STUDY OF PRESSURE AND COMPOSITION EFFECT ON MULTICOMPONENT MEMBRANE SEPARATION INVOLVING HEAVY HYDROCARBON GAS PENTANE

This work study the performance and characterize polyimide hollow fiber membranes for the separation of CO2-CH- C5H12 at difference pressure and feed composition as well as the effect of heavy hydrocarbon gas C5H12 on membrane performance. In Malaysia, approximately 13 trillion ft³ of high CO2 natural gas field are uneconomical to be developed. Development of high CO2 gas fields requires prudent management of carbon dioxide capture, transportation, and storage to enable commercialization of these fields. Research conducted on CO2 separation using membrane is limited especially on multicomponent and involving heavy hydrocarbon gas. Scope of experimental study focus on pure gas, gas mixture with and without heavy hydrocarbon gas C5H12 as well as varies the feed pressure from 10 bar to 18 bar and CO2 feed composition from 10% to 90%. Research methodologies include fabrication of membrane module, membrane characterization using FTIR, FESEM, and performances testing with CO2SMU and GC. FTIR finding show that membrane matrix’s polar sites enhance the preferential interaction and solubility of CO2 gas molecules, resulting in higher CO2 permeates flow compare to CH4 & C5H12. Decrease in flux, permeance and CO2 relative permeance is observed in gas mixture feed especially with present of heavy hydrocarbon gas C5H12. C5H12. As feed pressure increase, driving force increase preferentially sorbed of CO2 gas increase CO2 flux significantly, while CH4 and C5H12 flux only increase marginally. Furthermore, membrane layer compaction and plasticization increase CO2 permeance and relative permeance. As CO2 feed composition increase, membrane plasticize more, increasing preferentially sorbed of CO2 gas at matrix’s polar sites, thus increasing CO2 flux and permeance while, CH4 and C5H12 flux and permeance remain constant. So, CO2 relative permeance increases. In the nutshell, polyimide hollow fiber membranes show promising performance for separation of CO2-CH- C5H12 and experimental findings can be used for Multicomponent Hollow Fiber Membrane Module Performance Prediction Program (HFM3P)

Non-price determinants on intention to purchase of organic foods in State of Kedah, Malaysia

Organic food is becoming popular among todays‘ millennial consumers as consumer awareness towards healthy lifestyle had increased. Scholars and practitioners had put much consideration in understanding what drive consumers‘ attitude and behavior towards organic food mainly to strengthen their strategies and tactics to dominate the market. As past literatures consistently highlighted that organic food enjoyed slightly higher price, this study attempts to examine the influence of non-price determinants on intention to purchase organic food. The study among 117 respondents in state of Kedah, Malaysia revealed that environmental concern has a significant relationship with intention to purchase organic food. Another two determinants namely, product knowledge and attitude towards organic food found insignificant in influencing intention to purchase organic food. As a result, practitioners are urged to aggressively promote the benefits of organic food among public mainly to enhance their attitude towards organic food. Future study should focus in a larger sample as well as consider other non-price determinants on intention of purchase organic foo

Perceived leadership practices and organizational commitment of consulting engineers at their working place

The objectives of this study are to examine the issues confronting consulting engineers. The issues are: (a) the relationship between perceived leadership practices and consulting engineer's organizational commitment in their working place and, (b) the differences of consulting engineers’ organizational commitment based on gender, age and years of working experience. This study leverages on (a) Kouzes and Posner’s five perceived leadership practices (1987), and (b) Mowday, Porter and Steers’ organizational commitment (1979). This study was specifically addressed to 387 respondents who worked with consulting firms registered under the Association of Consulting Engineers, Malaysia (ACEM). The random sampling technique was used and a self-administered survey was performed for this research which included a set of questionnaires consisting of sections on personal information, leadership practices index (LPI) and organizational commitment (OCQ). The quantitative research method was used for data analysis. Firstly, it involved using the Spearman-rho correlation analysis to examine the relationship between the consulting engineers’ perceived leadership practices and organizational commitment at their work place. Secondly, the Kruskal Wallis test was used to investigate the differences between the consulting engineers’ organizational commitment based on age and years of experience. Thirdly, the Wilcoxon Signed Rank test was used to investigate the differences between the consulting engineers’ organizational commitment based on gender. The findings revealed that the five perceived leadership practices have significant relationships between perceived leadership practices and the consulting engineers’ organizational commitment at their work place. Another finding revealed that there is a significant difference between the consulting engineers’ organizational commitment based on gender, and age, and years of working experience. The findings contribute to the knowledge that consulting engineers’ organizational commitment is positively related to the engineering superior’s leadership skills of coaching, leading and guiding consulting engineers to achieve the same goa

Mining input sanitization patterns for predicting SQL injection and cross site scripting vulnerabilities

Static code attributes such as lines of code and cyclomatic complexity have been shown to be useful indicators of defects in software modules. As web applications adopt input sanitization routines to prevent web security risks, static code attributes that represent the characteristics of these routines may be useful for predicting web application vulnerabilities. In this paper, we classify various input sanitization methods into different types and propose a set of static code attributes that represent these types. Then we use data mining methods to predict SQL injection and cross site scripting vulnerabilities in web applications. Preliminary experiments show that our proposed attributes are important indicators of such vulnerabilities

Pseudo spin-orbit coupling of Dirac particles in graphene spintronics

We study the pseudo spin-orbital (SO) effects experienced by massive Dirac particles in graphene, which can potentially be of a larger magnitude compared to the conventional Rashba SO effects experienced by particles in a 2DEG semiconductor heterostructure. In order to generate a uniform vertical pseudo SO field, we propose an artificial atomic structure, consisting of a graphene ring and a charged nanodot at the center which produces a large radial electric field. In this structure, a large pseudo SO coupling strength can be achieved by accelerating the Dirac particles around the ring, due to the small energy gap in graphene and the large radial electric field emanating from the charged nanodot. We discuss the theoretical possibility of harnessing the pseudo SO effects in mesoscopic applications, e.g. pseudo spin relaxation and switching.Comment: 12 pages, 1 figur

Automated removal of cross site scripting vulnerabilities in web applications

Cross site scripting (XSS) vulnerability is among the top web application vulnerabilities according to recent surveys. This vulnerability occurs when a web application uses inputs received from users in web pages without properly checking them. This allows an attacker to inject malicious scripts in web pages via such inputs such that the scripts perform malicious actions when a client visits the exploited web pages. Such an attack may cause serious security violations such as account hijacking and cookie theft. Current approaches to mitigate this problem mainly focus on effective detection of XSS vulnerabilities in the programs or prevention of real time XSS attacks. As more sophisticated attack vectors are being discovered, vulnerabilities if not removed could be exploited anytime. To address this issue, this paper presents an approach for removing XSS vulnerabilities in web applications. Based on static analysis and pattern matching techniques, our approach identifies potential XSS vulnerabilities in program source code and secures them with appropriate escaping mechanisms which prevent input values from causing any script execution. We developed a tool, saferXSS, to implement the proposed approach. Using the tool, we evaluated the applicability and effectiveness of the proposed approach based on the experiments on five Java-based web applications. Our evaluation has shown that the tool can be applied to real-world web applications and it automatically removed all the real XSS vulnerabilities in the test subjects

Overlapping-gate architecture for silicon Hall bar MOSFET devices in the low electron density regime

We report the fabrication and study of Hall bar MOSFET devices in which an overlapping-gate architecture allows four-terminal measurements of low-density 2D electron systems, while maintaining a high density at the ohmic contacts. Comparison with devices made using a standard single gate show that measurements can be performed at much lower densities and higher channel resistances, despite a reduced peak mobility. We also observe a voltage threshold shift which we attribute to negative oxide charge, injected during electron-beam lithography processing.Comment: 4 pages, 4 figures, submitted for Applied Physics Letter