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Hassan Abdalla - One of the best experts on this subject based on the ideXlab platform.

  • surface roughness model for end milling a semi free cutting carbon casehardening steel en32 in dry condition
    Journal of Materials Processing Technology, 2002
    Co-Authors: A Mansour, Hassan Abdalla
    Abstract:

    Abstract This paper describes the development process of a surface roughness model for the end milling EN32M (a semi-free cutting carbon casehardening steel with improved merchantability). This steel can be carbonized and hardened to produce a hard wear resistant case, with core strength of approximately 460 N/mm 2 , and 160 BHN steel. Typical applications include cams, rollers, spindles, pins, etc. These materials are generally difficult to machine. The mathematical model for the surface roughness has been developed, in terms of cutting speed, feedrate, and axial depth of cut. The effect of these cutting parameters on the surface roughness has been carried out using design of experiments and the response surface methodology (RSM). A First-Order Equation covering the speed range 30–35 m/min and a second-order generation Equation covering the speed range 24–38 m/min were investigated in dry condition.

  • surface roughness model for end milling a semi free cutting carbon casehardening steel en32 in dry condition
    Journal of Materials Processing Technology, 2002
    Co-Authors: A Mansour, Hassan Abdalla
    Abstract:

    Abstract This paper describes the development process of a surface roughness model for the end milling EN32M (a semi-free cutting carbon casehardening steel with improved merchantability). This steel can be carbonized and hardened to produce a hard wear resistant case, with core strength of approximately 460 N/mm 2 , and 160 BHN steel. Typical applications include cams, rollers, spindles, pins, etc. These materials are generally difficult to machine. The mathematical model for the surface roughness has been developed, in terms of cutting speed, feedrate, and axial depth of cut. The effect of these cutting parameters on the surface roughness has been carried out using design of experiments and the response surface methodology (RSM). A First-Order Equation covering the speed range 30–35 m/min and a second-order generation Equation covering the speed range 24–38 m/min were investigated in dry condition.

A Mansour - One of the best experts on this subject based on the ideXlab platform.

  • surface roughness model for end milling a semi free cutting carbon casehardening steel en32 in dry condition
    Journal of Materials Processing Technology, 2002
    Co-Authors: A Mansour, Hassan Abdalla
    Abstract:

    Abstract This paper describes the development process of a surface roughness model for the end milling EN32M (a semi-free cutting carbon casehardening steel with improved merchantability). This steel can be carbonized and hardened to produce a hard wear resistant case, with core strength of approximately 460 N/mm 2 , and 160 BHN steel. Typical applications include cams, rollers, spindles, pins, etc. These materials are generally difficult to machine. The mathematical model for the surface roughness has been developed, in terms of cutting speed, feedrate, and axial depth of cut. The effect of these cutting parameters on the surface roughness has been carried out using design of experiments and the response surface methodology (RSM). A First-Order Equation covering the speed range 30–35 m/min and a second-order generation Equation covering the speed range 24–38 m/min were investigated in dry condition.

  • surface roughness model for end milling a semi free cutting carbon casehardening steel en32 in dry condition
    Journal of Materials Processing Technology, 2002
    Co-Authors: A Mansour, Hassan Abdalla
    Abstract:

    Abstract This paper describes the development process of a surface roughness model for the end milling EN32M (a semi-free cutting carbon casehardening steel with improved merchantability). This steel can be carbonized and hardened to produce a hard wear resistant case, with core strength of approximately 460 N/mm 2 , and 160 BHN steel. Typical applications include cams, rollers, spindles, pins, etc. These materials are generally difficult to machine. The mathematical model for the surface roughness has been developed, in terms of cutting speed, feedrate, and axial depth of cut. The effect of these cutting parameters on the surface roughness has been carried out using design of experiments and the response surface methodology (RSM). A First-Order Equation covering the speed range 30–35 m/min and a second-order generation Equation covering the speed range 24–38 m/min were investigated in dry condition.

Salman S Ashraf - One of the best experts on this subject based on the ideXlab platform.

  • a comparative study of neutral red decoloration by photo fenton and photocatalytic processes
    Dyes and Pigments, 2008
    Co-Authors: Maitha M Alnuaimi, Muhammad A. Rauf, Salman S Ashraf
    Abstract:

    Neutral Red was subjected to two different advanced oxidative processes, namely the photo-Fenton process and the photocatalytic process. The dye was found to undergo substantial and rapid decoloration by both the methods, however, the photo-Fenton-mediated decoloration of the dye was much more efficient. Conditions were optimized in both set of experiments to achieve the most efficient dye decoloration. Additionally the effects of added anions on photocatalytic and photo-Fenton-mediated dye decoloration were examined and compared to our previously published results with photolytic and Fenton-mediated Neutral Red decoloration. Most of the ions tested had an inhibitory effect on photo-Fenton process, but unexpectedly enhanced the photocatalytic process, except for chloride, which inhibited both the processes. The kinetics data in both the cases fitted well to the First-Order Equation. Comparison of the results among the four different advanced oxidation processes shows that Neutral Red is most efficiently degraded by photo-Fenton process, followed by Fenton process, then photolytic, and then with photocatalytic process.

  • comparative decoloration study of neutral red by different oxidative processes
    Dyes and Pigments, 2007
    Co-Authors: Maitha M Alnuaimi, Muhammad A. Rauf, Salman S Ashraf
    Abstract:

    Neutral Red was subjected to two different oxidative processes, namely the photo-oxidative process and the Fenton process. The dye was found to undergo substantial and rapid decoloration by both the methods. Conditions were optimized in both the sets of experiments to achieve the most efficient dye decoloration. Additionally the effects of added anions on dye decoloration were examined and it was found that in both cases, the chloride ions caused a significant decrease in the decoloration rate. The kinetics data in both the cases fitted well to the First-Order Equation. A comparison of the effects of various anions on the decoloration rate revealed dramatic differences in apparent rate constant of decoloration of the dye especially in the presence of phosphate ions. Additionally the Fenton process was found to be more efficient in decolorizing the dye as compared to the photo-oxidative process.

Rueyshin Juang - One of the best experts on this subject based on the ideXlab platform.

  • characteristics of elovich Equation used for the analysis of adsorption kinetics in dye chitosan systems
    Chemical Engineering Journal, 2009
    Co-Authors: Ruling Tseng, Rueyshin Juang
    Abstract:

    Abstract The Elovich Equation has been widely used in adsorption kinetics, which describes chemical adsorption (chemical reaction) mechanism in nature. The approaching equilibrium parameter of Elovich Equation ( R E ) was used here to describe the characteristic curves of adsorption kinetics. Of 64 adsorption systems surveyed in this work, 80% of the R E values were between 0.1 and 0.3 with an adsorption curve belonging to “mild rising”. The results of three examples revealed that the characteristic curve of Elovich Equation was between those of Lagergren's First-Order Equation and intraparticle diffusion model. Chitosans prepared from prawn, lobster, and crab shells were used for the adsorption of a reactive dye. The mean deviation obtained from the three kinetic models revealed that Elovich Equation was the most suitable one. All the adsorption systems were in the “mild rising” zone. The R E value was related to the type of raw material but not to the particle size of chitosan, which agreed with chemical adsorption nature of the Elovich Equation. According to an optimal adsorbent consumption of 85% coupled with its corresponding operating time ( t 0.85 ) proposed, these two parameters could be used for engineering design.

  • equilibrium and kinetic studies on the adsorption of surfactant organic acids and dyes from water onto natural biopolymers
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2005
    Co-Authors: Minyun Chang, Rueyshin Juang
    Abstract:

    Abstract In order to improve the mechanical property of chitosan beads, the powder of loofah fiber was added in chitosan/acetic acid slurry to prepare composite beads with and without freeze-drying. The former was called the dried bead and the latter was the wet bead. The equilibria and kinetics for adsorption of linear alkylbenzene sulfonate, tannic acid, humic acid, and three dyes (reactive, acidic, and basic) onto these two beads were compared at 30 °C. It was shown that the adsorption capacity with the wet bead was generally higher than that with the dried bead. Lumped kinetic analysis indicated that the pseudo-First-Order Equation could well describe the adsorption processes. On the other hand, the better fit of kinetic data by the Elovich Equation instead of by intraparticle diffusion model suggested the significance of chemisorption mechanism during the processes. The parameters of these kinetic models were also evaluated and discussed.

  • liquid phase adsorption of dyes and phenols using pinewood based activated carbons
    Carbon, 2003
    Co-Authors: Ruling Tseng, Rueyshin Juang
    Abstract:

    Abstract Physical properties of activated carbons prepared from pinewood at different activation times (0.5, 1.5, 2.7, and 4.0 h) in steam at 900 °C were studied. The adsorption equilibria and kinetics of three dyes and three phenols (phenol, 3-chlorophenol, and o-cresol) from aqueous solutions on such carbons were then examined at 30 °C. The adsorption isotherms of phenols could be well fitted by the Freundlich Equation, and those of dyes were adequately described by the Langmuir–Freundlich Equation. The effect of microporosity of the carbons on adsorption capacity was explored. Four simplified kinetic models including pseudo-First-Order Equation, pseudo-second-order Equation, intraparticle diffusion model, and the Elovich Equation were selected to follow the adsorption processes. The adsorption of all six adsorbates could be best described by the Elovich Equation. The kinetic parameters of this best-fit model were calculated and discussed.

  • characterization and use of activated carbons prepared from bagasses for liquid phase adsorption
    Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2002
    Co-Authors: Rueyshin Juang, Ruling Tseng
    Abstract:

    Abstract The adsorption of two commercial dyes and phenol from water on activated carbons was investigated at 30 °C. The carbons were prepared from bagasses and were activated by steam with different extents of burn-off by varying the temperature in the range of 750–840 °C. Pore structures of the carbons were characterized by the t -plot method based on N 2 adsorption isotherms. Three simplified models including the pseudo-First-Order Equation, pseudo-second-order Equation, and intraparticle diffusion models were used to test the adsorption kinetics. It was shown that the adsorption of dyes could be best fitted by the intraparticle diffusion model; the kinetic parameter was calculated and correlated with the extent of burn-off of the carbons. Neither of the three models had a preference for describing the adsorption of phenol, presumably due to its combined control of chemisorption and intraparticle diffusion.

Maitha M Alnuaimi - One of the best experts on this subject based on the ideXlab platform.

  • a comparative study of neutral red decoloration by photo fenton and photocatalytic processes
    Dyes and Pigments, 2008
    Co-Authors: Maitha M Alnuaimi, Muhammad A. Rauf, Salman S Ashraf
    Abstract:

    Neutral Red was subjected to two different advanced oxidative processes, namely the photo-Fenton process and the photocatalytic process. The dye was found to undergo substantial and rapid decoloration by both the methods, however, the photo-Fenton-mediated decoloration of the dye was much more efficient. Conditions were optimized in both set of experiments to achieve the most efficient dye decoloration. Additionally the effects of added anions on photocatalytic and photo-Fenton-mediated dye decoloration were examined and compared to our previously published results with photolytic and Fenton-mediated Neutral Red decoloration. Most of the ions tested had an inhibitory effect on photo-Fenton process, but unexpectedly enhanced the photocatalytic process, except for chloride, which inhibited both the processes. The kinetics data in both the cases fitted well to the First-Order Equation. Comparison of the results among the four different advanced oxidation processes shows that Neutral Red is most efficiently degraded by photo-Fenton process, followed by Fenton process, then photolytic, and then with photocatalytic process.

  • comparative decoloration study of neutral red by different oxidative processes
    Dyes and Pigments, 2007
    Co-Authors: Maitha M Alnuaimi, Muhammad A. Rauf, Salman S Ashraf
    Abstract:

    Neutral Red was subjected to two different oxidative processes, namely the photo-oxidative process and the Fenton process. The dye was found to undergo substantial and rapid decoloration by both the methods. Conditions were optimized in both the sets of experiments to achieve the most efficient dye decoloration. Additionally the effects of added anions on dye decoloration were examined and it was found that in both cases, the chloride ions caused a significant decrease in the decoloration rate. The kinetics data in both the cases fitted well to the First-Order Equation. A comparison of the effects of various anions on the decoloration rate revealed dramatic differences in apparent rate constant of decoloration of the dye especially in the presence of phosphate ions. Additionally the Fenton process was found to be more efficient in decolorizing the dye as compared to the photo-oxidative process.