Multidimensional spectrometry and mapping

One observes that the early developments in chemistry depended upon the improvement of the balance. Major milestones in chemistry can be related directly to improvements in balance design, precision, and accuracy. In a similar manner, the past three decades have seen dramatic improvements in spectrometers. The development of these instruments has greatly improved our understanding of polymer structure and properties. We discuss our current research in multidimensional spectrometry, imaging, and mapping. How does one determine the structure of molecules? One approach is the infrared and Raman study of the polymer vibrations to understand the structure and interactions so successfully applied by our awardee, Professor Jack Koenig. Historically, in the 1950s, the Perkin–Elmer Corp. introduced an infrared microscope for a limited number of applications. This development stimulated the thought of seeking more information about the microstructure. Today, we have a number of two-dimensional detectors for infrared and Raman studies. However, the expense of this instrumentation tends to limit its utilization. In this article, a new inexpensive approach for mapping molecular structure in polymeric materials is discussed. This new approach includes the combination of interferometers and Hadamard transform techniques to perform multidimensional spectrometry and mapping. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1307–1310, 1998     

Comparison of fat-splitting reagents in the twitchell process

Summary Commercial petroleum sulfonic acid reagents have been compared with Twitchell reagents, alkylarylsulfonic acids, and sulfoarylstearic acids as fat-splitting reagents in the hydrolysis of lard oil, tallow, cotton-seed oil, garbage grease, and inedible grease. The best reagents were made from commercial wetting agents of the alkylarylsulfonate type. Sulfoxylylstearic acid, seven petroleum sulfonic acids, and four Twitchell reagents followed in decreasing order. Observations have been made on the distribution of the fat-splitting reagent between phases, the necessity of removing the sweet water after a certain degree of hydrolysis, and the effect of the fat-splitting reagent upon the color of the crude fat acids. This is one of four Regional Research Laboratories operated by the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

A Hadamard-multiplexed spectrometer based on an acousto-optictunable filter

This paper presents a Hadamard-multiplexed spectrometer based on an acousto-optic tunable filter (AOTF). The multifrequency capability of the AOTF enables it to be operated in a multiplexed mode. The AOTF can then be operated at lower power to obtain improved passband characteristics without a reduction in the signal-to-noise ratio as compared to a higher-power, nonmultiplexing instrument. An expandable, PC-based spectrometer has been developed to illustrate this technique. The current implementation provides seven-frequency Hadamard multiplexing and collects the spectra in multiplexed blocks. The AOTF is controlled via IEEE-485 bussed VHF synthesizer modules based on a hybrid DDS/PLL technique. The modular design allows convenient system expansion. The design of and specifications for this instrument are discussed     

Cytochrome p-450 heme and the regulation of delta-aminolevulinic acid synthetase in the liver

Twenty-five human gastric and 11 human colonic adenocarcinomas were analysed for their ganglioside pattern and for their content of lipid-bound and protein-bound neuraminic acid. In most carcinomas the content of both lipid-bound and protein-bound neuraminic acid was increased by an average of four- and two-fold, respectively. The ganglioside pattern of all the carcinomas resembled that of normal tissue. In six gastric carcinomas the content of lipid-bound neuraminic acid and the ratio of lipid-bound neuraminic acid to protein-bound neuraminic acid (L/P ratio) were lower than those of normal gastric mucosa. These carcinomas were significantly larger than the rest of the tumours.     

Judging creativity: A method for assessing how and by what criteria it is done.

In 2 experiments with a total of 90 undergraduates, Ss evaluated fictitious protocols that varied in the number and uniqueness of the answers. In Exp I, Ss were instructed to use criteria for creativity; in Exp II, judgments were made according to creativity, intelligence, or gender. Productivity influenced the ratings under all 3 criteria with the largest effect being on intelligence, followed by creativity. Uniqueness had an independent influence on judgments of creativity, a borderline effect on intelligence, and no significant effect on gender. Protocols which had more answers were judged more "masculine." Results indicate that laymen share the same definition of creativity used by psychometricians and that intelligence is semantically different from creativity. It is concluded that the method offers an unobtrusive but objective way of assessing factors that enter into conceptual judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of deodorization and antioxidants on the stability of lard

Summary DEODORIZATION produced no appreciable increase in the stability of steam-rendered lard but significantly increased the stability of kettlerendered lard. A substantial increase in the stability of lard was produced by tocopherol, regardless of whether it was added as a pure compound, as a concentrate, or as a tocopherol-bearing oil. Accelerated tests showed that this increase was more than doubled when small amounts of synergists also were added. Deodorization of the lard prior to addition of the synergistic antioxidant compositions produced even greater stability. Nordihydroguaiaretic acid was more effective than tocopherol as an antioxidant for lard, as determined by both the active oxygen and the oxygen-absorption methods. Deodorization of the lard prior to addition of this antioxidant and synergists did not effect further increase in stability over that obtained by the addition of these materials to undeodorized lard. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Potential for using a digital micromirror device as a signal multiplexer in visible spectroscopy

A digital micromirror device (DMD) was tested to demonstrate its potential as a multiplexing device for the simultaneous detection of visible electromagnetic radiation. Using a Visual Basic program, four sections of the DMD were illuminated by a light source and each region of mirrors was modulated at different low frequencies (14.92, 20.00, 25.00, and 34.48 Hz). A time-domain, multiplexed signal was collected from the sectors and a Fourier transform was performed on these data. The resulting frequency-domain spectrum showed that signal intensities correlated well with what was expected. Three different times were used to establish the best frequency resolution. Using this calculated frequency resolution, a 16 s scan could allow simultaneous detection of up to 240 emission/absorption wavelengths. Data collected also shows the selectivity of micromirror regions and the ability to choose specific regions of the micromirror plane, which could be valuable for a number of spectroscopic techniques.