High speed operation design considerations for fractional slot axial flux PMSM

This paper discusses intensively the design considerations for the fractional slot axial flux permanent magnet synchronous (AFPMSMs) in order to work efficiently in the constant power speed range, also known as the field weakening (FW) region. The dominant parameter in the constant power speed region is called the characteristic current which equals the ratio of the magnet flux linkage over the synchronous inductance (− ψm/Ls). Several machine parameters is affecting the characteristic current including the machine geometry and the winding configurations. In this paper, the effect of many of these parameters on the FW has been discussed; including the outer diameter, inner to outer diameter ratio, magnet size, slot opening width, slots per poles combinations,and the multi phase configurations for the Axial flux permanent magnet synchronous machine (PMSM). Two main governors are considered to evaluate the parameters’ impact on the machine overall performance; the rated machine efficiency and the torque to weight ratio at the highest values. Selection of these governors is application driven where these governors are the most influencing factors on the axial flux PMSM design. The results of the present analysis show that the fine tuning of the discussed machine parameters would derive the motor to work in the required Constant Power Speed Region (CPSR) keeping the required high efficiency and torque to weight ratio. A previously proved analytical model has been used in this study to overcome the highly time consumption in the finite element model (FEM)

Study on longshore morphological changes using remote sensing data

Thesis (Ph. D. in Engineering)--University of Tsukuba, (A), no. 5349, 2010.3.25Includes bibliographical references (leaves 106-116

Serological and Molecular Identification of Brucella spp. in Pigs from Cairo and Giza Governorates, Egypt

Brucellosis is considered as endemic disease of animals and humans since thousands of years in Egypt. However, brucellosis in pigs has never been reported in Egypt. Thus, serological and molecular assays were applied to detect anti-Brucella antibodies and DNA in serum samples collected from pigs. In total 331 blood samples collected from male and female pigs at slaughterhouses of Cairo and Giza governorates were investigated using Brucella c- and i-ELISA and Brucella real-time PCR. Anti-Brucella antibodies were detected in 16 (4.83%) and 36 (10.8%) sera by i-ELISA and c-ELISA, respectively. Brucella DNA was detected in 10 (3.02%) seropositive samples and identified as Brucella melitensis (7/10) and Brucella suis (3/10). A higher prevelance was found in boars. This is the first study investigating pig brucellosis in Egypt. The results of this study will raise awareness for brucellosis in these farm animals and will help to develop effective control strategies

Evaluating the Effects of Human Activity over the Last Decades on the Soil Organic Carbon Pool Using Satellite Imagery and GIS Techniques in the Nile Delta Area, Egypt

The study aims to clarify the relationship between soil organic carbon (SOC) and human activity under arid conditions, in the east area of the Nile Delta, Egypt. SOC is one of the critical factors in food production and plays an important role in the climate change because it affects the physio-chemical soil characteristics, plant growth, and contributes to sustainable development on global levels. For the purpose of our investigations, 120 soil samples (0–30 cm) were collected throughout different land uses and soil types of the study area. Multiple linear regressions (MLR) were used to investigate the spatiotemporal relationship of SOC, soil characteristics, and environmental factors. Remote sensing data acquired from Landsat 5 TM in July 1995 and operational land imager (OLI) in July 2018 were used to model SOC pool. The results revealed significant variations of soil organic carbon pool (SOCP) among different soil textures and land-uses. Soil with high clay content revealed an increase in the percentage of soil organic carbon, and had mean SOCP of 6.08 ± 1.91 Mg C ha−1, followed by clay loams and loamy soils. The higher values of SOCP were observed in the northern regions of the study area. The phenomenon is associated with the expansion of the human activity of initiating fish ponds that reflected higher values of SOC that were related to the organic additions used as nutrients for fish. Nevertheless, the SOC values decreased in southeast of the study area with the decrease of soil moisture contents and the increase in the heavy texture profiles. As a whole, our findings pointed out that the human factor has had a significant impact on the variation of soil organic carbon values in the Eastern Nile Delta from 1995 to 2018. As land use changes from agricultural activity to fish ponds, the SOCP significantly increased. The agriculture land-use revealed higher SOCP with 60.77 Mg C ha−1 in clay soils followed by fish ponds with 53.43 Mg C ha−1. The results also showed a decrease in SOCP values due to an increasing in land surface temperature (LST) thus highlighting that influence of temperature and ambient soil conditions linked to land-use changes have a marked impact on surface SOCP and C sequestration

Anti-Alzheimer and Anti-cox2 Activities of the Newly Synthesized 2,3’-Bipyridine Derivatives (I)

3-Aryl-1-pyridin-3-ylprop-2-en-1-ones 1a,b reacted with2-cyanoethanethioamide (2) to afford the corresponding4-aryl-6-thioxo-1,6-dihydro-2,3’-bipyridine-5-carbonitriles6a,b. The synthetic potentiality of compounds 6a,b wasinvestigated in the present study via their reactions withseveral active-hydrogen containing compounds 8a-g aimingto synthesize 4-aryl-6-pyridin-3-ylthieno[2,3-b]pyridin-3-amines 10a-n via 6-(alkylthio)-4-aryl-2,3’-bipyridine-5-carbonitriles 9a-n. The structures of all newly synthesizedheterocyclic compounds were elucidated by considering the data of IR, 1H NMR, mass spectra as well as that of elementalanalyses. Anti-Alzheimer and anti-cox2 activities for all newly synthesized heterocyclic compounds were investigated

The appearance of vacancies during Cu and Zn diffusion in III-V compound semiconductors

GaAs und GaN sind derzeit die wichtigsten III-V-Verbindungshalbleiter. Sie werden aufgrund ihrer elektronischen Eigenschaften und der direkte Bandlücken verwendet, um eine Vielzahl von optoelektronischen Bauelementen herzustellen. Sie stellen auch die Grundmaterialien von Halbleiterlasern dar. Diese Materialien haben im Vergleich zu den Elementhalbleitern, bspw. Silizium, hervorragende Eigenschaften. Die Halbleiterbauelemente erfahren Wärmebehandlungen während des Herstellungsprozesses, so dass die Diffusion während ihrer Herstellung eine wichtige Rolle spielt. Das Verständnis der Diffusionsprozesse von Verunreinigungen und Dotieratomen ist von großer Bedeutung, um die Kontrolle über die Technologie zu behalten. Die Punktdefekte im Material spielen eine wichtige Rolle bei der Bestimmung und Gestaltung seiner Eigenschaften. Die Arbeit zielt darauf ab, die Defekteigenschaften während der Cu- und Zn- Diffusion in GaAs und GaN mittels Positronenannihilations-Spektroskopie zu untersuchen. Dazu wurde eine Kombination von Positronenlebensdauer- und Dopplerkoinzidenz-Spektroskopie mit einer theoretischen Berechnung der Annihilationsparameter benutzt. Thermodynamische Überlegungen und vor allem die Abhängigkeit der Defektkonzentration vom As-Dampfdruck half bei der Identifizierung von Defekten. As-Leerstellenkomplexe wurden in semi-isolierendem und Zn-dotiertem GaAs gefunden. Während einer Cu-Diffusion in Te-dotiertem GaAs wurden außerdem Ga-Leerstellen, die mit Cu dekoriert waren, identifiziert. Bei Zn-Diffusionsexperimenten in GaAs wurden Zn-dekorierte As-Leerstellen beobachtet. Die Defekte sind bis in dieselbe Tiefe vorhanden, in die auch die Dotieratome diffundiert waren. Das wurde mit korrelierten Experimenten der Positronenstrahltechnik (VEPAS), der Positronenlebensdauer (PALS) und der Sekundärionen-Massenspektroskopie (SIMS) gezeigt. Die Ergebnisse bei der Cu-Ein-Diffusion in GaAs sind gut mit dem Kick-Out-Mechanismus zu erklären. Bei der Aus-Diffusion von Cu treten allerdings Leerstellen auf, die sich mit den üblichen Diffusionsmodellen in Halbleitern nicht erklären lassen. Die Cu Ein-Diffusion in GaN kann ebenfalls mit dem Kick-Out-Mechanismus beschrieben werden.von Mohamed Elsaye

On-chip optical sensors

Adding more functionality to chips is an important trend in the advancement of technology. During the past couple of decades, integrated circuit developments have focused on keeping Moore\u27s Law alive More of Moore . Moore\u27s law predicts the doubling of the number of transistors on an integrated circuit every year. My research objectives revolve around More than Moore , where different functionalities are sought to be integrated on chip. Sensing in particular is becoming of paramount importance in a variety of applications. Booming healthcare costs can be reduced with early diagnosis, which requires improved sensitivity and lower cost. To halt global warming, environmental monitoring requires miniature gas sensors that are cheap enough to be deployed at mass scale. First, we explore a novel silicon waveguide platform that is expected to perform well as a sensor in comparison to the conventional 220 nm thick waveguide. 50 and 70 nm shallow silicon waveguides have the advantage of easier lithography than conventional 220 nm thick waveguides due to the large minimum feature size required of 1 µm. 1 µm wide waveguides in these shallow platforms are single mode. A multi-mode interference device is designed in this platform to function as the smallest MMI sensor, giving sensitivity of 427 nm / refractive index unit (RIU) at a length of 4 mm. The silicon photonic MMI sensor is based on detecting refractive index changes. Refractometric techniques such as the MMI sensor require surface functionalization to achieve selectivity or specificity. Spectroscopic methods, usually reserved for material characterization in a research setting, can be adapted for highly specific label-free sensing. Chapter 4 explores the use of a highly doped III-V semiconductor for on chip infrared spectroscopy. Finite element method and finite different time domain were both used to design a plasmonic slot waveguide for gas sensing. On chip lasers and detectors have been designed using InAs. While InAs is still considered more expensive than silicon, the electronics industry expects to start incorporating more materials in standard fabrication processes, including III-V semiconductors for their superior properties including mobility. Thus, experimental realization of this sensor is feasible. A drawback with infrared spectroscopy is that it is difficult to use with biological fluids. Chapter 5 explores the use of Raman spectroscopy as a sensing method. To adapt Raman spectroscopy for sensing, the most important task is to enhance the Raman signal. The way the Raman signal is generated means that the number of photons is generally very low and usually bulk material or concentrated fluids are used as samples. To measure low concentrations of a probe molecule, the probe molecule is placed on a surface enhanced Raman spectroscopy (SERS) substrate. A typical SERS substrate is composed of metal nanostructures for their surface plasmon resonance property, which causes a large amplification in the electric field in particular hot spots. By decorated silicon nanowires with silver nanoparticles, an enhancement factor of 1011 was realized and picomolar concentrations of pyridine were detected using Raman spectroscopy. In conclusion, this thesis provides new concepts and foundations in three directions that are all important for on chip optical sensing. First, silicon photonics is the technology of choice that is nearest to the market and a multi-mode interference sensor based on shallow silicon waveguides was designed. Further work can explore how to cascade such MMIs to increase sensitivity without sacrificing the free spectral range. Second, infrared plasmonics is a promising technology. Before semiconductor plasmonics, on chip devices operated in the visible or near IR and then microwave region of the electromagnetic spectrum. By using highly doped semiconductors, it is possible to bridge the gap and operate with mid-infrared wavelengths. The implications are highlighted by designing a waveguide platform that can be used for next generation on chip infrared spectroscopy. Third, Raman spectroscopy was exploited as a sensing technique by experimental realization of a SERS substrate using equipment-free fabrication methods

THE CONSUMER’S RIGHT TO CANCEL THE DISTANCE CONTRACT IN LIGHT OF THE EUROPEAN CONSUMER RIGHTS DIRECTIVES

There has been massive prevalence of products and services being sold remotely. In such sale contracts, consumers are in the vulnerable side: they do not have enough chance to inspect and examine products/services subject of the contract, hence they finalize contracts based on the effect of advertising, and wherein specifications of products/services are exaggerated beyond what is real. Therefore, in many regulations, consumers are given the right to cancel such contracts. This paper defines the limits and justifications of such right to rescind. It also addresses legal nature and legal base of rescinding, investigates the positive impacts on consumers resulted from practicing the option of rescinding, In addition to this, the effects resulting from exercisingthe right to cancel the contract on both the consumer and the supplier. This paper also will review terms stipulated by European directive on consumer protection and laws that are made according to such directive. It searches into the extent to which legislatures have the right to make such laws in other countries. There is no doubt that the international nature of remotely concluded contracts requires that consumer protection be extended to countries all over the world in order to reduce legal obstacles that make it difficult to put into effect legal provisions that give consumers the right to rescind remotely concluded contracts