Sharif Digital Repository

Catecholamine neurotransmitters, generally including dopamine (DA), epinephrine (EP) and norepinephrine (NE) are known as substantial indicators of various neurological diseases. Simultaneous detection of these compounds and their metabolites is highly recommended in early clinical diagnosis. To this aim, in the present contribution, a high performance colorimetric sensor array has been proposed for the detection and discrimination of catecholamines based on their reducing ability to deposit silver on the surface of gold nanorods (AuNRs). The amassed silver nanoshell led to a blue shift in the longitudinal localized surface plasmon resonance (LSPR) peak of AuNRs, creating a unique pattern... 

The economic growth or asset of country basically depends on the amount of goods which can be produced by the combination of land, capital, manpower and natural resources. Therefore, changing natural resources into production is the new process of economical development, and technology is the brain of this type of transformational activities. This tool not only makes the changing operation possible but also, in the world economy makes the survival and growth foundation of business enterprises. The Development of today's technology has caused some change in the productivity and costs, and because of this, the global and national structure in the areas of production, business and employment... 

Working with tree graphs is always easier than with loopy ones and spanning trees are the closest tree-like structures to a given graph. We find a correspondence between the solutions of random K-satisfiability problem and those of spanning trees in the associated factor graph. We introduce a modified survey propagation algorithm which returns null edges of the factor graph and helps us to find satisfiable spanning trees. This allows us to study organization of satisfiable spanning trees in the space spanned by spanning trees. © 2006 IOP Publishing Ltd  

Seismic response of large concrete tower structures with passive or active damping is important in terms of performance under earthquake loads. The conventional finite element method has been used successfully in linear and nonlinear analyses in large concrete structures. The method can be performed by subdividing the large structure into small uniform elements having approximate shape functions. Although this replaces a single complicated structural system with a number of simple uniform elements, in cases of tall concrete tower structures with cracking and crushing behaviour in the concrete material and yielding in the reinforcement, the computer time and memory can be large. Hence, it is... 

Nowadays, the development of nanotechnology is faster than before due to its interdisciplinary nature. Other branches of engineering have started employing this technology in the process of their development; one example would be concrete science and technology. Nearly a decade has passed since the first application of nano-particles in a matrix of concrete products. During this time period, two directions have formed in the process of researchers' investigations. The first route is the precise monitoring of the microstructure and macrostructure of concrete products with the help of nanotechnology tools and methods. The second route is the development of concrete products with... 

Unlike those on Internet, the media providers on P2P networks are ordinary nodes whose contribution bandwidth is limited. Multi-sender methods are the best solutions known to video streaming on P2P networks. In this paper, we propose use of a multi-cast method on the top of an arbitrary multi-sender method so that all requesting peers receive almost the same expected bit-rate. That is while the existing multi-sender methods maximize the bit-rate delivered to the first receiver and cannot provide acceptable bit-rates to the next requesting nodes. © 2006 IEEE  

Near field scanning optical microscopy exploiting differential interference contrast enhancement is demonstrated. Beam splitting in the near field region is implemented using a dual color probe based on plasmonic color sorter idea. This provides the ability to illuminate two neighboring points on the sample simultaneously. It is shown that by modulating the two wavelengths employed in exciting such a probe, phase difference information can be retrieved through measuring the near field photoinduced force at the difference of the two modulation frequencies. This difference in frequency is engineered to correspond to the first resonant frequency of the cantilever, resulting in improved SNR, and... 

By using the normalised least mean squared (NLMS) algorithm, a semi-active multi-variable adaptive controller is designed for a seismically excited structure. There is no need for a large power supply. A number of valves and battery size low-power supplies will suffice. The valves control the amount of flow of a fluid through bypass on-off orifice channels in installed energy dissipating mechanisms. Each mechanism is composed of a piston attached to a A-shaped chevron wind-bracing on each floor and to a cylinder attached to the upper floor. Adaptive controller parameters are estimated by the LMS optimiser, in order to search for optimal non-classical damping coefficients of the dissipating... 

The prerequisite of developing countries’ economic growth is to move along the technological development trajectory through technological learning, and large firms as hubs of technological knowledge, play an important role in this transition. In this paper, we tried to bridge two main taxonomies in the field of technological development, one of them referring to taxonomies of firms, and the other one referring to technological learning processes. We have identified technological learning processes in several post catch-up large firms through content analysis and then by employing a survey approach, we explore technological learning processes of Iranian large firms. The results indicate that... 

Societies today have come closer together as a result of the development of communication technologies and the greater ease with which business is transacted. Consequently, technological tools and devices are being transferred from industrial societies to other countries at dazzling speeds the transfer of technology to non-industrialized societies with their own histories, civilizations, and backgrounds has led to the emergence of cultural issues and conflicts that are specific to the modern period and that had not existed prior to this period. In this article, we have reviewed the ideas of Don Ihde, a leading contemporary philosopher who has done much work in the field of the philosophy of... 

The short history of the philosophy of technology has witnessed different and sometimes contradictory views about the relationship between society and modern technology, from the approaches that believe in technological determinism to those which believe in the deep influence of society on technology [5]. One famous example of technological determinism has emerged from autonomist approaches toward technology. In this approach, the development of modern technology is based on a special kind of internal logic and cannot be controlled by any element other than modern technology itself, such as human society. The autonomous approach, as seen in the works of the French thinker Ellul [8],... 

Iran's petroleum industry is facing challenges including maturity of hydrocarbon fields, growing population of the nation that demands additional revenues from petroleum exports, and international economic sanctions that have limited access to technology sources. Restrictions from international technology providers have led managers of the industry enterprises to try to develop their needed technologies inside the country. The Ministry of Petroleum has supervised this and as a result, a technology planning systems has been developed and implemented since 2009. In this paper, an overview of the Iranian petroleum industry is provided from a technology planning perspective. The focus has been... 

After the emergence of modern technologies in the field of information technologies (IT), virtual learning has attained a new form. The way of announcing exams' grades is an important topic in e-learning. For announcing exams' grades on the web, various methods have been proposed. In this paper, first some common methods for announcing students' grades are reviewed, then three new methods which are named "Virtual Grade", "Steganography Grades", and "Grade HIP" are introduced and the result of implementing these methods for announcing the grades of some courses at the some Iranian universities are provided. Also these methods and their results are analyzed. Finally these three new methods are... 

Management Technologies Strategy formulation (MTS formulation) in holding companies is carried out with the aim of achieving competitive advantages in the market and fulfilment of strategic goals of the corporation. This paper presents a modified technology strategy formulation model for MTS in holding companies. Prior to present an integrated model of MTS formulation, a number of technology strategy formulation models are analysed and their suitability for the headquarter of a holding company is discussed. Through a case study research method, the paper documents how MTS formulation was implemented in an Iranian conglomerate tasked with managing diversified subsidiaries. We concluded that... 

What purpose, according to Muslim scholars, should technological development serve? To answer this question, first we explain the views of seven Muslim scholars who have theorized about technology from an Islamic viewpoint. We then set out Carl Mitcham's fourfold analysis of technology, and summarize the views of philosophers of technology on technological volition. This places us in a position to classify Muslim scholars' opinions on technological development under seven broad headings, namely: meeting human beings' needs, implementation of an Islamic culture and lifestyle, serving human beings, serving nature, understanding the splendor of creation, providing personal and social happiness,... 

This paper aims to determine the factors influencing technology transfer (TT) in an empirical study using structural equation modelling (SEM). A sample of 100 experts working in the National Iranian Gas Company (NIGC) as empirical study is randomly selected. The data are collected through the questionnaire and then analysed using LISREL software. Results show that law and policy, companies’ capabilities, skilled human resource, localisation of technology, and characteristics of technology significantly influence on the technology transfer. In addition, it is shown that the highest correlation is between companies’ capabilities and technology transfer. Fit indices show that the model has an...