Graphene and graphene oxide
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Graphene is an exciting material with many potential applications. It has a large theoretical specific surface area, high intrinsic mobility, high Young's modulus, and high thermal conductivity. Graphene also has good electrical conductivity and optical transmittance of around 97.7%. The properties of graphene include its honeycomb lattice structure composed of carbon atoms bonded together with sigma bonds. Each carbon atom has a pi orbital contributing to a delocalized network of electrons. Graphene also has intrinsic ripples observed through transmission electron microscopy with a lateral dimension of 8-10 nm and height displacement of 0.7-1 nm. These ripples can be induced, suggesting local electrical and optical properties could be altered through 'ripple engineering
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![Introduction
Graphene is an exciting material. [ 1 ] It has a large theoretical
specific surface area (2630 m 2 g − 1 ), high intrinsic mobility
(200 000 cm 2 v − 1 s − 1 ), [ 2 , 3 ] high Young’s modulus ( ∼ 1.0 TPa) [
4 ]
and thermal conductivity ( ∼ 5000 Wm − 1 K − 1 ), [ 5 ] and its optical
transmittance ( ∼ 97.7%) and good electrical conductivityamong many
other potential applications](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1M...
Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1M...Scientific Review SR
The present work studies the microstructural and electrical properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 ceramics synthesized by solid-state route method. Microstructure and elemental analysis of both samples were carried out by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) method, respectively. Phase analysis by X-ray diffraction (XRD) indicated formation of single phase distorted structure. The XRD data were further analyzed by Rietveld refinement technique. Raman analysis reveals that Y atom substitutes La site into the LPMO with shifting of phonon modes. The temperature variation of resistivity of undoped and Y-doped La0.9Pb0.1MnO3 samples have been investigated. The electrical resistivity as a function of temperature showed that all samples undergo an metal-insulator (M-I) transition having a peak at transition temperature TMI. Y-doping increases the resistivity and the metal-insulator transition temperature (TMI) shifts to lower temperature. The temperature-dependent resistivity for temperatures less than metal-insulator transition is explained in terms the quadratic temperature dependence and for T > TMI, thermally activated conduction (TAC) is appropriate. Variation of frequency dispersion in permittivity and loss pattern due to La-site substitution in LPMO was observed in the dielectric response curve.1-s2.0-S1369800114000055-main
1) The document investigates the effect of cation and anion sizes on the charge storage capabilities of graphite nanosheets as electrode materials for electrochemical double layer capacitors.
2) Scanning electron microscope images confirm the layered structure of the graphite nanosheets used, which are 12nm thick with 3.36 Angstrom spacing between layers.
3) Electrochemical measurements using cyclic voltammetry and impedance spectroscopy indicate that the graphite electrodes exhibited better charge storage and delivery in 3M NaCl electrolyte compared to NaOH and KOH electrolytes, due to the smaller ion sizes matching better with the graphite structure.
A0310106
The document summarizes a study of the dielectric properties of nano-crystalline Mn-Zn ferrites. Samples of ZnxMn1-xFe2O4 where x ranges from 0.2 to 0.8 were synthesized using a solid-state route and characterized. The ac conductivity σ, dielectric constant ε', dielectric loss ε'', and loss tangent tan δ were measured from 100 Hz to 20 MHz. ε' and ε'' decreased with increasing frequency. σ was nearly frequency independent below 1 MHz and increased sharply above. The maximum dielectric constant and conductivity occurred for x=0.2, attributed to space charge polarization. The conduction mechanism was explained by electron hopping between Fe2+ and Fe
Properties Of Cnt
This document summarizes the electronic, thermal, and mechanical properties of carbon nanotubes. It discusses their cylindrical structure and how this leads to novel properties. Carbon nanotubes have extraordinary strength and stiffness, with some having a tensile strength over 60 times greater than steel. They are also highly thermally conductive and can transport heat more efficiently than copper. Carbon nanotubes can be metallic or semiconducting depending on their structure, and this quantum confinement of electrons leads to unique electrical properties including ballistic conduction. Their structure also results in sharp optical transitions that can be used to identify different nanotube types.
Electromagnetic studies on nano sized magnesium ferrite
The document summarizes research on the electromagnetic properties of nano-sized magnesium ferrite synthesized using microwave techniques. Key findings include:
1) Magnetic properties were measured using VSM which showed the material has a high coercivity of 785.12 Oe, classifying it as a hard magnetic material.
2) Dielectric measurements found the ac conductivity and dielectric constant decreased with increasing frequency. Both increased with temperature initially before decreasing.
3) The dielectric loss showed expected dispersion behavior, decreasing with frequency and generally increasing with temperature.
4) A high quality factor of 150 was obtained, higher than for bulk ferrites, indicating potential applications in microwave devices.
Electromagnetic studies on nano sized magnesium ferrite
The document summarizes research on the electromagnetic properties of nano-sized magnesium ferrite synthesized using microwave techniques. Key findings include:
1) Magnetic properties were measured using VSM which showed the material has a high coercivity of 785.12 Oe, classifying it as a hard magnetic material.
2) Dielectric measurements found the ac conductivity and dielectric constant decreased with increasing frequency. Both increased with temperature initially before decreasing.
3) The dielectric loss showed expected dispersion behavior, decreasing with frequency and generally increasing with temperature.
4) A high quality factor of 150 was obtained, higher than for bulk ferrites, indicating potential applications in microwave devices.
the effect of nickel incorporation on some physical properties of epoxy resin
The J-E characteristics of samples of epoxy resins mixed with nickel powder in different concentrations have been tested and a log-log straight line behaviour in both the low- and high field regions is observed. Ni-concentration has significant influence on the calculated constants of the J-E relationship. The d.c. electrical resistivity (ρ) of the samples are measured from the room temperature up to about 400 K. The variation of ρ with T obeys the exponential relation of ordinary dielectrics in three temperature regions. The parameters characterizing the ρ -T dependence change considerably with Ni-concentration. Due to the existence of nickel in different concentration a "true" compensation effect is observed with three characteristic compensation temperatures. The mechanical hardness of the samples was investigated as a function of Ni-concentration.
20320130406034
This document summarizes the fabrication and characterization of an AgAl/Si solar cell. AgAl alloys were used for electrical connections due to properties that affect electrical conductivity. A boron layer was diffused into an n-type silicon wafer to create a p-n heterojunction. XRD analysis showed boron inclusion in the silicon. The heterojunction had a direct optical bandgap of 3.1 eV. The solar cell demonstrated a conversion efficiency of 10.54% with a short circuit current of 2.042 mA, open circuit voltage of 0.592 V, and fill factor of 0.682.
Study of Structural and Dielectric properties of BaTiO3 Doped with Mg-Cu-Zn F...
The magnetoelectric (ME) composites having the general formula, (x) Mg0.25Cu0.25Zn0.5Fe2O4 + (1-x) BaTiO3 (x=15%, 30%, 45%) were synthesized by sintering mixtures of highly ferroelectric BaTiO3 and highly magnetostrictive magnetic component Mg0.25Cu0.25Zn0.5Fe2O4. The presence of constituent phases of ferrite, ferroelectric and their composites were confirmed by X-ray diffraction (XRD) studies. Surface morphology of the samples has been investigated using Field Emission Scanning Electron Microscope (FESEM), which revealed uniform mixing of two phases. The variations in dielectric constant and dissipation factor as a function of frequency from 100 Hz to 1 MHz were measured in a Hioki LCR Hi-Tester. The dielectric constant and dielectric loss were found to decrease rapidly in the low frequency region and became almost constant in the high frequency region. The electrical conductivity deduced from the measured dielectric parameters has been analyzed and found that the conduction mechanism in these composites is in conformity with small polaron hopping model.
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The document describes an experiment where quantum state transfer was realized between atomic and photonic qubits. Efficiencies of 0.04 and 0.03 were measured for the read and write processes respectively. It is estimated that implementing a second node and joint detection of signal photons could realize quantum repeater protocols and distant teleportation of atomic qubits at a rate of around 3 x 10-7 s-1. Improvements to efficiency through increasing optical thickness or eliminating transmission losses could increase the rate by several orders of magnitude. The results also demonstrate the possibility of multiple atomic qubits in a quantum node using multiple light beams.
Fabrication and electrical characteristic of quaternary ultrathin hf tiero th...
This document describes the fabrication and electrical characterization of quaternary ultrathin HfTiErO thin films grown by RF sputtering for MOS devices. HfTiErO thin films with different Ti and Er contents were deposited on silicon substrates. The films were annealed at 500°C and 700°C. Atomic force microscopy showed the surface roughness decreased with annealing. X-ray photoelectron spectroscopy analysis showed the chemical compositions. MOS capacitors were fabricated and capacitance-voltage measurements showed the annealed films at 500°C had improved electrical properties like higher dielectric constant. The HfTiErO film with composition HfTi6Er4O annealed at 500°C achieved the best electrical performance of the
Similar to Graphene and graphene oxide (20)
EFFECT OF ULTRAVIOLET RADIATION ON STRUCTURAL PROPERTIES OF NANOWIRES
EFFECT OF ULTRAVIOLET RADIATION ON STRUCTURAL PROPERTIES OF NANOWIRES
A Study of Hole Drilling on Stainless Steel AISI 431 by EDM Using Brass Tube ...
A Study of Hole Drilling on Stainless Steel AISI 431 by EDM Using Brass Tube ...
1994 atomic structure of longitudinal sections of a pitch based carbon fiber ...
1994 atomic structure of longitudinal sections of a pitch based carbon fiber ...
Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1M...
Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1M...
Electromagnetic studies on nano sized magnesium ferrite
Electromagnetic studies on nano sized magnesium ferrite
Electromagnetic studies on nano sized magnesium ferrite
Electromagnetic studies on nano sized magnesium ferrite
the effect of nickel incorporation on some physical properties of epoxy resin
the effect of nickel incorporation on some physical properties of epoxy resin
Study of Structural and Dielectric properties of BaTiO3 Doped with Mg-Cu-Zn F...
Study of Structural and Dielectric properties of BaTiO3 Doped with Mg-Cu-Zn F...
Fabrication and electrical characteristic of quaternary ultrathin hf tiero th...
Fabrication and electrical characteristic of quaternary ultrathin hf tiero th...
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Nucleophilic substitution reactions
Nucleophilic substitution reactions in organicchemistry, sterochemistry and factors affecting it. SN1, Sn2, Sni.
Introductory discussion to 13 C NMR
Introductory discussion to 13 C NMR, THE 13C NUCLEUS, Proton-coupled and Proton decoupled 13C spectra.
Manufacturing technique of Nanomaterial's
Nanomaterials are engineered materials that are 100 nm or less in at least one dimension. They can be classified as zero-dimensional, one-dimensional, two-dimensional, or three-dimensional structures. There are two main methods for synthesizing nanomaterials - the top-down approach breaks down bulk materials into nano-sized pieces, while the bottom-up approach assembles atoms and molecules into nanostructures. Common bottom-up synthesis techniques include sol-gel processing, where a sol transitions into a gel network, and gas-phase methods like chemical vapor deposition, which use gas-phase precursors and reactions to form nanoparticles. Nanomaterials have a variety of applications in electronics, energy, medicine and other fields due to their unique
Bioleaching
This document discusses bioleaching, which uses microorganisms to dissolve metals from ores. The most common microorganisms used are Thiobacillus thiooxidants and Thiobacillus ferrooxidants. Bioleaching can occur directly via microbial contact with ores or indirectly by microbes producing leaching agents. Common applications include copper, uranium, gold and silver, and silica leaching. Bioleaching is used commercially in slope, heap, and in situ leaching with ores placed in piles or left in the ground and irrigated with microbes.
WASTE WATER TREATMENT
The document discusses waste water treatment. It defines sewage and its classes. Sewage contains domestic and industrial waste waters. Treatment is necessary to prevent hazards and pollution. Methods include single dwelling unit treatment with septic tanks and municipal treatment processes. The municipal process involves primary treatment to remove solids, secondary treatment using biological methods like activated sludge to reduce organic compounds, and sludge processing. Activated sludge treatment uses aeration of sewage to form flocs to oxidize organic matter. The sludge is further treated through anaerobic digestion or composting.
Air pollution
The Clean Air Act requires EPA to regulate six common air pollutants: particle pollution, ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants can harm health, the environment, and cause property damage. Of these, particle pollution and ground-level ozone pose the most widespread health risks. EPA sets standards and tracks emissions and air concentrations of these pollutants, though many still live in areas with unhealthy levels of one or more pollutants.
An approach to green chemistry via microwave radiation. applications of micro...
An approach to green chemistry via microwave radiation. applications of micro...Sheama Farheen Savanur
An approach to green chemistry via microwave radiation. applications of microwave synthesis, microwave assisted organic reactions.Water supply and sanitation
The document discusses water supply and sanitation. It makes three key points:
1. Safe drinking water and sanitation are important for public health but over 1 billion people lack access to safe water and 2 billion lack adequate sanitation as of 1990. This lack of access is a major cause of disease in developing countries.
2. Many diseases are transmitted through contaminated water, including viral, bacterial, protozoal and helminthic diseases. Unsafe water is a primary reason for ill health globally.
3. There are various methods of purifying water for individual and community use, including boiling, chemical disinfection, rapid sand filters and chlorination, which reduces bacteria and controls algae but has limitations
Infection process of agrobacterium
Agrobacterium detects wounded plant cell phenolics using its VirA/VirG two component sensor system, which induces expression of virulence genes. This allows VirD1 and VirD2 to cut T-DNA from the bacterial plasmid at the right and left borders. VirD2 then attaches to the exposed 5' end of T-DNA, and associates with VIP1 and VIP2 to target the complex to the plant cell nucleus. There, the T-DNA integrates into the plant genome and initiates gall formation.
Bacteria
This document summarizes key characteristics and features of bacteria from the domain Eubacteria. It outlines that bacteria are unicellular prokaryotes found everywhere that lack nuclei and have cell walls without cellulose. Bacteria can be motile using flagella or pili and have various cellular structures including cell membranes, capsules, cytoplasm, and endospores. Bacteria can be both beneficial and harmful to organisms, playing important roles in ecosystems, industries, and human health.
Vermicomposting and Biogas
Vermicomposting is a process where earthworms consume organic materials and produce a nutrient-rich fertilizer called vermicast. It improves soil quality, increases crop yields, and reduces greenhouse gas emissions compared to traditional composting. The common earthworm species used are Eisenia fetida and Lumbricus rebellus. Biogas is a renewable fuel produced from anaerobic digestion of organic wastes like agricultural residues and cattle dung. It is composed primarily of methane and carbon dioxide and provides a cleaner energy source for rural areas. The digestion occurs in an airtight tank called a digester through three stages - solubilization, acidogenesis, and methanogenesis - carried out by different bacterial species to
Theories of corrosion
There are three main theories of corrosion: acid theory, dry/chemical theory, and galvanic/electrochemical theory. Acid theory suggests corrosion occurs due to acids like carbon dioxide and moisture reacting with metals like iron. Dry theory states corrosion results from direct reactions between atmospheric gases like oxygen and metals. Galvanic theory describes how corrosion occurs electrochemically when two dissimilar metals contact a conducting liquid, forming anodes and cathodes. Wet corrosion is often faster than dry corrosion and produces rust at cathode sites rather than corrosion sites.
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Gadgets for management of stored product pests_Dr.UPR.pdf
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Wellprovedthatnogranariescanbefilledwithgrainswithoutinsectsastheharvestedproducecontainegg(or)larvae(or)pupae(or)adultinsectinthembecauseoffieldcarryoverinfestationwhichcannotbeavoidedindevelopingcountrieslikeIndia
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Embracing Deep Variability For Reproducibility and Replicability
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Embracing Deep Variability For Reproducibility and Replicability
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https://hal.science/hal-04582287
Post translation modification by Suyash Garg
overview of PTM helps to the students who wants to clear their basics about it.
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Graphene and graphene oxide
- 1. Graphene and Graphene Oxide: Synthesis, Properties, and Applications Presented By: Sheama Farheen Savanur
- 2. Introduction Graphene is an exciting material. [ 1 ] It has a large theoretical specific surface area (2630 m 2 g − 1 ), high intrinsic mobility (200 000 cm 2 v − 1 s − 1 ), [ 2 , 3 ] high Young’s modulus ( ∼ 1.0 TPa) [ 4 ] and thermal conductivity ( ∼ 5000 Wm − 1 K − 1 ), [ 5 ] and its optical transmittance ( ∼ 97.7%) and good electrical conductivityamong many other potential applications
- 3. Properties a)Morphology and Structure The graphene honeycomb lattice is composed of two equivalent sub-lattices of carbon atoms bonded together with σ bonds. Each carbon atom in the lattice has a π orbital that contributes to a delocalized network of electrons. freely suspended graphene has ‘intrinsic’ ripples, observed by transmission electron microscopy (TEM) studies. The microscopiccorrugations (Figure 1b ) were estimated to have a lateral dimension of about 8 to 10 nm and a height displacement of about 0.7 to 1 nm Ripples can be induced, [ 40 ] suggesting that the local electrical and optical properties of graphene could be altered through ‘ripple-engineering’ for possible application in devices. Apart from ‘intrinsic’ corrugations, graphene in real 3D space can have other ‘defects,’ including topological defects (e.g., pentagons, heptagons, or their combination), vacancies edges/cracks, adsorbed impurities, and so on
- 4. TEM images with a stated sub-Ångstrom resolution showed that both ‘armchair’ and ‘zigzag’ confi gurations could be formed during the edge reconstruction and ‘zigzag’ edges were observed to be particularly stable under electron irradiation at 80 kV acceleration voltage.
- 6. c) Mechanical Properties The mechanical properties of monolayer graphene including the Young’s modulus and fracture strength have been investigated by atomic force microscopy (AFM) It was reported that defect-free graphene has a Young’s modulus of 1.0 TPa and a fracture strength of 130 GPa.