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In this work X-ray and elastic backscattered spectra from Pt and Bi thin targets were simultaneously measured using C-4, C-3+ ions in the energy range 2.5 MeV to 5 MeV. M alpha beta, M gamma and total M-shell X-ray production cross sections were extracted from collected X-ray and backscattered particle spectra using calibrated SDD X-ray and silicon solid state particle detectors. The obtained cross section values are compared to theoretical values employing commonly used datasets for fluorescence yields, emission rates, Coster-Kronig transitions and M- shell ionization cross sections based on the Semi-classical Approximation (United Atom and Separated Atom limits), PWBA (Plane Wave Born approximation), and ECPSSR models. The ISICS code was used for PWBA and ECPSSR calculations.

Although PIXE is usually performed with protons, PIXE with heavier ions can be useful in some specific cases. A number of Ion Beam Analysis (IBA) techniques, like ERDA (Elastic Recoil Detection Analysis), NRA (Nuclear Reaction Analysis), AMS (Accelerator Mass Spectrometry), or MeV-SIMS (MeV Secondary Ion Mass Spectrometry), require the use of heavier ions. In such cases the simultaneous use of PIXE could be beneficial. One of the prerequisites for such use of PIXE is good knowledge of X-ray production with heavier ions. In order to update the data base of heavy ion X-ray production cross sections, we have recently started with the systematic study of M-Shell X-ray production induced by carbon ions on heavy elements between W and Bi. Following previous works on Au and Pb (Haidra et al., 2018) and Pt and Bi (Haidra et al., 2019). In this work, we have measured particularly Mαβ, Mγ and total M-shell X-ray production cross section in tungsten and thallium induced by carbon ions of energy range 1.56 MeV to 5 MeV on respective thin targets. The obtained new experimental data are compared to the theoretical predictions given in the framework of the models Plane Wave Born Approximation (PWBA) (Brandt and Lapicki, 1981), ECPSSR (Brandt and Lapicki, 1981) and the Semi-Classical Approximation with united atom (SCA-UA) and separated atom (SCA-SA) correction (Bang and Hansteen, 1957) [5].

The aim of this research is to develop a fast analytical method for multielemental analysis of the tobacco plant Virginia tobacco (cultivated in Poland) and tobacco products (cigarettes, cigars, cigarillos, snuff and two kinds of properly crafted tobacco such as a shisha and cigarette tobacco) distributed in Polish markets by means of a low-power benchtop total reflection X-ray fluorescence (TXRF) system. For this purpose, a set of certified tobacco materials and real samples was employed. In leaves and stalks of V. tobacco and tobacco products, a concentration of 18 elements (P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr and Pb) was determined. Analyzing elemental composition of tobacco plants, one can see that concentrations of S, Ca, Ti, Mn, Zn, Sr and Pb are higher in leaves, whereas the concentrations of P, Cl, K, Fe Cu and Br are higher in stalks; the levels of Cr, Ni, As and Rb are comparable in both these parts of the tobacco plant. All of the parameters affecting sample preparation and TXRF measurements conditions were carefully evaluated. The accuracy and precision of the TXRF measurements were verified using an internal standardization approach for quantification.

Background The time course and extent of recovery after revascularization of viable dysfunctional myocardium are variable. Although fibrosis is a major determinant, myocyte structural and molecular remodeling may also play important roles. Objectives This study sought to determine whether persistent myocyte loss and/or irreversibility of protein changes that develop in hibernating myocardium have an impact on functional recovery in the absence of infarction. Methods Swine implanted with a chronic left anterior descending artery (LAD) stenosis to produce hibernating myocardium underwent percutaneous revascularization, with serial functional recovery evaluated for 1 month (n = 12). Myocardial tissue was evaluated to assess myocyte size, nuclear density, and proliferation indexes in comparison with those of normal animals and nonrevascularized controls. Proteomic analysis by 2-dimensional differential in-gel electrophoresis was used to determine the reversibility of molecular adaptations of hibernating myocytes. Results At 3 months, physiological features of hibernating myocardium were confirmed, with depressed LAD wall thickening and no significant infarction. Revascularization normalized LAD flow reserve, with no immediate change in LAD wall thickening. Regional LAD wall thickening slowly improved but remained depressed 1 month post–percutaneous coronary intervention. Surprisingly, revascularization was associated with histological evidence of myocytes re-entering the growth phase of the cell cycle and increases in the number of c-Kit+ cells. Myocyte nuclear density returned to normal, whereas regional myocyte hypertrophy regressed. Proteomic analysis demonstrated heterogeneous effects of revascularization. Up-regulated stress and cytoskeletal proteins normalized, whereas reduced contractile and metabolic proteins persisted. Conclusions Delayed recovery of hibernating myocardium in the absence of scar may reflect persistent reductions in the amounts of contractile and metabolic proteins. Although revascularization appeared to stimulate myocyte proliferation, the persistence of small immature myocytes may have contributed to delayed functional recovery.

Many survivors of sudden cardiac death (SCD) have normal global ventricular function and severe coronary artery disease but no evidence of symptomatic ischemia or infarction before the development of lethal ventricular arrhythmias, and the trigger for ventricular tachycardia (VT)/ventricular fibrillation (VF) remains unclear. We sought to identify the role of spontaneous ischemia and temporal hemodynamic factors preceding SCD using continuous telemetry of left ventricular (LV) pressure and the ECG for periods up to 5 mo in swine ( n = 37) with hibernating myocardium who experience spontaneous VT/VF in the absence of heart failure or infarction. Hemodynamics and ST deviation at the time of VT/VF were compared with survivors with hibernating myocardium as well as sham controls. All episodes of VT/VF occurred during sympathetic activation and were initiated by single premature ventricular contractions, and the VT degenerated into VF in ∼ 30 s. ECG evidence of ischemia was infrequent and no different from those that survived. Baseline hemodynamics were no different among groups, but LV end-diastolic pressure during sympathetic activation was higher at the time of SCD (37 ± 4 vs. 26 ± 4 mmHg, P < 0.05) and the ECG demonstrated QT shortening (155 ± 4 vs. 173 ± 5 ms, P < 0.05). The week before SCD, both parameters were no different from survivors. These data indicate that there are no differences in the degree of sympathetic activation or hemodynamic stress when VT/VF develops in swine with hibernating myocardium. The transiently elevated LV end-diastolic pressure and QT shortening preceding VT/VF raises the possibility that electrocardiographically silent subendocardial ischemia and/or mechanoelectrical feedback serve as a trigger for the development of SCD in chronic ischemic heart disease.

The population of magnetic sublevels in hydrogen-like uranium ions has been investigated in relativistic ion–atom collisions by observing the subsequent X-ray emission. Using the gas target at the experimental storage ring facility we observed the angular emission of Lyman-α radiation from hydrogen-like uranium ions. The alignment parameter for three different interaction energies was measured and found to agree well with theory. In addition, the use of different gas targets allowed for the electron-impact excitation process to be observed.

Regional cardiac sympathetic nerve dysfunction develops in hibernating myocardium and may play a role in its association with sudden cardiac death. Interventions to improve cardiac function (i.e., revascularization) improve survival, but the potential reversibility of sympathetic nerve dysfunction remains unclear.Pigs (n = 11) were chronically instrumented with a proximal left anterior descending coronary artery (LAD) stenosis to produce hibernating myocardium. Prior to therapeutic interventions, there was LAD occlusion with collateral-dependent myocardium, reduced regional function (echocardiographic LAD wall-thickening 23% +/- 4% vs 83% +/- 6% in Remote, P.001), and large defects in (11)C-meta-hydroxyephedrine (HED) PET (48% +/- 4% of LV area, 26% +/- 2% integrated reduction). Successful PCI or pravastatin therapy improved regional (LAD wall-thickening 23% +/- 4% to 42% +/- 6%, P.05) and global LV function (fractional shortening 24% +/- 2% to 31% +/- 2%, P.01), but did not alter regional HED uptake, retention, defect size, or defect severity.Despite significant functional improvement of hibernating myocardium as a result of PCI or pravastatin therapy, there were no changes in HED defect size or severity. Thus, inhomogeneity in myocardial sympathetic innervation persisted, and the lack of plasticity suggests that even in the absence of significant infarction, structural rather than functional defects are responsible for reduced myocardial norepinephrine uptake in chronic ischemic heart disease.

International audience; Expansion of aquaculture has increased concern over its environmental impact. The composition of effluents from intensive aquaculture is well documented, but few data on extensive aquaculture are available. During 12 draining operations, 523 water samples were collected downstream from six extensively-managed fishponds in northeastern France. Study ponds had surface areas of 2–620 ha and were managed for production of Cyprinids and Percids. Concentrations of total suspended solids, total phosphorus, and Kjeldahl nitrogen in effluents from the ponds were greatest during the final stage of draining. Loads of phosphorus were higher than those reported for effluents of more intensive aquaculture ponds in the USA, but the source of the potential pollutants was catchments and sediment rather than feeds and fertilizer. It will be necessary to reduce the water drawdown rate during the fishing stage and possibly implement other best management practices to prevent the TSS concentration from exceeding 1 g/L. Effluent phosphorus loads were higher than those reported for more intensive aquaculture ponds, but the pollutant source was catchments rather than feeds and fertilizers.

International audience; The Mirgenbach reservoir was filled in 1985 and received since 1986 the overheated cooling waters of the electronuclear power plant of Cattenom. Physicochemical conditions and chlorophyll biomass were studied from that time. Fishes were sampled according to a standardized protocol since the coupling of the last unit in 1991. The thermal evolution was described then compared with the other natural or overheated systems. In the Mirgenbach, the isolation of fish populations with well mixed waters, facilitated the observation of incidence of the discharges on community evolution, abundance of populations and individual biological traits. The high threshold of the wintry temperature and its early rise set off the reproduction and causes a fast individual development. The reservoir knew a regular decline of the biomass (chlorophyll and fishes) whereas copper contamination increased. The progressive decrease for several species, of population size, longevity, maximal lengths, size and age of sexual maturity, contributed to the decline of the global or individual maximal mass. These constraints pressed at first on perch and roach and then on thermophilic species (bream and silver bream, pumpkinseed fish). According to literature, these constraints may be explained by a sexual developmental impairment and the increasing shortage of trophic resource.; Depuis 1986, le réservoir du Mirgenbach, mis en eau en 1985 reçoit les eaux échauffées issues de la centrale électronucléaire de Cattenom. Les conditions physicochimiques et la biomasse chlorophyllienne sont étudiées depuis cette date, les poissons étant échantillonnés selon un protocole standardisé depuis le couplage de la dernière tranche, en 1991. L’évolution thermique est décrite puis comparée à d’autres systèmes naturels ou échauffés. Dans le Mirgenbach, l’isolement des populations de poissons et le brassage de l’eau facilitent l’observation d’une incidence des rejets sur l’évolution du peuplement, l’abondance des populations et les traits biologiques individuels. Le seuil élevé de la température hivernale et son augmentation précoce déclenchent une reproduction et un développement individuels rapides. Le plan d’eau connaît un déclin régulier de la biomasse (chlorophylle et poissons) tandis que la contamination cuprique augmente. La diminution progressive pour plusieurs espèces, des effectifs, de la longévité, des longueurs maximales, de l’âge et de la taille à maturité sexuelle contribuent au déclin de la masse globale ou individuelle maximale. L’effet de ces contraintes s’observa d’abord sur les perches et gardons avant de s’étendre aux espèces thermophiles (brèmes communes et bordelières, perche soleil). D’après l’examen de la littérature, ces observations résulteraient de l’altération du développement sexuel et du défaut croissant en ressource trophique.

Storage rings as the ESR and the future NESR in the FAIR project are unique tools to study the dynamics of electron-ion and ion-atom collisions in the realm of strong perturbations and short interaction times. A telling sign of the character of such collisions are the electrons emitted into the continuum. For high Z projectiles and low Z targets the projectile centred continuum is dominating. Precision studies of these electrons emitted in relativistic collisions thus are of paramount importance for an understanding of the ionization mechanisms active in transferring electrons into the continua. Forward electron spectroscopy thus appears to be the tool of choice. For high precision studies in collision spectroscopy of high Z projectiles we have implemented an imaging forward electron spectrometer into the ESR supersonic jet target zone. In combination with a reaction microscope to be implemented next this enables investigations of several fundamental processes ranging from kinematically complete studies of multiple ionization and (e, 2e) on ions to radiative and non-radiative electron transfer processes to the projectile continuum and for the first time kinematically complete measurements of the short-wavelength limit of the electron nucleus Bremsstrahlung. We report first results.

We report on an experiment aiming for a study of the radiative decay modes of the 1s(2s)2 level in Li-like uranium. The experiment was performed of initially Be-like uranium colliding with N2 molecules at an energy of 90 MeV/u. By measuring the x-ray production associated with K-shell ionization of the projectile, a high selectivity for the production of the 1s(2s)2 level is observed.

We have investigated the relation of forward emission cusp electron spectra and bremsstrahlung for 90AMeV U88+ + N2at the internal supersonic gas jet target of the ESR storage ring of GSI. We find that x ray photons measured in coincidence with cusp electrons originate from the short wavelength limit of the electron nucleus bremsstrahlung.

Radiative processes occurring in collision of decelerated bare uranium ions and molecular hydrogen are studied at the heavy-ion storage ring ESR. The combination of the deceleration technique and the narrow Compton profile of molecular hydrogen allowed us to resolve a multitude of REC transitions into the bound states of the projectile and to resolve unambiguously the tip region of primary bremsstahlung. For this purpose, a supersonic molecular hydrogen jet-target, precooled with liquid nitrogen and optimized for long-term stability, was applied.

The latest commissioning experiment of a two arm transmission crystal x-ray spectrometer along with high-performance position-sensitive microstrip germanium detectors is presented. The goal of the experiment was to observe with high resolution the Ly-α-transitions of H-like Pb81+produced in collisions with Kr atoms. Due to a photon e.ciency of only 10−8 the position sensitivity as well as the energy and time resolution of segmented solid state Germanium detectors are absolutely essential for experiments using crystal x-ray spectrometers dealing with beams of heavy ions. A detector system with the desired properties has become available through a collaboration with the Forschungszentrum Julich.

This paper analyses how information from user profile influences quality of recommendations. We first start with an overview of recommendation systems, their functions methods used. The empirical part focuses on collaborative filtering method with the aim to find improvement of recommendations based on the user profile. The main objective for realized experiments was to verify the hypothesis that using information stored in user's profiles can improve collaborative filtering recommendation results. All our experiments were realized in RapidMiner tool on well-known MovieLens dataset. For evaluation of results we used standard metrics such as RMSE, MAE and NMAE. Experiments did not confirm the above mentioned hypothesis, but we present additional analysis of identified clusters with best and worst recommendation results.

A numerical method for solving a class of constrained minimization problems encountered in quaternion data fusion is presented. The quaternion constraints are handled by the method of Lagrange multipliers. The number of the stationary points of the minimization problem is finite and all of them are found by solving via homotopy continuation a system of polynomial equations. The global minimizer is the stationary point that minimizes the loss function of the minimization problem. A numerical example of two-quaternion data fusion is given to illustrate the viability of the method as a global minimization method for quaternion data fusion.

Background Hibernating myocardium develops inhomogeneity in myocardial sympathetic innervation with spontaneous sudden cardiac death (SCD) because of ventricular fibrillation (VF). The triggers and prodromal arrhythmias initiating SCD in this substrate are unknown. Methods Swine chronically instrumented with a proximal left anterior descending coronary artery stenosis underwent placement of an implantable telemetry unit capable of continuously recording digitized electrocardiogram and left ventricular pressure signals at 1 kHz in conscious unrestrained animals for periods of up to 5 months. Results Spontaneous SCD (n = 10) was initiated by a close-coupled premature ventricular contraction followed by ventricular tachycardia (VT) that degenerated into VF during brief sympathetic activation. Peak heart rates were similar in animals that developed SCD vs survivors (250 ± 12 vs 261 ± 6 bpm). Electrocardiogram evidence of ischemia preceding VT/VF occurred in only 1 animal, and there was no significant infarction. Conclusions Spontaneous VT/VF in hibernating myocardium develops during brief sympathetic activation with only rare evidence of acute ischemia. This supports the notion that the regional remodeling accompanying hibernating myocardium may be a novel substrate for the development of SCD in chronic ischemic heart disease.

With the advanced accelerator technologies used at the SIS/ESR heavy ion facility at GSI, the highest charge states (bare, H-like, etc.) even for the heaviest ions can be provided for experiments at moderate collision velocities (vion

A crystal spectrometer has been constructed in the Focusing Compensated Asymmetric Laue geometry covering the energy range between 30 and 120 keV. We summarize the crystal optics and show the usefulness of the instrument for spectroscopy of stationary and fast moving X-ray sources. Results are reported from several tests employing a 169 Yb gamma-ray source and the Lyman radiation of one-electron Au 78+ ions travelling at a velocity corresponding to β = v / c o ≈0.44.

A new type of sediment trap, which overcomes a methodological gap in the study of sedimentation fluxes in shallow lentic systems, is described. The sedimentation rates measured in the field with these new traps were compared with those from other plate and cylindrical traps. As do other plate traps, the new traps allow the resuspension of deposited particles observed on bottom sediments. Furthermore, the new traps do not disturb particle sedimentation on the collecting area and allow to collect the net sedimentation rates in lentic systems.

The spectroscopy of atomic transitions in the hard X-ray regime above 15 keV utilizing position-sensitive solid state detectors is discussed. Special emphasis is given to the current detector developments for X-ray spectroscopy of heavy ions at the ESR storage ring where applications for precision spectroscopy as well as for polarization studies are of particular interest. For both cases, the advantages and new possibilities which are opened up by position and energy resolving solid state detectors are illustrated by the presentation of first experiments.

The ionization of L-subshell electrons in gold by the impact of 0.4-2.2 MeV amu-1 O ions was studied by observing excited Lγ(L-N, O) x-rays. We demonstrate that both the multiple ionization in outer M- and N-shells as well as the coupling effects in the L-shell play an important role in understanding the measured L-subshell ionization cross sections. The multiple ionization was found to be important in two aspects: first, the analysis of x-ray energy shifts and line broadening was crucial for proper interpretation of measured x-ray spectra; second, the additional vacancies in the M- and N-shells substantially influenced the L1-subshell fluorescence and Coster-Kronig (CK) yields, mainly by closing strong L1-L3M4,5 CK transitions. The data are compared with the simplified coupled-channels calculations using the `coupled-subshell model' (CSM) based on the semiclassical approximation (SCA), which describes both direct Coulomb ionization as well as the L-subshell couplings within the same theoretical approach. A good agreement of the present data with the theoretical predictions based on the discussed SCA-CSM approach is observed. Present findings partly explain the long-standing problem of inadequate theoretical description of L-shell ionization by heavy ion impact.

A collapse surface is developed for use in limit-load analysis of plates containing a large number of small circular penetrations arranged in an equilateral triangular array of holes with a ligament efficiency of 0.31733. The collapse surface is obtained by calculating the limit load for a unit cell model of the penetration pattern using a three-dimensional elastic-perfectly plastic [EPP] finite element analysis [FEA] computer program. The EPP response from incipient yielding to plastic collapse for the unit cell is obtained for a sufficient number of load cases to define the complete collapse surface. The collapse surface is expressed analytically by using a fourth-order function that incorporates the periodicity dictated by the triangular hole pattern. The coefficients of the fourth-order function were obtained by statistically fitting the collapse surface generated by the EPP-FEA results. The resulting collapse surface was shown to be appropriate for development of an EPP-EQS theory for perforated plates. The analytic surface agrees to within 7 percent of the actual collapse surface obtained by EPP-FEA of the unit cell representing the penetration.

Nineteen new traps which made it possible to sample almost the whole water column in shallow systems were exposed on a monthly basis during 18 months in two ponds. Quantitative and qualitative temporal variation of settled particles was shown even though seasonal variation was generally masked by bottom sediment resuspension in these shallow aquatic systems. Sedimentation rates fluctuated on a seasonal basis. They were minimum in spring and maximum in summer. These fluctuations were linked to the high primary production observed. These new traps showed that decaying submersed macrophytes can be an important source of organic matter, as well as decay of blue-green algal blooms which have always been considered responsible for anoxic problems in fish ponds. Interference by the fish farmer at various times of the year also caused sudden high sedimentation rates (>200 g m -2 d -1 ). Sedimentation in the fish ponds was controlled by natural mechanisms partly similar to those that occur in lakes, and by mechanisms specific to shallow systems and to aquatic systems managed by man.

In 1997 and 1998 we assessed the input and output of suspended matter, nitrogen and phosphorus during the exploitation period of a fishpond in the Domaine Departemental de Lindre (Moselle, north-eastern France). Special attention was given to the emptying period which was studied under different meteorological conditions (rainy and dry periods). The pond has a surface area of 2 ha, a volume of 16 000 m3 and is used for the production of various Cyprinidae (roach, bream, chub, pike, perch, carp). During the emptying operation, 630 and 2830 kg ha−1 of suspended matter, 10.8 and 36.5 kg ha−1 of Total-nitrogen and 1.2 and 5.1 kg ha−1 of Total-phosphorus were discharged from the pond during drought and heavy rainfall (50.5 mm in 166 h), respectively. Except for the emptying period, the pond retained 6850, 117 and 6.6 kg ha−1 of suspended matter, nitrogen and phosphorus, respectively. In the course of the emptying period, more than 32% of the suspended matter was discharged as was 8.5% of the nitrogen and 25% of the phosphate. For the whole exploitation period 4020 – 6220 kg ha−1 of suspended matter, 80–106 kg ha−1 of nitrogen and 1.6–5.5 kg ha−1 of phosphorus accumulated in the pond.

The radiative electron capture of a target electron into the projectile continuum has been studied for the collision system ${\text{U}}^{88+}+{\text{N}}_{2}\ensuremath{\rightarrow}{\text{U}}^{88+}+{[{\text{N}}_{2}^{+}]}^{*}+{e}^{\ensuremath{-}}+\ensuremath{\gamma}$ at 90 MeV/$\mathrm{u}$. Using a magnetic electron spectrometer, the energy distribution of cusp electrons emitted under an angle of ${0}^{\ensuremath{\circ}}$ with respect to the projectile beam and with a velocity close to the projectile velocity has been measured in coincidence with the emitted photons under various observation angles. The experimental results provide a stringent test for the corresponding process in inverse kinematics, namely, the theory of electron-nucleus bremsstrahlung at the high-energy endpoint. For comparison this process is calculated using fully relativistic Dirac wave functions and using semirelativistic Sommerfeld-Maue wave functions.

The results of a numerical simulation, performed to check the validity of a method developed for reconstruction of concentration distributions truncated by the detection limit, are reported in the context of trace element analysis in biomedical samples by total-reflection X-ray fluorescence. This method, by correcting a distribution over the whole range of concentrations in a population of samples, restores a number of measurements reporting results below the detection limit. We show by Monte Carlo simulations, assuming lognormal distributions to describe both the concentrations measured as well as the detection limits in the biomedical samples, that the method developed is accurate to within 5% for most typical situations. Moreover, we demonstrate that the factor limiting the accuracy of the correction is the number of measurements, not the correction procedure itself. We have found in simulations that the reconstruction of a concentration distribution, for a typical population size of N =100, is possible when the concentrations are measured only in 20–30% of samples. On the other hand, we show that by ignoring the truncation of a concentration distribution by the detection limit, the results can be systematically biased by as much as 50%. The method developed is applied to the analysis of trace elements in human breast tissue samples by total-reflection X-ray fluorescence (TXRF). The results are also discussed in terms of the size of the population studied.

Multiple ionization in outer M- and N-shells in Ta, Os, Au, Bi, Th and U targets was studied for O, Si and S ion impact at energies of 0.3-2.2 MeV amu-1. Excited Lγ(L-N, O) x-rays measured with a semiconductor Si(Li) detector were resolved by using a newly developed method accounting for simultaneous x-ray energy shift and line broadening due to the multiple ionization. The measured ionization probabilities, corrected for the effect of the vacancy rearrangement up to the moment of L x-ray emission, are interpreted as the ionization probabilities for M- and N-shells for the zero impact parameter. The ionization probabilities for the N-shell are found to be substantially increased by the super-Coster-Kronig transitions. Derived ionization probabilities for M- and N-shells are compared with the predictions of the geometrical model (GM) and the semiclassical (SCA) calculations in the united-atom limit. The universal scaling of the measured ionization probabilities for the M- and N-shells is discussed within the GM and SCA approaches.

This paper describes the formulation of an elastic-perfectly plastic flow theory applicable to equivalent solid (EQS) modeling of perforated materials. An equilateral triangular array of circular penetrations is considered. The usual assumptions regarding geometry and loading conditions applicable to the development of elastic constants for EQS modeling of perforated plates are considered to apply here. An elastic-perfectly plastic (EPP) EQS model is developed for a fourth-order collapse surface which is appropriate for plates with a triangular array of circular holes. A complete flow model is formulated using the consistent tangent modulus approach based on the fourth-order function. The EPP-EQS method is used to obtain a limit load solution for a plate subjected to transverse pressure and fixed at the outer edge. This solution is compared to a solution obtained with an EPP-FEA model in which each penetration in the plate is modeled explicitly. The limit load calculated by the EPP-EQS model is 6 percent lower than the limit load calculated by the explicit model.

A facility with a horizontal beam for radiobiological experiments with heavy ions has been designed and constructed at the Heavy Ion Laboratory in Warsaw University. The facility is optimal to investigate the radiobiological effects of charged heavy particles on a cellular or molecular level as in the region of the Bragg peak.

International audience; The K shell excitation of H-like uranium (U91+) in relativistic collisions with different gaseous targets has been studied at the experimental storage ring at GSI Darmstadt. By performing measurements with different targets as well as with different collision energies, we were able to observe for the first time the effect of electron-impact excitation (EIE) process in the heaviest hydrogenlike ion. The large fine-structure splitting in H-like uranium allowed us to unambiguously resolve excitation into different L shell levels. State-of-the-art calculations performed within the relativistic framework which include excitation mechanisms due to both protons (nucleus) and electrons are in good agreement with the experimental findings. Moreover, our experimental data clearly demonstrate the importance of including the generalized Breit interaction in the treatment of the EIE process.

The first experimental results of a high-resolution study of Th and U Lγ-X-rays induced in collisions with 230 MeV and 360 MeV oxygen ions, undertaken to investigate the dynamics of the multiple ionization in M-, N- and O-shells and the structure of M- and N-shell X-ray satellites, are reported. The measurements were performed using the transmission curved- crystal spectrometer installed in DuMond geometry. An instrumental resolution of about 10 eV was achieved for Lγ (L-N,O) X-ray transitions, allowing clear separation of M-shell X-ray satellites for Th and U. Moreover, the N-shell satellite structure in the Lγ6 (L2-O4) X-ray transition was observed for 360-MeV O ion impact on a thorium target. This, to our knowledge, is the first observation of this kind. Other observed Lγ X-ray diagram lines are shifted and widened, with respect to the photoinduced X-ray spectra excited by an X-ray tube, due to the unresolved N-shell and, probable the O-shell, satellite structure.

International audience; A twin crystal-spectrometer assembly, operated in the focusing compensated asymmetric Laue geometry has been developed for accurate spectroscopy of fast highly charged heavy ions in the hard-X-ray region. Coupled to the focusing crystal optics is a specially developed two-dimensional position-sensitive X-ray detector which is necessary for retaining spectral resolution also for fast moving sources. We summarize the crystal optics and demonstrate the usefulness of the instrument for spectroscopy of both stationary and fast moving X-ray sources. Results are reported from several tests employing a 169Yb gamma-ray source and the Lyman radiation of one-electron Pb81+ ions traveling at a velocity corresponding to [beta]†[reverse not equivalent]†v/c†[approximate]†0.59. The features of the instrument presented may be useful in many applications where it appears difficult to make the leap from conventional X-ray energy measurements to wavelength-dispersive spectroscopy based on crystal optics.

Novel high‐resolution spectrometer setups are presently commissioned for X‐ray experiments at the Experimental Storage Ring (ESR) at GSI, Darmstadt, aiming at an accurate determination of QED corrections in the critical field limit via an accurate determination of the ground‐state binding energy in a high‐Z, H‐like ion. Until now for H‐like uranium, an accuracy of 1% could be reached in an experiment performed at the electron cooler, due to the deceleration capability of the ESR. A further improvement by almost one order of magnitude is envisaged by a transmission x‐ray spectrometer setup in the FOcusing Compensated Asymmetric Laue (FOCAL) geometry, as well as by the implementation of high‐resolution microcalorimeter devices.Here we report on the latest commissioning experiment of a two‐arm transmission X‐ray spectrometer, along with high‐performance position‐sensitive microstrip germanium detectors. Due to a photon efficiency of only 10−8, the position sensitivity, as well as the energy and time resoluti...

International audience; In order to assess pollutant transfer in Camargue ponds from bordering agrosystems, a biomonitoring assay was conducted in irrigation and drainage channels of rice fields in the Rhone Delta (France). A filter-feeding bivalve, the Asian clam, Corbicula fluminea, was used as bioindicator and caged in upstream and downstream channels of an area of conventional rice fields. After 6 weeks incubation, many lipophilic biocides were identified in Corbicula tissues, including pesticides used in rice plantations (pretilachlor, oxadiazon), pesticides presumed in use in the Rhone basin [diuron and its metabolite 3,4 dichloroaniline (3,4-DCA)] and organochlorine pesticides (OCPs) banned for several decades. In addition, PCBs were highly bioaccumulated in Corbicula. Downstream bivalves had significantly lower concentrations of OCPs, PCB and 3,4-DCA. However, the exposure biomarkers (glutathione S-transferase, catalase and propionylcholinesterase) were not correlated with the decreased concentrations. The results of this experiment raise several questions concerning the potential role of immersed plants in a retention process.

We have measured the continuum momentum distribution for radiative electron capture to the continuum (RECC) cusp electrons in 90A MeV U{sup 88+}+N{sub 2}{yields}U{sup 88+}+(N{sub 2}{sup +}*)+e{sub cusp}(0 deg.)+h{nu} (RECC) collisions. We demonstrate that x rays coincident with RECC cusp electrons originate from the short-wavelength limit of the electron-nucleus bremsstrahlung and explain the asymmetric cusp shape by comparison with theory within the relativistic impulse approximation.

The x-ray satellite structure of Pd Lalpha1,2(L3M4,5) transition excited by an impact of O7+ and Ne6+ ions with energies 279 and 178 MeV, respectively, which were measured using a high-resolution von Hamos crystal spectrometer, is discussed in terms of the multi-configuration Dirac-Fock (MCDF) calculations. We demonstrate, by using the arguments of the general central limit theorem (GCLT), that a structure of complex M-shell satellites of Pd Lalpha1,2(M-m) transitions for a higher number of spectator vacancies (m > 4), which consists of hundreds of thousands of individual x-ray transitions as obtained from the MCDF calculations, can be well described by a single Voigtian profile. The Lorentzian width of such Voigtian line can be well modeled by using the results of the MCDF calculations for simpler configurations with a number of vacancies m < 4 . This method allows one to describe realistically a complex structure of M-shell satellites, thus extending the applicability of the MCDF calculations, which are limited by an increasing complexity of numerical calculations.

There is considerable variability in the sensitivity of inotropic reserve to identify viability in chronically dysfunctional myocardium. This is partially related to the underlying pathophysiology, with more frequent contractile reserve in chronically stunned (with normal resting perfusion) than hibernating myocardium (with reduced flow). This study was undertaken to determine the physiological responses to transient and graded stimulation in chronically stunned and hibernating myocardium to define the relative roles of acute catecholamine desensitization and biphasic responses. Pigs were chronically instrumented with a fixed left anterior descending artery stenosis that resulted in chronically stunned myocardium after 2 mo. One month later, hibernating myocardium was confirmed by regional dysfunction (wall thickening, 3.2 ± 0.3 vs. 5.5 ± 5 mm in remote, P = 0.01) with reduced resting flow (0.70 ± 0.07 vs. 0.92 ± 0.09 ml·min−1·g−1 in remote, P = 0.01) without infarction. Wall thickening in dysfunctional regions significantly increased during both graded and transient epinephrine stimulation in chronically stunned (from 3.6 ± 0.3 to 5.6 ± 0.5 and 4.9 ± 0.5 mm, respectively) and hibernating myocardium (from 3.3 ± 0.3 to 5.4 ± 0.6 and 5.0 ± 0.7 mm, respectively) and returned to baseline within 15 min. Although a biphasic response during graded stimulation was common, the subsequent decrement in function was small and similar in both groups (stunned, 0.7 ± 0.2 mm; hibernating, 1.1 ± 0.3 mm, P = 0.25). We conclude that 1) the extent of contractile reserve during β-adrenergic stimulation is similar in chronically stunned and hibernating myocardium, 2) there are no significant differences between the responses to transient compared with graded catecholamine stimulation, and 3) submaximal catecholamine stimulation does not induce additional stunning in either chronically stunned or hibernating myocardium.

We have measured the continuum momentum distribution for radiative electron capture to the continuum (RECC) cusp electrons in 90A MeV U88+ + N2--U88+ + N2 +* + ecusp(0 degrees ) + hnu (RECC) collisions. We demonstrate that x rays coincident with RECC cusp electrons originate from the short-wavelength limit of the electron-nucleus bremsstrahlung and explain the asymmetric cusp shape by comparison with theory within the relativistic impulse approximation.

Formation Flying is the concept that multiple spacecraft can be arranged in a formation to perform tasks that are not possible with a single spacecraft, or tasks that can be done more efficiently or inexpensively with a group of small spacecraft. One of the main engineering problems to be overcome is that of orienting or pointing a spacecraft to a very high degree of precision. Many approaches have focused on improving the performance and accuracy of the hardware used to determine the current orientation of the spacecraft. Here, orientation is related the line-of-sight accuracy between one spacecraft and another, not the overall relative attitude. The approach in this paper explores filtering algorithms for the goal of determining the minimum hardware requirements necessary to obtain microarcsecond line-of-sight pointing knowledge. This may allow for the use of less expensive hardware in future formation flying missions and may vastly improve mission capability.

Most of the fishponds are several hundred years old and subjected to various economical and ecological purposes. The draining period event during fish farming management affects negatively the fishpond image by its harmful characters towards the ecological affluent continuum. The lawful framing of this activity and its consequences for the environment are reported. They integrate socio-professional, hydrological and hydrobiologic approaches in order to appreciate exploitation pressure and risk management., L'étang piscicole, patrimoine souvent séculaire, a malgré ses forts enjeux économiques et écologiques, une image souvent négative, liée aux effets prévisibles des vidanges pour le continuum écologique de l'affluent. Pourtant, cette phase est une étape essentielle de la gestion piscicole. Son encadrement réglementaire et ses conséquences pour l'environnement sont rapportées en intégrant des approches socioprofessionnelles, hydrologiques et hydrobiologiques pour apprécier les contraintes d'exploitation et la gestion des risques., Masson G., BANAS D., FRANÇOIS D., Cizel O., Leglize L., Didier S., Corbonnois Jeannine. Vidange des étangs piscicoles : contraintes réglementaires et d'exploitation et Incidences environnementales (Emptying of extensive fishponds : practices, control and environnemental incidences). In: Bulletin de l'Association de géographes français, 82e année, 2005-2 ( juin). Territoires ruraux centre-européens / Lacs, étangs et zones humides. pp. 224-233.

Recent photon correlation studies for Radiative Electron Capture into high-Z projectiles are reviewed. Emphasis is given to the investigation of polarization phenomena which are now accessible due to recent developments in position sensitive solid-states detectors. It is shown, that REC may provide a tool for the diagnostics and detection of the spinâ€"polarization of particles involved in atomic collisions. Also the impact of REC studies for atomic structure studies is outlined. Here the strong alignment of excited states induced by REC allowed us to observe an interference between competing decay branches for the case of the Lyman-α1 transition in hydrogen-like ions.

reply: We appreciate Dr. Karagueuzian's ([3][1]) insight regarding the potential role of reduced cytosolic ATP (derived from glucose and glycogen) in explaining shortening of the QT interval (through activation of the ATP-sensitive K+ channel) as well as elevations in end-diastolic pressure (through

The utilization of the resonant atomic electron–ion collision process of dielectronic recombination (DR) as a tool to probe nuclear properties via isotope shifts and hyperfine effects is discussed. Based on DR, this resonance reaction spectroscopy at electron coolers of heavy-ion storage rings denotes a versatile approach to access nuclear parameters such as charge radius, spin, magnetic moment or lifetimes of long-lived excited nuclear states (isomers). The high sensitivity of DR allows for experiments with artificially synthesized rare isotopes and isomers. Recent experimental progress in the preparation of such exotic species at the ESR storage ring in Darmstadt is presented. The DR technique is exemplified for the case of 234Pa88+ (Z = 91).