scholarly journals Does Compound Nucleus remember its Isospin- An Evidence from the Fission Widths

2018 ◽  
Vol 178 ◽  
pp. 05008 ◽  
Author(s):  
Swati Garg ◽  
Ashok Kumar Jain

We present an evidence of isospin effects in nuclear fission by comparing the fission widths for reactions involving different isospin states of the same compound nucleus (CN). Yadrovsky [1] suggested this possibility in 1975. Yadrovsky obtained the fission widths for two reaction data sets, namely 206Pb(α,f) and 209Bi(p,f), both leading to same CN, and concluded that “a nucleus remembers the isospin value of the nuclear states leading to fission”. We obtain the fission decay widths for both the T0 + ½ and T0 − ½ states of CN by using two appropriate reaction data sets. We then compare the fission widths for the two isospin states of CN. More specifically, we have chosen the combination of 206Pb(α,f) and 209Bi(p,f) same as presented in Yadrovsky’s paper [1] in this study. A significant difference between the ratios of fission decay widths to total decay widths for different isospin values suggests that isospin plays an important role in fission.

2020 ◽  
Vol 5 (5) ◽  
pp. 912-920
Author(s):  
Christian P. Haas ◽  
Simon Biesenroth ◽  
Stephan Buckenmaier ◽  
Tom van de Goor ◽  
Ulrich Tallarek

Competing homo- and crossdimerization reactions between coumarin and 1-methyl-2-quinolinone are investigated by transient continuous-flow experiments combined with online HPLC, enabling the generation and acquisition of large reaction data sets.


2001 ◽  
Vol 16 (3) ◽  
pp. 99-101
Author(s):  
Cari Spence

The purpose of this study was to identify prevalence rates of medical problems among flautists. The Flute Health Survey (FHS), a questionnaire with items regarding musculoskeletal and nonmusculoskeletal problems, was distributed at the 1999 National Flute Association annual meeting (n = 40). This questionnaire was pilot tested at the 1999 Texas Flute Festival, which is hosted by the Texas Flute Society. The University of North Texas has posted on the Internet a similar questionnaire regarding the medical problems of all musicians. Responses from the University of North Texas Musician Health Survey (UNT-MHS) were filtered to include only those respondents who denoted flute as their primary instruments (n = 328). Data sets from both surveys were then processed using comparative statistics. Findings show that there was no significant difference between the demographics of the two populations. Only one musculoskeletal site, the left hand, was found to be statistically significant between the two groups. Four nonmusculoskeletal items, depression, earache, headache, and sleep disturbances, were found to be different between the two groups. The overall findings of this comparison show that there are many medical problems facing the flute playing community. Further investigation and observations of this population are necessary.


Author(s):  
Sang Lim Choi ◽  
Sung Bin Park ◽  
Seungwook Yang ◽  
Eun Sun Lee ◽  
Hyun Jeong Park ◽  
...  

Purpose: Kidney, ureter, and bladder radiography (KUB) has frequently been used in suspected urolithiasis, but its performance is known to be lower than that of computed tomography (CT). This study aimed to investigate the diagnostic performance of digitally post-processed kidney ureter bladder radiography (KUB) in the detection of ureteral stones. Materials And Methods: Thirty patients who underwent digital KUB and CT were included in this retrospective study. The original digital KUB underwent post-processing that involved noise estimation, reduction, and whitening to improve the visibility of ureteral stones. Thus, 60 digital original or post-processed KUB images were obtained and ordered randomly for blinded review. After a period, a second review was performed after unblinding stone laterality. The detection rates were evaluated at both initial and second review, using CT as reference standard. The objective (size) and subjective (visibility) parameters of ureteral stones were analyzed. Fisher’s exact test was used to compare the detection sensitivity between the original and post-processed KUB data set. Visibility analysis was assessed with a paired t-test. Correlation of stone size between CT and digital KUB data sets was assessed with Pearson’s correlation test. Results: The detection rate was higher for most reviewers once stone laterality was provided and was non-significantly better for the post-processed KUB images (p > 0.05). There was no significant difference in stone size among CT and digital KUB data sets. In all reviews, visibility grade was higher in the post-processed KUB images, irrespective of whether stone laterality was provided. Conclusion: Digital post-processing of KUB yielded higher visibility of ureteral stones and could improve stone detection, especially when stone laterality was available. Thus, digitally post-processed KUB can be an excellent modality for detecting ureteral stones and measuring their exact size.


2011 ◽  
Vol 11 (24) ◽  
pp. 12773-12786 ◽  
Author(s):  
S. Dhomse ◽  
M. P. Chipperfield ◽  
W. Feng ◽  
J. D. Haigh

Abstract. We have used an off-line 3-D chemical transport model (CTM) to investigate the 11-yr solar cycle response in tropical stratospheric ozone. The model is forced with European Centre for Medium-Range Weather Forecasts (ECMWF) (re)analysis (ERA-40/operational and ERA-Interim) data for the 1979–2005 time period. We have compared the modelled solar response in ozone to observation-based data sets that are constructed using satellite instruments such as Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter UltraViolet instrument (SBUV), Stratospheric Aerosol and Gas Experiment (SAGE) and Halogen Occultation Experiment (HALOE). A significant difference is seen between simulated and observed ozone during the 1980s, which is probably due to inhomogeneities in the ERA-40 reanalyses. In general, the model with ERA-Interim dynamics shows better agreement with the observations from 1990 onwards than with ERA-40. Overall both standard model simulations are partially able to simulate a "double peak"-structured ozone solar response with a minimum around 30 km, and these are in better agreement with HALOE than SAGE-corrected SBUV (SBUV/SAGE) or SAGE-based data sets. In the tropical lower stratosphere (TLS), the modelled solar response with time-varying aerosols is amplified through aliasing with a volcanic signal, as the model overestimates ozone loss during high aerosol loading years. However, the modelled solar response with fixed dynamics and constant aerosols shows a positive signal which is in better agreement with SBUV/SAGE and SAGE-based data sets in the TLS. Our model simulations suggests that photochemistry contributes to the ozone solar response in this region. The largest model-observation differences occur in the upper stratosphere where SBUV/SAGE and SAGE-based data show a significant (up to 4%) solar response whereas the standard model and HALOE do not. This is partly due to a positive solar response in the ECMWF upper stratospheric temperatures which reduces the modelled ozone signal. The large positive upper stratospheric solar response seen in SBUV/SAGE and SAGE-based data can be reproduced in model runs with fixed dynamical fields (i.e. no inter-annual meteorological changes). As these runs effectively assume no long-term temperature changes (solar-induced or otherwise), it should provide an upper limit of the ozone solar response. Overall, full quantification of the solar response in stratospheric ozone is limited by differences in the observed data sets and by uncertainties in the solar response in stratospheric temperatures.


2019 ◽  
Vol 100 (4) ◽  
Author(s):  
G. F. Bertsch ◽  
L. M. Robledo

2015 ◽  
Vol 22 (6) ◽  
pp. 715-731 ◽  
Author(s):  
Ha Duy Khanh ◽  
Soo Yong Kim

Purpose – The purpose of this paper is to evaluate the waste occurrence level in the construction industry. It includes: first, identifying the mean value of frequency of waste occurrence according to respondents’ characteristics; second, identifying the main predictive factors for waste occurrence based on latent relationships between initial waste factors; and third, identifying the waste occurrence-level indicator (WOLI) for the construction industry based on the main waste measurement factors. Design/methodology/approach – A total of 19 waste factors were sorted from the literature review. A structured questionnaire was adopted to carry out the survey. The respondents are professionals who have much experience in construction and management of project. Shapiro-Wilk test of normality, Levene’s test, ANOVA test, and factor analysis technique were used to analyze the collected data. Findings – Frequency of waste occurrence in construction projects is quite high. There was no statistically and practically significant difference in means for waste occurrence between selected population categories. Based on factor analysis technique, there were five principal components extracted with 56.7 percent of total variance. The WOLI in the construction industry was found as 61.55 per the scale of 100. Research limitations/implications – The non-probability sampling was applied to collect data because of several certain limitations and difficulties. The number of data sets is relatively small. This study has only examined the frequency of waste occurrence without quantitative information. Practical implications – This is another study of waste factors in the construction industry, which is different from traditional waste studies. Originality/value – The contribution of this study to the practical project management is that a proposed evaluation sheet for WOLI could be applied for any construction firm.


2006 ◽  
Vol 22 (5) ◽  
pp. 543-553 ◽  
Author(s):  
I. C. Baillie ◽  
P. S. Ashton ◽  
S. P. Chin ◽  
S. J. Davies ◽  
P. A. Palmiotto ◽  
...  

Discrete humus layers are common on podzols under temperate coniferous and tropical heath forests, and patchy layers also occur under some temperate broadleaved forests on non-podzolic soils. We used multiple data sets to test the reported association of humus with oligotrophic but non-podzolic soils under non-heath dipterocarp forest at Lambir, Sarawak. We examined the distribution, morphology and nutrient dynamics of necromass on soils derived from sandstone and shale. Concentrations of the main mineral nutrients were lower in fresh litter on the very oligotrophic sandstone soils than on shale. The rates of litterfall were similar, so that annual litterfall fluxes of all nutrients were lower on sandstone. The lower nutrient concentrations and fluxes in the litter on sandstone resulted in slower decomposition, longer residence times and larger standing crops of forest-floor necromass, with lower concentrations of nutrients. The necromass on sandstone sequestered significantly more N, K and Mg but less Ca and Mn than on shale, with no significant difference for P. The variations in necromass nutrient dynamics were associated with morphological differences. There were mats of densely rooted humus under the litter on sandstone, whereas litter lay directly over the mineral topsoil on shale. Spatial associations with soil nutrients were weak for necromass thickness, but clear for humus. The proportions of nutrients in the litterfall and necromass reflected the stoichiometric profiles of the soils. We attribute the differences in necromass nutrient dynamics and their association with soil reserve nutrients to lower rates of nutrient replenishment from the weathering of sandstone than from shale. Necromass characteristics are robust field indicators of multivariate edaphic differences in these and other tropical forests on Acrisols/Ultisols derived from Tertiary clastic sediments.


2004 ◽  
Vol 184 (S47) ◽  
pp. s87-s93 ◽  
Author(s):  
Chris Bushe ◽  
Brian Leonard

BackgroundMost evidence suggesting an association between schizophrenia, antipsychotic medications and diabetes has been based on retrospective studies not controlled for important confounders.AimsTo compare diabetogenic risk between antipsychotic medications; and to describe the limitations of current prospective data-sets.MethodSystematic review of prospective clinical data.ResultsNo difference in the incidence of glycaemic abnormalities between placebo cohorts and antipsychotic medication cohorts was identified. No significant difference between any of the antipsychotic medications studied in terms of their association with glycaemic abnormalities was identified. Treatment-related weight gain did not appear to increase the risk of developing diabetes.ConclusionsDiabetogenic potential ascribed to atypical antipsychotic drugs, resulting from retrospective studies, may be incorrect. Cohort sizes and incomplete sampling must preclude any definitive conclusions. Long-term, large, comparative prospective trials are needed, along with agreement upon glucose measurement of choice.


2021 ◽  
Vol 12 ◽  
pp. 136
Author(s):  
N. G. Nicolis

An extended Hauser-Feshbach approach has been employed in a multi-step Monte-Carlo evaporation code designed to study the de-excitation of highly excited compound nuclei. The code is intended to account for emission of light particles ($\gamma$, n, $^{1,2,3}$H, $^{3-6}$He) and intermediate mass fragments in their ground and excited states (particle-bound or unbound). As a study case, we consider the decay of the compound nucleus $^{120}$Te$^*$ at excitation energy 100, 200 and 300 MeV. First chance decay widths are compared with treatments based on the Weisskopf and the s-wave approximation. Preliminary calculations are compared with experimental isotopic yields of intermediate mass fragments emitted in E/A = 50 MeV $^{4}$He + $^{116,124}$Sn $\rightarrow$ $^{120,128}$Te$^*$ reactions.


2021 ◽  
Author(s):  
Alexander K. Bartella ◽  
Josefine Laser ◽  
Mohammad Kamal ◽  
Dirk Halama ◽  
Michael Neuhaus ◽  
...  

Abstract Introduction: Three-dimensional facial scan images have been showing an increasingly important role in peri-therapeutic management of oral and maxillofacial and head and neck surgery cases. Face scan images can be open using optical facial scanners utilizing line-laser, stereophotography, structured light modality, or from volumetric data obtained from cone beam computed tomography (CBCT). The aim of this study is to evaluate, if two low-cost procedures for creating a three-dimensional face scan images are able to produce a sufficient data set for clinical analysis. Materials and methods: 50 healthy volunteers were included in the study. Two test objects with defined dimensions were attached to the forehead and the left cheek. Anthropometric values were first measured manually, and consecutively, face scans were performed with a smart device and manual photogrammetry and compared to the manually measured data sets.Results: Anthropometric distances on average deviated 2.17 mm from the manual measurement (smart device scanning 3.01 mm vs. photogrammetry 1.34 mm), with 7 out of 8 deviations were statistically significant. Of a total of 32 angles, 19 values showed a significant difference to the original 90° angles. The average deviation was 6.5° (smart device scanning 10.1° vs. photogrammetry 2.8°).Conclusion: Manual photogrammetry with a regular photo-camera shows higher accuracy than scanning with smart device. However, the smart device was more intuitive in handling and further technical improvement of the cameras used should be watched carefully.


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