Gümüşhane ÜniversitesiGümüşhane ÜniversitesiAçık Erişim Arşivi · RDL Open

Sürdürülebilir Kalkınma Amaçları

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Yeniden eskiyeEskiden yeniye
  • MakaleYalnız künye2023
    Increased heat tolerance and transcriptome analysis of Salmonella enterica Enteritidis PT 30 heat-shocked at 42 ℃

    Qiu, Yan; Ozturk, Samet; Cui, Xinyao; Qin, Wen; Wu, Qingping; Liu, Shuxiang

    In this study, we compared the heat tolerance parameter (D65℃) values of Salmonella enterica serovar Enteritidis PT 30 (S. Enteritidis ) heat adapted at different degrees (at 42 ℃ for 20–180 min) and cultivated using two methods. The treated group with the highest D65℃ value (LP-42 ℃-60 min) and the untreated groups (Control-TSB and Control-TSA) were subjected to transcriptome analysis. Heat-adaptation increased the D65℃ values of S. Enteritidis by 24.5–60.8%. The D65℃ values of the LP-42 ℃-60 min group (1.85 ± 0.13 min, 7.7% higher) was comparable to that of the Control-TSA. A total of 483 up- and 443 downregulated genes of S. enteritidis were identified in the LP-42 ℃-60 min group (log2fold change > 1, adjusted p-value < 0.05). Among these genes, 5 co-expressed and 15 differentially expressed genes in the LP-42 ℃-60 min and Control-TSA grops possibly contributed to the high D65℃ values of S. Enteritidis. The Rpo regulon was involved in the heat adaptation of S. Enteritidis, as evidenced by the significant upregulation of rpoS, rpoN, and rpoE. KEGG enrichment pathways, such as biosynthesis of secondary metabolites, tricarboxylic acid, and ribosomes were identified and mapped to reveal the molecular mechanisms of S. enteritidis during heat adaptation. This study quantified the enhanced heat tolerance of S. Enteritidis heat adapted at different degrees of heat-adaptation. The results of this study may serve as a basis for elucidating the molecular mechanisms underlying the enhanced heat tolerance at the transcriptome level.

    • SDG 2 · Açlığa Son
    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleAçık Erişim2023
    On the solution of random linear difference equations with Laplace transform method

    Şişman, Şeyma; Merdan, Mehmet

    In this study, Laplace transformation, which is very important for solutions to initial value problems, is examined. To solve the initial value problem of a discrete-time equation, Laplace implements the conversion method. Here, Laplace transformation is used to obtain an approach to the solutions of random difference equations formed by randomizing components of deterministic difference equations. For random behavior of linear difference equations under random effects, uniform, geometric, binomial, Poisson, and Bernouilli distributions are used, and approximate expected value, variance, standard deviation, and confidence interval of equations obtained by Laplace transformation are calculated. The results were obtained through the Maple package program.

    İncele
  • MakaleAçık Erişim2023
    Adsorptive removal of Cr(VI) and Cu(II) ions from aqueous solutions by a natural moss

    Ozeken, Sengul Tugba; Ozdes, Duygu; Duran, Celal

    The aim of the present research is to develop a new, fast, and easily applicable adsorption method for the removal of hazardous Cr(VI) and Cu(II) ions from the polluted industrial wastewater by using Racomitrium ericoides (Brid.) Brid. (REB), a type of moss. Although there are studies in the literature in which different moss species were used for the removal of heavy metals (HMs), REB was used for the first time in this study. Adsorption experiments were carried out through a batch system. The impact of significant experimental parameters showed that the optimum values of initial pH were 2.0 for Cr(VI) retention and 5.0 for Cu(II), and 360 min was selected as the optimum contact time for both HMs. An artificial neural network (ANN) model was applied to create a predictive model for the uptake efficiency of HMs. Adsorption kinetics of Cr(VI) and Cu(II) ions followed the pseudo-second order model. The maximum adsorption capacities of REB identified through the Langmuir model were 41.2 mg g-1 for Cr(VI) and 22.7 mg g-1 for Cu(II) ions. The results of the study demonstrated that REB can be utilized as an abundant, low-cost, and effective adsorbent in removal of HMs from aqueous solutions.

    İncele
  • MakaleAçık Erişim2023
    Geographic information system approach in evaluating the geotechnical properties of soils: A case study of Oymaağaç in Kayseri; [Zeminlerin geoteknik özelliklerinin değerlendirilmesinde coğrafi bilgi sistemi yaklaşımı: Kayseri Oymaağaç örneği]

    Acar, Mehmet Cemal; Kaya, Dilek

    Kayseri, the ninth biggest city in Turkey, the regions opened to the ongoing construction of residential areas are expanding rapidly parallel to population growth. Soil improvement works are carried out in areas with the poor bearing capacity of foundations and in regions that are not suitable for safe construction. This event causes severe economic losses in urban development. This study proposes a (Geographic Information System) GIS-based approach to comprehensively understand the research area's underground conditions, predetermine the zones opened for construction by considering the parameters affecting the foundation of the buildings, and create an informative geotechnical model with visualization technology. For an exemplary application, a database was created with ArcGIS in the Kayseri Oymaağaç location, and geological and geotechnical data were combined. The soil properties of this one million five hundred thousand square meter area opened for new settlement were analyzed in a GIS environment. The variation of SPT-N values measured in 60 boreholes in the field with depth, soil types, groundwater levels, and Vs data were used to combine the data, and related maps were drawn. Then, maps of the liquefaction of the soil in a possible earthquake and visual maps showing the bearing capacity of the foundations were created. This study will offer the best and most reliable land-use scenarios and in situ soil properties to decision-makers such as engineers, government agencies and disaster management. It will contribute to making accurate and fast decisions in urban planning. In addition, it will also be able to use as a tool for risk management in emergencies.

    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    İncele
  • MakaleYalnız künye2023
    ON SOLUTION OF BG-VOLTERRA INTEGRAL EQUATIONS

    Güngör, N.

    In this study, we center upon obtaining the solution of linear bigeometric Volterra integral equations of the second kind in the sense of bigeometric calculus. The method of successive substitutions and resolvent kernel method are applied for solving the linear bigeometric Volterra integral equations of the second kind by using the concept of bigeometric integral. The necessary conditions for the bigeometric continuity and the uniqueness of the solution of linear bigeometric Volterra integral equations of the second kind are given in these methods. Finally, some numerical examples are presented to explain the procedure of the method of successive substitutions and resolvent kernel method

    İncele
  • MakaleAçık Erişim2023
    Predicting and Mapping Dominant Height of Oriental Beech Stands Using Environmental Variables in Sinop, Northern Turkey

    Yener, Ismet; Guvendi, Engin

    The dominant height of forest stands (SDH) is an essential indicator of site productivity in operational forest management. It refers to the capacity of a particular site to support stand growth. Sites with taller dominant trees are typically more productive and may be more suitable for certain management practices. The present study investigated the relationship between the dominant height of oriental beech stands and numerous environmental variables, including physiographic, climatic, and edaphic attributes. We developed models and generated maps of SDH using multilinear regression (MLR) and regression tree (RT) techniques based on environmental variables. With this aim, the total height, diameter at breast height, and age of sample trees were measured on 222 sample plots. Additionally, topsoil samples (0–20 cm) were collected from each plot to analyze the physical and chemical soil properties. The statistical results showed that latitude, elevation, mean annual maximum temperature, and several soil attributes (i.e., bulk density, field capacity, organic carbon, and pH) were significantly correlated with the SDH. The RT model outperformed the MLR model, explaining 57% of the variation in the SDH with an RMSE of 2.37 m. The maps generated by both models clearly indicated an increasing trend in the SDH from north to south, suggesting that elevation above sea level is a driving factor shaping forest canopy height. The assessments, models, and maps provided by this study can be used by forest planners and land managers, as there is no reliable data on site productivity in the studied region.

    İncele
  • MakaleYalnız künye2023
    Behaviors of a group of university students during an earthquake drill and their compliance with the emergency disaster plan: An action research

    Parlak, Lütfiye; Kaya, Nahsan; Duru, Pınar; Örsal, Özlem

    Approximately 60% of the casualties due to disasters occur due to earthquakes. This study aimed to discover and develop the strengths and weaknesses of a group of university students during a possible earthquake, their behavior towards evacuation and assembly areas, and their adaptation to the emergency disaster plan. The research was carried out between May–June 2022 as “liberating/developing/critical action research,” a subtype of action research, one of the qualitative research methods. Thirty-five students participated in the first drill, and 31 participated in the second. The study data were collected through “observations” made with the installed cameras and “focus group interviews” with the students through semi-structured interview forms. An average of 3.25 behaviors expected to be observed were displayed as expected by the students during the first drill. The average of the behaviors displayed during the second drill increased to 5.18. As a result of the synthesis of the qualitative data obtained from the focus group interviews, it was seen that two main themes were formed: “Drill management” and “Disaster experience.” The main theme of drill management was “Drill moment,” “Evacuation moment,” and “Drill experience” analytical themes. In contrast, the main theme of disaster experience was “Disaster cycle,” “Disaster perception,” “Disaster awareness,” and “Earthquake experience.” After the second drill, it was evaluated that the problems identified in the first were eliminated. The students' adaptation to the emergency disaster plan increased by re-applying to the observation and focus group interviews.

    • SDG 4 · Nitelikli Eğitim
    İncele
  • MakaleAçık Erişim2023
    3D data integration for geo-located cave mapping based on unmanned aerial vehicle and terrestrial laser scanner data

    Çömert, Resul; Özdemir, Samed; Bilgilioglu, Burhan Baha; Alemdag, Selçuk; Zeybek, Halil Ibrahim

    The Akçakale cave is a significant natural and cultural heritage site in the Black Sea region of eastern Turkey. The complex geometry and difficult-to-access areas of the cave have made the use of traditional mapping methods challenging. To overcome these limitations, this study utilized TLS and UAV technology to produce highly accurate 2D and 3D data for cave management and risk assessment purposes. The TLS system was used to create a detailed 3D point cloud of the cave interior, while the UAV system generated a 3D model of the surface topography outside the cave. The two sets of data were combined in the GIS environment using a geodetic network established in the study area, providing a common geodetic reference system for both TLS and UAV data. The study found that the cave area is 13,750 m2, which is smaller than the area of 18,000 m2 that was previously estimated using conventional measurement methods. The volume and ceiling heights of the cave were calculated using the elevation models generated from TLS point cloud data. The 3D point cloud data were also used to map dripstone locations on the floor and ceiling of the cave, and the boundaries of rock blocks on the ground were precisely determined. The study identified potential risks associated with the cave, particularly the risk of rockfall in the source rock areas around the cave entrance and the southern part of the cave. The nearest building to the cave is approximately 35 meters away, and all the buildings in the area are less than 300 meters from the cave. In the event of the cave collapse, the buildings in the southern part of the cave are at risk of rockfall. This study demonstrates the effectiveness of combining data from TLS and UAV systems to generate broad and sensitive cave mapping and risk assessment data, which are critical for cave management and safety. The collected data can be used for cave stability investigations and rockfall risk assessments. This study provides a foundation for future explorations of the Akcakale cave and highlights the potential for modern surveying techniques to enhance our understanding of complex geological structures such as caves.

    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    İncele
  • MakaleAçık Erişim2023
    Detection of COVID-19 infection from CT images using the medical photogrammetry technique

    Çatal Reis, Hatice; Türk, Veysel; Kaya, Serhat

    Medical data such as computed tomography (CT), magnetic resonance imaging (MRI), and Ultrasound images are used in medical photogrammetry. CT images have been used frequently in recent years for the diagnosis of COVID-19 disease, which has contagious and fatal symptoms. CT is an effective method for early detection of lung anomalies due to COVID-19 infection. Machine learning (ML) techniques can be used to detect and diagnose medical diseases. In particular, classification methods are applied for disease diagnosis and diagnosis. This study proposes traditional machine learning algorithms Random Forest, Logistic Regression, K-Nearest Neighbor and Naive Bayes, and an ensemble learning model to detect COVID-19 anomalies using CT images. According to the experimental findings, the proposed ensemble learning model produced an accuracy of 96.71%. This study can help identify the fastest and most accurate algorithm that predicts CT images with Covid-19 during the epidemic process. In addition, machine learning-based approaches can support healthcare professionals and radiologists in the diagnostic phase.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleAçık Erişim2023
    The effects of environmental value and ecological worldview on eco-recreative attitude: an application in Turkey; [O efeito do valor ambiental e visão de mundo ecológica na atitude eco-recreativa: um estudo na Turquia]

    Kement, Üzeyir; Çavuşoğlu, Sinan; Çalık, Ismail; Durmaz, Yakup

    This study aims to investigate the effects of environmental value and ecological worldview on eco-recreative attitudes. In recent years, human-related pollution has seriously increased. Therefore, it is critical to explain the eco-recreative attitudes of participants with an emphasis on how these attitudes support natural life. Another indicator of the significance of this study is that it explains the premises of the attitude. Environmental value in the proposed model was examined as three sub-factors: biospheric, altruistic, and egoistic. Also, an eco-recreative attitude has three sub-factors, which are affective, cognitive and behavioural. The study population consisted of individuals who participated in eco-recreation activities in Turkey. The data were collected through a questionnaire form using the convenience sampling method. The analyses were conducted using SmartPLS. The findings showed that biospheric (positive) and egoistic value (negative) had an effect on ecological worldview, while ecological worldview had a positive effect on affective, cognitive and behavioural attitude. Also, the altruistic value did not significantly affect the ecological worldview.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    İncele
  • MakaleAçık Erişim2023
    The Distinguishing Factor in Soccer Players is Aerobic Performance, not the ACTN3 Gene; [El Factor Distintivo en los Jugadores de Fútbol es el Rendimiento Aeróbico y no el gen ACTN3]

    Zileli, Raif; Söyler, Mehmet; Diker, Gürkan; Özkamçı, Hüseyin; Bayrakdaroglu, Serdar; Sever, Mehmet Onur; Can, Ibrahim; Ön, Sadi; Aslan, Beste Tacal; Ulucan, Korkut

    SUMMARY: The purpose of this study was to reveal the differences between ACTN3 genotype (RR, RX, XX) and aerobic performance [Yo-Yo IRT1 (m), VO2 max (ml/kg/min)] in professional and regional amateur league soccer players and to reveal which of these parameters was a distinctive factor in these athletes.71 professional soccer players (age: 23.66 ±4.11 years; body height: 1.79 ± 6.99 m; body weight: 76.02 ± 6.76 kg; body fat: 11.59±3.11 %) and 62 regional amateur soccer players (age: 23.63 ±3.77 years; body height: 1.81 ± 5.77 m; body weight: 76.36 ± 7.53 kg; body fat: 15.60±4.65 %) volunteered for the study. After DNA extraction from buccal epithelial cells via a commercial kit was performed for the genetic background of the athletes, Real-Time PCR was carried out for genotyping. Furthermore, Yo-Yo IRT1 test was performed to determine the aerobic performance of the soccer players. SPSS 23 (SPSS Inc., Chicago, IL, USA) package program was used for the statistical analysis of the data obtained in the tests. Shapiro-Wilk test for normality and Levene's test for homogeneity of variance were performed. Chi-Square, Independent Sample T Test and One Way ANOVA test were used in the analysis of the parameters. Statistical significance was set as p<0.05. In the study, there found no meaningful statistical significance in terms of the rs1815739 polymorphism in the ACTN3 gene between the groups (p>0.05); however, there was a statistical significance in favor of professional soccer players in terms of aerobic parameters (p<0.05). Consequently, it can be said that aerobic performance is the distinguishing factor, not the ACTN3 gene, in soccer players.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • BildiriYalnız künye2023
    Pedestrian Inertial Navigation with Multi-Head CNN

    Cetin, Gokhan; Kucuk, Mehmet Ali; Koroglu, Muhammed Taha

    Traditional pedestrian dead-reckoning (DR) methods utilizing inertial measurement units (IMU) have been successfully employed in GPS-denied environments over the past two decades. However, despite continuous advancements in wearable IMU technology, the long-term solution still suffers from the issue of drift. In light of this, Deep Learning (DL) has emerged as a potential candidate for inertial navigation solutions, leveraging its powerful non-linear regression capabilities. Recent research has demonstrated that DL models trained on public datasets can effectively serve as end-to-end solutions. Most studies focus on smartphones, where the IMU is typically situated at the torso, and generally work with transformed data represented in the navigation coordinate frame to estimate pedestrian velocity and heading change at rates lower than the IMU sampling rate. In contrast, this study uses raw foot-mounted IMU data as input to a multi-headed structure consisting of independent convolutional neural networks (CNNs) and targets displacement directly and heading change. The proposed model is trained on a publicly available foot-mounted IMU dataset where pseudo ground-truth (GT) data is generated heuristically to provide supervision for the learning process. The results indicate that the Multi-Head CNN (MHCNN) model is capable of producing pedestrian trajectories at the IMU sampling rate, with positioning errors of less than 2m throughout the duration of the walks. The code for the trained network can be accessed in the associated repository, i.e., github.com/mtkoroglu/PIN-MHCNN.

    İncele
  • MakaleAçık Erişim2023
    Engineering Properties of Cemented Paste Backfill with Full-Range Water-Reducing Admixture

    Cavusoglu, Ibrahim; Fall, Mamadou

    This paper presents the effects of a full-range water-reducing (FRWR) admixture on the key engineering properties of cemented paste backfill (CPB). CPB samples with a certain slump are prepared with 4.5% cement by mass of the tailings and different dosages of an FRWR admixture (superplasticizer contents of 1%, 3%, and 5%) to evaluate their water demand during hydration, rheological properties, self-desiccation ability, and microstructural and mechanical properties. Moreover, cement paste samples with a high water-to-cement ratio (w/c = 2) which are used to model the cement matrix of the CPB are prepared for x-ray diffraction (XRD) scanning and thermal analyses (TAns). The results show that the addition of an FRWR admixture to the studied CPB can reduce its water demand by up to 23% and significantly increase its strength from 1.0 MPa to 2.38 MPa (by approximately 2.4 times) at 28 days. The pore volume of the CPB samples is also significantly reduced from 27.17 to 18.27% due to the capability of the FRWR admixture to reduce water demand. Also, the addition of an FRWR admixture to the CPB results in a substantial decrease (up to 83%) of its yield stress, thereby improving its flowability. The CPB samples with an FRWR admixture are found to have a higher negative pore water pressure, i.e., higher self-desiccation, than the CPB sample without an FRWR admixture. The microstructural analysis also shows that the FRWR admixture has an increasing effect on the hydration products in the CPB mixture.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    İncele
  • MakaleAçık Erişim2023
    A study on the magnetite skarn mineralization (Gümüşhane, Türkiye): a magnetic survey

    Sipahi, Ferkan; Sadiklar, M. Burhan; Gücer, Mehmet Ali; Aydin, Ali; Kara, Rasim Taylan

    Iron (Fe)-skarn mineralizations (Çambaşı, Dereli, Eğrikar, Karadağ, Kopuz, Sekü, Donguldere, Arnastal, Özdil, Ögene, İkizdere, Ovit Dağı, Kartiba, etc.) in the eastern part of the Pontides (NE Türkiye) are accommodated in the Pontide paleomagmatic arc and the eastern part of the Pontides Metallogenic Belt containing numerous various deposits. Fe-skarn mineralization around the Arnastal Plateau (Gümüşhane-Türkiye) is fragmentary in this area, which is covered with plants (grasses, flowers, etc.). Thus, it was attempted to describe the subsurface structures and Fe mineralization using an interpretation of the available geological and existing magnetic data in this area. Granitoid and volcano-sedimentary series (Upper Cretaceous) outcrop in the study area. These volcanosedimentary series consist of limestone, sandy limestone, marl, andesite, quartz andesite, basalt, and their equivalent pyroclastics. They include a thin layer of the red limestone (Upper Cretaceous) and olistolith recrystallized limestones (Jurassic-Lower Cretaceous). Zigana granitoid, intruding into all of these rocks, is high-K calc-alkaline and metaluminous and is classified as quartz monzonite, monzogranite, granite, and syenogranite as a result of its modal composition. Contact pyrometasomatic mineralization occurs in between the limestone and granitoids in the Arnastal Plateau. In addition to petrographic and mineralogical studies, magnetic methods were applied to an area of approximately 10 km2 to find any covered Fe deposits. Magnetic susceptibility values measured on the outcropped rocks ranged from 1 to 34 (10–7 SI) for limestone, 78 to 3750 (10–7 SI) for basalt, and 105 to 3946 (10–7 SI) for granitoids. It is considered that these ranges express the alteration (physical or chemical) of the rocks, their homogeneity, and the lack or presence of Fe minerals. The magnetic survey was conducted along a study area measuring 12,075 m long with 25 and/or 50 m station spacing. Processing of the magnetic data revealed the presence of eight buried Fe ores that could represent either massive or disseminated mineralization between the Sarıtaş and Kurtdere plateaus. Magnetite ore bodies may be present from the surface to a depth of approximately 15–25 m inside the limestone. In addition to the identification of new magnetite ore mineralization or bodies, a new geological map was designed by determining probable formation boundaries with this magnetic survey.

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  • MakaleYayıncıda açık erişim2023
    The E-Learning Attitude of Talented Pre-service Teachers in the Online Learning Model Following the Kahramanmaraş and Hatay Earthquakes

    Türker, Üstün; Somoǧlu, Mustafa Bariş; Tezcan, Efecan; Koç, Mine

    This study, which aims to determine the e-learning attitudes of talented teacher candidates following the earthquakes in Kahramanmaraş and Hatay and to compare them according to some variables, was designed with a cross-sectional-survey model, one of the quantitative research methods. The research sample was comprised of 826 pre-service teachers from the fields of Physical Education and Sports, Music Education, and Visual Arts during the spring semester of 2022-2023. Data for the study were collected using the Test of E-Learning Related Attitudes Scale, with data collection conducted through Google Forms. Data analysis was used to SPSS program. In terms of the academic department variable, it was concluded that pre-service teachers specializing in Physical Education and Sports, Music Education, and Visual Arts demonstrated similar levels of E-learning attitudes, and no statistically significant differences were observed among them (p<0.05). Furthermore, in the context of education and instructional activities being carried out through online learning methods, it was determined that the choice of and utilization of computers and mobile devices as learning tools resulted in similar overall E-learning attitudes (p<0.05). Nevertheless, those who favored mobile devices demonstrated a statistically higher level of inclination toward technology use and perceived usefulness, while those who used computers reported statistically higher levels of satisfaction and motivation in their E-learning attitudes (p<0.05). According to the research results, it was observed that the E-learning attitudes of pre-service teachers following the Kahramanmaraş and Hatay earthquakes were at a moderate level, with satisfaction in online learning registering as the least favorable aspect of E-learning attitude.

    • SDG 4 · Nitelikli Eğitim
    İncele
  • MakaleAçık Erişim2023
    The Effect of Role Uncertainty of Students in University Team Sports on Team Combination

    Somoğlu, Mustafa Barış; Tezcan, Efecan; Albayrak, Ahmet Yılmaz; Türkmen, Muhammet Uhud

    The primary objective of this research is to assess the level of team cohesiveness and role ambiguity among students who participate in university team sports, and examine them based on pre-determined variables. The selection of participants was conducted through a convenient sampling approach. The study employed the cross-sectional scanning method and comprised a sample of 238 participants, consisting of 88 females (37%) and 150 males (63%), who are engaged in team sports at Gümüşhane University during the 2022-2023 academic year. A Personal Information Form, Team Cohesion Scale and Role Ambiguity Scale were utilised to gather data in this study. Data was then analysed using T-tests, ANAVO and correlation tests. Analysis results indicate that university students who participate in team sports demonstrate above average team unity, whilst exhibiting below average role ambiguity. Men were found to have better scores in the team unity and group attractiveness task dimensions, based on gender. In contrast, students studying in departments other than physical education and sports schools reported higher role ambiguity. It has been noted that university students who have played on the same sports team for 1-5 years encounter greater role ambiguity compared to those who have had longer experience. Playing different sports and the number of years spent playing sports did not impact participants' team unity or role ambiguity. An additional noteworthy finding is the negative significant connection between role ambiguity and team commitment. Copyright q 2023, SEPM (Society for Sedimentary Geology) 0883-1351/23/038-353.

    • SDG 4 · Nitelikli Eğitim
    İncele
  • MakaleYalnız künye2023
    Enhanced wear resistance and surface properties of oxide film coating on biocompatible Ti45Nb alloy by anodization method

    Şenaslan, Fatih; Taşdemir, Muharrem; Çelik, Ayhan; Bozkurt, Yusuf Burak

    β-Titanium alloys have become increasingly popular as biomaterials because of their low modulus of elasticity and superior corrosion properties in recent years. β-titanium alloy containing niobium is also a biocompatible and non-toxic material. Among β-Ti alloys, Ti45Nb is one of the most remarkable alloys for its superior properties as a biomaterial. This alloy has superior properties due to low elasticity modulus and non-toxic elements, but its surface properties are inadequate for biomaterial applications. Therefore, various surface treatments are applied to improve the surface properties of these alloys. In this study, an oxide film layer was formed on the Ti45Nb surface under different potential conditions by the anodizing method. The effects of these factors on friction, wear, and contact angle measurements were investigated. The structural properties of the oxide film coated samples were analyzed with XRD and their surfaces and cross-sectional images were observed by SEM. Also, the surface roughness and nanoindentation tests were performed. In this regard, it was determined that oxide film thickness, surface roughness and hardness increased with the increase of anodization potential. The contact angle of the samples decreased with the increase in the anodization potential and the surface tension of the materials increased. The highest nanohardness of about 4.19 GPa was obtained from 150 TA samples. The elasticity modulus of the untreated sample was about 63 GPa, while the anodized samples ranged from an average of 31 to 83 GPa. The wear results revealed that the anodization process improved the wear resistance of the Ti45Nb alloy. As a result, the sample anodized at 200 V for 30 min exhibited optimum surface roughness, morphology and high wear resistance.

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  • MakaleYalnız künye2023
    SPAN: An open-source plugin for photovoltaic potential estimation of individual roof segments using point cloud data

    Özdemir, Samed; Yavuzdoğan, Ahmet; Bilgilioğlu, Burhan Baha; Akbulut, Zeynep

    Decentralized solar PhotoVoltaic (PV) is one of the most promising energy sources for cities and individuals pursuing energy self-sufficiency. Especially, the already available rooftop surfaces are a major contributor to push for rooftop mounted PV systems. However, accurate PV potential estimation of individual buildings is still a challenging task since many parameters must be considered such as meteorological factors, panel technology, geographical location, available roof surface area, surface azimuth and tilt angle. In this study, we created an efficient approach that can be used for roof surface's PV potential estimation based on point cloud data and capable of processing various scales from single building to city scale. In the proposed approach, each roof surface's features were utilized for PV potential estimation by employing the PVGIS database. PV potential estimation was carried out on daily, monthly, and annual periods to provide a better estimation. Also, we developed a flexible and easy to use open-source plugin based on the QGIS software for rooftop mounted PV potential estimation capable of estimating every roof surface's PV potential. The method was tested on 80 buildings selected from ROOFN3D dataset. The proposed approach achieved an overall accuracy of 84% and an F1 score of 0.92.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 11 · Sürdürülebilir Şehirler ve Topluluklar
    • SDG 13 · İklim Eylemi
    İncele
  • MakaleYalnız künye2023
    Determination of the Antioxidant Capacity of Puerarin and Its Effect on Cholinesterases by in vitro and in silico Methods

    İnan Ergün, Aslı; Topal, Meryem

    Puerarin, which was used as a natural isoflavone in this study, was obtained from the Kudzu plant. The inhibitory effect of puerarin on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was investigated. The IC50 values of AChE (177.73 nM) and BChE (315.07 nM) were determined. The binding mechanism of puerarin, which has a high inhibitory effect on the active site of the enzyme, was demonstrated by the molecular docking method. The antioxidant activity was evaluated for the same molecule. For this purpose, Fe3+-Fe2+ reducing capacity, ABTS radical scavenging activity, CUPRAC method, DPPH⋅ scavenging activity and DMPD radical scavenging method were used. The percentage (%) inhibition amount of puerarin molecule was calculated as 99.33 % for ABTS radical scavenging activity, which is the more preferred method for natural products. The absorbtion value of iron reduction of Puerarin was 0.122±0.010, and the value of copper reduction was 0.633±0.026. Our research efforts include uncovering the potent antioxidant potential of puerarin and, simultaneously, a comparative study of tacrine, primarily emphasizing its inhibitory effects against AChE and BChE enzymes. The puerarin is expected to be a guide for drug discovery against many problems, especially oxidative cell damage in Alzheimer's disease, mitochondrial dysfunction (MD), cancer, and cardiovascular diseases.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • BildiriYalnız künye2023
    REGION-TIME-MAGNITUDE ANALYSES OF EARTHQAUKE ACTIVITY IN THE ELBASANI GEOTERMAL ZONE, ALBANIA

    Ormeni, Rrapo; Öztürk, Serkan; Hasimi, Albana; Silo, Erald; Como, Elvin; Trofymchuk, O.; Rivza, B.

    A detailed analysis of the b-value within the Elbasani fault zone, Albania, were studied. From instrumental seismicity in this area have been located 1830 seismic events, with magnitude Ml>0.5 Richter. In the zone of Elbasani, hot mineral water (thermal waters) spot out from natural springs which have been known since the 19th century. The statistical properties of seismicity are analysed by using b-value known as Gutenberg-Richter law. The magnitude of completeness (Mc) value is determined as 2.6, and the bvalue is calculated as 1.03 ± 0.06, and it is determined that the region has a normal stress level. It is seen that the Mc-value varies from 1.6 to 2.9, the b-value changes between 0.9 and 1.3. The regions with the large b-values (> 1.0) are estimated in the eastern parts of the of Elbasani zone. However, the regions with the low b-values (< 1.0) are observed in the north, west and southwest of Elbasani zone. The regions with the small b-values correspond to great-magnitude events, whereas the other large values are related to smallmagnitude earthquakes. These results reveal that b-values for all regions are well represented by a b-value typically close to 1.0. There are clear decreasing trends in temporal changes of b-values before the occurrences of some strong main shocks. The lower b-value indicate that there is still moderate stress accumulation in the southwest area of the Llinxha-Kozan thermal water belt. The b-values smaller than 1.0 indicate potential future earthquake area. Following the strong events, there are remarkable decreases in b-value as a function of time. Changes in b-value with time varies in a large band between 0.6 and 1.4. Probabilities of earthquake activity in different magnitude sizes show comparatively great values changing from 50-100 % for earthquakes of 0.5 ≤ Ml≤ 4.5 and the values relatively lower than 90 % for the earthquakes of 5.0 ≤ Ml. The Elbasani zone has a complex geological structure with a significant number of geothermal water resources and some features of seismicity.

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