Reaction Between Thin Gold Wires and Pb-Sn-In Solder (37.5%, 37.5%, 25%), Part A: The Radial Reaction Inside The Solder Mounds, Its Linear Reaction Model, Statistical Variation of Reaction Rate, and Induced Structural Changes In The Solder Mounds.

Thermodynamics favors the reaction between indium and gold, since the heat of formation of AuIn{sub 2} is 6 kcal/mole, substantially larger than the heat of formation of any other possible reaction product. Thermodynamic equilibrium between gold and the elements in the solder mound is reached only when ALL gold is converted to AuIn{sub 2}. There are two aspects to this conversion: (A) the reaction WITHIN the solder mound (called here 'radial reaction') and (B) the reaction OUTSIDE the solder mound (called here 'axial reaction') and the transition from (A) to (B). The reaction between thin gold detonator wires and the In/Pb/Sn solder mound in older detonators has been looked at repeatedly. There are, in addition, two studies which look at the reaction between indium and gold in planar geometry. All data are shown in tables I to V. It is the objective of this section dealing with aspect (A), to combine all of these results into a reaction model and to use this reaction model to reliably and conservatively predict the gold-solder reaction rate of soldered gold bridge-wires as a function of storage temperature and time

Surface structure and electronic properties of materials

A surface potential model is developed to explain dopant effects on chemical vapor deposition. Auger analysis of the interaction between allotropic forms of carbon and silicon films has shown Si-C formation for all forms by glassy carbon. LEED intensity measurements have been used to determine the mean square displacement of surface atoms of silicon single crystals, and electron loss spectroscopy has shown the effect of structure and impurities on surface states located within the band gap. A thin film of Al has been used to enhance film crystallinity at low temperature

Structures and Work Processes in Local Television : a Comparison between Germany and Canada

nicht vorhande

Reaction Between Thin Gold Wires and Pb-Sn-In Solder (37.5%, 37.5%, 25%), Part A: The Radial Reaction Inside The Solder Mounds, Its Linear Reaction Model, Statistical Variation of Reaction Rate, and Induced Structural Changes In The Solder Mounds.

Thermodynamics favors the reaction between indium and gold, since the heat of formation of AuIn{sub 2} is 6 kcal/mole, substantially larger than the heat of formation of any other possible reaction product. Thermodynamic equilibrium between gold and the elements in the solder mound is reached only when ALL gold is converted to AuIn{sub 2}. There are two aspects to this conversion: (A) the reaction WITHIN the solder mound (called here 'radial reaction') and (B) the reaction OUTSIDE the solder mound (called here 'axial reaction') and the transition from (A) to (B). The reaction between thin gold detonator wires and the In/Pb/Sn solder mound in older detonators has been looked at repeatedly. There are, in addition, two studies which look at the reaction between indium and gold in planar geometry. All data are shown in tables I to V. It is the objective of this section dealing with aspect (A), to combine all of these results into a reaction model and to use this reaction model to reliably and conservatively predict the gold-solder reaction rate of soldered gold bridge-wires as a function of storage temperature and time

Rab5-mediated endosome formation is regulated at the trans-Golgi network

Early endosomes, also called sorting endosomes, are known to mature into late endosomesvia the Rab5-mediated endolysosomal trafficking pathway. Thus, early endosome existence isthought to be maintained by the continual fusion of transport vesicles from the plasmamembrane and thetrans-Golgi network (TGN). Here we show instead that endocytosis isdispensable and post-Golgi vesicle transport is crucial for the formation of endosomes andthe subsequent endolysosomal traffic regulated by yeast Rab5 Vps21p. Fittingly, all threeproteins required for endosomal nucleotide exchange on Vps21p arefirst recruited to theTGN before transport to the endosome, namely the GEF Vps9p and the epsin-relatedadaptors Ent3/5p. The TGN recruitment of these components is distinctly controlled, withVps9p appearing to require the Arf1p GTPase, and the Rab11s, Ypt31p/32p. These resultsprovide a different view of endosome formation and identify the TGN as a critical location forregulating progress through the endolysosomal trafficking pathway

The growth of epitaxial uranium oxide observed by micro-Raman spectroscopy

Raman spectroscopy can be performed with micrometer resolution and can thus be used to determine the dependence of oxide thickness on the substrate's grain structure or local impurity inclusions. The Raman signal amplitude emitted from an epitaxial uranium oxide layer as a function of oxide thickness has been modeled for light of 632.8 nm wavelength incident on the oxide and reflected from the uranium substrate using the optical properties determined by spectrophotometry. The model shows that the Raman signal increases with oxide thickness and saturates at about 150 nm thickness. The model was compared with the measured Raman signal amplitude of an epitaxial uranium oxide layer growing in air with a known time dependence of oxide growth