Seismic Response of MSE Walls with Various Reinforcement Configurations: Effect of Input Ground Motion Frequency

Mechanically stabilized earth (MSE) walls perform well under earthquake loads, and hence they are preferred in earthquake-prone regions. The multifaceted load transfer between the components of the MSE wall under seismic loads can be captured using numerical analysis. This study presents the results of a series of numerical analyses performed to investigate the effects of the frequency of the input ground motion on the seismic response of MSE walls. MSE wall design configurations were prepared using various reinforcement designs (length, vertical spacing, and stiffness). A frequent wall height of 8 m was selected for the analysis. Using two-dimensional finite element analysis, each MSE model was excited with seven (7) different input ground motion accelerograms with equal Arias Intensity, but with different frequencies ranging between 1 Hz and 8 Hz. The results of the numerical analyses indicated rotation at the top of the MSE wall in seismic conditions. The frequency versus acceleration plot for a point close to the top of the MSE wall indicated peaks for the excitations with frequencies f = 1.5 Hz and f = 4 Hz, which are close to the estimated natural frequency of the overall model (including the foundation soil) and the MSE wall, respectively. The highest normalized acceleration amplification factor solely within the MSE wall was recorded as 1.86 for the excitation with a frequency equivalent to its fundamental frequency (f ≅ 4 Hz). In this study, the 8 m high MSE wall models placed on a firm clayey foundation soil with the reinforcement parameters with length over height ratio in 0.5–1 range, axial stiffness in 600–1200 kPa range, and reinforcement vertical spacing in 0.4–0.6 m range performed satisfactorily under moderate seismic loads

Evaluation of tensile strength of different esthetic coping materials to Ti-base and monolithic zirconia crowns

This study evaluated the tensile strength of three aesthetic abutment materials at two different angulations (0 and 15°) to Ti-base and monolithic zirconia crowns. Prefabricated polyvinylidene difluoride (Medentika Implant) abutments were obtained and zirconia (Kingch) and polyetheretherketone (Ceramill) copings were manufactured using a computer-aided design/computer-aided manufacturing system (n = 12). Bonding surfaces of the copings and Ti-bases were air-abraded with alumina and then metal primer was applied. Self-adhesive resin cement (Multilink Hybrid Abutment) was used for cementation of copings to Ti-base. The bonding surfaces of the monolithic zirconia crowns (Upcera ST ML) were air-abraded and crowns were cemented using self-adhesive cement (seT PP). Data were analyzed using Kruskal–Wallis and Mann–Whitney U tests. No significant difference was found in the tensile strength of abutment to the crown interface for 0° tapered abutments (p > 0.05). Regarding 15° tapered abutments, the highest tensile strength values were obtained with zirconia abutments (p < 0.05). The tensile strength of monolithic zirconia crowns was lower than the restorations used in routine clinical practice

Evaluation of different scale-up strategies for Haematococcus pluvialis cultivation in airlift photobioreactors

Large scale algal biomass production can be very challenging due to the potential issues of sustainability, environmental ethics, and economic concerns. A strategic approach to the transition from the laboratory to the industrial scale allows the prediction of process characteristics, design and analysis of large scale systems, and reduction of extra costs. In this study, a scale-up procedure that considered different approaches was carried out by selecting the Haematococcus pluvialis as a model organism. Three scale-up parameters (constant mixing time (t(m)), volumetric power consumption rate (P/V), and oxygen mass transfer coefficient (k(L)a)) were tested for biomass production in a 2-L airlift photobioreactor and they were compared with those obtained from a 1-L aerated cultivation bottle. Among three strategies, the maximum cell concentration, 4.60 +/- 0.20x10(5) cells/mL, was obtained in a constant volumetric power consumption rate experiment. Also, total carotenoid amount showed similar changes with the cell concentration and reached the maximum concentration of 2.02 +/- 0.11 mg/L under constant P/V experiment. However, the cultivation bottle presented the highest biomass amount of 0.62 g/L and specific growth rate of 0.38 day(-1) of all of the photobioreactors. This result might be attributed to the low aeration rates or improper configuration of the system, which created a non-homogenous culture medium and led to ineffective mass transfer.This study was funded by the Scientific and Technological Research Council of Turkey (TUBITAK) under grant number [115M014] . Acknowledgements: This study was a part of Cost action ES1408 and the authors would like to thank the Scientific and Technolog- ical Research Council of Turkey (TUBITAK) (project number 115M014) for the financial support.Scientific and Technological Research Council of Turkey (TUBITAK) [115M014

Evaluation of scale-up methodologies and computational fluid dynamics simulation for fucoxanthin production in airlift photobioareactor

Deniz, Irem/0000-0002-1171-8259; Imamoglu, Esra/0000-0001-8759-7388; Demirel, Zeliha/0000-0003-3675-7315WOS: 000539793500001Researches about commercial-scale production of fucoxanthin are increasing day by day due to the much interest of its broad beneficial health effects. the aim of this study was to investigate the scale-up methodologies in airlift photobioreactor and to simulate fluid flow using computational fluid dynamics (CFD) for fucoxanthin production fromPhaeodactylum tricornutummicroalgae. During the transition process from 1-L cultivation bottle to the 2-L airlift photobioreactor, the constant mixing time, the constant volumetric oxygen transfer coefficient, and the constant volumetric power consumption rate were evaluated as scale-up methodologies under laboratory conditions. Maximum fucoxanthin yield was found as 1.01 +/- 0.07 mg g(-1)using scale-up strategy based on constant volumetric power consumption rate. After that, CFD simulation was performed in order to examine flow characteristics, mixing efficiency, hydrodynamics, and gas holdup for selected operation conditions. It was observed that mixing efficiency was low because the draft tube configuration prevented the circulation of fluid and caused a heterogenic culture medium inside the reactor. It is possible to overcome this bottleneck by developing the effective draft tube.Turkiye Bilimsel ve Teknolojik Arastirma KurumuTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115M014]Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, Grant/Award Number: 115M01

Ovarian Ectopic Pregnancy in an Asymptomatic Patient

Ovarian pregnancy caused by the implantation of the fertilized ovum in the ovary is a rare type of ectopic pregnancy. In this study, our aim is to present an ovarian ectopic pregnancy case without any complaints except amenorrhea. A 34 year-old woman, gravida 2, para 1, was referred to our clinic with the diagnosis of ectopic pregnancy by the center which she had been admitted due to amenorrhea. She had no complaints and was clinically stable; however her pregnancy test was positive. Uterine bleeding was not observed and roughly 5 cm smooth edged and mobile right adnexal mass showing no tenderness with palpation was detected during pelvic examination. Transvaginal sonography showed that there was an endometrium in 25 mm thickness and there was no gestational sac. Left ovarian logy was normal, but an exitus embryo with a crown-rump length (CRL) measuring 11 mm (at 7 weeks, 2 days gestation) was detected on the right adnexal area. It was recorded that there was no fluid in the pouch of Douglas and the right ovary could not be distinguished. Laparoscopy was suggested and then laparoscopic right salpingo-oophorectomy was performed upon detection of ovarian pregnancy. Abdominal pain is the most frequent complaint in almost all ovarian ectopic pregnancy. Our patient is interesting because it is asymptomatic. The diagnosis of ovarian ectopic pregnancy is very difficult; patients may be asymptomatic and clinically stable. Ovarian ectopic pregnancy should be taken into consideration in the differential diagnosis of each ectopic pregnancy. The diagnosis is made surgically and histopathologically. Today, although laparoscopic conservative surgery is performed in the treatment, radical surgery may sometimes be required. [Cukurova Med J 2015; 40(Suppl 1): 42-46

Transition from start-up to scale-up for fucoxanthin production in flat plate photobioreactor

Deniz, Irem/0000-0002-1171-8259; Demirel, Zeliha/0000-0003-3675-7315; Imamoglu, Esra/0000-0001-8759-7388WOS: 000469393600002Fucoxanthin is one of the most important carotenoids and is found in diatoms such as Phaeodactylum tricornutum. the aim of this study was to evaluate the use of both the constant volumetric power consumption rate as scale-up strategy and the constant light energy per unit volume for transition from 1000-mL bottle to 2-L and 7-L flat plate photobioreactors for fucoxanthin production in P. tricornutum, considering whether an increase in the fucoxanthin yield could be achieved. the cell concentration and fucoxanthin content were enhanced with increasing the cultivation volume. It was found that the fucoxanthin yield increased 2.3 times in 2-L photobioreactor and 2.6 times in 7-L photobioreactor in comparison to the value of 1.05mgg(-1) dry weight in the cultivation bottle. Consequently, fucoxanthin production was successfully step-wise scaled-up from 1000-mL bottle to 7-L photobioreactor using both constant volumetric power consumption rate and the constant light energy per unit volume under laboratory conditions.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115M014]This study was a part of Cost action ES1408 and this study was financially supported by the Scientific and Technological Research Council of Turkey (TUBITAK) with the project number of 115M014

Computational fluid dynamics modelling of stirred tank photobioreactor for Haematococcus pluvialis production: Hydrodynamics and mixing conditions

Deniz, Irem/0000-0002-1171-8259; Imamoglu, Esra/0000-0001-8759-7388WOS: 000572122100023Agitated photobioreactors (PBR) have been widespread for the cultivation of microalgae because of their advantages in mixing and mass transfer conditions. However, it is difficult to investigate the behaviors of cultivation broth flow with experimental procedures in these PBRs. Computational Fluid Dynamics (CFD) is a common method that has been used to simulate the performance of fluid containing systems in order to investigate the fluid flow, reduce the design cost and improve the efficiency. the objective of this study was to evaluate hydrodynamics and mixing conditions of stirred tank PBR for Haematococcus pluvialis production experimentally and numerically. the cells were first cultivated in a stirred tank PBR containing Rushton turbine impeller and the cell growth was examined during 10 days. At the end of cultivation, the cell concentration was reached the value of 3.1 +/- 0.1 x 10(5) cells mL(-1) with the total carotenoid content of 2.47 +/- 0.01 mg L-1. Then, the hydrodynamic analyses were conducted to evaluate the average velocity magnitude, turbulence properties and dead zone inside the PBR. the simulation results obtained from realizable k-epsilon turbulence model showed that the uniformity index of average velocity was found as 0.86. This result showed that the fluid flow showed similar behavior in the most parts of PBR except around the impellers. the velocity contours supported that the mixing conditions were supplied efficiently, however the vortex formation was observed around the impellers in spite of the baffles. in addition, the turbulence kinetic energy having a vital influence on mixing characteristics was found between the values of 1.0 x 10(-2) and 3.0 x 10(-2) m(2) s(-2) and the lowest values were observed between two impellers due to extent of mixing. Obtained results could be used to re-design PBR configurations considering the impeller type, the distance between impellers and cultivation conditions.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115M014]This study was a part of Cost action ES1408 and the authors would like to thank the Scientific and Technological Research Council of Turkey (TUBITAK) with the project number of 115M014 for the financial support

A novel subcritical fucoxanthin extraction with a biorefinery approach

Eco-friendly, cost efficient and effective extraction methods have become significant for the industries applying zero waste principles. The two main objectives of this study were; to examine fucoxanthin extraction from wet Phaeodactylum tricornutum using subcritical fluid extraction and to characterize the residual biomass in order to determine the potential application areas. The highest fucoxanthin yield of 0.69 ± 0.05 mg/g wet cell weight was achieved using methanol with solvent-to-solid ratio of 200:1 at 120 rpm, 20 MPa pressure and at 35 °C for 60 min by subcritical extraction. Microscopy images showed that most of the cells were disrupted and intracellular components were effectively released. Based on the results of energy dispersive spectroscopy, biomass contained a mixture of organic molecules including mainly carbon (57–72%), oxygen (26–41%), magnesium (0.6–1.4%) and silica (0.4–1%) (wt%). These results make the residual biomass a potential candidate for various areas such as bioenergy, material sciences and sensor technologies