Sélection et Caractérisation d’Isolats de Levure à Aptitude Amylolytique provenant du Malt de Maïs (Zea mays sp.)

L’étude vise la sélection et la caractérisation d’isolats de levure à aptitude amylolytique provenant du malt de maïs (Zea mays sp.). Moyennant l’utilisation  de la méthode des quadrants, 17 isolats cultivés sur gélose de Sabouraud chloramphénicol en boîte de Pétri ont été prélevés, ensuite purifiés et soumis à  une sélection sur la gélose 4 % d’amidon. Après repiquages successifs effectués sur gélose de Sabouraud en boîte de Pétri, l’identification des colonies  sélectionnées a été réalisée. Toute chose égale par ailleurs, les colonies ont différé par leur taille, laquelle est moyenne pour l’isolat S7 et grande pour S8  et S9. La densité cellulaire de colonie, exprimée en 106 cellules/ml, a également différé d’une souche à l’autre, notamment 11,5 pour S7, 14 pour S8 et  28,1 pour S9. La capacité de transformation d’amidon est relativement plus élevée pour S9 avec 7 ° Brix d’extrait soluble à 2 heures d’incubation par  rapport à la valeur de 6 ° Brix pour S7 et S8. La valeur maximale pour S9 décroît ensuite de 7 à 5 ° Brix durant la période allant de 4 à 20 heures et reste  stable à 5 °Brix jusqu’à la fin d’incubation à 34 heures. Par contre elle reste stable à 6 ° Brix pour S7 et S8 durant la période de 2 à 34 heures. L’isolat     amylolytique S9 s’est révélé plus performant que les isolats S7 et S8

Equivalence and interchangeability of narrow therapeutic index drugs in organ transplantation

The editorial services of iS Health, involved in the preparation of this manuscript, were supported by Astellas Pharma Europe Ltd

Büyük ölçekli şebeke bağlantılı fotovoltaik sıstemlerde çok seviyeli çok fonksıyonlu evirgeç için çok amaçlı kontrol stratejisinin optimum tasarımı ve araştırılması.

TEZ10701Tez (Doktora) -- Çukurova Üniversitesi, Adana, 2017.Kaynakça (s. 263-282) var.xxxiv, 283 s. : res. (bzs. rnk.), tablo ; 29 cm.Bu çalışma şebekenin güç kalitesini iyileştirmek için fotovoltaik sistemlerin şebekeye nasıl bağlanacağını dikkate alarak, şebeke bağlantılı çok-seviyeli çok-fonksiyonlu eviricinin (ÇSÇFE) yapısına odaklanmaktadır. Bu çalışma, şebeke bağlantılı eviricilerin güç kalitesi ve güvenirliliği konularında araştırmaları sunmakta olup, bu sistemlerin verimliliğini arttırmak için ileri seviye topolojik ve kontrol yöntemi çözümlerini önermektedir. Bu kapsamda geliştirilen ÇSÇFE, şebeke bağlantılı evirici fotovoltaik sistem ve şebeke arasında yüksek kaliteli aktif güç transferini, ortak bağlantı noktasında (OBN) güç kalitesi problemlerinin giderilmesini ve şebekede etkin bir kontrolünün gerçekleştirilmesini sağlamıştır. Önerilen ÇSÇFE yüksek kaliteli aktif gücü şebekeye enjekte etmesinin yanı sıra OBN’deki farklı güç kalitesi problemleri ve reaktif gücü eşzamanlı olarak yeni kontrol yöntemleriyle kompanze edebilmektedir. Bunların yanısıra, fotovoltaik sistemlerinin verimliliğini arttırmak için normal ve kısmi gölgelenme şartları altında fotovoltaik sistemlerden maksimum gücü elde etmek için yeni bir maksimum güç noktası takibi yöntemi geliştirilmiştir. Ayrıca gerilim çukuru ve tepelerinin tespiti için dalgacık tabanlı yeni bir metot geliştirilmiştir.This thesis focuses on the multilevel multifunctional grid connected inverter architecture, taking into account how to interconnect photovoltaic (PV) systems into the future smart microgrid with maximizes efficiency, power quality (PQ) and reliability of the power system. The desirable approach should be capable to sustain high quality energy transfer between PV power plants and utility grid and to enhance the PQ at the both consumers and source side. This thesis presents investigations into issues of PQ and reliability of grid connected inverters and offers advanced topological and sophisticated control solutions to significantly improve performance of these systems. In this context, a PV based multilevel inverter proposed to simultaneously maintain high-quality power exchange between PV systems and the utility grid in disturbed grids and perform simultaneous mitigation of PQ problems using novel control algorithm. Furthermore, to produce optimum power and operate at the maximum proficiency a maximum power point tracking method proposed to extract maximum power of the PV system when the PV system receives uniform and non-uniform irradiance or subjected to partial shading. Additionally a wavelet transform based voltage sag/swell detectıon algorithm is proposed to detect voltage sag/swell disturbances.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: FDK-2016-6392

A novel wavelet transform based voltage sag/swell detection algorithm

This paper proposes a novel sag/swell detection algorithm based on wavelet transform (WT) operating even in the presence of flicker and harmonics in source voltage. The developed algorithm is the hybrid of Daubechies wavelets of order 2 (db2) and order 8 (db8) to detect voltage sag/swell with and without positive/negative phase jumps. The hybrid detection algorithm can detect the start and end times of voltage sag/swell with and without phase jumps within 0.5 ms and 1.15 ms, respectively. The performance of the proposed voltage sag/swell detection method is compared with the results of dq-transformation, Fast Fourier Transform (FFT) and Enhanced Phase Locked Loop (EPLL) based voltage sag/swell detection methods. The good robustness and faster processing time to detect balanced and unbalanced voltage sag/swell are provided using proposed method. With the proposed hybrid detection algorithm consisting of db2 and db8 wavelet functions, a robust sag/swell detection is achieved which can give precise and quick response. The performance of proposed hybrid algorithm is validated and confirmed through simulation studies using the PSCAD/EMTDC analysis program. ©2015 Elsevier Ltd. All rights reserved

Review of multifunctional inverter topologies and control schemes used in distributed generation systems

Recent developments in power electronics technology have spurred interest in the use of renewable energy sources as distributed generation (DG) generators. The key component in DG generators is a grid-connected inverter that serves as an effective interface between the renewable energy source and the utility grid. The multifunctional inverter (MFI) is special type of grid-connected inverter that has elicited much attention in recent years. MFIs not only generate power for DGs but also provide increased functionality through improved power quality and voltage and reactive power support; thus, the capability of the auxiliary service for the utility grid is improved. This paper presents a comprehensive review of the various MFI system configurations for single-phase (two-wire) and three-phase (three- or four-wire) systems and control strategies for the compensation of different power quality problems. The advances in practical applications and recent research on MFIs are presented through a review of nearly 200 papers

Investigation of inverter based shunt compensators for mitigation of power quality problems in power distribution system [Güç kalitesi problemlerini düzelten da?itim sistemine paralel ba?li evirici tabanli kompanzatörlerin incelenmesi]

Power quality (PQ) problems have become a serious concern of both power suppliers and end user customers with the deregulation of the electric power market. In the recent years, power electronics based compensation devices with advanced technology has been required due to the inadequate of conventional compensation devices to improve PQ in utility grid. This paper presents a comprehensive review of shunt compensating custom power devices (CPD) connected to distribution system mainly Distribution Synchronous Static Compensator (DSTATCOM) and Active Power Filter (APF). A broad overview on various control methods to compansate different PQ problems used in DSTATCOM and APF's and the main operation principles of these devices are provided. The practical applications and recent research advances on DSTATCOM and APF's are presented by reviewing nearly 120 papers

Multi-functional static synchronous compensator for distribution systems [Dagitim sistemleri için çok fonksiyonlu statik senkron kompanzatör]

Power quality problems cause the damage and inefficient operation of the electronic devices and sensitive loads, and lead to substantial economic losses. In order to eliminate these problems, Distribution Static Synchronous Compensator (D-STATCOM) is widely used due to the fast response to the changes in the system dynamics and the capability of controlling the power system parameters. In this research study, D-STATCOM, having a control method based on General Wavelet Transform, is firstly introduced and the balanced/unbalanced voltage fluctuations, current/voltage harmonics and reactive power that are most common types of power quality problems in the distribution systems are simultaneously compensated. With this study, it is the first time to formulate the general wavelet algorithm as mathematically in the literature. The performance of the proposed method is tested with several case studies by using PSCAD/EMTDC program