Greenhouse gas emissions from livestock production in rural area of Algeria, the case of Chemini (Kabylie)

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Greenhouse gas emissions from livestock production in rural area of Algeria, the case of Chemini (Kabylie)

The Algerian agricultural sector faces the challenge to meet the food needs of its population despite low agricultural capacity, resulting in increasing pressure on natural resources. This paper aims to inventory the greenhouse gas (GHG) emissions related to livestock sector in the rural area of Chemini (province of Bejaia), taking into account the emissions due to enteric fermentation, in the form of methane, and manure management, in the form of methane and nitrous oxide. Emissions intensity, expressed in CO2-equivalents (CO2-eq) per kg of edible protein, was included in the study. Ruminants contribute to 94% of livestock GHG emissions and to 53% of protein production, with a large share due to cattle. The main part of emissions is related to enteric fermentation. High-producing cattle present the lowest emission intensity of the ruminant category with 24 kg CO2-eq per kg protein. Chickens produce 2.7% of livestock related emissions but provide 47% of animal protein. It results in low emission intensities whereas important difference is noticed between backyard and industrialized systems (around 21 versus 1 kg CO2-eq per kg protein, respectively). Improvement of animal performance should contribute to mitigate the environmental impact of livestock production in Algeria

The electrochemical behavior of zn-mn alloy coating in carbonated concrete solution

In order to improve the protective performance of Zn coating on reinforcing steel in concrete, the electrochemical deposition of Zn-Mn coatings was conducted on steel surface. The morphology, chemical and phase compositions of Zn-Mn coatings obtained from sulfate-citrate bath were investigated in the first part of paper. In the second part, the obtained deposits were tested in solution simulating carbonated concrete, consisting of NaHCO3 and Na2CO3. Data obtained from Tafel analysis showed higher corrosion resistance for Zn-Mn alloy deposits obtained at -1700 and -1800 mV versus SCE, when compared to pure Zn deposit. Impedance spectroscopy investigations revealed that the total impedance of Zn-Mn coatings increased steadily with time, and was significantly higher as compared to pure Zn after 24 h in corrosion solution. On the contrary, for pure Zn, the impedance increased in the first 12 h, and then decreased during prolonged exposure time, which can be explained by rapid growth of nonprotective white rust and the degradation of zinc coating, as was confirmed by optical microscope after 24 h of immersion in carbonated concrete pore solution

Ponte et qualité d’oeufs de cailles élevées en conditions semi intensives dans l’est algérien

This work investigates laying performances and egg quality of 200 quails during 266 laying days. The first collected 240 eggs, for the periods: 12, 16, 20, 24, 28, 32, 36, 40, 44 weeks were used in this study. The average laying rate calculated over a period of 37 weeks is 74.44 %. All studied eggs quality parameters were significantly (p<0.001) influenced by the age of the quail. The average weight of the whole egg (13.66 g), yolk (3.99 g) and shell (2.28 g) reach their maximum value at the 40 th week. The maximum albumen average weight (7.45 g) was observed at 32 nd week. Albumen (12.02) and yolk (48.72) indices recorded their highest values at the 12 th and the 16 th weeks, respectively. The eggs freshness, expressed here by Haugh units decreased with age. They range from 89.56 at the 12 th week to 83.71 at the 44 th week of age. Yolk color registered values with irregular fluctuations (7.12 to 9.33) in a colorimetric scale of 15 ladders. Highly significant and positive correlations (p<0.001) and were recorded between the whole egg weight and the weight of albumen, yolk and shell. To conclude, the quail age affects significantly the various egg quality parameters.Le présent travail propose une évaluation des performances de ponte et de la qualité des œufs de cailles. Pour cette étude, les oeufs de 200 cailles ont été récoltés toutes les 4 semaines à partir de la 12 ème semaine d'âge jusque la 44 ème semaine d'âge. Pour chaque période de récolte, les 240 premiers oeufs ont été pris en compte. Le taux de ponte moyen calculé sur une période de 37 semaines est de 74,44 %. Tous les paramètres de qualité d'oeufs étudiés ont été significativement (p<0,001) influencés par l'âge des cailles. Les poids moyens de l'œuf entier (13,66 g), du jaune (3,99 g) et de la coquille (2,28 g) atteignent leurs valeurs maximales à la 40 ème semaine. Le poids moyen du blanc arrive à sa valeur maximale de 7,45 gr à la 32 ème semaine. Les indices du blanc (12,02) et du jaune (48,72) ont présenté leurs valeurs maximales respectivement à la 12 ème et à la 16 ème semaine d'âge. La fraicheur des oeufs, ex- primée par les unités d'Haugh diminue avec l'âge. Elle passe de 89,56 Unités d'Haugh (UH) à la 12 ème semaine d'âge à 83,71 UH à la 44 ème semaine d'âge. La couleur du jaune présente des valeurs avec des fluctuations irrégulières (7,12 à 9,33) selon une échelle colorimétrique de 15 échelles (l'éventail DSM de couleurs du jaune de l'oeuf). En conclusion, l'âge influence significativement les différents paramètres de qualité de l'oeuf de caille

A crash course on generalized possibilistic logic

International audienceThis paper proposes a concise overview of the role of possibility theory in logical approaches to reasoning under uncertainty. It shows that three traditions of reasoning under or about uncertainty (set-functions, epistemic logic and three-valued logics) can be reconciled in the setting of possibility theory. We offer a brief presentation of basic possibilistic logic, and of its generalisation that comes close to a modal logic albeit with simpler more natural epistemic semantics. Past applications to various reasoning tasks are surveyed, and future lines of research are also outlined