Preparation and characterizations of activated carbon from kenaf fiber for equilibrium adsorption studies of copper from wastewater

Zaira Zaman Chowdhury,Sharifuddin Mohd. Zain,Rashid Atta Khan,Md. Sakinul Islam 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.9

The potential of activated carbon prepared from kenaf fiber (KF) to remove copper (II) from aqueous effluents was investigated. The fibers were first semi-carbonized, then impregnated with potassium hydroxide (KOH) and finally activated by using carbon dioxide (CO2) gas to produce activated carbon. Pore structure and physical characteristics of the prepared kenaf fiber activated carbon (KFAC) were determined. Adsorption studies for divalent copper (Cu)ions were carried out to delineate the effect of contact time, temperature, pH and initial metal ion concentration on equilibrium adsorption capacity. The experimental data followed pseudo-second-order kinetics and Elovich Model than pseudo-first-order. Langmuir, Freundlich and Temkin models were implemented to analyze the parameters for adsorption at 30 oC, 50 oC and 70 oC. Thermodynamic parameters such as ΔGo, ΔHo and ΔSo which represent Gibbs free energy,enthalpy and entropy, respectively, were evaluated. It was concluded that activated carbon from kenaf fiber (KFAC)can be used as an efficient adsorbent for removal of Cu (II) from synthetic wastewater.

Kazakhstan’s science and its impact on the country’s social and economic development

Zaira T.SATPAYEVA,Zhansaya IMANGALI 한국유통과학회 2023 International Forum on Business Convergence (IFBC) Vol.2023 No.-

Genotoxic and Antigenotoxic Potential of Momordica charantia Linn (Cucurbitaceae) in the Wing Spot Test of Drosophila melanogaster

Zaira Rosa Guterres,Thalita Alves Zanetti,Tiago Felipe Sennes-Lopes,Ana Francisca Gomes da Silva 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.10

Momordica charantia, popularly known as bitter melon, is a plant widely used in ethnobotanical medicine. It has antibacterial, antifungal, anthelmintic, antidiabetic, antiviral, and antimalarial activities, among others. The goal of this study was to evaluate the genotoxic and/or antigenotoxic activity of the aqueous extracts obtained from the aerial parts and fruit of this plant by means of the Drosophila melanogaster wing spot test. Third-stage larvae that obtained standard (ST) cross and high bioactivation (HB) cross were treated with aqueous extracts of the aerial parts (IQA) and fruit (IQF) of M. charantia, following two protocols (genotoxicity and antigenotoxicity). The aqueous extracts are not genotoxic in lower concentrations. The frequencies of mutant spots observed in the descendants of the ST and HB crosses treated with doxorubicin (DXR) alone were 8.65 and 9.25, respectively, whereas in those cotreated with IQA and DXR, the frequencies ranged from 15.90 to 29 in the ST cross and from 15.05 to 24.78 in the HB cross. In cotreatment with IQF, the frequencies ranged from 30.10 to 30.65 in the ST cross and from 13.60 to 14.50 in the HB cross, whereas the frequencies obtained with DXR were 32.50 in the ST cross and 26.00 in the HB cross. In conclusion, the IQA has a synergistic effect, enhancing the genotoxicity of DXR in the ST cross and the HB cross, whereas the IQF has antigenotoxic effects in the HB cross.

Gender Equality and Women Business of Framework 5Ms in Kazakhstan: Analysis and Basic Directions

SATPAYEVA, Zaira T.,KIREYEVA, Anel A.,KENZHEGULOVA, Gaukhar,YERMEKBAYEVA, Dinara Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.3

This study aims to analyze of existing concepts of female entrepreneurship, evaluation of women's entrepreneurship in Kazakhstan and development of recommendations for its development in the country. This paper begins by reviewing research on female entrepreneurship. In this research, authors proposed the methodological tools based on systematic approach using economic and statistic methods and 5Ms concept. Analysis algorithm consists of four stages: evaluation of women entrepreneurship scale and business directions, analysis of employment in women's enterprises and business environment in Kazakhstan. The main limitation of this study was the lack of some gender-related indicators on the development of entrepreneurship. Further, the obtained results showed strong and weak points of female entrepreneurship in Kazakhstan. According to the results, there has observed increase in contribution of women in social-economic development of the republic, women's entrepreneurial activity is increasing, and the number of enterprises headed by them is growing. However, the growth of female entrepreneurship occurs while maintaining their insignificance in terms of turnover and number of employees. There is a pronounced industry specificity of female entrepreneurship: the service sector. In accordance with this, there were identified priority areas and there were developed recommendations for the development of female entrepreneurship in Kazakhstan.

Distribution of Knowledge through Online Learning and its Impact on the Intellectual Potential of PhD Students

Dana KANGALAKOVA(Dana KANGALAKOVA ),Aisulu DZHANEGIZOVA(Aisulu DZHANEGIZOVA ),Zaira T. SATPAYEVA(Zaira T. SATPAYEVA ),Kuralay NURGALIYEVA(Kuralay NURGALIYEVA ),Anel A. KIREYEVA(Anel A. KIREYEVA ) 한국유통과학회 2023 유통과학연구 Vol.21 No.4

Purpose: the research aims to analyze the impact of the distribution of knowledge through online learning on the intellectual potential of PhD students and produce recommendations for policy to improve intellectual capacity. During the literature review, it was determined that a large number of studies examined the impact of online learning on the quality of education at different levels. Research design, data and methodology: the research methodology is based on subjective assessment and studying the students’ opinions. The basis of the study was a comprehensive analysis of primary data obtained through a sociological survey of PhD students. 324 respondents from humanitarian, medical and natural faculties participated in the survey. Results: the study revealed that online learning helps increase students’ intellectual potential. PhD students had a positive attitude towards the transition from traditional education to online learning. It should be noted that, according to the results, the most popular gadgets were laptops and smartphones, which were characterized by high mobility and ease of use. Based on the obtained results, recommendations were developed for the formation of online learning with a focus on increasing students’ intellectual potential. Conclusions: based on the results of the assessment of educational and innovative potential, policy recommendations and further research in this area were proposed.

Synthesis of Ag-Loaded TiO2 Electrospun Nanofibers for Photocatalytic Decolorization of Methylene Blue

M. Raffi,Zaira Batool,Mashkoor Ahmad,M. Zakria,Rana I. Shakoor,Muhammad Aslam Mirza,Arshad Mahmood 한국섬유공학회 2018 Fibers and polymers Vol.19 No.9

Titanium dioxide (TiO2) is one of the excellent photocatalysts used for degradation of environmetal pollutants. In this work, 2.5, 5.0 and 7.5 wt.% of silver (Ag)-loaded TiO2 nanofibers of mean size 52-134 nm were synthesized by electrospinning method. These electrospun nanofibers were calcined at 500 oC to enable the transformation of Rutile (R) phase to Anatase (A), elimination of reaction moieties from the TiO2 matrix and subsequently formation of Ag clusters. The effect of Ag loading on the morphology, crystal structure, phase transformation, and band gap of these electrospun nanofibers have been characterized by scannining electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), raman spectroscopy and UV-visible spectroscopy. These nanofibers exhibited a red-shift in the absorbance edge and a significant enhancement of light absorption in the wavelength range of 250-550 nm. These electrospun nanofibers were investigated for photodecomposition of methylene blue (MB), and photocatalytic decolorization rates were determined by pseudo-first-order equation. The rate constants for the pure and those of 2.5, 5.0, and 7.5 wt% Agloaded TiO2 nanofibers were computed to be 0.1439 min-1, 0.1608 min-1, 0.1876 min-1, and 0.2251 min-1 respectively.

Women across Social Groups in Kazakhstan Labor Market

Anel A,KIREYEVA,Zaira T,SATPAYEVA,Gaukhar K,KENZHEGULOVA 한국유통과학회 2018 KODISA ICBE (International Conference on Business Vol.2018 No.-

This study aims is to analyze of existing concepts of gender stereotypes and gender differences in wages, defining of gender pay gap determinants, and to evaluate the level of discrimination against women in Kazakhstan. In the proposed study, the authors explore the conceptual framework and basic directions of the problem of gender wage differentials. In this research, authors propose the methodological tools for presenting a standard form of evaluation of gender pay gap. The developed methodological tools will allow providing authentic and formal analysis on gender pay gap and identifying the main determinants of gender pay differences. Further, the obtained results showed the distribution of wage gap in Kazakhstan s regions and the Duncan s dissimilation index allows us to trace the dynamics of changes in the professional structure between men and women. According to the results, gender pay gap is narrowing with the reduction of the job level and discrimination is related to differences in human capital and education. Wages in the industrial sector are higher for men than for women, because men s professions are characterized by severe and unhealthy working conditions. In addition, employers prefer male managers, but if they take woman managers, they give them salary 3 times less.

Solubility of celecoxib in N-methyl-2-pyrrolidone+water mixtures at various temperatures: Experimental data and thermodynamic analysis

Sarah Nozohouri,Ali Shayanfar,Zaira Johanna Cárdenas,Fleming Martinez,Abolghasem Jouyban 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.5

Solubility is one of the most significant physicochemical properties of drugs, and improving the solubility of drugs is still a challenging subject in pharmaceutical sciences due to requirements of enhancing their bioavailability. Celecoxib, according to the biopharmaceutics classification system (BCS), is a class 2 drug, possessing low water solubility (<5 μg·mL−1) and high permeability. Increasing the solubility of this group can lead to improved bioavailability, dose reduction and subsequently, increased efficiency and reduced side effects. In this study, celecoxib solubility was determined in binary mixtures of N-methyl-2-pyrrolidone (NMP)+water at 293.2, 298.2, 303.2, 308.2 and 313.2 K. The solubility of celecoxib is increased with the addition of NMP to the aqueous solutions and reaches a maximum value in neat NMP. In addition, increased temperature leads to enhanced solubility of celecoxib in a given solvent composition. The solubility data of celecoxib in NMP+water at different temperatures were correlated using different mathematical models including, the Jouyban-Acree model and a combination of the Jouyban-Acree and van’t Hoff models. Thermodynamic parameters, Gibbs energy, enthalpy and entropy of dissolution processes were performed based on Gibbs and van’t Hoff equations. Thermodynamic analysis allowed observing two main entropy or enthalpy-driven dissolution mechanisms, varying according to the composition of aqueous mixtures. Moreover, preferential solvation of celecoxib by water is observed in water-rich mixtures but preferential solvation by NMP was seen in mixtures with similar composition and also in NMP-rich mixtures.

Genotoxicity and Antigenotoxicity Assessments of the Flavonoid Vitexin by the Drosophila melanogaster Somatic Mutation and Recombination Test

Liliane Menezes Fernandes,Zaira da Rosa Guterres,Igor Vivian Almeida,Veronica Elisa Pimenta Vicentini 한국식품영양과학회 2017 Journal of medicinal food Vol.20 No.6

Vitexin is a C-glycosylated flavone found in various medicinal plants with several proven biological properties such as anti-inflammatory, antispasmodic, antimicrobial, cytotoxic, and antioxidant activities. Considering that the human population consumes many foods that contain this flavonoid, the objective of this study was to investigate the genotoxic and the antigenotoxic potentials of vitexin by the SMART (Somatic Mutation and Recombination Test) in Drosophila melanogaster wings, in vivo. To evaluate the genotoxic activity, larvae obtained from standard (ST) and high bioactivation (HB) crosses were chronically treated with different concentrations of vitexin (0.15, 0.3, and 0.6 mM). For the evaluation of antigenotoxic activity, the same vitexin concentrations were associated with two damage inducing agents: doxorubicin (0.2 mM) and benzo[a]pyrene (1.0 mM). The results obtained for genotoxic activity showed that vitexin did not induce a statistically significant increment in the frequency of mutant spots, when compared to control. The results for the evaluation of antigenotoxicity indicated that the flavonoid statistically reduced the frequency of mutant spots, when compared to those treated with only the damage inducing agents. Thus, this article presents results that have demonstrated the antigenotoxic activity of vitexin, which could be applied in new studies for the development of drugs with chemoprotective effects.

Curcumin promotes oxidative stress, apoptosis and autophagy in H9c2 rat cardiomyoblasts

Iván Zepeda‑Quiróz,Helen Sánchez‑Barrera,Zaira Colín‑Val,Diana Xochiquetzal Robledo‑Cadena,Sara Rodríguez‑Enríquez,Rebeca López‑Marure 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.4

Background Curcumin, a polyphenol derived from Curcuma longa, has some adverse efects on heart; however, its toxic efects on cardiac cells are poorly understood. Objective To evaluate the toxicity of curcumin on H9c2 rat cardiomyoblasts. To this, H9c2 cells were exposed to diferent concentrations of curcumin and proliferation, viability, cell cycle, oxidative stress, mitochondrial membrane potential (ΔΨm), death and autophagy were evaluated. Results Curcumin caused concentration-dependent inhibition of H9c2 cells proliferation and viability. A higher sub-G1 population was observed in cells treated with curcumin, which was related with phosphatidylserine translocation and increase of activated caspase-9, indicating apoptotic death. Curcumin induced oxidative stress and decreased ΔΨm causing mitochondrial dysfunction. Additionally, it promoted autophagy, revealed by higher LC3B and beclin-1 protein expression and mitophagy. Conclusion Curcumin exhibited toxic efects in cardiac cells and further studies are required to validate its therapeutic potential and use as anti-infammatory and anti-oxidant agent in the cardiovascular system.