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CONTENTS
Volume 2, Number 1, March 2014
 

Abstract
The green microalgae Chlamydomonas reinhardtti is well-known specie in the terms of H2 production by photo fermentation and has been studying for a long time. Although the H2 production yield is promising; there are some bottlenecks to enhance the yield and efficiency to focus on a well-designed, sustainable production and also scaling up for further studies. D1 protein of photosystem II (PSII) plays an important role in photosystem damage repair and related to H2 production. Because Chlamydomonas is the model algae and the genetic basis is well-studied; metabolic engineering tools are intended to use for enhanced production. Mutations are focused on D1 protein which aims long-lasting hydrogen production by blocking the PSII repair system thus O2 sensitive hydrogenases catalysis hydrogen production for a longer period of time under anaerobic and sulfur deprived conditions. Chlamydomonas CC124 as control strain and D1 mutant strains (D240, D239-40 and D240-41) are cultured photomixotrophically at 80μmol photons m-2 s-1, by two sides. Cells are grown in TAP medium as aerobic stage for culture growth; in logarithmic phase cells are transferred from aerobic to an anaerobic and sulfur deprived TAP – S medium and 12 mg/L initial chlorophyll content for H2 production which is monitored by the water columns and later detected by Gas Chromatography. Total produced hydrogen was 82±10, 180±20, 196±20, 290±30 mL for CC124, D240, D239-40, D240-41, respectively. H2 production rates for mutant strains was 1.3±0.5 mL/L.h meanwhile CC124 showed 2-3 fold lower rate as 0.57±0.2 mL/L.h. Hydrogen production period was 5±2 days for CC124 and mutants showed a longer production time for 9±2 days. It is seen from the results that H2 productions for mutant strains have a significant effect in terms of productivity, yield and production time.

Key Words
microalgae; biohydrogen; chlamydomonas reinhardtii

Address
Ayse Kosea and Suphi S. Oncel : Ege University Department of Bioengineering, Izmir, Turkey

Abstract
This paper examines the climatic and technical feasibilities of zero energy buildings in Seoul, Shanghai, Singapore and Riyadh. Annual and seasonal energy demands of office buildings of various scales in the above cities were compared. Using optimally tilted rooftop PV panels, solar energy production potentials of the buildings were estimated. Based on the estimates of onsite renewable energy production and building energy consumption, the energy self-sufficiencies of the test buildings were assessed. The economic feasibilities of the PV systems in the four locations were analyzed. Strategies for achieving zero energy buildings are suggested.

Key Words
zero energy building; solar energy production; climatic variation; Asian cities

Address
Jong-Jin Kim : College of Architecture, University of Michigan, 2000 Bonisteel Blvd, Ann Arbor, MI 48109, USA

Abstract
The use of a microporous membrane along with Au/C catalyst for direct glycerol alkaline fuel cell was investigated. In comparison with Nafion 112, the microporous Celgard 3401 membrane provides a better cell performance due to the lower ionic resistance as confirmed by impedance spectra. The single cell using Au/C as anode catalyst prepared by using PVA protection techniques provided a higher maximum power density than the single cell with commercial PtRu/C at 18.65 mW cm-2. The short-term current decay studies show a better stability of Au/C single cell. The higher activity of Au/C over PtRu/C was owing to the lower activation loss of Au/C. The magnitude of current decay indicates a low problem of glycerol crossover from anode to cathode side. The similar performance of single cell with and without humudification at cathode points out an adequate transport of water through the microporous membrane.

Key Words
direct alcohol fuel cell; Au/C; microporous membrane; glycerol; alkaline

Address
Sarayut Yongprapat and Apichai Therdthianwong : Fuel Cells and Hydrogen Research and Engineering Center, CES, Pilot Plant and Development Training Center, King Mongkut’s University of Technology Thonburi (KMUTT), Bang Mod, Thung Khru, Bangkok, 10140 Thailand
Supaporn Therdthianwong : Department of Chemical Engineering, Faculty of Engineering, King Mongkut’s University of Technology Thonburi (KMUTT), Bang Mod, Thung Khru, Bangkok, 10140 Thailand

Abstract
Photocatalytic hydrogen generation by water splitting (H2O (l) → H2 (g) +1/2O2 (g)) has been studied on photocatalysts based on Zn, Cd, Fe and Cu, synthesized by coprecipitation. Iron and copper nanoparticles were incorporated as cocatalysts to enhance the photocatalytic activity of the ZnCd solid solution. The effect of the different synthesis parameters (temperature, elemental atomic ratios, amount of Cu and Fe incorporated in the catalyst and calcination temperature) on the photocatalytic production of hydrogen has been studied in order to determine the best experimental synthesis conditions. The catalysts have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and BET. The experiments of photocatalytic water splitting were performed in aqueous solution of the photocatalysts previously dispersed in a soft ultrasound bath. The photocatalysts were irradiated under different lights ranging from 220 to 700 nm. The photocatalytic activity was found to be clearly dependent on the specific area of the photocatalyst.

Key Words
Hydrogen production; water splitting; photocatalyst; nanowires; solid solution

Address
Francisco Márquez, Antonio Masa, Marcía Cotto, Abraham García and Josè Ducongè : Nanomaterials Research Group-NRG, School of Science and Technology, University of Turabo, 00778 PR, USA
Teresa Campo, Eduardo Elizalde and Carmen Morant : Departamento de Física Aplicada, M-XII, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain

Abstract
Back-to-back STATCOM configuration is an extension of STATCOM in which the reactive power at two-sides and the real power flow through the DC link can be controlled concurrently and independently. This flexible operation brings many advantages to the micro-grids, distributed generation based systems, and deregulated power systems. In this paper, the dynamic control characteristics of the back-to-back STATCOM is investigated by simulating the detailed converter-level model of the converters in PSCAD. Various case studies in a single-machine test system are studied to present that the real power control feature of the BtB-STATCOM, even with a simple controller design, can enhance the transient stability of the machine under different fault scenarios.

Key Words
back-to-back STATCOM; quasi multi-pulse voltage source converter; real power flow control; reactive power control; voltage control; transient stability

Address
Ahmet M. Vural : Department of Electrical and Electronics Engineering, Gaziantep University, Gaziantep, Turkey
Kamil C. Bayindir : Department of Electrical and Electronics Engineering, Cukurova University, Adana, Turkey


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