scholarly journals Technology for obtaining modified oil sorbents

2021 ◽  
Vol 82 (4) ◽  
pp. 247-253
Author(s):  
R. Mejri ◽  
Y. S. Peregudov ◽  
E. M. Gorbunova
Keyword(s):  
Magnetic Properties ◽  
High Efficiency ◽  
Low Cost ◽  
Oil Products ◽  
Solid Surfaces ◽  
Environmental Friendliness ◽  
Transmission Electron ◽  
Oil Sorbent ◽  
High Degree ◽  
Oil And Oil Products

Expediency of using natural glauconite material as a basis for the production of an environmentally friendly sorbent with hydrophobic and magnetic properties for liquidating oil and oil products spills mechanically and using a magnetic field has been substantiated and experimentally proved. Fractional, elemental and oxide compositions of the original mineral have been studied. The structure of glauconite fraction 0.045-0.1 mm has been investigated by transmission electron microscopy. It was found that the surface of the sample particles is heterogeneous with a large number of pores and cracks. Based on the experimental data, the optimal conditions for the production and use of powder and granular sorbents based on glauconite with specified properties were determined, at which a high degree of recovery (more than 90%) of oil with water and hard surfaces. The optimum temperature for obtaining a magnetic oil sorbent is 400 °C. The doses of stearic acid and iron (III) oxide were established at 5 wt. %, which provide hydrophobicity and magnetic properties to the synthesized sorbent. A high degree of oil (97%) and oil (98%) recovery when using a sorbent is achieved at a ratio of 1: 10 to sorbate. To eliminate oil and oil product spills, it is proposed to use granular ferromagnetic sorbents obtained by introducing carboxymethyl cellulose into the modified glauconite composition. oil and oil products granular sorbent increases in comparison with the original mineral by 1.2–2.2 times. Technological schemes for obtaining ferromagnetic hydrophobic and granular sorbents based on glauconite for collecting oil and oil products from water and solid surfaces have been developed. The synthesized sorbents are characterized by high efficiency, low cost, and environmental friendliness.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Heteroepitaxy of Ge on Cube-Textured Ni(001) Foils Through CaF2 Buffer Layer

MRS Advances ◽  
2016 ◽  
Vol 1 (43) ◽  
pp. 2947-2952
Author(s):  
L. Chen ◽  
Z.-H. Lu ◽  
T.-M. Lu ◽  
I. Bhat ◽  
S.B. Zhang ◽  
...  
Keyword(s):  
Buffer Layer ◽  
High Efficiency ◽  
Electron Backscatter Diffraction ◽  
Low Cost ◽  
High Quality ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Electron Backscatter ◽  
Image Position ◽  
Backscatter Diffraction

ABSTRACTEpitaxial Ge films are useful as a substrate for high-efficiency solar cell applications. It is possible to grow epitaxial Ge films on low cost, cube textured Ni(001) sheets using CaF2(001) as a buffer layer. Transmission electron microscopy (TEM) analysis indicates that the CaF2(001) lattice has a 45o in-plane rotation relative to the Ni(001) lattice. The in-plane epitaxy relationships are CaF2[110]//Ni[100] and CaF2[$\bar 1$10]//Ni[010]. Energy dispersive spectroscopy (EDS) shows a sharp interface between Ge/CaF2 as well as between CaF2/Ni. Electron backscatter diffraction (EBSD) shows that the Ge(001) film has a large grain size (∼50 μm) with small angle grain boundaries (< 8o). The epitaxial Ge thin film has the potential to be used as a substrate to grow high quality III-V and II-VI semiconductors for optoelectronic applications.

scholarly journals Superhydrophobic photothermal icephobic surfaces based on candle soot

2020 ◽  
Vol 117 (21) ◽  
pp. 11240-11246 ◽  
Author(s):  
Shuwang Wu ◽  
Yingjie Du ◽  
Yousif Alsaid ◽  
Dong Wu ◽  
Mutian Hua ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
High Energy ◽  
Silica Shell ◽  
Oxygen Plasma Treatment ◽  
Human Society ◽  
Environmental Friendliness ◽  
Candle Soot ◽  
Low Surface Energy ◽  
Ice Accumulation

Ice accumulation causes various problems in our daily life for human society. The daunting challenges in ice prevention and removal call for novel efficient antiicing strategies. Recently, photothermal materials have gained attention for creating icephobic surfaces owing to their merits of energy conservation and environmental friendliness. However, it is always challenging to get an ideal photothermal material which is cheap, easily fabricating, and highly photothermally efficient. Here, we demonstrate a low-cost, high-efficiency superhydrophobic photothermal surface, uniquely based on inexpensive commonly seen candle soot. It consists of three components: candle soot, silica shell, and polydimethylsiloxane (PDMS) brushes. The candle soot provides hierarchical nano/microstructures and photothermal ability, the silica shell strengthens the hierarchical candle soot, and the grafted low-surface-energy PDMS brushes endow the surface with superhydrophobicity. Upon illumination under 1 sun, the surface temperature can increase by 53 °C, so that no ice can form at an environmental temperature as low as −50 °C and it can also rapidly melt the accumulated frost and ice in 300 s. The superhydrophobicity enables the melted water to slide away immediately, leaving a clean and dry surface. The surface can also self-clean, which further enhances its effectiveness by removing dust and other contaminants which absorb and scatter sunlight. In addition, after oxygen plasma treatment, the surface can restore superhydrophobicity with sunlight illumination. The presented icephobic surface shows great potential and broad impacts owing to its inexpensive component materials, simplicity, ecofriendliness, and high energy efficiency.

Novel synthesis of AlN nanowires with controlled diameters

2001 ◽  
Vol 16 (11) ◽  
pp. 3133-3138 ◽  
Author(s):  
Jun Liu ◽  
X. Zhang ◽  
Yingjiu Zhang ◽  
Rongrui He ◽  
Jing Zhu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
High Efficiency ◽  
Low Cost ◽  
X Ray Diffraction ◽  
Synthesis Mechanism ◽  
X Ray ◽  
Novel Synthesis ◽  
Transmission Electron ◽  
New Synthesis

A relatively low-cost, high-efficiency method is reported to synthesize AlN nanowires, using carbon nanotubes as templates. The AlN nanowires were fabricated at 1100 °C, for 60 min. The diameters of the product could be roughly controlled by the sizes of carbon nanotubes selected as starting materials. The AlN nanowires obtained were among the thinnest ever known. X-ray diffraction, selected-area diffraction, energy dispersive spectroscopy, and high-resolution transmission electron microscopy, etc. were employed to characterize the products, which were found to be single crystals with some defects. The axes of the nanowires are normal to {1010} crystal planes. A new synthesis mechanism is proposed.

scholarly journals Enhanced Physical Absorption Properties of ZnO Nanorods by Electrostatic Self-Assembly with Reduced Graphene Oxide and Decorated with Silver and Copper Nanoparticles

2021 ◽  
Vol 19 (48) ◽  
pp. 66-78
Author(s):  
Lina Zeki Yahiya ◽  
Mohamed K. Dhahir
Keyword(s):  
Self Assembly ◽  
Low Cost ◽  
Zno Nanorods ◽  
Zinc Oxide Nanorods ◽  
Environmental Friendliness ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Oxide Nanorods ◽  
Scale Preparation

The preparation and characterization of innovative nanocomposites based on zinc oxide nanorods (ZNR) encapsulated by graphene (Gr) nanosheets and decorated with silver (Ag), and cupper (Cu) nanoparticles (NP) were studied. The prepared nanocomposites (ZNR@Gr/Cu-Ag) were examined by different techniques including Field Emission Scanning Electron Microscope (FESEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), UV-Vis spectrophotometer and fluorescence spectroscopy. The results showed that the ZNR has been good cover by five layers of graphene and decorated with Ag and Cu NPs with particles size of about 10-15 nm. The ZNR@Gr/Cu-Ag nanocomposites exhibit high absorption behavior in ultraviolet (UV) region of spectrum. In comparison with ZNR, the ZNR@Gr/Cu-Ag nanocomposites reveal superior absorption in the entire region of 387–1000 nm. Moreover, the band gap decreases from 3.2 eV of ZNR to 1.2 eV for ZNR@Gr/Cu-Ag nanocomposites. Taking into account the superiority of ZNR@Gr/Cu-Ag nanocomposites in terms of easy fabrication, low cost method, and environmental friendliness which made it favorable for huge-scale preparation in many applications such as water splitting, sensor, solar cell, antibacterial and optoelectronic devices.

Study of Thermally Expanded Graphite for Rehabilitation of Oil-Polluted Water Ecosystems

2021 ◽  
Vol 25 (7) ◽  
pp. 37-41
Author(s):  
Z.H. Sultigova ◽  
B.A. Temirkhanov ◽  
R.D. Archakova
Keyword(s):  
High Efficiency ◽  
Oil Spills ◽  
Expanded Graphite ◽  
Oil Products ◽  
Polluted Water ◽  
Porous System ◽  
Specific Pore Volume ◽  
Mercury Porosimeter ◽  
Water Ecosystems ◽  
Oil And Oil Products

The properties of sorbent on the basis of thermoexplite (STRG) obtained from the engineering center of IngSU "Development of modified sorbation materials" have been investigated. This sorbent is proposed to be used in the elimination of oil spills and products of its processing from the water surface. The porosity of the STGR was analyzed using a mercury porosimeter Pascal 140 and 240 Evo. It is shown that the investigated sample is a volumetric porous tool with a specific pore volume of 35.5 cm3/g. It is found that the available porosity is more than 97.2%. The pore size distribution was studied. Based on the data of the porous system, research on the sorption of oil and oil products by this sorbent. Shown is the high efficiency of STRG in cleaning the water mirror from oil and oil products. The main properties of oil sorbents have been investigated.

scholarly journals Tunable magnetism on the lateral mesoscale by post-processing of Co/Pt heterostructures

2015 ◽  
Vol 6 ◽  
pp. 1082-1090 ◽  
Author(s):  
Oleksandr V Dobrovolskiy ◽  
Maksym Kompaniiets ◽  
Roland Sachser ◽  
Fabrizio Porrati ◽  
Christian Gspan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Behavior ◽  
Basic Research ◽  
Post Processing ◽  
Transmission Electron ◽  
Spin Dependent Transport ◽  
Complementary Approach ◽  
Dependent Transport ◽  
High Degree

Controlling magnetic properties on the nanometer-scale is essential for basic research in micro-magnetism and spin-dependent transport, as well as for various applications such as magnetic recording, imaging and sensing. This has been accomplished to a very high degree by means of layered heterostructures in the vertical dimension. Here we present a complementary approach that allows for a controlled tuning of the magnetic properties of Co/Pt heterostructures on the lateral mesoscale. By means of in situ post-processing of Pt- and Co-based nano-stripes prepared by focused electron beam induced deposition (FEBID) we are able to locally tune their coercive field and remanent magnetization. Whereas single Co-FEBID nano-stripes show no hysteresis, we find hard-magnetic behavior for post-processed Co/Pt nano-stripes with coercive fields up to 850 Oe. We attribute the observed effects to the locally controlled formation of the CoPt L10 phase, whose presence has been revealed by transmission electron microscopy.

scholarly journals High Quality GaAs Epilayers Grown on Si Substrate Using 100 nm Ge Buffer Layer

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Wei-Cheng Kuo ◽  
Hung-Chi Hsieh ◽  
Wu Chih-Hung ◽  
Huang Wen-Hsiang ◽  
Chien-Chieh Lee ◽  
...  
Keyword(s):  
Buffer Layer ◽  
High Efficiency ◽  
Electron Cyclotron Resonance ◽  
Low Cost ◽  
Chemical Vapor ◽  
Buffer Layers ◽  
High Quality ◽  
Tandem Solar Cells ◽  
Hydrogen Flow ◽  
Transmission Electron

We present high quality GaAs epilayers that grow on virtual substrate with 100 nm Ge buffer layers. The thin Ge buffer layers were modulated by hydrogen flow rate from 60 to 90 sccm to improve crystal quality by electron cyclotron resonance chemical vapor deposition (ECR-CVD) at low growth temperature (180°C). The GaAs and Ge epilayers quality was verified by X-ray diffraction (XRD) and spectroscopy ellipsometry (SE). The full width at half maximum (FWHM) of the Ge and GaAs epilayers in XRD is 406 arcsec and 220 arcsec, respectively. In addition, the GaAs/Ge/Si interface is observed by transmission electron microscopy (TEM) to demonstrate the epitaxial growth. The defects at GaAs/Ge interface are localized within a few nanometers. It is clearly showed that the dislocation is well suppressed. The quality of the Ge buffer layer is the key of III–V/Si tandem cell. Therefore, the high quality GaAs epilayers that grow on virtual substrate with 100 nm Ge buffer layers is suitable to develop the low cost and high efficiency III–V/Si tandem solar cells.

scholarly journals History and recent developments in divergent electrolytes towards high-efficiency lithium–sulfur batteries – a review

2021 ◽  
Author(s):  
Srikanth Ponnada ◽  
Maryam Sadat Kiai ◽  
Demudu Babu Gorle ◽  
Annapurna Nowduri
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Storage System ◽  
Specific Capacity ◽  
Energy Storage System ◽  
Environmental Friendliness ◽  
System P ◽  
Lithium Sulfur Batteries ◽  
Recent Developments ◽  
Lithium Sulfur

Lithium–sulfur batteries, with a high specific capacity, low cost and environmental friendliness, could be investigated as a next-generation energy-storage system.

scholarly journals High efficiency method to obtain supercoiled DNA with a commercial plasmid purification kit.

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Antonietta Carbone ◽  
Flavia Marialucia Fioretti ◽  
Laura Fucci ◽  
Juan Ausió ◽  
Marina Piscopo
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Active Form ◽  
Standard Protocol ◽  
Supercoiled Dna ◽  
Supercoiled Form ◽  
Circular Form ◽  
Dna Production ◽  
High Degree ◽  
Plasmid Purification

Supercoiled state corresponds to the active form for plasmid applications. The relaxed circular form of plasmids is often inactive or poorly active. To obtain significant amounts of almost fully supercoiled DNA, we modified the standard protocol of a commercially available Qiagen plasmid purification kit. Our changes led to isolation of almost 100% of the plasmids in the supercoiled state. The modified protocol was used to purify different plasmids with consistent results. The purified plasmids maintain supercoiled state for about two months. The modified protocol is very advantageous because it allows easy DNA production with high degree of supercoiled form at low cost.

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