scholarly journals Green Synthesis and Characterization of Biosilica Produced from Sugarcane Waste Ash

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Rodrigo Heleno Alves ◽  
Thais Vitória da Silva Reis ◽  
Suzimara Rovani ◽  
Denise Alves Fungaro
Keyword(s):  
Silica Particle ◽  
Value Added ◽  
Acid Precipitation ◽  
Gel Formation ◽  
X Ray ◽  
A Value ◽  
Adsorption Analysis ◽  
Amorphous Nature ◽  
Chemical Techniques

In this study, ash from sugarcane waste was used in the synthesis of biosilica using alkaline extraction followed by acid precipitation. Different parameters that could influence the silica particle synthesis were evaluated. The ash and synthesized biosilica were characterized by a combination of spectroscopic and chemical techniques such as XRD, XRF, SEM, particle size analyser, N2 adsorption analysis, TGA, and FTIR. The best condition for biosilica production was achieved with fusion method and aging temperature of 80°C for 1 h during gel formation. X-ray powder diffraction pattern confirms the amorphous nature of synthesized silica. The purity of the prepared silica was 99% silica which was confirmed by means of XRF. The experimental data suggest that the sugarcane waste ash could be converted into a value-added product, minimizing the environmental impact of disposal problems.

scholarly journals Characterization of Chromium Compensated GaAs Sensors with the Charge-Integrating JUNGFRAU Readout Chip by Means of a Highly Collimated Pencil Beam

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1550
Author(s):  
Dominic Greiffenberg ◽  
Marie Andrä ◽  
Rebecca Barten ◽  
Anna Bergamaschi ◽  
Martin Brückner ◽  
...  
Keyword(s):  
Low Noise ◽  
State University ◽  
Noise Performance ◽  
X Ray ◽  
A Value ◽  
Resolution Capability ◽  
Sensor Properties ◽  
Pixel Pitch ◽  
Lower Noise

Chromium compensated GaAs or GaAs:Cr sensors provided by the Tomsk State University (Russia) were characterized using the low noise, charge integrating readout chip JUNGFRAU with a pixel pitch of 75 × 75 µm2 regarding its application as an X-ray detector at synchrotrons sources or FELs. Sensor properties such as dark current, resistivity, noise performance, spectral resolution capability and charge transport properties were measured and compared with results from a previous batch of GaAs:Cr sensors which were produced from wafers obtained from a different supplier. The properties of the sample from the later batch of sensors from 2017 show a resistivity of 1.69 × 109 Ω/cm, which is 47% higher compared to the previous batch from 2016. Moreover, its noise performance is 14% lower with a value of (101.65 ± 0.04) e− ENC and the resolution of a monochromatic 60 keV photo peak is significantly improved by 38% to a FWHM of 4.3%. Likely, this is due to improvements in charge collection, lower noise, and more homogeneous effective pixel size. In a previous work, a hole lifetime of 1.4 ns for GaAs:Cr sensors was determined for the sensors of the 2016 sensor batch, explaining the so-called “crater effect” which describes the occurrence of negative signals in the pixels around a pixel with a photon hit due to the missing hole contribution to the overall signal causing an incomplete signal induction. In this publication, the “crater effect” is further elaborated by measuring GaAs:Cr sensors using the sensors from 2017. The hole lifetime of these sensors was 2.5 ns. A focused photon beam was used to illuminate well defined positions along the pixels in order to corroborate the findings from the previous work and to further characterize the consequences of the “crater effect” on the detector operation.

scholarly journals Preparation and characterization of polyani-line/polyvinyl alcohol nanocomposite by laser irradiation

2017 ◽  
Vol 6 (4) ◽  
pp. 77
Author(s):  
N A M Shahin ◽  
S Abd El Mongy ◽  
R Kamal ◽  
A B El- Bially ◽  
A A Shabaka ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Relaxation Time ◽  
Polyvinyl Alcohol ◽  
Laser Irradiation ◽  
Imaginary Part ◽  
Electronic Transition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Nature

Polyaniline (PANI) - Polyvinyl alcohol (PVA) nanocomposite were prepared using laser irradiation method. X-ray diffraction results showed that, (PANI/PVA) nanocomposite exhibited amorphous nature of polymer. The electronic transition will be studied using Ultraviolet-Visible spectrometer (UV-Vis). The real part of dielectric constant (έ) and imaginary part (ε") were studied. Also, the relaxation time was calculated.

Sol-Gel Synthesis of Nanocrystalline Ni-Ferrite and Co-Ferrite Redox Materials for Thermochemical Production of Solar Fuels

2014 ◽  
Vol 1675 ◽  
pp. 203-208 ◽  
Author(s):  
Rahul R. Bhosale ◽  
Ivo Alxneit ◽  
Leo L. P. van den Broeke ◽  
Anand Kumar ◽  
Mehak Jilani ◽  
...  
Keyword(s):  
Sol Gel ◽  
Solar Fuels ◽  
Bet Surface Area ◽  
Mixed Solution ◽  
Gel Formation ◽  
Thermochemical Cycles ◽  
X Ray ◽  
Thermogravimetric Analyzer ◽  
Sol Gel Synthesis

ABSTRACTIn this contribution, we report the synthesis and characterization of NixFe3-xO4 and CoxFe3-xO4 redox nanomaterials using sol-gel method. These materials will be used to produce solar fuels such as H2 or syngas from H2O and/or CO2 via solar thermochemical cycles (STCs). For the sol-gel synthesis of ferrites, the Ni, Co, Fe precursor salts were dissolved in ethanol and propylene oxide (PO) was added dropwise to the well mixed solution as a gelation agent to achieve gel formation. Freshly synthesized gels were aged, dried, and calcined by heating them to 600°C in air. The calcined powders were characterized by powder x-ray diffractometer (XRD), BET surface area, as well as scanning (SEM) and transmission (TEM) electron microscopy. Their suitability to be used in STCs for the production of solar fuels was assessed by performing several reduction/re-oxidation cycles using a thermogravimetric analyzer (TGA).

scholarly journals Inducing Nematic Ordering of Cellulose Nanofibers using Osmotic Dehydration

2018 ◽  
Author(s):  
Valentina Guccini ◽  
Shun Yu ◽  
Michael Agthe ◽  
Korneliya Gordeyeva ◽  
Yulia Trushkina ◽  
...  
Keyword(s):  
Osmotic Dehydration ◽  
Cellulose Nanofibers ◽  
Gel Formation ◽  
Fractal Structures ◽  
Maximum Order ◽  
X Ray ◽  
Nematic Ordering ◽  
X Ray Scattering ◽  
Wide Range

<div><div><p>The formation and characterization of nematically-ordered CNF materials (maximum order parameter f ≈ 0.8) has been studied by polarized optical microscopy, small angle x-ray scattering (SAXS), and rheological measurements as a function of CNF concentration. The wide range of CNF concentrations, from 0.5 wt% to 4.9 wt%, is obtained using osmotic dehydration with PEG. At concentrations >1.05 wt% the CNF suspension crosses an isotropic-anisotropic transition that is accompanied by a dramatic increase of the optical birefringence. The resulting nanostructures are depicted by a hierarchical model with mass fractal structures that converge into co-existing nematically-ordered regions and network-like regions, in which the correlation distances decrease upon increasing concentration. The use of rapid, upscaleble osmotic dehydration is an effective method to increase the concentration of CNF suspensions while partly circumventing the gel formation. The facile formation of highly ordered fibers can result in materials with interesting macroscopic properties.</p></div></div>

scholarly journals CRYSTAL STRUCTURE ANALYSIS OF CuCrO2 BASED ON XRD DATA USING GSAS SOFTWARE

2021 ◽  
Vol 4 (1) ◽  
pp. 7
Author(s):  
Lalu A. Didik ◽  
Muh. Wahyudi
Keyword(s):  
Reference Data ◽  
Measurement Data ◽  
Lattice Parameter ◽  
Crystal Structure Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
A Cell ◽  
Parameter Values

The synthesis of CuCrO2 crystals by mixing CuO and Cr2O3 has been carried out using the solid reaction method at a temperature of 1200 0C. The characterization of the structure used XRD and analyzed using GSAS software. The results of characterization using XRD showed that no other phase occurred. This is evidenced by the absence of other phases from the results of refinement of measurement data with reference data and a value of χ 2 which is 1.222. The lattice parameter values resulting from the refinement of the CuCrO2 X-ray diffraction pattern are a = b = 2.9715 Å and c = 17.1104 Å with a cell volume of 130.584 Å 3. In addition to the lattice parameter values, the distance between atoms was also obtained, both Cu - O, Cr - Cr, and Cr - O.

Preparation and Characterization of Doped Nanometer TiO2

2007 ◽  
Vol 26-28 ◽  
pp. 649-652 ◽  
Author(s):  
Lin Yun Song ◽  
Yu Cheng Wu ◽  
Xiang Fen Lu
Keyword(s):  
Degradation Rate ◽  
Sol Gel ◽  
Complexing Agent ◽  
Gel Formation ◽  
X Ray Diffraction ◽  
Nano Tio2 ◽  
Doped Tio2 ◽  
X Ray ◽  
Different Temperatures

With Ti(OBu)4 as precursor, and HAC as complexing agent, pure and Fe-doped TiO2 gelatins were prepared by sol-gel method. During the process of gel formation, metal ions were dispersed into the porous TiO2 matrix. Then, powders of pure nano-TiO2 and Fe-doped nano-TiO2 were prepared by drying, grinding and calcining at different temperatures. The grain size and phase structure of pure and Fe-doped TiO2 after calcined at different temperatures, were studied by X-ray diffraction (XRD) and Beckman Coulter Sorption Analysis. The results showed that, the Fe3+-TiO2 had better photocatalytic activity in degradation rate of methyl orange under sunlight. The degradation rate was up to 93% as the system was placed under sunlight for 5 h. The optimum calcination temperature for the best catalytic activity was determined to be 500°C, and the mechanism was discussed.

Process Optimization and Characterization of Pectin Derived from Underexploited Pineapple Peel Biowaste as a Value-Added Product

2021 ◽  
pp. 107141
Author(s):  
Chellam Somasundarar Shivamathi ◽  
Sathaiah Gunaseelan ◽  
Michael Rahul Soosai ◽  
Nagamalai Sakthi Vignesh ◽  
Perumal Varalakshmi ◽  
...  
Keyword(s):  
Process Optimization ◽  
Value Added ◽  
A Value ◽  
Pineapple Peel

STRUCTURAL CHARACTERIZATION OF SULFOBORATE GLASSES CONTAINING MAGNESIUM OXIDE

2016 ◽  
Vol 78 (6-11) ◽  
Author(s):  
S. A. Dalhatu ◽  
R. Hussin ◽  
Karim Deraman
Keyword(s):  
Molar Volume ◽  
Alkaline Earth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infra Red ◽  
Amorphous Nature ◽  
Quenching Method ◽  
The Fourier Transform ◽  
Glass Compositions

Magnesium sulfoborate glasses of different compositions were prepared using melt quenching method with the purpose of using it for optical properties. The Fourier Transform Infra-red (FTIR) Spectroscopy, Nuclear Magnetic Resonance (NMR) and X-Ray Diffraction (XRD) have been carried out. Density and molar volume have been evaluated and analysed. From the results of XRD, the absent of discrete and continuous sharp peaks confirmed the amorphous nature of the glass compositions while the results from both FTIR and NMR revealed the existence of BO3, BO4 units. Addition of MgO to sulfoborate influenced the conversion of the dominant BO3 groups to BO4 groups. The BO4 groups are known for creating complex defects that transform into that stable trap good for optical phenomena. It was observed that the density of glass increases while the molar volume is decreases with respect to increase in concentration of alkaline earth oxide in the glass compositions.

scholarly journals Dc electrical properties of semiconducting cobalt oxide substituted lead vanadate glasses

2018 ◽  
Vol 7 (4.5) ◽  
pp. 625
Author(s):  
K. K. Brahmananda Rao ◽  
K. V. Ramesh ◽  
P. Tejeswara Rao
Keyword(s):  
Electrical Conductivity ◽  
Present System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Electrical Conductivity ◽  
Amorphous Nature ◽  
Lead Vanadate ◽  
Vanadate Glasses ◽  
Dc Electrical Properties

Semiconducting lead vanadate glasses with CoO substitution represented as xCoO-(50-x) PbO-50V2O5 with x=5,10 and 15 mol% were prepared by melt quenching technique. They were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), differential thermal analysis (DTA) and DC electrical conductivity. The overall features of these XRD curves reveal the amorphous nature of present glasses. SEM investigations were conducted for the micro structural characterization of V2O5 crystal phases. Density was observed to decrease with an increase in CoO content. The dc electrical conductivity of the present system increases as the concentration of substitution of CoO increases with 5molpercentage to 15molpercentage.  

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