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Bioerosion and encrustation on Pliocene oysters of Lower Chelif basin (NW Algeria).- Two species of oysters (Hyotissa hyotis ; Ostrea lamellosa) have been identified in the Pliocene beds of the lower Chelif basin. They show a heterogeneous distribution between the different levels studied with a random distribution. The shells are almost completely disarticulated and are rarely fragmented. Seven ichnotaxa corresponding to bioerosion structures have been identified (Entobia, Trypanites, Maeandropolydora, Caulostrepsis, Oichnus, Gastrochaenolites and Rogerella), with a dominance of Entobia, Caulostrepsis and Trypanites. Rare traces of encrustation of bivalves and juvenile oysters, barnacles and bryozoans, are observed in particular on the external face of the left valves.The material undergoes multiple reworkings resulting in bio-erosion and bio-encrustation on either side of the valves. Most of the identified ichnotaxa were preserved post-mortem (hence episodes of eroded barnacle encrustations invaded by punctures, notably Entobia), with rare examples of preservation of still-living individuals, represented by Entobia and Caulostrepsis. The settling of oyster levels in both regions indicates a foreshore (estran) environment with medium energy and a short exposure time on the bottom, characterizing a regression phase.

Bu yazıda, her ikisini de kullanan bağımsız bir hibrit güç sistemi önerilmiştir: fotovoltaik jeneratör (PVG) ve Sabit Mıknatıslı Senkron Jeneratör (PMSG), DC veriyoluna bağlı lityum tipi bir batarya ile entegre edilmiştir. Genel sistemin performansının ve güvenilirliğinin iyileştirilmesi garanti edilir. Bu amaçla öncelikle Perturb ve Observe (P&O) yöntemi ve Bulanık Mantık Kontrolü (FLC) yaklaşımı gibi iki MPPT tekniği kullanılarak PVG sisteminin verimliliği arttırılabilir. Evrim, doğal seleksiyon ve genetik mutasyon ilkelerini kullanan Genetik Algoritmalar (ga'lar) daha sonra FLC kazanımlarının ayarlanmasındaki zorlukları ele almak için tanıtılır. Stabilite ve enerji depolama sağlamak için bir lityum-iyon pil modeli sunulmuştur. Ayrıca, pmsg'ye dayalı rüzgar enerjisi dönüşüm sistemi (WECS) modeli sunulmuştur. Bu nedenle, gradyan yöntemiyle kontrol, jeneratörün teslim edilen gücüne ve mekanik hızına dayalı bir MPPT tasarlamaya izin verir. Her iki kaynak da, Uzay Vektör Modülasyonu (SVM) tekniği ile kontrol edilen iki seviyeli bir voltaj kaynağı invertörü vasıtasıyla şebekeye bağlanır. Son olarak, MATLAB / SİMULİNK yazılımı kullanılarak elde edilen simülasyon sonuçları, önerilen kontrolörler kullanıldığında açıkça ortaya çıkan ve bağımsız hibrit sistemin performansına ışık tutan yüksek performansla önerilen kontrol stratejilerinin etkinliğini kanıtlamıştır., In this paper, a stand-alone hybrid power system has been proposed using both: photovoltaic generator (PVG) and permanent magnets synchronous generator (PMSG), integrated with a lithium-type battery connected to the DC bus. The improvement of performance and reliability of the overall system are guaranteed. For this aim, the efficiency of the PVG system can be enhanced firstly by using two MPPT's techniques, such as the Perturb and Observe (P&O) method and the Fuzzy Logic Control (FLC) approach. The Genetic Algorithms (GA’s), using the principles of evolution, natural selection, and genetic mutation, are then introduced to address difficulties in the adjustment of the FLC gains. A lithium-ion battery model is presented to ensure stability and energy storage. Furthermore, the model of the wind energy conversion system (WECS) based on PMSG is presented. Hence, the control by the gradient method, allowing designing an MPPT based on the delivered power and mechanical speed of the generator. Both sources are connected to the grid via a two-level voltage source inverter controlled by Space Vector Modulation (SVM) technique. Finally, simulation results obtained using MATLAB / SIMULINK software proved the effectiveness of proposed control strategies with high performance which is manifested clearly when the suggested controllers employed and shed light on the performance of the stand-alone hybrid system.

Resume Dans la partie sud-est des Monts des Ksour (Algerie), une etude stratigraphique, paleontologique et sedimentologique a ete effectuee sur les couches rouges qui affleurent sur la rive gauche de l’Oued Tafarahit. Il s’agit d’une serie continentale detritique granodecroissante composee de microconglomerats, de gres et d’argiles attribuees au Cenozoique sans preuve paleontologique. Les niveaux argileux ont livre des charophytes [Peckichara atlasensis, Maedleriella cristellata, Nitellopsis (Tectochara) thaleri, Grovesichara sp. et Lamprothamnium papulosum] et des ostracodes (Neocyprideis meguerchiensis, Cyprinotus? sp et Herpetocypris? sp). Cette flore et cette faune permettent d’assigner la Formation Detritique de l’Oued Tafarahit a l’Ypresien inferieur et de confirmer l’existence d’une relation paleobiogeographique etroite entre l’Afrique du Nord et l’Europe du Sud pendant l’Eocene inferieur. La sedimentologie et les microfossiles suggerent un depot dans un environnement fluviatile. Les ostracodes sont typiques des milieux dulcaquicoles a euryhalins. Les formes dulcaquicoles (Cyprinotus? sp. et Herpetocypris? sp.) correspondent probablement a des phases de dessalure lors des periodes de crue. En revanche, l’espece d’eau saumâtre (Neocyprideis meguerchiensis) est caracteristique des phases de salure lors des periodes d’etiage.

Environmental decontamination is a major challenge due to the rapid growth of industrial and technological development, requiring an important consumption of fossil energies. Nowadays, a new way to...

In this paper, an experimental study on the effects of the hydraulic diameter on heat transfer and fluid flow characteristics in fully developed turbulent flow in a rectangular channel with one wall (upper) exposed to the heat flux is presented. The hydraulic diameter of the channel was varied by using a wooden block mounted on the bottom wall of the channel. The block to channel height ratio, Hb/H was kept at 0.6, the block to channel length ratio L b /L was kept at 1, and the block to channel width ratio, B b /B was varied from 0 to 0.6. Four cases were investigated in this study for Reynolds number ranging from 6,000 to 20,000. The results of this investigation demonstrate that, the pressure drop is increased with decreasing hydraulic diameter and heat transfer coefficient is decreased with decreasing hydraulic diameter.

Resume Le Cretace superieur de la partie orientale des Monts des Ksour (Atlas saharien, Algerie) est classiquement subdivise en trois formations lithostratigraphiques fossiliferes : El Rhelida (Cenomanien inferieur), Mdaouer (Cenomanien inferieur-moyen) et Rhoundjaia (Cenomanien superieur-Turonien inferieur). La partie occidentale des Monts des Ksour, moins documentee et peu etudiee a ce jour, fait l’objet ici d’une etude sedimentologique et paleontologique detaillee. A Hassi Djeifa (region de Forthassa), le Cretace superieur est represente par la partie superieure de la Formation de Mdaouer puis par la Formation de Rhoundjaia. Les depots attribues a la Formation de Mdaouer sont constitues de marnes rougeâtres ou verdâtres, intercalees de calcaires bio-lamines, de calcaires bioclastiques a gasteropodes et bivalves et de gres. Les niveaux marneux ont livre une faune composee d’ostracodes (Damonella spp., Ilyocypris? sp., Cypridea sp. et Paracypria? sp.), de selaciens (Mafdetia tibniensis et Baharipristis bastetiae) et de pycnodontiformes. Les deux especes de selaciens (Ordre des Rajiformes) n’etaient jusqu’ici connues que du Cenomanien inferieur d’Egypte. Les donnees sedimentologiques et paleontologiques suggerent un âge cenomanien inferieur probable pour les depots etudies et indiquent un paleo-environnement de plaine cotiere continuellement influencee par l’action de marees.

A computational study of heat transfer augmentation in a rectangular channel having rectangular ribs on the upper wall and triangular baffles/fins on the opposite wall by using Computational Fluid Dynamics (CFD) software (ANSYS FLUENT R18.2) is presented in the paper. Effects of Reynolds number on both the flow variables (velocity, pressure, turbulent kinetic energy) and heat transfer variables (temperature and heat transfer coefficient) for three different types of ribs/fins configurations were investigated. The three cases of study are: 1. Ribs Top Smooth Bottom Channel; (RTSBC), 2. Smooth Top Fin Bottom Wall (STFBC) and 3. Ribs Top Fin Bottom Channel (RTFBC). The computation based on finite volume with SIMPLE algorithm have been conducted for air flow in terms of Reynolds number ranging from 4000-20000 has been carried out with SST k- turbulence model. It has been found that for the Case 1, ribs have negligible effect on heat transfer augmentation and pressure drop, unlike Case 2 where a moderate effect is observed. Maximum values for Nusselt number and friction factor are obtained for Ribs Top Fin Bottom Channel (RTFBC).

Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency.

In this paper computational and experimental work is presented on the forced-air precooling process. The process is a popular method normally used to minimize the post-harvest losses and to extend the shelf-life of a wide range of horticultural produce. In the method, cold air is forced by a fan to pass through vents and then around produce packed in a crate. During the cooling process, produce exposed to high air velocities are overcooled while others exposed to low air velocities are undercooled. This non-uniformity of airflow is a major problem and it is directly related to improper vents geometries in the crates. Therefore the correct venting is necessary to achieve rapid and uniform cooling of produce. However, package strength also needs to be taken into consideration. The influence of vent shapes on the cooling uniformity can be assessed by numerical and experimental means. This study therefore provides a viable means through numerical and experimental investigation to find the effect of variation in the size and location of vents in the crate including the effects of variation of inlet velocity on the airflow and heat transfer distribution within a crate filled with spherically shaped produce such as a plum. This work is, finally, an attempt to enhance the precooling process for spherically shaped produce.

In this paper, Slepian-Bangs-type formulas for Complex Elliptically Symmetric distributed (CES) data vectors in the presence of model misspecification are provided. The basic Slepian-Bangs (SB) formula has been introduced in the array processing literature as a convenient and compact representation of the Fisher Information Matrix (FIM) for parameter estimation under (parametric) Gaussian data model. Extending recent results on this topic, in this paper, we provide a new generalization of the classical SB formula to parametric estimation problems involving non-Gaussian, heavy-tailed, CES distributed data in the presence of model misspecification. Moreover, we show that our proposed formulas encompass the special cases of the SB formula for CES distributions under perfect model specification, the SB formulas in the presence of misspecified Gaussian models, and the SB formula for the estimation of the scatter matrix of a set of CES distributed data under misspecification of the density generator.

Atomic layer deposition (ALD), a gas-phase thin film deposition technique based on repeated, self-terminating gas-solid reactions, has become the method of choice in semiconductor manufacturing and many other technological areas for depositing thin conformal inorganic material layers for various applications. ALD has been discovered and developed independently, at least twice, under different names: atomic layer epitaxy (ALE) and molecular layering. ALE, dating back to 1974 in Finland, has been commonly known as the origin of ALD, while work done since the 1960s in the Soviet Union under the name "molecular layering" (and sometimes other names) has remained much less known. The virtual project on the history of ALD (VPHA) is a volunteer-based effort with open participation, set up to make the early days of ALD more transparent. In VPHA, started in July 2013, the target is to list, read and comment on all early ALD academic and patent literature up to 1986. VPHA has resulted in two essays and several presentations at international conferences. This paper, based on a poster presentation at the 16th International Conference on Atomic Layer Deposition in Dublin, Ireland, 2016, presents a recommended reading list of early ALD publications, created collectively by the VPHA participants through voting. The list contains 22 publications from Finland, Japan, Soviet Union, United Kingdom, and United States. Up to now, a balanced overview regarding the early history of ALD has been missing; the current list is an attempt to remedy this deficiency. (C) 2016 Author(s). Funding Agencies|Finnish Centre of Excellence in Atomic Layer Deposition by Academy of Finland; COST (European Cooperation in Science and Technology) [MP1402]

In this paper, we address the problem of detecting a range-spread target embedded in a non-Gaussian clutter with unknown covariance matrix and without using secondary data. We propose a new autoregressive method based on the generalized likelihood ratio test (GLRT) that requires only the cells under test. This method is used to derive two new detectors, corresponding to two different scenarios: a) when all range cells contain the target and share the same covariance matrix (homogeneous clutter), b) when different covariance matrices for different range cells are assumed (heterogeneous clutter). The proposed method is shown to outperform the state of the art on various scenarios in terms of false alarm probability and detection probability, especially in critical scenario as small data records or low number of secondary data. Finally, it exhibits the desired constant false alarm rate (CFAR) property.

The purpose of this work is to highlight the chemical kinetics in plasma of pure oxygen. A comprehensive model of ozone generation in wire-to-cylinder negative corona discharge is presented. The model combines the physical processes in the discharge with the chemistry of ozone formation. It is based on an extensive reaction scheme including the major electronic and ionic processes. The importance of excited atomic and molecular states is demonstrated. The obtained results show clearly that the surface material affect quite well the ozone decomposition.