85 research outputs found
Design of low power front-end receiver for bluetooth low energy/ZigBee in nano-scale CMOS technology / Zechariah Balan
No full textWith the increasing need for the internet of things (IoT), Bluetooth low energy (BLE) and ZigBee standards have become popular solutions for wireless devices. In the tremendous growth of wireless application, low voltage and low power consumption have become a major consideration in radio frequency integrated circuit (RFIC). The development of low power transceiver is driven by the need of withstanding longer battery life time and reduced cost, catering towards mobile application. The continuous downscaling of deep-submicron CMOS technologies to reduce overall power consumption and enable high frequency operation outlays design challenges in the construction of RF front end blocks, which results in less voltage headroom available for circuits to operate. This has driven the need in exploration of new low power/low voltage design technique for RF architecture. The performance of a receiver is dependent on that of the individual blocks such as low noise amplifier (LNA), mixer and voltage controlled oscillator (VCO). This dissertation focuses on the design and implementation of a 1.5V ultra-low power 2.4-GHz CMOS receiver powered by a coin battery. The proposed receiver is relaxed in the use of a low dropout regulator (LDO). By effective merging of the quadrature low noise amplifier (QLNA), in phase and quadrature (I/Q) mixers, VCO and trans-impedance amplifier (TIA) in one cell, while removing the LDO, the available 1.5-V voltage supply is fully utilized for current reuse between blocks, minimizing the dc current consumption. Specifically, a quadrature LNA operating as both common-source and common drain topologies provides the I/Q outputs in the RF signal path. The forward body bias technique is applied to the transconductance stage of the I/Q mixers to relax its voltage headroom consumption. Implemented in 180-nm CMOS technology, the receiver exhibits a conversion gain (CG) of 24 dB, a noise figure (NF) of 13.8 dB and an input-referred
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3rd-order intercept point (IIP3) of -14 dBm while consuming only 2 mA. The phase noise of the VCO is -118.5 dBc/Hz at 2.5 MHz offset. The low-cost technology and low current consumption renders the receiver suitable for Internet of Things (IoT) devices using the Bluetooth Low Energy (BLE) or ZigBee standards
Changing portrayal of a woman in Bollywood cinema: special reference of movies of Vidya Balan
No full textBollywood cinema had a stereotype image of woman in its movies since the beginning. Women were loaded with the patriarchal values. There portrayal matched with the image of woman which the society had in its mind like that of Sita and Radha (Hindu goddesses). Majority of the roles were those of obedient housewives or obedient daughters.
In the last decade i.e. after 2010, in India, there are more women centric films with women in leading and meaningful roles like Highway (2004, Imtiaz Ali), No one killed Jessica (2011, Raj Kumar Gupta), Kahani (2012, Sujoy Ghosh), Mardani (2014, Pradeep Sarkar, Pink (2016, Aniruddha Roy Chowdhury), Chhapaak (2020, Meghna Gulzar) Thappad (2020, Anubhav Sinha) etc. These movies also have special messages for the Indian masses, and they are helpful in bringing positive changes in the society.
This change is interactive in nature. The changing scenario has made much more space for and options for women in cinema and at same time such cinema can be a useful tool in bringing positive changes in society and that too at a fast pace. These changes as well as this interactive nature need to be properly assessed. The impact of these movies can be used for gender sensitization. Some important events that took place in India will also be summarized as they are catalyst to production of women-centric movies in India.
We will review the famous women-centric movies from that focused on representing strong women and their specific achievements. Comparative study of these movies, film reviews, interviews of stars and actors/actresses as well as various articles and books are consulted for this study. Ultimately, through my research and readings, I will conclude that Bollywood Industry has been finally successful in giving proper roles to the Indian actresses. Also, actresses like Vidya Balan have done highly commendable work that has brought glory to heroines. I chose to include Vidya Balan in this Capstone Research as she is a trendsetter when it comes to top women- centric movies in India like Kahani (2012, Sujoy Ghosh) and Dirty Picture (2011, Milan Luthria).M.A.Includes bibliographical reference
Probing the nature of AFEX-pretreated corn stover derived decomposition products that inhibit cellulase activity
No full textSequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24–28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60–65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34–43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44–56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69–70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.Published version: Humpula, James F., Uppugundla, Nirmal, Vismeh, Ramin, Sousa, Leonardo, Chundawat, Shishir P. S., Jones, A. Daniel, Balan, Venkatesh, Dale, Bruce E. & Cheh, Albert M. (2014). Probing the nature of AFEX-retreated corn stover derived decomposition products that inhibit cellulase activity. Bioresource Technology 152, 38-45. http://dx.doi.org/10.1016/j.biortech.2013.10.08
Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and Liquid Chromatography-Multiplexed Collision Induced Dissociation-Mass Spectrometry
No full textThermochemical pretreatment of cellulosic biomass improves cell wall enzymatic digestibility, while simultaneously releasing substantial amounts of soluble oligosaccharides. Profiling of oligosaccharides released during pretreatment yield information essential for choosing glycosyl hydrolases necessary for cost-effective conversion of cellulosic biomass to desired biofuel/biochemical end-products. In this report we present a methodology for profiling of soluble neutral oligosaccharides released from ammonia fiber expansion (AFEXTM)-pretreated corn stover. Our methodology employs solid phase extraction (SPE) enrichment of oligosaccharides based on porous graphitized carbon (PGC), followed by high performance liquid chromatography (HPLC) separation using a polymeric amine based column (Prevail Carbohydrate ES) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) in both positive and negative modes. For structural elucidation on the chromatographic time scale, nonselective multiplexed collision-induced dissociation was performed for quasi-simultaneous acquisition of accurate molecular and fragment masses of neutral oligosaccharids in a single analysis. These analyses directly revealed presence of glucans up to degree of polymerization (DP) 22 without side-chain modifications. Additionally, arabinoxylans with DP up to 6 were detected in the pretreated biomass samples (post-enzymatic digestion). All linkages between sugar units in glucans and arabinoxylans were identified to be p-1-4 linkages based on cross-ring fragment masses. Comprehensive profiling of soluble oligosaccharides also demonstrated that arabinoxylan acetylation was reduced by greater than 85% post-AFEXTM treatment.Published version: Vismeh, Ramin, Humpula, James F., Chundawat, Shishir P. S., Balan, Venkatesh, Dale, Bruce E. & Jones, A. Daniel. (2013). Profiling of Soluble Neutral Oligosaccharides from Treated Biomass using Solid Phase Extraction and LC-TOF MS. Carbohydrate Polymers 94(2), 791-799. http://dx.doi.org/10.1016/j.carbpol.2013.02.00
Essays on river mechanics
No full textCER89-90-PYJ-14.Presented by the Graduate Students in CE 717 River Mechanics (Spring 1990).Instructor: P. Y. Julien.Includes bibliographical references.May 1990.Predicting Sediment Yield of a Watershed by Margaret Tauzer -- Particle Entrainment by River Flows by Kathy Chase -- Bed Forms and Resistance to Flow by Yasser Raslan -- An Examination of the Dynamic Loop Rating Curve in Alluvial Rivers by Phil G. Combs -- Scour Downstream of Hydraulic Structures by T. K. Burke -- Distorted Physical Hydraulic Models, Theory and Practice by Fred L. Ogden -- Life Expectancy of Reservoirs by T. G. Anthony Balan
A 350 mV, 280 μW 1.5-to-4.5-GHz wideband folded mixer adopting capacitive-cross-plus-magnetic-coupling
No full textThis paper describes a 1.5–4.5 GHz CMOS wideband mixer that operates from a single supply of 350 mV, allowing direct powering from various energy harvesting sources. The key techniques adopted for low power and low voltage operation are: (1) complementary transconductance stage in folded topology and current reuse, (2) forward body bias, and (3) gm-boosting by capacitor-cross and transformer coupled (CCTC). The CCTC achieves a high conversion gain (Gc) and a wideband input impedance matching under low power operation. Designed in 130-nm CMOS process, the mixer exhibits Gc of 12.2–16.4 dB and noise figure (NF) of 8.2–12 dB. The maximum input-referred 3rd-order intercept point (IIP3) is −11 dBm while consuming only 280 μW of power at an intermediate frequency (IF) of 50 MHz. The low power and low supply operation render the proposed CMOS mixer suitable for communication among multiple sensor nodes in a wireless body-area sensor network (WBAN). © 202
'Cradle-to-grave' assessment of existing lignocellulose pretreatment technologies
No full textPretreatment is considered to be a central unit process in a biorefinery to convert lignocellulosic biomass into fuels and chemicals, affecting all other operations in the process. A variety of technologies to pretreat lignocellulosic biomass are available today, which encompass a wide range of physical, chemical, and biological based processes. Among these, chemical based pretreatments are considered to be the most promising for future biorefineries. However, several key criteria regarding technical, economical, and environmental considerations should be critically analyzed when adapting these technologies for the nascent biorefinery industry. This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.Peer reviewed
Optimizing Harvest of Corn Stover Fractions Based on Overall Sugar Yields following AFEX Pretreatment and Enzymatic Hydrolysis
No full textBackground: Corn stover composition changes considerably throughout the growing season and also varies between the various fractions of the plant. These differences can impact optimal pretreatment conditions, enzymatic digestibility and maximum achievable sugar yields in the process of converting lignocellulosics to ethanol. The goal of this project was to determine which combination of corn stover fractions provides the most benefit to the biorefinery in terms of sugar yields and to determine the preferential order in which fractions should be harvested. Ammonia fiber expansion (AFEX) pretreatment, followed by enzymatic hydrolysis, was performed on early and late harvest corn stover fractions (stem, leaf, husk and cob). Sugar yields were used to optimize scenarios for the selective harvest of corn stover assuming 70% or 30% collection of the total available stover.
Results: The optimal AFEX conditions for all stover fractions, regardless of harvest period, were: 1.5 (g NH(3) g(-1) biomass); 60% moisture content (dry-weight basis; dwb), 90 degrees C and 5 min residence time. Enzymatic hydrolysis was conducted using cellulase, beta-glucosidase, and xylanase at 31.3, 41.3, and 3.1 mg g(-1) glucan, respectively. The optimal harvest order for selectively harvested corn stover (SHCS) was husk > leaf > stem > cob. This harvest scenario, combined with optimal AFEX pretreatment conditions, gave a theoretical ethanol yield of 2051 L ha(-1) and 912 L ha(-1) for 70% and 30% corn stover collection, respectively.
Conclusion: Changing the proportion of stover fractions collected had a smaller impact on theoretical ethanol yields (29 - 141 L ha(-1)) compared to the effect of altering pretreatment and enzymatic hydrolysis conditions (150 - 462 L ha(-1)) or harvesting less stover (852 - 1139 L ha(-1)). Resources may be more effectively spent on improving sustainable harvesting, thereby increasing potential ethanol yields per hectare harvested, and optimizing biomass processing rather than focusing on the selective harvest of specific corn stover fractions.Peer reviewed
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