On the third boundary value problem for parabolic equations in a non-regular domain of Rᴺ +1

In this paper, we look for sufficient conditions on the lateral surface of the domain and on the coefficients of the boundary conditions of a N−space dimensional linear parabolic equation, in order to obtain existence, uniqueness and maximal regularity of the solution in a Hilbertian anisotropic Sobolev space when the right hand side of the equation is in a Lebesgue space. This work is an extension of solvability results obtained for a second order parabolic equation, set in a non-regular domain of R 3 obtained in [1], to the case where the domain is cylindrical, not with respect to the time variable, but with respect to N space variables, N > 1.Publisher's Versio

Prvi nalaz turčina Peristedion cataphractum (Linnaeus, 1758) (Scorpaenoidei: Peristediidae) uz sjeverozapadnu obalu Alžira

African Armoured searobin, Peristedion cataphractum, (Peristediidae), is recorded for the first time from the Algerian Northwest coast of the Mediterranean Sea, Oran (35°50’N, 0°31’W) at 30-40 depth. Only two specimens were captured. Fish individuals were identified and morphometric measurements were recorded.Turčin, Peristedion cataphractum (Peristediidae) po prvi put je zabilježen sa alžirske sjeveroza- padne obale Sredozemnog mora, Oran (35°50’N, 0°31’W) na dubini 30-40 m. Ulovjena su samo dva primjerka. Identificirane su jedinke riba i zabilježeni su prvi morfometri- jski podaci. Identificirane su jedinke riba i zabilježeni su prvi morfometrijski podaci

THE FIRST RECORD OF PURPURICENUS DESFONTAINII (FABRICIUS, 1793) (COLEOPTERA: CERAMBYCIDAE) FROM NORTHWESTERN ALGERIA AND ITS SEXUAL DIMORPHISM

Although the cerambycid fauna of Algeria has received a great deal of attention so far, additional collecting has produced one species that was not previously recorded in northwestern Algeria. Purpuricenus desfontainii (Fabricius, 1793) is recorded for the first time in northwestern Algeria from the Msila Forest. In May 2019, 50 males and 50 females of P. desfontainii were collected by hand on the flowers and stems of milk thistle. External morphological measurements were made to find possible sexual dimorphism in P. desfontainii. Results indicated that there are significant differences between males and females in the lengths of antennae and of flagellomeres. Moreover, males and females significantly differ in total body length and width, head width, ratio of antennal length to total body length, and elytral length and width

Study of the first boundary value problem for a fourth order parabolic equation in a nonregular domain of

This paper is concerned with the extension of solvability results obtained for a fourth order parabolic equation, set in a nonregular domain of R3 obtained in [1], to the case where the domain is cylindrical, not with respect to the time variable, but with respect to N space variables, N > 1. More precisely, we determine optimal conditions on the shape of the boundary of a (N + 1)-dimensional domain, N > 1, under which the solution is regular.Publisher's Versio

Effect of spatial correlation on the performances of modernized GPS and Galileo in relative positioning

In the context of processing GNSS (Global Navigation Satellite System) data, it is known that the estimation of the ionospheric delays decreases the strength of the observation model and makes significant the time required to fix the ambiguities namely in case of long baselines. However, considering the double-differenced (DD) ionospheric delays as stochastic quantities, the redundancy in this case increases and leads to the reduction of time of fixing the ambiguities. The approach developed in the present paper makes two considerations: 1) the DD ionospheric delays are assumed as stochastic quantities and, 2) the spatial correlation of errors is accounted for based on a simple model of correlation. A simulation is made and aims to study the effect of these two mentioned considerations on the performances of the three multifrequency GNSSs; modernized GPS, Galileo and BDS which are not yet in full capability. For each GNSS, dual-frequency combinations of frequencies as well as triple-frequency combination are investigated in the simulation. The performances studied include: the time to fix the ambiguities with high success rate and the precision of coordinates in static relative positioning with varying baseline length. A method is developed to derive what we call the spatial correlation model which approximately gives the covariance between the individual errors belonging to two stations. Furthermore, the stochastic models that follow from accounting and neglecting the spatial correlation are developed. The LAMBDA (Least-squares Ambiguity Decorrelation Adjustment) method is implemented for ambiguity decorrelation. The results show that the time to fix the ambiguities caused by accounting the spatial correlation is less than the time of fix without the spatial correlation. Also, a slight superiority of Galileo in terms of performances is seen compared to the other GNSS. For all the dualfrequency combinations investigated, when processing a baseline length of 500 km with accounted spatial correlation, the time needed to successfully fix the ambiguities lies between 5 and 9 min, whereas it becomes only between 2.5 and 3 min for all the triple-frequency combinations, this is with a sampling time of 5 s. In addition, for all different combinations, the coordinates precision is less than 8 mm even for 500 km. We think that these high performances result from: 1) the precise codes of future GNSS signals, 2) the high redundancy in the observations equation and, 3) taking into account the spatial correlation in the definition of the stochastic model

Effect of seawater irrigation on germination and seedling growth of Carob tree (Ceratonia siliqua L.) from Gouraya National park (Béjaïa, Algeria)

The carob tree (Ceratonia siliqua L.) is an important component of the Mediterranean vegetation and its cultivation is important environmentally and economically.  It is also an interesting leguminous species for afforestation-reforestation. In this study, carob seeds collected in a representative area of the Mediterranean basin at the national park of Gouraya (Béjaïa, Algeria), were subjected to germination tests under Mediterranean seawater (SW) irrigation of different concentrations (0, 10, 30, 50 and 100% SW) for 15-day period. Before germination tests, a 20 min pre-treatment with 96% sulphuric acid was necessary to overcome seed coat dormancy which does not permit germination. Results showed that the seeds of C. siliqua were able to germinate at different seawater concentration, except for 50% SW and 100% SW which resulted in total inhibition of germination. The maximum number of C. siliqua seed germination of 100% FGP (final germination percentage) appeared at 0% SW and 10% SW. Only 35.5% of the seeds have germinated in 30% SW. Ungerminated seeds of C. siliqua from different SW treatments showed medium germination recovery (FGPRecov) of 39.9% at 50% SW and low recovery of 18.2% at 100% SW when transferred to distilled water after 15 day-period. Seedlings length and seedling fresh and dry weight were significantly (P < 0.001) decreased with increasing SW concentrations. Seedling water content remained constant in 10% SW in comparison with the control, while it decreased very slightly in 30% SW. These findings may serve as useful information for C. siliqua habitat establishment and afforestation-reforestation programs in coastal sites and for exploiting seawater in the area

Contribution the Failure Mode Analysis and Criticality Evaluation Method to the Rehabilitation of Cork Oak (Quercus suber) Forests in Forest Massif of Tlemcen (Algeria)

The controling of forest sustainability and preforest ecosystems in achieving stability of forest ecosystem require the identification of biophysical indicators, anthropological, and technological. The significant degradation of Quercus suber formations in forest massif of Tlemcen (Algeria) are imposed by both climatic factors, the fires, the overgrazing land, anthropogenic aggression as well as by ineffective management. The making of a reference matrix would make possibility the identification of probable hazards and risks. This study aimed to identify the understanding how the mode of operation of a system to identify failures and treat, and the create the intention of eliminating or minimizing the associated risks. This matrix will consist of relevant indicators which easy guide to estimate and following the understanding of the forest degradation process in Algeria. The FMECA method allowed identification of 20 main defective targets which be grouped into 3 categories namely: technical, ecological, organizational, and facilitate of remediation. Each error can be scored and action plans can be prioritized, allowing different with all forest sector players to better understand the degradation of this natural space in order to implement efficient and appropriate remediation plans. &nbsp