Kinetic Model to Investigate the Effect of Cooling Rate on δ-Ferrite Behavior and Its Application in Continuous Casting of AISI 304 Stainless Steel

Tahereh Zargar,Fazlollah Sadeghi,Jong Wan Kim,Jae Sang Lee,Yoon‑Uk Heo,Chang Hee Yim 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.9

The prediction of M-shaped δ-ferrite content along the thickness direction of continuously cast 304 austenitic stainless steelslab was performed using a diffusion-controlled phase transformation module of Thermo-Calc software. The surface andcenter of the slab, which solidified with different cooling rates and secondary dendrite arm spacing, were used for kineticcalculations. Comparison between observations and calculations for slab specimens demonstrated that the moving-boundarymodel could predict retained δ-ferrite content according to various thermal histories. After this validation, the effects ofdifferent cooling rates at liquid and solid-state were analyzed to understand the importance of each stage on the diffusioncontrolledδ → phase transformation. Decrease in solid-state cooling rate generally had a larger effect on the reduction ofδ-ferrite during cooling when the solidification rate was fast (27.75 °C/s) than when it was slow (0.075 °C/s). This model canbe used to predict and control δ-ferrite behavior under different thermal histories during slab casting and welding practices.

Cre-Lox: A Tool for Removal of Marker Genes to Make GM Foods Safe

Zargar, Sajad M.,Mushtaq, Roohi,Joshi, Manisha,Prasad, D. Theertha,Bhat, Nazir Ahmad,Agrawal, Ganesh Kumar,Rakwal, Randeep The Korean Society of Crop Science 2007 Journal of crop science and biotechnology Vol.10 No.2

The green revolution has significantly helped in increasing the food production. So far, various breeding methods have been exploited, besides them recombination DNA technology provides another approach for increasing the food production. By means of this technology the losses in food production incurred by various biotic and abiotic stresses can be effectively controlled. In most of the transgenic studies scientists have used antibiotic resistant genes as markers for easy selection of transformants but there are risks involved in use of GM foods. To make such foods safer and environment friendly we have discussed a novel strategy i.e. Cre-lox which involves site specific recombination. By means of Cre-lox the marker genes can be specifically removed once the selection of transformants is over. In addition, this strategy can be used to module the hybrid chromosomes, avoid gene silencing and incorporate single copy of a transgene for its higher expression.

Comparing the empirical powers of several independence tests in generalized FGM family

Zargar, M.,Jabbari, H.,Amini, M. The Korean Statistical Society 2016 Communications for statistical applications and me Vol.23 No.3

The powers of some tests for independence hypothesis against positive (negative) quadrant dependence in generalized Farlie-Gumbel-Morgenstern distribution are compared graphically by simulation. Some of these tests are usual linear rank tests of independence. Two other possible rank tests of independence are locally most powerful rank test and a powerful nonparametric test based on the $Cram{\acute{e}}r-von$ Mises statistic. We also evaluate the empirical power of the class of distribution-free tests proposed by Kochar and Gupta (1987) based on the asymptotic distribution of a U-statistic and the test statistic proposed by $G{\ddot{u}}ven$ and Kotz (2008) in generalized Farlie-Gumbel-Morgenstern distribution. Tests of independence are also compared for sample sizes n = 20, 30, 50, empirically. Finally, we apply two examples to illustrate the results.

INEQUALITIES CONCERNING POLYNOMIAL AND ITS DERIVATIVE

Zargar, B.A.,Gulzar, M.H.,Akhter, Tawheeda The Kangwon-Kyungki Mathematical Society 2021 한국수학논문집 Vol.29 No.3

In this paper, some sharp inequalities for ordinary derivative P'(z) and polar derivative D_αP(z) = nP(z) + (α - z)P'(z) are obtained by including some of the coefficients and modulus of each individual zero of a polynomial P(z) of degree n not vanishing in the region |z| > k, k ≥ 1. Our results also improve the bounds of Turán's and Aziz's inequalities.

Extraction-Spectrophotometric Determination of Cimetidine in Pharmaceutical Samples as an Ion Pair with Bromothymol Blue

Zargar, B.,Pourreza, N.,Shahrouz, M. Korean Chemical Society 2011 대한화학회지 Vol.55 No.1

감도가 높고 선택적인 추출-분광광도법은 미량의 시메티딘의 측정을 위해 개발되어 왔다. 이 방법은 클로로포름안에 브로모티몰 블루(BTB)와 함께 이온 쌍으로 시메티딘의 추출에 기초했다. 그리고 417 nm에서 흡광도를 측정하고 있다. pH, BTB의 농도, 클로로포름의 부피, 섞는 시간과 같은 다른 변수들의 효과를 연구하였다. 또한, 추출에서 간섭이온의 효과도 연구하였다. 보정곡선은 0.9997의 상관계수와 함께 0.25~8 ug/mL의 범위에서 선형이다. 3Sb에 기초한 검출한계는 0.14 ug/mL이고 시메티딘의 0.1과 4.0 ug/mL의 10번 측정에 대한 상대표준편차는 3.2와 1.49%이었다. 제안된 방법은 좋은 회수와 함께 약제 샘플에서 시메티딘의 측정에 적용되었다. A highly sensitive and selective extraction-spectrophotometric method has been developed for determination of trace amounts of cimetidine. This method is based on the extraction of cimetidine as an ion pair with bromothymol blue (BTB) into chloroform and measuring its absorbance at 417 nm. The effect of different variables such as pH, concentration of BTB, volume of chloroform and shaking time was investigated. The effect of interfering ions on the extraction was also studied. The calibration curve was linear in the range of 0.25-8 ${\mu}gmL^{-1}$ with correlation coefficient of 0.9997. The detection limit based on 3Sb was 0.14 ${\mu}gmL^{-1}$ and relative standard deviation for 10 replicated measurements of 1.0 and 4.0 ${\mu}gmL^{-1}$ of cimetidine was 3.2 and 1.49%, respectively. The proposed method was applied to the determination of cimetidine in pharmaceutical samples with good recoveries.

Association of recurrent implantation failure and recurrent pregnancy loss with peripheral blood natural killer cells and interferon-gamma level

Mahvash Zargar,Mehri Ghafourian,Farnaz Behrahi,Roshan Nikbakht,Abdolah Mousavi Salehi 대한산부인과학회 2024 Obstetrics & Gynecology Science Vol.67 No.1

Objective Fetal uterine survival depends on maintaining an immune balance between the mother and fetus. This study aimed to investigate the correlation of blood peripheral natural killer (NK) cells and interferon-gamma (IFN-γ) with recurrent recurrent implantation failure (RIF) and recurrent pregnancy loss (RPL). Methods In this case-control study, peripheral blood samples were obtained from three groups of RPL, RIF, and parous women without a history of abortion or infertility problems and analyzed by lymphocyte-based flow cytometry. Afterward, the levels of NK cells and IFN-γ were determined. All data were analyzed using one-way analysis of variance and nonparametric Kruskal-Wallis tests. Results The level of IFN-γ in the RPL group was significantly higher than that in parous women and the RIF group (P<0.05), whereas its level in the RIF group was not significantly different from the control group (P>0.05). A significant correlation was found between the levels of IFN-γ and NK cells in the RPL group (r=0.481; P=0.02). However, no significant correlation was found between the levels of IFN-γ and the active NK cells in the RPL group (P=0.08). Moreover, no significant correlation was found between the levels of NK cells (whether activated or not) and IFN-γ in the RIF patients (P>0.05). Conclusion Immune dysfunction may not be involved in implantation failure during IVF but may be involved in recurrent miscarriage, probably by increasing IFN-γ levels.

Extraction-Spectrophotometric Determination of Cimetidine in Pharmaceutical Samples as an Ion Pair with Bromothymol Blue

B. Zargar,N. Pourreza,M. Shahrouz 대한화학회 2011 대한화학회지 Vol.55 No.1

A highly sensitive and selective extraction-spectrophotometric method has been developed for determination of trace amounts of cimetidine. This method is based on the extraction of cimetidine as an ion pair with bromothymol blue (BTB) into chloroform and measuring its absorbance at 417 nm. The effect of different variables such as pH, concentration of BTB, volume of chloroform and shaking time was investigated. The effect of interfering ions on the extraction was also studied. The calibration curve was linear in the range of 0.25-8 μg mL^(-1) with correlation coefficient of 0.9997. The detection limit based on 3S_b was 0.14 μg mL^(-1) and relative standard deviation for 10 replicated measurements of 1.0 and 4.0 μg mL^(-1) of cimetidine was 3.2 and 1.49%, respectively. The proposed method was applied to the determination of cimetidine in pharmaceutical samples with good recoveries.

Evaluation of PRE and POST Herbicides on Growth Features, Nodulation, and Nitrogen Fixation of Three Cultivars of Chickpea (Cicer aritinium L.)

Meisam Zargar,Amir Lakzian,Rahil Rasooli,Ebrahim Izadi-Darbandi 한국작물학회 2020 Journal of crop science and biotechnology Vol.23 No.2

It is exceptionally difficult to have productive farming without the use of herbicides. It has been found that they create difficulties in the growth and biological nitrogen fixation of some legume crops after their application. Adverse impacts may result from a direct effect of the herbicide on rhizobial growth and/or an indirect effect on plant growth. In order to study the effect of some PRE and POST herbicides on nodulation, nitrogen fixation, and growth characteristics of three chickpea cultivars, a greenhouse trial was conducted in a completely randomized design with factorial arrangement and three replications. Pyridate, imazethapyr, and trifluralin were applied with the recommended rates of 1100, 100, and 720 g ai ha-1, respectively, and also non-treated control on three chickpea cultivars (ILS482, Hashem, and Kaka). The results showed that trifluralin and pyridate herbicides had the highest and the least negative impact on growth characteristics of three examined cultivars. Pyridate showed a positive effect on vegetative characteristics but nodulation and total nitrogen contents in the shoots of chickpea cultivars decreased significantly. Results also revealed that root and shoot growth, nodulation, and nitrogen fixation diminished significantly when imazethapyr and trifluralin were applied to Hashem and ILC482 cultivars. It seems that pyridate is an appropriate herbicide for broadleaf weed control in chickpea fields.

Tularemia, a re-emerging infectious disease in Iran and neighboring countries

Afsaneh Zargar,Max Maurin,Ehsan Mostafavi 한국역학회 2015 Epidemiology and Health Vol.37 No.-

OBJECTIVES: Tularemia is a zoonotic disease transmitted by direct contact with infected animals and through arthropod bites, inhalation of contaminated aerosols, ingestion of contaminated meat or water, and skin contact with any infected material. It is widespread throughout the northern hemisphere, including Iran and its neigh-bors to the north, northeast, and northwest. METHODS: In this paper, the epidemiology of tularemia as a re-emerging infectious disease in the world with a focus on Iran and the neighboring countries is reviewed. RESULTS: In Iran, positive serological tests were first reported in 1973, in wildlife and domestic livestock in the northwestern and southeastern parts of the country. The first human case was reported in 1980 in the south-west of Iran, and recent studies conducted among at-risk populations in the western, southeastern, and south-western parts of Iran revealed seroprevalences of 14.4, 6.52, and 6%, respectively. CONCLUSIONS: Several factors may explain the absence of reported tularemia cases in Iran since 1980. Tula-remia may be underdiagnosed in Iran because Francisella tularensis subspecies holarctica is likely to be the major etiological agent and usually causes mild to moderately severe disease. Furthermore, tularemia is not a disease extensively studied in the medical educational system in Iran, and empirical therapy may be effective in many cases. Finally, it should be noted that laboratories capable of diagnosing tularemia have only been estab-lished in the last few years. Since both recent and older studies have consistently found tularemia antibodies in humans and animals, the surveillance of this disease should receive more attention. In particular, it would be worthwhile for clinical researchers to confirm tularemia cases more often by isolating F. tularensis from infected humans and animals.

Plant mediated green biosynthesis of silver nanoparticles using Vitex negundo L. extract

Mohsen Zargar,Kamyar Shameli,Gholam Reza Najafi,Farah Farahani 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

In the present study silver nanoparticles (Ag-NPs) were synthesized from aqueous silver nitrate througha biosynthetic route using water extract of Vitex negundo L. extract which acted as a reductant andstabilizer agents, simultaneously. Formations of Ag/V. negundo were determined by UV–vis spectroscopywhere surface plasmon absorption maxima can be observed at 423–432 nm. The XRD analysis showsthat the Ag-NPs are of face centered cubic structure. TEM images show the well dispersed of Ag-NPs withaverage particle size less than 20 nm. The FT-IR spectrum indicates the presence of V. negundo in cappingwith silver nanoparticles.