Importance of Mechatronics in Maritime Education

Yalçın DURMUŞOĞLU,Cengiz DENİZ,Y. Volkan Aydoğdu,A. Atıl TALAY 한국항해항만학회 2012 한국항해항만학회 학술대회논문집 Vol.2012 No.공동학술

Enhanced copper(II) biosorption on SiO2-alginate gel composite: A mechanistic study with surface characterization

Sibel Yalçın,Reşat Apak,İsmail Boz 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.10

A new SiO2-alginate biocomposite was synthesized with improved mechanical properties, showing chelation capability of divalent metal ions, especially Cu(II), through its carboxylic acid ends. The biocomposite was characterized using scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS) techniques. The adsorption of copper(II) onto both H- and Ca-forms of sorbent was investigated as a function of pH and contact time, and adsorption data were modeled with the aid of Langmuir and Freundlich isotherms. The release of Ca(II) ions accompanying copper(II) binding was evaluated by selective surface complexation concept involving ion-exchange. The IR spectra gave detailed information on complexation of carbonyl group with copper ions and on the relative contribution of SiO2 involved in copper uptake. The adsorption edge of copper was within the pH range 4.0-5.5, and the sorbent capacity was determined as 1.85 and 1.10mmolg−1 for H- and Ca-forms, respectively.

Effect of Partial Removal of Prolamins on Some Chemical and Functional Properties of Barley Flours

Erkan Yalçın 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.3

In this study, some chemical and functional properties of hulled (BF-1) and hull-less (BF-2) barley flours and their partial prolamin removed forms (PPRF-1and PPRF-2, respectively) were determined. Total dietary fiber and resistant starch values increased on dry weight basis, conversely β-glucan levels slightly decreased after partial prolamin removing (PPR). Sodium dodecyl sulphatepolyacrylamide gel electrophoresis (SDS-PAGE) patterns of PPRF-1 and PPRF-2 exhibited that PPR was highly achieved. Rapid visco analyzer (RVA) peak and breakdown viscosity values of PPRF-1 and PPRF-2 were higher than BF-1 and BF-2, conversely their setback, trough, and final viscosity values were lower than that of the BF-1 and BF-2, respectively. PPR also caused an increase in water binding capacity and resulted in a decrease on water solubility values of barley flours. Protein solubility of PPRF-1 and PPRF-2 were lower than BF-1 and BF-2,respectively. Emulsifying properties of PPRF-2 were affected negatively from the PPR.

The Enrichment of Hen Eggs with ω-3 Fatty Acids

Hasan Yalçın,Mustafa Kemal Unal 한국식품영양과학회 2010 Journal of medicinal food Vol.13 No.3

A study was conducted to determine the ω-3 fatty acid compositions of enriched eggs obtained from hens by feeding flaxseed and fish oil. Laying hens were fed a diet containing fish oil (FOD) (1.5%) or a mixture of flaxseed (10%) and fish oil (FFOD) (1.5%) for 15 and 30 days. Another group was fed commercial diet as a control. Eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) were not determined in the control group's eggs. However, the EPA level was 0.87% and 0.82% in the FOD group's eggs and 0.49% and 0.55% in the FFOD group's eggs, obtained after a 15- and 30-day feeding period, respectively. Corresponding values for DPA were 0.45% and 0.50% in the FOD group's eggs and 0.41% and 0.44% in the FFOD group's eggs. Docosahexaenoic acid contents of eggs obtained from the FOD group were 4.85% and 4.92% after a 15- and 30-day feeding period, respectively, compared with 3.29% and 3.91% in the FFOD group's eggs and 1.03% in the control group's eggs. The α-linolenic acid content of eggs was 0.45% and 0.49% in the FOD group's eggs after a 15- and 30-day feeding period, respectively, and 0.43% in the control group's eggs, whereas it was 3.61% and 4.10%, respectively, in the FFOD group's eggs.

Steady State Voltage Stability Estimation by Using Local Bus Parameters

Gümüş Talha Enes,Yalçın Mehmet Ali,Turan Mustafa,Aksoy Tırmıkçı Ceyda,Yavuz Cenk 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.2

In this study, an estimation approach based on local bus measurements of voltage, current and phase angle is presented to assess voltage stability at any of the system load bus. For this purpose, Thevenin equivalent circuit parameters of the IEEE 30-bus standard test system are estimated by using local measurements from Bus k which is selected to be evaluated in terms of voltage stability. Estimated Thevenin equivalent circuit parameters are used to calculate critical voltage values and voltage stability margin values of Bus k online for the voltage stability assessment. In conclusion, the voltage stability margin results of the proposed approach are compared with three diff erent Thevenin equivalent based voltage stability estimation approaches. Simulation results show that the proposed approach successfully estimates the voltage stability margins of any load bus in the system. From the perspective of voltage stability, estimated voltage stability margins can be used to assess the loading levels of any load bus, to defi ne critical busses and to make decision for load shedding.

Valuation of NDX Index Call Options with Fractional Black-Scholes Model

Sangwoo Heo,Joon Park,Yalçın Sarol 사람과세계경영학회 2009 Global Business and Finance Review Vol.14 No.2

This study compares the accuracy between the fractional Black-Scholes (FBS) option pricing model and the Black-Scholes (B-S) option pricing model using NASDAQ-100 (NDX) index call options data for the period of four years from January 2004 to December 2007. The degree of accuracy is measured by moneyness, variance estimate, and maturity. Although the accuracy of the FBS model is sensitive to Hurst parameter (H), the parameter is not directly observed. We recover the H value from the FBS model which depends on variance estimates. Because the FBS model has two unknown parameters, volatility and the Hurst parameter, we propose model predicting option prices to estimate H values using the implied volatility. We find that the FBS model outperforms the B-S model across the board. In particular, there is a great advantage of using the FBS model with historical volatility.

Valuation of American Equity Options with Quadratic Approximation Models Adopting Fractional Brownian Motion

Sang Woo Heo,Yalçın Sarol,Jun Gyu Kang 사람과세계경영학회 2010 Global Business and Finance Review Vol.15 No.2

In this article, we compare the accuracy of the American approximation models: MBAW model (Macmillian, 1986; Barone-Adesi and Whaley, 1987) and MQuad model (Ju and Zhong, 1999) as well as the Black-Scholes (B- S) model adopting fractional Brownian Motion (fBm) for three financial companies equity put options data for the period from January 2004 to February 2010. The degree of accuracy is measured according to moneyness, variance estimate, and maturity. We find that the models occupied with fBm are more accurate and stable than the corresponding models across the board. In particular, there is a great advantage of using the fBm-based models when historical volatility is used. Even though the fractional Black-Scholes (FBS) model is for pricing European options, it is the best choice for long term maturity options. The FBS model is also capable of correcting the overestimation of the B-S model.

The Determination of Fracture Characterization of Knitted Fabric Reinforced Composites Using Arcan Test

H. Ersen Balcıoğlu,Derviş Yalçın 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

Type, structure and orientation angle of the reinforcing material used in laminated composite structures directlyaffect the mechanical behavior of the composite material. Knitted fabrics are becoming increasingly widespread asreinforcing materials in laminated composites due to their superior mechanical and physical properties. In this study,mechanical properties and fracture toughness of knitted fabric reinforced laminated composites were investigated. 1×1 ribknitted fabric reinforced glass/epoxy and carbon/epoxy laminated composites were produced by hand lay-up method. Mechanical behaviors of the produced composites were determined under tensile, compressive and shear loads. The fracturetoughness of the knitted fabric reinforced composites was determined under Mode I (0 o), Mode II (90 o) and Mode I/II (30 o,45 o, and 60 o) loading conditions by using Arcan test apparatus. In addition, the fracture toughness of glass/epoxy andcarbon/epoxy laminated composites were numerically determined using the J integral method in the ANSYS finite elementprogram. Test results have shown that knitted fabrics can be used as an alternative reinforcing material in the production oflaminated composites.

Investigation of the hydrogen production of the PACER fusion blanket integrated with Fe–Cl thermochemical water splitting cycle

Özkaya Medine,Acır Adem,Yalçın Şenay 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11

In order to meet the energy demand, energy production must be done continuously. Hydrogen seems to be the best alternative for this energy production, because it is both an environmentally friendly and renewable energy source. In this study, the hydrogen fuel production of the peaceful nuclear explosives (PACER) fusion blanket as the energy source integrated with Fe–Cl thermochemical water splitting cycle have been investigated. Firstly, neutronic analyzes of the PACER fusion blanket were performed. Necessary neutronic studies were performed in the Monte Carlo calculation method. Molten salt fuel has been considered mole-fractions of heavy metal salt (ThF4, UF4 and ThF4+UF4) by 2, 6 and 12 mol. % with Flibe as the main constituent. Secondly, potential of the hydrogen fuel production as a result of the neutronic evaluations of the PACER fusion blanket integrated with Fe–Cl thermochemical cycle have been performed. In these calculations, tritium breeding (TBR), energy multiplication factor (M), thermal power ratio (1 ψ), total thermal power (Phpf ) and mass flow rate of hydrogen (m˙ H2 ) have been computed. As a results, the amount of the hydrogen production (m˙ H2 ) have been obtained in the range of 232.24x106 kg/year and 345.79 x106 kg/year for the all mole-fractions of heavy metal salts using in the blanket.

Assessment of Tissue Perfusion Following Conventional Liposuction of Perforator-Based Abdominal Flaps

Zeynep Deniz Akdeniz Doğan,Bülent Saçak,Doğuş Yalçın,Özgür Pilancı,Fatma Betül Tuncer,Özhan Çelebiler 대한성형외과학회 2017 Archives of Plastic Surgery Vol.44 No.2

Background The effect of liposuction on the perforators of the lower abdominal wall has been investigated in several studies. There are controversial results in the literature that have primarily demonstrated the number and patency of the perforators. The aim of this study was to determine the effect of liposuction on the perfusion of perforator-based abdominal flaps using a combined laser–Doppler spectrophotometer (O2C, Oxygen to See, LEA Medizintechnik). Methods Nine female patients undergoing classical abdominoplasty were included in the study. Perforators and the perfusion zones of the deep inferior epigastric artery flap were marked on the patient’s abdominal wall. Flap perfusion was quantitatively assessed by measuring blood flow, velocity, capillary oxygen saturation, and relative amount of hemoglobin for each zone preoperatively, after tumescent solution infiltration, following elevation of the flap on a single perforator, and after deep and superficial liposuction, respectively. Results The measurements taken after elevation of the flap were not significantly different than measurements taken after the liposuction procedures. Conclusions The liposuction procedure does not significantly alter the perfusion of perforatorbased abdominal flaps in the early period. The abdominal tissue discarded in a classic abdominoplasty operation can be raised as a perforator flap and has been demonstrated to be a unique model for clinical research.