489 research outputs found
No-Core shell model for A = 47 and A = 49
We apply an {\it ab-initio} approach to the nuclear structure of odd-mass
nuclei straddling . Starting with the NN interaction, that fits
two-body scattering and bound state data we evaluate the nuclear properties of
and nuclei in a no-core approach. Due to model space
limitations and the absence of 3-body interactions, we incorporate
phenomenological terms determined by fits to nuclei in a previous
effort. Our modified Hamiltonian produces reasonable spectra for these odd mass
nuclei. In addition to the differences in single-particle basis states, the
absence of a single-particle Hamiltonian in our no-core approach obscures
direct comparisons with valence effective NN interactions. Nevertheless, we
compare the fp-shell matrix elements of our initial and modified Hamiltonians
in the harmonic oscillator basis with a recent model fp-shell interaction, the
GXPF1 interaction of Honma, Otsuka, Brown and Mizusaki. Notable differences
emerge from these comparisons. In particular, our diagonal two-body
matrix elements are, on average, about 800-900keV more attractive. Furthermore,
while our initial and modified NN Hamiltonian fp-shell matrix elements are
strongly correlated, there is much less correlation with the GXPF1 matrix
elements.Comment: 17 pages including 14 figure
What spelling errors can tell us about the development of processes involved in children’s spelling
Introduction: Spelling is an essential foundation for reading and writing. However, many children leave school with spelling difficulties. By understanding the processes children use when they spell, we can intervene with appropriate instruction tailored to their needs. Methods: Our study aimed to identify key processes (lexical-semantic and phonological) by using a spelling assessment that distinguishes different printed letter strings/word types (regular and irregular words, and pseudowords). Misspellings in the test from 641 pupils in Reception Year to Year 6 were scored using alternatives to binary correct versus incorrect scoring systems. The measures looked at phonological plausibility, phoneme representations and letter distance. These have been used successfully in the past but not with a spelling test that distinguishes irregularly spelled words from regular words and pseudowords. Results: The findings suggest that children in primary school rely on both lexical-semantic and phonological processes to spell all types of letter string, but this varies depending on the level of spelling experience (younger Foundation/Key stage 1 and older Key stage 2). Although children in younger year groups seemed to rely more on phonics, based on the strongest correlation coefficients for all word types, with further spelling experience, lexical processes seemed to be more evident, depending on the type of word examined. Discussion: The findings have implications for the way we teach and assess spelling and could prove to be valuable for educators
Unveiling the intruder deformed 0 state in Si
The 0 state in Si has been populated at the {\sc Ganil/Lise3}
facility through the -decay of a newly discovered 1 isomer in
Al of 26(1) ms half-life. The simultaneous detection of pairs
allowed the determination of the excitation energy E(0)=2719(3) keV and
the half-life T=19.4(7) ns, from which an electric monopole strength of
(E0)=13.0(0.9) was deduced. The 2 state is
observed to decay both to the 0 ground state and to the newly observed
0 state (via a 607(2) keV transition) with a ratio
R(2)=1380(717). Gathering all
information, a weak mixing with the 0 and a large deformation parameter
of =0.29(4) are found for the 0 state, in good agreement with
shell model calculations using a new {\sc sdpf-u-mix} interaction allowing
\textit{np-nh} excitations across the N=20 shell gap.Comment: 5 pages, 3 figures, accepted for publication in Physical Review
Letter
Characterizations of hemirings by their -ideals
In this paper we characterize hemirings in which all -ideals or all fuzzy
-ideals are idempotent. It is proved, among other results, that every
-ideal of a hemiring is idempotent if and only if the lattice of fuzzy
-ideals of is distributive under the sum and -intrinsic product of
fuzzy -ideals or, equivalently, if and only if each fuzzy -ideal of
is intersection of those prime fuzzy -ideals of which contain it. We
also define two types of prime fuzzy -ideals of and prove that, a
non-constant -ideal of is prime in the second sense if and only if each
of its proper level set is a prime -ideal of
Comparison of Transfer-to-Continuum and Eikonal Models of Projectile Fragmentation Reactions
Spectroscopic properties of nuclei are accessible with projectile
fragmentation reactions, but approximations made in the reaction theory can
limit the accuracy of the determinations. We examine here two models that have
rather different approximations for the nucleon wave function, the target
interaction, and the treatment of the finite duration of the reaction. The
nucleon-target interaction is treated differently in the eikonal and the
transfer-to-continuum model, but the differences are more significant for light
targets. We propose a new parameterization with that in mind. We also propose a
new formula to calculate the amplitude that combines the better treatment of
the wave function in the eikonal model with the better treatment of the target
interaction in the transfer-to-continuum model.Comment: 21 pages, latex file including 3 tables. 5 figures. Submitted to
Phys. Rev.
Surgical treatment of pancreatic fistula after acute pancreatitis
Clinica I Chirurgie, Spitalul “Sf.Spiridon”, Departamentul de Chirurgie, Universitatea de Medicină şi Farmacie
“Gr.T.Popa”, Iași, România, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Fistula pancreatică este o complicație rară care apare în evoluția pancreatitei acute. Această complicație
agravează evoluția bolii și este dificil de tratat, mai ales dacă are un debit important. Posibilitățile de tratament și momentul
optim al intervenției chirurgicale rămân discutabile.
Prezentare de caz: Pacient de 51 ani, sex masculin, consumător de alcool, se internează pentru dureri în etajul abdominal
superior, grețuri, vărsături și meteorism. Se stabilește diagnosticul de pancreatită acută și se inițiază tratament conservator. La
două săptămâni de la debut dezvoltă un abces subhepatic pentru care se intervine chirurgical. Începînd din ziua a 7-a
postoperator pe tubul de dren subhepatic apare suc pancreatic cu un debit de 400-500 ml/zi. Explorările imagistice efectuate
confirmă diagnosticul de fistulă pancreatică. După maturarea traectului fistulos se intervine chirurgical și se practică fistulojejunoanastomoză
pe ansă în Y a la Roux. Evoluția postoperatorie a fost favorabilă. Pacientul se simte bine și nu are nici o
acuză la 6 luni postoperator.
Concluzie: Fistulo-jejunoanastomoza pe ansă Roux cu un traiect fistulos maturat este o soluție viabilă de tratament al fistulei
pancreatice apărute în pancreatita acută.Introduction: Pancreatic fistula is a rare complication of acute pancreatitis, which seriously worsens the evolution and is a
treatment challenge, especially when the output is high. The treatment options and timing are debatable.
Case report: Male patient, 51, with a history of alcohol abuse, is admitted with pain in the upper abdomen, nausea, vomiting,
abdominal distension, high amylasemia and lipasemia and the diagnosis of acute pancreatitis is established. After 2 weeks of
treatment, a subhepatic abscess is surgically drained. Starting on the 7th postoperative day the subhepatic drainage tube
produces 400-500 ml daily. Imaging explorations show a pancreatic fistula. After a delay for fistula maturation, Roux-en-Y
fistula-jejunal anastomosis has been performed. Postoperative period was uneventful, with asymptomatic patient 6 months later.
Conclusion: Roux-en-Y fistula-jejunal anastomosis of a mature pancreatic fistula is a valid approach in the management of
high output pancreatic fistula after acute pancreatitis
Breakup of loosely bound nuclei as indirect method in nuclear astrophysics: 8B, 9C, 23Al
We discuss the use of one-nucleon breakup reactions of loosely bound nuclei
at intermediate energies as an indirect method in nuclear astrophysics. These
are peripheral processes, therefore we can extract asymptotic normalization
coefficients (ANC) from which reaction rates of astrophysical interest can be
inferred. To show the usefulness of the method, three different cases are
discussed. In the first, existing experimental data for the breakup of 8B at
energies from 30 to 1000 MeV/u and of 9C at 285 MeV/u on light through heavy
targets are analyzed. Glauber model calculations in the eikonal approximation
and in the optical limit using different effective interactions give
consistent, though slightly different results, showing the limits of the
precision of the method. The results lead to the astrophysical factor
S_17(0)=18.7+/-1.9 eVb for the key reaction for solar neutrino production
7Be(p,\gamma)8B. It is consistent with the values from other indirect methods
and most direct measurements, but one. Breakup reactions can be measured with
radioactive beams as weak as a few particles per second, and therefore can be
used for cases where no direct measurements or other indirect methods for
nuclear astrophysics can be applied. We discuss a proposed use of the breakup
of the proton drip line nucleus 23Al to obtain spectroscopic information and
the stellar reaction rate for 22Mg(p,\gamma)23Al.Comment: 6 pages, 4 figures. Presented at the conference "Nuclear Physics for
Astrophysics 2", Debrecen, Hungary, May 2005. Prepared for the Proceeding
New pathway to bypass the 15O waiting point
We propose the sequential reaction process
O(,)O as a new pathway to bypass of the
O waiting point. This exotic reaction is found to have a surprisingly
high cross section, approximately 10 times higher than the
O(,)O. These cross sections were calculated after
precise measurements of energies and widths of the proton-unbound F low
lying states, obtained using the H(O,p)O reaction. The large
cross section can be understood to arise from the more
efficient feeding of the low energy wing of the ground state resonance by the
gamma decay. The implications of the new reaction in novae explosions and X-ray
bursts are discussed.Comment: submitte
Spectroscopy of F
The structure of the weakly-bound F odd-odd nucleus,
produced from Na nuclei, has been investigated at GANIL by means of
the in-beam -ray spectroscopy technique. A single -line is
observed at 657(7) keV in F which has been ascribed to the decay of
the excited J= state to the J=1 ground state. The possible presence of
intruder negative parity states in F is also discussed.Comment: 3 pages, 1 figure, accepted for publication in Physical Review
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