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Online since: June 2014
Authors: Fazlena Hamzah, Jagannathan Krishnan, Shareena Fairuz Abdul Manaf, Ani Idris, Farah Nur Zaiham Zulkifli, Mahanim Sarif, Nur Hamizah Ismail, Wan Asma Ibrahim
Bamboo was grinded into 200 to 500 µm using Octagon Digital Mechanical Sieve (London).
Activated carbons were prepared through different carbonization temperature (400oC and 500oC) and types of activation (AC1 and AC2) in order to determine the best physical properties of activated carbon produced as shown in Table 1.
Another factor that contributes to development of pores was the cavitation effect of microwave radiation.
The FTIR analysis revealed that microwave activated carbon gave more carbon properties than thermal activated carbon for analysis.
Functioning group analyses show the reduction of the group when exposed to the irradiation and results in more carbon properties which is good for activated carbon.
Activated carbons were prepared through different carbonization temperature (400oC and 500oC) and types of activation (AC1 and AC2) in order to determine the best physical properties of activated carbon produced as shown in Table 1.
Another factor that contributes to development of pores was the cavitation effect of microwave radiation.
The FTIR analysis revealed that microwave activated carbon gave more carbon properties than thermal activated carbon for analysis.
Functioning group analyses show the reduction of the group when exposed to the irradiation and results in more carbon properties which is good for activated carbon.
Online since: March 2017
Authors: Elkanah Oyetunji, Saheed Akande, Ayodeji Emmanuel Oluleye
Minimization of Total Tardiness and Total Flowtime on Single Machine with Non-Zero Release Dates
Saheed Akande1,a*, Ayodeji Emmanuel Oluleye2,b and Elkanah Oyetunji3,c
1Department of Mechanical and Mechatronics Engineering, Afe Babalola University,
Ado-Ekiti, Nigeria
2Department of Industrial and Production Engineering, University of Ibadan, Nigeria
3Department of Mechanical Engineering, Lagos State University, Nigeria
aakande4success@yahoo.com, bayodeji.aoluleye@ui.edu.ng, ceoyetunji@yahoo.com
Keywords: Bicriteria.
Problem Definition Given the following for a single machine problem: i. set of n jobs; J1 , J2 , … Jn ii. processing time of each job; Pi iii. release or ready time of each job; ri iv. due dates of each job; di The time the processing of job Ji starts on the machine (start time) is designated as Si with the property Si ≥ ri (1) The completion time of each job (Ci) is defined as: Ci = Si + Pi (2) The flow time of each job is defined as: Fi = Ci - ri (3) Therefore, the total flowtime (Ftot) is given by:
(6) Apply the scheduling notation, the problem is represented as: 1 | ri|(i=1nTi, i=1nFi) (7) Thus, the linear composite objective function (LCOF) is defined as: LCOF= αi=1nTi + βi=1nFi (8) Essentially, α and β represent the relative importance (weighting factors) of the total tardiness and the total flowtime criteria respectively.
The processing time and the release date affect the two objectives, while the due date affects only the tardiness.
This heuristic is based on the fact that the due date has no effect on the flow time function but it affects the overall objective function.
Problem Definition Given the following for a single machine problem: i. set of n jobs; J1 , J2 , … Jn ii. processing time of each job; Pi iii. release or ready time of each job; ri iv. due dates of each job; di The time the processing of job Ji starts on the machine (start time) is designated as Si with the property Si ≥ ri (1) The completion time of each job (Ci) is defined as: Ci = Si + Pi (2) The flow time of each job is defined as: Fi = Ci - ri (3) Therefore, the total flowtime (Ftot) is given by:
(6) Apply the scheduling notation, the problem is represented as: 1 | ri|(i=1nTi, i=1nFi) (7) Thus, the linear composite objective function (LCOF) is defined as: LCOF= αi=1nTi + βi=1nFi (8) Essentially, α and β represent the relative importance (weighting factors) of the total tardiness and the total flowtime criteria respectively.
The processing time and the release date affect the two objectives, while the due date affects only the tardiness.
This heuristic is based on the fact that the due date has no effect on the flow time function but it affects the overall objective function.
Online since: March 2009
Authors: Tatsuo Inoue
Thus obtained
strain rate reveals to include the transformation plastic part in addition to thermo-mechanical plastic
components.
,I � = as is shown in Fig.6(a) and that the mechanical and thermophysical property χχχχ is represented by the mixture law [17] such that 1 � I I I = = ∑χξχχ ξχχ ξχχ ξχ , with 11 � I I = =∑ξξξξ
The first term in Eq.(9) is the ordinal thermo-mechanical plastic strain rate in the I-th phase, which is supperimosed mechanical and thermal parts.
Ju and the author [3] available to simulate metallo-thermo-mechanical processes.
The equivalent stress σ in the matrix near the interface is 3 2 r r = − =θσ σ σ σ (29) will give a large value to cause the yielding, even if the stress is a little reduced due to stress concentration factor αis less than unity when subjected to tensile stress.
,I � = as is shown in Fig.6(a) and that the mechanical and thermophysical property χχχχ is represented by the mixture law [17] such that 1 � I I I = = ∑χξχχ ξχχ ξχχ ξχ , with 11 � I I = =∑ξξξξ
The first term in Eq.(9) is the ordinal thermo-mechanical plastic strain rate in the I-th phase, which is supperimosed mechanical and thermal parts.
Ju and the author [3] available to simulate metallo-thermo-mechanical processes.
The equivalent stress σ in the matrix near the interface is 3 2 r r = − =θσ σ σ σ (29) will give a large value to cause the yielding, even if the stress is a little reduced due to stress concentration factor αis less than unity when subjected to tensile stress.
Online since: June 2020
Authors: Yi Yan, Wei Jia Peng, Rui Jun Fan, Guo Lin Cao, Xiao Hui Shen, Zhan Yuan Tian, Hua Jun Guo
Another crucial factor that affects the cyclic performance is the solid-electrolyte-interface(SEI) which arises from the decomposition of the electrolyte.
[12] Wang, J.; Zhang, G.; Liu, Z.; Li, H.; Liu, Y.; Wang, Z.; Li, X.; Shih, K.; Mai, L., Li3V(MoO4) 3 as a novel electrode material with good lithium storage properties and improved initial coulombic efficiency.
[14] Li, T.; Li, X.; Wang, Z.; Guo, H.; Li, Y.; Wang, J., A new design concept for preparing nickel-foam-supported metal oxide microspheres with superior electrochemical properties.
C., Superior electrochemical properties of rutile VO2-carbon composite microspheres as a promising anode material for lithium ion batteries.
[40] Bosch, H.; Kip, B.J.; Van Ommen, J.G.; Gellings, P.J, Factors influencing the temperature-programmed reduction profiles of vanadium pentoxide.
[12] Wang, J.; Zhang, G.; Liu, Z.; Li, H.; Liu, Y.; Wang, Z.; Li, X.; Shih, K.; Mai, L., Li3V(MoO4) 3 as a novel electrode material with good lithium storage properties and improved initial coulombic efficiency.
[14] Li, T.; Li, X.; Wang, Z.; Guo, H.; Li, Y.; Wang, J., A new design concept for preparing nickel-foam-supported metal oxide microspheres with superior electrochemical properties.
C., Superior electrochemical properties of rutile VO2-carbon composite microspheres as a promising anode material for lithium ion batteries.
[40] Bosch, H.; Kip, B.J.; Van Ommen, J.G.; Gellings, P.J, Factors influencing the temperature-programmed reduction profiles of vanadium pentoxide.
Online since: February 2012
Authors: F. Suárez-García, J.I. Paredes, M. Pérez-Mendoza, J. Nauroy, A. Martínez-Alonso, J.M.D. Tascón
Introduction
Carbon nanofibers (CNFs) are currently the focus of intense research attention as a result of a number of attractive properties.
Simpson, Magnetic properties of Fe-Co catalysts used for carbon nanofiber synthesis, J.
Rice, A review of the fabrication and properties of vapor-grown carbon nanofiber/polymer composites, Compos.
Calafat, Factors affecting the preparation of activated carbons from coconut shell catalized by potassium, Carbon 29 (1991) 949-953. ].
Yang, Effect of activation temperature on the textural and chemical properties of potassium hydroxide activated carbon prepared from pistachio-nut shell, J.
Simpson, Magnetic properties of Fe-Co catalysts used for carbon nanofiber synthesis, J.
Rice, A review of the fabrication and properties of vapor-grown carbon nanofiber/polymer composites, Compos.
Calafat, Factors affecting the preparation of activated carbons from coconut shell catalized by potassium, Carbon 29 (1991) 949-953. ].
Yang, Effect of activation temperature on the textural and chemical properties of potassium hydroxide activated carbon prepared from pistachio-nut shell, J.
Online since: April 2013
Authors: Anna Gazi, George Skevis, Maria Founti
Finishing equipment includes two polishing machines that are used to adjust the product thickness to a prescribed tolerance and to give light reflecting properties to the marble surface.
The total score is based on the sum of individual scores given for each indicator, multiplied by a corrective weighting factor.
Each indicator is also multiplied by a corrective weighting factor, W1-W3, also shown in Table 3.
A low “sufficient” score has been assigned to the quarry impact ratio since a large part of the surrounding area is affected by the quarry operations.
Although the population density near the particular quarries is rather low, naturally there is no room for improvement in the corresponding weighting factor (W2) which affects four out of six indicators.
The total score is based on the sum of individual scores given for each indicator, multiplied by a corrective weighting factor.
Each indicator is also multiplied by a corrective weighting factor, W1-W3, also shown in Table 3.
A low “sufficient” score has been assigned to the quarry impact ratio since a large part of the surrounding area is affected by the quarry operations.
Although the population density near the particular quarries is rather low, naturally there is no room for improvement in the corresponding weighting factor (W2) which affects four out of six indicators.
Online since: November 2011
Authors: Hai Yan Wang, Ke Gao, Jing Zhuo Shi
System of ultrasonic motor is time-varying, coupling nonlinear seriously, such as driving circuit nonlinear, piezoelectric materials nonlinear, mechanical friction transmission nonlinear between the stator and rotor of ultrasonic motor and so on [1,2].
So, It is a key of ultrasonic motor speed control study how to overcome the motor inherent nonlinear for getting a good speed control properties [3].
Because the limiting amplitude is caused, the speed control modulation is the open-loop at now, it is unable to continue to control the speed change with factors such as temperature and so on.
Experimental results show that voltage amplitude gradually is reduced and will not affect the motor starter to high speed after the motor begins to rotate, which can reduce the initial voltage amplitude given value when it enter to the adjustment amplitude control.
So, It is a key of ultrasonic motor speed control study how to overcome the motor inherent nonlinear for getting a good speed control properties [3].
Because the limiting amplitude is caused, the speed control modulation is the open-loop at now, it is unable to continue to control the speed change with factors such as temperature and so on.
Experimental results show that voltage amplitude gradually is reduced and will not affect the motor starter to high speed after the motor begins to rotate, which can reduce the initial voltage amplitude given value when it enter to the adjustment amplitude control.
Online since: July 2014
Authors: K.R. Balasubramanian, T. Suthakar, K. Sankaranarayanasamy, G. Buvanashekaran
Buvanashekaran4d
1, 2, 3 Department of Mechanical Engineering, National Institute of Technology,
Tiruchirappalli – 620015
4Welding Research Institute, Bharat Heavy Electrical Limited, Tiruchirappalli – 620014
akrbalas@gmail.com, bsuthakar@nitt.edu, cksnsamy@nitt.edu, dgbs@bheltry.co.in
Keywords: Laser beam welding, cooling rate, thermal cycles, Finite volume method, Velocity profiles, fluid flow.
The weld bead formation of the laser welding process relies on many process parameters like laser beam incident power, beam spot diameter, beam configuration, worktable travelling speed, focal position, shield gas shroud design, gas flow rate, joint geometries, gap tolerance, surface condition (roughness, temperature), thickness and thermophysical properties of the work piece.
However, the 2-D modeling does not include many factors such as the surface tension gradient at the weld pool surfaces and the buoyancy effect within the melt zone to enable one to predict the effects on metal flow and heat transfer [7- 9].
The heat affected zone is very small.
The weld bead formation of the laser welding process relies on many process parameters like laser beam incident power, beam spot diameter, beam configuration, worktable travelling speed, focal position, shield gas shroud design, gas flow rate, joint geometries, gap tolerance, surface condition (roughness, temperature), thickness and thermophysical properties of the work piece.
However, the 2-D modeling does not include many factors such as the surface tension gradient at the weld pool surfaces and the buoyancy effect within the melt zone to enable one to predict the effects on metal flow and heat transfer [7- 9].
The heat affected zone is very small.
Online since: May 2021
Authors: Darmadi Darmadi, Siti Syifa Azzahra, Munadiya Masrura, Mahidin Mahidin
The removal of mercury from the waterbody remains a severe challenge in ensuring environmental safety due to its highly toxic and non-biodegradable properties.
Bentonite is a natural aluminium phyllosilicate with subtantial adsorption properties such as highly porous silicate and crystal structures are formed by combination of silica tetrahedral and alumino octahedral which advancing adsorbent quality [3].
Honeycomb-monolith as structurized adsorbent is believed to be advantageous prior to its low pressure drop, easier for the adsorbate stream to pass, good thermal and mechanical properties, and simple scale up [8].
By examining the experimental data, we acquired that adsorption rate is affected by initial concentration of adsorbate and the highest efficiency of BBM adsorbent in mercury removal is 63,9%.
Marmier, Adsorptive properties of Moroccan clays for the removal of arsenic(V) from aqueous solution, Appl.
Bentonite is a natural aluminium phyllosilicate with subtantial adsorption properties such as highly porous silicate and crystal structures are formed by combination of silica tetrahedral and alumino octahedral which advancing adsorbent quality [3].
Honeycomb-monolith as structurized adsorbent is believed to be advantageous prior to its low pressure drop, easier for the adsorbate stream to pass, good thermal and mechanical properties, and simple scale up [8].
By examining the experimental data, we acquired that adsorption rate is affected by initial concentration of adsorbate and the highest efficiency of BBM adsorbent in mercury removal is 63,9%.
Marmier, Adsorptive properties of Moroccan clays for the removal of arsenic(V) from aqueous solution, Appl.