Composite Deposits Developed by Welding on Horizontal Mill Hammers

2018 ◽  
Vol 1146 ◽  
pp. 27-31
Author(s):  
Emilia Florina Binchiciu ◽  
Traian Fleșer ◽  
Ionelia Voiculescu ◽  
Victor Geanta
Keyword(s):  
Centripetal Force ◽  
Low Alloy Steel ◽  
Mechanical Fatigue ◽  
Grinding Mills ◽  
Composite Layers ◽  
Present Solution ◽  
Combined Action ◽  
Composite Deposits ◽  
New Generation ◽  
Ground Load

The paper presents the concept of designing active hammer edges of horizontal mills for grinding tungsten carbide waste by making composite layers deposited by welding. The new generation of hammers is carried out on the principles of preventive and repetitive maintenance, by endowment with wear addition, predetermined as volume and geometric configuration, depending on the specific conditions of uninterrupted use for a period of time established for economic reasons. The main demands that affect the integrity of the active areas of grinding mills (high pressure abrasion wear, thermo-mechanical fatigue) generate both material losses and output from working rates, as well as excessive elongation of the support elements under the combined action of centripetal force and of the pressure exerted by the ground load. Under these conditions, the technically and economically optimized solution is to design the modular active elements in the form of easily assembled detachable components, made of a low alloy steel with average tear resistance (450-600MPa) on which we deposit by welding layers of composite austenitic steel, hardened by compression, so as to increase the lifetime of the hammers by up to 35% compared to the present solution, which can be upgraded up to 3 times for reuse.

Analytic solution of angle-ply laminated plates under extension, bending, and torsion

2019 ◽  
Vol 54 (8) ◽  
pp. 1093-1106
Author(s):  
Shen-Haw Ju ◽  
Wen-Yu Liang ◽  
Hsin-Hsiang Hsu ◽  
Jiann-Quo Tarn
Keyword(s):  
Numerical Solutions ◽  
Anisotropic Elasticity ◽  
Laminated Plates ◽  
Rectangular Section ◽  
State Space Approach ◽  
Present Solution ◽  
End Conditions ◽  
Combined Action ◽  
Space Approach

This paper develops a Hamiltonian state space approach for analytic determination of deformation and stress fields in multilayered monoclinic angle-ply laminates under the combined action of extension, bending, and torsion. The present solution satisfies the equations of anisotropic elasticity, the end conditions, the traction-free boundary conditions on the four edge surfaces of the rectangular section, and the interfacial continuity conditions in multilayered laminates. The proposed method only requires the solutions of matrix and eigen equations, regardless of the number or lamination of the layers. The finite element analyses are used to validate the accuracy of the analysis. The analytical solution and the numerical solutions are in excellent agreement.

scholarly journals Tailoring the morphology and electrocatalytic properties of electrochemically formed Ag/TiO2 composite deposits on titanium surfaces

2007 ◽  
Vol 72 (12) ◽  
pp. 1403-1418 ◽  
Author(s):  
S.V. Mentus ◽  
I. Boskovic ◽  
J.M. Pjescic ◽  
V. Grudic ◽  
Z. Bogdanov
Keyword(s):  
Oxygen Reduction ◽  
Reduction Reaction ◽  
Electrode Polarization ◽  
Silver Deposition ◽  
Agno3 Solution ◽  
Composite Layers ◽  
Silver Electrodes ◽  
Titanium Surfaces ◽  
Composite Deposits ◽  
Polycrystalline Silver

Three different forms of Ag/TiO2 composite layers, which have whisker-, dot- and island-like distribution of silver were obtained on a mechanically polished titanium surface by adjusting the conditions of silver deposition from an aqueous AgNO3 solution. The deposit morphology was the result of both the program of electrode polarization and the template action of the simultaneously formed TiO2 layer. The catalytic activity of the composite layers toward the oxygen reduction reaction was studied in aqueous 0.1 M NaOH solutions and found to be a function of both the surface loading of silver and the type of silver distribution within the Ag/TiO2 composite layers. The reaction path of oxygen reduction on the composite layers was found to be always a 4e- one, characteristic otherwise of polycrystalline silver electrodes.

scholarly journals Cytopathological Effects of Bacillus sphaericus Cry48Aa/Cry49Aa Toxin on Binary Toxin-Susceptible and -Resistant Culex quinquefasciatus Larvae

2009 ◽  
Vol 75 (14) ◽  
pp. 4782-4789 ◽  
Author(s):  
Janaina Viana de Melo ◽  
Gareth Wyn Jones ◽  
Colin Berry ◽  
Romero Henrique Teixeira Vasconcelos ◽  
Cláudia Maria Fontes de Oliveira ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Bacillus Sphaericus ◽  
Binary Toxin ◽  
Cry Protein ◽  
Remarkable Feature ◽  
Protein Toxin ◽  
Cytoplasmic Vacuoles ◽  
Combined Action ◽  
Sites Of Action ◽  
New Generation

ABSTRACT The Cry48Aa/Cry49Aa mosquitocidal two-component toxin was recently characterized from Bacillus sphaericus strain IAB59 and is uniquely composed of a three-domain Cry protein toxin (Cry48Aa) and a binary (Bin) toxin-like protein (Cry49Aa). Its mode of action has not been elucidated, but a remarkable feature of this protein is the high toxicity against species from the Culex complex, besides its capacity to overcome Culex resistance to the Bin toxin, the major insecticidal factor in B. sphaericus-based larvicides. The goal of this work was to investigate the ultrastructural effects of Cry48Aa/Cry49Aa on midgut cells of Bin-toxin-susceptible and -resistant Culex quinquefasciatus larvae. The major cytopathological effects observed after Cry48Aa/Cry49Aa treatment were intense mitochondrial vacuolation, breakdown of endoplasmic reticulum, production of cytoplasmic vacuoles, and microvillus disruption. These effects were similar in Bin-toxin-susceptible and -resistant larvae and demonstrated that Cry48Aa/Cry49Aa toxin interacts with and displays toxic effects on cells lacking receptors for the Bin toxin, while B. sphaericus IAB59-resistant larvae did not show mortality after treatment with Cry48Aa/Cry49Aa toxin. The cytopathological alterations in Bin-toxin-resistant larvae provoked by Cry48Aa/Cry49Aa treatment were similar to those observed when larvae were exposed to a synergistic mixture of Bin/Cry11Aa toxins. Such effects seemed to result from a combined action of Cry-like and Bin-like toxins. The complex effects caused by Cry48Aa/Cry49Aa provide evidence for the potential of these toxins as active ingredients of a new generation of biolarvicides that conjugate insecticidal factors with distinct sites of action, in order to manage mosquito resistance.

Effect of Strain Wave Shape on Thermal-Mechanical Fatigue Crack Propagation in a Cast Low-Alloy Steel

1983 ◽  
Vol 105 (2) ◽  
pp. 81-87 ◽  
Author(s):  
M. Okazaki ◽  
T. Koizumi
Keyword(s):  
Fatigue Crack ◽  
Crack Propagation ◽  
Creep Strain ◽  
Strain Range ◽  
Tensile Creep ◽  
Low Alloy Steel ◽  
Wave Shape ◽  
Strain Wave ◽  
Thermal Mechanical Fatigue ◽  
Mechanical Fatigue

The effect of strain wave shape on low cycle thermal-mechanical fatigue crack propagation in a cast low-alloy steel was investigated under in-phase loading condition with a temperature range of 300–550°C. It was found that the rate of crack propagation increased with the asymmetry of strain wave shape, the effect being greatest in the high strain range. This behavior was discussed on the basis of observations in electron fractography and the change of inelastic tensile creep strain range with the repeated strain cycles. It was shown that the accumulation of inelastic tensile creep strain, which was not recovered during the compressive strain period contributed to this behavior. Further, the parameter called the range of total J-integral was introduced by applying the strain range partitioning approach and the rate of crack propagation was correlated with this.

Study on Nano-Oxide Powder Dispersed Ni-Electroplated Composites for Components Materials of NPPs

2009 ◽  
Author(s):  
Joung Soo Kim ◽  
Myeng Jin Kim ◽  
Dong Jin Kim ◽  
Hong Pyo Kim
Keyword(s):  
Oxide Powder ◽  
Corrosion Properties ◽  
Alloy Plate ◽  
Oxide Powders ◽  
Nano Oxide ◽  
Composite Layers ◽  
Erosion Corrosion ◽  
Different Types ◽  
Composite Deposits ◽  
As Stress

In this study, Ni composite layers embedding nano-oxide powders were electroplated on an alloy plate to mitigate and/or prevent various corrosion damages such as stress corrosion cracking, pitting, erosion-corrosion, etc.. Al2O3, TiO2, Y2O3, and ZrO2 nano-oxide powders were used to make Ni composite deposits in a sulfamate solution. After electrodeposition, their microstructures were examined using OM, SEM and TEM, and their mechanical properties were evaluated. According to the results, the amount of the co-deposited oxide powders in the composite increased regardless of the types of the nano-oxide, as the amount of oxide powder in the electrolyte bath increased. The hardness was measured to be relatively higher for the specimens produced in the electrolyte bath with higher concentrations of the nano-oxide powders and to decrease with increasing aging temperatures. even after aging at high temperatures. However, the behavior of the tensile properties was observed to be different with the different types of the oxide powders, possibly due to heavy agglomeration and inhomogeneous distribution of the oxide powders in the composites. Their corrosion properties can’t be presented this time, but they will be open at the next meeting.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

Total etch dentin bonding systems: scanning electron microscopy of the resin-dentin hybrid layer

1992 ◽  
Vol 50 (2) ◽  
pp. 1092-1093
Author(s):  
Jorge Perdigao
Keyword(s):  
Composite Resin ◽  
Mechanical Interlocking ◽  
Hybrid Layer ◽  
Agent Based ◽  
Dentin Bonding ◽  
Acid Agent ◽  
Bond Strengths ◽  
Main Component ◽  
Bonding Systems ◽  
New Generation

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.

Low-voltage, high-resolution scanning electron microscopy of polymers

1987 ◽  
Vol 45 ◽  
pp. 466-467 ◽  
Author(s):  
S. J. Krause ◽  
W.W. Adams ◽  
S. Kumar ◽  
T. Reilly ◽  
T. Suziki
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Resolution Limit ◽  
Crossover Point ◽  
New Generation ◽  
Beam Damage ◽  
Scanning Electron

Scanning electron microscopy (SEM) of polymers at routine operating voltages of 15 to 25 keV can lead to beam damage and sample image distortion due to charging. Imaging polymer samples with low accelerating voltages (0.1 to 2.0 keV), at or near the “crossover point”, can reduce beam damage, eliminate charging, and improve contrast of surface detail. However, at low voltage, beam brightness is reduced and image resolution is degraded due to chromatic aberration. A new generation of instruments has improved brightness at low voltages, but a typical SEM with a tungsten hairpin filament will have a resolution limit of about 100nm at 1keV. Recently, a new field emission gun (FEG) SEM, the Hitachi S900, was introduced with a reported resolution of 0.8nm at 30keV and 5nm at 1keV. In this research we are reporting the results of imaging coated and uncoated polymer samples at accelerating voltages between 1keV and 30keV in a tungsten hairpin SEM and in the Hitachi S900 FEG SEM.

3-Dimensional immunolabeling and in situ hybridization detection using fluorescence photooxidation and intermediate-voltage Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 164-165
Author(s):  
Thomas J. Deerinck ◽  
Maryann E. Martone ◽  
Varda Lev-Ram ◽  
David P. L. Green ◽  
Roger Y. Tsien ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Reactive Oxygen ◽  
Confocal Laser Scanning Microscope ◽  
Fluorescent Dye ◽  
Confocal Laser ◽  
3 Dimensional ◽  
Voltage Electron ◽  
Dimensional Distribution ◽  
Electron Microscopes ◽  
New Generation

The confocal laser scanning microscope has become a powerful tool in the study of the 3-dimensional distribution of proteins and specific nucleic acid sequences in cells and tissues. This is also proving to be true for a new generation of high contrast intermediate voltage electron microscopes (IVEM). Until recently, the number of labeling techniques that could be employed to allow examination of the same sample with both confocal and IVEM was rather limited. One method that can be used to take full advantage of these two technologies is fluorescence photooxidation. Specimens are labeled by a fluorescent dye and viewed with confocal microscopy followed by fluorescence photooxidation of diaminobenzidine (DAB). In this technique, a fluorescent dye is used to photooxidize DAB into an osmiophilic reaction product that can be subsequently visualized with the electron microscope. The precise reaction mechanism by which the photooxidation occurs is not known but evidence suggests that the radiationless transfer of energy from the excited-state dye molecule undergoing the phenomenon of intersystem crossing leads to the formation of reactive oxygen species such as singlet oxygen. It is this reactive oxygen that is likely crucial in the photooxidation of DAB.

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