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Çevre Dostu Çözücüler ile Trioktil Amin Kullanılarak Laktik Asitin Reaktif Ekstraksiyonu
(2022) Mehmet, Yetişen; Baltacıoğl, Hande; Uslu, Hasan
Bu çalışmada, laktik asitin sulu çözeltilerinden trioktil amin (TOA) reaktanı ve ayçiçek ve pirinç kepek yağı gibi çevre dostu çözücüler kullanılarak ayrılması incelenmiş ve reaktif ekstraksiyon ile laktik asitin ayrılmasına katkı sağlayacağı amaçlanmıştır. Reaktif ekstraksiyon analizleri ile en uygun reaktant / çözücü oranlarını tespit etmek hedeflenmiştir. Çalışmalar sonucunda TOA reaktanı ile en yüksek verime (%72,91) ulaşılmıştır. Hem ayçiçek yağı hem de pirinç kepek yağının (1:1) birlikte kullanılması neticesinde verimde artış meydana gelmiştir. Araştırma sonuçlarına göre karboksilik asitlerin sulu çözeltilerden geri kazanımında organik faza TOA eklemesinin ekstraksiyon verimliliğini arttırdığı tespit edilmiştir. Fiziksel ekstraksiyonda verim %11,85 bulunurken, reaktif ekstraksiyonda verim %72,91’e kadar çıkmıştır. Yaklaşık 7 kat verimde artış gözlenmiştir. Elde edilen veriler neticesinde ekstraktan konsantrasyonunun artmasıyla birlikte dağılma katsayısı (0,13’dan 2,69’a) değerlenin de arttığı, yükleme faktörü (1,79’dan 0,69’a) değerlerinin azaldığı anlaşılmıştır. Ekstrakttan ve seyreltici kombinasyonlarıyla oluşturulan organik faz karışımları incelendiğinde ekstraksiyon verimliliği açısından en iyi sonuçların laktik asit için 3,62 M TOA kullanıldığında elde edildiği tespit edilmiştir.
Determining the impact of pre-pressing pretreatments applied to sugarcane on the aroma compounds and quality characteristics of sugarcane juice
(Wiley, 2024) Yetisen, Mehmet; Baltacioglu, Cem; Baltacioglu, Hande; Uslu, Hasan
The study examined the effects of three pretreatments, blanching (5, 10, and 30 min), ultrasound (15, 20, and 30 min), and steam blanching (10, 20, and 30 min) on sugarcane, assessing their impact on sugarcane juice quality parameters and aroma compounds. The control had the highest soluble solid content, while the ultrasound-15 min (US-15 min)-treated sample had the lowest, affecting pH, total acidity, and color values significantly. Color analysis showed lower L* values and less greenish tones in treated samples. The implemented pretreatments effectively reduce the browning index, with the US-20 min treatment showing the most significant reduction compared to the control sample. All pretreatments deactivated polyphenol oxidase. Carbon isotope analysis yielded significant results. Principal component analysis and hierarchical clustering linked 1,1-diphenyl-2-picrylhydrazyl (DPPH) with 2,2 '-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 5-hydroxymethyl furfural (HMF) with total phenolic content. The study also highlights significant variations in aroma compound profiles among pretreated sugarcane juice samples, with blanching for 10 min showing notable increases in specific compounds like 2-heptanone and nonanol. Hierarchical clustering showed similarities between blanching-30 min and US-30 min, contrasting with the control. Blanching-10 min had a positive impact on sugarcane juice quality. In conclusion, the study emphasized how pretreatments affect physicochemical properties and aroma compounds in sugarcane juice.
Determining the quality level of ready to-eat stuffed mussels with Arduino-based electronic nose
(Springer, 2024) Yavuzer, Emre; Kose, Memduh; Uslu, Hasan
In this study, the performance of a pre-designed and low-cost Arduino electronic nose for determining the quality of stuffed mussels was analyzed. In addition, 1000 images were taken on each storage day in order to determine the quality levels of stuffed mussel groups with open and closed shells by machine learning. Freshness limit values of stuffed mussels were determined as 200 for MQ3 and MQ135 sensors and 100 for MQ9 on the 3rd storage day when the total viable count (TVC) value exceeded 3 log CFU/g. In the study, faster neural networks with lower prediction times, such as SqueezeNet and GoogLeNet, were compared with ResNet-50, ResNet-101 and DenseNet-201 neural networks, which have larger prediction times but better accuracy. Study data showed that residual network (ResNet) 50 and Teachable Machine (TM) had high success in determining the quality levels of stuffed mussels.
Effect of temperature and production method on some quality parameters of fermented carrot juice (Shalgam)
(Elsevier, 2021) Tanguler, Hasan; Cankaya, Akkiz; Agcam, Erdal; Uslu, Hasan
This study is a paper in which compared the effect of fermentation temperature on antioxidant activity, anthocyanin profiles and phenolic compounds of Shalgam were investigated. 3D-molecular demonstration of lactic acid, which is the main molecule in Shalgam, was realized. As the fermentation temperature increased, titration acidity increased faster, and thus the fermentation time was shortened. Total phenolic content and anthocyanin profiles were higher in Shalgams produced by traditional method, while antioxidant activity was found to be lower. Moreover, for total phenolics, anthocyanin profiles and antioxidant activity, and minimum scores for sensory analysis, the lowest values were generally determined in Shalgams produced by both methods at 10 degrees C. It could be said that Shalgam fermented higher than 10 degrees C was more acceptable for consumers. This study is important in terms of showing that Shalgam can be produced in a shorter time in accordance with the standards. Experimental fermentation procedure, the production rate of the fermentation was studied as a kinetic character. Pseudo first order and Pseudo second order models were applied. PSO was fitted well to fermentation production rate.
Ekmek üretiminde ekşi maya üzerine taze meyvelerin kullanımının etkisi
(2021) Yıldız, Bihter; Çakıcı, Avni; Uslu, Dı Lek Yaprak; Uslu, Hasan
Bu çalışmada, eski zamanlardan beri bilinen ancak son yıllarda dünya da ve özellikle ülkemizde tüketicilerin bilinçlenmesi ile birlikte daha çok bilinir ve tüketilir hale gelen ekşi mayalı ekmekler hakkında araştırmalar yapılmıştır. Gün geçtikçe artan doğal ve sağlıklı gıdaya olan tüketici taleplerini karşılayan ekşi maya ekmeği üretimi için çeşitli meyveler kullanılarak ekşi mayaların geliştirilmesi üzerine çalışmalar yürütülmüştür. Bu çalışma aynı yöntemlerle ancak farklı tercih kaynakları kullanılarak ekşitilmiş hamurlardan üretilen ekmekleri belirlenen özellikler yönünden karşılaştırmak amacıyla gerçekleştirilmiştir. Bu amaçla çalışmada tercih kaynağı olarak farklı familyalarda yer alan elma (Rosaceae) ve incir (Moraceae) meyveleri tercih edilmiştir. Ekşi maya hazırlık aşamasında geleneksel yöntemlerden türetilmiş dört aşamalı bir yol izlenmiş ve ekşi mayaların özelliklerinin belirlenmesinde pH, toplam titrasyon asitliği, laktik asit bakteri sayımı, küf ve maya sayımı analizleri gerçekleştirilmiştir. Elde edilen elma ve incir olmak üzere iki ayrı ekşi hamur farklı konsantrasyonlarda tam buğday unlu ekmek hamurlarına ilave edilmiştir. Türk Gıda Kodeksi Ekmek ve Ekmek çeşitleri Tebliğine uygun olarak üretilen Tam buğday unlu ekşi mayalı ekmeklerin özelliklerinin belirlenmesinde ise ağırlık, pişme kaybı, spesifik hacim, kalite indeksi (en-boy-yükseklik), pH tayini, toplam titre edilebilir asitlik (%10.37 – 11.40) , nem tayini (%35.50 – 35.53), su aktivitesi (aw) (0.944 – 0.941), ekmek içi ve kabuk renk analizi, tekstürel analizler ve duyusal analizler gerçekleştirilmiştir. Yapılan çalışma sonucunda ekşi maya ilavesinin hem duyusal hemde deneysel testler sonucunda ekmeğin tat ve aromasını geliştirdiği, ürünün kabuk ve iç rengi üzerinde etkili olduğu, nem kaybını azaltarak raf ömrü süresini uzattığı sonucuna varılabilmektedir.
Experimental investigation of CO2 absorption process using nanofluids
(Elsevier, 2022) Thakur, Parag; Uslu, Hasan; Sonawane, Shriram S.
In recent decades, the energy consumption of humans is increased. Growing population and urbanization is the main reasons for the increase in energy consumption. However, most of the energy is produced from the combustion of fossil fuels, and this combustion produces the greenhouse gases like COx, NOx, and methane. These gases are responsible for global warming. Thus, it very much requires discovering new techniques and efficient designs for carbon capture and storage. In recent times, nanofluids have proven a good tool for CO2 absorption. However, the detailed mechanism and scale-up study of the CO2 absorption using nanofluids is not reported in the literature. Among all other nanoparticles, Because of the higher pore size and better CO2 capture ability carbon nanotubes are preferred to study as carbon nanotubes. In this study, we used MWCNT with various concentrations of based nanofluids for the CO2 absorption application. The performance of these nanofluids is compared with each other. We have found that the performance of nanofluid made up of MWCNT as a base nanoparticle and amine as a base fluid gave 42% more absorption than di-ethyl amine alone as a solvent. Absorption of the carbon dioxide in the same nanofluid system with water as a base fluid is 28% only. The high-speed camera is used to capture the bubble dynamics of the CO2 absorption to study the effect of bubble dynamics on absorption efficiency. © 2022 Elsevier Inc. All rights reserved.
Extraction of mandelic acid with tri-octyl-phosphine oxide (TOPO) in different solvents: Equilibrium and neural network analysis
(Elsevier, 2024) Kiris, Baris; Uslu, Hasan; Santos, Dheiver; Kiris, Sinem Buyuksaatci; Asci, Yavuz Selim
Mandelic acid is an important carboxylic acid used in pharmaceutical industries. It is also important to use it as a purified form. In this study, selective extraction of mandelic acid was done by tri-octyl-phosphine oxide (TOPO) diluted in different solvents such as methyl isobutyl ketone, 1-octanol, octyl acetate, dimethyl phthalate, 2-octanone, cyclohexane and toluene. The high selectivity of mandelic acid from aqueous solution was supported by thermodynamic parameters (loading factor, distribution coefficient, and extraction efficiency). The obtained values for each solvent were applied to the Neural Network Analysis to predict phase equilibrium behaviour in ternary systems. The results showed the highest mandelic acid extraction efficiency (93.65 %) and distribution coefficient (14.74) were attained with the organic phase mixture prepared with MIBK and TOPO. Also, it was found that extraction efficiencies increased with increasing TOPO amount in the medium for all studied solvents.
Extraction of Propionic Acid from Aqueous Solutions Using Tri-n-octylphosphine Oxide and Dioctylamine in Different Solvents
(Amer Chemical Soc, 2019) Uslu, Hasan; Hasret, Erdem; Kirbaslar, Sah Ismail
This work examines the reactive extraction of propionic acid, a promising liquid-liquid extraction technique, using tri-n-octylphosphine oxide (TOPO) or dioctylamine (DOA) diluted with eight different solvents (n-octane, methyl isobutyl ketone (MIBK), 1-octanol, ethyl methyl ketone, diisobutyl ketone, n-decane, diethyl sabecate, 1-decanol) at 298.15 K to determine the most efficient mixture for the extraction processes. A phosphorous-based extractant, TOPO, has been chosen for the extraction tests since it has low water solvency and is more ecologically agreeable than the amine-type extractants. Among the other amine extractants reported in reactive extraction studies, there is no study on propionic acid extraction using DOA in the literature. Physical extraction experiments with pure solvents were also performed to analyze the effect of TOPO and DOA on the extraction process. Distribution coefficients, loading factors, and extraction yields of the processes were determined for the explanation of the results. It was concluded that the addition of TOPO or DOA to the organic phase significantly improves the extraction of propionic acid from its aqueous media. The extraction of propionic acid, using the binary solutions of TOPO/diluent or DOA/diluent, improves with an increase in the initial TOPO or DOA concentration. The highest extraction yield, E % = 98.01, was achieved with the DOA + methyl isobutyl ketone (MIBK) extractant system (1.652 mol kg(-1)), with a distribution coefficient of K-D = 49.352; thus, the use of the DOA/methyl isobutyl ketone system in the organic phase is suggested for the propionic acid extraction methods.
High power microbial fuel cell operating at low temperature using cow dung waste
(Walter De Gruyter Gmbh, 2022) Cek, Nurettin; Erensoy, Ahmet; Ak, Namik; Uslu, Hasan
Moving towards green technology, alternatives to current detrimental, unsustainable, and expensive energy applications for eco-friendly energy are attracting great attention. Resource recycling and the convenient treatment of animal waste to diminish its nature impact are recently momentous subjects. Microbial fuel cells used cow waste have remarkable potential in electrical energy generation for clean, renewable and sustainable operation. In this study, double-chambered MFC was manufactured using cow manure as raw material at the anode chamber, graphite as the anode and cathode electrodes, fountain water in the cathode chamber, and proton exchange membrane. Because bacteria a catalytic reaction for the latent chemical energy of the cow manure was effectuated as a result of this, MFCs produced electricity. Electricity production performance of this MFC at low temperature (0-10 degrees C) conditions was examined. This MFC produced a maximum of 204.9 +/- 0.1 mV open circuit voltage and 57.387 mW/m(2) power density under low temperature conditions. In particular, the sustainability and applicability of MFCs have been increased thanks to this operation done at low temperatures (0-10 degrees C).
High-efficiency, environment-friendly moss-enriched microbial fuel cell
(Walter De Gruyter Gmbh, 2022) Cek, Nurettin; Erensoy, Ahmet; Ak, Namdc; Demirbas, Ayhan; Gorgulu, Ahmet Orhan; Uslu, Hasan
Microbial fuel cells (MFCs) can be used to produce clean energy from organic wastes. Various biomasses for MFCs can be used as biofuel materials. Moss (Bryophyta) is a source of biomass materials and can be used as an alternative fuel for microbial fuel cells. In this study, moss-enriched MFCs were produced by using moss as a biofuel source and aluminum and silver as an electrode. As a result of the good electrochemical performance of the metal electrodes (aluminum and silver), higher power density than previous studies involving moss was obtained, with the highest power density in this study being 20 mW/m(2). Moreover, in this study, bacterial activity, biofilm formation, soil utilization, pH change, and corrosion were investigated in MFCs and the effects of MFC on power density were discussed. The addition of soil increased the corrosion rate and internal resistance while reducing the power density. As a result of the addition of soil, the power density dropped to 16.13 mW/m(2). The corrosion rate was lower than industrial corrosion. Changes in pH confirmed that organic material dissolved and chemical reactions took place. Scanning electron microscope (SEM)-Energy dispersive spectroscopy (EDS) analyzes showed the presence of Bacillus and Coccus bacteria species on the electrode surfaces. These bacteria were acted as biocatalysts by forming a biofilm on the electrode surfaces.
Life Cycle Assessment (LCA) of Plastics
(wiley, 2022) Wasewar, Kailas L.; Kumar, Sushil; Pal, Dharm; Uslu, Hasan
Plastic is one of the most essential parts of dayâ€toâ€day life and has been used everywhere for many the applications. Plastics are a type of synthetic polymers mostly comprised of various elements such as carbon, nitrogen, oxygen, hydrogen, and chloride. Plastics are mainly manufactred from fossil sources such as coal, oil, and natural gas. Various popular and widely used plastics are polyethylene (PE), polyethyleneterephthalate (PET), polypropylene (PP), nylons, polystyrene (PS), polyurethane (PU), and polyvinylchloride (PVC). Plastics are mostly considered as a pollutant to the environment because of inefficient and nonâ€sustainable methods for disposal of them. Plastic wastes are responsible for increasing the ecological threat to all inhabitants of our planet. In 2015, almost 381 million tons of plastic was produced and it was cumulative as 7.81 billion tons by 2015. The used plastics are mainly discarded, incinerated, and recycled as methods of disposal. In view of the new circular economy and sustainable development context, the environmental performance of various services and products is a very important aspect, which has been gaining importance over the last few years. Environmental impacts during the lifecycle of products and services may be quantified with the help of various methods, such as strategic environmental assessment (SEA), environmental risk assessment (ERA), material flow analysis (MFA), life cycle assessment (LCA), environmental impact assessment (EIA), costâ€benefit analysis (CBA), and the ecological footprint (EF) method. Life cycle assessment is the most promising and popular method for assessing the environmental impact, and this methodology may be easily applied to every product and system to explain the type and the disparity among various results. This chapter focuses on life cycle assessment of plastics for the issues of sustainability. In view of this, various basic consideration of life cycle assessment such as basic approach, definitions, tools, frameworks, methodologies, ways, and classifications have been presented, and its application for plastic and plastic industries have been discussed. © 2022 John Wiley & Sons Ltd. All rights reserved.
Measurement and Correlational Study of Phase Equilibria in Aqueous Solutions of N,N-Dimethylacetamide with 1-Pentanol and 1-Hexanol at 298.15 and 308.15 K
(Amer Chemical Soc, 2020) Lami, Nassima; Merzougui, Abdelkrim; Uslu, Hasan
Tie-line data were determined for the systems (water + N,N-dimethylacetamide + 1-pentanol) and (water + N,Ndimethylacetamide + 1-hexanol) at the temperatures of 298.15 and 308.15 K under 101.1 KPa. The phase diagrams for these systems are of type I according to the Treyball classification. The thermodynamic consistency of the measured tie-line data was verified using the Hand and Othmer-Tobias equations. The distribution ratios (D) and selectivity (S) values were computed according to the measured tie-line data to assess the extracting behaviors of the selected solvents. The experimental data were correlated using the nonrandom two liquid and the universal quasichemical activity coefficient equations and the Elephant Herding Optimization Algorithm (EHA). EHA is an emerging nature-inspired stochastic global optimization method, and it has been used for liquid-liquid equilibrium (LLE) parameter estimation of local composition models in multicomponent mixtures. The performance of this new swarm-based metaheuristic search method for LLE modeling with and without the closure equation has been analyzed.
Optimization and modelling of pravastatin recovery from aqueous solutions using reactive extraction methodology
(Wiley, 2024) Yetisen, Mehmet; Uslu, Hasan; Baltacioglu, Cem
This research endeavour primarily aimed to optimize and establish a model for the recovery of pravastatin, a well-known statin drug recognized for its cholesterol-lowering properties, from aqueous solutions using reactive extraction. This study used the Box-Behnken design to investigate extraction parameters and create a concise model equation illustrating the relationship between variables and responses. The investigation showed a strong agreement between the model equation and experimental outcomes. It highlighted a positive correlation, demonstrating that higher concentrations of reactant and pravastatin led to notable improvements in extraction efficiency. Two out of 90 experiments had extraction efficiencies below 10%, both with constant factors except for solvent type, while 14 experiments exceeding 80% efficiency highlighted the positive impact of a 50% reactant concentration on extraction efficiency. According to a statistical second-order polynomial, the predicted extraction efficiency stands at 75.14%. In the culminating phase of the study, optimal extraction conditions were meticulously determined, resulting in the identification of an optimal set of parameters: a pravastatin concentration of 35 mg center dot L-1, an adogen concentration of 20.91% (v/v), and a butanol phase ratio of 0.2% (v/v). Under optimal conditions, the experimental extraction efficiency reached 72.69%, closely aligning with values predicted through numerical optimization employing response surface methodology.
Production of Styrene from Dehydrogenation of Ethylbenzene
(Wiley-V C H Verlag Gmbh, 2022) Gupta, Rahul; Uslu, Hasan; Majumder, Subhajit
A pseudo-homogeneous model based on intrinsic rate equations for dehydrogenation of ethylbenzene to styrene in an adiabatic fixed-bed reactor is developed. Steam and ethylbenzene are the main reactants with styrene as the desired product, and benzene and toluene as by-products. Styrene production is an endothermic reaction depends on various factors such as temperature, pressure, steam to ethylbenzene ratio, styrene to ethylbenzene ratio in feed. These factors affects the properties like styrene selectivity, ethylbenzene and by-product conversion etc. The development of the mathematic model includes the application of mass balance, energy balance, and basic thermodynamic relations, momentum balance, Langmuir and Hinshelwood model, Ergun relation, etc. The effects of temperature as well as of the steam-to-ethylbenzene and styrene-to-ethylbenzene molar ratios in the feed on the selectivity for styrene, ethylbenzene conversion, and conversion to by-products are also evaluated. The maximum selectivity for styrene can be achieved at increased steam-to-ethylbenzene feed ratio and a lower ethylbenzene conversion.
Reactive Extraction as an Intensifying Approach for the Recovery of Organic Acids from Aqueous Solution: A Comprehensive Review on Experimental and Theoretical Studies
(Amer Chemical Soc, 2021) Kumar, Sushil; Pandey, Shitanshu; Wasewar, Kailas L.; Ak, Namik; Uslu, Hasan
Organic acids are important targeted chemicals worldwide due to their variety of functionalities in various fields. Organic acids can be produced through chemical processes of fossil raw materials as well as by the microbial fermentation of natural occurring biomass. Because of growing environmental concern, the production pathways are shifting toward biobased green technologies. The primary challenge in the biological synthesis of organic acids is the downstream recovery of the main products from the fermentation broth/aqueous stream. Among the various techniques for the downstream processing, reactive (liquid) extraction is deemed as a great opportunity for this purpose. It is an energy-saving process with flexibility in production scale and a high degree of separation and selectivity. In this review, starting with highlighting the bioproduction and various alternatives available for the recovery of organic acids from aqueous solution, the reactive extraction, an intensified approach is described in detail. The influence of reactive extraction parameters, insights of equilibrium and kinetic mechanisms, and thermodynamic aspects are discussed and analyzed. Different theoretical models for process optimization, determination of equilibrium, kinetic, and thermodynamic parameters, and quantification of solvents' effect are also explained in detail. This paper also highlights recent experimental and theoretical studies for the recovery of different organic acids using amine, phosphorus, and ionic liquid based extractants from fermentation broth/industrial waste streams. In addition, industrial development on the recovery of organic acids using the reactive extraction approach is also described.
Reactive extraction of cis,cis-muconic acid from aqueous solution using phosphorus-bonded extractants, tri-n-octylphosphineoxide and tri-n-butyl phosphate: Equilibrium and thermodynamic study
(Elsevier, 2021) Demir, Ozge; Gok, Asli; Uslu, Hasan; Kirbaslar, Sah Ismail
cis,cis-Muconic acid falls under the category of carboxylic acids and finds application mostly in biodegradable polymers, agrochemicals, and the food industry. Owing to the high thermal reactivity based upon the twoterminal carboxylic groups present in their structure, the chemical industry has widely used carboxylic acids. The major obstacle encountered during the production of carboxylic acids is their recovery from aqueous solutions and fermentation media. Therefore, the recovery of HccMA by reactive extraction as a particular product capture method, using tri-n-octylphosphine oxide (TOPO) and tri-n-butyl phosphate (TBP) in organic diluents such as 1-butanol, isoamyl alcohol, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), diisobutyl ketone, isobutanol, n-hexane, dimethyl glutarate, ethyl propionate, and diethyl carbonate (DEC) was executed in this study. This method was experimentally conducted to explore the most proper extractant and diluent combination. Extraction experiments were also conducted with pure diluents alone to examine the extractant effect on the extraction system. The important extraction parameters like distribution coefficient (KD), extraction efficiency (E %), loading ratio (Z), dimerization constant (D), partition coefficient (P), and complexation constant (KE11) were determined. Mass action law model interpreted the obtained results. For HccMA/TOPO extraction system, the maximum extraction efficiency was found 93.19% in the presence of n-hexane as a diluent. For HccMA/TBP extraction system, the maximum extraction efficiency was found 90.37% in the presence of ethyl propionate as a diluent. Thermodynamic studies at variable temperatures were also carried out to estimate Delta H, Delta S, and Delta G of the process. To investigate the feasibility of designing a counter-current liquid-liquid extraction column, the number of theoretical stages (NTS) were assessed by theodified Kremser equation and found between 3 and 5 to et the desired extraction efficiency.
Statistical modeling and optimization of itaconic acid reactive extraction using response surface methodology (RSM) and artificial neural network (ANN)
(Elsevier, 2022) Chellapan, Suchith; Datta, Dipaloy; Kumar, Sushil; Uslu, Hasan
In this paper, regression models were proposed to predict the degrees of extraction (%Y) for the reactive extraction of itaconic acid using response surface methodology (RSM) and artificial neural network (ANN). The prominent design parameters like itaconic acid concentration, extractant (tri-n-octylamine), and modifier (dichloromethane, an active diluent) composition were considered, and their impact on the extraction efficiency was determined. RSM and ANN fitted the experimental data with a correlation coefficient of 0.970 and 0.993, respectively. The statistical significance of the models (RSM and ANN) was ascertained by ANOVA analysis. The optimal design factors were determined to be 0.072 mol center dot L-1 acid concentration, 16.075 %v/v extractant composition, and 62.15 %v/v modifier composition at which the values of experimental and predicted %Y of 98.86% and 100.69%, respectively, were obtained by RSM model.
Structural, morphological and dielectrical properties of acorn cupule extract doped hydrogels
(Elsevier, 2024) Gorguluer, Omer; Coskun, Ramazan; Yalcin, Orhan; Okutan, Mustafa; Uslu, Hasan; Doganay, B. Seyma
Acorn cupule extract doped different hydrogels were prepared to examine their structural morphological and dielectrical properties at room temperature. Structural, morphological and dielectrical parameters for all samples were found by using the XRD, SEM, EDX and impedance spectroscopy. The conductivity, capacitive effect and electronic circuit properties for acorn cupule extract doped hydrogels have not studied before in the literature. Therefore, the complex impedance, capacitance, phase angles, dielectric constant, tangent factor, electric modulus and frequency evolution of ionic conductivity (s -parameters) were successfully analyzed in detail using impedance spectroscopy in the frequency range of 10 2 to 10 7 rad/s at RT. Furthermore, the Cole -Cole plots of the dielectric constant adapted to the Smith chart and general RC equivalent circuit was showed in detail. It was determined that the dielectric effect was at its highest values in the frequency range of 10 2 to 10 5 rad/s.
Study on Oxalic Acid Extraction by Tripropylamine: Equilibrium and Computational COSMO-SAC Analysis
(Amer Chemical Soc, 2020) Uslu, Hasan; Baykal, Esma; Gok, Asli; Kirbaslar, Sah Ismail; Santos, Dheiver
Oxalic acid was extracted from aqueous solution using tripropylamine (TPA) in different organic solvents. Ten organic solvents such as 1-butanol, isoamyl alcohol, methyl ethyl ketone (MEK), methyl isobutyl ketone, diisobutyl ketone (DIBK), isobutanol, n-hexane, dimethyl glutarate, ethyl propionate, and diethyl carbonate (DEC) were used to prepare an organic phase with TPA. From the experimental data, some thermodynamic coefficients were calculated such as the distribution coefficient (K-D), loading factor (Z), and the extraction yield (E %). It is discovered upon examination that the physical extraction analyses performed with pure solvents for oxalic acid extraction from aqueous media can be improved essentially by adding TPA. As per the results obtained, the most effective oxalic acid extraction is achieved with an extraction productivity (efficiency) of 99.86% and a K-D of 716.948 if 2.608 mol kg(-1) of TPA diluted in MEK is utilized as the extractant mixture. The COSMO-SAC model has been used to analyze the experimental data for the first time. This model provides insight into the interactions between substances with good results.
Study on the Biocompatible Solvent Systems for the Reactive Extraction of Itaconic Acid
(Amer Chemical Soc, 2019) Datta, Dipaloy; Chomal, Neha; Uslu, Hasan; Kumar, Sushil
The separation of itaconic acid (0.2 mmol-kg(-1)) from its aqueous solution is performed by dissolving tri-n-octylamine (TOA) in the biocompatible mixtures of 1-decanol + n-dodecane, dodecanol + n-dodecane, and oleyl alcohol + n-dodecane at different compositions. Also, the physical extraction data are presented with dodecane, oleyl alcohol, dodecanol, and 1-decanol. Here, fixing the TOA composition at 20 vol %, the vol % of modifiers (oleyl alcohol, dodecanol, and 1-decanol) is changed from 20 to 60 vol % in dodecane (diluent) to find the best combination for the extraction of the acid. The extraction system comprised of 20 vol % TOA + 40 vol % dodecanol + 20 vol % n-dodecane gives the best separation efficiency (95.06%). Then, with this solvent system, equilibrium studies are carried out at different acid concentrations (0.05 and 0.251 mmol.kg(-1)). Based on the theoretical study, the insights of the extraction mechanism are determined in terms of equilibrium constants (overall and individual, K-E, K-11, and K-21) and stoichiometry (m and n) at 298 K.

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