Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2738

Table of Content: 5 November, 2012; 7(43)

November 2012

A numerical method for second order strain gradient theory

In classical mechanics, based on the generalized Hook’s law, stress is only a function of strain. However, in the strain gradient theory, stress is not only a function of strain, but also a function of high-order gradients of strain. This relationship between stress and strain and its new boundary conditions is derived using the principle of minimum total potential energy. Meanwhile, a new stress tensor called...

Author(s): Gerhard Silber, Mansour Alizadeh, Mostafa Homayouni and S. Mohammad Ali Alvani

November 2012

Study on ringing effect in ultrasonic transducer

This paper presents theoretical experimental and evidence of the effect of internal resonance at silicon substrate in micro fabrication ultrasonic transducer. This ringing is clearly observed in immersion transducers with 4.2 MHz and harmonics. A mathematical analytical model of the attenuation yield by ringing effective and simulation is introduced. Experimental results are further compared to simulations...

Author(s): M. S. Salim, M. F. Abd Malek, Naseer Sabri and K. M. Juni

November 2012

Phytochemical screening and biological activity of the aerial parts of Elaeagnus umbellata

The methanolic crude extract of the aerial parts of Elaeagnus umbellata and its various solvent fractions was screened for the secondary metabolites and biological activity. Phytochemical analysis of the aerial parts showed the presence of bioactive secondary metabolites; alkaloids, steroids, terpenoids, saponins while flavonoids, anthraquinones, tannins, phlobatanins and glycosides were absent. The ethyl...

Author(s): Ghias Uddin and Abdur Rauf

November 2012

Genetically tuning of lead-lag controller in order to control of fuel cell voltage

The aim of this article is to introduce, implement and control the voltage of one of the most important types of fuel cell, namely proton exchange membrane fuel cell (PEMFC) during system load variations. Fuel cell output voltage should be kept in a constant value against the load variations, and a controller should be designed for this purpose. Here, the Lead-Lag Controller is used in which its coefficients are...

Author(s): Noradin Ghadimi

November 2012

Genetically tuning of lead-lag controller in order to control of fuel cell voltage

The aim of this article is to introduce, implement and control the voltage of one of the most important types of fuel cell, namely proton exchange membrane fuel cell (PEMFC) during system load variations. Fuel cell output voltage should be kept in a constant value against the load variations, and a controller should be designed for this purpose. Here, the Lead-Lag Controller is used in which its coefficients are...

Author(s): Noradin Ghadimi

November 2012

A decision support system for supplier selection using fuzzy analytic network process (Fuzzy ANP) and artificial neural network integration

Selection of appropriate supplier(s) for success of an organization is particularly a valuable necessity, hence apart from the common criteria such as logistics, service and quality, this paper discusses most of the key decision variables which can play a critical role in case of the supplier selection. In this study, analytic network process (ANP) method is used because it considers the relationship between the...

Author(s): Kerim Goztepe and Semra Boran

November 2012

Kinetic studies of some hazardous metal ions in the particles of titanium potassium vanadate as a cation exchanger

Titanium potassium vanadate (TiKV) as an inorganic ion exchange material was synthesized from titanium tetrachloride, potassium chloride and sodium monovanadate with molar ratio Ti: K: V = 1: 1: 1. The kinetic behaviour of Cs+, Co2+and Cd2+ have been studied under different conditions of concentration, particle size, reaction temperatures and drying temperatures. The experimental conditions were set to favour...

Author(s): M. M. El-Shorbagy, A. Bendary and A. M. Ali  

November 2012

Effects of tillage, fertilization and weed control methods on corn yield in Khuzestan province

This work was carried out to evaluate the effects of seed bed preparation, fertilization and weed control (after planting) methods on growth and corn yield in Khuzestan. One field experiment was conducted as strip plot within randomized complete block design with 4 replications during 2009 and 2010. Three seed bed preparation consisted of planting in wet soil (locally named Makhar) + conventional tillage (plough + disk...

Author(s): Ghasemi Nejad Raeini Mahmoud, Sheikhdavoodi Mohamad Javad, Almassi Morteza, Bahrami Houshang, Zand Eskandar and Alamisaeid Khalil

November 2012

Influence of heat and mass transfer on Phan-Thien-Tanner fluid model for blood flow through a tapered artery with a stenosis

In the present investigation, we study the influence of heat and mass transfer on blood flow through tapered artery with a stenosis. The non-Newtonian nature of blood in small arteries is analyzed mathematically by considering the blood as Phan-Thien-Tanner fluid. The representation for the blood flow is through an axially symmetrical stenosis. Symmetry of the distribution of the wall shearing stress and resistive...

Author(s): Noreen Sher Akbar, S. Nadeem and Changhoon Lee

November 2012

Preparation and identification of two new phthalocyanines and study of their anti-cancer activity and anti-bacterial properties

Nickel phthalocyanines chloride and nickel phthalocyanines nitrate abbreviated as NiPcCl and NiPc (NO3) respectively were synthesized and characterized. These nickel phthalocyanines are prepared by reaction of phetalic anhydride with urea, ammonium chloride and ammonium heptamolybdate, nickel related salt. Characterization of them was made by microanalyses, Fourier transform infrared spectroscopy (FT-IR) and...

Author(s): Shahriar Ghammamy, Mina Azimi and Sajjad Sedaghat  

November 2012

Optimizing tilt angles and orientations of solar panels for Kuala Lumpur, Malaysia

Shading of solar panels drastically reduces the solar collector’s efficiency “η” by reducing cell power “PMP”, and altering the short circuit-current “ISC”, the open-circuit voltage “VOC”, and the fill factor “FF”. Therefore, the orientation and tilt angle of solar collectors play an important role in minimizing shading and consequently in...

Author(s): B. R. Elhab, K. Sopian, Sohif Mat, Ch Lim, M. Y. Sulaiman, M. H. Ruslan, Omidreza Saadatian