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Interfacial effect on the microwave absorption properties in Y3Fe5O12/ Fe2O3
No full textIn this work, the interfacial effect on the electromagnetic wave (EMW) absorbing performance in Y3Fe5O12 and Fe2O3 material system synthesized by one-step sol-gel method followed by various sintering temperature was studied. The synthesized samples were first characterized by performing x-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM) measurements. A linear dependence of the saturation magnetization with the YIG content in the samples was observed that the saturation magnetization increases from 4.18 to 20.2 emu/g when the YIG crystal content is increased from 43 % to 88 %. Then, the EMW absorbing performance were studied by measuring dielectric parameters of the samples in the X-band. The experimental results indicate that the higher sintering temperature reduce the intensity of Fe2O3 peaks and enhance the formation of YIG chemical structure. Due to the both Fe2O3 and YIG crystal phases, the Fe2O3/ Y3Fe5O12 interface enhances the EMW polarization and thus EMW absorbing performance. The minimum reflection loss was determined as -15.4 dB at 9.5 GHz frequency in YF1000 sample. The experimental results demonstrate that the sintering temperature has the prominent effect on the structural, magnetic and EMW absorbing properties of YIG. The results would be useful for the YIG-based microwave device applications.Adana Alparslan Turkes Science and Technology University Scientific Research Council [22303007]This work was supported by Adana Alparslan Turkes Science and Technology University Scientific Research Council under Project No: 22303007
Novel applications of black pepper essential oil as an antioxidant agent in sodium caseinate and chitosan based active edible films
No full textIn the current study, sodium caseinate and chitosan-based composite edible films were developed with the incorporation of black pepper (Piper nigrum) essential oil (BPO) in various concentrations (0.05, 0.1 and 0.15 %) for potential food packaging applications. The chemical composition of BPO was determined using GCMS and the major compound detected were beta-caryophyllene, limonene, beta-phellandren, pinene, copaene and alpha-humulene. The addition of BPO resulted in an increase in the thickness, EAB, WVP, moisture content and swelling index values of the films; however, the TS and water solubility decreased. The inclusion of BPO led to a substantial enhancement in the DPPH and ABTS radical scavenging capabilities of the edible films. SEM micrographs demonstrated intermolecular interaction between BPO, sodium caseinate, and chitosan. FTIR spectra confirmed the interaction of the functional groups of the polymers and BPO. The incorporation of the BPO increased the crystallinity of the films. Moreover, the thermal analysis including TGA, DSC and DTG demonstrated an increase in the thermal stability of the edible films with the addition of the BPO. These findings demonstrated that sodium caseinate and chitosan composite based edible films loaded with BPO can be used as sustainable active food packaging material.TRC grant [BFP/RGP/HSS/22/007, MoHERI/SRPP/MoAFWR/1/2022/RI/01]The study was supported by TRC grant numbers BFP/RGP/HSS/22/007 and MoHERI/SRPP/MoAFWR/1/2022/RI/01
Tanik asit salımına yönelik epitop baskılı antimikrobiyal kriyojel disklerin geliştirilmesi
No full textFen Bilimleri Enstitüsü, Biyomühendislik Ana Bilim DalıMoleküler baskılama yöntemi, istenen moleküle duyarlı polimerlerin sentezlenmesine olanak tanır. Kriyojeller, bu polimerlerden biri olup çözücünün donma sıcaklığı altında üretilen jel matrisleridir. Kriyojeller, por yapıcı malzeme olarak toksik organik bileşikler içermeyip, bunun yerine por yapıcı malzeme olarak buz kristallerini kullanır. Doğal malzemelerle desteklenen kriyojeller, biyouyumluluk, esneklik ve yüksek mekanik kararlılık gibi avantajlar sunar, bu da onları yara iyileşmesi, doku iskeleti oluşturma, ilaç salımı gibi birçok uygulamada destekleyici bir tedavi yöntemi haline getirir. Bu araştırmada, Tannik asit molekülünün antimikrobiyal etkilerinden faydalanarak epitop baskılanmış kriyojel disklerin hazırlanması amaçlanmaktadır. Bu diskler, akut yara iyileştirici ve antimikrobiyal özelliklere sahip bir biyomalzemenin literatüre kazandırılmasını hedefler. Jelatin yapılı gallik asit baskılanmış biyouyumlu kriyojeller üretilmiş ve bu kriyojellerin yapısına farklı konsantrasyonlarda tannik asit eklenerek antimikrobiyal özellik kazandırılması amaçlanmıştır. Sentezlenen kriyojeller FTIR, şişme testleri ve SEM ile karakterize edilmiştir. Ayrıca, farklı konsantrasyonlardaki tannik asit yüklenmiş kriyojel disklerden tannik asidin kümülatif salımı ve disklerin S. aureus ve E. coli üzerindeki antimikrobiyal özellikleri değerlendirilmiştir. Yapılan çalışmalar, polimerdeki ilaç yükleme oranının arttıkça salım hızının da arttığını göstermektedir. Güç yasasına göre, salım mekanizmasının türünü gösteren "n" üsteli 0.5'ten küçük bulunmuş, bu da hazırlanan kriyojel disklerde difüzyon mekanizmasının non-Fickian olduğu sonucuna varmamıza yardımcı olmuştur. Anahtar Kelimeler: Epitop baskılı polimerler, kriyojel diskler, tannik asit, kontrollü ilaç salım sistemleri, yara iyileşmesiThe molecular imprinting method allows for the synthesis of polymers sensitive to the desired molecule. Cryogels, one of these polymers, are gel matrices produced below the freezing temperature of the solvent. In contrast to many polymers containing toxic organic compounds as pore-forming agents, cryogels utilize ice crystals as the pore-forming material. Cryogels supported structurally by natural materials offer advantages such as biocompatibility, flexibility, and high mechanical stability, making them suitable for various applications like wound healing, tissue scaffolding, and drug release. In this study, the aim is to take advantage of the antimicrobial effects of Tannic acid molecules by preparing epitope-imprinted cryogel discs. These discs are intended to introduce a biomaterial with acute wound healing and antimicrobial properties to the literature. Biocompatible cryogels imprinted with gallic acid were prepared, and the goal was to impart antimicrobial properties by incorporating Tannic acid at different concentrations into the structure of the cryogels. The synthesized cryogels were characterized using FTIR, swelling tests, and SEM. Additionally, the cumulative release of Tannic acid from cryogel discs at different concentrations and their antimicrobial properties against S. aureus and E. coli were evaluated. The studies revealed that as the drug loading rate in the polymer increased, the release rate also increased. According to the power law, the exponent "n" was found to be less than 0.5, suggesting that the release mechanism in the prepared cryogel discs is non-Fickian diffusion. Keywords: Epitope-imprinted polymers, cryogel discs, tannic acid, controlled drug release systems, wound healin
Using BERT models for breast cancer diagnosis from Turkish radiology reports
No full textDiagnostic radiology is concerned with obtaining images of the internal organs using radiological imaging procedures. These images are then interpreted by a diagnostic radiologist, who produces a textual report that assists in the diagnosis of illness or injury. Early detection of certain illnesses, particularly cancer, is critical, and the reports produced by diagnostic radiologists play a key role in this process. To develop models for the early detection of cancer, text classification techniques can be applied to radiological reports. However, this process requires access to a dataset of radiology reports, which is not widely available. Currently, radiology report datasets exist for high-resource languages such as English and Dutch, but not for low-resource languages such as Turkish. This article describes the collection of a mammography report dataset for Turkish, consisting of 62 reports from real patients that were manually labeled by an expert for diagnosing breast cancer. Basic machine learning models were applied to this dataset using pre-trained BERT, DistilBERT, and an ensemble learning hard voting approach. The results showed that BERT on Turkish achieved the best performance, with a 91% F1-score. Hard Voting, which combined the results of BERTTurkish, BERTClinical, and BERTMultilingual, achieved the highest F1-score of 93%. The results show that BERT and Hard Voting outperform the other machine learning models for breast cancer diagnosis from Turkish radiology reports.Scientific Research Project Unit of Cukurova University [FDK-2016-6931]; Nazarbayev University (Kazakhstan) Faculty-development competitive research [FY2019-FGP-1-STEMM]This work was supported by Scientific Research Project Unit of Cukurova University [grant number FDK-2016-6931]; and Nazarbayev University (Kazakhstan) Faculty-development competitive research [grant number FY2019-FGP-1-STEMM
A Bibliographic Mapping Study: Concepts and Their Relationships in Information Literacy before and after COVID 19 Pandemic
No full text8th European Conference on Information Literacy (ECIL) - Experiencing Information and Information Literacy -- OCT 09-12, 2023 -- Jagiellonian Univ, Krakow, POLANDThe aim of the study was to reveal the Information Literacy (IL) concept and relationship between the concept of IL before and after the pandemic. Also, common keywords were examined. The period between 2016-11-01 and 2019-12-31 was considered as pre-pandemic, and between 2020-01-01 - 2022-11-26 as post-pandemic, in both groups. Trend analysis on the information literacy pre- and post-pandemic period was performed by VOSviewer software and in-app algorithms thereby visualizing Web of Science database on the related concept. The co-occurrence analysis of the keywords of articles conducted to reveal common concepts and the most associated concepts. After the bibliographic analysis of common keywords of the sample articles, 25 most common concepts before and after the pandemic were obtained and visualized. Some distinctive concepts before the pandemic were library instruction, collaboration, and students, while fake news, misinformation, and social media were observed in the post-pandemic period. Occurrences of the concepts in both periods were discussed within the scope of the related literature.Hacettepe Univ, Dept Informat Management,Zagreb Univ, Dept Informat & Commun Sci,Informat Literacy Asso
An improved African vultures optimization algorithm using different fitness functions for multi-level thresholding image segmentation
No full textImage segmentation is one of the most significant and required procedures in pre-processing and analyzing images. Metaheuristic optimization algorithms are used to solve a wide range of different problems because they can solve problems with different dimensions in an acceptable time and with quality results. It can show different functions in solving various problems. So, a metaheuristic algorithm should be adapted to solve the target problem with different mechanisms to find the best performance. In this paper, we have used the improved African Vultures Optimization Algorithm (AVOA) that uses the three binary thresholds (Kapur's entropy, Tsallis entropy, and Ostu's entropy) in multi-threshold image segmentation. The Quantum Rotation Gate (QRG) mechanism has increased population diversity in optimization stages, and optimal local trap escapes to improve AVOA performance. The Association Strategy (AS) mechanism is used to obtain and faster search for optimal solutions. These two mechanisms increase the diversity of production solutions in all optimization stages because the AVOA algorithm focuses on the exploration phase almost in the first half of the iterations. So, in this approach, it is possible to guarantee a wide variety of solutions and avoid falling into the local optimum trap. Standard criteria and datasets were used to evaluate the performance of the proposed algorithm and then compared with other optimization algorithms. Eight images with large dimensions have been used to evaluate the proposed algorithm so that the ability of the proposed algorithm and other compared algorithms can be accurately checked. A better solution to large-scale problems requires good performance of the algorithm in both the exploitation and exploration phases, and a balance must be created between these two phases. According to the experimental results from the proposed algorithm, it is determined that it has a good and significant performance
Damped response of porous functionally graded viscoelastic cylindrical shells
No full textIn this article, the behavior of viscoelastic porous functionally graded (FG) shells regarding the free and damped forced vibration analysis is investigated. The differential equations are derived by using higher order shear deformation theory. Using Hamilton's principle and the energy method, the equations of motion are obtained and solved using Navier's method. The damping effect is implemented into the analysis by means of Kelvin and linear standard viscoelastic models. With the correspondence principle, the transition from elastic material properties to viscoelastic material properties is achieved. First, a free vibration analysis is performed to verify the accuracy of the developed algorithm and obtained results are compared with the existing studies in the literature. Afterwards, a parametric study considering two different viscoelasticity models is performed. In the first parametric example, damped forced vibration analysis is performed for simply supported FG cylindrical shell using linear standard viscoelastic model as the viscoelastic model. Then, damped forced analysis is performed using Kelvin viscoelastic model for simply supported FG cylindrical shell. Analyses are performed in Laplace domain. The obtained results are transferred to time domain using Durbin's inverse Laplace transform method. The displacement graphs are given for the damped forced vibration examples. In the performed parametric studies, the effects of various porosity coefficients, ratios of instantaneous value, retardation times of the relaxation function and damping ratios on the analysis are investigated
Practical Evaluation and Performance Comparison of Data Driven and Model Based Control Techniques for an Electromechanical System with Uncertainties
No full textASME Design Engineering Division (DED)20th IEEE/ASME International Conference on Mechatronic, Embedded Systems and Applications, MESA 2024 -- 2 September 2024 through 4 September 2024 -- Genova -- 203262This paper addresses a design guide and real-time implementation of Linear Active Disturbance Rejection Control (LADRC) based control strategy for achieving high precision servo control performance. A number of essential concerns related to Active Disturbance Rejection Control (ADRC) implementations are experimentally investigated, such as design procedure, parameter adjustment, structural alterations, and real-time realization. The applicability of LADRC is validated for an electromechanical system comprising uncertainties and disturbances. The reduced-order approximated model of the system is obtained experimentally. The proposed controller can handle the problem in control parameter adjustment and accomplish enhanced control response. In terms of Maximum Absolute Error (MAE) which is 12.68 RPM for 1200 RPM reference and variance of control input which is 0.49 V for 4.48 V, LADRC algorithm for the electromechanical system is more suitable than Sliding Mode Control (SMC) and Proportion Integral Derivative (PID) control methodologies. The study shows that LADRC provides an efficient way of operation because it is possible to get less amount of MAE with less amount of control signal amplitude. ©2024 IEEE
Observational study of ground-level ozone and climatic factors in Craiova, Romania, based on one-year high-resolution data
No full textAir pollution is a multifaceted issue affecting people's health, environment, and biodiversity. Gaining comprehension of the interactions between natural and anthropocentric pollutant concentrations and local climate is challenging. This study aims to address the following two questions: (1) What is the influential mechanism of climatic and anthropogenic factors on the ground-level ozone (O3) concentrations in an urban environment during different seasons? (2) Can the ozone weekend effect be observed in a medium-sized city like Craiova, and under which conditions? In order to answer these questions, ozone interactions with meteorological parameters (temperature, pressure, relative humidity) and pollutant concentrations (particulate matter, carbon dioxide, volatile organic compounds, formaldehyde, nitrogen dioxide, nitric oxide and carbon monoxide) is evaluated based on a one-year dataset given by a low-cost sensor and one-year dataset provided by the National Environment Agency. Using two statistical analysis programs, Python and SPSS, a good understanding of the correlations between these variables and ozone concentration is obtained. The SPSS analysis underscores the significant impact of three meteorological factors and nine other pollutants on the ozone level. A positive correlation is noticed in the summer when sunlight is intense and photochemical reactions are elevated. The relationship between temperature and ozone concentration is strong and positive, as confirmed by Spearman's rho correlation coefficient (r = 0.880). A significant negative correlation is found between relative humidity and ozone (r = -0.590). Moreover, the analysis shows that particulate matter concentrations exhibit a significant negative correlation with ozone (r approximate to -0.542), indicating that higher particulate matter concentrations reduce ozone levels. Volatile organic compounds show a significant negative correlation with ozone (r = -0.156). A negative relationship between ozone and carbon dioxide (r = -0.343), indicates that elevated carbon dioxide levels might also suppress ozone concentrations. A significant positive correlation between nitrogen dioxide and ozone (r = 0.060), highlights the role of nitrogen dioxide in the production of ozone through photochemical reactions. However, nitric oxide shows a negative correlation with ozone (r = -0.055) due to its role in ozone formation. Carbon monoxide has no statistically significant effect on ozone concentration. To observe the differences between weekdays and weekends, T-Test was used. Even though significant differences were observed in temperature, humidity, carbon dioxide, volatile organic compounds, nitrogen dioxide, nitric oxide and carbon monoxide levels between weekdays and weekends, the T-Test did not highlight a significant weekend ozone effect in a mid-sized city as Craiova. Using Python, the daily values were calculated and compared with the limit values recommended by the World Health Organization (WHO) and European Environment Agency (EEA). The WHO O3 recommended levels were exceeded for 13 times in one year. This study offers a comprehensive understanding of ozone pollution in a mid-sized city as Craiova, serving as a valuable reference for local decision-makers. It provides critical insights into the seasonal dynamics of ozone levels, emphasizing the significant role of temperature in ozone formation and the complex interactions between various pollutants and meteorological factors.University of GavleThe authors declare that there is no funding for this article.Open access funding provided by University of Gavle
Comparative Performance Analysis of PMSGs Using Various Core Materials for Wind Turbine Application
No full textPermanent Magnet Synchronous Generator (PMSG) cores play an important role in determining the performance of wind power. Core materials of PMSGs influence magnetic flux density, minimize losses, facilitate heat dissipation, ensure mechanical stability, and balance cost considerations. The use of different core materials has a significant impact on PMSG systems efficiency and overall performance in wind generation. Therefore, this study provides a comparative performance analysis for PMSG systems using diverse core materials in wind turbine applications. The design and analysis methodology is based on ANSYS/MAXWELL simulation software. The proposed model for a wind turbine is designed with 380 V, 50 Hz, and 24 HP output power. The study investigates the performance characteristics of PMSG systems utilizing various core materials such as silicon steel, amorphous steel, and ferrite materials. During the design phase, the Finite Element Analysis (FEA) is performed to compare core materials using ANSYS Maxwell. The results demonstrate the effectiveness and accuracy of the design approach using different core materials. The results help guide the selection of the best core materials to improve the efficiency and sustainability of wind energy systems based on PMSG