Publications

In Algeria, Opuntia ficus-indica production is important. This seasonal fruit is a characteristic of arid and semiarid regions. Taking into account its high content in antioxidants, it has an excellent nutritional value. The aim of this research is the prickly pear morphological and physicochemical characterization study, which is widely present in the Arris (Batna, Algeria) area. The results of this experimental study are comparative to those of the same species from other world regions. The whole fruit weight is estimated to reach 63.38 g with a juice ratio of 71.42 %, a pH of 5.54, moisture of 89.3 % and a brix of 10.4 %. The quantitative amount of the phenolic compounds of the fruit revealed contents of 45.70 mg GAE / 100 g of MF for total polyphenols.

In this paper we have developed an algorithm of boron diffusion after thermal annealing in a highly doped polysilicon film. This algorithm takes into account electrically active point defects by associating some parameters such as boron solubility limit and diffusion coefficient. We have studied effect of annealing temperature in order to perform impact of this parameter on maximum depth diffusion of junction and maximum of concentration by analysis of Secondary Ion Mass Spectrometry (SIMS) profiles. In fact we have proposed numerical model based on Fick's equation, resolved by finite difference method under Matlab also we have simulated this phenomenon by Silvaco software.

The complexity of systems in the current process industry is conducive to the concerns of industrialists about the risks that may be inherent in these systems. Risk reduction measures should be considered and implemented to reduce the initial risk to an acceptable level. This is usually achieved by using a combination of systems that provide security, inter alia, Safety Instrumented Systems (SIS). The implementation of a SIS requires the determination of its Safety Integrity Level (SIL) which it must have in order to attain the tolerable risk. The standards IEC 61508 and 61511 provide a framework for the determination of SIL and propose different methods. The objective of this work consists in proposing an approach of allocation and optimization of the security barriers, using the methods of risk graph and LOPA (Layer Of Protection Analysis) In order to evaluate the performance of the safety measures put in place for the control of risks in a hydrocarbon storage station. A cost benefit analysis (CBA), as a decision support tool, is carried out to improve the safety level of the process studied.

This paper aim is to propose a radio transmission analysing method for the site survey of telemetry systems (e.g., SCADA: Supervisory Control And Data Acquisition), these systems are usually used to supervise remote process installations in large oil and gas fields. This method is presented over a software design and development which includes all radio propagation data and calculations, needed during the technical site survey phase of a telemetry system project execution. The approach is applied for the acquisition, control and online modeling of an oil collection pipeline network using a SCADA system.

The designed software we named "SCADA Radio Transmission," is to perform the radio propagation analysis. By introducing data (topographic coordinates, obstacles heights and characteristics data of the transmission equipment) it allows calculation of towers heights that ensure good radio clearance (Fresnel Zone), plot of the radio transmission link and to visulize results of the radio link budget. Complete calculations equations of this software are provided with detailed radio propagation analysis sample results of the studied oil collection pipeline network, to permit more comprehension for readers. The designed software role is to:

 

• –

  determine the correct height of the towers by inserting the topographical data of the field, thus providing a radio clearance of the Fresnel first ellipsoid;

• –

  Draw up, for the established link, a link budget including the received signal power as well as the margin against the reception threshold;

• –

  In addition, this software allows the adjustment of the pylons heights in order to rectify any diffraction, due to bad visibility hop.

 

A case study application of this software is presented for the data acquisition, control and online modeling of an oil collection pipeline network at Hassi Messaoud oilfield.

Stability of slurry trenches is an important issue during the construction of groundwater cutoff and diaphragm walls and, thus, has gradually drawn additional attention. With the aim of controlling the stability and collapse mechanism of slurry walls better, an analytical approach based on interactions between horizontal and vertical arching effects was conducted to estimate the stability factors for general and local stability of a slurry-supported trench panel in cohesionless soils. The results show that arching has certain characteristics that affect soil behavior near the trench, including directions of loading and unloading of soil, variation of active pressure coefficient on the sidewall interface, and a created downward load transfer mechanism. The trench stability depends on two types of safety factors; the first factor prevents sliding collapse (overall stability), and the second factor prevents collapse of the soil interface (local stability) because local interface instability triggers overall trench collapse in cohesionless soil. The solution was compared with field measurements and three-dimensional (3D) finite-element analyses (with the effect of the third dimension), which permitted study of the influence of the arch located in the third direction. The satisfactory correspondence validates this approach and shows that the 3D analytical analysis perfectly describes the phenomenon.

The experiments were led to study the effect of pretreatments and their duration on germination behavior of three Acacia species A. cyanophylla Lindl., A. farnesiana L. and A. decurrens Willd. by analyzing three parameters (GP: germination percentage; MGT: germination mean time (days) and GRI: germination rate index) for various times of incubation (5, 10 and 15 days) in Petri dishes. Pre-sowing treatment included immersion in concentrated sulphuric acid for 60, 90 and 120 minutes. The sowing in distilled water (Control) had no positive effect on the germination induction. Generally, the seed pretreatments were very useful to improve germination. Time of immersion significantly (P < 0.0001) affected GP, MGT and GRI in all species. Increasing the duration of sulphuric acid immersion (from 60 to 120 min) improved the germination percentages for A. cyanophylla and A. farnesiana seeds to (98% and 99%), respectively. However, increasing this duration had a negative effect on A. decurrens seed germination, reducing the final germination percentage from 97% at 60 minutes of immersion to 43% at 120 minutes.