2,277 research outputs found
Design of Multi-Antenna System for UMTS Clamshell Mobile Phones with Ground Plane Effects Considerations
In this paper, the influence of the ground plane dimensions on the port-to-port isolation of two closely-spaced Universal Mobile Telecommunications System (UMTS) Planar Inverted-F Antennas (PIFAs) with and without neutralization line is first presented. Parametric studies show the existence of an optimal size of the ground plane allowing optimizing the isolation and the efficiency of the considered antenna-system. The results obtained with this study are used in the second part to develop an efficient neutralized multi-antenna system for clamshell-type mobile phones. The obtained results, in terms of isolation, matching and diversity for the two possible configurations of the clamshell system in use namely the open and the closed states, show that good performance are obtained in the open state and preserved in the closed state. Prototypes of these two configurations are realized and measurement results are in good agreement with the simulations
Dynamics of plasma blobs in a shear flow
The global dynamic of plasma blobs in a shear flow is investigated in a simple magnetized torus using
the spatial Fourier harmonics (k-space) framework. Direct experimental evidence of a linear drift in
k space of the density fluctuation energy synchronized with blob events is presented. During this drift, an
increase of the fluctuation energy and a production of the kinetic energy associated with blobs are observed.
The energy source of the blob is analyzed using an advection-dissipation-type equation that includes
blob-flow exchange energy, linear drift in k space, nonlinear processes, and viscous dissipations.
We show that blobs tap their energy from the dominant E B vertical background flow during the linear
drift stage. The exchange of energy is unidirectional as there is no evidence that blobs return energy to the
flow
Evaluation of B3LYP, X3LYP, and M06-class density functionals for predicting the binding energies of neutral, protonated, and deprotonated water clusters
In this paper we assess the accuracy of the B3LYP, X3LYP, and newly developed M06-L, M06-2X, and M06 functionals to predict the binding energies of neutral and charged water clusters including (H_2O)_n, n = 2â8, 20), H_3O+(H_2O_)n, n = 1â6, and OHâ(H_2O)_n, n = 1â6. We also compare the predicted energies of two ion hydration and neutralization reactions on the basis of the calculated binding energies. In all cases, we use as benchmarks calculated binding energies of water clusters extrapolated to the complete basis set limit of the second-order MĂžllerâPlesset perturbation theory with the effects of higher order correlation estimated at the coupled-cluster theory with single, double, and perturbative triple excitations in the aug-cc-pVDZ basis set. We rank the accuracy of the functionals on the basis of the mean unsigned error (MUE) between calculated benchmark and density functional theory energies. The corresponding MUE (kcal/mol) for each functional is listed in parentheses. We find that M06-L (0.73) and M06 (0.84) give the most accurate binding energies using very extended basis sets such as aug-cc-pV5Z. For more affordable basis sets, the best methods for predicting the binding energies of water clusters are M06-L/aug-cc-pVTZ (1.24), B3LYP/6-311++G(2d,2p) (1.29), and M06/aug-cc-PVTZ (1.33). M06-L/aug-cc-pVTZ also gives more accurate energies for the neutralization reactions (1.38), whereas B3LYP/6-311++G(2d,2p) gives more accurate energies for the ion hydration reactions (1.69)
Evaluation in vitro de la sensibilitĂ© de Pythium aphanidermatum aux fongicides utilisĂ©s dans les plantations de papayers en CĂŽte dâIvoire
La pourriture des racines et du collet du papayer en CĂŽte dâIvoire sĂ©vit dans les plantations, causant des pertes Ă©normes. Cependant, malgrĂ© les traitements fongiques, la maladie persiste. Lâobjectif de cette Ă©tudeest de tester in vitro la sensibilitĂ© de Pythium aphanidermatum, responsable de la maladie, aux fongicides utilisĂ©s dans les plantations de papaye. Ainsi, lâefficacitĂ© des fongicides Callomil, Aliette, Volley, Opal et Callicuivre a Ă©tĂ© testĂ© in vitro sur P. aphanidermatum. Ces pesticides ont Ă©tĂ© incorporĂ©s dans le milieu synthĂ©tique PDA, avec le milieu tĂ©moin constituĂ© de PDA sans fongicide. Le diamĂštre moyen du mycĂ©lium du champignon a Ă©tĂ© mesurĂ©. Puis, lâinhibition de la croissance du champignon a Ă©tĂ© dĂ©terminĂ©e en fonction du fongicide utilisĂ©. Pythium aphanidermatum sâest montrĂ© hautement sensible Ă Callomil, sensible Ă Aliette, rĂ©sistant Ă Volley et hautement rĂ©sistant Ă Opal et Callicuivre. La sensibilitĂ© du pathogĂšne vis-Ă -vis des fongicides varie Ă©galement en fonction de la quantitĂ© de matiĂšre active (ÎŒg/ml) apportĂ©e en boĂźte de PĂ©tri Ă lâexception de Callicuivre pour lequel le champignon sâest rĂ©vĂ©lĂ© hautement rĂ©sistant Ă toutes les doses utilisĂ©es. Les rĂ©sultats confirment lâinefficacitĂ© de lâoxychlorure de cuivre observĂ©e en plantation. Des tests in vivo permettront de confirmer les rĂ©sultats.© 2009 International Formulae Group. All rights reservedMots clĂ©s : Champignon; pesticides ; milieu synthĂ©tique ; rĂ©sistant
Financial services for resilience: how to assess the impacts
This is the final version. Available from BRACED via the link in this recordkey messages
âą Niger is a least developed country prone
to recurrent drought, which affects a large
share of the population and results in
severe food security issues.
âą Support mechanisms, including access to
adequate financial resources, are important for
individuals and communities to better prepare
for and cope with climate extremes.
âą Village savings and loan associations
(VSLAs) are implemented as a means to
support rural communities, address livelihood
shocks and strengthen social capital.
âą Two innovative research methods â financial
diaries and serious games â have been
carried out in Niger, to help support a better
understanding of VSLAsâ contribution to
climate resilience.
âą These innovative tools reveal
behavioural changes that help complete our
understanding of how VSLAs can contribute
to resilience-building in dimensions that
are often unexplored, including (i) gender
empowerment; (ii) social trust; and
(iii) natural resource management.
âą This paper paves the way for further analysis
of the role of VSLAs in building communitiesâ
resilience by documenting the linkages
between financial inclusion and resilience
to climate extremes.
âą These methods, based on community
participation, provide a complementary
alternative to traditional monitoring and
evaluation methods. They contribute
to the âmonitoringâevaluationâlearningâ
trinity by blending evaluation and learningDFI
Fruit and seed production in a natural population of a dioecious plant: Piliostigma reticulatum HOSCHT (CaesalpinioĂŻdeae)
Plant fruit/seed production is a central subject of many questions in plant evolutionary and conservation biology. In the Sudano-Sahelian forest of Burkina Faso, fruit and seed production of a common dioecious shrub, Piliostigma reticulatum, were assessed by considering plant size, fruiting success and distance between male and female individuals. The results showed that P. reticulatum has a low production of fruits and seeds (17.63 g ± 3.33 SE of fruit per plant and 0.1045 g ± 0.0018 SE per seed). A large percentage of the seeds aborted (40%) and were damaged by herbivory (10%). The fruiting success ranged from 0.1 to 0.4. The percentage of seeds attacked by insects was negatively correlated with the mean diameter of the canopy and the height of trees. When the female of P. reticulatum was more than 10 meters from the male, fruit and seed productions were greater. The conclusion was that losses of flowers and fruits were important and suggested further information on pollination limitation or genetic studies to identify the cause of the insufficient quality and quantity of fruit and seed productions of P. reticulatum.Keywords: Piliostigma reticulatum, dioecious, fruiting success, soudanian forest, Burkina Fas
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