Aspects of determining the surface activity of dispersed systems based on mineral powders

2021 ◽  
Vol 0 (7) ◽  
pp. 30-36
Author(s):  
A. V. Shamanina ◽  
◽  
V. M. Kononova ◽  
V. E. Danilov ◽  
A. M. Ayzenstadt ◽  
...  
Keyword(s):  
Surface Activity ◽  
Ball Mill ◽  
Free Surface Energy ◽  
Mass Energy ◽  
Specific Mass ◽  
Dispersed Systems ◽  
Mechanical Dispersion ◽  
Total Potential ◽  
A Value ◽  
Time Parameters

Samples of mechanically activated quartz sand powder were obtained by grinding on a planetary ball mill to different specific surface values (1200-3000 m2/kg). For these dispersed systems, the surface activity criterion (kS) was calculated as a value equal to the ratio of the free surface energy of the system to its total potential value (specific mass energy of atomization). It is established that the value of this criterion does not depend linearly on the time parameters of mechanical dispersion of the initial samples. The kS parameter is recommended for evaluating the effectiveness of the process of mechanical activation of rocks.

scholarly journals Evaluation of the Tung’s fruits as a possible source of sustainable energy

2017 ◽  
Vol 39 (4) ◽  
pp. 487
Author(s):  
Nelson Zornitta ◽  
Willian Cézar Nadaleti ◽  
Reinaldo Aparecido Bariccatti ◽  
Reginaldo Ferreira dos Santos ◽  
Rafael Linzmeyer Zornitta ◽  
...  
Keyword(s):  
Potassium Hydroxide ◽  
Second Generation ◽  
Seed Oil ◽  
Sustainable Energy ◽  
Specific Mass ◽  
Drying Characteristics ◽  
Residual Biomass ◽  
A Value ◽  
Fruit Oil ◽  
Acid Index

 Tung’s fruits (Aleurites fordii) produce oil of great applicability in the market of painting and covering due to its drying characteristics. Tung’s oil may be an alternative for the production of new biofuels. In this study, it was evaluated the energetic potential of the fruit, oil and biodiesel obtained from the Tung. The average yielding of the extracted seed oil was 50.6%, a value similar to those presented in literature. Moreover, its density presented a value of 931.5 g L-1 and its acid index, 4.5 mg KOH g-1. In the last step of this study, biodiesel was produced by basic methyl route using potassium hydroxide. The specific mass of the produced biodiesel was 909.2 kg m-3 at 20°C; its acid index was 0.473 mg KOH g-1 and its flash point was 178°C. The values of heating values in natura and the low level of ashes in the residual biomass makes the Tung’s fruits a promising renewable clean source of energy of second generation fuel. 

scholarly journals ESTIMATION OF THE EFFICIENCY OF MECHANICAL ACTIVATION OF SILICA-CONTAINING ROCKS

2021 ◽  
Vol 6 (5) ◽  
pp. 19-27
Author(s):  
A. Shamanina ◽  
Arkadiy Ayzenshtadt ◽  
V. Kononova ◽  
V. Danilov
Keyword(s):  
Mechanical Activation ◽  
Surface Activity ◽  
Raw Materials ◽  
Functional Dependence ◽  
Construction Materials ◽  
Mineralogical Composition ◽  
Optimal Time ◽  
Energy Potential ◽  
Mineral Components ◽  
Time Parameters

Rocks of various chemical and mineralogical composition are widely used as raw materials in the construction materials industry. At the same time, preliminary mechanical activation of mineral raw materials to a finely dispersed state contributes to a change in the energy potential of the system and affects the tendency of the surface of a finely dispersed system to transformations. Studies of the physicochemical activity of mechanically activated rocks allow to determine the rational areas of use of mineral components. The paper presents the results of evaluating the efficiency of mechanical activation of silica-containing raw materials by the values of surface activity (ks), defined as the ratio of the value of the free surface energy to the specific mass energy of atomization. Fine powders are obtained by grinding in a planetary ball mill to a different specific surface area of quartz sand (1200 – 3000 m2/kg) and polymineral sand (700 – 1335 m2/kg). The presence of a functional dependence of the surface activity on the time parameters of mechanical activation of the studied rocks is shown. The mechanical activation of the feedstock at the optimal time of its grinding makes it possible to achieve a given value of the surface activity. It is recommended to use the ks parameter as a criterion for assessing the efficiency of the process of mechanical activation of silica-containing rocks

Effectiveness Evaluation Criteria of Using Fine Powders of Secondary Concrete as a Component of Composite Binder

2021 ◽  
Vol 1017 ◽  
pp. 163-171
Author(s):  
Tatiana Drozdyuk ◽  
Arkady Ayzenshtadt ◽  
Sergey Aksenov
Keyword(s):  
Free Surface ◽  
Surface Energy ◽  
Surface Activity ◽  
Free Surface Energy ◽  
Hydration Reaction ◽  
Critical Surface ◽  
Critical Surface Tension ◽  
Composite Binder ◽  
Fine Powders ◽  
Highly Dispersed

The paper considers the possibility of using energy criteria (surface activity, free surface energy) to quantify the efficiency of a highly dispersed system consisting of fine particles of secondary concrete as a component of composite binder of the hydration type of hardening. Using the G.A. Zisman method, the value of the critical surface tension was determined for secondary concrete fractions with different degrees of dispersion, which gives an idea of the free surface energy of a surface area unit. Based on the experimental data for determining the specific surface area and critical surface tension, the free surface energy and surface activity of the studied concrete powder were calculated, which can serve as criteria for quantitative energy characteristics of raw materials for the production of composite binders. Calorimetric studies related to measurements of the thermal effects of the hydration reaction of highly dispersed samples of secondary concrete have shown that this process is exothermic, the enthalpy of hydration of which is comparable to a similar parameter for cement. It was experimentally shown that fine powders of secondary concrete are effective as components of a composite binder, but they need to be pre-activated to optimal parameters, one of which is surface activity. In addition, the symbasis of changes in surface activity, the specific heat of the hydration reaction of highly dispersed concrete fractions and the compressive strength of fine-grained concrete samples made by using a composite binder containing a highly dispersed fraction of secondary concrete was established.

scholarly journals Synthesis Polymer Matrix Composite Epoxy-FeNdB-Mn for Radar Absorbing Material Application

2021 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Gibran Juniansyah ◽  
Sri Mulyati Lathifah ◽  
Djoko Hadi Prajitno
Keyword(s):  
Matrix Composite ◽  
Polymer Matrix ◽  
Ball Mill ◽  
Milling Process ◽  
Polymer Matrix Composite ◽  
Radar Absorbing Material ◽  
A Value ◽  
Absorbing Material ◽  
The Military ◽  
High Reflection

<p style="margin-bottom: 0in; line-height: 115%;" align="justify"><span style="font-family: Times New Roman, serif;">In recent years, applications using electromagnetic wave technology have grown rapidly. One of them is in the military field, the wave-absorbing material used to avoid detection such as aircraft, ships, or tanks requires a super thin absorbent material which has extraordinary absorption. One of the criteria for a wave absorbing material is a soft magnet and has a high Reflection Loss (RL). This research aims to see the effect of the addition of FeNdB and Mn on the synthesis of Polymer Matrix Composite (PMC) as a wave-absorbing material.</span><span style="font-family: Times New Roman, serif;">The FeNdB milling process and Mechanical Alloying (MA) with Mn were carried out using a Planetary Ball Mill (PBM) at a speed of 1000 rpm for 60 minutes. synthesis of PMC by varying the composition of epoxy resin with magnetic powder 95: 5; 90:10; 85: 5. Based on the characterization results, the optimum RL was obtained at a composition of 85: 5 with a value of -22.40 dB at a frequency of 10.40 GHz and the magnetic properties after the addition of Mn were obtained HcJ 0.116 kOe and Br 0.41 kG. PMC hardness increased with the increase of powder in the sample with the highest value of 29.2 HD Shore D and the adhesion decreased with the addition of powder in the sample with the lowest value of 1 MPa.</span></p>

scholarly journals An Electrochemical Study of Aluminum Corrosion in Boiling High Purity Water

CORROSION ◽  
1967 ◽  
Vol 23 (12) ◽  
pp. 365-370 ◽  
Author(s):  
R. A. LEGAULT ◽  
J. E. DRALEY
Keyword(s):  
Experimental Data ◽  
Protective Layer ◽  
Potential Drop ◽  
R And D ◽  
Total Potential ◽  
A Value ◽  
Wide Range ◽  
Aluminum Corrosion ◽  
Simplifying Assumptions

Abstract An equation relating current and electrochemical potential has been derived on the basis of a physical model of the corrosion process. In the model, the total potential drop from metal to solution is the sum of potential contributions arising from the interfacial reactions at the metal-oxide and oxide-solution interfaces and that which derives from the transport of charged species through the film. On the basis of some simplifying assumptions, the derived equation reduces to ΔE = IR + Ksℓn (1 + ID), where R and D are complex constants and Ks is equal to RT/αzF for the liberation of hydrogen at the surface of the protective layer. This equation has been fitted successfully to experimental data. Assigning the value usually attributed to α for the hydrogen reaction, 1/2, optimum values of the constants were found to vary reasonably with time. If a value of α is not assigned, the equation can be fitted to experimental data over a wide range of values for the three constants. Polarization measurements alone are not sufficient to determine unequivocal values for the constants, hence a determination of the mechanism of the aqueous oxidation of aluminum will require additional independent measurements.

Specific mass energy capacity of disk flywheels produced from composites

1981 ◽  
Vol 16 (5) ◽  
pp. 605-611
Author(s):  
G. G. Portnov ◽  
V. L. Kulakov
Keyword(s):  
Energy Capacity ◽  
Mass Energy ◽  
Specific Mass

Investigations of Dispersing Agents and Stabilizing Agents for Latex Mixtures, and the Behavior of Latex Mixtures When Stored

1936 ◽  
Vol 9 (2) ◽  
pp. 252-263
Author(s):  
Otto Bächle
Keyword(s):  
Chemical Industry ◽  
Ball Mill ◽  
High Efficiency ◽  
Great Sensitivity ◽  
Stabilizing Agents ◽  
Mechanical Dispersion ◽  
Dispersing Agent ◽  
Long Time ◽  
Good Medium ◽  
Dispersing Agents

Abstract The great sensitivity to mechanical as well as to chemical influences which is possessed by latex, in common with all hydrophobic colloids, leads to immediate difficulties in the preparation of its mixtures. The ingredients, which in most cases are insoluble in water, must first be finely ground and then dispersed in water before being added to the latex mixture. Good dispersion is effected only by the use of high efficiency mechanical dispersion apparatus (ball mill, pigment grinding mill, etc.) and at the same time by the use of a suitable dispersing agent. Moreover, since latex mixtures may have to be stored for a long time, and since premature coagulation may take place during the preparation of such mixtures by the ingredients added or by mechanical influences, and later by incipient vulcanization, it is necessary to stabilize these latex mixtures in practice so that they can be handled safely. Much work has already been done on the stabilization of latex and latex mixtures, as a result of which a great number of products are recommended and used today. A certain stabilizing action is obtained by the addition of water, a greater stabilizing action by aqueous solutions of alkalies. Furthermore, soaps and soap-like compounds are used, e. g., casein is in general a good medium. A few special products are offered today by the chemical industry.

scholarly journals Deducing the proton energy configuration

2016 ◽  
Vol 2 (11) ◽  
pp. 284
Author(s):  
William S. Oakley
Keyword(s):  
Proton Energy ◽  
Near Field ◽  
Rest Mass ◽  
Far Field ◽  
Mass Energy ◽  
Proton Radius ◽  
Proton Mass ◽  
A Value ◽  
Partial Charges ◽  
The Standard Model

<p class="abstract">Articles published prior to 1994 by various authors indicate a mass energy sequence for the pion, muon, and electron in the ratios 4: 3: 2 respectively with increments of about 35.3 MeV, with the electron “rest mass” energy rotationally relativistic at α<sup>-1</sup>m<sub>e</sub>c<sup>2</sup>, ~ 70 MeV. Considering 35.3 MeV rotationally relativistic by α<sup>-2/3</sup> (≈ 26.58) extends the sequence to include the proton mass energy at 938 MeV, i.e. 26.58 <em>x</em> 35.3 MeV = 938.274 MeV. This observation leads to describing the proton as a single EM wave propagating in a toroidal path with volume contracted by α and thereby exhibiting unit charge in the far field, and evidencing partial charges in the near field consistent with the UUD quarks of the Standard Model. As with quantum chromodynamics (QCD), over 99% of the proton rest mass is relativistic in nature. A value for the proton radius is obtained within the empirical uncertainty<span lang="EN-IN">s. </span></p>

scholarly journals Неоствальдовское поведение дисперсных систем в процессах испарения и кристаллизации капель водно-органических растворов

2020 ◽  
Vol 90 (6) ◽  
pp. 879
Author(s):  
Е.Н. Федосеева ◽  
В.Б. Федосеев
Keyword(s):  
Chemical Composition ◽  
Organic Compounds ◽  
Surface Activity ◽  
Small Volume ◽  
Ostwald Ripening ◽  
Inorganic Salts ◽  
Size Distributions ◽  
Dispersed Systems ◽  
Water Solutions ◽  
Water Based

In this paper, experiments with water-based solutions of some organic compounds, which demonstrate non-Ostwald behavior have been described. Small-volume droplets demonstrate higher stability during evaporation and crystallization in comparison with larger ones, such an effect has been previously described only for water-based solutions of inorganic salts. It has been shown that non-Ostwald behavior has the same thermodynamic nature with Ostwald ripening and could occur in dispersed systems of a complicated chemical composition. Peculiar realization of such phenomena driven by surface activity of organic compounds in water solutions has also been described. The studied regularities could be used to obtain solutions of organic and bioorganic substances with concentrations significantly higher than their solubility limits under normal conditions as well as to reproduce narrow size distributions of droplets in various spray technologies.

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

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