Hydropower–water and renewable energy in Turkey: Sources and policy

Turkey's energy consumption has been growing much faster than its production. It forces Turkey to make a rapid action to supply energy demand. From the viewpoint of primary energy sources (petroleum and natural gas), Turkey is not a rich country, but it has an abundant hydropower potential to be used for generation of electricity. Hydropower is the most important kind of renewable, sustainable energy and a proven technology for electricity generation. The aim of this paper is to discuss sources and policy of hydropower, water and renewable energy in Turkey and compares the hydropower application with Europe.     

Post-test evaluation of oxygen electrodes from solid oxide electrolysis stacks

The oxygen electrodes from two solid oxide electrolysis stacks that performed high-temperature steam electrolysis (HTSE) and produced hydrogen for 1000 and 2000 h, respectively, were examined using X-ray fluorescence, X-ray absorption near edge structure (XANES), four-point resistivity, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and Raman micro-spectroscopy to determine possible causes for the degradation in stack performance over the test periods. These techniques yielded information such as elemental distribution, oxidation state, phases present, electrode delamination, and porosity within the electrode layers. From these studies, we found two phenomena that were likely the cause of increasingly poor oxygen electrode performance over time. The first source of degradation was chromium substitution into the oxygen electrode bond layer, which serves to bond the cell to the flow field and interconnect. This is caused by migration of a chromium species from the bipolar plate. The effect of this is a significant increase in the electrical resistance of the bond layer material. The other source of degradation identified was oxygen electrode delamination. The cause of electrode delamination, which is locally catastrophic to the operation of the cell, is unclear; however, we will discuss two possible mechanisms that might cause this phenomenon.     

Numerical modelling and experimental validation of a planar type pre-reformer in SOFC technology

A computational model of the Jülich type pre-reformer and its experimental validation used in solid oxide fuel cells (SOFCs) is introduced. A continuum modelling approach has been attended and its feasibility verified. The fluid flow, heat transfer and chemical reacting species transport within the pre-reformer are numerically solved using 3D computational fluid dynamics (CFD) based on the finite volume method. The model considers the typical sub-components of the pre-reformer including the solid frame, air channels, catalyst and the wire mesh structures. Experimental measurements are used to supply appropriate boundary conditions for the simulations. The predicted results of the simulations are experimentally validated using thermocouples and gas chromatography. The results show good agreement, implying that the proposed model is an invaluable tool that can be used to reduce costly experiments in the design and process optimisation of the pre-reformer.     

On the All-to-All Broadcast Problem in Optical Networks1

This paper considers the transmission of uniform deterministic traffic in an optical broadcast-star network using Wavelength Division Multiplexing. Lower bounds are established on the minimum time to exchange information between every node pair in such a network with tunable transmitters and fixed-tuned receivers. Three different scheduling algorithms are developed that are strictly optimal in three regimes of system parameters. The results are applicable to arbitrary tuning delays and arbitrary numbers of wavelength channels, and indicate the existence of a well-defined transition regime from tuning-limited operation to bandwidth-limited operation. Finally, the problem of computing the optimal number of wavelengths is addressed to achieve a schedule with minimum schedule length, and exact solutions are given.     

In Silico and Experimental ADAM17 Kinetic Modeling as Basis for Future Screening System for Modulators

Understanding the mechanisms of modulators’ action on enzymes is crucial for optimizing and designing pharmaceutical substances. The acute inflammatory response, in particular, is regulated mainly by a disintegrin and metalloproteinase (ADAM) 17. ADAM17 processes several disease mediators such as TNFα and APP, releasing their soluble ectodomains (shedding). A malfunction of this process leads to a disturbed inflammatory response. Chemical protease inhibitors such as TAPI-1 were used in the past to inhibit ADAM17 proteolytic activity. However, due to ADAM17′s broad expression and activity profile, the development of active-site-directed ADAM17 inhibitor was discontinued. New ‘exosite’ (secondary substrate binding site) inhibitors with substrate selectivity raised the hope of a substrate-selective modulation as a promising approach for inflammatory disease therapy. This work aimed to develop a high-throughput screen for potential ADAM17 modulators as therapeutic drugs. By combining experimental and in silico methods (structural modeling and docking), we modeled the kinetics of ADAM17 inhibitor. The results explain ADAM17 inhibition mechanisms and give a methodology for studying selective inhibition towards the design of pharmaceutical substances with higher selectivity.     

Pseudomonas aeruginosa Triggered Exosomal Release of ADAM10 Mediates Proteolytic Cleavage in Trans

Pneumonia is a life-threatening disease often caused by infection with Streptococcus pneumoniae and Pseudomonas aeruginosa. Many of the mediators (e.g., TNF, IL-6R) and junction molecules (e.g., E-cadherin) orchestrating inflammatory cell recruitment and loss of barrier integrity are proteolytically cleaved through a disintegrin and metalloproteinases (ADAMs). We could show by Western blot, surface expression analysis and measurement of proteolytic activity in cell-based assays, that ADAM10 in epithelial cells is upregulated and activated upon infection with Pseudomonas aeruginosa and Exotoxin A (ExoA), but not upon infection with Streptococcus pneumoniae. Targeting ADAM10 by pharmacological inhibition or gene silencing, we demonstrated that this activation was critical for cleavage of E-cadherin and modulated permeability and epithelial integrity. Stimulation with heat-inactivated bacteria revealed that the activation was based on the toxin repertoire rather than the interaction with the bacterial particle itself. Furthermore, calcium imaging experiments showed that the ExoA action was based on the induction of calcium influx. Investigating the extracellular vesicles and their proteolytic activity, we could show that Pseudomonas aeruginosa triggered exosomal release of ADAM10 and proteolytic cleavage in trans. This newly described mechanism could constitute an essential mechanism causing systemic inflammation in patients suffering from Pseudomonas aeruginosa-induced pneumonia stimulating future translational studies.     

An implementation framework for trajectory-based routing in ad hoc networks

Routing in ad hoc networks is a complicated task because of many reasons. The nodes are low-memory, low-powered, and they cannot maintain routing tables large enough for well-known routing protocols. Because of that, greedy forwarding at intermediate nodes is desirable in ad hoc networks. Also, for traffic engineering, multi-path capabilities are important. So, it is desirable to define routes at the source like in source based routing (SBR) while performing greedy forwarding at intermediate nodes.We investigate trajectory-based routing (TBR) which was proposed as a middle-ground between SBR and greedy forwarding techniques. In TBR, source encodes trajectory to be traversed and embeds it into each packet. Upon the arrival of each packet, intermediate nodes decode the trajectory and employ greedy forwarding techniques such that the packet follows its trajectory as much as possible.In this paper, we address various issues regarding implementation of TBR. We also provide techniques to efficiently forward packets along a trajectory defined as a parametric curve. We use the well-known Bezier parametric curve for encoding trajectories into packets at source. Based on this trajectory encoding, we develop and evaluate various greedy forwarding algorithms     

Electronic Structure and Lattice Dynamics of BaCeO3 Compound in Cubic Phase

In this paper, electronic band structure, total density of states, and optical, lattice dynamic and thermo-dynamic properties of BaCeO₃ compound in cubic phase were investigated using density functional theory within the generalized gradient approximation. The calculated lattice constant is consistent with the experimental result. In cubic phase, BaCeO₃ has a semiconductor character with 2.17 eV band gap.     

Microbial and Sensory Effects of Combined High Hydrostatic Pressure and Dense Phase Carbon Dioxide Process on Feijoa Puree

High hydrostatic pressure (HHP) is used for microbial inactivation in foods. Addition of carbon dioxide (CO₂) to HHP can improve microbial and enzyme inactivation. This study investigated microbial effects of combined HHP and CO₂ on Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae, and evaluated sensory attributes of treated feijoa fruit puree (pH 3.2). Microorganisms in their growth media and feijoa puree were treated with HHP alone (HHP), or saturated with CO₂ at 1 atm (HHPcarb), or 0.4%w/w of CO₂ was injected into the package (HHPcarb+CO₂). Microbial samples were processed at 200 to 400 MPa, 25 °C, 2 to 6 min. Feijoa samples were processed at 600 MPa, 20 °C, 5 min, then served with and without added sucrose (10%w/w). Treated samples were analyzed for microbial viability and sensory evaluation. Addition of CO₂ enhanced microbial inactivation of HHP from 1.7‐log to 4.3‐log reduction in E. coli at 400 MPa, 4 min, and reduction of >6.5 logs in B. subtilis (vegetative cells) starting at 200 MPa, 2 min. For yeast, HHPcarb+CO₂ increased the inactivation of HHP from 4.7‐log to 6.2‐log reduction at 250 MPa, 4 min. The synergistic effect of CO₂ with HHP increased with increasing time and pressure. HHPcarb+CO₂ treatment did not alter the appearance and color, while affecting the texture and flavor of unsweetened feijoa samples. There were no differences in sensory attributes and preferences between HHPcarb+CO₂ and fresh sweetened products. Addition of CO₂ in HHP treatment can reduce process pressure and time, and better preserve product quality.     

Analytical Modeling of Dual Winding Surface-mounted Permanent Magnet Synchronous Machine for Hybrid Electric Vehicle Accessory Drive Systems

Fast and accurate electromagnetic torque calculation of unconventional Permanent Magnet Synchronous Machines (PMSMs) is very important in order to reduce design effort. Dual winding PMSMs (DWPMSMs) can be categorized as unconventional and commonly available fast design software that usually lacks predicting machine performance. In this study, an analytical modeling approach has been proposed to calculate electromagnetic torque of DWPMSMs, which has motor and generator windings in a single stator core. Conformal mapping is used for the calculation of flux levels at various locations in the machine. Radial and tangential components of flux densities due to magnet and winding are determined analytically. Instantaneous value of electromagnetic torque due to generator or motor windings is calculated by integrating the Maxwell stress tensor in the middle of the air gap. Accuracy of the proposed analytical solution is confirmed with finite element analysis results. For further validation, an experimental setup with a 24-slot 22-pole DWPMSM is used. Experimental results have close agreement with analytical results obtained by conformal transform-based modeling.