Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512189
S. Zafar, A. Kashif, S. Hussain, N. Akhtar, N. Bhatti, M. Imran
The terrific carrier transport properties of III-V compound semiconductors have attraction for THz applications due to outstanding high-frequency characteristics. III-V HEMTs based on InGaAs/InAlAs have emerged as particularly promising for high frequencies applications. In this paper, we present two-dimensional (2-D) HEMTs structures based on InAlAs/ InGaAs using Silvaco TCAD software. Two types of HEMT structures were focused to enhance the frequency of operation: a) conventional single gate HEMT (SGHEMT) structure, and b) double gate HEMT (DGHEMT) structure. In SGHEMT devices, two different gate lengths (300 and 100nm) were studied while DGHEMT device was designed with 50nm gate length. In SGHEMT devices, fmax is increased from 349 to 432 GHz by the reduction in gate length. Similarly, fT is increased from 108 to 144 GHz. Hence, 33% enhancement in cut-off frequency is achieved. For further enhancement in frequency, DGHEMT structure is implemented to increase the cut-off frequency upto 175 GHz.
{"title":"Designing of double gate HEMT in TCAD for THz applications","authors":"S. Zafar, A. Kashif, S. Hussain, N. Akhtar, N. Bhatti, M. Imran","doi":"10.1109/IBCAST.2013.6512189","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512189","url":null,"abstract":"The terrific carrier transport properties of III-V compound semiconductors have attraction for THz applications due to outstanding high-frequency characteristics. III-V HEMTs based on InGaAs/InAlAs have emerged as particularly promising for high frequencies applications. In this paper, we present two-dimensional (2-D) HEMTs structures based on InAlAs/ InGaAs using Silvaco TCAD software. Two types of HEMT structures were focused to enhance the frequency of operation: a) conventional single gate HEMT (SGHEMT) structure, and b) double gate HEMT (DGHEMT) structure. In SGHEMT devices, two different gate lengths (300 and 100nm) were studied while DGHEMT device was designed with 50nm gate length. In SGHEMT devices, fmax is increased from 349 to 432 GHz by the reduction in gate length. Similarly, fT is increased from 108 to 144 GHz. Hence, 33% enhancement in cut-off frequency is achieved. For further enhancement in frequency, DGHEMT structure is implemented to increase the cut-off frequency upto 175 GHz.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128076405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512187
M. I. Nawaz, M. Kashif, A. Mueed, Zhao Huiling
This research contribution highlights the design process of a compact wideband microstrip bandpass filter for IF stage of Millimeterwave Systems. The composite BPF technique is utilized in this publication for its wideband and compact nature. The filter structure consists of series hi-low impedance microstrip transmission lines and shunt shorted high-impedance stubs. The lengths and widths of these microstrip sections are optimized to obtain the desired bandpass filter characteristics. Additionally, 50 percent size reduction is achieved by the application of meandered structure to the high-impedance lines and stubs. The bandwith of the filter is 2.3GHz with pass band of 1-3.3GHz. The insertion loss of the filter is less than 1.2dB and return loss is better than 10dB in the 1 - 3.3GHz pass band. The 3-dB fractional bandwidth of filter is 120%.The upper out-of-band rejection is 25dB at 4.5GHz. The size of the filter is 1200mil × 440mil which is extremely small at the operating frequency band.
{"title":"Compact wideband microstrip bandpass filter for IF stage of millimeterwave systems","authors":"M. I. Nawaz, M. Kashif, A. Mueed, Zhao Huiling","doi":"10.1109/IBCAST.2013.6512187","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512187","url":null,"abstract":"This research contribution highlights the design process of a compact wideband microstrip bandpass filter for IF stage of Millimeterwave Systems. The composite BPF technique is utilized in this publication for its wideband and compact nature. The filter structure consists of series hi-low impedance microstrip transmission lines and shunt shorted high-impedance stubs. The lengths and widths of these microstrip sections are optimized to obtain the desired bandpass filter characteristics. Additionally, 50 percent size reduction is achieved by the application of meandered structure to the high-impedance lines and stubs. The bandwith of the filter is 2.3GHz with pass band of 1-3.3GHz. The insertion loss of the filter is less than 1.2dB and return loss is better than 10dB in the 1 - 3.3GHz pass band. The 3-dB fractional bandwidth of filter is 120%.The upper out-of-band rejection is 25dB at 4.5GHz. The size of the filter is 1200mil × 440mil which is extremely small at the operating frequency band.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124944382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512157
K. Ahmad, W. Wuzhigang, H. Rahman
High altitude long endurance (HALE) UAVs have very flexible wing because of mission requirements. High lifts to drag ratio and more surveillance time in air requirements make their structure highly flexible and large tip deflections can occur which can be as large as 30% of wing semi span. Linear theory fails to accurately analyze such deformation and the changes in the structural and aerodynamic characteristics of the wing accompanying such deformation. Low aspect ratio wing and stiff structures can be best simulated by normal modes in aeroelastic analysis. However high aspect ratio restricts the use of reduce order model based on linear normal modes in aeroelastic analysis. The reason not to use the linear elastic normal modes in high AR wings is the stiffening effects because of large deflections. These effects cause the normal modes to fail as a good basis set. In such situation one needs to use the modified basis function. The computational model used in this work consists of a modified modal based reduced order nonlinear structural dynamics model coupled to a ZONA6's lifting surface method which is a higher-order panel method. Using modified modal basis, geometrical nonlinearities has been captured very well. Aeroelastic analyses agree well with the published data.
{"title":"Aeroelastic analysis of high aspect ratio wing in subsonic flow","authors":"K. Ahmad, W. Wuzhigang, H. Rahman","doi":"10.1109/IBCAST.2013.6512157","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512157","url":null,"abstract":"High altitude long endurance (HALE) UAVs have very flexible wing because of mission requirements. High lifts to drag ratio and more surveillance time in air requirements make their structure highly flexible and large tip deflections can occur which can be as large as 30% of wing semi span. Linear theory fails to accurately analyze such deformation and the changes in the structural and aerodynamic characteristics of the wing accompanying such deformation. Low aspect ratio wing and stiff structures can be best simulated by normal modes in aeroelastic analysis. However high aspect ratio restricts the use of reduce order model based on linear normal modes in aeroelastic analysis. The reason not to use the linear elastic normal modes in high AR wings is the stiffening effects because of large deflections. These effects cause the normal modes to fail as a good basis set. In such situation one needs to use the modified basis function. The computational model used in this work consists of a modified modal based reduced order nonlinear structural dynamics model coupled to a ZONA6's lifting surface method which is a higher-order panel method. Using modified modal basis, geometrical nonlinearities has been captured very well. Aeroelastic analyses agree well with the published data.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"310 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122780250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512194
M. Niaz, R. Bhatti, I. Majid
Lossy frequency selective surfaces have been used to design thin and broadband electromagnetic absorbers. Unit cell of the FSS is based on two concentric Minkowski loops. In the first design, the Minkowski loops are loaded with lumped resistors in different configurations. In the second design, Minkowski loops are designed using the concept of resistive sheets. Resistive Minkowski loops offer very wide bandwidth from 2.2GHz to 9.4GHz and 4.5GHz to 17GHz for reflection loss greater than 10dB. Thickness of the absorber with resistive Minkowski loops is 0.09λ.
{"title":"Design of broadband electromagnetic absorber using resistive Minkowski loops","authors":"M. Niaz, R. Bhatti, I. Majid","doi":"10.1109/IBCAST.2013.6512194","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512194","url":null,"abstract":"Lossy frequency selective surfaces have been used to design thin and broadband electromagnetic absorbers. Unit cell of the FSS is based on two concentric Minkowski loops. In the first design, the Minkowski loops are loaded with lumped resistors in different configurations. In the second design, Minkowski loops are designed using the concept of resistive sheets. Resistive Minkowski loops offer very wide bandwidth from 2.2GHz to 9.4GHz and 4.5GHz to 17GHz for reflection loss greater than 10dB. Thickness of the absorber with resistive Minkowski loops is 0.09λ.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126437294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512148
A. Ali
Feedback with Carry Shift Registers (FCSRs) are being explored for their usage as building blocks in stream ciphers. Linearisation attacks are most effective attacks on a class of FCSR-based stream ciphers, which use filtered Galois FCSRs as building blocks. This paper presents techniques for software simulation of these attacks on such ciphers. In order to describe these techniques, the paper uses a small scale variant of the F-FCSR-H v2 type keystream generators, which is known as T-cipher. The paper uses the pseudorandom keystream generator of the T-cipher to develop a statistical analysis. The paper uses this analysis to demonstrate various aspects of the implementation of linearisation attacks on such ciphers. Moreover the paper presents a pseudocode algorithm along with its implementation details for computing the success characteristics of linearisation attacks. The paper also presents enumeration and pseudocode algorithms for solving systems of polynomial equations in the finite field F2.
{"title":"On software simulation of linearisation attacks on FCSR-based stream ciphers","authors":"A. Ali","doi":"10.1109/IBCAST.2013.6512148","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512148","url":null,"abstract":"Feedback with Carry Shift Registers (FCSRs) are being explored for their usage as building blocks in stream ciphers. Linearisation attacks are most effective attacks on a class of FCSR-based stream ciphers, which use filtered Galois FCSRs as building blocks. This paper presents techniques for software simulation of these attacks on such ciphers. In order to describe these techniques, the paper uses a small scale variant of the F-FCSR-H v2 type keystream generators, which is known as T-cipher. The paper uses the pseudorandom keystream generator of the T-cipher to develop a statistical analysis. The paper uses this analysis to demonstrate various aspects of the implementation of linearisation attacks on such ciphers. Moreover the paper presents a pseudocode algorithm along with its implementation details for computing the success characteristics of linearisation attacks. The paper also presents enumeration and pseudocode algorithms for solving systems of polynomial equations in the finite field F2.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123370232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512131
M. Abid, A. Q. Khan, M. Rehan, M. Adil
There has been extensive research for sensor fault reconstruction / estimation for Lipschitz nonlinear systems (LNS). This paper extends the existing theory to a recently introduced class of nonlinear systems called one-sided Lipschitz nonlinear systems (OLNS). One-sided Lipschitz nonlinear systems not only cover a wider class of nonlinear systems but also generate less conservative results compared to Lipschitz nonlinear systems. The proposed solution is presented in form of linear matrix inequalities which are easily tractable with standard algorithms. The proposed method is outlined by an illustrative example.
{"title":"Sensor fault reconstruction for one-sided Lipschitz nonlinear systems","authors":"M. Abid, A. Q. Khan, M. Rehan, M. Adil","doi":"10.1109/IBCAST.2013.6512131","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512131","url":null,"abstract":"There has been extensive research for sensor fault reconstruction / estimation for Lipschitz nonlinear systems (LNS). This paper extends the existing theory to a recently introduced class of nonlinear systems called one-sided Lipschitz nonlinear systems (OLNS). One-sided Lipschitz nonlinear systems not only cover a wider class of nonlinear systems but also generate less conservative results compared to Lipschitz nonlinear systems. The proposed solution is presented in form of linear matrix inequalities which are easily tractable with standard algorithms. The proposed method is outlined by an illustrative example.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114391805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512176
M. S. Khan, M. F. Shafique, A. Capobianco, E. Autizi, I. Shoaib
In this paper, a compact planar Ultra-Wideband (UWB) Multiple-input Multiple-output (MIMO) antenna array is proposed. This UWB-MIMO antenna array consists of two identical monopole antenna elements with a novel decoupling structure etched on the ground plane. The antenna performs very well over the UWB frequency range of 3.1-10.6 GHz. The decoupling structure improves the isolation between the antennas over the complete frequency band which can only be achieved otherwise by increasing the separation between the antenna elements. The analysis of antenna performance with and without stub is provided to demonstrate the significance of adding the decoupling stub to the design. The proposed compact and cost efficient antenna array system measures 27 × 47 mm2 only.
{"title":"Compact UWB-MIMO antenna array with a novel decoupling structure","authors":"M. S. Khan, M. F. Shafique, A. Capobianco, E. Autizi, I. Shoaib","doi":"10.1109/IBCAST.2013.6512176","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512176","url":null,"abstract":"In this paper, a compact planar Ultra-Wideband (UWB) Multiple-input Multiple-output (MIMO) antenna array is proposed. This UWB-MIMO antenna array consists of two identical monopole antenna elements with a novel decoupling structure etched on the ground plane. The antenna performs very well over the UWB frequency range of 3.1-10.6 GHz. The decoupling structure improves the isolation between the antennas over the complete frequency band which can only be achieved otherwise by increasing the separation between the antenna elements. The analysis of antenna performance with and without stub is provided to demonstrate the significance of adding the decoupling stub to the design. The proposed compact and cost efficient antenna array system measures 27 × 47 mm2 only.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134462263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512169
O. Mubarak, A. Dempster
The paper presents analysis for using China based Beidou as satellite navigation system in Pakistan's naval vessels as an alternative or additional aid to US based GPS, which is currently most widely used system. A full scale Beidou will have lower dilution of precision implying better coverage in Arabian Sea as compared to GPS. The paper also compares Beidou open service signal B1 with conventional GPS signal L1. B1 has better performance in terms of multipath error and cross correlation noise. Lastly, design considerations for receiving B1 signal on L1 receiver are addressed in the paper in terms of modifications required in RF front end, signal processing and computing navigation solution.
{"title":"Beidou: A GPS alternative for Pakistan's naval vessels","authors":"O. Mubarak, A. Dempster","doi":"10.1109/IBCAST.2013.6512169","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512169","url":null,"abstract":"The paper presents analysis for using China based Beidou as satellite navigation system in Pakistan's naval vessels as an alternative or additional aid to US based GPS, which is currently most widely used system. A full scale Beidou will have lower dilution of precision implying better coverage in Arabian Sea as compared to GPS. The paper also compares Beidou open service signal B1 with conventional GPS signal L1. B1 has better performance in terms of multipath error and cross correlation noise. Lastly, design considerations for receiving B1 signal on L1 receiver are addressed in the paper in terms of modifications required in RF front end, signal processing and computing navigation solution.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124932834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512121
Haibo Jin, Qun Zhao
A three level layout optimization strategy is proposed in this paper for large-scale composite wing structures. Design requirements are adjusted at the primary level according to structural deformation and strength, then the stringers and ribs layout are designed by the instability criteria at the second level, at last the laminate optimization is used to increase the composite panel carrying efficiency. In this paper, stiffened wing panels first are modeled by the equivalent laminate plates, whose thickness is determined by the global wing structure's deformation and strength. At last a detailed FEM model is build to reflect accurate instability limit and is used to do global synthetical optimization. Finally, the three level optimization of large-scale wing structure is completed as an example. The result fulfills design requirements and shows the feasibility of this method.
{"title":"Modified multilevel layout optimization method of composite wing structure","authors":"Haibo Jin, Qun Zhao","doi":"10.1109/IBCAST.2013.6512121","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512121","url":null,"abstract":"A three level layout optimization strategy is proposed in this paper for large-scale composite wing structures. Design requirements are adjusted at the primary level according to structural deformation and strength, then the stringers and ribs layout are designed by the instability criteria at the second level, at last the laminate optimization is used to increase the composite panel carrying efficiency. In this paper, stiffened wing panels first are modeled by the equivalent laminate plates, whose thickness is determined by the global wing structure's deformation and strength. At last a detailed FEM model is build to reflect accurate instability limit and is used to do global synthetical optimization. Finally, the three level optimization of large-scale wing structure is completed as an example. The result fulfills design requirements and shows the feasibility of this method.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126178921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-05-02DOI: 10.1109/IBCAST.2013.6512122
N. Ahmad, S. Hussain, B. Muhammad, J. A. Anderson, N. Ali, S. Abbas
In order to enhance the catalytic activity of Alumina supported cobalt catalyst (Co/Al2O3) for Fischer Tropsch synthesis, 1.5 and 2.5 wt% Au promoted 10% Co/Al2O3 is synthesized by coprecipitation and impregnation methods. The synthesized catalysts are characterized using XRD, TPR, TGA and BET techniques while fixed bed micro reactor is used to evaluate the activity and selectivity of prepared catalysts. The results confirm that 1.5 wt% Au loading shows higher CO conversion and C5+ hydrocarbons selectivity along with decreased selectivity towards methane and lower hydrocarbons. It is proposed through TPR studies that Au addition enhances the reduction of cobalt oxide thereby increasing the number of active sites and hence catalytic efficiency. Additionally, an increase in pressure and reduced feed flow rate led to excessive hydrocarbons production and subsequent conversion of syngas, possibly due to extended contact time between catalyst and reactants.
{"title":"Influence of gold promoter on Fischer Tropsch synthesis Over Co/Al2O3 catalysts","authors":"N. Ahmad, S. Hussain, B. Muhammad, J. A. Anderson, N. Ali, S. Abbas","doi":"10.1109/IBCAST.2013.6512122","DOIUrl":"https://doi.org/10.1109/IBCAST.2013.6512122","url":null,"abstract":"In order to enhance the catalytic activity of Alumina supported cobalt catalyst (Co/Al2O3) for Fischer Tropsch synthesis, 1.5 and 2.5 wt% Au promoted 10% Co/Al2O3 is synthesized by coprecipitation and impregnation methods. The synthesized catalysts are characterized using XRD, TPR, TGA and BET techniques while fixed bed micro reactor is used to evaluate the activity and selectivity of prepared catalysts. The results confirm that 1.5 wt% Au loading shows higher CO conversion and C5+ hydrocarbons selectivity along with decreased selectivity towards methane and lower hydrocarbons. It is proposed through TPR studies that Au addition enhances the reduction of cobalt oxide thereby increasing the number of active sites and hence catalytic efficiency. Additionally, an increase in pressure and reduced feed flow rate led to excessive hydrocarbons production and subsequent conversion of syngas, possibly due to extended contact time between catalyst and reactants.","PeriodicalId":276834,"journal":{"name":"Proceedings of 2013 10th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128865213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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