The study of the obstructive factor by Hawkes (11) showed a relation
between the obstructive factor and velocity using a continuous
method. Later, Bowers and Hawkes (12) developed a similar method with
some improvements in the apparatus and found out that the obstructive
factor was not flow dependent. This study...
A specially designed gas chromatograph with both TCD and FID has
been tested for the measurement of the diffusion coefficients of methane and propane in helium. Knox's arrested elution technique(⁴) was used and yielded a value of 0.6431 cm²/sec averaged with the value
obtained by Yang and Hawkes(⁷). Values of...
Ultraviolet spectroscopy and dispersive solubility parameters
correlated to the ratios of retention times have proven valuable in
classification of gas chromatography stationary phases by the donor-acceptor
properties. Iodine was directly dissolved into stationary
phases and the absorption frequency shift of complexes was correlated
with the carbon tetrachloride/chloroform retention ratio on...
Significant figures have been a nebulous area in the physical sciences. The results of a literature survey, and of a questionaire distributed among the Chemistry Department faculty at Oregon State University, revealed widely differing interpretations regarding the proper role of significant figures. The present study has a two-fold nature. First...
Our experiments aimed to investigate responses of the marine cyanobacteria Prochlorococcus and Synechococcus to toxic arsenic species, such as arsenate, and to understand cellular mechanisms that contribute to arsenic tolerance. We used two strains of Prochlorococcus, a high-light adapted MED4 and low-light adapted MIT9313, both axenic, for cultivation experiments. For...
Oligotrophic bacteria are adapted to low nutrient concentrations. As most of the ocean is oligotrophic (low in nutrients), oligotrophic bacteria thrive in the ocean and make up the majority of planktonic cells. Because of this, oligotrophs are crucial to oceanic nutrient cycles. However, marine oligotrophic bacteria are dwarfed by their...
Oceanic carbon cycling plays a major role in determining global atmospheric CO₂. A better understanding of dissolved organic matter and its constituents in the water column and how it affects marine carbon cycling is sought after. This study successfully measured osmolytes, low molecular zwitterionic compounds derived from amino acids, in...
Historically, the difficulty of obtaining pure cultures of abundant marine
microbial plankton has an obstacle to reconstructing the underlying
mechanisms of biogeochemistry in the ocean. While a number of dominant
marine species from the ocean surface have been cultured, the dominant
microbial plankton of the dark ocean proved far more...
Over 100 monthly bacterioplankton DNA samples, from each of the surface and 200 m depths at the Bermuda Atlantic Time-series Study (BATS) site, were analyzed for community assembly processes. Correlation networks, filtered for potential autocorrelation artifacts, were constructed for each depth. Network characteristics for the two depths were remarkably similar...