Li(2p $leftarrow$ 2s) + Na(3s) pressure broadening in the far-wing and line-core profiles

This work reports pressure-broadening line-wing and line-core of the lithium Li (2p $leftarrow$ 2s) resonance line perturbed by ground sodium Na (3s) atoms. In far-wing regions, the calculations are performed quantum-mechanically and are intended to examine the photoabsorption coefficients at diverse temperatures. The results show the existence of three satellites, in the blue wing near the wavelengths 470 nm and in the red wing around 862 nm and 1070 nm. For the line-core region, by adopting the simplified Baranger model, the line-width and line-shift rates are determined, and their variation law with temperature is examined. No published data were found to compare these results with.     

Sequential MCR/Fisher indolization strategy for the construction of polycyclic carbazole derivatives

A one-pot method for the synthesis of novel polycyclic carbazole derivatives from readily available starting materials using a sequential multicomponent reaction/Fisher indolization strategy is described.     

Water retention of nonwoven polyester geotextiles

Planar polymeric geotextile materials are increasingly used in geotechnical and geoenvironmental engineering applications to perform various functions such as filtration, drainage and reinforcement. In most cases, they are placed above the groundwater table where soil and geotextiles pores are filled with water and air (i.e. under unsaturated conditions). In this respect, the development of the geotextile water-retention curves is of great importance to model the transient water flow in earthen systems containing geotextiles where unsaturated conditions may prevail. This paper, presents the results of a study on the cross-plane and in-plane water-retention characteristics of two nonwoven, polyester geotextiles. The geotextiles’ cross plane water-retention data demonstrated their hydrophobic nature with both specimens being essentially non-conductive to water beyond suction heads of 0.2–0.3 kPa. Pore size and porosity seemed to have a controlling effect on both the desaturation and resaturation processes. The geotextile with the larger apparent opening size and porosity de-saturated at very low suction pressure (0.4 kPa), whereas a slightly higher suction (0.9 kPa) was needed to de-saturate the geotextile with smaller apparent opening size and porosity. Both specimens exhibited significant hysteresis in their water-retention function, such that at a given suction a geotextile contained more water when drying than when wetting. The in-plane water retention of drying geotextiles indicates that both geotextile specimens absorbed no water at suctions greater than zero; thus the water retention of a dry specimen in the in-plane direction is effectively equal to zero. This implies that the geotextiles used in the present study were more hydrophobic in the in-plane than the cross-plane direction during wetting.     

Inhibition of Pro-inflammatory Secreted Phospholipase A2 by Extracts from <Emphasis Type="Italic">Cynara cardunculus L</Emphasis>.

The aim of the present work was to evaluate the anti-inflammatory properties of Cynara cardunculus L. (Asteraceae) during its growth using various solvents such as n-hexane, dichloromethane, acetone, and methanol for air-dried leaves and stems. The anti-inflammatory activities of crude extracts were evaluated by measuring the inhibition potency of mammalian non-pancreatic phospholipases A2 (hG-IIA). The methanol and acetone extracts of leaves harvested in February exhibit potent inhibition of hG-IIA (IC₅₀ = 50 and 70 μg/ml, respectively). However, the acetone extract of stems harvested in December inhibits the hG-IIA with a lower IC₅₀ around 130 μg/ml. Fractionation on silica gel and hydrophobic gel of the methanol extract of leaves harvested in February increases the inhibitory effect, and the IC₅₀ reached 10 μg/ml.     

Actively mode-locked optical parametric oscillator

We report on what we believe to be the first demonstration of active mode locking of an optical parametric oscillator. An acousto-optic modulator is inserted into a nearly degenerate (approximately 1064 nm) and doubly resonant optical parametric oscillator based on periodically poled LiNbO3 and pumped with the second harmonic of a quasi-continuous-wave single-frequency Nd:YAG laser. When the modulation frequency is matched to the free spectral range of the cavity (120 MHz), a pulsed regime is observed, with pulse durations as short as 700 ps.     

Quartz enhanced photoacoustic spectroscopy with a 3.38 μm antimonide distributed feedback laser

A system for gas sensing based on the quartz-enhanced photoacoustic spectroscopy technique has been developed. It makes use of a quantum well distributed feedback (DFB) laser diode emitting at 3.38 μm. This laser emits near room temperature in the continuous wave regime. A spectrophone, consisting of a quartz tuning fork and two steel microresonators were used. Second derivative wavelength modulation detection is used to perform low concentration measurements. The sensitivity and the linearity of the Quartz enhanced photoacoustic spectroscopy (QEPAS) sensor were studied. A normalized noise equivalent absorption coefficient of 4.06×10(-9) cm(-1)·W/Hz(1/2) was achieved.     

On the explicit formulas for zeta functions

In this paper, we study the properties of a large class of zeta functions that arises in geometric analysis and mathematical physics. They are attached to some elliptic operators. This method can be used to evaluate explicitly the special values of zeta functions of elliptic operators defined on some symmetric spaces.     

Magnetic hyperfine structure in the 4p 3 and 4p 25s configurations of arsenic

The magnetic hyperfine structure factorA of the quasi-totality of the levels of the low 4p ³ and 4p ²5s configurations of As I has been measured by Fabry-Perot interferometry in the far UV range. A good agreement is observed between experimental results and theoretical evaluations, which allows us to confirm that the 4p ²5^s configuration only mixes very weakly (less than 1%) with 4s4p ⁴.     

Projectively Equivariant Quantization Map

Let M be a manifold endowed with a symmetric affine connection . The aim of this Letter is to describe a quantization map between the space of second-order polynomials on the cotangent bundle T* M and the space of second-order linear differential operators, both viewed as modules over the group of diffeomorphisms and the Lie algebra of vector fields on M. This map is an isomorphism, for almost all values of certain constants, and it depends only on the projective class of the affine connection .