Evaluating the Catalytic Effects of Carbon Materials on the Photocatalytic Reduction and Oxidation Reactions of TiO2

Gulzar Khan,Young Kwang Kim,최성규,한동석,Ahmed Abdel-Wahab,박현웅 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

TiO2 composites with seven different carbon materials (activated carbons, graphite, carbon fibers, singlewalled carbon nanotubes, multi-walled carbon nanotubes, graphene oxides, and reduced graphene oxides) that are virgin or treated with nitric acid are prepared through an evaporation method. The photocatalytic activities of the as-prepared samples are evaluated in terms of H2 production from aqueous methanol solution (photocatalytic reduction: PCR) and degradation of aqueous pollutants (phenol, methylene blue, and rhodamine B) (photocatalytic oxidation: PCO) under AM 1.5-light irradiation. Despite varying effects depending on the kinds of carbon materials and their surface treatment, composites typically show enhanced PCR activity with maximum 50 times higher H2 production as compared to bare TiO2. Conversely, the carbon-induced synergy effects on PCO activities are insignificant for all three substrates. Colorimetric quantification of hydroxyl radicals supports the absence of carbon effects. However, platinum deposition on the binary composites displays the enhanced effect on both PCR and PCO reactions. These differing effects of carbon materials on PCR and PCO reactions of TiO2 are discussed in terms of physicochemical properties of carbon materials, coupling states of TiO2/carbon composites, interfacial charge transfers. Various surface characterizations of composites (UV-Vis diffuse reflectance, SEM, FTIR, surface area, electrical conductivity, and photoluminescence) are performed to gain insight on their photocatalytic redox behaviors.

Polymorphic Variation in Glutathione-S-transferase Genes and Risk of Chronic Myeloid Leukaemia in the Kashmiri Population

Bhat, Gulzar,Bhat, Ashaqullah,Wani, Aadil,Sadiq, Nida,Jeelani, Samoon,Kaur, Rajinder,Masood, Akbar,Ganai, Bashir Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Cancer is a complex disease and the genetic susceptibility to it could be an outcome of the inherited difference in the capacity of xenobiotic metabolizing enzymes. Glutathione-S-transferases (GSTs) are phase II metabolizing enzymes whose various genotypes have been associated with increased risk of different types of cancer. Null mutations caused by the deletion of the entire gene result in the absence of the enzymatic activity and increase in the risk of developing cancer including chronic myeloid leukaemia (CML). In the present case-control study we evaluated the effect of null mutations in GSTM1 and GSTT1 genes on the risk of developing CML. The study included 75 CML patients (43 males and 32 females; age (mean ${\pm}$ S.D) $42.3{\pm}13.4$ years) and unrelated non-malignant controls (76 male and 48 females; age (mean ${\pm}$ S.D) $41.5{\pm}12.9$). The distribution of GSTM1 and GSTT1 genotypes in CML patients and controls was assessed by multiplex-PCR method. Logistic regression was used to assess the relationship between GSTM1 and GSTT1 genotypes and risk of CML. Chi-square test was used to evaluate the trend in modulating the risk to CML by one or more potential high risk genotype. Although GSTM1 null genotype frequency was higher in CML patients (41%) than in the controls (35%), it did not reached a statistical significance (OD = 1.32, 95% CI: 0.73-2.40; P value = 0.4295). The frequency of GSTT1 null genotypes was higher in the CML patients (36%) than in the controls (21%) and the difference was found to be statistically significant (OD = 2.12, 95% CI: 1.12-4.02; P value = 0.0308). This suggests that the presence of GSTT1genotype may have protective role against the CML. We found a statistically significant (OD = 3.09, 95% CI: 1.122-8.528; P value = 0.0472) interaction between the GSTM1 and GSTT1 null genotypes and thus individuals carrying null genotypes of both GSTM1 and GSTT1 genes are at elevated risk of CML.

SIMPLE RANKED SAMPLING SCHEME: MODIFICATION AND APPLICATION IN THE THEORY OF ESTIMATION OF ERLANG DISTRIBUTION

RAFIA GULZAR,IRSA SAJJAD,M. YOUNUS BHAT,SHAKEEL UL REHMAN The Korean Society for Computational and Applied M 2023 Journal of applied mathematics & informatics Vol.41 No.2

This paper deals in the study of the estimation of the parameters of Erlang distribution based on rank set sampling and some of its modifications. Here we considered Maximum Likelihood (ML) and the Bayesian technique to estimate the shape and scale parameter of Erlang distribution based on RSS and its some modifications such as ERSS, MRSS, and MRSSu. The derivation for unknown parameters of Erlang distribution is well presented using normal approximation to the asymptotic distribution of ML estimators. But due to the complexity involves in the integral, the Bayes estimator of unknown parameters is obtained using MCMC method. Further, we compared the MSE of estimation in different sampling schemes with different set sizes and cycle size. A real-life data application is also given to illustrate the efficiency of the proposed scheme.

Evaluating the Catalytic Effects of Carbon Materials on the Photocatalytic Reduction and Oxidation Reactions of TiO₂

Khan, Gulzar,Kim, Young Kwang,Choi, Sung Kyu,Han, Dong Suk,Abdel-Wahab, Ahmed,Park, Hyunwoong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.4

$TiO_2$ composites with seven different carbon materials (activated carbons, graphite, carbon fibers, single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene oxides, and reduced graphene oxides) that are virgin or treated with nitric acid are prepared through an evaporation method. The photocatalytic activities of the as-prepared samples are evaluated in terms of $H_2$ production from aqueous methanol solution (photo-catalytic reduction: PCR) and degradation of aqueous pollutants (phenol, methylene blue, and rhodamine B) (photocatalytic oxidation: PCO) under AM 1.5-light irradiation. Despite varying effects depending on the kinds of carbon materials and their surface treatment, composites typically show enhanced PCR activity with maximum 50 times higher $H_2$ production as compared to bare $TiO_2$. Conversely, the carbon-induced synergy effects on PCO activities are insignificant for all three substrates. Colorimetric quantification of hydroxyl radicals supports the absence of carbon effects. However, platinum deposition on the binary composites displays the enhanced effect on both PCR and PCO reactions. These differing effects of carbon materials on PCR and PCO reactions of $TiO_2$ are discussed in terms of physicochemical properties of carbon materials, coupling states of $TiO_2$/carbon composites, interfacial charge transfers. Various surface characterizations of composites (UV-Vis diffuse reflectance, SEM, FTIR, surface area, electrical conductivity, and photoluminescence) are performed to gain insight on their photocatalytic redox behaviors.

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.

SWNTs-catalyzed solar hydrogen production

Kim, Young Kwang,Khan, Gulzar,Jeong, Hye Won,Park, Hyunwoong Korean Society of Photoscience 2014 Rapid communication in photoscience Vol.3 No.3

Single-walled carbon nanotubes (SWNTs) catalyzed hydrogen production from water containing various electron donors under visible light (${\lambda}$ > 420 nm). As-received SWNTs were effective for hydrogen production, yet the effect vanished when they underwent surface chemical treatments. Upon coupling with CdSe particles, however, the surface treated SWNTs were far superior to non-treated SWNTs by a factor of ~30 for hydrogen production.

Inequalities for B-operator

Rubia Akhter,M. H. Gulzar 강원경기수학회 2022 한국수학논문집 Vol.30 No.3

Let $\mathcal{P}_n$ denote the space of all complex polynomials $P(z)=\sum\limits_{j=0}^{n}a_j z^j$ of degree $n$. Let $P\in\mathcal{P}_n$, for any complex number $\alpha$, $D_\alpha P(z)=nP(z)+(\alpha -z)P'(z)$, denote the polar derivative of the polynomial $P(z)$ with respect to $\alpha$ and $B_n$ denote a family of operators that maps $\mathcal{P}_n$ into itself. In this paper, we combine the operators $B$ and $D_\alpha$ and establish certain operator preserving inequalities concerning polynomials, from which a variety of interesting results can be obtained as special cases.

The potential for interaction of tolbutamide with pomegranate juice against diabetic induced complications in rats

Manodeep Chakraborty,Mohammed Gulzar Ahmed,Ananya Bhattacharjee 한국한의학연구원 2017 Integrative Medicine Research Vol.6 No.4

Background: Pomegranate can inhibit cytochrome P450 (CYP) 2C9 activity, which is largely responsible for the metabolism of sulfonylureas. The present study was undertaken to evaluate the pharmacokinetic and pharmacodynamic interaction of pomegranate and tolbutamide (TOL) against diabetic-induced complications. Methods: Diabetes was induced via administration of alloxan (150 mg/kg, intraperitoneally). Rats (n = 8) were treated with pomegranate juice (PJ) [3 mL/animal, per os (p.o.)], TOL (20 mg/kg, p.o.), and their combination for 4 weeks. Twenty-four hours after the last treatment, the pharmacodynamic interaction of PJ and TOL was evaluated by antinociceptive activity, electrocardiographic parameters, serum glucose, biomarkers, and lipid profile values. The influence of PJ on the pharmacokinetics of TOL was studied using the high performance liquid chromatography method. Results: The combination of PJ and TOL resulted in a significant improvement against diabetic complications compared to the group treated with TOL alone. The combination group was found to be the best protective group by significant improvement of antinociceptive activity, restoration of electrocardiographic parameters, serum glucose, biomarkers, and lipid profile compared to the group treated with TOL alone. Results of the pharmacokinetic study revealed that PJ increases bioavailability and half-life, along with a decrease in clearance and elimination rate of TOL. Conclusion: From this study, it can be concluded that the combination of PJ and TOL exhibited profound protection compared to TOL alone against diabetic complications. The findings of pharmacokinetic interaction justified the results of pharmacodynamic interaction.

Automatic Voltage Regulation of Grid Connected Photovoltaic System Using Lyapunov Based Sliding Mode Controller: A Finite - Time Approach

Mingyang Xie,Muhammad Majid Gulzar,Huma Tehreem,Muhammad Yaqoob Javed,Syed Tahir Hussain Rizvi 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.6

Importance of PV based energy systems cannot be denied with quickly increase in renewable energy demand. Due to inherent uncertainties and non-linear behaviour of grid tied PV system, conventional control strategies are unable to provide satisfactory performance. Therefore, key purpose of this paper is to design non linear controller for the control of grid tied PV system. A novel control strategy is devised by utilizing Lyapunov base finite time non-linear reactive power and dc link voltage control. This strategy employes Lyapunov approach to ensure stability and guarantees robustness. With this control strategy, better and superior performance is observed in comparison to proportional integral controller. Furthermore, simulation results are provided to illustrate the effectiveness of proposed algorithm. Various disturbances of system such as change in solar insolation level, change in reference parameters, faults on buses are considered. With this control strategy, settling time and oscillations are found significantly less than PI controller.

Foliar Application of Growth Bioregulators Influences Floral Traits, Cormassociated Traits and Chemical Constituents in Gladiolus grandiflorus L.

Yasar Sajjad,Muhammad Jafar Jaskani,Muhammad Qasim,Gulzar Akhtar,Asim Mehmood 한국원예학회 2015 원예과학기술지 Vol.33 No.6

Gladiolus is one of the most popular cut flowers in the world floral market and is highly attractive to consumers. The production of poor-quality gladiolus spikes is one of the most important hurdles to obtaining high prices for this crop. The main objectives of this study were to improve the quantitative characteristics of gladiolus spikes, to increase propagule production and to enhance chemical constituent levels in leaves to help improve plant growth. We performed foliar application of bioregulators, including polyamines (putrescine and spermine) and vitamins (ascorbic acid and thiamine), at different concentrations (0, 0.1, 0.4, 0.7 and 1 mM) to gladiolus plants at the three leaf, five leaf and slipping stages. Application of 1 mM putrescine was the most effective treatment, with prominent effects on economically important spike traits including spike length (55.53 ㎝), spike diameter (7.53 ㎜), florets per spike (13.99), first floret diameter (9.66 ㎝) and first floret weight (4.90 g), followed by spermine treatment. The 1 mM putrescine treatment also had positive effects on corm-associated traits including corm diameter and corm weight, with values of 4.57 ㎝ and 26.16 g compared to 3.47 ㎝ and 17.16 g in control plants, respectively. The contents of chemical constituents in leaves, including total chlorophylls (8.06 ㎎·g<SUP>-1</SUP>), total carotenoids (1.66 ㎎·g<SUP>-1</SUP>), total soluble sugars (4.75 ㎎·g<SUP>-1</SUP>) and phenolics (0.89 ㎎·g<SUP>-1</SUP>) increased in response to foliar application of 1 mM putrescine compared to the control. Ascorbic acid and thiamine also had positive effects on various plant morphological traits and chemical constituents in leaves compared to control plants, but the growth-promoting effects of polyamines were more pronounced. Hence, applying polyamines to gladiolus leaves will help improve spike production and increasing propagule (cormel) yields.