Papers by SHASHANK SHARMA
International Journal of Research in Orthopaedics
Background: Over the past decades the incidence of intertrochanteric fractures has increased and ... more Background: Over the past decades the incidence of intertrochanteric fractures has increased and there is a universal agreement about the intramedullary nail being the preferred implant of fixation for these fractures.Methods: In this study we have attempted to assess and compare the results and immediate as well as long term outcome of fractures managed by proximal femoral nail anti rotation and the intertan nail. We included 102 patients in our study, half in the group managed by proximal femoral nail anti rotation group and half in the group managed by intertan nail. Over a period of almost one and half years we evaluated the patients in immediate and late post op period for the union of the fracture, functional outcomes and the short- and long-term complications.Results: The results were evaluated in the terms of intraoperative variables like fluoroscopy time, mean blood loss and reduction achieved and postoperatively in terms of superficial wound infections and Harris hip score...
Metallurgical and Materials Transactions A
The spatial variation of thermokinetic parameters has a significant influence on solidification a... more The spatial variation of thermokinetic parameters has a significant influence on solidification and microstructural aspects such as grain orientation, types and dimensions of the microstructural features, and crystallographic defects. In laser-based additive manufacturing, these factors are mainly dependent on the process parameters and have a wide implication on the microstructural aspects and, in turn, on the mechanical properties. In view of this, the current study focuses on the spatial variation on thermokinetic parameters such as cooling rate, thermal gradient (G), and solidification velocity (R) within the melt pool formed during laser processing of IN718. The continuous-wave Nd-YAG laser was employed at a laser fluence of 14.85, 19.10, and 23.34J/mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$23.34\text { J/mm}^2$$\end{document} with varying power (700, 900, 1100 W) at a constant scanning speed of 100 mm/s. The finite element method-based multiphysics heat transfer model, coupled with the dynamic fluid flow, was developed to predict these parameters. The model was correlated with microstructural aspects such as melt pool dimensions, orientation of columnar grains, and secondary dendritic arm spacing. The cumulative diffusion length of Nb obtained via thermo-diffusion calculation during multiple heating/cooling cycles was enough to dissolve the fine intragranular plate-shaped δ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\delta $$\end{document} precipitates in the heat-affected zone.The spatial variation of the G/R ratio recognized the transition of columnar to equiaxed solidification grains which was associated with the G/R ratio lower than 10Ks/mm2\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$10 \text {K s/mm}^2$$\end{document} in the top region (∼25μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sim 25 \mu \text {m}$$\end{document}) of the melt pool. In addition, the coupled solid mechanics model predicted the evolution of thermal stresses during solidification of the melt pool under a high thermal gradient, which marked the generation of high dislocation density in the solidified melt pool.
Lecture Notes on Data Engineering and Communications Technologies, 2020
In today’s world, satellites are vital nodes in collecting and sharing information. Such informat... more In today’s world, satellites are vital nodes in collecting and sharing information. Such information is in the form of images and is accurate. It is of use only if analyzed properly. However, the sheer volume of information in the form of images discourages analysis by manual scrutiny. Therefore, computers are taking over the job of image processing and analysis. First step in image processing is image detection and identification. Next step is tracking the image if need be. The algorithms developed so far have inherent disadvantage of dependency on white or plain background as edge tracking was dependent upon pixel delineation. So, these algorithms enjoyed limited success. ‘Detection of windmills using satellite images through neural networks’ is an attempt to detect windmills in satellite images. It is known that the satellite images set do change in every one to three months. This will be beneficial to get the data of any new windmill installed in any area and subsequently predict the energy production. This project can further be implemented to detect solar power panels and further predict their energy production as well.
Mobile manipulation is a hot topic of research due to the increased flexibility in tasks they off... more Mobile manipulation is a hot topic of research due to the increased flexibility in tasks they offer. However, ‘true’ mobile manipulation, that is seamless integration and synchronization of mobility and manipulation is rarely performed in a standard industrial or service robotics scenario. Even though, there is huge demand for such applications for example, a mobile robot applying sealant on a large aircraft wing, off the shelf solutions are missing. The reason being, basic challenges like positioning of mobile platform for a task, dealing with redundancies from a planning and control point of view, a repeatable fast inverse kinematics and dealing with high dimensional Configuration space of the highly redundant mobile robot are still not solved. In this paper we present a novel and generalized algorithm to solve inverse kinematics for mobile manipulators in closed form. We also define reusable, generalized redundancy parameters which have meaning in the task space. The algorithm is implemented on the real-time KUKA Sunrise robot controller and Nullspace motions have been performed on our 12 DOF Valeri robot.
ECS Transactions, 2018
Scaling of semiconductor devices over past decades has been made possible by continuous innovatio... more Scaling of semiconductor devices over past decades has been made possible by continuous innovations in materials engineering as well as device geometries and integration [1,2]. Shrinking device features necessitate precise engineering of various materials and interfaces. Thermal processing plays a key role in engineering of ever-evolving materials and processes governed by thermodynamics and kinetics. High-k metal gate (HKMG) and contact to source-drain present key challenges in meeting device performance and yield requirements for continued logic CMOS scaling. In this paper, we will present equipment and process innovations in millisecond annealing that enable HKMG and source-drain contact scaling. Key requirements for HKMG architecture include EOT scaling, device reliability, maintaining desired effective work function, and minimal Vfb roll-off effect. Thermal treatment of HKMG film stack leads to HfO2 crystallization, reaction of HfO2 with the SiO2 interface layer (IL), diffusion of nitrogen (N) and reaction with HfO2, and displacement of oxygen vacancies from HfO2. In addition, nitridation of HfO2 suppresses charge traps, improving reliability. Nitrogen placement in the HKMG stack is a function of annealing conditions, and needs to be controlled precisely to meet device performance and reliability requirements. HKMG integration can benefit greatly from millisecond annealing that offers high temperature processing but in millisecond time scales. In this paper, we will introduce millisecond annealing in ammonia (NH3) ambient. We will demonstrate that millisecond annealing in NH3 ambient offers unique capabilities in controlling the N dose and placement in the HKMG stack. It is extremely important to control the N profile since N penetration to the interface layer degrades PMOS reliability. Fig 1 shows the three film stacks investigated in this work. Millisecond annealing was performed using a scanning continuous wave laser to reach desired surface temperature of a wafer placed on a heated stage. This approach allows for millisecond scale control of thermal energy delivery to the wafer. Fig 2 shows the N concentration as a function of millisecond anneal peak temperature for different heater temperatures. N incorporation increases with peak temperature. Lower heater temperature enables higher N incorporation. As shown in Fig 3, lower heater temperature also results in lesser IL thickening, which is desirable for EOT scaling. Fig 4 shows angle-resolved X-Ray Photoelectron Spectroscopy (AR-XPS) profiles for HfO2/IL film stack annealed at the same peak temperature but with different heater temperatures. Clearly, lower heater temperature leads to shallower, Gaussian-like N profile contained within HfO2. In this paper, we will also demonstrate nitridation of other HKMG film stacks such as TiN/HfO2/IL, and TaN/HfO2/IL with excellent control over N dose and depth profile. We will show that this approach leads to conformal nitridation of HKMG film stack. We will also present MOSCAP data complementing the physical characterization and demonstrating device performance and reliability benefits of millisecond annealing in NH3 ambient. Continued CMOS scaling requires geometric shrinking of device features such as contact to source and drain. Smaller contact dimensions necessitate reduction of bulk and interface resistivity of various materials deposited in the contact structure. Advanced logic devices beyond 10nm node are expected to use Cobalt as contact fill metal [3]. Oxidation of barrier TiN is detrimental to the quality of subsequent Cobalt metal fill and introduces an additional contributor to the overall external resistance of the device. Silicidation anneal after Ti liner/TiN barrier deposition results in oxidation of TiN surface due to the presence of trace amounts of O2 in the anneal chamber. Hence, it is paramount to minimize surface oxidation of TiN to enable optimal contact metal fill. In this paper, we will demonstrate that TiN oxidation can be minimized by improving millisecond anneal chamber background O2 level and cooling down wafers in controlled ambient. The importance of ambient control during silicide anneal was investigated by comparing surface oxidation resulting from annealing with various ambient control schemes. Fig. 5 shows that a silicide anneal run with X ppm ambient O2 during the anneal resulted in significant oxidation of TiN, and oxidation was reduced with reduced ambient O2 during anneal. The least degree of TiN oxidation was achieved with improved ambient control during both the anneal process and wafer cooldown. Improvement in chamber O2 level along with cooler wafer extraction also resulted in better Co adhesion to TiN and ~17% reduction in contact resistivity (Fig 6). Enhanced ambient control capability in the millisecond anneal system is expected to provide further benefits in HKMG EOT scaling and reliability in combination with NH3 thermal processing. Figure 1
European Respiratory Journal, 2016
Background: Sleep studies at St.Peter9s Hospital are performed upon request of the respiratory an... more Background: Sleep studies at St.Peter9s Hospital are performed upon request of the respiratory and bariatric health departments. There are a finite number of sleep study kits, that can fail to meet the demand, and results in delays in diagnosis and treatment. Subjectively, in those with high body mass indexes (BMI), the oxygen desaturation index (ODI) was thought to be closely related to the apnoea-hyponeic index (AHI), suggesting that a diagnosis of sleep apnoea in these patients could be made with oxygen saturation monitoring alone. Objective: To qualify the link between ODI and AHI in patients suspected of having sleep apnoea. Methods: A retrospective analysis of 6 months worth of sleep study data at St. Peter9s Hospital. We focused on all studies performed on patients with a BMI of over 40. We focused on the AHI, ODI, Weight/ BMI and age of the patients involved. Results: There were 79 patients with a BMI of over 40 who had a sleep study performed. 74 of these studies were positive for sleep apnoea, and we found a strong correlation between the ODI and AHI (Spearmans Rank correlation = 0.976). Conclusion: Given the strong correlation between ODI and AHI demonstrated, we would consider monitoring oxygen levels alone overnight for the diagnosis of sleep apnoea in people with a BMI of over 40. This would enable us to perform more studies and aim to start people on treatment sooner.
SPE EOR Conference at Oil and Gas West Asia, 2016
Many decisions in enhanced oil recovery (EOR) pilot design are required to plan an EOR pilot that... more Many decisions in enhanced oil recovery (EOR) pilot design are required to plan an EOR pilot that, if executed successfully, gives a reliable data set and sufficient information to make full field EOR development decisions in the future. A miscible gas EOR pilot was designed for the formation "X" in the field "Y" of Kuwait using an uncertainty driven approach. The method presented in this is paper is a qualitative way of linking key miscible gas EOR performance parameters of the formation to the intrinsic uncertainties of the properties impacting them. An assessment of the impact of the uncertainty itself, likelihood of impact and the acceptance, or required uncertainty reduction, provided the direct link to the selection of the pilot concept, the pilot type, the pilot location and the operational sequence of executing the pilot. The key miscible EOR performance drivers for the formation in, with unacceptable high uncertainty, are vertical sweep efficiency (Ev) a...
Oriental Journal of Chemistry, 2015
Paracetamol (acetaminophen, N-acetyl-pamino-phenol) is a safe and effective analgesic and antipyr... more Paracetamol (acetaminophen, N-acetyl-pamino-phenol) is a safe and effective analgesic and antipyretic agent although its anti-inflammatory effect is weak. In case of an overdose, it may cause severe hepatic necrosis. Paracetamol is rapidly absorbed from the gastrointestinal tract but it is incompletely available due to first pass effect. Extensive metabolism occurs, predominantly in the liver, the major metabolites being the sulphate and the glucuronide conjugates.
Topics in Mining, Metallurgy and Materials Engineering, 2015
Micro lens arrays are widely used in optical devices such as photo-sensors, digital projectors, p... more Micro lens arrays are widely used in optical devices such as photo-sensors, digital projectors, photovoltaic cells, 3D imaging etc. These have traditionally been fabricated by photolithography, moulding and embossing, reactive ion etching and electroforming. These processes are wet processes and require expensive setup and running cost. A novel method is presented in this work that allows fabrication of micro lens array using excimer laser micromachining. The fabrication has been done using mask projection with workpiece scanning. A KrF excimer laser has been used to micromachine lenses on a poly(methyl methacrylate) substrate. The surface profile of the lens array is measured and then related to the laser-material coupling and the energy of the laser pulses. Using this method, it is possible to fabricate micro lenses down to a diameter of 5 µm over a considerably large area.
MRS Proceedings, 2002
ABSTRACTWe have synthesized highly crystalline β-gallium oxide tubes, nanowires, and unique one-d... more ABSTRACTWe have synthesized highly crystalline β-gallium oxide tubes, nanowires, and unique one-dimensional structures in the form of nanopaintbrushes using molten gallium and microwave plasma containing a mixture of monoatomic oxygen and hydrogen. Multiple nucleation and growth of gallium oxide nanostructures occurred directly out of molten gallium upon exposure to an appropriate composition of hydrogen and oxygen in the gas phase. Gallium oxide nanowires were 20 to 100 nm thick and tens to hundreds of microns long. In addition to these morphologies, we also report for the first time, non-template based synthesis of novel 2-D networks of crystalline gallium oxide nanowires and nanotubes. Demonstration of this technique with gallium oxide certainly presents a new route for synthesis of nanostructures of other important metal oxides such as indium oxide, tin oxide, and zinc oxide.
2014 20th International Conference on Ion Implantation Technology (IIT), 2014
Scaling of semiconductor devices over past decades has been made possible by continuous innovatio... more Scaling of semiconductor devices over past decades has been made possible by continuous innovations in materials engineering as well as device integration and geometries. Thermal processing has been an enabler for manufacturing advanced devices, both as a unit process and in concert with other key technologies like ion implantation, epitaxy, and film deposition. This paper reviews the evolution of annealing technology with a special consideration to thermodynamics, kinetics and integration thermal budgets. Equipment and process innovations to meet ever-changing material and device fabrication requirements are presented.
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 2001
A new method of selectively patterning a silicon substrate with silicon dioxide and silicon nitri... more A new method of selectively patterning a silicon substrate with silicon dioxide and silicon nitride is demonstrated. An oxide patterned silicon substrate is directly nitrided using a microwave generated nitrogen plasma. Upon subsequent selective wet chemical etching using KOH, the oxide is removed and etching proceeds into the silicon, revealing a contrast reversed pattern of the oxide. The etch resistance of the nitrided surface is maximized by increasing the microwave power, pressure, and nitridation duration. The etch rate of silicon dioxide is negligibly affected and its etch rate is nearly the same as before nitridation. Compositional analysis of the nitride and the nitrided oxide using x-ray photoelectron spectroscopy confirms that microwave plasma nitridation produces SiN covalent bonds.
Journal of Parallel and Distributed Computing, 2015
ABSTRACT Graph algorithms play a prominent role in several fields of sciences and engineering. No... more ABSTRACT Graph algorithms play a prominent role in several fields of sciences and engineering. Notable among them are graph traversal, finding the connected components of a graph, and computing shortest paths. There are several efficient implementations of the above problems on a variety of modern multiprocessor architectures. It can be noticed in recent times that the size of the graphs that correspond to real world datasets has been increasing. Parallelism offers only a limited succor to this situation as current parallel architectures have severe short-comings when deployed for most graph algorithms. At the same time, these graphs are also getting very sparse in nature. This calls for particular solution strategies aimed at processing large, sparse graphs on modern parallel architectures. In this paper, we introduce graph pruning as a technique that aims to reduce the size of the graph. Certain elements of the graph can be pruned depending on the nature of the computation. Once a solution is obtained on the pruned graph, the solution is extended to the entire graph. Towards, this end we investigate pruning based on two strategies that justifies their use in current real world graphs. We apply the above technique on three fundamental graph algorithms: breadth first search (BFS), Connected Components (CC), and All Pairs Shortest Paths (APSP). For experimentations, we use three different sources for real world graphs. To validate our technique, we implement our algorithms on a heterogeneous platform consisting of a multicore CPU and a GPU. On this platform, we achieve an average of 35% improvement compared to state-of-the-art solutions. Such an improvement has the potential to speed up other applications reliant on these algorithms.
Nanosensing: Materials and Devices, 2004
Enormous manufacturing cost and technical complexity of continued shrinking of electronic devices... more Enormous manufacturing cost and technical complexity of continued shrinking of electronic devices through the conventional transformative" top-down" approach have motivated efforts worldwide to explore simpler alternatives. New nano-scale assembly technology, such as ...
SSRN Electronic Journal, 2013
The Philippine stock market despite being the one of the oldest stock exchanges in Southeast Asia... more The Philippine stock market despite being the one of the oldest stock exchanges in Southeast Asia and its recent boom and glory is the smallest among the other contemporary stock exchanges . The growth of the local stock market depends in part on the push for internal reforms within the PSE so that it is in proper tune with the demands of the market place. Much also rests on what the national government does to assure that the economic growth path of the country is sustained.
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Papers by SHASHANK SHARMA