January 2020 – Love of nature

GC-MS issue: GC initialization failure and system insensitivity

Posted on January 24, 2020December 13, 2021 by fumin

GC: Trace 1310 MS: TSQ 8000 Issue: Trace 1310 failed to get initiated after turing on the GC system. Solution: The PS (power supply) switching module built in GC was replaced, since its burning signs and smells on connections. Also the EI source from MS was cleaned to increase its sensitivity; pump oil was also…

Two potential issues encounted by working with summarize() after group_by() in dplyr

Posted on January 5, 2020January 6, 2020 by fumin

In both cases, summarize() does not display expected results no matter how you group_by(). (1) Loading both ‘dplyr’ and ‘plyr’. (2) Changing the data layout after group_by(). The data below is from an insect feeding experiment divided into six groups in which insects were introduced on feeding diets containing different chemicals that were extracted by…