Graduation date: 2003 / Presentation date: 2002-06-03

This investigation deals with the suspension of a lightweight medium-class vehicle for four passengers with a curb weight of 1000 kg. The suspension layout consists of a transversal leaf spring and is supported by an active air spring which is included in the damper. The lower control arms are replaced by the leaf spring ends. Active ride height control is introduced to compensate for different vehicle load states. Active steering is applied using electric linear actuators with steer-by wire design. Besides intense use of light material the inquiry should investigate whether elimination of suspension parts or a lighter component is concordant with the stability demands of the vehicle. The investigation is based on simulations obtained with MSC Software ADAMS/Car and Matlab. The suspension is modeled in Adams/Car and has to proof it's compliance in normal driving conditions and under extreme forces. Evaluation criteria are suspension kinematics and compliance such as camber, caster and toe change during wheel travel in different load states. Also the leaf spring deflection, anti-dive and anti-squat measures and brake force distribution are investigated. Based on a simplified version of the leaf spring suspension design a full vehicle model is created. The comparison between the suspension models evaluates the same basic suspension parameters to ensure the compliance. Additionally roll rate and understeer gradient are investigated. It can be shown that the vehicle equipped with transversal leaf spring instead of lower control arms fulfils the set kinematics and compliance requirements. Road holding performance is assured for normal driving conditions on public roads.

Seasonal variation in zooplanton abundance and diversity in Spring Lake, Florida was studies between 1973 - 1976. This clear, sand bottom lake is considered among the most oligotrophic in central Florida. Sixty rotifer species, sixteen cladoceran species, and seven copepod species were collected during the three year study. Annual mean zooplanton abundances ranged between 70 individuals/l and 80 individuals/l. Rotifers were more abundant than either cladocerans or adult copepods. Rotifers and immature crustaceans comprised nearly 75% of the annual mean zooplankton abundance. There was no significant difference (P < 0.05) between years for the annual mean abundance of zooplankton. The monthly mean abundance of cladocerans and adult copepods was generally less than 5 individuals/l. The greater abundance of rotifers in comparison to other zooplankton was mainly responsible for the variation in the values of the Shannon and Simpson Indices. The monthly mean Shannon Index was usually between 3.0 and 4.0. Seasonal differences in zooplankton abundance were apparently due to water temperature and specific conductivity for the 1974 - 1975 and 1975 - 1976 study years. Shannon diversity was significantly correlated with dissolved oxygen for the 1973 - 1974 and 1974 - 1975 study years.

<p>Examensarbetet har genomförts på Siemens Industrial Turbomachinery AB i Finspång. Arbetet innebär modernisering av ventiler till ångturbiner. Uppgiften består av två delar, där den första delen är att modernisera dagens tätningar i spindelgenomföringen. Syftet är att finna en mer vibrationstålig, driftsäker och mindre utrymmeskrävande lösning. Det andra delprojektet är att finna alternativ till dagens tallriksfjädrar i de servomotorer som reglerar ventilen. Anledningen till att nya fjädrar skall tas fram är att öka livslängden, minska slitaget och utrymmesbehovet på servomotorerna.</p><p>För att kunna genomföra uppgiften på ett effektivt och strukturerat sätt har en metodik för systematisk konceptutvecklings används. Denna metodik har varit hjälpfull för att finna nytänkande lösningar. För att kunna dimensionera komponenterna har beräkningsmodeller tagits fram för de ångkrafter som verkar i en ångventil samt för olika typer av packboxar och fjädrar.</p><p>Arbetet med moderniseringen av spindeltätningar har resulterat i att en ny typ av packbox har valts som minskar friktionen samt behovet av efterdragning. Två olika lösningar har tagits fram för att skapa den förspänningskraft som gör att packningen tätar. Båda lösningar minskar behovet av underhållsarbete samt underlättar monteringen. En indikation ges även när rätt kraft är uppnådd, vilket minimerar risken för läckage eller att ventilen inte går att manövrera.</p><p>Analysen av servomotorer resulterade i att inga möjliga alternativ till tallriksfjädrar hittades. Modifieringar har därför tagits fram för att förbättra dagens tallriksfjädrar. Dessa ändringar innebär att slitaget minskas och livslängden ökas betydligt.</p> / <p>This thesis was preformed at Siemens Industrial Turbomachinery AB in Finspång. The work is to make modernizations of steam turbine valves. The first part of the project is to modernize stem packing with the purpose to find a more reliable and space-saving solution that is less sensitive to vibrations. The second part is to find an alternative solution for cup springs in servomotors. A new spring type is desirable to increase the lifetime, lower the wear on stem shafts and to make it more space-saving.</p><p>To be able to perform the task efficiently and organized a method for systematic design has been used. This method has turned out to be quite useful tool in order to find new approaches to problems. Calculations of steam forces in a valve together with different types of box packing and springs have been done.</p><p>The modernization of stem packing has resulted in a new type of box packing. The winnings of changing packing are lowered friction and need of maintenance. Two solutions of live load systems have been created. Both solutions minimize the need of maintenance and make the mount and dismount easier. An indication makes sure that a sufficient force is applied on the box packing.</p><p>An analysis shows no alternative to replace the existing cup springs. The main goal was changed and modifications were made to improve the cup springs. The modifications results in a lowered wear and a significant increase of cup spring lifetime.</p>

Examensarbetet har genomförts på Siemens Industrial Turbomachinery AB i Finspång. Arbetet innebär modernisering av ventiler till ångturbiner. Uppgiften består av två delar, där den första delen är att modernisera dagens tätningar i spindelgenomföringen. Syftet är att finna en mer vibrationstålig, driftsäker och mindre utrymmeskrävande lösning. Det andra delprojektet är att finna alternativ till dagens tallriksfjädrar i de servomotorer som reglerar ventilen. Anledningen till att nya fjädrar skall tas fram är att öka livslängden, minska slitaget och utrymmesbehovet på servomotorerna. För att kunna genomföra uppgiften på ett effektivt och strukturerat sätt har en metodik för systematisk konceptutvecklings används. Denna metodik har varit hjälpfull för att finna nytänkande lösningar. För att kunna dimensionera komponenterna har beräkningsmodeller tagits fram för de ångkrafter som verkar i en ångventil samt för olika typer av packboxar och fjädrar. Arbetet med moderniseringen av spindeltätningar har resulterat i att en ny typ av packbox har valts som minskar friktionen samt behovet av efterdragning. Två olika lösningar har tagits fram för att skapa den förspänningskraft som gör att packningen tätar. Båda lösningar minskar behovet av underhållsarbete samt underlättar monteringen. En indikation ges även när rätt kraft är uppnådd, vilket minimerar risken för läckage eller att ventilen inte går att manövrera. Analysen av servomotorer resulterade i att inga möjliga alternativ till tallriksfjädrar hittades. Modifieringar har därför tagits fram för att förbättra dagens tallriksfjädrar. Dessa ändringar innebär att slitaget minskas och livslängden ökas betydligt. / This thesis was preformed at Siemens Industrial Turbomachinery AB in Finspång. The work is to make modernizations of steam turbine valves. The first part of the project is to modernize stem packing with the purpose to find a more reliable and space-saving solution that is less sensitive to vibrations. The second part is to find an alternative solution for cup springs in servomotors. A new spring type is desirable to increase the lifetime, lower the wear on stem shafts and to make it more space-saving. To be able to perform the task efficiently and organized a method for systematic design has been used. This method has turned out to be quite useful tool in order to find new approaches to problems. Calculations of steam forces in a valve together with different types of box packing and springs have been done. The modernization of stem packing has resulted in a new type of box packing. The winnings of changing packing are lowered friction and need of maintenance. Two solutions of live load systems have been created. Both solutions minimize the need of maintenance and make the mount and dismount easier. An indication makes sure that a sufficient force is applied on the box packing. An analysis shows no alternative to replace the existing cup springs. The main goal was changed and modifications were made to improve the cup springs. The modifications results in a lowered wear and a significant increase of cup spring lifetime.

This work deals with the springs and dampers questions. It focuses on their classification, characteristics and testing. The main part of this thesis describes the design and sizing dimensions of machine for measuring characteristics of automotive springs and conceptual design of machine for detection characteristics of hydraulic shock absorbers.

published_or_final_version / abstract / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

In games, reverb is used to convey the audial space of game environments. This thesis explores the possibilities of using spring and plate reverb, and if they enhance or detract from the experience compared to a realistic natural reverb. Under evaluation, a quantitative study with a secondary qualitative discussion was carried out where participants played a gameplay prototype that switched between using spring reverb, plate reverb and a realistic natural reverb. A survey was answered relating to the gameplay sequence, which was used to evaluate how players perceived the differences in the different reverbs. The conclusion shows that although spring and plate reverb have different associations and are perceived in a different way compared to a natural realistic reverb, a majority still preferred a natural reverb and felt that spring plate were overall more distracting to the game experience.

This thesis analyses the problematic trajectory of the Syrian Revolution 2011, which was inspired by the Arab Spring. It first evaluates the causes of the revolution during Bashar al-Asad's era. An era was aimed to be a transition from authoritarianism to democracy and from suppression to fair openness. It second investigates the factors behind turning the Arab Spring into a Syrian winter, plunging the country into internal war and uncontrolled violence. The research is based on a qualitative approach that includes interviews as a source of information and analysis. Factors covered are the disintegration of Syrian society as the greatest challenge for the civil uprising and mass mobilization as well as the regime's coherent inner core accounting for the regime's violence and persistence. As violence breeds violence, the revolutionaries decided to react violently towards the regime brutality descending the country into an internal war. The formulation of the Free Syrian Army was formalized, but could not transform into a proper military formation, and so could not control the spread of violence in the country. The inclination towards Jihad was evident and common, and associated with resorting to violence because the revolutionaries are Muslims, and believed in Jihad as a way to defend themselves and their families. However, Jihad became more formalized with the arrival of global Jihadists to Syria, forming Jihadist groups and controlling parts of Syria. The stance of the international community was another big obstacle helped escalating, but not terminating the conflict. A conflict could develop into a devastating regional crisis changing the structure of the Middle East and changing the international politics of this vital region.

Wheat leaf rust, caused by Puccinia triticina Eriks. (= P. recondita Rob. Ex Desmaz. f. sp. tritici), is the most widespread disease of wheat worldwide and causes average annual yield losses of 5 to 25%. The emergence of a new predominant race of leaf rust, TDBG, in the 2004 Canadian virulence survey led to the identification of a second leaf rust resistance gene segregating in the Thatcher-Lr1 near-isogenic differential line, RL6003, which produced an unusual mesothetic infection type. This gene was subsequently isolated in a Thatcher background and temporarily designated as LrCen (Tc-LrCen). A cross was made with a susceptible parent (Tc-LrCen/ Sumai3-lr34) and a doubled haploid (DH) mapping population was generated from the hybrids. Parental lines and 180 double haploid (DH) individuals were phenotyped with race TDBG and a 1:1 ratio was observed in the DH population. Parental lines and 94 DH individuals were genotyped with the Illumina Infinium assay using a custom iSelect 90K wheat SNP array. Two-point linkage between the phenotype and polymorphic SNP markers identified linked markers. A BLAST search of linked SNP sequences was performed against the Wheat Survey Sequence providing a putative chromosomal location of 7AL. Subsequent mapping with microsatellite markers confirmed LrCen was located on the long arm of chromosome 7A flanked by gwm344 (9.5 cM) and cfa2240 (0.6 cM) as well as a group of co-segregating SNPs also at a genetic distance of 0.6 cM. When the SNP sequences were converted to the kompetitive allele specific PCR (KASP) markers they were found to be dominant, making them less useful for marker assisted selection in populations with heterozygotes. LrCen mapped distal to Lr20; the only other Lr gene previously identified on chromosome 7AL. / October 2016