An inverted base pavement is a new pavement structure that consists of an unbound aggregate base between a stiff cement-treated foundation layer and a thin asphalt cover. Unlike conventional pavements which rely on upper stiff layers to bear and spread traffic loads, the unbound aggregate inter-layer in an inverted base pavement plays a major role in the mechanical response of the pavement structure. Traditional empirical pavement design methods rely on rules developed through long-term experience with conventional flexible or rigid pavement structures. The boundaries imposed on the unbound aggregate base in an inverted pavement structure change radically from those in conventional pavements. Therefore, current empirically derived design methods are unsuitable for the analysis of inverted base pavements. The present work documents a comprehensive experimental study on a full-scale inverted pavement test section built near LaGrange, Georgia. A detailed description of the mechanical behavior of the test section before, during and after construction provides critically needed understanding of the internal behavior and macro-scale performance of this pavement structure. Given the critical role of the unbound aggregate base and its proximity to the surface, a new field test was developed to characterize the stress-dependent stiffness of the as-built layer. A complementary numerical study that incorporates state-of-the-art concepts in constitutive modeling of unbound aggregates is used to analyze experimental results and to develop preliminary guidelines for inverted base pavement design. Simulation results show that an inverted pavement can deliver superior rutting resistance compared to a conventional flexible pavement structure with the same fatigue life. Furthermore, results show that an inverted base pavement structure can exceed the structural capacity of conventional flexible pavement designs for three typical road types both in rutting and fatigue while saving up to 40% of the initial construction costs.

Strut-and-tie modeling (STM) is a versatile, lower-bound (i.e. conservative) design method for reinforced concrete structural components. Uncertainty expressed by engineers related to the implementation of existing STM code specifications as well as a growing inventory of distressed in-service bent caps exhibiting diagonal cracking was the impetus for the Texas Department of Transportation (TxDOT) to fund research project 0-5253, D-Region Strength and Serviceability Design, and the current implementation project (5-5253-01). As part of these projects, simple, accurate STM specifications were developed. This thesis acts as a guidebook for application of the proposed specifications and is intended to clarify any remaining uncertainties associated with strut-and-tie modeling. A series of five detailed design examples feature the application of the STM specifications. A brief overview of each design example is provided below. The examples are prefaced with a review of the theoretical background and fundamental design process of STM (Chapter 2). • Example 1: Five-Column Bent Cap of a Skewed Bridge - This design example serves as an introduction to the application of STM. Challenges are introduced by the bridge’s skew and complicated loading pattern. A clear procedure for defining relatively complex nodal geometries is presented. • Example 2: Cantilever Bent Cap - A strut-and-tie model is developed to represent the flow of forces around a frame corner subjected to closing loads. The design and detailing of a curved-bar node at the outside of the frame corner is described. • Example 3a: Inverted-T Straddle Bent Cap (Moment Frame) - An inverted-T straddle bent cap is modeled as a component within a moment frame. Bottom-chord (ledge) loading of the inverted-T necessitates the use of local STMs to model the flow of forces through the bent cap’s cross section. • Example 3b: Inverted-T Straddle Bent Cap (Simply Supported) - The inverted-T bent cap of Example 3a is designed as a member that is simply supported at the columns. • Example 4: Drilled-Shaft Footing - Three-dimensional STMs are developed to properly model the flow of forces through a deep drilled-shaft footing. Two unique load cases are considered to familiarize the designer with the development of such models. / text

Significant diagonal cracking in reinforced concrete inverted-T straddle bent caps has been reported throughout the State of Texas. Many of the distressed structures were recently constructed and all have been in service for less than two decades. The unique nature of the problem prompted a more detailed look into the design and behavior of such structural components. Strut-and-tie modeling is currently recommended for design of deep (rectangular) beams, but its application to more complex structures has not been fully explored. Due to concerns with current design provisions the application of strut-and-tie modeling to inverted-T beams was investigated along with serviceability-related considerations in this dissertation. An experimental study was conducted in which thirty-three reinforced concrete inverted-T beam tests were conducted. The effects of the following variables were evaluated: ledge depth and length, quantity of web reinforcement, number of point loads, member depth, and shear span-to-depth ratio. A strut-and-tie design method proposed by Birrcher et. al (2009), initially calibrated for compression-chord loaded deep beams, was investigated. It was concluded that the strut-and-tie method was a simple and accurate design method, and it was recommended for use in inverted-T beam design. A vi recommendation was also made for the amount of minimum web reinforcement needed for strength and serviceability considerations. A simple service-load check was proposed for the purpose of limiting diagonal cracking under service loads. Finally, a chart was created to aid in the evaluation of distressed, diagonally-cracked inverted-T bent caps in the field. / text

Significant diagonal cracking in reinforced concrete inverted-T (IT) straddle bent caps has been reported throughout the State of Texas. Many of the distressed structures were recently constructed and have generally been in service for less than two decades. The unique nature of the problem prompted a closer look into the design and behavior of such structural components. A preliminary investigation highlighted outdated design requirements and a scarcity of experimental investigations pertaining to inverted-T bent caps. This research project (TxDOT Project 0-6416, Shear Cracking in Inverted-T Straddle Bents) aims to improve current understanding of the behavior of inverted-T caps, while providing updated design provisions. In order to develop strength and serviceability guidelines for inverted-T beams, an extensive experimental program was developed. This series of large scale tests was used to evaluate the strength and serviceability of IT deep beams in relation to the following parameters – shear span-to-depth (a/d) ratio, web reinforcement ratio, ledge height, ledge length, number of point loads, and member depth. This report focuses mainly on results from a first series of tests conducted within this experimental program. / text

Chromosomal rearrangements occur in all organisms and are important both in the evolution of species and in pathology. In this dissertation I show that in Saccharomyces cerevisiae, or budding yeast, one type of chromosomal rearrangement occurs when inverted repeats fuse, likely during DNA replication by a novel mechanism termed "faulty template switching". This fusion can lead to the formation of either a dicentric or acentric chromosome, depending on the direction of the replication fork. Dicentric chromosomes are inherently unstable due to their abnormal number of centromeres, and thus undergo additional chromosomal rearrangements and chromosome loss.

The restoration of arm-free standing in paraplegic individuals can be accomplished with the help of functional electrical stimulation (FES). The key component of such a system is a controller that can modulate FES induced muscle contractions in real-time, such that artificially produced forces in the legs and abdominal muscles are able to generate stable standing posture. A 57 year-old individual with chronic ASIA-A (American Spinal Injury Association), T3/4 level spinal cord injury (SCI) participated in this study. The objective was to determine if a proportional-derivative (PD) or proportional-integral-derivative (PID) controller could be used to regulate FES induced muscle contractions in the ankle joint to allow it to maintain balance of the entire body during quiet standing, while exhibiting physiological dynamics seen in able-bodied individuals while doing so.

Kabutės – dar menkai tetyrinėtas skyrybos ženklas, keliantis sunkumų ne tik autoriams ar redaktoriams, bet ir skaitytojams. Kabučių šiandienėje spaudoje yra išties daug, tad kyla klausimas, ar jos visuomet vartojamos pagrįstai. Taigi šiuo darbu buvo siekiama aptarti kabučių funkcijas ir, jomis remiantis, nustatyti kabučių vartojimo pagrįstumą Lietuvos dienraščiuose, išeivijos spaudoje ir mokslo populiarinamuosiuose žurnaluose. Be to, siekta statistiškai nustatyti, ar skiriasi Lietuvos ir išeivijos spaudos bei mokslo populiarinamojo postilio žurnalų nemotyvuotas kabučių vartojimas ir ar tam turi įtakos funkcinis stilius. Kabutėmis motyvuotai skiriama tiesioginė kalba, citatos ir jų atmainos, pavadinimai ir nenorminė leksika. Pačiam autoriui siūloma rinktis, ar skirti kabutėmis okazionalizmus, eufeminę leksiką, ironiją, ar ne. Nagrinėtoje spaudoje nemotyvuotai kabutėmis skiriami ne tik perkeltinės reikšmės žodžiai, kurių reikšmė kaip perkeltinė yra užfiksuota žodyne, frazeologizmai, posakiai, įvairūs tropai (metaforos, metonimijos, personifikacijos), su įvedamaisiais žodžiais rašomi bendrinei kalbai teiktini žodžiai, pravardės, bet net ir uzualinę reikšmę turintys žodžiai, įvairūs simboliai. Daugiausia nepagrįstai kabutes vartoja išeivijos laikraštis „Amerikos lietuvis“, o mažiausiai nemotyvuotai pavartotų kabučių rasta žurnale „Gamta“. Išaiškėjo, kad vis dėlto vartojamų kabučių motyvacija nuo funkcinio stiliaus nepriklauso, nes mokslo populiarinamojo postilio žurnale „Mokslas... [toliau žr. visą tekstą] / Inverted commas are punctuation marks that have been subject to little research and cause difficulties not only for authors and editors, but also for readers. The use of inverted commas in today’s press is really abundant, therefore raising the question as to whether their use is always reasonable. This work aims to discuss the functions of inverted commas and on this basis to identify the validity of the use of inverted commas in the dailies of Lithuania, the press of Lithuanian immigrants abroad, and magazines in popular scientific sub-style. In addition, it was sought to identify statistically whether there was any difference in the unjustified use of inverted commas between the Lithuanian press and magazines in popular scientific sub-style and those in the Lithuanian language abroad and whether functional style has any impact on this. The justified use of inverted commas includes direct speech, quotes and variations of quotes, names, and substandard lexis. The author may make a free choice of whether to use inverted commas in the cases of euphemisms, irony, and rarely used words. Research of the press shows that inverted commas are unjustifiably used not only for words that are used in a figurative sense and have the figurative meaning recorded in the dictionary, phraseological units, sayings, various tropes (metaphors, metonymies, and personifications), newly introduced words together with the suggested versions for standard usage, and surnames, but also for words with... [to full text]

Augmented reality (AR) systems that use head mounted displays to overlay synthetic imagery on the user's view of the real world require accurate viewpoint tracking for quality applications. However, achieving accurate registration is one of the most significant unsolved problems within AR systems, particularly during dynamic motions in unprepared environments. As a result, registration error is a major issue hindering the more widespread growth of AR applications. The main objective for this thesis was to improve dynamic orientation tracking of the head using low-cost inertial sensors. The approach taken within this thesis was to extend the excellent static orientation sensing abilities of accelerometers to a dynamic case by utilising a model of head motion. Head motion is modelled by an inverted pendulum, initially for one degree of rotational freedom, but later this is extended to a more general two dimensional case by including a translational freedom of the centre of rotation. However, the inverted pendulum model consists of an unstable coupled set of differential equations which cannot be solved by conventional solution approaches. A unique method is developed which consists of a highly accurate approximated analytical solution to the full non linear tangential ODE. The major advantage of the analytical solution is that it allows a separation of the unstable transient part of the solution from the stable solution. The analytical solution is written directly in terms of the unknown initial conditions. Optimal initial conditions are found that remove the unstable transient part completely by utilising the independent radial ODE. Thus, leaving the required orientation. The methods are validated experimentally with data collected using accelerometers and a physical inverted pendulum apparatus. A range of tests were performed demonstrating the stability of the methods and solution over time and the robust performance to increasing signal frequency, over the range expected for head motion. The key advantage of this accelerometer model-based method is that the orientation remains registered to the gravitational vector, providing a drift free solution that outperforms existing, state of the art, gyroscope based methods. This proof of concept, uses low-cost accelerometer sensors to show significant potential to improve head tracking in dynamic AR environments, such as outdoors.

The current economic situation has severely affected the US road infrastructure and funding has become inadequate for either maintenance or future growth. The inverted base pavement structure is a promising alternative to achieve high quality roads at considerably lower cost than conventional pavements. The proximity of the unbound granular base layer to the tire load makes the response of the granular base critical to the performance of the pavement structure. Therefore extensive material characterization is conducted on the granular materials that make the base. In particular, a true triaxial chamber is developed to study the mechanical response and the stress-dependent stiffness of granular bases compacted at different water contents. A novel method is developed to assess the as-built stress-dependent anisotropic stiffness of granular bases in-situ using both crosshole and uphole test configurations. The two inverted base pavements built in Georgia at the Morgan County quarry haul road and the Lagrange south Loop are tested as part of this study. A nonlinear orthotropic constitutive model is selected to capture the deformational behavior of compacted granular bases. The response of the pavement is analyzed by implementing this constitutive behavior in a three-dimensional finite-element model. Different pavement structures are simulated. It is shown that thin asphalt concrete layers resting directly on granular bases deform as membranes. Finally, numerical simulations are extended to compare inverted base pavements to conventional pavements used in practice. Results highlight the inadequacy of ASSHTO’s structural layer coefficient for the analysis of inverted base pavement structures as well as the potential economic advantages of inverted base pavements.

Abstract When traditional lecture methods prove ineffective, some professors turn to alternative teaching styles. In particular, a flipped or inverted classroom, where students watch conceptual videos before coming to class and use class time for application and fine tuning of these concepts has become popular in recent years. However, little consensus exists on the efficacy of these strategies. The purpose of this study is to determine whether a flipped classroom structure implemented in a medical school course successfully improved student performance. To do so, I analyzed exam data from the University of Nebraska Medical Center before and after implementation of the alternate method in a course, and compared to another class taken in the same semester that did not undergo any change in teaching style. In addition, I investigated differences among particular student academic and demographic groups that may benefit from learning in an inverted classroom environment. My findings suggest that the flipped classroom strategy is advantageous to student learning and can significantly increase the performance of particular divisions of students such as those with lower-than-average MCAT scores and students who performed highly in their first year of medical school.