scholarly journals Thermodynamics of equilibrium states and approaches to analyzing the mass transport in metal-oxide systems

2020 ◽  
Vol 6 (4) ◽  
pp. 261-268
Author(s):  
Olga V. Lavrova ◽  
Aleksandr Yu. Legkikh
Keyword(s):  
Mass Transport ◽  
Metal Oxide ◽  
Potential Temperature ◽  
Experimental Studies ◽  
Oxide System ◽  
Oxidation Potential ◽  
Molten Metals ◽  
Oxide Systems ◽  
Steel Grades ◽  
New Generation

Analysis of corrosion processes has a major role in justifying the reliability and safety of developed nuclear reactors of a new generation with heavy liquid metal coolants. An approach has been developed which allows practical conclusions to be made with respect to the processes in the given metal-oxide system based on analyzing state diagrams for these systems in the "oxidation potential – temperature" coordinates. The proposed approach relies on a long-term experience of experimental and computational studies concerned with the interaction of various steel grades with molten lead and lead-bismuth, as well as with the transport of metal impurities within these molten metals. The oxidation potential of a metal-oxide system is measured in experimental studies using oxygen activity sensors developed and manufactured at IPPE. The applicability of the proposed approach to analyzing the processes of mass transport in iron-oxygen, lead-oxygen, sodium-oxygen, and iron-water vapor systems has been demonstrated.

Method and tools for determining heat transfer coefficients in organic liquids and solutions

2020 ◽  
pp. 45-55
Author(s):  
Aleksandr S. MYAKOCHIN ◽  
Petr V. NIKITIN ◽  
Sergey Yu. POBEREZHSKIY ◽  
Anna A. SHKURATENKO
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Pulse Method ◽  
Organic Liquids ◽  
Transfer Coefficients ◽  
Resistance Thermometer ◽  
Film Sensor ◽  
Heat Transfer Coefficients ◽  
Aerospace Technology ◽  
New Generation

The paper presents a method, tools and a newly developed algorithm for experimentally determining heat transfer coefficients in organic liquids and solutions. This work is made relevant by the problem of development of a new generation of aerospace technology. In this connection, improvements have been made to the pulse method of determining heat transfer coefficients that is based on the use of a micron-thick film sensor. The measurement setup was modified. A math model was constructed for the measuring sensor. Algorithms were developed for conducting the experiment and processing measurement results to determine heat transfer coefficients. Experimental uncertainties were analyzed. The paper provides results of experimental studies on certain organic liquids. The authors believe that the material presented in the paper will find application in research conducted at research institutions, engineering offices and universities, among researches, postgraduates and students. Key words: thermal and physical characteristics, organic liquids and their solutions, film-type electrical resistor, thin-film temperature sensor, voltage pulse, resistance thermometer, irregular heat transfer regime.

Rare earth—platinum group mixed metal oxide systems

1994 ◽  
Vol 210 (1-2) ◽  
pp. 177-184 ◽  
Author(s):  
K.M. Cruickshank ◽  
F.P. Glasser
Keyword(s):  
Rare Earth ◽  
Metal Oxide ◽  
Mixed Metal Oxide ◽  
Oxide Systems ◽  
Mixed Metal ◽  
Platinum Group

scholarly journals Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

2003 ◽  
Vol 800 ◽  
Author(s):  
Brady J. Clapsaddle ◽  
Lihua Zhao ◽  
Alex E. Gash ◽  
Joe H. Satcher ◽  
Kenneth J. Shea ◽  
...  
Keyword(s):  
Mass Transport ◽  
Metal Oxide ◽  
Energetic Materials ◽  
Silicon Oxide ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Mixed Metal Oxide ◽  
Organic Additives ◽  
Metal Oxide Silicon

ABSTRACTIn the field of composite energetic materials, properties such as ingredient distribution, particle size, and morphology, affect both sensitivity and performance. Since the reaction kinetics of composite energetic materials are typically controlled by the mass transport rates between reactants, one would anticipate new and potentially exceptional performance from energetic nanocomposites. We have developed a new method of making nanostructured energetic materials, specifically explosives, propellants, and pyrotechnics, using sol-gel chemistry. A novel sol-gel approach has proven successful in preparing metal oxide/silicon oxide nanocomposites in which the metal oxide is the major component. Two of the metal oxides are tungsten trioxide and iron(III) oxide, both of which are of interest in the field of energetic materials. Furthermore, due to the large availability of organically functionalized silanes, the silicon oxide phase can be used as a unique way of introducing organic additives into the bulk metal oxide materials. As a result, the desired organic functionality is well dispersed throughout the composite material on the nanoscale. By introducing a fuel metal into the metal oxide/silicon oxide matrix, energetic materials based on thermite reactions can be fabricated. The resulting nanoscale distribution of all the ingredients displays energetic properties not seen in its microscale counterparts due to the expected increase of mass transport rates between the reactants. The synthesis and characterization of these metal oxide/silicon oxide nanocomposites and their performance as energetic materials will be discussed.

Theoretical and Experimental Studies of Sulfur and Boron Distribution between the Slag of the CaO-SiO2-B2O3-MgO-Al2O3 System and the Metal

2021 ◽  
Vol 410 ◽  
pp. 287-292
Author(s):  
Anatolij A. Babenko ◽  
Leonid A. Smirnov ◽  
Alena G. Upolovnikova
Keyword(s):  
Distribution Coefficient ◽  
Thermodynamic Modeling ◽  
Experimental Studies ◽  
Oxide System ◽  
Slag Basicity ◽  
Interphase Distribution ◽  
Desulfurization Process ◽  
Simplex Lattice ◽  
High Degree ◽  
Effect Of The Composition

The equilibrium interfacial distribution of sulfur and boron was estimated using the HSC 6.1 Chemistry software package (Outokumpu) and the simplex-lattice planning method. Adequate mathematical models have been constructed in the form of III degree polynomial, which describe the effect of the composition of the studied oxide system on the equilibrium distribution of sulfur and boron between the slag and the metal. Generalization of the results of experimental studies and thermodynamic modeling made it possible to obtain new data on the influence of the basicity and content of B2O3 in the slag of the CaO-SiO2-B2O3-MgO-Al2O3 system on the interphase distribution of sulfur and boron. It was found that in the range of boron oxide concentration of 1.0-10%, an increase in slag basicity from 2 to 5 at 1600°C leads to an increase in the sulfur distribution coefficient from 1 to 20 and, as a consequence, a decrease in the sulfur content in the metal from 0.02 to 0.0014 %, i.e. an increase in slag basicity favorably affects the development of the metal desulfurization process. An increase in the B2O3 content from 2.0 to 10.0% in slags formed in the region of moderate basicity, not exceeding 2-3, is accompanied at 1600°C by a decrease in the boron interphase distribution coefficient from 450 to 150 and an increase in the boron concentration in the metal from 0.006 to 0.021 %, which indicates the progress of boron reduction from slag to metal. The shift of the formed slags to the area of ​​increased basicity up to 5.0 shows a high degree of boron reduction from slag to metal. The results of the laboratory experiment confirmed the results of thermodynamic modeling.

Abstract 120: Surpass Flow Diverter for Endovascular Treatment of Intracranial Aneurysms - A Multicenter Preliminary Clinical and Angiographic Experience in 161 Patients with 186 Aneurysms

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Ajay K Wakhloo ◽  
Pedro Lylyk ◽  
Joost de Vries ◽  
Matthew J Gounis ◽  
Alexandra Biondi ◽  
...  
Keyword(s):  
Intracranial Aneurysms ◽  
Experimental Studies ◽  
Flow Diverter ◽  
Posterior Circulation ◽  
Parent Artery ◽  
Anterior Circulation ◽  
Neck Size ◽  
Wide Range ◽  
New Generation

Objective: Validated through experimental studies a new generation of flow diverters (Surpass™ FD) was evaluated for treatment of intracranial aneurysms (IA). We present our multicenter preliminary clinical and angiographic experience. METHODS: To achieve the calculated flow disruption between the parent artery and aneurysm for thrombosis, single FDs were placed endovascularly in parent arteries. Implants measured 2.5-5.3mm in diameter with a length of 10-80mm. Patients were enrolled harboring a wide range large and giant wide-neck, fusiform and multiple small and blister-type aneurysm. Clinical and angiographic follow-up were performed at 1-3, 6, and 12 months. RESULTS: A total of 186 consecutive IA in 161 patients (mean age 57.1 years) were treated at 33 centers. Fifty-three aneurysms were smaller than 5 mm, 64 were 5-9.9mm in diameter, 47 were 10-20mm in diameter, and 22 were larger than 20mm (10.4±0.7mm, neck size 6.0±0.5mm [mean±SEM]) . The aneurysms originated in 63.4% from the internal carotid artery; 22% and 14.5% of the lesions were located in the anterior circulation distal to Circle of Willis and posterior circulation respectively. Technical success was achieved in 182 aneurysms (98%); average number of devices used per aneurysm was 1.05. Permanent morbidity and mortality during the follow-up period of mean 8.4months (range 1-24 months) including periprocedural complications for patients with aneurysms of the anterior circulation were encountered in 5 (3.7%) and 2 (1.5 %) patients respectively and 1 (3.7%) and 4 (14.8%) respectively for patients with aneurysms of the posterior circulation location. One-hundred-ten patients (70.5%) harboring 127 (70.2%) were available for clinical and angiographic follow-up and showed a complete or near complete aneurysm occlusion in 63 (81.8%) of the ICA. Aneurysms of the ICA≥10mm that were completely covered by FD and not previously stent-treated with a minimum of 6 months follow-up available in 16 patients showed a complete obliteration in 81.3% (n=13) and >90% occlusion in remaining 3 patients. CONCLUSION: Preliminary data demonstrate high safety and efficacy of a new generation of FD for a wide range of IA of the anterior and posterior circulation with a single implant.

New approaches to pharmacotherapy of allergic eye diseases

2015 ◽  
pp. 18-26
Author(s):  
Zoya Veselovska ◽  
Nataliia Veselovska
Keyword(s):  
Effective Means ◽  
Experimental Studies ◽  
Tear Film ◽  
Eye Diseases ◽  
Eye Drops ◽  
Lipid Layer ◽  
Ophthalmic Surgery ◽  
Promising Alternative ◽  
New Approaches ◽  
New Generation

The problem of studying the prеvalencе of allergic diseases of the eye and the search for new approaches and effective means to correct this condition does not lose its relevance. The presented data on the state of profound biochemical studies of the tear film in allergic conditions justify the expediency of the use of eye drops of a new generation. As a result of experimental studies on the effect on the lipid layer ectoine was discovered the mechanism of its therapeutic action. This paper presents compelling evidence that new eye drops based on natural molecules ectoine which are able to restore and maintain the functional state of the lipid layer of the tear film in the pharmacotherapy of аllergic diseases of anterior surface of the eye. The analyzes of multiple experimental data revealed the clear evidence of mechanisms of action on the eye and the first clinical experience with a new pharmacological agent testifies to its strong anti-inflammatory and regenerative effect due to the stabilization of the lipid layer of the tear film and the protection of the front surface of the eye tissue from the hyperosmolarity. It was confirmed by the subjective and objective reducing eye irritation and dryness in reducing itching and burning from the conjunctiva, to improve the moisture level of the surface of the eye, to reduce discomfort of the eyes. The drug can be used in children older than 2 years and adults, when wearing contact lenses, ophthalmic surgery and after an eye injury. Based on this, it can be conclude that the appearance in the arsenal of new-generation antiallergic eye drops (EYE-t) with sufficient efficacy and safety profile can be regarded as a promising alternative approach to the treatment of allergic and inflammatory eye diseases.

Thermodynamic Database of P2O5-containing Oxide Systems for the Dephosphorization Process in Steelmaking

2013 ◽  
Vol 32 (3) ◽  
pp. 247-254 ◽  
Author(s):  
In-Ho Jung ◽  
Pierre Hudon ◽  
Wan-Yi Kim ◽  
Marie-Aline van Ende ◽  
Miftaur Rahman ◽  
...  
Keyword(s):  
Thermodynamic Modeling ◽  
Basic Oxygen Furnace ◽  
Oxide System ◽  
Thermodynamic Database ◽  
Experimental Investigations ◽  
Oxide Systems ◽  
Basic Oxide ◽  
Basic Oxygen ◽  
Process Route ◽  
P Removal

AbstractThe Na2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2-P2O5 system is a basic oxide system for the Basic Oxygen Furnace (BOF) process as well as the hot metal dephosphorization process. Numerous experimental investigations on this oxide system are being carried out to find out an advanced process route for P removal from molten iron. In spite of their industrial importance, however, phase equilibria in oxide systems containing P2O5 have not been well investigated due to the complexity of their chemistry. No systematic thermodynamic modeling of these systems has been conducted to date, either. In order to meet the strong demands of steelmaking and other industries, new systematic thermodynamic modeling of the P2O5-containing oxide systems (Na2O-MgO-CaO-FeO-Fe2O3-Al2O3-SiO2-P2O5) and key phase diagram experiments have been carried out over the past years. In the present study, the results of the thermodynamic modeling of unary, binary and ternary P2O5-containing systems and the applications of the thermodynamic database to the dephosphorization by multi-component slag in BOF process are presented in comparison with experimental data. All thermodynamic calculations were performed using FactSage thermodynamic software.

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