Current-Type Nine-Switch Inverters

Dehghan, Seyed Mohammad,Mohamadian, Mustafa,Yazdian, Ali The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

In this paper two dual output current-type inverters are proposed. These inverters have been called a current source nines-witch inverter and a current-type z-source nine-switch inverter by the authors. The proposed inverters have two independent current source outputs. Compared to two independent current source inverters, the proposed converters are implemented with fewer semiconductor switches. Space vector modulation (SVM) is proposed for these converters. Simulation results show the validity and performance of the proposed inverters.

Quantitative corrosion imaging of pipelines using multi helical guided ultrasonic waves

Dehghan-Niri, Ehsan,Salamone, Salvatore Techno-Press 2016 Structural monitoring and maintenance Vol.3 No.3

This paper presents a multi helical ultrasonic imaging approach for quantitative corrosion damage monitoring of cylindrical structures. The approach consists of two stages. First a multi helical ultrasonic imaging (MHUI) algorithm is used to provide qualitative images of the structure of interest. Then, an optimization problem is solved in order to obtain quantitative damage information, such as thickness map. Experimental tests are carried out on a steel pipe instrumented with six piezoelectric transducers to validate the proposed approach. Three thickness recesses are considered to simulate corrosion damage. The results show the efficiency of the proposed approach for quantifying corrosion location, area and remnant thickness.

The TP53 intron 6 G13964C Polymorphism and Risk of Thyroid and Breast Cancer Development in the Iranian Azeri Population

Dehghan, Roghayeh,Feizi, Mohammad Ali Hosseinpour,Pouladi, Nasser,Adampourezare, Mina,Farajzadeh, Davoud Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: TP53 mutations are the most common genetic alterations in human cancers. There are also several polymorphisms in both exons and introns of TP53 that may influence its anti-tumor functions and increase the risk of cancer development. Associations of the TP53 intron 6 G13964C polymorphism with increased risk of development of several cancers have been investigated in numerous studies, but the results were controversial and conflicting. In this study, we aimed to investigate the probable association of this polymorphism with risk of both thyroid and breast cancers among the Iranian-Azeri population. Materials and Methods: We performed two separate case control studies on associations of the intron 6 polymorphism with two different kinds of cancer. In one case-control study, a total of 75 patients with thyroid carcinoma and 180 controls were analyzed and the other study included 170 patients with breast cancer and 135 healthy women. The intron 6 genotype was determined by RFLP-PCR and the SPSS 16 program was applied for data analysis. Results: For thyroid cancer, the frequencies of GG genotype were 96.0% in patients and 93.3% in controls. The GC genotype had a frequency of 4.0 % in patients and 6.7% in controls. In the study on breast cancer, the frequency of GG and GC genotypes in patients were 95.3% and 4.7%, respectively. In breast related control group, the frequency of GG genotype was 93.3 % and the frequency of GC genotype was 6.7%. None of the cases and controls had the CC genotype. Conclusions: There was no significant association between the TP53 intron 6 G13964C polymorphism and risk of development of both thyroid and breast cancer in Iranian-Azeri patients.

ON THE REFLEXIVE SOLUTIONS OF THE MATRIX EQUATION AXB + CYD = E

Dehghan, Mehdi,Hajarian, Masoud Korean Mathematical Society 2009 대한수학회보 Vol.46 No.3

A matrix $P{\in}\mathbb{C}^{n{\times}n}$ is called a generalized reflection matrix if $P^*$ = P and $P^2$ = I. An $n{\times}n$ complex matrix A is said to be a reflexive (anti-reflexive) matrix with respect to the generalized reflection matrix P if A = PAP (A = -PAP). It is well-known that the reflexive and anti-reflexive matrices with respect to the generalized reflection matrix P have many special properties and widely used in engineering and scientific computations. In this paper, we give new necessary and sufficient conditions for the existence of the reflexive (anti-reflexive) solutions to the linear matrix equation AXB + CY D = E and derive representation of the general reflexive (anti-reflexive) solutions to this matrix equation. By using the obtained results, we investigate the reflexive (anti-reflexive) solutions of some special cases of this matrix equation.

Isolation, Characterization, and Investigation of Surface and Hemolytic Activities of a Lipopeptide Biosurfactant Produced by Bacillus subtilis ATCC 6633

Dehghan-Noudeh Gholamreza,Housaindokht Mohammadreza,Bazzaz Bibi Sedigeh Fazly The Microbiological Society of Korea 2005 The journal of microbiology Vol.43 No.3

Bacillus subtilis ATCC 6633 was grown in BHIB medium supplemented with $Mn^{2+}$ for 96 h at $37^{\circ}C$ in a shaker incubator. After removing the microbial biomass, a lipopeptide biosurfactant was extracted from the supernatant. Its structure was established by chemical and spectroscopy methods. The structure was confirmed by physical properties, such as Hydrophile-Lipophile Balance (HLB), surface activity and erythrocyte hemolytic capacity. The critical micelle concentration (cmc) and erythrocyte hemolytic capacity of the biosurfactant were compared to those of surfactants such as SDS, BC (benzalkonium chloride), TTAB (tetradecyltrimethylammonium bromide) and HTAB (hexadecyltrimethylammonium bromide). The maximum hemolytic effect for all surfactants mentioned was observed at concentrations above cmc. The maximum hemolytic effect of synthetic surfactants was more than that of the biosurfactant produced by B. subtilis ATCC 6633. Therefore, biosurfactant would be considered a suitable surface-active agent due to low toxicity to the membrane.

Green Synthesis of ZnO/αFe2O3 Nano-photocatalyst for Efficient Removal of Carbamate Pesticides in Wastewater: Optimization, Mineralization, and Financial Analysis

Dehghan Ali,Aliasghar Arash,Rahmati Roxana,Delnavaz Mohammad,Khoshvaght Hoda 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.1

As emerging organic agricultural pollutants, carbamate pesticides can react with other contaminants in aquatic environments to produce new toxic compounds threatening aquatic life and ecosystems. This study introduces a novel, nonhazardous, and greener method to synthesize a cross-linked ZnO/αFe 2 O 3 nano-photocatalyst to treat carbamate pesticides via ball milling. ZnO/αFe 2 O 3 was characterized through various methods, including XRD, EDX, XRF, DRS, BET, FE-SEM, PL, and FTIR analyses. Using the Response Surface Methodology (RSM), the ability of ZnO/αFe 2 O 3 nano-photocatalyst to remove carbamate from synthesized wastewater was assessed. The BET result indicated a decrease in the diameter of the nanocomposite size after the synthesis. At the same time, the BET surface area and total pores increased from 4.9871 m 2 .g −1 and 0.02806 cm 3 .g −1 to 6.8524 m 2 .g −1 and 0.069497 cm 3 .g −1 , respectively. In addition, the band-gap energy decreased from 3.179 eV for ZnO to 1.907 eV for ZnO/αFe 2 O 3 and eventually reached 1.878 eV for heat-treated ZnO/αFe 2 O 3 nanocomposite. The catalyst concentrations used in the experiments were 0.5, 1, and 1.5 g/L. The solution pH was set to 5, 8, and 11, and three diff erent residence times of 1, 2, and 3 h were used. The model’s results indicated a strong agreement between the experimental and predicted data (R 2 = 0.99). When the nanocomposite’s concentration, pH, and retention time were set at 1 g/L ZnO/αFe 2 O 3 , 8.51, and 3 h respectively, the optimized conditions predicted a removal effi ciency of 89%. In addition, the cost of COD removal was reduced by 50% using ball milling and heat-treatment synthesis. The photocatalyst’s reusability was tested in three stages, and the outcomes demonstrated its stability throughout these three stages.

Dry-powder form of chitosan nanospheres containing influenza virus and adjuvants for nasal immunization

S. Dehghan,M. Tavassoti Kheiri,M. Tabatabaiean,S. Darzi,M. Tafaghodi 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.8

The objective of this study was to develop andstatistically optimize chitosan nanospheres. For this purposechitosan powder was turned into nanospheres using tripolyphosphateas a crosslinker and through ionic gelation. D-optimal response surface design was applied to optimizethe nanospheres. Their size and polydispersity index (PDI)were measured as the dependant variables. Then the inactivatedinfluenza virus and/or CpG ODN or Quillaja saponin(QS) were incorporated into the chitosan nanospheres. Therelease profiles of the antigen and both adjuvants wereobtained. The toxicity of the formulations was tested byXTT using Calu 6 cell lines. The size distribution and PDIof plain chitosan nanospheres was 581.1 ± 32.6 and0.478 ± 0.04. After 4 h the release of antigen, QS and CpGfrom the chitosan matrix were 33, 36 and 62 %, respectively. The inactivated virus remained intact during preparation,as revealed by the SDS-PAGE method. Differentialscanning calorimetry and Fourier Transform InfraredSpectroscopy indicated no serious structural changes in thechitosan carrier in the presence of either the antigen or theimmunoadjuvants. Although the antigen loaded into chitosannanospheres showed slight cytotoxicity on lung-cancercells, co-encapsulation of the adjuvant (especially CpG)lowered this effect. The results demonstrated that chitosanas a carrier and immunostimulator, along with CpG or QSadjuvants, creates a potential influenza vaccine deliverysystem which can be administered nasally.

Solving Coupled Matrix Equations over Generalized Bisymmetric Matrices

Mehdi Dehghan,Masoud Hajarian 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.5

In this paper, an iterative algorithm is established for finding the generalized bisymmetric solution group to the coupled matrix equations (including the generalized (coupled) Lyapunov and Sylvester matrix equations as special cases). It is proved that proposed algorithm consistently converges to the generalized bisymmetric solution group for any initial generalized bisymmetric matrix group. Finally a numerical example indicates that proposed algorithm works quite effectively in practice.

Goal Orientations in an EFL Advanced Academic Writing Context

( Farzaneh Dehghan ) 범태평양 응용언어학회 2015 Journal of Pan-Pacific Association of Applied Ling Vol.19 No.1

Academic writing at advanced levels is the most important way of demonstrating one``s expertise in a discipline. Developing this kind of competence is especially a challenging effort for students in foreign language contexts. Many factors may be involved in determining why some students are more and some are less motivated in writing successful, discipline-specific academic texts. One of these important factors is motivation. In educational psychology, one view of academic motivation is in telms of different goal orientations that students hold in their academic activities. This study, as part of a larger project, tries to explore different goal orientations that postgraduate students in a foreign language academic context hold while they are involved in writing practices necessary to achieve success in an academic context. The sample was chosen according to convenience sampling. Following a qualitative design, 28 postgraduate students of TEFL (Ph. D. candidates, M.A. holders, and M.A. students) were selected for this study. The participants took part in in-depth interviews. They were asked questions on the way they compose their professional texts, the required compositions (especially paper assignments) and any factor that motivates them in their writings. Analyzing the transcribed interviews, the researchers were able to identify four categories of goal orientations. These categories were named as career-directed, context-directed, mastery, and work avoidance goal categories. This taxonomy brings together the issue of motivation as goal orientation in educational psychology and the socio-cognitive view of writing in a foreign languagc academic contcxt.

Solving the Generalized Sylvester Matrix Equation ∑^p_i=1 A_iXB_i + ∑_q_j=1 C_jYD_j = E Over Reflexive and Anti-reflexive Matrices

Mehdi Dehghan,Masoud Hajarian 제어·로봇·시스템학회 2011 International Journal of Control, Automation, and Vol.9 No.1

A matrix is P ∈ R^n×n called a generalized reflection if P^T = P and P^2=I. An n×n matrix A is said to be a reflexive (anti-reflexive) with respect to P if A=PAP(A=-PAP). In the present paper, two iterative methods are derived for solving the generalized Sylvester matrix equation ∑^p_i=1 A_iXB_i + ∑_q_j=1 C_jYD_j = E, (including the Sylvester and Lyapunov matrix equations as special cases) over reflexive and anti-reflexive matrices respectively. It is proven that the iterative methods, re-spectively, consistently converge to the reflexive and anti-reflexive solutions of the matrix equation for any initial reflexive and anti-reflexive matrices. Finally, a numerical example is given to demonstrate the effectiveness of the derived methods.