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Abstract Laminar burning velocities are of great importance in many combustion models as well as for validation and improvement of chemical kinetic schemes. Determining laminar burning velocities with high accuracy is quite challenging and different approaches exist. Hence, a comparison of existing methods measuring and evaluating laminar burning velocities is of interest. Here, two optical diagnostics, high speed tomography and Schlieren cinematography, are simultaneously set up to investigate methods for evaluating laminar flame speed in a spherical flame configuration. The hypothesis to obtain the same flame propagation radii over time with the two different techniques is addressed. Another important aspect is the estimation of flame properties, such as the unstretched flame propagation speed and Markstein length in the burnt gas phase and if these are estimated satisfactorily by common experimental approaches. Thorough evaluation of the data with several extrapolation techniques is undertaken. A systematic extrapolation approach is presented to give more confidence into results generated experimentally. The significance of the linear extrapolation routine is highlighted in this context. Measurements of spherically expanding flames are carried out in two high-pressure, high-temperature, constant-volume vessels at RWTH in Aachen, Germany and at ICARE in Orleans, France. For the discussion of the systematic extrapolation approach, flame speed measurements of methane / air mixtures with mixture Lewis numbers moderately away from unity are used. Conditions were varied from lean to rich mixtures, at temperatures of 298–373 K, and pressures of 1 atm and 5 bar. [ABSTRACT FROM AUTHOR]

SrCu2O2/ZnO interface is interesting for application in blue and UV light emission devices. Measurements of the valence band offset at SrCu2O2/ZnO interface using photoelectron spectroscopy result in an offset of 2.0 eV (cliff), meaning that the interface band gap is reduced to 1.4 eV. Blue and UV light emission observed previously can be attained in this material system presumably by injection of minority carriers involving tunneling through a narrow barrier at the interface. Additional intensive infrared light emission due to interface recombination can be predicted. [ABSTRACT FROM AUTHOR]

Visco-resistive magnetohydrodynamic simulations are used to investigate the role of resistivity and viscosity in the reversed field pinch sawtooth crash. Specifically, we examine the temporal behavior of the linearly stable (m, n) = (0, 1) mode. Both volume-averaged dissipation and dissipation levels in the region near the m = 0 resonance are found to influence characteristic time scales. Increasing resistivity causes the mode rise time, fall time, and total crash duration to decrease, while increasing viscosity has the opposite effect. Examination of energy flow during the sawtooth crash reveals that despite the linear stability of the (0, 1) mode, it receives most of its energy from the mean current profile during the crash rather than from nonlinear interactions with other modes. Resistivity and viscosity do not impact mode behavior directly through dissipative energy loss but rather through modification of the large scale current profile evolution and radial structure of the mode. Computational results are compared to experimental data from the Madison Symmetric Torus and found to largely agree when resistivity and viscosity are similar. [ABSTRACT FROM AUTHOR]

Summary: Swine enteric coronaviruses, including porcine epidemic diarrhoea virus (PEDV) and porcine deltacoronavirus (PDCoV), have emerged and spread throughout the North American swine industry over the last four years. These diseases cause significant losses within the pork industry and within the first year after PEDV introduction, approximately 10% of the US herd died due to the disease. Similar to other enteric coronaviruses, such as transmissible gastroenteritis virus (TGEV), these emerging swine enteric coronavirus diseases (SECD) are age‐dependent, with high morbidity and mortality in neonatal pigs. Since the introduction of SECD, research has focused on investigating viral pathogenesis through experimental inoculation, increasing maternal antibody for neonatal protection, understanding transmission risks through feed and transportation, and outlining the importance of biosecurity in preventing SECD introduction and spread. A survey of swine professionals conducted for this review revealed that the majority of respondents (75%) believe SECD can be eradicated and that most herds have been successful at long‐term elimination of SECD after exposure (80%). However, unique properties of SECD, such as ineffective immunity through parenteral vaccination and a low oral infectious dose, play a major role in management of SECD. This review serves to describe the current knowledge of SECD and the characteristics of these viruses which provide both opportunities and challenges for long‐term disease control and potential eradication from the US swine population. [ABSTRACT FROM AUTHOR]

A new method for the fitting of X-ray photoelectron spectra using an advanced Tougaard-background model for laterally inhomogeneous samples is presented. New is the use of a separate loss function for each spectral component. Additionally, a new Five-parameter inelastic electron scattering cross section (5-PIESCS) including a variable parameter to treat the electronic band gap energy is introduced for a better modelling of the loss structures of insulators. Synthetically generated test spectra using two peaks with strongly different loss structures and measured spectra from different samples are fitted with the traditionally used Shirley background ( B S ), the Tougaard background for homogeneous samples ( B TH ), and the newly developed advanced Tougaard background for laterally inhomogeneous samples ( B TI ). It was found that the fit results for the peak areas and peak positions of the three methods could be strongly different. In many cases the use of the Shirley background and the Tougaard background for homogeneous samples resulted in completely wrong component areas in spite of sometimes rather satisfying residual functions and Abbe criteria. In contrast, the advanced Tougaard background for inhomogeneous samples gave excellent results for all wide range spectra including pronounced loss structures. The new source code of the UNIFIT software (Version 2016 or higher) to calculate the advanced Tougaard-background parameters for inhomogeneous samples was verified. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS) is a high-consequence animal disease with current vaccines providing limited protection from infection due to the high degree of genetic variation of field PRRS virus. Therefore, understanding host immune responses elicited by different PRRSV strains will facilitate the development of more effective vaccines. Using IngelVac modified live PRRSV vaccine (MLV), its parental strain VR-2332, and the heterologous KS-06-72109 strain (a Kansas isolate of PRRSV), we compared immune responses induced by vaccination and/or PRRSV infection. Our results showed that MLV can provide complete protection from homologous virus (VR-2332) and partial protection from heterologous (KS-06) challenge. The protection was associated with the levels of PRRSV neutralizing antibodies at the time of challenge, with vaccinated pigs having higher titers to VR-2332 compared to KS-06 strain. Challenge strain did not alter the cytokine expression profiles in the serum of vaccinated pigs or subpopulations of T cells. However, higher frequencies of IFN-γ-secreting PBMCs were generated from pigs challenged with heterologous PRRSV in a recall response when PBMCs were re-stimulated with PRRSV. Thus, this study indicates that serum neutralizing antibody titers are associated with PRRSV vaccination-induced protection against homologous and heterologous challenge. [ABSTRACT FROM AUTHOR]

Abstract: A comparative study for the fitting of x-ray photoelectron spectra using different background model functions is presented. Synthetically generated test spectra and measured spectra from an SrTiO3 (STO) sample are fitted with the traditionally used Shirley background and the so-called improved Tougaard background calculated with four fit parameters of the inelastic electron scattering cross section. It was found that the results obtained with both methods are strongly different. In many cases the use of the Shirley background resulted in completely wrong component areas in spite of sometimes rather satisfying residual functions and Abbe criteria. In contrast, the improved Tougaard background gave excellent results for all wide range spectra including pronounced loss structures. The new source code of the current UNIFIT software (Version 2011 or higher) to calculate the Tougaard-background parameters was verified. [Copyright &y& Elsevier]

A shift in the binding energies in Ba 3d and Ti 2p core-level spectra was observed when the electronic properties of nonprepolarized and prepolarized BaTiO3 surfaces were studied using x-ray photoelectron spectroscopy during heating and cooling near the Curie temperature (TC). From a comparison of this shift for nonprepolarized and prepolarized crystals, different magnitudes and directions were noted. The differences are not connected with chemical shifts induced by any new chemical bonds. The shift in binding energy is considered to be a change of surface potential due to surface charging caused by the heating of the ferroelectric crystal through TC. [ABSTRACT FROM AUTHOR]

The objectives of this experiment were to determine how long porcine reproductive and respiratory syndrome virus (PRRSV) could be detected in muscle tissues of experimentally infected pigs and to evaluate the transmissibility of PRRSV to pigs via ingestion of quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR)-positive muscle tissues. Serum, lymphoid tissues, and muscle ( M. longissimus dorsi) samples were collected from 135 pigs (89 PRRSV-inoculated pigs and 46 negative control). Between 28 and 202 days post-inoculation, 13 of 89 (14.6%) muscle samples were positive by qRT-PCR. Among these 13, PRRSV was isolated from four of the 13 corresponding serum samples and three of 13 lymphoid tissue samples. In addition, infectious virus was detected in lymphoid tissue homogenates of six of 13 pigs by intramuscular bioassay. Swine transmissibility studies were performed by feeding thirteen 3-week-old PRRSV-naive pigs (recipient pigs) qRT-PCR-positive muscle and then monitoring recipients for evidence of PRRSV viremia by qRT-PCR. No transmission of PRRSV to recipient pigs via consumption of muscle samples was observed. These data suggested that qRT-PCR detected non-infectious PRRSV in pig meat and/or PRRSV is not highly transmissible to susceptible pigs via consumption of PRRSV-contaminated meat. [ABSTRACT FROM AUTHOR]

The author comments on the research about the palaeoenvironmental changes and the impact of the geoarchaeological evidence found in the Nazca-Palpa Region in Southern Peru to the pre-Columbian cultures. He stresses that the authors of the research attempted to determine the age of the desert plain surfaces and based it on a particular interpretation of geomorphic evidence. However, some of the evidence on palaeoenvironmental reconstruction is open to alternative interpretations.

At Ocean Drilling Program Site 997 in Blake Ridge gas-hydrate field in West Atlantic, pore-water studies revealed a pronounced downward depletion of the heavy chlorine isotope to nearly −4‰ δ37Cl at approximately 750 m below sea floor (mbsf) associated with a 10% downward chlorinity decrease. This is one of the stronger 37Cl depletions hitherto reported for marine pore waters. Chlorinity reductions in hydrate-bearing sediments commonly result from fresh-water release by hydrate melting. However, in situ measurements at Site 997 suggest that >50% of the chlorinity reduction occurred prior to hydrate dissociation. Modeling the chlorinity profile shows that advection of a strongly 37Cl-depleted, low-chlorinity water (506 mm) from below the drilled sequence can explain the reduction prior to sampling. Fitting the model to the δ37Cl curve yielded an advection rate of 0.18 mm year−1. Diffusive mixing with near-0‰- δ37Cl paleo-seawater with maximum chlorinity at shallow subsurface depths (561 mm at approximately 20 mbsf) produced the smooth, steady trend. Separating that part of the freshening caused by advection and diffusion from that due to hydrate dissociation allowed estimation of average hydrate concentrations of 3.8% of the pore space (up to 24.5% in hydrate-rich layers; near-100% in rare massive hydrate layers). The deep-seated source of the 37Cl-depleted, low-chlorinity water remains unknown and might be located below the sedimentary section in the oceanic basement. [ABSTRACT FROM AUTHOR]

The article focuses on the impact of fast transient power excursions on the performance of optical networks due to receiver constraints. It was found that if fast power transients occur at the input of the receiver, then during the transients the bit error rate performance will be significantly affected due to changes in the optimum receiver threshold caused by the high-pass frequency response of the AC-coupled receiver. For dynamic transient power changes that occur in a time frame much slower than the receiver cut-off frequency, the impact of power changes can be described by the static receiver behaviour.

The transport performance of a regional area wavelength division multiplexing (WDM) transparent optical network is studied. We present excellent performance results (Q factors for all received signals greater than 10 with small power penalties) for a ring network based on application-optimized cost-effective optical layer components and fiber. The network consists of six network nodes, interconnected with 86.5-km spans of uncompensated negative dispersion fiber, resulting in a maximum transmission distance around the ring of 519 km, and it supports 32 directly modulated channels operating at 2.5 Gb/s (80-Gb/s network capacity). The novel design of the network nodes ensures great flexibility in terms of scalability and transparency, as well as great performance. To our knowledge, the capacity-length product of this transparent network, using cost-effective directly modulated lasers (DMLs) and no dispersion compensation, is the highest ever reported [ABSTRACT FROM PUBLISHER]

Abstract. Hard amorphous carbon silicon nitride thin films have been grown by pulsed laser deposition (PLD) of various carbon silicon nitride targets by using an additional nitrogen RF plasma source on [100] oriented silicon substrates at room temperature. The influence of the number of laser shots per target site on the growth rate and film surface morphology was studied. Up to about 30 at. % nitrogen and up to 20 at. % silicon were found in the films by Rutherford backscattering spectroscopy (RBS) and X-ray photoelectron spectroscopy (XPS). The XPS of the films showed a clear correlation of binding energy to the variation of PLD parameters. The films show a universal hardness value up to 23 GPa (reference value for silicon substrate 14GPa) in dependence on target composition and PLD parameters. The results emphasise the possibility of variation of chemical bonding and corresponding properties, such as nanohardness, of amorphous CSi[sub x]N[sub y] thin films by the plasma-assisted PLD process. [ABSTRACT FROM AUTHOR]

The replication of five bovine respiratory viruses in cultured bovine alveolar macrophages (BAM) was investigated. The bovine herpesvirus DN-599 strain did not cause cytophatic effect (CPE), extracellular virus and intracellular antigen were not demonstrated. Although a small number of bovine respiratory syncytial virions were consistently released and about 1 percent of the BAM were fluorescence antibody (FA) positive the virus caused no CPE. Infectious bovine rhinotracheitis virus caused CPE at an input multiplicity of about 0.5, and 5 percent of the BAM were FA positive. Both bovine parainfluenza-3 and bovine viral diarrhea viruses caused CPE, infective virions were released and considerable proportions of the BAM were FA positive. [ABSTRACT FROM AUTHOR]