Narrow structure in the coherent population trapping resonances in rubidium and Rayleigh scattering

The measurement of the coherent-population-trapping (CPT) resonances in uncoated Rb vacuum cells has shown that the shape of the resonances is different in different cells. In some cells the resonance has a complex shape - a narrow Lorentzian structure, which is not power broadened, superimposed on the power broadened CPT resonance. The results of the performed investigations on the fluorescence angular distribution are in agreement with the assumption that the narrow structure is a result of atom interaction with Rayleigh scattering light. The results are interesting for indication of the vacuum cleanness of the cells and building of magnetooptical sensors

Unfeasible body mass index and its association with low haemoglobin concentration: a correlation study among undergraduate medical students

Background: Low hemoglobin concentration and unfeasible body mass index adversely affect the health of people, consequently increasing morbidity and mortality among them. Hemoglobin concentration among individuals is associated with their body mass index. The prevalence of iron deficiency anemia is higher among underweight and overweight/obese people compared to those with normal BMI. Thus, the present study aimed to determine the correlation between hemoglobin concentration and BMI of undergraduate medical students.Methods: A cross-sectional study was carried out among 210 undergraduate medical students. Body mass index was calculated and hemoglobin estimation was done by Sahli's hemoglobinometer. Correlation between hemoglobin concentration and body mass index of subjects was assessed by Pearson’s correlation coefficient.Results: Underweight students had lowest mean hemoglobin concentration and the mean hemoglobin concentrations increased significantly (p<0.001) with increase in the BMI of subjects. A highly significant positive correlation (r=0.307, p<0.001) between BMI and hemoglobin concentration was observed. Further, significant positive correlation was observed among males (r=0.268, p=0.013), students with normal BMI (r=0.283, p=0.003) and overweight students (r=0.415, p=0.035) only.Conclusions: Hemoglobin concentration and BMI show a positive correlation, however this correlation tends to become negative in obese individuals. As both low hemoglobin concentration and unfeasible body mass index have detrimental effects on the health, diligent screening and management of both is essential for better outcome

On the Possibility of Determining the Distribution of a Substance Penetrating into a Dense Medium Using Gamma-Ray Detection and Ranging Approach

The possibility has been investigated of determining, using graydar (Gamma RAY Detection And Ranging) approach, the in-depth partial-density profile of some substance absorbed in a dense medium. Analytical algorithms have been derived for retrieving the in-depth profile of the partial density of the absorbed substance on the basis of the conjecturally known in-depth profile of the extinction of the absorbing medium and the experimentally determinable graydar profile. The retrieval error under the Poisson noise conditions has also been estimated analytically. The simulations performed of the Poisson-noise effect concern the case of soil moisture. The results obtained confirm the validity of the derived retrieval algorithms and error estimates and show that the soil moisture profile may be accurately determined to depths of 50 cm, depending on the dry-soil bulk density, the sensing photon flux, and the measurement time