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Anacyclus pyrethrum is a herbaceous plant that belongs to the Asteraceae family. The focus of the present study is to extract the essential oil from this plant, to determine its chemical composition and to evaluate its insecticidal activity against the larvae of the mosquito Culex pipiens. The essential oil from A. pyrethrum collected from the region of Bensliman in Morocco was extracted by hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry were studied. Essential oil yield obtained by hydrodistillation was 0.09%. The major aroma constituents were Spathulenol (20.47%), Germacrene D (16.48%), Caryophyllene oxide (13.20%), 4(14)-Salviale-1-one (8.27%) and Caryophyllene 4(14),8(15)-dien-5α-ol (7.30%). The larvicidal test carried out according to a methodology based on the standard protocol of the World Health Organization was studied on 4th instar larvae of C. pipiens and showed that A. pyrethrum essential oil possesses remarkable insecticidal properties.  After 24 hours of exposition, larvicidal assays revealed a 100% mortality of C. pipiens larvae. The dose of 40 μL/mL was toxic enough to cause 100% larval mortality of C. pipiens. The lethal concentrations LC50 and LC90 calculated for the essential oil studied were of the order of 14.79 μL/mL and 19.95 μL/mL, respectively. To control mosquitoes, this essential oil extracted from A. pyrethrum might be used as a natural insecticide and therefore could be an alternative to synthetic insecticides already present on the market.

The role of packaging has been extended from passive protection to an active role in improving food quality. Active packaging works with the food to produce a desired effect. Often, micro-organism growth causes food spoilage, so active packaging allows for the controlled release of an anti-microbial agent into the food. Thus, packaging is made of two layers, at least, one with an impermeable polymer protecting the system from the environment, and the other with a polymer carrier containing the agent, the polymer carrier being bound to the inside of the packaging and in contact with the food. This study is undertaken in order to describe the process of the agent release. The agent diffuses through the polymer carrier with a constant diffusivity into the liquid food, with a finite coefficient of convective transfer at the interface. Because of the high convective effect in the liquid, the concentration of the agent in the liquid food is uniform. Moreover, the rate of consumption of the agent resulting from its action on the micro-organisms is controlled by a first-order reaction with respect to its concentration in the liquid. The results are expressed in terms of the profiles of concentration of the agent developed through the thickness of the polymer carrier, the kinetics of the agent remaining free in the liquid, and the kinetics of consumption of the anti-microbial agent by the microorganisms. Two new dimensionless numbers are introduced, taking into account the rate of consumption of the agent and either the diffusivity, when the process is controlled by diffusion, or the rate of convection coefficient when it is controlled by convection, in order to clarify the process an help those who are not specialists in modelling.

The process of absorption of water within a cross-section of a sheet of Scots pine sapwood, and the following step of desorption, are studied, whcn the moisture content is beyond the fiber Saturation point. A two dimcnsional transfer through this cross-section is considered with the two principal diffusions: longitudinal and radial. Anumerical model with finite differences is able to describe the process, by calculating the kinetics of transfer äs well äs the profiles of moisture content devcloped through the wood section. KeywordsWater absorption/drying of wood Moisture content beyond FSP Modelling the process Two-dimensional transfer Scots pine sapwood Pinus sylvestris Holzforschung /Vol. 46 /1992 / No. 3