European freight vehicle running gear: Today's position and future demands

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The running gear of most of the rail freight vehicles in operation today tends to be built to very old designs. The running gear for new freight rolling stock and, in particular, new types of bogie must have significantly improved performance if they are to satisfy the demands of all the stakeholders associated with the railways. Improved performance in this context means reduced inspection time and brake manipulation time in marshalling yards, lower weight, lower noise emissions and lower lateral track forces. All this can be achieved by new designs of bogie running gear, at little extra first cost and at lower whole life cost

Critical speed and limit cycles in the empty Y25-freight wagon

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.In this research, an empty freight wagon with Y25 bogies have been modelled. Non-linear creep forces with spin moment between wheel and rail have been used, and also all impacts and friction forces have been modelled. Non-linear equations of motion and kinematical constraints have been solved in time domain, and limit cycles, saddle nodes, and critical speeds have been shown. Both primary and secondary hunting can be seen in the responses of the wagons. The relation between frequency of oscillations and speed can be seen, also, there are chaotic oscillations. Results show that stiffness in impacts affects calculation time and limit cycles

Wear and energy-saving freight bogie designs with rubber primary springs: principles and experiences

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The traditional radial steering bogie with swing hanger links is known to be track-friendly but heavy, and expensive in investment and maintenance costs. Whereas the actual bogies with longitudinal stiff axle guidance such as Y25 cause severe wear on wheels and rails in curves, and also develop high running resistance in curves. Bogies with rubbers springs like double rubber ring spring (DRRS), Leicht und LaermArm (LEILA) low weight and low noise, and Gigabox are a new feature with good behaviour in curves and on straight tracks. Good experience over many years with DRRS and 35 t axle load on the German Rheinisch Westfaelische Elektrizitaetswerke (RWE) coal line prove its benefits. For the new designs, LEILA and Gigabox, which are being introduced into the market now, even higher benefits can be demonstrated. The principle design features and the benefits regarding lateral track forces, wear, and traction resistance are evident. Also noise behaviour is an increasing demand for freight operation

Effect of suspension system in the lateral stability of railway freight trucks

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.In the current research an empty freight wagon with BA652 and an old BA661 bogies have been modelled. Non-linear creep forces with spin moment between wheel and rail have been used and also all impacts and friction forces have been modelled. The characteristics of primary suspension systems for BA652 and an old BA661 have been evaluated by means of test. Non-linear equations of motions and kinematical constraints have been solved in time domain and limit cycles have been showed. Both primary and secondary hunting can be seen in responses of wagon. For BA652 there are non-linear and linear critical speeds and also saddle nodes but for old BA661 the situation is too critical and the system can oscillate in very low speeds

Strahlensensibilisierung durch das antiretrovirale Therapieschema Efavirenz plus Tenofovir plus Emtricitabin

2.1 Background and aims If a carcinoma occurs in a HIV-positive patient, radiotherapy of a patient who is on HAART medication (Highly Active Anti-Retroviral Therapy) can be necessary. It is well known that the Nucleoside Reverse Transcriptase Inhibitor Zidovudin used in HIV-Therapy, as well as some Protease Inhibitors, cause radiosensitivity. On the one hand radiosensitivity can cause harmful side effects of radiation in normal tissue; on the other hand it can improve the susceptibility of a tumor to radiation. In this paper the antiretroviral treatment scheme consisting of the Non Nucleoside Reverse Transcriptase Inhibitor (NNRTI) Efavirenz (EFV) and the two Nucleoside Reverse Transcriptase Inhibitors (NRTI) Tenofovir (TDF) and Emtricitabin (FTC) was tested for radiosensitizing effects in vitro. 2.2 Methods The drugs were tested separately as well as in the combinations Tenofovir plus Emtricitabin and Efavirenz plus Tenofovir plus Emtricitabin, because these assemblies are available as combination drugs Truvada® and Atripla® respectively. Clonogenic assays were performed with a pancreatic cancer cell line for the drugs combined with radiation. The effect of the drugs on the cell cycle of fibroblasts and a pancreatic cancer cell line was examined by flow cytometry, because radiosensitivity of cells depends on the actual phase in the cell cycle. Furthermore the effect on the activated factors of DNA damage sensing NBS1, ATM, H2AX and 53BP1 was examined by Immunostaining of fibroblasts. 2.3 Results and observations In the clonogenic assay the NNRTI Efavirenz was radiosensitizing, whereas for both NRTIs Tenofovir and Emtricitabin a radioprotective effect was found. The combination Tenofovir plus Emtricitabin was also radioprotective. The combination Efavirenz plus Tenofovir plus Emtricitabin showed a radiosensitizing effect with a radiation dose below 5 Gy and a radioprotective effect above 5 Gy. Flow cytometry showed no effect of the drugs on the cell cycle of fibroblasts. In the pancreatic cancer cell line the combination of Efavirenz, Tenofovir and Emtricitabin caused an increase of the number of cells in G1/G0-phasis and a decrease of the number of cells in S-and G2/M-phasis, which can not be the reason for enhanced radiosensitivity. Immunostaining revealed a little increase of the number of foci per cell of NBS1, H2AX and 53BP1 with the NNRTI Efavirenz as well as the NRTI Tenofovir. With the NRTI Emtricitabin only the 53BP1 foci per cell were elevated. The combination of all three drugs together with radiation showed a larger and significant increase of the number of foci per cell of all four tested factors NBS1, ATM, H2AX and 53BP1 of DNA damage sensing. 2.4 Conclusion The triple therapy Efavirenz plus Tenofovir plus Emtricitabin, which is also available as combination drug Atripla®, is radiosensitizing in vitro. Consequently the risk of frequent and dangerous radiation induced side effects is elevated in patients on this medication. The practical implications of these results are that in patients on this medication either the therapy regime should be changed or they should be examined for individual radiosensitivity. For this examination the chromosomal break analysis by fluorescence in situ hybridization (FISH) is an established technique. Furthermore these drugs could be used purposefully as radiosensitizers to improve the susceptibility of a tumor to radiation.1.1 Hintergrund und Ziele Kommt es bei HIV-positiven Patienten zu Tumorerkrankungen, kann eine Strahlentherapie bei Patienten unter HAART (Highly Active Anti-Retroviral Therapy) erforderlich sein. Von den in der HIV-Therapie eingesetzten Nukleosidischen Reverse-Transkriptase-Inhibitor Zidovudin (AZT), sowie von einigen Protease-Inhibitoren ist bekannt, dass sie strahlensensibilisierend wirken. Eine Strahlensensibilisierung kann bei Patienten einerseits im Normalgewebe zu starken strahlenbedingten Nebenwirkungen führen, andererseits einen Tumor empfindlicher für eine Radiotherapie machen. In dieser Arbeit soll das HIV-Therapieschema aus dem Nicht-Nukleosidischen Reverse-Transkriptase-Inhibitor (NNRTI) Efavirenz (EFV) und den beiden Nukleosidischen Reverse-Transkriptase-Inhibitoren (NRTI) Tenofovir (TDF) und Emtricitabin (FTC) hinsichtlich strahlensensibilisierender Effekte in vitro getestet werden. 1.2 Methoden Die Substanzen wurden einzeln sowie in den Kombinationen Tenofovir plus Emtricitabin und Efavirenz plus Tenofovir plus Emtricitabin untersucht, da diese Zusammenstellungen als Kombinationsmedikamente Truvada® bzw. Atripla® verwendet werden. Es wurden Koloniebildungstests mit Pankreastumorzellen für die Substanzen in Kombination mit Bestrahlung durchgeführt. Der Einfluss der Medikamente auf den Zellzyklus wurde mittels flusszytometrischen Messungen bei Fibroblasten und Pankreastumorzellen untersucht, da Zellen je nach Zellzyklusphase unterschiedlich strahlensensibel sind. Zudem wurden durch Immunostaining von Fibroblasten die Auswirkungen der antiretroviralen Substanzen auf die aktivierten Faktoren der DNA-Schadenserkennung NBS1, ATM, H2AX und 53BP1 untersucht. 1.3 Ergebnisse und Beobachtungen Im Koloniebildungstest mit Pankreastumorzellen erwies sich der NNRTI Efavirenz als strahlensensibilisierend, wogegen die beiden NRTI Tenofovir und Emtricitabin strahlenschützende Effekte zeigten. Die Kombination Tenofovir plus Emtricitabin war ebenfalls strahlenschützend. Kombiniert man Efavirenz, Tenofovir und Emtricitabin miteinander, so zeigt sich im Dosisbereich bis 5 Gy ein strahlensensibilisierender und über 5 Gy ein strahlenschützender Effekt. Die flusszytometrischen Messungen zeigten keinen Einfluss der Medikamente auf den Zellzyklus der Fibroblasten. Bei den Pankreastumorzellen zeigte sich bei der Kombination von Efavirenz, Tenofovir und Emtricitabin eine Zunahme der Zellen in der G1/G0-Phase auf Kosten der S-und G2/M-Phase, wodurch eine Strahlensensibilisierung aber nicht erklärt werden kann. Beim Immunostaining von Fibroblasten fiel beim NNRTI Efavirenz sowie beim NRTI Tenofovir eine geringe Zunahme der Foci pro Zelle von NBS1, H2AX und 53BP1 auf. Beim NRTI Emtricitabin waren ausschließlich 53BP1 Foci vermehrt. Bei der Kombination aller drei Substanzen zeigte sich bei Bestrahlung eine deutliche und signifikante Steigerung der Foci pro Zelle der vier untersuchten Faktoren NBS1, ATM, H2AX und 53BP1 der DNA-Schadenerkennung im Vergleich zur bestrahlten Kontrolle. 1.4 Praktische Schlussfolgerungen Die Tripeltherapie Efavirenz plus Tenofovir plus Emtricitabin, auch als Kombinationsmedikament Atripla® erhältlich, ist in vitro strahlensensibilisierend. Folglich besteht bei Patienten die Gefahr von häufigen und starken strahlenbedingten Nebenwirkungen. Deshalb sollte man bei Patienten mit entsprechender Medikation entweder diese vor Bestrahlung umsetzen oder die Patienten hinsichtlich individueller Strahlenempfindlichkeit untersuchen. Eine Möglichkeit hierfür bietet die Chromosomenbruchanalyse mittels Fluoreszenz in situ Hybridisierung (FISH). Zudem könnten die Medikamente gezielt als Radiosensitizer eingesetzt werden, um die Wirkung der Bestrahlung auf einen Tumor zu verstärken

NLO QCD and electroweak corrections to W+\gamma\ production with leptonic W-boson decays

We present a calculation of the next-to-leading-order electroweak corrections to W+\gamma\ production, including the leptonic decay of the W boson and taking into account all off-shell effects of the W boson, where the finite width of the W boson is implemented using the complex-mass scheme. Corrections induced by incoming photons are fully included and find particular emphasis in the discussion of phenomenological predictions for the LHC. The corresponding next-to-leading-order QCD corrections are reproduced as well. In order to separate hard photons from jets, a quark-to-photon fragmentation function a la Glover and Morgan is employed. Our results are implemented into Monte Carlo programs allowing for the evaluation of arbitrary differential cross sections. We present integrated cross sections for the LHC at 7TeV, 8TeV, and 14TeV as well as differential distributions at 14TeV for bare muons and dressed leptons. Finally, we discuss the impact of anomalous WW\gamma\ couplings.Comment: 33 pages latex, 16 figures, typos in Table 1 correcte

Evolutionary optimization of optical antennas

The design of nano-antennas is so far mainly inspired by radio-frequency technology. However, material properties and experimental settings need to be reconsidered at optical frequencies, which entails the need for alternative optimal antenna designs. Here a checkerboard-type, initially random array of gold cubes is subjected to evolutionary optimization. To illustrate the power of the approach we demonstrate that by optimizing the near-field intensity enhancement the evolutionary algorithm finds a new antenna geometry, essentially a split-ring/two-wire antenna hybrid which surpasses by far the performance of a conventional gap antenna by shifting the n=1 split-ring resonance into the optical regime.Comment: Also see Supplementary material, as attached to the main pape

Automated Image Analysis of Transmission Electron Micrographs: Nanoscale Evaluation of Radiation-Induced DNA Damage in the Context of Chromatin

Background: Heavy ion irradiation (IR) with high-linear energy transfer (LET) is characterized by a unique depth dose distribution and increased biological effectiveness. Following high-LET IR, localized energy deposition along the particle trajectories induces clustered DNA lesions, leading to low electron density domains (LEDDs). To investigate the spatiotemporal dynamics of DNA repair and chromatin remodeling, we established the automated image analysis of transmission electron micrographs. Methods: Human fibroblasts were irradiated with high-LET carbon ions or low-LET photons. At 0.1 h, 0.5 h, 5 h, and 24 h post-IR, nanoparticle-labeled repair factors (53BP1, pKu70, pKu80, DNA-PKcs) were visualized using transmission electron microscopy in interphase nuclei to monitor the formation and repair of DNA damage in the chromatin ultrastructure. Using AI-based software tools, advanced image analysis techniques were established to assess the DNA damage pattern following low-LET versus high-LET IR. Results: Low-LET IR induced single DNA lesions throughout the nucleus, and most DNA double-strand breaks (DSBs) were efficiently rejoined with no visible chromatin decondensation. High-LET IR induced clustered DNA damage concentrated along the particle trajectories, resulting in circumscribed LEDDs. Automated image analysis was used to determine the exact number of differently sized nanoparticles, their distance from one another, and their precise location within the micrographs (based on size, shape, and density). Chromatin densities were determined from grayscale features, and nanoparticles were automatically assigned to euchromatin or heterochromatin. High-LET IR-induced LEDDs were delineated using automated segmentation, and the spatial distribution of nanoparticles in relation to segmented LEDDs was determined. Conclusions: The results of our image analysis suggest that high-LET IR induces chromatin relaxation along particle trajectories, enabling the critical repair of successive DNA damage. Following exposure to different radiation qualities, automated image analysis of nanoparticle-labeled DNA repair proteins in the chromatin ultrastructure enables precise characterization of specific DNA damage patterns