I dagsläget dimensioneras bullerskärmar efter varje projekt med den enda gemensamma nämnaren att de skall uppfylla utformade riktlinjer och bullerkrav. De kan skilja sig enormt vad gäller estetisk utformning och konstruktion. Denna arbetsgång är både tids - och kostnadsineffektiv med konsekvenser som följd, framförallt då externa arkitekter anställs för att sätta sin egen prägel. Uppgiften har utdelats gemensamt utav Trafikverket och Peab som ser ett behov utav standardiserade bullerskärmar. Slutsatsen har dragits utav tidigare projekt och då framförallt projekt Mälarbanan. Denna rapport syftar till att, med utgångspunkt Mälarbanan, ta fram ett förslag till ett standardiserat system som skall kunna användas runt om i Sverige. Detta system, skall motverka dagens problematik med nuvarande bullerskärmar. Systemet kommer i texten att benämnas som Bsk 14F som står för Bullerskärm 14 Försök. Resultatet utav Bsk 14F kommer att redovisas med ljudmodelleringar i dataprogrammet INSUL som används i dagens utformningar. Ritningar i CAD kommer att påvisa Bsk 14Fs konstruktion och kalkylräkning för kostnaderna. Vi har även jämfört olika bullerskärmar som finns att tillgå på marknaden idag för att undersöka möjligheten att välja ett befintligt system. Med hjälp av en yrkesverksam akustiker, konstruktörer, platschefer och arbetsledare har vi kunnat erhålla underlag för att producera ett slutligt resultat. Här påvisas att med ett standardiserat system går det att uppnå ljudkraven som erfordras till ett lägre pris utan att behöva kompromissa utrymme för arkitektoniskt prägel. / Ideally, the basic standard forms of how and why noise barriers are created are to fulfill the purpose of reducing sound. They vary greatly regarding their esthetics and design. Particular mechanics are both time and cost ineffective consequentially when external architects are contracted to put their trademark on them. Trafikverket and Peab, whom identify the need of standardizing noise barriers, have collaboratively delegated the assignment. The conclusion has been drawn from earlier projects and Project Mälarbanan. The premise of the report (having Mälarbanan as an example) is to offer a standardized system which would be used throughout Sweden. This system would, thus, counter the current problems with noise barriers that exist today. The system will be noted in the text as Bsk 14F, which stands for Bullerskärm 14 Försök (Noise Barrier 14 experimental). A computer sound-model program using today’s configurations will present the results of Bsk 14F, whereas drawings in CAD will show Bsk 14F’s design and calculation costs. A comparison has also been made to examine the possibility of choosing a noise barrier currently existing on the market today. With the help of effectively using a professional acoustician, engineers, site managers, and project leaders was it possible to obtain the core material to produce an ultimate and final result. The following demonstrates that establishing a standardized system, which fulfills the sound requirements and be constructed at a lower cost, is attainable without having to comprise the architectural trademark.

Background: Due to unforeseen world events such as the Covid-19 pandemic or war inUkraine, the discussion of risk management in supply chains is increasing. Supply chains areinherently subject to risk as they are completely susceptible to outside entities’ behaviour thatare largely out of their control. Supply chains that have less risk in them, are clearly desirableas they will be more resilient in times of crisis. Companies are searching for ways to increaseresiliency in their supply chains through various methods, which include internal and externaltransparency. However, SC partners can experience barriers to releasing SC information. Therefore, improvements in incentivization strategies will be the goal moving forward. Purpose: This study aims to contribute to supply chain risk management theory by developinga comprehensive and practicable framework of incentivization to increase supply chain transparency. The proposed framework will provide businesses with a clear overview of barriers,benefits, and drawbacks of internal and external transparency, as well as explain how and whento employ specific incentivization methods. Method: This study will be accomplished by analysing supply chain management literatureand carrying out a qualitative interview study with industry professionals. Seven interviews areconducted with various supply chain professionals to gather a broad scope of transparency benefits, incentivization methods, and barriers to transparency. This deductive approach will allowfor comparing and combining of theory and practice, resulting in a more accurate and holisticmodel. Conclusion: The findings of this study reveal the existence of numerous incentivization methods, barriers, and benefits associated with transparency. In addition, this study highlights somedisparity between literature and actual practices. Moreover, this study identifies additional barriers to transparency that were not previously addressed in examined literature. In light of thesefindings, a comprehensive incentivization framework has been developed to provide guidancefor businesses in addressing relevant barriers by selecting appropriate incentivization methods.

No description available.

This work demonstrates how local, randomized tailoring of bond stiffness can affect the activation energy of diffusion in model alloys using density functional theory-based computations. This work is organized into two parts. The first part deals with the vacancy diffusion mechanism, and it compares the in–plane (IP) vs out-of-plane (OOP) diffusion paths in prototypical binary Mg-X (Ca, Y, and Gd) and ternary Mg-X (Ca, Y, and Gd)-Zn alloys. We examine how vacancy formation, migration, and solute vacancy binding energies in binary Mg-X alloys influence diffusion activation and correlated them with conventional diffusion model based solely on the solute sizes. Next, we explore how Zn addition to binary Mg-X (Ca, Y, and Gd) alloys influences the OOP activation energy barrier is discussed in terms of detailed energetic computations and bond characterization in the present work. Our results indicate that Zn addition further enhances the OOP activation energy barrier compared to corresponding activation energies in Mg binaries. This work concludes that engineering stiffer directional bonds via micro-alloying additions in Mg is a promising route to dramatically improve their high temperature creep response. The second part of my work investigates the effects of Si, P, and S solutes on H interstitial diffusion mechanism in Ni. It examines how H interacts with vacancy, impurity atom, and vacancy-impurity atom defect pair by performing binding energy calculations. Results indicate that vacancy-impurity atom defect pair strongly traps the H atom compared to isolated defects. Finally, the effect of impurities on activation energy barrier of H diffusing in Ni is discussed by correlating migration energetics with bonding characteristics by performing charge density and electron density calculations. Our study validates experimental hypothesis of Berkowitz and Kane which postulates that P enhances the H diffusion in Ni. The present work also shows that H diffusion speeds up in Ni in the presence of Si and S solutes. In conclusion, we show that micro-alloying additions induce local lattice level pockets with covalent character, which substantially enhances the local bond stiffness. This will increase activation energy for vacancy diffusion mechanism while it reduces activation energy for interstitial H diffusion.

Thermal barrier coatings (TBCs) are widely used for thermal protection of hot section components in turbines for propulsion and power generation. Applications of TBCs based on a clearer understanding of failure mechanisms can help increase the performance and life-cycle cost of advanced gas turbine engines. Development and refinement of robust nondestructive evaluation techniques can also enhance the reliability, availability and maintainability of hot section components in gas turbines engines. In this work, degradation of TBCs was non-destructively examined by photostimulated luminescence spectroscopy (PSLS) and electrochemical impedance spectroscopy (EIS) as a function of furnace thermal cycling carried out in air with 10-minute heat-up, 0.67, 9.6 and 49.6 - hour dwell duration at 1121°C (2050°F), and 10-minute forced-air quench. TBCs examined in this study consisted of either electron beam physical vapor deposited and air plasma sprayed yttria-stabilized zirconia (YSZ) on a variety of bond coat / superalloy substrates including bond coats of NiCoCrAlY and (Ni,Pt)Al, and superalloys of CMSX-4, Rene‟N5, Haynes 230 and MAR-M-509. Detailed microstructural characterization by scanning electron microscopy and energy dispersive spectroscopy was carried out to document the degradation and failure characteristics of TBC failure, and correlate results of PSLS and EIS. Mechanisms of microstructural damage initiation and progression varied as a function of TBC architecture and thermal cycling dwell time, and included undulation of the interface between the thermally grown oxide (TGO) and bond coats, internal oxidation of the bond coats, and formation of Ni/Co-rich TGO. These microstructural observations were correlated to the evolution in compressive residual stress in the TGO scale determined by PSLS shift. Correlations iv include stress-relief and corresponding luminescence shift towards stress-free luminescence (i.e. = 14402 cm-1 and  = 14432 cm-1 ) associated with subcritical cracking of the TGO scale and stress-relaxation associated with gradual shift in the luminescence towards stress-free luminescence (i.e.  = 14402 cm-1 and  =14432 cm-1 ) is related to the undulation of TGO/bondcoat interface (e.g., rumpling and ratcheting). Microstructural changes in TBCs such as YSZ sintering, TGO growth, and subcritical damages within the YSZ and TGO scale were also correlated to the changes in electrochemical resistance and capacitance of the YSZ and TGO, respectively. With thermal exposure the YSZ/TGO resistance and capacitance increased and decreased as result of sintering and TGO growth. With progressive thermal cycling damages in the TGO was related to the TGO capacitance showing a continuous increase and at failure TGO capacitance abruptly increased with the exposure of bondcoat. Further correlations among the microstructural development, PSLS and EIS are documented and discussed, particularly as a function of dwell time used during furnace thermal cycling test, with due respect for changes in failure characteristics and mechanisms for various types of TBCs

The purpose of this research was to examine whether a transition schedule of contextual interference facilitated learning in retention and transfer equal to or better than random and blocked schedules among children. The author selected participants from the central coast of California and from youth activity leagues. The author selected children between the ages of 10 to 13 with a mean age of 11.5. There were a total of 36 subjects, half male and half female. Unfortunately, due to computer error, only data from 15 subjects were saved and available for analysis. Researchers randomly assigned participants to one of three groups: the random group, the blocked group, or the transition group. Each group performed 60 trials during the acquisition phase and practiced a total of 3 different arm patterns. All three groups practiced each pattern a total of 20 times during acquisition. The random group practiced each pattern in random fashion such that no one pattern was repeated more than twice in a row. The blocked group performed 20 trials of the green pattern, followed by 20 trials of the blue pattern, and lastly 20 trials of the red pattern. The transition group performed the first 24 trials in a blocked fashion, that is 8 trials of the green pattern were practiced, followed by 8 trials of the blue pattern, and then 8 trials of the red pattern. The group then practiced smaller blocks and performed 5 trials of each color. Another 9 trials were performed in a blocked fashion with 3 trials of each pattern. The final 12 trials were presented randomly to this group. Following acquisition, participants took an immediate retention test that was counter balanced following a 10 minute rest. The retention test consisted of 9 random trials of the three various patterns. Researchers gave a transfer test following the retention test, which consisted of six trials of a novel (white) pattern. Researchers tested all three groups one week later with a delayed retention and transfer test similar to the tests described above. One-way ANOVA analysis of the data revealed a significant movement time difference (F=4.28; P=.039) during the delayed retention test. The follow up Tukey test demonstrated that the transition group had a significantly faster movement time than the blocked group but that random group was not significantly different from either the blocked or transition group. The other retention and transfer tests revealed no significance, however the trend in the data suggest that with a bigger sample size, the transition group would demonstrate learning equal to or better than both random and blocked groups. Further research is needed in the area of transition practice schedules.

No description available.

Carbon nanotube templated microfabrication (CNT-M) is a method that allows high-aspect ratio structures to be made for microelectromechanical systems (MEMS) devices. One concern when making monolithic electrical devices using CNT-M is that the aluminum oxide diffusion barrier will create too large of a resistance in the device. However, in developing CNT based MEMS devices, it has been observed that an electrical DC current is capable of transport from a conductive substrate, across the aluminum oxide, and through to the CNT structure grown on top of it. This thesis attempts to determine the mechanisms responsible for current being able to cross the aluminum oxide diffusion barrier easily through sample characterizations. Principally, current-voltage measurements, electron microscopy, XEDS, and SIMS analysis are used to characterize the various samples and determine the process responsible for the observed phenomenon. Through these techniques, it is determined exposure to ethylene gas during the CNT growth recipe used in our lab, regardless of whether CNTs grow on the sample or not, is necessary to cause a drop in resistance across the aluminum oxide, but the that the overall content of iron and carbon in the aluminum oxide do not correlate with this drop in resistance.

The stability and safety of robotic systems are heavily impacted by delays and parametric uncertainties due to external disturbances, modeling inaccuracies, reaction forces, and variations in dynamics. This work addresses the effects of parametric uncertainties in the application of payload transportation by robotic systems that involve time delays and state constraints. The problem is split into two research questions: control of a quadrotor UAV in the presence of delays and control of robotic systems with state constraints. The first two papers explore the approaches for remotely operated quadrotors in the presence of delays and uncertainties. Specifically, the first paper surveys the existing methods for controlling a payload-carrying UAV and further presents a class of control techniques in theory that focus on time-delayed systems. The second paper proposes an adaptive control solution for the tracking control of a quadrotor UAV to transport various unknown payloads in the presence of unknown time-varying delays. The proposed controller is robust to modeling uncertainties and does not require knowledge of the uncertainties' bounds. The performance of the controller is verified on a MATLAB-SIMULINK simulated environment. The final three papers deal with enforcing state constraints on tracking control to ensure the safety of the robots in the presence of parametric uncertainties. The third paper exploits state constraints in the post-grasping scenario of the space debris disposal application. This work proposes a robust control for a space robot to follow the desired trajectory without any violation to safely grasp, carry, and release unknown payloads in their respective regions. The controller is tested in a MATLAB-SIMULINK environment with the dynamics of a planar space robot. The fourth paper introduces an adaptive control technique without any a priori knowledge of the system dynamics or the bounds of uncertainties to impose state constraints in control. The proposed controller is designed for a generic Euler-Lagrangian system in the presence of parametric uncertainties, where the state-dependent nature of the uncertainties introduces unboundedness in the overall uncertainty. The controller is validated in simulation using a robotic manipulator in a pick-and-place operation. The final paper proposes an adaptive controller for the tracking control of an experimental planar space robot. The proposed controller enforces constraints on the robot's states and their derivatives on the tracking control for transporting different payloads without any knowledge of the dynamics of the robot or the bounds of the uncertainties. The controller is validated on the experimental space robot. The stability of the proposed controllers is studied analytically using the Lyapunov theory. The results are presented with various plots and numerically analyzed on the metrics of root mean squared errors and peak errors.

No description available.