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This work is devoted to a non-intrusive experimental approach, based on Laser Multi-reflection technique, in the investigation of thickness distribution variations and wave's dynamics of a liquid film flowing over an inclined plane. This investigation was first founded on the needs of quantifying the liquid film thickness and on minimizing, as much as possible, some drawbacks pointed out, in the literature, throughout the experimental techniques available. Moreover, the technique could be applied to transparent, opaque as well as particle laden liquid films. The technique is validated and evaluated using two approaches according to the flow case: stable or instable. In case of stable flow, the comparison was made using Spectroscopic Ellipsometry and theoretical prediction established by the Nusselt model. For a wavy interface a setup, especially devoted to that purpose, was used to validate the accuracy of the measurements. In both cases the uncertainties were within 5%. The experiments are discussed hereafter including the accuracy of the results. Some experimental data, for plane inclination ranging from 1° to 10°, are reported. The data takes into account the film thickness at various positions. The instability threshold is also reported. [ABSTRACT FROM AUTHOR]

Experimental investigations were conducted to study the evolution of air/water slug flow characteristics through a horizontal sudden expansion having a ratio of σA = 0.444. A series of acquisition of differential pressure upstream and downstream were carried out leading to statistical as well as spectral analyses. The influences of both liquid and gas superficial velocities on flow behavior as well as standard deviation were studied. Substantial modifications of two-phase flow distribution were reported downstream the singularity with a quantitative reduction in standard deviation. Besides the fact that the slug flow regime didn’t persist downstream the singularity for low values of superficial phasic-velocities, the latter (Jℓ and Jg) seem to have no noticeable effects downstream the expansion. Reduction of slug frequency between upstream and downstream the singularity was also observed. [ABSTRACT FROM AUTHOR]

This study aims to investigate the triacylglycerol (TAG) productivity of Parachlorella kessleri grown under continuous illumination and to investigate its metabolism in simulated day/night cycles in order to estimate the feasibility of a large-scale production in outdoor solar photobioreactors. The strain was chosen for its ability to accumulate large amounts of triacylglycerol during nitrogen starvation. Several protocols of nitrogen starvation were tested in continuous illumination as well as in simulated day/night cycles. Sudden and progressive nitrogen starvation conditions have enhanced the TAG concentration and productivity of P. kessleri reaching up to 48 dry wt% and 4.4 × 10−3 kg m−2 day−1, respectively. Microalgal cell metabolism was significantly affected by the day/night illumination cycles. The energy-rich compounds (TAGs and carbohydrates) were accumulated by P. kessleri during the photoperiods and partly consumed during the dark to sustain the microalgae vitality. This TAG oxidation ultimately led to a 26% decrease in TAG productivity in cultures exposed to day/night cycles compared to ones exposed to continuous illumination of equal 24-h average photon flux density. The results can dictate the optimal time for harvesting cells for recovering the largest amount of TAGs. [ABSTRACT FROM AUTHOR]

This paper reports the conclusions of the three panel discussions held during the WasteEng2016 Conference in Albi, France (). It explores the research and development trends aiming at the production of energy and added value materials from waste and/or biomass. Three approaches are investigated: thermochemical conversion (Panel chairs: M. Castaldi, J.M. Lavoie, C. Vandecasteele), biochemical conversion (Panel chairs: J. Legrand, P.T. Vasudevan, W. Verstraete) and, sustainable construction and energy storage (Panel chairs: J. van Deventer, Y. Pontikes, X. Py). The thermochemical conversion session addressed feedstock, technologies for energy recovery and material recycling, gas cleaning and the marketplace. It is shown that combustion (WtE) is the leading technology and that also much research is devoted to gasification and pyrolysis. The biochemical conversion session noted the ability to yield products applied to different sectors such as food and feed, chemical, biofuels, biomaterials and many others. Innovation oriented towards better exploitation of the existing biocatalytic activity of known enzymes and microbes is also discussed. Recycling of solid and liquid waste received substantial focus in construction. Materials for thermal energy storage from waste are considered a promising use of recycled materials. The paper also shows how entrepreneurs introducing new technology have to work with both technical and commercial uncertainty, which renders investment into new technology a high risk. Finally, this paper identifies, in the three sections developed below, the trends for ongoing research and highlights the direction where the research is trending from this point forward. [ABSTRACT FROM AUTHOR]

To better understand how receiver antenna calibration models contribute to GPS positioning error budget, we compare station positions estimated with different calibration models: igs05.atx, igs08.atx and individual antenna calibrations. First, the impact of switching from the igs05.atx antenna calibration model to the igs08.atx antenna calibration model is investigated using the EUREF Permanent Network historical data set from 1996 until April 2011. It is confirmed that these position offsets can be effectively represented by the igs05.atx to igs08.atx latitude-dependent model. Then, we demonstrate that the position offsets resulting from the use of individual calibrations instead of type mean igs08.atx calibrations can reach up to 1 cm in the up component, while in the horizontal, the offsets generally stay below 4 mm. Finally, using six antennas individually calibrated by a robot as well as in an anechoic chamber, we observe a position agreement of 2 mm in the horizontal component and a bias of 5 mm in the up component. Larger position offsets, dependent on the antenna/radome type, are, however, found when these individual calibrations are compared to type mean calibrations of two tested antennas. [ABSTRACT FROM AUTHOR]

45% semi-crystalline parylene-C (-HC-CHCl-CH-) thin films (5.8 μm) polymers have been investigated by broadband dielectric spectroscopy for temperatures above the glass transition ( T=90°C). Good insulating properties of parylene-C were obtained until operating temperatures as high as 200°C. Thus, low-frequency conductivities from 10 to 10 S/cm were obtained for temperatures varying from 90 to 185°C, respectively. This conductivity is at the origin of a significant increase in the dielectric constant at low frequency and at high temperature. As a consequence, Maxwell-Wagner-Sillars (MWS) polarization at the amorphous/crystalline interfaces is put in evidence with activation energy of 1.5 eV. Coupled TGA (Thermogravimetric analysis) and DTA (differential thermal analysis) revealed that the material is stable up to 400°C. This is particularly interesting to integrate this material for new applications as organic field effect transistors (OFETs). Electric conductivity measured at temperatures up to 200°C obeys to the well-known Jonscher law. The plateau observed in the low frequency part of this conductivity is temperature-dependent and follows Arrhenius behavior with activation energy of 0.97 eV (deep traps). [ABSTRACT FROM AUTHOR]

The particular benefits of microfluidic systems, in terms of heat and mass transfer enhancement, require conducting local flow diagnostics, especially when unsteady properties of the microflow can play a critical role at the reaction interface, as currently observed in the fields of bioengineering and chemical engineering. The present paper focuses on unsteady confined flows within microsystems characterized by various geometries of crossing channels and exhibiting high surface-to-volume ratios. An experimental analysis of the signal measured at microsensors embedded to the wall of microsystems is discussed. In the objective of performing flow diagnostics, including regime identification and wall flow structure recognition, two methods for electrochemical signal processing are investigated and compared within an experimental network of crossing minichannels. One method is based on the use of a transfer function, while the other, the so-called Sobolik solution (Sobolik et al . in Coll Czech Chem Commun 52:913-928, ), consists of finding a direct solution to the mass balance equation. Sobolik's method has been selected given its ability to provide a description, over a wide range of Reynolds numbers (317 < Re < 3,535), for all wall shear rate fluctuations, as well as for the associated mixing scales in the power spectra density (PSD). This technique is then applied to flow within micromixers composed of two crossing microchannels in order to study highly unsteady and inhomogeneous microflows. The hydraulic diameters of the studied channels are 500 and 833 μm, respectively. Two flow patterns are investigated herein: the crossing-flow type and the impinging flow (or so called co-flow) for a Reynolds number range between 173 and 3,356. The PSD of wall shear rate fluctuations reveals various flow characteristics depending on the microchannel aspect ratio. [ABSTRACT FROM AUTHOR]

Using dual-frequency data from 36 GPS stations from the EUREF Permanent Network (EPN), the influence of the October 30, 2003 Halloween geomagnetic storm on kinematic GPS positioning is investigated. The Halloween storm induced ionospheric disturbances above the northern part of Europe and Scandinavia. It is shown that kinematic position repeatabilities for this period are mainly affected for stations in northern Europe with outliers reaching 12 cm in the horizontal, and 26 cm in the vertical. These magnitudes are shown to be possibly due to the second-order ionospheric delays on GPS signals, not accounted for in the kinematic GPS positioning analysis performed. In parallel, we generate hourly TEC (Total Electron Content) maps on a 1° × 1° grid using the dense EPN network. These TEC maps do not use any interpolation but provide a high resolution in the time and space and therefore allow to better evidence small structures in the ionosphere than the classical 2-hourly 2.5° × 5° grid Global Ionospheric TEC Maps (GIM). Using the hourly 1° × 1° TEC maps, we reconstruct and refine exactly the zones of intense ionosphere activity during the storm, and we show the correlation between the ionospheric activity and assess the quality of GPS-based kinematic positioning performed in the European region. [ABSTRACT FROM AUTHOR]

When a gas sample of 13CH3F is prepared with a population of isomers (ortho and para forms) far from the equilibrium given by nuclear spin statistics, it relaxes towards this equilibrium with an exponential decay rate. This phenomenon called nuclear spin conversion is mainly governed by intramolecular spin-spin and spin-rotation interactions. In the quantum relaxation model [P.L. Chapovsky, Phys. Rev. A 43, 3624 (1991)], two pairs of ortho-para levels (J = 9, K = 3; J′ = 11, K′ = 1) and (J = 20, K = 3; J′ = 21, K′ = 1) are principally responsible for the conversion. The levels of the second pair are coupled by both spin-spin and spin-rotation interactions. The application of an electric field (up to 10 kV/cm) induces a crossing of the Stark components of this pair, which is observed for the first time. A specific experimental set-up based on an electric field of alternating triangular shape is used, which allows the determination of the strength of both interactions via the measurement of the spin conversion decay rates. This work yields the first experimental value for the electronic contribution to the spin-rotation interaction in 13CH3F. [ABSTRACT FROM AUTHOR]

The electrodiffusion technique has been used to investigate reattaching and recirculating flows behind a backward-facing step. The instantaneous wall shear rate vectors were determined using the current signals provided by a three-segment electrodiffusion probe. The near-wall extents of two counter-rotating recirculation zones located behind the step were determined under turbulent flow conditions in a water channel. The near-wall flow inside these recirculation zones was found to be very unsteady, with strong low-frequency fluctuations. The streamwise profiles of the wall shear stress were measured at several values of the Reynolds number and a high level of skin friction was obtained in the reverse-flow region. The strong dependence of the peak value of skin friction on the Reynolds number confirms the viscous-dominated character of the reverse flow appearing inside the recirculation zone. [ABSTRACT FROM AUTHOR]

The influence of different fluid inlet types, slits or tubes, on mass transfer in a rectangular reactor was studied. Measurements of mass transfer coefficients were made using the limiting diffusion current technique based on ferricyanide ion reduction at a large nickel electrode located downstream of abrupt expansions. The overall mass transfer coefficients obtained were 3 to 13 times greater than those obtained in fully developed flows. Overall mass transfer coefficients were correlated for Reynolds numbers ranging from 400 to 3500 by a unique equation by introducing a nondimensional expansion factor defined by the ratio of the fluid inlet cross-section to that of the reactor. The correlation equation obtained was compared with literature data. [ABSTRACT FROM AUTHOR]

A new method is proposed for the experimental determination of the hyperfine coupling in molecules. The method is based on the level-crossing effect in the spin isomer conversion in alternating electric fields. An experiment performed with the 13CH3F molecules has revealed the strength of the off-diagonal in K ( ) nuclear spin-spin coupling kHz, which is only by kHz larger than the theoretical value calculated on the basis of the molecular structure. [ABSTRACT FROM AUTHOR]

Particle image velocimetry (PIV) has been used in order to measure the three mean components and turbulence intensities of the velocity vector in a swirling decaying flow induced by a tangential inlet in an annulus. This kind of flow motion is found to be very complex, exhibiting three-dimensional and non-axisymmetric characteristics coupled with a free decay of the swirling intensity along the flow path, thereby making it difficult to study. A method allowing the measurement of the three components of the velocity flow-field with a standard PIV system with two-dimensional acquisitions, is presented. The evolution of each velocity component between the inlet and the outlet of the annulus is obtained. Furthermore, the PIV technique is extended to the measurement of turbulent characteristics such as turbulent intensities and dimensionless turbulent energy. The main characteristics of the swirling flow are discussed and the swirl number is estimated as a function of the axial distance from the tangential inlet. [ABSTRACT FROM AUTHOR]

The nuclear spin conversion in CH3F molecules subjected to an alternating electric field was investigated experimentally. The conversion rate was found to be almost unaffected by low electric fields ( V/cm) but sharply increased tenfold when the electric field amplitude exceeds the values ( V/cm) sufficiently high to produce crossings of the ortho and para states of the molecule. A theoretical model for the molecular conversion in alternating electric field was developed. The results of the experiment were found to be in a good agreement with the theory. [ABSTRACT FROM AUTHOR]

Local and simultaneous velocity and concentration fluctuations were analysed in an axisymmetric jet of an aqueous electrolyte solution moving in a codirectional water stream. The determination of the convection velocity of the turbulent eddies as well as correlation between axial velocity and concentration fluctuations was made possible by coupling L.D.A. to an electrochemical technique. The influence of the ratio of the coflowing stream velocity to the jet exit velocity was investigated. The mean velocity and concentration profiles, the turbulence intensity, the integral length scales relative to axial velocity and concentration were also determined. [ABSTRACT FROM AUTHOR]

An electrochemical method is used to measure mass transfer coefficients between an electrolytic solution and the inner core of a system formed by stationary coaxial cones of the same apex angle. A swirling decaying flow is induced by means of a tangential inlet at the system base. The average mass transfer coefficients are measured at three axial positions from the tangential inlet for both laminar and turbulent flow regimes. Pressure drops between the inlet and the outlet of the experimental device are also investigated. Flow visualization revealed the existence of axially fixed toroidal vortices. The overall mass transfer coefficients along the conical gap are found to be greater than those measured in annular swirling decaying flow for the same values of the annular gap thickness, of the tangential inlet diameter and of the Reynolds number based on the mean axial velocity at the bottom of the conical gap. The enhancement in mass transfer, up to 50% compared with that measured in a cylindrical arrangement, is not counter-balanced by an increase in pressure drop, which remains of the same order of magnitude as that measured in a classical annular configuration. [ABSTRACT FROM AUTHOR]

The morphometric parameters of the human gingival elastic fiber network were determined by image analysis and compared with human skin elastic fibers in relation to age. Similarly, collagen fibers were also investigated in both tissues. In this study, 47 healthy patients, 10 – 75 years old were studied for gingiva and another 50 patients in the same age range were included for skin biopsies. Three groups were compared: group 1 from the age of 10 – 24 years, group 2 from 25 to 49 years, and group 3 from 50 to 75 years. The diameters of the oxytalan fibers were invariable in both tissues, whatever the age considered. On the other hand, the diameters of elastic fibers increased regularly with age in the gingiva ( P<0.01) and in the skin ( P<0.01) between each age group. The area fraction occupied by the oxytalan fibers decreased significantly in both tissues ( P<0.01) for the skin and ( P<0.001) for the gingiva. The area fraction occupied by the gingival elastic fibers remained constant with age while the skin elastic fibers increased significantly with age between groups 2 and 1 ( P<0.01) and between groups 3 and 2 ( P<0.001). In the mid-dermis and in the mid-gingiva, the diameters of the collagen fibers increased strongly with age, between groups 2 and 1 ( P<0.01) and between groups 3 and 2 ( P<0.001). The area fraction occupied by the collagen bundles increased regularly with age in the mid-gingival ( P<0.05 between each age group), while a significant decrease was observed in the mid-dermis from the age of 50 – 75 years ( P<0.05). The results obtained contribute to a better understanding of some modifications which dermis and gingiva undergo with aging and provide data to perfect diagnosis and therapy in odontology and dermatology. [ABSTRACT FROM AUTHOR]

The action of two epimers of a new vinblastine derivative that differ in their in vivo antitumor activity and their cytotoxicity was studied in vitro in brain microtubule proteins. These two compounds, called S-12363 and S-12362, could not be distinguished from one another or from other active vinca alkaloids by their ability to prevent microtubule assembly. However, they differed strongly both from one another and from vincristine and vinblastine in their ability to induce the formation of tubulin paracrystals and in the stability of the paracrystals following temperature shifts from 0 degree to 37 degrees C and vice versa. The most potent drug, S-12363, induced considerable tubulin aggregation, which was even more pronounced than that observed in the presence of vincristine. Previous results have shown that S-12363, in contrast to vincristine, induces no neurotoxic effects. This observation is in disagreement with a direct relationship between tubulin aggregation and neurotoxicity. [ABSTRACT FROM AUTHOR]

We report the realization of a tunable sub-Doppler heterodyne spectrometer with high absolute accuracy, employing side-band generation with a CO laser. The fixed-frequency CO-gas laser, working from 4.7 to 8.4 µm, is made partially tunable by the use of microwave side-band generation in a CdTe Electro-Optical Modulator (EOM). This leads to tunable radiation of high spectral purity. We describe the design of the microwave EOM, adapted to the CO laser, its performance and its first application to highly accurate frequency measurements. The side-band radiation is used for sub-Doppler stabilization of the CO laser, while the carrier frequency is mixed with the frequencies of two CO reference lasers. As a first result, we present measurements of OCS transitions in the 4.9 µm (61 THz) region, reaching an absolute accuracy of 30 kHz ( Δν/ν = 5×1O). Further application of our spectrometer to calibration gases will establish a variety of InfraRed (IR) calibration standards with a new quality of accuracy. [ABSTRACT FROM AUTHOR]

In acromegaly the plasma volume is chronically elevated and it returns to normal when the disease is successfully treated. To define the role of ANF in such a chronic disorder of extracellular fluid volume homeostasis the plasma level was assayed in 37 acromegalic patients with active or inactive (successfully treated) disease. Five patients were studied before and after therapy. The effects of acute change in sodium-fluid status on plasma ANF levels was examined in 7 active and 4 inactive acromegalic patients and in 7 healthy subjects. As compared to 14 patients with inactive acromegaly, 23 patients with active acromegaly had an expanded plasma volume ( n=12; 50.1 vs 37.6 ml · kg BW) and an increased blood concentration of growth hormone ( n=23; 22.5 vs 2.1 ng · ml). Plasma ANF concentrations in active and inactive acromegalic patients (33.2 and 26.6 pg · ml, respectively) did not differ significantly from one another or from the level in the controls (26.9 pg · ml). In those patients there was no correlation between plasma volume and ANF level. Infusion of 21 isotonic saline in 2 h led to a similar, significant increase in ANF levels in active (from 26.2 to 72.4 pg · ml) and in inactive acromegalic patients (from 33.6 to 96.7 pg · ml) as well as in healthy subjects (from 21 to 70.6 pg · ml). Successful treatment reduced the plasma volume (from 49.2 to 35.8 ml · kg BW) and growth hormone level (from 10.1 to 2.6 pg · ml), while the ANF level remained unchanged (from 33.8 to 35.5 pg · ml). In the patients with active or inactive acromegaly and cardiac failure the plasma ANF level was markedly increased (89.9 and 66.1 pg · ml, respectively) as compared to all the other groups. It is concluded that ANF levels are not elevated in chronically volume expanded acromegalic patients. In the present patients ANF was released in response to acute volume expansion, therefore it may be important in the cardiovascular and renal response to acute changes in extracellular fluid volume. [ABSTRACT FROM AUTHOR]

The effect of a non selective and a cardio-selective beta-blocker on basal and exercise-stimulated plasma atrial natriuretic peptide concentrations in healthy volunteers has been studied. Nine healthy volunteers received single oral doses of 5 mg tertatolol, 100 mg atenolol or placebo, at one week intervals, in a double blind cross over trial. At rest plasma atrial natriuretic peptide, aldosterone, antidiuretic hormone and cyclic GMP concentrations and plasma renin activity were not modified by the treatments. During exercise plasma atrial natriuretic peptide concentrations were significantly increased by each treatment, the increment being significantly greater on beta-blockers than on placebo. The rise in atrial natriuretic peptide was 72% after placebo (from 24 to 42 pg/ml), 184% after atenolol (from 30 to 86 pg/ml), and 183% after tertatolol (from 34 to 95 pg/ml), respectively. Thus, the study has shown that in healthy subjects the plasma natriuretic peptide concentration is increased by exercise and that the increase is considerably and equally potentiated by selective and non selective beta-adrenoceptor blockade. The effect may be mainly due to a reduction in ventricular contractility with an increase in atrial pressure. The beta-blockers did not influence the resting plasma atrial natriuretic peptide levels, which suggests that in healthy subjects basal atrial natriuretic peptide secretion is not controlled via beta-receptors. [ABSTRACT FROM AUTHOR]

In a two-component cycle, the generation of the dipole field by a separate mechanism as well as the strong link occurring, with a 5-6-yr delay, between the sunspot cycle and the preceding dipole cycle, sets in new terms the problem of the mechanisms at the origin of the solar cycle. In this paper, from various series of synoptic solar data, we identify some of the mechanisms to incorporate in a model of a two-component solar cycle. The first one concerns the dipole field which is not a surface phenomenon. We establish the cyclic behaviour and the various properties of the dipole-field sources which are deep-seated in the solar interior and have a rigid rotation of 'about 27 days'. We identify two cyclic phenomena which, in each hemisphere, link with a 5-6-yr delay, the dipole field generation which occurs at high latitudes, to the bipolar field emergence occurring at 'sunspot' latitudes. They are the 'signatures' of a coupling mechanism taking place deep in the solar interior. Then we study the constraints imposed on the mechanisms of the sunspot field generation both by a two-component cycle and by new observational results. These last ones concern the links occurring between the birth of new sunspot groups and the occurrence of pre-existing features of the photospheric field and of 'pivot-points' in rigid rotation at 27.3 days. Our final discussion is devoted to a first sketch of the distribution of the relevant mechanisms among separate regions of the convective zone. Unfortunately neither the helioseismology, nor our data analysis has yet supplied us with appropriate pieces of information for building a physical model of this two-component cycle. [ABSTRACT FROM AUTHOR]

From a previous analysis of a long series of geomagnetic data, we came to the conclusion that, during 91.5% of the time, geomagnetic activity is controlled by the solar wind flow at the Earth's orbit. In this paper, we consider the flow of the solar wind plasma in a coronal field whose source is a dipole. The temporal evolution of the dipole source as well as any small scale evolution occurring in the associated coronal field topology can be closely monitored from the latitudinal distribution of the wind velocity. In the geomagnetic data series, the index Aa is closely linked to the wind velocity at the power 2.25. From this data set, we can reconstruct the behavior of the solar dipole field from 1868 onward. The main results of our analysis are as follows. The solar cycle has two distinct components, dipole and toroidal, of which the respective cycles are out of phase. The toroidal component is strongly linked, with a 5-6 yr delay, to the preceding dipole component. This finding is in contradistinction to the view that the dipole field is a result of the poleward migration of the decaying toroidal field. This result should contribute to improve our understanding of the Sun's cyclical behaviour. [ABSTRACT FROM AUTHOR]

Series of 110 years of sunspot numbers and indices of geomagnetic activity are used with 17 years of solar wind data in order to study through solar cycles both stream and shock event solar activity. According to their patterns on Bartels diagrams of geomagnetic indices, stable wind streams and transient solar activities are separated from each other. Two classes of stable streams are identified: equatorial streams occurring sporadically, for several months, during the main phase of sunspot cycles and both polar streams established, for several years, at each cycle, before sunspot minimum. Polar streams are the first activity of solar cycles. For study of the relationship between transient geomagnetic phenomena and sunspot activity, we raise the importance of the contribution, at high spot number, of severe storms and, at low spot number, of short lived and unstable streams. Solar wind data are used to check and complete the above results. As a conclusion, we suggest a unified scheme of solar activity evolution with a starting point every eleventh year, a total duration of 17 years and an overlapping of 6 years between the first and the last phase of both successive series of phenomena: first, from polar field reversal to sunspot minimum, a phase of polar wind activity of the beginning cycle is superimposed on the weak contribution of shock events of the ending cycle; secondly, an equatorial phase mostly of shock events is superimposed on a variable contribution of short lived and sporadic stable equatorial stream activities; and thirdly a phase of low latitude shock events is superimposed on the polar stream interval of the following cycle. [ABSTRACT FROM AUTHOR]

Measurements of nitrogen atom density, by means of NO chemical titration, along with an evaluation of the densities of some excited species N2 (B, v= 11), N2 (B, v= 2), N2 (C, v= 0), and N(B,v=0), by means of a spectroscopic study of some bands of dinitrogen, are achieved along the flowing afterglow of a dinitrogen microwave plasma (2450 MHz) for several pressures. The concentrations obtained are in the following range: [N]∼10 +15 , [N2 (B, 2)]∼10 +9 –10 +10 , [N2 (B, 11)]∼10 +8 –10+9 , [N2 (C, 0)]∼10 +6 –10 +7, [N(B,0) ]∼10 +6 -10 +8(cm-3). From a kinetic study of the formation and decay of excited and charged species, an estimation of N2 (A, v ), N2 (X, v, and N(X) densities can be derived: [N2 (A , v )]∼10 +12 , [N2 (X, v≥ 6)]∼10 +15 –10 +16 , [N2 (X, v≥ 12)]∼10 +14 –10 +15, [N (X )]∼10 +10 (cm -3). [ABSTRACT FROM AUTHOR]

Activation of methane is carried out by means of an air microwave plasma (2.45 GHz). The experiments cover the absorbed microwave power range 350-650 W (20-50 W cm with 17-62%, of methane in the gas mixture, with pressures of 10-66 mbar and flow rates of 140-700 ml min. Methane, dioxygen, and dinitrogen consumptions as well as C hydrocarbons, carbon monoxide, and dihydrogen yields are analyzed hr gas chromatography. The distance of methane addition from the end of the discharge plays an important role in the composition and the concentration of the products obtained. This distance mainly determines the energy concentrated in the active species of the plasma when they react with methane. A kinetic mechanism jar the activation and decay of inethane and for the formation of C hydrocarbons and carbon monoxide is discussed based on the experimental results and kinetic data in the literature. [ABSTRACT FROM AUTHOR]

Conversion of CH with a N microwave plasma (2.45 GHz) is studied. The experiments cover the absorbed microwave power range 300-700 W with 17-62% of methane in the gas mixture, with pressures of 10-40 mbar and flow rates of 140-650 ml· min. The yields of C hydrocarbons and dihydrogen are analyzed by gas chromatography. The distance of methane addition downstream of the plasma plays an important role on the composition and the concentration of the products obtained. This distance mainly determines the energy concentrated in the active species of the plasma when they react with methane. Different behaviors for acetylene formation, on the one hand, and for ethane and ethene formation, on the other hand, have been observed, and this finding allows us to propose a kinetic mechanism for the decay of methane and for the formation of C hydrocarbons. [ABSTRACT FROM AUTHOR]

Electron temperature and ion density are measured in an air microwave-induced plasma (2450 MHz) by means of a floating double probe. A 'cinetic scheme for ion formation and decay is set up, and a relationship between atomic oxygen and ion densities is obtained. From this relationship an order-of-magnitude of atomic oxygen concentration in the discharge is derived and compared with results obtained by optical actinometry in another work. [ABSTRACT FROM AUTHOR]

The hypersonic and thermal behaviour of mechanically oriented and electrically poled random copolymers of vinylidenefluoride and trifluoroethylene (70 mol % / 30 mol %) has been investigated by Brillouin spectroscopy and Differential Scanning Calorimetry (DSC) around the glass transition temperature T and the ferroelectric transition temperature T. From the DSC measurements it appears that a further structural transition may exist in the vicinity of T. The influence of poling and annealing the samples on the elastic stiffness constants at room temperature has been studied. Appropriate sound velocity polar plots are compared. Both glass and ferroelectric transtitions are clearly seen in acoustic behaviour and are discussed from the view point of the degree of crystallinity and disorder, respectively. [ABSTRACT FROM AUTHOR]

The ability of latex agglutination (Slidex Pneumokit) and counterimmunoelectrophoresis to detect Streptococcus pneumoniae antigen in body fluids was evaluated. The patients were classified as having proven Streptococcus pneumoniae infection, suspected Streptococcus pneumoniae infection, acute superinfection of chronic bronchitis or non-pneumoccal respiratory infection. Sixtytwo non-pneumococcal meningitis patients were also included in the study. Latex agglutination and counterimmunoelectrophoresis tests were performed on serum, urine and cerebrospinal fluid specimens when indicated and repeated each week until the patient was discharged. Latex agglutination was done on samples boiled for 10 min. In vitro sensitivity of counterimmuno-electrophoresis and latex agglutination were 10 and 1 ng/ml respectively for type three antigen. In pulmonary disease (proven and suspected Streptococcus pneumoniae infection) counterimmunoelectrophoresis and latex agglutination had a clinical sensitivity of 72.9 and 87.5 % respectively, a specificity of 96.3 and 92.6 %, a predictive value for a positive test of 97.2 and 95.4 % and for a negative test of 66.6 and 80.6 %. Latex agglutination may offer an alternative to counterimmunoelectrophoresis in the rapid diagnosis of Streptococcus pneumoniae infections since it is easier to perform and gives a reliable result within 15 min. [ABSTRACT FROM AUTHOR]

This paper deals with the visualization of swirling decaying flow in an annular cell fitted with a tangential inlet. A wall visualization method, the so-called dot-paint method, allows the determination of the flow direction on both cylinders of the cell. This study showed the complex structure of the flow field just downstream of the inlet, where a recirculation zone exists, the effects of which are more sensitive on the inner cylinder. The flow structure can be considered as three-dimensional in the whole entrance section. The swirl number and the entrance length were estimated using the measured angle of the streamlines. Experimental correlations of these two parameters, taking into account the Reynolds number and the axial distance from the tangential inlet, are given. [ABSTRACT FROM AUTHOR]

A study of flow visualization and residence time distribution is provided in order to model the flow between two electrodes in a commercial filter-press reactor, the ElectroSynCell® from Electrocell AB. Flow visualization indicates that both axial and lateral dispersion phenomena occur and a global plug flow behaviour is observed. The flow distribution is asymmetric due to the design of the inlet system in the active zone. The flow throughout the cell is described by a dispersed plug flow model for which the mean residence time and the Pe´clet number are determined. The reaction area and the inlet system are separately analysed by locating conductimetric probes inside the electrochemical cell. The reaction area is also well described by a dispersed plug flow model, and characterized by high dispersion. The inlet system is, respectively, described by a dispersed plug flow model and by a cascade of continuous stirred tank reactors. The high number of reactors in the cascade denotes a quasi plug flow behaviour. The results are confirmed by two cascades of continuously stirred tank reactors in series. The dispersion coefficients obtained throughout the reaction area of the cell are not constant. This shows that the flow is not well established at the entrance of the reaction zone and depends on the entrance conditions. [ABSTRACT FROM AUTHOR]

This determination was made using the electron capture decay ofMn. Two methods were employed to measure the K X-ray emission rate: by means of a pressurized 4 π proportional counter with the gas at 1.5 MPa, and by means of a medium geometry-defined solid angle counter. The final result was ω=0.2901±0.003. Special care was taken in determining the corrections, some of which do not appear to have been allowed for so far. It is noteworthy that additional corrections, each about +3 %, had to be applied to the results obtained with each of the two methods. Thus there remains complete agreement between them, but at a higher value of ω than those appearing in recent publications. [ABSTRACT FROM AUTHOR]

On September 29, 1968 a proton event has been recorded during three balloon flights performed at Reykjavik, Iceland (64.2 N, 21.7 W) with GM telescopes and scintillation detector. Solar X-rays have been recorded at 1620 UT when a flare of Importance 2B occurred at N 16, W 52. A comparison between X-rays and microwave emissions is made; the time of the maximum of X-ray intensity is taken as the time of the acceleration and ejection of the particles. The beginning of the proton event is at 1650 UT, and particles were observed for almost 24 h. The spectrum of solar protons E>120 MeV is given for several periods between 7 and 20 h after the flare using three independent methods. The solar particle source spectrum is found as: 321-01 (particles/MeV ster), which implies that (1.2±0.1) × 10 protons ( E>120 MeV)/ster have been ejected by the Sun. The time behaviour of the event fits well with Krimigis' model for solar particles diffusion in the interplanetary space. Comparison with other events shows that the radial dependence of the diffusion coefficient is the same ( β≈1) on September 28, 1961, July 7, 1966 and September 29, 1968. The diffusion mean free path at 1 AU is 0.11 AU for 1966, period of low solar activity, and decreases with solar activity (0.08 AU for 1961 and 1968). The fit of the time behaviour of the event with Burlaga's ADB model is also discussed. [ABSTRACT FROM AUTHOR]

Blood pressures and plasma atrial natriuretic peptide (ANP) concentrations have been measured in venous and intracardiac sites in 11 patients (10 men and 1 woman) given cardiac transplants. The mean plasma ANP level was 214.4 pg·ml in the superior veina cava and 281 pg·ml in the right atrium. This significantly higher level was maintained in the right ventricle (269) and in the pulmonary artery (295). The level in controls was 25 pg·ml. Intra cardiac and mean arterial pressures were in normal range in all patients, and there was no correlation between plasma ANP level and intracardiac pressure. The data suggest that in cardiac transplant patients right atrial pressure does not have a primary role in releasing ANP. The transplanted heart is denervated and remains so for many months after operation, thus suggesting that innervation is not obligatory for ANP secretion. Further studies are required to determine the relative contribution of donor and recipient atrial tissues to ANP secretion. [ABSTRACT FROM AUTHOR]

A correction to the article "Influence of different GPS receiver antenna calibration models on geodetic positioning" in the issue is presented.

The effect of 50 and 150 mg cicletanine, a new vasodilator antihypertensive, on plasma atrial natriuretic peptide (ANP), cyclic GMP and antidiuretic hormone has been investigated at rest and during standardized exercise, in a double blind cross over study in healthy subjects. Exercise significantly increased the plasma ANP, cyclic GMP and antidiuretic hormone concentrations, and cicletanine did not affect any of them either at rest or during exercise. Since the alpha-1 adrenoceptor blocker prazosine decreases, beta-adrenoceptor blockers increase and the vasodilator cicletanine does not alter the plasma ANP response to exercise, it is suggested that adrenergic receptors may be directly involved in the regulation of ANP secretion. [ABSTRACT FROM AUTHOR]