Performance Analysis of Different Grid-Connected PV technologies under Fez weather conditions

The main objective of this study is to compare the one-year performance of 5.94 KWp grid- connected PV array systems, consisting of three types of mono-Si (2.04KWp), poly-Si (2,04KWp) and a-Si (1,86KWp) photovoltaic solar panels, installed on the roof of the Faculty of Sciences Dhar El Mahraz in Fez. The study is based on data collected in 2017 on energy production. The performance elements evaluated monthly and annually include: energy output, system efficiency, reference yield, final yield, performance ratio, annual capacity factor. The results show that poly-Si technology has the best performance. A comparison between PV Production in different locations in the world and will presented, also we can conclude that Northern Morocco is a good region for PV production.

On local behavior of one class of inverse mappings

As is known, the local behavior of maps is one of the most important problems of analysis. This, in particular, relates to the study of mappings with bounded and finite distortion, which have been actively studied recently. As for this work, here we solve the problem of the behavior of maps, the inverse of which satisfies the Poletsky inequality. The main result is the statement about the equicontinuity of the indicated mappings inside the domain in the case when the majorant corresponding to the distortion of the module under the mapping is integrable in the original domain. It should be emphasized that the proof of this result is largely geometric, at the same time, it uses only the conditions of boundedness of the direct and mapped domains and does not involve any requirements on their boundaries. The study of families of mappings inverse to a given class may turn out to be trivial if we are talking about quasiconformal mappings. In the latter case, we do not go beyond the limits of the class under study in the transition to inverse maps. Nevertheless, when studying mappings with unbounded characteristic, this question is quite substantial, as simple examples of the corresponding classes show. The idea of the proof of the main result is based on the fact that the inner points of an arbitrary domain are weakly flat. The last statement can be called the Väisälä lemma, which was established in his monograph and related to families of curves joining two continua between the plates of a spherical condenser. The proof is also based on the fact that the module of families of curves joining two converging continua in a good domain must tend to infinity. In this case, the neighborhood of some inner point of the mapped domain serves as ''good'' region, in which we check the equicontinuity of the inverse family of maps. The results of this article are applicable to many other classes of mappings such as mappings with a finite distortion in the sense of Iwaniec, Sobolev classes on the plane and in space, and so on.

Flaw Quantification in Colmonoy Overlays Using Immersion Ultrasonic Testing

Corrosion, wear and galling resistance under high temperature service conditions are highly essential in nuclear components such as grid plate and diverse safety rod drive mechanism. In order to protect the components from these worst service conditions, hard facing alloys like colmonoy are overlaid on the nuclear components using plasma transfer arc and Gas Tungsten Arc Deposition techniques. Typical defects that occurred during deposition include lack of bonding between substrate and overlay, cracks and porosities. Hence the characterization of such defects is highly essential before using it for the intended application. Conventionally radiography, liquid penetrant testing and ultrasonic testing are used. Radiography cannot detect debonds which are parallel to the surface of the specimen. Though liquid penetrant testing is used for detecting surface cracks, ultrasonic testing could be effectively used in order to characterize highly planar defects which are parallel to the surface. This paper highlights the successful application of immersion ultrasonic testing for characterization of colmonoy overlays. The sample consisted of Colmonoy coating (4-5 mm) on a 316 LN substrate. Ultrasonic examination was carried out using the Immersion Ultrasonic flaw detector. Typical A scans of good region and debonded regions were considered and compared in order to predict the actual location of the defect. In addition B and C scans were also considered for exact characterisation of the defects. Results clearly indicated the superior defect detectability by the use of immersion ultrasonic testing on colmonoy overlays.

3-Point Block Methods for Direct Integration of General Second-Order Ordinary Differential Equations

A Multistep collocation techniques is used in this paper to develop a 3-point explicit and implicit block methods, which are suitable for generating solutions of the general second-order ordinary differential equations of the form . The derivation of both explicit and implicit block schemes is given for the purpose of comparison of results. The Stability and Convergence of the individual methods of the block schemes are investigated, and the methods are found to be 0-stable with good region of absolute stability. The 3-point block schemes derived are tested on standard mechanical problems, and it is shown that the implicit block methods are superior to the explicit ones in terms of accuracy.

Compartments, wingless and engrailed: patterning the ventral epidermis of Drosophila embryos

Recent experiments on the wing disc of Drosophila have shown that cells at the interface between the anterior and posterior compartments drive pattern formation by becoming the source of a morphogen. Here we ask whether this model applies to the ventral embryonic epidermis. First, we show that interfaces between posterior (engrailed ON) and anterior (engrailed OFF) cells are required for pattern formation. Second, we provide evidence that Wingless could play the role of the morphogen, at least within part of the segmental pattern. We looked at the cuticular structures that develop after different levels of uniform Wingless activity are added back to unsegmented embryos (wingless- engrailed-). Because it is rich in landmarks, the T1 segment is a good region to analyse. There, we find that the cuticle formed depends on the amount of added Wingless activity. For example, a high concentration of Wingless gives the cuticle elements normally found near the top of the presumed gradient. Unsegmented embryos are much shorter than wild type. If Wingless activity is added in stripes, the embryos are longer than if it is added uniformly. We suggest that the Wingless gradient landscape affects the size of the embryo, so that steep slopes would allow cells to survive and divide, while an even distribution of morphogen would promote cell death. Supporting the hypothesis that Wingless acts as a morphogen, we find that these stripes affect, at a distance, the type of cuticle formed and the planar polarity of the cells.