22 research outputs found
Induced pseudoscalar coupling of the proton weak interaction
The induced pseudoscalar coupling is the least well known of the weak
coupling constants of the proton's charged--current interaction. Its size is
dictated by chiral symmetry arguments, and its measurement represents an
important test of quantum chromodynamics at low energies. During the past
decade a large body of new data relevant to the coupling has been
accumulated. This data includes measurements of radiative and non radiative
muon capture on targets ranging from hydrogen and few--nucleon systems to
complex nuclei. Herein the authors review the theoretical underpinnings of
, the experimental studies of , and the procedures and uncertainties
in extracting the coupling from data. Current puzzles are highlighted and
future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic
Problemy montaĆŒowe i lutownicze w bezoĆowiowej technice lutowania rozpĆywowego elementĂłw przewlekanych
Through hole, reflow THR is a technique that allows through-hole components to be soldered, together with SMD (Surface Mount Device) in the same reflow soldering process. The investigation results of lead-free THR manufacturing process were shown in this paper. The test boards containing different SMT passive and active components as well as components dedicated to the THR technique were used in the investigation. The influence of solder paste printing process as well as lead-free reflow soldering process on solder joints quality were reported. The obtained results have shown that parameters of the both above-mentioned processes are the most crucial in SMT containing THR technique.THR jest technikÄ
lutowania, ktĂłra umoĆŒliwia jednoczesne lutowanie rozpĆywowe elementĂłw przewlekanych i SMD. W artykule przedstawiono wyniki badaĆ bezoĆowiowego procesu THR. Podczas badaĆ wykorzystano pĆytki testowe zawierajÄ
ce rĂłĆŒnorodne elementy SMD oraz podzespoĆy dedykowane do techniki THR. Zbadano wpĆyw procesu nadruku pasty lutowniczej oraz bezoĆowiowego procesu lutowania rozpĆywowego na jakoĆÄ poĆÄ
czeĆ lutowanych. Wyniki badaĆ ukazaĆy, ĆŒe parametry obu wspomnianych wyĆŒej operacji sÄ
bardzo istotne w SMT zawierajÄ
cej technikÄ THR
Comparisons of nano-additives influence on properties of the bi-modal solder pastes for special applications
The paper presented the results of investigation of two solder pastes SnBi and SAC with different nano-particles, which could be applied for special application. It was presented that materials and samples preparation for investigation. The results of SEM analyzer of solder joints executed using these pastes and their shear strength measurements enable to make the comparison of nano-additives influence on properties of the bi-modal solders pastes. It was observed that addition of nano-particles into both solder pastes changed the microstructure of solder joints, and formed a large number of nano-sized grains with uniform distribution. For the SAC solder joints with nano-Ag particles it was also observed that specific Ag3Sn crystallites. We supposed that the Ag3Sn crystals, which created "internal net" and nano-sized grains with uniform distribution must influence the mechanical properties of the solder joints. The results of shear strength measurements of solder joints confirmed the significantly higher shear strength of bimodal solder joints in comparison to reference solder joints without nano-additives