Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence

Background The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo. Findings In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%). Conclusions This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms

Superparamagnetic nanoparticle ensembles

Magnetic single-domain nanoparticles constitute an important model system in magnetism. In particular ensembles of superparamagnetic nanoparticles can exhibit a rich variety of different behaviors depending on the inter-particle interactions. Starting from isolated single-domain ferro- or ferrimagnetic nanoparticles the magnetization behavior of both non-interacting and interacting particle-ensembles is reviewed. A particular focus is drawn onto the relaxation time of the system. In case of interacting nanoparticles the usual Neel-Brown relaxation law becomes modified. With increasing interactions modified superparamagnetism, spin glass behavior and superferromagnetism is encountered.Comment: Corrected formula: Eq. (1

Experimental evidence of three-dimensional acoustic propagation caused by nonlinear internal waves

Author Posting. © Acoustical Society of America, 2005. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 118 (2005): 723-734, doi:10.1121/1.1942428.The 1995 SWARM experiment collected high quality environmental and acoustic data. One goal was to investigate nonlinear internal wave effects on acoustic signals. This study continues an investigation of broadband airgun data from the two southwest propagation tracks. One notable feature of the experiment is that a packet of nonlinear internal waves crossed these tracks at two different incidence angles. Observed variations for the lower angle track were modeled using two-dimensional parabolic equation calculations in a previous study. The higher incidence angle is close to critical for total internal reflection, suggesting that acoustic horizontal refraction occurs as nonlinear internal waves traverse this track. Three-dimensional adiabatic mode parabolic equation calculations reproduce principal features of observed acoustic intensity variations. The correspondence between data and simulation results provides strong evidence of the actual occurrence of horizontal refraction due to nonlinear internal waves.This work was supported by an ONR Ocean Acoustics Graduate Traineeship Award and by ONR grants to Rensselaer, the University of Delaware, and the Woods Hole Oceanographic Institution

Spin-filter effect of the europium chalcogenides: An exactly solved many-body model

A model Hamiltonian is introduced which considers the main features of the experimental spin filter situation as s-f interaction, planar geometry and the strong external electric field. The proposed many-body model can be solved analytically and exactly using Green functions. The spin polarization of the field-emitted electrons is expressed in terms of spin-flip probabilities, which on their part are put down to the exactly known dynamic quantities of the system. The calculated electron spin polarization shows remarkable dependencies on the electron velocity perpendicular to the emitting plane and the strength of s-f coupling. Experimentally observed polarization values of about 90% are well understood within the framework of the proposed model.Comment: accepted (Physical Review B); 10 pages, 11 figures; http://orion.physik.hu-berlin.de

Characterization of silicon drift detectors with electrons for the TRISTAN project

Sterile neutrinos are a minimal extension of the standard model of particle physics. A promising model-independent way to search for sterile neutrinos is via high-precision β-spectroscopy. The Karlsruhe tritium neutrino (KATRIN) experiment, equipped with a novel multi-pixel silicon drift detector focal plane array and read-out system, named the TRISTAN detector, has the potential to supersede the sensitivity of previous laboratory-based searches. In this work we present the characterization of the first silicon drift detector prototypes with electrons and we investigate the impact of uncertainties of the detector\u27s response to electrons on the final sterile neutrino sensitivity

Experimental correlations for transient soot measurement in diesel exhaust aerosol with light extinction, electrical mobility and diffusion charger sensor techniques

A study of soot measurement deviation using a diffusion charger sensor with three dilution ratios was conducted in order to obtain an optimum setting that can be used to obtain accurate measurements in terms of soot mass emitted by a light-duty diesel engine under transient operating conditions. The paper includes three experimental phases: an experimental validation of the measurement settings in steady-state operating conditions; evaluation of the proposed setting under the New European Driving Cycle; and a study of correlations for different measurement techniques. These correlations provide a reliable tool for estimating soot emission from light extinction measurement or from accumulation particle mode concentration. There are several methods and correlations to estimate soot concentration in the literature but most of them were assessed for steady-state operating points. In this case, the correlations are obtained by more than 4000 points measured in transient conditions. The results of the new two correlations, with less than 4% deviation from the reference measurement, are presented in this paper.Bermúdez, V.; Pastor Soriano, JV.; López, JJ.; Campos, D. (2014). Experimental correlations for transient soot measurement in diesel exhaust aerosol with light extinction, electrical mobility and diffusion charger sensor techniques. Measurement Science and Technology. 25(6):1-13. doi:10.1088/0957-0233/25/6/065204S113256Davidson, C. I., Phalen, R. F., & Solomon, P. A. (2005). Airborne Particulate Matter and Human Health: A Review. Aerosol Science and Technology, 39(8), 737-749. doi:10.1080/02786820500191348Pope, C. A., Bates, D. V., & Raizenne, M. E. (1995). Health effects of particulate air pollution: time for reassessment? Environmental Health Perspectives, 103(5), 472-480. doi:10.1289/ehp.95103472Giechaskiel, B., Dilara, P., Sandbach, E., & Andersson, J. (2008). Particle measurement programme (PMP) light-duty inter-laboratory exercise: comparison of different particle number measurement systems. Measurement Science and Technology, 19(9), 095401. doi:10.1088/0957-0233/19/9/095401Park, K., Kittelson, D. B., & McMurry, P. H. (2004). Structural Properties of Diesel Exhaust Particles Measured by Transmission Electron Microscopy (TEM): Relationships to Particle Mass and Mobility. Aerosol Science and Technology, 38(9), 881-889. doi:10.1080/027868290505189LUO, C.-H., LEE, W.-M., & LIAW, J.-J. (2009). Morphological and semi-quantitative characteristics of diesel soot agglomerates emitted from commercial vehicles and a dynamometer. Journal of Environmental Sciences, 21(4), 452-457. doi:10.1016/s1001-0742(08)62291-3Matti Maricq, M. (2007). Chemical characterization of particulate emissions from diesel engines: A review. Journal of Aerosol Science, 38(11), 1079-1118. doi:10.1016/j.jaerosci.2007.08.001Smith, O. I. (1981). Fundamentals of soot formation in flames with application to diesel engine particulate emissions. Progress in Energy and Combustion Science, 7(4), 275-291. doi:10.1016/0360-1285(81)90002-2Haynes, B. S., & Wagner, H. G. (1981). Soot formation. Progress in Energy and Combustion Science, 7(4), 229-273. doi:10.1016/0360-1285(81)90001-0Bockhorn, H. (Ed.). (1994). Soot Formation in Combustion. Springer Series in Chemical Physics. doi:10.1007/978-3-642-85167-4Tree, D. R., & Svensson, K. I. (2007). Soot processes in compression ignition engines. Progress in Energy and Combustion Science, 33(3), 272-309. doi:10.1016/j.pecs.2006.03.002Kennedy, I. M. (1997). Models of soot formation and oxidation. Progress in Energy and Combustion Science, 23(2), 95-132. doi:10.1016/s0360-1285(97)00007-5Buonanno, G., Dell’Isola, M., Stabile, L., & Viola, A. (2011). Critical aspects of the uncertainty budget in the gravimetric PM measurements. Measurement, 44(1), 139-147. doi:10.1016/j.measurement.2010.09.037Symonds, J. P. R., Reavell, K. S. J., Olfert, J. S., Campbell, B. W., & Swift, S. J. (2007). Diesel soot mass calculation in real-time with a differential mobility spectrometer. Journal of Aerosol Science, 38(1), 52-68. doi:10.1016/j.jaerosci.2006.10.001Luque de Castro, M. D., & Priego-Capote, F. (2010). Soxhlet extraction: Past and present panacea. Journal of Chromatography A, 1217(16), 2383-2389. doi:10.1016/j.chroma.2009.11.027Wang, S. C., & Flagan, R. C. (1990). Scanning Electrical Mobility Spectrometer. Aerosol Science and Technology, 13(2), 230-240. doi:10.1080/02786829008959441Snegirev, A. Y., Makhviladze, G. ., & Roberts, J. . (2001). The effect of particle coagulation and fractal structure on the optical properties and detection of smoke. Fire Safety Journal, 36(1), 73-95. doi:10.1016/s0379-7112(00)00037-0Zhou, Z.-Q., Ahmed, T. U., & Y. Choi, M. (1998). Measurement of dimensionless soot extinction constant using a gravimetric sampling technique. Experimental Thermal and Fluid Science, 18(1), 27-32. doi:10.1016/s0894-1777(98)10005-5Arregle, J., Bermúdez, V., Serrano, J. R., & Fuentes, E. (2006). Procedure for engine transient cycle emissions testing in real time. Experimental Thermal and Fluid Science, 30(5), 485-496. doi:10.1016/j.expthermflusci.2005.10.002Bermúdez, V., Luján, J. M., Serrano, J. R., & Pla, B. (2008). Transient particle emission measurement with optical techniques. Measurement Science and Technology, 19(6), 065404. doi:10.1088/0957-0233/19/6/065404Giechaskiel, B., Maricq, M., Ntziachristos, L., Dardiotis, C., Wang, X., Axmann, H., … Schindler, W. (2014). Review of motor vehicle particulate emissions sampling and measurement: From smoke and filter mass to particle number. Journal of Aerosol Science, 67, 48-86. doi:10.1016/j.jaerosci.2013.09.003Lapuerta, M., Armas, O., & Gómez, A. (2003). Diesel Particle Size Distribution Estimation from Digital Image Analysis. Aerosol Science and Technology, 37(4), 369-381. doi:10.1080/02786820300970Desantes, J. M., Bermúdez, V., Molina, S., & Linares, W. G. (2011). Methodology for measuring exhaust aerosol size distributions using an engine test under transient operating conditions. Measurement Science and Technology, 22(11), 115101. doi:10.1088/0957-0233/22/11/115101Roessler, D. M. (1982). Diesel particle mass concentration by optical techniques. Applied Optics, 21(22), 4077. doi:10.1364/ao.21.004077Park, D., Kim, S., An, M., & Hwang, J. (2007). Real-time measurement of submicron aerosol particles having a log-normal size distribution by simultaneously using unipolar diffusion charger and unipolar field charger. Journal of Aerosol Science, 38(12), 1240-1245. doi:10.1016/j.jaerosci.2007.09.00

Characterization of Silicon Drift Detectors with Electrons for the TRISTAN Project

Sterile neutrinos are a minimal extension of the Standard Model of Particle Physics. A promising model-independent way to search for sterile neutrinos is via high-precision beta spectroscopy. The Karlsruhe Tritium Neutrino (KATRIN) experiment, equipped with a novel multi-pixel silicon drift detector focal plane array and read-out system, named the TRISTAN detector, has the potential to supersede the sensitivity of previous laboratory-based searches. In this work we present the characterization of the first silicon drift detector prototypes with electrons and we investigate the impact of uncertainties of the detector's response to electrons on the final sterile neutrino sensitivity.Comment: 18 pages, 8 figures. J. Phys. G: Nucl. Part. Phys. 48 01500