Khaled M Itani - Academia.edu (original) (raw)
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Papers by Khaled M Itani
British Poultry Science, 2019
1. A 2x2 factorial design was used to test the hypothesis that impaired intestinal starch digesti... more 1. A 2x2 factorial design was used to test the hypothesis that impaired intestinal starch digestibility is attributable to rapid passage of digesta from the gizzard to the intestine, and that compared to steam pelleting, increasing the availability of starch through extrusion cooking may alleviate the potential negative effect of rapid digesta flow on starch utilisation. 2. Thus, 7-d-old broilers chickens were distributed to 48 cages and given a wheat-based (WB) pelleted diet containing either coarse oat hulls (OH-Pel) or fine cellulose (Cel-Pel) until d 19 to stimulate divergent development of the gizzard. Thereafter, both groups were further subdivided and challenged with a WB diet with cellulose in either pelleted (Cel-Pel) or extruded (Cel-Ext) form on d 20 and 22. Either excreta or intestinal contents were collected at time intervals after feeding and analysed for marker and starch. 3. OH-Pel increased gizzard size and holding capacity. No excessively high starch levels (max 25 g/kg) were detected in the excreta. However, 8 h feed-deprived birds given Cel-Pel and challenged with Cel-Pel exhibited higher starch-excretion and showed large individual variation during the first 135 min of collection. 4. Contrary to OH-Pel group, more digesta and starch passed to the jejunum at 1 and 2 h and ileum at 2 and 3 h after feeding for birds given Cel-Pel, resulting in lower jejunal and ileal starch digestibility. 2 5. Increased starch gelatinisation through extrusion processing significantly improved starch digestibility regardless of gizzard function. However, at 1, 2 and 3 h after feeding, more digesta was retained in the foregut of birds given Cel-Ext. 6. The current data showed that starch degradation rate is associated with the flow of digesta which is linked to gizzard development and that enzymatic hydrolysis of intact starch granules may be limited with more rapid feed passage through the gut.
Energy Conversion and Management
This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two fr... more This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.
British Poultry Science, 2019
1. A 2x2 factorial design was used to test the hypothesis that impaired intestinal starch digesti... more 1. A 2x2 factorial design was used to test the hypothesis that impaired intestinal starch digestibility is attributable to rapid passage of digesta from the gizzard to the intestine, and that compared to steam pelleting, increasing the availability of starch through extrusion cooking may alleviate the potential negative effect of rapid digesta flow on starch utilisation. 2. Thus, 7-d-old broilers chickens were distributed to 48 cages and given a wheat-based (WB) pelleted diet containing either coarse oat hulls (OH-Pel) or fine cellulose (Cel-Pel) until d 19 to stimulate divergent development of the gizzard. Thereafter, both groups were further subdivided and challenged with a WB diet with cellulose in either pelleted (Cel-Pel) or extruded (Cel-Ext) form on d 20 and 22. Either excreta or intestinal contents were collected at time intervals after feeding and analysed for marker and starch. 3. OH-Pel increased gizzard size and holding capacity. No excessively high starch levels (max 25 g/kg) were detected in the excreta. However, 8 h feed-deprived birds given Cel-Pel and challenged with Cel-Pel exhibited higher starch-excretion and showed large individual variation during the first 135 min of collection. 4. Contrary to OH-Pel group, more digesta and starch passed to the jejunum at 1 and 2 h and ileum at 2 and 3 h after feeding for birds given Cel-Pel, resulting in lower jejunal and ileal starch digestibility. 2 5. Increased starch gelatinisation through extrusion processing significantly improved starch digestibility regardless of gizzard function. However, at 1, 2 and 3 h after feeding, more digesta was retained in the foregut of birds given Cel-Ext. 6. The current data showed that starch degradation rate is associated with the flow of digesta which is linked to gizzard development and that enzymatic hydrolysis of intact starch granules may be limited with more rapid feed passage through the gut.
Energy Conversion and Management
This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two fr... more This paper presents the comparative study of two hybrid energy storage systems (HESS) of a two front wheel driven electric vehicle. The primary energy source of the HESS is a Li-Ion battery, whereas the secondary energy source is either an ultracapacitor (UC) or a flywheel energy system (FES). The main role of the secondary source is to deliver/recover energy during high peak power demand, but also to increase battery lifetime, considered among the most expensive items in the electric vehicle. As a first step, a techno-economic comparative study, supported by strong literature research, is performed between the UC and the FES. The design and sizing of each element will be presented. The comparison criteria and specifications are also described. The adopted approach in this paper is based on an academic non-oriented point of view. In a second step, each of the HESS will be integrated in a more global Simulink model which includes the vehicle model, the traction control system (TCS), the regenerative braking system and the vehicle actuators. Simulation tests are performed for an extreme braking and vehicle starting-up operations. Tests are realized on two different surface road types and conditions (high and low friction roads) and for different initial system states. In order to show the most appropriate storage system regarding compactness, weight and battery constraints minimization, deep comparative analysis is provided.