最適オフセット平均化処理 : 反射記録のS/N比向上のための新解析手法と上町断層への適用

博士(理学)大阪市立大

Design and evaluation of an energy storage system for helicopters

This paper presents the design and evaluation of an energy storage system (ESS) for helicopters with the aim to recover the kinetic energy in the rotor available after landing and to be able to control the 270V dc bus voltage during load disturbances. A study is conducted in order to identify the suitable mix of commercially available energy storage devices with the aim of obtaining the minimum weight, exploring also the possibility to implement a hybrid supercapacitor-battery system. On the converter side, commercially available Silicon and Silicon-Carbide devices have been evaluated to achieve also the smallest size/weight

High performance multilevel converter topology for interfacing energy storage systems with medium voltage grids

This paper proposes a high performance hybrid cascaded H-Bridge (HB) Multilevel Converter (MLC) with integrated Series Active Power Filter SAPF for interfacing energy storage systems with medium voltage grids. Isolated DC sources comprised of modular dual DC/DC converters and Medium Frequency Transformers MFT are used to energise the MLC HBs. The primary sides of the DC/DC converters are connected to a common low voltage DC bus, which is supplied by supercapacitors energy stacks. Simple hybrid stair-case/SVM modulation strategy is used to synthesise the converter output voltage waveforms and to guarantee even sharing of power between the converter’s HBs. The converter power losses and efficiency are evaluated and compared for two design cases of using small or large DC link capacitor banks. The converter is investigated under various operating conditions and the results show excellent dynamic and steady state performance

Dynamic phasor analysis and design of phase-locked loops for single phase grid connected converters

The purpose of the paper is to introduce the Dynamic Phasor Modelling (DPM) approach for stability investigation and control design of single-phase Phase Locked Loops PLLs. The aim is to identify the system instabilities not predicted using the existent analysis and design methods based on the simplified average model approach

Improvement in the efficiency of hydrolysis of anaerobic digestion in sewage sludge by the use of enzymes

The effects of enzymatic pre-treatment on a mixture of sludge (primary, secondary, digested) collected from different municipal wastewater-treatment plants was investigated by Batch experiments in the laboratory to enhance the hydrolysis of sludge. The experiments were carried out at mesophilic (37 degrees C) temperature. Six commercially available enzymes, supplied by Novo Industries, were used which ware Alcalase, Caresyme, Celluclast, Lipolase, Termamyl and Viscosyme. The experiment showed that with 50% digested sludge and 0.1% enzyme dosage of Carezyme and the mixed enzymes there was 11.5% and 10.6% decrease in volatile solids (VS), whereas with 25% digested sludge and 0.1% Viscosyme enzyme was very much effective for VS reduction compared with the blank (it shows 16.3% higher than blank). In another set of experiments, which differed in sludge characteristics with 25% digested sludge and 0.5% enzyme dosage the culture containing the mixed enzymes presents the highest percentage of VS reduction among all the samples (13.6% higher than blank), where with 25% digested sludge and 0.5% enzyme dosage of Termamyl and mixed enzymes show 13.5% and 12.8% greater VS reduction respectively compared with the blank. The experimental work showed that enzymatic pre-treatment can be successfully used as a pre-treatment step for treating sludge mixture produced from municipal wastewater treatment plant and the performance of individual enzymes largely depends on the characteristics of sludge

Hybrid cascaded multilevel converter with integrated series Active Power Filter for interfacing energy storage system to medium voltage grid

This paper presents a new control strategy for a high performance hybrid cascaded H-Bridge HB multilevel converter with integrated series Active Power Filter Stage APFS. Unequal DC voltage sources are used to energise the converter's HBs. This offers increased number of voltage levels using fewer number of series connected HBs. Simple hybrid stair-case/SVM modulation strategy is proposed to synthesise the converter output voltage waveforms and to guarantee even sharing of power between the converter's HBs. Novel capacitor voltage balancing controller is proposed and designed to guarantee decouple control of the APFS active power during the capacitors' charging and discharging modes without compromising the quality of the converter output voltage. The proposed converter is investigated under different operating conditions and the results show excellent dynamic and steady state performance

A hybrid inverter solution for medium voltage applications using series capacitor and a CSI Active Power Filter (SC-APF)

This paper proposes a new hybrid inverter solution for medium/high voltage applications that consists of a slow switching inverter using high voltage or series connected switching devices, fitted with a low kVA rated auxiliary current source inverter to cancel the switching ripple produced by the main inverter. The reduction in CSI voltage stress is obtained by connecting it to the MV grid via a series capacitor which makes the solution suitable for retrofitting older inverters equipped with large passive filters. The paper describes the design procedure, the control scheme and validates the feasibility of the idea by including simulation results and evaluation of the waveform quality and also an estimation of the semiconductor losses

THE CHALLENGES OF SUSTAINABLE HISTORICAL CENTERS: THE CASE OF ROSETTE, EGYPT

Historical centers of many Egyptian cities managed to survive as living cities in spite of physical decline and economic depression. Their fabric carries out the spiritual and cultural messages that communicate with their present citizens. The heritage of these historic city centers are not only Material character, but much more. Generally, the conservation of historic centers is fundamentally different from conservation of single monument. While a single monument can be kept on a chosen state of evolution, the historic centers cannot be preserved in particular state \u201cwith exception of the small areas conserved for tourist purposes\u201d. The historic centers, as living cities must meet the varying needs of citizens with sustainable transformations. The challenge is not how to preserve, but how to create dynamic living spaces and places that produce rich in cultural traditions that lead organically from the past to the future. The research will study and analyze the historical center of \u201cRosetta\u201d, which is one of the intermediate cities in northern Egypt that has a particular architectural heritage and many urban problems. The city of Rosetta (Rashid in Arabic) is located on the west bank of the Rosetta branch of the Nile, approximately 65km east of Alexandria on the Mediterranean coast. Today it is best known for the Rosetta stone, which was discovered in the Qayitbay castle in 1799. The city history passed over many periods of increase and decrease in its importance due to economical and political reasons. Its architectural heritage reveals the influence of various ages, but the most unique are merchant houses and mosques from the ottoman period. The city also has a particular suburban landscape of agricultural land and palm groves that are of great importance. Although Rosetta is no longer a leading commercial center, its citizens are employed in various typical activities, which are mainly agriculture, stocking and processing rice from the Delta, fishing and building ships and yachts. The main problem that faces the historic buildings of Rosetta is moisture from the soil, caused by an excess of underground salt water. The historic merchant houses have been the subject of many restoration projects over the past 20 years, but many of them have regularly been re-damaged by water and humidity and are currently under re-restoration. Unfortunately, some have even collapsed or were demolished. However, there are a number of activities that may take place in the historic buildings no longer used, maintaining the characteristics, such as crafts centers, libraries and cultural places that serve the local communities. Rosetta's historic center future must include renovation and modernization of basic infrastructure and development of traditional production sectors, based on the exploitation of this natural and cultural heritage to promote tourism locally and internationally. Physical restoration of the buildings is not enough to keep the historic center of the city alive, but a project for rehabilitation based on sustainability should be initiated. Not only to preserve and restore the outer shell, but inside the shell should insert some activities, social and economic dynamics that can make best use of resources and potential. The revitalization of Rosetta provides a mix of cultural, social, economic, technical and institutional that needs coordinated investments by the government. Must involve residents, landowners and all those have interest to ensure the careful maintenance and replacement of the elements of the built environment. This does not only depend on the availability of funding but also the specific technical and social skills that make up the traditional know-how. Unfortunately, many historical cities, especially the intermediate cities in Egypt suffer from lack of funds and local expertise. But the main problem is the lack of cooperation between the authorities who make the decisions