scholarly journals The influence of temperature conditions of melting on changes in interplanar distances in quartzite

2018 ◽  
pp. 34-38
Author(s):  
V. A. Kukartsev ◽  
V. V. Kukartsev ◽  
A. V. Kukartsev
Keyword(s):  
Research Work ◽  
Furnace Lining ◽  
Influence Of Temperature ◽  
Foundry Industry ◽  
Melting Temperatures ◽  
Temperature Regimes ◽  
Crucible Furnace ◽  
The Stability ◽  
Acid Lining ◽  
Industrial Frequency

The reliability of the operation of an induction crucible furnace of industrial frequency (IFC) used in the foundry industry depends on the durability of its lining. For this reason, a lot of research work is devoted to quartzite, as the cheapest material of the acidic lining, both in our country and abroad. The goal of the research is to develop the technology for the manufacture and operation of acid lining, which is used for smelting alloys at operating melting temperatures above 1450 ° C. The effect of melting temperature regimes on changes in interplanar distances in the structure of quartzite, affecting the stability of the furnace lining, is considered.Ill.4. Ref. 14.

The Peculiarities of Smelting of Wear-Resistant Cast Iron IChH28N2 in the Induction Crucible Furnace IChT10

2020 ◽  
Vol 299 ◽  
pp. 397-402
Author(s):  
Viktor A. Kukartsev ◽  
Vladislav V. Kukartsev ◽  
Vadim S. Tynchenko
Keyword(s):  
Cast Iron ◽  
Steel Scrap ◽  
Wear Resistant ◽  
Melting Temperatures ◽  
Arc Furnaces ◽  
Iron Smelting ◽  
Crucible Furnace ◽  
Iron Scrap ◽  
Induction Crucible Furnaces ◽  
Industrial Frequency

Wear-resistant cast iron smelting is produced in electric arc furnaces, due to the use of steel scrap in metal charge, ferrochrome and refund if there is one. Scrap of cast iron with the necessary chemical composition is not present because the proportion of manufacturing parts from wear-resistant cast iron is very small. Thus, there is no opportunity to form castings of wear-resistant cast iron using foundries equipped only with induction crucible furnaces of industrial frequency (IChT), since the furnace is designed for melting temperatures not above 1500 °C. In addition, the lining of induction furnaces of industrial frequency is made of quartzite, which provides the necessary durability when operating at temperatures not above 1500 °C. The ability to manufacture blanks from wear-resistant cast iron gives an additional opportunity to expand the range of orders and prevent a reduction in production in factories equipped only with the smelting furnaces of the IChT. The article describes the peculiarities of smelting cast iron IChH28N2 in the furnace IChT10 with acid lining. The technology of conducting melting on pure charge materials without use of cast iron scrap and return is briefly described.

scholarly journals Fabrication and Characterization of Laser Scribed Supercapacitor Based on Polyimide for Energy Storage

2018 ◽  
Vol 778 ◽  
pp. 181-186 ◽  
Author(s):  
Tayyaba Malik ◽  
Shayan Naveed ◽  
Muhammad Muneer ◽  
Mohammad Ali Mohammad
Keyword(s):  
Energy Storage ◽  
Research Work ◽  
Electrical Energy ◽  
Energy Storage Devices ◽  
Super Capacitor ◽  
Storage Devices ◽  
Voltage Sweep ◽  
Tremendous Amount ◽  
The Stability

Recently, supercapacitors have attracted a tremendous amount of attention as energy-storage devices due to their high-power density, fast charge–discharge ability, excellent reversibility, and long cycling life. In this research work, we demonstrate a laser scribed super capacitor based on polyimide (PI) substrate for the storage of electrical energy. PI substrate of thickness 200μm and area 1cm × 1cm was reduced by a laser engraver with a 450 nm wavelength in the form of stackable supercapacitor electrodes. Although, PI itself exhibits non-conductive behavior; however, by laser irradiation we change the surface properties of PI and reduce its resistance. The chemical property of irradiated PI was characterized with XRD where the carbon peak was observed at 2*theta = 25.44, which confirms the reduction of PI material in to a graphene-like substance. The electrical conductivity was analyzed with a probe station and observed to be 1.6mS. Two conductive regions were assembled into a capacitor device by sandwiching a PVA/H3PO4 electrolyte in between. During the charging and discharging characterization of the capacitor device, current density was observed to be 1.5mA/cm2. Capacitance versus voltage analysis was carried out and the device showed 75mF/cm2 against a voltage sweep of ±2V. The galvanostatic charging and discharging curve shows a symmetric behavior with respect to time exhibiting the stability and durability of the device.

scholarly journals Hybrid K Mean Clustering Algorithm for Crop Production Analysis in Agriculture

2019 ◽  
Vol 9 (2S) ◽  
pp. 9-13
Keyword(s):  
Cluster Analysis ◽  
Precision Agriculture ◽  
Crop Production ◽  
Clustering Algorithm ◽  
Research Work ◽  
K Value ◽  
Clustering Technique ◽  
Production Analysis ◽  
Initial Cluster ◽  
The Stability

The proposed research work aims to perform the cluster analysis in the field of Precision Agriculture. The k-means technique is implemented to cluster the agriculture data. Selecting K value plays a major role in k-mean algorithm. Different techniques are used to identify the number of cluster value (k-value). Identification of suitable initial centroid has an important role in k-means algorithm. In general it will be selected randomly. In the proposed work to get the stability in the result Hybrid K-Mean clustering is used to identify the initial centroids. Since initial cluster centers are well defined Hybrid K-Means acts as a stable clustering technique.

scholarly journals Preservatives Stability: Stability Study of Parabens under Different Conditions of Stress Degradation

2020 ◽  
Vol 11 (3) ◽  
pp. 4187-4194
Author(s):  
Ismail Bennani ◽  
Madiha Alami Chentoufi ◽  
Miloud El Karbane ◽  
Ibrahim Sbai El Otmani ◽  
Amine Cheikh ◽  
...  
Keyword(s):  
Extreme Values ◽  
Stability Study ◽  
Wide Field ◽  
Direct Influence ◽  
Light Conditions ◽  
Influence Of Temperature ◽  
Stress Degradation ◽  
Quality Of Products ◽  
The Stability

Preservatives are used in a wide field of application to maintain the quality of products. They are used to deal with the chemical, physical and microbiological problems and the constraints of the development of several formulations. In this work, we tested the stability of antimicrobial preservatives which are the parabens under different stress degradation conditions to evaluate their degree of effectiveness. The tested parabens were incubated in different solutions at different pH, Temperatures, light conditions, and presence or absence of sucrose in solution (create a medium similar of syrups). The HPLC was used for the assay, by a validated method for the parabens assay and the statistical analysis of the data is carried out by JMP software. The results show a direct influence of temperature and pH on the level of parabens, while the influence of light remains negligible. The increase in temperature gives a degree of immunity of parabens levels, especially with the extreme values of pH. This study is one of the first studies of forced decomposition of parabens carried out under the various conditions suggested. The results give an idea of the stability profile of the tested parabens and suggest a model of the conditions of conservation and use of these products in different domains and under different conditions.

Hot-hardness comparisons among isostructural Be12X intermetallic compounds

1993 ◽  
Vol 8 (7) ◽  
pp. 1550-1557 ◽  
Author(s):  
S.M. Bruemmer ◽  
B.W. Arey ◽  
J.L. Brimhall ◽  
J.P. Hirth
Keyword(s):  
Sharp Decrease ◽  
Slip Systems ◽  
Processing Conditions ◽  
Dislocation Mobility ◽  
Melting Temperatures ◽  
Brittle Transition ◽  
Metal Atoms ◽  
Macroscopic Plasticity ◽  
The Stability ◽  
Hot Hardness

Hot hardness has been measured in seven isostructural Be12X compounds: Be12Cr, Be12Mn, Be12V, Be12Mo, Be12Ti, Be12Ta, and Be12Nb. All vacuum-hot-pressed (VHP) materials exhibited similar hardness levels (800 to 1000 kg/mm2) at low temperatures (<600 °C), but sharply diverged at higher temperatures. Most compounds showed a sharp decrease in hardness above about one-half their melting temperatures except for Be12Nb and Be12Ti which maintained strength until higher temperatures. Ductile-brittle transition temperatures (DBTT's) of 600, 625, 690, 700, 700, and 850 °C were determined for Be12Cr, Be12Mn, Be12V, Be12Mo, Be12Ti, and Be12Nb, respectively. Hot-isostatically-pressed (HIP) and VHP Be12Nb heats both showed comparable behavior, indicating that the temperature required for macroscopic plasticity is not dependent on processing conditions. Differences in slip characteristics were observed between beryllides with similar melting temperatures, but differing DBTT's. Dislocations were activated on multiple slip systems in Bei2V during compressive deformation at 800 °C. Similar behavior was not observed in Be12Nb until test temperatures above 1000 °C. It is proposed that dislocation mobility may be related to the stability between Be12X and Be17X2 phases. Larger refractory metal atoms such as Nb may form faulted layers related to Be17X2 structures and thereby impede deformation at intermediate temperatures. Smaller atoms such as Cr, Mn, V, and Mo do not form a stable Be17X2 phase and thereby allow enhanced dislocation mobility at these temperatures.

scholarly journals Effect of Degassing Treatment on the Interfacial Reaction of Molten Aluminum and Solid Steel

2017 ◽  
Vol 17 (2) ◽  
pp. 227-239 ◽  
Author(s):  
T. Triyono ◽  
N. Muhayat ◽  
A. Supriyanto ◽  
L. Lutiyatmi
Keyword(s):  
Electron Microscope ◽  
Intermetallic Compound ◽  
Scanning Electron Microscope ◽  
Interfacial Reaction ◽  
Immersion Time ◽  
Molten Aluminum ◽  
Furnace Lining ◽  
Brittle Phase ◽  
Crucible Furnace ◽  
Scanning Electron

AbstractThe gas porosity is one of the most serious problems in the casting of aluminum. There are several degassing methods that have been studied. During smelting of aluminum, the intermetallic compound (IMC) may be formed at the interface between molten aluminum and solid steel of crucible furnace lining. In this study, the effect of degassing treatment on the formations of IMC has been investigated. The rectangular substrate specimens were immersed in a molten aluminum bath. The holding times of the substrate immersions were in the range from 300 s to 1500 s. Two degassing treatments, argon degassing and hexachloroethane tablet degassing, were conducted to investigate their effect on the IMC formation. The IMC was examined under scanning electron microscope with EDX attachment. The thickness of the IMC layer increased with increasing immersion time for all treatments. Due to the high content of hydrogen, substrate specimens immersed in molten aluminum without degasser had IMC layer which was thicker than others. Argon degassing treatment was more effective than tablet degassing to reduce the IMC growth. Furthermore, the hard and brittle phase of IMC, FeAl3, was formed dominantly in specimens immersed for 900 s without degasser while in argon and tablet degasser specimens, it was formed partially.

Dynamics of a Continuous System With Clearance and Motion Limiting Stops

1999 ◽  
Author(s):  
P. Metallidis ◽  
S. Natsiavas
Keyword(s):  
Piecewise Linear ◽  
Research Work ◽  
Continuous System ◽  
Continuous Model ◽  
Equation Of Motion ◽  
Model System ◽  
Periodic Motions ◽  
System Parameters ◽  
Rigid Rods ◽  
The Stability

Abstract The present study generalises previous research work on the dynamics of discrete oscillators with piecewise linear characteristics and investigates the response of a continuous model system with clearance and motion-limiting constraints. More specifically, in the first part of this work, an analysis is presented for determining exact periodic response of a periodically excited deformable rod, whose motion is constrained by a flexible obstacle. This methodology is based on the exact solution form obtained within response intervals where the system parameters remain constant and its behavior is governed by a linear equation of motion. The unknowns of the problem are subsequently determined by imposing an appropriate set of periodicity and matching conditions. The analytical part is complemented by a suitable method for determining the stability properties of the located periodic motions. In the second part of the study, the analysis is applied to several cases in order to investigate the effect of the system parameters on its dynamics. Special emphasis is placed on comparing these results with results obtained for similar but rigid rods. Finally, direct integration of the equation of motion in selected areas reveals the existence of motions, which are more complicated than the periodic motions determined analytically.

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