Transient phenomena of the codeposition of PTFE with electroless Ni?P coating at the early stage

2004 ◽  
Author(s):  
M GER
Keyword(s):  
Early Stage ◽  
Transient Phenomena ◽  
Electroless Ni

Transient lunar phenomena, deep moonquakes, and high-frequency teleseismic events: possible connections

1977 ◽  
Vol 285 (1327) ◽  
pp. 485-487 ◽  
Keyword(s):  
High Frequency ◽  
Early Stage ◽  
The Moon ◽  
Surface Phenomena ◽  
Transient Phenomena ◽  
Teleseismic Events

The positions of the epicentres of the recently discovered, high-frequency teleseismic (h.f.t.), shallow moonquakes have been compared with those of the surface phenomena known as lunar transient phenomena (l.t.p.). About 300 sites for the latter and about 17 shallow moonquake epicentres have been recorded. Most of the epicentres are within 5° of at least one l.t.p. site and the depths are given by Nakamura et al. (1974) as up to 265 km. The present paper considers some of the implications of the correlations between the two classes of sites and between the l.t.p. and the epicentres of the deep moonquakes at levels of about 800-1000 km below the surface. It appears likely that channels produced by the outrush of gases from the interior of the Moon are associated with the sites of the h.f.t. and of the l.t.p. that are almost vertically above them, and that release of gases through poorly consolidated soils at an early stage of the Moon’s history may have led to the formation of at least some of the craters on the Moon.

Spalling of intermetallic compounds during the reaction between lead-free solders and electroless Ni-P metallization

2004 ◽  
Vol 19 (8) ◽  
pp. 2428-2436 ◽  
Author(s):  
Y.C. Sohn ◽  
Jin Yu ◽  
S.K. Kang ◽  
D.Y. Shih ◽  
T.Y. Lee
Keyword(s):  
Early Stage ◽  
Thin Foil ◽  
Lead Free ◽  
Solder Paste ◽  
Deposition Method ◽  
Solder Volume ◽  
P Content ◽  
Lead Free Solders ◽  
Electroless Ni ◽  
Solder Composition

Intermetallic compound (IMC) spalling from electroless Ni-P film was investigated with lead-free solders in terms of solder-deposition methods (electroplating, solder paste, and thin foil), P content in the Ni-P film (4.6, 9, and 13 wt% P), and solder thickness (120 versus .200 μm). The reaction of Ni-P with Sn3.5Ag paste easily led to IMC spalling after 2-min reflow at 250 °C while IMCs adhered to the Ni-P layer after 10-min reflow with electroplated Sn or Sn3.5Ag. It has been shown that not only the solder composition but also the deposition method is important for IMC spalling from the Ni-P layer. The spalling increased with P content as well as with solder volume. Ni3Sn4 intermetallics formed as a needle-shaped morphology at an early stage and changed into a chunk-shape. Needle-shaped compounds exhibited a higher propensity for spalling than chunk-shaped compounds because many channels among the needle-shaped IMCs facilitated Sn penetration. A reaction between the penetrated Sn and the Ni3P layer formed a Ni3SnP layer and Ni3Sn4 IMCs spalled off the Ni3SnP surface. Dewetting of solder from the Ni3SnP layer, however, did not occur even after spalling of most IMCs.

Insights into the Electrochemical Corrosion Behavior and Mechanism of Electroless Ni-P Coating in the CO2/H2S/Cl− Environment

CORROSION ◽  
10.5006/3371 ◽  
2020 ◽  
Vol 76 (6) ◽  
pp. 578-590 ◽  
Author(s):  
Jiankuan Li ◽  
Chong Sun ◽  
Morteza Roostaei ◽  
Mahdi Mahmoudi ◽  
Vahidoddin Fattahpour ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Surface Characterization ◽  
Early Stage ◽  
Adsorbed Layer ◽  
Electrochemical Corrosion ◽  
Degradation Process ◽  
Localized Corrosion ◽  
Co2 Corrosion ◽  
Electrochemical Corrosion Behavior ◽  
Electroless Ni

The electrochemical corrosion behavior of Ni-P coating in 3.5 wt% NaCl solution-containing CO2 and H2S was investigated using electrochemical methods and surface characterization techniques. The results show that the presence of H2S can enhance the CO2 corrosion of Ni-P coated carbon steel by affecting both anodic and cathodic processes. The adsorbed layer only exists in the very early stage of corrosion and barely improves the anticorrosion performance of the coating. The formation of corrosion products (NiO and Ni3S2) renders temporary protection during immersion, but the addition of H2S accelerates the diffusion process at the electrolyte/coating interface and promotes the electrolyte penetration through the coating, causing severe localized corrosion and coating disbondment. A corrosion model is proposed to illustrate the corrosion and degradation process of Ni-P coated steel in the CO2/H2S/Cl− environment.

Alterations in the number of motoneurons containing immunoreactive calcitonin gene-related peptide(CGRP)& choline acetyltransferase(ChAT) in the cervical spinal cord of the wobbler mouse during the development of the motoneuron disease

1995 ◽  
Vol 53 ◽  
pp. 970-971
Author(s):  
L. Vacca-Galloway ◽  
Y.Q. Zhang ◽  
P. Bose ◽  
S.H. Zhang
Keyword(s):  
Spinal Cord ◽  
Early Stage ◽  
Cervical Spinal Cord ◽  
Wild Type Mouse ◽  
Reflex Response ◽  
Mouse Strains ◽  
Behavioral Tests ◽  
Wobbler Mouse ◽  
Stage 4 ◽  
Stage 1

The Wobbler mouse (wr) has been studied as a model for inherited human motoneuron diseases (MNDs). Using behavioral tests for forelimb power, walking, climbing, and the “clasp-like reflex” response, the progress of the MND can be categorized into early (Stage 1, age 21 days) and late (Stage 4, age 3 months) stages. Age-and sex-matched normal phenotype littermates (NFR/wr) were used as controls (Stage 0), as well as mice from two related wild-type mouse strains: NFR/N and a C57BI/6N. Using behavioral tests, we also detected pre-symptomatic Wobblers at postnatal ages 7 and 14 days. The mice were anesthetized and perfusion-fixed for immunocytochemical (ICC) of CGRP and ChAT in the spinal cord (C3 to C5).Using computerized morphomety (Vidas, Zeiss), the numbers of IR-CGRP labelled motoneurons were significantly lower in 14 day old Wobbler specimens compared with the controls (Fig. 1). The same trend was observed at 21 days (Stage 1) and 3 months (Stage 4). The IR-CGRP-containing motoneurons in the Wobbler specimens declined progressively with age.

Automated high-resolution microscopy: the approaches so far

1987 ◽  
Vol 45 ◽  
pp. 58-61
Author(s):  
W. O. Saxton
Keyword(s):  
High Resolution ◽  
Early Stage ◽  
Automatic Recording ◽  
Microprocessor Control ◽  
Alternative Systems ◽  
Electron Image ◽  
Complete Automation ◽  
Analysis System ◽  
High Resolution Microscopy

Recent commercial microscopes with internal microprocessor control of all major functions have already demonstrated some of the benefits anticipated from such systems, such as continuous magnification, rotation-free diffraction and magnification, automatic recording of mutually registered focal series, and fewer control knobs. Complete automation of the focusing, stigmating and alignment of a high resolution microscope, allowing focal series to be recorded at preselected focus values as well, is still imminent rather than accomplished, however; some kind of image pick-up and analysis system, fed with the electron image via a TV camera, is clearly essential for this, but several alternative systems and algorithms are still being explored. This paper reviews the options critically in turn, and stresses the need to consider alignment and focusing at an early stage, and not merely as an optional extension to a basic proposal.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

Anisotropy of interfacial defects in the initial stage of MOVPE GaAs growth On Si

1990 ◽  
Vol 48 (4) ◽  
pp. 592-593
Author(s):  
C. Vannuffel ◽  
C. Schiller ◽  
J. P. Chevalier
Keyword(s):  
Early Stage ◽  
Threading Dislocations ◽  
Mbe Growth ◽  
Detailed Mechanism ◽  
Si Substrates ◽  
Initial Stage ◽  
Interfacial Defects ◽  
Interfacial Dislocations ◽  
Step Growth ◽  
Essential Problem

Recently, interest has focused on the epitaxy of GaAs on Si as a promising material for electronic applications, potentially for integration of optoelectronic devices on silicon wafers. The essential problem concerns the 4% misfit between the two materials, and this must be accommodated by a network of interfacial dislocations with the lowest number of threading dislocations. It is thus important to understand the detailed mechanism of the formation of this network, in order to eventually reduce the dislocation density at the top of the layers.MOVPE growth is carried out on slightly misoriented, (3.5°) from (001) towards , Si substrates. Here we report on the effect of this misorientation on the interfacial defects, at a very early stage of growth. Only the first stage, of the well-known two step growth process, is thus considered. Previously, we showed that full substrate coverage occured for GaAs thicknesses of 5 nm in contrast to MBE growth, where substantially greater thicknesses are required.

1596: Choices for Definitive Treatment of Early-Stage Prostate Cancer: Results from the Compare Registry

2006 ◽  
Vol 175 (4S) ◽  
pp. 514-514
Author(s):  
David G. McLeod ◽  
Oliver Sartor ◽  
Paul F. Schellhammer ◽  
Anthony V. D'Amico ◽  
Susan Halabi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Early Stage ◽  
Definitive Treatment

644: Cathepsin D is a Marker for Early Stage Renal Cell Cancer and Predicts the Presence of Distant Metastases

2005 ◽  
Vol 173 (4S) ◽  
pp. 175-175
Author(s):  
Axel S. Merseburger ◽  
Joerg Hennenlotter ◽  
Perikles Simon ◽  
Marcus Horstmann ◽  
Arnulf Stenzl ◽  
...  
Keyword(s):  
Renal Cell Cancer ◽  
Renal Cell ◽  
Cathepsin D ◽  
Early Stage ◽  
Cell Cancer ◽  
Distant Metastases
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