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For testing of OTR (Off-The-Road) tires for dump trucks during development, radial loads are applied between the tested tire and a rotating roller drum by using a parallel kinematic wheel guide unit. Additional lateral loads are created by setting a slip angle. The bolt connection between rim and test bench axle must be able to transmit the occurring forces and moments fatigue endurable. Three different procedures for evaluating the bolt connection are compared: Purely analytical evaluation as well as manual and automated evaluation of FEA results. Thereby the frictional connection in the joint and the bending moments in the bolts, resulting from elastic deformation of the components, are identified as the most critical factors. It is shown how these factors are considered in the individual methods and what causes differences in the calculation results. Using various optimization approaches, the bolt connection is designed for fatigue strength. / Zur entwicklungsbegleitenden Erprobung von OTR (Off-The-Road) Reifen für Muldenkipper werden an einem Prüfstand mittels einer parallelkinematischen Radführungseinheit Radialkräfte zwischen dem zu prüfenden Reifen und einer rotierenden Laufrolle aufgebracht. Durch Einstellung eines Schräglaufwinkels entstehen zusätzlich Seitenführungskräfte. Der Schraubverband zwischen Radfelge und Prüfstandsachse muss die auftretenden Kräfte und Momente dauerfest übertragen können. Es werden drei verschiedene Vorgehensweisen zur Bewertung des Schraubverbands gegenübergestellt: Rein analytische Auswertung sowie manuelle und automatisierte Auswertung von FE-Ergebnissen. Dabei werden der Reibschluss in der Trennfuge sowie Biegemomente in der Schraube, resultierend aus der elastischen Verformung der Bauteile, als die kritischsten Faktoren identifiziert. Es wird gezeigt, wie diese Größen in den einzelnen Verfahren berücksichtigt werden und worauf Unterschiede in den Berechnungsergebnissen zurückzuführen sind. Unter Anwendung verschiedener Optimierungsansätze wird der Schraubverband auf Dauerfestigkeit ausgelegt.

Timber-concrete composite (TCC) structures are becoming more popular in several industrial applications as an efficient method for optimizing the structural performance and the cost of construction as well as lowering the emissions of carbon dioxide. TCC floors are more sustainable than pure concrete floors and more resistant to vibrations and excessive deflections than pure wooden floors. The effectiveness of a TCC floor is dependent on the connection between the materials. The stiffness and strength of the composite element increases by having a rigid connection. An example of a rigid connection is an adhesive-bonded connection, however obtaining a connection without slip is difficult considering there will always be certain amount of slippage in the connection. In this thesis adhesive connections are investigated with two different types of adhesive, one called Sikasil SG-500 and the other Sika PS. The application of the adhesives for the test specimen differ. Since Sika PS is a more fluid glue, a different approach was necessary than for the Sikasil SG-500. Five test specimen were tested of each adhesive by performing double shear push out tests and comparing the results to a numerical model, which was performed in ABAQUS. In the numerical model, the adhesive was created as a cohesive element. Furthermore the properties of the modeled adhesive was based on the experimental results for respective adhesive. The experimental results showed that both adhesives managed the estimated shear force in the serviceability limit state and the ultimate limit state and yet remained in the elastic region. Sikasil SG-500 turned out to be more flexible while Sika PS specimen resulted in higher shear strength. The short creep tests (30 minutes of a constant load) showed that the deformation increased more for Sika PS than for Sikasil SG-500. However both adhesives had large deformations after only 30 minutes. There was also a difference in the average longitudinal shear strength, where it resulted in 1.06 MPa for Sikasil SG-500 and 2.02 MPa for Sika PS. This study indicates that Sika PS is more preferable in TCC structures than Sikasil SG-500.

This study tested a self-generated utility value intervention aimed at increasing undergraduate statistics students’ motivation and achievement. The intervention was based on Situated Expectancy-Value Theory (Eccles & Wigfield, 2020) and encouraged students to make relevant connections between statistics learning content and their lives, primarily emphasising the content’s usefulness to the student, or utility value. In testing a self-generated utility value intervention within the domain of undergraduate statistics, the study extended research previously conducted in high school and undergraduate sciences (psychology and biology) and replicated Hulleman et al. (2017) which tested the role of frequency of students’ connections between the learning content and their lives in their motivation and achievement. In addition to transferring a self-generated utility value intervention to the domain of statistics, the study’s main contribution was made by investigating the role of connection quality—the quality of utility value connections undergraduate statistics students made between the learning content and their lives in their motivation and achievement. The study used collected data from a blindly randomised longitudinal field experiment conducted with undergraduate business school students from a research-intensive university located in the north-eastern USA. The students were of two differing sections of the same 15-week introductory statistics course. The self-generated utility value intervention consisted of prompts, twice during the semester, which instructed stud¬¬ents to write 2-3 paragraphs in response to. Data collected was comprised of students’ gender, first-generation status, initial/final achievement assessments, pre/post self-reports on motivation (expectancy, cost, intrinsic value, utility value) and connection frequency, and researcher scaled ratings coding on student intervention responses for connection quality. Part I Results from this study suggest that the intervention significantly increased students’ achievement (d = .42)—an approximately 7-percentage point difference between intervention and control group conditions. Furthermore, the intervention was found to be especially effective at increasing at-risk, low initial achievement, students’ motivation (expectancy, d = .54) and achievement (d = .87)—an approximately 14.5-percentage point difference between group conditions. Study results also suggest that the intervention’s impact on at-risk students’ achievement was mediated via motivation increases—through students’ expectancy for success, though, not through students’ utility value. The Part I results were confirmatory of Hulleman et al.’s (2017) findings—the intervention effected students’ achievement, but the pathway of indirect effects traversed through students’ expectancy, not their utility value which Hulleman et al. (2017) and this study both hypothesised it would do instead. Part II Results attempted to explain the intervention’s pathways of effects through expectancy to achievement by creating new measures, connection quality measures. Connection quality measures were constructed to capture students’ utility value more effectively than the self-reported utility value survey measure. This study’s Part II Results suggest that the intervention was found, again, to significantly increase students’ achievement (d = 1.46), but the indirect intervention effects traversed a pathway to affecting students’ achievement, not through their expectancy, but through their utility value (as captured via the newly minted connection quality measures), to their motivation (cost and interest), and then to their achievement. The new connection quality measures, exploratorily, were found to capture students’ utility value more effectively than the self-reported utility value survey measure, enabling the self-generated utility value intervention’s effects on students’ achievement and motivation to be further explained. / Math & Science Education

With the emergence of novel cloud applications and their critical latency demand [1], Quick UDP Internet Connection (QUIC) [2] was proposed as a new transport protocol that is promising to reduce the connection establishment overhead while providing security properties similar to Transport Layer Security (TLS) [3]. However, without an efficient task scheduling mechanism, the high cost for encryption and decryption in QUIC can easily lead to load imbalance among multiple Central Processing Unit (CPU) cores and thus cause a high tail latency. In this paper, we proposed a QUIC connection inter-core migration scheme that can dynamically dispatch QUIC connections among CPU cores while keeping the service continuity. We emulated a scenario where the traffic load on two CPU cores is not even and tried to migrate connections from an overloaded CPU to another idle one. The results showed that the load imbalance can be reduced and both of the two CPU cores can be efficiently utilized. Moreover, the throughput can be improved by around 15% with a set of proper parameters thanks to the inter-core connection migration scheme. It was also revealed that the overhead introduced by the connection inter-core migration mechanism is relatively low when applying the migration to a large connection. / Med uppkomsten av nya molnprogram och deras kritiska latens efterfrågan [1], QUIC [2] föreslogs som ett nytt transportprotokoll som lovar att minska anslutningen etableringskostnader samtidigt som de tillhandahåller säkerhetsfastigheter som liknar TLS [3]. Dock utan en effektiv uppgift schemaläggningsmekanism, den höga kostnaden för kryptering och dekryptering i QUIC kan enkelt leda till obalans mellan flera CPU kärnor och orsakar därför en hög svanslatens. I detta dokument föreslog vi a QUIC-anslutning mellan kärnmigrationsschema som dynamiskt kan skickas SNABBA anslutningar mellan CPU kärnor samtidigt som servicekontinuiteten bibehålls. Vi emulerat ett scenario där trafikbelastningen på två CPU kärnor inte är jämn och försökte migrera anslutningar från en överbelastad CPU till en annan inaktiv. De resultaten visade att belastningsobalansen kan reduceras och båda de två CPU: erna kärnor kan utnyttjas effektivt. Dessutom kan genomströmningen förbättras med cirka 15% med en uppsättning korrekta parametrar tack vare anslutningen mellan kärnor migrationsschema. Det avslöjades också att de omkostnader som infördes av anslutning mellan kärnmigrationsmekanismen är relativt låg vid ansökan migreringen till en stor anslutning.

<p>In safety-related nuclear structures, steel-plate composite (SC) walls are often used in combination with reinforced concrete (RC) walls or foundations. The design demands need to be transferred between the two different structural systems through appropriate connections without connection failure, which is often associated with brittle failure mode. This study presents a design procedure developed for mechanical connections between SC and RC walls. This procedure implements the full-strength connection design approach as per Specifications for Safety-Related Steel Structures for Nuclear Facilities, AISC N690-18, which requires connections to be stronger than the weaker of the connected walls. The study also presents the results from experimental and numerical investigations conducted to verify the structural performance of the full-strength SC wall-to-RC wall mechanical connection.</p> <p>The experimental program involved testing six mechanical connections comprising four full-scale and two scaled specimens. The four specimens subjected to out-of-plane moment (OOPM) and out-of-plane shear (OOPV) represented a unit cell of a typical wall in a nuclear facility. The remaining two specimens subjected to in-plane shear (IPV) were scaled (1:3) to facilitate testing using the existing loading setup. Two specimens were tested for each loading scenario. The two specimens per loading case were differentiated by longitudinal rebar-to-baseplate connection plans: coupler (C) and double nut (DN). The performance, strength, ductility, and failure mode of the proposed mechanical connection were evaluated based on the experimental observations.</p> <p>The observed governing failure mode of all test specimens was either RC wall flexural yielding or RC wall shear failure. The connection region steel plates (tie plates, wing plates, and baseplates) remained within their elastic range until failure ensuring energy dissipation away from the connection region. Additionally, the wing plates and baseplates strains remained comparatively lower than the tie plate strain values. This was attributed to the contribution of concrete during the force transfer between the two structural elements indicating that the proposed connection design procedure is suitable and conservative for SC wall-to-RC wall mechanical connections.</p> <p>Three-dimensional (3D) finite element models (FEM) were developed and benchmarked against the experimental data to gain an additional insight into the connection behavior. Parametric studies were conducted to compensate for the limited experimental database and evaluate the influence of design parameters such as wall thickness and RC wall longitudinal reinforcement layers on the performance of the designed mechanical connection. Numerically predicted results compared favorably with experimental observations. The recommended design procedure is intended to help designers consider mechanically connecting SC-RC walls where non-contact lap splicing is not feasible and in an attempt to utilize the potential for accelerated construction time and enhanced structural performance of SC walls.</p> <p><br></p>

A case study which examines the agreement between prediction and data is performed for three, complex interplanetary shocks which were detected at the Sun-Earth Lagrange point L1 and induced moderate to intense geomagnetic storms. We use model output from previous runs of the coupled coronal-heliosphere WSA-Enlil+Cone model, available through the Community Coordinated Modeling Center (CCMC), and in-situ data from the OMNI data set. Code written in MATLAB is used to compare the model output with the in-situ measurements of the interplanetary magnetic field as well as the density, speed and temperature of the solar wind. In addition, the difference between the predicted and actual shock arrival time is computed and regions of potential temperature depression are identified. A considerable discrepancy is found between data and model for the studied events. The main reason is deemed to be an inadequate representation of the ambient solar wind as well as the complex interactions between interplanetary coronal mass ejections and corotating interaction regions. We suggest future steps to be taken for the further development of the model as well as for the general understanding of space weather and the Sun-Earth connection. / Denna fallstudie undersöker överensstämmelsen mellan modell och data för tre interplanetära chockvågor, som kunde detekteras vid jordens Lagrangepunkt 1, och som orsakade geomagnetiska stormar av måttlig till kraftig styrka. Vi använder oss av tidigare genomförda körningar av den sammansatta WSA-Enlil+Cone modellen, som avbildar fortplantningen av temporära störningar med ursprung i solens korona, såsom koronamassutkastningar, ut i heliosfären. Modellen gjordes tillgänglig av Community Coordinated Modeling Center (CCMC) och datan inhämtades från OMNI. Kod skriven i MATLAB nyttjades för att göra en jämförelse mellan modell och faktiska mätningar av det interplanetära magnetfältet samt solvindens hastighet, densitet och temperatur. Utöver detta, beräknas också skillnaden mellan förväntad och faktisk ankomsttid av respektive interplanetär chock, och tidsperioder med en temperatursänkning utöver det normala identifieras. Vi finner en omfattande avvikelse mellan modell och data, i synnerhet för de fall där på varandra följande koronamassutkastningar förväntas interagera eller rent av slås ihop samt för uppskattningen av den omgivande solvindens egenskaper och det interplanetära fältet under pågående geomagnetisk störning. Interaktionen mellan koronamassutkastningar och närliggande ko-roterande interaktionsregioner har ej heller återskapats väl av modellen ifråga. Slutligen ger vi förslag på möjliga, framtida åtgärder som kan bör tas i åtanke vid konstruerandet av framtida versioner av nämnda modell, liksom för den allmänna förståelsen för rymdvädrets inverkan på Jorden.

In an attempt to address the disregard for holistic practices in much of Western culture and education, I present yoga as an alternative learning strategy to banking instruction often used in current educational practices. Specifically, I examine Hatha yoga in its content and methodology as a platform from which K-5 students can learn to engage in strategies of mindfulness practices to counter underlying causes of cognitive and behavioral problems seen in many public schools. Drawing from research based in the field of somatics and feminist/critical pedagogy, I articulate a yoga curriculum that supports bodily knowing and encourages the cultivation of self-/social awareness and empathy. I organize my findings into two separate curriculums: one for students in the grades K-2 and another for grades 3-5. Each curriculum is further divided into three units to include learning objectives, themed activities, lists of skills and concepts, and specific notes for instructors that take into consideration the motor and cognitive developmental patterns of students at each grade level. By establishing a curriculum consistent with current curricular standards in California, my hope is that policy-makers, administrators, educators, and parents alike will take into consideration the importance of embodied knowledge in the classroom and further advocate for its role in public schools.

Cross frames and diaphragms are essential to the stability of straight steel girder bridge systems as they help to resist lateral torsional buckling during construction and horizontal loading conditions. In skewed bridge systems, cross frames are often oriented parallel to the supports and hence, at an angle to the girder. To facilitate construction fit-up, plates, bent to match the skew angle, form the cross frame to stiffener connection. While the bent plate connection is a simple solution, it could introduce undesirable flexibility into the system, potentially compromising the effective brace stiffness. A proposed detail utilizing half pipe stiffeners may provide enhanced structural performance, while possibly reducing overall fabrication costs. Field and laboratory tests to determine the stiffness of both connection types are presented in the thesis. / text

Ductile plastic hinge zones in beams of reinforced concrete frames are known to incur extensive damage and elongate. This ‘beam elongation’ can inflict serious damage to adjacent floor diaphragms, raising concerns of life safety. In light of this, the slotted reinforced concrete beam was investigated as a promising non-tearing floor substitute for conventional design. It consists of a conventional reinforced concrete beam, modified with a narrow vertical slot adjacent to the column face, running approximately three-quarters of the beam depth. Seismic rotations occur about the remaining concrete “top-hinge”, such that deformations are concentrated in the bottom bars of the beam, away from the floor slab, and beam elongation is minimised. The inclusion of the slot raised several design issues which needed to be addressed. These were the shear transfer across the top-hinge, buckling of bottom longitudinal reinforcement, low cycle fatigue, bond anchorage of reinforcement in interior joints, interior joint design, detailing with floor units and beam torsion resulting from eccentric floor gravity loads. These issues were conceptually investigated in this project. It was found that most issues could be resolved by providing additional reinforcement and/or specifying alternative detailing. As part of the experimental investigation, quasi-static cyclic tests were performed on in-plane beam-column joint subassemblies. Specimens tested included exterior and interior joint subassemblies with slotted-beams and a conventional exterior joint as a benchmark. This was followed by a test on a slotted-beam interior joint subassembly with precast floor units and imposed gravity load. Experimental tests revealed significant reductions in damage to both the beam and floor when compared to conventional beams. Issues of bar buckling, bond-slip and altered joint behaviour were also highlighted, but were resolved in the final test. A simple analytical procedure to predict the moment-rotation response of slotted-beams was developed and verified with experimental results. This was used to perform sensitivity studies to determine appropriate limits for the concrete top-hinge depth, top-to-bottom reinforcement ratio and depth of diagonal shear reinforcement. For the numerical investigation, a multi-spring model was developed to represent the flexural response of slotted-beams. This was verified with experimental tests and implemented into a five-storey, three-bay frame for earthquake time history analyses. To provide a benchmark, a conventional frame was also setup using the plastic hinge element developed by Peng (2009). Time history analyses showed that the slotted-beam frame response was very similar to the response of a conventional frame. Due to greater hysteretic damping, there was a slight reduction in the average interstorey drift and lateral displacement envelopes. The slotted-beam frame also exhibited 40% smaller residual drifts than the conventional frame. The research carried out in this thesis showed slotted reinforced concrete beams to be an effective non-tearing floor solution, which could provide a simple and practical substitute for conventional reinforced concrete design.