serial and parallel tone modem functionality is integrated with embedded, AIM-based KY-99A, KWR-46, and KG-84C cryptographic algorithms plus single-sideband (SSB) radio frequency (RF) modulation to provide four channels of HF plain text (PT) and cipher text (CT) communication....

[1] ELF/VLF (0.3–30 kHz) wave generation is achievable via modulated HF (3–30 MHz) heating of the lower ionosphere in the presence of natural currents such as the auroral electrojet. Using the 3.6 MWHigh Frequency Active Auroral Research Program (HAARP) facility near Gakona, AK, we investigate the effect of HF frequency and beam size on the generated ELF/VLF amplitudes, as a function of modulat...

Studies of arterial elasticity in patients with heart failure (HF) have produced varying results. In addition, the direct effects of smooth muscle relaxation on arterial wall mechanics in these patients have not been well characterized. Nineteen patients with New York Heart Association class II to IV HF and 17 age- and size-matched normal subjects were studied by using a recently validated tech...

OBJECTIVES To determine the prevalence of cognitive impairment in older adults with heart failure (HF). DESIGN Cross-sectional analysis of the 2004 wave of the nationally representative Health and Retirement Study linked to 2002 to 2004 Medicare administrative claims. SETTING United States, community. PARTICIPANTS Six thousand one hundred eighty-nine individuals aged 67 and older. MEASU...

In this study, a mathematical model is developed based on algebraic equations which is capable of generating artificially normal events of electrocardiogram (ECG) signals such as P-wave, QRS complex, and T-wave. This model can also be implemented for the simulation of abnormal phenomena of electrocardiographic signals such as ST-segment episodes (i.e. depression, elevation, and sloped ascending...

HF surface-wave radars (HFSWRs) offer two distinct advantages when used over the sea: with vertical polarization, they see beyond the horizon, and the interaction of their signals with ocean waves is simple and well understood. As a result, many HFSWR research test programs were conducted in the U.S., beginning 35 years ago. This author was fortunate to have been immersed in these programs from...

The remote sensing group of the University of Hamburg is working in the field of HF radar since 1980. For the start three CODAR systems have been purchased from NOAA/ERL (developed by D. Barrick’s NOAA group). Based on 16 years of experience a new system called WEllen RAdar (WERA) has been designed at the University of Hamburg in 1996. The new design aims to be as flexible as possible in order ...

in this paper,the molecular geometry for three tautomers of uracil and four tautomers of cytosine has been analyzed. vibrational ir spectra of the tautomers were   investigated at hf and b3lyp level using the ab initio 6-31g* and lanl2dz basis sets from the program package gaussian 98 (a.7 public domain version). the physico-chemical and biochemical properties of uracil and cytosine are one of...

Two multiline cw HF lasers employing unstable resonators were coupled by injecting 20% of each laser output into the other laser. The mutual coherence of the two output beams was measured by recording the visibility V of the interference fringes generated when the beams are overlapped. Both single-line and multiline interference patterns were observed. The output from the two lasers in the pres...