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1.
Mohammad Abu Shayed Heike Hund Rolf Dieter Hund Chokri Cherif 《Fibers and Polymers》2016,17(2):229-240
Thermal and oxidation resistant coating is necessary for carbon fiber (CF) in CF reinforced concrete (CFRC) composite application in order to fulfil a high level of safety standard in case of fire. Pre-ceramic coatings such as Polysilazane, Polysiloxane, and Methyl silicone resin have been deposited on CF filament yarn by means of wet chemical continuous dip coating method. The surface analyses e.g. scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (IR) results showed the changes of surface morphology by the coatings. Thermo gravimetric analysis (TGA) revealed that the high temperature (up to 800 °C) oxidation stability of CF was significantly improved with coatings. Thermo-mechanical properties also significantly enhanced up to 600 °C. CF yarn retains its original strength and elasticity modulus/stiffness at 700 °C due to thermal and oxidation resistant coatings. 相似文献
2.
Assessing solid waste compost application as a practical approach for salt-affected soil reclamation
Abdelbasset Lakhdar Chokri Hafsi Ahmed Debez Francesco Montemurro Naceur Jedidi Chedly Abdelly 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):284-288
Abstract A short-term pot experiment was made to evaluate the effectiveness of municipal solid waste compost amendment on salt-affected soil. Hordeum maritimum plants were cultivated in pots filled with a clay-loam soil containing 0 or 40 t ha?1 of compost and irrigated with tap water at 0 or 4 g l?1 NaCl. Soil properties and heavy metal (Zn2 +, Pb2 +, Cd2 +) accumulation were investigated. Municipal solid waste compost application significantly increased the soil contents of carbon, nitrogen and potassium under both non-saline and saline conditions. Soil heavy metal concentrations increased substantially too, but the recorded values were below the toxicity limits. Interestingly, plants subjected to the salt–compost interaction were more vigorous, compared with those grown on non-amended soil. Altogether, our data indicate that short-term utilization of municipal solid waste compost at 40 t ha?1 may be of potential interest in the perspective of the rehabilitation of salt-affected soils. Yet, it must be stressed that the present findings are preliminary and need to be further evaluated under field conditions before practical recommendations can be inferred. 相似文献
3.
This article correlates draw frame settings with quality characteristics of sliver and ring spun yarn using artificial neural
networks. Considering the importance of draw frame as the last quality improvement machine in the spinning process, the quality
influencing parameters of the draw frame were used as input for artificial neural networks. The neural networks were trained
using a combination of Levenberg-Marquardt algorithm and Bayesian regularization for better generalization of the networks.
Cross validation was performed for each trained network to test the performance of networks. The promising results achieved
by this research work emphasize the ability of neural networks to predict the quality characteristics of sliver and yarn using
the artificial neural networks. Therefore, draw frame parameters can be adjusted on the basis of required sliver and yarn
quality. Furthermore, machines can be involved in the decision making process in spinning mills. 相似文献
4.
Makrem Afif Chokri Messaoud Abdennacer Boulila Hnia Chograni Afef Bejaoui Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2008,65(7):710-710
5.
Najla Dhen Imen Ben Ammar Chokri Bayoudh Bouthaina Al Mohandes Dridi 《Communications in Soil Science and Plant Analysis》2019,50(8):959-973
Quality of vegetable seedlings is affected by nursery management practices, essentially growing media. For sustainable greenhouse horticulture, it is important to characterize biologically based approaches to improve plantlet quality. Here, we investigate the possibility of developing a biotized growth substrate for nursery production using date palm wastes (DPWs) peat as an alternative to commercial sphagnum peat and indigenous arbuscular mycorrhizal fungi (AMF). A greenhouse experiment was established using different rates of DPWs peat to substitute commercial peat in both conventional and organic nursery production systems. Lettuce seedlings were inoculated or not with native AMF isolated from plots with conventional or organic production system (CM and OM respectively). When lettuce plantlets attained commercial size, a microscopic observation revealed that the establishment of mycorrhizal association was successful in all mixtures of growing media. Significant increase in growth parameters (height shoot, number and area of leaves, shoot and root biomass) were observed on plantlets inoculated with indigenous AMF isolated from organic plot compared to those isolated from conventional plot and to control (without AMF). Commercial peat partial substitution with DPWs peat in proportion of 25–50% improves better lettuce performance than complete-peat use. Consequently, these mixtures seem to be an appropriate formulation for sustainable nursery production. 相似文献
6.
Naziha Ayeb Margherita Addis Myriam Fiori Naziha Atti Ahmed Barmat Mohamed Hammadi Hager Boukhris Chokri Damergi Touhami Khorchani 《Journal of animal physiology and animal nutrition》2019,103(6):1637-1645
The valorization of natural resources in small ruminants feeding can reduce the cost of feed and produce good meat quality. The objective was to evaluate the effects of local feed resources on the physico‐chemical aspects, the sensorial characteristics and the fatty acid profile of goat kid's meat. Twenty‐six kids are divided in three groups (average body weight = 15.85 kg; age = 4 months). The groups received oat hay (group control C), dried olive leaves + dried Stipa tenacissima (group OL) or grass hay (group Ko). The animals were slaughtered after 90 days of experience, with an approximate final live weight of 18.5 kg. Total solids, pH, fat, crude protein, vitamin, cholesterol and fatty acid contents of meat were determined. The OL group had the highest ultimate pH (6.82 vs. 6.73); cooking loss, gross composition (total solids, protein and fat), cholesterol and colour coordinates (L, a* and b*) were similar among groups. The vitamin E, affected by diet, was higher in group OL than the other groups (3.71 mg/kg vs. 1.32 and 2.17 mg/kg, respectively, for C and Ko groups). Moreover, meat from this group showed the highest saturated fatty acid. Unsaturated fatty acids content was higher in the meat of C and Ko groups. On the other side, polyunsaturated fatty acid level was not affected by the diet treatment. The n6/n3 ratio was significantly affected by the diet; it was lower in meat of groups Ko and OL (3.17 and 3.38 respectively). The feeding effect on sensory quality of meat was not significant. 相似文献
7.
Inert polyethylene terephthalate (PET) yarns, which were spooled crosswise onto a cylindrical dyeing bobbin, were silvered successfully with a wet-chemical method by using a newly developed one-bath method on a laboratory scale. In order to characterize the silver coating such as design, homogeneity, and crack formation, the surface morphology (SM) was analyzed using scanning electron microscopy (SEM). The chemical compositions of the surface (percentage of carbon, oxygen, nitrogen, silicium, and silver) were investigated with energy-dispersive x-ray spectroscopy (EDX). Furthermore, the testing of textile-chemical and textile-physical properties such as the washing-fastness, tensile strength, and electrical conductivity was carried out. 相似文献
8.
Heat resistant coatings of textile materials are required so that they can fulfill the high security demand in the case of resistance to fire and improve thermo-mechanical properties. These coatings also enhance the interface properties of textiles in the composites. Liquid phase coatings, based on polysilazane and polysiloxane polymers were deposited onto the basalt fiber (BF) yarn using impregnation coating method. Tensile testing under thermal stress was conducted to examine the thermo-mechanical properties of both coated and uncoated yarns. The thermo-mechanical study indicated that the heat resistant coatings enhanced 40–70 % tensile strength and 25–40 % stiffness of original BF yarns up to 400 °C. BF yarn retained 65–90 % of its tensile strength at 500 °C due to coatings, whereas the uncoated BF yarn lost 85 % strength at this temperature. Thermo gravimetric analysis (TGA) showed that the coatings have good thermal stability. In addition, scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, optical microscopy and fourier transform infrared (FTIR) spectroscopy analyses were executed in order to evaluate the surface microstructure as well as surface chemical compositions of the BF yarns. 相似文献
9.
Chayma Rajeb Chokri Messaoud Hnia Chograni Afef Bejaoui Abdennacer Boulila Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2010,67(5):512-512
10.
Chokri Messaoud Makrem Afif Abdennacer Boulila Mohamed Nejib Rejeb Mohamed Boussaid 《Annals of Forest Science》2007,64(8):845-853
The genetic variation of six Tunisian Myrtus communis L. (Myrtaceae) populations was assessed using nine isozymes coding for 17 putative loci and 79 RAPD markers, amplified by five decamer random primers. The analysed populations belonged to three bioclimatic zones (lower humid, sub-humid and upper semi-arid). A high genetic diversity within populations was detected both by isozymes and RAPDs. The level of variation differed according to bioclimate. Populations collected from sub-humid bioclimate showed more polymorphism than those grown in the upper semi-arid zone. For all populations, the genetic diversity revealed by RAPDs was more pronounced than that detected with isozymes. A high differentiation among populations related to bioclimate and geographic distance was revealed by both methods. Population’s structure based on RAPD markers was more concordant with bioclimatic zones in comparison with isozymes. Differentiation between ecological groups was higher than that revealed within groups. Conservation programs should take into account the level of genetic diversity within population revealed by the two complementary classes of markers according to bioclimate. 相似文献