ESSENTIAL OIL COMPOSITION OF SALVIA VERBENACA L. GROWING WILD IN TUNISIA

The essential oil of aerial parts of Salvia verbenaca L., collected in three different locations in Tunisia, were obtained by hydrodistillation and analyzed by gas chromatography (GC) and GC–mass spectrometry. The oil yields of dried plants (w/w) were 0.09, 0.10 and 0.12% in Sabelet Ben Ammar, Sers and Somaa, respectively. Seventy-seven compounds were identified. The monoterpene hydrocarbons and oxygenated sesquiterpenes had the highest contributions. The major constituents in Sabelet Ben Ammar were viridiflorol (21.8%), camphene (17.6%), methyl eugenol (9.4%) and β-caryophyllene (7.1%), while those of essential oil collected from Somaa, were tricyclene (18.8%), nonane (10.3%), methyl eugenol (7.7%) and terpinolene (7.3%). In samples collected from Sers, essential oil consists mainly of (Z)-β-ocimene (29.5%), β-phellandrene (8.2%), β-thujone (7.9%) and α-pinene (5.5%).

PRACTICAL APPLICATIONS

In this study, it has been found that the oils of wild-growing Salvia verbenaca L. in Tunisia are rich in oxygenated sesquiterpenes and monoterpene hydrocarbons with great economical values. The plant family Labiatae contains several species with potential therapeutic activity due to their essential oils. Pharmacology, pharmaceutical botany, medical and clinical microbiology, phytopathology and food preservation are some fields in which essential oils can be applied. Many Salvia spp. are used as herbal tea and for food flavoring, as well as in cosmetics, perfumery and the pharmaceutical industry. It has shown that essential oil of S. verbenaca have strong antibacterial, antioxidant, antifungal, anti-inflammatory activities and peripheral analgesic properties.     

Evaluation of four high-protein rice-soy snack formulations

Four different formulations of rice-soy snack containing 4.5%, 9.0%, 13.5%, and 18.0% full-fat soy flour (FFSF) were evaluated for their nutritional values and acceptance. Protein content increased from 9.54% to 15.44% and chemical scores of the snacks from 86 to 100 but there was no difference in Net Protein Utilization although values were higher in snacks than in either rice or FFSF alone. All formulations were well accepted but at the highest level of FFSF (18%) acceptability was significantly ( P <0.01) reduced.     

The use of carbon dioxide in the processing and packaging of milk and dairy products: A review

The upswing in consumer demand for fresh and high quality preservative‐free foods has led to the development of modified atmosphere packaging (MAP). Increasingly, MAP is being used with high carbon dioxide (CO₂) concentration as well as CO₂/N₂ gas mixes. Modified atmosphere packaging or ‘gas flushing’ as it is also known is an increasingly popular technique used to extend the shelf life (both quality and safety) of a number of dairy products. Carbon dioxide is an active constituent of MAP, naturally present in freshly drawn raw milk. Addition of CO₂ to raw milk or flushing the package headspace has proved to be a simple and cost‐effective method, depending upon the initial microbiological quality of the food product. Carbon dioxide addition through MAP or direct injection as an economically affordable shelf life extension strategy is used commercially worldwide for some dairy products. The development of food packaging machines with integrated gas flushing capabilities and the supply of ‘food grade’ gases allow dairy foods manufacturers to enhance the quality of their products. This review presents a broad spectrum of current research and the current trends with respect to CO₂ as a natural microbial hurdle with special focus on its precise mechanism and its role in quality improvement of dairy products.     

Review:Botnet detection techniques: review,future trends,and issue

In recent years, the Internet has enabled access to widespread remote services in the distributed computing environment; however, integrity of data transmission in the distributed computing platform is hindered by a number of security issues. For instance, the botnet phenomenon is a prominent threat to Internet security, including the threat of malicious codes. The botnet phenomenon supports a wide range of criminal activities, including distributed denial of service(DDoS) attacks, click fraud, phishing, malware distribution, spam emails, and building machines for illegitimate exchange of information/materials. Therefore, it is imperative to design and develop a robust mechanism for improving the botnet detection, analysis, and removal process. Currently, botnet detection techniques have been reviewed in different ways; however, such studies are limited in scope and lack discussions on the latest botnet detection techniques. This paper presents a comprehensive review of the latest state-of-the-art techniques for botnet detection and figures out the trends of previous and current research. It provides a thematic taxonomy for the classification of botnet detection techniques and highlights the implications and critical aspects by qualitatively analyzing such techniques. Related to our comprehensive review, we highlight future directions for improving the schemes that broadly span the entire botnet detection research field and identify the persistent and prominent research challenges that remain open.     

Self-centring segmental retaining walls—A new construction system for retaining walls

This paper reports on an experimental study on a new self-centring retaining wall system. Four post-tensioned segmental retaining walls (PSRWs) were experimentally tested. Each of the walls was constructed using seven T-shaped concrete segments with a dry stack. The walls were tested under incrementally increasing cyclic lateral load. The effect of the wall height, levels of post-tensioning (PT) force, and bonded versus unbonded condition of PT reinforcement on the structural behavior of the PSRWs was investigated. The results showed that such PSRWs are structurally adequate for water retaining structures. According to the results, increasing the wall height decreases initial strength but increases the deformation capacity of the wall. The larger deformation capacity and ductility of PSRW make it a suitable structural system for fluctuating loads or deformation, e.g., seawall. It was also found that increasing the PT force increases the wall’s stiffness; however, reduces its ductility. The residual drift and the extent of damage of the unbonded PSRWs were significantly smaller than those of the bonded ones. Results suggest that this newly developed self-centring retaining wall can be a suitable structural system to retain lateral loads. Due to its unique deformation capacity and self-centring behavior, it can potentially be used for seawall application.     

Treatment of Potato Processing Wastewater with Coagulating and Polymeric Flocculating Agents

Reduction of wastewater strength in abrasive-peeled, lye-peeled, and steam-peeled potato processing wastewater using 4 inorganic salts and 11 polymers was investigated. Treatment of wastewater with 150 mg/ L FeCl₃ 6H₂O + 20 mg/L Purifloc Anionic Polymer #23 aided in coagulation and flocculation of suspended solids of effluent from abrasive-peeled potatoes including greater than 90% reduction in chemical oxygen demand (COD), total suspended solids (TSS) and turbidity. Treatment with 300 mg/L CaCl₂+ 25 mg/L Purifloc #23 reduced COD and TSS levels in wastewater from lye-peeled potato by 69% and 76%, respectively. In steam-peeled effluent, 350 mg/L CaCl₂+ 25 mg/L Nalco 7122 reduced TSS by 90% and COD by 60%. Waste strength of effluent from processing potatoes can be substantially reduced by treating with coagulating and flocculating agents before discharging into municipal or other treatment systems.     

Nonlinear control of a bioreactor model using exact and I/O linearization

A nonlinear multivariable bioreactor system has been the subject of two differential geometry feedback control design approaches. Exact linearization and input/output linearization are applied to the bioreactor model and verified by simulation experiments. Exact linearization via state feedback shows a high degree of coupling on the controlled variables and large changes on the manipulated variables. Input/output linearization, with the ability of implementing independent, decoupled control loops, gives more satisfactory results. The issues of invertabiity and parameter uncertainties are also discussed in this paper.     

Behaviour of self-centring shear walls——A state of the art review

The application of unbonded post-tensioning (PT) in structural walls has led to the development of advanced self-centring (rocking) shear wall systems that has significant advantages, including accelerated construction due to the incorporation of prefabricated elements and segmental construction for different materials (e.g., concrete, masonry, and timber), reduced residual drifts, and little damage upon extreme seismic and wind loads. Concrete, masonry, and timber are often used for the construction of unbonded PT structural wall systems. Despite extensive research since the 1980s, there are no well-established design guidelines available on the shear wall configuration with the required energy dissipation system, joint’s locations and acceptance criteria for shear sliding, confinement, seismic performance factors, PT loss, PT force range and residual drifts of shear walls subjected to lateral loads. In this research a comprehensive state-of-the-art literature review was performed on self-centring shear wall system. An extensive study was carried out to collect a database of 100 concrete, masonry, and self-centring shear wall tests from the literature. The established database was then used to review shear walls’ configurations, material, and components to benchmark requirements applicable for design purposes. The behaviour of concrete, masonry and timber shear walls were compared and critically analysed. The general behaviour, force-displacement performance of the walls, ductility, and seismic response factors, were critically reviewed and analysed for different self-centring wall systems to understand the effect of different parameters including configurations of the walls, material used for construction of the wall (concrete, masonry, timber) and axial stress ratio. The outcome of this research can be used to better understand the behaviour of self-centring wall system in order to develop design guidelines for such walls.