The infrared absorption spectra in the out-of-plane
bending (v₂) region of potassium nitrate were studied for
three phases. Several types of sampled were used: nujol
mulls, fused samples, and N¹⁴-N¹⁵ isotopic mixtures. The
existence of three of the reported polymorphic phases was
confirmed by the spectra. The transitions between phase...
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...
The effects of different levels of copper in the diet on growth
rates, blood and liver copper concentrations, hemoglobin levels,
and cytochrome c oxidase activities were determined in the cotton
rat. The response of the cotton rat to different levels of copper was
analagous to that of the common laboratory...
Diffusion of short chain n-alkanes was found to be faster in the
polydimethylsilicone elastomer SE-30 than in the polydimethylsilicone
oil SF-96-2000. The opposite was true for the longer chain n-alkanes
suggesting that choice of stationary phase for gas chromatography
would depend on the chain length of sample components. The dependence...
A critical study of the cold vapor atomic absorption and fluorescence instrumentation for the analysis of mercury is described. Some of the important modifications involve the reduction vessel, absorption cell, fluorescence cell, and radiation source. The new modified systems have much greater calibration sensitivities and lower detection limits than those...
A multielement spectrometer has been developed for the simultaneous determination of four elements by atomic absorption (AA) or atomic fluorescence (AF). The spectrometer is based on a multiple exit slit monochromator and uses a mirrored funnel to direct light from the various exit slits to a single photomultiplier. There are...
Both oxy-Cope and siloxy-Cope rearrangements involve
(1, 3) and (3, 3) sigrnatropic shifts. Both the concerted mechanism,
and the stepwise mechanism via a diradical intermediate are possible.
In a cyclic system such as cis-l-vinylcyclooct-3-en-l-ol, the thermal
rearrangement takes place preferably through a diradical intermediate.
At high temperature, the reaction also...
Polyhalogenated benzenes have been analyzed by standard electron capture
chemical ionization mass spectrometry (ECCI/MS), and electron monochromator mass
spectrometer (EM/MS) systems. The EM/MS experiments distinguished electronegative
compounds (especially isomers) by transient negative ions (TNIs) of the same mass but
differing energies and/or the formation of distinct TNIs of different masses...
An instrument was developed which performs analysis of the
oxygen content of air by means of a commercial polarographic oxygen
electrode. The oxygen analyzer is part of a portable instrument
which converts the current from the oxygen electrode into a pulse
whose width is proportional to the oxygen concentration. This...
The plant Senecio jacobaea (tansy ragwort) produces several macrocyclic pyrrolizidine alkaloids which cause irreversible liver cirrhosis. All of the pyrrolizidine alkaloids in Senecio jacobaea are macrocyclic diesters of the necine base retronecine, with the two most predominant being seneciphylline and jacobine. Unlike horses and cattle, sheep and goats are generally...
Phospholipids and cerebrosides of the normal chick sciatic
nerve were extracted by Folch procedures and separated with silica
gel thin-layer chromatography using various chloroform-methanol
solvents. The subsequent chemical assays were expressed as a function
of the developmental stages of the chick from 15 days of incubation
to 7 days after...
New syntheses for 2-bicyclo(3.3.1)nonanone and 7-bicyclo-(3.3.1)nonen-2-one were developed. The saturated ketone was prepared
from phenol and acrylonitrile via a novel intramolecular
S[subscript N]2 cyclization process. A Friedel-Crafts cyclization of 3-(3-cyclohexenyl)propanoyl chloride permitted synthesis of the unsaturated
ketone from 4-cyclohexene carboxaldehyde. The formation of
the bicyclo(3.3.1)nonane rather than a bicyclo(3.2.2)nonane skeleton...
Cyclopropylcyclobutene was prepared via the intermediate
dicyclopropylcarbinyl carbene which was generated by the thermal
decomposition of the sodium salt of dicyclopropylketone p-toluenesulfonylhydrazone.
The successive thermal isomerization of cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene and to vinylcyclopentene
was studied. Kinetic data were obtained for the cyclopropylcyclobutene
to 2-cyclopropyl-1, 3-butadiene isomerization in the gas...
Copper in blood and liver can be divided into several fractions.
Copper in blood is about evenly divided between erythrocytes and
plasma. Normal concentrations for most species range between one and
two parts per million. Plasma copper is mainly a copper protein,
ceruloplasmin and a loosely bound form, reacting directly...