Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Uzun, Sevda(66)
- Merdan, Mehmet(56)
- Duran, Celal(50)
- Ozdes, Duygu(47)
- Kaygusuz, Abdullah(42)
- Demir, Selim(37)
- Turan, Ibrahim(37)
- Ashyralyyev, Charyyar(34)
- Dokuz, Abdurrahman(33)
- Araz, Onur(31)
- Öztürk, Serkan(31)
- Sipahi, Ferkan(30)
- Kandemir, Raif(28)
- Arslan, Mehmet(27)
- Karsli, Orhan(27)
- Kulakaç, Nurşen(26)
- Baltacı, Cemalettin(25)
- Gücer, Mehmet Ali(25)
- Kurt, Kemal(25)
- Maden, Nafiz(25)
- Ozturk, Samet(25)
- Topal, Fevzi(25)
- Baltaci, Cemalettin(24)
- Yücel, Cem(24)
- Aliyazicioglu, Yuksel(23)
- Bayrakdaroglu, Serdar(23)
- Kankal, Murat(23)
- Peker, Iskender(23)
- Yolcu, Halil(23)
- Reis, Hatice Catal(21)
- Topal, Meryem(21)
- Vural, Alaaddin(21)
- Aydin, Aydanur(20)
- Aydin, Faruk(20)
- Bayraktar, Alemdar(20)
- Kurnaz, Muammer(20)
- Çelik, Necati(20)
- Ürkek, Bayram(20)
- Cakir, Tufan(18)
- Günen, Mehmet Akif(18)
Yayınlar
- MakaleYalnız künye2020Scopus SJRQ2A review study on using diethyl ether in diesel engines: Effects on fuel properties, injection, and combustion characteristics
Sezer, İsmet
This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in diesel engines. Three different techniques are used, the reduction of the harmful exhaust emissions of diesel engines. The first technique for the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time-consuming. The second technique is the use of various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique to reduce emissions and also improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutants of diesel engines are nitrogen oxides and particulate matter. It is very difficult to reduce nitrogen oxides and particulate matter emissions simultaneously in practice. Most researches declare that the best way to reduce these emissions is the use of various alternative fuels i.e. natural gas, biogas, biodiesel, or the use of fuel additives with these alternative fuels or conventional diesel fuel. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together for practice applications. Especially, this study focuses on the use of diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether on the fuel properties, injection, and combustion characteristics.
AtıfScopus55WoS42OpenAlex61
İncele - MakaleYalnız künye2020Scopus SJRQ1The effect of expressed breast milk, swaddling and facilitated tucking methods in reducing the pain caused by orogastric tube insertion in preterm infants: A randomized controlled trial
Apaydin Cirik, Vildan; Efe, Emine
Background: Orogastric tube feeding is used to support the nutrition of preterm infants. Although nonpharmacological methods are effective in reducing the pain caused by orogastric tube insertion, only limited studies have been found addressing this pain. No study has used combined nonpharmacological methods to reduce this orogastric tube insertion pain. Objective: This randomized controlled study aims to compare the effects of expressed breast milk, swaddling, facilitated tucking, expressed breast milk+swaddling, expressed breast milk+facilitated tucking and routine care methods on preterm infant pain and the physiological parameters (i.e., heart rate, oxygen saturation) before, during and after orogastric tube insertion procedures. Design: Randomised controlled trial. Setting: Three level III neonatal intensive care units in Turkey. Method: Preterm infants born at 32–34 weeks gestation were randomly assigned to six groups: routine care (n = 33), swaddling (n = 30), facilitated tucking (n = 32), expressed breast milk (n = 31), swaddling+expressed breast milk group (n = 30), and facilitated tucking+expressed breast milk group (n = 31). Orogastric tube insertion included four phases: baseline (the last one minute of 30 min without stimuli), the insertion, recovery (one minute after insertion), and recovery (two minutes after insertion). The four phases were videotaped. Premature infant pain profile score, heart rate and oxygen saturation were assessed by two independent evaluators who were blinded to the purpose of the study. Data were assessed by analysis of variance for the multiple repeated measurements, bonferroni and generalised estimating equation logistic regression. Results: There was a significant main effect of the intervention groups for all the pain and physiological parameters (heart rate: F = 3.99, p = 0.001; oxygen saturation: F = 5.22, p<0.001; pain profile 1 score: F = 9.55, p<0.001; pain profile 2 score: F = 9.74, p<0.001). The use of the nonpharmacological methods combined or alone was more effective in reducing infants’ pain profile score and physiological variables than routine care. Infants receiving swaddling+expressed breast milk had significantly lower pain profile scores during the insertion (phase2) (5.2 ± 1.7) than those receiving routine care (9.5 ± 3.6), swaddling (8.8 ± 2.9), facilitated tucking (7.2 ± 3.2), expressed breast milk (7.9 ± 2.6), facilitated tucking+expressed breast milk (6.6 ± 2.3) (p<0.001). The breast milk group had 6.195 times more pain than the swaddling+expressed breast milk, while the facilitated tucking group had 6.301, the facilitated tucking+expressed breast milk group had 3.107, the control group had 13.015, and the swaddling group had 7.892 times more pain. Conclusion: The swaddling+expressed breast milk method is clinically better pain relief nonpharmalogical option and is the recommended method to nurses for the orogastric tube insertion procedures, preterm infants.
AtıfScopus49WoS40OpenAlex71
İncele - MakaleYalnız künye2020Scopus SJRQ1Simulation optimization of the berth allocation in a container terminal with flexible vessel priority management
Yıldırım, Mehmet Sinan; Aydın, Metin Mutlu; Gökkuş, Ümit
Solving the berth allocation problem (BAP) in ports is not trivial where the berth resources are limited and various sizes of vessels arrive with dramatically dissimilar loads. Especially in real scenarios, arriving vessels are accepted for a berth with the first come first served (FCFS) priority rule. This study proposes a decision support system coupled with a simulation optimization module based on the swarm-based Artificial Bee Colony optimization algorithm for solving the BAP. The proposed methodology was implemented for the Izmir port in Turkey. To investigate the influences of the vessel priorities on the BAP, four different experimental scenarios based on the single (SQM) and multiple queue models (MQM) were coupled with FCFS and proposed hybrid queue priority (HQP) rule. The results indicated that SQM scenarios were superior to MQM scenarios in a manner of minimizing the average vessel waiting times and the implementation of a dynamic berth allocation strategy for the MQM significantly decreases the vessel waiting times. Results of the SQM also imply that utilization of the HQP approach further minimizes the average vessel waiting times and increases the berth utilization and port throughput without yielding excessive waiting times for the larger vessels compared with the FCFS priority rule.
AtıfScopus44WoS37OpenAlex45İncele - MakaleYalnız künye2020MODELING OF BOOST AND CUK CONVERTERS AND COMPARISON OF THEIR PERFORMANCE IN MPPT
Güngör, Okan; Yüksek, Halil İbrahim
The efficiency of photovoltaic (PV) panel systems depends on the structure of the photovoltaic cells and the transfer of energy from the PV panel to load. The focus of this study is energy transfer. The most important component in the energy transfer is maximum power point tracking (MPPT). The MPPT consists of two components: the algorithm for calculation the maximum power and the hardware for power generating. This study investigates how some the DC-DC converters (hardware) impact on the performance of the MPPT under six different environmental conditions by using two different duty cycle calculation methods. Contribution of this study to the literatüre is to analyze the performance of some the DC-DC converters in MPPT by completely eliminating the effect of MPPT algorithms. As a result of this study, while using the Boost converter in MPPT applications, the internal resistance of the PV panel must be equal or smaller than load resistance. However, the Cuk converter can reach to maximum power point in all conditions such as temperature, radiation and load.
AtıfScopus2WoS1İncele - MakaleYalnız künye2020Scopus SJRQ1Finite element study on axially loaded reinforced Square Hollow Section T-joints at elevated temperatures
Ozyurt, E.
This study numerically investigates the elevated temperature resistance of collar plate and doubler plate reinforced Square Hollow Section (SHS) T-joints subjected to brace axial compressive load. The extensive numerical simulations were performed to examine the effects of the geometrical parameters of main members and reinforcing plate on the fire resistance of reinforced SHS T-joints after verification of the numerical models based on the available test results. The corresponding unreinforced joints were also analysed as reference resistance at five different temperature levels (20 °C, 400 °C, 500 °C, 600 °C, and 700 °C). Results indicate that the elevated temperature capacity of SHS T-joints can be significantly increased by using a collar plate or a doubler plate. Although the initial stiffness of the doubler plate reinforced joints was higher than the collar plate reinforced joints, their capacity was similar to each other. Also, the fire resistance of the reinforced joints mainly depended on the brace-to-chord width ratio and reinforcing plate thickness to chord wall thickness ratio. However, there was no beneficial effect on the fire resistance of reinforced joints when the thickness of the reinforcing plate was greater than 1.5 times the chord wall thickness. Moreover, there was an insignificant effect of half-width to thickness ratio of the chord, reinforcing length and reinforcing type as long as the required limit values of the reinforcing length and width were used based on the Eurocode 3 EN 1993-1-8. It is worth mentioning that modifying the steel yield strength in the ambient temperature design method to calculate the capacity of the reinforced SHS T-joints at elevated temperatures may be unsafe. A new design method was developed to predict the capacity of a collar plate and doubler plate reinforced SHS T-joints subjected to brace compressive load in fire.
AtıfScopus14WoS13OpenAlex14İncele - MakaleAçık Erişim2020Scopus SJRQ3Mistletoe (Viscum album l.) damage and its economic effects in scots pine (pinus sylvestris l.) natural regeneration and afforestation areas
Ertuğrul, M.H.; Komut, O.
This study discusses the development of mistletoe (Viscum album L.) and its economic impacts on natural afforestation and regeneration areas. In this context, a total of 16 sample areas were determined in Scots pine natural regeneration and afforestation areas with resembling habitat characteristics. The occurrence status of mistletoe in Scots pine (Pinus sylvestris L.) individuals in these areas was determined according to stem, branch and corolla parts and morphological age determination was also conducted for the plants. Additionally, the relationship between diameter and length increase of healthy individuals, and ones affected by mistletoe were modelled with simple linear regression analysis. Besides, the tree asset values of the stands were calculated by estimating maintenance and afforestation costs at the working sites, and economic loss potential was determined through the targeted forest product revenue. Study results have revealed that natural regeneration sites are less exposed to mistletoe damage than afforestation sites. While the mistletoe exposure was found to be 27% in the study areas, it was determined that there was a potential revenue loss of 21% concerning the target economic revenue as well as additional labour and afforestation costs.
AtıfScopus3WoS3OpenAlex2İncele - MakaleYalnız künye2020Scopus SJRQ1The role of blockchain in reducing the impact of barriers to humanitarian supply chain management
Ozdemir, Ali Ihsan; Erol, Ismail; Ar, Ilker Murat; Peker, Iskender; Asgary, Ali; Medeni, Tunc Durmus; Medeni, Ihsan Tolga
Purpose: The objective of this study is to investigate the role of blockchain in reducing the impact of barriers to humanitarian supply chain management (HSCM) using a list of blockchain benefits. Design/methodology/approach: A decision aid was used to explore the suitability of blockchain in humanitarian supply chains. To achieve that, first, a list of barriers to HSCM was identified. Then, the intuitionistic fuzzy decision-making trial and evaluation laboratory (IF–DEMATEL) method was utilized to determine the relationships and the level of interdependencies among the criteria. Finally, the intuitionistic fuzzyanalytic network process (IF–ANP) technique was employed, as it successfully handles dependencies among the criteria. Findings: The findings of this study suggest that interorganizational barriers are the most suitable ones, the impacts of which blockchain may alleviate. This study further suggests that trust turned out to be the most significant benefit criterion for the analysis. Research limitations/implications: The readers should construe the findings of this study with caution since it was carried out using the data collected from the experts of a particular country. Moreover, the proposed decision aid contemplates a limited set of criteria to assess a possible role of blockchain in overcoming the barriers to HSCM. Practical implications: The findings of this study can assist humanitarian supply chain managers to make more judicious assessments on whether they implement the blockchain in humanitarian supply chain operations. Specifically, this research may help decision makers to identify the certain barriers, the impact of which may be reduced by using the blockchain. The findings of this research will also help various decision makers make more rational decisions and allocate their resources more effectively. Originality/value: To the best of authors’ knowledge, no single study exists to investigate the role of blockchain in reducing the impact of barriers to HSCM using an intuitionistic fuzzy multi-criteria decision-making approach.
AtıfScopus87WoS65OpenAlex87İncele - MakaleYalnız künye2020Scopus SJRQ1Dynamic properties of sand-bitumen mixtures as a geotechnical seismic isolation material
Kuvat, Ahmet; Sadoglu, Erol
Geotechnical seismic isolation (GSI) has been emerged as an economical and alternative method in recent years that reduces earthquake that will affect the superstructure. Crumb rubber-granular soil mixtures (SRM) are generally used as damping geomaterial in this method. However, the major disadvantage of SRM is that the addition of rubber leads to significant reduction in stiffness of the granular soil. In this study, dynamic properties (secant shear modulus (Gsec) and damping ratio (D)) of sand and bitumen mixtures (SB) which can be used as damping materials in GSI systems were determined by cyclic triaxial tests. In addition, monotonic triaxial tests were performed to determine the pre- and post-cyclic behavior of the mixtures. In the cyclic tests, the effect of bitumen penetration and content on the energy absorption capacity of the bituminous specimens was examined depending on cyclic stress ratio (CSR), cell pressure and loading frequency. According to the findings, it was determined that higher bitumen penetration and (CSR) result in decrease of Gsec and increase of D, yet the increase in confining pressure and the increase in loading frequency have the opposite effect. For the specimens prepared with both bitumen types, it was specified that the D increased depending on the increase of bitumen content, and the highest Gsec value was observed to be bitumen content of 8%. Moreover, the findings obtained from the monotonic triaxial tests showed that after a high number of cyclic loading, the peak deviatoric stresses of the SB samples increase slightly.
AtıfScopus37WoS32OpenAlex31İncele - MakaleYalnız künye2020Scopus SJRQ2Effect of indentation loading type on the mechanical properties of advanced high strength steel grade DP 800
Ekmekci, Dursun; Cora, Ömer Necati
The goal of this study was to acquire mechanical properties of a dual-phase grade advanced high strength steel (AHSS) by means of different microindentation loading conditions. Conventional, cyclic, and multi-step indentations were performed on DP 800 sample; and Young’s modulus, hardness values were obtained by the depth-sensing indentation technique. Effects of different load levels (50–300 mN) and type of indentation on the results were also analyzed through ANOVA. The load levels experimented yielded overall material response rather than its constituents (e.g., martensite and ferrite). Both hardness and Young’s modulus tend to decrease with increasing maximum indentation load level, especially from 50 to 100 mN, which is regarded as indentation size effect.
AtıfScopus8WoS8OpenAlex9İncele - MakaleYalnız künye2020Scopus SJRQ2Degradation kinetics of bioactive compounds and antioxidant activity in strawberry juice concentrate stored at high and low temperatures
Menevseoglu, Ahmed; Dıblan, Sevgin; Türkyılmaz, Meltem; Özkan, Mehmet
In this study, changes in ascorbic acid (AA), phenolics, anthocyanins (ACNs) and antioxidant activity (AOA) were monitored during storage at − 25, 4, 10 and 20 °C to observe the stability of bioactive compound in strawberry juice concentrates (SJCs). Half-life periods (t1/2) for ACN and AA degradations were 7.9 and 50 days at 20 °C, respectively. On the contrary, much higher t1/2 values were found for the reduction in AOA and phenolics, i.e. 251 and 430 days at 20 °C, respectively. AOA and phenolics were more stable during storage than AA and ACNs. p-Coumaric acid was the major phenolic identified in SJC. p-coumaric acid (33.8%), catechin (23.1%), vanilic acid (18.6%) and epicatechin (16.1%), which constituted 91.6% of phenolics in SJC, followed by chlorogenic acid (4.9%) and caffeic acid (3.2%). Chlorogenic acid was the least stable phenolic in SJC stored at 20 °C. Strong correlations were found between AOA and ACNs (r = 0.99), phenolics (r = 0.94) and AA (r = 0.92) in SJC stored at 20 °C. Significant ACN and AA degradations occurred at storage temperature as low as 4 °C. Therefore, storage at − 25 ℃ was suggested for SJC to maximize the stabilities of especially ACNs and AA in SJC.
AtıfScopus19WoS17OpenAlex17İncele - MakaleYalnız künye2020Scopus SJRQ1Symbiotic Organisms Search Algorithm for multilevel thresholding of images
Küçükuğurlu, Büşranur; Gedikli, Eyüp
Thresholding is a frequently used method in image processing because of its consistency and low computational cost. Otsu's and Kapur's methods are two important techniques that were proved to be best thresholding methods. However, they have high computational complexity when extended to multilevel thresholding because of their exhaustively search. Recently, meta-heuristic algorithms have been successfully applied for thresholding problems. In this study, six different meta-heuristic algorithms based on Otsu's and Kapur's functions; Particle Swarm Optimization (PSO), Firefly Algorithm (FA), Symbiotic Organisms Search (SOS), Artifical Bee Colony (ABC), Genetic Algorithm (GA) and grey Wolf Optimizer (GWO) were used for multilevel thresholding problem and compared. Experimental results suggest that SOS, PSO and FA algorithms often have higher fitness values than other algorithms. Especially when more than two threshold values are determined, SOS algorithm mostly gives higher fitness values. PSNR and SSIM results of the algorithms are similar. In terms of computational complexity, the GWO algorithm has the fastest convergence. For standard deviations of objective functions; more stable results were obtained with SOS based on Kapur's function, SOS and PSO based on Otsu's function. Also, SOS based on Kapur's function was found to be the most successful algorithm in the Friedman test. As a result, although the GWO approached faster, the SOS algorithm produced more consistent results for both objective functions.
AtıfScopus36WoS24OpenAlex36İncele - MakaleAçık Erişim2020Scopus SJRQ3Emplacement conditions of magma(s) forming Jurassic plutonic rocks in Gümüşhane (Eastern Pontides, Turkey)
Aydinçakir, Emre; Gündüz, Ramazan; Yücel, Cem
In this study, the petrography, mineral chemistry and crystallization conditions were reported for the Alemdar and Işıkdere plutons located in limited areas in the south of the Eastern Pontides. These plutons, which trend mostly in NE-SW directions, were emplaced by cutting the Early-Middle Carboniferous-aged Gümüşhane Granitoid and Early-Middle Jurassic Şenköy formation. Petrographically, the studied plutons are compositionally fine to medium grained quartz-diorite, quartz monzodiorite and tonalite. The rocks in the plutons have granular, poikilitic, monzonitic, graphic and rare porphyritic textures with consist of plagioclase, (An05-92), hornblende (Mg# = 0.52-0.81), biotite (Mg# = 0.32-0.67), orthoclase, quartz and Fe-Ti oxide. According to thermobarometric calculations, plutons have crystallization temperatures, pressures and oxygen fugacity values ranging from 541°C to 938°C, 0.1 to 4.4 kbar, and -23 to-12, respectively. The estimated water content calculated from amphibole is between 4.4 to 7.8%. It can be concluded that the studied plutons were emplaced at mid to shallow crustal depths (~4-15 km).
AtıfScopus12WoS11OpenAlex4TR Dizin7
İncele - MakaleAçık Erişim2020Scopus SJRQ4Effect of the COVID-19 pandemic on eating habits and food purchasing behaviors of university students
Yılmaz, Hacı Ömer; Aslan, Ramazan; Unal, Cihan
COVID-19 disease, which has spread rapidly all over the world since the first case was detected in December 2019, has become the primary focus in every country. Radical measures have been taken by governments to prevent the spread of the disease. Precautions and social rules have required drastic changes to daily life activities everywhere. University students who have had to interrupt their educations are one of the affected groups by this disease sociologically, psychologically and physiologically. The aim of this study was planned and conducted to determine the effect of COVID-19 on university students' eating habits and food purchasing behaviors. The study was completed in April 2020 with 866 university students studying and training at the Faculty of Health Sciences, Gümüşhane, Turkey. Research data was obtained by online questionnaire. The questionnaire was prepared with information obtained from a literature review and the opinions of experts. It included questions about eating habits and food purchasing behaviors. The basic result of the study was that COVID-19 disease has caused significant changes in the eating habits and food purchasing behaviors of university students. Primarily, they now paid greater attention to hygiene when food purchasing, and had increased their consumption compared to previously, since they were now home 24 hours a day, seven days a week.
AtıfScopus30WoS22OpenAlex55İncele - MakaleAçık Erişim2020Scopus SJRQ1Forest Biodiversity, Carbon Sequestration, and Wood Production: Modeling Synergies and Trade-Offs for Ten Forest Landscapes Across Europe
Biber, Peter; Felton, Adam; Nieuwenhuis, Maarten; Lindbladh, Matts; Black, Kevin; Bahyl, Jan; Bingöl, Ozkan; Borges, Jose G.; Botequim, Brigite; Brukas, Vilis
Europe's forests provide vital habitat for biodiversity and essential ecosystem services whose provision must be sustained or enhanced over the coming century. However, the potential to secure or increase forest ecosystem services, while securing the habitat requirements of taxa remains unclear, especially within the context of uncertain climate and socio-economic developments. To tease out the associated trade-offs and synergies, we used 10 case study landscapes within nine countries throughout Europe. Starting with the current status of the forests in the case study landscapes, we simulated forest development 100 years into the future. Simulations were embedded in three combined climate and socio-economic frame scenarios based on global and European policies which varied in their climate change mitigation efficiency. Scenarios were translated into country specific projections of climate variables, and resultant demands for wood products. Forest management regimes were projected to vary in response to these scenarios at local scales. The specific combinations of alternative forest management practices were based on parallel research and input from local forest stakeholders. For each case study, a specific forest growth simulator was used. In general, the climate scenarios applied did not cause fundamentally different ecosystem service outputs at the case study level. Our results revealed almost no reduction in outcomes for biodiversity indicators with an increase in wood production, and in some cases synergistic results occurred when diversity was actively promoted as part of the management concept. Net carbon uptake was not strongly correlated with biodiversity, indicating that biodiversity-friendly forest management doesn't need to curtail carbon sequestration. Notably, we obtained heterogeneous results for the relation between sustainable wood production and net carbon uptake. Most scenarios resulted in a more or less reduced net carbon uptake over the long term, often due to stand age class distribution shifts. Levels of sustainable wood production varied widely during the simulation period, from significant increases (Sweden, Lithuania) to minor changes (Slovakia, Turkey) and slight decreases (Ireland, Netherlands). We place our results within the larger context of European forest policy and the challenges of simulating and contrasting forest biodiversity and the ecosystem services that societies depend on.
AtıfScopus75WoS67OpenAlex76İncele - MakaleAçık Erişim2020Scopus SJRQ1Tracking the timing of Neotethyan oceanic slab break-off: Geochronology and geochemistry of the quartz diorite porphyries, NE Turkey
Karsli, Orhan; Dokuz, Abdurrahman; Aydin, Faruk; Uysal, Ibrahim; Sengün, Firat; Kandemir, Raif; Santos, Jose Francisco; Andersen, Tom
The initiation of the break-off of the northern branch of the Neotethyan oceanic lithosphere is an important but poorly understood event in the geology of the Sakarya Zone (SZ) in northeastern Turkey. Although it is wellknown that Latest Cretaceous intrusives (-70 Ma) and early Eocene adakitic magmatic rocks are present in the eastern SZ, the outcrops of the early Eocene non-adakitic rocks are very limited, and their tectono-magmatic evolution has not been studied. We describe a small outcrop of non-adakitic quartz diorite porphyry in the Kov area of the Gumushane region in northeastern Turkey. The genesis of these porphyries is significant in evaluating the syn-to post-collision-related magmatism. The LA-ICP-MS zircon U-Pb dating revealed that the Kov quartz diorite porphyries (KQDP) formed at ca. 50 Ma, coeval with adakitic rocks, and-20 Myr later than the slab rollback-related intrusive rocks. The KQDPs are calc-alkaline in composition and enriched in large ion lithophile elements (LILEs) and light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs; e.g., Nb, Ta, Ti), with significant negative anomalies of Nb, Ta, and Ti but positive anomalies of Th, U, and Pb. Isotopic compositions of the samples show limited range of variation and slight enrichment of 87Sr/86Sr(t) (0.70489 to 0.70555), epsilon Nd(t) (-1.4 to -1.2) with TDM of 1.11 to 1.61 Ga. Pb isotopic ratios of the samples point to an enriched mantle source. They were likely crystallized from the melt that originated from an EM2-type spinel-facies subcontinental lithospheric mantle (SCLM), followed by the fractionation with insignificant crustal assimilation. The SCLM was metasomatically enriched, and the metasomatic agent was likely H2O-rich fluids rather than sediments released from subducting oceanic crust during the Late Cretaceous closure of the Neotethyan oceanic lithosphere. In conjunction with the geological background and previous data, we propose that the generation of the KQDPs resulted from a slab break-off event that caused ascending or infiltration of hot asthenosphere, triggering mantle melting. Such sporadic occurrences of the KQDPs, with coeval adakitic rocks in the SZ, are likely associated with the onset of extensional tectonics due to the earlier stage of slab break-off along the region during the early Eocene period.
AtıfScopus6WoS6OpenAlex7İncele - MakaleYalnız künye2020Scopus SJRQ1Silurian to Early Devonian arc magmatism in the western Sakarya Zone (NW Turkey), with inference to the closure of the Rheic Ocean
Karsli, Orhan; Sengün, Firat; Dokuz, Abdurrahman; Kandemir, Raif; Aydin, Faruk; Andersen, Tom
The Rheic Ocean is the most significant Paleozoic ocean that detached peri-Gondwana terranes from the northern Gondwana margin throughout the closure of the Iapetus Ocean. The suture of the Rheic Ocean spreads from Mexico to the Middle East, and the timing of its final closure is well-documented by the rocks formed in the Variscan-Alleghanian-Ouachita orogeny which led to the formation of the supercontinent Pangaea. However, as robust paleomagnetic and quantitative data are mostly lacking, the onset and evolution of the subduction of the Rheic Ocean are highly speculative, and they require further confirmation. Recently, the well-preserved metagranitoids along the western Sakarya Zone (SZ) in Anatolia have been identified, and they provide new data that improve our knowledge on the evolution of the Early Paleozoic Rheic Ocean along the northern Gondwana. Here, we present new geochronological, in situ zircon Hf isotope, and whole-rock geochemical analyses of these metagranitoids from the western SZ to enhance our understanding of the subduction processes of the Rheic Ocean. IA-ICP-MS zircon U-Pb dating demonstrated that the Boziiyuk and Borcak metagranitoids from the western SZ were emplaced during the Silurian to Early Devonian (431 +/- 2.7 to 403 +/- 3.5 Ma). The both granitoids have medium- to high-K. calc-alkaline magmatic character, and exhibit peraluminous to slightly metaluminous geochemical signature. They show a typical arc pattern in terms of trace elements and have a uniform, moderate negative epsilon(Hf) (t) of -3.2 to -9.7, with Mesoproterozoic Hf depleted mantle model ages (T-DM1 = 12 to 1.4 Ga). The geochemical and isotopic characteristics are not consistent with those of depleted mantle melts and melts derived from the crustal rocks in an intracontinental environment. Instead, the parental magma is likely generated from the partial melting of a homogeneous and enriched mantle wedge source. We propose that the Silurian to Early Devonian arc-related magmatism is associated with a northward subduction episode of the Rheic Oceanic lithosphere beneath the peri-Gondwana terranes. Hence, we consider that the opening of Paleotethys Ocean formed in a back-arc basin of subduction in Andean style to the north rather than a continental rift to the south in response to south-directed and short-lived supra-subduction zone (SSZ)-type subduction during the Silurian to Early Devonian. (C) 2020 Elsevier B.V. All rights reserved.
AtıfScopus21WoS18OpenAlex17İncele - MakaleAçık Erişim2020Scopus SJRQ1Dynamic thermal modelling of PV performance and effect of heat capacity on the module temperature
Tuncel, B.; Ozden, T.; Balog, R. S.; Akinoglu, B. G.
One of the main weaknesses of Si-based Photovoltaic (PV) solar modules is the sensitivity of their efficiency to module (cell) temperature. Especially in locations with long hot seasons, the efficiency loss of PVs due to high temperatures should be considered carefully. Thermal modelling is a method to predict the performance of a PV module using essentially the 1st law of thermodynamics and available data. In this paper, a transient thermal model is described, which considers hourly meteorological data, including wind speed and direction, module parameters, and locational information. In transient analysis, the heat capacity value of PV panel is required, but it is not a parameter specified in the manufacturer's datasheet. Experiments on the heat capacity of PV modules are missing in the literature. The thermal model provides verified performance analysis for a poly-c-Si PV module installed in Ankara, Turkey, with a calculated heat capacity value. And a sensitivity analysis for the heat capacity of the transient thermal model is performed. It is found that the model results are almost invariant under changing module heat capacity values.
AtıfScopus39WoS27OpenAlex41İncele - MakaleAçık Erişim2020Scopus SJRQ1Effect of ultrasonication treatment on structural, physicochemical and bioactive properties of pasteurized rosehip (Rosa canina L.) nectar
Atalar, Ilyas; Saricaoglu, Furkan T.; Odabas, Halil I.; Yilmaz, Volkan A.; Gul, Osman
The effect of ultrasonication process (US) on the physical and bioactive properties of pasteurized rosehip nectar was investigated. In order to solve sedimentation problem, two amplitude levels (50 and 100%) and different treatment times (5, 10, 15 and 30 min) were applied to rosehip nectars. Mean particle size decreased as amplitude and treatment time increased. US treatment caused to increase in redness and yellowness values of nectars and also color change was found noticeable as 1.9-2.6 at 100% amplitudes. US treated samples showed no sedimentation during storage for 15 days while control sample displayed 74% colloidal stability. All samples showed shear-thinning behavior and were characterized as weak gel network. Total phenolic and carotenoid contents and antioxidant activity was increased by US treatment, however, ascorbic acid content decreased. US treatment can be an alternative technology preventing sedimentation problems during shelf life with minimally affecting bioactive and physical properties of rosehip nectar.
AtıfScopus19WoS12OpenAlex20İncele - MakaleAçık Erişim2020The Value of Cardiotrophin-1 in the Diagnosis, Severity, and Prognosis of Pulmonary Embolism
Pasli, Sinan; Asik, Olgun; Imamoglu, Melih; Çiçek, Mustafa; Yadigaroglu, Metin; Dogramaci, Seniz; Mentese, Ahmet; Sahin, Mursel; Tatli, Ozgur
Aim: Pulmonary embolism (PE) is a life-threatening condition that requires early diagnosis and treatment. There is still a need for precise and non-invasive biomarkers that can be used to diagnose PE. This study aimed to determine the diagnostic value of Cardiotrophin-1 (CT-1) in patients with acute PE and ascertain the relationship between serum CT-1 level and disease prognosis and severity. Materials and Methods: In this prospective study, the serum CT-1 levels of 165 patients with suspected acute PE were measured. The patients were divided into two groups, PE (+) and PE (-), based on their computed tomography angiography results. Their serum CT-1 levels were compared. Results: The CT-1 levels of the PE (+) group (median=4.18 pg/mL, range=3.57-9.55 pg/mL) was non-significantly (p=0.08) different from those of the PE (-) group (median=4.38 pg/mL, range=3.57-51.64 pg/mL). Based on the severity of the condition, there were significant differences (p=0.001) in the CT-1 levels of the patients in the intermediate-low risk group (median=4.19 pg/mL, range=3.62-5.32 pg/mL), intermediate-high risk group (median=4.06 pg/mL, range=3.57-9.31 pg/mL) and high risk group (median=5.01 pg/mL, range=3.89-9.55 pg/mL). Based on the clinical course, the CT-1 levels of the patients in the good clinical course group (median=4.15 pg/mL, range=3.57-9.31 pg/ml) were significantly different (p=0.004) from those in the poor clinical course group (median=4.53 pg/mL, range=3.66-9.55 pg/mL). Conclusion: CT-1 level was not observed to be a precise biomarker for the diagnosis of acute PE. However, our study demonstrated that the serum CT-1 levels can be used as a biomarker for ascertaining the severity and prognosis of patients with PE.
- MakaleYalnız künye2020Scopus SJRQ2Mineralogy, chemistry, and genesis of zeolitization in Eocene tuffs from the Bayburt area (NE Turkey): Constraints on alteration processes of acidic pyroclastic deposits
Cicerali, Derya; Arslan, Mehmet; Yazar, Emel Abdioglu; Yücel, Cem; Temizel, Irfan; Park, Sohyun; Schroeder, Paul A.
Eocene vitric tuffs in the Bayburt area (NE Turkey) possess a dacite-rhyodacite composition and contain abundant altered glass shards and flattened fibrous pumice with lesser amounts of pyrogenic minerals (plagioclase, quartz, biotite, and sanidine). Zeolitization is common and generally develops in the glassy components. The main zeolite mineral found in the tuffs is clinoptilolite, with lesser amounts of analcime and mordenite (?). Smectite is the dominant clay mineral, with lesser amounts of kaolinite also present. Opal-CT, calcite, and dolomite occur as secondary minerals. Scanning electron microscopy studies reveal the dissolution of glass, with the development of popcorn-textured smectites and tabular clinoptilolites developed. The opal-CT spheres found on the clinoptilolite crystals appear to have crystallized simultaneously and are due to excess silica in the environment. Fibrous mordenite (?) also developed on the clinoptilolites. In the clinoptilolites R-r = 0.81-0.82, Si/Al = 4.20-4.70, and K+ is the dominant exchangeable cation (0.65-3.30) seen, together with lesser amount of Ca2+ (0.39-2.25) and Na+ (0.02-2.16). The degree of zeolitization increases with the content of glassy component in the tuffs. The formation of K-clinoptilolite is controlled by the SiO2/Al2O3 (4.9-7.0) and K2O/Na2O (0.8-10.8) ratios in the zeolitized tuffs. delta O-18(V-SMOW) and delta DV-SMOW values of clinoptilolite-rich tuffs range from 22 to 25.6960 and from -96 to -111 parts per thousand, respectively, which suggests that zeolitization occurred at low temperatures (30-55 degrees C) via fluid-rock interactions. Smectite was initially formed from the devitrification of glassy components and is associated with the increase in (Na+ +K+ +Ca2+)/H+ activity and the presence of high pH similar to-9-10) fluids. The zeolites subsequently developed within a saline-alkali shallow marine environment.
AtıfScopus14WoS10OpenAlex14İncele