Growth and spawning period of Sepia officinalis, (Lineaus, 1758) in the Algiers region (centre of Algeria)

A total of 1,364 specimens of Sepia officinalis (Lineaus, 1758), including 643 females and 532 males were measured from February 2010 to January 2011 catching by the commercial trawling fisheries of Algiers region. The sex, dorsal mantle, wet body mass, nidamental gland weight and female gonadal weight were recorded. The mean length of the dorsal mantle for females was 11.68±0.03 cm and for males 12.04±0.04 cm. The difference between the two averages was not significant. The Powell-Wetherall method for determining the asymptotic dorsal length of the mantle (DML∞) was applied (26.93 cm for both sexes combined) and the growth coefficient K, of 0.38 yr^-1, was established using the ELEFAN method. A seasonal analysis of this coefficient shows a slowdown in growth in autumn and winter. The value of t_0 determined by the Pauly method is 0.704 y^-1. Relative growth shows a negative allometry of 2.55 for both sexes and a constant of proportionality is about 0.391. The study of the overall sex ratio showed a slight predominance of females with a ratio of 1:1.2. In autumn and winter, the females predominate with 67.3% and 52.5%, respectively. Considering the gonad and the nidamento-somatic index, S. officinalis in the Algiers region seems to breed between March and July

Analysis of the phenotypic variability of some varieties of durum wheat (Triticum durum Desf) to improve the efficiency of performance under the constraining conditions of semiarid environments

The experiment was conducted during three growing seasons and two planting dates. The cultivation site is placed at the ITGC Setif characterized by a semi-arid environment. The objective of the study is the analysis of phenotypic variability of traits measured for 15 varieties of durum wheat, through the average effects, to decline the ways, characters and varieties could play in favour of performance under the constraining semi-arid conditions. The year effect indicates that given the difficulty of predicting the performance enabled by years, it then makes sense to go straight for this performance within genotypes. Analysis of the effect genotype highlights characters connected to performance and is the Setifis variety that lends itself well. For the effect of sowing date, it is that early sowing promotes a better expression of the characteristics compared to late sowing.Keywords: Effect; genotype; year; date; variation; character

Methane adsorption in metal-organic frameworks containing nanographene linkers: a computational study

Metal-organic framework (MOF) materials are known to be amenable to expansion through elongation of the parent organic linker. For a family of model (3,24)-connected MOFs with the rht topology, in which the central part of organic linker comprises a hexabenzocoronene unit, the effect of the linker type and length on their structural and gas adsorption properties is studied computationally. The obtained results compare favourably with known MOF materials of similar structure and topology. We find that the presence of a flat nanographene-like central core increases the geometric surface area of the frameworks, sustains additional benzene rings, promotes linker elongation and the efficient occupation of the void space by guest molecules. This provides a viable linker modification method with potential for enhancement of uptake for methane and other gas molecules

Ternary Mixtures of N-Docosane, N-Tricosane and N-Tetracosane Mélanges ternaires de n-docosane, n-tricosane et n-tétracosane

Binary phase diagrams of the systems: n-docosane: n-tricosane (C22H46 : C23H48), n-tricosane: n-tetracosane (C23H48: C24H50) and n-docosane: n-tetracosane (C22H46: C24H50) have been established by means of structural and differential scanning calorimetry analyses. On the basis of these results and of X-ray examination of forty one ternary mixtures, it is proposed the ternary phase diagram (C22H46: C23H48: C24H50) at room temperature. This work has indicated the existence of limited terminal solid solutions near the three pure n-alkanes and three domains of orthorhombic intermediate phases (noted ß' 1, ß'' 1, ß' 2) identical to those observed in the binary systems. X-ray experiments have showed that the phases ß' 1, ß'' 2 situated on the both sides of the middle intermediate phase ß' 1, are isostructural as in the binary systems. <br> Les diagrammes de phases des systèmes binaires : n-docosane : n-tricosane (C22H46 : C23H48), n-tricosane : n-tétracosane (C23H48 : C24H50) et n-docosane : n-tétracosane (C22H46 : C24H50) ont été établis à partir d'analyses thermiques différentielles (ATD) et structurales. Sur la base de ces résultats, ainsi que de l'examen aux rayons X de 41 mélanges ternaires, le diagramme de phases du ternaire (C22H46 : C23H48 : C24H50) à température ambiante est proposé. Ce travail a indiqué l'existence de domaines limités de solutions solides au voisinage des trois n-alcanes purs, ainsi que de trois régions de phases intermédiaires orthorhombiques (notées ß' 1, ß 1, ß' 2) identiques à celles observées avec les systèmes binaires. Les analyses aux rayons X ont montré que les phases ß' 1 et ß' 2 situées de part et d'autre de la phase médiane intermédiaire ß1 sont isostructurales, tout comme dans le cas des systèmes binaires

The Tadjena Earthquake (Mw = 5.0) of December 16, 2006 in the Cheliff Region (Northern Algeria): Waveform Modelling, Regional Stresses, and Relation with the Boukadir Fault

International audienceThe Cheliff region has experienced some significant earthquakes in the last century (1937, 1954, and 1980). The most destructive one is that of El Asnam on October 10, 1980, Ms = 7.3 (Io = IX), which destroyed the Chlef city (formerly El Asnam) and its surrounding villages. On December 16, 2006 a moderate earthquake (Mw = 5.0) hit the Cheliff region. The maximum observed intensity (Io = V: MSK-scale) was observed at Abou El Hassen, Benaria, Bouzghaïa and Tadjena. No damages or human losses were recorded. Nevertheless, minor cracks on walls of the old school at Tadjena were observed. The point source focal mechanism of the event was determined by inverting the waveforms of three regional broadband stations of the ADSN (Algerian Digital Seismic Network). It corresponds to thrust-reverse faulting with a strike-slip component. The stress tensor obtained by the inversion of the 15 focal mechanisms available in the Cheliff region exhibits a well constrained compression axis σ1 horizontal and trending N145°. The NW dipping nodal plane indicating a NE-SW thrust fault with a right-lateral component (strike, dip, rake = 249, 38, 137) is more compatible with the regional stress tensor than the steep dipping NNE-SSW nodal plane showing reverse faulting with a left-lateral component (strike, dip, rake = 15, 65, 60). Accordingly, the Tadjena moderate size earthquake can be related to the Boukadir active fault bordering the lower Cheliff basin to the north, a situation similar to that of the El Asnam fault bordering the middle Cheliff basin to the north

Diffusion of Carbon Dioxide and Nitrogen in the Small-Pore Titanium Bis(phosphonate) Metal-Organic Framework MIL-91 (Ti): A Combination of Quasielastic Neutron Scattering Measurements and Molecular Dynamics Simulations

SSCI-VIDE+ATARI+HJOInternational audiencecarbon dioxid

Diffusion of H-2, CO2, and Their Mixtures in the Porous Zirconium Based Metal Organic Framework MIL-140A(Zr): Combination of Quasi-Elastic Neutron Scattering Measurements and Molecular Dynamics Simulations

SSCI-VIDE+ATARI+HJOInternational audienceThe diffusivity of H-2 and CO2 in the small pore Zr based metalorganic framework (MOF) MIL-140A(Zr) has been evaluated using a combination of quasi-elastic neutron scattering measurements and molecular dynamics simulations. These two techniques were used to determine the self-diffusivities of H-2, and the corrected and transport diffusivities of CO2, as single components and binary mixture. H-2 was shown to be the faster of the two gases to diffuse through the narrow triangular channel of MIL-140A(Zr), its self-diffusivity value being 1 order of magnitude higher than that of CO2, at the same temperature. In this case, although no specific interaction sites are present, the CO2 interacts more strongly with the pore wall than H-2, partly a consequence of its greater kinetic radius, which renders it slower than H-2. In the context of a binary mixture, H-2 still diffuses faster between the two, although with a slightly lower self-diffusivity, while that of CO2 increases slightly. However, the difference in terms of order of magnitude is not altered and makes MIL-140A(Zr) a potential candidate for H-2/CO2 separation based on kinetics

Analysis of Photocarrier Dynamics at Interfaces in Perovskite Solar Cells by Time-Resolved Photoluminescence

The power conversion efficiency of perovskite solar cells is drastically affected by photocarrier dynamics at the interfaces. Experimental measurements show quenching of the photoluminescence (PL) signal from the perovskite layer when it is capped with a hole transport medium (HTM). Furthermore, time-resolved PL (TRPL) data show a faster decay of the PL signal in the presence of the perovskite/HTM interface. The experimental decay is usually fitted using one or two exponential functions with an incomplete physical picture. In this work, an extensive model is used to extract the key physical parameters characterizing carrier dynamics in the bulk and at the interfaces. The decay of the TRPL signal is calculated in the presence of both defect-assisted recombination (Shockley Read Hall) and band-to-band radiative recombination where carrier extraction/recombination at the interfaces is described by interface recombination velocities. By proper curve fitting of the modeling results and the measured TRPL signal, meaningful optoelectronic parameters governing photophysical processes in mixed halide perovskite thin films and single crystals are extracted. Furthermore, a sensitivity analysis to assess the contribution of these parameters on TRPL kinetics is also performed. Notably, the inclusion of the diffusion and surface recombination velocity at the interfaces allows to obtain the important physical parameters that govern the TRPL kinetics and improve the conformity of fits to experiments