Effect of fluorine on surface tension of CaO-SiO2-Al2O3-Na2O-CaF2 mold flux

2021 ◽  
Vol 118 (3) ◽  
pp. 316
Author(s):  
Qiang Gao ◽  
Longhu Cao
Keyword(s):  
Surface Tension ◽  
Mold Flux ◽  
Complex Structure ◽  
Change Mechanism ◽  
Ft Ir ◽  
Higher Temperature ◽  
Oxygen Anions ◽  
Cylinder Method ◽  
Silicon Oxygen

The surface tension of mold flux is an important parameter for controlling the quality of continuous billet, affected deeply by the compositions of mold flux and temperature, andclosed related with the structure of mold flux. In the present study, the effect of CaF2and temperature on the surface tension of CaO-SiO2-Al2O3-Na2O-CaF2 mold flux melts is investigated by the pulling cylinder method; furthermore, the structure of melts is determined by FT-IR spectroscopy to analyze the change mechanism of surface tension. The results indicate that the variation of surface tension is in accord with that of structure of melts. The surface tension of melt decreases with the increase of CaF2 mass fraction, and this tendency becomes more apparent at higher temperature. The FT-IR spectra show thatboth the amount of Obandthe degree of structural polymerization of melts decrease as the CaF2 content increases. This is because the Si-Ob bonds in the [SiO4]-tetrahedrons are broken by F− and transformed into Si-F bonds, and the silicon-oxygen anions with more complex structure were depolymerized into silicon-oxygen anions containing fluorine with simpler structure, resulting in an increase of Si-F saturated bonds on the melt surface, and thusreducing the surface tension of melts.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

Automation of selected brazes' dynamic properties in high-temperatures' measurement process

2013 ◽  
Vol 18 (2-3) ◽  
pp. 33-41
Author(s):  
Dominik Sankowski ◽  
Marcin Bakala ◽  
Rafał Wojciechowski
Keyword(s):  
Surface Tension ◽  
High Temperatures ◽  
Dynamic Properties ◽  
Automatic Measurement ◽  
Measurement Methodology ◽  
Joining Process ◽  
Wetting Force ◽  
Research Grant

Abstract The good quality of several manufactured components frequently depends on solidliquid interactions existing during processing. Nowadays, the research in material engineering focuses also on modern, automatic measurement methods of joining process properties, i.a. wetting force and surface tension, which allows for quantitative determination of above mentioned parameters. In the paper, the brazes’ dynamic properties in high-temperatures’ measurement methodology and the stand for automatic determination of braze’s properties, constructed and implmented within the research grant nr KBN N N519 441 839 - An integrated platform for automatic measurement of wettability and surface tension of solders at high temperatures, are widely described

scholarly journals Optimization of the Production Process and Product Quality of Titanate Nanotube–Drug Composites

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1406 ◽  
Author(s):  
Yasmin Ranjous ◽  
Géza Regdon ◽  
Klára Pintye-Hódi ◽  
Tamás Varga ◽  
Imre Szenti ◽  
...  
Keyword(s):  
Scanning Calorimetry ◽  
Good Solubility ◽  
Composite Formation ◽  
Alternative Materials ◽  
High Volatility ◽  
Ft Ir ◽  
Fast Disintegrating Tablets ◽  
As Solubility ◽  
Properties Of Composites

Recently, there has been an increasing interest in the application of nanotubular structures for drug delivery. There are several promising results with carbon nanotubes; however, in light of some toxicity issues, the search for alternative materials has come into focus. The objective of the present study was to investigate the influence of the applied solvent on the composite formation of titanate nanotubes (TNTs) with various drugs in order to improve their pharmacokinetics, such as solubility, stability, and bioavailability. Composites were formed by the dissolution of atenolol (ATN) and hydrochlorothiazide (HCT) in ethanol, methanol, 0.01 M hydrochloric acid or in ethanol, 1M sodium hydroxide, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), respectively, and then they were mixed with a suspension of TNTs under sonication for 30 min and vacuum-dried for 24 h. The structural properties of composites were characterized by SEM, TEM, FT-IR, differential scanning calorimetry (DSC), thermogravimetric (TG) analysis, and optical contact angle (OCA) measurements. Drug release was determined from the fast disintegrating tablets using a dissolution tester coupled with a UV–Vis spectrometer. The results revealed that not only the good solubility of the drug in the applied solvent, but also the high volatility of the solvent, is necessary for an optimal composite-formation process.

scholarly journals A Methodology Based on FT-IR Data Combined with Random Forest Model to Generate Spectralprints for the Characterization of High-Quality Vinegars

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1411
Author(s):  
José Luis P. Calle ◽  
Marta Ferreiro-González ◽  
Ana Ruiz-Rodríguez ◽  
Gerardo F. Barbero ◽  
José Á. Álvarez ◽  
...  
Keyword(s):  
Random Forest ◽  
Raw Materials ◽  
Principal Component ◽  
Hierarchical Cluster ◽  
Raw Material ◽  
Support Vector ◽  
Protected Designation Of Origin ◽  
Ft Ir

Sherry wine vinegar is a Spanish gourmet product under Protected Designation of Origin (PDO). Before a vinegar can be labeled as Sherry vinegar, the product must meet certain requirements as established by its PDO, which, in this case, means that it has been produced following the traditional solera and criadera ageing system. The quality of the vinegar is determined by many factors such as the raw material, the acetification process or the aging system. For this reason, mainly producers, but also consumers, would benefit from the employment of effective analytical tools that allow precisely determining the origin and quality of vinegar. In the present study, a total of 48 Sherry vinegar samples manufactured from three different starting wines (Palomino Fino, Moscatel, and Pedro Ximénez wine) were analyzed by Fourier-transform infrared (FT-IR) spectroscopy. The spectroscopic data were combined with unsupervised exploratory techniques such as hierarchical cluster analysis (HCA) and principal component analysis (PCA), as well as other nonparametric supervised techniques, namely, support vector machine (SVM) and random forest (RF), for the characterization of the samples. The HCA and PCA results present a clear grouping trend of the vinegar samples according to their raw materials. SVM in combination with leave-one-out cross-validation (LOOCV) successfully classified 100% of the samples, according to the type of wine used for their production. The RF method allowed selecting the most important variables to develop the characteristic fingerprint (“spectralprint”) of the vinegar samples according to their starting wine. Furthermore, the RF model reached 100% accuracy for both LOOCV and out-of-bag (OOB) sets.

A Comparison of FT-IR/PA and FT-IR/PBD Spectra of Powders

1986 ◽  
Vol 40 (5) ◽  
pp. 636-641 ◽  
Author(s):  
P. G. Varlashkin ◽  
M. J. D. Low ◽  
G. A. Parodi ◽  
C. Morterra
Keyword(s):  
Probe Beam ◽  
Beam Deflection ◽  
Signal To Noise ◽  
Absorption Bands ◽  
Ir Radiation ◽  
Laser Probe ◽  
Ft Ir ◽  
Better Than

FT-IR photoacoustic (PA) and also photothermal beam deflection (PBD) spectra were recorded with the same particulate samples (graphite, charcoal, aspirin, and silica) under the same conditions in order to compare the quality of the spectra obtainable with the two techniques. A PA cell fitted with windows for the PBD laser probe beam was used, and PA and PBD spectra of each sample were recorded at 8 cm−1 resolution at each of the four different interferometer scan velocities. Although the overall aspects of FT-IR/PA and FT-IR/PBD spectra are the same, the signal-to-noise ratios of PA spectra are appreciably better than those of PBD spectra because PBD detection is more prone to disturbance by vibration than is PA detection. Absorption bands appear at the same wavenumbers in PA and PBD spectra. However, the relative intensities of bands of PBD spectra depend on the absorptive properties of the powdered solids; with weak absorbers, some bands may not be detected at all. PAS can be used with all powders. PBDS is of little or no use for the examination of weakly absorbing powders unless they scatter IR radiation extensively.

Probing Inclusion Complexes of Pentoxifylline and Pralidoxim inside Cyclic Oligosaccharides by Physicochemical Methodologies

2019 ◽  
Vol 233 (8) ◽  
pp. 1109-1127
Author(s):  
Biraj Kumar Barman ◽  
Kanak Roy ◽  
Mahendra Nath Roy
Keyword(s):  
Surface Tension ◽  
Free Energy ◽  
Inclusion Complexes ◽  
Apparent Molar Volume ◽  
Nmr Spectra ◽  
Drug Delivery Systems ◽  
Surface Tension Data ◽  
H Nmr ◽  
Ft Ir ◽  
Inclusion Phenomena

Abstract Structurally different Molecules namely Pentoxifylline and Pralidoxim were chosen along with α-cyclodextrin and β-cyclodextrin to study host-guest inclusion phenomena. The formations of host guest inclusion complexes were confirmed by studying 1H-NMR spectra, FT-IR spectra, apparent molar volume and viscosity co-efficient. The stabilities of inclusion complexes were compared calculating the binding constant from UV-VIS spectroscopic study. The 1:1 stoichiometry of the inclusion complexes were also determined by analysing the Jobs plot and surface tension data. The values for Gibbs’ free energy were found negative for both the processes. Based on all the above experiments the inclusion processes were found feasible for both the compounds. These types of inclusion complexes are of high interest in the field of research and industry as these are used as drug delivery systems.

scholarly journals Microbiological Quality Assessment of Chicken Thigh Fillets Using Spectroscopic Sensors and Multivariate Data Analysis

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2723
Author(s):  
Evgenia D. Spyrelli ◽  
Christina Papachristou ◽  
George-John E. Nychas ◽  
Efstathios Z. Panagou
Keyword(s):  
Support Vector Machines ◽  
Discriminant Analysis ◽  
Microbiological Quality ◽  
Poultry Meat ◽  
Support Vector ◽  
Classification Models ◽  
Pseudomonas Spp ◽  
Vector Machines ◽  
Ft Ir

Fourier transform infrared spectroscopy (FT-IR) and multispectral imaging (MSI) were evaluated for the prediction of the microbiological quality of poultry meat via regression and classification models. Chicken thigh fillets (n = 402) were subjected to spoilage experiments at eight isothermal and two dynamic temperature profiles. Samples were analyzed microbiologically (total viable counts (TVCs) and Pseudomonas spp.), while simultaneously MSI and FT-IR spectra were acquired. The organoleptic quality of the samples was also evaluated by a sensory panel, establishing a TVC spoilage threshold at 6.99 log CFU/cm2. Partial least squares regression (PLS-R) models were employed in the assessment of TVCs and Pseudomonas spp. counts on chicken’s surface. Furthermore, classification models (linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), support vector machines (SVMs), and quadratic support vector machines (QSVMs)) were developed to discriminate the samples in two quality classes (fresh vs. spoiled). PLS-R models developed on MSI data predicted TVCs and Pseudomonas spp. counts satisfactorily, with root mean squared error (RMSE) values of 0.987 and 1.215 log CFU/cm2, respectively. SVM model coupled to MSI data exhibited the highest performance with an overall accuracy of 94.4%, while in the case of FT-IR, improved classification was obtained with the QDA model (overall accuracy 71.4%). These results confirm the efficacy of MSI and FT-IR as rapid methods to assess the quality in poultry products.

scholarly journals Multicriterial Evaluation of the Transport and Logistic System of the Moscow Region

2021 ◽  
Vol 334 ◽  
pp. 02029
Author(s):  
Vasily Demin ◽  
Alexey Terentyev
Keyword(s):  
Radio Frequency ◽  
Control Method ◽  
Complex Structure ◽  
Moscow Region ◽  
Logistics System ◽  
System Parameters ◽  
Complex Problems ◽  
Control Technologies ◽  
And Control

The article deals with the direction of solving complex problems of interaction between the elements of the transport and logistics system of the Moscow region as a complex structure of management methods in multi-criteria systems and technologies for monitoring the quality of processes. The control method should optimize the system parameters, and control technologies (radio frequency cargo identification) implement feedback in the system.

scholarly journals Properties of Humic Acids in Meadow Soils Irrigated With the Slope-And Flooding System

2021 ◽  
Author(s):  
Magdalena Banach-Szott ◽  
Andrzej Dziamski
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Soil Samples ◽  
Hydrophobic Properties ◽  
Irrigation Ditch ◽  
Ft Ir ◽  
Degree Of Maturity

Abstract The aim of the research has been to determine the effect of many-year irrigation of unique grasslands on the properties of humic acids defining the quality of organic matter. The research was performed based on the soil (Albic Brunic Arenosol, the A, AE and Bsv horizons) sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years, applying the slope-and-flooding system; the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS range, hydrophilic and hydrophobic properties and the infrared spectra were produced. The research results have shown that the HAs properties depended on the depth and the distance from the irrigation ditch. The HAs of the A horizon of the soils were identified with a lower “degree of maturity”, as reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR spectra, as compared with the HAs of the Bsv horizon. The HAs molecules of the soils sampled furthest from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled within the closest distance. The results have demonstrated that many-year grassland irrigation affected the structure and the properties of humic acids.

Modelling the reduction of zinc from oxide melt

2021 ◽  
pp. 18-22
Author(s):  
A. S. Vusikhis ◽  
E. N. Selivanov ◽  
L. I. Leontiev ◽  
S. N. Tyushnyakov
Keyword(s):  
Experimental Data ◽  
Carbon Monoxide ◽  
Basic Research ◽  
Metallic Phase ◽  
Thermodynamic Modelling ◽  
Reduction Degree ◽  
Similar Reduction ◽  
Oxide Melt ◽  
Higher Temperature

For predicting the results of sparging processes to understand how much metal can be reduced from oxide melt, a method of thermodynamic modelling has been developed that ensures approximation to real systems in which the metallic phase and gases are removed from the liquid at a certain interval. The key principle of this method is that equilibrium is determined for every single portion of introduced gas, and the concentration of oxides of the reduced metals in each cycle is taken from the previous data. Such approach enables a very close simulation of real processes so that one can have an idea about the quality of reactions taking place in pyrometallurgical units. When the thermodynamic modelling method was applied to the processes of iron and nickel reduction, the obtained results well matched the experimental data. A comparative analysis was carried out to understand how the temperature T and the amount of introduced gas VСО or VН2 influence the process of zinc reduction from oxide melt. For the purposes of modelling, a B2O3 – CaO – ZnO melt was used with the B2O3/CaO ratio equal to 3 (which corresponds to the eutectic composition) and with the initial ZnO concentration in the range from 3 to 12 %; the temperature range used was 1273–1673 K. The concentration of zinc oxide СZnO in the melt, as well as the reduction degree Zn were analyzed. The correlation dependences СZnO, φZn = f(C0, T, VCO or VH2) are presented in the form of second order polynomials. Reduction of zinc with hydrogen is a more intense process than when zinc is reduced with carbon monoxide. Therefore, less gas is required to reach a similar reduction degree. A higher temperature facilitates the reduction of zinc while less СО or Н2 is required to achieve the target reduction degree φZn. Irrespective of the initial composition of the melt, it takes 1.5 times less hydrogen that carbon monoxide to obtain the unit mass of zinc with the process temperature being the same. The obtained data explain the changing zinc distillation performance when changing the temperature. The established relationships between CZnO and φZn and the temperature and the amount of introduced gas are useful for predicting the zinc distillation performance and can be used as basic relationships for analyzing experimental data. This research was funded by the Russian Foundation for Basic Research under the Project No. 18-29-24093мк.

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