РЕСУРС ТЕПЛОВОЗНЫХ ДИЗЕЛЕЙ: РЕТРОСПЕКТИВНЫЙ АНАЛИЗ

This is the final part of the review article (for the first part see World of Transport and Transportation, 2014, Vol.12, Iss. 6, pp.212–221) showing that diesel engines of the first post-war II generation were characterized by inherent structural deficiencies of new developments, unfinished ideas. The results of studies carried out in that period are considered, technical solutions taken at that time are critically analyzed, including those that aimed at addressing identified problems. The analysis allowed the authors, in particular, to draw conclusions that for this generation of diesel engines brands of used metals, wear resistance and fatigue strength of cast iron, features of bearing fillets, cylinder block group, the quality of welded joints had the fundamental importance. As follows from the obtained data, engine components are not equal in their impact on engine reliability and working life, form their levels of importance, have their own «place» in the design of the engine structure as a system.В публикуемой обзорной статье (начало см.: «МТ», 2014, № 6) показано, что для тепловозных дизелей первого послевоенного поколения были характерны свойственные новым разработкам конструкционные недостатки, незавершенные идеи. Рассмотрены результаты исследований, выполненных в тот период, проанализированы с критических позиций принятые в то время технические решения, в том числе нацеленные и на устранение выявленных проблем. Анализ позволил, в частности, сделать выводы о том, что для дизелей этого поколения принципиально важными являлись марки применяемых металлов, износостойкость и усталостная прочность чугуна, особенности галтелей коленчатого вала, элементов блока цилиндров, качество сварных соединений.

РЕСУРС ТЕПЛОВОЗНЫХ ДИЗЕЛЕЙ: РЕТРОСПЕКТИВНЫЙ АНАЛИЗ

This published review article shows that diesel engines of the first post World II generation were characterized by inherent structural deficiencies of new developments, unfinished ideas. The results of studies carried out in that period are considered, technical solutions taken at that time are critically analyzed, including those that aimed at addressing identified problems. The analysis allowed the authors, in particular, to draw conclusions that there were brands of used metals, wear resistance and fatigue strength of cast iron, features of bearing fillets, cylinder block group, the quality of welded joints that had fundamental importance for that generation of diesel engines. As follows from the obtained data, engine components are not equivalent in their impact on its reliability and working life, form a certain hierachy as for their importance for design of the engine structure as a system.В публикуемой обзорной статье показано, что для тепловозных дизелей первого послевоенного поколения были характерны свойственные новым разработкам конструкционные недостатки, незавершенные идеи. Рассмотрены результаты исследований, выполненных в тот период, проанализированы с критических позиций принятые в то время технические решения, в том числе нацеленные и на устранение выявленных проблем. Как вытекает из полученных данных, узлы двигателя неравнозначны по влиянию на его безотказность и ресурс, образуют свои уровни по значимости, «месту» в конструкции дизеля как системы

Charged current events with neutral strange particles in high-energy antineutrino interactions

The results of a study of strange particle production in charged current interactions in the Fermilab 15 ft bubble chamber filled with a heavy Ne---H2 mixture are presented. Production rates and average multiplicities of K0's and [Lambda]'s as functions of W2 and Q2 are given. The experimental data agree well with the quark-parton model predictions if a yield of 0.06 +/- 0.02 of K0's and [Lambda]'s from charm production is included. Upper limits for D-meson production are given and the shape of the charmed quark fragmentation function is discussed. Inclusive production of the K*(890) and [Sigma](1385) resonances is measured and it is shown that only about 5% of the K0 mesons and [Lambda] hyperons results from resonance decays. Relative production rates of neutral strange particles on proton and neutron targets are studied.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24478/1/0000753.pd

The A‐dependenc of ψ production in π− nucleus collisions at 530 GeV/c

The E672/E706 Spectrometer, located in the MW beam at Fermilab, was used to collect data on events containing a pair of muons in the final state with large effective mass. The momentum of incident pions and protons was 530 GeV/c. Nuclear targets included Be, C, Al, Cu and Pb. We report on a preliminary measurement of the A‐dependence of the per nucleus cross section for forward J/ψ production. The apparatus also detected charged particles and γ’s produced in association with the muon pair. The expected physics results on the hadroproduction of χ states and beauty particles are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87663/2/624_1.pd

Search for bottom squarks in pbarp collisions at sqrt(s)=1.8 TeV

We report on a search for bottom squarks produced in pbarp collisions at sqrt(s) = 1.8 TeV using the D0 detector at Fermilab. Bottom squarks are assumed to be produced in pairs and to decay to the lightest supersymmetric particle (LSP) and a b quark with branching fraction of 100%. The LSP is assumed to be the lightest neutralino and stable. We set limits on the production cross section as a function of bottom squark mass and LSP mass.Comment: 5 pages, Latex. submitted 3-12-1999 to PRD - Rapid Communicatio

Probing BFKL Dynamics in the Dijet Cross Section at Large Rapidity Intervals in ppbar Collisions at sqrt{s}=1800 and 630 GeV

Inclusive dijet production at large pseudorapidity intervals (delta_eta) between the two jets has been suggested as a regime for observing BFKL dynamics. We have measured the dijet cross section for large delta_eta in ppbar collisions at sqrt{s}=1800 and 630 GeV using the DO detector. The partonic cross section increases strongly with the size of delta_eta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of a_{BFKL}(20GeV)=1.65+/-0.07.Comment: Published in Physical Review Letter

Spin Correlation in tt-bar Production from pp-bar Collisions at sqrt(s)=1.8 TeV

The D0 collaboration has performed a study of spin correlation in tt-bar production for the process tt-bar to bb-bar W^+W^-, where the W bosons decay to e-nu or mu-nu. A sample of six events was collected during an exposure of the D0 detector to an integrated luminosity of approximately 125 pb^-1 of sqrt{s}=1.8 TeV pp-bar collisions. The standard model (SM) predicts that the short lifetime of the top quark ensures the transmission of any spin information at production to the tt-bar decay products. The degree of spin correlation is characterized by a correlation coefficient k. We find that k>-0.25 at the 68% confidence level, in agreement with the SM prediction of k=0.88.Comment: Submitted to PRL, Added references, minor changes to tex

Search for Electroweak Production of Single Top Quarks in ppbar Collisions

We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb.Comment: 11 pages, 2 figures. This is the published versio

Search for Large Extra Dimensions in Dielectron and Diphoton Production

We report a search for effects of large extra spatial dimensions in ppbar collisions at a center-of-mass energy of 1.8 TeV with the DZero detector, using events containing a pair of electrons or photons. The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% confidence level, on the effective Planck scale between 1.0 TeV and 1.4 TeV for several formalisms and numbers of extra dimensions.Comment: 6 pages, 2 figures, submitted to Phys. Rev. Let

GEANT4 : a simulation toolkit

Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 2