988 research outputs found
Three-centre cluster structure in 11C and 11B
Studies of the 16O(9Be,alpha 7Be)14C, 7Li(9Be,alpha 7Li)5He and 7Li(9Be,alpha
alpha t)5He reactions at E(beam)=70 and 55 MeV have been performed using
resonant particle spectroscopy techniques. The 11C excited states decaying into
alpha+7Be(gs) are observed between 8.5 and 13.5 MeV. The alpha+7Li(gs),
alpha+7Li*(4.652 MeV) and t+8Be(gs) decays of 11B excited states between 9 and
19 MeV are observed. The decay processes are used to indicate the possible
three-centre 2alpha+3He (2alpha+3H) cluster structure of observed states. This
cluster structure is more prominent in the positive-parity states, where two
rotational bands with large deformations are suggested. Excitations of some of
the observed T=1/2 resonances coincide with the energies of previously measured
T=3/2 isobaric analogs of the 11Be states,indicating that these states may have
mixed isospin.Comment: Contribution for the proceedings of the NUSTAR'05: NUclear STructure,
Astrophysics and Reactions, University of Surrey, Guildford, UK; accepted for
publication in Journal of Physics
Biological invasions as burdens to primary economic sectors
Many human-introduced alien species economically impact industries worldwide. Management prioritisation and coordination efforts towards biological invasions are hampered by a lack of comprehensive quantification of costs to key economic sectors. Here, we quantify and estimate global invasion costs to seven major sectors and unravel the introduction pathways of species causing these costs — focusing mainly on primary economic sectors: agriculture, fisheries and forestry. From 1970 to 2020, costs reported in the InvaCost database as pertaining to Agriculture, Fisheries, and Forestry totaled 1.3 bn, and 365 bn), followed by China (36 bn). We further identified 19 countries highly economically reliant on Agriculture, Fisheries, and Forestry that are experiencing massive economic impacts from biological invasions, especially in the Global South. Based on an extrapolation to fill cost data gaps, we estimated total global costs ranging from at least 5.7–6.5 bn for Fisheries, and 600 bn in impacts has been incurred across Agriculture, Fisheries and Forestry, with the largest share reported in Agriculture. We further identify 19 countries, which rely heavily on primary sectors, facing comparatively high impacts from invasions, requiring urgent action. However, gaps in cost reporting across invasive taxa and countries suggest that these impacts are grossly underestimated. Proactive prioritisation by policymakers is needed to mitigate future impacts to primary sectors.</p
Structure of 12Be: intruder d-wave strength at N=8
The breaking of the N=8 shell-model magic number in the 12Be ground state has
been determined to include significant occupancy of the intruder d-wave
orbital. This is in marked contrast with all other N=8 isotones, both more and
less exotic than 12Be. The occupancies of the 0 hbar omega neutron p1/2-orbital
and the 1 hbar omega, neutron d5/2 intruder orbital were deduced from a
measurement of neutron removal from a high-energy 12Be beam leading to bound
and unbound states in 11Be.Comment: 5 pages, 2 figure
Evaluasi Program Pembelajaran Bahasa Inggris
The aims of this research were to evaluate English learning in context, input, process, product. This research was an evaluation research. The sources of the research were students of English for Children class at English Smart Bandar Jaya. The data was collected through observation, test, and documentation which was analyzed descriptive quantitative. The conclusions in this research were : 1) the of context value of sub component at the pre-condition is fair, the input value of component sub component infrastructure,human resources and curriculum is poor, the result of process component sub component of planning and english learning implementation is fair, and the product component value in the learning result of the students is fair, and 2) the recommendation of this research,the general manager needs to observe and change the curriculum for a better future, then provide laboratory room for listening, the teachers should make a lesson plan based on the syllabus for each competency.Penelitian ini bertujuan untuk mengevaluasi pembelajaran Bahasa Inggris pada komponen context, input, process, product. Penelitian ini merupakan penelitian evaluasi. Sumber penelitian adalah pembelajar kelas English for Children di English Smart Bandar Jaya. Data dikumpulkan dengan observasi, tes dan dokumentasi kemudian dianalisis secara deskriptif kuantitatif. Kesimpulan dalam penelitian ini : 1) nilai context sub komponen kondisi awal lembaga cukup, nilai input sub komponen fasilitas sarana prasarana, tenaga pendidik dan kurikulum cukup, nilai process sub komponen perencanaan dan pelaksanaan pembelajaran bahasa Inggris kurang, dan nilai komponen product pada hasil belajar pembelajar cukup, dan 2) rekomendasi penelitian ini, kepala lembaga perlu meninjau atau mengubah kurikulum lembaga untuk pembaruan ke arah yang lebih baik, disediakan ruang laboratorium untuk menunjang pembelajaran listening, tentor harus membuat lesson plan yang disusun berdasarkan silabus unit kompetensi
Individual differences in second language speech learning in classroom settings: roles of awareness in the longitudinal development of Japanese learners’ English /ɹ/ pronunciation
The current study longitudinally examined a crucial individual difference variable—i.e., awareness (operationalized as explicit attention and articulatory knowledge)—in adult second language (L2) speech learning in the context of 40 Japanese learners’ English /ɹ/ pronunciation development in an EFL classroom. The participants’ speech, elicited from word reading, sentence reading and timed picture description tasks at the beginning and end of one academic semester, were analyzed in terms of three acoustic dimensions of English /ɹ/—third formant (F3), second formant (F2) and duration. Whereas the participants showed gains in the relatively easy aspect of the English /ɹ/ acquisition (F2 reduction) as a function of increased L2 input, their explicit awareness of accurate English /ɹ/ pronunciation played a significant role in the acquisition of the relatively difficult dimension (lengthening phonemic duration). The awareness-acquisition link was not found, however, for the most difficult dimension (F3 reduction) at least within the timeframe of the project
Structure of Be probed via secondary beam reactions
The low-lying level structure of the unbound neutron-rich nucleus Be
has been investigated via breakup on a carbon target of secondary beams of
B at 35 MeV/nucleon. The coincident detection of the beam velocity
Be fragments and neutrons permitted the invariant mass of the
Be+ and Be++ systems to be reconstructed. In the case of
the breakup of B, a very narrow structure at threshold was observed in
the Be+ channel. Contrary to earlier stable beam fragmentation
studies which identified this as a strongly interacting -wave virtual state
in Be, analysis here of the Be++ events demonstrated that
this was an artifact resulting from the sequential-decay of the
Be(2) state. Single-proton removal from B was found to
populate a broad low-lying structure some 0.70 MeV above the neutron-decay
threshold in addition to a less prominent feature at around 2.4 MeV. Based on
the selectivity of the reaction and a comparison with (0-3)
shell-model calculations, the low-lying structure is concluded to most probably
arise from closely spaced J=1/2 and 5/2 resonances
(E=0.400.03 and 0.85 MeV), whilst the broad
higher-lying feature is a second 5/2 level (E=2.350.14 MeV). Taken
in conjunction with earlier studies, it would appear that the lowest 1/2
and 1/2 levels lie relatively close together below 1 MeV.Comment: 14 pages, 13 figures, 2 tables. Accepted for publication in Physical
Review
Spectroscopic studies of Dy-168,170 using CLARA and PRISMA
Preliminary results from an experiment aiming at Dy-170. Submitted to the LNL
Annual Report 2008.Comment: 2 pages, 4 figures, Submitted to the LNL Annual Report 200
Native Speaker Perceptions of Accented Speech: The English Pronunciation of Macedonian EFL Learners
The paper reports on the results of a study that aimed to describe the vocalic and consonantal features of the English pronunciation of Macedonian EFL learners as perceived by native speakers of English and to find out whether native speakers who speak different standard variants of English perceive the same segments as non-native. A specially designed computer web application was employed to gather two types of data: a) quantitative (frequency of segment variables and global foreign accent ratings on a 5-point scale), and b) qualitative (open-ended questions). The result analysis points out to three most frequent markers of foreign accent in the English speech of Macedonian EFL learners: final obstruent devoicing, vowel shortening and substitution of English dental fricatives with Macedonian dental plosives. It also reflects additional phonetic aspects poorly explained in the available reference literature such as allophonic distributional differences between the two languages and intonational mismatch
Emergence of the N=16 shell gap in 21O
The spectroscopy of O21 has been investigated using a radioactive O20 beam and the (d,p) reaction in inverse kinematics. The ground and first excited states have been determined to be Jπ=5/2+ and 1/2+, respectively. Two neutron unbound states were observed at excitation energies of 4.77(10) and 6.17(11) MeV. The spectroscopic factor deduced for the lower of these, interpreted as a 3/2+ level, reveals a relatively pure (60%) 0d3/2 single-particle configuration, in good agreement with shell-model calculations that predict O26 to be unbound. The large energy difference between the 3/2+ and 1/2+ states is indicative of the emergence of the N=16 shell gap, which is estimated to be 5.1(11) MeV. For the higher-lying resonance, which has a character consistent with a spin-parity assignment of 3/2+ or 7/2-, a 0.71(22) branching ratio to the first 2+ state in O20 has been observed.Unión Europea EURISOL 515768 RIDSNSF PHY-075809
4He decay of excited states in 14C
A study of the 7Li(9Be,4He 10Be)2H reaction at E{beam}=70 MeV has been
performed using resonant particle spectroscopy techniques and provides the
first measurements of alpha-decaying states in 14C. Excited states are observed
at 14.7, 15.5, 16.4, 18.5, 19.8, 20.6, 21.4, 22.4 and 24.0 MeV. The
experimental technique was able to resolve decays to the various particle bound
states in 10Be, and provides evidence for the preferential decay of the high
energy excited states into states in 10Be at ~6 MeV. The decay processes are
used to indicate the possible cluster structure of the 14C excited states.Comment: accepted for publication in PR
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