Purification,structural data and biological properties of polysaccharide from Prunus amygdalus gum

This work demonstrates the efficiency of almond gum polysaccharides (AGPs) as bioactive compounds. AGPs were first extracted using H₂O₂, in the presence of NaOH, at different times and temperatures. The optimal extraction conditions were 4% H₂O₂ and 2 N NaOH, for 7 h at 50 °C, leading to an extraction yield of 58.2% (w/w). After a purification step, the retained AGPs were characterised using high‐performance liquid chromatography showing a molecular weight of 99.3 kDa. The monosaccharide composition of AGPs were assessed using gas chromatography–mass spectrometry. AGPs were found to be a complex heteropolysaccharide with a repeating unit mainly composed of galactose, arabinose, xylose, mannose, rhamnose, and glucuronic acid with the respective ratios: 45:26:7:10:1:11. The acidic nature of the polysaccharide is due to the presence of glucuronic acid. Total antioxidant activity, free radical‐scavenging activity and reducing power assay of AGPs were investigated. The obtained results showed high antioxidant activities of AGPs. Furthermore, beyond 60 mg mL^?1, AGPs exhibited bacterial growth inhibition for five pathogenic strains: Escherichia coli, Staphylococcus aureus, Enterococcus feacalis, Pseudomonas aeruginosa and Salmonella typhimurium.     

Effects of almond gum as texture and sensory quality improver in wheat bread

The aim of this work was to investigate the effect of almond gum as dietary fibre source in enhancing the wheat bread quality. Different amounts of almond gum (2%, 5% and 10% (w/w)) were used in bread formulation. The volume, texture, crust and crumb colour, as well as the sensorial properties, were evaluated and compared to control (without almond gum). The obtained results showed that almond gum addition enhanced significantly the volume of bread. The highest volume was obtained using 2% almond gum concentration with 23.6% increase, compared to control. Using almond gum in bread formulation improved considerably its texture with a notable decrease in hardness by 61.7% and 42.5% when using 2% and 5% almond gum, respectively. The sensory analysis scores showed that the better overall acceptability was found for breads supplemented with 2% almond gum, as compared to control and breads supplemented with 5% or 10% almond gum.     

Optimising operating conditions in ultrafiltration fouling of pomegranate juice by response surface methodology

The resistance‐in‐series model was used to analyse flux behaviour, which involved the resistances of membrane itself, the fouling and solute concentration polarisation. Response surface methodology was used to establish the relationships between operating parameters and ultrafiltration (UF) efficiency and thus to determine optimal conditions. Experiments were performed according to Box–Behnken design by changing the levels of three parameters, namely transmembrane pressure, feed flow rate and temperature. The fitted mathematical models allowed us to plot isoresponse curves. It was shown that the resistance due to solute concentration polarisation (R_cp) dominated the flux decline (40–74%). The fouling resistance (R_f) varied from 12 to 46%. To optimise simultaneously the three responses studied (R_f, R_cp and permeate limit flux), we applied the desirability function approach which allowed us to determine the best acceptable compromise. The selected UF conditions of the compromise were as follows: three bars, 0.95 L min^?1 and 30 °C. Optimal values of R_f, R_cp and permeate limit flux were equal to 18%, 72% and 19 L h^?1 m^?2, respectively.     

Estimation of the atmospheric corrosion on metal containers in industrial waste disposal

Solid industrial waste are often stored in metal containers filled with concrete, and placed in well-aerated warehouses. Depending on meteorological conditions, atmospheric corrosion can induce severe material damages to the metal casing, and this damage has to be predicted to achieve safe storage. This work provides a first estimation of the corrosivity of the local atmosphere adjacent to the walls of the container through a realistic modeling of heat transfer phenomena which was developed for this purpose. Subsequent simulations of condensation/evaporation of the water vapor in the atmosphere were carried out. Atmospheric corrosion rates and material losses are easily deduced. For handling realistic data and comparison, two different meteorological contexts were chosen: (1) an oceanic and damp atmosphere and (2) a drier storage location. Some conclusions were also made for the storage configuration in order to reduce the extent of corrosion phenomena.     

Mechanical Properties of Dry-Pressed Ceramic Green Products: The Effect of the Binder

The strength of alumina green samples prepared by uniaxial pressing of powders spray-dried with two binders such as poly(ethylene glycol) or poly(vinyl alcohol) is discussed in terms of (i) the adhesive properties of the polymer-rich external layer of spray-dried granules and (ii) the mechanical properties of this layer. A transition from intra- to intergranular fracture is observed when the glass transition temperature of the binder increases. The influence of the binder on the defect size distribution in the green products is investigated using the classical Weibull statistics.     

Impact of surface hardening treatment generated by shot peening on the fatigue life of brass alloy

Brass alloy is widely used because of some attractive properties such as high electrical and thermal conductivity. But its fatigue performance after surface treatment is not very well explored in literature. Thus, in the present work, particular emphasis was given to the influence of surface treatment by shot peening on the fatigue life of brass alloy, throughout surface roughness and microstructural evolution. Fatigue tests were performed on unpeened, peened and peened then polished specimens. Various times of surface hardening treatment as 30, 60 and 120 min were considered. Experimental results reveal that the fatigue life of peened brass alloy decrease for all studied hardening treatment conditions. Surface roughness and microstructural properties showed large sensitivity to the shot peening process of brass alloy.     

Impact of Treated Wastewater Reuse on Agriculture and Aquifer Recharge in a Coastal Area: Korba Case Study

Treated wastewater (TWW) reuse has increasingly been integrated in the planning and development of water resources in Tunisia. The present study aimed the evaluation of the environmental and health impact that would have the reuse of TWW for crops direct irrigation or for the recharge of the local aquifer in Korba (Tunisia). For this purpose water analyses were carried on the TWW intended for the aquifer recharge and on underground water of this area. As for underground water before recharge, no contamination by organic matter or heavy metals is shown but high salinity, nitrate, potassium and chloride concentrations are detected. The bacteriological analyses show the occurrence of faecal streptococcus, thermo-tolerant coliforms, total coliforms and E coli, but absence of salmonella. These results indicate that this water is not suitable for irrigation worse still for drinking purpose. The monitoring of TWW pollutants has demonstrated that oxygen demands (COD and BOD) do not exceed the Tunisian standards for TWW used in agriculture (NT 106.03) except for August when samples reach high values (COD = 139 mg O₂ L^− 1, BOD = 34). It is also the case for temperature, electrical conductivity (EC), salinity and pH. Heavy metal concentrations are under the detection limit. The determination of nutrients shows relatively low concentrations of nitrates, nitrites and orthophosphate (the maxima in mg L^− 1 are respectively 6.6, 5.6 and 0.92) whereas the potassium levels are high (up to 48.8 mg L^− 1) and the ammonia levels very high, reaching 60.6 mg L^− 1. As for bacteriological pollution, while no salmonella and intestinal nematods are detected, high concentrations of total coliforms, thermo-tolerant coliforms, faecal streptococci and E. coli are analysed. Consequently, the better use of TWW in this region would be the use of infiltration basins for the recharge of the deteriorated aquifer by TWW. It would give the opportunity to better the quality of the TWW reaching the groundwater by an additional treatment for bacteriological and suspended solid (TSS) contaminants while being an alternative water for the aquifer recharge and a coastal barrier against seawater intrusion.     

Scalable mpNoC for massively parallel systems – Design and implementation on FPGA

The high chip-level integration enables the implementation of large-scale parallel processing architectures with 64 and more processing nodes on a single chip or on an FPGA device. These parallel systems require a cost-effective yet high-performance interconnection scheme to provide the needed communications between processors. The massively parallel Network on Chip (mpNoC) was proposed to address the demand for parallel irregular communications for massively parallel processing System on Chip (mppSoC). Targeting FPGA-based design, an efficient mpNoC low level RTL implementation is proposed taking into account design constraints. The proposed network is designed as an FPGA based Intellectual Property (IP) able to be configured in different communication modes. It can communicate between processors and also perform parallel I/O data transfer which is clearly a key issue in an SIMD system. The mpNoC RTL implementation presents good performances in terms of area, throughput and power consumption which are important metrics targeting an on chip implementation. mpNoC is a flexible architecture that is suitable for use in FPGA-based parallel systems. This paper introduces the basic mppSoC architecture. It mainly focuses on the mpNoC flexible IP based design and its implementation on FPGA. The integration of mpNoC in mppSoC is also described. Implementation results on a Stratix II FPGA device are given for three data-parallel applications ran on mppSoC. The obtained good performances justify the effectiveness of the proposed parallel network. It is shown that the mpNoC is a lightweight parallel network making it suitable for both small as well as large FPGA-based parallel systems.