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2005

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Articles 601 - 630 of 3074

Full-Text Articles in Engineering

Effects Of Long-Term Wastewater Application On Chemical Properties And Phosphorus Adsorption Capacity In Soils Of A Wastewater Land Treatment System, Cong Hu, Tian Zhang, Yong Huang, Mohamed F. Dahab, Rao Surampalli Aug 2005

Effects Of Long-Term Wastewater Application On Chemical Properties And Phosphorus Adsorption Capacity In Soils Of A Wastewater Land Treatment System, Cong Hu, Tian Zhang, Yong Huang, Mohamed F. Dahab, Rao Surampalli

Department of Civil and Environmental Engineering: Faculty Publications

The buildup of phosphorus (P) in the soil is a major factor limiting the operating life of a wastewater land treatment system. In this study, we evaluated changes of chemical properties, P profiles, and adsorption isotherms in the soils of a Muskegon wastewater land treatment system, which has received wastewater for ~30 years. It was found that the pH in the 15-cm topsoil increased from ~5-6 in 1973 to ~7.4-7.8 in 2003; a large amount of salt (e.g., Ca, Mg) in wastewater was adsorbed by the soil; the soil Al content (either exchangeable or oxalate extractable) decreased, while the oxalate-extractable …

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Quantified Model Of Cobit For Corporate It Governance, M. Sibghatullah Siddiqui, Dr. Syed Jamal Hussain Aug 2005

Quantified Model Of Cobit For Corporate It Governance, M. Sibghatullah Siddiqui, Dr. Syed Jamal Hussain

International Conference on Information and Communication Technologies

Now organizations are more concerned about the appropriate IT governance. The growing dependency on IT due to the increasing volume of business process automation further challenges the role of Information System Auditor. IT Governance Institute has developed COBIT1 as a model for this purpose [1][2]. The model proposed in this research quantifies the COBIT by developing matrices for all four domains of COBIT; hence it provides a quantitative approach for better implementation of corporate IT governance through effective audit and control.

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Irrigation Network Regulation Through Cad System, Dr. Mumtaz Ahmed Sohag, Ali Asghar Mahessar Aug 2005

Irrigation Network Regulation Through Cad System, Dr. Mumtaz Ahmed Sohag, Ali Asghar Mahessar

International Conference on Information and Communication Technologies

The irrigation system of Pakistan is the largest integrated network in the world. There are 3 major storage reservoirs, 19 barrages, 12 inter-river link canals, 45 independent irrigation canal commands and over 1,22,268 watercourses. The network of irrigation of the province of Sindh consists of 3 barrages and 14 canal commands. The irrigation water is being used for agricultural, industrial and domestic purposes. Owing to mismanagement and inequitable distribution of water, it is necessary to have a fool-proof system where water is supplied to the end-users judiciously. Therefore water managers and farmers cannot know, how much quantum of water has …

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Poster Session A: A Multi-Priority Application Framework For Mobile Ad Hoc Networks, M. Ibrahim Channa, Ahsan Chaudhry, Kashif Sharif, Irum Memon Aug 2005

Poster Session A: A Multi-Priority Application Framework For Mobile Ad Hoc Networks, M. Ibrahim Channa, Ahsan Chaudhry, Kashif Sharif, Irum Memon

International Conference on Information and Communication Technologies

The fast spread of small wireless computers has enabled the design and deployment of wireless Ad Hoc networks. Typical applications proposed for such networks include both Real Time and Non-Real Time applications. We propose an architecture that provides a complete framework for Real Time applications and Best Effort traffic. The proposed architecture comprises of an Ad Hoc Routing Protocol for route setup and route repair, a Bandwidth Allocation and Reservation Scheme for Real Time traffic, and a MAC layer protocol that provides traffic differentiation. The Admission Control module is used to admit or reject a new Real Time flow request …

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An Integrated Model For Signalized Traffic Intersection Control, Xiao-Hua Yu Aug 2005

An Integrated Model For Signalized Traffic Intersection Control, Xiao-Hua Yu

Electrical Engineering

Traffic signal control is an effective way to regulate traffic flow to avoid conflict and reduce congestions. This research investigates a real-time traffic signal control system that integrates a traffic flow prediction model and an adaptive control scheme based on dynamic programming with rolling horizon. The proposed approach estimates the parameter of the arriving traffic flow at the intersection, predicts the state transition probabilities, and then formulates the traffic signal control problem as a decision-making problem of a stochastic system. Two different traffic arrival patterns are considered, including the normal distribution and the Poission distribution.

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Nafion Emulsion Method For Fuel Cell Membrane-Electrode-Assembly Preparation, Chao-Yang Xia, Lin Zhuang, Jun-Tao Lu Aug 2005

Nafion Emulsion Method For Fuel Cell Membrane-Electrode-Assembly Preparation, Chao-Yang Xia, Lin Zhuang, Jun-Tao Lu

Journal of Electrochemistry

A Nafion emulsion method for fuel cell membrane-electrode-assembly (MEA) preparation was reported for the first time in this paper. 5 %(by mass) Nafion alcohol solution and non-polar solvent (e.g., cyclohexane) were ultrasonicallymixed to produce Nafion emulsion. The catalyst ink prepared using the thus-obtained Nafion emulsion can be directly cast onto Nafion membrane to make MEA. This method is simple in operation, and effectively preventsthe Nafion membrane swelling, hence is suitable for large-scale application. The MEA thus-prepared showed comparable catalyst efficiencywith respect to the popular transfer-method, and the preliminary performance in room-temperature H2/O2 fuel cell test was satisfying.

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Surface And Sructure Investigations Of Membrane Electrode Assembly In Dmfc Lifetime Testing, Xuan Cheng, Cheng Peng, Meng-Di You, Jing Liu, Ying Zhang Aug 2005

Surface And Sructure Investigations Of Membrane Electrode Assembly In Dmfc Lifetime Testing, Xuan Cheng, Cheng Peng, Meng-Di You, Jing Liu, Ying Zhang

Journal of Electrochemistry

The lifetime and performance of a direct methanol fuel cell (DMFC) were investigatedto understand the correlation between thestructure of catalysts/membrane and cell performanceversus time. The cell polarization and performance curves were obtained during the DMFC operation with the time. The catalysts and Nafion membrane of the membrane electrode assembly (MEA) from the lifetime test were comprehensively examined by XRD, HRTEM, FTIR and Raman spectroscope techniques. The results revealed that there was significant performance degradation during the first 200 hours operation; while the degradation was slowing down between 200 and 704 hours operation. The degradation became worse after 1002 h operation. …

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Effects Of Aluminide And Platinum-Aluminide Coatings On The Hot Corrosion Behavior Of Mar-M247 Nickel-Based Superalloy, I.K. Lee, W.T. Tasi, J.T. Lee Aug 2005

Effects Of Aluminide And Platinum-Aluminide Coatings On The Hot Corrosion Behavior Of Mar-M247 Nickel-Based Superalloy, I.K. Lee, W.T. Tasi, J.T. Lee

Journal of Electrochemistry

This study is to investigate the high temperature hot corrosion behavior of aluminide coating and platinum-aluminide coating on Ni-base superalloy MAR-M247. On the platinum-aluminide, aluminide and the base metal, respectively, by the salt spraying method. The resistances to hot corrosion of platinum-aluminide coating, aluminide coating and the base metal were evaluated by the variations of weight gains. Aluminide and platinum-aluminide coating showed significanty beneficial effect on inhibiting the hot corrosion of MAR-M247. But that of the platinum-aluminide coating was even much better. The aluminide coating surface was composed of β-NiAl, and that of the platinum-aluminide coating was PtAl2. …

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Cyclic Voltammetry And Surface Enhanced Raman Spectroscopy Of Dissociative Adsorption Of Ethanol On Pt-Ru Electrodes, Bin Zhang, Hai-Hui Zhou, Zu-Biao Wen, Qi-Ling Zhong, Peng Huang, Xiong-Yuan Yang, Bin Ren, Tian Aug 2005

Cyclic Voltammetry And Surface Enhanced Raman Spectroscopy Of Dissociative Adsorption Of Ethanol On Pt-Ru Electrodes, Bin Zhang, Hai-Hui Zhou, Zu-Biao Wen, Qi-Ling Zhong, Peng Huang, Xiong-Yuan Yang, Bin Ren, Tian

Journal of Electrochemistry

The behaviors of dissociative adsorption of ethanol on roughened platinum-ruthenium electrode with high activity of SERS were studied by using cyclic voltammetry and in-situ surface enhanced Raman spectroscopy, surface enhanced Raman spectra of dissociative adsorption of ethanol on Pt electrode in acid was obtained for the first time. It is shown that the Pt-Ru could lower the over-potential of CO oxidation when compared to Pt electrode. The results show that the ethanol in acid medium can be self-dissociated at Pt-Ru electrode to produce CO, which discourage the further oxidation of ethanol, some information of Pt-C and Pt-C-Pt stretching vibration from …

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Adsorption Of Polyaspartic Acid From Sulphur Acid Solution On Carbon Steel And Its Corrosion Inhibition, Rong-Jing Cui, Ning Gu, Chun-Mei Li Aug 2005

Adsorption Of Polyaspartic Acid From Sulphur Acid Solution On Carbon Steel And Its Corrosion Inhibition, Rong-Jing Cui, Ning Gu, Chun-Mei Li

Journal of Electrochemistry

The role of Polyaspartic acid in the corrosion inhibition of 45# carbon steel in sulphuric acid solution has been investigated by polarization curve andelectrochemical impedance spectroscopy (EIS). The influences of the concentration and the temperature of PASP on the corrosion inhibition efficiency were determined. The results indicated that the PASP as the corrosion inhibitor mainly inhibitated the anode; within the experiment temperature, the inhibitor efficiency decreased with the raising of the temperature and PASP had a good inhibiting performance at 10℃, the corrosion inhibition efficiency of PASP for carbon steel increased with the increase of the concentration of PASP when …

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An Electrochemical Behavior Of Limn2O4 Electrode In Electrolyte Based On Room Temperature Ionic Liquid, Hong-He Zheng, Lei Shi, Shu-Yan Gao, Jian-Ji Wang Aug 2005

An Electrochemical Behavior Of Limn2O4 Electrode In Electrolyte Based On Room Temperature Ionic Liquid, Hong-He Zheng, Lei Shi, Shu-Yan Gao, Jian-Ji Wang

Journal of Electrochemistry

The electrochemical behavior of spinel LiMn2O4 electrode in ionic liquid electrolyte was investigated by using cyclic voltammetry, galvanostatic charge-discharge and ACimpedance techniques. The results reveal that the spinel LiMn2O4 can be effectively cycled in electrolyte based on the ionic liquid with discharge capacity of 108.2mAh/g and Coulombic efficiency of more than 90% in the first cycle at room temperature. Temperature and current density play an important role in the electrode performances. The activation energy for lithium ion transfer through interface between the electrode and the electrolyte was evaluated by AC impedance spectroscopy. The high …

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Surface-Enhanced Raman Spectra Of Cytosine Adsorbed On A Roughened Gold Electrode, Yuan-Fei Wu, Jian-Feng Li, De-Yin Wu, Bin Ren, Zhong-Qun Tian Aug 2005

Surface-Enhanced Raman Spectra Of Cytosine Adsorbed On A Roughened Gold Electrode, Yuan-Fei Wu, Jian-Feng Li, De-Yin Wu, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

Cytosine adsorbed on a roughened gold electrode has been investigated by using electrochemical cyclic voltammetry and surface-enhanced Raman spectroscopy (SERS). The results indicate that cytosine was adsorbed on the Au electrode in a perpendicular orientation via the N3 position. As the maximum enhancement of ring breathing mode appears at negative potentials compared with other modes, both the electromagnetic enhancement and the charge transfer mechanism were considered to contribute to the SERS intensity. The binding interaction between cytosine and the gold electrode was weakened when the potential was negatively moved. The result also indicates that the SERS technique can be used …

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A Conjugate Dissolution/Deposition Behavior In Thin Layer Electrodeposition, Sun Bin, Xian-Wu Zou, Zhun-Zhi Jin Aug 2005

A Conjugate Dissolution/Deposition Behavior In Thin Layer Electrodeposition, Sun Bin, Xian-Wu Zou, Zhun-Zhi Jin

Journal of Electrochemistry

During the electrodeposition of lead, the dendrite deposit segregates from the cathode due to the disturbance of hydrogen gas. The segregated deposit could move toward the anode spontaneously rather than keep stationary. The studies show that this novel phenomenon was caused by the conjugate electrodissolution and electrodeposition reactions taking place at two ends of the isolated segment of the deposit. The mechanism inducing this phenomenon is suggested.

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Corrosion Behavior Of Sml, Erw Pipeline Steels Exposed To Seamud, Wei Hua, Xiu-Tong Wang, Rong-Jie Gao, Yan Li Aug 2005

Corrosion Behavior Of Sml, Erw Pipeline Steels Exposed To Seamud, Wei Hua, Xiu-Tong Wang, Rong-Jie Gao, Yan Li

Journal of Electrochemistry

The corrosion behavior of API Spec X60 pipeline steels, including electric resistance welding(ERW) and Seamless (SML) types, in sea mud gathered fromYangtse River estuaryof the East China Sea was investigatedthrough linear polarization resistance, potentio-dynamic polarizationand electrochemical impedance measurements. The result indicate the improved corrosion resistance of SML in sea mud. The oxygen diffusion in the cathode zone determines the corrosion behavior of pipeline steel in sea mud.

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Investigation, On The Accelerated Dissolution Of Metal Induced By Afm Tip Scratching And Suppressed By Inhibitors, Jun-E Qu, Xing-Peng Guo Aug 2005

Investigation, On The Accelerated Dissolution Of Metal Induced By Afm Tip Scratching And Suppressed By Inhibitors, Jun-E Qu, Xing-Peng Guo

Journal of Electrochemistry

The accelerated dissolution behavior of Cu-Ni alloy induced by AFM tip scratching and the inhibition effect of corrosion inhibitors were investigated. The results showedthat, with a tip loading of 750nN, continuous scan for 30 min in a contact mode on 4×4 μm2 of copper-nickel alloy in 1.5mol/L NaCl and 0.01mol/L HCl could enhance the dissolution of the sample and produced pits on the scratched area. Adding inorganic inhibitors, sodium chromateand organic inhibitor dodecylamine, to the solution suppressed the dissolution of copper-nickel alloyinduced by tip scratching, respectively, by improving the surface passivationperformance of metal surface and forming adsorption films on …

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Electrocatalytic Oxidation And Degration Of Active Red X-3b By Nanotubes Catalytic Electrodes, Yi Wen, Jian-Hui Fang, Wei-Min Cao, Li-Yi Shi Aug 2005

Electrocatalytic Oxidation And Degration Of Active Red X-3b By Nanotubes Catalytic Electrodes, Yi Wen, Jian-Hui Fang, Wei-Min Cao, Li-Yi Shi

Journal of Electrochemistry

The catalytic splitting decomposition of carbon nanotubes isprocessed by dispersing with dilute nitric acid and thermal oxidation. Then well-proportionedphenolic resin is mixed in the carbon nanotubes. Then, the carbon nanotubesare made into electrodes by hot-press molding after the process of milling with high speed. The surface of the carbon nanotubes electrodes is analyzed by SEM. Active red X-3B simulated waster water is disposed by carbon nanotubes catalyticelectrode (anode) and stainless steel(cathode). The influencing factors of degradation by current density, concentrationof electrolyte, systemtemperature and pH are investigated. The experimental results indicated that acidiccondition is propitious tothe degradationreaction of organicdyestuff and wastewater …

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Effect Of Chloride Ions On The Corrosion Behavior Of Reinforcing Steel In Simulated Concrete Pore Solutions, Yu Liu, Rong-Gui Du, Chang-Jian Lin Aug 2005

Effect Of Chloride Ions On The Corrosion Behavior Of Reinforcing Steel In Simulated Concrete Pore Solutions, Yu Liu, Rong-Gui Du, Chang-Jian Lin

Journal of Electrochemistry

The potentiodynamic anodic polarization was used to study the corrosion behavior of the reinforcing steel in simulated concrete pore solutions with different pH and chloride ion concentrations. The effect of chloride ions on passivity breakdown of the steel was examined by measuring the breaking potentials of reinforcing steel, and the critical chloride concentrations for depassivation were found in simulated concrete pore solutions at pH 12.50 and pH 12.00.

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Electrochemical Reduction Characteristics Of Nitrobenzene At The Copper Electrode, Jin-Hong Fan, Wen-Ying Xu, Ting-Yao Gao Aug 2005

Electrochemical Reduction Characteristics Of Nitrobenzene At The Copper Electrode, Jin-Hong Fan, Wen-Ying Xu, Ting-Yao Gao

Journal of Electrochemistry

The electrochemical reduction characteristics and transition steps of nitrobenzene aqueous solution at the copper electrode, as well as its reduction mechanism were extensively investigatedby using the techniques such as cyclic voltammetry (CV) and linear scan voltammetry (LSV). The results showed that the reduction peaks of nitrobenzene at the copper electrode were located at 0.58 V and 1.32 V or so (vs. SCE), both acidity and alkalinesolutionsfavoredthe reduction of nitrobenzene. The adsorption of compounds followed by the reduction process, which is controlled by the mass transfer step at higher nitrobenzene concentration. In addition, the higher anaerobic degree led to faster reduction …

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Research Progresses In A Flow Redox Battery, Quan-Feng Dong, Hua-Min Zhang, Ming-Gang Jin, Ming-Sen Zheng, Ya-Ding Zhan, Shi-Gang Sun, Zu-Geng Lin Aug 2005

Research Progresses In A Flow Redox Battery, Quan-Feng Dong, Hua-Min Zhang, Ming-Gang Jin, Ming-Sen Zheng, Ya-Ding Zhan, Shi-Gang Sun, Zu-Geng Lin

Journal of Electrochemistry

As a large scale electrochemical storage device, flow redox battery in which the active materials are flowing electrolytes is different from the common batteries employing solid or gas materials as an electrode. In this paper we introduced flow redox battery in brief, reviewed its development and actual state on (study). The main problem existed in the new device was discussed when viewed with its future developments.

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The Growth Of Aluminide-Layer During The Hot-Dipping Al-(Si) Coating Onto 430 Stainless Steels, Peng-Chicao Chen, Chaur-Jeng Wang, Yu-Chang Lin, Hsuan Ching Aug 2005

The Growth Of Aluminide-Layer During The Hot-Dipping Al-(Si) Coating Onto 430 Stainless Steels, Peng-Chicao Chen, Chaur-Jeng Wang, Yu-Chang Lin, Hsuan Ching

Journal of Electrochemistry

The 430 stainless steels have been hot dipped in the molten Al-6.5%Si melts from 680 to 800℃, respectively. The effects of the hot dipping temperature and time on the thickness of the internal alloy layer have been investigated. The activation energy of the growth kinetic of aluminized layer was also calculated. The results showed that the thickness of aluminized layer increased with increasing dipping time and temperature. Besides, the growth kinetic of aluminized layer obeys parabolic rate law. The FeAl3 and Fe2Al5 were formed by the inward diffusion, and the interface of intermetallic layer will be …

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The Application Of Astm C1202-93 On Evaluating The Performance Of Anti-Corrosion Of Concrete, Yuan-Chen Yuan, Tsung-Yueh Tu, Chao-Lung Hwang Aug 2005

The Application Of Astm C1202-93 On Evaluating The Performance Of Anti-Corrosion Of Concrete, Yuan-Chen Yuan, Tsung-Yueh Tu, Chao-Lung Hwang

Journal of Electrochemistry

The test of chloride ion penetration based on the standards of ASTM C1202-93 is applied to evaluate the anti-corrosion performance of concrete in this research. Concrete specimens were produced according to ACI 318-89 mixture proportioning design and the Desenfied Mixture Design Algorithm (DMDA) and were measured the 6-hour coulombs at the age of 91 days. Results show that w/b is not the factor influencing chloride penetration of ACI concrete, as the ion penetration of ACI specimens is all higher than 2 000 Coulombs and can even be poorer than 10 000 Coulombs. With a proper amount of pozzolanic material, the …

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Effect Of Sintering Temperatures On Synthesis Of Mgco0.4Mn1.6O4 Positive Materials In Magnesium Ion Battery, Xiu-Ling Gao, Li-Fang Jiao, Hua-Tang Yuan, Jian-Sheng Cao, Ming Zhao, Hai-Xia Li, Yong-Mei Wang Aug 2005

Effect Of Sintering Temperatures On Synthesis Of Mgco0.4Mn1.6O4 Positive Materials In Magnesium Ion Battery, Xiu-Ling Gao, Li-Fang Jiao, Hua-Tang Yuan, Jian-Sheng Cao, Ming Zhao, Hai-Xia Li, Yong-Mei Wang

Journal of Electrochemistry

The cathode material MgCo0.4Mn1.6O4 for magnesium ion battery was synthesized by sol-gel method. The TG-DTA and XRD analyses showed that the prepared samples has simple spinel structure. Effect of annealing temperature on electrochemical properties was researched. The result shows that the sample sintered at 700℃ has the best electrochemical properties.

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The Research Of Nano-Sized Nio Anode Materials For Lithium Ion Batteries, Jun-Mei Yan, Jing Zhang, Yong Yang Aug 2005

The Research Of Nano-Sized Nio Anode Materials For Lithium Ion Batteries, Jun-Mei Yan, Jing Zhang, Yong Yang

Journal of Electrochemistry

The nano-sized NiO materials were synthesized by solid phase method and sol-gel method. The synthesis conditions were optimized by DSC and TG techniques. The sol-gel method was optimized by changing the solvent and regulating the solution's pH for preparing NiO material. The structure and morphology of the materials were also characterized by means of XRD and TEM techniques, and the electrochemical performances of the materials were studied by the galvanostatically charge and discharge experiments.

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Secured Network Model For Management Information System Based On Ip Security (Ipsec) Encryption Using Multilayered Approach Of Network Security, Dr. Amir Hassan Pathan, Muniza Irshad Aug 2005

Secured Network Model For Management Information System Based On Ip Security (Ipsec) Encryption Using Multilayered Approach Of Network Security, Dr. Amir Hassan Pathan, Muniza Irshad

International Conference on Information and Communication Technologies

Secured flow of information through the network and play important role in the management information systems. In this paper I describe Secured Network Model For Corporate & Business Organization In Based On Network Level IP Security (IPSec) Encryption & Its Physical Layout Using Multilayered Approach. I have four important considerations for adoption of secured network model as secured network model for management information system.

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G-Value Decoding Of Greedy Codes, Khalil Ahmad Aug 2005

G-Value Decoding Of Greedy Codes, Khalil Ahmad

International Conference on Information and Communication Technologies

Error-correcting codes are widely used to increase the reliability of transmission of information over various forms of communication channels. Codes with a given minimum distance d can be constructed by a greedy algorithm [2]. In this paper, I proposed a new algorithm for the allocation of g-values to the binary vectors. Hamming (7, 4, 3) code can be generated by the application of greedy algorithm on the binary vectors of length 7 arranged in B-ordering. This code is used to demonstrate a new decoding technique for linear codes in addition to the schemes already known for decoding such as Syndrome …

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A Review Study On Digital Watermarking, Jian Liu, Xiangjian He Aug 2005

A Review Study On Digital Watermarking, Jian Liu, Xiangjian He

International Conference on Information and Communication Technologies

There has been a rapid development in the growth of multimedia and communications in the past few years. With the widespread use of the networks, intellectual properties can be obtained, reproduced or redistributed easily. This creates a high demand for content protection techniques. Watermarking, one of the most efficient ways to protect the digital properties has won more and more concern in recent years. This paper reviews several aspects about digital watermarking. Among them, we mainly focus on three processes of digital watermarking. Also, we will examine the properties of watermarking and several applications of watermarking. At last, this paper …

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Keynote: Role Of Values & Culture In Information Technology, Prof. Dr. Anis Ahmad Aug 2005

Keynote: Role Of Values & Culture In Information Technology, Prof. Dr. Anis Ahmad

International Conference on Information and Communication Technologies

It is no longer unusual to see, in a remote town in northern area in Pakistan, a practically non-literate wagon driver calling from his Nokia cell phone his uncle in Dubai or in Karachi. He enjoys sharing with him about his success in business and the settlement of family disputes. While he is driving on dangerous curvy roads and having this conversation, in the back seat of the wagon a comparatively young person is playing games on his cell phone. All this was unimaginable a quarter of a century ago.

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Keynote: Research And Education In Telecommunication Engineering, Akhtar Kalam Aug 2005

Keynote: Research And Education In Telecommunication Engineering, Akhtar Kalam

International Conference on Information and Communication Technologies

Telecommunications over the past one hundred years has had a major influence on the development of society. Telecommunications will continue to play an increasingly important role in nearly every human endeavour in all nations of the earth. Telecommunication industry is currently facing a technological revolution. In many countries, the number of cellular radio subscribers exceeds the subscribers of fixed telephony services. Internet technologies, such as VoIP and SIP, allow the convergence of traditional switched telephony services and data services of the internet to converge. New wireless access technologies compete and complete the services provided by the modern cellular radio networks. …

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An Investigation Of Improving Wear Of 390 Die-Cast Aluminum Through Hardcoat Anodizing, Michael J. Whiting Aug 2005

An Investigation Of Improving Wear Of 390 Die-Cast Aluminum Through Hardcoat Anodizing, Michael J. Whiting

Theses and Dissertations

The objectives of this research were to investigate the wear that occurs on the surface of a Hardcoat anodized die-cast aluminum surface, which was sliding against a composite rubber belt. This research investigated known wear theories and the results for previous testing to understand the mechanisms that were likely occurring in this application. These theories indicated that the wear occurring may be reduced by changing the hardness of the materials involved. Archard's equation gave tangible evidence of this fact, but related to the base material and not a surface coating. It was hypothesized that Hardcoat anodizing would follow the theory …

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Generation Of Biomarkers From Anthrax Spores By Catalysis And Analytical Pyrolysis, Phillip R. Smith Aug 2005

Generation Of Biomarkers From Anthrax Spores By Catalysis And Analytical Pyrolysis, Phillip R. Smith

Theses and Dissertations

Anthrax spores, in weaponized form, are dangerous biological warfare agents. Handheld technology for the rapid detection of anthrax is greatly needed to improve national security. Methods to detect anthrax spores are diverse, with most taking at least an hour for positive identification. A viable option for rapid detection is analytical pyrolysis (AP), which produces chemicals containing taxonomical information (biomarkers). AP methods are reviewed and critically analyzed to show that reproducible detection of anthrax spores in a rapid manner (< 5 min) with a handheld device is not currently possible. A promising alternative to AP is the use of a catalyst to produce biomarkers from anthrax spores with improved selectivity and reproducibility. Catalytic materials having promise for this include platinum, nickel, and superacids. Experiments evaluating several of these materials are described. A biomarker mass spectral library was created, based on information available in the scientific literature, to facilitate analysis and identification of the biomarkers produced experimentally. The RAMFAC algorithm was used to deconvolute chromatographic peaks to produce clean mass spectra and match them against entries in the biomarker library. While the library is not complete, its use with the RAMFAC algorithm enabled detection of many important biomarkers in experiments involving catalytic breakdown of anthrax spores. Experimental results from preliminary tests of several catalysts are presented and discussed. Addition of catalysts in the form of platinum nanoclusters and superacids to bacterial spores in a commercial pyrolyzer effected an increase in the amount of biomarkers produced at mild conditions over traditional pyrolysis methods. Electroformed nickel mesh, on the other hand, demonstrated low catalytic activity for the production of biomarkers, likely due to poor contact of the spores with the mesh. Biomarkers similar to those published in the literature were observed, including dipicolinic acid, picolinic acid, propionamide, acetamide, diketopiperazines, fatty acids, furfuryl alcohol, and DNA bases. A statistically designed factorial study was used to determine the importance of temperature, spore loading, and nanocluster loading on the production of three important biomarkers. The relative importance of these variables differs for each of the three important biomarkers, suggesting they are produced by different reaction mechanisms.

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