Preparation of proton exchange membrane by radiation-induced grafting method : Grafting of styrene onto poly(ethylene tetrafluoroethylene) copolymer films

Radiation induced grafting of styrene onto poly(ethylene-tetrafluoroethylene) (ETFE) copolymer film was carried out to prepare graft copolymer (ETFE-g-polystyrene) that can host sulfonic acid groups and form proton exchange membrane for polymer electrolyte fuel cell (PEFC). The effect of monomer concentration and type of solvent on the degree of grafting was investigated. The formation of graft copolymer film was confirmed by FTIR spectrum analysis

Challenges and Opportunities to Improve Tuberculosis Screening Among Immigrant Plantation Workers in Sabah, Malaysia

Tuberculosis (TB) among immigrants has substantial contribution to the TB epidemiology in Sabah. This study aimed to determine the yield of screening for TB disease among immigrant plantation workers in Sabah, Malaysia. This was a prospective cohort study involving 482 legal immigrant workers aged 18 years and above, consented and available at study sites during the study period. Workers with previous history of TB or currently on TB treatment were excluded from participation. Symptom based questionnaire was administered along with both chest radiograph and sputum samples collection for symptomatics participants. Out of 482 plantation workers creened, there was no case of active TB detected among the 44 (9.1%) symptomatics participants. Finding of low TB yield in this study was rather unexpected but this indicates the real challenges for the local health authority to come out with more cost effective screening programs, including reducing stigma, in active TB screening among migrant population

Numerical models for the circumstellar medium around Betelgeuse

The nearby red supergiant (RSG) Betelgeuse has a complex circumstellar medium out to at least 0.5 parsecs from its surface, shaped by its mass-loss history within the past 0.1 Myr, its environment, and its motion through the interstellar medium (ISM). In principle its mass-loss history can be constrained by comparing hydrodynamic models with observations. Observations and numerical simulations indicate that Betelgeuse has a very young bow shock, hence the star may have only recently become a RSG. To test this possibility we calculated a stellar evolution model for a single star with properties consistent with Betelgeuse. We incorporated the resulting evolving stellar wind into 2D hydrodynamic simulations to model a runaway blue supergiant (BSG) undergoing the transition to a RSG near the end of its life. The collapsing BSG wind bubble induces a bow shock-shaped inner shell which at least superficially resembles Betelgeuse's bow shock, and has a similar mass. Surrounding this is the larger-scale retreating bow shock generated by the now defunct BSG wind's interaction with the ISM. We investigate whether this outer shell could explain the bar feature located (at least in projection) just in front of Betelgeuse's bow shock.Comment: 5 pages, 3 figures; to appear in proceedings of the Betelgeuse 2012 Workshop, Paris, Nov. 201

Shariah Screening Methodologies: SAC-SC Vs DJIM Comparative Study and Impact Assessment on Their Performance

Purpose – The purpose of this paper is to compare between two screening methodologies in terms of applied methods and the impact assessment. Other than this the paper measures the performance of screened stocks in terms of risk & return and compare it to the conventional onesDesign/methodology/approach – The methods used are a combination of archival and bibliographic research based on some previously published articles. Also the papers use secondary data from published reports.Findings – The paper identifies the impact assessment of the screening methodologies and how investors will not sacrifice part of their returns in order to achieve their moral and ethical values.Originality/value – Many studies compared the two screening indices in term of methodologies; however this paper investigates and uses a quantitative analysis on the impact and performance of the screening methodologies. Furthermore it compares the stages of screening between Shariah Advisory Council of Securities commission (SAC-SC) and Dow Jones Islamic Market Index (DJIM)Keywords – screening, methodologies, impact assessmentPaper type – comparative case stud

Nonlinear dynamics of the interface of dielectric liquids in a strong electric field: Reduced equations of motion

The evolution of the interface between two ideal dielectric liquids in a strong vertical electric field is studied. It is found that a particular flow regime, for which the velocity potential and the electric field potential are linearly dependent functions, is possible if the ratio of the permittivities of liquids is inversely proportional to the ratio of their densities. The corresponding reduced equations for interface motion are derived. In the limit of small density ratio, these equations coincide with the well-known equations describing the Laplacian growth.Comment: 10 page

Linear-nonlinear stiffness responses of carbon fiber-reinforced polymer composite materials and structures: a numerical study

The stiffness response or load-deformation/displacement behavior is the most important mechanical behavior that frequently being utilized for validation of the mathematical-physical models representing the mechanical behavior of solid objects in numerical method, compared to actual experimental data. This numerical study aims to investigate the linear-nonlinear stiffness behavior of carbon fiber-reinforced polymer (CFRP) composites at material and structural levels, and its dependency to the sets of individual/group elastic and damage model parameters. In this regard, a validated constitutive damage model, elastic-damage properties as reference data, and simulation process, that account for elastic, yielding, and damage evolution, are considered in the finite element model development process. The linear-nonlinear stiffness responses of four cases are examined, including a unidirectional CFRP composite laminate (material level) under tensile load, and also three multidirectional composite structures under flexural loads. The result indicated a direct dependency of the stiffness response at the material level to the elastic properties. However, the stiffness behavior of the composite structures depends both on the structural configuration, geometry, lay-ups as well as the mechanical properties of the CFRP composite. The value of maximum reaction force and displacement of the composite structures, as well as the nonlinear response of the structures are highly dependent not only to the mechanical properties, but also to the geometry and the configuration of the structures

A Pattern-Based Password Authentication Scheme for Minimizing Shoulder Surfing Attack

The user usually uses password to avoid the attacks like a dictionary attack, brute force attack and shoulder surfing attack which is the famous attack nowadays. The shoulder surfing attack is a direct observation technique by watching over the user’s shoulder when they enter their password to get information. The most common authentication method used by the user is textual password. But, the textual password has many disadvantages because it is vulnerable to attack as it tends to shoulder surfing attack. In this project, a pattern-based password authentication will develop to overcome this problem. Using this scheme, the user needs to select the type of pattern that they like during registration. To login to their account, the user needs to enter the password in the form of the textual password in ordering manner based on a pattern that they choose during registration. The text password grid presented with a different style as it filled with random objects whether characters, numbers or images. This method is suitable to minimizing shoulder surfing attack as it can improve the security of user’s password and they can efficiently login to the system