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Koleksiyondaki öğeler
- Derleme MakaleAçık Erişim2023Scopus SJRQ1“Who am I?” A qualitative meta-synthesis of Chemotherapy‐induced alopecia and body image perception in breast cancer patients
Kocan, Sema; Aktug, Cemile; Gursoy, Ayla
Background: Since alopecia may be the first physical evidence and sign of cancer diagnosis and treatment, it may have a more serious and challenging effect on a woman than the loss of breast tissue. Objective: The purpose of this study was to summarize the current qualitative research which explores the body image perceptions of breast cancer patients with chemotherapy-induced alopecia. Material and methods: We searched three electronic databases and reviewed studies from December 2011 to December 2021 for qualitative results analysing the experiences of women with breast cancer and chemotherapy-induced alopecia. The Joanna Briggs Institute critical (JBI) appraisal tool was used to assess the quality of the targeted studies. The Meta-synthesis process developed by Sandelowski and Barroso was used to collect and analyse the data. Results: We discovered two main and five sub-themes from the meta-synthesis findings of 11 qualitative studies involving 225 women. The main themes were “I am not comfortable in this body” and “Who am I?”. The first main theme revealed patients’ intense reactions to their hair loss: “I'm in emotional chaos”, “I am looking for a place to hide” and “I knew it and now I’m experiencing it”.The second main theme of “Who am I?” contained two sub-themes: “What did my hair take from my femininity when it was gone?” and “Will I lose my partner after my hair?”. Conclusion: Meta-synthesis provided an up-to-date and integrated interpretation of scientific results about the experiences of women with breast cancer, alopecia, and their body image perceptions. This interpretation will facilitate a more comprehensive understanding of the alopecia-body image relationship. Thus, the aim of the meta-synthesis results is that these will contribute to nurses’ understanding of how alopecia, although a temporary symptom, affects women's perceptions of body image.
AtıfScopus27WoS24OpenAlex23
İncele - MakaleYalnız künye2024Scopus SJRQ1Human health risk assessment of heavy metals accumulation in different genders and tissues of whiting fish (Merlangius merlangus euxinus Nordmann, 1840) from Rize, Turkey
Şirin, Murat; Bayrak, Esra Yılmaz; Baltaş, Hasan
The contamination of fish resulting from marine pollution is a major concern, as it poses potential adverse effects on human health. Therefore, heavy metal concentrations (Cr, Fe, Ni, Cu, Zn, and Pb) in different genders and tissues (muscle, liver, gonads and gills) of whiting fish collected from fish markets in Rize province were determined by Inductively–coupled plasma optic emission spectrometry (ICP–OES). The concentration ranges of heavy metals in all tissue samples, based on the overall average, were as follows (mg/kg wet weight): Cr: 0.081–0.25, Fe: 2.3–40, Ni: 0.070–0.095, Cu: 0.33–1.01, Zn: 3.0–20, and Pb: 0.015–0.043. The results indicated that the liver and gills exhibited a higher metal accumulation capacity compared to other tissues, whereas the muscle consistently displayed the lowest metal concentrations. The metal concentrations in the muscle were found to be below the maximum permissible levels set by international organizations for seafood. Additionally, calculated estimated daily intake (EDI), metal pollution index (MPI), target hazard quotient (THQ), total exposure hazard index (HI), and target carcinogenic risk (TR) indicate no potential risk to humans from whiting fish consumption.
AtıfScopus22WoS21OpenAlex21İncele - MakaleAçık Erişim2023Scopus SJRQ2Double-edged perspectives on service robots: working with robots and robots’ future career impacts
Seyitoğlu, Faruk; Atsız, Ozan; Taş, Sedat; Kaya, Fazıl
This study investigates the perspectives of undergraduate tourism and hospitality students on working with robots and the influence of the widespread use of robots on future careers. Accordingly, interviews were conducted with thirty students. The findings include two main categories: working with robots in the tourism and hospitality industry (advantages of working with robots, disadvantages of working with robots, and willingness to work with or implement robots) and future career impacts of the widespread use of robots (threatening human employment, reducing the motivation toward working in the industry, unfair competition between humans and robots, negative psychological impact/feeling of being less skilled than robots, and giving up/changing the industry). This research contributes to the literature by revealing the dimensions of working with robots and the future career impacts of the widespread use of robots. A model of future career impacts of the widespread use of robots was also proposed.
AtıfScopus11WoS11OpenAlex12İncele - MakaleAçık Erişim2022Automatic prediction of covid-19 from chest-computed tomography (CT) images using deep learning architectures; [Derin öğrenme mimarilerini kullanarak göğüs BT görüntülerinden otomatik Covid-19 tahmini]
Turk, Veysel; Catal Reis, Hatice; Kaya, Serhat
Machine learning has been actively used in disease detection and segmentation in recent years. For the last few years, the world has been coping with the Coronavirus disease 2019 (COVID-19) pandemic. Chest-computerized tomography (CT) is often a meaningful way to detect and detect patients with possible COVID-19. This study aims to classify COVID-19 and non-COVID-19 chest-CT images using deep learning (DL) algorithms and investigate whether we can achieve successful results in different parameters using four architectures. The study was performed on proved positive COVID-19 CT images, and the datasets were obtained from the GitHub public platform. The study evaluated four different deep learning architectures of VGG16, VGG19, LeNet-5, and MobileNet. The performance evaluations were used with ROC curve, recall, accuracy, F1-score, precision, and Root Mean Square Error (RMSE). MobileNet model showed the best result ; F1 score of 95%, the accuracy of 95%, the precision of 100%, recall of 90%, AUC of 95%, and RMSE of 0.23. On the other hand, VGG 19 model gave the lowest performance; F1 score of 90%, the accuracy of 89%, the precision of 90%, recall of 90%, AUC of 89%, and RMSE of 0.32. When the algorithms' performances were compared, the highest accuracy was obtained from MobileNet, LeNet-5, VGG16, and VGG19, respectively. This study has proven the usefulness of deep learning models to detect COVID-19 in chest-CT images based on the proposed model framework. Therefore, it can contribute to the literature in Medical and Engineering in COVID-19 detection research.
AtıfScopus2OpenAlex2
İncele - MakaleYalnız künye2022Scopus SJRQ2Effect of different objective functions on control performance of tuned mass damper for a high-rise building considering soil–structure interaction
Araz, Onur; Ozturk, Kasif Furkan; Cakir, Tufan
This paper deals with the optimization of the tuned mass damper (TMD) with different objective functions for high-rise building under earthquake motions considering soil–structure interaction (SSI). A study is conducted to search for the TMD that outperforms five objective functions (i.e., OF-1–OF-5) containing combinations of the structural responses and foundation responses. The main goal of the present study is to evaluate and compare the control performance of these five objective functions. The optimum parameters of TMD are obtained by particle swarm algorithm (PSA) to minimize the acceleration transfer function. To determine the dynamic response of a 40-story building under the influence of SSI, six different foundation soil conditions and eight different earthquake records are considered. The results show that the SSI effects on the dynamic response of the high-rise building resting on relatively soft soil types such as SD and SE are of critical importance. It is shown that the effectiveness of the optimum TMD designed by OF-1 is better than the others in suppressing the peak response values for all soil types. After OF-1, the best performances are obtained for OF-3 and OF-5 which yield approximately the same effectiveness. It is also found that different earthquake records, soil types and objective functions are very effective on the effectiveness of TMD.
AtıfScopus22WoS22OpenAlex25İncele - MakaleYalnız künye2024Scopus SJRQ1Axial resistance of elliptical hollow section K-joints made of high strength steel
Ozyurt, E.
The present study examined the axial resistance of welded elliptical hollow section (EHS) K-joints made of high-strength steel (HSS). The axial resistance of EHS K-joints was affected by a range of factors, including the geometrical parameters, orientations, chord pre-stress levels, and the mechanical properties of the high-strength steel grades. This research aimed to investigate the performance of welded EHS K-joints made of HSS under axial loading conditions with or without chord pre-stresses. Finite element analysis was employed for numerical simulations to analyze the nonlinear behaviour of EHS K-joints with HSS. It was observed from the numerical results that the orientation types significantly affected normalised resistance ratios. In contrast, β, γ, θ, and chord pre-stress levels had minimal impact, as comparisons were based on normalised resistance ratios. However, non-dimensional geometric parameters and chord pre-stress levels notably influenced the axial joint resistance of the HSS K-joints. As for predicting the axial resistances of EHS K-joints with HSS, the numerical results indicated that the existing reduction factor might be unsafe for the equivalent RHS method to be applied in the current design guides. Therefore, a new reduction factor was proposed for EHS K-joints with HSS that yield unsafe results.
AtıfScopus8WoS7OpenAlex7İncele - MakaleAçık Erişim2022Scopus SJRQ240Ar–39 Ar dating, whole-rock and Sr-Nd isotope geochemistry of the Middle Eocene calc-alkaline volcanic rocks in the Bayburt area, Eastern Pontides (NE Turkey): Implications for magma evolution in an extension-related setting
Kaygusuz, Abdullah; Yücel, Cem; Aydınçakır, Emre; Gücer, Mehmet Ali; Ruffet, Gilles
Discussions continue about whether Middle Eocene magmatism in the Eastern Pontides is associated with collision or subduction. This paper presents new whole-rock geochemistry, Sr-Nd isotopic and 40Ar-39Ar age data for Middle Eocene volcanic rocks from the Bayburt area of the Eastern Pontides (NE Turkey) to investigate their sources and evolutionary history. The new 40Ar–39Ar ages reveal that these volcanic rocks erupted between 44.6 ± 0.1 Ma and 43.5 ± 0.1 Ma, within the Lutetian (Middle Eocene). The studied volcanic rocks are composed of basalt, andesite, basaltic andesite and minor dacite lava and pyroclastic rocks. These rocks consist of plagioclase, amphibole, pyroxene, olivine, biotite, sanidine and minor quartz phenocrysts with Fe-Ti oxides. They have microlithic, hyalo-microlithic, porphyritic and rarely glomeroporphyritic textures. The volcanic rocks have low to high-K calc-alkaline affinities. They display enrichment in large-ion lithophile elements and depletion in high-field strength elements with high Th/Yb ratios, which indicate that the magmas forming the volcanic rocks were derived from lithospheric mantle sources enriched by mostly slab-derived fluids in the spinel stability field. 87Sr/86Sr(i) values vary between 0.70485 and 0.70551 and 143Nd/144Nd(i) values vary between 0.51255 and 0.51267. These data correspond to the mantle array on the isotope ratio diagram. The main solidification processes consist of fractional crystallization with minor assimilation. In light of the data obtained in this study together with data from previous studies, petrogenetic character of the Middle Eocene magmas from the southern parts of the Eastern Pontides may be explained by melting of an enriched lithospheric mantle source initially metasomatized by subduction fluids in a post-collisional extensional-related tectonic setting.
AtıfScopus17WoS14OpenAlex20İncele - DüzeltmeAçık Erişim2023Scopus SJRQ1Corrigendum to Understanding university students WHO do not want to volunteer in disasters: A qualitative study from Türkiye [Int. J. Disaster Risk Reduc. 96 (2023) 103994] (International Journal of Disaster Risk Reduction (2023) 96, (S2212420923004740), (10.1016/j.ijdrr.2023.103994))
Demirbilek, Ömer; Öztürk, Serkan
The authors would like to add the below sentence in the Acknowledgment section. This study was produced from a doctoral thesis. The authors would like to apologise for any inconvenience caused. Ömer Demirbilek completed his undergraduate and graduate education in disaster management. He is currently pursuing his doctorate in disaster management. He works as a lecturer in the Disaster Management Department of Sinop University. Her areas of interest are disaster education, management, and volunteering in disasters. He has works published in international books and journals.
- MakaleAçık Erişim2023Scopus SJRQ1Testing the Short, Medium, and Long-Term Effects of Shocks on Ecological Balance
Yilanci, Veli; Adali, Zafer; Çelik, Orkun; Bari, Bilgin
Ecological balance is an indicator of environmental degradation, which is computed as the difference between biocapacity and ecological footprint. In this study, we examine whether the effect of shocks on the ecological balance is permanent or temporary in the EU-15 countries, considering the period from 1961 to 2018. The application of unit root tests, with and without a Fourier function, indicates that the effects of shocks are temporary in only four countries. To reveal the persistence of shocks at different frequencies, that is, the short-, medium-, and long-run, we decomposed the ecological balance series by using the Discrete Wavelet Transform method. The unit root test results show that the effects of shocks are temporary in all countries in the short-run. However, the results also show that the shocks are temporary in nine countries in the medium-run and ten countries in the long-run. Thus, the implemented policies to balance ecology are not effective in the short-run but are effective in only six countries in the medium-term and in only five countries in the long-term. These findings demonstrate the importance of considering different frequencies when testing the effectiveness of empirically implemented policies. Regarding policy implications, this study suggests focusing on medium- and long-term environmental policies rather than short-term ones.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2022Scopus SJRQ1A countrywide analysis of 27 solar power plants installed at different climates
Ozden, Talat
The world is still heavily using nonconventional energy sources, which are worryingly based on carbon. The step is now alternative energy sources hoping that they will be more environmentally friendly. One of the important energy conversion forms by using these sources is photovoltaic solar systems. These type of power plants is on the increase in everyday on the world. Before investment a solar power plant in a specified region, a techno-economic analyse is performed for that power plant by using several meteorological data like solar irradiance and ambient temperature. However, this analyses generally lacks evaluation on effects of climatic and geographical conditions. In this work, 5 years of data of 27 grid-connected photovoltaic power plants are investigated, which are installed on seven different climate types in Turkey. Firstly, the power plants are categorized considering the tilt angles and Köppen–Gieger climate classification. The performance evaluations of the plants are mainly conducted using monthly average efficiencies and specific yields. The monthly average efficiencies, which were classified using the tilts and climate types were from 12 to 17%, from 12 to 16% and from 13 to 15% for tilts 30°/10°, 25° and 20°, respectively. The variation in the specific yields decrease with elevation as y(x) = − 0.068x + 1707.29 (kWh/kWp). As the performances of photovoltaic systems for some locations within the Csb climatic regions may relatively lower than some other regions with same climate type. Thus, techno-economic performance for PVPP located in this climate classification should be carefully treated.
AtıfScopus6WoS2OpenAlex8İncele - MakaleAçık Erişim2023Agus Moh Najib's Thoughts on the Interconnection of Islamic Law and National Law
Muhajir; Nisa, Ihda Shofiyatun; Munawar, Akhmad; Karimullah, Suud Sarim
The number of controversies and debates about integrating Islamic law into the national legal system in Indonesia has led to many counter-productive perceptions, so progressive thinking is needed all parties can accept that. Therefore, this study examines the thoughts of Agus Moh Najib, a Muslim scholar, on integrating Islamic law into the national legal system to create a fair legal system by the demands of society and the state. Methodologically, this research uses a philosophical approach with library research and is also descriptive-analytical qualitative research. The results of this study state that Islamic Law and Indonesian law have several interrelationships and interconnections perspectives on Agus Moh Najib's. He provides recommendations that to maximise the interconnectivity of Islamic law to national law, the first step that needs to be taken is to redesign, reformulate and renovate the ushul fiqh building, which is the basis for the formation of Islamic law without having to tear it down by reviewing existing concepts and theories so that the role of ushul fiqh can be more optimal in developing Islamic legal science that contributes to the formation of laws and regulations in Indonesia. Then harmonisation is carried out between Islamic law and various legal sciences developed in Indonesia regarding subject matter and language. In other words, it is necessary to strive for the formation of the Islamic law that is in harmony with legal science in general based on the ideal moral norms of the core teachings of Islam and also considers the culture and empirical realities that exist in plural Indonesian society.
AtıfScopus13OpenAlex12İncele - MakaleYalnız künye2024Scopus SJRQ1The Elephant in the Room: New Skills and Work Dimensions of Turkish White Goods Industry Engineers in Industry 4.0 Era
Demirbag, Kubra Simsek; Yildirim, Nihan
While the emergence of the Industry 4.0 (I4.0) concept has heightened concerns about how digital transformation will affect employees, engineers who create, develop, and spread the I4.0 tools and technologies are ignored. Also, the industries with the highest digital maturity should be prioritized since they are the readiest ones for the I4.0 transformation. In this context, our focus is the engineers in the Turkish white goods industry, one of the three industries with the highest level of digital maturity in Turkey. We aim to determine the new skills expected from engineers and to uncover the impact of the perceived usage level of I4.0 technologies by engineers on the dimensions of engineering work. In this article, we conducted two separate surveys for engineers and managers and sought answers to four research questions using factor analysis and regression analysis. The results show that the new skills are divided into intrinsic motivation, technology, and data and information skills. At the same time, the perceived usage level of I4.0 technologies influences the social characteristics dimension of engineering work. We revealed that the sociability level of the engineers who use data analytics, artificial intelligence, simulation, and RFID/RTLS technologies while performing their jobs tends to decrease, while the sociability level of the engineers who use adaptive robots and additive manufacturing technologies gets higher.
AtıfScopus4WoS2OpenAlex6İncele - MakaleYayıncıda açık erişim2023Scopus SJRQ3A facile and sensitive coprecipitation method coupled with flame atomic absorption spectrometry for quantification of Cu(II) ions in complex matrices
Ozdes, Duygu; Duran, Celal; Bektas, Hakan; Mentese, Emre
In the present investigation, the application of an organic coprecipitant, 2-[5,6-dichloro-2-(2-bromobenzyl)-1H-benzimidazole-1-yl]acetohydrazide (DIBBA), for separation and preconcentration of Cu(II) ions in fruit and water samples through a new carrier element free coprecipitation (CEFC) method was researched for the first time. Flame atomic absorption spectrometer (FAAS) was used for the analyses of Cu(II) ions. The main effective experimental factors such as solution pH, DIBBA quantity, waiting time, centrifuge speed and duration and volume of sample on the recovery efficiency of Cu(II) ions were explored in detail. Under the optimized conditions the preconcentration factor (PF), relative standard deviation (RSD), and limits of detection (LOD) was achieved as 50, 3.4 % and 0.44 µg L-1, respectively. No interference effects were detected by virtue of the presence of various foreign ions. Satisfactory recoveries (in the range of 94.4 to 103.0 %) in the environmental sample matrix were acquired. After being validated the recommended selective, low cost, simple and rapid CEFC method by spike/recovery tests, it was properly implemented for the low levels detection of Cu(II) ions in sour cherry, mulberry, apple, and peach as fruit samples and stream and sea water samples without any significant matrix effects.
AtıfScopus4WoS4OpenAlex4İncele - MakaleAçık Erişim2022Scopus SJRQ1Seismic performance of a high-rise building by using linear and nonlinear methods
Çavdar, Özlem
In this paper, the seismic behavior of the existing reinforced concrete tall building is investigated by using the linear and nonlinear dynamic methods. The selected existing reinforced concrete structure was designed according to Turkey Seismic Code-2007. The performance analysis according to the Turkey Building Earthquake Code-2019 is realized in a 41-story reinforced concrete shear wall-framed structure in Istanbul where active fault lines are located. For high-rise building, firstly, spectrum analysis according to mode superposition methods of linear computational methods used within the scope of strength-based design is performed. Turkey Building Earthquake Code-2019 advises a nonlinear deformation-based design approach to determine more accurately the behavior of high-rise building, as in the earthquake regulations of other developed countries. In addition, the nonlinear time history analyses of building were performed. At the end of the study, torsional irregularity is seen on the normal floors and intermediate floor; stiffness irregularity was found on second floors. In addition, it has been observed in some of the oblique columns of the building that load bearing capacities were exceeded due to creep, axial compressive loads and severe damages occurred. According to the Turkey Building Earthquake Code-2019, the high-rise reinforced concrete shear wall building is not expected to satisfy life safety performance levels under design earthquake.
AtıfScopus5WoS3OpenAlex6İncele - MakaleAçık Erişim2024Scopus SJRQ2Design and fabrication of low-cost microsystems for production of chitosan particles; [Kitosan parçacıklarının üretimi için düşük maliyetli mikrosistemlerin tasarımı ve fabrikasyonu]
Akay, Seref; Özdilek, Hasret
Recent research has focused on the methods for administration of medications in a controlled manner while minimizing side effects. Cross-linked hydrogels have wide application area as nanocarriers. There are many approaches for developing suitable methods to produce ideal particles. Advances in microtechnology have been considered as a solution to produce controlled drug delivery systems, however, it is limited due to the necessity for specialized laboratories. In this study, a simple method to produce antibiotic-loaded chitosan particles is proposed. Production was carried out with two different designs, a syringe-based flow focusing system (outer diameter of 1 mm, inner diameter of 120 µm) and microchannel with 250 µm width and 100 µm height fabricated with the computer numerical control (CNC). Sodium Triphosphate (TPP) was used as cross-linking agent for the production of particles and the effects of the concentration and flow rates on the particle formation was investigated. It has been observed that particles can be produced in a syringe-based system, but the resulting particles are not homogeneous. In the studies carried out with CNC microchannel, it was determined by SEM analysis that the obtained particles ranged in size from 39 to 771 nm, and it was seen that the CNC microchannel was more effective at low and equal flow rates (25 µl/min). It has been found that increasing the flow rate and concentration of chitosan increases the particle size. It was determined that Ampicillin loaded particles synthesized with the CNC microchannel exhibited high inhibition against Gram positive and Gram negative bacteria. These results show that the proposed approaches for the design of microsystems can be used in the formation of drug carriers without the need for specialized laboratories and expertise.
AtıfScopus1İncele - MakaleYalnız künye2023Scopus SJRQ2Application of Magnetic Fe3O4 Alnus glutinosa Sawdust Biochar/SiO2/CTAB as a New Sorbent for Magnetic Solid Phase Extraction of Heavy Metals from Fruit and Waters Samples
Duran, Celal; Ozdes, Duygu
The coating of magnetic Fe3O4 Alnus glutinosa sawdust biochar with SiO2 and further functionalising by cetyltrimethyl ammonium bromide (CTAB), a cationic surfactant, was described for the first time in the current paper. The magnetic Fe3O4 Alnus glutinosa sawdust biochar/SiO2/CTAB(MAGBC/SiO2/CTAB) was implemented to separate and preconcentrate the Cu2+, Cd2+, and Pb2+ions efficiently in waters and a number of fruit samples by solid-phase extraction (SPE) method. Adsorbent characterisation was realised by fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Fundamental factors affecting the extraction yield of the analyte ions including solution pH, adsorbent amount, sample volume and desorption contact time were fully researched and optimised as 8.0, 0.25 g, 500 mL and 60 min, respectively, and the eluent was specified as 5.0 mL of 0.1 M of HCl solution. The adsorption equilibrium eventuated after 15 min of contact time and it was noticed that the chemisorption mechanism was dominant upon the analyte ions adsorption. The limits of detection (LOD) were calculated as 0.24, 0.62 and 1.55 µg L−1 and the limits of quantitation (LOQ) were determined as 0.81, 2.08, and 5.17 µg L−1 for Cu2+, Cd2+, and Pb2+ ions, respectively. The relative recoveries (RR%) were in the ranges of 93.3–103.4%, 92.5–102.8%, and 91.8–101.9% for Cu2+, Cd2+, and Pb2+ ions, respectively, while the relative standard deviations (RSD%) were obtained lower than 4.0% (n = 10) by applying the method at optimised conditions. The maximum adsorption capacities of MAGBC/SiO2/CTAB were obtained as 123.7, 80.0 and 118.5 mg g−1for Cu2+, Cd2+, and Pb2+ions, respectively. Consequently, the developed new, simple, rapid, sensitive, and economical SPE method based on MAGBC/SiO2/CTAB was successfully implemented to waters and some of the fruit samples to determine the Cu2+, Cd2+, and Pb2+ions simultaneously.
AtıfScopus15WoS17OpenAlex17İncele - MakaleYalnız künye2022Scopus SJRQ2A note on linear non-Newtonian Volterra integral equations
Güngör, Nihan
In this study, the Volterra integral equations are defined in the non-Newtonian calculus with the aid of ∗ -integral. The focus of this study is obtaining the solution of linear non-Newtonian integral equations. The ∗ -resolvent kernel method, successive approximations method and Adomian decomposition method are applied for solving non-Newtonian integral equations in the non-Newtonian sense. Some numerical examples are presented to explain the procedure of these methods. Finally, a model that describes a type of the exponential growth model is proposed in the sense of non-Newtonian calculus as an example.
AtıfScopus8WoS8OpenAlex7İncele - MakaleYalnız künye2019Scopus SJRQ43Bio-Based Additives to Improve Diesel Engine Performance and Emissions
Sezer, İsmet
This study investigates addition of ethanol and diethyl ether into diesel fuel. Base fuel and three different blends were used in the tests. The experiments were performed at engine speed of 1500 rpm and under various loads by single cylinder diesel engine. Injection, combustion, performance and emissions parameters were evaluated for base fuel and blends. Results show that injection pressure decreases for all blends, and DEE addition causes delay in injection timing. Burnt mass fraction is lower for ethanol and DEE blends during early combustion phase, while it increases with DEE blends during progressive combustion phase. Ethanol and DEE blends also give reductions in cylinder pressure and temperature. Generally, air excess coefficients increase but exhaust gas temperature decreases when using ethanol and DEE blends. Although ethanol blend causes decrements in engine power and torque, DEE blends give closer values to diesel fuel. Both ethanol and DEE blends yield improvement in brake thermal efficiency and reduction in brake specific fuel consumption. When using fuel blends, generally, decrements in NOx and CO2 emissions and increments in HC emission occur, while CO emission shows fluctuations depending on engine load.
- MakaleYalnız künye2016Scopus SJRQ1Systemic oxidant/antioxidant balance in human abdominal aortic aneurysm
Menteşe, Umit; Turan, Ibrahim; Usta, Sefer; Demir, Selim; Koral, Özgür; Öztaş Menteşe, Seda; Çavuşoǧlu, Ismail Gökhan; Karahan, Süleyman Caner; Alver, Ahmet; Doǧan, Orhan Veli
The aim of this study was to evaluate the oxidant-antioxidant balance in patients with abdominal aortic aneurysms (AAA). Forty-two consecutive patients with AAA and 46 control subjects were included. Total oxidant status (TOS) and total antioxidant status (TAS) levels were measured and the oxidative stress index (OSI) value determined. Serum TOS and OSI values in patients with AAA were higher than those in the controls (p<0.001, p<0.001, respectively). There was a positive correlation between abdominal aortic diameters, serum TOS levels (r=0.592, p<0.001) and OSI values (r=0.598, p<0.001). A cut-off value of 17.68 μmol H2O2 equivalent/L for TOS was associated with 86% sensitivity and 83% specificity and a cut-off value of 1.77 for OSI was associated with 86% sensitivity and 81% specificity for predicting AAA. Systemic oxidative imbalance develops in patients with AAA, particularly as a result of an increase in TOS.
AtıfScopus11WoS10OpenAlex10İncele - MakaleAçık Erişim2016Scopus SJRQ2Investigation of the inhibitory properties of some phenolic standards and bee products against human carbonic anhydrase I and II
Aygul, Imdat; Yaylaci Karahalil, Fatma; Supuran, Claudiu T.
Polyphenols are important secondary products of plants with the potential to inhibit carbonic anhydrases. The aim of this study was to investigate the inhibition effects of various phenolic standards, honey, propolis, and pollen species on human carbonic anhydrase I and II. The inhibition values (IC50) of the phenolics (gallic acid, protocatechuic acid, quercetin, catechin, tannic acid, and chrysin) ranged from 0.009 to 0.32 μg/mL, tannic acid emerging as the best inhibitor. The inhibition values of three different types of honey, heather, rhododendron, and chestnut ranged between 2.32 and 25.10 μg/mL, the chestnut honeys exhibiting the best inhibition. The ethanolic extracts of pollen and propolis exhibited good inhibitory properties, with IC50 values between 0.486 and 3.320 μg/mL. In order to evaluate the phenolic composition of bee products, phenolic profiles and total phenolic contents (TFC) were also measured. The inhibition ranking among the natural products studied was phenolic standards > propolis > pollen > honeys, and inhibition was related to TFC.
AtıfScopus13WoS12OpenAlex13İncele
