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

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

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

Prevalence of active hepatitis C virus infections among general public of Lahore, Pakistan

BACKGROUND: To find out the prevalence of active hepatitis C virus (HCV) infections among general public in Lahore city, since data concerning the prevalence of active HCV in this city is currently unavailable. METHODS: Blood samples were collected randomly from individuals visiting different clinical laboratories in Lahore. Serum was separated and processed by nested PCR qualitative assay for the detection of HCV RNA. The samples were categorized into different age groups on the basis of pre-test questionnaires in order to record the age-wise differences regarding the prevalence of active HCV. Data were analyzed statistically using Chi-Square test. RESULTS: Out of the 4246 blood samples analyzed in this study, 210 were confirmed to be positive for active HCV infection. Gender-wise active HCV prevalence revealed no significant difference [OR = 1.10 CI = (0.83-1.46), p > 0.05]. However, among the age groups the highest prevalence was observed in the age groups 20–29 (7.7%) and 30–39 years (6.4%) with odds of prevalence of 14.8% (OR = 2.48, CI = (1.40-4.38), p < 0.05) and 10.3% (OR = 2.03, CI = (1.10-3.71), respectively. In age groups above 40 years (40–49, 50–59 and >59 years), a decrease in levels of active HCV prevalence was observed. CONCLUSIONS: Among tested samples, 4.9% of the subjects were confirmed to harbour active HCV infections and the “middle aged” population in Lahore was found to be at a higher risk of the HCV ailments compared to both their younger and older peers

Multicriteria Decision Making for Carbon Dioxide (CO2) Emission Reduction

The fast industrial revolution all over the world has increased emission of carbon dioxide (CO2), which has badly affected the atmosphere. Main sources of CO2 emission include vehicles and factories, which use oil, gas, and coal. Similarly, due to the increased mobility of automobiles, CO2 emission increases day-by-day. Roughly, 40% of the world’s total CO2 emission is due to the use of personal cars on busy and congested roads, which burn more fuel. In addition to this, the unavailability of parking in all parts of the cities and the use of conventional methods for searching parking areas have added more to this problem. To solve the problem of reducing CO2 emission, a novel cloud-based smart parking methodology is proposed. This methodology enables drivers to automatically search for nearest parking(s) and recommend the most preferred ones that have empty lots. For determining preferences, the methodology uses the analytical hierarchy process (AHP) of multicriteria decision-making methods. For aggregating the decisions, the weighted sum model (WSM) is adopted. The methods of sorting, multilevel multifeatures filtering, exploratory data analysis (EDA), and weighted sum model (WSM) are used for ranking parking areas and recommending top-k parking to the drivers for parking their cars. To implement the methodology, a scenario comprising cars, smart parkings are considered. To use EDA, a freely available dataset “2020testcar-2020-03-03” is used for the estimation of CO2 emitted by cars. For evaluation purpose, the results obtained are compared with the results of traditional approach. The comparison results show that the proposed methodology outperforms the traditional approach

Intracranial CT Scan Findings in the Patients of Head Injury: An Early Experience at Dera Ghazi Khan Teaching Hospital

Introduction:&nbsp;&nbsp;Head injury patients constitute a major number to any trauma emergency. Every head injury patient whose level of consciousness seems to alter, must be checked for brain injury. With the help of Computed Tomography (CT), Radiological evaluation has experienced a drastic change because it precisely explores the location and nature of lesion(s). Material and Methods:&nbsp;&nbsp;This study included 408 patients that were admitted to the emergency of Teaching Hospital Dera Ghazi Khan, from October 2017 to September 2019. In this study, the location as well as nature of lesions were evaluated with the help of CT. Results:&nbsp;&nbsp;CT results expressed that there was skull fracture (28.4%), extra dural hematoma (20.6%), diffuse intra cerebral hematoma (18.6%), brain contusions (18%), subdural hematoma (5.9%), diffuse axonal injury (DAI) (4.4%), subarachnoid hemorrhage (2.5%) and pneumocranium (1.5%). It was also noted that the males having age group between 20 – 35 years were mostly involved in head trauma and the reason for this was a road accident. Conclusion:&nbsp;&nbsp;CT scan explained the location and nature of brain and skull lesions. Keywords:&nbsp;&nbsp;Computed Tomography (CT), Road Accident, Head Trauma

Results of Endoscopic Septostomy in Isolated Lateral Ventricular Hydrocephalus

Objective:&nbsp;&nbsp;To determine the success of endoscopic septostomy in the management of isolated lateral ventricular hydrocephalus. Material and Methods:&nbsp;&nbsp;A retrospective analysis of data was done and records of all patients who underwent endoscopic septostomy for isolated lateral ventricular hydrocephalus due to any cause for the last 4 years, December 2017 to December 2021 at Punjab Institute of Neurosciences, Lahore. Radiological and clinical outcomes and complications were recorded. A total of 60 cases were reviewed. Results:&nbsp;&nbsp;Out of 60 patients, 95% were in the age group of 3 – 25 years and 5% were in the age group of 26 – 71 years. There was 54% male whereas 46% were female. Septostomy was successful in relieving hydrocephalus in 75% of cases. Conclusion:&nbsp;&nbsp;Endoscopic septostomy is an effective procedure for the management of isolated lateral ventricles. Keywords:&nbsp;&nbsp;Septostomy, Hydrocephalus, Isolated Lateral Ventricles

Determinants and Consequences of Deforestation in the Indus River Belt Area of Dera Ghazi Khan, Pakistan

Deforestation persists as a main environmental issue in majority of the nations of the world and decreases the number of trees and wildlife species. Many species of animals and plants has become threatened with extension due to loss and fragmentation of habitats. Households’ perception knowledge regarding deforestation is significant for establishing suitable conservation and management strategies. To our know-how, this was the 1st research study that determined the perceptions of villagers’ about the factor of deforestation and their effect on environment of Riverine forest which are important for their livelihoods. About 150 male respondents were interviewed from three villages in Dera Ghazi Khan, Pakistan. The data was analyzed with the aid of statistical package for social sciences (SPSS). The respondents perceived that fuel wood collection (74%), cutting of trees for income (92.5%), poverty (81%), population pressure (46%), political involvement (39.3%), corruption (74 %) and mismanagement (64%) were the key causes of deforestation. The major effects of deforestation as per perceptions were climate change (87.4%), increase in CO2 (74.7%), increase in temperature (92.7%), lack of rain (63.2%) and decrease of wildlife species (73.3%). The respondents perceived that provision of alternate fuel source, control of corruption, creation of awareness among the people regarding the importance of forest and reforestation can minimized the deforestation rate. Keywords: Deforestation, Perception, Riverine Forests. Rural Peopl