scholarly journals An improved descriptor of cluster stability: application to small carbon clusters

2018 ◽  
Vol 20 (43) ◽  
pp. 27368-27374 ◽  
Author(s):  
José I. Martínez ◽  
Julio A. Alonso
Keyword(s):  
Mass Spectrum ◽  
Carbon Clusters ◽  
Cluster Stability ◽  
Perfect Correlation ◽  
Experimental Mass Spectrum

A novel cluster stability descriptor applied to small cation carbon clusters reveals a perfect correlation with the experimental mass spectrum.

Excited state baryon masses in a quark–diquark model

1989 ◽  
Vol 67 (9) ◽  
pp. 876-880 ◽  
Author(s):  
John W. Norbury
Keyword(s):  
Excited State ◽  
Mass Spectrum ◽  
Qualitative Agreement ◽  
Mass Spectra ◽  
Present Form ◽  
Linear Potential ◽  
Diquark Model ◽  
Experimental Mass Spectrum ◽  
State Baryon

The Lichtenberg diquark model is used to analyze the nucleon and isobar mass spectra using a spin-independent, nonrelativistic linear potential. Qualitative agreement with data is found, leading to the conclusion that the Lichtenberg diquark model, in its present form, is consistent with the experimental mass spectrum.

scholarly journals A reference peptide database for proteome quantification based on experimental mass spectrum response curves

2018 ◽  
Vol 34 (16) ◽  
pp. 2766-2772
Author(s):  
Wanlin Liu ◽  
Lai Wei ◽  
Jianan Sun ◽  
Jinwen Feng ◽  
Gaigai Guo ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Response Curves ◽  
Experimental Mass Spectrum ◽  
Peptide Database ◽  
Reference Peptide ◽  
Spectrum Response

Polymer oxidation catalyst containing acidic functional groups

1981 ◽  
Vol 46 (5) ◽  
pp. 1237-1247
Author(s):  
Zdeněk Prokop ◽  
Karel Setínek
Keyword(s):  
Functional Groups ◽  
Elevated Temperatures ◽  
Redox Properties ◽  
Oxidation Catalyst ◽  
Carbon Clusters ◽  
Oxidation Activity ◽  
Redox Sites ◽  
Styrene Divinylbenzene ◽  
Proportional Decrease ◽  
Polymer Oxidation

The catalyst containing redox sites in addition to acid functional groups was prepared by sulphonation of a macroporous chloromethylated styrene-divinylbenzene copolymer with concentrated sulphuric acid at elevated temperatures. Its activity was tested for the oxidation of 2-propanol by molecular oxygen at 120 °C and was found to be comparable to that of the iridium on carbon catalyst.Neutralisation of acid functional groups by alkali metal led to proportional decrease in the oxidation activity. The results of EPR spectroscopic study of these catalysts show that the redox properties of the polymer are caused by carbon clusters which are capable of electron exchange.

scholarly journals Analysis of Butyl Butyrate Mass Spectrum

2018 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Abdalla Mustafa Walwil
Keyword(s):  
Mass Spectrum ◽  
Proton Transfer ◽  
Educational Work ◽  
Butyl Butyrate ◽  
Chemistry Students ◽  
Double Proton Transfer

The aim of this educational work is targeting chemistry students and interested instructors. The presented work will analyze the mass spectrum of butyl butyrate (butyl butanoate). The analysis will concentrate on the mechanisms showing how the characteristic fragments are formed. The mechanisms discussed in this paper include α-cleavage, β-cleavage, McLafferty Rearrangements, first and second proton transfer, a double proton transfer. 

scholarly journals An event excess observed in the deeply bound region of the 12C (K−, p) missing-mass spectrum

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Yudai Ichikawa ◽  
Junko Yamagata-Sekihara ◽  
Jung Keun Ahn ◽  
Yuya Akazawa ◽  
Kanae Aoki ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Binding Energy ◽  
Decay Channel ◽  
Peak Shift ◽  
Bound State ◽  
Elastic Peak ◽  
Missing Mass ◽  
Decay Modes ◽  
Kaon Momentum ◽  
First Time

Abstract We have measured, for the first time, the inclusive missing-mass spectrum of the $^{12}$C$(K^-, p)$ reaction at an incident kaon momentum of 1.8 GeV/$c$ at the J-PARC K1.8 beamline. We observed a prominent quasi-elastic peak ($K^-p \rightarrow K^-p$) in this spectrum. In the quasi-elastic peak region, the effect of secondary interaction is apparently observed as a peak shift, and the peak exhibits a tail in the bound region. We compared the spectrum with a theoretical calculation based on the Green’s function method by assuming different values of the parameters for the $\bar{K}$–nucleus optical potential. We found that the spectrum shape in the binding-energy region $-300 \, \text{MeV} < B_{K} < 40$ MeV is best reproduced with the potential depths $V_0 = -80$ MeV (real part) and $W_0 = -40$ MeV (imaginary part). On the other hand, we observed a significant event excess in the deeply bound region around $B_{K} \sim 100$ MeV, where the major decay channel of $K^- NN \to \pi\Sigma N$ is energetically closed, and the non-mesonic decay modes ($K^- NN \to \Lambda N$ and $\Sigma N$) should mainly contribute. The enhancement is fitted well by a Breit–Wigner function with a kaon-binding energy of 90 MeV and width 100 MeV. A possible interpretation is a deeply bound state of a $Y^{*}$-nucleus system.

scholarly journals The prevalence of underweight in 9–10-year-old schoolchildren in Liverpool: 1998–2006

2009 ◽  
Vol 12 (7) ◽  
pp. 953-956 ◽  
Author(s):  
Lynne M Boddy ◽  
Allan F Hackett ◽  
Gareth Stratton
Keyword(s):  
Mass Spectrum ◽  
Body Mass ◽  
The Body ◽  
Fitness Testing ◽  
Policy Makers ◽  
Substantial Problem ◽  
Prevalence Of Obesity ◽  
Grade 3 ◽  
The City ◽  
Over Time

AbstractObjectiveTo estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9–10 years using recently published underweight cut-off points.Design and settingStature and body mass data collected at the LiverpoolSportsLinx project’s fitness testing sessions were used to calculate BMI.SubjectsData were available on 26 782 (n13 637 boys, 13 145 girls) participants.ResultsOverall underweight declined in boys from 10·3 % in 1998–1999 to 6·9 % in 2005–2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0·1 %. In girls, the prevalence of underweight declined from 10·8 % in 1998–1999 to 7·5 % in 2005–2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005–2006 represents over 200 children across the city.ConclusionsUnderweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.

scholarly journals First-Principles Identification of Single Photon Emitters Based on Carbon Clusters in Hexagonal Boron Nitride

2021 ◽  
Vol 125 (6) ◽  
pp. 1325-1335 ◽  
Author(s):  
Cesar Jara ◽  
Tomáš Rauch ◽  
Silvana Botti ◽  
Miguel A. L. Marques ◽  
Ariel Norambuena ◽  
...  
Keyword(s):  
Boron Nitride ◽  
First Principles ◽  
Single Photon ◽  
Hexagonal Boron Nitride ◽  
Carbon Clusters ◽  
Single Photon Emitters

scholarly journals Comparison of the Mayo Endoscopy Score and the Ulcerative Colitis Endoscopy Index of Severity and the Ulcerative Colitis Colonoscopy Index of Severity

2021 ◽  
Vol 09 (02) ◽  
pp. E130-E136
Author(s):  
María Belvis Jiménez ◽  
Pedro Hergueta-Delgado ◽  
Blas Gómez Rodríguez ◽  
Belén Maldonado Pérez ◽  
Luisa Castro Laria ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Interobserver Variability ◽  
Intraclass Correlation ◽  
Weighted Kappa ◽  
Clinical Situation ◽  
Kappa Index ◽  
Perfect Correlation ◽  
Index Of Severity ◽  
Severity Of The Disease ◽  
Normal Clinical Practice

Abstract Background and study aims: Endoscopy plays an essential role in managing patients with ulcerative colitis (UC), as it allows us to visualize and assess the severity of the disease. As such assessments are not always objective, different scores have been devised to standardize the findings. The main aim of this study was to assess the interobserver variability between the Mayo Endoscopy Score (MES), Ulcerative Colitis Endoscopy Index of Severity (UCEIS) and Ulcerative Colitis Colonoscopy Index of Severity (UCCIS) analyzing the severity of the endoscopic lesions in patients with ulcerative colitis. Patients and methods: This was a single-cohort observational study in which a colonoscopy was carried out on patients with UC, as normal clinical practice, and a video was recorded. The results from the video were classified according to the MES, UCEIS and UCCIS by three endoscopic specialists independently, and they were compared to each other. The Mayo Endoscopy Score (MES) was used to assess the clinical situation of the patient. The therapeutic impact was analyzed after colonoscopy was carried out. Results: Sixty-seven patients were included in the study. The average age was 51 (SD ± 16.7) and the average MES was 3.07 (SD ± 2.54). The weighted Kappa index between endoscopists A and B for the MES was 0.8; between A and C 0.52; and between B and C 0.49. The intraclass correlation coefficient for UCEIS was 0.92 among the three endoscopists (CI 95 %: 0.83–0.96) and 0.96 for UCCIS among the three endoscopists (CI 95 % 0.94–0.97). A change in treatment for 34.3 % of the patients was implemented on seeing the results of the colonoscopy. Conclusions: There was an adequate, but not perfect, correlation between the different endoscopists for MES, UCEIS, UCCIS. This was higher with the last two scores. Thus, there is still some subjectivity to be minimized through special training, on assessing the seriousness of the endoscopic lesions in patients with UC.

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