Generalized Steinberg representations of split reductive linear algebraic groups

We generalize results of P. Schneider and U. Stuhler for GL_l+1 to a reductive algebraic group G defined and split over a non-archimedean local field K. Following their lines, we prove that the generalized Steinberg representations of G with coefficients in any abelian group are cyclic. When G is semi-simple of adjoint type, we give an expression of these representations, whenever it is possible and in particular for those that are of maximal degree, in terms of the parahoric subgroups of G.Comment: 17 page

Nestrukturirani modeli mliječno-kiselog vrenja

To describe a microbial process, two kinds of models can be developed, structured and unstructured models. Contrary to structured models, which take into account some basic aspects of cell structure, their function and composition, no physiological characterization of cells is considered in unstructured models, which only consider total cellular concentration. However, in spite of their simplicity, unstructured models have proven to accurately describe lactic acid fermentation in a wide range of experimental conditions and media. A partial link between cell growth and production, namely the Luedeking and Piret model, is mostly considered by the authors. Culture pH is the main parameter to be considered for model development. Acidic pH leads to inhibitory concentrations of undissociated lactic acid, the main inhibitory component, which causes cessation of growth and then production. On the other hand, pH control at optimal value for LAB growth allows to overcome product inhibition (by the total lactic acid produced or its undissociated part); hence nutritional limitations have to be considered for model development. Nitrogen is mainly involved in cessation of growth, owing to the fastidious nutritional requirements of LAB, while lactic acid production ceased when carbon was exhausted from the medium. The lack of substrate inhibition when usual concentrations of carbon substrate are used should be noted.Da bi se opisao mikrobni proces, upotijebljeni su strukturirani i nestrukturirani modeli. Strukturirani modeli uzimaju u obzir strukturu, funkciju i raspored stanica, a nestrukturirani ne uzimaju fiziološka svojstva, već samo ukupnu koncentraciju stanica. Ipak, usprkos njihovoj jednostavnosti, nestrukturirani modeli precizno opisuju mliječno-kiselo vrenje u različitim eksperimentalnim uvjetima i na raznim podlogama. Autori najčešće koriste Luedekingov i Piretov model, koji opisuje djelomičnu vezu između rasta stanica i proizvodnje mliječne kiseline. U razvoju ovoga modela najčešće je pH-vrijednost glavni parametar. Pri niskoj pH-vrijednosti nastaju inhibicijske koncentracije nedisocirane mliječne kiseline, što zaustavlja rast mliječno-kiselih bakterija, a time i proizvodnju mliječne kiseline. Taj se inhibicijski učinak može prevladati održavanjem optimalne pH-vrijednosti, ali pritom treba uzeti u obzir utjecaj hranjivih tvari na rast mliječno-kiselih bakterija. Nedostatak dušika je najčešći uzrok inhibicije mliječno-kiselih bakterija, jer im je prijeko potreban za rast, dok nakon iscrpljivanja ugljika iz podloge prestaje proizvodnja mliječne kiseline, što se može izbjeći korištenjem odgovarajućih koncentracija ugljika

Warped Poisson Brackets on Warped Products

In this paper, we generalize the geometry of the product pseudo-Riemannian manifold equipped with the product Poisson structure (\cite{Nas2}) to the geometry of a warped product of pseudo-Riemannian manifolds equipped with a warped Poisson structure. We construct three bivector fields on a product manifold and show that each of them lead under certain conditions to a Poisson structure. One of these bivector fields will be called the warped bivector field. For a warped product of pseudo-Riemannian manifolds equipped with a warped bivector field, we compute the corresponding contravariant Levi-Civita connection and the curvatures associated with.Comment: 18 page

Full potential linear augmented plane wave calculations of Electronic and Optical properties in ZnO

 In this work we present self-consistent calculations for the electronic and optical properties of Zinc oxide. A theoretical investigation of the electronic properties (band structure, density of charge and contour map) and optical properties (refractive index, absorption coefficient, dielectric constants and reflectivity) of Zinc oxide semiconductor ZnO. A full-potential linearized augmented plane-wave (FPLAPW) method was used within the density functional theory (DFT) along with the generalized gradient approximation (GGA96) exchange correlation potential. The results are compared with the experimental data available and some other theoretical work. We found that the GGA approximation yields only a small improvement to the band gap, however, if we allow for a rigid shift of the band structure, the so-called scissors operator, the optical properties are excellently reproduced

Biodegradation by bioaugmentation of dairy wastewater by fungal consortium on a bioreactor lab-scale and on a pilot-scale

International audienceA fungal consortium including Aspergillus niger, Mucor hiemalis and Galactomyces geotrichum was tested for the treatment of dairy wastewater. The bio-augmentation method was tested at lab-scale (4 L), at pilot scale (110 L) and at an industrial scale in Wastewater Treatment Plants (WWTP). The positive impact of fungal addition was confirmed when fungi was beforehand accelerated by pre-culture on whey (5 g/L lactose) or on the dairy effluent. Indeed, chemical oxygen demand (COD) removal yields increased from 55% to 75% for model medium, diluted milk. While after inoculation of an industrial biological tank from a dairy factory with the fungal consortium accelerated by pre-cultivation in a 1000 L pilot plant, the outlet COD values decreased from values above the standard one (100 mg/L) to values in the range of 50-70 mg/L. In addition, there was a clear impact of fungal addition on the 'hard' or non-biodegradable COD owing to the significant reduction of the increase of the COD on BOD5 ratio between the inlet and the outlet of the biological tank of WWTP. It was in the range of 451%-1111% before adding fungal consortium, and in the range of 257%-153% after bio-augmentation with fungi. An inoculated bioreactor with fungal consortium was developed at lab-scale and demonstrated successfully at pilot scale in WWTP

AHRI Low Global Warming Potential Alternative Refrigerants Evaluation Program (Low-GWP AREP) – Summary of Phase I Testing Results

The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) recently completed the first phase of its low global warming potential alternative refrigerants evaluation program (Low-GWP AREP). This industry-wide cooperative research program identified and evaluated promising alternative refrigerants’ performance over the past two years. Thirty-eight low-GWP refrigerants were tested during the first phase of the program in a variety of products; including air conditioners, heat pumps, chillers, ice makers and commercial bottle coolers. This paper provides a comprehensive summary of the test results obtained during phase I. Furthermore, AHRI is launching a second phase of testing at the beginning of 2014 that includes newly developed refrigerants and performance testing under high ambient conditions that were not covered in the first phase. A status update of Phase II testing will also be provided

AHRI Low Global Warming Potential Alternative Refrigerants Evaluation Program (Low-GWP AREP) – Summary of Phase II Testing Results

The Air-Conditioning, Heating, and Refrigeration Institute (AHRI) recently completed the second phase of its Low Global Warming Potential Alternative Refrigerants Evaluation Program (Low-GWP AREP). This industry-wide cooperative research program identified and evaluated promising alternative refrigerants over the past two years. Twenty-eight low-GWP refrigerants were tested during the second phase of the program in a variety of products; including air conditioners, heat pumps, chillers, ice makers and commercial refrigeration displace cases. Phase II testing also included the performance testing under high ambient conditions up to 125°F. This paper provides a comprehensive summary of the refrigerants tested and results obtained during phase II.Â

First Principles Calculations on The Electronic and Optical Properties of Zincblende Bxga1-Xas and Bxin1-Xas Semiconductor Alloys.

A theoretical study of the electronic and optical properties of zincblende BxGa1-xAs and BxIn1-xAs  semiconductor alloys is presented, using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange correlation potential. Ground state properties such as lattice parameter and band structure are calculated as a function of the mole fraction. We have also analyzed the optical properties (refractive index, dielectric function, real and imaginary), the 4x4 Kanes interaction matrix is calculated in order to ease simulations of optoelectronic devices. The results have been discussed in terms of previously existing experimental and theoretical data, and comparisons with similar compounds have been made