MA

thesisSulphur exists in metallurgical coke as a source of annoyance and difficulties in the economic progress of the metal industries. It ie present in coal in several different forms under two heads as organic and inorganic sulphur. The percentage of the forms vary widely in different coals. In the manufacture of coke, varying ajnounte of sulphur a=a retained by the same coal under different methods of carbonization, and, by different coals under the same method of treatment . It is desirable to know the factors that influence the distribution of the element between the gases and the residues of coal in the manufacture of metallurgical coke, and, for that reason it is an important problem at present which means a saving of millions of dollars to the metal industry. Analyses of the forms of sulphur in several samples of Utah coals appear elsewhere in this paper. The samples were received from the offices of the yards in Salt Lake Oity and analyzed according to the methods used by Prof- S. W. Parr and A. R. Powell on several Eastern coals

Thermal rearrangement studies of deuterium labeled dibenzo [a,e] cyclooctatetraenes

In an attempt to further substantiate the findings of Stiles and Salisbury on the rearrangement of aryl disubstiuted dibenzo [a, e] cyclooctatetraenes a new pair of derivatives were synthesized. The 5,6 and 5,11 dideuteriodibenzo-[a,e] cyclcoctetetraenes were prepared. The 5,6 derivative was prepared starting with dibenzo [a,e] cyclooctene-5,6-dione. The 5,11 derivative was prepared starting with o-tolualdehyde. In the case of the 5,6 derivative the deuterium was introduced by a LiAlD4 reduction of the dibenzo [a,e]-cyclooctene-5,6-dione. The 5,11 derivative had been labeled with deuterium in the final step during the Wittig reaction. The use of methanol-d1 as the solvent in place of methanol facilitated the exchange. These compounds can be distinguished by proton nuclear magnetic resonance spectroscopy. The 5,6 derivative had a n.m.r. spectrum with a sharp singlet in the olefinic region. The 5,11 derivative had a n.m.r. spectrum with an unresolved triplet in the olefinic region. The corresponding 5,6 aryl disubstituted dibenzo [a,e] cycloocta-tetraenes were shown by Stiles and Salisbury to rearrange to the 5,11 isomer. Supporting evidence for a diradical intermediate was developed by use of benzenethiol in trapping experiments. Our thermolysis studies revealed no rearrangement with the deuterium labeled species. The temperature at which our experiments were conducted exceeds other published experimental data with aryl substituents which underwent yield rearrangements. Therefore the lack of stabilization by the deuterium as opposed to the phenyl substituents in this rearrangement lends credence to the diradical intermediates

Interactive digital signal processor

The Interactive Digital Signal Processor (IDSP) is examined. It consists of a set of time series analysis Operators each of which operates on an input file to produce an output file. The operators can be executed in any order that makes sense and recursively, if desired. The operators are the various algorithms used in digital time series analysis work. User written operators can be easily interfaced to the sysatem. The system can be operated both interactively and in batch mode. In IDSP a file can consist of up to n (currently n=8) simultaneous time series. IDSP currently includes over thirty standard operators that range from Fourier transform operations, design and application of digital filters, eigenvalue analysis, to operators that provide graphical output, allow batch operation, editing and display information

High-Mass Star Formation in the Outer Scutum-Centaurus Arm

The Outer Scutum-Centaurus (OSC) spiral arm is the most distant molecular spiral arm in the Milky Way, but until recently little was known about this structure. Discovered by Dame and Thaddeus (2011), the OSC lies $\sim$15 kpc from the Galactic Center. Due to the Galactic warp, it rises to nearly 4$^{\circ}$ above the Galactic Plane in the first Galactic quadrant, leaving it unsampled by most Galactic plane surveys. Here we observe HII region candidates spatially coincident with the OSC using the Very Large Array to image radio continuum emission from 65 targets and the Green Bank Telescope to search for ammonia and water maser emission from 75 targets. This sample, drawn from the WISE Catalog of Galactic HII Regions, represents every HII region candidate near the longitude-latitude (l,v) locus of the OSC. Coupled with their characteristic mid-infrared morphologies, detection of radio continuum emission strongly suggests that a target is a bona fide HII region. Detections of associated ammonia or water maser emission allow us to derive a kinematic distance and determine if the velocity of the region is consistent with that of the OSC. Nearly 60% of the observed sources were detected in radio continuum, and over 20% have ammonia or water maser detections. The velocities of these sources mainly place them beyond the Solar orbit. These very distant high-mass stars have stellar spectral types as early as O4. We associate high-mass star formation at 2 new locations with the OSC, increasing the total number of detected HII regions in the OSC to 12.Comment: 14 pages text and tables + 10 pages supplemental figure

Bulk Segregant Analysis by High-Throughput Sequencing Reveals a Novel Xylose Utilization Gene from Saccharomyces cerevisiae

Fermentation of xylose is a fundamental requirement for the efficient production of ethanol from lignocellulosic biomass sources. Although they aggressively ferment hexoses, it has long been thought that native Saccharomyces cerevisiae strains cannot grow fermentatively or non-fermentatively on xylose. Population surveys have uncovered a few naturally occurring strains that are weakly xylose-positive, and some S. cerevisiae have been genetically engineered to ferment xylose, but no strain, either natural or engineered, has yet been reported to ferment xylose as efficiently as glucose. Here, we used a medium-throughput screen to identify Saccharomyces strains that can increase in optical density when xylose is presented as the sole carbon source. We identified 38 strains that have this xylose utilization phenotype, including strains of S. cerevisiae, other sensu stricto members, and hybrids between them. All the S. cerevisiae xylose-utilizing strains we identified are wine yeasts, and for those that could produce meiotic progeny, the xylose phenotype segregates as a single gene trait. We mapped this gene by Bulk Segregant Analysis (BSA) using tiling microarrays and high-throughput sequencing. The gene is a putative xylitol dehydrogenase, which we name XDH1, and is located in the subtelomeric region of the right end of chromosome XV in a region not present in the S288c reference genome. We further characterized the xylose phenotype by performing gene expression microarrays and by genetically dissecting the endogenous Saccharomyces xylose pathway. We have demonstrated that natural S. cerevisiae yeasts are capable of utilizing xylose as the sole carbon source, characterized the genetic basis for this trait as well as the endogenous xylose utilization pathway, and demonstrated the feasibility of BSA using high-throughput sequencing