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Your search keyword '"MANSOURI, Masoud"' showing total 3 results
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3 results on '"MANSOURI, Masoud"'

1. Lithium Borohydride (LiBH4): An Innovative Material for Neutron Radiation Shielding

Author

Lotfalian, Mohammadreza, Allaf, Mitra Athari, and Mansouri, Masoud

Subjects
Physics - Atomic and Molecular Clusters, Physics - Atomic Physics
Abstract

Radiation shielding plays a crucial role in various industries, including nuclear and space exploration. Among the most abundant elements and isotopes found in nature, 10B has one of the highest neutron absorption cross-sections, closely followed by 6Li. It is worth noting that hydrogen, with its light nucleus, serves as an excellent neutron reflector. Surprisingly, the potential of the lithium borohydride molecule (LiBH4), which consists exclusively of these elements, as a shield against neutron radiation has not yet been explored. This study investigates various materials that can potentially be used as shields. First, we assessed traditional shields and previous optimizations for shielding. The findings showed that concrete containing 10% B4C yielded the best results. High-performance concrete (HPC) replaced regular concrete. By gradually incorporating lithium borohydride into the shield, along with the appropriate level of boron carbide, further optimization was achieved. Calculations were performed using the MCNPX 2.7E code. The introduction of the new shield resulted in a significant 40% reduction in volume compared with the previous sample. The study findings showed that a 30 cm thick shield effectively blocked 95% of the total neutrons and 92% of the total gamma radiation. Additionally, it was noted that the shielding effects of lithium borohydride against fast neutrons are greater than those of boron carbide. Various parameters and data of the designed shield were calculated and compared with those of the previous sample.

Published
2024

3. Screening Tools for Obstructive Sleep Apnea in Pregnant Women: An Extended and Updated Systematic Review and Meta-analysis.

Author

Amra, Babak, Mansouri, Masoud, Soltaninejad, Forogh, Feizi, Awat, and Kaminska, Marta

Subjects
*RECEIVER operating characteristic curves, *RANDOM effects model, *SLEEP apnea syndromes, *PREGNANT women, *EPWORTH Sleepiness Scale
Abstract

The prevalence of obstructive sleep apnea syndrome (OSA) increases in women during pregnancy and negatively affects maternal and fetal outcomes. The updated systematic review and meta-analysis aimed to evaluate the validity of the Berlin, STOP-Bang, and Epworth sleepiness scale (ESS) questionnaires in detecting OSA in pregnant women. PubMed, Embase, and Web of Science were searched systematically up to March 2022. After eligible studies inclusion, two independent reviewers extracted demographic and clinical data. Bivariate random effects models were used to estimate the pooled accuracy measures including sensitivity and specificity, positive (PPV) and negative predictive values (NPVs), diagnostic odds ratio (DOR), and receiver operating characteristic curve (ROC) curve. We included 8 studies including 710 pregnant women with suspected OSA. The performance values of Berlin, STOP-Bang, and ESS questionnaires were as follows: the pooled sensitivity were 61% (95% confidence interval (CI): 40%-80%), 59% (95% CI: 49%-69%), and 29%, (95% CI: 10%-60%); pooled specificity were 61% (95% CI: 42%-78%), 80% (95% CI: 55%-93%), and 80% (95% CI: 50%-94%); pooled PPVs were 60% (95% CI: 0.49-0.72), 73% (95% CI: 61%-85%), and 59% (95% CI: 31%-87%); pooled NPVs were 60% (95% CI: 0.49-0.71), 65% (95% CI: 54%-76%), and 53% (95% CI: 41%-64%); and pooled DORs were 3 (95% CI: 1-5), 6 (95% CI: 2-19), and 2 (95% CI: 1-3), respectively. It seems that the Berlin, STOP-Bang, and ESS questionnaires had poor to moderate sensitivity and specificity in pregnancy, with the ESS showing the worst characteristics. Further studies are required to evaluate the performance of alternative screening methods for OSA in pregnancy. [ABSTRACT FROM AUTHOR]

Published
2024
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