The role of superfluidity in nuclear incompressibilities

Nuclei are propitious tools to investigate the role of the superfluidity in the compressibility of a Fermionic system. The centroid of the Giant Monopole Resonance (GMR) in Tin isotopes is predicted using a constrained Hartree-Fock Bogoliubov approach, ensuring a full self-consistent treatment. Superfluidity is found to favour the compressibitily of nuclei. Pairing correlations explain why doubly magic nuclei such as $^{208}$Pb are stiffer compared to open-shell nuclei. Fully self-consistent predictions of the GMR on an isotopic chain should be the way to microscopically extract both the incompressibility and the density dependence of a given energy functional. The macroscopic extraction of K$_{sym}$, the asymmetry incompressibility, is questioned. Investigations of the GMR in unstable nuclei are called for. Pairing gap dependence of the nuclear matter incompressibility should also be investigated.Comment: 5 page

Cluster-liquid transition in finite saturated fermionic systems

The role of saturation for cluster formation in finite systems such as atomic nuclei is analyzed by considering three length-scale ratios, and performing deformation-constrained self-consistent mean-field calculations. The effect of clusterisation in deformed light systems is related to the saturation property of the inter-nucleon interaction. The formation of clusters at low nucleon density is illustrated by expanding the radius of $^{16}$O. A phase diagram shows that the formation of clusters can be interpreted as a hybrid state between the crystal and the liquid phases. In the hybrid cluster phase the confining potential attenuates the delocalization generated by the effective nuclear interaction

Suppression, persistence and reentrance of superfluidity in overflowing nuclear systems

International audienceBased on a microscopic description of superfluidity in overflowing nuclear systems, it is shown that continuum coupling plays an important role in the suppression, the persistence and the reentrance of pairing. In such systems, the structure of the drip-line nucleus determines the suppression and the persistence of superfluidity. The reentrance of pairing with increasing temperature leads to additional critical temperatures between the normal and superfluid phases

Constraining the nuclear pairing gap with pairing vibrations

Pairing interactions with various density dependencies (surface/volume mixing) are constrained with the two-neutron separation energy in the Tin isotopic chain. The response associated with pairing vibrations in very neutron-rich nuclei is sensitive to the density dependence of the pairing interaction. Using the same pairing interaction in nuclear matter and in Tin nuclei, the range of densities where the LDA is valid in the pairing channel is also studied

Game of regional environmental policy: Europe and US

We analyse a different timing implementation of environmental regulation and compare the effects on the markets from a policy innovation perspective. The paper addresses the question: Should a regulator try to commit to a policy (ex-ante regulation) or rather adapt its policy to a firm's decisions (ex-post)? The findings are of interest towards improving regulatory effectiveness and economics efficiencies, e.g. for the transatlantic regional relationship between EU and USA. Our findings highlight differences in policy timing between markets may be harmful. The transatlantic regulators should consider the timing of the policy innovation for the achievement of mutual benefits

TRANSITIONING TO ONLINE EDUCATION IN ENGLISH DEPARTMENTS IN BANGLADESH: LEARNER PERSPECTIVES

During the brief coronavirus-induced hiatus in March and April 2020, educational institutions in Bangladesh including public universities began preparations for online classes. By the end of June, almost all private universities and a few public universities had started online classes with limited or no preparation, which was met with appreciation as well as censure from different stakeholders. Against this backdrop, this study was conducted with a view to examining the online teaching-learning scenario at Bangladeshi public universities from the perspective of one important stakeholder, the students, with a specific focus on the challenges they faced with this new mode of instruction. Suggestions were also sought from them regarding how the barriers to online instruction could be overcome. Data were collected from 26 students of English Departments of 11 public universities through semi-structured interviews. The major challenges reported include issues of access and equity, inadequate logistic support and poor infrastructure. Concerns related to curriculum, pedagogy, assessment and psychological issues were also highlighted. In addition, lack of prior experience and inadequate training were identified as serious obstacles. Major suggestions from the participants include ensuring access and equity, providing training opportunities and digital devices to students, and engaging in curriculum and assessment reforms.

Première mesure des résonances géantes isoscalaires dans un noyau exotique riche en neutrons (le 68Ni avec la cible active Maya)

L étude des résonances géantes monopolaires isoscalaires (ISGMR) et des résonances géantes quadrupolaires isoscalaires (ISGQR) dans les noyaux stables, a permis d obtenir ces dernières décennies des informations fondamentales sur la structure et la matière nucléaire. En particulier, le centroïde de la ISGMR peut être relié au module d incompressibilité de la matière nucléaire infinie. Des données dans les noyaux exotiques nous aideraient à contraindre ce module d incompressibilité. Dans les noyaux instables, une seule mesure a, à l heure actuelle, été réalisée (56Ni). Afin d étudier l évolution de la ISGMR et de la ISGQR le long d une chaîne isotopique, des mesures dans un noyau exotique riche en neutrons sont donc nécessaires.L expérience étudiée dans cette thèse a été réalisée au Grand Accélérateur National d Ions Lourds (GANIL) à Caen en septembre 2010. Un faisceau de 68Ni à 50 AMeV et d une intensité de 10^4 pps a été produit et purifié sur la ligne LISE. Les réactions de diffusion inélastique de particules alpha (alpha, alpha ) et de deutons (d,d ) sur 68Ni en cinématique inverse ont été étudiées avec la cible active Maya. Il s agit de la première mesure de la ISGMR et de la ISGQR dans un noyau instable riche en neutrons.Pour chaque expérience, le spectre en énergie d excitation a été reconstruit et les distributions angulaires étudiées par deux méthodes indépendantes. Les sections efficaces expérimentales ont été comparées à celles issues de calculs DWBA utilisant des densités de transition RPA. L analyse en (alpha, alpha ) a permis l observation d une ISGMR fragmentée avec un épaulement à 21.1+/-0.6 MeV, d une ISGQR concentrée à 16.9+/-0.8 MeV qui épuise 61+/-17% de la règle de somme pondérée en énergie (EWSR). De plus, un mode soft GMR , prédit mais jamais observé, a été identifié à 13.4+/-0.5 MeV. Tous ces résultats sont confirmés par l analyse en (d,d ), à l exception de l observation de la ISGQR pour laquelle les conditions de fonctionnement n étaient pas favorables.The study of the Isoscalar Giant Monopole Resonance (ISGMR) and the Isoscalar Giant Quadrupole Resonance (ISGQR) in stable nuclei provided relevant information on both nuclear matter and nuclear structure in past decades. For instance the centroid of the ISGMR can be linked to the incompressibility modulus of the infinite nuclear matter. Values for exotic nuclei would help in constraining it. In unstable nuclei, only one measurement has been performed so far (56Ni) and in order to study the evolution of the ISGMR and the ISGQR along an isotopic chain, measurements in neutron-rich Ni are called for.To reach this goal, a dedicated experiment was performed at GANIL in Septembre 2010. A 68Ni beam at 50 AMeV and with an intensity of 10^4 pps has been produced on LISE beamline. The inelastic scattering of alpha (alpha, alpha ) and deuteron particles (d,d ) on 68Ni in inverse kinematics has been studied with the active target Maya. It is the first attempt to measure the ISGMR and ISGQR in an unstable neutron-rich nucleus. For each experiment, the excitation energy spectrum has been reconstructed and the angular distributions have been studied with two independant methods. Experimental differential cross sections have been compared to DWBA calculations using RPA transition density in order to deduce the properties of the states observed. Concerning the analysis in (alpha, alpha ), the ISGMR is fragmented with a shoulder at 21.1+/-0.6 MeV, the ISGQR is concentred at 16.9+/-0.8 MeV and exhausted 61+/-17% of the Energy Weighted Sum Rule (EWSR). Moreover, a soft GMR , predicted but never observed, is identified at 13.4+/-0.5 MeV. All these results are confirmed with the experiment in (d,d ), with the exception of the ISGQR due to unadapted experimental conditions.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

The Effectiveness of Learning Instruments of Speaking Containing Character Values toward Speaking Learning

This development research aimed at describing the effectiveness of learning instruments of speaking that were contained in character values. The objects of the study were a syllabus, lesson plan, textbook, and assessment. The subjects of the study were the lecturers of Speaking and the 2nd-semester students of IIA, IIB, and IIC in the academic year of 2015/2016. The data was collected through observation, questionnaire, and test. The data was analyzed by administering descriptive qualitative technique and descriptive statistics. The results of the study showed that the learning instruments was effective to be used in the teaching and learning process, to improve students understanding on the materials, to improve students speaking skill, and to shape characters such as religious, polite, communicative, open, democratic, respectful, responsible, curious, discipline, confident, cooperative, appreciate achievement, logic, critic, creative and innovative, and love reading. The results of the study indicated that the learning instruments of speaking contained of character values were effective so that it was feasible to be used by both lecturers and students of Indonesian Language and Literature Department, Language and Art Faculty of Ganesha University of Education

Proton-neutron pairing correlations in atomic nuclei

La compréhension usuelle de l'appariement proton-neutron, dont les traces sont actuellement étudiées en noyaux N = Z, s'appuie sur le mécanisme de paires de Cooper et modèles BCS type. Dans cette thèse, nous présentons une approche alternative qui, contrairement aux modèles BCS, conserve exactement le nombre de particules et l'isospin. Dans cette approche, l'état fondamental de noyaux N = Z est décrit comme un condensé de quartets alpha-similaires faits de deux neutrons et deux protons couplés à l'isospin total T = 0 et de spin J total = 0. La comparaison avec des calculs exacts du modèle en couches montre que le modèle de condensation quartet (QCM) donne une description très précise de l'appariement des corrélations à noyaux N = Z, bien mieux que les modèles BCS. Il est également montré que l'appariement proton-neutron et alpha de type condensation sont importantes non seulement pour les noyaux N = Z, mais aussi pour les noyaux avec des neutrons excédentaires. Dans ce dernier cas, le condensat de quartets d'alpha coexiste avec le condensat des paires de neutrons en excès par rapport au isotopes N = Z. En utilisant le cadre de QCM, nous avons également étudié la compétition entre l appariement proton-neutron isovectoriel et isoscalaire dans les noyaux N = Z. Nos résultats indiquent que la contribution de l'appariement isoscalaire aux corrélations d'appariement du fondamental est très faible par rapport à l'appariement isovectoriel.The common understanding of proton-neutron pairing, whose fingerprints are currently investigated in N = Z nuclei, relies on Cooper pair mechanism and BCS-type models. In the present thesis we present an alternative approach which, contrary to BCS models, conserves exactly the particle number and the isospin. In this approach the ground state of N=Z nuclei is described as a condensate of alpha-like quartets built by two neutrons and two protons coupled to the total isospin T=0 and total spin J=0. The comparison with exact shell model calculations shows that the quartet condensation model (QCM) gives a very accurate description of pairing correlations in N=Z nuclei, much better than the BCS models. It is also shown that proton-neutron pairing and alpha-type condensation are important not only for N=Z nuclei but also for nuclei with excess neutrons. In the latter case the condensate of alpha-like quartets coexist with the condensate of the neutron pairs in excess relative to the N=Z isotope. Using the framework of QCM we have also studied the competition between the isovector and the isoscalar proton-neutron pairing in nuclei with N=Z. Our results indicate that the contribution of isoscalar pairing to the ground state pairing correlations is very small compared to the isovector pairing.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Multi-criteria analysis and ex-ante assessment to prioritize and scale up climate smart agriculture in semi–arid tropics, India

The strategies that integrate food security, adaptation and mitigation options in agriculture are of high importance to manage the increasing risk of climate change in vulnerable semi-arid regions for the livelihood security of poor agriculture-dependent people. To address the growing problems of food security and climate change, multiple institutions and programs have demonstrated evidences for developing Climate-Smart Villages (CSVs) across regions which can act as a sustainable model for adapting to changing climate and improve farmers’ welfare. However, it remain a major challenge to upscale CSV approach. This paper presents a framework and evidence based designing of a strategy for scaling up Climate Smart Agriculture (CSA) in Telangana State of India. Climate risk and vulnerability mapping at disaggregate level; Inventory of CSA practices and respective technical coefficients; multicriteria analysis for participatory prioritization of location specific CSA practices and identification of barriers and incentives; ex-ante impact analysis of potential adoption and investment and infrastructure needs to implement CSA practices at local level and strategy for CSA integration into district level plans have been the key steps of this CSV approach. Local level vulnerability assessments and participatory prioritization based on index calculated for climate smartness and ease of adoption for each proposed practice, formed the basis of prioritizing CSA interventions suitable for particular location. Further the ex-ante impact analysis of selected climate smart interventions in different regions of Telangana was the next step. We also generated relevant geospatial maps for irrigated as well as rainfed major crops under vertisols and light soils. These maps helped in identifying context specificity of CSA interventions. Based on participatory prioritization, five CSA practices such as Ridges and Furrows, Broad bed and furrow for soil and moisture conservation and drainage, Farm pond for critical/supplemental irrigation, Crop residue management (cotton) and drip irrigation system were considered for ex-ante assessment considering district wise actual area and yields of major crops and rainfall level for 5 years from 2010-11 to 2014-15. The proposed framework and different tools help to understand the district wise potential for promotion of CSA practices/technologies, public and private investment needs, economic impacts of the interventions to enable informed decision making for climate smart agriculture. Stakeholders’ consultations during different stages of this process was very important for integrating their perspective and creating ownership. Piloting of evidence based scientific framework guides investments and policy making decisions on scaling up CSA in Telangana state