Engineering topics
Kelly, Robert
Publications and source records attributed to Kelly, Robert.
Towards Understanding the Controlling Nature of Crack Tip Chemistry on the Stress Corrosion Cracking of Austenitic Stainless Steels.
Abstract not provided.
Thousands of small, novel genes predicted in global phage genomes
Small genes (<150nucleotides) have been systematically overlooked in phage genomes. We employ a large scale comparative genomics approach to predict >40,000 small-gene families in 2.3 million phage genome contigs. We find that small genes in phage genomes are approximately 3-fold more prevalent than in host prokaryotic genomes. Our approach enriches for small genes that are translated in microbiomes, suggesting the small genes identified are coding. More than 9,000 families encode potentially secreted or transmembrane proteins, more than 5,000families encode predicted anti-CRISPR proteins, and more than500families encode predicted antimicrobial proteins. By combining homology and genomic-neighborhood analyses, we reveal substantial novelty and diversity within phage biology, including small phage genes found in multiple host phyla, small genes encoding proteins that play essential roles in host infection, and small genes that share genomic neighborhoods and whose encoded proteins may share related functions.
Towards Understanding the Controlling Nature of Crack Tip Chemistry on the Stress Corrosion Cracking of Austenitic Stainless Steels.
Abstract not provided.
Towards Understanding the Controlling Nature of Crack Tip Chemistry on the Stress Corrosion Cracking of Austenitic Stainless Steels .
Abstract not provided.
Predicting Electrochemical Conditions in a Stress Corrosion Crack Tip and the Influence of Exposure Environment.
Abstract not provided.
Predicting Stress Corrosion Crack Tip Electrochemical Conditions and the Influence of Exposure Environment.
Abstract not provided.
Understanding Environmental Influences on an AA/SS Galvanic Couple.
Abstract not provided.
Localized Corrosion of Additively Manufactured Stainless Steels.
Abstract not provided.
Sensor Design Construction and Validation for in-situ Water Layer Thickness Determination during Accelerated Corrosion Testing.
Abstract not provided.
Determination of Key Marine Environment Effects on Maximum Pit Size Predictions.
Abstract not provided.
International Space Station (ISS) Orbital Replaceable Unit (ORU) Wet Storage Risk Assessment
The International Space Station (ISS) Program requested the NASA Engineering and Safety Center (NESC) to evaluate the risks posed by the practice of long-term wet storage of ISS Environmental Control and Life Support (ECLS) regeneration system orbital replacement units (ORUs). The ISS ECLS regeneration system removes water from urine and humidity condensate and converts it into potable water and oxygen. A total of 29 ORUs are in the ECLS system, each designed to be replaced by the ISS crew when necessary. The NESC assembled a team to review the ISS ECLS regeneration system and evaluate the potential for biofouling and corrosion. This document contains the outcome of the evaluation.
Technical Consultation of the International Space Station (ISS) Internal Active Thermal Control System (IATCS) Cooling Water Chemistry
The Internal Active Thermal Control System (IATCS) coolant exhibited unexpected chemical changes during the first year of on-orbit operation following the launch and activation in February 2001. The coolant pH dropped from 9.3 to below the minimum specification limit of 9.0, and re-equilibrated between 8.3 and 8.5. This drop in coolant pH was shown to be the result of permeation of CO2 from the cabin into the coolant via Teflon flexible hoses which created carbonic acid in the fluid. This unexpected diffusion was the result of having a cabin CO2 partial pressure higher than the ground partial pressure (average 4.0 mmHg vs. less than 0.2 mmHg). This drop in pH was followed by a concurrent increasing coolant nickel concentration. No other metal ions were observed in the coolant and based on previous tests, the source of nickel ion was thought to be the boron nickel (BNi) braze intermetallics used in the construction of HXs and cold plates. Specifically, BNi2 braze alloy was used for the IATCS IFHX and BNi3 braze alloy was used for the IATCS Airlock Servicing and Performance Checkout Unit (SPCU) HX and cold plates. Given the failure criticality of the HXs, a Corrosion Team was established by the IATCS CWG to determine the impact of the nickel corrosion on hardware performance life.