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Articles 61 - 90 of 10317
Full-Text Articles in Physical Sciences and Mathematics
On A Class Of Permutation Trinomials Over Finite Fields, Burcu Gülmez Temür, Buket Özkaya
On A Class Of Permutation Trinomials Over Finite Fields, Burcu Gülmez Temür, Buket Özkaya
Turkish Journal of Mathematics
In this paper, we study the permutation properties of the class of trinomials of the form f(x) = x4q+1 +λ1xq+4 +λ2x2q+3 ∈ Fq2 [x] , where λ1, λ2 ∈ Fq and they are not simultaneously zero. We find all necessary and sufficientconditions on λ1 and λ2 such that f(x) permutes Fq2 , where q is odd and q = 22k+1, k ∈ N.
Interior Schauder-Type Estimates For M − Th Order Elliptic Operators Inrearrangement-Invariant Sobolev Spaces, Emi̇nağa M. Mamedov, Şeyma Çeti̇n
Interior Schauder-Type Estimates For M − Th Order Elliptic Operators Inrearrangement-Invariant Sobolev Spaces, Emi̇nağa M. Mamedov, Şeyma Çeti̇n
Turkish Journal of Mathematics
In this study, we investigate the m-th order elliptic operators on n-dimensional bounded domain Ω ⊂ Rnwith discontinuous coefficients in the rearrangement-invariant Sobolev space WmX (Ω). In general, the consideredrearrangement-invariant spaces are not separable, so the use of classical methods in these spaces requires substantialmodification of classical methods and a lot of preparation, concerning correctness of substitution operator, problemsrelated to the extension operator in such spaces, etc. For this purpose, the corresponding separable subspaces of thesespaces, in which the set of compact supported infinitely differentiable functions is dense, are introduced based on theshift operator. We establish interior Schauder-type estimates in …
Antiviral And Cytotoxic Activities And Chemical Profiles Of Two Species Of Abies Nordmanniana From Türkiye, Nazli Sarikahya, Gaye Sümer Okkali, Furkan Ozan Çöven, Sevda Zeinali̇, Gülce Gucur, Ayşe Di̇la Çağlar, Ece Uyar, Ahmet Ceyhan Gören, Ayşe Nalbantsoy
Antiviral And Cytotoxic Activities And Chemical Profiles Of Two Species Of Abies Nordmanniana From Türkiye, Nazli Sarikahya, Gaye Sümer Okkali, Furkan Ozan Çöven, Sevda Zeinali̇, Gülce Gucur, Ayşe Di̇la Çağlar, Ece Uyar, Ahmet Ceyhan Gören, Ayşe Nalbantsoy
Turkish Journal of Chemistry
Abies is an important genus of the family Pinaceae, with about 50 species found in the highlands of Asia, Europe, North Africa, and North and Central America. The principal aim of the present work was to investigate the chemical content and biological potential of the resin and cone from Abies nordmanniana subsp. bornmulleriana and Abies nordmanniana subsp. equi-trojani, respectively. The flavonoid and phenolic contents of the resin and cones were evaluated using liquid chromatography-high resolution mass spectrometry (LC-HRMS). Additionally, the essential oil and fatty acid compositions were analyzed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-flame ionization detector (GC-FID).. Cytotoxicity …
Design And Characterization Of Phosphonic Acid-Functionalized Grafted Sepiolite Nanohybrids And Their Adsorption Studies For Removal Of Copper Ions From Aqueous Solution, Mehwish Tahir, Asif Raza, Amara Nasir, Tariq Yasin, Shamila Imtiaz
Design And Characterization Of Phosphonic Acid-Functionalized Grafted Sepiolite Nanohybrids And Their Adsorption Studies For Removal Of Copper Ions From Aqueous Solution, Mehwish Tahir, Asif Raza, Amara Nasir, Tariq Yasin, Shamila Imtiaz
Turkish Journal of Chemistry
In this study, we synthesized novel, economically efficient phosphonic acid-functionalized grafted sepiolite nanohybrids for selective elimination of copper ions from water. These nanohybrids were prepared by graft polymerization of glycidyl methacrylate onto sepiolite. We utilized free radical graft polymerization to graft glycidyl methacrylate (GMA) onto silanized sepiolite. The nanohybrids obtained exhibited a grafting percentage of 479% at 0.3 g of KPS initiator, 15% GMA monomer, and after 4 h of reaction. In pursuit of selectively removing metal ions from water, the nanohybrid with the highest grafting (PGE3) was chemically treated with phosphoric acid to introduce phosphonic acid groups on it. …
Effect Of Quince Seed Gum (Qsg) On The Performance Of Injectable Hyaluronic Acid Hydrogels In Terms Of The Rheological, Morphological, And Mechanical Aspect, Serdar Kolay, Ni̇lhan Kayaman Apohan, Erdi̇nç Babuç, Gökay Gün
Effect Of Quince Seed Gum (Qsg) On The Performance Of Injectable Hyaluronic Acid Hydrogels In Terms Of The Rheological, Morphological, And Mechanical Aspect, Serdar Kolay, Ni̇lhan Kayaman Apohan, Erdi̇nç Babuç, Gökay Gün
Turkish Journal of Chemistry
Injectable hydrogels play an important role in tissue engineering as a filling and repairing material. This study aimed to develop a new injectable hydrogel based on hyaluronic acid (HA) and quince seed gum (QSG) and investigate the effect of QSG on hydrogel performance. The amount of unreacted 1,4-Butanediol diglycidyl ether (BDDE) is maintained at an undetectable level for HA-QSG hydrogels. Amino acid analysis showed that the HA-QSG hydrogel had rich amino acid concentrations of leucine, arginine, and valine. After thermal sterilization, the elastic modulus of HA-QSG gels for dermal and intra-articular filler applications is 63 Pa and 92 Pa respectively. …
Dft Modeling Of Water-Assisted Hydrogen Peroxide Formation From A C(4a)-(Hydro)Peroxyflavin, Yilmaz Özkiliç
Dft Modeling Of Water-Assisted Hydrogen Peroxide Formation From A C(4a)-(Hydro)Peroxyflavin, Yilmaz Özkiliç
Turkish Journal of Chemistry
The cofactor of a class A monooxygenase is reduced at an external location of the enzyme and is subsequently pulled back into the active site after the reduction. This observation brings the question; is there any defense mechanism of the active site of a monooxygenase against the formation of the harmful hydrogen peroxide from the reactive C(4a)-(hydro)peroxide intermediate? In this study, the barrier energies of one to three water molecule-mediated uncoupling reaction mechanisms in water exposed reaction conditions were determined. These were found to be facile barriers. Secondly, uncoupling was modeled in the active site of kynurenine 3-monooxygenase complex which …
Rapid Synthesis Of Azoindolizine Derivatives Via Aryldiazonium Salts, Ferruh Lafzi̇
Rapid Synthesis Of Azoindolizine Derivatives Via Aryldiazonium Salts, Ferruh Lafzi̇
Turkish Journal of Chemistry
A practical, rapid, and efficient method for the synthesis of azoindolizine derivatives via aryldiazonium salts with excellent yields was reported. Firstly, the corresponding aniline derivatives were synthesized via a simple and rapid method. Then, the optimal reaction conditions were investigated using a variety of protic and aprotic solvents that demonstrating the robustness of the approach. Finally, the applicability of this method to various sources of indolizine and phenyldiazonium tetrafluoroborate salts was expanded.
Theoretical Study On The Insertion Reaction Of The Stannylenoid H2snlif With X-H Bonds (X = N, O, F), Shuo Wu, Bingfei Yan, Shaoli Liu, Wenzuo Li
Theoretical Study On The Insertion Reaction Of The Stannylenoid H2snlif With X-H Bonds (X = N, O, F), Shuo Wu, Bingfei Yan, Shaoli Liu, Wenzuo Li
Turkish Journal of Chemistry
The insertion reactions of p-complex (RP) and three-membered ring configuration (RS) of stannylenoid H2SnLiF with NH3, H2O and HF have been studied theoretically by quantum chemical calculation. The structures of reactants, precursors, transition states, intermediates and products have been fully optimized at the M06-2X/def2-TZVP level. The single point energy of all fixed points were calculated using the QCISD method. The calculation results show that the three-membered ring configuration is easier to conduct the insertion reaction. Comparing the reaction energy barriers of RP, RS to NH3, H2O and HF, we found that the difficulty of the insertion reaction is NH3 > H2O …
Senggani Fruit (Melastoma Malabathricum Linn.) Extract As A Natural Indicator In Ph-Responsive Pva-Taro Starch Plastic Packaging, Rika Risma Dewi, Intan Syahbanu, Winda Rahmalia
Senggani Fruit (Melastoma Malabathricum Linn.) Extract As A Natural Indicator In Ph-Responsive Pva-Taro Starch Plastic Packaging, Rika Risma Dewi, Intan Syahbanu, Winda Rahmalia
Turkish Journal of Chemistry
Polyvinyl alcohol (PVA)-starch-based bioplastics are widely used in many applications. pH-responsive plastic packaging was produced through the incorporation of senggani (Melastoma malabathricum Linn.) fruit extract into PVA-taro starch-based plastic packaging. The objective of this research was to examine the characteristics of senggani fruit extract under different pH conditions and explore its application as a pH indicator in intelligent packaging. The senggani fruit was extracted through the maceration method using a solvent comprising 96% ethanol and 3% citric acid, with a ratio of 85:15 (v/v). The senggani fruit extract solution underwent color changes, appearing pink at pH levels below 6, pale …
Axion Dark Matter With Not Quite Black Hole Domination, Ufuk Aydemi̇r
Axion Dark Matter With Not Quite Black Hole Domination, Ufuk Aydemi̇r
Turkish Journal of Physics
No abstract provided.
Comparative Study Of Α-Α Interaction Potentials Constructed Using Various Phenomenological Models, Ayushi Awasthi, O S K S Sastri
Comparative Study Of Α-Α Interaction Potentials Constructed Using Various Phenomenological Models, Ayushi Awasthi, O S K S Sastri
Turkish Journal of Physics
No abstract provided.
Weyl Tensor Decomposition To The Formation Of Black Hole, Gauree Shanker, Zakia Issa Ndidi
Weyl Tensor Decomposition To The Formation Of Black Hole, Gauree Shanker, Zakia Issa Ndidi
Turkish Journal of Physics
No abstract provided.
Mechanical Calculations On Atomically Thin Membranes, Burak Aslan
Mechanical Calculations On Atomically Thin Membranes, Burak Aslan
Turkish Journal of Physics
No abstract provided.
Deposition Of Organic And Inorganic Carbons On The Turkish Continental Margins (1984–1996), Vedat Edi̇ger, Di̇lek Edi̇ger
Deposition Of Organic And Inorganic Carbons On The Turkish Continental Margins (1984–1996), Vedat Edi̇ger, Di̇lek Edi̇ger
Turkish Journal of Earth Sciences
This study reevaluates the published total inorganic carbon (TIC) and total organic carbon (TOC) percentages of 695 seafloor sediment samples collected from the continental margins of the Black Sea, Sea of Marmara, Aegean Sea and Mediterranean Sea between 1984 and 1996. An inverse relationship is observed between the average TIC and TOC percentages in the four seas surrounding Türkiye. The explanation for this phenomenon is closely connected to the terrestrial, marine, climatic, and environmental factors of the continental margins from which the samples were collected.
Derivation Of A 1-D Seismic Velocity Model For The Lake Van Region, Mehveş Feyza Akkoyunlu, Bülent Kaypak, Bülent Oruç, Doğan Kalafat
Derivation Of A 1-D Seismic Velocity Model For The Lake Van Region, Mehveş Feyza Akkoyunlu, Bülent Kaypak, Bülent Oruç, Doğan Kalafat
Turkish Journal of Earth Sciences
We present a detailed one-dimensional (1-D) velocity model of the Lake Van Basin and its surrounding region, alongside precise hypocenter locations, utilizing seismic data from the aftershocks of the 23 October 2011 Lake Van earthquake (Mw = 7.1). The 1-D minimum velocity model is computed by the VELEST program by analyzing body wave traveltimes and station corrections. Encompassing a geographical area of 180 × 90 km² centered around Lake Van, the study incorporated seismic data from 10 newly deployed stations, complementing the existing network of the Kandilli Earthquake Research Institute. A comprehensive manual analysis was conducted on a dataset comprising …
Enhanced Dip Angle Map Using Kuwahara And Gaussian Filters: An Example From Burdur Region, Türkiye, Özkan Kafadar, Erdi̇nç Öksüm
Enhanced Dip Angle Map Using Kuwahara And Gaussian Filters: An Example From Burdur Region, Türkiye, Özkan Kafadar, Erdi̇nç Öksüm
Turkish Journal of Earth Sciences
Recently, many edge detection and enhancement techniques have been used to transform geophysical data into a more suitable form for interpretation. The dip angle, a surface-derived attribute that has been frequently used in the interpretation of seismic data, is one of these transforms, and recently, it has started to be utilized as an edge detector in the interpretation of potential field data. In this study, it is proposed to use the potential field data filtered using the Kuwahara and Gaussian filters to obtain clearer and more detailed edges from both the conventional dip angle and its rescaled version. Two synthetic …
Geomagnetic Response To The Earthquake In Türkiye And Syria On February 6, 2023, Svetlana Riabova, Sergey Shalimov
Geomagnetic Response To The Earthquake In Türkiye And Syria On February 6, 2023, Svetlana Riabova, Sergey Shalimov
Turkish Journal of Earth Sciences
The disturbances in the lower ionosphere during the strong earthquake in Türkiye and Syria and its strongest aftershock on February 6, 2023, are analyzed using data from ground-based magnetometers. The observation points are located at distances 700 to 1600 km from the epicenter of the seismic event. As a characteristic of the ionospheric response to these events, variations in the magnetic field have been analyzed at the İznik, Grocka, Panagjurishte, and Surlari magnetic observatories. Earthquake epicenter is known to be a source of both seismic Rayleigh waves and atmospheric acoustic-gravity waves. Using the difference in velocities, at which these waves …
Stochastic 1-D Reactive Transport Simulations To Assess Silica And Carbonate Phases During The Co2 Reinjection Process In Metasediments, Selçuk Erol
Turkish Journal of Earth Sciences
One proposed method to mitigate carbon emission is to mineralize the CO2 in deep geothermal reservoirs while mixing the coproduced CO2 with the effluent fluid for reinjection. The injection fluid temperature fluctuates due to the mixing process between CO2-charged water and the effluent fluid, and compressor interruptions change the thermodynamic conditions that influence the fluid-rock interaction in the reservoir. Mineral dissolution or precipitations are associated with changes in permeability and porosity that affect the flow and, eventually, the lifespan of the reservoir. A combined stochastic–reactive transport simulation approach is useful for inspection purposes. Moreover, the stochastic algorithm validates the deterministic …
Carboniferous Graptolites (Hemichordata: Graptolithina) From The Dnipro-Donets Depression And Donets Basin, Ukraine, Vitaly Dernov
Carboniferous Graptolites (Hemichordata: Graptolithina) From The Dnipro-Donets Depression And Donets Basin, Ukraine, Vitaly Dernov
Turkish Journal of Earth Sciences
Remains of the Carboniferous graptolites ?Ptiograptus sp. and Dictyonema sp. are described from the Donets Basin and the border zone of the Dnipro-Donets Depression and Donets Basin (eastern Ukraine). These graptolites were found in the Mezhova (Visean, Mississippian) and Avilovka (Kasimovian, Pennsylvanian) formations. Dictyonema sp. from the Avilovka Formation is probably the youngest dendroid graptolite to date. The analysis of geological data allowed to make a reasonable assumption about the Late Devonian rather than the Carboniferous age of the graptolite fauna from the Englewood Formation of South Dakota (USA) and the Tournaisian rather than the Cisuralian age of graptolites from …
Unveiling Anomalies: A Survey On Xai-Based Anomaly Detection For Iot, Esin Eren, Feyza Yildirim Okay, Suat Özdemi̇r
Unveiling Anomalies: A Survey On Xai-Based Anomaly Detection For Iot, Esin Eren, Feyza Yildirim Okay, Suat Özdemi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
In recent years, the rapid growth of the Internet of Things (IoT) has raised concerns about the security and reliability of IoT systems. Anomaly detection is vital for recognizing potential risks and ensuring the optimal functionality of IoT networks. However, traditional anomaly detection methods often lack transparency and interpretability, hindering the understanding of their decisions. As a solution, Explainable Artificial Intelligence (XAI) techniques have emerged to provide human-understandable explanations for the decisions made by anomaly detection models. In this study, we present a comprehensive survey of XAI-based anomaly detection methods for IoT. We review and analyze various XAI techniques, including …
Security Fusion Method Of Physical Fitness Training Data Based On The Internet Of Things, Bin Zhou
Security Fusion Method Of Physical Fitness Training Data Based On The Internet Of Things, Bin Zhou
Turkish Journal of Electrical Engineering and Computer Sciences
Physical fitness training, an important way to improve physical fitness, is the basic guarantee for forming combat effectiveness. At present, the evaluation types of physical fitness training are mostly conducted manually. It has problems such as low efficiency, high consumption of human and material resources, and subjective factors affecting the evaluation results. ”Internet+” has greatly expanded the traditional network from the perspective of technological convergence and network coverage objects. It has expedited and promoted the rapid development of Internet of Things (IoT) technology and its applications. The IoT with many sensor nodes shows the characteristics of acquisition information redundancy, node …
Dpafy-Gcaps: Denoising Patch-And-Amplify Gabor Capsule Network For The Recognition Of Gastrointestinal Diseases, Henrietta Adjei Pokuaa, Adeboya Felix Adekoya, Benjamin Asubam Weyori, Owusu Nyarko-Boateng
Dpafy-Gcaps: Denoising Patch-And-Amplify Gabor Capsule Network For The Recognition Of Gastrointestinal Diseases, Henrietta Adjei Pokuaa, Adeboya Felix Adekoya, Benjamin Asubam Weyori, Owusu Nyarko-Boateng
Turkish Journal of Electrical Engineering and Computer Sciences
Deep learning (DL) models have performed tremendously well in image classification. This good performance can be attributed to the availability of massive data in most domains. However, some domains are known to have few datasets, especially the health sector. This makes it difficult to develop domain-specific high-performing DL algorithms for these fields. The field of health is critical and requires accurate detection of diseases. In the United States Gastrointestinal diseases are prevalent and affect 60 to 70 million people. Ulcerative colitis, polyps, and esophagitis are some gastrointestinal diseases. Colorectal polyps is the third most diagnosed malignancy in the world. This …
Joint Control Of A Flying Robot And A Ground Vehicle Using Leader-Follower Paradigm, Ayşen Süheyla Bağbaşi, Ali Emre Turgut, Kutluk Bilge Arikan
Joint Control Of A Flying Robot And A Ground Vehicle Using Leader-Follower Paradigm, Ayşen Süheyla Bağbaşi, Ali Emre Turgut, Kutluk Bilge Arikan
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, a novel control framework for the collaboration of an aerial robot and a ground vehicle that is connected via a taut tether is proposed. The framework is based on a leader-follower paradigm. The leader follows a desired trajectory while the motion of the follower is controlled by an admittance controller using an extended state observer to estimate the tether force. Additionally, a velocity estimator is also incorporated to accurately assess the leader’s velocity. An essential feature of our system is its adaptability, enabling role switching between the robots when needed. Furthermore, the synchronization performance of the robots …
Signer-Independent Sign Language Recognition With Feature Disentanglement, İnci̇ Meli̇ha Baytaş, İpek Erdoğan
Signer-Independent Sign Language Recognition With Feature Disentanglement, İnci̇ Meli̇ha Baytaş, İpek Erdoğan
Turkish Journal of Electrical Engineering and Computer Sciences
Learning a robust and invariant representation of various unwanted factors in sign language recognition (SLR) applications is essential. One of the factors that might degrade the sign recognition performance is the lack of signer diversity in the training datasets, causing a dependence on the singer’s identity during representation learning. Consequently, capturing signer-specific features hinders the generalizability of SLR systems. This study proposes a feature disentanglement framework comprising a convolutional neural network (CNN) and a long short-term memory (LSTM) network based on adversarial training to learn a signer-independent sign language representation that might enhance the recognition of signs. We aim to …
Deep Learning-Based Breast Cancer Diagnosis With Multiview Of Mammography Screening To Reduce False Positive Recall Rate, Meryem Altın Karagöz, Özkan Ufuk Nalbantoğlu, Derviş Karaboğa, Bahriye Akay, Alper Baştürk, Halil Ulutabanca, Serap Doğan, Damla Coşkun, Osman Demi̇r
Deep Learning-Based Breast Cancer Diagnosis With Multiview Of Mammography Screening To Reduce False Positive Recall Rate, Meryem Altın Karagöz, Özkan Ufuk Nalbantoğlu, Derviş Karaboğa, Bahriye Akay, Alper Baştürk, Halil Ulutabanca, Serap Doğan, Damla Coşkun, Osman Demi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Breast cancer is the most prevalent and crucial cancer type that should be diagnosed early to reduce mortality. Therefore, mammography is essential for early diagnosis owing to high-resolution imaging and appropriate visualization. However, the major problem of mammography screening is the high false positive recall rate for breast cancer diagnosis. High false positive recall rates psychologically affect patients, leading to anxiety, depression, and stress. Moreover, false positive recalls increase costs and create an unnecessary expert workload. Thus, this study proposes a deep learning based breast cancer diagnosis model to reduce false positive and false negative rates. The proposed model has …
Text-To-Sql: A Methodical Review Of Challenges And Models, Ali Buğra Kanburoğlu, Faik Boray Tek
Text-To-Sql: A Methodical Review Of Challenges And Models, Ali Buğra Kanburoğlu, Faik Boray Tek
Turkish Journal of Electrical Engineering and Computer Sciences
This survey focuses on Text-to-SQL, automated translation of natural language queries into SQL queries. Initially, we describe the problem and its main challenges. Then, by following the PRISMA systematic review methodology, we survey the existing Text-to-SQL review papers in the literature. We apply the same method to extract proposed Text-to-SQL models and classify them with respect to used evaluation metrics and benchmarks. We highlight the accuracies achieved by various models on Text-to-SQL datasets and discuss execution-guided evaluation strategies. We present insights into model training times and implementations of different models. We also explore the availability of Text-to-SQL datasets in non-English …
Stereo-Image-Based Ground-Line Prediction And Obstacle Detection, Emre Güngör, Ahmet Özmen
Stereo-Image-Based Ground-Line Prediction And Obstacle Detection, Emre Güngör, Ahmet Özmen
Turkish Journal of Electrical Engineering and Computer Sciences
In recent years, vision systems have become essential in the development of advanced driver assistance systems or autonomous vehicles. Although deep learning methods have been the center of focus in recent years to develop fast and reliable obstacle detection solutions, they face difficulties in complex and unknown environments where objects of varying types and shapes are present. In this study, a novel non-AI approach is presented for finding the ground-line and detecting the obstacles in roads using v-disparity data. The main motivation behind the study is that the ground-line estimation errors cause greater deviations at the output. Hence, a novel …
Performance Test Of Zn-Astaxanthin Complex-Sensitized Solar Cell: Effect Of Light Intensity On Open-Circuit Voltage And Short-Circuit Current Values, Septiani Septiani, Winda Rahmalia, Thamrin Usman
Performance Test Of Zn-Astaxanthin Complex-Sensitized Solar Cell: Effect Of Light Intensity On Open-Circuit Voltage And Short-Circuit Current Values, Septiani Septiani, Winda Rahmalia, Thamrin Usman
Turkish Journal of Chemistry
The sensitizer is one of the most essential dye-sensitized solar cell (DSSC) components. In the present research, a Zn-astaxanthin complex was investigated as a sensitizer, compared to pure astaxanthin. The complex with a 1:1 mole ratio between astaxanthin and Zn2+ was synthesized in a reflux reactor at 37–60 °C. The product was analyzed using Proton Nuclear Resonance (1H-NMR), which indicates the presence of chelate formation between Zn2+ with two atoms of oxygen on the terminal cyclohexane ring of astaxanthin. The interaction of sensitizers (astaxanthin and Zn-astaxanthin) on the photoelectrode surface in this study was analyzed using a Fourier Transform Infra-Red …
Phosphorus And Nitrogen-Containing Soybean Oil Polyols: Effect On The Mechanical Properties And Flame Retardancy Of Polyurethane Foam, Deni̇z Öztaşkin, Lütfullah Yusuf Yi̇vli̇k, İlayda Acaroğlu Degitz, Tarik Eren
Phosphorus And Nitrogen-Containing Soybean Oil Polyols: Effect On The Mechanical Properties And Flame Retardancy Of Polyurethane Foam, Deni̇z Öztaşkin, Lütfullah Yusuf Yi̇vli̇k, İlayda Acaroğlu Degitz, Tarik Eren
Turkish Journal of Chemistry
In recent years, there has been an increasing interest in producing new materials that use renewable resources and halogen-free flame retardants with nonleaching properties. This research focuses on designing and synthesizing phosphorus-nitrogen-based biopolyols for use in polyurethane (PU) foam production. Polyol (ESBO-DYM) with dual functionalities, renewability, and nonflammability is synthesized through the epoxy ring-opening reaction of epoxidized soybean oil with phosphorus and nitrogen-containing tetraol products (DYM). The mechanical and flame retardant properties of PU foams with the addition of an ESBO-DYM were investigated. Increasing the amount of phosphorus in the PU foams increased the thermal stability properties. Using 100% ESBO-DYM …
Supramolecular Solvent-Based-Vortex-Assisted-Dispersive Liquid Liquid Microextraction Of Sudan Black B In Food Samples Prior To Spectrophotometric Detection, Fi̇gen Erek, Mustafa Tüzen
Supramolecular Solvent-Based-Vortex-Assisted-Dispersive Liquid Liquid Microextraction Of Sudan Black B In Food Samples Prior To Spectrophotometric Detection, Fi̇gen Erek, Mustafa Tüzen
Turkish Journal of Chemistry
A new, simple and rapid spectrophotometric method was developed for determination of Sudan Black B in food products by supramolecular solvent-based-vortex-assisted-dispersive liquid liquid microextraction (SUPRAS-VA-DLLME). Extraction solvent type, volume of solvent, pH, volume of THF, centrifugation time, vortex time, and sample volume were investigated as optimization parameters of the developed method. Under the optimum conditions, limit of detection and limit of quantification, preconcentration factor and enhancement factor of the developed method were calculated to be 9.01 µg L–1, 29.73 µg L–1, 20, and 55, respectively. The developed microextraction method was successfully applied to food samples for the determination of Sudan …