Measuring The Difference In Collisional Interaction Of Hcn/hnc With He At Low Temperatures Using The Cpuf Technique

The T$_{2}$ time of HCN and HNC in He was measured at low temperatures using chirped pulse Fourier transform millimeter wave spectroscopy, to compare to scattering calculations and to investigate the difference of interaction between the two structural isomers. These molecules are commonly observed in the interstellar medium (ISM), where their abundance ratio can be used to elucidate conditions within an interstellar environment. Within these environments, they are expected to collide with He and H$_{2}$, which could lead to non-thermal excitation. Previous ab initio calculations of the collisions with He and H2 with HCN and HNC have shown that the rates for HNC with these colliders are much greater, despite their similarities in structure. We have performed CPUF (Chirped pulse in Uniform Flow) experiments to measure the difference in T$_{2}$ of HCN and HNC at cold temperatures in He. The J=1-0 transitions of HCN and HNC were observed in under CRESU (Reaction Kinetics in Uniform Supersonic Flow) conditions using cold flows of He. Pulsed laser photolysis of vinyl cyanide was used to produce HCN and HNC under comparable conditions. The T$_{2}$ time was fit directly from the free induction decays of these experiments at different temperatures, which is directly comparable to the linewidth in the frequency domain. This was then compared to pressure broadening cross sections produced from close coupling scattering calculations performed on ab initio potential energy surfaces. We find that there is a difference in interaction of HCN and HNC with He at low temperatures and will discuss the impacts this may have for observing these species in the ISM

Chirped pulse microwave spectroscopy on methyl butanoate

The microwave spectrum of methyl butanoate has been taken from 8-18 GHz using a chirped pulse spectrometer. This molecule is a model biofuel, and its thermal decomposition products are of interest due to its many dissociation channels. As a preliminary step before such pyrolysis studies, we have examined the jet cooled spectrum of methyl butanoate in a chirped pulse spectrometer, which shows a very rich spectrum. Several conformers have been identified, each with tunneling splittings in the methyl ester group due to internal rotation. These spectra have been fit to obtain rotational constants, relative populations, and methyl rotor barriers for each conformational isomer. The results of these studies are compared to high level calculations

FAST SWEEPING DIRECT ABSORPTION (SUB)MILLIMETER SPECTROSCOPY BASED ON CHIRPED-PULSE TECHNOLOGY

Chriped-pulse Fourier Transform Microwave (CP-FTMW) technology has transformed traditional microwave spectroscopy into a rapid-acquisition, broadband spectral technique. The CP-FT technique has recently been expanded to the millimeter-wave region, but this approach requires costly equipment that is not readily available in most spectroscopy labs. To overcome this challenge, a new experiment has been designed that combines the broadband aspects of CP-FTMW with the high sensitivity of (sub) millimeter absorption spectroscopy. Using the arbitrary waveform generator from a CP-FTMW experiment, and the frequency multipliers and hot electron bolometer detector from a (sub) millimeter wave experiment, we have designed and benchmarked a highly sensitive spectrometer that offers broad spectral coverage and rapid spectral acquisition speeds. This technique is comparable in performance to other rapid-acquisition techniques currently used in the (sub) millimeter range, but offers more sensitivity after averaging. The design of this instrument and the benchmarking results will be presented

FAST SWEEPING DOUBLE RESONANCE MICROWAVE-(SUB)MILLIMETER SPECTROSCOPY BASED ON CHIRPED PULSE TECHNOLOGY

Microwave-millimeter double resonance spectroscopy has been commonly applied by driving absorption with the millimeter light and then probing the resonance using a Fourier Transform Microwave (FTMW) spectrometer. We will present data from an inverse scheme, in which millimeter light is used to probe a transition whose intensity is modulated by the application of microwave radiation. This detection scheme is effective in aiding the assignment of millimeter-wave transitions by revealing which energy levels are associated with particular spectral lines. To increase the speed of this detection technique, we incorporated an arbitrary waveform generator into the microwave source to rapidly sweep the microwave radiation through a broad frequency range. We will discuss this approach as applied to pulsed valve experiments and in combination with a laser-induced chemistry experiment. Potential applications to other experimental designs will also be discussed

DETECTING BRANCHING RATIOS OF CHEMICAL REACTIONS AT ASTROPHYSICALLY RELEVANT TEMPERATURES USING CHIRPED PULSE MILLIMETER WAVE SPECTROSCOPY IN CONTINUOUS CRESU FLOWS

The reactions of molecules in interstellar space occur over a wide range of temperatures, down to 10 K or colder. The study of gas-phase chemical reactions at these temperatures has been difficult until the development and implementation of the CRESU (French acronym for Reaction Kinetics in Uniform Supersonic Flow) technique in Rennes. Reaction kinetics at temperatures as low as 6 K has been monitored, but product branching ratios have not yet been measured at such low temperatures. The recent development of the CPUF (Chirped Pulse in Uniform supersonic Flow) technique has shown that chirped pulse spectroscopy can be combined with uniform supersonic flows, so that the branching ratios of chemical reactions can be examined. This has been extended to the continuous CRESU flows at Rennes, taking advantage of the deep averaging capabilities of chirped pulse Fourier transform spectrometers complementing the continuous flows. An E-band chirped pulse Fourier transform spectrometer has been incorporated into a current CRESU instrument to detect reaction products. The effects that the uniform flow has on molecular spectra have been characterized in this frequency range. Reactions of ethylene and cyanide radicals have been monitored using pulsed laser photolysis for product detection. The branching ratios of reactions will be discussed, as well as future directions of the instrument

Can Secondary Teaching Graduates Support Literacy in the Classroom? Evidence from Undergraduate Assignments

Education policy in Australia and comparable countries requires that all secondary content teachers actively teach the literacy of their learning area and support the literacy development of students in their classes. In this paper we present evidence on the capacity of graduating teachers to meet that obligation. We review assessment data from 393 Initial Teacher Education students who completed a core unit in secondary curriculum literacy prior to graduation. We report that while the majority met the unit requirements, approximately 30% graduated as teachers with marginal or inadequate capacity to teach the literacy of their subject or support student learning through literacy. Approximately 12% of the sampled cohort failed the unit on their first attempt; yet 76% of those who failed went on to graduate. We show that such performance is consistent across the secondary disciplines included in the survey. We pose the questions as to whether secondary teachers with a marginal command of literacy strategies and poor literacy knowledge can be expected to provide effective literacy support, and whether education policy goals and provision of training in this area are therefore realistic

ROTATIONAL SPECTROSCOPY AND CONFORMATIONAL STUDIES OF 4-PENTYNENITRILE, 4-PENTENENITRILE, AND GLUTARONITRILE

The pure rotational spectra of 4-pentynenitrile, 4-pentenenitrile, and glutaronitrile were acquired using chirped pulse Fouirer transform microwave spectroscopy. 4-pentynenitrile and 4-pentenenitrile are the recombination products of two resonance stabilized radicals, propargyl + cyanomethyl or allyl + cyanomethyl, respectively, and are thus anticipated to be significant among the more complex nitriles in Titan's atmosphere. Indeed, these partially unsaturated alkyl cyanides have been found in laboratory analogs of tholins and are also expected to have interesting photochemistry. The optimized structures of all conformers below predicted energies of 500 wn were calculated for each molecule. Both of the conformers, trans and gauche, for 4-pentynenitrile have been identified and assigned. Five conformers were assigned in 4-pentenenitrile. The eclipsed conformers, with respect to the vinyl group, dominate the spectrum but some population was found in the syn conformers including the syn-gauche conformer, calculated to be 324 wn above the global minimum. The glutaronitrile spectrum contained only the two conformers below 500 wn, with reduced amount of the gauche trans conformer. The assigned spectra and structural assignments will be presented

Restoring Native Grasslands

4 pp., 5 color photos, 1 map, 3 graphsMuch of Texas' native grasslands has been converted to improved pastures and cropland, neither of which is suitable for wildlife habitat. Now, many landowners are interested in restoring native grasses because they are cheaper to produce for forage than are improved pastures and they also encourage wildlife. This publication explains how to carry out such restoration and the results to expect

Potential hazards of air pollutant emissions from unconventional oil and natural gas operations on the respiratory health of children and infants

Abstract: Research on air pollutant emissions associated with unconventional oil and gas (UOG) development has grown significantly in recent years. Empirical investigations have focused on the identification and measurement of oil and gas air pollutants [e.g. volatile organic compounds (VOCs), particulate matter (PM), methane] and the influence of UOG on local and regional ambient air quality (e.g. tropospheric ozone). While more studies to better characterize spatial and temporal trends in exposure among children and newborns near UOG sites are needed, existing research suggests that exposure to air pollutants emitted during lifecycle operations can potentially lead to adverse respiratory outcomes in this population. Children are known to be at a greater risk from exposure to air pollutants, which can impair lung function and neurodevelopment, or exacerbate existing conditions, such as asthma, because the respiratory system is particularly vulnerable during development inutero, the postnatal period, and early childhood. In this article, we review the literature relevant to respiratory risks of UOG on infants and children. Existing epidemiology studies document the impact of air pollutant exposure on children in other contexts and suggest impacts near UOG. Research is sparse on long-term health risks associated with frequent acute exposures -especially in children -hence our interpretation of these findings may be conservative. Many data gaps remain, but existing data support precautionary measures to protect the health of infants and children

Prospectus, February 23, 1983

TA PROGRAM DROPPED; News Digest; Senator says monies spent to benefit college, students: StuGo answers students responses; 3 aides say board unfair; Handicap is no barrier; Spring players needed; Tests taken; Skylines; Millikin to visit, talk; Age is no barrier to senior citizens; Time to stop playing games; PAL lends an ear to students; Lab teaches learning skills; Different views expressed on how to celebrate: How do you think Black History Month should be celebrated?; Theresa Yoder wins Taxley scholarship; Job seekers can learn; C-U happenings; Club News; Classified; Trivia quiz!; Touchy subject is beautifully handled; Dio outdoes Osborne; MVP award goes to Sue Cline; Intramural Results; Point spread takes game; PC second in CIAChttps://spark.parkland.edu/prospectus_1983/1024/thumbnail.jp