Technologies for single chip integrated optical gyroscopes

Optical gyroscopes are being employed for navigational purposes for decades now and have achieved comparable or better reliability and performance than rotor-based gyroscopes. Mechanical gyros are however generally bulky, heavy and consume more power which make them unsuitable for miniaturized applications such as cube satellites and drones etc. Therefore, much effort is being expended worldwide to fabricate optical gyros having tactical grade robustness and reliability, small size, weight, cost and power consumption with minimal sacrifice of sensitivity. Integrated optics is an obvious approach to achieving this. This work comprises detailed comparative analysis of different types and structures of integrated optical gyroscopes to find out the suitable option for applications which require a resolution of <10 o/h. Based on the numerical analysis, Add-drop ring resonator-based gyro is found to be a suitable structure for integration which has a predicted shot noise limited resolution of 27 o/h and 2.71 o/h for propagation losses of 0.1 dB/cm and 0.01 dB/cm respectively. An integrated gyro is composed of several optical components which include a laser, 3dB couplers, phase/frequency modulators, sensing cavity and photodetectors. This requires hybrid integration of multiple materials technologies and so choices about which component should be implemented in which technology. This project also undertakes theoretical optimization of few of the above-mentioned optical components in materials systems that might offer the most convenient/tolerant option, this including 3dB coupler, thermo-optic phase modulator and sensing cavity (resonator and waveguide loop). In particular, the sensing element requires very low propagation loss waveguides which can best be realised from Si3N4 or Ta2O5. The optimised Si3N4 or Ta2O5 waveguides however are not optimal for other functions and this is shown and alternatives explored where the Si3N4 or Ta2O5 can easily be co-integrated. The fabrication process of low loss Si3N4 and Ta2O5 waveguides are also reported in this thesis. Si3N4 films were grown by using low pressure chemical vapor deposition (LPCVD) technique. Dry etching of Si3N4 films have been optimized to produce smooth and vertical sidewalls. Experimental results predicted that the propagation loss of 0.009 dB/cm is achievable by using optimum waveguide dimensions and silica cladding with the relatively standard processes available within the Laser Physics Centre at the Australian National University. A CMOS back end of line compatible method was developed to deposit good quality Ta2O5 films and silica claddings through ion beam sputtering (IBS) method. Plasma etching of Ta2O5 waveguides has been demonstrated by using a gas combination of CHF3/SF6/Ar/O2. Oxygen was introduced into the chamber to produce non-vertical sidewalls, so the waveguides could be cladded without voids with IBS silica. Average propagation losses of 0.17 dB/cm were achieved from Ta2O5 waveguides which appeared after extensive investigation to be limited by the spatial inhomogeneity of the processing. Lastly, a detailed theoretical and experimental analysis was performed to find out the possible causes of the higher average propagation loss in Ta2O5 waveguides, some sections being observed with 0.02 dB/cm or lower losses

Delayed intrinsic activation of an NMDA-independent CaM-kinase II in a critical time window is necessary for late consolidation of an associative memory

Calcium/calmodulin-dependent kinases (CaM-kinases) are central to various forms of long-term memory (LTM) in a number of evolutionarily diverse organisms. However, it is still largely unknown what contributions specific CaM-kinases make to different phases of the same specific type of memory, such as acquisition, or early, intermediate, and late consolidation of associative LTM after classical conditioning. Here, we investigated the involvement of CaM-kinase II (CaMKII) in different phases of associative LTM induced by single-trial reward classical conditioning in Lymnaea, a well established invertebrate experimental system for studying molecular mechanisms of learning and memory. First, by using a general CaM-kinase inhibitor, KN-62, we found that CaM-kinase activation was necessary for acquisition and late consolidation, but not early or intermediate consolidation or retrieval of LTM. Then, we used Western blot-based phosphorylation assays and treatment with CaMKIINtide to identify CaMKII as the main CaM-kinase, the intrinsic activation of which, in a critical time window ( approximately 24 h after learning), is central to late consolidation of LTM. Additionally, using MK-801 and CaMKIINtide we found that acquisition was dependent on both NMDA receptor and CaMKII activation. However, unlike acquisition, CaMKII-dependent late memory consolidation does not require the activation of NMDA receptors. Our new findings support the notion that even apparently stable memory traces may undergo further molecular changes and identify NMDA-independent intrinsic activation of CaMKII as a mechanism underlying this "lingering consolidation." This process may facilitate the preservation of LTM in the face of protein turnover or active molecular processes that underlie forgetting

Poverty and Reefs: Volume 1 A Global Overview

The Bangladesh Environmental Lawyers Association (BELA) provided legal support to the CBFM-2 project and in particular to the 130 Community Based Organisations established under the project. The project was implemented against an uncertain legal background due to many changes in the way that wetlands and fisheries in Bangladesh have been managed over recent decades. Many of the key interventions, such as sanctuaries have yet to receive legal recognition. Many currently accepted norms and practices have come about through gazette notifications or individual decisions rather than being supported by Acts or clear policies. This paper outlines the legal background for community managed fisheries in Bangladesh and the challenges faced during implementation of the project. It also suggests what needs to happen if community managed fisheries are to become more widespread in Bangladesh

Insecticidal potential of some indigenous weeds extracts of Bahawalpur Pakistan againstdusky cotton bug (Oxycarenus hyalinipennis) (Costa) (Hemiptera: Lygaidae) under laboratory conditions

Owing to large scale use of chemical insecticides there is always need to find new alternatives to chemical insecticides. This study evaluated the aqueous extracts of three weeds namely Datura alba (Nees), Withania somnifera (Linnaeus) and Chenopodium album (Linnaeus) for insecticidal potential against Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae) under laboratory conditions. Extracts were prepared from three plant parts e.g., leaves, stems and roots and applied at five concentrations ranging from 1 to 20 %. To check the mortality not because of weed extracts control treatment (water only) was also included as sixth treatment. Mortality of pest insects was assessed after three exposure periods e.g., 24h, 48 hand 72 h. Among the three weeds tested, mortality was more due to extract of D. alba weed which thus proved more toxic compared to other two weeds. Among plant parts, root extracts were more potent than leaves and stem extracts and the more concentration of 20 per cent usually resulted in maximum mortality. Maximum mortality of insects was after 72 h period followed by 48 h and minimum was after 24 h period. However maximum mortality of 60 % in case of D. alba warrants attention towards the options of either increasing concentration (> 20 %) of this extract or to evaluate other extraction type e.g., ethanolic extract to gain maximum mortality against this notorious pest

ON PERFORMANCE OF QUANTUM LOCKING FOR WHEEL-LESS TRANSPORTATION

Transportation has continuously been a vital side of human civilization reflective the extent of general economic and technological advancement of a given society. The recent technological advancements in power electronics are pushing for Maglev train using Quantum locking. For levitation the most important factor is temperature which is affecting the efficiency of the train. In this work we have compared different prototypes of Maglev trains including Japanese, German and Chinese technologies. We also did mathematical modeling to relate the magnetic force required for a certain weight of the train to levitate.  We suggest that Japanese maglev is better than Germany and china maglev

Identification and Prioritization of CSFS and Perception of the Stake Holders for Fast Track Construction Projects in Pakistan

Construction industry is characterized by its unpredictability in terms of time and cost. Worldwide 85% of the projects suffer time overrun resulting in cost increase. Project management being a neglected aspect in Pakistan results in project time overrun. Many scheduling techniques are employed to regain the lost schedule, fast tracking is one such technique. Fast tracking is overlapping the project activities in order to reduce project duration with increased activity and project cost. Globally fast tracking has seen ages of practical implementation since 1960s. However being a newer trend in Pakistan, it is yet to witness maturity. Fast track projects opt for time and quality over cost and in fast track projects we accept the tradeoff between the high cost of buying time while maintaining quality. The main idea behind fast tracking is to overlap the activities which otherwise are executed in sequence. Particularly the emphasis is kept on overlapping design and the construction activities. After an extensive literature review a preliminary questionnaire containing 93 success factors was used for the pilot survey. After the pilot survey full scale survey questionnaire was prepared containing 45 success factors. The questionnaires were sent to a sample size of 63 comprising of the contractors, consultants and the construction clients. The data collected was analyzed using PASW-18 and MS Excel. After conducting the statistical tests the success factors were ranked in order of importance using RII and mean values. Keeping the mean value as the yard stick, success factors with mean value of 4 and above were identified and prioritized as the CSFs (Critical Success Factors). Similarly the stakeholder’s perception on the CSFs was also evaluated. At the end conclusions and recommendations were formulated. Keeping in view the research parameters, the research’s contribution is twofold, one to the local CI (Construction Industry) and other to R&amp;D (Research and Development) community. Keywords: Fast Tracking, Construction Industry, Critical Success Factors, Stakeholder’s Perceptio

مماثلة الشعر الثوري في كلام فيض أحمد فيض و مفدي زكريا: Similarities of the revolutionary poetry in the poetry of Faiz Ahmad Faiz and Mufdi Zakaria

A study of human history reveals that man has been on a journey of evolution from the very beginning. In this evolutionary journey, man has used every means at his disposal to move forward. However, in this journey, the expression of mental imagination and heartfelt emotions has been the greatest support of man. &nbsp;The journey of human evolution continues even in modern times and it would not be wrong to call the twentieth century the century of revolutions. The end of the Ottoman Empire, the two world wars, many events emerging and disappearing on the world stage, many emerging movements in the Arab world and the Western world, the independence of the Indian subcontinent and many other movements have been characteristic of the twentieth century. &nbsp;In the middle of the twentieth century, the subcontinent was the center of a similar evolutionary movement. On the one hand, the independence movement was at its peak, on the other hand, the movement of human evolution against social oppression and discrimination was going on, and the writers were also playing their full role in this movement. An emerging name among those writers was Faiz Ahmed Faiz who breathed new life into the progressive revolution through his Urdu poetry. At a time when Faiz Ahmed Faiz's poetry was playing a role in the progressive movement in the subcontinent, the Arab world was enjoying the literary masterpieces of Algerian progressive and revolutionary poet Mufdi Zakaria. In the poetry of Mufdi Zakaria, the revolutionary color is very prominent which is seen in the poetry of Urdu poet Faiz Ahmed Faiz. Even Mufdi Zakaria faced almost all the accusations and hardships that Faiz Ahmed Faiz used to face. He made an effective contribution to literary, political and revolutionary activity. These two people have a lot in common in their poetry. That's why I chose both for my research work. So that people can be introduced to this great literary heritage of Urdu and Arabic language. I hope that this work of mine will prove to be an important milestone in both Urdu and Arabic language literature