This thesis is on the space--time variational multiscale (ST-VMS) computation of wind-turbine rotor and tower aerodynamics. The rotor geometry is that of the NREL 5MW offshore baseline wind turbine. We compute with a given wind speed and a specified rotor speed. The computation is challenging because of the large Reynolds numbers and rotating turbulent flows, and computing the correct torque requires an accurate and meticulous numerical approach. The presence of the tower increases the computational challenge because of the fast, rotational relative motion between the rotor and tower. The ST-VMS method is the residual-based VMS version of the Deforming-Spatial-Domain/Stabilized ST (DSD/SST) method, and is also called ``DSD/SST-VMST'' method (i.e., the version with the VMS turbulence model). In calculating the stabilization parameters embedded in the method, we are using a new element length definition for the diffusion-dominated limit. The DSD/SST method, which was introduced as a general-purpose moving-mesh method for computation of flows with moving interfaces, requires a mesh update method. Mesh update typically consists of moving the mesh for as long as possible and remeshing as needed. In the computations reported here, NURBS basis functions are used for the temporal representation of the rotor motion, enabling us to represent the circular paths associated with that motion exactly and specify a constant angular velocity corresponding to the invariant speeds along those paths. In addition, temporal NURBS basis functions are used in representation of the motion and deformation of the volume meshes computed and also in remeshing. We name this ``ST/NURBS Mesh Update Method (STNMUM).'' The STNMUM increases computational efficiency in terms of computer time and storage, and computational flexibility in terms of being able to change the time-step size of the computation. We use layers of thin elements near the blade surfaces, which undergo rigid-body motion with the rotor. We compare the results from computations with and without tower, and we also compare using NURBS and linear finite element basis functions in temporal representation of the mesh motion.

Satellites have become absolute necessity in the growing modern space technology. At present, launch pads are the only means for launching of satellites or any other space vehicles. Due to the large magnitude of current and the associated rate of rise, a lightning strike to launch pads can be quite disastrous. Satellite launch complex forms typically the tallest object in that region. This makes them the more vulnerable to cloud-to-ground lightning. In addition, most of the launch pads are situated near the coastal area, where the isokeraunic levels are quite high. In view of these, almost all the satellite launch pads are provided with suitable Lightning Protection Systems (LPS). The LPS is basically intended for protecting against a direct lightning hit. The present work is related with the LPS to Indian satellite launch pads, Pad-I and Pad-II. The protection system for Pad-I consists of three 120 m tall towers placed approximately at the vertices of an equilateral triangle of 180 m. The same for Pad-II consist of 120 m tall towers placed at vertices of rectangle of size 90 m x 105 m. Towers are interconnected by 6 shield wires at the top. A mast of 10m length forms the top of the tower. Significant work on the analysis of interception efficacy of these protection systems has been reported in the literature. The lightning surge response of these systems have also been analysed and reported. The interception efficacy of these LPS in field can be ascertained by pertinent measurements. Measuring the lightning current on LPS seems to be one of the most suitable choices for this purpose. It would also greatly facilitate collection of local lightning current statistics, data on which is almost absent. Several considerations suggest that the tower bases form ideal place for such measurement. However, such lightning current records would involve mainly the current resulting from stroke interception, as well as, induced current due to strokes nearby. Literature on categorisation of measured currents to the type of stroke and correlation of measured currents to the incident stroke currents is rather limited. This is especially true for interconnected protection system of the type dealt in the present work. Considering these the present work is taken up and its scope is defined as: (i) Evolve a suitable model for study of current distribution in LPS due to Lightning and using the same deduce the current due to stroke interception and that due to stroke nearby. (ii) For the purpose of categorization identify the salient characteristics of current due to the intercepted strokes and that due to bypass/nearby strokes (iii) For the intercepted strokes, develop a processor for estimating the injected stroke current from the measured tower base currents. Lightning event, apart from other associated physical phenomena, is strongly governed by electromagnetic fields. Any method employed for the analysis, either theoretical or experimental, should satisfy the governing electromagnetic equations. As experimentation on actual system, as well as, their laboratory simulation is nearly impossible, theoretical modelling approach is selected. Modelling involves modelling of the channel along with its excitation, modelling of the LPS and modelling of the ground. Channel, following the literature, is represented as a loaded conductor with a lumped current source at the junction point. Such models have quite successfully predicted the electromagnetic fields and current in other places on the down conductor. For the LPS, some simplifications on the geometry are very essential. Tower lattice elements of dimensions much smaller than the wavelength of highest dominant frequency component of lightning current spectrum are neglected. Suitable modification is made for the tower top involving a plate and interconnection of several short members. For the close range within 200 – 400 m, even for the induced currents, the influence of ground in the literature has been reported to be small. Also, there is an extensive grounding network in these systems. In view of the same, a perfectly conducting ground along with suitable ground termination impedance is considered. Only the numerical solution of the problem is feasible and for the same, following the literature, NEC-2 is employed. All the guidelines of NEC are respected in the discretisation. Geometric mean radius is employed for modelling the complex tower elements. Fourier Transform Techniques are employed for time domain conversion of the computed frequency domain quantities. Occasionally, numerical inversion error of magnitude less than 5% is encountered. For the validation of the numerical modelling for both direct stroke and that nearby, time domain experimentation on electromagnetically reduced scale models (35:1) is employed. As the channel electrical and geometrical parameters are stochastic in nature, it is necessary to ensure that the deduction made using the model is practically relevant. For this, some parametric studies are conducted. The influence of channel length and inclination, stroke current velocity etc. has been shown to be insignificant for the case of intercepted strokes. Simulations are carried out for the stroke intercepted (i.e. direct strikes) by the LPS. The characteristics of the tower base currents are investigated. The base currents indicate a dispersive propagation along the towers and further a frequency dependent current division at the tower-shield wire junctions. Base currents contain superimposed oscillations, which basically originate from various junctions of the system. The magnitude of the oscillations is obviously dependent on the rise time of the incident currents. The tower base currents settle within about 10 -15 µs, which is shorter than that for isolated tower. Further, the full-frequency model could be limited to this time period. The corresponding current transfer functions are deduced. For the stroke interception by shield wires, based on the earlier work, only stroke to midspan is found to be relevant and hence it is considered. The nature of tower base currents for a stroke to midspan of the shield wires seem to be similar. However there are some distinct features, which are helpful in identifying the stroke location on the LPS. From the time correlated tower base currents, a suitable methodology for identifying the stroke interception location on LPS is developed. Next, simulations for induced current due to a bypass stroke, as well as, stroke to ground outside the LPS, however, within 1 km radius are taken up. In fact, it is estimated that latter is nearly 5 – 13 times higher than the strokes collected by LPS, indicating it as the most probable event. The objective here is characterization, rather than correlation. In this study, the influence of charge induced on the LPS by the descending leader is neglected and the upward leader activity is approximately considered. To the best of author’s knowledge, studies on such induced currents in down conductors are very scarce. Considering this and noting that the number of parameters is quite large, first the basic study is taken up on simple cylindrical down conductors. Many important and interesting deductions are made. The nature of the induced current is highly dependent on the rate of rise as well as the velocity of propagation of the stroke current. The magnitude and to some extent, the wave shape of the induced current is found to depend on the average as well as maximum di/dt of the stroke current. For a given wave shape, the magnitude of the induced current increases with rate of rise of the wave front; however, saturating trend will onset after some point. The height of the down conductor mainly governs the frequency of the oscillatory component of the induced current. The dependency of the induced current on the radius of the down conductor seems to be logarithmic (which is in accordance with the antenna theory). Based on these results, the parameters for the corresponding study on LPS under consideration, is chosen. The results of the investigation on the induced currents in LPS show that they have quite distinct waveform. They are basically bipolar and oscillatory in nature, with relatively short duration. These unique features facilitate clear distinction of the induced currents from that due to stroke interception. Basic characteristics are reasonably insensitive to the separation distance of the protection system and the channel, current propagation velocity along the channel, channel inclination and shape of the current front. The salient features of the induced current due to a bypass stroke are also enumerated. • The noise, if any, in the measured current can be addressed only after acquiring sufficient data. Based on the above, the following procedure is suggested for the stroke classification and estimation. • By employing the distinct features of the resulting tower base currents, analyze the measured tower base currents and classify the strokes into the intercepted stroke or stroke to ground. • For the latter case, using the salient features of the bypass strokes, further classify the strokes to bypass strokes and stroke to ground outside the protected volume. • For the intercepted strokes, using the relative strengths and wave shapes, identify the interception point to either tower top or the midspan of the shield wires. • Then by using the corresponding transfer functions and Fourier Transform techniques, compute the injected stroke current. • Using the above, other tower base currents are computed and compared with the measured currents. This gives quantification for the accuracy of the method. In summary the present work has made some original contribution to the classification and estimation of stroke currents measured on the interconnected LPS.

Zur Kühlung von Prozessströmen kommen aufgrund hoher Leistungsdichten häufig Verdunstungskühltürme zum Einsatz. Um die Übertragungsfläche für Wärme und Stoff zu vergrößern, werden in diesen Kühltürmen Struktureinbauten integriert. Die Weiterentwicklung von Kühlturmeinbauten und die Untersuchung der den Kühlprozess beeinflussenden Faktoren erfolgt empirisch, was eine Vielzahl von Versuchen notwendig macht. Eine numerische Simulation des Kühlprozesses kann diese Messungen unterstützen und so helfen eine Vielzahl an Versuchen einzusparen. Des Weiteren können bei versuchsbegleitender Simulation mit einem geeigneten Modell weitere Untersuchungen durchgeführt und Erkenntnisse gewonnen werden, die bei Messungen am Versuchskühlturm verborgen bleiben. In dieser Arbeit werden zwei Ansätze der numerischen Simulation eines Verdunstungskühlturms betrachtet. Es werden eine CFD-Simulation und ein vereinfachtes Modellkonzept hinsichtlich der Anwendbarkeit auf diese Problemstellung untersucht. Schwerpunkt der vorliegenden Arbeit ist die methodische Entwicklung eines solchen vereinfachten mathematischen Modells. Dieses beruht auf der physikalisch deterministischen Beschreibung der im Kühlturm ablaufenden Prozesse der Wärme- und Stoffübertragung unter Berücksichtigung des Stoffverhaltens. Aufgrund der Nichtlinearität des Stoffverhaltens und der erforderlichen Inkrementierung des Berechnungsgebiets ist ein methodisches Vorgehen erforderlich, um die Erstellung der Modellgleichungen und deren Lösung überhaupt realisieren zu können. Hierfür wird auf allgemeine Methoden der gleichungsorientierten Simulation technischer Systeme zurückgegriffen. Das entwickelte Modellkonzept wird für die Modellierung und Simulation eines Versuchskühlturms angewandt. Mit den so ermittelten Messdaten wird das Modell kalibriert und validiert. Es zeigt sich, dass mit dem erstellten Modell quantitativ und qualitativ valide Ergebnisse erzielt werden können. / Due to the high power density, the cooling of process streams is often done bei evaporative cooling towers. To enlarge the exchange area for the heat and mass transfer, these cooling towers contain integrated structural fills. The future development of cooling tower fills and the research regarding the cooling process and its influencing parameters will be carried out empirically, resulting in a large number of required experiments. A numeric simulation of the cooling process can support theses measurements and reduce the vast number of needed experiments. Furthermore, with the use of test-related simulations and adapted models, it will be possible to gain knowledge and do research in areas which are omitted during regular measurements on cooling towers. In this study it is looked to two different approaches of numeric simulation of a evaporative cooling tower. There will be an examination of a CFD-Simulation and a simplified model concept regarding their respective applicability for this problem. This work is focussed on the systematic developement of such simplified mathematical models, based on the physical deterministic description of the occurring processes of heat and mass transfer in cooling towers considering the stock behaviour. Due to the non-linearity of the stock behaviour and the required incrementation of the calculation area, a systematic approach is needed to model equations and their respective solutions. For this purpose it is necessary to access general techniques of equation-based simulations of technological systems. The developed model concept will be applied for the modelation and simulation of an experimental cooling tower. The model will be calibrated and validated with data from this experimental tower. It shows, that the results from this model are qualitatively and quantitatevily valid.

This study is one of the responses by the National Park Service to requirements in NAGPRA. The study was commissioned by the NPS Applied Ethnography Program in Washington, D.C., to identify individuals and tribes affiliated with the objects of cultural patrimony, sacred objects, or unassociated funerary objects at five NPS units, review those unit summaries, assist park or center staff in initiating consultation regarding those objects, and conduct a case demonstration consultation for Pipe Spring National Monument. The project was administered under Cooperative Agreement #8100 -1 -0001 between the Western Archeological and Conservation Center, National Park Service and the University of Arizona. While this study was specific to NAGPRA- related issues, the NPS does stipulate in its Management Policies (1988) that consultation with Native Americans will occur with regard to cultural resource issues. NAGPRA is not the only consultation arena the NPS is currently involved in with Native Americans.

Syftet med den här undersökningen är att beskriva och analysera vilka fördelar och nackdelar det finns med att utkontraktera en transportplaneringsprocess till en extern part. Undersökningen genomfördes på uppdrag av BT-Europe i Mjölby på avdelningen som ansvarar för distribution av produkter och reservdelar. BT är i grunden ett svenskt företag som startade sin verksamhet 1946 och är idag världsledande tillverkare av eldrivna lagertruckar. År 2000 förvärvades BT av Toyota och detta skapade en världsledande konstellation inom truckbranschen. Bakgrunden till undersökningens syfte är att arbetet med att effektivisera och förbättra transportplaneringsprocessen inom BT har blivit eftersatt på grund av den kraftiga produktionsökningen de senaste 5 åren. Detta har lett till stigande kostnader för distribution av färdiga produkter och reservdelar. I dagsläget finns inget centralt kontrollorgan över transportplaneringsprocessen på BT utan all transportplanering av produkter och reservdelar till truckar, sker lokalt på varje marknadsbolag i Västeuropa. I en framtid har BT som förhoppning att bedriva transportplaneringsprocessen på central nivå, antingen inom koncernen eller genom att utkontraktera transportplaneringsprocessen till en extern part, det vill säga till ett fjärdepartslogistikföretag. Vid beslut om transportplaneringsprocessen ska genomföras centralt internt eller utföras externt med hjälp av en fjärdepartslogistiker finns en rad viktiga faktorer att ta i beaktning. De faktorer som valts att studera i denna undersökning är kärnverksamhet, processens mognad, flexibilitet, kontroll, beroende och transaktionskostnader. Dessa faktorer studeras genom att undersöka inom vilka områden BT anser sig att besitta kärnkompetens idag och i en framtid, samt hur BT ser på faktorer som flexibilitet, beroende och kontroll vid en eventuell outsourcing. Genom att ställa detta mot vad fjärdepartlogistikföretag erbjuder för lösningar till sina kunder och hur de hantera faktorer som flexibilitet, kontroll och beroende, kan för- och nackdelar med en utkontraktering av transportplaneringsprocessen definieras. En fördel med att utkontraktera transportplaneringsprocessen uppnås genom att ingå ett samarbete med en fjärdepartslogistiker och därigenom kan BT få tillgång till spetskompetens och tillgång till större distributionsnätverk. En annan fördel med ett nära samarbete med en leverantör av fjärdepartslogistiska tjänster är att det kan skapa ökad flexibilitet för BT. Detta genom att BT i ett samarbete kan tillgå skräddarsydda lösningar för företagsunika behov samtidigt som möjligheten att byta transportleverantörer ökar, då fjärdepartsaktörer vanligen arbeter med korttidskontrakt emot transportföretagen Nackdelar som kan uppkomma med utkontraktering av transportplaneringsprocessen är att denna process kan komma att ses som betydande för framtida verksamhet. Det kan då vara förenat med risk att tappa kompetens inom området. En nackdel är även att outsourcing av transportplaneringsprocessen kan innebär en beroendeställning för BT gentemot en tilltänkt fjärdepartsleverantör. Kontrollen av processen som koordinerar försörjningen av färdiga produkter och reservdelar från BT till företagets kunder eller marknadsbolag överlämnas därmed till en extern part.

Among the vast assembly of Biblical mythology, the tower of Babel stands as an exclusive representation of the limits of human endeavor. As a paradigmatic extremity, it circumscribes the field of civic artifice. Babel is the absolute limit, and in that regard, its presence is enduring and timeless. The legacy of exegetic readings are textual shades, emanating from the point source of the paradigm. Athanasius Kircher's Turris Babel is an appropriate and intentional unfolding of this condition. / Firstly, that in the awakening of the Baroque scholar to history, origin materializes as the sole legitimate chronological reference. / Secondly, that the paradigmatic extremities collapse into the empirical standard of the theoretical discourse. / This thesis is a speculative study of architecture, drawn through Turris Babel, in the shadow of the paradigmatic limits of Babel. Written in three parts, each dealing with the implications of artifice in confrontation with the post-Babel adversaries of dispersion, tyranny, and decay.

Recently, there have been intense discussions about the humanities and their role in society. Internationally, as well as in a Swedish context, the humanities have been regarded to be in a state of crisis. However, these discussions usually demonstrate a lack of historical perspectives based on thorough empirical research. The notion of a crisis needs to be historicized. In this study, a case is being examined where the relationship between science and society was renegotiated. In the context of World War II, a discourse has been identified in a borderland between science and politics through an analysis of Swedish journals and anthologies during the time period 1937-1947. Historical actors were then highlighting that the humanities faced several challenges. The study argues that these discussions should be regarded as parts of a renegotiation of the humanities’ social contract. In the context of the war and fundamental societal changes, there occurred a greater pressure than before to mobilize science socially in order to make science appear as a legitimate undertaking. For the humanities, such demands seemed to conflict with their scientific ethos. During the interwar period this ethos was often based on a norm that demanded the drawing of a strict boundary between science and politics. But if they did not mobilize socially, scholars risked getting blamed for being isolated in the so-called ‘ivory tower’. How the humanities could be effectively mobilized in order to satisfy the needs of society while still maintaining their legitimacy in a scientific context emerged as a fundamental problem with no clear solutions. Part of this problem was the exclusion of the humanities from politically hegemonic narratives of society’s development, in contrast to natural and social sciences. Reactions to specific historical experiences and distinct expectations for the future thus seem – at least on a discursive level – to have put the humanities in a state of marginalization as early as the time period examined in this thesis.

The rapid movement of machines is a challenging control problem because it often results in high levels of vibration. As a result, flexible machines are typically moved relatively slowly to avoid such vibration. Therefore, motion-induced vibration limits the operational speed of the system. Input shaping is one method that eliminates motion-induced vibrations by intelligently designing the reference command such that system vibration is cancelled. It has been successfully implemented on a number of systems, including bridge and tower cranes. The implementation of input shaping on cranes provides a substantial increase in the operational efficiency. Unfortunately, most cranes, once erected, have limited or no base mobility. This limits their workspace. The addition of base mobility could help extend the operational effectiveness of cranes and may also expand crane functionality. Mobile cranes may also be better suited for use in harsh and/or distant environments. Teleoperation of oscillatory systems, such as cranes, then becomes another avenue for advancement of crane functionality. Base mobility in cranes presents both additional control challenges and operational opportunities. A crane with base mobility is redundantly actuated (overactuated), such that multiple combinations of actuators can be used to move a payload from one location to another. This opens the possibility for the selection of a combination of actuation that provides both rapid motion and limited system vibration. The extension of input shaping into this operational domain will provide a method to maximize effective actuation combinations. Toward addressing these issues, new multi-input shaping methods were developed and applied to a mobile, portable tower crane. During this development, a firm understanding of robust input shaping techniques and the compromises inherent to input shaper design was formed. In addition, input shaping was compared to other command generation techniques, namely lowpass and notch filtering, and proven to be superior for vibration reduction in mechanical systems. Another, new class of input shapers was also introduced that limit the input shaper induced overshoot in human operated systems. Finally, a series of crane operator studies investigated the application of input shaping techniques to teleoperated cranes. These studies suggested that input shaping is able to dramatically improve remote crane operator performance.

A majority of utilities conduct maintenance of transmission line components based on the results of routine visual inspection. The inspection is normally done by inspectors who detect defects by visually checking transmission line components either from the air (in helicopters), from the ground (by using high-powered binoculars) or from the top of the structure (by climbing the structure). The main problems with visual inspection of transmission lines are that the determination of the defects varies depending on the inspectors' knowledge and experience and that the defects are often reported qualitatively using vague and linguistic terms such as "medium crack", "heavy rust", "small deflection". As a result of these drawbacks, there is a large variance and inconsistency in defect reporting (which, in time, makes it difficult for the utility to monitor the condition of the components) leading to ineffective or wrong maintenance decisions. The use of inspection guides has not been able to fully address these uncertainties. This thesis reports on the application of a visual inspection methodology that is aimed at addressing the above-mentioned problems. A knowledge-based Fuzzy Inference System (FIS) is designed using Matlab's Fuzzy Logic Toolbox as part of the methodology and its application is demonstrated on utility visual inspection practice of porcelain cap and pin insulators. The FIS consists of expert-specified input membership functions (representing various insulator defect levels), output membership functions (indicating the overall conditions of the insulator) and IF-THEN rules. Consistency in the inspection results is achieved because the condition of the insulator is inferred using the same knowledge-base in the FIS rather than by individual inspectors. The output of the FIS is also used in a mathematical model that is developed to suggest appropriate component replacement date. It is hoped that the methodology that is introduced in this research will help utilities achieve better maintenance management of transmission line assets.

Honors Project--Smith College, Northampton, Mass., 2009. / Includes bibliographical references (p. 71-73).