SiGe Millimeter-Wave (W-Band) Down-Converter for Phased Focal Plane Array

A millimeter-wave (W-Band) down-converter for Phased Focal Plane Arrays (PFPAs) has been designed and fabricated using the IBM Silicon-Germanium (SiGe) BiCMOS 8HP process technology. The radio frequency (RF) input range of the down-converter chip is from 70 95GHz. The intermediate frequency (IF) range is from 5 30GHz. The local oscillator (LO) frequency is fixed at 65GHz. The down-converter chip has been designed to achieve a conversion gain greater than 20dB, a noise figure (NF) below 10dB and input return loss greater than 10dB. The chip also has novel LO circuitry facilitating LO feed-through among down-converters chips in parallel. This wide bandwidth down-converter will be part of millimeter-wave PFPA receiver designed and fabricated in collaboration with the University of Massachusetts-Amherst Department of Astronomy. This PFPA receiver will be installed on Green Bank Telescope (GMT) / Large millimeter wave telescope (LMT) in Q2 of 2014. This project is collaboration between the University of Massachusetts-Amherst (UMass), Brigham Young University (BYU) and National Radio Astronomy Observatory (NRAO). To the best of the author’s knowledge, this is first wide bandwidth down-converter at W-band to achieve this high gain and low noise figure among Si/SiGe based systems

Flexible high frequency electronics and plasmonics using two dimensional nanomaterials

In this work, we have demonstrated novel flexible electronics and plasmonic devices using 2-dimensional (2D) nanomaterials (graphene and MoS2). The first part of this work is about design of flexible high frequency electronics using 2D nanomaterials. We report sub-THz graphene transistors with fT ~ 100GHz. We also discuss how to integrate graphene based sub blocks (antenna, mixer and speaker) to fabricate all graphene based wireless receiver. We report for the first time flexible RF transistors with GHz frequency response using CVD grown monolayer MoS2. We also demonstrate flexible low power RF nanosystems (amplifiers, mixers, AM receiver) using CVD MoS2. We have developed MoS2 transistor models for integrated circuit design application. RF MoS2 transistors results are very promising for low power internet of things (IOT) applications. In second part, we have shown design of novel plasmonic devices using 2D nanomaterials. We have demonstrated large area tunable graphene metasurface using moiré nanosphere lithography (MNSL). We have shown novel method to fabricate large area graphene nanoribbons (GNRs) using block copolymer lithography (BCPL) and its potential application towards tunable mid-IR plasmonic sensing. We report for the first time nanopatterning of CVD MoS2 on plasmonic substrate using bubble pen lithography (BPL). We have also shown light enhancement of monolayer CVD MoS2 using plasmonic nanoantenna array (PNA). These results are very useful for design of highly efficient 2D nanomaterial based LEDs, photodetectors, lasers and sensors.Electrical and Computer Engineerin

Development and Validation of Chemometrics - Assisted Spectrophotometry and Liquid Chromatography for the Simultaneous Determination of Some Novel Drugs in Pharmaceuticals

A simple and precise method involving four chemometric techniques, First order derivative and RP-HPLC was developed for the determination of various combinations of drugs in pharmaceutical formulations. CHEMOMETRICS-ASSISTED SPECTROPHOTOMETRY: Chemometric techniques are wide applied for the resolution of the selected drug combinations. A 25 calibration set of sample mixtures were used to construct the best model. The levels were in the calibration range of 8.0 – 32.0 μg mL−1 , 1 – 5 μg mL−1 and 3 – 5 μg mL−1 for losartan potassium, amlodipine besylate and hydrochlorothiazide, 1.0 – 5.0 μg mL−1 , 15 – 75 μg mL−1 and 0.5 – 2.5 μg mL−1 for atorvastatin calcium, fenofibrate and folic acid, 0.05 - 0.25 μg mL−1 , 0.5 - 2.5 μg mL−1 and 7 - 35 μg mL−1for rosiglitazone maleate, glibenclamide and metformin HCl, 1.0 – 5.0 μg mL−1 and 2 - 10 μg mL−1 for nebivolol HCl and hydrochlorothizide, 0.3 – 1.5 μg mL−1 and 7 - 35 μg mL−1 for pioglitazone HCl and metformin HCl, 8 – 40 μg mL−1 and 1.2 - 4.8 μg mL−1 for losartan potassium and ramipril. The UV absorbance data were recorded by measuring the absorbances in the region of 200 – 400 nm with 0.1 nm difference for the mixtures. The obtained data were processed on a Pentium IV computer with PLS-Toolbox software version 4.1 and 5.0 in Matlab 6.5 (math works). The fit model was constructed by using the absorption data matrix corresponding to the concentration data matrix in the CLS, MLR, PCR and PLS. Before constructing the model preprocessing was carried out to reduce the effect of noise, improve the predictive ability of the model and simplify the model by making the data more normally distributed and wavelength selection based on best outcome reduced the error of the spectral data. The predictive ability of a model in chemometric methods was estimated from their RMSEC, RMSECV, r and RMSEP values of the drugs. Hence, good agreement was seen in the assay results of pharmaceutical formulation. We conclude that the chemometric technique in combination with CLS, MLR, PCR and PLS calibration methods is a good approach for obtaining reliable results. DERIVATIVE SPECTROSCOPY DETERMINATION: Derivative method involving first derivative UV spectroscopic determination of zero crossing points in derivative mode completely eliminates the interference from unwanted component and thus concentration determination of each drug can be easily calculated without prior separation from combined dosage form, from their respective calibration curve. Atorvastatin calcium and fenofibrate, atorvastatin calcium and ezetimibe, Levofloxacin hemihydrate and ornidazole were determined simultaneously without prior separation from tablets dosage form. RP- HPLC METHOD: Selection of mobile phase, column, pH and wavelength The mobile phase, column, pH and wavelength were selected on the basis of peak purity and acceptable limit of system suitability parameter and resolution of the peak, which were listed below: 1. Losartan potassium, amlodipine besylate and hydrochlorothiazide: 10mM KH2PO4 (adjusted to pH -3): ACN (60:40), 225 nm (C18, ODS). 2. Atorvastatin calcium, fenofibrate, folic acid: 10mM KH2PO4 (adjusted to pH -2.5): ACN (30:70), 248 nm (C18, BDS). 3. Rosiglitazone, glibenclamide, metformin HCl: 0.02M CH3COONH4 (adjusted to pH -4.2): ACN (45:55), 230 nm (C18, ODS). 4. Nebivolol HCl, hydrochlorothiazide: 0.4% Triethylamine: ACN (70:30), 240 nm (C18, BDS). 5. Pioglitazone HCl, metformin HCl: 0.02M CH3COONH4 (adjusted to pH - 4.2): ACN (45:55), 230 nm (C18, ODS). 6. Ramipril, losartan potassium: 0.05M KH2PO4 (adjusted to pH -2): ACN (62:38), 210 nm (C18, BDS). CHROMATOGRAPHIC CONDITIONS: Chromatographic separations were performed at ambient temperature with the use of respective mobile phase. The mobile phase was filtered and degassed before use. The flow rate of mobile phase was adjusted to 1.5 and 1 mL min-1. the detection wavelength was set at their nm. The injection volume of the standard and sample solutions was 20 μL−1. The system suitability parameters as specified in USP results are found to be acceptable. The developed method was found to be accurate. Hence, good agreement was seen in the assay results of pharmaceutical formulation by chemometric, derivative spectroscopic and RP-HPLC. We conclude that the chemometric technique when coupled with CLS, MLR, PCR and PLS calibration methods sounds a good approach for obtaining reliable results, when compared with RP-HPLC method. Chemometric techniques are precise, rapid, selective, sensitive and less expensive. Hence it can be applied for the routine analysis of these combinations of drugs in the tablet formulation without any pre-treatment and without time consumption in quality control laboratories

Overview of T-cell Lymphomas

T-cell lymphomas are a mixed bag of diseases with a similar origin but diverse in biology and behavior. This review aims to highlight the key changes to the WHO classification and summarize the therapeutic paradigm as of the time of writing in November 2018

Multi-Operator Gesture Control of Robotic Swarms Using Wearable Devices

The theory and design of effective interfaces for human interaction with multi-robot systems has recently gained significant interest. Robotic swarms are multi-robot systems where local interactions between robots and neighbors within their spatial neighborhood generate emergent collective behaviors. Most prior work has studied interfaces for human interaction with remote swarms, but swarms also have great potential in applications working alongside humans, motivating the need for interfaces for local interaction. Given the collective nature of swarms, human interaction may occur at many levels of abstraction ranging from swarm behavior selection to teleoperation. Wearable gesture control is an intuitive interaction modality that can meet this requirement while keeping operator hands usually unencumbered. In this paper, we present an interaction method using a gesture-based wearable device with a limited number of gestures for robust control of a complex system: a robotic swarm. Experiments conducted with a real robot swarm compare performance in single and two-operator conditions illustrating the effectiveness of the method. Results show human operators using our interaction method are able to successfully complete the task in all trials, illustrating the effectiveness of the method, with better performance in the two-operator condition, indicating separation of function is beneficial for our method. The primary contribution of our work is the development and demonstration of interaction methods that allow robust control of a difficult to understand multi robot system using only the noisy inputs typical of smartphones and other on-body sensor driven devices

Visualization in Anatomical Sciences for Effective Teaching and Learning

Anatomy is one of the basic subjects of medical science. Medical students gain detailed knowledge of human body by dissecting cadavers. Hence, cadaveric dissection has become an essential tool in teaching and learning anatomy. In anatomy, visualization plays an important role in understanding the spatial orientation of structures. Due to technological advancement and a shortage of cadavers, there is a need to look for various complementary tools which can provide an adequate visualization of bodily structures. This issue was very well understood and reflected during the recent pandemic when cadaveric dissection was substituted by experimenting with various teaching tools. In this paper, we have tried to briefly describe the various options that can complement/supplement dissection and assist in self-directed learning

Online Learning Modules in Anatomical Sciences: Effective Sources for Continued Learning for Medical Undergraduates During the Unprecedent COVID-19 Pandemic

Introduction. During the COVID-19 pandemic-induced lockdown, the selection of simple and authentic online material among plethora of web content is difficult for both students and teachers. This forces students and teachers to explore various avenues of learning. The objective of this research was to evaluate free open-access anatomy e-learning resources in accordance with required standard learning outcomes for medical students. Methods. During February 2021, an extensive search for online modules for learning anatomy across six Massive Open Online Courses, including edX, Coursera, Udemy, Khan Academy, Canvas and FutureLearn, along with Google and YouTube was conducted. Courses or modules on e-learning platforms, YouTube channels, standalone videos, anatomy atlases, 3D models were considered as learning resources and evaluated. Online materials were classified as structured learning resources if they had a defined syllabus, time duration and instructional design. Resources lacking these characteristics were considered as unstructured ones. Results. Twenty structured learning courses were identified on the Udemy (6 courses), Coursera (3 courses), edX (2 courses), FutureLearn and Khan academy platforms. Learning resources available through Swayam Prabha were aligned with the defined syllabus and video lectures. The content hosted within Clinical Anatomy, Medvizz and Kenhub was eye-catching. Thirty-two YouTube channels offering standalone learning material were identified. Seven resource materials, other than YouTube channels, offered anatomy learning material in the form of charts and tables. Four websites noted to have 3D interactive learning content regarding gross anatomy. Conclusions. During the pandemic-induced lockdown, the list presented in the study may act as guide in selection of the simplest and best materials for those teaching and learning anatomy in medical undergraduate courses. However, in most cases, there is no alignment with standard learning outcomes as defined by medical education regulatory authorities

Pyramidal Lobe Variations of the Thyroid Gland and Its Clinical Implications: A Short Review and Case Report

The thyroid gland is characterized by significant anatomical variability, which may lead to difficulties in diagnostic and treatment outcomes. The pyramidal lobe is the most common variation present in up to 30% of the population. Literature has witnessed research on different variations of the pyramidal lobe, preference for the lobe from which it arises, gender preference, etc. Understanding such variations is essential for successful treatment outcomes for thyroid diseases. This short review was aimed to highlight embryological aspects of the thyroid gland, variation of its pyramidal lobe and present a rare case of demarcated left lobe, pyramidal lobe, and an associated cyst

Hyperostosis Frontalis Interna and Temporalis Interna: A Rare Case Report

Hyperostosis is a slow-growing benign bone tumour often seen in the bones of the cranial vault, more commonly found in elderly females. It is an incidental finding noted during radiological examination. The clinical manifestation of such tumour depends on its location inside the cranial cavity: the proximity to the paranasal sinuses, brain tissue, nerves, or blood vessels, etc. Its clinical findings may range from mild obstruction of the paranasal sinuses or blood vessels to severe compression of the surrounding cranial nerves. Here a rare case of hyperostosis of the frontal and temporal bones found during a routine cadaveric dissection in the Department of Anatomy is presented. Causes of the formation of such unusually enlarged bone masses inside the cranial cavity and their clinical presentation are discussed