A Low Cost Shading Analyzer and Site Evaluator Design to Determine Solar Power System Installation Area

Shading analyzer systems are necessary for selecting the most suitable installation site to sustain enough solar power. Afterwards, changes in solar data throughout the year must be evaluated along with the identification of obstructions surrounding the installation site in order to analyze shading effects on productivity of the solar power system. In this study, the shading analysis tools are introduced briefly, and a new and different device is developed and explained to analyze shading effect of the environmental obstruction on the site on which the solar power system will be established. Thus, exposure duration of the PV panels to the sunlight can be measured effectively. The device is explained with an application on the installation area selected as a pilot site, Denizli, in Turkey

Učinkovito upravljanje brzinom induktivnog motora korištenjem metode adaptivnog upravljanja s referentnim modelom zasnovane na RBF-u

This paper proposes a model reference adaptive speed controller based on artificial neural network for induction motor drives. The performance of traditional feedback controllers has been insufficient in speed control of induction motors due to nonlinear structure of the system, changing environmental conditions, and disturbance input effects. A successful speed control of induction motor requires a nonlinear control system. On the other hand, in recent years, it has been demonstrated that artificial intelligence based control methods were much more successful in the nonlinear system control applications. In this work, it has been developed an intelligent controller for induction motor speed control with combination of radial basis function type neural network (RBF) and model reference adaptive control (MRAC) strategy. RBF is utilized to adaptively compensate the unknown nonlinearity in the control system. The indirect field-oriented control (IFOC) technique and space vector pulse width modulation (SVPWM) methods which are widespread used in high performance induction motor drives has been preferred for drive method. In order to demonstrate the reliability of the control technique, the proposed adaptive controller has been tested under different operating conditions and compared performance of conventional PI controller. The results show that the proposed controller has got a clear superiority to the conventional linear controllers.Ovaj rad prikazuje adaptivni regulator s referentnim modelom zasnovan na neuronskoj mreži za induktivne motore. Ponašanje tradicionalnih regulatora s povratnom vezom pokazalo se nedovoljno dobrom za upravljanje brzinom induktivnih motora zbog nelineatnosti strukture sustava, promjene okolišnih uvjeta, i efekta ulaznih poremećaja. Uspješno upravljanje brzinom induktivnog motora zahtjeva nealinearne upravljačke sustave. S druge strane, posljednjih godina pokazano je kako su upravljačke metode zasnovane na umjetnoj inteligenciji bitno uspješnije u primjenama upravljanja nelinearnim sustavima. U ovome radu razvijen je inteligentni regulator za upravljanje brzinom induktivnog motora s kombinacijom radijalne neuronske mreže (RBF) i strategije adaptivnog regulatora s referentnim modelom (MRAC). RBF je realiziran kako bi adaptivno kompenzirao nepoznatu nelinearnost u sustavu upravljanja. Tehnika indirektnog vektorskog upravljanja (IFOC) i metoda prostorno vektorske širinsko impulsne modulacije koje su široko korištene za induktivne motore visokih performansi preferirani su kao metode u ovome radu. Kako bi se prikazala pouzdanost tehnike upravljanja, predloženi adaptivni regulator ispitan je u različitih uvjetima rada i uspoređeno je vladanje s obzirom na konvencionalni PI regulator. Rezultati pokazuju kako predloženi regulator očito pokazuje bolje vladanje od konvencionalnih linearnih regulatora

AN ANALYSIS OF EXPORT PARADOX: THE TURKISH CASE IN THE AFTERMATH OF APRIL 5TH 1994 AUSTERITY MEASURES PACKAGE

The combined impact of the fragility of Turkish economy, variable currency rates and global scale crises have greatly contributed to the formation of probable shocks. Alongside with the financial deregulation of post-1980s economic setting in Turkey, a favorite hub of short-term foreign direct investment in the mentioned time period, in particular, the post 1990s multitude economic crises have led to the shortening of the time interval of foreign direct investments stay and affected the infrastructure of Turkish economics. In this regard, this study aims to elucidate and elaborate the changes in foreign trade in the light of economic austerity measures by means of VAR analysi

Turkey

The next century will witness a breakthrough in terms of renewable energy sources, particularly solar energy and its derivatives. This renewable and enormous energy source offers a solution to the energy problem all over the world. One of the areas in which solar energy is used is the photovoltaic (PV) systems. The main element of this sector, however, is the pure silicon technology. Because, most efficient PV cells are made of silicon and its degree of purity is very important. The most commonly used types of these materials for PV energy conversion are thin Film, mono-crystalline and poly-crystalline silicon, which are also known as silicon modules or panels. However, performances of these modules vary by region. This study focuses on analyzing different three-type PV panels and determining the optimal panel type for Kahramanmaras with three separate PV systems, each 3-kWp and grid-connected. Besides, this study is the first research project to consider all aspects to determine optimal PV power system in the region. To this aim, three different PV systems consisting of thin film, mono-crystalline and poly-crystalline silicon panels were installed. The amount of energy generated by each system, cost analysis, annual incomes, breakeven points, installation area occupied by the system and total weights of each system are evaluated for each panel type used in the installed system and potential energy to be generated by solar energy in the region was considered. Following energy generation which lasted one year and at the end of the 30-year operation period, it is concluded that poly-crystalline silicon panels are the most optimal panel for the region because it yields the highest annual incomes and the shortest breakeven point for the investors. (C) 2015 Published by Elsevier Ltd

The analysis of different PV power systems for the determination of optimal PV panels and system installation - A case study in Kahramanmaras, Turkey

The next century will witness a breakthrough in terms of renewable energy sources, particularly solar energy and its derivatives. This renewable and enormous energy source offers a solution to the energy problem all over the world. One of the areas in which solar energy is used is the photovoltaic (PV) systems. The main element of this sector, however, is the pure silicon technology. Because, most efficient PV cells are made of silicon and its degree of purity is very important. The most commonly used types of these materials for PV energy conversion are thin Film, mono-crystalline and poly-crystalline silicon, which are also known as silicon modules or panels. However, performances of these modules vary by region. This study focuses on analyzing different three-type PV panels and determining the optimal panel type for Kahramanmaras with three separate PV systems, each 3-kWp and grid-connected. Besides, this study is the first research project to consider all aspects to determine optimal PV power system in the region. To this aim, three different PV systems consisting of thin film, mono-crystalline and poly-crystalline silicon panels were installed. The amount of energy generated by each system, cost analysis, annual incomes, breakeven points, installation area occupied by the system and total weights of each system are evaluated for each panel type used in the installed system and potential energy to be generated by solar energy in the region was considered. Following energy generation which lasted one year and at the end of the 30-year operation period, it is concluded that poly-crystalline silicon panels are the most optimal panel for the region because it yields the highest annual incomes and the shortest breakeven point for the investors. © 2015 Published by Elsevier Ltd

Power System Installation Area

Shading analyzer systems are necessary for selecting the most suitable installation site to sustain enough solar power. Afterwards, changes in solar data throughout the year must be evaluated along with the identification of obstructions surrounding the installation site in order to analyze shading effects on productivity of the solar power system. In this study, the shading analysis tools are introduced briefly, and a new and different device is developed and explained to analyze shading effect of the environmental obstruction on the site on which the solar power system will be established. Thus, exposure duration of the PV panels to the sunlight can be measured effectively. The device is explained with an application on the installation area selected as a pilot site, Denizli, in Turkey

Is there a relationship between resistin levels and left ventricular end-diastolic pressure?

Objective: Resistin, a cysteine-rich peptide, is associated with atherosclerosis and diabetes. Resistin levels increase corresponding to coronary artery disease (CAD) and heart failure severity. Since resistin level tends to elevate with symptomatic heart failure, it is expected to be associated with left ventricular end-diastolic pressure (LVEDP). However, there is no relevant literature on the relationship between resistin levels and LVEDP. We aimed to evaluate the association between resistin levels and LVEDP, severity of CAD, carotid intima-media thickness (CIMT), and echocardiographic diastolic dysfunction parameters. Methods: For this study, 128 euvolemic patients with creatinine clearance >50 mg/dL and without acute coronary syndrome, who had typical chest pain or were stress test positive, were enrolled. Resistin level was measured by Enzyme-linked immunosorbent assays (ELISA) method. Severe CAD is defined as >= 50% stenosis in one of the major coronary arteries. LVEDP was measured during left heart catheterization. Results: After coronary angiography, 60 patients (46.9%) had severe CAD. The mean LVEDPs were similar for patients with and without severe CAD (p=0.480). The resistin levels did not differ between the groups (p=0.154). The resistin levels did not correlate with LVEDP (r=-0.045, p=0.627), ejection fraction (EF; r=0.110, p=0.228), the Gensini score (r=-0.091, p=0.328), and CIMT (r=0.082, p=0.457). No significant correlation was found between the echocardiographic diastolic dysfunction parameters and resistin levels. Conclusion: There was no significant correlation between resistin level and LVEDP, CAD severity, echocardiographic diastolic dysfunction parameters, and CIMT. Further studies are warranted to determine the efficacy of resistin in clinical use

Effect of TiO 2 nanoparticles on thermo-mechanical properties of cast zein protein films

Zein protein (ZP) films embedded with core-and-shell nanoparticles, with titanium dioxide as core and silica as shell (TiO2@@SiO2), were prepared by solution-casting method for its effect on mechanical properties. ZP (\u3e90% protein) at 1.5% w/w was prepared in aqueous ethanol solution with addition of TiO2@@SiO2 nanoparticles and sonicated at 0, 16, 80 and 160 μm amplitudes prior to casting on leveled glass plates or petri dishes. The physical and mechanical properties of prepared films were characterized. Storage modulus below the glass transition temperature Tg (∼40 °C) decreased after sonication at all levels. Multiple peaks for DSC measurements of ZP films starting at −33.74 to −25.43 °C, and 122 to 138 °C indicated different glass transition temperatures and degradation profiles. Temperature range for thermal degradation of films was between 280 and 340 °C, which corresponds to the decomposition of ZP proteins. Presence of three to four degradation stages were observed in oxidizing the protein films in the temperature range of 30 to 850 °C. Incorporation of 1.5% (w/w) of TiO2@@SiO2 nanoparticles into ZP films was shown to change the film properties and helped to improve their mechanical properties; however, reduced the elongation-to-break by almost half to two-third. Initial contact angle of ZP films with and without nanoparticles varied from 19.6 to 25.3° and 17.9 to 22.8°, respectively, irrespective of sonication levels. Water vapor permeability (WVP) (10−11 g m/m2 s Pa) was affected by film thickness, however, were not significantly affected by sonication conditions and nanoparticle loading at study levels