Study of electron traps associated with oxygen superlattices in n‐type silicon

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Opportunistic Networks: Present Scenario- A Mirror Review

Opportunistic Network is form of Delay Tolerant Network (DTN) and regarded as extension to Mobile Ad Hoc Network. OPPNETS are designed to operate especially in those environments which are surrounded by various issues like- High Error Rate, Intermittent Connectivity, High Delay and no defined route between source to destination node. OPPNETS works on the principle of “Store-and-Forward” mechanism as intermediate nodes perform the task of routing from node to node. The intermediate nodes store the messages in their memory until the suitable node is not located in communication range to transfer the message to the destination. OPPNETs suffer from various issues like High Delay, Energy Efficiency of Nodes, Security, High Error Rate and High Latency. The aim of this research paper is to overview various routing protocols available till date for OPPNETs and classify the protocols in terms of their performance. The paper also gives quick review of various Mobility Models and Simulation tools available for OPPNETs simulation

Effect of nutrients and spacing on growth characters, yield attributes and yield under high-density planting system of cotton

Field experiments were conducted at the farmer's field, Madathanoor village, Pochamapalli taluk, Krishnagiri district, from August to January 2023-2024 and at the Experimental Farm, Department of Agronomy, Faculty of Agriculture, Annamalai University, from January to June 2024 to study the yield maximization through agronomic strategies under high-density planting system (HDPS) of cotton. The field experiment was laid out in a factorial randomized block design with three replications. The experiment comprised 12 treatment combinations containing three levels of nutrients and four levels of spacing. The nutrient levels of N1- 80:40:40 nitrogen, phosphorus, potassium (NPK) kg ha-1 , N2 - 100:50:50 NPK kg ha-1 and N3 - 120:60:60 NPK kg ha-1 recommended doses of fertilizers (RDF) were tried with S1 - 60 x 10 cm, S2 - 60 x 15 cm, S3 - 70 x 10 cm and S4 - 100 x 10 cm spacing. The results revealed that the combination of 120:60:60 NPK kg ha-1 + 60 x 10 cm spacing registered higher plant height. Also, the combination of 120:60:60 NPK kg ha-1 + 100 x 10 cm spacing registered higher leaf area index (LAI) and dry matter production (DMP), yield attributing characters (sympodial branches plant-1 , number of squares plant-1 and boll weight) and seed cotton yield. In controversially, the combination of 120:60:60 NPK kg ha-1 + 60 x 10 cm spacing registered higher plant height

Electron microscopy of quantum dots

This brief review describes the different types of semiconductor quantum dost systems, their main applications and which types of microscopy methods are used to characterize them. Emphasis is put on the need for a comprehensive investigation of their size distribution, microstructure, chemical composition, strain state and electronic properties, all of which influence the optical properties and can be measured by different types of imaging, diffraction and spectroscopy methods in an electron microscope

Garbage Monitoring And Management Using Deep Learning

Rapid urbanisation and population growth have led to an unprecedented increase in waste generation. In addition to this, increasing tourism has also increased the challenge of maintaining coastal areas. Inefficient and inadequate waste management practices pose significant environmental and health hazards to both humans and wildlife. Through deep learning and computer vision techniques, the garbage can be identified and its location can be extracted directly from the images. Videos are collected using UAVs. Auto generation of waste reports and additional services like chat-bots are also implemented. Furthermore, the system implements OR tools using which the routes of garbage collector vehicles is optimised. By minimising travel distances and maximising cleanup efficiency, the system reduces operational costs and enhances the overall effectiveness of beach cleanup initiatives. Predominant spots of garbage are analysed and the nearest dustbins are mapped along with the route to reach the dustbin. The garbage detection model gave a mAP of 0.845. The silhouette score of clustering was 70.1% for chameleon and 99.02% for k means. All of the above mentioned modules were integrated and presented on the user interface of the application developed

Effect of organic manures and silicon nutrition on the productivity and profitability of rice

Field experiments were conducted in 2022 and 2023 during the Kharif season at experimental farm, Department of Agronomy, Annamalai University, Tamil Nadu, India to study the effect of organic manures and silicon nutrition on the productivity and profitability of rice. The treatments included both organic manures (farmyard manure (FYM), green manure (GM), poultry manure (PM)) and recommended doses of fertilizers (RDF)). Silicon through Diatomaceous earth (DE) was tested in combination with the above nutrient sources. The treatments were arranged in randomized block design with three replications. The highest growth parameters (plant height, number of tillers hill-1, leaf area index and dry matter production), yield parameters (number of panicles m-2, number of filled grains panicles-1 and Test weight) and rice yields (grain and straw yields) were found in both seasons with RDF + GM @ 6.25 t ha-1 + PM @ 2 t ha-1 + Si @ 200 kg ha-1.  However, applying RDF + PM @ 2 t ha-1 + Si @ 200 kg ha-1 through DE increased net income and benefit cost ratio in 2022 and 2023. Based on the results of two-year field experiment, it can be concluded that rice productivity and profitability can be improved through the application of RDF + PM @ 2 t ha-1 + Si @ 200 kg ha-1 through DE

A deep-level transient spectroscopy study of p-type silicon Schottky barriers containing a Si-O superlattice

The presence of deep levels in a silicon-oxygen (Si-O) superlattice (SL) deposited on p-type silicon substrates has been investigated by deep-level transient spectroscopy (DLTS) on thermally evaporated Cr Schottky barriers (SBs). The SLs have been fabricated with different thicknesses of the silicon interlayers, formed by chemical vapor deposition. It is shown that a broad band of hole traps is present near the surface of the SB, which is associated with the SL. In addition, the activation energy corresponding with the peak maximum shifts to higher values with respect to the valence band and gives rise to a higher trap concentration with increasing silicon interlayer thickness. It is proposed that these states are associated with the structural defects found in similar SL structures, that is, with the epitaxial quality and not with the SiO bonds in the atomic layers. The change in the DLT-spectra with silicon thickness could be related with the transformation of the structural defects from small self-interstitial clusters to stacking faults

Quasi 2D Si-O Superlattices for Future Nanoelectronic Applications

Graphite-like 2D nanolattices of dielectrics andsemiconductors with enhanced anisotropic electronic properties are goodcandidates to pave the way to the ultimate scaling and performances of future nanoelectronic devices. Graphene, the most studied representativeof the 2D graphitic materials, has overshadowed research on other potential quasi-2D nanolattices with totally unexplored physical properties. For instance, 3D materials, in which strong anisotropic is introduced inthe band structure, could potentially lead to enhanced mobility and display quasi-2D properties. Such structures could be induced in Si and Ge lattices, by epitaxial layering with non-semiconducting monolayers, so called superlattices. In such a case, the band structure and the density of states could be strongly modified reducing in-plane effective mass while inhibiting the transport perpendicular to the layers. This could reduce gate leakage and carrier scattering, thus maintaining high mobility at low equivalent oxide thickness. A first goal of the PhD project is to develop processes for the fabrication of Si/O, Si/N, Si/C and Si/S superlattices. The fabrication of such superlatticesrequires precise control at the (sub)-monolayer level to maintain the epitaxial Si structure. The approach is therefore based on atomically controlled processing by CVD. Self-limiting chemisorption reactions are used to control the amount of O, N, C, and S in the superlattices. This technique has already been used for epitaxial layering of Si and N. Structural characterization of these superlattices is done using Transmission Electron Microscopy (TEM). X-ray Photoelectron Spectroscopy (XPS) is usedfor having the bonding information at the interfaces and Secondary Ion Mass Spectroscopy (SIMS) is used to determine the atom density at the interface. Understanding of the deposition process will contribute to the development of superlattices with optimal transport properties. A second goal of the PhD project is the study of the carrier transport properties of these materials. Especially the carrier mobility, current carrier capability and the band gap of these materials are important parameters in this respect. MOS-type test structures including simple transistors will be made on the engineered Si superlattices to evaluate the electrical properties of these materials, such as mobility and gate leakage. Low temperature processing will be needed for the gate stackand source/drain contact formation in order not disturb the nanolatticestructure. The results of the electrical tests will provide insight in the basic properties of these materials and allow benchmarking them against other candidates for advanced nano-electronic applications, such as graphene and high mobility channel materials (III-V).status: publishe

Identification and characterization of host genes involved in regulating replication of brome mosaic virus

Brome mosaic virus (BMV) belongs to a viral class called positive-strand RNA [(+)RNA] viruses. This is the largest class of viruses and includes numerous important pathogens. BMV infects monocotyledonous plants and its replication can be recapitulated in the baker's yeast (Saccharomyces cerevisiae) under laboratory conditions to use yeast as an experimental model system. BMV generally does not infect dicotyledonous plants including the model plant Arabidopsis thaliana. One important shared feature of (+)RNA viruses is that they all make use of host proteins to aid in their own viral replication. In particular, (+)RNA viruses use host intracellular membranes for their replication and lipid composition of these membranes is crucial for viral replication. I show here that BMV replication protein 1a causes redistribution of host Lam5 (Lipid transfer protein Anchored at a Membrane contact site 5) and that Lam5 is necessary for BMV replication in yeast. Furthermore, in the absence of Lam5, BMV 1a affects the distribution of lipid droplets throughout yeast cells. Host factors also play critical roles in defense against viruses. Although wild-type Arabidopsis is not a host for BMV, the Arabidopsis cpr5 (Constitutive expression of Pathogenesis-Related genes 5) mutant can support systemic infection of BMV. I performed screens in Arabidopsis and have identified four genes that contribute to defense against BMV. These include two RNA-binding proteins, a lectin superfamily protein, and an alternative oxidase. My results also contribute to the growing evidence that reactive oxygen species play a key role in BMV replication. In summary, my work provided new insights into BMV replication in hosts and plant defense against BMV infection. The information gained from these projects aids in our understanding of (+)RNA virus biology in general and may identify targets for developing broad-spectrum antiviral strategies.Doctor of PhilosophyViruses are important pathogens that can cause devastating diseases not only in humans, but also in animals and plants. It is important to study viruses and their interactions with their hosts to develop antiviral drugs and engineer plant resistance to viruses. Positive-strand RNA viruses are the largest class of viruses and are responsible for numerous human, animal, and plant diseases. Brome mosaic virus (BMV) belongs to this class of viruses and has a simple genome organization. Furthermore, the baker's yeast can support BMV replication. BMV serves as a model to study (+)RNA virus replication and virus-host interactions. I show here that BMV depends on the lipid transport protein Lam5 for proper replication in yeast. Furthermore, although much is known about BMV replication in yeast, more information is needed on BMV replication in plants. To aid in this goal, I performed screens in the model plant Arabidopsis thaliana to identify Arabidopsis mutants that could allow for systemic BMV infection. This project has uncovered four new genes that contribute to defense against BMV. This research aids in our understanding of how BMV replication works and also how plants defend themselves against viruses. This work is important for understanding of the biology of (+)RNA viruses and the plant immune system in general