scholarly journals Effect of Magnesium Oxide Nanoparticles on Water Glass Structure

2012 ◽  
Vol 12 (3) ◽  
pp. 9-12 ◽  
Author(s):  
A. Bobrowski ◽  
A. Kmita ◽  
M. Starowicz ◽  
B. Hutera ◽  
B. Stypuła
Keyword(s):  
Magnesium Oxide ◽  
Water Glass ◽  
Structural Changes ◽  
Glass Structure ◽  
Colloidal Suspensions ◽  
Ir Absorption ◽  
Structure Of Water ◽  
Magnesium Oxide Nanoparticles ◽  
Ir Absorption Spectra ◽  
Ft Ir

Abstract An attempt has been made to determine the effect of an addition of colloidal suspensions of the nanoparticles of magnesium oxide on the structure of water glass, which is a binder for moulding and core sands. Nanoparticles of magnesium oxide MgO in propanol and ethanol were introduced in the same mass content (5wt.%) and structural changes were determined by measurement of the FT-IR absorption spectra.

IR SPECTRAL INVESTIGATION OF THE xCuO(100 - x)[2B2O3 · As2O3] GLASS SYSTEM

2001 ◽  
Vol 15 (12n13) ◽  
pp. 385-390
Author(s):  
I. ARDELEAN ◽  
RALUCA CICEO-LUCACEL
Keyword(s):  
Vibrational Spectra ◽  
Glass Matrix ◽  
Room Temperature ◽  
Wave Number ◽  
Local Order ◽  
Ir Absorption ◽  
Monoclinic Form ◽  
Ir Absorption Spectra ◽  
Ft Ir ◽  
Wave Number Region

The infrared (FT–IR) absorption spectra for the glasses of the x CuO (100 - x)[ 2B 2 O 3 · As 2 O 3] system with 0 ≤ x ≤ 30 mol% CuO were measured in the wave number region 500–4000 cm -1 at room temperature following the KBr pellet techniques. The aim was to obtain information about the influence of CuO on the local order of the 2B 2 O 3 · As 2 O 3 glass matrix. The interpretation of the obtained vibrational spectra revealed the presence of BO 3, BO 4 units, boroxol rings and the monoclinic form of vitreous As 2 O 3 in the structure of investigated glasses.

THE STRUCTURAL STUDY OF Fe2O3–TeO2–B2O3–SrF2 GLASSES BY EPR AND IR SPECTROSCOPIES

2000 ◽  
Vol 14 (17n18) ◽  
pp. 653-661 ◽  
Author(s):  
I. ARDELEAN ◽  
F. CIORCAS ◽  
M. PETEANU ◽  
I. BRATU ◽  
V. IONCU
Keyword(s):  
Structural Changes ◽  
Mixed Valence ◽  
Ir Absorption ◽  
Iron Ions ◽  
Structural Units ◽  
Spectra Analysis ◽  
Valence States ◽  
Ir Absorption Spectra ◽  
Distorted Octahedral ◽  
Paramagnetic Ions

The local structure of Fe2O3–TeO2–B2O3–SrF2 glasses was studied by recording the EPR and IR absorption spectra. Structural changes and increasing glass stability were evidenced with the addition of Fe2O3 in the sample. The distribution of isolated paramagnetic ions in sites of strongly distorted octahedral symmetry was detected at low concentration (up to 3 mol% Fe2O3) by means of EPR measurements. For x>3 mol% Fe2O3, the clustered iron ions become progressively preponderent in the system. Mixed valence states of iron ions involved in dipole–dipole and superexchange type interactions were also evidenced. The IR spectra analysis revealed the BO3, BO4 and B2O6 units in the structure of tellurite investigated glasses. Among these structural units, those containing the threefold boron atoms are predominant.

scholarly journals FT-IR Absorption Spectra of Polycrystalline Pressed Sample soft he Organic Metals and Superconductorsa α-β-(BEDT-TTF)2I3 and(BEDT-TTF)2Cu(NCS)2

1989 ◽  
Vol 44 (4) ◽  
pp. 295-299 ◽  
Author(s):  
R. Zamboni ◽  
D. Schweitzer ◽  
H. J. Keller ◽  
C. Taliani
Keyword(s):  
Absorption Spectra ◽  
Special Interest ◽  
Electronic Devices ◽  
Organic Superconductors ◽  
Ir Absorption ◽  
Bulk Superconductivity ◽  
Organic Metals ◽  
Ir Absorption Spectra ◽  
Ir Reflectance ◽  
Ft Ir

Abstract IR absorption spectra of polycrystalline pressed samples of the organic metals α-(BEDT-TTF)2I3, β-BEDT-TTF)2I3 and (BEDT-TTF)2Cu(NCS)2 are presented and discussed. Normal protonated as well as deuterated materials were studied. The spectra range from 400 cm-1 to 5000 cm-1 and are similar to the IR reflectance spectra reported ealier. The data are of special interest in view of the fact that recently bulk superconductivity was observed in such polycrystalline samples of organic metals, and therefore the application of organic superconductors for the preparation of electronic devices seems possible.

scholarly journals An Eco-Friendly Approach to the Control of Pathogenic Microbes and Anopheles stephensi Malarial Vector Using Magnesium Oxide Nanoparticles (Mg-NPs) Fabricated by Penicillium chrysogenum

2021 ◽  
Vol 22 (10) ◽  
pp. 5096
Author(s):  
Amr Fouda ◽  
Mohamed A. Awad ◽  
Ahmed M. Eid ◽  
Ebrahim Saied ◽  
Mohammed G. Barghoth ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Penicillium Chrysogenum ◽  
Anopheles Stephensi ◽  
Cost Effective ◽  
Oxide Nanoparticles ◽  
Magnesium Oxide Nanoparticles ◽  
Ft Ir ◽  
Pathogenic Microbes ◽  
Main Components ◽  
Malarial Vector

The discovery of eco-friendly, rapid, and cost-effective compounds to control diseases caused by microbes and insects are the main challenges. Herein, the magnesium oxide nanoparticles (MgO-NPs) are successfully fabricated by harnessing the metabolites secreted by Penicillium chrysogenum. The fabricated MgO-NPs were characterized using UV-Vis, XRD, TEM, DLS, EDX, FT-IR, and XPS analyses. Data showed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with sizes of 7–40 nm at a maximum wavelength of 250 nm. The EDX analysis confirms the presence of Mg and O ions as the main components with weight percentages of 13.62% and 7.76%, respectively. The activity of MgO-NPs as an antimicrobial agent was investigated against pathogens Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans, and exhibited zone of inhibitions of 12.0 ± 0.0, 12.7 ± 0.9, 23.3 ± 0.8, 17.7 ± 1.6, and 14.7 ± 0.6 mm respectively, at 200 µg mL−1. The activity is decreased by decreasing the MgO-NPs concentration. The biogenic MgO-NPs exhibit high efficacy against different larvae instar and pupa of Anopheles stephensi, with LC50 values of 12.5–15.5 ppm for I–IV larvae instar and 16.5 ppm for the pupa. Additionally, 5 mg/cm2 of MgO-NPs showed the highest protection percentages against adults of Anopheles stephensi, with values of 100% for 150 min and 67.6% ± 1.4% for 210 min.

Quantitative Analysis of Sphene (CaTiOSiO4) and Wollastonite (CaSiO3) Crystallizations in Annealed Ceramic Frits by FT-IR Absorption Spectroscopy

1993 ◽  
Vol 47 (7) ◽  
pp. 965-972 ◽  
Author(s):  
S. K. Chen ◽  
H. S. Liu ◽  
C. S. Wu
Keyword(s):  
Absorption Spectra ◽  
Crystalline Phase ◽  
Least Squares Method ◽  
Broad Band ◽  
Correlation Coefficients ◽  
Ir Absorption ◽  
Scanning Electron Micrographs ◽  
Ir Absorption Spectra ◽  
Ft Ir

Results of this study have shown the feasibility of FT-IR absorption spectra (between 500 and 700 cm−1) for the quantitative determination of the nucleation and crystal growths of sphene (CaTiOSiO4) and wollastonite (β-CaSiO3) in two separate typical ceramic frits that have been annealed between 800 and 1000°C. Synthetic sphene ceramics and natural wollastonite, both of high purity and excellent crystallinity, serve as standard materials for calibration by the classical least-squares method (Basic Quant), employing the peaks of a sharp band at 561–566 cm−1 assigned to the SiO4 vibration and that of a shoulder (676 cm−1) of a broad band assigned to TiO6 vibrations. The correlation coefficients for these calibrations (absorbance vs. concentration of crystalline phase) are given as 0.9964, 0.9936, and 0.9937, respectively. Between annealing temperatures of 850 and 1000°C, both sphene and wollastonite phases appear to grow steadily in frit-S and frit-W, when the highest value of crystal growth is noted for specimens annealed at 1000°C, being approximately 80 wt % and 66 wt % of the formulated content, respectively. Scanning electron micrographs provide pictorial evidence to show that quantitative characterization of crystalline phase growth in ceramic frits by FT-IR absorption spectra is an appropriate technique.

Super-Dynamic-Range and Super-Quantization Methods for FT-IR Spectra

1993 ◽  
Vol 47 (4) ◽  
pp. 441-445 ◽  
Author(s):  
Kei-Ichiroh Minami ◽  
Hiroaki Okayama ◽  
Satoshi Kawata
Keyword(s):  
Fourier Transform ◽  
Numerical Methods ◽  
Infrared Spectrum ◽  
Dynamic Range ◽  
Full Range ◽  
Sampling Rate ◽  
Ir Absorption ◽  
Ir Absorption Spectra ◽  
Ft Ir ◽  
Spectrum Data

Numerical methods are proposed for expanding the dynamic range and increasing the quantization resolution of Fourier transform infrared spectrum data. In these methods, an interferogram is oversampled at a rate higher than the Nyquist sampling rate. From the oversampled interferogram data, the full-range interferogram or the lost quantization bits are recovered by using the Gerchberg-Papoulis iterative algorithm, incorporating constraints on the amplitude range of the interferogram and on the band limitation and non-negativity of the spectrum. Experimental results for IR absorption spectra of cyclohexene are shown in order to demonstrate the capabilities of the methods.

scholarly journals Phytoassisted synthesis of magnesium oxide nanoparticles from Pterocarpus marsupium rox.b heartwood extract and its biomedical applications

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Manne Anupama Ammulu ◽  
K. Vinay Viswanath ◽  
Ajay Kumar Giduturi ◽  
Praveen Kumar Vemuri ◽  
Ushakiranmayi Mangamuri ◽  
...  
Keyword(s):  
Magnesium Oxide ◽  
Cost Effective ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Pterocarpus Marsupium ◽  
X Ray ◽  
Magnesium Oxide Nanoparticles ◽  
Cost Effective Method ◽  
Ft Ir ◽  
Crystalline Nature

Abstract Background Unlike chemical techniques, the combination of metal oxide nanoparticles utilizing plant concentrate is a promising choice. The purpose of this work was to synthesize magnesium oxide nanoparticles (MgO-NPs) utilizing heartwood aqueous extract of Pterocarpus marsupium. The heartwood extract of Pterocarpus marsupium is rich in polyphenolic compounds and flavonoids that can be used as a green source for large-scale, simple, and eco-friendly production of MgO-NPs. The phytoassisted synthesis of MgO is characterized by UV-Visible spectroscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with EDS (energy dispersive X-ray spectroscopy), and transmission electron microscopy (TEM). Results The formation of MgO-NPs is confirmed by a visual color change from colorless to dark brown and they displayed a wavelength of 310 nm in UV-Spectrophotometry analysis. The crystalline nature of the obtained biosynthesized nanoparticles are revealed by X-ray diffraction analysis. SEM results revealed the synthesized magnesium oxide nanoparticles formed by this cost-effective method are spherically shaped with an average size of < 20 nm. The presence of magnesium and oxygen were confirmed by the EDS data. TEM analysis proved the spherical shape of the nanoparticles with average particle size of 13.28 nm and SAED analysis confirms the crystalline nature of MgO-NPs. FT-IR investigation confirms the existence of the active compounds required to stabilize the magnesium oxide nanoparticles with hydroxyl and carboxyl and phenolic groups that act as reducing, stabilizing, and capping agent. All the nanoparticles vary in particle sizes between 15 and 25 nm and obtained a polydispersity index value of 0.248. The zeta-potential was measured and found to be − 2.9 mV. Further, MgO-NPs were tested for antibacterial action against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) by minimum inhibitory concentration technique were found to be potent against both the bacteria. The blended nanoparticles showed good antioxidant activity examined by the DPPH radical scavenging method, showed good anti-diabetic activity determined by alpha-amylase inhibitory activity, and displayed strong anti-inflammatory activity evaluated by the albumin denaturation method. Conclusions The investigation reports the eco-friendly, cost-effective method for synthesizing magnesium oxide nanoparticles from Pterocarpus marsupium Rox.b heartwood extract with biomedical applications. Graphical abstract

Time-Resolved Step-Scan FT-IR Spectroscopy of the Photodynamics of Carbonmonoxymyoglobin

1995 ◽  
Vol 49 (6) ◽  
pp. 702-708 ◽  
Author(s):  
Susan E. Plunkett ◽  
James L. Chao ◽  
Thomas J. Tague ◽  
Richard A. Palmer
Keyword(s):  
Ir Spectroscopy ◽  
Structural Changes ◽  
Biological Molecules ◽  
Single Frequency ◽  
Ir Absorption ◽  
Time Resolved ◽  
Ft Ir ◽  
Ir Instrumentation ◽  
Protein Response ◽  
Ft Ir Spectroscopy

The kinetics of protein response and of CO recombination after photolysis of the Fe-CO bond in carbonmonoxymyoglobin have been monitored via time-resolved step-scan FT-IR absorption difference spectroscopy in D2O solution. Although the initial photodissociation is too fast to observe with currently available FT-IR instrumentation, we have been able to correlate the CO recombination kinetics with protein secondary structural changes via changes in the amide I band of the polypeptide chain with microsecond time resolution. The spectral and kinetic data corroborate and confirm previously published single-frequency infrared studies. This is the first application of time-resolved step-scan FT-IR spectroscopy in the absorbance difference mode to study the photodynamics of an aqueous protein solution at room temperature. This work also demonstrates the potential of the technique for the sub-microsecond kinetic analysis of other biological molecules of interest.

Antibacterial activity of magnesium oxide nanoparticles prepared by Calcination method

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Diffusion Method ◽  
Oxide Nanoparticles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Magnesium Oxide Nanoparticles ◽  
Agar Disc

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.

Near-IR Absorption Spectra for the Buckminsterfullerene Anions: An Experimental and Theoretical Study

1992 ◽  
Author(s):  
Del R. Lawson ◽  
Daniel L. Feldheim ◽  
Colby A. Foss ◽  
Peter K. Dorhoug ◽  
C. M. Elliott
Keyword(s):  
Absorption Spectra ◽  
Theoretical Study ◽  
Ir Absorption ◽  
Near Ir ◽  
Ir Absorption Spectra
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