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Search Results: 1 - 10 of 207 matches for " Moncef Hammami "
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Chemical composition and in sacco digestibility of some Tunisian roughages
Moncef Hammami,,Rachid Bouraoui,Hamadi Rouissi
Research Opinions in Animal & Veterinary Sciences , 2011,
Abstract: The present study aims at measuring the chemical composition and the ruminal degradability of some Tunisian roughage. The roughages were analysed to determine their chemical composition. Ruminal degradability of the roughages was determined using the technique of nylon bags. There were significant differences (P<0.05) among roughages with regard to immediately soluble fraction, insoluble but degradable fraction, and fraction rate of degradation.
Effect of replacing Soya by broad beans on fermentation parameters in the rumen of Sicilo-Sarde rams
Moncef Hammami,,Abderrahmane Ben Gara,,Boulbaba Rekik,Hamadi Rouissi
Research Opinions in Animal & Veterinary Sciences , 2011,
Abstract: The objective of this work was to study the effects of replacing Soybean meal by broad bean (Vicia faba L.) in the formulation of concentrates on fermentation parameters in the rumen of Sicilo-Sarde rams. Parameters were pH, N-NH3 concentrations, protozoa, total gas and methane productions and in sacco digestibility of oat hay for different protein sources. Four Sicilo-Sarde rams with permanent canulas were used in this trial. Rams (mean age = 4.75±0.5; mean live weight = 53.3±6.6 kg) were kept in individual boxes and received a ration distributed in two meals. The ration included 1.5 kg dry matter of oat hay and 500 g /ram/day of Soybean (S) during one month and there after the broad bean (V) during another one month period. Each of the trial periods was preceded by a two weeks adaptation period. Water was ad libitum. The S concentrate was 82.5% barley, 13.5% Soya, and 4% mineral mixture, while the F concentrate included 71.5% barley, 17.5% Vicia faba, 7% Soya and 4% mineral mixture. The energy and protein contents were 0.54, 0.96 and 0.96 UFV/kg DM and 5.20, 16.8 and 16.2 % for hay, S and V concentrates, respectively. Samples of 50 ml of rumen juice were taken before the morning meal and after 2, 5 and 8 hours to determine pH and ammonia nitrogen concentration. Types and counts of protozoa were determined on unfiltered rumen juice taken 2 hours after the morning meal and kept in a 100 ml fixing mixture. Protozoa types were counted by means of a HAWSKLEY counter. To determine gas production (CO and CH ), rumen content was 2 4 collected in 100 ml plastic syringes before the morning meal and was filtered through four surgical gas layers. Rams were deprived from drinking water during the night before sampling. The DM degradability was determined by in sacco method using nylon bags with 50 micron diameter. Each bag contained 3 g of crushed hay and was incubated in the rumen for 48 hours. The pH of ruminal juice was comparable (P>0.05) for the S and V concentrates. Total counts of protozoa types showed that animals fed the V concentrate had higher protozoa population in the rumen (6.07 vs 5.24×105/ml) than other animals. However, proportions of protozoa types (Entodinium, Isotricha, Ophryoscolex, Polyplastron) were similar for both regimen (P<0.05).The proportion of ammonia nitrogen tended to be higher for the V compared to the S regimen (P>0.05). Total gas production was comparable for the V and S concentrates (mean = 53.5 ml, STD = 6.31 ml and mean = 51.8 ml, STD =11.5 ml, respectively), whereas potential gas production was significantly higher (p<0.05) f
Effect of replacing Soya by broad beans on fermentation parameters in the rumen of Sicilo-Sarde rams
Moncef Hammami,,Abderrahmane Ben Gara,,Boulbaba Rekik,Hamadi Rouissi
Research Opinions in Animal & Veterinary Sciences , 2011,
Abstract: The objective of this work was to study the effects of replacing Soybean meal by broad bean (Vicia faba L.) in the formulation of concentrates on fermentation parameters in the rumen of Sicilo-Sarde rams. Parameters were pH, N-NH3 concentrations, protozoa, total gas and methane productions and in sacco digestibility of oat hay for different protein sources. Four Sicilo-Sarde rams with permanent canulas were used in this trial. Rams (mean age = 4.75±0.5; mean live weight = 53.3±6.6 kg) were kept in individual boxes and received a ration distributed in two meals. The ration included 1.5 kg dry matter of oat hay and 500 g /ram/day of Soybean (S) during one month and there after the broad bean (V) during another one month period. Each of the trial periods was preceded by a two weeks adaptation period. Water was ad libitum. The S concentrate was 82.5% barley, 13.5% Soya, and 4% mineral mixture, while the F concentrate included 71.5% barley, 17.5% Vicia faba, 7% Soya and 4% mineral mixture. The energy and protein contents were 0.54, 0.96 and 0.96 UFV/kg DM and 5.20, 16.8 and 16.2 % for hay, S and V concentrates, respectively. Samples of 50 ml of rumen juice were taken before the morning meal and after 2, 5 and 8 hours to determine pH and ammonia nitrogen concentration. Types and counts of protozoa were determined on unfiltered rumen juice taken 2 hours after the morning meal and kept in a 100 ml fixing mixture. Protozoa types were counted by means of a HAWSKLEY counter. To determine gas production (CO and CH ), rumen content was 2 4 collected in 100 ml plastic syringes before the morning meal and was filtered through four surgical gas layers. Rams were deprived from drinking water during the night before sampling. The DM degradability was determined by in sacco method using nylon bags with 50 micron diameter. Each bag contained 3 g of crushed hay and was incubated in the rumen for 48 hours. The pH of ruminal juice was comparable (P>0.05) for the S and V concentrates. Total counts of protozoa types showed that animals fed the V concentrate had higher protozoa population in the rumen (6.07 vs 5.24×105/ml) than other animals. However, proportions of protozoa types (Entodinium, Isotricha, Ophryoscolex, Polyplastron) were similar for both regimen (P<0.05).The proportion of ammonia nitrogen tended to be higher for the V compared to the S regimen (P>0.05). Total gas production was comparable for the V and S concentrates (mean = 53.5 ml, STD = 6.31 ml and mean = 51.8 ml, STD =11.5 ml, respectively), whereas potential gas production was significantly higher (p<0.05) f
Required Lateral Inlet Pressure Head for Automated Subsurface Drip Irrigation Management
Moncef Hammami,Khemaies Zayani,Hédi Ben Ali
International Journal of Agronomy , 2013, DOI: 10.1155/2013/162354
Abstract: Subsurface drip irrigation (SDI) is one of the most promising irrigation systems. It is based on small and frequent water supplies. Because SDI emitters are buried, their discharges are dependent on the water status at the vicinity of the outlets. This paper was targeted to design the SDI laterals accounting for the soil water-retention characteristics and the roots water extraction. The proposed approach provides systematic triggering and cut-off of irrigation events based on fixed water suctions in the vadose zone. In doing so, the soil water content is maintained at an optimal threshold ascertaining the best plant growth. Knowing the soil water-retention curve, the appropriate water suction for the plant growth, and the emitter discharge-pressure head relationship, the developed method allows the computation of the required hydraulics of the lateral (e.g., inlet pressure head, inside diameter, etc.). The proposed approach is a helpful tool for best SDI systems design and appropriate water management. An illustrative example is presented for SDI laterals’ design on tomato crop. 1. Introduction In subsurface drip irrigation (SDI), water seeps from the buried emitters into the soil and spreads out in the vadose zone under the conjugate effect of capillary and gravity forces [1, 2]. Thus, SDI system allows the direct application of water to the rhizosphere maintaining dry the nonrooted topsoil. This pattern generates numerous advantages such as minimizing soil evaporation and then evapoconcentration phenomenon. The rationale is that SDI improves the water application uniformity, increases the laterals and emitters longevity, reduces the occurrence of soil-borne diseases, and allows the control of weeds infestation. Several field trials revealed relevant profits on managing SDI for crop production. Nevertheless, the appropriate depth of buried laterals remains debatable [3–6]. Comparing evaporation from surface and subsurface drip irrigation systems, Evett et al. [7] reported that 51?mm and 81?mm were saved with drip laterals buried at 15?cm and 30?cm, respectively. Neelam and Rajput [1] recorded maximum onion yield (25.7?t?ha?1) with drip laterals buried at 10?cm. According to these authors, the maximum drainage occurred when drip laterals are laid at 30?cm depth. On the other hand, numerous studies were devoted to the analysis of the effect of the soil properties on the SDI emitters discharge and water distribution uniformity [8–10]. The analytical approach proposed by Sinobas et al. [2] predicts reasonably well the soil water suction and the pressure
Genetic polymorphism of casein alpha-S1 gene in Tunisian local Goat
Borni Jemmali*; Mounir Kamoun; Marwa Haddar; Abderrahmene Ben Gara; Houcine Selmi; Moncef Hammami; Marouene Amraoui; Hamadi Rouissi; Rekik Boulbaba
Biomirror , 2012,
Abstract: The genetic polymorphism of the casein alpha-S1 locus wasinvestigated in Tunisian goat. Blood samples were collected from localgoat breed. Genomic DNA samples were obtained from leukocytes of75 dairy goats and regions of interest in the gene were amplifiedthrough Polymerase Chain Reaction (PCR), then evaluated in agarosegels. For better characterization of the single nucleotidepolymorphism, if exist, a PCR-Restriction Fragment LengthPolymorphism study was performed employing the endonucleaseXmnI. DNA amplification using primers produced fragments withsizes of 457 bp. The PCR products of primer (223 bp) digested byrestriction enzyme Xmn1 produced four fragments at 223 bp, 212bp,161bp and 150-bp. The results showed that local goat breed haddifferent genotypes A/A, B/C, C/C and DD. Our results revealed thatthe CSN1S1 allelic variants in tested breed showed differentgenotypes, three of them were homozygous 12.5%, 60.5% and 12.8%respectively for A/A, C/C and D/D and the other was heterozygousB/C (14.2%). Identification of different variants of the casein alpha-S1 can be used to improve milk quality of local goat breed.
Concentration phenomena for fourth-order elliptic equations with critical exponent
Mokhless Hammami
Electronic Journal of Differential Equations , 2004,
Abstract: We consider the nonlinear equation $$ Delta ^2u= u^{frac{n+4}{n-4}}-varepsilon u $$ with $u$ greater than 0 in $Omega$ and $u=Delta u=0$ on $partialOmega$. Where $Omega$ is a smooth bounded domain in $mathbb{R}^n$, $ngeq 9$, and $varepsilon$ is a small positive parameter. We study the existence of solutions which concentrate around one or two points of $Omega$. We show that this problem has no solutions that concentrate around a point of $Omega$ as $varepsilon$ approaches 0. In contrast to this, we construct a domain for which there exists a family of solutions which blow-up and concentrate in two different points of $Omega$ as $varepsilon$ approaches 0.
The Use of Reported Cash Flows versus Earnings to Predict Cash Flows: Preliminary Evidence from Qatar
Helmi Hammami
Business Systems Review , 2012, DOI: 10.7350/bsr.a10.2012
Abstract: The study aims to empirically investigate the predictive ability of reported cash flows versus earnings to predict future cash flows in a market situated in a high growth rate economy such as Qatar. The sample of the study consists of companies on the Doha Securities Market (Qatar Exchange) for the period 2004-09. Qatar is a very interesting context to explore especially after the quick reputation it is gaining at the international scene. We provide evidence on the ability of earnings and cash flow measures to forecast one period or two-period ahead cash flows. However, the results support the superiority of cash flows over earnings in predicting future cash flows. Furthermore, with the exception of CFOP, our research model reports that CFFIA and CFFA are better predictors of themselves. NIDPR – A traditional cash flow measure is a good predictor of CFOP. Finally empirical findings show that cash flow measures and earnings are not correlated suggesting the specificities of each are different.
Maintenance de l'outil Wr2fdr de traduction de Wright vers CSP
Mouti Hammami
Computer Science , 2012,
Abstract: The use of formal ADL like Wright is critically dependent on the tools that are made available to architects. The Wr2fdr tools accompanying the formal Wright ADL provides translation to Wright to CSP. Wr2fdr automates four standard properties concerning consistency Connectors (properties 2 and 3), Component (a property 1) and Configuration Management (Property 8) Wright using the model checker FDR. After conducting an audit activity of this tool, we were able to correct errors related to both properties 2 and 3. In addition, we proposed an implementation of both properties 1 and 8. Finally, we added the tool Wr2fdr with a semantic analyzer of Wright.
A generalized thermoelastic diffusion problem for an infinitely long solid cylinder
Moncef Aouadi
International Journal of Mathematics and Mathematical Sciences , 2006, DOI: 10.1155/ijmms/2006/25976
Abstract: The theory of generalized thermoelastic diffusion, based on the theory of Lord and Shulman, is used to study the thermoelastic-diffusion interactions in an infinitely long solid cylinder subjected to a thermal shock on its surface which is in contact with a permeating substance. By means of the Laplace transform and numerical Laplace inversion the problem is solved. Numerical results predict finite speeds of propagation for thermoelastic and diffusive waves and the presence of a tensile stress region close to the cylinder surface. The problem of generalized thermoelasticity has been reduced as a special case of our problem.
Discontinuities in an axisymmetric generalized thermoelastic problem
Moncef Aouadi
International Journal of Mathematics and Mathematical Sciences , 2005, DOI: 10.1155/ijmms.2005.1015
Abstract: This paper deals with discontinuities analysis in the temperature, displacement, and stress fields of a thick plate whose lower and upper surfaces are traction-free and subjected to a given axisymmetric temperature distribution. The analysis is carried out under three thermoelastic theories. Potential functions together with Laplace and Hankel transform techniques are used to derive the solution in the transformed domain. Exact expressions for the magnitude of discontinuities are computed by using an exact method developed by Boley (1962). It is found that there exist two coupled waves, one of which is elastic and the other is thermal, both propagating with finite speeds with exponential attenuation, and a third which is called shear wave, propagating with constant speed but with no exponential attenuation. The Hankel transforms are inverted analytically. The inversion of the Laplace transforms is carried out using the inversion formula of the transform together with Fourier expansion techniques. Numerical results are presented graphically along with a comparison of the three theories of thermoelasticity.
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