Gümüşhane ÜniversitesiGümüşhane ÜniversitesiAçık Erişim Arşivi · RDL Open

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  • MakaleAçık Erişim2024
    Modified REL-Based Piecewise Path Loss Modeling Approach for Shore-to-Ship Communication at 5.6 GHz

    Eyuboglu, Ekrem; Hasirci Tugcu, Zeynep; Kuzulugil, Kenan; Cavdar, Ismail Hakki

    The need for reliable and uninterrupted communication systems in the marine environment has become critically important with increasing maritime activities, environmental monitoring, and the spread of autonomous systems. However, the complex structure of electromagnetic wave propagation in a sea environment limits the accuracy of the existing propagation models. Thus, the Modified Round Earth Loss (REL) model was first developed in this study to estimate the path loss more accurately in shore-to-ship communication. Subsequently, a piecewise modeling approach based on the principle of two-segment data modeling was proposed. In the Modified REL model, unlike the traditional REL model, the paths and gains of the direct and reflected waves were not considered equal in the calculations. Moreover, unlike in the classical approach, the receiver height was not taken as a fixed value; the estimated best receiver height value for each measurement was included in the calculations as a representation of the effect of roughness in the sea environment. Thus, the model is better adapted to various environmental conditions. In addition, the proposed piecewise model divides the propagation medium into two regions using a break point calculated by Fresnel zone theory. The Modified REL model was used for the first region and the log-distance model was used for the second region. This method allows for more accurate modeling of signal behaviors, especially at different distances. Experimental measurements and performance evaluations conducted using four different shore-to-ship communication scenarios show that the Modified REL model shows an average improvement of up to 3% in Root Mean Square Error (RMSE) values compared to the classical REL model. Additionally, the proposed piecewise model improves the fitting error of the Modified REL model, which models the data as a single whole, by an average of 22.25%. These findings emphasize the necessity of propagation models that are sensitive and adaptable to environmental changes for maritime communication.

    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    İncele
  • MakaleAçık Erişim2024
    Comparison with carbonate rocks hosted iron skarn in the eastern Sakarya Zone (Gümüşhane, NE Turkey): a geomorphologic, geochemical and stable isotopic approach

    Sipahi, Ferkan; Zeybek, Halil İbrahim; Gücer, Mehmet Ali; Işık, Fatih

    The carbonate rocks in the eastern part of NE Turkey are situated within the Pontide paleo-magmatic arc and are frequently in contact with granitoid formations, often hosting skarn mineralization in the region. These carbonate rocks, typically found on ridges and hillsides exhibit predominant orientations along east–west, northeast-southwest, and northwest-southeast directions. A part of limestone, named as biomicrite, metamorphosed and display a saccharoidal texture. Comprised mainly of calcite, with less secondary quartz and iron oxide minerals, these carbonate rocks are classified as Fe-poor calcio-carbonate and magnesio-carbonate, having higher CaO and LOI contents. Marble and recrystallized limestone with granoblastic texture mainly comprise of calcite, less quartz, magnetite, and hematite. Marble classification diagrams suggest calcic skarn mineralization, indicated by decreasing CaO (or CO2) and increasing MgO from limestone to marble (or skarn). Strontium contents deviate slightly from the lithosphere carbonate average, while low Rb contents, attributed to skarn metamorphism, indicate the absence of K-bearing minerals. The high Al2O3/SiO2 in the carbonate rocks can points out hydrothermal activity and carbonate disengagement can indicate to actualize at temperatures that can affect Ce and Al mobilities. The low authigenic U value, low U/Th and Ni/Co ratios in carbonate rocks have been implied that protolith constituents deposited under oxic conditions. Positive Eu anomalies in limestone and marble suggest the influence of hydrothermal fluids. Carbon and oxygen isotope values in marble are similar with those of metamorphic and skarn marbles, indicating a magmatic origin. Overall, mineralogical and geochemical analyses propose a uniform source and/or geological process for all studied marbles.

    İncele
  • MakaleAçık Erişim2024
    Anti-inflammatory activities of some Anthemis species used in the treatment of inflammation-related diseases, GC/MS and LC-MS/MS analysis with bioactivity-guided fractionation

    Yıldırım, Aybeniz; Gül, Abdulkadir; Başaran, Nihal; Şen, Ali; Bitiş, Leyla; Tanyıldızı, M.Şaban

    Recent studies have focused on Anthemis sp. because of their rich chemical composition and application in the treatment of diseases associated with inflammation. The purpose of this study was to determine the active chemicals responsible for the anti-inflammatory properties of Anthemis cotula, A. tomentosa, A. austriaca, and A. tinctoria var. tinctoria. Therefore, the 5-Lipoxygenase (5-LOX) was used to assess the anti-inflammatory properties of methanol extracts that were extracted from the aerial parts of the mentioned species, with an IC50 value of 23.88 μg/mL, the methanol extract of A. tinctoria var. tinctoria demonstrated anti-inflammatory effects close to the standard (Indomethacin, IC50: 18.05 μg/mL). Compared to the other extracts, the methanol extract of A. tinctoria var. tinctoria demonstrated significantly greater anti-inflammatory activity. A. tinctoria var. tinctoria and A. tomentosa methanol extracts, which were the most active in comparison to other extracts, were fractionated using the bioactivity-guided fractionation method. Their anti-inflammatory properties were evaluated to determine the compounds responsible for the activity. With an IC50 value of 3.44 μg/mL, the ethyl acetate fraction of A. tinctoria var. tinctoria (ATiEA) was found to be the most active of all the fractions. After ATiEA was further fractionated using column chromatography, it was found that ATiEA-II, one of its sub-fractions, was more effective than other sub-fractions against the 5-LOX, with an IC50 value of 2.93 μg/mL. Furthermore, the sub-fractions' total phenol and flavonoid contents were examined to confirm their anti-inflammatory properties. The sub-fraction ATiEA-II exhibited higher total flavonoid content (743,86 μg QE/g dry weight) and total phenol content (4659.36 μg GA/g dry weight) than other sub-fractions, which was in line with its anti-inflammatory activity. GC/MS and LC-MS/MS were used to clarify the effective compounds of the sub-fraction ATiEA-II. Experiments on the anti-inflammatory properties of different Anthemis sp. have demonstrated the good anti-inflammatory potential of this species. Specifically, ATiEA-II, a sub-fraction of A. tinctoria var. tinctoria, may contain a novel anti-inflammatory drug molecule.

    İncele
  • MakaleAçık Erişim2024
    Approximate Solutions of Fractional Differential Equations Using Optimal q-Homotopy Analysis Method: A Case Study of Abel Differential Equations

    Şengül, Süleyman; Bekiryazici, Zafer; Merdan, Mehmet

    In this study, the optimal q-Homotopy Analysis Method (optimal q-HAM) has been used to investigate fractional Abel differential equations. This article is designed as a case study, where several forms of Abel equations, containing Bernoulli and Riccati equations, are given with ordinary derivatives and fractional derivatives in the Caputo sense to present the application of the method. The optimal q-HAM is an improved version of the Homotopy Analysis Method (HAM) and its modification q-HAM and focuses on finding the optimal value of the convergence parameters for a better approximation. Numerical applications are given where optimal values of the convergence control parameters are found. Additionally, the correspondence of the approximate solutions obtained for these optimal values and the exact or numerical solutions are shown with figures and tables. The results show that the optimal q-HAM improves the convergence of the approximate solutions obtained with the q-HAM. Approximate solutions obtained with the fractional Differential Transform Method, q-HAM and predictor–corrector method are also used to highlight the superiority of the optimal q-HAM. Analysis of the results from various methods points out that optimal q-HAM is a strong tool for the analysis of the approximate analytical solution in Abel-type differential equations. This approach can be used to analyze other fractional differential equations arising in mathematical investigations.

    İncele
  • MakaleAçık Erişim2024
    Characterization of Water-Soluble Extracellular Polysaccharide from Aeribacillus pallidus IM17

    Genc, Berna; Tunç, Merve Tuğçe; Adiguzel, Ahmet

    The production of the extracellular polysaccharide from the thermophilic bacterium Aeribacillus pallidus was carried out in the study. The polysaccharide was isolated and characterized by means of GC–MS, FT-IR, DSC, and XRD analyses. The rheological, foaming, and emulsifying properties of the polysaccharide were determined. Using a sucrose-rich medium, 27.1 mg dried EPS/100 mL was obtained with 94% carbohydrate and 1.5% protein. The monosaccharide profile of water-soluble EPS-IM17 was composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose. The foaming capacity and stability of EPS-IM17 were 26.67% (± 4.71) and 40.01% (± 4.95), respectively, and the foaming stability was not affected by time. The emulsification index of EPS-IM17 was 64.54 (± 8.71) and decreased to 38.47 (± 10.44) after 24 h. EPS-IM17 had a crystalline structure. Solutions at different concentrations (10, 20, 40 mgmL-1) showed pseudoplastic behavior. In conclusion, this report could be a lead study for the use of Aeribacillus pallidus extracellular polysaccharide for different applications.

    İncele
  • Kitap BölümüYalnız künye2024
    Ombudsman in Turkey and cooperation with universities: The case of Ombudsman Student Clubs

    Doğan, Kadir Caner

    The ombudsman is an institution that accepts citizens' complaints about bad governance practices and the behavior of public administration. Today, it is seen in almost all states of the world. One of its application areas is universities. University ombudsman offices in some parts of the world mostly solve problems between students and the administration. Although there is no example of a university ombudsman in Turkey yet, there is cooperation between the Ombudsman Institution of Turkey and universities. Indeed, ombudsman student clubs established within universities in Turkey create mutual cooperation and synergy between the two institutions. This study aims to identify the ombudsman student clubs in universities in Turkey and evaluate their activities, projects, and academic contributions to the ombudsman. In this way, it is aimed to analyze the contributions of universities, which are higher education institutions, to the ombudsman, their awareness in society and their benefits to justice at the educational level. Document analysis based on qualitative analysis will be used as a method in the research. It is aimed to collect the necessary data, documents and data through contact with ombudsman clubs via e-mail, web, newsletter, report or telephone. In addition, the necessary activities, projects and data will be obtained from the Ombudsman Institution of Turkey, and the information will be analyzed.

    • SDG 4 · Nitelikli Eğitim
    • SDG 16 · Barış, Adalet ve Güçlü Kurumlar
    İncele
  • MakaleAçık Erişim2024
    Exploring the enablers for building resilience in solar photovoltaic Energy supply chains

    Erol, Ismail; Peker, Iskender; Benli, Tolga; Ar, Ilker Murat; Searcy, Cory

    A solar photovoltaic energy supply chain (SPvESC) is a global network with several linkages, including mineral and metal mining, material processing, and module and panel manufacturing. Due to the wide range of uncertainties and the unfavorable environmental effects associated with current linear business models, this global network is vulnerable to disruptions. Strengthening the resilience of SPvESCs is crucial for addressing any disturbances. This requires identifying the key enablers of resilience in SPvESCs, an area that has been understudied in the existing literature. An enabler is an aspect that facilitates the achievement of a goal by another aspect. This research contributes to the existing literature by systematically investigating the enablers for SPvESCs to achieve resilience. Thus, the objective of this analysis is to identify enablers that have the potential to enhance the resilience of SPvESCs in Türkiye. This was done by applying the Nominal Group Technique (NGT) in conjunction with a review of the current literature. Neutrosophic (N)-DEMATEL was then utilized to determine the relationships between the identified enablers. Finally, the results were validated using N-DELPHI. The results revealed that sensing and seizing new business models, adaptability to changes in novel energy generation and information technologies, and business contingency plans for natural and man-made disasters were the most influential enablers. The findings provide implications for practitioners, policymakers, and researchers to help ensure improved resilience in SPvESCs.

    • SDG 7 · Erişilebilir ve Temiz Enerji
    • SDG 9 · Sanayi, Yenilikçilik ve Altyapı
    • SDG 13 · İklim Eylemi
    İncele
  • MakaleAçık Erişim2024
    Physicochemical properties of chestnut honey vinegars enriched with pollen and propolis, and their analyses of mineral, colour, and antioxidant activity

    Kobya, H.N.; Baltaci, C.; Karpuz, O.

    Honey vinegar is little known in Turkey, while pollen- or propolis-added honey vinegar is yet to be found. Therefore, the objectives of the present work were to produce chestnut honey vinegar enriched with pollen and propolis, and to analyse their physicochemical compositions, mineral contents, colours, and antioxidant activities. Eleven different honey vinegars were produced using various methods. There were significant increases in the total antioxidant activity of both pollen- and propolis-enriched vinegars, with 73 and 56% increases, respectively, compared to plain honey vinegar, and these increases were more than twice that of grape vinegar. The ferric-reducing activity and phenolic content of vinegar enriched with propolis increased by 43 and 52%, respectively, compared to plain honey vinegar, and more than threefold compared to grape vinegar. Principal component analysis revealed a strong positive correlation among all antioxidant tests and the most significant components, including antioxidant capacity, total phenolic content, and total flavonoid content. The colour difference was determined as follows: 5 < total colour difference (∆E*ab). All vinegar samples exhibited highly variable physicochemical properties. High amounts of Na, K, Mg, and Ca were also detected. Vinegar samples containing pollen and propolis are suitable under the Turkish Food Codex legislation. The findings of the present work would encourage the production of honey vinegar enriched with pollen and propolis, as well as increase attention to honey vinegar.

    İncele
  • MakaleAçık Erişim2024
    Effect of micro-arc oxidation coatings with graphene oxide and graphite on osseointegration of titanium implants-an in vivo study

    Tekin, Bahar; Dundar, Serkan; Tekin, Samet; Emine Sukuroglu, Ebru; Khurshid, Zohaib; Ezgi, Yusuf; Demirci, Fatih; Faheemuddin, Muhammad

    Background: This in vivo study evaluated the effect of graphene oxide and graphite coatings, coupled with the micro-arc oxidation (MAO) surface roughening technique, known for their mechanical strength, chemical stability, and antibacterial properties. The main objective was to assess the degree of improvement in osseointegration of titanium implants resulting from these interventions. Materials and methods: In this study, 32 female rats were utilized and randomly allocated into four groups (n = 8 each): machined surface titanium implants (control), those roughened by the MAO method, those coated with graphene oxide-doped MAO, and those with a graphite-doped MAO coating. Titanium implants were surgically placed in the right tibia of the rats. Rats undergoing no additional procedures during the 4-week experimental period were sacrificed at the end. Then, the implants and surrounding bone tissues were separated and embedded in acrylic blocks for reverse torque analysis. Using a digital torque device, the rotational force was applied to all samples using a hex driver and racquet until implant separation from the bone occurred, with the corresponding values recorded on the digital display. Then, statistical analysis was performed to analyze the data. Results: No statistically significant difference between the groups was observed in the biomechanical bone–implant connection levels (N/cm) (P = 0.268). Post-hoc tests were not required because no discernible differences were identified between the groups. Conclusion: Within the scope of this study, implants treated with the MAO method, along with those coated with graphene oxide- and graphite-doped MAO method, did not exhibit significant superiority in terms of osseointegration compared to machined surface titanium implants.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleAçık Erişim2024
    Influence of nickel addition on the microstructure, mechanical, and wear properties of Zn-40Al-2Cu alloy; [Einfluss des Nickelzusatzes auf das Gefüge, die mechanischen und die Verschleißeigenschaften der Legierung Zn-40Al-2Cu]

    Savaşkan, T.; Azaklı, Z.; Tan, H.O.

    To study the influence of nickel addition on the microstructure, mechanical and lubricated wear properties of Zn-40Al-2Cu alloy, one ternary and five quaternary Zn-40Al-2Cu-(0.5-2.5)Ni alloys were made by permanent mold casting. The wear behavior of these alloys was studied using a block-on-cylinder type test machine, after examining their microstructural and mechanical features. The microstructure of Zn-40Al-2Cu alloy was comprised of aluminum-rich α dendrites and a eutectoid α+η phase mixture. The addition of nickel caused the formation of intermetallic Al3Ni particles in the microstructure of this alloy. As the nickel content of alloys increased their hardness, friction coefficient, working temperature, and average surface roughness increased to certain extents but their strength, ductility, impact resistance, and wear volume decreased. However, the values of their wear volume and average surface roughness exhibited opposite changes with increasing nickel content. The worn surfaces of Zn-40Al-2Cu-Ni alloys were observed to be characterized by smearing and scratching marks. Furthermore, the wear and mechanical properties of these alloys were correlated, and the results were discussed in terms of their microstructural features. Finally, it may be concluded that the nickel addition adversely affects the ductility of Zn-40Al-2Cu alloy but increases its wear resistance.

    İncele
  • MakaleAçık Erişim2024
    Physicochemical Properties, Antioxidant Capacity and Sensory Acceptability of Instant Rosehip Teas Prepared by Spray-Drying and Freeze-Drying Methods

    Baltaci, Cemalettin; Bostanci, Dilara Erkmen; Altintaş, Rahime; Dalkiran, Yusuf; Akdoğan, Arda; Okan, Onur T.

    In this study, the physicochemical properties, antioxidant capacity, sensory properties, and phenolic and mineral profiles of instant rosehip teas prepared using spray-drying (SD) and freeze-drying (FD) were compared. The yield of instant tea produced using FD and SD was 23.75 and 21.25 g/100 g, respectively. The total color difference between the FD and SD tea was 50.74, with the SD sample exhibiting higher redness and yellowness. The FD tea was richer in ascorbic acid than SD tea (67.2 and 59.4 mg/100 g dry weight, DW, respectively). The mineral content ranged from 0.20 mg/kg DW (copper) to 2,837 mg/kg DW (potassium) in SD tea, and from 0.31 mg/kg DW (copper) to 3,083 mg/kg DW (potassium) in FD samples. The total phenolic content was 1,315 and 1,495 mg GAE/100 g DW of SD and FD samples, respectively. The antioxidant capacity of instant rosehip teas was determined as total antioxidant capacity, ferric reducing antioxidant power and DPPH radical scavenging activity. In all these assays, FD tea was found to have a higher antioxidant capacity. In the phenolic profile determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique, protocatechuic acid dominated in instant rosehip teas prepared using both methods. The main flavonoids identified were quercetin, quercitrin, hyperoside and luteolin 7-glucoside. Following the sensory analysis, the panelists have generally preferred the FD tea in terms of aroma and flavor, while opting for the SD tea in terms of appearance and color. In conclusion, although freeze-drying allowed obtaining a product with a higher antioxidant capacity and antioxidant content than spray-drying, both drying methods may be considered suitable for the production of instant rosehip teas and ensure obtaining a functional food product.

    • SDG 2 · Açlığa Son
    İncele
  • MakaleAçık Erişim2024
    Four bryophyte species new to Türkiye and South-West Asia

    Batan, Nevzat; Taşçi, Nurtaç; Mamontov, Yuriy S.; Erata, Hüseyin; Alataş, Mevlüt; Ezer, Tülay

    Scapania praetervisa, Scapania mucronata, Solenostoma confertissimum, and Platyhypnum alpinum found as new to Türkiye following a recent bryofloristic excursion in Artvin region (Caucasian part of Türkiye). Platyhypnum alpinum is also new to Asia. Descriptions, illustrations, distributions, habitat characteristics, and comparisons with morphologically similar taxa are briefly given.

    İncele
  • MakaleAçık Erişim2024
    Examination of Mental Stamina and Athlete Injury Anxiety Levels of Wrestlers

    Ünlü, Çisem; Çevi̇Ker, Abdulkerim; Turgut, Abdüsselam; Kusan, Osman; Tezcan, Efecan; Gür, Kübra; Yildirim, Turgut

    The aim of this research is to examine the mental endurance and athlete injury anxiety levels of athletes interested in wrestling from some demographic perspectives. In the study, a descriptive scanning model was used. The universe of the research consists of athletes from various cities of Turkey who are interested in wrestling, and the sample consists of 341 athletes selected by random sampling method among wrestling athletes from Ankara, Gümüşhane, Istanbul, Samsun and İzmir, Kayseri. As a data collection tool, the demographic information form developed by the researchers was used "Athlete Injury Anxiety Scale". In the study, the assumption of normality was first examined with the Kolmogorov-Smirnov and Shapiro-Wilk tests in the statistical evaluation of the data. The research findings were given as n (%), mean and standard deviation values, and the findings were considered significant at the p<0.05 level. In the study, there was no significant relationship between age, undergraduate status and educational status variables, athlete injury anxiety levels and mental toughness levels; When the athlete's age, athlete's injury status, gender, number of nationality variables were examined, it was determined that there was a significant difference in some sub-dimensions of the mental toughness inventory and in the total scores of the scale. As a result, it can be said that demographic variables such as age, gender, being a national athlete are effective on the mental endurance and disability anxiety of the athletes.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleYalnız künye2024
    Sulfonamide derivatives with benzothiazole scaffold: Synthesis and carbonic anhydrase I–II inhibition properties

    Öztürk, Cansu; Kalay, Erbay; Gerni, Serpil; Balci, Neslihan; Tokali, Feyzi Sinan; Aslan, Osman Nuri; Polat, Emrah

    The secondary sulfonamide derivatives containing benzothiazole scaffold (1–10) were synthesized to determine their inhibition properties on two physiologically essential human carbonic anhydrases isoforms (hCAs, EC, 4.2.1.1), hCA I, and hCA II. The inhibitory effects of the compounds on hCA I and hCA II isoenzymes were investigated by comparing their IC50 and Ki values. The Ki values of compounds (1–10) against hCA I and hCA II are in the range of 0.052 ± 0.022–0.971 ± 0.280 and 0.025 ± 0.010–0.682 ± 0.335, respectively. Some of these inhibited the enzyme more effectively than the standard drug, acetazolamide. In particular, compounds 5 and 4 were found to be most effective on hCA I and hCA II.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleYalnız künye2024
    Is environment destiny? Spatial analysis of the relationship between geographic factors and obesity in Türkiye

    Yılmaz, Hacı Ömer; Günen, Mehmet Akif

    This study aims to evaluate the relationship of geographical factors, including precipitation, slope, air pollution and elevation with adult obesity prevalence in Türkiye (TR) using a cross-regional study design. Ordinary least squares (OLS) and geographically weighted regression (GWR) were performed to evaluate the spatial variation in the relationship between all geographic factors and obesity prevalence. In the model, a positive relationship was found between obesity prevalence and slope, whereas a negative significant relationship was determined between obesity prevalence and elevation (p < 0.05). These results, revealing spatially varying associations, were very useful in refining the interpretations of the statistical results on adult obesity. This research suggests that geographical factors should be considered as one of the components of the obesogenic environment. In addition, it is recommended that national and international strategies to overcome obesity should be restructured by taking into account the geographical characteristics of the region.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleAçık Erişim2024
    PRODUCTION OF DEEP-FRIED WHEAT CHIPS USING PURPLE WHEAT FLOUR: PHYSICOCHEMICAL, TEXTURAL, SENSORY PROPERTIES AND OPTIMIZATION

    Kaya, Şemsettin; Yuksel, Ferhat

    The aim of this study was to develop alternative and healthy deep-fried chips by fortifying wheat chips with purple wheat flour (PWF). The effect of process variables (PWF content: 0-100%, frying temp. and time: 170-190 °C and 40-60 s) on the physicochemical, textural, instrumental color, sensorial properties, and optimization of the chips were investigated using response surface methodology. The levels of PWF in the chips receipt dramatically reduced oil uptake (by 23%), whereas the protein content of chips increased of the end products. The instrumental hardness of the enriched chips increased while sensory firmness decreased with increasing PWF. Generally, the chips enriched with PWF received the highest overall acceptability score by the panelists. Higher desirability (optimization results) and the process variables were determined as a 0.73 and 92.72 g/100g PWF, 170 °C, 40 s, respectively. These findings show that PWF can be easily incorporated into products that involve deep-fried chips.

    • SDG 2 · Açlığa Son
    İncele
  • MakaleAçık Erişim2024
    Performance of different fibre types in alkaline-activated concrete produced with industrial wastes: volcanic rock powder and blast furnace slag

    Aksüt, Yavuz Selim; Külekçi, Gökhan; Çullu, Mustafa; Yetgin, Şükrü

    The objective of the study is to determine the effects of different fibre types and ratios on the mechanical and physical properties of alkali-activated concrete (AAC) and to optimise important properties such as workability, unit weight, water absorption, compressive strength, modulus of elasticity and abrasion resistance of these concretes. Concrete samples were produced using steel and polyester fibres at ratios of 0.25%, 0.50%, 0.75% and 1%. The fibre ratios were varied, and various tests were conducted to determine the mechanical and physical properties of the concrete samples. The experiments clearly revealed the effects of fibre types and ratios on the performance of concrete. These results clearly demonstrate the effects of different fibre types and ratios on the mechanical and physical properties of AACs. Particularly noteworthy is the water-retaining property of polyester fibres, their effect on workability and their enhancing effect on abrasion resistance. The effects of steel fibres on compressive strength and modulus of elasticity are more pronounced, but they may present disadvantages in terms of workability and abrasion resistance. It is observed that mixed fibre usage provides a good balance in some properties. This study provides a roadmap for evaluating sustainable material options in the concrete industry and guiding future research.

    • SDG 12 · Sorumlu Üretim ve Tüketim
    İncele
  • MakaleAçık Erişim2024
    L0-Norm based Image Pansharpening by using population-based algorithms

    Günen, Mehmet Akif; Pérez-Delgado, María-Luisa; Beşdok, Erkan

    Earth observation satellites capture panchromatic images at high spatial resolution and multispectral images at lower resolution to optimize the use of their onboard energy sources. This results in a technical necessity to synthesize high-resolution multispectral images from these data. Pansharpening techniques aim to combine the spatial detail of panchromatic images with the spectral information of multispectral images. However, due to the discrete nature of these images and their varying local statistical properties, many pansharpening methods suffer from numerical artifacts such as chromatic and spatial distortions. This paper introduces the L0-Norm-based pansharpening method (L0pan), which addressed these challenges by maximizing the number of similar pixels between the synthesized pansharpened image and the original panchromatic and multispectral images. L0pan was optimized using a population-based colony search algorithm, enabling it to effectively balance both chromatic fidelity and spatial resolution. Extensive experiments across nine different datasets and comparison with nine other pansharpening methods using ten quality metrics demonstrated that L0pan significantly outperformed its counterparts. Notably, the colony search algorithm yielded the best overall results, highlighting the algorithm’s strength in refining pansharpening accuracy. This study contributed to the advancement of pansharpening techniques, offering a method that preserved both chromatic and spatial details more effectively than existing approaches.

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  • MakaleAçık Erişim2024
    Impact of Preoperative Progressive Relaxation Exercises on Postoperative Pain, Comfort, and Recovery : A Randomized Controlled Trial

    Kulakaç, Nurşen; Sayılan, Aylin Aydın

    This randomized controlled trial aimed to investigate the impact of preoperative progressive relaxation exercises on postoperative pain, comfort, and quality of recovery. The study was conducted between June and November 2023, involving 68 patients undergoing surgical intervention and hospitalized in the surgical clinic. Data were collected using the Personal Information Form, the Visual Analog Scale (VAS)-Pain, the Perianesthesia Comfort Scale, and the Quality of Recovery Questionnaire. At the sixth postoperative hour, no significant difference was observed in pain levels between the experimental and control groups (P > .05). However, the VAS scores for the experimental group at the 12th and 24th postoperative hours were significantly lower than those of the control group (P < .001). Furthermore, 24 hours postoperatively, the experimental group demonstrated significantly higher quality of recovery (P < .001) and comfort levels (P < .001) than the control group. This study concludes that patients engaged in relaxation exercises exhibited lower VAS scores and higher levels of recovery and comfort.

    • SDG 3 · Sağlık ve Kaliteli Yaşam
    İncele
  • MakaleAçık Erişim2024
    EVALUATION OF CONSUMERS’ USE OF SMART ROBOTIC VACUUM CLEANERS UNDER EXTENDED EXPECTATIONCONFIRMATION MODEL; [VREDNOVANJE PROVEDENO MEĐU POTROŠAČIMA PAMETNIH ROBOTSKIH USISAVAČA U OKVIRU PROŠIRENOGA MODELA POTVRDE OČEKIVANJA]

    Avci, Ibrahim; Kocan, Mahmut; Kirmizibiber, Ahmet

    Purpose – The present research study extends the Expectation-Confirmation Model (ECM) by focusing on satisfaction, continuance intention, and recommendation intention among smart robotic vacuum cleaner users. The impacts of battery life concern and perceived privacy factors on satisfaction and continuance intention of the smart robotic vacuum cleaner were investigated by adding the variables of battery life concern, perceived privacy, and recommendation intention in the ECM. Design/methodology/approach – The participants of this study consisted of smart robotic vacuum cleaner users in Turkey. The snowball sampling method, as one of the non-random sampling methods, was used to reach the participants; data was collected using an online survey created with Google Forms, asking the participants to share the survey link with people around them who have smart robotic vacuum cleaners. A total of 218 smart robotic vacuum cleaner users participated in the study between March 1 and May 1, 2023. Findings and implications – Structural equation modeling (SEM) was used as the data analysis technique in the study. While the ECM was confirmed as a result of the SEM analysis, an important finding was that consumers with battery life concerns intend to continue using the smart robotic vacuum cleaner despite a negative relationship between battery life concern and satisfaction. While the effect of perceived privacy on continuance intention was not significant, satisfaction was found to have a significant effect on continuance intention. Given that rtificial intelligence-related businesses face fierce competition, organizations that wish to prosper in this environment must excel in a variety of areas, ranging from product design to marketing and from sales policies to post-sales assistance. Considering the findings, determining the factors that affect the satisfaction and intention to continue using robot vacuum cleaners will be a guide for smart robot vacuum cleaner manufacturers and marketers. At the same time, the fact that the issue has been investigated within the framework of a model will also make significant contributions to the literature. Limitations – Different factors influence smart robotic vacuum cleaner users’ satisfaction and desire to continue using them, but only battery-life concerns and perceived privacy variables were incorporated into the ECM model in this research study. Another limitation is connected to the research sample. Because the snowball sampling method was employed to obtain data for the research, its findings cannot be generalized as they cover only smart robotic vacuum cleaner users who participated in the survey. Originality/value – The ECM employed in the study was expanded by including the variables of battery-life concern, perceived privacy, and recommendation intention. A general lack of information among potential consumers regarding artificial intelligence and smart robotic vacuum cleaners, which is highly fascinating and a source of curiosity, as well as the lack of research on this issue in the literature, underscore the significance of this research study. By integrating and expanding the ECM for application to consumers using smart robotic vacuum cleaners, this study adds a fresh viewpoint to the literature.

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