Design of an 866 MHz On-chip Frequency Synthesizer

There is a strong need for stable frequency references with large tuning ranges in today\u27s communication systems. While the crystal oscillators assure good frequency stability, it is not possible to achieve a large frequency range by tuning the passive components attached to them. Frequency synthesizers are usually used for this purpose because of their ability to produce a variety of output frequencies. The Phase Locked Loop (PLL) based frequency synthesizer is the most preferred of all types of synthesizers available because of its additional features like programmability, low noise and low cost as well as high accuracy and stability. The main idea of this PLL-based synthesizer is to phase-lock its output signal with an input reference signal and to produce a synchronous output. It does this by generating an error signal to correct the oscillator frequency. This functionality is achieved by integrating a phase detector, charge pump, loop filter and voltage controlled oscillator block in series with a frequency divider in feedback. This thesis presents, in detail, the design of all the individual PLL blocks, the strategies employed in the design, issues faced in testing and the test data from simulation and measurement. All the above mentioned PLL blocks are designed in the 130 nm IBM-CMOS cmrf8sf process and optimized for low power consumption. PLLs are used in almost all kinds of communication systems, transmitters and receivers for applications such as carrier recovery, carrier generation, clock slew correction, frequency modulation and demodulation

Who is calling? Optimizing source identification from marmoset vocalizations with hierarchical machine learning classifiers

With their highly social nature and complex vocal communication system, marmosets are important models for comparative studies of vocal communication and, eventually, language evolution. However, our knowledge about marmoset vocalizations predominantly originates from playback studies or vocal interactions between dyads, and there is a need to move towards studying group-level communication dynamics. Efficient source identification from marmoset vocalizations is essential for this challenge, and machine learning algorithms (MLAs) can aid it. Here we built a pipeline capable of plentiful feature extraction, meaningful feature selection, and supervised classification of vocalizations of up to 18 marmosets. We optimized the classifier by building a hierarchical MLA that first learned to determine the sex of the source, narrowed down the possible source individuals based on their sex and then determined the source identity. We were able to correctly identify the source individual with high precisions (87.21%–94.42%, depending on call type, and up to 97.79% after the removal of twins from the dataset). We also examine the robustness of identification across varying sample sizes. Our pipeline is a promising tool not only for source identification from marmoset vocalizations but also for analysing vocalizations of other species

AN EXPLORATORY ANALYSIS OF WELL ABANDONMENT DECISION

The Oklahoma Corporation Commission Oil and Gas conservation division reports that as of 2012, there have been roughly 500,000 wells drilled in Oklahoma since 1978. 350,000 of those have been plugged and abandoned. The decision to abandon a well mainly depends on its economic viability. Most efficient production rate is one of the critical drivers in the decision to abandon wells. There are however other potentially important factors that can influence the decision such as government regulation, physical properties of the oil field, and most importantly, expected volatility of oil or natural gas prices as well as the trajectory and uncertainly associated with the operating cost as technology changes. Using application of data analytics tools and techniques, we examine the choices made by oil producers in Oklahoma regarding drilling and abandonment and present a study of the interactions and interrelations between a number of well related factors and prices which can potentially influence the well abandonment choice. Well production and well attributes were collected for all wells with completion dates between January 1975 and January 2015. Arkoma basin, with a history of 14,000 wells was chosen for the initial analysis. From our study, we understand that government regulations, well operator, complexity of decommissioning process are some of the factors along with the oil and gas price that influence well abandonment decisions

Optimising source identification from marmoset vocalisations with hierarchical machine learning classifiers

Marmosets, with their highly social nature and complex vocal communication system, are important models for comparative studies of vocal communication and, eventually, language evolution. However, our knowledge about marmoset vocalisations predominantly originates from playback studies or vocal interactions between dyads, and there is a need to move towards studying group-level communication dynamics. Efficient source identification from marmoset vocalisations is essential for this challenge, and machine learning algorithms (MLAs) can aid it. Here we built a pipeline capable of plentiful feature extraction, meaningful feature selection, and supervised classification of vocalisations of up to 18 marmosets. We optimised the classifier by building a hierarchical MLA that first learned to determine the sex of the source, narrowed down the possible source individuals based on their sex, and then determined the source identity. We were able to correctly identify the source individual with high precisions (87.21% – 94.42%, depending on call type, and up to 97.79% after the removal of twins from the dataset). We also examine the robustness of identification across varying sample sizes. Our pipeline is a promising tool not only for source identification from marmoset vocalisations but also for analysing vocalisations and tracking vocal learning trajectories of other species

Creep strength behavior of boron added P91 steel and its weld in the temperature range of 600–650 degree C

One of the promising ways for mitigation of Type IV cracking – a failure by cracking at the intercritical /fine grained heat affected zone, a life limiting problem in advanced 9–12 Cr ferritic steel weld like that of P91 is through modification of alloy composition by addition of boron. Addition of boron was observed to improve the microstructure at the weld zone and hence the creep strength. In the present work, boron (100 ppm with controlled nitrogen) added P91 steel after normalizing at 1050C and 1150C and tempered at 760C were studied for the creep behavior in the base metal and welded condition in the temperature range of 600–650C. Creep strength was characterized in terms of stress and temperature dependence of creep rate and rupture time. Weld creep life was reduced compared to the base metal with rupture occurring at the ICHAZ (Type IV crack). However at longer time (at lower stress levels) exposure creep crack moves from weld metal to HAZ (Type II crack). Rupture life was found to superior for the base and weld in the boron containing steel when higher normalizing temperature is used. Estimation of 10 5 h was attempted based on short term rupture data available and weld strength factors were calculated. Observed values are better for P91BH condition than the values for P91BL condition as well as those available for P91 in open literatur

Sensors Based Trash Can Using IOT

The main theme of our project is to develop a sensor based dustbin for a proper garbage management. This project depicts a worthy elucidation for maintaining green environment. The disposal of waste can be done efficiently by segregating between dry waste and wet waste. This system reduces the maintenance stress. A smart handling technology is used to avoid all such hazardous scenario and maintain cleanliness. The whole process is upheld by an embedded system integrated with microcontroller and sensors. The dustbin lid will automatically open when something is sensed within its boundary or limit. This project works on the basis of colour sensor. The sensor distinguishes the colour for efficient disposal of garbage. Thus the system is solution for environmental maintenance and reduces the work of human intervention in garbage maintenance

Management of Saline and Electricity using IOT

The main theme of our project is to reduce the negligence in the hospitals. Sometimes the number of equipment such as fans and lights are kept ON even when not required. Hence, using the device we can reduce the consumption of electricity. Also, due to inattentiveness of the staff members sometimes the level of saline bottle is not kept in track due to which “AERO EMBOLISM” occurs which may lead to heart attack, stroke or respiratory failure. Thus, this paper describes the various ways to control electricity consumption and keep track of the level of saline bottle from distinct places

A tuberculosis prevalence survey based on symptoms questioning and sputum examination

A sample survey was undertaken in Raichur district of Karnataka State to estimate the prevalence of bacteriologically positive pulmonary tuberculosis among symptomatics aged 15 years and above. A population of 72,448 persons was registered in a representative sample of 57 villages and 21 enumeration blocks. Of the 42,580 persons aged 15 years and above eligible for symptoms questioning, 40,657 (95.5%) were examined and 3,846 (9.5%) were found to be symptomatics and eligible for sputum examination. Sputum was collected from 3,685 (95.8%) of the 3,846 symptomatics, and subjected to bacteriological examination i.e., smear, culture and drug susceptibility. Certain important findings were as follows: (i) the number of symptomatics increased with increase in age, more often among males (11.9%) than among females (7.1%), (ii) the prevalence of tuberculosis, as assessed by smear and/or culture was 10.9 per 1,000 in population aged 15 years and above, (iii) the prevalence increased with age and was 3 times higher among males as compared to females, (iv) cough was found to be the predominant symptom among the symptomatics (87%) as well as among the cases detected (92%), (v) the prevalence rate based on smear examination of the sputum specimens, using the two microscopy methods (Ziehl-Neelsen and Fluorescence) was 7.6 per 1,000, (vi) culture examination of these specimens yielded 3.3 per 1,100 additional cases, (vii) both the microscopy methods were equally efficient in detecting smear positives, (vii) of the 355 culture positive cases, 17.7% were resistant to Streptomycin, 29.6% to Isoniazid and 7.6% to Rifampicin either alone or in combination with other drugs

Characterisation of strain-induced precipitation behaviour in microalloyed steels during thermomechanical controlled processing

The temperature at which thermomechanical controlled processing is undertaken strongly influences strain-induced precipitation (SIP) in microalloyed steels. In this study, the recrystallisation-precipitation-time-temperature curve was simulated to determine the full recrystallisation temperature, recrystallisation-stop temperature and the temperature where precipitation would occur at the shortest time. The calculated temperatures were verified by experimental testing for rolling between 1100 °C and 850 °C. On the basis of this a finishing deformation of 850 °C was chosen in order to maximise the precipitate number density formed in a fully unrecrystallised austenite. The orientation relationship between the SIP in austenite, and subsequent transformation to ferrite was identified by calculation from the coordinate transformation matrix, and by electron diffraction in the transmission electron microscope. The NbC formed as coherent/semi-coherent precipitates in the austenite, and remained coherent/semi-coherent in the ferrite, indicating a Kurdjumov-Sachs orientation relationship between the austenite and ferrite on transformation

Small Molecule Inhibitors of the BfrB-Bfd Interaction Decrease Pseudomonas aeruginosa Fitness and Potentiate Fluoroquinolone Activity

© 2019 American Chemical Society. All rights reserved. The iron storage protein bacterioferritin (BfrB) is central to bacterial iron homeostasis. The mobilization of iron from BfrB, which requires binding by a cognate ferredoxin (Bfd), is essential to the regulation of cytosolic iron levels in P. aeruginosa. This paper describes the structure-guided development of small molecule inhibitors of the BfrB-Bfd protein-protein interaction. The process was initiated by screening a fragment library and followed by obtaining the structure of a fragment hit bound to BfrB. The structural insights were used to develop a series of 4-(benzylamino)- A nd 4-((3-phenylpropyl)amino)-isoindoline-1,3-dione analogs that selectively bind BfrB at the Bfd binding site. Challenging P. aeruginosa cells with the 4-substituted isoindoline analogs revealed a dose-dependent growth phenotype. Further investigation determined that the analogs elicit a pyoverdin hyperproduction phenotype that is consistent with blockade of the BfrB-Bfd interaction and ensuing irreversible accumulation of iron in BfrB, with concomitant depletion of iron in the cytosol. The irreversible accumulation of iron in BfrB prompted by the 4-substituted isoindoline analogs was confirmed by visualization of BfrB-iron in P. aeruginosa cell lysates separated on native PAGE gels and stained for iron with Ferene S. Challenging P. aeruginosa cultures with a combination of commercial fluoroquinolone and our isoindoline analogs results in significantly lower cell survival relative to treatment with either antibiotic or analog alone. Collectively, these findings furnish proof of concept for the usefulness of small molecule probes designed to dysregulate bacterial iron homeostasis by targeting a protein-protein interaction pivotal for iron storage in the bacterial cell