The changes in microstructure and microhardness of Sn-0.5%Ag, Sn-1.0%Ag, and Sn-0.7%Cu Pb-free solders were investigated during high temperature aging at 200°C for 2 h. As-solidified microstructures, revealed by cross-polarized light microscopy, consist of relatively large grains of β-Sn phase with twinned microstructure in both Sn-Ag and Sn-Cu solders. The bright-field light microscopy display...

The structures of medium sized tin cluster anions Sn(n)(-) (n = 16-29) were determined by a combination of density functional theory, trapped ion electron diffraction and collision induced dissociation (CID). Mostly prolate structures were found with a structural motif based on only three repeatedly appearing subunit clusters, the Sn(7) pentagonal bipyramid, the Sn(9) tricapped trigonal prism a...

  Data envelopment analysis (DEA) is a nonparametric approach to evaluate theefficiency of decision making units (DMU) using mathematical programmingtechniques. Almost, all of the previous researches in stochastic DEA have been usedthe stochastic data when the inputs and outputs are normally distributed. But, thisassumption may not be true in practice. Therefore, using a normal distribution wi...

As only about 20% of sentinel node (SN) positive melanoma patients have additional non-SN lymph node involvement in the Completion Lymph Node Dissection (CLND) specimen, we tried to identify a SN positive patient group, which can be spared CLND. Micro anatomic analyses of metastatic SNs were performed to identify patient/tumor and/or SN factors predicting additional non-SN positivity as well as...

7-Ethyl-10-hydroxycamptothecin (SN-38) is a potent broad-spectrum antitumor drug derived from irinotecan hydrochloride (CPT-11). Due to its poor solubility and instability of the active lactone ring, its clinical use is significantly limited. As one of the most promising formulations for poorly water-soluble drugs, nanocrystals have attracted increasing attention. In order to solve these proble...

In this study the intermetallic (IMC) thickness of Sn-Pb, Sn-Zn and Sn-Zn-Bi solders on copper (Cu) substrate were measured at different temperatures using reflow methods. Cu6Sn5 intermetallic phase was detected between Sn-Pb solder and Cu substrate. The -Cu5Zn8 phase was detected between Sn-Zn and Sn-Zn-Bi lead-free solders with Cu substrate. The thickness of the intermetallics increases with ...

Let f : Sn → Rk be a continuous map where Sn is the unit n-sphere. Then there exists a point z ∈ Rk such that the spherical n-volumes of the ε-neighbours of the level Yz = f−1(z) ⊂ Sn, denoted Yz + ε ⊂ Sn, satisfy Vol(Yz + ε) ≥ Vol(Sn−k + ε) ( )Sn for all ε > 0, where Sn−k ⊂ Sn denotes an equatorial (n− k)-sphere. This is proven in §5.9. Remarks. (a) If k = n, and card f−1(z) ≤ 2, z ∈ Rn, then ...