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Nano-based particles synthesized via green routes have a particular structure that is useful in biomedical applications as they provide cheap, eco-friendly, and non-toxic nanoparticles. In the present study, we reported the effect of various concentrations of Zinc oxide nanoparticles synthesized using A. lebbeck stem bark extract (ZnO NPsAL) as stabilizing agent on rat biochemical profiles and tissue morphology. Adult Wistar rats weighing 170 ± 5 g were randomly classified into eight groups of five rats each; Group A served as a control fed with normal diet and water. Groups B1, B2, C1, C2, D1, D2, and E were treated with 40 mg/kg and 80 mg/kg of the 0.01, 0.05, and 0.1 M biosynthesized ZnO NPsAL and zinc nitrate daily by the gavage method, respectively. The rats were anesthetized 24 h after the last treatment, blood samples, kidney, heart, and liver tissues were collected for biochemical and histopathological analysis. The rats mean body weight, serum alkaline phosphatase, alanine aminotransferase, creatinine, urea, bilirubin, protein, albumin, globulin, total cholesterol, triacylglycerol, and high-density lipoprotein were significantly altered with an increased concentration of biosynthesized ZnO NPsAL when compared with the control group (p< 0.05; n ≥ 5). Furthermore, histopathological analysis of treated rats’ kidney, heart, and liver tissue revealed vascular congestion, tubular necrosis, inflammation, and cytoplasmic vacuolation. Biosynthesized ZnO NPsAL showed significant alteration in biochemical parameters and tissue morphology in rats with increasing concentrations of the nanoparticles.
Doga Kavaz; Amina Abubakar; Nahit Rizaner; Huzaifa Umar. Biosynthesized ZnO Nanoparticles Using Albizia lebbeck Extract Induced Biochemical and Morphological Alterations in Wistar Rats. Molecules 2021, 26, 3864 .
AMA StyleDoga Kavaz, Amina Abubakar, Nahit Rizaner, Huzaifa Umar. Biosynthesized ZnO Nanoparticles Using Albizia lebbeck Extract Induced Biochemical and Morphological Alterations in Wistar Rats. Molecules. 2021; 26 (13):3864.
Chicago/Turabian StyleDoga Kavaz; Amina Abubakar; Nahit Rizaner; Huzaifa Umar. 2021. "Biosynthesized ZnO Nanoparticles Using Albizia lebbeck Extract Induced Biochemical and Morphological Alterations in Wistar Rats." Molecules 26, no. 13: 3864.
The deployment of photovoltaic technology in global electricity generation has reduced the dependence on fossil fuels and the adverse effect of global warming climate changes. However, the variability of PV output due to its reliance on meteorological parameters hinders the total maximization of the technology. In this paper, the interdependence of meteorological parameters on accurate estimation of the specific yield of the PV system is examined using machine learning algorithms. The analysis uses 2 years of meteorological data in a 10-min interval. The meteorological parameters used as input are global solar radiation (GR), wind speed (WS), wind direction (WD), the standard deviation of wind direction (WSD), air temperature (AT), and relative humidity (RH), while the output variable is the PV specific yield (PVSY). This study uses a Python-based “all regressor” machine learning algorithm, to analyze their accuracy for the estimation analysis at different input feature space. The accuracy of the models and algorithms is analyzed using mean absolute error (MAE), mean square error (MSE), root mean square error (RMSE), and coefficient of correlation (R2). The best performance in the two feature space was retrieved for AT, and GR with MSE and MAE values of 0.113 and 0.252, respectively. The best performance in the three feature space was retrieved for WSD, AT, and GR with MSE and MAE values of 0.109 and 0.255, respectively. The results show that the most accurate PVSY estimation was for the four input feature space with input variables of WS, AT, GR, and RH. The K-nearest neighbor (KNN) proved to be the most appropriate algorithm for this feature space with an RMSE and MAE score of 0.101 and 0.266, respectively. The study also shows that the most significant meteorological inputs in PV yield estimation are air temperature and global solar radiation. The study also noted that a large feature space adds uncertainties to the training process. Finally, the paper concludes that the sunshine-based parameters are key inputs for high-quality PV yield estimation regardless of the number of input combinations. It is also concluded that, in this study, the most accurate regression algorithms for estimation are the Least Absolute Shrinkage and Selection Operator (LASSO), KNN, Elastic Net (EN), Decision Tree regressor (DT), and Extra Tree regression (ET).
Humphrey Adun; Olusola Bamisile; Mustapha Mukhtar; Mustafa Dagbasi; Doga Kavaz; Ariyo Oluwasanmi. Novel Python-based “ all-regressor model ” application for photovoltaic plant-specific yield estimation and systematic analysis. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects 2021, 1 -19.
AMA StyleHumphrey Adun, Olusola Bamisile, Mustapha Mukhtar, Mustafa Dagbasi, Doga Kavaz, Ariyo Oluwasanmi. Novel Python-based “ all-regressor model ” application for photovoltaic plant-specific yield estimation and systematic analysis. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects. 2021; ():1-19.
Chicago/Turabian StyleHumphrey Adun; Olusola Bamisile; Mustapha Mukhtar; Mustafa Dagbasi; Doga Kavaz; Ariyo Oluwasanmi. 2021. "Novel Python-based “ all-regressor model ” application for photovoltaic plant-specific yield estimation and systematic analysis." Energy Sources, Part A: Recovery, Utilization, and Environmental Effects , no. : 1-19.
Water contamination by petroleum and its byproducts presents a major challenge worldwide. It is critical that sustainable treatment methods be employed for the removal of such contaminants from polluted water. For this investigation, magnetic nano silica (M-NS) was synthesized using agricultural waste from barley husk using a two-step process that is environmentally friendly and uses green chemistry synthesis. The barley husk waste was used as a precursor for the synthesis of nano-silica following a low energy and sustainable method of acid reflux and heat treatment. Nano-silica was then used for the synthesis of M-NS, with the addition of a magnetic solution of Fe3O4 nanoparticles. The magnetic nano-silica particles were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Zeta potential analysis (ZETA) and X-Ray Diffraction (XRD). Magnetic nano-silica particles were observed to have an average diameter of 162 nm and appeared to be hydrophobic, with a large surface area of ~120 m2/gm. Due to these characteristics, magnetic nano-silica was used as an adsorbent for the removal of petrol contaminants from water. The experimental procedure showed that only 0.6 gm. of M-NS was used on 40 mg/L concentration of petroleum and the experiments recorded a high uptake efficiency of 85%. The sorption was shown to be an effective process since a high amount of petroleum was removed. The study further demonstrates that as the amount of sorbent is increased, the sorption capacity also increases until an equilibrium is reached. The results of this study establish that synthesis of M-NS, using environmentally sustainable processes, has the required characteristics to serve as sorbent for petroleum and its byproducts from contaminated water, thus enhancing environmental sustainability.
Evidence Akhayere; Ashok Vaseashta; Doga Kavaz. Novel Magnetic Nano Silica Synthesis Using Barley Husk Waste for Removing Petroleum from Polluted Water for Environmental Sustainability. Sustainability 2020, 12, 10646 .
AMA StyleEvidence Akhayere, Ashok Vaseashta, Doga Kavaz. Novel Magnetic Nano Silica Synthesis Using Barley Husk Waste for Removing Petroleum from Polluted Water for Environmental Sustainability. Sustainability. 2020; 12 (24):10646.
Chicago/Turabian StyleEvidence Akhayere; Ashok Vaseashta; Doga Kavaz. 2020. "Novel Magnetic Nano Silica Synthesis Using Barley Husk Waste for Removing Petroleum from Polluted Water for Environmental Sustainability." Sustainability 12, no. 24: 10646.
In this study, nano-silica (NS) was synthesized from barley grass straw through a combination of acid and heat treatments. The synthesized nano-silica was then used as the precursor silica material for the synthesis of nano-zeolite (NZ). NS and NZ were characterized using X-ray fluorescence (XRF), dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and Bruner–Emmett–Teller method (BET) measurements. The NS and NZ particles were observed to be hydrophobic and possess large surface areas (128 and 106 m2/g, respectively); this results in high uptake of gasoline compared to other sorbents. NS and NZ particles (0.5 g) were each applied to a 40 mg/g concentration of gasoline-contaminated water at pH 7, which resulted in high uptake efficiencies of 95% for NS and 85% for NZ. Kinetics and equilibrium studies were performed, and the obtained results were processed to produce relevant parameters. The sorption was significantly effective, and the percentage of contaminants removed was seen to depend heavily on the amount of sorbent added. The kinetics results indicated that the second-order sorption kinetics exhibited the best fit for the gasoline sorption data. It was also apparent that the Langmuir isotherms described the sorption the most closely. The results suggest that nanoparticles provide a clean-up solution for petroleum spillage and contamination in water.
Evidence Akhayere; Doga Kavaz. Nano-silica and nano-zeolite synthesized from barley grass straw for effective removal of gasoline from aqueous solution: a comparative study. Chemical Engineering Communications 2020, 208, 1419 -1435.
AMA StyleEvidence Akhayere, Doga Kavaz. Nano-silica and nano-zeolite synthesized from barley grass straw for effective removal of gasoline from aqueous solution: a comparative study. Chemical Engineering Communications. 2020; 208 (10):1419-1435.
Chicago/Turabian StyleEvidence Akhayere; Doga Kavaz. 2020. "Nano-silica and nano-zeolite synthesized from barley grass straw for effective removal of gasoline from aqueous solution: a comparative study." Chemical Engineering Communications 208, no. 10: 1419-1435.
Background: The encapsulation of plant essential oils (EOs) with polymeric materials (e.g. chitosan (CS) and N, N, N-trimethyl chitosan (TMC)) and the further reduction of the polymers into their nano sizes are gaining research interest in nanotechnology due to potential applications in medical drug delivery systems as well as the food and pharmaceutical industry. The present study reports a novel approach for the synthesis of Ocimum gratissimum essential oil (OGEO)-loaded CS and TMC nanoparticles with distinct bioactive and physiochemical properties. Methods: The OGEO-loaded CS and TMC nanoparticles were characterised using various microscopic and spectroscopic techniques. The bioactive compounds in Ocimum gratissimum methanolic extract (OG-MeOH) and EOs was evinced with gas chromatography-mass spectrometry (GC-MS). Total phenolic content (TPC) of OGEO and OG-MeOH was determined using the Folin-Ciocalteu method. The in vitro drug release kinetic pattern was ascertained by membrane dialysis, while antioxidant activity was determined by the 2,2-diphenyl-1picrylhydrozyl (DPPH) free radical scavenging method. The disc diffusion method was used for antibacterial activity evaluation, while MTT and a trypan blue dye exclusion assay were used to assess cytotoxic activity on MDA-MB-231 breast cancer cells. Results: GC-MS analysis revealed components that have not been previously reported for Ocimum gratissimum. The maximum OGEO cumulative drug release percentage in vitro was observed at pH 3 for both OGEO-loaded chitosan nanoparticles (OGEO-CSNPs) and OGEO-loaded N, N, N-trimethyl chitosan nanoparticles (OGEO-TMCNPs). The antioxidant activity of OGEO-CSNPs and OGEO-TMCNPs never reached a steady state after 75 h. OGEO-TMCNPs exhibited antibacterial activity at a lower concentration for both Gram-negative and Gram-positive food pathogens. In vitro cytotoxicity revealed the increased toxicity of OGEO-TMCNPs on MDA-MB-231 breast cancer cell lines. Conclusion: OGEO-loaded CS and TMC nanoparticles were synthesised using a novel material optimisation approach. The synthesised nanoparticles have shown a promising application in the pharmaceutical and food industries.
Confidence Onyebuchi; Doğa Kavaz. Chitosan And N, N, N-Trimethyl Chitosan Nanoparticle Encapsulation Of Ocimum Gratissimum Essential Oil: Optimised Synthesis, In Vitro Release And Bioactivity. International Journal of Nanomedicine 2019, ume 14, 7707 -7727.
AMA StyleConfidence Onyebuchi, Doğa Kavaz. Chitosan And N, N, N-Trimethyl Chitosan Nanoparticle Encapsulation Of Ocimum Gratissimum Essential Oil: Optimised Synthesis, In Vitro Release And Bioactivity. International Journal of Nanomedicine. 2019; ume 14 ():7707-7727.
Chicago/Turabian StyleConfidence Onyebuchi; Doğa Kavaz. 2019. "Chitosan And N, N, N-Trimethyl Chitosan Nanoparticle Encapsulation Of Ocimum Gratissimum Essential Oil: Optimised Synthesis, In Vitro Release And Bioactivity." International Journal of Nanomedicine ume 14, no. : 7707-7727.
In the present study, a comparative analysis was performed on the extraction of nickel ions (Ni2+) from agricultural wastewater using nanosilica (NS) synthesized from barley (NS-B) and wheat (NS-W) grass waste with a yield of 92.4%. The experimental procedure was conducted on barley and wheat waste to obtain an 85% pure NS that served as the adsorbent for nickel extraction in wastewater. The NS was characterized and studied using X-ray fluorescence (XRF), which demonstrated that NS synthesized from barley contained 94.2% SiO2, while NS synthesized from wheat contained 93.0% SiO2. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to determine the surface morphology of the nanoparticles. The energy-dispersive X-ray (EDX) analysis and Fourier transform infrared (FTIR) analysis were used to determine the elements and functional groups of the synthesized particles, respectively. Lastly, particle size and surface area analyses were performed using the Brunauer–Emmett–Teller (BET) method, which determined that the nanoparticles were 70 and 102 nm for NS-B and NS-W, respectively. The adsorption of nickel ions from agricultural wastewater was studied at various concentrations (10–200 mg/L). The kinetic models indicate that sorption equilibrium time was 65 min and that the reaction followed the pseudo-first-order kinetics model with a regression coefficient (R2) of 0.9289. Corresponding studies indicated that the Freundlich isotherms best describe the sorption reaction with an R2 value of 0.9958, which indicates the multilayer adsorption of nickel on the adsorbent. In their standard and real states, the samples indicated that NS-B and NS-W provided high levels of nickel (Ni2+) removal at 95 and 90%, respectively.
Evidence Akhayere; Edidiong Augustine Essien; Doga Kavaz. Effective and reusable nano-silica synthesized from barley and wheat grass for the removal of nickel from agricultural wastewater. Environmental Science and Pollution Research 2019, 26, 25802 -25813.
AMA StyleEvidence Akhayere, Edidiong Augustine Essien, Doga Kavaz. Effective and reusable nano-silica synthesized from barley and wheat grass for the removal of nickel from agricultural wastewater. Environmental Science and Pollution Research. 2019; 26 (25):25802-25813.
Chicago/Turabian StyleEvidence Akhayere; Edidiong Augustine Essien; Doga Kavaz. 2019. "Effective and reusable nano-silica synthesized from barley and wheat grass for the removal of nickel from agricultural wastewater." Environmental Science and Pollution Research 26, no. 25: 25802-25813.
This study presents a novel performance evaluation of the commercially available LS-2 collector operating with an oil-based olive leaf-synthesized nanofluid. The nanoparticles were synthesized experimentally from olive leaf extracts (OLEs): OLE-ZVI and OLE-TiO2. The thermophysical properties of the nanoparticles were then added to Syltherm-800 thermal oil, and its performance on the parabolic trough solar collector (PTC) was evaluated numerically. The PTC under study was modeled on the engineering equation solver (EES) and validated thermally with results found in the literature. The synthesized nanoparticles were also found to possess anticorrosion properties, nontoxic, and less expensive to produce when compared to commercially available ones. The use of the nanofluids (Syltherm-800/OLE-ZVI and Syltherm-800/OLE-TiO2) was evaluated against the parameters of thermal and exergetic efficiencies, heat transfer coefficient, thermal losses, and pressure drop. The study shows that an enhancement in thermal performance of 0.51% and 0.48% was achieved by using Syltherm-800/OLE-ZVI and Syltherm-800/OLE-TiO2 nanofluids, respectively. A heat transfer coefficient enhancement of 42.9% and 51.2% was also observed for Syltherm-800/OLE-TiO2 and Syltherm-800/OLE-ZVI nanofluids, respectively. Also, a mean variation in pressure drop of 11.5% was observed by using the nanofluids at a nanoparticle volumetric concentration of 3%. A comparison of the results of this study with related literature shows that the proposed nanofluids outperform those found in literature.
Eric Chekwube Okonkwo; Edidiong A. Essien; Doga Kavaz; Muhammad Abid; Tahir A. H. Ratlamwala. Olive Leaf-Synthesized Nanofluids for Solar Parabolic Trough Collector—Thermal Performance Evaluation. Journal of Thermal Science and Engineering Applications 2019, 11, 041009 .
AMA StyleEric Chekwube Okonkwo, Edidiong A. Essien, Doga Kavaz, Muhammad Abid, Tahir A. H. Ratlamwala. Olive Leaf-Synthesized Nanofluids for Solar Parabolic Trough Collector—Thermal Performance Evaluation. Journal of Thermal Science and Engineering Applications. 2019; 11 (4):041009.
Chicago/Turabian StyleEric Chekwube Okonkwo; Edidiong A. Essien; Doga Kavaz; Muhammad Abid; Tahir A. H. Ratlamwala. 2019. "Olive Leaf-Synthesized Nanofluids for Solar Parabolic Trough Collector—Thermal Performance Evaluation." Journal of Thermal Science and Engineering Applications 11, no. 4: 041009.
In this investigation we report the synthesis of nano silica (NS) nanoparticles from barley grass waste – an environmental burden – using varying temperatures during preparation. The temperatures used during the investigation were 400, 500, 600, and 700ºC, and we studied its effects on the...
Evidence Akhayere; Doga Kavaz; Ashok Vaseashta. Synthesizing Nano Silica Nanoparticles from Barley Grain Waste: Effect of Temperature on Mechanical Properties. Polish Journal of Environmental Studies 2019, 28, 2513 -2521.
AMA StyleEvidence Akhayere, Doga Kavaz, Ashok Vaseashta. Synthesizing Nano Silica Nanoparticles from Barley Grain Waste: Effect of Temperature on Mechanical Properties. Polish Journal of Environmental Studies. 2019; 28 (4):2513-2521.
Chicago/Turabian StyleEvidence Akhayere; Doga Kavaz; Ashok Vaseashta. 2019. "Synthesizing Nano Silica Nanoparticles from Barley Grain Waste: Effect of Temperature on Mechanical Properties." Polish Journal of Environmental Studies 28, no. 4: 2513-2521.
Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines Huzaifa Umar,1–3 Doga Kavaz,1–3 Nahit Rizaner1–3 1Department of Bioengineering, Institute of Graduate Studies and Research, Cyprus International University, Mersin, Turkey; 2Biotechnology Research Center, Cyprus International University, Mersin, Turkey; 3Bioengineering Department, Cyprus International University, Mersin, Turkey Background: Biocompatibility and stability of zinc oxide nanoparticles (ZnO NPs) synthesized using plants is an interesting research area of study in nanotechnology, due to its wide applications in biomedical, industrial, cell imaging, and biosensor fields. The present study reports the novel green synthesis of stable ZnO NPs using various concentrations of zinc nitrate (0.01M, 0.05M, 0.1M) and Albizia lebbeck stem bark extracts as an efficient chelating agent. Antimicrobial, antioxidant, cytotoxic, and antiproliferative activities of the synthesized NPs on human breast cancer cell lines were evaluated using different assays. Methods: Characterization of the synthesized ZnO NPs were carried out using various spectroscopic and microscopic techniques. Antimicrobial activity evaluation using disc diffusion method, antioxidant activity using hydrogen peroxide (H2O2) free radical scavenging assay and cytotoxic activity on MDA-MB 231 and MCF-7 using tryphan blue dye exclusion and MTT assay. Results: The UV–vis spectroscopy result revealed an absorption peak in the range of 370 nm. The involvements of A. lebbeck bioactive compounds in the stabilization of the ZnO NPs were confirmed by X-ray diffraction and Fourier transform infrared analysis. Zeta sizer studies showed an average size of 66.25 nm with a polydisparity index of 0.262. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) analyses results revealed irregular spherical morphology and the presence of primarily Zn, C, O, Na, P, and K, respectively. The biosynthesized ZnO NPs revealed strong antimicrobial potentials against various gram-negative and gram-positive bacterial pathogens. Antioxidant activities carried out using H2O2 free radical scavenging assay revealed higher IC50 values of 48.5, 48.7, and 60.2 µg/mL for 0.1M, 0.05M, and 0.01M ZnO NPs, respectively. Moreover, the biosynthesized ZnO NPs showed significant cytotoxic effects on MDA-MB 231 and MCF-7 breast cancer cell lines (P< 0.001, n≥3) in a concentration-dependent manner. Conclusion: Overall, various concentrations of ZnO NPs were synthesized through a stable, simple, and eco-friendly green route via the use of A. lebbeck stem bark extract. The biosynthesized ZnO NPs showed strong antimicrobial, antioxidant and cytotoxic activity against strongly and weakly metastatic breast cancer cell lines. Keywords: biosynthesis, antimicrobial, antioxidant, cytotoxic, biocompatibility
Huzaifa Umar; Doga Kavaz; Nahit Rizaner. Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines. International Journal of Nanomedicine 2018, ume 14, 87 -100.
AMA StyleHuzaifa Umar, Doga Kavaz, Nahit Rizaner. Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines. International Journal of Nanomedicine. 2018; ume 14 ():87-100.
Chicago/Turabian StyleHuzaifa Umar; Doga Kavaz; Nahit Rizaner. 2018. "Biosynthesis of zinc oxide nanoparticles using Albizia lebbeck stem bark, and evaluation of its antimicrobial, antioxidant, and cytotoxic activities on human breast cancer cell lines." International Journal of Nanomedicine ume 14, no. : 87-100.
Essential oil of Cyperus articulatus have known bioactivities, the qualitative chemical composition analysis of the Essential Oils (EOs) by Gas Chromatography-Mass Spectrometry (GC–MS) revealed the presence of new compounds not previously known to the plant rhizome which includes, sesquiterpenes, monoterpenes, nootkatone, 6-methyl-3,5-heptadien-2-one, retinene, nopinone, cycloeucalenol, anozol, toosendanin, furanone, ethanone and vitamin A. Cyperus articulatus Essential Oils (CPEOs) loaded Chitosan Nanoparticles (CSNPs) was successful synthesized using an oil-in-water mixture and ionic gelation method and were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and UV–Vis spectrophotometry. CPEOs had more radical-scavenging bioactivity in vitro than CSNPs and CPEO-CSNPs at initial storage times. CPEO-CSNPs showed the highest (P < 0.05) antioxidant activity over a prolonged period of time. Antimicrobial activity of two strains of bacteria, Staphylococcus aureus (ATCC6538), and Escherichia coli (ATCC 8739) showed that all CPEO-loaded chitosan nanoparticle inhibited bacterial growth at lower (P < 0.05) CPEO–CSNP concentration (5 mg/mL MIC) compared to free CPEOs (10 mg/mL MIC). Trypan blue in vitro exclusion assay showed CPEO-CSNPs to be more cytotoxic against MDA-MB-231 breast cancer cells after 48 h. The bioactivity and physiochemical properties of CPEO-CSNPs have shown promising applications in food and pharmaceutical industries.
Doğa Kavaz; Maryam Idris; Confidence Onyebuchi. Physiochemical characterization, antioxidative, anticancer cells proliferation and food pathogens antibacterial activity of chitosan nanoparticles loaded with Cyperus articulatus rhizome essential oils. International Journal of Biological Macromolecules 2018, 123, 837 -845.
AMA StyleDoğa Kavaz, Maryam Idris, Confidence Onyebuchi. Physiochemical characterization, antioxidative, anticancer cells proliferation and food pathogens antibacterial activity of chitosan nanoparticles loaded with Cyperus articulatus rhizome essential oils. International Journal of Biological Macromolecules. 2018; 123 ():837-845.
Chicago/Turabian StyleDoğa Kavaz; Maryam Idris; Confidence Onyebuchi. 2018. "Physiochemical characterization, antioxidative, anticancer cells proliferation and food pathogens antibacterial activity of chitosan nanoparticles loaded with Cyperus articulatus rhizome essential oils." International Journal of Biological Macromolecules 123, no. : 837-845.
The parabolic trough collector (PTC) is one of the most advanced solar concentrating technology available. The study employed experimental synthesis and numerical modeling to present possible solutions to the challenges of nanofluids application in solar collectors. A green alternative of using nanoparticles synthesized from green bio-matter (Olive leaf extract OLE) and agricultural waste (barley husk BH) is proposed. The synthesized nanoparticles were characterized using analytical and morphological techniques and were found to be efficient corrosion inhibitor, non-toxic and cheap to produce when compared to the conventional ones. The study presents an innovative thermal performance evaluation of a parabolic trough collector operating with green-synthesized nanofluids: water/BH-SiO2 and water/OLE-TiO2. The model of the PTC was developed on the engineering equation solver (EES) and validated using the experimental results of the Sandia National Laboratory (SNL), AZTRAK platform LS-2 test. The results of the analysis show that a 0.073% mean enhancement in the thermal efficiency is observed with the use of water/BH-SiO2 nanofluids and 0.077% mean enhancement with the use of water/OLE-TiO2 nanofluids. The heat transfer performance of the nanofluids shows a mean enhancement in heat transfer coefficient of 128% and 138% for water/OLE-TiO2 and water/BH-SiO2 nanofluids respectively. The mean variation in pressure losses between the nanofluids and base fluid was also observed to be less than 14.85% at a 3% volumetric fraction of nanoparticles.
Eric Chekwube Okonkwo; Edidiong A. Essien; Evidence Akhayere; Muhammad Abid; Doga Kavaz; Tahir Abdul Hussain Ratlamwala. Thermal performance analysis of a parabolic trough collector using water-based green-synthesized nanofluids. Solar Energy 2018, 170, 658 -670.
AMA StyleEric Chekwube Okonkwo, Edidiong A. Essien, Evidence Akhayere, Muhammad Abid, Doga Kavaz, Tahir Abdul Hussain Ratlamwala. Thermal performance analysis of a parabolic trough collector using water-based green-synthesized nanofluids. Solar Energy. 2018; 170 ():658-670.
Chicago/Turabian StyleEric Chekwube Okonkwo; Edidiong A. Essien; Evidence Akhayere; Muhammad Abid; Doga Kavaz; Tahir Abdul Hussain Ratlamwala. 2018. "Thermal performance analysis of a parabolic trough collector using water-based green-synthesized nanofluids." Solar Energy 170, no. : 658-670.
Zero-valent iron nanoparticles (NZVI-NPs) possess significantly high surface area and volume ratio, and this unique surface characteristic has enhanced reactivity to their adsorption potential. In this work, a bio-matter (Olive leaves extract) is deployed as a nature-inspired reducing agent for the synthesis of NZVI-NPs. The particle size of NZVI-NPs has been determined using particle sizer. The NZVI-NPs are characterized using analytical and morphological techniques such as ultraviolet − visible spectroscopy (UV − vis), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction spectroscopy (XRD), scanning electron microscope (SEM), Brunauer–Emmett–Teller (BET), and Fourier transform infrared (FTIR) spectroscopy. The average crystalline size of NZVI-NPs are around 30–60 nm while maximum adsorption is at 225 nm. XRD spectrum shows two distinctive diffraction peaks at 25.40° and 42.50° corresponding to lattice plane value indexed at (200) and (222) planes of faced centered cubic (FCC). At optimized experimental conditions, NZVI-NPs show 97% removal efficiency of Ni+2 ions from aqueous solution. The equilibrium time has been found to be 55 min and the monolayer maximum adsorption capacity is 139.5 mg/g. Kinetically, Ni+2 ions adsorption has been modelled using various physical isotherms and the data best fitted Freundlich isotherm model and pseudo-first-order kinetic; revealing a maximum adsorption capacity of 139.5 mg/g at 25 ± 3 °C and pH of 6.5. Desorption tests affirm the possibility of recovering reasonable amount of NZVI-NPs after used. The specific surface area of the NZVI-NPs sample measured by BET analysis is 21.9967 m2/g indicating a high adsorption capacity.
Edidiong A. Essien; Doga Kavaz; Moses M. Solomon. Olive leaves extract mediated zero-valent iron nanoparticles: synthesis, characterization, and assessment as adsorbent for nickel (II) ions in aqueous medium. Chemical Engineering Communications 2018, 205, 1568 -1582.
AMA StyleEdidiong A. Essien, Doga Kavaz, Moses M. Solomon. Olive leaves extract mediated zero-valent iron nanoparticles: synthesis, characterization, and assessment as adsorbent for nickel (II) ions in aqueous medium. Chemical Engineering Communications. 2018; 205 (11):1568-1582.
Chicago/Turabian StyleEdidiong A. Essien; Doga Kavaz; Moses M. Solomon. 2018. "Olive leaves extract mediated zero-valent iron nanoparticles: synthesis, characterization, and assessment as adsorbent for nickel (II) ions in aqueous medium." Chemical Engineering Communications 205, no. 11: 1568-1582.
Ethanolic extracts of olive leaves (OLE) in the presence of TiCl4 solution was used to form OLE – Ti nanoparticles composite (OLE-Nano). The particle size of Ti nanoparticles in the composite was determined using particle sizer and the nanoparticles were characterized using UV–vis, FTIR, SEM/EDAX and XRD techniques. Results show that the particles were around 70–74 nm in size and show maximum absorption around 420 nm. Prominent FTIR peaks correspond to C=C, N–H, O–H and C=O functionalities. XRD spectrum shows four distinctive diffraction peaks at 27.42°, 36.07°, 41.23°, and 54.30° corresponding to lattice plane value indexed at (101), (104), (200) and (211) planes of face centered cubic (FCC). The anticorrosion property of the OLE-Nano for mild steel in 1 M HCl at 30–60 °C was assessed using weight loss and electrochemical techniques complemented by surface analysis of the corroded steel specimen in the absence and presence of OLE – Nano with SEM and AFM. Results obtained show that OLE inhibited the acid corrosion of mild steel and the inhibition performance was enhanced in the presence of Ti nanoparticles. The corrosion inhibition effect was found to be concentration and temperature dependent. The inhibition efficiency of the OLE and OLE-Nano were 83.5 and 94.3% respectively at 30 °C but decreased to 51.7 and 85.4% at 60 °C respectively. The OLE-Nano adsorbed on mild steel surface by physical adsorption mechanism as predicted by Langmuir adsorption isotherm model. Potentiodynamic polarization results show that OLE-Nano behaves as mixed type inhibitor.
Edidiong A. Essien; Doga Kavaz; Ekemini B. Ituen; Saviour A. Umoren. Synthesis, characterization and anticorrosion property of olive leaves extract-titanium nanoparticles composite. Journal of Adhesion Science and Technology 2018, 32, 1773 -1794.
AMA StyleEdidiong A. Essien, Doga Kavaz, Ekemini B. Ituen, Saviour A. Umoren. Synthesis, characterization and anticorrosion property of olive leaves extract-titanium nanoparticles composite. Journal of Adhesion Science and Technology. 2018; 32 (16):1773-1794.
Chicago/Turabian StyleEdidiong A. Essien; Doga Kavaz; Ekemini B. Ituen; Saviour A. Umoren. 2018. "Synthesis, characterization and anticorrosion property of olive leaves extract-titanium nanoparticles composite." Journal of Adhesion Science and Technology 32, no. 16: 1773-1794.
Universal environmental contamination is a real situation that deteriorates our world step by step. The dairy factory out flowing is the second greatest source of contamination in water streams. The environmental impact of these factories can be very high, especially due to the discharge of...
Doga Kavaz; Hüseyin Öztoprak. Environmental Awareness of University Students on White Cheese Waste Water. Eurasia Journal of Mathematics, Science and Technology Education 2017, 13, 8003 -8015.
AMA StyleDoga Kavaz, Hüseyin Öztoprak. Environmental Awareness of University Students on White Cheese Waste Water. Eurasia Journal of Mathematics, Science and Technology Education. 2017; 13 (12):8003-8015.
Chicago/Turabian StyleDoga Kavaz; Hüseyin Öztoprak. 2017. "Environmental Awareness of University Students on White Cheese Waste Water." Eurasia Journal of Mathematics, Science and Technology Education 13, no. 12: 8003-8015.
Mustafa B.A. Djamgoz; Ertan Akun; Beste Arslan; Ruhsan Onbasi; Ovgu Isbilen; Doga Kavaz; Ender Volkan; Nahit Rizaner. Cancer in North Cyprus: 2. Biomedical Research Activities. Cyprus Journal of Medical Sciences 2017, 2, 13 -18.
AMA StyleMustafa B.A. Djamgoz, Ertan Akun, Beste Arslan, Ruhsan Onbasi, Ovgu Isbilen, Doga Kavaz, Ender Volkan, Nahit Rizaner. Cancer in North Cyprus: 2. Biomedical Research Activities. Cyprus Journal of Medical Sciences. 2017; 2 (1):13-18.
Chicago/Turabian StyleMustafa B.A. Djamgoz; Ertan Akun; Beste Arslan; Ruhsan Onbasi; Ovgu Isbilen; Doga Kavaz; Ender Volkan; Nahit Rizaner. 2017. "Cancer in North Cyprus: 2. Biomedical Research Activities." Cyprus Journal of Medical Sciences 2, no. 1: 13-18.
In this study, human serum albumin (HSA) was used as a protein-based material and poly (3-hydroxybutyrate) (PHB)-carboxymethyl chitosan (CMCh) as a polysaccharide-based material for the production of nanoparticles to be used as nanocarriers in cancer therapy. HSA and PHB-CMCh nanoparticles were prepared and characterized with a Zeta Sizer, Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscope. The effects of the pH value of the suspending medium and the amounts of crosslinker and polymer concentration on nanoparticle size and size distribution were investigated. The anticancer-agent etoposide was used as a model drug and encapsulated in nanoparticles to obtain drug release profiles. The entrapment efficiency of HSA nanoparticles was found to be greater than that of PHB-CMCh nanoparticles. To achieve "active" targeting of cancer cells, the nanoparticles were modified with concanavalin A. In the final step of the study, the interaction of nanoparticles with cancer cells was investigated in cytotoxicity and cellular uptake studies.
Öznur Akbal; Ebru Erdal; Tayfun Vural; Doga Kavaz; Emir Baki Denkbaş. Comparison of protein- and polysaccharide-based nanoparticles for cancer therapy: synthesis, characterization, drug release, and interaction with a breast cancer cell line. Artificial Cells, Nanomedicine, and Biotechnology 2016, 45, 193 -203.
AMA StyleÖznur Akbal, Ebru Erdal, Tayfun Vural, Doga Kavaz, Emir Baki Denkbaş. Comparison of protein- and polysaccharide-based nanoparticles for cancer therapy: synthesis, characterization, drug release, and interaction with a breast cancer cell line. Artificial Cells, Nanomedicine, and Biotechnology. 2016; 45 (2):193-203.
Chicago/Turabian StyleÖznur Akbal; Ebru Erdal; Tayfun Vural; Doga Kavaz; Emir Baki Denkbaş. 2016. "Comparison of protein- and polysaccharide-based nanoparticles for cancer therapy: synthesis, characterization, drug release, and interaction with a breast cancer cell line." Artificial Cells, Nanomedicine, and Biotechnology 45, no. 2: 193-203.
Emir Baki Denkbaş; Ekin Celik; Ebru Erdal; Doga Kavaz; Öznur Akbal; Göknur Kara; Cem Bayram. Magnetically based nanocarriers in drug delivery. Nanobiomaterials in Drug Delivery 2016, 285 -331.
AMA StyleEmir Baki Denkbaş, Ekin Celik, Ebru Erdal, Doga Kavaz, Öznur Akbal, Göknur Kara, Cem Bayram. Magnetically based nanocarriers in drug delivery. Nanobiomaterials in Drug Delivery. 2016; ():285-331.
Chicago/Turabian StyleEmir Baki Denkbaş; Ekin Celik; Ebru Erdal; Doga Kavaz; Öznur Akbal; Göknur Kara; Cem Bayram. 2016. "Magnetically based nanocarriers in drug delivery." Nanobiomaterials in Drug Delivery , no. : 285-331.
Manipulation and assembly of cell‐encapsulating hydrogels offer unique opportunities for regenerative medicine, microphysiological system engineering, pharmaceutical research, biological research, and space sciences. Utkan Demirci and co‐workers show on page 1137 that temporal and spatial control over hydrogels in microscale can be exerted by exploiting their paramagnetic properties without using magnetic nanoparticles.
Savas Tasoglu; Doga Kavaz; Umut Atakan Gurkan; Sinan Güven; Pu Chen; Reila Zheng; Utkan Demirci. Hydrogels: Paramagnetic Levitational Assembly of Hydrogels (Adv. Mater. 8/2013). Advanced Materials 2013, 25, 1081 -1081.
AMA StyleSavas Tasoglu, Doga Kavaz, Umut Atakan Gurkan, Sinan Güven, Pu Chen, Reila Zheng, Utkan Demirci. Hydrogels: Paramagnetic Levitational Assembly of Hydrogels (Adv. Mater. 8/2013). Advanced Materials. 2013; 25 (8):1081-1081.
Chicago/Turabian StyleSavas Tasoglu; Doga Kavaz; Umut Atakan Gurkan; Sinan Güven; Pu Chen; Reila Zheng; Utkan Demirci. 2013. "Hydrogels: Paramagnetic Levitational Assembly of Hydrogels (Adv. Mater. 8/2013)." Advanced Materials 25, no. 8: 1081-1081.
We have presented, for the first time, hydrogels that can be directed and assembled into 3D constructs by exploiting their magnetic properties without using magnetic particles. We have performed experimental and theoretical analyses to describe hydrogel motion in a fluidic environment under a magnetic field.
Savas Tasoglu; Doga Kavaz; Umut Atakan Gurkan; Sinan Güven; Pu Chen; Reila Zheng; Utkan Demirci. Paramagnetic levitational assembly of hydrogels. Advanced Materials 2012, 25, 1137 -43, 1081.
AMA StyleSavas Tasoglu, Doga Kavaz, Umut Atakan Gurkan, Sinan Güven, Pu Chen, Reila Zheng, Utkan Demirci. Paramagnetic levitational assembly of hydrogels. Advanced Materials. 2012; 25 (8):1137-43, 1081.
Chicago/Turabian StyleSavas Tasoglu; Doga Kavaz; Umut Atakan Gurkan; Sinan Güven; Pu Chen; Reila Zheng; Utkan Demirci. 2012. "Paramagnetic levitational assembly of hydrogels." Advanced Materials 25, no. 8: 1137-43, 1081.
Polyhydroxyalkanoates (PHA) are natural, thermoplastic polyesters and due to their biocompatible and biodegradable properties they are good alternatives for the production of scaffolds for engineered tissues or nanoparticles for drug delivery. As a member of polyhydroxyalkanoate family, polyhydroxybutyrates (PHB) have been widely used as a biomaterial for in vitro and in vivo studies since their mechanical properties are very similar to conventional plastics. By using multi-emulsion technique, iron oxide particles were coated with polyhydroxybutyrate (PHB) polymer synthesized from Alcaligenes eutrophus bacteria and the magnetic carrier system was prepared accordingly. The bare nanoparticles and magnetic nanoparticles were morphologically, structurally and magnetically characterized by using Scanning electron microscope (SEM) and Atomic force microscope (AFM); Fourier Transform Infrared Spectrometry (FTIR), and Electron Spin Resonance (ESR) and Vibrating Sample Magnetometer (VSM) techniques, respectively. Particle size of PHB nanoparticles was determined by Zeta Sizer. It was found that the smallest particles were in the range of 239.43 +/- 5.25 nm in diameter. Concanavalin-A (Con-A) was used for targeting the cancer cells while etoposide was used as drug. Con-A and etoposide were loaded onto the particles. Release studies of etoposide were evaluated and the system was optimized for the further in vivo applications. Finally different formulation magnetic PHB nanoparticles cytotoxicity were evaluated in cell culture studies and used HeLa cell line (cervical cancer cells) as a cancer cells and L929 cells (mouse fibroblast cells) as a non-cancer cell line.
Ebru Erdal; Doga Kavaz; Mesut Sam; Murat Demirbilek; Melike Erol Demirbilek; Necdet Saglam; Emir Baki Denkbaş. Preparation and characterization of magnetically responsive bacterial polyester based nanospheres for cancer therapy. Journal of Biomedical Nanotechnology 2012, 8, 800 -808.
AMA StyleEbru Erdal, Doga Kavaz, Mesut Sam, Murat Demirbilek, Melike Erol Demirbilek, Necdet Saglam, Emir Baki Denkbaş. Preparation and characterization of magnetically responsive bacterial polyester based nanospheres for cancer therapy. Journal of Biomedical Nanotechnology. 2012; 8 (5):800-808.
Chicago/Turabian StyleEbru Erdal; Doga Kavaz; Mesut Sam; Murat Demirbilek; Melike Erol Demirbilek; Necdet Saglam; Emir Baki Denkbaş. 2012. "Preparation and characterization of magnetically responsive bacterial polyester based nanospheres for cancer therapy." Journal of Biomedical Nanotechnology 8, no. 5: 800-808.