Les PME Algeriennes dans l’ere de la mondialisation : Etude de cas des PME de la region Oranaise

En 2007, plus de 3000 petites et moyennes entreprises (PME) ont été radiées; dont 2000 rien que dans le  remier semestre 2007 bien que quasiment toutes les politiques du gouvernement sont axées sur ce type d’entreprises depuis des années. Ce chiffre est inquiétant et à plusieurs niveaux. Ce constat anime le coeur de notre travail. Nous nous posons la question du pourquoi de la mortalité des PME et des difficultés rencontrées par ces entreprises. Pour des raisons de proximité, nous prenons le cas des PME de la région oranaise.  L’enquête réalisée a touché une quarantaine de PME de secteurs différents.MOTS-CLES: PME, Oran, approche qualitative, échec des PME

Neobična pristunost juvenilnih primjeraka vrste Synagrops japonicus u jugozapadnom Mediteranu

This paper reports additional records of the Indo-Pacific fish Synagrops japonicus (Doderlein, 1884) in Western Mediterranean. Twenty juveniles of this species ranging from 4 to 4.8 cm (TL) were caught in Annaba Bay, Algeria, using beach seine, in Summer of 2011 (9 specimens, 4 ≤ TL ≤ 4.6 cm) and 2012 (11 specimens, 4.2 ≤ TL ≤ 4.8 cm). Some hypotheses on the origin of this unusual presence are discussed.U ovom radu se navode dodatni nalazi vrste Synagrops japonicus (Doderlein, 1884) u zapadnom Mediteranu. Uhvaćeno je dvadeset juvenilnih primjeraka ove vrste u rasponu od 4 do 4,8 cm (TL) u Annaba zaljevu, Alžir, pomoću obalne mreže potegače, u ljeto 2011. godine (9 primjeraka, 4 ≤ TL ≤ 4,6 cm) i 2012. (11 primjeraka, 4.2 ≤ TL ≤ 4,8 cm). U radu su iznesene neke hipoteze o podrijetlu ove neobične prisutnosti

Étude numérique de l'effet d'air enrichie en oxygène sur les émissions de NOx dans un four de réchauffage (S03)

Ce travail s'inscrit dans le cadre d'une étude visant la réduction des émissions polluantes émises par les fours de réchauffage sidérurgique et l'optimisation des paramètres de fonctionnement des brûleurs industriels à flamme de diffusion. Dans le présent travail, on s'intéresse à l'influence de l'air enrichie en oxygène sur les émissions de NOx ainsi que sur les caractéristiques dynamique et thermique de l'écoulement. L'étude est menée sur un brûleur industriel à gaz de 250 kilowatt. Le calcul numérique a été effectué en utilisant le code commercial FLUENT, en utilisant le modèle de turbulence k-ɛ standard couplé au modèle de combustion turbulente ED (Eddy Dissipation). Le modèle de fonction de densité de probabilité PDF (6 espèces et 3 réactions) avec un modèle d'équilibre chimique. Les résultats obtenus pour un comburant considéré un mélange oxygène-air. La proportion volumique d'oxygène varie de 20 à 100%, montrent que les émissions de NOx dépendent de la composition du comburant

Experimental study on the effects of big particles physical characteristics on the hydraulic transport inside a horizontal pipe

This paper presents an experimental study of the physical characteristic effects of large particles on hydraulic transport in a horizontal pipe. The particles are spherical and are large with respect to the diameter of the pipe (8%, 10%, 16% and 25%). Experiments were done to test the important parameters in solid transport (pressure, velocity, etc.). As a result, the relationship between the pressure gradient forces and the mixture velocity was substantially different from the pure liquid flow. However, in a single-phase flow a monotonous behavior of the pressure drop curve is observed, and the curve of the solid particle flow attains its minimum at the critical velocity. The regimes are characterized with differential pressure measurements and visualizations

(Benzene­carbothio­amide-κS)­penta­carbonyl­tungsten(0)

The asymmetric unit of the title complex, [W(C7H7NS)(CO)5], comprises two independent mol­ecules. In each, the W atom is coordinated by five CO groups and the S atom of the benzencarbothioamide ligand in a distorted octa­hedral geometry. The crystal packing can be described as undulating layers of W(CO)5 and benzene­carbothio­amide parallel to (001). In the crystal, components are linked via inter­molecular N—H⋯O and C—H⋯O hydrogen bonds to form a dimeric chains along the [010] direction. Intra­molecular N—H⋯C inter­actions are also observed

(3RS,4SR)-Methyl 4-(2-chloro-5,8-di­methoxy­quinolin-3-yl)-1-phenyl­pyrrolidine-3-carboxyl­ate

The mol­ecule of the title compound, C23H23ClN2O4, contains a quinolyl unit linked to a functionalized pyrrolidine system with a 3,4-trans arrangement of the substituents. The unit cell contains two stereoisomers that have the absolute stereochemistry 3S,4R and 3R,4S. The pyrrolidine ring adopts a twist conformation with pseudo-rotation parameters P = 258.2 (3)° and τ(M) = 35.3 (1)°. The packing is stabilized by C—H⋯π inter­actions and offset π–π stacking (centroid-to-centroid distance = 3.849 Å, inter­planar distance = 3.293 Å and slippage = 1.994 Å) between phenyl rings, leading to a two-dimensional network

Massive X-ray screening reveals two allosteric drug binding sites of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous health problems and economical challenges for mankind. To date, no effective drug is available to directly treat the disease and prevent virus spreading. In a search for a drug against COVID-19, we have performed a massive X-ray crystallographic screen of repurposing drug libraries containing 5953 individual compounds against the SARS-CoV-2 main protease (Mpro), which is a potent drug target as it is essential for the virus replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds binding to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and five non-peptidic compounds showed antiviral activity at non-toxic concentrations. Interestingly, two compounds bind outside the active site to the native dimer interface in close proximity to the S1 binding pocket. Another compound binds in a cleft between the catalytic and dimerization domain of Mpro. Neither binding site is related to the enzymatic active site and both represent attractive targets for drug development against SARS-CoV-2. This X-ray screening approach thus has the potential to help deliver an approved drug on an accelerated time-scale for this and future pandemics

X-ray screening identifies active site and allosteric inhibitors of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous human suffering. To date, no effective drug is available to directly treat the disease. In a search for a drug against COVID-19, we have performed a high-throughput X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (M^(pro)), which is essential for viral replication. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds that bind to M^(pro). In subsequent cell-based viral reduction assays, one peptidomimetic and six non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2