Amirkabir University of Technology

About: Amirkabir University of Technology is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Nonlinear system & Finite element method. The organization has 15254 authors who have published 31165 publications receiving 487551 citations. The organization is also known as: Tehran Polytechnic & Tehran Polytechnic University.

Highly sensitive and flexible ammonia sensor based on S and N co-doped graphene quantum dots/polyaniline hybrid at room temperature

Abstract: Here we present an innovative flexible ammonia (NH3) sensor based on S and N co-doped graphene quantum dots (S, N: GQDs)/polyaniline (PANI) hybrid loading on flexible polyethylene terephthalate thin film by chemical oxidative polymerization. The sensor exhibited not only excellent response, good selectivity and fast response and recovery time at room temperature but also flexibility, low cost and wearable characteristics. The experimental results reveal that the response of S, N: GQDs/PANI hybrid was about 5 fold higher than that of pure PANI at 100 ppm of NH3 and the attained gas-sensing performance may be attributed to the increased hole like carriers by S, N: GQDs and enhanced interactions between the hybrid sensing film and NH3 molecules via π electron networks. The NH3-sensing mechanisms of the flexible S, N: GQDs/PANI gas sensor based on acid-base doping/de-doping process, carriers mobility, and swelling process are highlighted.

Numerical solution of hyperbolic telegraph equation using the Chebyshev tau method

Abstract: In this article we propose a numerical scheme to solve the one-dimensional hyperbolic telegraph equation. The method consists of expanding the required approximate solution as the elements of shifted Chebyshev polynomials. Using the operational matrices of integral and derivative, we reduce the problem to a set of linear algebraic equations. Some numerical examples are included to demonstrate the validity and applicability of the technique. The method is easy to implement and produces very accurate results. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2010

Social life cycle assessment for material selection: a case study of building materials

Abstract: Purpose Sustainability of a material-based product mainly depends on the materials used for the product itself or during its lifetime. A material selection decision should not only capture the functional performance required but should also consider the economical, social, and environmental impacts originated during the product life cycle. There is a need to assess social impacts of materials along the full life cycle, not only to be able to address the “social dimension” in sustainable material selection but also for potentially improving the circumstances of affected stakeholders. This paper presents the method and a case study of social life cycle assessment (S-LCA) specialized for comparative studies. Although the authors’ focus is on material selection, the proposed methodology can be used for comparative assessment of products in general.