bluuebunny/crossref_metadata_2025 huggingface dataset:
A new brain mitochondrial sodium-sensitive potassium channel: effect of sodium ions on respiratory chain activity
Authors: Fahanik-babaei Javad , Rezaee Bahareh , Nazari Maryam , Torabi Nihad , Saghiri Reza , Sauve Remy , Eliassi Afsaneh
Published: April 2020

We have determined the electropharmacological properties of a new potassium channel from brain mitochondrial membrane using a planar lipid bilayer method. Our results show the presence of a channel with a conductance of 150 pS at potentials between 0 and −60 mV in 200 mM cis/50 mM trans KCl solutions. The channel was voltage independent, with an open probability value of approximately 0.6 at different voltages. ATP did not affect current amplitude or open probability at positive and negative voltages. Notably, adding iberiotoxin, charybdotoxin, lidocaine or margatoxin had no effect on the channel behavior. Similarly, no changes were observed by decreasing the cis pH to 6. Interestingly, the channel was inhibited by adding sodium in a dose-dependent manner. Our results also indicated a significant increase in mitochondrial complex IV activity and membrane potential and a decrease in complex I activity and mitochondrial ROS production in the presence of sodium ions. We propose that inhibition of mitochondrial potassium transport by sodium ions on potassium channel opening could be important for cell protection and ATP synthesis.
Head Impact Telemetry System’s Video-based Impact Detection and Location Accuracy
Authors: CAMPBELL KODY R. , MARSHALL STEPHEN W. , LUCK JASON F. , PINTON GIANMARCO F. , STITZEL JOEL D. , BOONE JOSHUA S. , GUSKIEWICZ KEVIN M. , MIHALIK JASON P.
Published: April 2020

Purpose

This study aimed to quantify the Head Impact Telemetry (HIT) System’s impact detection and location measurement accuracy using an impact biomechanics data set paired with video of high school football special teams plays.

Methods

The head impact biomechanics data set and video were collected from 22 high school football players, wearing HIT System instrumented helmets, competing in 218 special teams plays over a single high school football season. We used two separate video analysis approaches. To quantify the impact detection accuracy, we evaluated the video for head impacts independently of the impact data collection triggers collected by the HIT System. Video-observed impacts matched to valid and invalid head impacts by the HIT System algorithm were categorized as true positives, false positives, false negatives, and true negatives. To quantify impact location accuracy, we analyzed video-synchronized head impacts for impact location independent of the HIT System’s impact location measurement and quantified the estimated percent agreement of impact location between the HIT System recorded impact location and the impact location observed on video.

Results

The HIT System’s impact-filtering algorithm had 69% sensitivity, 72% specificity, and 70% accuracy in categorizing true and non–head impact data collection triggers. The HIT System agreed with video-observed impact locations on 64% of the 129 impacts we analyzed (unweighted k = 0.43, 95% confidence interval = 0.31–0.54).

Conclusion

This work provides data on the HIT System’s impact detection and location accuracy during high school football special teams plays using game video analysis that has not been previously published. Based on our data, we believe that the HIT System is useful for estimating population-based impact location distributions for special teams plays.
Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise
Authors: FLACK KYLE D. , HAYS HARRY M. , MORELAND JACK , LONG DOUGLAS E.
Published: April 2020

Purpose

This study assessed how individuals compensate for energy expended during a 12-wk aerobic exercise intervention, elucidating potential mechanisms and the role exercise dose plays in the compensatory response.

Participants and Design

Three-arm, randomized controlled trial among sedentary adults age 18 to 40 yr, body mass index of 25 to 35. Groups included six exercise sessions per week, two sessions per week, and sedentary control.

Methods

Rate of exercise energy expenditure was calculated from a graded exercise test averaged across five heart rate zones. Energy compensation was calculated as the difference between expected weight loss (based on exercise energy expenditure) and changes in fat and fat-free mass (DXA). Resting energy expenditure was assessed via indirect calorimetry and concentrations of acylated ghrelin, leptin, insulin, and Glucagon-like peptide 1 (GLP-1) were assessed fasting and postprandial (six timepoints over 2 h).

Results

The 6-d·wk−1 group expended more energy (2753.5 kcal) and exercised longer (320.5 min) per week than the 2-d·wk−1 group (1490.7 kcal, 1888.8 min, P < 0.05), resulting in greater fat loss compared with the 2-d or control groups (P < 0.05). Exercise groups did not differ in the % or total kcal compensated. Greater decreases in area under the curve (AUC) for acylated ghrelin predicted greater fat loss, regardless of group, energy expended per week, exercise duration, or exercise intensity. Changes in leptin AUC was the only independent predictor for energy compensation, with a greater decrease in leptin AUC predicting less energy compensation. Exercise frequency, energy expended, duration, or intensity did not influence energy compensation.

Conclusions

Leptin is an important factor in successful weight loss through exercise, with greater postprandial decreases promoting less compensation. Greater amounts of exercise do not influence the compensatory response to an exercise-induced energy deficit.
Pitfalls in Expiratory Flow Limitation Assessment at Peak Exercise in Children: Role of Thoracic Gas Compression
Authors: STROZZA DANIELLE , WILHITE DANIEL P. , BABB TONY G. , BHAMMAR DHARINI M.
Published: April 2020

Purpose

Thoracic gas compression and exercise-induced bronchodilation can influence the assessment of expiratory flow limitation (EFL) during cardiopulmonary exercise tests. The purpose of this study was to examine the effect of thoracic gas compression and exercise-induced bronchodilation on the assessment of EFL in children with and without obesity.

Methods

Forty children (10.7 ± 1.0 yr; 27 obese; 15 with EFL) completed pulmonary function tests and incremental exercise tests. Inspiratory capacity maneuvers were performed during the incremental exercise test for the placement of tidal flow volume loops within the maximal expiratory flow volume (MEFV) loops, and EFL was calculated as the overlap between the tidal and the MEFV loops. MEFV loops were plotted with volume measured at the lung using plethysmography (MEFVp), with volume measured at the mouth using spirometry concurrent with measurements in the plethysmograph (MEFVm), and from spirometry before (MEFVpre) and after (MEFVpost) the incremental exercise test. Only the MEFVp loops were corrected for thoracic gas compression.

Results

Not correcting for thoracic gas compression resulted in incorrect diagnosis of EFL in 23% of children at peak exercise. EFL was 26% ± 15% V
T higher for MEFVm compared with MEFVp (P < 0.001), with no differences between children with and without obesity (P = 0.833). The difference in EFL estimation using MEFVpre (37% ± 30% V
T) and MEFVpost (31% ± 26% V
T) did not reach statistical significance (P = 0.346).

Conclusions

Not correcting the MEFV loops for thoracic gas compression leads to the overdiagnosis and overestimation of EFL. Because most commercially available metabolic measurement systems do not correct for thoracic gas compression during spirometry, there may be a significant overdiagnosis of EFL in cardiopulmonary exercise testing. Therefore, clinicians must exercise caution while interpreting EFL when the MEFV loop is derived through spirometry.
Sex and Sport Differences in College Lacrosse and Soccer Head Impact Biomechanics
Authors: MIHALIK JASON P. , AMALFE STEPHANIE A. , ROBY PATRICIA R. , FORD CASSIE B. , LYNALL ROBERT C. , RIEGLER KAITLIN E. , TEEL ELIZABETH F. , WASSERMAN ERIN B. , PUTUKIAN MARGOT
Published: April 2020

Purpose

Sport-related head impact biomechanics research has been male-centric and focused primarily on American football and ice hockey, which do not address popular sports in which both sexes participate. The purpose of this study was to quantify college female and male lacrosse and soccer head impact biomechanics.

Methods

Head impact biomechanics were collected from college lacrosse and soccer players across two Division 1 college athletic programs (96 female athletes, 141 male athletes; age, 19.8 ± 1.3 yr; height, 174.8 ± 9.2 cm; mass, 72.4 ± 11.7 kg). We deployed helmetless head impact measurement devices (X2 Biosystems xPatch) before each event. Peak linear and rotational accelerations were log-transformed for random intercepts general linear mixed models, and subsequently categorized based on impact magnitude for additional categorical analyses.

Results

Most linear (69.4%) and rotational (72.3%) head impact accelerations sustained by our study cohort were categorized as mild. On average, male athletes sustained impacts with higher linear accelerations than females (P = 0.04), and lacrosse athletes sustained higher linear acceleration impacts than soccer athletes (P = 0.023). Soccer athletes sustained significantly higher-magnitude impacts during competitions versus practices (linear, P < 0.001, rotational, P < 0.001), whereas lacrosse athletes sustained higher-magnitude impacts during practices versus competition (linear, P < 0.001; rotational, P < 0.001). Male athletes sustained higher accelerations in competitions versus practice (linear, P = 0.004; rotational, P < 0.001), whereas female athletes sustained higher accelerations in practice versus competitions (linear, P < 0.001; rotational, P = 0.02). There were no interactions between sex and sport on impact magnitude.

Conclusions

Male athletes and lacrosse athletes experience higher-magnitude head impacts. Given the limited literature in this area, future research should continue characterizing head impact biomechanics in women’s and nonhelmeted sports as well as validate nonhelmeted head impact technologies.
Synergetic Effect of NO Precursor Supplementation and Exercise Training
Authors: LE ROUX-MALLOUF THIBAULT , VALLEJO ANGELA , PELEN FELIX , HALIMAOUI IDIR , DOUTRELEAU STÉPHANE , VERGES SAMUEL
Published: April 2020

Introduction

Nitric oxide (NO) precursor supplementation has been shown to increase NO bioavailability and can potentially improve vascular function and exercise performance. It remains unclear whether the combination of NO precursor supplementation and exercise training has synergic effects on exercise performance. This study aims to assess the effect of chronic nitrate and citrulline intake on exercise training adaptations in healthy young individuals.

Methods

In this randomized, double-bind trial, 24 healthy young (12 females) subjects performed vascular function assessment (blood pressure, pulse wave velocity, postischemia vasodilation, and cerebrovascular reactivity) and both local (submaximal isometric unilateral knee extension) and whole-body (incremental cycling) exercise tests to exhaustion before and after a 2-month exercise training program and daily intake of a placebo or a nitrate-rich salad and citrulline (N + C, 520 mg nitrate and 6 g citrulline) drink. Prefrontal cortex and quadriceps oxygenation was monitored continuously during exercise by near-infrared spectroscopy.

Results

N + C supplementation had no effect on vascular function and muscle and cerebral oxygenation during both local and whole-body exercise. N + C supplementation induced a significantly larger increase in maximal knee extensor strength (+5.1 ± 3.5 vs +0.2 ± 5.5 kg, P = 0.008) as well as a trend toward a larger increase in knee extensor endurance (+35.2 ± 26.1 vs +24.0 ± 10.4 contractions, P = 0.092) than placebo, but no effect on exercise training-induced maximal aerobic performance improvement.

Conclusion

These results suggest that chronic nitrate and citrulline supplementation enhances the effect of exercise training on quadriceps muscle function in healthy active young individuals, but this does not translate into improved maximal aerobic performances.
Simulation of a muographic analysis of a volcanic dome in Geant4
Authors: Athanassas Constantin D. , Kitsaki C. , Alexopoulos T. , Gika V. , Maltezos S.
Published: April 2020

Here we present a Monte Carlo simulation of a muographic campaign on Methana volcano, Greece. In order to estimate the absorption parameters and the pattern of muon scattering at various incident energies (GeV to TeV), a radar-derived digital terrain model (DTM) was submitted to irradiation by horizontal muons in Geant4 and the penetrating muons were collected by a hypothetical MicroMegas particle detector on the other side of the DTM. Monte Carlo simulation demonstrated that muon energies at least as high as 10 TeV are required for whole-scale radiography of Methana and one has to reduce the scale of study to smaller structures (e.g. ~ 600 m - wide volcanic domes) in order to exploit the more affluent lower energy muons (~ 600 GeV).  Coulomb scattering, on the other hand, brings about deflection of muon trajectories away from the detector, resulting in loss of information. Additionally, scattering adds Gaussian blurring to the scanned objects. With the intention of improving contrast and extract objects in muographic image we recommend the use of spatial operators (filters) employed in image analysis.
Radon retrospective dosimetry in different environments
Authors: Giaritzoglou I. , Aslanoglou X. , Stamoulis K. C. , Alexandropoulou S. , Ioannides K. G.
Published: April 2020

In the present study of retrospective dosimetry, measurements or Radon (222Rn) and Polonium (210Po) were performed. Radon is a radioactive gas and is concentrated in the interior of residential buildings and working places and is considered as a primary cause of lung cancer. To evaluate measurements in different environments, alpha spectrometry was employed in estimating exposure to radon in various locations over a long period of time (hence, the use of the term “retrospective”) through exposure of plastic and glass surfaces. Following these measurements, the Conversion Factor (CF) was calculated. This factor correlates the measured surface concentrations of 210Po with the 222Rn concentrations in the environments under study.
GENERAL CHARACTERISTICS OF INTERMEDIATE MASS FRAGMENT INCLUSIVE CROSS SECTIONS IN 20Ne INDUCED INTERACTIONS
Authors: Papadakis N. H. , Et al. -
Published: April 2020

Inclusive integrated cross sections of intermediate mass fragments have been measured in 20Ne induced reactions on silver and gold targets at 20, 30, 40, 50 and 60 MeV/nucleon incident energies. Whereas the production yields remain approximately constant for the Ne+Ag system, for incident energies greater than 30 MeV/nucleon, they increase by a factor of 3.5 for the Ne+Au system over the full energy range studied.
AN APPLICATION OF THE DEMOCRATIC MAPPING IN REALISTIC SYSTEMS
Authors: Bonatsos Dennis , Skouras L. D. , Van Isacker P. , Nagarajan M. A.
Published: April 2020

The democratic mapping is used for the calculation of low lying states of nuclei in the sd and fp shells. In addition to demonstrating the applicability of the method in realistic cases where many non-degenerate levels are present, the method allows for the ranking of the various bosons according to their importance as building blocks of low lying states. It is proven that the s and d bosons are the most important building blocks, followed by the d' and g bosons. Thus one of the basic assumptions of the Interacting Boson Model (IBM) is proven to be correct. Very good agreement between the boson calculation and the shell model results is obtained for A = 20 nuclei when 12 bosons are taken into account, while an even larger number of bosons is required to reproduce the low-lying states of the A = 44 nuclei. In order to obtain equally good results with a smaller number of bosons one needs to introduce effective boson hamiltonians which correspond to truncated fermion spaces.
COLLECTIVE POTENTIAL FOR HEAVY ION NUCLEAR REACTIONS
Authors: Syros C.
Published: April 2020

It is shown that the nuclear charge polarisation during heavy ion nuclear reactions enhances the secondary maximum of the collective energy surface and produces a secondary minimum in the deformation energy near R ~ Rmin + 2fm. The potential energy and mass formulas are given as a function of A and Z. It has been shown that charge polarisation without shape deformation and indeed of the prolate type does not produce any secondary minimum. It is also seen that the relativity effect consists in shifting the secondary minimum towards higher rest excentricities. For deformation of the oblate type the collective potential has a similar form like that in the spherical case. Entry and exit channel collective potentials are also given for the case of strong nucléon transfer. The mass for the two-body interacting system has been calculated and for large distances it tends to the corresponding reduced mass. The present theory is based on a particular form of the single particle potential following from the scalar π-meson classical field theory.
NUCLEAR MOMENTUM DISTRIBUTION WITH FRACTIONAL OCCUPATION PROBABILITIES OF THE SURFACE ORBITS
Authors: Kosmas T. S. , Vergados J. D.
Published: April 2020

Simplified expressions for calculating nucléon momentum distributions are derived in the context of the harmonic oscillator shell model and in its modification in which fractional occupation probabilities of the surface orbits are used. The method is applied to study the proton momentum distribution of the spherical nucleus 40Ca. The values of the partial occupation probabilities used had been previously determined by fitting to the experimental elastic form factor data.
THE USE OF PIGE AS A MULTIELEMENT ANALYTICAL METHOD FOR LOW Ζ ELEMENTS
Authors: Savidou A. , Paradellis T. , Aslanoglou X. , Pilakouta M.
Published: April 2020

N/A
K-SHELL IONIZATION AND X-RAY PRODUCTION CROSS SECTIONS BY PROTONS IN VACUUM AND GASEOUS ENVIRONMENT
Authors: Kallithrakas-Kontos N. , Katsanos A. A.
Published: April 2020

The Κα ionization and x-ray production cross sections from the bombardment of three metal targets with protons were measured in vacuum and in gaseous environment (external beam technique). Proton energies between 1.5 and 8 MeV were used. The experimental Κ shell ionization and x-ray production cross sections were calculated for the same targets and com­ pared with three theoretical and two semiempirical approxima­ tions. For the measurements in gaseous environment the influ­ence of the secondary electrons (delta electrons) emitted from the gas, to the x-ray yields was investigated. For this pur­ pose a suitable model was introduced and tested experimen­tally.
ADVANCES IN EXPERIMENTAL TECHNOLOGY BY THE EUROGAM DETECTOR SYSTEM
Authors: Kossionides S.
Published: April 2020

For the high resolution gamma ray detector array EUROGAM new data acquisition solutions are being developed. Large volume high purity Ge detectors, with new shapes for increased efficiency, have been proposed and prototypes are now being tested. High resolution analog and digital electronics will be integrated within the VXIbus system to be used as the front end instrumentation bus. Also, distributed processing solutions are adopted in order to cope with the high data rates.
SPECTROSCOPY IN A ROTATING DEFORMED NUCLEUS
Authors: Papadopoulos C. T. , Vlastou R.
Published: April 2020

Recent advances in the physics of nuclei at high spin are presented. In particular the new phenomena observed by the latest generation of γ-rays spectrometers are discussed. An overview of experimental and theoretical treatment of "backbending·'' effect, quasiparticle alignment and band crossing is described in more detail. The outlines of the Cranked Shell Model, which is a successful framework for the interpretation of experimental data, are also reported.
LIFETIMES OF TRANSISTIONAL NUCLEI IN THE A~130 REGION
Authors: Harissopulos S. , Dewald A. , Zell K. O. , Gelberg A. , Von Brentano P.
Published: April 2020

N/A
THE 16O+12C RESONANCES INVESTIGATION BY THE pn TO d COMPETITION RATIO TECHNIQUE
Authors: Gazis E. N. , Et al. -
Published: April 2020

N/A
PHENOMENOLOGICAL RELATIVISTIC STUDY OF THE ENERGY OF Α Λ IN ITS GROUND AND EXCITED STATES IN HYPERNUCLEI
Authors: Papadopoulos G. J. , Koutroulos C. G. , Grypeos M. E.
Published: April 2020

The binding energy B_Λ of a Λ-particle in hypernuclei is studied by means of the Dirac equation containing attractive and repulsive potentials of orthogonal shapes. The energy eigenvalue equation in this case is obtained analytically for every bound state. An attempt is also made to investigate the possibility of deriving in particular cases approximate ana­lytic expressions for B_Λ.
ALPHA PARTICLE MOMENTUM DISTRIBUTION IN NUCLEI WITHIN THE COHERENT DENSITY FLUCTUATION MODEL
Authors: Antonov A. N. , Hodgson P. E. , Lalazissis G. A. , Nikolov E. N. , Petkov I. Zh.
Published: April 2020

The alpha particle centre of mass momentum distribution in nuclei is determined on the basis of the four-body density matrix obtained within the coherent density fluctuation model. The calculations are carried out for a number of nuclei. The results are compared with those deduced from analyses of experimental data on alpha-particle knockout reactions induced by electrons,protons and alpha-particles which provide information on the alpha-particle momentum distribution.
Strong interaction effects in Σ- atoms
Authors: Petridou Th.
Published: April 2020

An approximation is made for the Σ- atomic energy shifts and widths due to strong interaction central and spin-orbit parts of the potential with the use of the S-Matrix Approach, introduced by DelofF. This simplified model is applied in 12C_Σ in connection with the Σ-hypernuclear data: 12C_Σ. It is concluded that there is an essential influence of the strong interaction and especially of the nuclear spin-orbit coupling in the spectra of Σ-12C, mainly for the p-shell.
Parametrization of the effective potential in sodium clusters
Authors: Kotsos B. A. , Grypeos M. E.
Published: April 2020

The effective radial electronic potentials for neutral sodium clus­ters determined by the local density approximation and the jellium model are parametrized by means οf (symmetrized) Woods-Saxon and "Wine-Bottle" symmetrized Woods-Saxon potentials. The potential parameters are deter­ mined by various least-squares fitting procedures. Particular attention is paid to the dependence of the radius parameter R on the particle number Ν and it is realized that for relatively smaller values of N, complex expressions of R as a function of N, are more appropriate than the standard one R = r_0N^{1/3}. It is also found that improved results in these cases are obtained with an expression, of the form R = r_0N^{1/3} + 6, which is still very simple.
Nuclear structure dependence of the coherent (μ-,e-) conversion matrix elements
Authors: Kosmas T. S. , Faessler Amand , Simkovic F. , Vergados J. D.
Published: April 2020

Coherent rates for the neutrinoless muon to electron conversion. (μ-, e-) in the presence of nuclei, are studied throughout the periodic table. The relevant ground state to ground state transition matrix elements are obtained in the context of the quasi-particle RPA. The results are discussed in view of the existing experimental data extracted at TRIUMF and PSI for 48Ti and 208Pb nuclei and compared with: (i) the single particle shell model results calculated with a determinantal ground state wave function and (ii) the results deduced in a local density approximation.
Quantum Algebraic Description of the Pairing Correlations in a Single-j Nuclear Shell
Authors: Bonatsos Dennis , Daskaloyannis C. , Faessler Amand
Published: April 2020

Pairing in a single-j shell is described in terms of two Q-oscillators, one describing the J=0 fermion pairs and the other corresponding to the J≠0 pairs, the deformation parameter Τ = lnQ being related to the inverse of the size of the shell. Using these two oscillators an SUQ(2) algebra is constructed, while a pairing Hamiltonian giving the correct energy eigenvalues up to terms of first order in the small parameter can be written in terms of the Casimir operators of the algebras appearing in the UQ(2) > UQ(1) chain, thus exhibiting a quantum algebraic dynamical symmetry. The additional terms introduced by the Q-oscillator are found to improve the agreement with the experimental data for the neutron pair separation energies of the Sn isotopes, with no extra parameter introduced.
Inclusive neutrino-nucleus reaction cross sections at intermediate energies
Authors: Kosmas T. S. , Oset E.
Published: April 2020

Inclusive neutrino-nucleus reaction cross sections at intermediate energies (20 MeV < Ey < 500 MeV) are calculated throughout the periodic table for the most interesting nu­ clei from an experimental point of view. The method used had previously proved to be very accurate in calculating the induced reaction cross section for T=0 light nuclei (12C and 16O) and in the study of other similar processes like the ordinary muon capture. The electron-neutrino (ve) cross section weighted by the Michel distribution is also discussed in conjuction with the existing experimental results at LAMPF and ΚARMEN.
Shell model calculations in the A=90-98 mass region. A study of the N=51. nuclei
Authors: Divari P. , Skouras L. D.
Published: April 2020

The properties of nuclei with 39 < Ζ < 47 and N=51 are investigated in large scale shell-model calculations. The doubly closed nucleus 100Sn is selected as the reference state and the nuclei under examination are described in terms of proton holes and a single neutron outside the inert core. The proton holes are distributed in a model space consisting of the orbitals g9/2, p1/2, p3/2 while f5/2 is sometimes also considerd. Similary the model space for the single neutron includes the orbitals g7/2, d5/2, d3/2, s1/2 and in certain cases h11/2. The effective two-body interaction and the matrix elements of the effective operators were determined by introducing second-order correctios to the Sussex matrix elements. The single proton holes as well as the single-neutron energies were treated as parameters which were determined by least-squares fit to the observed levels of 39 < Ζ < 47, N=50 and Ν=51 respectively. The results of the calculation were found to be in satisfactory agreement with experimental data and this enable us to make predictions about the properties of some exotic nuclei in the vicinity of 100Sn.
Study of the Generalized Momentum Distribution of Model Nuclear Matter
Authors: Mavrommatis E. , Petraki M. , Clark J. W.
Published: April 2020

Valuable information on the correlation structure of the nuclear medium is stored in the generalized momentum distribution n(p,Q), the Fourier transform of the half-diagonal two-body density matrix ρ_{2η}(r_1,r_2,r'). In this paper, we present a numerical calculation of n(p,Q) for two Jastrow-correlated models of symmetrical nuclear matter based on the structural decomposition of n(p,Q) derived by Ristig and Clark and on a Fermi-hypernetted-chain procedure. Results exhibit significant departures from the ideal Fermi gas case in certain kinematic domains; this behaviour indicates the strong short-range correlations present in these models. Nevertheless, such deviations are less prominent than in earlier low- cluster-order calculations. The results are also used to judge the quality of Silver's approximation for n(p,Q).
High-spin phenomena in 194Hg
Authors: Fotiades N. , Et al. -
Published: April 2020

High-spin states in the isotope 194Hg were populated using the 150Nd(40Ca,4n) reaction at a beam energy of 213 MeV. The analysis of γ-γ coincidences, which were detected using the EUROGAM detector array, has revealed two new structures at excitation energies above 6 MeV and at moderate spin. The first one could be interpreted as a manifestation of a band termination phenomenon while the second one is associated with a single-particle decay mode.
Materials analysis by ion channeling at "Demokritos"
Authors: Harissopulos S. , Kossionides S. , Paradellis T. , Maggiore G.
Published: April 2020

A new fully automated Goniometer system installed recently at the Institute of Nuclear Physics of "Demokritos" is presented. This system enables to perform materials analysis not only via the Rutherford Backscattering method, which has been used so far at "Demokritos", but also by the ion channeling technique. The first experiments carried out using the Goniometer are also presented.
Recent Developments in High Temperature Thermodynamic Properties of Nuclear Reactor Oxide Fuel
Authors: Ronchi C.
Published: April 2020

N/A
Nuclear shape coexistence in 193Hg
Authors: Fotiades N. , Et al. -
Published: April 2020

Excited states of the 193Hg nucleus have been investigated by the reaction 150Nd(48Ca,5n) at a beam energy of 213 MeV. The level scheme has been extended up to 10.7 MeV. Three different level pattern regions have been identified. A lower region with rotational bands, an intermediate region with single-particle character and an upper region with sequences of dipole transitions. The nature and the corresponding nuclear shape in these regions are discussed and compared with similar phenomena in the neighbouring nuclei.
Determination of light elements using the RBS method
Authors: Kokkoris M. , Zarkadas Ch. , Harissopulos S. , Kossionides E. , Paradellis T.
Published: April 2020

The RBS (Rutherford Backscattering Spectroscopy) method is a classical method which has been successfully used for the study and analysis of surface elements. The strong points as well as the weaknesses of the technique are briefly outlined and emphasis is given in the determination of light elements. A method is proposed in order to overcome the problem and the first results and prospects for the future are analysed.
Assessment of arrangements for the detection of radon emanating from soil
Authors: Papachristodoulou C. A. , Ioannides K. G. , Mertzimekis T. J. , Karamanis D. T. , Stamoulis K. C.
Published: April 2020

CR-39 solid state nuclear track detectors were used to measure radon (222Rn) concentration in the soil near ground surface. The measurements were performed in the campus of the University of Ioannina, using PVC tubes at 0.25 m intervals down to depths of 1.25 m. The track detectors were etched in 7N NaOH solutions at 80°C. The tracks were counted using a microscope - camera - computer system, developed for automatic counting. The results provide evidence for the non-diffusive transport of radon in soils. A transport length of (46.9 ± 3.2) cm was estimated for radon transport near ground surface. Also the variation of soil's radon was correlated to meteorological variations.
Environmental study of natural radioactivity regime of the Ikaria island and the radiological impact
Authors: Trabidou G. , Florou H. , Angelopoulos A. , Sakelliou L. , Katsikis I.
Published: April 2020

This is a preliminary study on the natural radioactivity of the spas in the Icaria island and the consequent impact to the public health. In order to carry out this research : a) Car-borne radiometry has been applied in the areas around the spas as well as in some reference areas in the island b) The activity concentrations of the natural radionuclides of the 238U-226Ra and 232Th decay series, as well as 40K, in spa water, soil, sediment, surface sea water and marine flora samples in the areas of the spas were measured, from the results derived one notes that elevated concentrations of the environmental abiotic materials are presented, which are reflected to the concentrations observed in marine flora. Consequently, higher population doses in comparison with other Greek regions are resulted.
The Compton electron beam Polarimeter for the AmPS ring
Authors: Vodinas N. P. , De Jager C. W. , Papadakis N. H. , Passchier I.
Published: April 2020

The longitudinal polarization of the stored electron beam in the AmPS ring will be measured through the laser Compton backscattering technique. With the outlined design the measurement of the expected 70% degree of polarization to a statistical precision of 3% requires less than 60 sec under ideal conditions.
Radon Gas Profiles and Exposure Estimates in the Perama Cave, Greece
Authors: Papachristodoulou C. A. , Ioannides K. G. , Stamoulis K. C. , Patiris D. L. , Pavlides S. B.
Published: April 2020

An investigation of atmospheric radon levels in the Perama Cave, North-western Greece, has been carried out using CR-39 detectors. The detectors were placed at various locations along the guided cave pathway and exposed during different sampling periods. Mean concentrations amounting to 925±418 and 1311±352 Bq m-3 were recorded in the summer and winter months, respectively. The quantification of effective doses from radon daughters' inhalation was important, as the Perama Cave is one of the most popular in Greece, attracting more than 85,000 tourists per year. Due to the short duration of the guided tour along the cave, exposure of tourists was found to be insignificant, lying below 5.1 μSv per visit. Permanent cave guides receive doses ranging from 4.2 to 5.9 mSv y-1. Considering the ICRP-65 recommendation that action levels in dwellings and workplaces should be set between 3 and 10 mSv y-1 untertaking remedial measures to reduce the exposure of cave staff may be appropriate.
FAIR: The Future European Facility for Antiproton And Ion Research
Authors: Münzenberg G.
Published: April 2020

FAIR, the new international Facility for Antiproton and Ion Research at GSI, will cover a broad spectrum of hadronic, nuclear, and atomic physics research and appli- cation. A system of synchrotrons will provide intense proton and heavy ion beams of intermediate energy with the option to produce secondary beams of radioactive nuclei and antiprotons. NUSTAR, NUclear STructure, Astrophysics and Reactions, will play a premier role within the FAIR research program. Nuclei at the limits of binding will become accessible and new probes for reaction studies with unstable nuclei become available.
Ion Beam Analysis for the Investigation of Diffusion Processes
Authors: Becker H.-W.
Published: April 2020

The unique advantages of ion beam analysis, such as the depth resolved unam- biguous stoichometric information of RBS or the possibility to detect hydrogen with high depth resolution still opens new applications in fundamental as well as applied science. Two examples are presented here.The diffusion of hydrogen in cement during the formation of cement has been studied with the 15N hydrogen depth profiling. It could be shown, that the known stages of the hydration process are correlated with the diffusion of hydrogen on a nanometer scale.Diffusion processes play also an important role in geology. The investigation of such processes with RBS will be presented. Prospects of diffusion studies using isotopie tracing with low lying resonances will be discussed.
Simulations of Fragment Correlations in the Disintegration of Non-Compact Nuclear Configurations
Authors: Nicolis N. G.
Published: April 2020

Non-spherical and hollow nuclear configurations have been predicted for intermediate-energy heavy-ion collisions. We have developed a simulation of the emitted heavy fragments in order to establish observables indicative of non-spherical break-up geometries. Starting with a spherical, bubble, spheroidal or a toroidal freeze-out volume configuration, a primary fragment distribution is defined with a given radial collective energy, thermal momentum distribution and intrinsic excitation energy. The outgoing fragments are allowed to propagate along their Coulomb trajectories in a self-consistent manner. Account is taken of the de-excitation of the primary fragments by nucléon and cluster evaporation. Considering 5-fragment partitions, azimuthal distributions and two-fragment correlation functions are constructed and discussed in connection with their associated break-up geometries.
Energy calibration of He-3, He-4 Neutron Proportional Counters
Authors: Manolopoulou M. , Fragopoulou M. , Stoulos S. , Koukorava C. , Zamani M.
Published: April 2020

Two helium filled proportional counters (He-3, He-4) were irradiated with neu- trons in the energy range 0.025 eV - 10.7 MeV, in the Tandem accelerator, NCSR Demokritos, Athens. The full energy peak in He-3 proportional counter as well as the recoil peaks in He-3 and He-4 counters show linear dependence with neutron energy. A study of gamma ray contribution to the neutron spectra of He-4 counter was performed as a function of the pulse shaping time.
Dating of Obsidian Tools by Water Diffusion (SIMS-SS) with a Novel Software
Authors: Liritzis I. , Ganetsos T. , Laskaris N.
Published: April 2020

Diffusion of environmental water into the surface of obsidian tools of archaeological origin is monitored by secondary ion mass spectrometry (SIMS), which provides a H+ concentration (C) versus hydration depth profile. The modeling of this diffusion process, as one-dimensional phenomena, is based on the idea that a saturated surface (SS) layer is encountered near the surface. A novel software program has been developed, using MATLAB, incorporating all numerical parameters for the dating of hydrated obsidians using the SIMS profile. This approach has been applied to several archaeological obsidians from the Aegean, Hungary, and Asia Minor and compared with samples from radiocarbon dated cultural phases where the agreement is excellent.
Determination of 137Cs in Sea Water Samples Using Gamma Spectrometry
Authors: Evaggeliou N. , Lykomitrou Ch. , Zafiropoulou A.
Published: April 2020

In the present study a comparative evaluation of two methods for 137Cs determination (pretreatment for gamma spectrometry) is attempted. One of them is the conventional AMP (ammonium molybdophosphate, (ΝΗ4)3Ρ(Μo3O10)4) method (radiochemical treatment based on coprecipitation) and the other one is a method based on pre-concentration of cesium in situ by using the Mark III Centrifugal Pump. The pump, which is described analytically in the study, is composed of a mo­tor (pump), four cartridge housings (containing the scavengers), a flow meter and a pressure tube (containing the battery pack and the timer board). For justification, this method is compared with the AMP co-precipitation one. Following up the radioanalytical procedures, the gamma spectrometry system (relative efficiency of high purity germanium detector 90%) is also demonstrated, as conformed to mea­ suring obtained parameters. Finally, the advantages and disadvantages of these two methods are recorded and the application of each one is suggested.
The Role of Λ-Effective Mass in a Phenomenological Analysis of the Λ-Energy in Hypernuclei
Authors: Efthimiou C. A. , Grypeos M. E. , Koutroulos C. G.
Published: April 2020

A preliminary account is given of an effort undertaken to allow for the effective mass of the Λ-particle in a phenomenological analysis of existing experimental data for the (ground state) energy of the Λ : EΛ in hypernuclei. The non - relativistic treatment is adopted to describe the motion of the Λ - particle, by considering a central potential well V (r), formed by the nuclear "host" medium of the Λ in the hypernucleus. The Λ - effective mass in the medium is taken to be an r-dependent effective mass mΛ(r) representing approximately some non-local effects in a way suggested in the past. Certain preliminary numerical results are obtained and discussed.
MottCalc: A new tool for calculating Mott scattering differential cross sections for analytical purposes
Authors: Maragkos Fotis , Kokkoris Michael , Lagogiannis Anastasios
Published: April 2020

In the last few years, the popularity of ERDA applications has soared along with the implementation of time of flight (TOF) type measurements. However, ERDA and other forward scattering IBA techniques suffer from the possibility of the occurence of Mott scattering. This leads to deviations in the elastic differential cross sections which in turn demand special care in the treatment of the obtained experimental spectra. To address this issue, a new code has been developed, called MottCalc (Mott Calculator). Based on the analytical formula, first developed by Mott, which describes the phenomenon, the code is capable of producing theoretical angular and energy distributions of such differential cross sections along with the appropriate R33 files, which in turn can be implemented in all the widely used analytical codes (SIMNRA, DF, POTKU etc.). The electronic screening effect is taken into account in these calculations by implementing the Andersen model. A list of 314 different isotopes is available to choose from as projectile and target nuclei. The list can be expanded with radioactive isotopes. The program is available in two distinct versions, an Excel Spreadsheet and a stand-alone application. Both versions of the program can be freely downloaded from the webpage of the Nuclear Physics group of NTUA (nuclearphysics.ntua.gr/downloads.php). The implementation of the code as well as the features and capabilities of both versions of the program are presented in the current work along with a brief synopsis of the elastic Mott scattering phenomenon.
NLD Equation of State for compressed, hot and relativistic nuclear matter
Authors: Chorozidou Arsenia , Gaitanos Theodoros
Published: April 2020

We investigate the properties of compressed and hot hadronic matter within the Non-Linear Derivative (NLD) formalism. The novel feature of the NLD model is an explicit momentum dependence of the mean-fields, which is regulated by cut-off’s of natural hadronic scale. It is covariantly and thermodynamical-consistently formulated at the basis of a field-theoretical level. We show that the NLD model describes adequately all the empirical information of cold nuclear matter as function of density (equation of state) and, in particular, as function of particle momenta (optical potential). Finally, we present predictions of the NLD approach for hot and compressed hadronic matter in terms of the Equation of state as function of density and temperature. These studies are relevant for the forthcoming experiments at FAIR@GSI. They are also important for astrophysical purposes, e.g., static neutron stars and dynamic neutron star binary systems.
Measurement of differential cross sections of deuteron elastic scattering on 31P for EBS purposes
Authors: Bligoura Natalia , Ntemou Eleni , Aslanoglou Xenophon , Kokkoris Michael - , Lagoyannis Anastasios , Maragkos Fotis , Misaelides Panagiotis , Patronis Nikolaos , Preketes-Sigalas Kostas
Published: April 2020

The 31P(d,d0)31P elastic scattering differential cross-sections were measured, for the first time, in the energy range Ed,lab=900-2400 keV, using a variable energy step, for elastic backscattering spectrometry (EBS) purposes. The measurements were performed at the 5.5 MV TN11 HV Tandem Accelerator of the N.C.S.R. “Demokritos”, implementing a high precision goniometer. The experimental setup consisted of five silicon surface barrier (SSB) detectors, placed at the laboratory scattering angles between 130° and 170° (in steps of 10°). The target used was a thin GaP layer evaporated on a self-supporting carbon foil. To validate the obtained results, benchmarking measurements were performed, using a polished GaP crystal. The determined cross-section datasets are compared with the corresponding ones using Rutherford’s formula, and similarities and discrepancies will be discussed and analyzed.
Study of the 165Ho(n,2n)164Ho reaction at near threshold energies
Authors: Georgali Efstathia , Patronis N. , Anastasiadis A. , Axiotis M. , Eleme Z. , Harissopulos S. , Kalamara A. , Karfopoulos K. , Kokkoris M. , Lagoyannis A. , Peoviti M. , Potiriadis C. , Savva M. I. , Stamatelatos I. , Stamati M. E. , Stamatopoulos A. , Vasilopoulou T. , Vlastou R.
Published: April 2020

The present work concerns the preliminary analysis for the study of the (n,2n) reaction channel of the 165Ho isotope at near threshold energies: 10.1, 10.4 and 10.7 MeV (Eth=8.04 MeV). The cross sections for the population of both the ground state (Jπ=1+) and the isomeric state (Jπ=6-, Eex=139.8 keV) of the 164Ho product-nucleus were measured at the afore mentioned energies via the activation technique relative to the 27Al(n,α)24Na and 197Au(n,2n)196Au reactions. The quasi-monoenergetic neutron beams were produced through the 2H(d,n)3He reaction in the 5.5 MV Tandem Van de Graaf accelerator of N.C.S.R ''Demokritos''. The preliminary experimental results are compared with theoretical predictions based on TALYS code.
Exploring the astrophysical conditions for the creation of the first r-process peak, and the impact of nuclear physics uncertainties
Authors: Nikas Stylianos , Martínez-Pinedo G. , Wu M. R. , Sieverding A. , Reiter M. P.
Published: April 2020

We present a study of nucleosynthesis for conditions of high Ye outflows from NeutronStar Mergers (NSMs). We investigate the effect of new beta-decay rates measurements and uncertaintiesin nuclear masses of the newly measured 84,85 Ga to the r-process nucleosynthesis calculations. The impactof these quantities to the production of the elements of the r-process abundance pattern for A < 100 isquantified and presented.
Optimisation and standardisation of a multiplex immunoassay of diverse Plasmodium falciparum antigens to assess changes in malaria transmission using sero-epidemiology
Authors: Wu Lindsey , Hall Tom , Ssewanyana Isaac , Oulton Tate , Patterson Catriona , Vasileva Hristina , Singh Susheel , Affara Muna , Mwesigwa Julia , Correa Simon , Bah Mamadou , D'Alessandro Umberto , Sepúlveda Nuno , Drakeley Chris , Tetteh Kevin K A
Published: April 2020

Background: Antibody responses have been used to characterise transmission and exposure history in malaria-endemic settings for over a decade. Such studies have typically been conducted on well-standardised enzyme-linked immunosorbent assays (ELISAs). However, recently developed quantitative suspension array technologies (qSAT) are now capable of high-throughput and multiplexed screening of up to hundreds of analytes at a time. This study presents a customised protocol for the Luminex MAGPIX© qSAT using a diverse set of malaria antigens. The aim is to develop a standardised assay for routine serological surveillance that is implementable across laboratories and epidemiological settings.

Methods: A panel of eight Plasmodium falciparum recombinant antigens, associated with long- and short-lived antibody responses, was designed for the Luminex MAGPIX© platform. The assay was optimised for key steps in the protocol: antigen-bead coupling concentration, buffer composition, serum sample dilution, and bead storage conditions. Quality control procedures and data normalisation methods were developed to address high-throughput assay processing.  Antigen-specific limits of quantification (LOQs) were also estimated using both in-house and WHO reference serum as positive controls.

Results: Antigen-specific bead coupling was optimised across five serum dilutions and two positive controls, resulting in concentrations operational within stable analytical ranges. Coupled beads were stable after storage at room temperature (22⁰C) for up to eight weeks. High sensitivity and specificity for distinguishing positive and negative controls at serum sample dilutions of 1:500 (AUC 0.94 95%CI 0.91-0.96) and 1:1000 (AUC 0.96 95%CI 0.94-0.98) were observed. LOQs were also successfully estimated for all analytes but varied by antigen and positive control.

Conclusions: This study demonstrates that developing a standardised malaria-specific qSAT protocol for a diverse set of antigens is achievable, though further optimisations may be required. Quality control and data standardisation methods may also be useful for future analysis of large sero-epidemiological surveys.