Galactic cosmic rays are the high-energy particles that stream into our solar system from distant corners of our Galaxy. The Earth's atmosphere serves as an ideal detector for the high energy cosmic rays which interact with the air molecule nuclei causing propagation of extensive air showers. The primary cosmic ray particles interact with the molecules in the atmosphere and produce showers of secondary particles (mainly pions) at about 15 km altitude. These pions decay into muons which are the dominant particles of radiation (about 80%) at the surface of the Earth. In recent years, there are growing interests in the applications of the cosmic ray measurements such as space/earth weather monitoring, homeland security activities based on the cosmic ray muon tomography, radiation effects on health via air travel, etc. A simulation program (based on the Geant4 software package developed at CERN) has been developed at Georgia State University for studying cosmic ray showers in the atmosphere. The results of this simulation study will provide unprecedented knowledge of geo-position-dependent cosmic ray shower profiles and will significantly advance cosmic ray applications. Simulation results are critically important for determining the temperature coefficients in every pressure layer in the atmosphere in order to calculate the temperature variations using the cosmic ray data. Using a single particle shower simulation, the weighted particle altitude distributions on a global scale are calculated with geomagnetic field implementation. The results of the simulation can aid the computation of the effective temperature in stratosphere.

Orientador: Orlando Luís Goulart Peres / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-28T09:46:02Z (GMT). No. of bitstreams: 1 Stenico_GabrielaVitti_M.pdf: 1514550 bytes, checksum: b70ae6f3e134ec870b16bf48feb2f637 (MD5) Previous issue date: 2015 / Resumo: Neutrinos atmosféricos são produzidos a partir de interações de raios cósmicos com a atmosfera terrestre que geram partículas secundárias instáveis as quais decaem fracamente em neutrinos. Por possuirem um amplo espectro de energia, que engloba algumas centenas de MeV a energias na ordem de TeV, esses neutrinos são bons objetos no teste de novas teorias, bem como no estudo do fenômeno de oscilação de neutrinos, onde há mudança do estado de sabor do neutrino para outro. Além disso, neutrinos atmosféricos constituem o ruído de fundo na calibração de telescópios de neutrinos astrofísicos e na busca por processos raros, o que nos motiva a estudar como se dá sua produção e evolução na atmosfera. Desse modo, buscamos determinar o fluxo de neutrinos atmosféricos através das reações básicas de criação dos mesmos por interações fracas e dos processos de absorção e espalhamento das partículas-mães carregadas, como píons e múons, gerados pela interação de prótons, principal constituinte dos raios cósmicos, com a atmosfera. Para isso, procederemos a resolver sistemas de equações de cascatas que relacionam termos sumidouros e fonte das partículas do fluxo para obtermos sua evolução até a superfície terrestre, de modo a incluir as características da atmosfera e geometria de incidência do feixe de partículas primárias, avaliando a consistência dos cálculos e comparando-os com resultados presentes na literatura. Feito isso, estenderemos o resultado incluindo um decaimento exótico, que não existe no Modelo Padrão, para ver se podemos testá-lo em experimentos de neutrinos atmosféricos / Abstract: Atmospheric neutrinos are produced by interactions of cosmic rays with the Earth¿s atmosphere that create unstable secondary particles which weakly decay into neutrinos. Because of its wide energy spectrum, that covers energies of few hundred of MeV until energies on the order of TeV, these neutrinos are good objects on the test of new theories as well as the study of neutrino oscillation phenomenon where there is a change in the state of neutrino flavour to another. In addition, atmospheric neutrinos constitute background and calibration beam for astrophysical neutrino telescopes and the search for rare processes, which motivates us to study how is its production and evolution in the atmosphere. In this way, we want to determine the flux of atmospheric neutrinos through the basic reactions of its creation by weak interactions and the processes of absorption and scattering of charged parent particles, as pions and muons, generated by the interaction of protons, main constituent of cosmic rays with the atmosphere. For this, we will solve cascade equations that relate source and sink terms of the particle flux to obtain its evolution until the earth surface, including the atmosphere characteristics and geometry of primary particle incidence beam, evaluating the consistency of the calculations and comparing them with the results found in the literature. Done that, we will extend the results including an exotic decay, which does not exist in the Standard Model, to see if we can test it on atmospheric neutrino experiments / Mestrado / Física / Mestra em Física / 156339/2013 / 2014/00347-3 / CNPQ / FAPESP

This diploma thesis deals with measuring the tightness of the hermetic area of nuclear power plant in the way of improving safety. Describes the layout and function of this area - the primary circuit of NPP with WWER 440/213 reactors, as well as methodology for leakage search and leakage calculation procedures. Personal contribution to the issue is a proposal improving tightness of the current state in hermetic area of NPP Jaslovské Bohunice – transition of jacketed pipe designed to collect water from the floor in the box of the steam generator to the heat exchanger of the shower system. This system belongs to the safety system designed to reduce pressure in the LOCA type of accident.

Syfte och frågeställningar Syftet med studien är att undersöka om och hur lärare från olika generationer som undervisar i idrott och hälsa på grundskolenivå upplever att synen på ombyte och dusch förändrats över tid. De frågeställningar som kommer användas för att uppnå studiens syfte är: - Hur upplever lärare från olika generationer den förändring som skett i synen på ombyte och dusch i samband med idrott och hälsa? - Hur legitimerar lärare i idrott och hälsa från olika generationer ombytet och duschens vara eller icke vara i samband med lektioner i ämnet idrott och hälsa?   Metod Studien har en kvalitativ metodologisk ansats, med semistrukturerade intervjuer som metod. Urvalet gjordes genom ett strategiskt urval. Urvalet bestod av sex aktiva examinerade grundskollärare i idrott och hälsa. Intervjuerna genomfördes i videokonferensprogrammet Zoom. För analys av datainsamlingen tillämpades tematisk analys. Studien har influerats i huvudsak av två teoretiska ramverk. Dessa är läroplansteorin och Pierre Bourdieus habitus och reproduktionsteorier.  Resultat Resultatet av studien visar på att de lärare som intervjuats är till majoritet överens om att förändringen som skett i synen på ombyte och dusch i samband med ämnet idrott och hälsa över tid, snarare ligger i en förändring av attityd hos eleverna än något annat. Resultatet visar också att majoriteten av lärarna som intervjuats legitimerar ombytet och duschens vara eller icke vara med någon form av nedärvd metod från sin egen skolgång.  Slutsats De slutsatser som dras i den föreliggande studien är att genom Pierre Bourdieus habitus och sociala reproduktion visar samtliga respondenterna i studien att en förändring skett i synen på ombyte och dusch över tid. Detta oavsett vilken generation läraren tillhör. En anledning till detta kan ses i läroplanen som i studien använts som ett tidsdokument utifrån läroplansteorin. Där förändringar i samhällssynen lett till förändringar i formuleringen av läroplanen. / Aim The aim of the study was to examine whether and how teachers from different generations who teach physical education and health at primary school level experience that the view of change and showering changes over time. The research questions that will be used to achieve the purpose of the study are: - How do teachers from different generations experience the change that has taken place in the view of changing and shower in connection with physical education? - How do teachers of physical education from different generations legitimize the change and the shower to be or not to be in connection with lessons in the subject of physical education? Method The study has a qualitative methodological approach, with semi-structured interviews as a method. The selection was made through a strategic selection. The sample consisted of six active graduate primary school teachers in physical education. The interviews are conducted in the video conferencing program Zoom. Thematic analysis is applied for analysis of the data collection. The study has been influenced mainly by two theoretical frameworks. These are curriculum theory and Pierre Bourdieu's habitus and reproduction theories. Results The results of studies show that teachers interviewed for the most part agree that the change that has taken place in the view of change and shower in connection with the subject of physical education over time, is rather a change in the attitude of the students than anything else. The results also show that most of the teachers interviewed legitimize the change and the presence or absence of the shower with some form of inherited method from their own schooling. Conclusion The conclusions drawn in the present study are that through Pierre Bourdieu's habitus and social reproduction, all respondents in the study show that there has been a change in the view of changing and showering over time. This regardless of which generation the teacher belongs to. One reason why this can be seen in the curriculum, which in the study was used as a time document based on the curriculum theory. Where changes in the view of society have led to changes in the formulation of the curriculum.

With the constantly increasing precision of experimental data acquired at the current collider experiments Tevatron and LHC the theoretical uncertainty on the prediction of multiparticle final states has to decrease accordingly in order to have meaningful tests of the underlying theories such as the Standard Model. A pure leading order calculation, defined in the perturbative expansion of said theory in the interaction constant, represents the classical limit to such a quantum field theory and was already found to be insufficient at past collider experiments, e.g. LEP or Hera. Such a leading order calculation can be systematically improved in various limits. If the typical scales of a process are large and the respective coupling constants are small, the inclusion of fixed-order higher-order corrections then yields quickly converging predictions with much reduced uncertainties. In certain regions of the phase space, still well within the perturbative regime of the underlying theory, a clear hierarchy of the inherent scales, however, leads to large logarithms occurring at every order in perturbation theory. In many cases these logarithms are universal and can be resummed to all orders leading to precise predictions in these limits. Multiparticle final states now exhibit both small and large scales, necessitating a description using both resummed and fixed-order results. This thesis presents the consistent combination of two such resummation schemes with fixed-order results. The main objective therefor is to identify and properly treat terms that are present in both formulations in a process and observable independent manner. In the first part the resummation scheme introduced by Yennie, Frautschi and Suura (YFS), resumming large logarithms associated with the emission of soft photons in massive Qed, is combined with fixed-order next-to-leading matrix elements. The implementation of a universal algorithm is detailed and results are studied for various precision observables in e.g. Drell-Yan production or semileptonic B meson decays. The results obtained for radiative tau and muon decays are also compared to experimental data. In the second part the resummation scheme introduced by Dokshitzer, Gribov, Lipatov, Altarelli and Parisi (DGLAP), resumming large logarithms associated with the emission of collinear partons applicable to both Qcd and Qed, is combined with fixed-order next-to-leading matrix elements. While the focus rests on its application to Qcd corrections, this combination is discussed in detail and the implementation is presented. The resulting predictions are evaluated and compared to experimental data for a multitude of processes in four different collider environments. This formulation has been further extended to accommodate real emission corrections to beyond next-to-leading order radiation otherwise described only by the DGLAP resummation. Its results are also carefully evaluated and compared to a wide range of experimental data.

With the constantly increasing precision of experimental data acquired at the current collider experiments Tevatron and LHC the theoretical uncertainty on the prediction of multiparticle final states has to decrease accordingly in order to have meaningful tests of the underlying theories such as the Standard Model. A pure leading order calculation, defined in the perturbative expansion of said theory in the interaction constant, represents the classical limit to such a quantum field theory and was already found to be insufficient at past collider experiments, e.g. LEP or Hera. Such a leading order calculation can be systematically improved in various limits. If the typical scales of a process are large and the respective coupling constants are small, the inclusion of fixed-order higher-order corrections then yields quickly converging predictions with much reduced uncertainties. In certain regions of the phase space, still well within the perturbative regime of the underlying theory, a clear hierarchy of the inherent scales, however, leads to large logarithms occurring at every order in perturbation theory. In many cases these logarithms are universal and can be resummed to all orders leading to precise predictions in these limits. Multiparticle final states now exhibit both small and large scales, necessitating a description using both resummed and fixed-order results. This thesis presents the consistent combination of two such resummation schemes with fixed-order results. The main objective therefor is to identify and properly treat terms that are present in both formulations in a process and observable independent manner. In the first part the resummation scheme introduced by Yennie, Frautschi and Suura (YFS), resumming large logarithms associated with the emission of soft photons in massive Qed, is combined with fixed-order next-to-leading matrix elements. The implementation of a universal algorithm is detailed and results are studied for various precision observables in e.g. Drell-Yan production or semileptonic B meson decays. The results obtained for radiative tau and muon decays are also compared to experimental data. In the second part the resummation scheme introduced by Dokshitzer, Gribov, Lipatov, Altarelli and Parisi (DGLAP), resumming large logarithms associated with the emission of collinear partons applicable to both Qcd and Qed, is combined with fixed-order next-to-leading matrix elements. While the focus rests on its application to Qcd corrections, this combination is discussed in detail and the implementation is presented. The resulting predictions are evaluated and compared to experimental data for a multitude of processes in four different collider environments. This formulation has been further extended to accommodate real emission corrections to beyond next-to-leading order radiation otherwise described only by the DGLAP resummation. Its results are also carefully evaluated and compared to a wide range of experimental data.:1. Introduction 1.1 Event generators 1.2 The event generator Sherpa 1.3 Outline of this thesis Part I YFS resummation & fixed order calculations 2 Yennie-Frautschi-Suura resummation 2.1 Resummation of virtual photon corrections 2.2 Resummation of real emission corrections 2.3 The Yennie-Frautschi-Suura form factor 3 A process independent implementation in Sherpa 3.1 The Algorithm 3.1.1 The master formula 3.1.2 Phase space transformation 3.1.3 Mapping of momenta 3.1.4 Event generation 3.2 Higher Order Corrections 3.2.1 Approximations for real emission matrix elements 3.2.2 Real emission corrections 3.2.3 Virtual emission corrections 4 The Z lineshape and radiative lepton decay corrections 4.1 The Z lineshape 4.1.1 Radiation pattern 4.1.2 Numerical stability 4.2 Radiative lepton decays 4.3 Summary and conclusions 5 Electroweak corrections to semileptonic B decays 5.1 Tree-level decay 5.2 Next-to-leading order corrections 5.2.1 Matching of different energy regimes 5.2.2 Short-distance next-to-leading order corrections 5.2.3 Long-distance next-to-leading order corrections 5.2.4 Structure dependent terms 5.2.5 Soft-resummation and inclusive exponentiation 5.3 Methods 5.3.1 BLOR 5.3.2 Sherpa/Photons 5.3.3 PHOTOS 5.4 Results 5.4.1 Next-to-leading order corrections to decay rates 5.4.2 Next-to-leading order corrections to differential rates 5.4.3 Influence of explicit short-distance terms 5.5 Summary and conclusions Part II DGLAP resummation & fixed order calculations 6 DGLAP resummation & approximate higher order corrections 6.1 Dokshitzer-Gribov-Lipatov-Altarelli-Parisi resummation 6.1.1 The naive parton model 6.1.2 QCD corrections to the parton model 6.1.3 Factorisation and the collinear counterterm 6.1.4 The DGLAP equations 6.2 Parton evolution 6.2.1 Approximate real emission cross sections 6.2.2 Parton evolution 6.2.3 Scale choices for the running coupling 6.3 Soft emission corrections 7 The reinterpretation and automisation of the POWHEG method 7.1 Decomposition of the real-emission cross sections 7.2 Construction of a parton shower 7.3 Matrix element corrections to parton showers 7.4 The reformulation of the POWHEG method 7.4.1 Approximate NLO cross sections 7.4.2 The POWHEG method and its accuracy 7.5 The single-singularity projectors 7.6 Theoretical ambiguities 7.7 MC@NLO 7.8 Realisation of the POWHEG method in the Sherpa Monte Carlo 7.8.1 Matrix elements and subtraction terms 7.8.2 The parton shower 7.8.3 Implementation & techniques 7.8.4 Automatic identification of Born zeros 7.9 Results for processes with trivial colour structures 7.9.1 Process listing 7.9.2 Tests of internal consistency 7.9.3 Comparison with tree-level matrix-element parton-shower merging 7.9.4 Comparison with experimental data 7.9.5 Comparison with existing POWHEG 7.10 Results for processes with non-trivial colour structures 7.10.1 Comparison with experimental data 7.11 Summary and conclusions 8 MENLOPS 8.1 Improving parton showers with higher-order matrix elements 8.1.1 The POWHEG approach 8.1.2 The ME+PS approach 8.2 Merging POWHEG and ME+PS - The MENLOPS 8.3 Results 8.3.1 Merging Systematics 8.3.2 ee -> jets 8.3.3 Deep-inelastic lepton-nucleon scattering 8.3.4 Drell-Yan lepton-pair production 8.3.5 W+jets Production 8.3.6 Higgs boson production 8.3.7 W-pair+jets production 8.4 Summary and conclusions Summary Appendix A Details on the YFS resummation implementation A.1 The YFS-Form-Factor A.1.1 Special cases A.2 A.2.1 Avarage photon multiplicity A.2.2 Photon energy A.2.3 Photon angles A.2.4 Photons from multipoles A.3 Massive dipole splitting functions A.3.1 Final State Emitter, Final State Spectator A.3.2 Final State Emitter, Initial State Spectator A.3.3 Initial State Emitter, Final State Spectator B Formfactors and higher order matrix elements for semileptonic B decays B.1 Form factor models of exclusive semileptonic B meson decays B.1.1 Form factors for B -> D l nu B.1.2 Form factors for B -> pi l nu B.1.3 Form factors for B -> D0* l nu B.2 NLO matrix elements B.2.1 Real emission matrix elements B.2.2 Virtual emission matrix elements B.3 Scalar Integrals B.3.1 General definitions B.3.2 Tadpole integrals B.3.3 Bubble integrals B.3.4 Triangle integrals C Explicit form of the leading order Altarelli-Parisi splitting functions C.1 Collinear limit of real emission matrix elements C.1.1 q -> gq splittings C.1.2 q -> qg splittings C.1.3 g -> qq splittings C.1.4 g -> gg splittings Bibliography

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Detta examensarbete inom integrerad produktutveckling utfördes vid Högskolan i Skövde i samarbete med Ericsindustrier i Töreboda. Rapporten beskriver metodiken samt processen som utförts i projektet för att uppnå samtliga målsättningar. Syftet bestämdes till en omkonstruktion av en justerskruv placerad i en expanderbar duschstång. Denna duschstång anses vara en viktig del av Ericsindustriers produktsortiment. Grunden till behovet av en omkonstruktion ansågs vara antalet komponenter samt komponenternas montering. Detta krävde att komponentantalet minimerades genom DFx-principer där samma material eftersträvades genom produkten. Försämrad kvalité och hållfasthet definierades som kritiska områden då Ericsindustrier önskade att upprätthålla likvärdig kundnöjdhet samt att produkten skulle hålla för minst 200 N efter omkonstruktionen. Projektets struktur följde en femstegsmodell där designprocessen inleddes med en förstudie. Fokus låg på informationsinsamling, observationer samt kartläggning av nuläget. Genereringsfasen genomsyrades av metodik för att utforska lösningsrymden. Detta innefattade bland annat brainstorming, morfologisk matris samt skissning. I projektet har prototyper haft en stor inverkan då de har fungerat både som generering samt utvärdering av lösningar. De har även agerat som kommunikation till företag samt användare genom hela processen. Iterationer har präglat hela processen för att uppnå en produktutveckling. För att upprätthålla en användarcentrerad design innefattade projektet flertalet användartester. Fötterna till duschstången samt de två rören som bildar själva duschstången identifierades till separata problem. Dessa problem har diskuterats med företaget. Konceptval utfördes efter önskemål från företaget, tester, DFxprinciper samt diskussioner tills det mynnade ut i ett slutgiltigt koncept. Detta koncept uppfyllde de utsatta kraven samt behoven. Konceptet ansågs vara en prisvärd, högkvalitativ samt miljövänlig produkt. / This bachelor degree project in integrated product development was carried out at the University of Skövde in collaboration with Ericsindustrier in Töreboda. The report describes the methodology and the process that has been carried out in the project to achieve all the stated objectives. The scope was determined to be a redesign of an adjusting screw placed in an expandable shower rod. The shower rod is considered an important part of Ericsindustrier's product range. The reason for the need of a reconstruction was the number of components and the components assembly. The component number was required to be minimized by using DFx principles where the same material was sought throughout the product. Decreased quality and lower durability were defined as critical areas since Ericsindustrier wanted to maintain customer satisfaction and the product must hold for at least 200 N after the redesign. A five-stage model formed the basis of the project structure where the design process began with a preliminary study. The focus was on information gathering, observations and mapping of the current situation. The generation phase was imbued with methodology to explore solution space. This included, among other things, brainstorming, morphological matrix and sketching. In the project, prototypes had a great impact as they functioned as both generation and evaluation of solutions. They have also acted as communication with companies and users throughout the process. Iterations have characterized the whole process to achieve a product development. In order to maintain a user-centred design, the project included several user tests. The feet of the shower rod and the two pipes that form the shower rod itself were identified as separate problems. These issues have been discussed with the company. Concept selection was carried out according to the wishes of the company, tests, DFx principles and discussions until it ended in a final concept. This concept met the required requirements and needs. Therefore, it was an affordable, high quality and environmentally friendly product.

This thesis details the application of a medium frequency (MF) Doppler radar to observations of meteoroids entering the Earth's atmosphere. MF radars make possible a greater height coverage of the meteor region (70 to 160 km) than conventional meteor radars. However this type of radar has generally been under-utilised for meteor observations, primarily due to the less than ideal radio environment associated with MF systems. This situation demanded selection of the most appropriate radar meteor techniques and in this respect a variety of techniques are evaluated for application at this frequency. The 2 MHz radar system used in this study is located at the Buckland Park research facility (35.6 deg. S, 138.5 deg. E), near Adelaide, South Australia and is operated by the Department of Physics of the University of Adelaide. This radar has the largest antenna of any MF radar with 89 crossed dipoles distributed over an area of about 1 km in diameter. Beam forming is achieved by varying the phase to groups of elements of the array. The array was constructed in the 1960's, and while having several upgrades, a preliminary examination of the array and associated systems indicated that a significant amount of maintenance work would be required to enable the system to be used for meteor observations. It was also apparent that the software used with the radar hardware for atmospheric studies was not suitable for processing meteor data. Thus a major refurbishment of the radar hardware, as well as the development of appropriate software, was initiated. The complete radar system was divided into its constituent components of antenna array, transmitter, receiver and computer systems. The transmitter and receiver systems were examined and various improvements made including increasing total output power and enhancing beam steering capability. Time domain reflectometry (TDR) techniques were extensively used on the antenna array, as many feed cables showed the presence of moisture. New hardware in the form of a portable power combining system was designed, constructed and tested to further increase radar experimental capabilities. Techniques were developed that verified system performance was to specification. Extensive night time observations of sporadic and shower meteor events were made over a two and a half year period. A particular study was made of the Orionids shower as well as other meteor activity on the night of 22 October 2000. Using the upgraded beam swinging features of the array, a narrow radar beam was used to track the shower radiant in an orthogonal sense so as to maximise the number of shower meteors detected. From each echo, various intrinsic meteoroid parameters were determined, including meteor reflection point angle-of-arrival using a five-element interferometer, echo duration and height; meteoroid speeds were determined using the Fresnel phase time technique. Meteor echoes belonging to the Orionids radiant were selected using a coordinate transform technique. The speed was then used as an additional discriminant to confirm the Orionid shower members. A second radiant, observed at a slightly higher declination is classified as also part of the Orionid stream. The sporadic meteor component in the data set was examined and found to exhibit speeds much higher than expected for sporadic meteors at the time of the observations. However, these results are consistent with a selection bias based on meteoroid speed, that is inherent in radar observations. The Orionid observations indicate that the refurbishment of the radar system and the introduction of new software for meteor analysis has been successfully achieved and that radar meteor studies can now be carried out routinely with the Buckland Park 2 MHz radar. Moreover it has been shown for the first time that meteoroid speeds can be determined with a MF radar operating on a PRF as low as 60 Hz. / Thesis (Ph.D.)--School of Chemistry and Physics, 2003.

Syfte: Att undersöka hur patienter på ett universitetssjukhus uppfattar information gällande preoperativ dusch samt patientens genomförande av duschen på avdelningen. Introduktion: Vårdrelaterade infektioner är vanliga och kan leda till ökade kostnader, långvarig sjukhusvistelse och ökad lidande för patienter. Ett sätt att förhindra detta är att duscha med klorhexidin före operation. Det är sjuksköterskans ansvar att informera patienten om den preoperativa duschen, kontrollera att patienten uppfattat informationen och har möjlighet och resurser att följa den. Metod: En kvalitativ deskriptiv intervjustudie med semistrukturerade frågor. Materialet analyserades enligt Granheim och Lundmans beskrivning av innehållsanalys på manifest nivå. Urvalet utfördes genom bekvämlighetsurval. Deltagarna i studien var 12 patienter. Resultat: Deltagarna var övergripande nöjda med informationen om den preoperativa duschen. De kände att de hade fått tillräcklig information och att den var lättförståelig. Patienternas hade uppfattat informationen på olika sätt. Utförandet av duschen, uppfattning om särskilt viktiga delar på kroppen och vad patienterna upplevde som viktigt att tänka på efter duschen varierade. Slutsats: Information måste individanpassas och sjuksköterskan bör se till att patienten förstår informationen genom att be patienten återberätta informationen. / Aim: To investigate how patients in a university hospital in Sweden perceive the information about the preoperative shower and the patients execution of the shower in the hospital ward. Introduction: Healthcare-associated infections are common and can lead to increased costs, prolonged hospital stay and increased patient suffering. One way to prevent this is to shower with chlorhexidine before surgery. It’s the nurses’ responsibility to give the patient information about the preoperative shower and check that the patient knows about the shower procedure and is able to follow the instructions. Method: A qualitative descriptive interview study with semi-structured questions. The material was analyzed according to Granheim and Lundman's description of content analysis on a manifest level. The selection was carried out by convenience sample. Participants in the study were 12 patients. Results: Participants were overall satisfied with the information about the preoperative shower. They felt they had sufficient information and that it was easy to understand. Patients understood the information in different way. The performance of the shower, the knowledge of key areas of the body and what the patients experienced as important to consider after the shower varied. Conclusion: Information must be individually adapted and the nurse should ensure that the patient understands the information by asking to retell the information.