National and statewide (California) collision numbers are currently on the decline; however, the U.S. is declining at a much slower rate than most other developed countries, and in some aspects is actually regressing in terms of traffic safety. Although state highway safety is improving, local roadway safety may actually be regressing. Approximately three-quarters of all U.S. public roadways, and approximately 80% of all injury accidents fall under the jurisdiction of cities. However, cities may not be allocating the proper level of resources, or operating under the proper administrative methodologies to adequately address these safety issues. This research finds that on average, California cities are experiencing increasing annual collision rates. In particular, small cities with populations of less than 25,000 are experiencing the largest increases, whereas larger cities are experiencing static or slightly decreasing collision rates. California’s statewide collision statistics and the administration surveys conducted as part of this study indicate that there is a correlation between a city’s administrative analysis/mitigation methodologies and their annual collision rate trends. Specifically, cities with lower traffic engineering staff to population ratios tend to have increasing collision rates, as opposed to cities with high staff to population ratios, which have decreasing collision rates. Also, this research shows that cities that allocate more traffic safety resources to enforcement over engineering tend to have increasing collision rates, as opposed to cities allocating more resources to engineering that have decreasing collision rates. This research also finds that there are predominant and correctable factors that lead to the various collision types. Cities that employ routine system wide traffic safety audits addressing location-specific collision trends based on these predominant factors tend to have decreasing collision rates, as opposed to those that do not. In general, collision rates among U.S. cities are increasing largely due to increasing rates on roadways within the jurisdiction of smaller cities, most commonly with populations under 25,000. Over one-third of cities are not staffed at the proper levels, not allocating the necessary resources to traffic engineering activities, and are not employing an adequate evaluation/mitigation strategy. The findings of this study provide guidance and framework to cities for developing effective traffic safety strategies by identifying the characteristics of those cities that have been successful in reducing collision rates as examples. In particular the value of this research is important for non-engineering administrative staff and political bodies in terms of establishing appropriate staffing levels and resource allocations necessary for an effective traffic safety program. The findings of this study provide guidance and framework to cities for developing effective traffic safety policy preference by identifying the characteristics of those cities that have been successful in reducing collision rates as examples. In particular this research is important for non-engineering administrative staff and political bodies in terms of establishing appropriate staffing levels and resource allocations necessary for a transportation department to be effective in reducing traffic collisions and resulting damages.

No description available.

Le terme d’énergie de symétrie (Csym) contenu à l’intérieur de l’équation d’état de la matière nucléaire est étudié via l’isoscaling et les formes des distributions isotopiques pour les réactions 40,48Ca+40,48Ca à une énergie incidente de 35 MeV/A. Les collisions périphériques et semi-périphériques sont étudiées. Un couplage entre deux appareils expérimentaux, le spectromètre VAMOS et le multidétecteur INDRA, a été fait. VAMOS a permis de mesurer la charge et la masse des résidus d’évaporation du quasi-projectile (PLF) avec grande précision. Les particules légères chargées ont été mesurées simultanément avec INDRA, permettant d’estimer le paramètre d’impact et l’énergie d’excitation ainsi que de reconstruire le fragment primaire, parent du PLF. L’étude des PLF montre la présence d’un effet pair-impair associé aux effets de désintégrations secondaires. L’extraction d’une information concernant Csym par l’étude des PLF, dans le cadre de cette thèse, est donc difficile, d’où la nécessité de reconstruire le fragment primaire. En étudiant les fragments primaires reconstruits, nous observons une évolution du paramètre Csym/T en fonction de la charge. Cette évolution est attribuée au degré d’excitation des fragments. De plus, la forme des distributions globales de Csym/T nous permet d’extraire le rapport des contributions de surface et de volume à l’énergie de symétrie. Ces rapports nous montrent des effets de surface importants, appuyés par les calculs théoriques. À partir des températures extraites par les spectres en énergie des protons, une valeur de Csym est extraite. Ces valeurs, autour de 30 MeV, sont cohérentes avec des valeurs autour de la densité de saturation. / Symmetry term (Csym) inside the nuclear equation of state is studied with the help of the isoscaling parameters and the isotopic distributions widths for 40,48Ca+40,48Ca reactions at an incident energy of 35 MeV/A. Peripheral et semi-peripheral collisions are studied. A coupling between two experimental setups, VAMOS spectrometer and INDRA multidetector was done. VAMOS was able to measure the charge and mass of the projectile like fragment (PLF) with a high precision. Light charged particles were measured in coincidence with INDRA, and they give us an impact parameter and excitation energy estimations They are also used in the primary fragment reconstruction, which are the PLF parent. PLF study shows the presence of an important odd-even effect, which can be associated to the secondary decay effects. The extracted values of the symmetry energy term directly from the PLF are not reliable. Therefore, it is necessary to reconstruct the primary fragment in order to take into account the secondary decay effects. By studying primary fragments, we observe an evolution of the parameter Csym/T as a function of the charge. This evolution is attributed to the fragment excitation energy. Also, global distributions of Csym/T give us an information on the surface over the volume contributions to the symmetry energy ratio. Those ratios show important surface contributions, same results given by simulations. With extracted temperatures from proton energy spectra, a Csym value can be obtained. Those values, around 30 MeV, are coherent with values around the saturation density.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Neste trabalho implementamos um programa computacional capaz de descrever passo-a-passo o processo de colisão entre dois átomos confinados numa armadilha magneto-óptica em regime frio. Para isso utilizamos o formalismo de Wigner, que é uma formulação equivalente à mecânica quântica, para encontrar-mos uma aproximação quase-clássica para as equações que descrevem o sistema. Este formalismo permite-nos separar os graus de liberdade externos dos átomos colidentes, que podem ser tratados de maneira quase-clássica, dos graus internos de liberdade, os quais não tem contraparte clássica e, portanto, são tratados quanticamente / In this work we implement a computer program that describes, step by step, the collision process between two atoms confined in a magneto-optical trap in the cold regime. Here we utilize the Wigner-function theory, which is a formulation of quantum mechanics in terms of a phase space, to find a quasi-classical approx¬imation of the dynamical equations that govern the time evolution of the system. This approach allows us to describe the dynamics in terms of external and internal degrees of freedom. The former degrees of freedom are treated quasi-classically, while the latter, because they do not have a classical counterpart, are treated quan¬tum mechanically

Jets are a useful probe of the hot, dense medium produced in heavy ion collisions since partons are expected to lose energy in interactions with the medium through a phenomena called jet quenching. Recent results studying jet quenching in relativistic heavy ion collisions at the LHC with the ATLAS detector are presented here. The jets are reconstructed using the anti-kt algorithm with a background subtraction that removes the large underlying event. A fully unfolded measurement of the dijet asymmetry in Pb+Pb and pp collisions with an integrated luminosity of 0.14 nb^−1 and 4.0 pb^−1, respectively, at √sNN =2.76 TeV is shown. The dijets are found to be highly asymmetric in central Pb+Pb collisions and become more symmetric, or like pp, in more peripheral collisions. A strong p_T dependence to the asymmetry is also observed. This measurement is shown to have similar qualitative features at jet radii of R=0.3 and R=0.4, implying that the underlying event is under control. Measurements of the nuclear modification factor, R_AA, for R=0.4 jets in Pb+Pb and pp collisions with an integrated luminosity of 0.49 nb^−1 and 25 pb^−1, respectively, at √sNN = 5.02 TeV are also presented. The R_AA shows the strongest suppression in central collisions and the least suppression in peripheral collisions. It shows a slight increase with jet p_T and a decrease with increasing rapidity at high p_T. Finally, the dijet asymmetry for R=0.4 jets is also reported in Xe+Xe collisions at √sNN = 5.44 TeV compared to Pb+Pb and pp collisions at √sNN = 5.02 TeV. No difference is observed between Pb+Pb and Xe+Xe collisions, within the uncertainties of the measurement, as a function of the number of participants or the collision centrality.

Title: Study of jet production in nucleus-nucleus collisions at RHIC Author: Mgr. Zuzana Barnovská Department: Institute of Particle and Nuclear Physics Supervisor: RNDr. Jana Bielčíková, Ph.D., Nuclear Physics Institute of the ASCR Abstract: The goal of this thesis is to study strange particles (Λ, ¯Λ a K0 S) in jets at the energy of √ sNN = 200 GeV in d+Au and Au+Au collisions measured by the STAR experiment at RHIC in 2007 and 2008. After the application of geometrical and topological limits, jets were reconstructed with the kT and anti- kT jet algorithms and special selection criteria for strange particles were applied. Ratios of the production of strange baryons and mesons in jets were calculated and compared to previous results of inclusive V0 particle production measured by the STAR experiment. Study of centrality dependence of these ratios was performed and compared to values in d+Au collisions. Keywords: jets, d+Au collisions, Au+Au collisions, STAR, RHIC 1

Le plasma de quarks et de gluons (QGP) est un état de la matière nucléaire apparaissant à hautedensité d’énergie. En laboratoire, il est possible de reproduire de telles conditions grâce aux collisionsd’ions lourds aux énergies ultra-relativistes. ALICE (A Large Ion Collider Experiment) estl’expérience du LHC dédiée à la mise en évidence du QGP.Différentes signatures ont été proposées et étudiées expérimentalement comme manifestations duQGP. Parmi celles-ci, le méson J/ψ joue un rôle central. Il fait partie de la famille des quarkonia,états mésoniques (Q¯Q) formées d’un quark lourd c ou b et de son anti-quark, liés par un potentield’interaction forte. En 1986, Matsui et Satz proposèrent la suppression des charmonia (états liés cc)et notamment du J/ψ comme signature de la formation du plasma de quarks et de gluons.ALICE peut détecter le J/ψ à grande rapidité (2.5 < y < 4) via le canal de désintégration en deuxmuons. Cette thèse porte sur la mesure de la production du J/ψ, via le canal muonique, dans lescollisions pp à une énergie dans le centre de masse de 2.76 et 7 TeV. Elle a exploité les donnéesacquises en 2010 et 2011 auprès du collisionneur LHC.Tenter d’appréhender le mécanisme de production du J/ψ (et plus généralement du quarkonium)dans les collisions pp est un préalable nécessaire avant d’aborder le degré de complexité suivantque constitue le cas des collisions noyau-noyau. Il est également un test important pour la QuantumChromo Dynamics (QCD), la théorie de l’interaction forte, aux énergies très élevées du LHC. / Quarkonia are meson states whose constituents are a charm or bottom quark and its correspondingantiquark (Q¯Q). The study of the production of such bound states in high-energy hadron collisionsrepresents an important test for the Quantum Chromo-Dynamics. Despite the fact that the quarkoniumsaga has already a 40-year history, the quarkonium production mechanism is still an open issue.Therefore, measurements at the new CERN Large Hadron Collider (LHC) energy regimes are extremelyinteresting.In this thesis, the study of inclusive J/ψ production in proton-proton (pp) collisions at √s = 2.76and 7 TeV, obtained with the ALICE experiment, is presented. J/ψ mesons are measured at forwardrapidity (2.5 < y < 4), down to zero pT, via their decay into muon pairs (μ+μ−).Quarkonium resonances also play an important role in probing the properties of the stronglyinteracting hadronic matter created, at high energy densities, in heavy-ion collisions. Under suchextreme conditions, the created system, according to QCD, undergoes a phase transition from ordinaryhadronic matter to a new state of deconfined quarks and gluons, called Quark Gluon Plasma(QGP). The ALICE experiment at CERN LHC has been specifically designed to study this state ofmatter. Quarkonia, among other probes, represents one of the most promising tools to prove the QGPformation. In order to correctly interpret the measurements of quarkonium production in heavy-ioncollisions, a solid baseline is provided by the analogous results obtained in pp collisions.Hence, the work discussed in this thesis, concerning the inclusive J/ψ production in pp collisions,also provides the necessary reference for the corresponding measurements performed in Pb-Pb collisionswhich were collected, by the ALICE experiment, at the very same center-of-mass energy pernucleon pair (√sNN = 2.76 TeV).

Roads are essential in modern societies, but as populations grow and traffic volumes rise, roads will continue to be built and expanded. As a result, the effects that roads have on wildlife will likely intensify, making it imperative that managers understand those effects so mitigation can be directed accordingly. In Utah, considerable areas of mule deer (Odocoileus hemionus) habitat have been bisected by roads. Mule deer are commonly involved in vehicle collisions and there is concern that roads and vehicle traffic are impacting populations. This project was conducted to determine the number and demographic effects of deer-vehicle collisions, to examine how movements and survival of deer were impacted by roads, and to develop a smartphone-based reporting system for wildlife-vehicle collisions. Accurate estimates of DVCs are needed to effectively mitigate the effects of roads, but great uncertainty exists with most deer-vehicle collision estimates. I estimated the number of deer-vehicle collisions using carcass surveys, while accounting for several sources of bias to improve accuracy. I estimated that 2-5 % of the statewide deer population was killed in vehicle collisions annually. The effect that vehicle collisions have on deer abundance depended not only on the number of deer killed but also on the demographic groups removed. I found that 65 % of deer killed in vehicle collisions were female and 40 % were adult females. As female deer are the primary drivers of population growth, my data suggest vehicle collisions could significantly affect population abundance. However I was unable to detect a decreasing trend in deer abundance. Deer have distinct movement patterns that affect their distribution in relationship to roads. I analyzed deer movements during two consecutive winters (2010-11 & 2011-12) to determine what effect climate had on deer movements and vehicle collision rates. I observed that as snow depth decreased, the distance that deer occurred from roads increased. As a result road crossing rates declined, as did the number of vehicle collisions. This suggests a causal mechanism by which winter conditions influence vehicle collision rates. Currently there is a need for an efficient wildlife-vehicle collision data collection. I envisioned and, working with colleagues, helped develop a smartphone-based system for reporting wildlife-vehicle collision data. The WVC Reporter system consisted of a mobile web application for data collection, a database for centralized storage of data, and a desktop application for viewing data. The system greatly improved accuracy and increased efficiency of data collection efforts, which will likely result in improved mitigation and ultimately increased safety for motorists and deer.

[Truncated abstract] This work investigated electron correlation and spin-dependent effects in electron scattering from zinc for incident electron energies from the lowest excitation threshold at 4.003 eV to 50 eV. Experiments were performed using a crossed-beams electron impact spectrometer, which included an unpolarised electron gun, and also a spin-polarised electron gun. The apparatus was tested, and shown to be operating well, by repeating past studies of electron scattering from helium and argon. Emission cross sections for the 4s4p 3P1, 4s4p 1P1, 4s5s 3S1, 4s4d; 5d; 6d 3D1;2;3 and 4s4d; 5d 1D2 states were measured from the respective thresholds to 50 eV. These were compared with Convergent Close-Coupling (CCC) and B-spline R-matrix (BSRM) calculations of the 4s4p 3P1, 4s4p 1P1, 4s5s 3S1, 4s4d 1D2 and 4s4d 3D1;2;3 emission cross sections. There are serious discrepancies between the theories, and between the theories and experiment, which indicates strong continuum coupling and innershell excitation effects in the electron excitation of zinc. The differential elastic scattering signal at scattering angles of 30 , 54 , 90 and 110 was measured for incident electron energies from just below the lowest excitation threshold at 4.003 eV, to the ionisation threshold at 9.394 eV. Some assignments given by Sullivan et al [1] and Zatsarinny and Bartschat [2] were confirmed by the present experiment. An area of disagreement in the literature concerning the nature of a feature observed at the 4s4p 1P1 threshold at 5.796 eV was resolved in favour of Zatsarinny and Bartschat, who assign the feature as a cusp. ... Below the ionisation threshold, the 4s4p 3P1 photon excitation function supports the assignment of the near-4s4p 1P1 threshold feature as a cusp. Some of the overlapping negative-ion resonances which were observed near 7.5 eV in the 4s4p 3P1, 4s4p 1P1 and 4s5s 3S1 photon excitation functions were assigned with the assistance of the BSRM calculations of Zatsarinny and Bartschat. However, continuum coupling effects above 8 eV seem to cause the theoretical negative-ion resonance predictions to break down. Above the ionisation threshold, the near-11 eV negative-ion resonance effects depend on the configuration n, L and S of the neutral state excitation observed. This may be due to the properties of the mixed negative ion component states. Postcollision interaction (PCI) effects the 4s5s 3S1, 4s4d; 5d; 6d 3D1;2;3 and 4s4d; 5d 1D2 photon excitation functions. The PCI mechanism can populate the 4s4d; 5d; 6d 3D1;2;3 and 4s4d; 5d 1D2 states because the scattered and ejected electrons have a similar energy, and can thus exchange a large amount of orbital angular momentum. The present work demonstrates that electron correlation effects, especially those associated with innershell excitation, are very significant in electron scattering from zinc. Existing theoretical models of electron scattering from zinc inadequately treat electron correlations, and as a result of this are inaccurate, as shown here. The studies presented here should guide the development of models that accurately describe the innershell excitation effects, which are important for zinc and a great many other atoms.