Recently, advanced ab initio computations were used to generate the three-dimensional potential energy surface (3D-PES) of the phosphine-He (PH
3
-He) van der Waals complex along the intermonomer ...coordinates. This 3D-PES describes correctly the complex features of the intermolecular interactions between PH
3
and He, which are on the origin of pressure broadening phenomena. At present, we take advantage of this accurate 3D-PES to compute the phosphine line broadenings perturbed by He at room temperature. First, we adjusted this 3D-PES by a new 'fractional' function in order to be able to incorporated it into our collisional broadening calculation code. Then, we considered the semi-classical model of Modified Robert and Bonamy improved by so-called the notion of exact trajectory to deduce the He-broadening coefficients of phosphine lines at room temperature. Room temperature data are given in the case of different branches of the parallel, ν
2
, and perpendicular, ν
4
, PH
3
vibrational bands. Our results show an improved agreement with the experimental measurements. This work should be of great help for the precise determination of PH
3
abundances in planetary atmospheres spectra.
In the physical conditions of the troposphere, Carbonyl sulphide (
16
O
12
C
32
S) and Argon (Ar) are present. In the goal of studying the rate coefficients for rotational excitations of OCS with an ...abundant element in the troposphere, such as Ar, a new potential energy surface (PES) of OCS-Ar system over their ground electronic states: OCS (
X
1
Σ
+
) and Ar(
S
u
1
), has been investigated with the ab initio explicitly correlated Coupled Cluster including single, double and perturbative treatment of triple excitations (CCSD(T)-F12) level of theory, associated to the augmented correlation consistent valence triple zeta Aug-cc-pVTZ basis set. In this paper, the Coupled State approximate method “CS” was used in order to calculate inelastic cross-sections at energies up to
2000
cm
−
1
. The collisional rate coefficients derived from these rotational inelastic cross-sections were determined and discussed for kinetic temperature
T
≤
400
K
and for OCS rotational levels
J
≤
20
.
Background. Allergic contact dermatitis (ACD) is a common chronic skin disease that generates considerable public-health and socioeconomic costs. This disease affects the quality of life and the ...occupational activity of patients. Aims. To assess the quality of life (QOL) of patients with ACD and study the impact of this disease on their work productivity. Methods. This is a cross-sectional study carried out from January 2012 to December 2014. All patients diagnosed with ACD in the Dermato-Allergology Unit of the Occupational Medicine Department at Farhat Hached University Hospital, in Sousse, were included. The impact of skin disease on the QOL of affected persons was assessed using the Dermatology Life Quality Index (DLQI). The work productivity was measured using the Work Productivity and Activity Impairment Allergic Specific questionnaire (WPAI: AS). Results. The study population consisted of 150 patients. The average score of DLQI was 6.5. Over the previous 7 days, absenteeism rate was 25.9 ± 15.3%, presenteeism rate was 50.2 ± 32%, overall work productivity loss was 29.6 ± 19.4%, and daily activity impairment was 50.4 ± 32.3%. The DLQI score was significantly associated with atopy (p = 0.03), relapses strictly greater than 10 (p = 0.02), presenteeism (p <10−3), overall work productivity loss (p = 0.01), and daily activity impairment (p = 0.03). Conclusion. The impact of ACD on QOL and occupational activity seems important and requires specific attention from the occupational physician.
Urban agriculture has been of growing interest for a decade because it can address many economic and societal issues in the development of modern cities. However, urban agriculture is often limited ...by the availability of fertile and non-contaminated soils in the cities. Recycling excavated mineral wastes from building activities to construct fertile soils may be a more sustainable alternative than the importation of topsoils from rural zones. The present study aims to evaluate the possibility to grow green vegetables on soils made with excavated deep horizon of soils and green waste compost. During three consecutive seasons, we tested
in situ
the effects of different amounts of compost (10, 20, and 30%) and the addition of an earthworm species (
Lumbricus terrestris
) on the production of lettuce (
Lactuca sativa
L.), arugula (
Eruca sativa
Mill.), and spinach (
Spinacia oleracea
L.) in mono- and co-culture. Our results demonstrate that it is possible to reuse mineral and organic urban wastes to engineer soils adapted to agriculture. Here, we observed that higher doses of compost significantly increased plant biomass, especially when earthworms were introduced. For example, in the autumn, going from 10 to 30% of compost in the soil mixture allows to multiply by 2 the arugula biomass, and even by 4 in the presence of earthworms. These results were partly due to the positive effects of these two factors on soil physical properties (micro- and macro-porosity). This preliminary study also showed that some plants (arugula) are more adapted than others (lettuce) to the soil properties and that it only takes few months to get the highest yields. These promising results for the development of urban agricultures encourage to test many other combination of plant and earthworm species but also to conduct experiments over long-term periods.
Line-mixing effect on NH3 line intensities Aroui, H.; Ben Mabrouk, K.; Boussassi, R.
Journal of quantitative spectroscopy & radiative transfer,
November 2013, 2013-11-00, 20131101, Volume:
130
Journal Article
Peer reviewed
Line intensities belonging to nine branches of the ν2, 2ν2 and ν4 vibrational bands of ammonia have been measured between 1000 and 2000cm−1. The laboratory spectra at room temperature (T=295K) were ...recorded using a high-resolution Fourier transform spectrometer Bruker IFS 120 HR.
More than 460 lines with J≤12 were analyzed using a non-linear least-squares multi-pressure fitting procedure. The fits were performed with and without including the line mixing effects using 11 experimental spectra recorded at different pressures of pure NH3. On average the line intensities uncertainty is estimated to be 2%. The dependence of the line intensities on the J and K quantum numbers is discussed. The effect of line mixing on the line intensities is analyzed as a function of the rotational quantum numbers, of the branches, and of the bands.
On average the values of line intensities obtained in the ν4 band when taking into account line mixing have been found to be 6% smaller than those obtained using the Voigt profile.
The transition dipole moments squared, determined for each line from the measured intensities, exhibit significant rotational dependencies which are mainly caused by vibration–rotation interactions. These moments are discussed as a function of vibrational and rotational states. Finally the measurements are compared with previous measurements and with values from spectroscopic databases.
The whole set of line intensities and transition dipole moments are given as supplementary data for use in spectroscopic databases.
•Studied NH3 in the 1000–2000cm−1 using broad-band high-resolution FTIR spectra.•Measured line intensities and transition dipole moments squared for 462 transitions in the ν2, 2ν2 and ν4 bands.•Considered line mixing effect, which was observed to produce intensities smaller by ∼6%.•Discussed rotational quantum number, J and K, dependence of line intensities and transition dipole moments squared.•Compared the measured line intensities to be lower than earlier work by up to ∼10%.
Context. Rapid rotation is a common feature for massive stars, with important consequences on their physical structure, flux distribution and evolution. Fast-rotating stars are flattened and show ...gravity darkening (non-uniform surface intensity distribution). Another important and less studied impact of fast-rotation in early-type stars is its influence on the surface brightness colour relation (hereafter SBCR), which could be used to derive the distance of eclipsing binaries. Aims. The purpose of this paper is to determine the flattening of the fast-rotating B-type star δ Per using visible long-baseline interferometry. A second goal is to evaluate the impact of rotation and gravity darkening on the V − K colour and surface brightness of the star. Methods. The B-type star δ Per was observed with the VEGA/CHARA interferometer, which can measure spatial resolutions down to 0.3 mas and spectral resolving power of 5000 in the visible. We first used a toy model to derive the position angle of the rotation axis of the star in the plane of the sky. Then we used a code of stellar rotation, CHARRON, in order to derive the physical parameters of the star. Finally, by considering two cases, a static reference star and our best model of δ Per, we can quantify the impact of fast rotation on the surface brightness colour relation (SBCR). Results. We find a position angle of 23 ± 6 degrees. The polar axis angular diameter of δ Per is θp = 0.544 ± 0.007 mas, and the derived flatness is r = 1.121 ± 0.013. We derive an inclination angle for the star of i = 85+ 5-20 degrees and a projected rotation velocity Vsini = 175+ 8-11 km s-1 (or 57% of the critical velocity). We find also that the rotation and inclination angle of δ Per keeps the V − K colour unchanged while it decreasing its surface-brightness by about 0.05 mag. Conclusions. Correcting the impact of rotation on the SBCR of early-type stars appears feasible using visible interferometry and dedicated models.
For some temperatures of atmospheric interest from 200 to 298 K, the self-broadening coefficients of OCS-OCS and HCN-HCN collisional systems, at different strengths of electrostatic interactions, ...were calculated respectively for ν
and ν
bands for a wide range of rotational quantum numbers J. In particular, we have considered some lines that were not studied previously. We have employed the approximation of bi-resonance functions (Starikov, 2012) in the frame of the semiclassical model of Robert and Bonamy with exact trajectory (RBE). The calculated results are found to be fully consistent with the available experimental values of self-broadening coefficients of OCS and HCN. A comparative study shows that the RBE calculations reproduce the dependence of broadening coefficients on quantum number J much better than the simpler Robert and Bonamy model with parabolic trajectory (RB) for all considered temperatures.
In this study, we used Mid-Infrared Spectroscopy (MIRS) to analyze the biochemical fingerprints of nine termite colonies (soldiers, minor and major workers). We then examined whether these spectra ...could be used to differentiate termite colonies and if their differences could be explained by the geographical distances between colonies and/or their ages. We demonstrated that when only data from the heads of minor workers were considered, the specific fingerprint of each colony appeared to reflect its coordinate position in the study site. However, termite mound height, a proxy for colony age, was the main factor governing these signatures when data from the abdomen of major workers were used. Thus, this study shows the potential of MIRS for differentiating termite colonies in the field. It also highlights the close relationship between the physiological states of termite colonies and their environment.
Introduction. Noise is one of the most common worldwide environmental pollutants, especially in occupational fields. As a stressor, it affects not only the ear but also the entire body. Its ...physiological and psychological impacts have been well established in many conditions such as cardiovascular diseases. However, there is a dearth of evidence regarding diabetes risk related to noises. Aim. To evaluate the relationship between occupational exposure to noise and the risk of developing diabetes. Methods. This is a cross-sectional analytical study enrolling two groups of 151 workers each. The first group (noise exposed group: EG) included the employees of a Tunisian power plant, who worked during the day shift and had a permanent position. The second group (unexposed to noise group: NEG) included workers assigned to two academic institutions, who were randomly selected in the Occupational Medicine Department of the Farhat Hached University Hospital in Sousse, during periodical fitness to work visits. Both populations (exposed and unexposed) were matched by age and gender. Data collection was based on a preestablished questionnaire, a physical examination, a biological assessment, and a sonometric study. Results. The mean equivalent continuous sound level was 89 dB for the EG and 44.6 dB for the NEG. Diabetes was diagnosed in 24 workers from EG (15.9%) and 14 workers from NEG (9.3%), with no statistically significant difference (p=0.08). After multiple binary logistic regression, including variables of interest, noise did not appear to be associated with diabetes. Conclusion. Our results did not reveal a higher risk of developing diabetes in workers exposed to noise. Further studies assessing both level and duration of noise exposure are needed before any definitive conclusion.
Context. The eclipsing binary method for determining distance in the local group is based on the surface brightness-color relation (SBCR), and early-type stars are preferred targets because of their ...intrinsic brightness. However, this type of star exhibits wind, mass-loss, pulsation, and rotation, which may generate bias on the angular diameter determination. An accurate calibration of the SBCR relation thus requires careful analysis. Aims. In this paper we aim to quantify the impact of stellar rotation on the SBCR when the calibration of the relation is based on interferometric measurements of angular diameters. Methods. Six stars with V − K color indices ranging between –1 and 0.5 were modeled using the code for high angular resolution of rotating objects in nature (CHARRON) with various rotational velocities (0, 25, 50, 75, and 95% of the critical rotational velocity) and inclination (0, 25, 50, 75, and 90 degrees). All these models have their equatorial axis aligned in an east-west orientation in the sky. We then simulated interferometric observations of these theoretical stars using three representative sets of the CHARA baseline configurations. The simulated data were then interpreted as if the stars were non-rotating to determine an angular diameter and estimate the surface-brightness relation. The V − K color of the rotating star was calculated directly from the CHARRON code. This provides an estimate of the intrinsic dispersion of the SBCR relation when the rotation effects of flattening and gravity darkening are not considered in the analysis of interferometric data. Results. We find a clear relation between the rotational velocity and (1) the shift in zero point (Δa0) of the SBCR (compared to the static relation) and (2) its dispersion (σ). When considering stars rotating at less than 50% of their critical velocity, Δa0 and σ have about 0.01 mag, while these quantities can reach 0.08 and 0.04 mag, respectively, when the rotation is larger than 75% of the critical velocity. Besides this, the inclination angle mostly has an impact on the V − K color: i< 50° (resp. i> 50°) makes the star redder (resp. bluer). When considering the 150 models, Δa0 and σ have 0.03 and 0.04 mag, respectively. These values are slightly but not significantly modified (about 0.03 and 0.01 mag in Δa0 and σ, respectively) when considering different CHARA configurations. Interestingly, these 150 models, regardless of the interferometric configuration, are consistent with the empirical SBCR, which is within its dispersion of 0.16 mag. In addition, if one only considers projected rotational velocity Vrotsini lower than 100 km s-1, then Δa0 and σ have 0.02 and 0.03 mag, respectively. Conclusions. To calibrate the SBCR interferometrically at the 0.02 mag precision (or lower), one should consider (1) a baseline configuration covering all directions of the (u, v) plan; (2) a sample of stars with rotational velocity lower than 50% of their critical velocity or, alternatively, stars with Vrotsini lower than 100 km s-1; (3) homogeneous visible and infrared photometry precisely at the 0.02 mag level or lower.
PDF
