Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(115)
- Kaya, Yunus(50)
- Ayata, Ümit(48)
- Şahin, Engin(48)
- İspirli, Hümeyra(46)
- Bayraktar, Bülent(42)
- Şenay, Volkan(41)
- Can, Zehra(39)
- Özen, Soner(37)
- Bayram, Sinan(35)
- Pat, Suat(35)
- Öztürk, Mesut(35)
- Ecem Bayram, Nesrin(34)
- Esmer, Yusuf(34)
- Battal, Fetullah(33)
- Artar, Musa(32)
- Öner, Erdal(32)
- Korkmaz, Şadan(31)
- Yilmaz, Mustafa Tahsin(31)
- Ertugrul, Mehmet(30)
- Mercan, Emin(30)
- Hasar, Ugur Cem(29)
- Kutlu, Naciye(28)
- Özdemir, Akın(27)
- Kul, Murat(26)
- Cuce, Erdem(25)
- Kamiloğlu, Aybike(25)
- Bayram, Ozkan(24)
- Sefali, Abdurrahman(24)
- Sert, Durmuş(24)
- Çolak, Murat(24)
- Ayazoglu, Rabil(22)
- Gıdık, Betül(22)
- Maden, Sedat(22)
- Ustabulut, Mete Yusuf(22)
- Uçurum, Metin(22)
- Akeren, Zahide(21)
- Dirican, Ebubekir(21)
- Kara, Yakup(21)
- Abdioglu, Murat(20)
Yayınlar
- MakaleYalnız künye2019Scopus SJRQ2Leaded brass alloys for gamma-ray shielding applications
Şakar, Erdem; Büyükyıldız, Mehmet; Alım, Bünyamin; Şakar, Betül Ceviz; Kurudirek, Murat
The leaded brasses show high machinability and atmospheric corrosion resistance. Hence, they are being used in different applications such as machine parts, valves, fittings etc. Besides, they can serve as radiation shields as they contain lead and their radiation shielding properties were not investigated so far. Thus, the aim of this study is to determine the radiation shielding properties of leaded brasses. Standard (CuZn) and leaded (CuZnPb) brasses were prepared and their mass attenuation coefficients (μ/ρ), half-value layers (HVL), tenth-value layers (TVL), mean free paths (MFP) and effective atomic numbers (Z eff ) were determined. Linear attenuation coefficients (μ) of the alloys were measured first at 53, 276, 302, 356 and 383 keV using a HPGe detector and a 133 Ba radioactive source. These values were then used to obtain other parameters. A good agreement was observed between experimental and theoretical results for HVL, TVL and MFP (Dif. ≤ 9%). Photon buildup through the present materials was studied in terms of exposure buildup factor (EBF). Results were presented and discussed regarding the photon energy and penetration depths. Fast neutron removal cross sections were also calculated for the given alloys. Some alloys were also evaluated morphologically by using EDX mapping. The leaded brasses were compared with standard shielding concretes and superior shielding properties against gammas and fast neutrons were obtained when compared with concretes.
AtıfScopus114WoS108OpenAlex128
İncele - MakaleYalnız künye2019Scopus SJRQ4Evaluating the grinding process of granitic rocks using the physico-mechanical and mineralogical properties
Kahraman, Sair; Ucurum, Metin; Yogurtcuoglu, Emine; Fener, Mustafa
Granitic rocks are sometimes ground for different purposes. Predicting the mean particle size (d50) is useful for planning and cost estimation of purposes. In order to investigate the possibility of predicting the d50 of ground rock from the physico-mechanical rock properties, six different granites were tested in the laboratory. First, the d50 values were correlated with the corresponding physico-mechanical properties. The simple regression analysis showed that there were no good correlations between the d50 and the physico-mechanical properties. Then, the multiple regression analysis was carried out and strong prediction equations were developed. It was also shown that the dominant parameter in grinding was the abrasive mineral content of rock. It is concluded that the d50 of granites can be predicted from the derived multiple regression equations especially for preliminary investigations. The developed estimation equations including index test values are especially useful since they are easy to use.
AtıfScopus2WoS1İncele - MakaleAçık Erişim2019Scopus SJRQ3Characterization of a glucansucrase from Lactobacillus reuteri E81 and production of malto-oligosaccharides
İspirli, Hümeyra; Yüzer, Mustafa Onur; Skory, Christopher; Colquhoun, Ian J.; Sağdıç, Osman; Dertli, Enes
Glucansucrases, which can be produced by different Lactic Acid Bacteria (LAB), catalyze the synthesis of α-glucans with different structures and properties using sucrose as substrate. In this study, a novel glucansucrase (GTFA) from Lactobacillus reuteri E81 was identified and heterologously expressed. Alignments of GTFA with other glucansucrases revealed its novelty and a putative 3D model structure was obtained. The biochemical properties of the truncated enzyme without the N-terminal variable region, GTFA-ΔN, was characterized. The Km and Vmax were found to be 7.5 mM and 1.49 IU/mg, respectively, and it showed optimum activities at pH 7 and at 50 °C. The GTFA-ΔN produced in vitro an α-glucan with (α1 → 3) and (α1 → 6) glycosidic linkages using sucrose as the substrate. Importantly, GTFA-ΔN synthesized DP = 9 oligosaccharides using sucrose and maltose as the donor and acceptor sugars, respectively, as detected by TLC, HPLC, LC-MS and NMR analysis.
AtıfScopus40WoS40OpenAlex40İncele - MakaleAçık Erişim2019Scopus SJRQ2Prediction of critical fraction of solid in low-pressure die casting of aluminum alloys using artificial neural network
Teke, C.; Colak, M.; Kiraz, A.; Ipek, M.
Casting simulation programs are computer programs that digitally model the casting of an alloy in the sand, shell, or permanent mold and, then, the cooling and solidification processes. However, obtaining consistent results out of casting modeling depends on the incorporation of many accurate parameters and boundary conditions. Critical Fraction of Solid (CFS), which is one of the most important of these parameters, is defined as the point where solid dendrites do not allow any flow of the liquid metal in the mushy zone. Since the CFS value varies based on many factors, inconsistent results can be experienced in the modeling applications. In this study, the CFS value obtained during the solidification of various commercial aluminum alloys' casting process, carried out using low-pressure die casting method, is predicted by using Artificial Neural Network (ANN) method based on alloy type, grain refiner and modifier additions, initial mold temperature, and pressure level parameters. In the scope of the study, 162 experiments are conducted. The results obtained from the low-pressure die casting experiments using a special model designed for the study are validated by using SOLIDCast casting simulation. The CFS values are obtained in this validation range of 33% to 61%. These CFS values are used in the development of ANN models. Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Mean Square Error (MSE) are used to assess the prediction accuracy of the ANN models. Calculated values of MAE, MAPE, and MSE are 0.0188, 7.06%, and 0.0006, respectively. The results show that the proposed ANN model predicts a CFS value with high accuracy.
AtıfScopus6WoS6OpenAlex4İncele - MakaleYalnız künye2019Scopus SJRQ1Effect of electrospun nisin and curcumin loaded nanomats on the microbial quality, hardness and sensory characteristics of rainbow trout fillet
Meral, Raciye; Alav, Aslıhan; Karakas, CananYagmur; Dertli, Enes; Yilmaz, Mustafa Tahsin; Ceylan, Zafer
Nisin and curcumin loaded (NCL) nanomats having 172 nm mean diameter were successfully fabricated. The effect of NCL nanomats in terms of limitation of Total Mesophilic Aerobic (TMAB) and Lactic acid bacteria (LAB) in fish fillets was tested during the analysis period. On the 4th day, while TMAB load of C was 6.61 log CFU g−1, that of the sample coated with NCL nanomats was found to be 3.28 log CFU g−1. TMAB load of control samples reached above 6 log CFU g−1 on the 4th day of cold storage, TMAB load of fish samples coated with nanomats reached the same level up to the 12th day. The shelf life of coated fillets was extended to 12 day. 3–4 logarithmic decrease was obtained in LAB count by NCL nanomats during the analysis period. On the 4th storage day, the hardness value of C sample decreased 21% compared to NCL samples. All sensory attributes of C samples were acceptable by the 4th day of the storage; while sensory attributes of NCL samples were acceptable by the 10th day of storage. The study revealed that nisin and curcumin loaded nanomats could be effectively used to improve the quality of fish fillets.
AtıfScopus92WoS84OpenAlex91İncele - MakaleAçık Erişim2019Scopus SJRQ2Preparation of gentiobiose-derived oligosaccharides by glucansucrase E81 and determination of prebiotic and immune-modulatory functions
İspirli, Hümeyra; Colquhoun, Ian J.; Şahin, Engin; Sagdic, Osman; Dertli, Enes
Gentiobiose-derived oligosaccharides were synthesized by the acceptor reaction of glucansucrase E81 obtained from Lactobacillus reuteri E81 with sucrose and gentiobiose as donor-acceptor sugars, respectively. The reaction products were monitored by TLC analysis and gentiobiose-derived oligosaccharides up to DP 8 were formed during the acceptor reaction as determined by ESI-MS/MS analysis. The glycosylation of the gentiobiose with α-(1 → 6) linkages and α-(1 → 3) linkages was shown by 1H and 13C NMR analysis confirming the structure of these gentiobiose-derived oligosaccharides. The in vitro prebiotic function of the oligosaccharides was determined in which probiotic strains were stimulated whereas no growth was observed in pathogen strains. Gentiobiose-derived oligosaccharides showed immune-modulatory functions in vitro and triggered the production of IL-4, IL12 and TNF-α cytokines in HT29 cells in a dose dependent manner. This study showed the production and functional characterisation of gentiobiose-derived oligosaccharides establishing a promising avenue for future applications.
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İncele - MakaleAçık Erişim2019Scopus SJRQ2Modeling design parameters with taguchi experimental method for obtaining operating conditions for cu(Ii) removal through adsorption process
Serencam, Hüseyin; Özdemir, Akın; Teke, Çağatay; Uçurum, Metin
One of the environmental concerns deals with the removal process of pollutants in water and wastewater. In this paper, a removal process was used to eliminate pollutants in water and wastewater. The aim of this paper was to obtain an optimum adsorption condition for the highest metal ions adsorbed (MIA) mg/g. For this particular purpose, a Taguchi L18 design was conducted. In addition, the signal-to-noise ratio was analyzed for optimum adsorption levels. The analysis of variance was also performed to evaluate the effect of each adsorption condition on MIA (mg/g) values. Moreover, an optimization model was also proposed to find the best optimal setting of adsorption levels. Then, the confirmation tests were performed using optimum coded levels of the adsorption parameters for the verification purpose. The results of the experimental study showed a good performance that Cu(II) removal capacity was found to be 43.66 mg/g. To the best of our knowledge, this research is the first to study natural stone as an efficient, inexpensive and cheap adsorbent for the removal process.
AtıfScopus6WoS5OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ2Innovative trend analysis of total annual rainfall and temperature variability case study: Yesilirmak region, Turkey
Serencam, Uğur
It is well known that any kind of ordinary hydrometeorological parameter trend may have increasing or decreasing tendency systematically. Various methodologies are developed for possible trend identification such as the well-known Mann-Kendall test and recently Şen innovative trend analysis (ITA) approaches. The former has a set of assumptions, whereas the latter is almost without any restrictive assumption. The main purpose of this paper is to present precipitation and temperature trend behaviors by applying ITA in Yesilirmak drainage basin. Selected observation stations are mainly located at the Black Sea confluence region of Yesilirmak while few others at the middle and upper drainage basins. ITA provided visual inspection with quantitative trend slopes distinctively for low, medium, and high sub-levels with physical interpretations. Based on categorization, precipitation records have significant decreasing trends in low, medium, and high levels as an average − 3.4%, − 3.8%, and − 2.4%, respectively. In contrary to precipitation trend, and consistent to global expectation in climate change, temperature records have significantly strong increasing tendency along the basin. In sub-level of temperature, this strong trend tendencies are detected + 4.6%, + 4.8%, and + 7.2% from low to high ranges, respectively.
AtıfScopus40WoS36OpenAlex45İncele - MakaleAçık Erişim2019Scopus SJRQ2Optimal Material Selection for Total Hip Implant: A Finite Element Case Study
Şensoy, Abdullah Tahir; Çolak, Murat; Kaymaz, Irfan; Findik, Fehim
The selection of most proper materials in engineering design is known as an important stage of the design process. In order to successfully complete this stage, it is necessary to have sufficient knowledge about the structure of materials, density, melting point, thermal expansion coefficient, tensile and yield strength, elongation, modulus of elasticity, hardness and many other properties. There are several selection systems that help the design engineer to choose most suitable material that meet the required properties. In the field of bioengineering, the selection of materials and the development of new materials for the clinical needs are increasingly important. In this study, the cases of optimal implant stabilization were investigated, material alternatives for hip prosthesis were evaluated, and optimal materials were determined. Using computerized tomography data with MIMICS software, virtual surgery was applied the hip bone and the implant was attached to bone. Boundary conditions and material properties have been defined, and finite element model has been created. FEA investigation of the mechanical behavior of the hip implant for various material alternatives determined by the CES software showed that the best material candidate is austenitic, annealed and biodurable stainless steel in terms of the micromotions at the implant–bone cement interface regarding osseointegration. This candidate showed 20.69% less strain value than the most commercially used hip implant material, Ti6Al4V. Therefore, the findings of this study suggest that the use of some specific stainless steel materials for implants may reduce the operation cost and increase the operation success for the total hip arthroplasty.
AtıfScopus36WoS28OpenAlex41İncele - MakaleAçık Erişim2019Scopus SJRQ1Transient plane-wave transmission through an N-Layer structure by the method of subregions
Hasar, Ugur Cem; Kaya, Yunus; Barroso, Joaquim J.
The temporal transmission properties of an N-layer structure under planar wave incidence are investigated by the method of subregions via the wave matrix approach. The transmission coefficient expression is first expressed in the frequency-domain by reduced transmission coefficients and then transformed into the time domain, which includes unit step functions with different effective time periods and weightings. The analysis is validated by numerical computations and three-dimensional electromagnetic simulations at gigahertz frequencies.
AtıfScopus12WoS12OpenAlex13İncele - MakaleYalnız künye2019Scopus SJRQ1Hydrogen generation via the catalytic hydrolysis of morpholine-borane: A new, efficient and cost-effective hydrogen storage medium
Can, Hasan; Metin, Önder
Herein, for the first time, we introduce the morpholine-borane complex (MB) as a new, efficient, cost-effective and commercially available chemical hydrogen storage material for mobile applications. In this regard, hydrogen production from the hydrolysis of MB catalyzed by in situ generated water-soluble polymer stabilized Ag(0) and Pd(0) nanoparticles (NPs) is reported for the first time. In situ generated PSMA-stabilized Ag(0) and Pd(0) NPs showed remarkable activity in hydrogen production from the hydrolysis of MB at room temperature, providing initial TOFs of 16.1 min−1 and 37.3 min−1, respectively. A set of kinetic studies on the catalytic hydrolysis of MB were conducted by changing the catalyst/substrate amount and temperature, and the rate law expression and activation parameters were produced by collecting the kinetic data. The apparent activation energies for the in situ generated Ag(0) and Pd(0) NPs catalyzed MB hydrolysis were calculated to be 71.4 and 32.5 kJ mol−1, respectively.
AtıfScopus20WoS20OpenAlex22İncele - MakaleAçık Erişim2019Scopus SJRQ1Piezoelectric and electromagnetic hybrid energy harvesting with low-frequency vibrations of an aerodynamic profile under the air effect
Bolat, Fevzi Cakmak; Basaran, S.; Sivrioglu, S.
In this study, a novel hybrid energy harvesting system consisting of a piezoelectric material and an electromagnetic induction device is experimentally inevstigated. Flow-induced vibrations can be considered as an aerodynamics air effect and can be converted to electrical energy. By connecting an airfoil profile to a beam element, vibrations are occurred on the proposed structure by creating an aerodynamic air effect. This aerodynamic air effect is controlled by using an Arduino board with a solenoid valve connected to the air line. A piezoelectric transduction is attached on the beam, and an electromagnetic-Lorentz induction is connected to the airfoil element at the end of this beam. Energy is simultaneously harvested by using electromagnetic induction and piezoelectric transduction with respect to the vibration motion of the beam. Within the scope of the study, the amount of energy obtained using the piezoelectric material and Lorentz actuator by connecting resistors of different sizes are measured with an oscilloscope. The experimental results show that the amount of energy obtained from the proposed structure is at promising levels that can be used to run small electronic units which commonly used in aerospace applications.
AtıfScopus60WoS51OpenAlex57İncele - MakaleYalnız künye2019Scopus SJRQ3Biocatalyzed Enantiomerically Pure Production of (S)-Phenyl(thiophen-2-yl)methanol
Şahin, Engin; Dertli, Enes
Chiral aryl heteroaryl methanols are important precursors for the synthesis of pharmaceutically important molecules. The aims of this study were to use a biocatalyst that could efficiently bioreduce phenyl(thiophen2- yl) methanone 1 to (S)-phenyl(thiophen-2-yl) methanol 2, to identify the impact of the physicochemical factors that might affect the bioreduction by the biocatalyst, and to obtain multigram production of aryl heteroaryl secondary alcohol 2 with the biocatalyst under optimized conditions. Over the years, the (S)phenyl( thiophen-2-yl) methanol was synthesized on a small scale using a chemical catalyst without its enantiomerically pure form. In this study, Lactobacillus paracasei BD101 was used for the asymmetric reduction of phenyl(thiophen-2-yl) methanone to (S)-phenyl(thiophen-2-yl) methanol in the large-scale production. The asymmetric bioreduction conditions were systematically optimized, and the production of 3.77 g of (S)-phenyl(thiophen-2-yl) methanol was carried out in enantiomerically pure form > 99% enantiomeric excess (ee), > 99% conversion, and 90% yield. This method obtained with this biocatalyst is a process that can be used industrially in terms of conversion, ee, and yield. This study provides guidance for the application of L. paracasei BD101 in the production of optically active aryl heteroaryl alcohols.
AtıfScopus12WoS12OpenAlex12İncele - MakaleYalnız künye2019Scopus SJRQ1Partial characterization of a levan type exopolysaccharide (EPS) produced by Leuconostoc mesenteroides showing immunostimulatory and antioxidant activities
Taylan, Osman; Yilmaz, Mustafa Tahsin; Dertli, Enes
Leuconostoc mesenteroides S81 was isolated from traditional sourdough as an exopolysaccharide (EPS) producer strain. The monosaccharide composition of the EPS from strain S81 was characterized by HPLC analysis and only fructose was found in the repeating unit structure. The NMR spectroscopy analysis revealed that EPS was a levan type EPS as a β-(2 → 6)-linked fructan. The FTIR analysis further confirmed the presence of the furanoid rings in the EPS structure. The levan S81 showed high level of thermal stability determined by DSC and TGA analysis. The lyophilised levan S81 showed a sheet-like compact morphology and its aqueous solution formed spheroidal lumps with a compact structure detected by SEM and AFM analysis, respectively. Importantly the levan S81 showed a high level of immunomodulatory role, induced the anti-inflammatory cytokine IL-4, and exhibited a strong antioxidant capacity with EC50 value 1.7 mg mL−1 obtained by hydroxyl radical scavenging activity test under in vitro conditions. These findings reveal potential of levan S81 for technological purposes and as a potential natural immunomodulatory and antioxidant.
AtıfScopus132WoS112OpenAlex126İncele - MakaleAçık Erişim2019Articles on biotechnology teaching: Thematic content analysis study
Toman, Ufuk
This thematic content analysis done about teaching biotechnology which is researched in Turkey is conducted with 64 articles, from a total of 45 magazines published in Turkey from 2003 to 2018. An analysis of the research trends of Turkish researchers based on teaching biotechnology. In this research, it has been tried to guide the researchers by determining the trends in the field and research methods frequently used(changes according to publication years and languages, what kind of research problems on qualitative research subjects are emphasised, what research methods are used, data collection tools, sample or working group, data analysis methods). In studies conducted to investigate the biotechnology education in Turkey, it shows that there is not adequate studies to address the issue of biotechnology education. Biotechnology and its sub-rules, cloning, genetically modified organisms, biotechnological vaccines, genetic engineering and microbiology may require more space in curricula at early learning levels.
AtıfScopus7OpenAlex8İncele - MakaleAçık Erişim2019Scopus SJRQ3Integrated QFD, fuzzy linear regression and ZOGP: An application of e-store design
Celik, Pelin; Ustasuleyman, Talha
In the current, highly competitive marketplace, customer demand is a major factor in the product design process. Most firms make an effort to indicate that their products differ from the competitors’ products. The purpose of this paper is to understand customers’ expectations of and technical requirements for e-stores and to evaluate most popular e-stores in Turkey (i.e., ES1, ES2, ES3). In this study, the authors aim to understand the customer expectations and technical requirements by using quality function deployment (QFD). To prepare the house of quality (HoQ), the authors surveyed 20 experts who are customers who have elite membership (their expenses for these e-stores are more than regular customers and have elite cards) of the three e-stores and academicians. After creating the HoQ, the authors employ fuzzy linear regression to evaluate the relationships between customer expectations and technical requirements and among technical requirements themselves. Finally, the authors use zero-one goal programming (ZOGP) to select the most desirable e-store.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2019Scopus SJRQ1Impact of heat treatment and acid gelation on polyphenol enriched milk samples
Bayraktar, M. Kilic; Harbourne, N.B.; Fagan, C.C.
The effects of heat treatment and the stage of polyphenol addition to milk before or after heat treatment on the total phenolic content (TPC), ferric-ion reducing antioxidant power (FRAP), pH, casein micelle size (CMS) and whey protein denaturation content of milk-polyphenol mixtures were investigated. Four sources of phenolic compounds (green tea, white grape, tannic acid, gallic acid) were incorporated into pasteurized-skim milk. A heat treatment (85 °C for 30 min) was applied to pasteurized-skim milk either before (MhP) or after polyphenols addition (MhPh). Acid milk gels were produced using MhPh samples, and their TPC and FRAP were determined. Heat treatment decreased the TPC and FRAP values of the samples, except for tannic acid, probably due to increased polyphenol-protein interactions. However, MhPh tannic acid sample resulted in significantly higher FRAP value than MhP. The addition of gallic acid before heat treatment (MhPh) significantly increased CMS due to the lower pH of this sample during heating. Acid gelation decreased the extractable polyphenols, however there was no significant different on FRAP between acid gel and MhPh milk samples. This study showed that the properties of phenolic source, particularly pH, and the stage of polyphenol addition to milk had an impact on selected properties.
AtıfScopus25WoS23OpenAlex24İncele - MakaleYalnız künye2019Scopus SJRQ2Comparative study of hot and cold press and their effect on superconducting properties of coronene added bulk MgB2
Erdem, O.
In this study, the superconducting properties of 4 wt% coronene (C24H12) added polycrystalline bulk MgB2 samples prepared by hot pressing and cold pressing, were reported in detail. The results were compared to determine one of which pressing methods is more useful to substitute of carbon released from C24H12 into MgB2 structure and to increase the superconducting properties of MgB2. The lattice strain, crystallite size, residual resistivity, superconducting transition temperature (Tc), critical current density (Jc), flux pinning force density (Fp) and vertical/lateral levitation force (Fz, Fx) were analysed for the hot and cold pressed samples. The a-lattice parameter and Tc value reduced sharply for 4 wt% C24H12 added cold pressed sample, resulting in a notable decrease of increment ratio of Jc and Fp values, while the depressing of Tc is lower for 4 wt% C24H12 added hot pressed sample. The cold pressing strongly increased the lattice strain, confirming more C substitution, while the hot pressing ensured smaller crystallite size. The Jc and Fp values were respectively found as 4.6 × 103 A/cm2, 1.3 × 104 A/cm2, 5.8 × 103 A/cm2 and 1.8 × 108 N/m3, 5.1 × 108 N/m3, 2.3 × 108 N/m3 for the pure sample and, 4 wt% C24H12 added hot and cold pressed samples at 20 K, 4 T. The maximum repulsive and attractive levitation force values at 20 K in ZFC and FC regimes were obtained for the 4 wt% C24H12 added hot pressed sample. Finally, the hot pressing provides an effective way to substitute C into MgB2 lattice without a remarkable decrease of Tc value, ensuring more homogenous and compacted structure, more electron–phonon interaction and strong flux pinning force.
AtıfScopus6WoS6OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ3Green synthesis of enantiopure (S)-1-(benzofuran-2-yl)ethanol by whole-cell biocatalyst
Şahin, Engin
Optically active aromatic alcohols are valuable chiral building blocks of many natural products and chiral drugs. Lactobacillus paracasei BD87E6, which was isolated from a cereal-based fermented beverage, was shown as a biocatalyst for the bioreduction of 1-(benzofuran-2-yl) ethanone to (S)-1-(benzofuran-2-yl) ethanol with highly stereoselectivity. The bioreduction conditions were optimized using L. paracasei BD87E6 to obtain high enantiomeric excess (ee) and conversion. After optimization of the bioreduction conditions, it was shown that the bioreduction of 1-(benzofuran-2-yl)ethanone was performed in mild reaction conditions. The asymmetric bioreduction of the 1-(benzofuran-2-yl)ethanone had reached 92% yield with ee of higher than 99.9% at 6.73 g of substrate. Our study gave the first example for enantiopure production of (S)-1-(benzofuran-2-yl)ethanol by a biological green method. This process is also scalable and has potential in application. In this study, a basic and novel whole-cell mediated biocatalytic method was performed for the enantiopure production of (S)-1-(benzofuran-2-yl)ethanol in the aqueous medium, which empowered the synthesis of a precious chiral intermediary process to be converted into a sophisticated molecule for drug production.
AtıfScopus32WoS30OpenAlex34İncele - MakaleAçık Erişim2019Scopus SJRQ2Modification of eutectic Al-Si alloys by Sr and CuSn5
Çolak, Murat
Enhanced properties can be achieved in Al-Si alloys by several alloying element additions. Typical modifiers are Na, Sr, and Sb that alters Si into a fibrous structure. Fluidity and mechanical properties increase as well as machinability can be improved. In this work, eutectic Al-Si alloy was modified with Al10Sr, CuSn5, and Al10Sr + CuSn5 master alloys. Microstructural characterization was carried out by optical and scanning electron microscopy. Density and hardness of the samples were measured. Wear tests were carried out. It was found that Sr modified Al12Si revealed better performance than CuSn modified.
AtıfScopus21WoS19OpenAlex21İncele