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Stability regions in time delayed two-area LFC system enhanced by EVs
(TÜBİTAK / Türkiye Bilimsel ve Teknik Araştırma Kurumu / Scientific and Technical research Council of Turkey, 2022) Naveed, Ausnain; Sönmez, Şahin; Ayasun, Saffet
With the extensive usage of open communication networks, time delays have become a great concern in load frequency control (LFC) systems since such inevitable large delays weaken the controller performance and even may lead to instabilities. Electric vehicles (EVs) have a potential tool in the frequency regulation. The integration of a large number of EVs via an aggregator amplifies the adverse effects of time delays on the stability and controller design of LFC systems. This paper investigates the impacts of the EVs aggregator with communication time delay on the stability. Primarily, a graphical method characterizing stability boundary locus is implemented. The approach is based on the stability boundary locus that can be easily determined by equating the real and the imaginary parts of the characteristic equation to zero. For a given time delay, the method computes all the stabilizing proportional-integral (PI) controller gains, which constitutes a stability region in the parameter space of PI controller.The effects of communication delay and participation factor of EVs aggregator on the obtained stability regions is thoroughly examined. Results clearly illustrate that stability regions become smaller as the time delay and participation factor of EVs increase. Finally, the accuracy of region boundaries known as real root boundary and complex root boundary is confirmed by time-domain simulations along with an independent algorithm, quasipolynomial mapping-based root finder (QPmR) algorithm.
Sinovac vaccination and the course of COVID-19 disease in hospitalized patients in Turkey
(King Faisal Specialist Hospital and Research Centre, 2022) Acun Delen, Leman; Öterkuş, Mesut
BACKGROUND: The Alpha variant of SARS-CoV-2 has a higher transmission rate than the first variant identified. The efficacy of vaccines is affected by the characteristics of SARS-CoV-2 variants. OBJECTIVE: Investigate the relationship of vaccination and virus variant on the course of the disease in patients who were hospitalized with a diagnosis of COVID-19. DESIGN: Retrospective, cohort study SETTING: Tertiary health institution PATIENTS AND METHODS: The study included patients older than the age of 18 years who were hospitalized in a COVID-19 service or the intensive care unit with a diagnosis of COVID-19 between 1 January 2021 and 30 April 2021. Demographic characteristics, vaccination and the Alpha virus variant status, comorbidities, and information about hospitalization were obtained from the hospital automation system and patient files. MAIN OUTCOME MEASURES: Vaccination rate and relationship with course of disease. SAMPLE SIZE: 608 RESULTS: Most of the patients (n=482, 79.3%) were admitted to the COVID-19 service. More of the COVID-19 service patients had the Alpha variant than the patients admitted to ICU (P<.009). The Alpha variant was also more common in younger patients (P<.001). There was no relationship between the Alpha virus and comorbid diseases such as diabetes mellitus and hypertension. Mortality was lower in the patients who had received a second dose of the Sinovac vaccine (P=.004) compared with unvaccinated patients. CONCLUSION: Although the Alpha variant spreads faster, it has a milder course. If only the Sinovac vaccine is available, we recommend that the two doses of the Sinovac vaccine be administered. LIMITATIONS: Our study is single-center and did not include pregnant and pediatric patients. CONFLICT OF INTEREST: None.
Enhancement of Heat Transfer Performance of a Heat Pipe by Using Calcium Magnesium Carbonate-Ethylene Glycol/Water Nanofluid with Sodium Dodecylbenzene Sulfonate
(Budapest University of Technology and Economics, 2022) Yılmaz Aydın, Duygu; Gürü, Metin; Sözen, Adnan
In this paper, the effect of using CaMg(CO3)2/Ethylene Glycol-water (50:50%) as a working fluid on the thermal performance of thermosyphon heat pipe was experimentally studied. Nanofluid was prepared by two-step method using 2% concentration of CaMg(CO3)2 nanoparticle and 0.05% surfactant (Sodium dodecylbenzene sulfonate). For the experimental set-up, a straight copper pipe of one-meter length was used. The inner diameter of the pipe is 13 mm, and the outer diameter is 15 mm. Experiments were conducted at three different cooling water mass flow rates (5, 7.5, and 10 g/s) and different heating powers (200, 300, 400 W) to test heat pipe performance. It was observed that the CaMg(CO3)2 nanofluid reduced the average wall temperature of the heat pipe according to the base fluid. Furthermore, the efficiency and thermal resistance of the heat pipe were investigated separately for EG/water and CaMg(CO3)2 nanofluid. The maximum heat transfer enhancement was obtained as 9.55% under 400 W heating power and 10 g/s cooling water mass flow rate conditions and the maximum improvement in thermal resistance was observed as 21% at 200 W and 10 g/s cooling mass flow rate. Viscosity and specific heat of base fluid and CaMg(CO3)2 nanofluid were also determined and compared to each other.
Bakımevinde Kalan Yaşlılarda Dermatolojik Hastalıklar ve Malnütrisyon Durumunun Değerlendirilmesi: Kesitsel Bir Çalışma
(2022) Kalaycı, Bülent Nuri; Datlı Yakaryılmaz, Funda
Amaç: Yaşlı bakımevi sakinleri, yüksek dermatolojik hastalık sıklığına ve malnütrisyon oranına sahiptir. Bu çalışmada, bakımevinde kalan yaşlılarda, dermatolojik hastalıkları ve malnütrisyon durumları ile ilişkisinin belirlenmesi amaçlandı. Gereç ve Yöntemler: Bu çalışma, Malatya’da bulunan 3 farklı bakım merkezinde gerçekleştirildi. Hastaların sosyodemografik verileri, dermatolojik hastalıkları, sistemik hastalıkları ve malnütrisyon durumları belirlendi. Hastalar, nütrisyonel durumlarına göre malnütre, riskli ve normal olarak 3 gruba ayrıldı. Bulgular: Bu çalışmaya 211 kişi katıldı. Çalışmaya katılanların 139’u (%65,9) erkek, 72’si (%34,1) kadın ve hastaların yaş ortalamaları 75,8±7,2 (medyan: 75, minimum: 62, maksimum: 102) yıl idi. Katılımcıların %29,9’unda malnütrisyon, %24,2’sinde malnütrisyon riski mevcuttu. Dermatolojik hastalıklar gruplandırıldığında sırasıyla eritemli skuamlı hastalıklar %81,5, yaşa bağlı değişiklikler %75,4, benign deri lezyonları %58,3, enfeksiyöz hastalıklar %56,9, prekanseröz ve malign lezyonlar %30, inflamatuar hastalıklar %11,8 oranında mevcuttu. Yaş grup larına göre, 75 yaş ve üzeri hastalarda enfeksiyon hastalıkları istatistiksel olarak önemli derecede daha fazla izlendi (p<0,05). Dermatolojik hastalıklar ile malnutrisyon durumları karşılaştırıldığında, eritemli skuamlı hastalıklar ve enfeksiyon hastalıkları; malnütre ve riskli grupta normal gruptaki hastalardan daha fazla izlendi. Bu durum istatistiksel açıdan anlamlı bulundu (p<0,05). Sonuç: Bakımevlerinde kalan yaşlılarda dermatolojik hastalıklar sık izlenmektedir. Çeşitli faktörlerin etkisiyle meydana gelen malnütrisyon da önemli bir sorundur. Bu nedenle dermatolojik hastalıkların varlığında, hastaların nütrisyonel durumlarının araştırılması altta yatan sebeplerin belirlenmesi açısından önemlidir.
Deep learning model developed by multiparametric MRI in differential diagnosis of parotid gland tumors
(Springer, 2022) Gündüz, Emrah; Alçin, Ömer Faruk; Kızılay, Ahmet; Yıldırım, İsmail Okan
Purpose: To create a new artificial intelligence approach based on deep learning (DL) from multiparametric MRI in the differential diagnosis of common parotid tumors. Methods: Parotid tumors were classified using the InceptionResNetV2 DL model and majority voting approach with MRI images of 123 patients. The study was conducted in three stages. At stage I, the classification of the control, pleomorphic adenoma, Warthin tumor and malignant tumor (MT) groups was examined, and two approaches in which MRI sequences were given in combined and non-combined forms were established. At stage II, the classification of the benign tumor, MT and control groups was made. At stage III, patients with a tumor in the parotid gland and those with a healthy parotid gland were classified. Results: A stage I, the accuracy value for classification in the non-combined and combined approaches was 86.43% and 92.86%, respectively. This value at stage II and stage III was found respectively as 92.14% and 99.29%. Conclusions: The approach presented in this study classifies parotid tumors automatically and with high accuracy using DL models.
Levels of metals and elements in tissues of fish species in the Kızılırmak River (Turkey) and assessment of health risks and nutritional benefits
(Elsevier, 2022) Varol, Memet; Kaçar, Emel; Sünbül, Muhammet Raşit; Md Towfiqul Islam, Abu Reza
Although the Kızılırmak River, the longest river in Turkey, is home to many fish species, there are a few studies reporting metal levels in fish in the river. The contents of 17 metals and elements (MEs) in various tissues of three fish species and surface water from the river were investigated. Significant differences in the ME levels among tissues were recorded, and the highest levels of most MEs were recorded in the gills and liver. The results revealed that correlations between MEs in tissues and fish size were not clear and consistent. Among the MEs, P (6058–109489) and Zn (933–47556) had the highest bioconcentration factor values. The levels of As and Cd in the river water exceeded water quality criteria. Health risk assessment methods (Target Hazard Quotient, Estimated Daily Intake and Lifetime Carcinogenic Risk) indicated that consumption of the studied fish species is safe. It was estimated that a weekly consumption of 490 g of C. gibelio, or 350 g of C. carpio or 280 g of T. tinca would not cause any health risks. Furthermore, it was found that fish species would provide significant benefits in terms of intake of nutrients such as P, K, Ca, Mg, Cu, Zn, Fe and Mn. These findings revealed that nutritional benefits from consumption of fish species outweigh the health risks posed by metals in fish.
Inductive Power Transfer for Electric Vehicle Charging Applications: A Comprehensive Review
(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Aydın, Emrullah; Aydemir, Mehmet Timur; Aksöz, Ahmet; Hegazy, Omar
Nowadays, Wireless Power Transfer (WPT) technology is receiving more attention in the automotive sector, introducing a safe, flexible and promising alternative to the standard battery chargers. Considering these advantages, charging electric vehicle (EV) batteries using the WPT method can be an important alternative to plug-in charging systems. This paper focuses on the Inductive Power Transfer (IPT) method, which is based on the magnetic coupling of coils exchanging power from a stationary primary unit to a secondary system onboard the EV. A comprehensive review has been performed on the history of the evolution, working principles and phenomena, design considerations, control methods and health issues of IPT systems, especially those based on EV charging. In particular, the coil design, operating frequency selection, efficiency values and the preferred compensation topologies in the literature have been discussed. The published guidelines and reports that have studied the effects of WPT systems on human health are also given. In addition, suggested methods in the literature for protection from exposure are discussed. The control section gives the common charging control techniques and focuses on the constant current-constant voltage (CC-CV) approach, which is usually used for EV battery chargers.
An evaluation of the efficiency of beekeeping enterprises in Turkey: The case of Mersin City
(Ankara Üniversitesi, 2022) Uysal, Osman
Beekeeping contributes significantly to both beekeeping enterprises and the country's economy, as it provides jobs, income, and nutrition for the rural population of developing countries. Mersin City is an essential region for beekeeping, both in terms of honey production and migratory beekeeping in Turkey. In this study, the efficiency of beekeeping enterprises was revealed, and the factors causing inefficiency were examined. The efficiency measure of enterprises was determined using data envelopment analysis (DEA). According to the findings obtained, beekeeping enterprises' technical efficiency, allocation efficiency, and economic efficiency were calculated as 0.89, 0.84, and 0.81, respectively. The economic efficiency score showed that inefficient enterprises could effectively reduce their production costs by 19%. When the factors causing inefficiency are examined, it is revealed that income per hive, subsidy rate, and credit use have adverse effects on efficiency, education level, experience, number of honey frames used per hive, and migratory beekeeping effects. According to the results, it is thought that increasing education and extension activities, improving marketing opportunities, legal regulations in using agricultural credits, and extending consultancy services can also help to increase economic efficiency in the research field.
The Effects of SARS CoV-2 nsp13 Mutations on the Structure and Stability of Helicase in Chinese Isolates
(İstanbul Üniversitesi / İstanbul University, 2022) Akbulut, Ekrem
Objective: Coronavirus Disease 2019 (COVID19) is a viral disease caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2). The high mutation propensity of the SARS CoV-2 genome is one of the biggest threats to the long-term validity of treatment options. Helicases are anti-viral targets because of the vital role they play in the viral life cycle. In this study, changes in the protein structure caused by SARS CoV-2 nsp13 mutations were investigated to contribute to the development of effective antiviral drugs. Materials and Methods: Genome data of 298 individuals located in the China location were examined. The mutant model was built using deep learning algorithms. Model quality assessment was done with QMEAN. Protein stability analyses were performed with DynaMut2 and Cutoff Scanning Matrix stability. Changes in substrate affinity were performed with Haddock v2.4. Results: In this study, twenty-eight mutations in nsp13 were identified (23 sense, 5 missense). The changes in protein structure caused by the five missense mutations (Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr) were modeled. The mutations caused a decrease in the stability of SARS CoV-2 helicase (-0.99, -1.66, -1.15, -0.54, and -0.73 for Leu14Phe, Arg15Ser, Arg21Ser, Leu235Phe, Ala454Thr, respectively). The mutations reduced the helicase's affinity to the substrate. The docking scores for wild-type and mutant helicase were -84.4±1.4 kcal.mol-1 and -71.1±6.7 kcal.mol-1, respectively. Conclusion: Helicase mutations caused a decrease in the protein stability and nucleic acid affinity of the SARS CoV-2 helicase. The results provide important data on the development of potential antivirals and the effect of mutation on the functions of viral proteins.
An efficient fault classification method in solar photovoltaic modules using transfer learning and multi-scale convolutional neural network
(Elsevier, 2022) Korkmaz, Deniz; Açıkgöz, Hakan
Photovoltaic (PV) power generation is one of the remarkable energy types to provide clean and sustainable energy. Therefore, rapid fault detection and classification of PV modules can help to increase the reliability of the PV systems and reduce operating costs. In this study, an efficient PV fault detection method is proposed to classify different types of PV module anomalies using thermographic images. The proposed method is designed as a multi-scale convolutional neural network (CNN) with three branches based on the transfer learning strategy. The convolutional branches include multi-scale kernels with levels of visual perception and utilize pre-trained knowledge of the transferred network to improve the representation capability of the network. To overcome the imbalanced class distribution of the raw dataset, the oversampling technique is performed with the offline augmentation method, and the network performance is increased. In the experiments, 11 types of PV module faults such as cracking, diode, hot spot, offline module, and other classes are utilized. The average accuracy is obtained as 97.32% for fault detection and 93.51% for 11 anomaly types. The experimental results indicate that the proposed method gives higher classification accuracy and robustness in PV panel faults and outperforms the other deep learning methods and existing studies
NCA-based hybrid convolutional neural network model for classification of cervical cancer on gauss-enhanced pap-smear images
(Wiley-Blackwell, 2022) Bingöl, Harun
Cervical cancer is a very serious disease that deeply affects women's lives, often resulting in death. This type of cancer, which is very common in women, is diagnosed at an early stage and is of vital importance for the success of the treatment. Pap-smear tests are used by physicians as the primary diagnostic tool to diagnose the disease. In this study, a hybrid deep model is proposed to classify pap-smear images to detect cervical cancer. In addition, the Gaussian method was applied to improve the images in the original dataset. Feature maps were taken from both the original dataset and the Gaussian-enhanced dataset in the built hybrid architecture, which used Darknet53 and Mobilenetv2 models as the base. After these obtained feature maps were combined, useless features were extracted and the number of features was reduced by using the Neighborhood Component Analysis (NCA) dimension reduction method. Finally, this optimized feature map was classified into different classifiers. As a result of the experimental studies, it was determined that the proposed hybrid model performed better when compared to other studies in the literature and the accuracy rate was 98.90% in the Support Vector Machines (SVM) classifier.
A comparative melissopalynological study of royal jelly from Turkey
(Taylor & Francis, 2022) Yıl, Gülşah; Karlıdağ, Semiramis; Akyol, Abuzer; Köseman, Abdurrahman; Uyumlu, Ayşe Burçin; Yılmaztekin, Murat; Erdoğan, Selim; Şeker, İbrahim
Three treatments (Glucose, Sucrose, Bee Feed Syrup) were used to examine the influence of supplementary feeding on the pollen spectrum of the royal jelly produced by Apis mellifera L. colonies. Apis mellifera colonies were located in the Battalgazi and Dogansehir districts of Malatya province in Turkey. In total 255 royal jelly samples were investigated and the analysis recorded over 30 taxa. In both sites the control group heavily utilised Quercus, Verbascum, Astragalus, and Lamiaceae. The feeding treatments saw Quercus, Verbascum, and Astragalus still being used but in different proportions. The utilisation of Lamiaceae was much reduced and Echium became an important component in colonies that had supplementary feeding. © 2022 Collegium Palynologicum Scandinavicum.
Evaluation of the relationship between nasal septal deviation and development of facial asymmetry with anthropometric measurements depending on age: The effect of nasal septum deviation on craniofacial asymmetry and somatotype
(Elsevier, 2022) Arpacı, Muhammed Furkan; Özbağ, Davut; Aydın, Şükrü; Şenol, Deniz; Baykara, Rabia Aydoğan; Çiçek, İpek Balıkçı
Aim: It was aimed to determine the change of facial asymmetry resulting from nasal septal deviation (SD) depending on age, gender, degree of deviation and the affected area besides the effect of SD on somatotype and craniofacial morphology. Materials and methods: 171 volunteers (90 males, 81 females), 27 individuals aged 9–13, 44 individuals aged 14–18, 44 individuals aged 19–23 and 56 individuals in control group participated in the study conducted in otorhinolaryngology polyclinic.11 photometric, 16 anthropometric measurements were taken from the participants. Results: SD affects facial asymmetry formation, although not statistically significant compared to healthy individuals asymmetry rates (p?0.05). It was determined that the degree of SD affected asymmetry only between the ages of 14–18 (in adolescence) and the development of asymmetry in all SD patients was not statistically dependent on age and gender (p?0.05). Photometric measurements demonstrated asymmetries in horizontally-extending parameters of 1/3 middle part of face. There was no statistically significant difference in the cranial anthropometric measurements of the upper and lower 1/3 of the face compared to the control group (p?0.05). The order of the most asymmetrical parameters is Alare-Zygion, Alare-Subnasale, Cheilion-Gonion, Exocanthion-Cheilion, Midsagittal plane-Zygion, Zygion-Cheilion, Zygion-Gonion, Subalare-Cheilion, Glabella-Exocanthion. In all participants were determined that endomorph somatotype was dominant in female and mesomorph somatotype was dominant in male besides SD did not affect somatotype and somatotype did not alter with age. Conclusion: The development of facial asymmetry due to SD is not affected by age and gender furthermore SD does not affect craniofacial asymmetry and somatotype.
Invariant convergent and invariant ideal convergent sequence in intuitionistic fuzzy normed space
(IOS Press, 2022) Khan, Vakeel A.; Ali Khan, Izhar; Esi, Ayhan; Alam, Masood
The main purpose of this paper is to introduce invariant convergence in intuitionistic fuzzy normed space. Following which we present some characteristics of this notion with respect to intuitionistic fuzzy norm. We also define strongly invariant convergence, ideal invariant convergence and invariant ideal convergence in intuitionistic fuzzy normed space. After that, we establish the relationship between these notions with respect to intuitionistic fuzzy norm. Lastly, we define ideal invariant Cauchy and invariant ideal Cauchy criteria for sequences in intuitionistic fuzzy normed space and relate it to their convergence notion.
Clinical and Molecular Findings in a Turkish Family Who Had a (c.869-1G>A) Splicing Variant in PSEN1 Gene with A Rare Condition: The Variant Alzheimer's Disease with Spastic Paraparesis
(Bentham Science, 2022) Doğan, Mustafa; Eröz, Recep; Tecellioğlu, Mehmet; Gezdirici, Alper; Çevik, Betül; Barış, İbrahim
Background: Early-onset Alzheimer's disease (EOAD) is commonly diagnosed with an onset age of earlier than 65 years and accounts for 5–10% of all Alzheimer's disease (AD) cases. To date, although only 10-15% of familial EOAD cases have been explained, the genetic cause of the vast proportion of cases has not been explained. The variant Alzheimer's disease with spastic paraparesis (var- AD) is defined as a rare clinical entity characterized by early-onset dementia, spasticity of the lower extremities, and gait disturbance. Although the disease was first associated with variants in exon 9 of the PSEN1 gene, it was later shown that variations in other exons were also responsible for the disease. Objective: The current study aims to raise awareness of varAD, which occurs as a rare phenotype due to pathogenic variants in PSEN1. In addition, we aimed to evaluate the spectrum of mutations in varAD patients identified to date. Methods: Detailed family histories and clinical data were recorded. Whole exome sequencing was performed and co-segregation analysis of the family was done by Sanger sequencing. Also, a review of the molecularly confirmed patients with (varAD) from the literature was evaluated. Results: We identified a heterozygous splicing variant (c.869-1G>A) in the PSEN1 gene, in a family with two affected individuals who present with varAD. We reported the clinical and genetic findings from the affected individuals. Conclusion: We present the detailed clinical and genetic profiles of a Turkish patient with the diagnosis of varAD together with subjects from the literature. Together, we think that the clinical characteristics and the effect of the (c.869-1G>A) variant will facilitate our understanding of the PSEN1 gene in AD pathogenesis.
Preparation of 10-undecenoic acid based polyurethane/PCL fibers by electrospinning method and investigation of their antifungal properties
(Springer, 2022) Açarı Karaca, İdil; Boran, Filiz; Kolak, Seda; Tatlıcı, Eray; Yeşilada, Özfer; Köytepe, Süleyman; Ateş, Burhan
Nowadays, in the treatment of such fungal infections, antifungal drugs in various forms are one of the most preferred methods. These medications can be in the form of creams and lotions, shampoos, pills, suppositories, powders, or sprays. The dose of the drugs is adjusted according to the type and growth area of the fungus, the severity of the symptoms, and the medical history of the patients. Dressing materials with antifungal properties are an alternative treatment method used for the treatment of fungal skin infections. These covers not only treat fungal infections but also prevent their spread. Within the scope of this study, polyurethane-based wound dressing materials (PU-UDA/PCL) with antifungal properties were developed. Electrospining method was used to produce these dressing materials and the surface area of the wound dressing material was increased, thereby increasing the effect of antifungal property. Polypropylene glycol, glycerol, and catechin as polyol were preferred in polyurethane (PU) synthesis. These structures were polymerized with isophorone diisocyanate and modified with 10-undecenoic acid. Obtained 10-undecenoic acid modified polyurethane (PU-UDA) structures were transformed into wound dressing structure with polycaprolactone (PCL) by electrospinning method. Structural, morphological, and thermal properties of the wound dressing materials were analyzed with different instrumental analysis methods. The antifungal activities of PU-UDA/PCL were tested. Antifungal tests were performed on C. albicans and C. tropicalis. Therefore, PU-UDA/PCL series could be used as an efficient antifungal agent. Finally, it was determined that the obtained 10-undecenoic acid-based polyurethane fibers have a suitable structure and feature for the treatment of many fungal infections.
Synthesis and analysis of TiO2 nanotubes by electrochemical anodization and machine learning method for hydrogen sensors
(Elsevier, 2022) Işık, Eşme; Taşyürek, Lütfi Bilal; Işık, İbrahim; Kılınç, Necmettin
The conductometric hydrogen gas sensors were used to explore TiO2 nanotubes in this study. TiO2 nanotubes are synthesized by anodization of the titanium foils using a neutral 0.5% and 1% (wt) NH4F in glycerol solution depending on anodization time and anodization voltage at the temperature of 20 °C. The amorphous, rutile and anatase phases of TiO2 are observed for as-prepared TiO2 nanotubes, annealed at 700 and 300 °C, respectively. The diameters of the nanotubes grow as the anodization time and voltage increase, according to scanning electron microscopy (SEM) images. The inner diameter of nanotubes is changed between ~70 nm to ~225 nm. Hydrogen sensing properties of Ti/TiO2 nanotubes/Pd device has been tested at room temperature under concertation range from 0.5% to 10% depending on the crystalline phase. The highest sensor response is observed for anatase crystalline TiO2 nanotubes. Typical Schottky-type behavior is observed from the I-V measurement. All the fabricated nanotube diameters are also simulated by using Support Vector Machine and Artificial Neural Network models. And also, some of the nanotube diameters which are not obtained experimentally (anodization voltage of 70 V) are estimated using the Support Vector Machine and Artificial Neural Network models. In addition, an analytical model is also proposed using Jacobi numeric analysis method alternative to the simulation model for the nanotube diameter. Finally, the analytical, simulation, and experimental results are compared, and the best result is obtained using the 1 Hidden Layer Artificial Neural Network model.
Experimental characterization and theoretical investigation of Zn/Sm co-doped hydroxyapatites
(Elsevier, 2022) Hssain, Ala Hamd; Bulut, Niyazi; Ateş, Tankut; Köytepe, Süleyman; Kuruçay, Ali; Kebiroğlu, Hanifi; Kaygılı, Ömer
In this study, the wet chemical method was used to synthesize Zn-doped hydroxyapatite (HAp) samples, and the effects of varying the amount of Sm addition on structural, thermal, and biocompatibility in vitro properties were studied. In addition, a density functional theory was used for modeling the as-synthesized samples to obtain the theoretical calculation results. XRD results confirmed the formation of biphasic compositions for all samples, and FTIR data supported the formation of the functional groups of hydroxyl and phosphate. More than 98% of samples showed the formation of the HAp phase. The addition of Sm resulted in an increase in the secondary phase of the ?-TCP from 0.60% to 1.49%. The lattice parameters (aandc),unit cell volume (V), lattice strain(?), and lattice stress? varied when Sm was added as a dopant. The crystallite size and crystallinity decreased as the Sm content increased, however, the anisotropic energy density gradually increased. Thermal analysis results confirmed that all samples seemed to be thermally stable. The addition of Sm did not result in any notable morphological modifications. Cell viability values of theZn-based HAp sharply decreased as a result of an increase in the Sm additive. Theoretical studies show that when the amount of Sm in the Zn-based HAp structure increases, the bandgap energy decreases from 4.68 to 4.40eV. An increasing density and decreasing unit cell volume have been observed, as confirmed by the theoretical results. In addition, there was a decrease in crystallinity as well as an increase in anisotropic energy density.
Cyberchondria, Covid-19 phobia, and well-being: a relational study on teachers
(Mattioli1885, 2022) Karakaş, Neşe; Tekin, Çiğdem; Bentli, Recep; Demir, Ekrem
Background: This study aims at investigating level and contributor factors of Cyberchondria, COVID-19-related Phobia, and Well-Being in a sample of teachers in Turkey. Methods: The study was conducted on teachers (n=1000) working in a province in eastern Turkey. Data for the study were collected using a form that included particitest, and Kruskal Wallis analysis of variance were used to analyze the data. Results: As participant's cyberchondria levels rose, C19P-SE scores increased (r=0.271, p<0.001), and WHO-5 scores decreased (r=-0.224, p<0.05). Corona-phobia was higher in those who used social media than in those who did not (p<0.05). Cyberchondria scale scores were higher among those who had taken medications without a physician's recommendation during the pandemic. Participants who had a disabled person or a person in need of care in their household had higher scores for distrust of the physician and C19P-SE than for the cyberchondria severity scale sub-dimension, and the WHO-5 mean scores were lower (p<0.001, P=0.016, and P=0.020, respectively).Conclusions: The study results show that increasing levels of cyberchondria trigger COVID-19 phobias in teachers during the COVID-19 pandemic and negatively affect their well-being. This descriptive study can help understand the risk group for cyberchondria, the influencing factors, and the health and economic consequences, and identify strategies for effective combating with cyberchondria.
Determination of tensile strength of cementitious composites using fracture parameters of two-parameter model for concrete fracture
(Elsevier, 2022) İnce, Ragıp; Fenerli, Cenk
In this study, the formulation of the two-parameter model based on the size effect proposed by previous researchers was initially improved to be much more practical. Subsequently, six series of notched and unnotched beams with a size ratio of 1:4 and notched and unnotched square prismatic specimens with a size ratio of 1:6 were tested to verify this modified formulation. The peak loads obtained from the fracture tests of the notched specimens were examined using the two-parameter model. Then, the test results of the unnotched bending and splitting specimens were simulated according to the modified formulation. Furthermore, this formulation was applied to extensive test data obtained from the direct tension specimens with double edge notches and from the unnotched specimens in the literature to derive the direct tensile strength of concrete. Finally, when comparing the results of this study to the previous studies, there were slight differences among the other formulas, except for the one that covered splitting specimens.

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