Portable mass spectrometers provide convenience for applications where conventional mass spectrometers are not suitable. However, a series of miniaturization issues show up in small mass spectrometers, specifically mass analyzers, that need to be thoroughly addressed before further miniaturization. The work in this dissertation focuses on miniaturization issues of ion trap mass analyzers. Space-charge is one of the major issues in small ion traps affecting their analytical performance. It limits ion trapping capacity when ion-ion repulsion causes spreading of a packet of ions. Simulation studies on the relationship between different trap dimensions and trapping capacity was done on a geometry-optimized cylindrical ion trap. A reasonable way of scaling the two important operating parameters (trapping voltage and trapping frequency as functions of the trap dimension) was discussed and applied in the simulation. The trapping capacity (N) decreased with the physical trap dimension (r0) as expected, and N is scaled exponentially as r0. Scaling laws for trapping parameters are proposed, confirmed by SIMION simulations that evaluate the space charge issue in small ion traps. This effect represents a practical limit in ion trap miniaturization.Geometry deviation is another issue that cannot be neglected in miniaturized ion traps, especially in small linear ion traps (LIT). The LIT our group is working on consists of an assembly of two plates, of which each was made by lithographically patterning a series of electrodes on an insulating plate. It is a promising way of expanding the trap capacity at a small trap dimension. However, misalignment of the two plates might seriously affect its performance, specifically resolution and signal intensity. Simulations were done on the misalignment of two-plate planar LIT in the six possible degrees of freedom (DOF) of misalignment between the two plates. Each DOF's influence on the mass resolution and the ion detection efficiency were discussed. Preliminary data from a previous ceramic plate design was collected while most of the misalignment experiments were done on an improved version. A platform was designed incorporating four motorized stages to precisely control the alignment of the ion trap in vacuum. The new plate design was demonstrated to achieve a better than unit resolution for toluene and deuterated toluene after the plates were aligned. The impact on the resolution and signal intensity from pitch, x-, y- and z-displacement were also experimentally studied.

This paper provides empirical study of whether there was a misalignment of the real exchange rate (RER) in the Bangladesh economy during 1976-1991. The time series of multilateral and bilateral RER indexes were computed for the period 1976-1991. The computed series of RER were indexed to a base year of when the RER attained its highest level and thereby appeared to be closer to the actual long-run equilibrium RER. In the empirical part of this thesis, five different RER indexes were computed: multilateral real exchange rate index 1 (MRER1), multilateral real exchange rate index 2 (MRER2), bilateral real exchange index 1 (BRER1), bilateral real exchange rate index 2 (BRER2), and black market bilateral exchange rate index 1 (BMRER1). Computation of the multilateral and bilateral RER indexes involved data on trade weights and wholesale and consumer price indexes of the domestic economy and its trading partners, besides their nominal official exchange rates. As a result, the study period was not large enough due to the unavailability of data on all variables involved. Misalignment of RER refers to the sustained deviation of the observed RER from its long-run equilibrium level. Three different measures of RER misalignment were constructed: purchasing power parity (RERMISPP), instability (RERMISINSTA), and black market (RERMISBLK). The MRER1, BRER2, and BMRER1 indexes were used respectively, in contrasting RERMISPP, RERMISINSTA, and RERMISBLK measures of RER misalignment. All of these measures demonstrated RER misalignment in Bangladesh during 1976-1991. In order to compute the long-run equilibrium RER, a multivariate regression was executed with respect to the RER fundamental real variables. Later, a time series of three different measures of RER misalignment index was regressed on the time series of the growth rate of real GDP (gross domestic product), exports, imports, savings, and investment for 1976-1991 to bring about the effects of RER misalignment on the macroeconomic performance of Bangladesh. It was found that RER misalignment adversely affected the macroeconomic performance of Bangladesh. An effectiveness index of nominal devaluation as a preventive policy eroded in later years. Consequently, a cross episode regression was executed to appraise the efficacy of 10 nominal devaluation episodes. It was found that when supplementary macroeconomic policies, such as the growth rate of domestic credit, growth rate of domestic credit to the public sector, and the growth rate in the ratio of public sector to total domestic credit were taken into consideration, nominal devaluation became more effective in bringing about the real devaluation.

This dissertation presents a Bayesian hierarchical model to combine two-resolution metrology data for inspecting the geometric quality of manufactured parts. The high- resolution data points are scarce, and thus scatter over the surface being measured, while the low-resolution data are pervasive, but less accurate or less precise. Combining the two datasets could supposedly make a better prediction of the geometric surface of a manufactured part than using a single dataset. One challenge in combining the metrology datasets is the misalignment which exists between the low- and high-resolution data points. This dissertation attempts to provide a Bayesian hierarchical model that can handle such misaligned datasets, and includes the following components: (a) a Gaussian process for modeling metrology data at the low-resolution level; (b) a heuristic matching and alignment method that produces a pool of candidate matches and transformations between the two datasets; (c) a linkage model, conditioned on a given match and its associated transformation, that connects a high-resolution data point to a set of low-resolution data points in its neighborhood and makes a combined prediction; and finally (d) Bayesian model averaging of the predictive models in (c) over the pool of candidate matches found in (b). This Bayesian model averaging procedure assigns weights to different matches according to how much they support the observed data, and then produces the final combined prediction of the surface based on the data of both resolutions. The proposed method improves upon the methods of using a single dataset as well as a combined prediction without addressing the misalignment problem. This dissertation demonstrates the improvements over alternative methods using both simulated data and the datasets from a milled sine-wave part, measured by two coordinate measuring machines of different resolutions, respectively.

Gear stress analysis and understanding the effect of misalignment and microgeometry is important for gear designers and for those who work in gear maintenance. The misalignment can lead to the higher stress acting in one side of the gear tooth and the micro-geometry modification can improve the stress distribution in the gear teeth. In this research, a helical gear pair was modeled using three different software and tools; LDP, KISSsoft and Abaqus. Three different cases were modeled to study the effect of misalignment and microgeometry. Finally, the results from different tools were presented and discussed. It was observed that the tooth contact analysis software resulted in significantly higher stresses than the FE software. The results have been discussed to understand the differences in the cases obtained from the used tools. The results showed how bad is the effect of the misalignment on the gear mesh and the stress distribution and how the microgeometry modifications are used to compensate that effect.

Dowel bars are provided at the transverse joints of the Jointed Plain Concrete Pavement (JPCP) to transfer the load between adjoining slabs and to allow for expansion and contraction of the pavement due to temperature and moisture changes. The current study involved evaluation of the performance of Glass Fibre Reinforced Polymer (GFRP) dowels in JPCP as an alternative to the conventional epoxy-coated steel dowel bars, especially in the presence of dowel misalignment. This research involved two main sets of experimental tests. The first set focused on the evaluation of load-deflection response of GFRP dowels using a scaled model of pavement slabs. The second set investigated the combined effect of dowel misalignment and cyclic wheel load on the performance of steel and GFRP dowels. The tested slabs (in the second set) were supported on a steel-beam base with stiffness such that the effects of the underlying layers of real pavements are incorporated. In both of these sets of experiment the GFRP dowels were compared with the steel dowels of similar flexural rigidity. The research also involved detailed numerical investigations using ABAQUS for all experimental tests in the current study. The validated numerical model was used to conduct three sets of parametric studies: to propose design considerations for the GFRP dowels; to simulate all important cases of dowel misalignment (111 cases) for steel and GFRP dowels and to give an insight into the damaged volume in the surrounding concrete pavement; and to investigate the effects of diameter, length and type of dowel bar, concrete grade, pavement thickness, and slab-base friction on the joint-opening behaviour. The results from the first set of experiments showed that the 38 mm GFRP dowels perform better in terms of deflection response compared to the 25 mm steel dowels. Also, it was observed that the relative deflection (RD) is more sensitive to the changes in the joint width rather than the concrete strength. The numerical results from the first set showed a good agreement with the experimental results and showed lower magnitude and better distribution of stress in the concrete underneath the GFRP dowels as compared with the steel dowels. Finally, on the basis of a detailed parametric study (70 different cases), design considerations for GFRP dowels in JPCP were suggested. The second set of experimental results showed that the GFRP dowels can withstand a cyclic traffic load and significantly reduce joint lockup and dowel looseness (DL) and can provide sufficient load transfer efficiency (LTE). It was also observed that the dowel misalignment affects DL significantly more than the repeated traffic load. Slab-base separation and the orientation of misaligned dowels have significant effects on the pull-out load required to open the joint. The numerical results from the second set indicated that the pull-out load was small for the vertical misalignment cases compared to the horizontal and combined misalignment cases. The results also indicated the occurrence of concrete spalling and deterioration at smaller joint openings for combined misalignment when compared to other misalignment types. The use of GFRP dowels significantly reduced the pull-out load and joint lockup when dowel misalignment exists. Consequently, the deterioration of the surrounding pavement substantially decreased. The long term performance of the JPCP fitted with GFRP dowels improves because of a reduction in the DL and the RD, and by maintaining a good LTE even for misaligned dowels. The numerical results also showed that the pull-out load increases significantly for an increase in the concrete compressive strength and the dowel bar diameter. Small increase in pull-out load was observed for higher embedded length of the dowel bar, whereas the increase was insignificant for an increase in the pavement thickness and slab-base friction. In general, the study showed the GFRP dowel can be a potential alternative for the conventional steel dowel bars in JPCP.

No description available.

No description available.

A handheld heavy-duty nut runner, commonly used to assemble windmills and oil pipe lines, and capable of producing 4100 Nm of torque, experiences low cycle fatigue and usually fails after 20 000 cycles at the specified torque. A full assembly Finite element model of the last stage of the four-stage planetary gearbox is constructed and simulated over one complete load cycle. The results from the simulation is compared with, and used to verify a KISSsoft simulation of the same model. Using the Finite Element model, a parametric optimization is performed using a full factorial design. The results show that misalignment issues are difficult to prevent due to the planetary gearbox design. Comparing the two models shows similar characteristics and stress levels but that local differences are common. A proposed design improvement results in better load distribution in the planet – ring interaction, which was previously impaired compared to the planet – sun interaction due to deformation induced misalignment. The result shows that by balancing the rotational stiffness of the side 1 and side 2 carrier pin mountings, it is possible to reduce the contact misalignment and improve the load distribution in the gearbox. / En handhållen mutterdragare vars användningsområde innefattar bland annat montering av vindkraftverk och oljeledningar, producerar ett vridmoment om 4100 Nm. På grund av det här havererar vanligtvis verktyget av utmattning vid ca 20 000 cykler, något som tros vara kopplat till vinkelfel som uppkommer vid deformation av verktygets växellåda. Vinkelfelen resulterar i att lastfördelningen mellan kugghjulen blir skev och spänningskoncentrationer uppstår. Finita elementmetoden används för att undersöka uppkomsten av vinkelfelen och en komplett modell av hela det sista steget i den fyrstegade planetväxellådan undersöks. Simuleringen jämförs med en liknande modell i KISSsoft, dels för att bekräfta resultatet från simuleringen, dels för att undersöka skillnader och svagheter i de båda modellerna. FE-modellen används även för att bygga upp en parametrisk optimering baserat på faktoriell design. Resultatet visar att vinkelfel är svårt att motverka på grund av växellådans design och konfiguration. Jämförelsen av de två simuleringsmodellerna uppvisar liknande karaktärsdrag och spänningsnivåer men att lokala skillnader finns mellan de båda modellerna. Optimeringen resulterar i en föreslagen designförändring som visar sig förbättra lastfördelningen i planet – ring – interaktionen utan att påverka lastfördelningen i planet – sol – interaktionen. Det här är att föredra eftersom lastfördelningen mellan planet och sol är bättre än lastfördelningen mellan planet och ring. Resultatet visar också att det är möjligt att minimera vinkelfelet mellan kontaktytorna, och förbättra lastfördelningen i växellådan genom att balansera rotationsstyvheten på var sida om planeten i planetbäraren.

Title: Leadership Roles and Their Misalignment in the Workplace - A quantitative approach to analyzing employee engagement from a follower perspective. Leadership is a concept that has been studied for centuries and there are multiple theories, concepts, and understandings on the subject. For this study, the focus has been to examine and understand the association of different levels of employee engagement (cognitive, physical, and emotional) in the theoretical framework of the five ”p’s” by Alvesson et al. (2017). This research is aimed to find out what the most preferred leadership role and employee need is to later analyze and find out if the different levels of employee engagement have a positive correlation. In this study, we found that there are clear correlations and there is a positive corelations on the preferred leadership role identified and employee engagement. We also established that there were clear preferences for leadership roles and traits the followers deemed more important than others. Lastly, we also found no significant relationship between the most important needs of the participants in this study on their work engagement.

This study has analysed the misalignment of the real exchange rates of the eleven original euro members at the introduction of the euro, and their consequences for inflation in the first five and ten years of the monetary union. Using four separate models of real equilibrium exchange rates, the largest overvaluations are found for Portugal and Germany, and the largest undervaluations are found for Ireland and Finland. In accordance with theory, adjustment towards equilibrium through inflation rate differentials seems to have occurred: the effect being clear with regard to two of the models, and ambiguous according to the two remaining. The study sheds light on the appropriateness of the conversion rates at the introduction of the euro in 1999, and the macroeconomic consequences of real exchange rate misalignment.