Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(47)
- Pat, Suat(29)
- Özen, Soner(29)
- Şenay, Volkan(24)
- Korkmaz, Şadan(23)
- Esmer, Yusuf(21)
- Şahin, Engin(21)
- Korkmaz, Özge(20)
- Cuce, Erdem(19)
- Öner, Erdal(18)
- Öztürk, Mesut(18)
- Artar, Musa(17)
- Yilmaz, Mustafa Tahsin(17)
- İspirli, Hümeyra(16)
- Ecem Bayram, Nesrin(15)
- Kaya, Yunus(15)
- Cinar, Mehmet(13)
- Cuce, Pinar Mert(12)
- Kamiloğlu, Aybike(12)
- Kutlu, Naciye(12)
- Mercan, Emin(12)
- Birinci, Ahmet(11)
- Bulut, Mehmet(11)
- Yaylacı, Murat(11)
- Bayram, Ozkan(10)
- Can, Zehra(10)
- Doğan, Zeki(10)
- Kahya, Cem(10)
- Karaali, Rabi(10)
- Pabuçcu, Hakan(10)
- Tosun, Figen Çam(10)
- Özdemir, Akın(10)
- Ayazoglu, Rabil(9)
- Battal, Fetullah(9)
- Bayram, Nesrin Ecem(9)
- Büte, Mustafa(9)
- Ertugrul, Mehmet(9)
- Kadakal, Mahir(9)
- Kaplan, Abdullah(9)
- Sarikaya, İsmail(9)
Yayınlar
- MakaleYalnız künye2022Scopus SJRQ1Structural and bioactive characteristics of a dextran produced by Lactobacillus kunkeei AK1
Yilmaz, Mustafa Tahsin; İspirli, Hümeyra; Taylan, Osman; Bilgrami, Anwar L.; Dertli, Enes
In this study, structural and techno-functional characteristics of an exopolysaccharide (EPS) produced by Lactobacillus kunkeei AK1 were determined. High-performance liquid chromatography (HPLC) analysis demonstrated that EPS AK1 was composed of only glucose units. 1H and 13C Nuclear magnetic resonance (NMR) analysis revealed that EPS AK1 was a dextran type EPS containing 4.78% (1 → 4)-linked α-D-glucose branches. The molecular weight of EPS AK1 was determined to be 45 kDa by Gel Permeation Chromatography (GPC) analysis. A high level of thermal stability up to 280 °C was determined for dextran AK1 detected by Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). Dextran AK1 appeared as regular spheres with compact morphology and as irregular particles in the solution with no clear cross-linking between the chains of the polysaccharide observed by Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) analysis, respectively. X-ray diffraction analysis (XRD) analysis demonstrated that dextran AK1 had a crystalline structure. A relatively strong antioxidant activity was observed for dextran AK1 determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging and cupric reducing antioxidant capacity (CUPRAC) tests. Finally, only a digestion ratio of 3.1% was observed for dextran AK1 following the in vitro simulated gastric digestion test.
AtıfScopus43WoS39OpenAlex41
İncele - MakaleYalnız künye2022Scopus SJRQ3Biocatalytic asymmetric synthesis of (S)-1-indanol using Lactobacillus paracasei BD71
Kalay, Erbay; Dertli, Enes; Şahin, Engin
Enantiopure benzo-fused cyclic alcohols have been used as a building block of a drug for Parkinson’s disease. Biocatalytic reduction of ketones is one of the most promising and significant routes to prepare optically active alcohols. In this study, the reductive capacity of seven lactic acid bacteria (LAB) strains were investigated as whole-cell biocatalyst in the enantioselective reduction of 1-indanone (1). Lactobacillus paracasei BD71 was found to have the best reductive capacity. Effects of different parameters such as pH, incubation time, agitation speed and temperature, on enantiomeric excess (ee) and conversion were investigated in a bioconversion. (S)-1-indanol ((S)-2) could be used as precursor for the synthesis of rasagiline mesylate TVP1012 for the therapy of Parkinson’s illness. It was produced in gram-scale (5.24 g), high yield (93%) and enantiomerically pure form using L. paracasei BD71 whole-cell biocatalysts. Also, to our knowledge, this is the first report on production of (S)-2 using whole-cell catalyst in enantiopure form, excellent yield, conversion and gram scale. This is a cheap, clean and eco-friendly process for production of (S)-2 compared to chemical processes.
AtıfScopus6WoS6OpenAlex6İncele - MakaleYalnız künye2022Scopus SJRQ3Optimization of asymmetric reduction conditions of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone by Lactobacillus fermentum P1 using D-optimal experimental design-based model
Özdemir, Akın; Dertli, Enes; Şahin, Engin
The biocatalytic asymmetric reduction of prochiral ketones is a significant transformation in organic chemistry as chiral carbinols are biologically active molecules and may be used as precursors of many drugs. In this study, the bioreduction of 1-(benzo [d] [1,3] dioxol-5-yl) ethanone for the production of enantiomerically pure (S)-1-(1,3-benzodioxal-5-yl) ethanol was investigated using freeze-dried whole-cell of Lactobacillus fermentum P1 and the reduction conditions was optimized with a D-optimal experimental design-based optimization methodology. This is the first study using this optimization methodology in a biocatalytic asymmetric reduction. Using D-optimal experimental design-based optimization, optimum reaction conditions were predicted as pH 6.20, temperature 30 °C, incubation time 30 h, and agitation speed 193 rpm. For these operating conditions, it was estimated that the product could be obtained with 94% enantiomeric excess (ee) and 95% conversion rate (cr). Besides, the actual ee and cr were found to be 99% tested under optimized reaction conditions. These findings demonstrated that L. fermentum P1 as an effective biocatalyst to obtain (S)-1-(1,3-benzodioxal-5-yl) ethanol and with the D-optimal experimental design-based optimization, this product could be obtained with the 99% ee and 99% cr. Finally, the proposed mathematical optimization technique showed the applicability of the obtained results for asymmetric reduction reactions.
AtıfScopus6WoS6OpenAlex7İncele - MakaleYalnız künye2022Scopus SJRQ1Comparison of the probiotic characteristics of Lactic Acid Bacteria (LAB) isolated from sourdough and infant feces
Kaya, Yasemin; Erten, Tayyibe; Vurmaz, Melike; İspirli, Hümeyra; Şimşek, Ömer; Dertli, Enes
Probiotics are beneficial microorganisms with certain characteristics such as survival under gastrointestinal conditions, adhesion to intestinal surface and different functions which result in several health benefits to host. With this regards, this study aimed to isolate Lactic Acid Bacteria (LAB) from sourdough and human feces as two different environments and to test their potential probiotic functions. In total nine distinct isolates were assessed with several probiotic functions such as in vitro adhesion to human colon cells, antimicrobial activities and survival under harsh gastrointestinal conditions. In general, distinct strains showed strong antimicrobial activity against the pathogenic and fungal strains tested in this study. Importantly, the adhesion levels to HT29 cells were determined between 0.29 % and 9.54% and Lactobacillus paracasei F7B showed the highest adhesion. All isolates tolerated the bile salt after 24 h and the infant feces isolates showed good survival characteristics at pH 4.
AtıfScopus18WoS15OpenAlex18İncele - MakaleYayıncıda açık erişim2022Scopus SJRQ3EFFECTS OF MOLAR RATIO, FREQUENCY, WATER CONTENT AND TEMPERATURE ON DIELECTRIC PROPERTIES OF DEEP EUTECTIC SOLVENTS
Kutlu, N.; Yilmaz, M.S.; Erdem, G.M.; Sakiyan, O.; Isci, A.
The aim of the study is to determine the effect of process parameters on dielectric propertiesof deep eutectic solvents (DESs), which have beenwidely used in recent years. In this study, DESs wereprepared using choline-chloride as the hydrogenbondacceptor and glycerol, formic acid and aceticacid as the hydrogen-bond donor. The effect of differentprocess parameters such as molar ratio (1:2, 1:3and 1:4), water content (15%, 30% and 45%), temperature(25, 50 and 75 °C) and frequency on dielectricproperties of the DESs were examined. The highestdielectric constant values were found to be38.13±0.54, 44.96±0.07 and 46.74±0.02 for glycerol,formic acid and acetic acid, respectively for the processconditions of 25 °C temperature, 45% water contentand 1:4 molar ratio (at 2450 MHz). Moreover, forall DESs, it was found that a decrease in water contentresulted in a decrease in both dielectric constant andloss factor values. This can be explained by the absenceof free water molecules which are responsiblefrom dipole rotation mechanism. In light of the results,if DES will be used in microwave processes, formicor acetic acid containing DESs might give moresuccessful results compared to the ones with glycerol
AtıfScopus7WoS6OpenAlex8İncele - MakaleYalnız künye2022Scopus SJRQ3Investigation of Manganese Ion Removal from Waters Using Sewage Sludge Ash
Şahset, İrdemez; Duygu, Yeşılyurt; Torun, Ekmekyapar; Fatma; Sinan, Kul; Züleyha, Bıngül
In this study, the removal of Mn2+ ions from waters by the adsorption method using ash obtained from a treatment plant sludge burning unit, which is treatment plant waste and mostly disposed of in a landfill, was investigated. By determining the most suitable conditions for adsorption, adsorption kinetics, isotherms, and thermodynamic values were determined. In the experiments, 63.9% removal efficiency was achieved using 10 g/L adsorbent concentration for 10 mg/L Mn+2 under optimum conditions. As a result of the research, it was determined that the adsorption proceeds according to the pseudo-second-degree reaction and abides by the Langmuir isotherm. The thermodynamic constants of ΔH°=-4.866 kJ/mol and ΔS°= 21.44 J/mol were determined. As a result of this, the reaction was exothermic, spontaneous, and random, and adsorption was physical adsorption. As a result of the study, sewage sludge ash can be used in the treatment of water containing low concentrations of Mn2+.
AtıfScopus4OpenAlex2İncele - MakaleYalnız künye2022Scopus SJRQ2A study on the effects of nanostructure reinforcement on the failure load in adhesively bonded joints after the subjected to fully reversed fatigue load
Akpinar, Salih; Demir, Kübra; Gavgali, Esma; Yetim, Ali Fatih
Today, adhesively bonded joints are frequently used in the space and aviation industries. Joints used in these sectors are generally subject to dynamic loads due to environmental factors. This study experimentally and numerically investigated the static tensile loads of adhesively bonded joints after fully reversed (combination of tensile and compressive) fatigue loading where nanoadhesives–obtained by adding carbon nanostructures into aerospace grade structural adhesive–were used to bond the joints. Single lap joint specimens were produced using a nanocomposite adhesive obtained by adding 1 wt. % graphene, 1 wt. % carbon nanotubes-COOH and 1 wt. % fullerene C60 nanostructures to a DP460 structural adhesive. AA2024-T3 aluminum alloy and carbon fiber-reinforced composites (CFRCs) with a plain weave fabric (0/90°) were used as adherend materials. First, static tensile tests were applied to these joints to obtain their failure loads and then fully reversed sinusoidal fatigue tests were applied under a constant load amplitude, a frequency of 20 Hz and a load ratio of R = −1. Considering the failure loads obtained from the static tensile tests, 106 fully reversed fatigue loading cycles were applied–which was accepted as an infinite life–at 400 N, 800 N and 1200 N load levels. The static tensile failure loads and energy values absorbed of these joints were obtained and the change in the failure loads and energy values absorbed of the joints subjected to fatigue was investigated. The static failure loads of aluminum joints bonded with nanoadhesive and subjected to fully reversed fatigue loading increased by approximately 5% to 17%, depending on the nanostructure type added to the adhesive. Moreover, it was observed that there was an increase in loading of approximately 3% to 20% for the nanostructure reinforced joints obtained by using CFRCs with [0/90]6 stacking sequence.
AtıfScopus24WoS26OpenAlex28İncele - Kitap BölümüYalnız künye2022Foreign Language Apprehension and Interview Success
Dolgunsöz, Emrah
A job interview (or employment interview) is a common hiring method involving a conversation between a job applicant (interviewee) and a representative of an employer (interviewer) which is conducted to assess and evaluate the suitability of the applicant for the job (Dipboye, Macan and Shahani-Denning 2012). Depending on the company profile, the type of position and the job requirements, applicants are assessed and evaluated by companies in various dimensions ranging from presentability to academic efficiency. Although the criteria of companies vary a lot, all interviews engender a phenomenon called interview anxiety. It is generally the sum of annoying and unpleasant feelings before or during a job interview (McCarthy and Goffin 2004) due to reasons such as lack of control during interviews (Jones and Pinkney 1989) or being evaluated by a stranger in an interactional environment (Ayres et al. 1998). Common symptoms of interview anxiety manifest in long and frequent pauses while talking, slow speech or licking lips (Feiler and Powell 2016). Besides the regular procedures of employment interviews, global companies operating in non-English-speaking countries also assess the English language competency of the applicants during interviews. These companies value proficiency in English and it is a vital prerequisite of international communication for these types of companies. Foreign language (mostly English) assessment commonly focuses on the oral skills of the applicants and how good they are at communicating in the English language. The inclusion of this evaluation in job interviews certainly has merit; however, it also has the potential to increase the anxiety experienced during interviews due to the phenomenon called foreign language anxiety (FLA). Anxiety, in general, is defined as a common subjective feeling of unease, discomfort, and worry often accompanied by some physiological symptoms. FLA refers to the specific type of anxiety that emerges in a foreign language context (MacIntyre 1999). FLA causes low foreign language performance causing anxious individuals to commit various linguistic and phonological errors. Considering that employment interviews are already anxiety-provoking processes, this study hypothesizes that the inclusion of foreign language assessment during interviews elevates anxiety due to FLA, and aims to examine how this experience affects employment interview success.
- Kitap BölümüYalnız künye2022Reflections on sustainable consumption in the time of the COVID-19 pandemic
Yildiz, Tuğba; Başar, Enes Emre
The COVID-19 pandemic, which has caused severe diseases and deaths around the world, impacts not only health, but also daily lives, economies, and social systems. It is observed that consumers' purchasing patterns and preferences have changed significantly along with the new normal brought by the pandemic. For example, tons of plastic waste each day caused by disposable masks used to prevent the spread of viruses and the dramatic increase in disposable plastic tableware waste caused by the increasing number of food deliveries and takeaway meals as a result of measures such as social distancing and quarantine lead to significant environmental concerns. Furthermore, the additional packaging waste generated by e-commerce trades, which increases incrementally every day, is also an important source of environmental concerns. Although a growing number of consumers are interested in preserving the environment and participating more actively in sustainable consumption around the world, the changes caused by COVID-19 in their lives deeply affect sustainable consumption behaviors. Therefore, the discussion of how sustainable consumption behaviors of consumers are affected during the pandemic may contribute to the development of new strategies in this field. From this point of view, the effects of environmental concerns and sensitivity on sustainable consumption were first discussed from different aspects in this section. Then, the reflection of the pandemic on consumer behaviors was analyzed within a general framework. Finally, how the pandemic influenced the tendency toward sustainability was revealed.
- BildiriYalnız künye2022Boosting Dependency Parsing Performance by Incorporating Additional Features for Agglutinative Languages
Altıntaş, Mücahit; Tantuğ, A. Cüneyd; Vicic, J.; Kavsek, B.
In recent studies, the use of language models has increased noticeably and has made quite good contributions. However, using the proper representation and taking into account the complementary components are still among the issues to be considered. In this research, the impact of sub-word level sentence piece based word representation on the performance of dependency parsing has been demonstrated for agglutinative languages. Furthermore, we propose to use the sentence representation that holds all meaning of the sentence as an additional feature to improve dependency parsing. Our proposed enhancements are experimented on nine agglutinative languages; Estonian, Finnish, Hungarian, Indonesian, Japanese, Kazakh, Korean, Turkish, and Uyghur. We found that the sentence piece based token encoding has contributed parsing performance for the majority of the experimented languages. Using the entire meaning of the sentence as a complementary feature has enhanced parsing performance for six languages out of nine.
- MakaleYalnız künye2022Scopus SJRQ2Improvement of corrosion and stress corrosion properties of magnesium alloys by coating aluminum with the electric arc spray method
Catar, Recep; Altun, Hikmet
In this study, corrosion and stress corrosion behaviors of AZ31, AZ61, and AZ91 magnesium alloys coated with aluminum by the electric arc spray method were investigated in 3.5 wt.% NaCl solution. Structural properties of coated materials were investigated by scanning electron microscopy (SEM), energy dispersive X-ray analysis, and X-ray diffraction. Electrochemical properties were determined using the potentiodynamic polarization method in 3.5 wt.% NaCl solution. Potentiodynamic polarization curves showed that corrosion current density values did not change with coating in aluminum-coated samples by the electric arc spray method. In contrast, corrosion potential value increased toward positive values. Slow strain rate test (SSRT) was used to determine the stress corrosion behavior and stress corrosion indexes (ISCC), ultimate tensile strength (UTS), and elongation of AZ31, AZ61, and AZ91 magnesium (Mg) alloys were determined. As a result of the SSRT, the aluminum coating process decreased significantly the stress corrosion indexes of AZ31, AZ61, and AZ91 Mg alloys. The fracture of surface images was also examined in the SEM, and both intergranular and transgranular stress corrosion cracking were observed in all three alloys.
AtıfScopus6WoS5OpenAlex5İncele - MakaleYalnız künye2022Scopus SJRQ1Bioactive compounds of deep eutectic solvents extracts of Hypericum perforatum L.: Polyphenolic- organic acid profile by LC-MS/MS and pharmaceutical activity
Bayram, Sinan; Kutlu, Naciye; Gerçek, Yusuf Can; Çelik, Saffet; Ecem Bayram, Nesrin
Deep eutectic solvents (DESs) are known as environmentally-friendly solvents that have emerged as an alternative to conventional organic solvents in recent years. In this study, the effects of ten different DESs on the extraction of bioactive components from the Hypericum perforatum were investigated. Total phenolic content, total flavonoid content, phenolic profile (32 phenolics), organic acid profile (52 organic acids), as well as antioxidant and antimicrobial activities of H. perforatum extracts prepared using DESs and ultrasonic-assisted extraction method were determined. Total phenolic, total flavonoid content, and antioxidant activities of extracts were determined between 3.10 ± 0.86–16.64 ± 2.09 mg GA/g, 0.02 ± 0.00–12.29 ± 0.30 mg QE/g, and 8.40 ± 0.50–44.78 ± 2.66 mg TE/g, respectively. DES2 (choline chloride:ethylene glycol) and DES7 (choline chloride:lactic acid) demonstrated higher extraction success than other DESs for extracting phenolics and organic acids, respectively. DESs prepared using organic acid as hydrogen bond donor were found to have an antibacterial effect against all bacterial samples. However, the inhibitory effect against yeast-like fungi was observed in a narrower spectrum. Moreover, the results from principal component analysis also confirmed that the type of solvent used for extraction has a significant influence on the phenolics, organic acid, and other parameters. As a result, it was seen that DES components directly affect the extraction efficiency of target compounds from H. perforatum. This is a first and original report about use of DESs in extracting different bioactive components from H. perforatum.
AtıfScopus33WoS31OpenAlex32İncele - MakaleYalnız künye2022Scopus SJRQ1High-speed treatment of low strength domestic wastewater for irrigation water production in pilot-scale classical, moving bed and fixed bed hybrid MBRs
Tuluk, Banu; Yildiz, Ergun; Nuhoglu, Alper; Tataroglu, Numan Suadi; Gulluce, Ekrem; Cengiz, Ibrahim; Degermenci, Nejdet; Angin, Ilker
To evaluate the treatability of domestic wastewater under conditions of low hydraulic retention time and high organic loadings, 3 pilot-scale automatically controlled membrane bioreactors (MBRs) as classical (C-MBR), moving bed (MB-MBR), and fixed bed (FB-MBR) were established and operated for a total of 268 days. Established pilot plants were compared in terms of treatment performance, membrane fouling, irrigation water criteria, and power consumption values. Results obtained have shown that all three systems were able to achieve more than 93% removal of chemical oxygen demand (COD) in an average hydraulic retention time (HRT) of 1 hour, and MB-MBR and FB-MBR were superior in terms of total nitrogen (TN) and total phosphorus (TP) removals. It has been determined that MB-MBR and FB-MBR are also advantageous in terms of power consumption. Especially it has been found that FB-MBR can produce better quality irrigation water with 40% lower power consumption than C-MBR under the same conditions. It was concluded that biofilm-supported hybrid systems could be a practical application in the fight against increasing water scarcity and global warming, both in obtaining clean water with less power consumption and in protecting human and environmental health.
AtıfScopus16WoS11OpenAlex17İncele - MakaleYalnız künye2022Scopus SJRQ3The Importance of Nutrition and a Balanced Diet in the Elderly during the COVID-19 Pandemic
Esgin, Özge; Erten, Tayyibe
Background: Age is an important risk factor for the mortality rate in the COVID-19 disease, and mostly, hospitalised patients over 60 years with chronic diseases are at high risk of death due to this disease. Along with preventive measures, proper nutrient intake might be helpful in maintaining a healthy state or reduce the severity of the COVID-19 disease in the elderly. Methods: The search was carried out in the PubMed, Scopus, Medline, Google Scholar and Web of Science using the following terms: COVID-19, coronavirus, elderly, elderly nutrition. Results: The requirement for some macro and micronutrients, especially the nutrients that support the immune activity, increases in this disease. During the pandemic, the daily energy requirement for the elderly is 27-30 kcal/kg, while the protein intake is at least 1g/kg, and the ratio of fat and carbohydrate is 30:70 or less than 50:50. The daily intake of vitamin A, B6, B12, C, D, zinc and selenium can also be increased due to their supporting function in the immune system. Probiotics include Bifidobacterium longum MM-2, Lactobacillus plantarum 06CC2, Lactobacillus bulgaricus OLL1073R-1 and Lactobacillus rhamnosus M21, and the consumption of prebiotics in diet enhances the immune function. Additionally, flavonoids, such as baicalin, epigallocatechin gallate, gallocatechin gallate, kaempferol, luteolin, resveratrol and quercetin, improve immunity by reducing oxidative stress in the elderly. Conclusion: Adequate and balanced nutrition diet should be applied during the pandemic; in addition to this, micronutrient deficiencies should also be overcome in the elderly at every stage of life. Nuron&The novel coronavirus, called SARS-CoV2 (Severe Acute Respiratory Syndrome CoronaVirus-2), emerged at the end of 2019 in China and was announced as a global pandemic by the World Health Organisation (WHO) on March 11th, 2020 [1]. It has spread more rapidly than previous coronavirus outbreaks, such as SARS-CoV and MERS-CoV (Middle East respiratory syndrome coronavirus); thus, it has affected most countries [2, 3]. By August 2021, WHO reported globally 206.958.371 confirmed cases of COVID-19, including 4.357.179 deaths [4]. Since SARS-CoV-2 enters the cells through angiotensin-converting enzyme 2 (ACE2), it binds to the ACE2 membrane of alveolar epithelial cells and attacks firstly the respiratory system [5].
AtıfScopus1WoS1OpenAlex1İncele - Kitap BölümüYalnız künye2022Diplomatic transformation of series narrative: Velvet evolution of representation from valley of the wolves to valley of the wolves-ambush
Keskin, Savaş
In addition to what the studies on the discourse and character modeling of the Valley of the Wolves series say, this chapter argues that there has been a Neo-Ottomanization and religiosity evolution in terms of the discourse and the hero's semiosis. The thesis of this section is that Valley of the Wolves series has evolved in terms of narrative and character since it began to appeal to international target audiences. It is the main assumption of the section that there is a parallel transformation with the public diplomacy practices of the Republic of Turkiye in the process following the fact that the audience groups, especially in Arab geography, Afghanistan and Pakistan, where Islamic influence is dominant, become fans of the Valley of the Wolves. In this section, it is aimed to explain the velvet evolution, which exemplifies the transition from the Republican ideology to the Neo-Ottoman ideology in diplomatic media narratives, through the historical rupture of the Valley of the Wolves.
AtıfScopus1İncele - MakaleYayıncıda açık erişim2022Scopus SJRQ1Time-dependent fresh properties characterization of 3D printing engineered cementitious composites (3DP-ECC): On the evaluation of buildability
Zhou, Wen; McGee, Wes; Zhu, He; Gökçe, H. Süleyman; Li, Victor C.
Failure of the structure due to poor buildability is a major concern in 3D printing of cementitious materials. Evaluation of buildability based on fresh material properties and print parameters is of significance. In this paper, the buildability of printable engineered cementitious composites was investigated and quantified at the material and the structural scale. Fresh ECC material showed excellent load capacity and deformation resistance at the material scale, therefore preventing material failure of the bottom layers, as confirmed by constant shear rate tests and incremental loading tests. To predict vertical deformation of a 3DP structure, a time-dependent strain-stress model of printable ECC was proposed and validated based on the green strength evolution of the material and the buildup rate of the designed structure. At the structural scale, the approach of predicting critical height at self-buckling failure based on stiffness evolution was validated by printing a straight wall and a cylinder structure.
AtıfScopus56WoS46OpenAlex52İncele - MakaleYalnız künye2022Scopus SJRQ3Comparison of Statistical Methods to Graphical Method in Precipitation Trend Analysis, A Case Study: Coruh Basin, Turkey
Hırca, Tuğçe; Eryılmaz Türkkan, Gökçen
It is a known fact that the precipitation characteristics will become irregular as a result of climate change resulting from global warming. Trend analysis is one of the most effective methods of observing the effects of climate change on precipitation. This study compares the changes in precipitation with traditional trend analysis methods and graphical method (divided into subcategories using the Z-Score Index). Some preliminary analyzes (missing data estimation, homogeneity check, autocorrelation, and removal of the autocorrelation), which are lacking in many studies in the literature, have been performed. In this context, the monthly total precipitation data of the precipitation stations belonging to the Coruh Basin, one of the most important basins of Turkey, for the period 1972–2011 were used. As a result of the study, it was determined that all the stations’ data were homogeneous, and 92% of them were at the Class A level. While 100% trend is determined in Innovative Trend Analysis in total annual precipitation, this rate was just 40% at Mann–Kendall and Spearman's rho at 95% confidence. An increasing trend was determined in the “high” group of total spring precipitation at all stations.
AtıfScopus5WoS4OpenAlex5İncele - MakaleYalnız künye2022Scopus SJRQ1Effect of using hybrid nanofluids as a coolant on the thermal performance of portable thermoelectric refrigerators
Mert Cuce, Pinar; Cuce, Erdem; Guclu, Tamer; Shaik, Saboor; Alshahrani, Saad; Ahamed Saleel, C.
This study investigated the effect of using hybrid nanofluids as a refrigerant in portable thermoelectric refrigerator applications on thermal performance. For this purpose, a cooling cabinet with an internal volume of 36 L was designed and produced. Then, the Peltier assembly, with a water-cooled block attached to its hot surface, was placed in this cooling cabinet from the middle of its front cover. With the help of a refrigerant, the heat was removed from the Peltier's hot surface and transferred to the atmosphere via a water-to-air heat exchanger. Hybrid nanofluids prepared with Al2O3-TiO2-SiO2 and nanoparticles and water were used as the refrigerant in the system. To evaluate the thermal performances of these hybrid nanofluids, the tests were repeated using water without added nanoparticles as the reference case. According to the results obtained from the experimental study, it was observed that in all cases, tests using nanofluids gave better results than the reference cases. In addition, it was determined that the efficiency obtained from the system increased as the nanoparticle ratio in the mixture increased in all cases. Despite significant improvements in cooling cabinet and cooled product temperatures in hybrid nanofluids, the COP values of the systems are slightly lower than in the reference case due to the Peltier effect. Considering the difference between the first and last temperatures of the cooled cabinet, the greatest improvement compared to the reference situation was determined as 30.3 % in the case of loaded state conditions and in the case of using 2 % Al2O3-TiO2-SiO2-Water nanofluid. For the unloaded conditions, this value was obtained as 25.1 % in the case of using 2 % Al2O3-TiO2-SiO2-Water nanofluid. On the other hand, for the unloaded condition, the lowest COP value was calculated as 0.47 and 0.45 when Al2O3-TiO2-SiO2-Water nanofluid was used in 1 % and 2 % mass fraction, respectively. For the loaded condition, this value was found as 0.48 in the case where 1 % Al2O3-TiO2-SiO2-Water and 0.47 in the case where 2 % Al2O3-TiO2-SiO2-Water nanofluid was used.
AtıfScopus27WoS21İncele - MakaleYalnız künye2022Scopus SJRQ1Global boundedness of solutions to a quasilinear parabolic-parabolic Keller-Segel system with variable logistic source
Ayazoglu, Rabil
This paper deals with the higher dimension quasilinear parabolic-parabolic Keller-Segel system involving a source term of variable logistic type ut=∇⋅(ϕ(u)∇u)−∇⋅(ψ(u)∇υ)+g(x,u), −Δυ=−υ+u, in (x,t)∈Ω×(0,T), subject to nonnegative initial data and homogeneous Neumann boundary condition, where Ω is a smooth and bounded domain in RN (N≥1) and g∈C1(Ω‾×[0,∞)) function satisfies g(x,s)≤ηsk(x)−μsm(x),s>0 with g(x,0)≥0, x∈Ω and η≥0,μ>0 are constants, k,m are measurable functions with 1<k−:=ess infx∈Ωk(x)≤k(x)≤k+:=esssup k(x)x∈Ω<+∞, 2≤m−:=ess infx∈Ωm(x)≤m(x)≤m+:=esssup m(x)x∈Ω<+∞. Positive functions ψ,ϕ∈C2([0,∞)) satisfy νsq≤ψ≤χsq and ϕ≥σsp with p,q∈R, ν,χ,σ>0 when s≥0. It is proved that if q=m−−1 (critical case) and [Formula presented] then there exists a classical solution which is global in time and bounded. Moreover, if q∈(k+−1,m−−1), we obtain that there is a classical solution of the above system uniformly in time bounded without any restrictions on m− and μ.
AtıfScopus10WoS8OpenAlex10İncele - MakaleYalnız künye2022Scopus SJRQ1Avanafil as a Novel Therapeutic Agent Against LPS-Induced Acute Lung Injury via Increasing CGMP to Downregulate the TLR4-NF-κB-NLRP3 Inflammasome Signaling Pathway
Aydin, Pelin; Magden, Zeynep Berna Aksakalli; Uzuncakmak, Sevgi Karabulut; Halici, Hamza; Akgun, Nurullah; Mendil, Ali Sefa; Mokhtare, Behzad; Cadirci, Elif
Aim: We demonstrate the effect of PDE5 inhibitors in cases of acute lung injury via the relationship between cGMP/NO and the TLR4-NF-κB-NLRP3 pathway. Materials and Methods: This study was performed with 30 male Wistar albino rats. Lipopolysaccharide (LPS) was administered intratracheally to the rats and acute lung injury (ALI) was induced. Twelve hours after LPS administration, avanafil, prepared at suitable doses according to the body weights of the animals, was administered by oral gavage. Lung tissue samples of all groups were examined histopathologically and by immunochemical staining (IL-1β, iNOS, TLR4, and NF-κB). The iNOS, NLRP3, and IL-1B mRNA expression levels in the lung tissues were measured by RT-PCR. The left upper lobes of the rat lungs were dried at 70 °C for 48 h and lung water content was calculated. Result: Statistically significant increases in iNOS, NLRP3, and IL-1β mRNA expressions were observed in the rats with ALI compared to the healthy controls (p < 0.0001). Those increased expressions were reduced at both doses of avanafil (p < 0.0001). This reduction was found to be greater at 20 mg/kg (p < 0.0001). IL-1β, iNOS, TLR4, and NF-κB immunopositivity was moderate/severe in the ALI group and mild in the group with ALI + avanafil at 20 mg/kg (p < 0.05). When the wet/dry lung ratios were calculated, a statistically significant increase was seen in the ALI group compared to the healthy rats (p < 0.05). That increase was decreased with both avanafil doses (p < 0.05). Conclusion: We suggest that avanafil may prevent the progression of ALI and be effective in its treatment. We hope that this study will be supported by future clinical studies to yield a new indication for avanafil.
AtıfScopus18WoS21OpenAlex17İncele