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I nuläget finns flertalet företag som tillverkar distanser som är kompatibla med originalimplantat. Det finns dock ingen evidens för att dessa distanser är likvärdiga med originaldistanser när de används på originalimplantat. God passform hos implantatkomponenter är en viktig faktor för att undvika biologiska och tekniska komplikationer.Syftet med den här studien var att jämföra passformen mellan originaldistans och originlimplantat med kompatibel kopiadistans och originalimplantat.Material och metod: Fem originaldistanser och fem kompatibla distanser skruvades till originalimplantat. Provkroppar bäddades in och delade på mitten för att sedan analyseras i ljusmikroskop och SEM. Där mättes kontaktytans längd och mellanrummet mellan implantat och distans och distans och distansskruv. All data analyserades i SPSS.Resultatet: Implantatkoplex med kopiadistans hade fem gånger kortare kontaktyta mellan komponenterna och mellanrummet var större, vilket ger en försämrad stabilitet under andvändning. Analysen av distansskruvens yta visade morfologiska skillnader mot den inre ytan av distansen vilket kan leda till deformation och/eller fraktur av skruven.Konklusion: Användning av lågpris kopiadistanser till Astra originalimplantat kan leda till signifikant avvikande passform hos distansen och en lägre tolerans för stress hos distansskruven. / Nowadays there exist different abutments from different companies that are compatible to a certain manufacturer implant. But no scientific evidence exists on whether the fit of the compatible abutments are comparable to that of the genuine abutments when connected to the genuine implants. God fitting of implant components is an essential factor to avoid microgap formation in implant-abutment interface due to microgaps lead to biological and biomechanical complications. The aim of this study was to compare interface in original abutment and copy compatible abutment connected to original implant.Material and Methods: Five original abutments and five compatible abutments were connected to the original implants. The complex were sectioned in the middle and thereafter analyzed in a light microscope and SEM by measuring contact length and interface thickness between the implant and abutment and also between the abutment and abutment screw. All data was analyzed with SPSS-program.Result: Compatible implant complex had about five times shorter contact surface between components and interface was thicker which gives less stability under clinical function. The analyze of screw-abutment interface showed morphologic differences with the inner surface of the abutment which could lead to screw deformation and even fracture.Conclusion: Using low-cost compatible abutments connected to original Astra implants could lead to significant fit discrepancy of the copy abutments and lower stress tolerance in the abutment screw.

On-blade hot wire anemometry measurements as well as far field sound measurements at several receiving angles have been previously made for a rotor partially embedded in a boundary layer. The inflow distortion effect on the rotor angle of attack distribution was determined directly from the on-blade measurements, and was found to minimally affect the angle of attack at the blade tips and lower the angle attack in the rotor disk plane as the radial location moves towards the hub. A narrow, sharp increase in angle of attack as the rotor blades approached the wall was also observed, indicating blade interaction with flow reversal. The haystacking pattern, or spectral humps that appear at multiples of the blade passage frequency, was studied for a wide range of advance ratios. At high advance ratios, evidence of vortex shedding from the blade trailing edges was observed. For low advance ratios, the haystacks narrowed, became more symmetric and increased in number. A method of determining the average acoustic signature of an eddy passage through a rotor was developed from time delay aligning multiple microphone signals and eddy passages detected using the continuous wavelet transform. It was found that the eddy passage signatures were similar to a cosine wave with a Gaussian window. It was also found that normalized timescales obtained directly from the eddy passage signatures remained somewhat constant with advance ratio, but increases slightly for fixed free stream velocities with increasing rotor RPM. For advance ratios less than 0.6, the eddy passage signatures were dominated by a tonal component due to rotor ingestion of misaligned flow caused by a boundary layer separation at the wall. This indicates that flow reversal known as the Pirouette Effect is interacting with the rotor blades. / Master of Science

Allochthonous nutrients were monitored during three storm events on one of the major tributaries entering the shallow VPI&SU Duck Ponds. Autochthonous nutrients were monitored for a period of ten months. During these storms, the stormwater runoff contributed large amounts of organic matter and fertilizer nutrients that settled in the ponds and during anoxic conditions, recycled to stimulate algal blooms. Alum was applied to one pond to reduce internal cycling of nutrients. A 25 mg/L dose of alum produced an aluminum hydroxide floc that settled to the bottom and afterwards, lowered othophosphate-phosphorus concentrations below 10 µg/L in the water column. The longevity of the one-time treatment in reducing the sediment-phosphate release rate is unknown because the monitoring program was not continued beyond July of 1988. A pond-treatment program involving copper sulfate was initiated to control algal blooms consisting mainly of the green alga, Chlamydomonas. Based on the complexing properties of the water, such as alkalinity and humics, a copper sulfate dose of 13.6 kg was determined to be a safe and effective dose that reduced algal densities but did not result in any visible adverse effects upon other aquatic life. Both of the pond management schemes were designed to aid managers of small urban ponds who have low operating budgets and a lack of technical equipment. / Master of Science

The objective of this study was to develop a voice interface for the on-line catalog of VTLS. Three major components of the system, namely, voice recognition system, text-to-speech synthesizer, and screen review program, were identified. These components were selected after a comparative study of several commercially available systems. Once the components were selected they were integrated to form a complete voice recognition and synthesis system. Using this system, a voice interface was realized to suit the operations of VTLS. A telephone interface for the system was investigated and recommendations were made for future research. / Master of Science

This study examines the stressful responses of faculty/staff and students after experiencing the April 16, 2007 school shootings at Virginia Tech. Understanding people's responses to trauma not only assists in more knowledge about what is stressful after a traumatic event but also may facilitate the finessing of tools and strategies for resilience and recovery in the aftermath of trauma. After investigating stressful responses to the April 16, 2007 shootings at Virginia Tech, and in particular those with probable PTSD (posttraumatic stress disorder), I found it was not always necessary to meet the "stressor" A criterion of PTSD. This is crucial because the "stressor" criterion A of PTSD is required to receive the diagnosis of PTSD. Although I found subtle stress differences for women compared to men, and faculty/staff compared to students, none of the differences were statistically significant. This research additionally contributes to the literature by detailing a profile of stressors for both faculty/staff and students in the aftermath of the worst college campus shooting in U.S. history to date. Findings suggest future research should examine the "stressor" criterion A of PTSD as well as the full spectrum of stressful responses both in the "immediate" and "delayed" aftermath of trauma(s). / Ph. D.

The focus of the project is to provide an elegant, spiritual chapel for Virginia Tech that provides space for people of all religions while offering indoor and outdoor spaces for meditation. The differentiation of spaces is established through the use of light, color and form. The light is structured to utilize the color system devised from Goethe's Color theory. / Master of Architecture

In the aftermath of the rampage at Virginia Tech, the community experienced a surge of social solidarity. Using a longitudinal study of 478 students, this thesis examines the impact of attitudinal solidarity on well-being nine months after the shootings. In particular, this study focuses on the interaction effects of sex and solidarity on later well-being, providing a theoretical and empirical basis for understanding the connections between these factors. Quantitative analysis, conducted using linear regression with interaction variables, found that social solidarity four months after the shootings positively and significantly predicted well-being nine months after the shootings. The predictive power, however, was stratified by sex; women experienced diminished benefits of solidarity relative to their male counterparts. The literature suggests that this disparity may be attributed to additional social burdens placed on women after traumatic stressors. Other negative predictors of well-being include knowing victims and conversations with the media in the week after the attacks, This research has the potential to shed light on effective methods of responding to community-level trauma and may provide guidance to future policy-makers in when faced with these challenging situations. / Master of Science

In the legal domain, documents of various types are created in connection with a particular case, such as testimony of people, transcripts, depositions, memos, and emails. Deposition transcripts are one such type of legal document, which consists of conversations between the different parties in the legal proceedings that are recorded by a court reporter. Court reporting has been traced back to 63 B.C. It has transformed from the initial scripts of ``Cuneiform", ``Running Script", and ``Grass Script" to Certified Access Real-time Translation (CART). Since the boom of digitization, there has been a shift to storing these in the PDF/A format. Deposition transcripts are in the form of question-answer (QA) pairs and can be quite lengthy for common people to read. This gives us a need to develop some automatic text-summarization method for the same. The present-day summarization systems do not support this form of text, entailing a need to process them. This creates a need to parse such documents and extract QA pairs as well as any relevant supporting information. These QA pairs can then be converted into complete canonical sentences, i.e., in a declarative form, from which we could extract some insights and use for further downstream tasks. This work investigates the same, as well as using deep-learning techniques for such transformations. / Master of Science / In the legal domain, documents of various types are created in connection with a particular case, such as the testimony of people, transcripts, memos, and emails. Deposition transcripts are one such type of legal document, which consists of conversations between a lawyer and one of the parties in the legal proceedings, captured by a court reporter. Since the boom of digitization, there has been a shift to storing these in the PDF/A format. Deposition transcripts are in the form of question-answer (QA) pairs and can be quite lengthy. Though automatic summarization could help, present-day systems do not work well with such texts. This creates a need to parse these documents and extract QA pairs as well as any relevant supporting information. The QA pairs can then be converted into canonical sentences, i.e., in a declarative form, from which we could extract some insights and support downstream tasks. This work describes these conversions, as well as using deep-learning techniques for such transformations.