Usual Values Research Articles

Growth and characterization of ferrite film prepared by pulsed laser deposition

Ba2+Fe12O19 (BaO.6Fe2O3) films have been grown on (0001) sapphire substrate using pulsed laser deposition (PLD) technique. Prepared films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray reflectivity (XRR), atomic force microscopy (AFM) and magnetic measurements. XRD confirms the formation of Ba2+Fe12O19 phase, whereas presence of Fe2O3 was also identified. X-ray photoelectron spectroscopy (XPS) shows the signature of all the elements present in the barium ferrite. XRR data show the thickness of the film is ~ 24.2 nm with top layer roughness of ~ 3.7 nm. AFM measurement suggests the formation of clusters with average roughness of ~ 3.9 nm. Magnetic measurements of the target reveal its anisotropic nature with coercivity values: 0.23 and 0.24 T, obtained along two orthogonal directions. For the prepared thin film, the obtained coercivity ~80 mT and saturation induction 0.13 T are lower than the usual values obtained for Ba2+Fe12O19 compound (coercivity and saturation induction values are 0.19 Tesla and 0.48 T respectively), can be ascribed to the presence of Fe2O3 phase.

The effect of volcanic activity of the Eyjafjallajökul volcano on iodine concentration in precipitation in the Czech Republic

Our measurements noticed elevated iodine concentration in precipitation due to volcanic activity. The concentrations determined in two regions of the Czech Republic increased significantly during the passage of dust cloud from Icelandic volcano Eyjafjallajökul over the sampling areas. Iodine concentration in the rainwater was up to 6.68μgdm−3 during the critical period between 16 and 20 April 2010. Measured levels were up to six times higher than background values. The increased concentrations decreased to the usual values within approximately two weeks.

A Difference Picard Theorem for Meromorphic Functions of Several Variables

It is shown that if n ∈ ℕ, c ∈ ℂn, and three distinct values of a meromorphic function f: ℂn sr 1 of hyper-order gV(f) strictly less than 2/3 have forward invariant pre-images with respect to a translation τ: ℂn sr ℂn, τ (z) = z + c, then f is a periodic function with period c. This result can be seen as a generalization of M. Green’s Picard-Type Theorem in the special case where gV(f) < 2/3, since the empty pre-images of the usual Picard exceptional values are by definition always forward invariant. In addition, difference analogues of the Lemma on the Logarithmic Derivative and of the Second Main Theorem of Nevanlinna theory for meromorphic functions ℂn → ℙ P1 are given, and their applications to partial difference equations are discussed.

Weak values in nonideal spin measurements: An exact treatment beyond the asymptotic regime

We consider weak measurements (WM) of a spin observable in quantum mechanics beyond the usual asymptotic regime. This is done by obtaining the exact time-dependent wave functions of the measuring apparatus for general non-ideal measurements. Ideal strong measurements and the usual WM regime are obtained as the two extreme limiting cases of our exact treatment. We show that in the intermediate regime non-ideal measurements lead to "semiweak" eccentric values that differ from the usual weak values. We further show that even in the WM regime the exact treatment leads to a meter behavior that can be markedly distinct from the one predicted by the usual WM formalism. We give several illustrations and discuss an application to the distinction of different realizations of the same density matrix.

Plaster Hydration at Different Plaster-to-Water Ratios: Acoustic Emission and 3-Dimensional Submicrometric Simulations

To relate the dynamics of the reaction to the structure and properties of the resulting material, we develop a three-dimensional submicrometric simulation model for plaster hydration, valid in the entire range of plaster-to-water ratios. Stochastic rules govern the growth without overlap of gypsum needles. The precipitation process is assumed to drive the dissolution of plaster grains. The comparison of the simulation results with optical microscopy images at different times and acoustic emission monitoring during the reaction enable us to assign physical values to the length and time scales and to the main parameters of the model. In agreement with X-ray microtomography images of plaster available online (http://visiblecement.nist.gov/plaster.html), the simulation model predicts that hydration of plaster of Paris is incomplete for the usual values of plaster-to-water ratios used in industry.

The 8 June 2000 ULF wave activity: A case study

We examine the characteristics of a train of ULF waves observed in the magnetosphere and at ground after the sudden impulse (SI) onset of 8 June 2000. A highly monochromatic and large‐amplitude wave atf =3.3 mHz was observed between 9:10 and 9:50 UT at the GOES8 orbit (on the dawn flank of the magnetosphere) and across a wide longitudinal range of ground stations from low to high latitudes. The combination of the long period of these pulsations (5 min), their extended duration (∼40 min), the latitude‐independent frequency, and the small azimuthal wave number suggests the occurrence of a global magnetospheric mode driven by the sudden enhancements of the solar wind dynamic pressure. The amplitude and cross‐phase analysis of the wave activity on the ground and the polarization pattern indicate that the global mode coupled to the field line resonance (FLR) occurs at different latitudes at different local times. Such FLRs occurred at latitudes smaller than usually observed at the same frequency, suggesting a significant reduction of the local field line eigenfrequencies as compared with usual values. A model estimation (time of flight approximation) of such eigenfrequencies suggests a change in the magnetospheric field geometry characterized by more elongated field lines than those for usual conditions. It was probably caused by the compression of the magnetosphere driven by the pressure pulse coupled with the stable northward orientation of the interplanetary magnetic field.

Testing for Partial Exogeneity with Weak Identification

We consider the following problem. A structural equation of interest contains two sets of explanatory variables which economic theory predicts may be endogenous. The researcher is interesting in testing the exogeneity of only one of them. Standard exogeneity tests are in general unreliable from the view point of size control to assess such a problem. We develop four alternative tests to address this issue in a convenient way. We provide a characterization of their distributions under both the null hypothesis (level) and the alternative hypothesis (power), with or without identification. We show that the usual chi-squares critical values are still applicable even when identification is weak. So, all proposed tests can be described as robust to weak instruments. We also show that test consistency may still hold even if the overall identification fails, provided partial identification is satisfied. We present a Monte Carlo experiment which confirms our theory. We illustrate our theory with the widely considered returns to education example. The results underscore: (1) how the use of standard tests to assess partial exogeneity hypotheses may be misleading, and (2) the relevance of using our procedures when checking for partial exogeneity.

Quantitation of human herpesvirus-6A, -6B and -7 DNAs in whole blood, mononuclear and polymorphonuclear cell fractions from healthy blood donors

Background Diagnosis of human herpesvirus-6A (HHV-6A), -6B (HHV-6B) or -7 (HHV-7) infections is often based on the measure of viral load in blood. Objectives The aim of this study was to define usual values of HHV-6A, HHV-6B and HHV-7 loads in blood fractions (whole blood [WB], mononuclear cells [PBMCs], polymorphonuclear leukocytes [PMNLs]) of blood donors. Study design HHV-6A, HHV-6B and -7 DNAs were quantitated using real-time PCR assays in WB, PBMCs and PMNLs separated on Ficoll or dextran gradients, respectively, for 200 blood donors. Viral loads were expressed as the number of viral genomic copies per million cells (Cop/M) for all fractions, and also per milliliter for WB. Results HHV-6B DNA was rarely detected in WB (8%), PBMCs (16.5%), and PMNLs (10.5%), HHV-6A was never detected, whereas HHV-7 DNA was often present in WB (51.5%), PBMCs (62%) and PMNLs (51.5%). Median loads were low with 81 Cop/M in WB, 62 Cop/M in PBMCs and 34.5 Cop/M in PMNLs for HHV-6B, and 129 Cop/M in WB, 225 Cop/M in PBMCs and 62 Cop/M in PMNLs for HHV-7. Viral load expression per million cells and per mL were equivalent. One subject had chromosomally integrated HHV-6 with high viral loads ranging from 2.23 × 10 6 to 3.21 × 10 6 Cop/M in all compartments and plasma. Conclusions These results allow to propose viral load in WB as a sensitive and suitable marker, with values for healthy subjects at approximately 100 Cop/M for both viruses. The prevalence of chromosomally integrated HHV-6 was 0.5%.

Climate change analysis of precipitation data for North Rhine-Westphalia

In order to be able to make regionally differentiated statements on the past and the projected future precipitation development in North Rhine-Westphalia (NRW), measurements and climate model results have been analysed. The measurement data comprised data from 750 stations for the period 1950–2008. The climate change projections were the results of the three regional climate models CLM, WETTREG and STAR2. The results shown here give an overview on the past and projected future change of several precipitation statistics in NRW. Aside from the usual aggregated values (annual, semi-annual and monthly amounts of total precipitation) the development of heavy rainfall statistics was also examined on the basis of daily values as well as shorter time steps in the measurement data.

Laboratory Investigation on High Values of Restitution Coefficients

Restitution coefficients are used to quantify the energy dissipation upon impact when predicting rock fall events. These coefficients can be determined in situ or in the laboratory. In any case, the usual values for the normal restitution coefficient k n are below unity. Values greater than one are quite rare, seen as unusual and barely explained. Previous experimental research conducted in Australia has shown consistent and systematic values of the normal restitution coefficient greater than one. This was tentatively explained by a combination of parameters such as low impacting angle, rotational energy and block angularity. The study presented in this paper aims at (1) identifying the critical parameters conducting to high k n values and (2) at explaining the associated motion mechanisms. The objective was reached with values of k n up to almost 2. In addition, the study has confirmed the significance of low impacting angle, rotational energy and block shape in this context.

Bond Models for FRP Bars Anchorage in Concrete Slabs under Fire

Experimental tests were recently performed to evaluate resistance and deformability of nine concrete slabs reinforced with Fiber Reinforced Polymer (FRP) bars in fire situation by varying (a) external loads in the range of the service loads, (b) concrete cover in the range of usual values (30-50mm), (c) bar end shape (straight or bent) and its length at the end of the concrete members, namely in the zone not directly exposed to fire (250-500mm). Experimental results showed the importance of concrete cover in the zone directly exposed to fire for the protection provided to FRP bars, due to its low thermal conductivity. Moreover, the length of the FRP bars in the zone of slab not directly exposed to fire and its shape at the end of the members was crucial to ensures slab resistance once the resin softening reduced the adhesion at the FRP-concrete interface in the fire exposed zone of slab. In particular the anchorage obtained simply by bending bars at the end of member in a short zone (250mm) allowed attaining a good structural behavior in case of fire equivalent to that showed by slabs characterized by a large anchoring length (500mm). Tests results are briefly compared and discussed in this paper, whereas the behavior of the bar anchorage is carefully examined based on both the results of numerical thermal analysis and the predictions of a bond theoretical model adjusted for fire situation.

On the role of a weak hydrogen bond OH…O in the formation of the anomalous dielectric response of crystals and polymers near 40°C

In some crystals, polymers, and gels that contain hydrogen bonds OH…O, NH…O of length 2.8–3 A or water molecules, gigantic anomaly of dielectric permittivity (ɛ ∼ 103–106) is observed in certain circumstances at frequencies of 1–106 Hz, which is accompanied by peculiarities in conductivity σ and dielectric losses tanδ. In crystals this effect appears after a sudden cooling to −50°C and it is observed at slow heating in the range of 20–40°C. At the return temperature course from 40°C dependences ɛ(T), σ(T), and tanδ(T) have their usual values. Anomalies in objects that differ by their compositions are unified by their temperatures, which are all close to 40°C. Authors have made an attempt to explain the similarity of these phenomena by the features of hydrogen bonds that are present in the objects.

Singular semi-classical approximation on Liouville surfaces

The usual theory of semi-classical approximation for the laplacian on riemannian manifolds says that the energy levels of certain lagrangean submanifolds in the cotangent bundle provide approximate eigenvalues of the laplacian asymptotically. In this paper we consider a class of surfaces whose geodesic flows are completely integrable (Liouville surfaces defined over 2-sphere), and show the two results: One is the absence of the corresponding lagrangean submanifolds for certain eigenvalues; and the other is the existence of new approximate values, which are asymptotically finer along a certain direction even where the usual semi-classical approximate values exist.

High Speed Stream Properties and Related Geomagnetic Activity During the Whole Heliosphere Interval (WHI): 20 March to 16 April 2008

We study the interplanetary features and concomitant geomagnetic activity of the two high-speed streams (HSSs) selected by the Whole Heliosphere Interval (WHI) campaign participants: 20 March to 16 April 2008 in Carrington rotation (CR) 2068. This interval was chosen to perform a comprehensive study of HSSs and their geoeffectiveness during this “deep” solar minimum. The two HSSs within the interval were characterized by fast solar-wind speeds (peak values > 600 km s−1) containing large-amplitude Alfvenic fluctuations, as is typical of HSSs during normal solar minima. However, the interplanetary magnetic field (IMF) magnitude [Bo] was exceptionally low (≈3 – 5 nT) during these HSSs, leading to lower than usual IMF Bz values. The first HSS (HSS1) had favorable IMF polarity for geomagnetic activity (negative during northern Spring). The average AE and Dst for the HSS1 proper (HSS1P) were + 258 nT and − 21 nT, respectively. The second HSS (HSS2) had a positive sector IMF polarity, one that is less favorable for geomagnetic activity. The AE and Dst index averages were + 188 nT and − 7 nT, both lower than corresponding numbers for the first event, as expected. The HSS1P geomagnetic activity is comparable to, and the HSS2P geomagnetic activity lower than, corresponding observations for the previous minimum (1996). Both events’ geomagnetic activities are lower than HSS events previously studied in the declining phase (in 2003). In general, Vsw was faster for the HSSs in 2008 compared to 1996. The southward IMF Bz was lower in the former. The product of these two parameters [Vsw and IMF Bz] comprises the solar-wind electric field, which is most directly associated with the energy input into the magnetosphere during the HSS intervals. Thus the combined effects led to the solar wind energy input in 2008 being slightly less than that in 1996. A detailed analysis of magnetic-field variances and Alfvenicity is performed to explore the characteristics of Alfven waves (a central element in the geoeffectiveness of HSSs) during the WHI. The Bz variances in the proto-CIR (PCIR) were ≈ 30 nT2 and < 10 nT2 in the high speed streams proper.

P03-207 Sexual dysfunction in a tunisian sample of drug free schizophrenic patients: A case-control-study

IntroductionSexual dysfunction is reported by up to 80% of schizophrenic patients and seems to be mainly associated with antipsychotic medications.ObjectiveThis study aimed to compare sexual functioning and sexual dysfunction, as assessed by the Arizona Sexual Experience Scale, in drug naïve or drug free schizophrenic patients and in healthy controls.MethodA consecutive sample of 109 patients meeting DSM-IV criteria of schizophrenia was constituted in psychiatry department of Sousse Farhat Hached hospital (Tunisia), during a 24 months period. They were drug naïve or drug free for at least three months. 109 age and gender matched, consenting controls were recruited among blood donors attending Farhat Hached hospital during the same period. They were free from psychotic disorders as screened by MINI-Plus. Sexual functioning was assessed using the Arizona Sexual Experience Scale (ASEX) in sexually active patients (N = 84) and controls (N = 94).ResultsThere were no statistical differences in sexual dysfunction rates between schizophrenic patients (20.6%) and healthy controls (13.1%), according to usual threshold values. Also, global ASEX score was similar in schizophrenic patients (12.93 ± 4.48) as in healthy controls (12.61 ± 2.60). Besides, different ASEX item scores including sex drive, arousal, vaginal lubrification/penile erection and orgasm have not shown any differences between patients and controls. Only sexual satisfaction score was higher in schizophrenic patients than in healthy controls (2.73 ± 0.95 vs. 2.43 ± 0.77; p = 0.02).ConclusionOur results showed a low rate of sexual dysfunction in drug free schizophrenic patients without statistical differences with healthy controls. Only sexual satisfaction was lower in schizophrenic patients.

Wien effect in CuCl, CuBr and CuI superionic crystals and their melts

The dependence of conductivity of copper (I) halides (CuCl, CuBr, and CuI) and their melts on the electric field strength is studied. Conductivity of superconducting phases and their melts reaches limiting high-voltage values exceeding the usual values by up to 100% even at ∼0.5 MV/m.

Texture coefficients for the simulation of cordierite thermal expansion: A comparison of different approaches

The dependence of the coefficient of thermal expansion (CTE) from the texture description in porous ceramics is presented, in the example of cordierite. The texture description usually adopted for industrial ceramics, the I-ratio, is compared with the more rigorous approach of neutron diffraction (ND) pole figures. It is shown that the use of the I-ratio represents a coarse approximation of the complete materials texture and it yields different values of the texture coefficients used to model the CTE from lattice expansion data (according to the integrity function). For extruded and fired samples, it is shown that if for the transverse direction all approximations are equivalent, for the axial CTE the usual I-ratio values bring contradictory simulation results. On the contrary, the use of ND pole figures and of the Popa–Bruno method allows predicting sensible CTE values, consistent with other physical properties, such as Young's modulus.

The effects of phytophagous insects on water and soil nutrient concentrations and fluxes through forest stands of the Level II monitoring network in the UK

The effects of insect defoliators on throughfall and soil nutrient fluxes were studied in coniferous and deciduous stands at five UK intensive monitoring plots (1998 to 2008). Links were found between the dissolved organic carbon (DOC), nitrogen (N) and potassium (K) fluxes through the forest system to biological activity within the canopy. Underlying soil type determined the leaching or accumulation of these elements. Under oak, monitored at two sites, frass from caterpillars of Tortrix viridana and Operophtera brumata added direct deposition of ~ 16 kg ha −1extra N during defoliation. Peaks of nitrate (NO 3–N) flux between 5 and 9 kg ha −1 (×5 usual winter values) were recorded in consecutive years in shallow soil waters. Synchronous rises in deep soil NO 3–N fluxes at the Grizedale sandy site indicate downward flushing, not seen at the clay site. Under three Sitka spruce stands, generation of honeydew (DOC) was attributed to two aphid species ( Elatobium abietinum and Cinara pilicornis) with distinctive feeding strategies. Throughfall DOC showed mean annual fluxes (6 seasons) ~ 45–60 kg ha −1 compared with rainfall values of 14–22 kg ha −1. Increases of total N in throughfall and NO 3–N fluxes in shallow soil solution were detected — soil water fluxes reached 8 kg ha −1 in Llyn Brianne, ~ 25 kg ha −1 in Tummel, and ~ 40 kg NO 3–N ha −1 in Coalburn. At Tummel, on sandy soil, NO 3–N leaching showed increased concentration at depth, attributed to microbiological activity within the soil. By contrast, at Coalburn and Llyn Brianne, sites on peaty gleys, soil water NO 3–N was retained mostly within the humus layer. Soil type is thus key to predicting N movement and retention patterns. These long term analyses show important direct and indirect effects of phytophagous insects in forest ecosystems, on above and below ground processes affecting tree growth, soil condition, vegetation and water quality.

Fundamental solutions and Liouville type theorems for nonlinear integral operators

In this article we study basic properties for a class of nonlinear integral operators related to their fundamental solutions. Our goal is to establish Liouville type theorems: non-existence theorems for positive entire solutions for Iu⩽0 and for Iu+up⩽0, p>1. We prove the existence of fundamental solutions and use them, via comparison principle, to prove the theorems for entire solutions. The non-local nature of the operators poses various difficulties in the use of comparison techniques, since usual values of the functions at the boundary of the domain are replaced here by values in the complement of the domain. In particular, we are not able to prove the Hadamard Three Spheres Theorem, but we still obtain some of its consequences that are sufficient for the arguments.

A simple unified model for withdrawal of lag screws and glued-in rods

A mean stress failure criterion is applied to the Volkersen-model used for analysis of lag screws and glued-in rods subjected to withdrawal. Expressions are derived for pull-pull as well as pull-push loading conditions. The solutions for glued-in rods appear as special cases of the theory for lag screws, and the usual solutions for a maximum stress failure criterion appear as special cases of the solutions for a mean stress failure criterion. The theoretical solutions for lag screws are compared with test results, and a suggestion is made for taking into account initial shear stresses caused by the thread of the screw when driving the screw into the wood. The main advantage of considering initial shear stresses is that the number of necessary fitting parameters is limited to one, and that the usual values of shear strength and mode II fracture energy of wood can be applied.