10 research outputs found
Analysis of power balance in a helicon plasma source
No full textThis thesis analyses the Helicon Injected Inertial Plasma Electrostatic Rocket (HIIPER), a space propulsion concept consisting of a helicon source for plasma generation and an ion extraction method using a nested pair of inertial electrostatic confinement (IEC) grids that are asymmetrically designed. In this study, the HIIPER setup was modelled based on the previous experimental data of the plasma characteristics obtained to account for various power loses and understand the major contributors to the low efficiency and final thrust performance. The loses to the quartz tube wall was substantially higher than the loses at the metal bellow region and the loses due to ionization and excitation. Future improvements in Langmuir probe design to characterize the plasma and the feasible changes to the experimental setup are provided in this study.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2022-05-01The student, Hariharan Manickam Vaithiyanathan, accepted the attached license on 2020-04-30 at 11:52.The student, Hariharan Manickam Vaithiyanathan, submitted this Thesis for approval on 2020-04-30 at 12:09.This Thesis was approved for publication on 2020-05-12 at 11:33.DSpace SAF Submission Ingestion Package generated from Vireo submission #15126 on 2020-08-25 at 17:28:30Made available in DSpace on 2020-08-26T23:57:20Z (GMT). No. of bitstreams: 2
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Previous issue date: 2020-05-12Embargo set by: Seth Robbins for item 115750
Lift date: 2022-08-26T23:57:28Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 115750
Lift date: 2022-08-26T23:58:55Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
Development and Metabolic Characterization of Horse Gram (Macrotyloma uniflorum Lam. (Verdc.)) Mutants for Powdery Mildew Resistance
No full textHorse gram is one of the lesser-known beans widely grown in India. One hundred and twenty-three homozygous horse gram mutants were screened for powdery mildew (PM) disease resistance using the grade 0 to 4. The mutants were grouped based on the disease level of 0 to 2 (resistant) and susceptible (3 to 4). The PM altered the chlorophyll fluorescence (a/b ratio), maturity duration, and yield attributing traits. The yield loss ranged from 4.55% to 72.66%. After affirming the resistance level, the resistant mutant (RM) with minimum yield loss (scale:0) and the susceptible mutant (SM) with maximum loss (scale:4) were used for metabolomic analysis through GC-MS. PM infection induced expression of 66 metabolites representing 32 functional classes. The number of unique classes in RM and SM was 13 and 11, respectively, while eight were common. A fold change in the common metabolites indicated an enhanced accumulation of amine, alcohol, and ester in RM. Along with pathogen-induced defensive metabolites, RM produced silane and fluorene, whose biological significance in disease resistance is unknown. Though SM expressed defence-related bio-molecules, it failed to yield better
Development and Metabolic Characterization of Horse Gram (Macrotyloma uniflorum Lam. (Verdc.)) Mutants for Powdery Mildew Resistance
No full textHorse gram is one of the lesser-known beans widely grown in India. One hundred and twenty-three homozygous horse gram mutants were screened for powdery mildew (PM) disease resistance using the grade 0 to 4. The mutants were grouped based on the disease level of 0 to 2 (resistant) and susceptible (3 to 4). The PM altered the chlorophyll fluorescence (a/b ratio), maturity duration, and yield attributing traits. The yield loss ranged from 4.55% to 72.66%. After affirming the resistance level, the resistant mutant (RM) with minimum yield loss (scale:0) and the susceptible mutant (SM) with maximum loss (scale:4) were used for metabolomic analysis through GC-MS. PM infection induced expression of 66 metabolites representing 32 functional classes. The number of unique classes in RM and SM was 13 and 11, respectively, while eight were common. A fold change in the common metabolites indicated an enhanced accumulation of amine, alcohol, and ester in RM. Along with pathogen-induced defensive metabolites, RM produced silane and fluorene, whose biological significance in disease resistance is unknown. Though SM expressed defence-related bio-molecules, it failed to yield better
An efficient architecture for carry select adder
No full text
Purpose
Adders play a vital role in almost all digital designs, as all four arithmetic operations can be confined within addition. Hence, area and power optimization of the adders will result in overall circuit optimization. Being the fastest adder, the carry select adder (CSLA) gains higher importance among the different adder styles. However, it suffers from the drawback of increased power and area. The implementation of CSLA in digital circuits requires lots of study for optimization. Hence, to overcome this problem, various improvements were made to the CSLA structure to reduce area and, consequently, reduce power. Among these, modified CSLAs show a significant improvement, as they utilize a binary excess-1 code (BEC) to replace the add-one circuit.
Design/methodology/approach
This paper presents further enhancement in the modified CSLA by proposing a decision-based CSLA, which activates BEC on demand. This leads to reduced switching activity. The performance of the proposal is done by analyzing and comparing it with different adders. The comparison is done on the basis of three performance parameters: area, speed and power consumption. This is done by implementing the architecture on Xilinx Virtex5 XC5VLX30 in Verilog environment and is synthesized using Cadence® RTL Compiler® using TSMC 180-nm CMOS cell library.
Findings
Optimization of power, area and increasing the speed of operation are the three main areas of research in very-large-scale integration (VLSI) design for portable devices. As adders are the most fundamental units for any VLSI design, optimization at the adder level has a huge impact on the overall circuit. The modified CSLA has a BEC which continuously switches irrespective of the previous carry bit generated. The unwanted switching results in excess power consumption while also introducing additional delay. Hence, the author has proposed a decider circuit to avoid this excess switching activity. This allows switching of the BEC only when a previous carry is generated. The modified CSLA is based on the ripple carry adder, while the decider-based CSLA utilizes a carry look-ahead adder. This makes a decider-based CSLA faster while utilizing less area and power consumption when compared to the modified CSLA.
Originality/value
The efficiency of the proposed decider-based CSLA has been verified using Cadence RTL Compiler using TSMC 180-nm CMOS cell library and has been found to have 17 per cent power and 11.57 per cent area optimization when compared to the modified CSLA, while maintaining operating frequency.
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Mapping of mango cropping area using machine learning techniques in Tamil Nadu
No full textMango area mapping is crucial for forecasting production prior to harvest and developing policies that ensure food and nutritional security. This study focuses on the integration of remote sensing and machine learning algorithms for real time prediction of mango cropped area in Krishnagiri and Dharmapuri districts of Tamil Nadu state in India. The cloud free images of Sentinel 2 were acquired corresponding to the fruit setting stage of the crop during the main crop season (January to June 2024) and pre-processed in ArcGIS 10.8 software. Supervised classification was carried out using eCognition Developer 10.3 software by combining object-based image analysis (OBIA) and Random Forest algorithm. Based on the analysis, the area under mango cultivation in Krishnagiri district was 31824.22 hectares, showing a 1.5 % deviation from the Department of Economics and Statistics data. The overall classification accuracy was 0.85, with a kappa index of 0.70. In Dharmapuri district, the mango area was slightly overestimated (14950.24 ha) compared to the government data (14589 ha), with a percent deviation of -2.5 %. The overall classification accuracy was 0.88, with a kappa index was 0.76. Accurate mango area mapping supports precision agriculture, efficient resource management and yield optimization, thereby aiding farmers, scholars and policymakers in informed decision-making
Climate Change as an Existential Threat to Tropical Fruit Crop Production—A Review
No full textClimate change is an emerging threat to global food and nutritional security. The tropical fruits such as mango, bananas, passionfruit, custard apples, and papaya are highly sensitive to weather changes especially; changes of monsoon onset and elevated temperature are influencing crop growth and production. There is a need for more specific studies concerning individual crops and regional variations. Long-term effects and interactions of weather parameters and increased concentration of greenhouse gases, especially carbon dioxide, with phenological stages of the plant, pests, and diseases remain understudied, while adaptation strategies require further exploration for comprehensive understanding and effective mitigation. Few researchers have addressed the issues on the effect of climate change on tropical fruits. This paper focuses on the impact of abiotic (temperature, rainfall, humidity, wind speed, evaporation, carbon dioxide concentration) and biotic (pest and pathogens dynamics) factors affecting the fruit crop ecosystem. These factors influence flowering, pollination, fruit set, fruit yield and quality. This review paper will help develop adaptive strategies, policy interventions and technological innovations aimed at mitigating the adverse effects of climate change on tropical fruit production and safeguarding global food and nutritional security
A 1.2V 25MSPS Pipelined ADC Using Split CLS with Op-amp Sharing
No full textabstract: ABSTRACT As the technology length shrinks down, achieving higher gain is becoming very difficult in deep sub-micron technologies. As the supply voltages drop, cascodes are very difficult to implement and cascade amplifiers are needed to achieve sufficient gain with required output swing. This sets the fundamental limit on the SNR and hence the maximum resolution that can be achieved by ADC. With the RSD algorithm and the range overlap, the sub ADC can tolerate large comparator offsets leaving the linearity and accuracy requirement for the DAC and residue gain stage. Typically, the multiplying DAC requires high gain wide bandwidth op-amp and the design of this high gain op-amp becomes challenging in the deep submicron technologies. This work presents `A 12 bit 25MSPS 1.2V pipelined ADC using split CLS technique' in IBM 130nm 8HP process using only CMOS devices for the application of Large Hadron Collider (LHC). CLS technique relaxes the gain requirement of op-amp and improves the signal-to-noise ratio without increase in power or input sampling capacitor with rail-to-rail swing. An op-amp sharing technique has been incorporated with split CLS technique which decreases the number of op-amps and hence the power further. Entire pipelined converter has been implemented as six 2.5 bit RSD stages and hence decreases the latency associated with the pipelined architecture - one of the main requirements for LHC along with the power requirement. Two different OTAs have been designed to use in the split-CLS technique. Bootstrap switches and pass gate switches are used in the circuit along with a low power dynamic kick-back compensated comparator.Dissertation/ThesisM.S. Electrical Engineering 201
Molecular insights of pigeonpea sterility mosaic virus mixed infections and its variability in pigeonpea
No full textPigeonpea sterility mosaic virus-1 (PPSMV-1) and Pigeonpea sterility mosaic virus-2 (PPSMV-2) are the two distinct Emaraviruses causing Sterility Mosaic Disease (SMD), which is an emerging threat to the pigeonpea (Cajanus cajan L. Millspaugh) production in India. The dissemination of virus is progressing at an accelerated rate and existence of PPSMV-1 (Emaravirus cajani) and PPSMV-2 (Emaravirus toordali) exhibiting diversity across the ecosystems. A total of 34 symptomatic and healthy samples were collected from six districts covering Western, North-Eastern, Cauvery Delta Zone and North-Western agro-climatic zones of Tamil Nadu. The disease incidence ranged from 12.8% to 71.6% and the highest mean incidence of 52.67% was recorded in the North-Eastern agroclimatic zone of Tamil Nadu. The RT-PCR and multiplex RT-PCR analysis differentiated the presence of both PPSMV-1, PPSMV-2 and mixed infections. Sequence analysis of RNA1 and RNA3 segments of the virus genomes demonstrated significant genetic heterogeneity among isolates, while phylogenetic relatedness of PPSMV-1 and PPSMV-2 were grouped into distinct clusters. Intra-specific recombination events were observed in the RNA3 segments of both PPSMV-1 and PPSMV-2. There were no recombination events in RNA1 segments of the virus genomes. These results emphasise the widespread distribution and genetic diversity of PPSMV-1 and PPSMV-2 in Tamil Nadu and provide valuable insights for the development of rapid diagnostic tools for effective field management
Enhancing Cotton Production and Sustainability through Multi-Tier Cropping Systems: Growth, Efficiency, and Profitability Analysis
No full textIntercropping presents an opportunity to optimise land use and resource efficiency in cotton cultivation, particularly for small and marginal farmers facing climate-related challenges and rising input costs. This study explores the potential of intercropping short-duration vegetables with cotton to transform this production system into a more economically viable and sustainable one. The study was conducted in the Cotton Department of Tamil Nadu Agricultural University in Coimbatore during the winter irrigated season, from August to January, in both 2020 and 2021. The growth, yield parameters, equivalent yield (3645 and 4234 kg ha−1), and net return (Rs. 123,434 ha−1 and Rs. 154,034 ha−1) were higher in the intercropping system with the paired row planting of Bt cotton with two rows of cluster bean. Upon comparing sole cropping and the paired row method of planting, it was found that adopting the paired row system of planting Bt cotton with two rows of cluster bean was highly profitable in all aspects of crop production. Therefore, the adoption of paired row cropping systems with compatible intercrops that promote synergistic effects on the main crop should be considered for enhancing overall productivity, as well as sustainability
Complete Genome Sequence Analysis of Bacillus subtilis Bbv57, a Promising Biocontrol Agent against Phytopathogens
No full textPlant growth-promoting rhizobacteria (PGPR) are a group of root-associated beneficial bacteria emerging as one of the powerful agents in sustainable plant disease management. Among the PGPR, Bacillus sp. has become a popular biocontrol agent for controlling pests and the diseases of several crops of agricultural and horticultural importance. Understanding the molecular basis of the plant growth-promoting and biocontrol abilities of Bacillus spp. will allow us to develop multifunctional microbial consortia for sustainable agriculture. In our study, we attempted to unravel the genome complexity of the potential biocontrol agent Bacillus subtilis Bbv57 (isolated from the betelvine’s rhizosphere), available at TNAU, Coimbatore. A WGS analysis generated 26 million reads, and a de novo assembly resulted in the generation of 4,302,465 bp genome of Bacillus subtilis Bbv57 containing 4363 coding sequences (CDS), of which 4281 were functionally annotated. An analysis of 16S rRNA revealed its 100% identity to Bacillus subtilis IAM 12118. A detailed data analysis identified the presence of >100 CAZymes and nine gene clusters involved in the production of secondary metabolites that exhibited antimicrobial properties. Further, Bbv57 was found to harbor 282 unique genes in comparison with 19 other Bacillus strains, requiring further exploration
