The Hausa Lexicographic Tradition

Hausa, a major language of West Africa, is one of the most widely studied languages of Sub-Saharan Africa. It has a rich lexicographic tradition dating back some two centuries. Since the first major vocabulary published in 1843 up to the present time, almost 60 lexicographic works - dictionaries, vocabularies, glossaries - have been published, in a range of metalanguages, from English to Hausa itself. This article traces the historical development of the major studies according to their type and function as general reference works, specialized works, pedagogical works, and terminological works. For each work, there is a general discussion of its size, accuracy of the phonological, lexical, and grammatical information, and the adequacy of its definitions and illustrative material. A complete list of the lexicographic works is included

Dinoflagellate abundance in the Laguna Botos, Poás Volcano, Costa Rica

Phytoplankton of the Botos lagoon of Poás volcano is dominated by dinoflagellates. The two species of greatest abundance in March 1979 were Peridinium incospicuum Lemm. and P. volzii Lemm, which represented 96% of total cells. The identity of these species was confirmed by electron microscopy. Both species are cosmopolitan. Without further resealch it is premature to compare Botos Lagoon with similar lakes in Central America

R-matrix formalism for electron scattering in two dimensions

We investigate the scattering phenomena in two dimensions produced by a general finite-range nonseparable potential. This situation can appear either in a Cartesian geometry or in a heterostructure with cylindrical symmetry. Increasing the dimensionality of the scattering problem new processes as the scattering between conducting channels and the scattering from conducting to evanescent channels are allowed. For certain values of the energy, called resonance energy, the transmission through the scattering region changes dramatically in comparison with an one-dimensional problem. If the potential has an attractive character even the evanescent channels can be seen as dips of the total transmission. The multi-channel current scattering matrix is determined using its representation in terms of the R-matrix. The resonant transmission peaks are characterized quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. Our formalism is applied to a quantum dot in a two dimensional electron gas and a conical quantum dot embedded inside a nanowir

R-matrix formalism for electron scattering in two dimensions

We investigate the scattering phenomena in two dimensions produced by a general finite-range nonseparable potential. This situation can appear either in a Cartesian geometry or in a heterostructure with cylindrical symmetry. Increasing the dimensionality of the scattering problem new processes as the scattering between conducting channels and the scattering from conducting to evanescent channels are allowed. For certain values of the energy, called resonance energy, the transmission through the scattering region changes dramatically in comparison with an one-dimensional problem. If the potential has an attractive character even the evanescent channels can be seen as dips of the total transmission. The multi-channel current scattering matrix is determined using its representation in terms of the R-matrix. The resonant transmission peaks are characterized quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. Our formalism is applied to a quantum dot in a two dimensional electron gas and a conical quantum dot embedded inside a nanowir

Evanescent channels and scattering in cylindrical nanowire heterostructures

We investigate the scattering phenomena produced by a general finite range non-separable potential in a multi-channel two-probe cylindrical nanowire heterostructure. The multi-channel current scattering matrix is efficiently computed using the R-matrix formalism extended for cylindrical coordinates. Considering the contribution of the evanescent channels to the scattering matrix, we are able to put in evidence the specific dips in the tunneling coefficient in the case of an attractive potential. The cylindrical symmetry cancels the ''selection rules'' known for Cartesian coordinates. If the attractive potential is superposed over a non-uniform potential along the nanowire, then resonant transmission peaks appear. We can characterize them quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances (dips and peaks). Our formalism is applied to a variety of model systems like a quantum dot, a core/shell quantum ring or a double barrier, embedded into the nano-cylinder

Fano regime of transport through open quantum dots

We analyze a quantum dot strongly coupled to the conducting leads via quantum point contacts - Fano regime of transport - and report a variety of resonant states which demonstrate the dominance of the interacting resonances in the scattering process in a low confining potential. There are resonant states similar to the eigenstates of the isolated dot, whose widths increase with increasing the coupling strength to the environment, and hybrid resonant states. The last ones are approximatively obtained as a linear combination of eigenstates with the same parity in the lateral direction, and the corresponding resonances show the phenomena of resonance trapping or level repulsion. The existence of the hybrid modes suggests that the open quantum dot behaves in the Fano regime like an artificial molecule

R-matrix formalism for electron scattering in two dimensions

We investigate the scattering phenomena in two dimensions produced by a general finite-range nonseparable potential. This situation can appear either in a Cartesian geometry or in a heterostructure with cylindrical symmetry. Increasing the dimensionality of the scattering problem new processes as the scattering between conducting channels and the scattering from conducting to evanescent channels are allowed. For certain values of the energy, called resonance energy, the transmission through the scattering region changes dramatically in comparison with an one-dimensional problem. If the potential has an attractive character even the evanescent channels can be seen as dips of the total transmission. The multi-channel current scattering matrix is determined using its representation in terms of the R-matrix. The resonant transmission peaks are characterized quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. Our formalism is applied to a quantum dot in a two dimensional electron gas and a conical quantum dot embedded inside a nanowir

R-matrix formalism for electron scattering in two dimensions

We investigate the scattering phenomena in two dimensions produced by a general finite-range nonseparable potential. This situation can appear either in a Cartesian geometry or in a heterostructure with cylindrical symmetry. Increasing the dimensionality of the scattering problem new processes as the scattering between conducting channels and the scattering from conducting to evanescent channels are allowed. For certain values of the energy, called resonance energy, the transmission through the scattering region changes dramatically in comparison with an one-dimensional problem. If the potential has an attractive character even the evanescent channels can be seen as dips of the total transmission. The multi-channel current scattering matrix is determined using its representation in terms of the R-matrix. The resonant transmission peaks are characterized quantitatively through the poles of the current scattering matrix. Detailed maps of the localization probability density sustain the physical interpretation of the resonances. Our formalism is applied to a quantum dot in a two dimensional electron gas and a conical quantum dot embedded inside a nanowire

Influence of Temperature and Freezing Time on Broiler Chicken Meat Colour

Due to the fact that meat colour represents an important aspect for sensorial evaluation of any food product,research in the field of poultry meat processing regarding efficient methods for hoarding/storage on long term ofindustrially slaughtered poultry carcasses approaches a continuous finding/optimization of certain solutions foravoiding negative consequences due to oxidation, which could include colour loss and/or its modification.The current study aimed to evaluate the effects of three storage regimes differing by temperature and time(L = -14°C, 30 days; L = -16°C, 60 days; L = -18°C, 90 days) on three anatomical cut regions (breast, upper thighand lower thigh), to characterize the colour of broiler chicken meat. Objective description of colour for frozen anddefrosted chicken meat was realised through the CIEL*a*b* Cartesian coordinate system.Overall, the preservation method determines a higher luminosity at samples gathered from L batch chickencarcasses for breast and upper thigh musculature, and L for lower thigh musculature in comparison with thecounterparts from the other experimental batche