Complete Assignments of ¹H and 13C-NMR Spectra of the 3,4-seco-Triterpene Canaric Acid isolated from Rudgea jasminoides

O ácido canárico 1 foi isolado das folhas de Rudgea jasminoides. A substância isolada é um derivado triterpênico do tipo seco-lupano e teve sua estrutura elucidada com base nos dados espectrais, principalmente em experimentos de RMN a 1D e 2D. O sitosterol, o estigmasterol e os ácidos ursólico e oleanólico também foram isolados.

FAR INFRARED-LASER LINES AND ASSIGNMENTS OF CH3OH - A REVIEW

Methyl alcohol is the most important lasing molecule in the Far-Infrared (FIR) spectral region, and the most widely used for investigation and for applications. Since the last critical review of 1984, over seventy papers have been published dealing with the FIR laser lines and the infrared spectroscopy of CH3OH. In 1984 we could list about 330 FIR laser lines, 98 of which were measured in frequency and 105 assigned. Since then more than 70 papers were published increasing the number of the known laser lines to 575 (103 measured in frequency). Also the FIR and IR spectroscopy was largely improved thanks to the analysis of high resolution FT spectra, and the number of the correctly assigned laser lines has been increased to 224. The wavenumbers of the assigned lines can now be predicted with an accuracy of about 0.001 cm-1 or better, thus approaching the accuracy of the experimental frequency measurements.

High resolution spectroscopy of (CH3OH)-C-13 around the 10R(20) CO2 laser emission: New FIR laser lines, frequency measurements and assignments

We investigated the IR absorption spectrum of (CH3OH)-C-13 around the frequency of the 10R(20) CO2 laser line. We found two absorption lines which can be excited by 10R(20) and studied the FIR laser emissions excited by this pump line using a waveguide CO2 laser of 300 MHz tunability: We report two new FIR laser lines of large offset, not previously observed due to their weakness and closeness to other stronger lines. We measured the frequencies of five FIR laser lines for the first time by an accurate heterodyne technique and present the complete assignments of the IR-FIR laser systems relative to this pump line. Furthermore we present new frequency values for two FIR laser lines whose frequencies had been previously wrongly measured. Copyright (C) 1997 Elsevier B.V. Ltd.

Investigation of (CH3OH)-C-13 methanol: new laser lines and assignments

We have reinvestigated (CH3OH)-C-13 as a source of far-infrared (FIR) laser emission using a CO2 laser as a pumping source. Thirty new FIR laser lines in the range 36.5 mum to 202.6 mum were observed and characterized. Five of them have wavelengths between 36.5 and 75 mum and have sufficient intensity to be used in LMR spectroscopy. Using Fourier-transform spectroscopic data in the infrared (IR) and FIR regions we have determined the assignment for 10 FIR laser transitions and predict nine frequencies for laser lines which have yet to be observed.

CH3OH optically pumped by a (CO2)-C-13 laser: new laser lines and assignments

We report 12 new THz (far-infrared) laser lines from methanol (CH3OH), ranging from 58.1 mu m (5.2 THz) to 624.6 mu m (0.5 THz). A(13) CO2 laser of wide tunability (110 MHz) has been used for optical pumping, allowing access to previously unexplored spectral regions. Optoacoustic absorption spectra were used as a guide to search for new THz laser lines, which have been characterized in wavelength, polarization, offset, relative intensity, and optimum operation pressure. For 20 laser lines previously observed, we have measured the absorption offset with respect to the (CO2)-C-13 laser line center.

Infrared and far-infrared spectroscopy of (CH3OH)-C-13: TeraHertz laser lines and assignments

We use a (CO2)-C-13 laser as optical pumping source to search for new THz laser lines generated from (CH3OH)-C-13. Nineteen new THz laser lines (also identified as far-infrared, FIR) ranging from 42.3 mu m (7.1 THz) to 717.7 mu m (0.42 THz) are reported. They are characterized in wavelength, offset, relative polarization, relative intensity, and optimum working pressure. We have assigned eight laser lines to specific rotational energy levels in the excited state associated with the C-O stretching mode. (c) 2006 Elsevier B.V. All rights reserved.

Assignments of FIR laser lines from optically pumped (CH3OH)-C-13

We have revisited the assignments of the far-infrared laser lines emitted by (CH3OH)-C-13 by comparing the laser systems to a high resolution Fourier transform absorption spectrum of (CH3OH)-C-13. The absorption spectrum was analyzed by means of the ''Ritz'' program, which calculates the energy level values directly from the Rydberg-Ritz combination principle. We report new assignments for 11 FIR laser transitions, 17 frequency predictions for new possible laser lines, and we confirm 11 previous assignments. (C) 1996 Academic Press, Inc.

Investigation of C-O stretching band of CD3OH: Assignments of far-infrared laser lines

We have investigated the high-resolution Fourier transform spectrum of the C-O stretching fundamental band of CD3OH in order to assign far-infrared (FIR) laser transitions. The absorption spectrum was analyzed by means of the ''Ritz'' program, which calculates the energy level values directly from the Rydberg-Ritz combination principle. We have also used the ''LaseRitz'' program to facilitate the assignment of the FIR laser lines. As a consequence we could determine 12 new assignments, confirming 4 previously proposed ones and predicting new FIR laser emissions. (C) 1997 Academic Press.

High resolution spectroscopy of 13CH3OH around the 10R(20) CO2 laser emission: New FIR laser lines, frequency measurement and assignments

We investigated the IR absorption spectrum of 13CH3OH around the frequency of the 10R(20) CO2 laser line. We found two absorption lines which can be excited by 10R(20) and studied the FIR laser emissions excited by this pump line using a waveguide CO2 laser of 300 MHz tunability. We report two new FIR laser lines of large offset, not previously observed due to their weakness and closeness to other stronger lines. We measured the frequencies of five FIR laser lines for the first time by an accurate heterodyne technique and present the complete assignments of the IR-FIR laser systems relative to this pump line. Furthermore we present new frequency values for two FIR laser lines whose frequencies had been previously wrongly measured. Copyright © 1997 Elsevier Science Ltd.

Methanol laser line assignments: evidence of four-level laser systems

The Ritz computer program, developed for facilitating the assignment of molecular Fourier transform absorption spectra and described in a previous work, determines the energy level values involved in the assigned transitions by the Rydberg-Ritz combination principle. Combining the data obtained from the analyses of high-resolution infrared (IR) and far-infrared (FIR) spectra, it is possible to predict possible FIR laser emissions of molecules. In the present work we have applied this method to the common isotopomer methanol, 12CH3 16OH, and obtained 14 proposed assignments for previously unassigned FIR laser lines. We also predict 15 possible new FIR laser emissions. For the first time, an assignment involving a four-level laser system with collisional population transfer to a slightly higher energy level is reported. © 1998 Academic Press.

Laser frequency measurements and spectroscopic assignments of optically pumped 13CH3OH

A three-laser heterodyne system was used to measure the frequencies of twelve optically pumped laser emissions from 13CH3OH in the far-infrared (FIR) region. These emissions, ranging from 54 to 142 μm, are reported with fractional uncertainties up to ±2 × 10-7 along with their polarization relative to the CO2 pump. Using the 9P32 and 10R14 CO2 lines, complete spectroscopic assignments for two laser systems were confirmed.

Sesquiterpene lactones as allelochemicals

Six new sesquiterpene lactones, annuolide H ( 3), helivypolides F, H-J ( 4, 11-13), and helieudesmanolide A ( 6), together with known compounds, were isolated from polar bioactive fractions of Helianthus annuus cv. SH-222 and Stella fresh leaf water extracts. Spectroscopic analysis of the new data for 1,2-anhydroniveusin A and 1-methoxy-4,5-dihydroniveusin A corrects some previous assignments. The compounds were tested using the etiolated wheat coleoptile bioassay, and the most active compounds were assayed in standard target species ( STS) ( Lepidium sativum, Allium cepa, Lactuca sativa, Lycopersicon esculentum, and Triticum aestivum) from 5 x 10(-4) to 10(-5) M. The most phytotoxic compounds were helivypolide F and 15-hydroxy-3-dehydrodeoxyfruticin, both of which have a carbonyl group at C-3 conjugated with two double bonds.

Um Ensaio Sobre História Oral e Educação Matemática: pontuando princípios e procedimentos

Recently, we can perceive an intensification of assignments developed into Mathematical Education with the use of oral history as a research methodology. In this article, facing the living experiences during the preparation of our Phd tasks and later, when we had the role of advisors of scientific papers and of Postgraduate students in their researches also using the same methodology, we discussed the implication of ethics, mathematical education and oral history. Furthermore, we enunciated possibilities of the posture of the researcher before interviews, texts and iconography - photos and several images-provided by collaborators of our projects on Oral history and Mathematical Education.

Systematic analysis of the Fourier transform spectrum of (CH3OH)-C-13 between 400 and 950 cm(-1)

We have investigated a high-resolution Fourier transform (FT) absorption spectrum of the (CH3OH)-C-13 isotopomer of methanol from 400 to 950 cm(-1) with the Ritz program. We present the assignments of 7160 transitions, 3021 of which belong to Asymmetry, and 4139 to E-symmetry. These transitions occur between states labeled by K quantum numbers up to 14, and by torsional quantum numbers n up to 4. The Ritz program evaluated the energies of the 4684 involved levels with an accuracy of the order of 10(-4) cm(-1). All of the assigned lines correspond to transitions involving torsionally excited levels within the ground small-amplitude vibrational state. (c) 2005 Elsevier B.V. All rights reserved.

Estudo de caso de dois acidentes do trabalho investigados com o método de árvore de causas

São apresentados dois acidentes do trabalho típicos, ocorridos em empresa de grande porte, investigados com o Método de Árvore de Causas ­ ADC, método que permite identificar o papel desempenhado por fatores gerenciais e de organização do trabalho no desencadeamento desses fenômenos. Os casos apresentados revelam a participação, na gênese dos acidentes, de fatores como designação temporária e improvisada de trabalhadores para funções e postos de trabalho, execução de tarefas deixadas à iniciativa e ao arbítrio dos trabalhadores, falta de ferramentas e de materiais apropriados à execução de tarefas e falhas na circulação de informações, entre outros. São também analisadas as indicações para o uso do método, suas potencialidades em termos de prevenção, bem como as implicações decorrentes de dificuldades de aplicação, de necessidades de treinamento e reciclagens e do dispêndio elevado de tempo para investigação de cada acidente.