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AbstractThe essential oils from twigs and seeds of Pituranthos scoparius(Coss et Dur.) Benth. et Hook. (Umbelliferae) obtained by hydrodistillation, were analyzed by GC/MS. From the two oils, 150 and 50 mass spectra were recorded, respectively. Approximately, 94 compounds were identified including 34 hydrocarbons (4 aromatic, 12 monoterpene, 18 sesquiterpene), 2 oxides, 8 aldehydes, 10 ketones, 24 alcohols, 9 phenolic derivatives and 7 miscellaneous compounds. Numerous additional compounds, mainly sesquiterpenoids, remain unidentified. The twig oil contained α-pinene (34%) and apiole (15%) as the two principal components. The major constituents in the seed oil were apiole (52%), bornyl acetate (21%) and α-pinene (11%).

ABSTRACTThe GC/MS analysis of an essential oil of Artemisia herba albafrom Algeria has shown the presence often cis-chrysanthenyl esters among more than 300 compounds separated. Identifications were based upon mass spectra and Kovats indices of known cis-chrysanthenol and its acetate.

We measure the wavefront coherence and the irradiance fluctuations of stellar sources to obtain integrated refractive-turbulence profiles of two regions of the atmosphere. Comparison of experimental data during our measurement program shows an equal contribution of upper and lower layers to the limitation of the optical seeing. We also note the great variability of turbulence located above 3 km up to the stratosphere, from night to night. When simultaneously operated, these two methods are suitable for astronomical site testing.

The separation of the structure functions of the (e,e'p) cross-sections is presented. Results of this separation are given for light nuclei : 2H, 3He and 4He and a comparison with theoretical calculations is made. These results may be interpreted as a modification of the nucleon form-factors in the nuclear medium.

We measured three out of four structure functions of the (e,e'p) cross-section on 2H and 3He nuclei as a function of the initial proton momentum. Comparison with theoretical calculations indicates no significant departure from PWIA. The deduced spectral functions are in good agreement with recent calculations of the two or three-body wave functions.

AbstractHelichrysum stoechasL. plants were hydrodistilled and the oil, which was obtained in 0.04% yield, was analyzed by GC and GC/MS. The major components were α-pinene (63%), limonene (14%), β-caryophyllene (2.8%) and α-humulene (2%). Other separated components (≃90) accounted for less than 10% of the oil.

The results obtained from 3398 vertical profiles of atmospheric turbulence measured during 11 nights at the Observatorio Astronómico Nacional in San Pedro Mártir (Baja California, México) are presented. The observations were carried out with the generalized scidar (GS) installed at the 1.5 m and the 2.1 m telescopes of that site, in 1997 March and April. The open-air seeing was measured with a differential image motion monitor (DIMM). The GS can detect turbulence profiles along the whole optical path, unlike the classical scidar, which is insensitive to low-altitude turbulence. For the first time, to our knowledge, profiles including turbulence near the ground are monitored and statistically analyzed. Isoplanatic angles for speckle interferometry and adaptive optics (AO) in either full or partial compensation are deduced, as well as the focus anisoplanatism parameter for sodium laser guide stars. The advantage of minimizing the distance between the turbulent layers and the conjugated plane of the deformable mirror of an AO system is studied. The comparison of GS profiles obtained at both telescopes, together with DIMM measurements, show that the turbulence near the ground is more strongly dominant at the 1.5 m telescope than at the 2.1 m telescope, where the median values of the seeing near the ground, in the free atmosphere and in the whole optical path are 0.?56, 0.?44 and 0.?77, respectively. These values are comparable to or better than those of the major astronomical observatories, although a larger data sample is needed for a definitive comparison.

During the last two decades, much effort has been put into the remote sensing of atmospheric turbulent layers, using optical devices. The main scientific interest concerns optical path fluctuations relevant to communication and astronomy and the widening of our understanding of atmospheric physics. Here we describe an original technique that involves moving a virtual plane of analysis in the atmosphere. Using this technique, a simple optical combination allows us to explore the atmosphere, wiping out a particular layer while distant layers located beneath or above are reinforced. When combined with the SCIDAR technique, this phenomenon leads to the "generalized SCIDAR" concept, allowing turbulence profiles to be remotely assessed throughout the whole atmosphere, including the boundary layer. The potential of this new concept is shown in a laboratory experiment using a vein to simulate an atmospheric turbulent layer.

Using a combination of gas chromatography-mass spectrometry (electron impact) as well as the headspace technique, more than 70 compounds were found in the juniper needle oil obtained from plants growing in southeastern France (Provence). A comparison between the headspace of fresh and bottled black berries shows a significant loss of the monoterpenoid fraction with time. In the green berries (unripe) this loss is more marked. A sesquiterpenoid fraction of the Juniperus communisneedle oil was also investigated by means of the GC (FID) and GC-MS (EI, PCI). Among more than 100 isolated constituents, 64 were sesquiterpenoids. The presence of several oxygen-containing derivatives based on the calamene and calacorene isomers was established but their structures were not fully determined. The various compounds were identified on the basis of our SPECMA data bank (mass spectra and Kováts indices) and our own files.

ABSTRACTThe essential oil from Cistus ladaniferusL. was separated into acidic/phenolic fraction and neutral fraction by extraction with a sodium hydroxide solution. The acidic/phenolic fraction was converted into methyl esters and ethers. The analysis of this fraction by GC/MS on a nonpolar column resulted in the identification of 40 acids (aliphatic and terpenic) and 14 phenols.

ABSTRACTThe GC/MS analysis of an essential oil of Cistus ladaniferusL. has shown the presence of 300 compounds. Four phenyl propanoic acid esters were identified on the basis of their fragmentation patterns and Kovats indices.

Correlation measurements of the scintillation of single and double stars are described and interpreted in terms of discrete turbulent layers. For each observed layer, an approximate altitude is determined and the index and temperature structure constants integrated over the layer thickness are estimated. Results are in good agreement with in situ measurements performed elsewhere.

Lens-atmosphere modulation transfer function measurements are presented for speckle interferometry using the 193 cm telescope of the Observatoire de Haute Provence, France. A single photoelectric scanning detector is used to record the speckle pattern, and real-time data processing is achieved using a power spectrum analyser. Normal and log-normal models are used to compare theory with experiment. The results are in substantial agreement with Korff's log-normal assumptions.

Two-color single-star scintillation cross-correlation functions are estimated involving the use of two wavelength filters centered on 409 and 800 nm. From these estimations and using the atmospheric dispersion theory already proposed by Hudgin, turbulent layer heights are measured. Then, vertical Cn2Δh profiles are obtained every 2 min 45 sec using the slowly decreasing elevation of Sirius. The coherence with another method proves its interest. Furthermore, when the zenith angle of the observed star exceeds ~70°, turbulence heights smaller than 800 m (otherwise unattainable with stellar scintillation measurements) can be detected with a vertical resolution of 300 m.

The spatiotemporal cross-correlation function of single-star scintillation is estimated. From this estimation and using a priori knowledge of the theoretical shape of the correlation peaks, a method for simultaneously measuring horizontal velocity, altitude, and integrated CN2 value for each atmospheric turbulent layer between 2 and 20 km is described. Taylor’s hypothesis is tested for one particular layer and the lifetime of certain turbulent eddies is estimated. Results are in good agreement with two other methods.

ABSTRACTGC/MS analysis of the leaf oil of Cryptomeria japonicaD. Don obtained from Reunion allowed us to identify more than 70 compounds thanks to our SPECMA data bank. Among the volatiles, monoterpene hydrocarbons (45%), monoterpene alcohols (10%), monoterpene esters (2%), sesquiterpenes (25%) and diterpenes (12%) have been found. The presence of a moderate amount of α-kaurene (10%) and its 16-hydroxylated derivative (0.6%) was noted. The composition of the C. japonicafrom Reunion was found to be similar to that originating from Japan. Unidentified sesquiterpene and diterpene derivatives require further attention.

ABSTRACTThe essential oil, which was obtained by hydrodistillation from aerial parts of Achillea millefoliumL. complex (Compositae), was analyzed using both GC/MS and Kovat's indices. The major components extracted from the stems, leaves and inflorescences were found to be β-thujone (8.3–21.7%), camphor (8.6–11.7%), 1, 8-cineole (7.7–15.2%), β-pinene (3.8–7.8%) and sabinene (5.7–8.9%). More than sixty components have been identified; forty of which, mainly oxygenated compounds, are reported for the first time. Variations in the essential oil composition and yield during hydrodistillation are also reported.

ABSTRACTThe essential oil of Santolina chamaecyparissusL. was analyzed by a combination of gas chromatography and mass spectrometry. The oil was found to contain over 140 constituents of which 70 were identified. The major components were artemisia ketone (ca. 45%) and myrcene (15%).

Up to now only a few numerical or experimental simulations of atmospheric turbulent layers have been performed in the laboratory. These are devoted mainly to show the validity of Kolmogorov behavior but are not suitable to implement in an optical bench to test light propagation. Here we present a small size experimental simulation of an optical turbulent layer. With optical and in situ measurements, we managed to determine its characteristics: the mean variance of the refractive-index fluctuations integrated over the thickness of the turbulent flow and longitudinal and transverse structure functions of angles of arrival. From these measurements we found that the power spectrum of the refractive index is well fitted by a Von Karman function with an outer scale of 91 mm and an inner scale of 4.7 mm. Moreover, the temporal stationarity of these parameters indicates the reproducibility of this simulated turbulent flow.

Data from balloon soundings taken at sites in the Canary Islands, France, and Chile are used to show that hydrodynamic instability, perhaps engendered by the propagation of buoyancy (gravity) or other waves, leads to the formation of thin, turbulent laminae, or “seeing layers.” These seeing layers occur almost invariably in pairs and exhibit large values for the temperature-structure coefficient CT^2 because they form where the gradient of temperature is particularly steep. The refractive-index-structure coefficient is correspondingly large, and so these layers adversely affect the quality of optical propagation. The mechanism proposed here is already known to create clear air turbulence in the stratosphere, and we show how it is consistent with the formation of thin turbulent seeing layers in the troposphere and the stratosphere at night, when the atmosphere is generally stably stratified.

The small value found for the outer scale of turbulence (namely, ≤5 m) implies a narrow range of validity for application of Kolmogorov’s law to calculate the atmospheric limitations to the performance of telescopes and interferometers. Optical and radio seeing measurements are analyzed in support of a proposed turbulence spectrum which exhibits a spectral gap for scales (and hence interferometer baselines) between ∼10 and 1500 m but which obeys a 5/3 power law between 1500 and 20,000 m. The implications for forecasting the performance of optical and radio telescopes and interferometers are important.

A photoelectric apparatus enabled us to obtain new estimates of the longitudinal and transverse correlation functions for the angle-of-arrival fluctuations on the entrance pupil of a solar telescope. The inertial model of turbulence was verified for spatial shifts up to 35 cm. Measurements of the turbulent-layers velocity were taken. The values found for Fried’s parameter r_0, the integral ∫C^2Ndh of the structure constant for the variations of the refractive index of the air over the thickness of the lower atmosphere, and the root-mean-square fluctuation of the angles of arrival appear to agree with independent estimates.

Accurate, absolute and reproducible measurements are the expected qualities of any instrument. A Differential Image Motion Monitor (DIMM) is presented which assesses astronomical seeing with those requirements. It has been designed also to be reliable, simple, trasportable, and to be easy to set up, operate and maintain. Its accuracy has been studied, both from theoretical and experimental points of view, mainly with respect to CCD sampling, photon noise and threshold influence on centroid determination. The DA/IAC DIMM has been cross-calibrated with the existing ESO DIMM. It monitors the seeing with a temporal resolution better than half a minute. This type of instrument is essential for testing new and already existing sites and to ascertain that the surroundings of telescopes do not generate additional turbulence. It is also indispensible to optimize astronomical instrument selection in "flexible scheduling.".

The outer scale of turbulence L_0 has been calculated from values of the refractive-index structure coefficient CN2 obtained from spatio-angular correlation measurements of stellar scintillation. It is found that L_0 ≤ 5 m for a large range of observations in France, U.S.A., and Chile and that its dependence on altitude Z follows the same general form at all these sites. The prediction of CN2(Z) profiles is shown to be feasible utilizing standard meteorological radiosonde data and this L_0(Z) curve. A simple model based on dimensional analysis and a more complicated stochastic model are compared, but the latter appears to have no advantage.

In this paper we describe a two-part experiment: measuring atmospheric turbulence both optically and thermally from 2 km up to the stratosphere. The consistency of the results shows that the optical technique may be a powerful tool for studying atmospheric turbulence from ground-based equipment.

A retrospective study was done to determine the epidemiology of infection and/or colonization due to Pseudomonas aeruginosa in a Brazilian general hospital. In 1966, 1968, and 1969, there were only two instances where probable cross-contamination was shown; the remaining isolates were unrelated. In late 1971 the hospital experienced a marked increase in P. aeruginosa isolation. Contaminated dextrose solutions used in the infant feeding were the apparent cause of the problem which occurred in the premature and special care nurseries. A contaminated oxygen humidifying bottle was the source of a different outbreak in surgery. There was also evidence in four instances that cross-infection and/or contamination had occurred. Pyocin and serological typing revealed that many strains were involved and led to a clear understanding of the complex epidemiological relationships among all the strains.

Data obtained by two optical ground-based experiments, a scidar (scintillation detection and ranging) and a lidar, during a coordinated campaign conducted on the same site, are analyzed in terms of atmospheric dynamics. It is shown that the conjunction of the two measurements allows to characterize the parameters of a tropospheric gravity wave and thus could be of importance for the study of such phenomena.

Two-dimensional spatiotemporal power spectra of shadow patterns associated with stellar light scintillation has been determined experimentally by optical filtering of the spatial frequencies. The results show evidence for a multilayer structure of the air turbulence in the upper troposphere. Altitude and wind speed can be deduced for each layer. They are in good agreement with wind profiles from meteorological data.

PAIX, acronym for Photometer AntarctIc eXtinction, is a new photometer which has just been installed at Dome C in December 2006. PAIX consists of a 40 cm telescope equipped with a KAF-0401E CCD detector. The goal is to qualify the site of Dome C and to get continuous observations for making the best from stellar pulsation studies across the HR diagram.