61 research outputs found
THE DISSOCIATIVE RECOMBINATION OF AND CATIONS
No full textAuthor Institution: Roslagstullsbacken 5:310 ZIP 114 21 Stockholm SwedenReactions with the methoxy radical CHO have found to be significant pathways of production and destruction of important interstellar molecules and ions like NH, NH, HO, HO }. These processes compete with the dissociative recombination of the named ions. Therefore, measurements of the rates, cross-sections and branching ratios of the dissociative recombination of the iosotopomers and have been perfomed at the CRYRING storage ring located at Stockholm, Sweden. Preliminary evaluation of the data yielded a reaction rate coefficient of cmmols and cm% mols for and respectively. Calculation of the branching ratios rendered the following branching ratios for the reaction channels leading to the fissure of the C-O bond:, \ \ \ respectively. The rest of the dissociative recombination rates was contributed from channels leaving the C-O bond intact: 92\% and 98\% for and , respectively. Contrary to the ion}, the pathways preserving the bond between the heavy atoms dominate
Peer culture in preschool : A study of preschool teachers' attitudeand way of working
No full textArbetets art: Examensarbete i lärarutbildningen, avancerad nivå, 15hp. Högskolan Skövde. Titel: Kamratkultur i förskolan. En studie om förskollärares förhållningssätt och arbetssätt. Sidantal: 32 Författare: Ida Christesen, Helen Fredriksson och Malin Hamberg Handledare: Mirella Forsberg Ahlcrona Datum: 7 januari 2013 Nyckelord: Förskola, kamratkultur, gemenskap, samhörighet, uteslutning och etik Denna studie belyser kamratkulturer i förskolan mot bakgrund av förskollärares förhållningssätt och arbetssätt. Med kamratkultur, menar vi gemenskap, samhörighet och uteslutning. Studiens teoretiska perspektiv tar sin utgångspunkt i det sociokulturella perspektivet. Vi har i denna studie genomfört tolv kvalitativa intervjuer. Resultatet visar att förskollärare använder sig av snarlika metoder för att stödja barnen i deras gemenskap och samhörighet. Det visar sig också att förskollärare har olika strategier för att hjälpa barn komma in i leken, bland annat genom att göra barn ”attraktiva” för varandra, som ett sätt att motverka uteslutning bland barn i förskolan.Study: Degree project in teacher education, advanced level, 15 hp. University of Skövde Title: Peer culture in preschool. A study of preschool teachers’ attitude and way of working Number of pages: 32 Author: Ida Christesen, Helen Fredriksson and Malin Hamberg Tutor: Mirella Forsberg Ahlcrona Date: 7th of January 2013 Keywords: Preschool, peer culture, fellowship, togetherness, exclusion and ethics This study highlights the peer cultures of preschool on the basis of preschool teachers' attitudes and practices. With peer culture, we mean fellowship, togheterness and exclusion. The theoretical approach is based on the socio-cultural perspective. We have in this study carried through twelve qualitative interviews. The result shows that preschool teachers use similar methods to support children in their fellowship and togetherness. It also turns out that preschool teachers have different strategies to help children enter the play activity, for instance making children "attractive" for each other, as a way to work against exclusion among children in preschool
Differential susceptibility of Iowa waterhemp (Amaranthus tuberculatus) populations to 2,4-D, dicamba, and glufosinate
No full textMultiple herbicide-resistant waterhemp (Amaranthus tuberculatus (Moq.) J.D. Sauer) has limited herbicide options for Iowa row crop production. Soybean (Glycine max (L.) Merr.) cultivars and corn (Zea mays L.) hybrids resistant to 2,4-D, dicamba, and glufosinate have provided more herbicide options for waterhemp management. A probability-based survey of Iowa fields was conducted in fall 2019 wherein waterhemp seeds were collected and their susceptibility to 2,4-D, dicamba, and glufosinate was determined. The average survival of all populations treated with 1× 2,4-D, dicamba, and glufosinate was 17%, 5%, and 4%, respectively. Seven percent of treated populations exhibited ≥50% survival to 1× rates of 2,4-D.This article is published as Ryan C. Hamberg, Ramawatar Yadav, Micheal D.K. Owen, and Mark A. Licht. Differential susceptibility of Iowa waterhemp (Amaranthus tuberculatus) populations to 2,4-D, dicamba, and glufosinate. Canadian Journal of Plant Science. (2023). https://doi.org/10.1139/cjps-2023-0081. © 2023 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are credited
Dissociative Recombination of Astrochemically Interesting Ions
No full textIn this thesis the major work described concerns experimental determination of the dissociative recombination (DR) reaction for several molecular ions of astrochemical interest. DR is the process where an electron recombines with a molecular ion to form an excited neutral that disintegrates into two or more neutral fragments to release the gained excess energy. It is very efficient under cold conditions and therefore ubiquitously occurring in interstellar environments such as dark clouds and plays an important role in aeronomical plasmae, lightnings and in man-made plasmas such as in combustion engines and fusion reactors. Although DR reactions are crucial processes in all these environments, product branching fractions of DR reactions have proven to be very unpredictable and present one of the great remaining challenges for theoreticians. The experimental work includes determination of reaction rates and product distribution of DR of complex ions such as protonated alcohols and ethers. The following species have been investigated and are discussed in this thesis: CH3OH2+ (protonated methanol), CD3OD2+ (deuteronated methanol), CD3OCD2+ (methoxymethyl cation), CD3CDOD+ (deuteronated acetaldehyde), CH3CH2OH2+ (protonated ethanol) and (CD3)2OD+ (deuteronated dimethyl ether). The results of these measurements are used in astrochemical model calculations in which the rates used hitherto greatly have been based on educated guesses. Employing the outcome of the DR investigations of the CH3OH2+ and CD3OD2+ ions have shown a great impact on such models. The DR investigations have been followed up by astronomical observations. Theoretical models and laboratory experiments show that methanol should be formed from CO on cold grains. This scenario was tested by astronomical observations of gas associated with young stellar objects (YSOs). Two independent tests were showing consistency with methanol formation on grain surfaces.I den här avhandlingen redovisas mitt arbete som till stor del baseras på experimentell bestämning av dissociativa rekombinations (DR) processer för molekylära joner av astrokemiskt intresse. DR är en process där en elektron rekombinerar med en molekylär jon som splittras up i två eller fler neutrala fragment för att göra sig av med den extra energi som erhållits. Processen är väldigt effektiv i kalla miljöer varför den är allestädes återkommande i omgivningar som interstellära moln och kometkoman och spelar en betydande roll i aeronomiska plasman, blixturladdningar men även i mänskligt skapade plasman såsom de i förbränningsmotorer och fusionsreaktorer. Det har dock visat sig att produkt distributionsförhållandena från DR reaktioner är mycket oförutsägbara och kvarstår som en av de stora återstående utmaningarna för teoretiker. Det experimentella arbetet består av bestämning av reaktionshastigheter samt produktdistribution för DR av komplexa joner som protonerade alkoholer och etrar. De följande jonerna har blivit undersökta och diskuteras i denna avhandling: CH3OH2+ (protonerad metanol), CD3OD2+ (deuteronerad metanol), CD3OCD2+ (metoxymetyl katjon), CD3CDOD+ (deuteronerad acetaldehyd), CH3CH2OH2+ (protonerad etanol) och (CD3)2OD+ (deuteronerad dimetyleter). Resultaten av mätningarna används i astrokemiska modelberäkningar i vilka reaktionshastigheterna som hittills använts till stor del baserats på kvalificerade gissningar. Insättning av resultaten av CH3OH2+ och CD3OD2+ jonerna har visat sig ha en stor effekt på sådana modeller. DR undersökningarna har följts upp av astronomiska observationer. Teoretiska modeller och laboratorieundersökningar visar att metanol borde kunna formas från CO på kalla iskornsytor, detta scenario har testats med astronomiska observationer av gas som associeras med unga stjärnor. Två oberoende undersökningar visade på förenlighet med metanolformation på kornytor.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 2: In press. Paper 3: Manuscript. Paper 5: Manuscript
The Degree of Goal Fulfilment in the Swedish Correctional System Concerning the Central Objectives for Prison Guards’ Work Satisfaction at the Prison of Härnösand
No full textABSTRACT Titel: Graden av måluppfyllelse vad gäller kriminalvårdens centrala målsättningar för vårdares arbetstillfredsställelse på kriminalvårdsanstalten Härnösand Nivå: C-uppsats i ämnet företagsekonomi Författare: Jennie Hamberg Handledare: Ernst Hollander Datum: 2011 - januari Syfte: Ett syfte med denna uppsats var att försöka ta reda på i vilken grad kriminalvårdarna på anstalten Härnösand kände arbetstillfredsställelse. Ett ytterligare huvudsyfte var att undersöka i vilken grad kriminalvårdens målsättningar angående kriminalvårdares arbetstillfredsställelse samstämde med hur kriminalvårdarna på anstalten Härnösand upplevde sin arbetstillfredsställelse. Metod: Jag har framförallt använt en kvalitativ metod, men även av en kvantitativ. Jag har gjort en semistrukturerad intervju med en kriminalvårdsinspektör, en deltagande observationsstudie och en vårdarenkät som hade både kvalitativa och kvantitativa inslag. Resultat & slutsats: Jag kom fram till att majoriteten av vårdarna på kriminalvårdsanstalten Härnösand hade en ganska låg arbetstillfredsställelse. Många faktorer bidrog till den minskade arbetstillfredsställelsen. En viktig omständighet var att många vårdare kände att de hade en låg grad av egenkontroll och inflytande över t.ex. sin arbetssituation och hur de ska utföra sina arbetsuppgifter. Ledarna hade också en, till stor del, negativ effekt på vårdarnas arbetstillfredsställelse. Ytterligare en ytterst viktig aspekt för vårdarnas arbetstillfredsställelse var ledarskapsprocessen, dvs. om relationen kriminalvårdsinspektör och vårdare var positivt. I vårdarnas enkätsvar antyddes det att flertalet vårdare tyckte att förhållandet mellan ledare och medarbetare inte var ändamålsenligt. De ansåg t.ex. att det fanns brister i förtroendet mellan vårdarna och kriminalvårdsinspektörerna. Vårdarna trodde även att ledningen var ointresserad av personalen och de ansåg att kriminalvårdsinspektörerna borde vara mer aktiva och stödjande. En aspekt som dock delvis påverkade vårdarnas arbetstillfredsställelse positivt var olika medarbetarfaktorer. Vårdarna var t.ex. överlag nöjda med sina kollegor. En negativ medarbetarfaktor var dock att vårdare överlag inte var tillfredsställda med sina arbetsuppgifter. Slutligen undersökte jag i vilken grad man på kriminalvårdsanstalten Härnösand hade lyckats uppfylla kriminalvårdens centrala målsättningar för en hög arbetstillfredsställelse hos vårdarna. På anstalten Härnösand hade ledningen misslyckats med att nå de flesta av de centrala målsättningarna och bristerna verkade framförallt bero på den dåliga relationen mellan kriminalvårdsinspektörerna och vårdarna, och på vårdarnas bristande egenkontroll. Förslag till fortsatt forskning: Ett område som inte kunde inkluderas i denna uppsats och som skulle lämpa sig för fortsatt forskning är hur man skulle kunna skapa mer nöjda medarbetare inom kriminalvårdens befintliga organisationsstruktur. Uppsatsens bidrag: Jag tror att denna uppsats kan bidra till ny kunskap genom att tydliggöra det komplexa nät av faktorer som påverkar människors arbetstillfredsställelse. Detta har jag försökt göra genom att använda mig av ett situationssynsätt. Nyckelord: Kontingensteori, arbetstillfredsställelse, kriminalvården, byråkratisk organisation, ledarstil, ledare, medarbetare.ABSTRACT Title: The Degree of Goal Fulfilment in the Swedish Correctional System Concerning the Central Objectives for Prison Guards’ Work Satisfaction at the Prison of Härnösand Level: Final Assignment for Bachelor Degree in Business Administration Author: Jennie Hamberg Supervisor: Ernst Hollander Date: 2011 - January Aim: An aim with this essay was to investigate to what degree the guards at the prison of Härnösand felt work satisfaction. Another aim was to investigate to what degree the Swedish Correctional System’s central objectives for prison guards’ work satisfaction were fulfilled at the prison of Härnösand. Method: I have used a qualitative method but also a quantitative method. I have made a semi-structured interview, an observation and prison guard questionnaire with both qualitative and quantitative elements. Result & Conclusions: In my essay I concluded that a majority of guards in Härnösand had a rather low degree of work satisfaction. Many factors contributed to this. One important factor was that many guards felt that they had little control over their own work situation and how they went about their job assignments. The leaders also had a negative effect on the guards’ job satisfaction. Another central element for high work satisfaction is the leadership process, i.e. that a functional relationship exists between the prison inspectors and the guards. Many guards said they felt that the relationship between leaders and followers was not satisfactory. They felt that there was a lack of trust between the inspectors and themselves. They also stated that they felt that the management was not interested in the staff and they also felt that the inspectors should be less passive and more supportive. One contributing factor to a more possive work satisfaction was the guards’ high satisfaction with the collegues. But a negative co-worker factor was the fact that the guards were not satisfied with their job assignments. I also concluded that the management at the prison of Härnösand had failed to fulfill the central objectives for prison guards’ work satisfaction. The failures could mostly be ascribed to the unsatisfactory relationship between the inspectors and the prison guards, but also to the guards’ low degree of control over their job situation. Suggestions for future research: An area for future research could be to investigate how to create more content workers within the current organizational structure of the Swedish correctional system. Contribution of the thesis: This essay may contribute to new knowledge by emphasizing the complex net of contributing factors which affects people’s degree of work satisfaction. I have tried to do this by using a contingency theory. Key words: Contingency theory, work satisfaction, the Swedish Correctional System, bureaucratic organization, management style, leader, follower
Simulations of Magnetic Fields and Forces in Highly Adjustable Magnet (HAM) Undulator Concept Using COMSOL [Elektronisk resurs]
No full textA design for a new type of undulator insertion device has been proposed. The undulator would consist of a stack of disks that each contain a pair of magnet structures, each disk being a half period of the minimum planar case. The disks could rotate independently about the beam axis, and the distance of the magnets from the center line is adjustable, so the magnetic field is adjustable in magnitude and orientation within the transverse plane along the beam axis. This would allow the undulator to be configured for generating a wide variety of radiation. Plane polarization would be attained with undulator periods as integer multiples of the base period. In the base case the direction of magnetization alternates between each disk, and for the case of multiple periods the magnetization alternates each M:th disk. Helical polarization would be attained with a period greater than two times the base period such that an integer number of periods fit inside the undulator structure. Initial numerical simulations have been made, and are reported in this paper. Building on a previous study [1] further simulations were requested to study the behavior of the magnets closer, and to calculate the forces acting on the magnet structures for use in feasibility assessment. In the previous study simple magnetic structures with uniform direction of magnetization were simulated. In this study a more complex structure was also investigated: a type of partial transverse Halbach configuration. This structure would concentrate the magnetic flux along the beamline and could lead to a more compact design, and limit the magnetic field outside the device.The simulations were made using COMSOL Multiphysics modelling software.</p
Simulations of Magnetic Fields and Forces in Highly Adjustable Magnet (HAM) Undulator Concept Using COMSOL
No full textA design for a new type of undulator insertion device has been proposed. The undulator would consist of a stack of disks that each contain a pair of magnet structures, each disk being a half period of the minimum planar case. The disks could rotate independently about the beam axis, and the distance of the magnets from the center line is adjustable, so the magnetic field is adjustable in magnitude and orientation within the transverse plane along the beam axis. This would allow the undulator to be configured for generating a wide variety of radiation. Plane polarization would be attained with undulator periods as integer multiples of the base period. In the base case the direction of magnetization alternates between each disk, and for the case of multiple periods the magnetization alternates each M:th disk. Helical polarization would be attained with a period greater than two times the base period such that an integer number of periods fit inside the undulator structure. Initial numerical simulations have been made, and are reported in this paper. Building on a previous study [1] further simulations were requested to study the behavior of the magnets closer, and to calculate the forces acting on the magnet structures for use in feasibility assessment. In the previous study simple magnetic structures with uniform direction of magnetization were simulated. In this study a more complex structure was also investigated: a type of partial transverse Halbach configuration. This structure would concentrate the magnetic flux along the beamline and could lead to a more compact design, and limit the magnetic field outside the device.The simulations were made using COMSOL Multiphysics modelling software
STATUS OF THE EU-XFEL LASER HEATER
No full textWe describe the technical layout and the status of the laser heater system for the EuXFEL. The laser heater is needed to increase the momentum spread of the electron beam to prevent micro-bunching instabilities in the linac.</p
Combined crossed beam and theoretical studies of the N(2D)+C2H4 reaction and implications for atmospheric models of Titan
No full textThe dynamics of the H-displacement channels in the reaction N(2D) + C2H4 have been investigated by the crossed molecular beam technique with mass spectrometric detection and time-of-flight analysis at two different collision energies (17.2 and 28.2 kJ/mol). The interpretation of the scattering results is assisted by new electronic structure calculations of stationary points and product energetics for the C2H4N ground state doublet potential energy surface. RRKM statistical calculations have been performed to derive the product branching ratio under the conditions of the present experiments and of the atmosphere of Titan. Similarities and differences with respect to a recent study performed in cross beam experiments coupled to ionization via tunable VUV synchrotron radiation are discussed [Lee, S.-H. et al., Phys. Chem. Chem. Phys. 2011, 13, 8515]. Implications for the atmospheric chemistry of Titan are presented
Health impact assessment, housing stock upgrade initiative, Curry County, OR
No full textTitle from PDF cover (viewed on November 14, 2017).This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references (pages 39-43).Funding from the Oregon Health Authority from the Centers for Disease Control and Prevention.Mode of access: Internet from the Oregon Government Publications Collection.Text in English
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