Simultaneous transmission and scattering Mössbauer measurements of powder samples

A vertical experimental set-up for simultaneous recording transmission and scattering Mössbauer spectra is described. Application of the apparatus for the study of model powder mixture of two components with different grain sizes shows differences in the relative intensity ratio of these fractions in absorption and conversion electron Mössbauer spectroscopy (CEMS) spectra. This effect, explained as a result of the size selectivity of CEMS technique, is parameterized by the grain radius ratio of components. The possible application for investigation of isolated surface nano- and microobjects is discussed

Sedimentation of Fe_{2}O_{3} and metallic iron nanoparticles exhibiting Brownian movement

Sedimentation of nanoparticles in water solutions was studied in situ by transmission Mossbauer spectroscopy in horizontal and vertical geometry. The studied specimens were Fe_{2}O_{3} of a commercial pigment and metallic iron nanoparticles in slurry used in a water purification technology. The sedimentation is selective and leads to the gradual removing of the bigger particles from a solution. The iron nanoparticles in the solution are relatively chemically stable until, due to the drying, the sediment becomes exposed to the air

Local electronic and charge state of iron in FeTe_{2}

From 57Fe Mössbauer spectrum of FeTe2 taken in high external magnetic field (B = 4.6 T), the sign of electric field gradient was determined as negative, with an asymmetry parameter of 0.2. A comparison of these data with results of calculation of the electric field gradient within point charge model suggests the lattice character of electric field gradient with some contribution from covalency effects. The effective magnetic field acting on 57Fe is less than the applied, which points out the diamagnetic Fe+2 state of iron. This "electronic state" is in a contradiction to Fe+3 "charge state" concluded from 125Te experiments on 3d transition metal ditellurides as well as from 57Fe quadrupole splitting and isomer shift

Mobility of interacting inorganic nanoparticles

The mobility of the 110 nm-Fe_{2}O_{3} particles in a viscous sucrose solution depends on the concentration of the nanoparticles. When the average particle particle nearest neighbor distance is less than 250 rim, the particle interaction slows down their mobility. When is more than 170 rim, the small mobility of nanoparticles does not depend on their concentration. The critical distance is approximately equal to 2R_{h} = 260 nm, where R_{h} is the hydrodynamic radius, determined by the dynamic light scattering (DLS) method

Longitudinal effects of a nurse-managed comprehensive cardiovascular disease prevention program for hospitalized coronary heart disease patients and primary care high-risk patients

Background: The EUROACTION study (nurse‑coordinated multidisciplinary, family‑based cardiovascular disease prevention program) documented the efficacy of a nurse‑managed, comprehensive prevention program in reducing risk factors for cardiovascular disease (CVD). No information was available on survival. Aims: The aim of the study was to assess the effects of EUROACTION intervention on CVD risk factors and 12‑year survival in the Polish component of the study. Methods: Two district hospitals and 2 primary care practices were allocated randomly to intervention (INT) or usual care (UC). The primary endpoints were lifestyle and risk factors changes at 1‑year follow‑up. Differences in survival were analyzed using the multivariable Cox proportional hazards regression models. Results: The study involved 628 patients with coronary heart disease (CHD) and 711 high‑risk patients. Compared to UC, INT patients achieved healthier lifestyles and a larger reduction of risk factors at 1 year but these differences were not maintained 12 years after the intervention. Less deaths occurred in patients from the INT hospital and from INT primary practice (hazard ratio [HR], 0.58; 95% CI, 0.42–0.82 and HR, 0.53; 95% CI, 0.3–0.95, respectively). Adjustment for the covariates slightly attenuated the estimates and removed significance (HR, 0.74; 95% CI, 0.52–1.04 and HR, 0.66; 95% CI, 0.36–1.24, respectively). For combined CHD and high‑risk patient groups, compared with UC, INT patients had a 36% lower risk of death after adjustment for age, sex, and history of CHD (HR, 0.64; 95% CI, 0.48–0.86). Conclusions: The impact of the EUROACTION intervention on lifestyle and CVD risk factors could have contributed to lower mortality in INT coronary and high‑risk patients. These results emphasize the need for sustaining the interventions to help patients maintain a healthy lifestyle

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects