Dynamics and Mechanism of Carbon Filament Formation during Methane Reforming on Supported Nickel Clusters

2020 ◽  
Vol 124 (37) ◽  
pp. 20143-20160
Author(s):  
Samuel L. Leung ◽  
Junmei Wei ◽  
William L. Holstein ◽  
Miguel Avalos-Borja ◽  
Enrique Iglesia
Keyword(s):  
Methane Reforming ◽  
Filament Formation ◽  
Carbon Filament ◽  
Nickel Clusters

Conductive Filament Formation in Printed Circuit Boards – Effects of Reflow Conditions and Flame Retardants

2009 ◽  
Author(s):  
Bhanu Sood ◽  
Michael Pecht
Keyword(s):  
Flame Retardants ◽  
Printed Circuit Boards ◽  
Electrochemical Process ◽  
Lead Free ◽  
Circuit Boards ◽  
Filament Formation ◽  
Conductive Filament ◽  
Printed Circuit ◽  
Free Solder ◽  
Halogen Free

Abstract Failures in printed circuit boards account for a significant percentage of field returns in electronic products and systems. Conductive filament formation is an electrochemical process that requires the transport of a metal through or across a nonmetallic medium under the influence of an applied electric field. With the advent of lead-free initiatives, boards are being exposed to higher temperatures during lead-free solder processing. This can weaken the glass-fiber bonding, thus enhancing conductive filament formation. The effect of the inclusion of halogen-free flame retardants on conductive filament formation in printed circuit boards is also not completely understood. Previous studies, along with analysis and examinations conducted on printed circuit boards with failure sites that were due to conductive filament formation, have shown that the conductive path is typically formed along the delaminated fiber glass and epoxy resin interfaces. This paper is a result of a year-long study on the effects of reflow temperatures, halogen-free flame retardants, glass reinforcement weave style, and conductor spacing on times to failure due to conductive filament formation.

scholarly journals The epigenetic regulator LSH maintains fork protection and genomic stability via MacroH2A deposition and RAD51 filament formation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoping Xu ◽  
Kai Ni ◽  
Yafeng He ◽  
Jianke Ren ◽  
Chongkui Sun ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Critical Role ◽  
Genomic Stability ◽  
Dna Degradation ◽  
Replication Forks ◽  
Filament Formation ◽  
Epigenetic Regulator ◽  
Centromeric Instability ◽  
Stalled Replication Forks

AbstractThe Immunodeficiency Centromeric Instability Facial Anomalies (ICF) 4 syndrome is caused by mutations in LSH/HELLS, a chromatin remodeler promoting incorporation of histone variant macroH2A. Here, we demonstrate that LSH depletion results in degradation of nascent DNA at stalled replication forks and the generation of genomic instability. The protection of stalled forks is mediated by macroH2A, whose knockdown mimics LSH depletion and whose overexpression rescues nascent DNA degradation. LSH or macroH2A deficiency leads to an impairment of RAD51 loading, a factor that prevents MRE11 and EXO1 mediated nascent DNA degradation. The defect in RAD51 loading is linked to a disbalance of BRCA1 and 53BP1 accumulation at stalled forks. This is associated with perturbed histone modifications, including abnormal H4K20 methylation that is critical for BRCA1 enrichment and 53BP1 exclusion. Altogether, our results illuminate the mechanism underlying a human syndrome and reveal a critical role of LSH mediated chromatin remodeling in genomic stability.

First principles investigation of physically conductive bridge filament formation of aluminum doped perovskite materials for neuromorphic memristive applications

2021 ◽  
Vol 150 ◽  
pp. 111111
Author(s):  
Turki Alsuwian ◽  
Farhana Kousar ◽  
Umbreen Rasheed ◽  
Muhammad Imran ◽  
Fayyaz Hussain ◽  
...  
Keyword(s):  
First Principles ◽  
Filament Formation ◽  
Perovskite Materials ◽  
Conductive Bridge
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