Municipal water supply dams as a source of small hydropower in Turkey

In Turkey the laws published in recent years succeeded in promoting the utilization of renewable energy for electricity generation. After the publication of Renewable Energy Law on 18 May 2005 in Turkey there occurred a boost in renewable energy projects along with hydropower development. Thus, the economically feasible hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. From this perspective, this paper was aimed to evaluate the small hydropower potential of municipal water supply dams of Turkey and discussed the current situation of SHP plants in terms of the government policy. It is estimated that the installing small hydropower plants to exiting 45 municipal water supply dams in Turkey will generate 173 GWh/year electric energy without effecting the natural environment. For a case study, Zonguldak Ulutan Dam and its water treatment plant has been investigated in detail.     

INVESTIGATIONS ON THE SYNTHETIC AUXIN RESIDUES OF GREENHOUSE TOMATOES (LYCOPERSICON ESCULENTUM) GROWN IN TURKEY

Normal and misshapen greenhouse‐grown tomatoes (n= 100 for each group) were analyzed separately in order to compare their synthetic auxin residue contents. Sharply elongated blossom‐ends, “hook‐like” and “slice‐like” deformations were the auxin‐induced shape abnormalities most often observed. The greenhouse tomatoes were found to contain only 4‐chlorophenoxyacetic acid (4‐CPA), but no 2,4‐dichlorophenoxyacetic acid (2,4‐D) or β‐naphtoxyacetic acid (BNOA) residues. Seasonal variations in the mean 4‐CPA residues of greenhouse tomatoes were significant (p<0.05) through 1994‐97. Mean 4‐CPA residues of normal and misshapen greenhouse tomatoes were 0.323/pm0.187 mg kg^?1 and 0.363/pm0.150 mg kg^?1, respectively. The difference was not statistically significant (p>0.05). The average 4‐CPA residue in abnormally shaped fruit is greater than 0.3 mg kg^?1. While misshapen fruit always contained residues of at least 0.1 mg kg^?1, 95% of normal‐shaped fruit also contained residues exceeding 0.1 mg/kg^?1.     

Accessibility of Turkish university Web sites

Universal Access in the Information Society - In 2010, the author of this paper conducted an evaluation of the accessibility level of the home pages of Turkish Universities (Kurt in Univers Access...     

Unified performance analysis with exact solutions for uplink non-orthogonal multiple access system-based cellular networks

This research presents a unified performance analysis methodology for the power domains of uplink non-orthogonal multiple access (NOMA) system consisting of a base station and an arbitrary number of users over Rayleigh fading channels. The study derives exact closed-form expressions for key performance metrics, such as outage probability (OP), symbol error rate (SER), outage capacity (OC), average channel capacity (AVC), and amount of fading, using binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK) modulations. The analysis encompasses all necessary channel parameters for evaluating the performance of an uplink NOMA system. The theoretical and simulation results completely supported one another. Furthermore, the results were compared with experiments in the literature using similar parameters. The proposed system was determined to increase performance by 40% for OP, 62% for SER, and 4.74 times for AVC at SNR = 20 dB. Finally, this study introduced exact solutions that can significantly accelerate NOMA systems analysis by exploiting the information in the existing database for analytical design processes in communications theory.     

Symbiotic organisms search algorithm for dynamic economic dispatch with valve-point effects

Abstract

In this study, symbiotic organisms search (SOS) algorithm is proposed to solve the dynamic economic dispatch with valve-point effects problem, which is one of the most important problems of the modern power system. Some practical constraints like valve-point effects, ramp rate limits and prohibited operating zones have been considered as solutions. Proposed algorithm was tested on five different test cases in 5 units, 10 units and 13 units systems. The obtained results have been compared with other well-known metaheuristic methods reported before. Results show that proposed algorithm has a good convergence and produces better results than other methods.     

Influence of Carbonic Maceration Pre-treatment on Functional Quality of Dried Tomato Quarters

As a novel pre-treatment, carbonic maceration (CM) was investigated in this study to figure out its effect on functional quality of conventionally dried tomato quarters (60 °C, 1.3 m/s air velocity). Carotenoids, tocopherols, total flavonoid, total phenolic and DPPH radical scavenging potential were determined for dried tomato samples (directly dried as a control and CM treated samples). Lycopene and β-carotene contents of CM treated tomato quarters were high compared to control samples (only conventionally dried). β-, γ-Tocopherol contents in dried tomato were raised with CM pre-treatment, as α-tocopherol decreased. Total flavonoid was found to be more than 2.5 times higher for CM treated samples compared to that in fresh tomato. CM displayed a promoter effect on total phenolic content and antioxidant activity of hydrophilic extracts, whereas there was no difference between those values determined for lipophilic extracts from control and pre-treated samples. CM has a potential as a pre-treatment before conventional drying of tomato to improve its nutritional contents and functional potential.     

Effect of Untreated Surface Disbonds on Performance of FRP-Retrofitted Concrete Beams

Retrofitting concrete structures with externally bonded fiber-reinforced polymer (FRP) laminates has become an increasingly common practice. Disbonds at the concrete-FRP interface, if left untreated, may adversely affect the performance of the retrofitted system. Disbonds in the form of surface voids and cracks are the subject of this paper. Voids may occur due to poor compaction or defective formwork, or in the form of air entrapment between resin and FRP laminate during application. Cracks, on the other hand, generally result from loading. This study is comprised of a detailed experimental program and a nonlinear finite-element analysis. In the experiments, surface cracks were simulated by cutting slits in concrete, herein termed as surface cuts. The study shows that leaving surface disbonds untreated, within the considered range of disbond variables, does not have a significant impact on the overall structural performance. A threshold of 12.7 mm for void diameter was deemed conservative for structural performance. On the other hand, 38 mm spacing was considered an appropriate threshold for epoxy injection in crack widths between 0.25 and 0.8 mm. Hence, conservative thresholds in current practice may be revised accordingly, unless considered necessary to avoid environmental effects.     

Jitter performance of neural network equivalent MPSK schemes over microwave channels

In this paper a new microwave channel model with realizable and practical parameters is defined for indoor mobile communication. The emphasis is on the jitter and error performance of trellis-coded MPSK and neural network equivalent systems over microwave channels with no channel state information (CSI) and no side information on the phase noise process. Analytical upper bounds are derived using the Chernoff bounding technique combined with a modified generating functional approach. It is shown that the neurocomputing results confirm the analytical results. © 1998 John Wiley & Sons, Ltd.