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Guarino Guarini's SS. Sindone Chapel : between reliquary and cenotaphDebanné, Janine January 1995 (has links)
No description available.
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Performance of Multitone Direct Sequence Spread Spectrum in the Presence of Imperfect Carrier SynchronizationLi, Hongxiang January 2004 (has links)
No description available.
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An investigation of reheat cracking in the weld heat affected zone of type 347 stainless steelPhung-on, Isaratat 19 September 2007 (has links)
No description available.
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Optimum linear single user detection in direct-sequence spread-spectrum multiple access systemsAue, Volker 10 July 2009 (has links)
After Qualcomm's proposal of the IS-95 standard, <i>code-division multiple access</i> (CDMA) gained popularity as an alternative multiple-access scheme in cellular and <i>personal communication systems</i> (PCS). Besides the advantage of allowing asynchronous operation of the users, CDMA <i>direct-sequence spread spectrum</i> (DS-SS) offers resistance to frequency selective fading and graceful degradation of the performance as the number of users increases.
Orthogonality of the signals in time-division multiple access and frequency-division multiple access is inherent from the nature of the multiple access scheme. In a CDMA system, orthogonality of the signals is not guaranteed in general. Consequently, the performance of conventional correlation receivers suffers.
Sub-optimum receivers which use knowledge of the interfering signals have been investigated by other researchers. These receivers attempt to cancel the multi-user interference by despreading the interfering users. Hence, these receivers require knowledge about all the spreading codes, amplitude levels, and signal timing, and are, in general, computationally intensive.
In this thesis, a technique is presented for which a high degree of interference rejection can be obtained without the necessity of despreading each user. It is shown that exploiting spectral correlation can help mitigate the effects of the multiple-access interference. If <i>code-on-pulse</i> DS-SS modulation is used, a cyclic form of the Wiener filter provides substantial improvements in performance in terms of bit error rate and user capacity. Furthermore, it is shown, that a special error-criterion should be used to adapt the weights of the filter.
The computational complexity of the receiver is equivalent to that of conventional equalizers. / Master of Science
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Integration of Insoluble and Soluble Dopants into Steel Using Laser Powder Bed FusionSperry, McKay Goodman 26 June 2023 (has links) (PDF)
Laser Powder Bed Fusion (LPBF) is an Additive Manufacturing (AM) method whereby complex parts can be built to near net geometry in an automated environment. Parts formed by LPBF have excellent properties and require little post-processing. While LPBF allows for creative designs to reduce weight and part count by integrating sub-components of assemblies, designers are limited to one material within any LPBF print. Although various materials can be used in LPBF, metals are of special interest to many industrial customers due to their high strength and toughness. The metals commonly used for LPBF include iron, aluminum, and titanium alloys. These alloys are generally designed to fulfill specific needs and even small variations in composition are detrimental to the functionality. However, some alloys are intentionally modified to achieve specific results. For example, Yttria is dispersed in stainless steel to enhance its resistance to radiation damage. The sensitivity of metal alloys to small changes in composition can be exploited to change the properties of LPBF material within a single print. An en-situ doping technique, which is under development, allows for the introduction of small quantities of liquid-suspended additives to any part of the powder bed. The liquid is then evaporated, and these additives integrate with the solid material upon laser fusion to change the properties of the base material. In this thesis, steel-insoluble (zirconia) and soluble (carbon) dopants are introduced into multi-layer parts formed by LPBF. Zirconia significantly increased the porosity of the steel with continuous pores which disrupt the columnar grain structure. The majority of the added zirconia segregated to the outer surface and porous surfaces within the bulk. Although hardness did not increase as expected, the porosity can aid in osseointegration when used for implants, or as a reduced-conductivity thermal barrier in heat sensitive applications. Carbon-doped samples, on the other hand, had nearly 30% increased hardness and more homogeneous microstructure than unmodified material. Hardened surfaces may be a valuable tool for designers who require wear resistance. Although porosity increased from ~0% to over 10% in the worst case, modified parameters resulted in only 1% porosity. The data indicate that changing the processing conditions affects porosity, so the amount of porosity could be adjusted. Finally, carbon was shown to create preferential etching which enables easy removal of support structures. Supports doped with carbon to promote sensitization and etched in an electrolyte bath either broke free without tension, or using no more than 20% of the force required to remove unmodified supports. This is a valuable step for reducing the post-processing required of many LPBF designs.
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Studie om individers kontrastkänslighet och preferenser för horisontell och vertikal belysningsstyrka / A Study about individual contrast sensitivity and preferences for horizontal and vertical lighting intensityFolkesson, Phliip, Kjellström, Andreas January 2009 (has links)
<p>The purpose of this study is to survey and evaluate if the individual contrast sensitivity and preferences for horizontal and vertical lighting level correspond to the values that standard SS-EN 12464-1 recommends for the workplace- and surrounding light levels.</p><p>This study examines if lighting should be adapted after the individuals’ need or if a general value can be found that will cover every individuals’ need for a workplace and surrounding light level. This study also examines if parameters like sex, age and/or glasses/lenses have an effect on the amount of lighting that the test subjects need. Lastly we compared the values concerning the relationship between workplace- and surrounding light levels with standard SS-EN 12464-1’s recommendations.</p><p>The study is carried out with an experimental design that surveys 220 test subjects who were chosen by a selection of convenience. The test subjects did perform a test where they estimated their individual need for lighting in office environments regarding lighting for workplace and its surroundings. Every test subject carried out the test where they repeated the same attempt three times, to establish if the individual lighting need oscillated or if it was constant, whereupon the results were analyzed, compiled and compared to standard SS-EN 12464-1.</p><p>The results show that the minim- and maxim value for the test subjects is between 70 – 4300 lux. The result varies with different parameters such as sex, age and glasses/lenses. We could also state that the relationship between workplace- and surrounding light levels is slightly higher than what standard SS-EN 12464-1 recommends, which should be taken into consideration when planning future lighting constructions.</p><p>Based on the results in this study, our conclusion is that standard SS-EN 12464-1 does not cover the needs on the comfort levels that the test subjects indicated. The values that the test subjects indicated differ from the values that standard SS-EN 12464-1 recommends.</p><p>Since there is a huge spread of the experienced need for lighting between individuals and age groups, we draw the conclusion that general values of measure can’t be applied as a standard on neither workplace- nor surrounding light levels. To fulfill the needs that users have, the lighting construction should be adapted for the individual and give a lighting flood that will fill the individual needs for workplace lighting.</p>
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Život pod Goetheho dubem. Koncentrační tábor Buchenwald v letech 1937-1945 / Life under the Goetheʼs Oak. The Concentration Camp Buchenwald in 1937-1945Diviš, Jakub January 2014 (has links)
The theme and primary purpose of this thesis is illustration everyday life in the concentration camp Buchenwald. Buchenwald was a concentration camp where the Nazis imprisoned a lagre number of citizens of the Protectorate of Bohemia and Moravia. The thesis will primary consist of three categories. First of all it is the issue of "the space", in which will be incorporated a brief outline of the development of concentration camps in Germany before the war, the function of administrative, technical and military buildings of SS units. Another theme of the thesis points to the physical labor of prisoners, which was daily content during their stay in a concentration camp. The purpose of their work should lead to rapid death with the lowest cost of their meals. In favor of or against the prisoners decided ideological-political, and economic aspects of the later mode. The concept of work in the Nazi concentration camps in successive years significantly changed, which were causing the preparations for war and the later development of the war conflict itself. The third theme contents the social relations and cultural life of the prisoners, which refer to the human adaptability in these inhuman conditions. In an effort to describe social days coexistence in this concentration camp is put emphasis on the...
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OLYCKSLASTER I ETT PREFABRICERAT FLERBOSTADSHUS / ACCIDENTAL ACTIONS IN A PRECAST CONCRETE BUILDINGBertilsson, Erik, Latifi, Egzon January 2019 (has links)
Det här examensarbetet går ut på att jämföra EKS 11 och SS-EN 1991-1-7 olika beräkningsmodeller för olyckslaster. Ifall en byggnad endast har ett trapphus som enda nödutgång krävs det att den dimensioneras för olyckslaster. Dessa olyckslaster delas upp i två olika grupper, kända- och okända olyckslaster. Kända olyckslaster är exempelvis påkörning när byggnaden ligger nära en väg och explosion ifall det finns exempelvis gasledningar i byggnaden. Okända olyckslaster är de laster där man inte kan dimensionera för ett exakt värde. Istället dimensionerar man för att minska konsekvenserna av lasten där främsta alternativet är att använda de krav som ställs på väsentliga bärverksdelar och applicera dem på de bärande konstruktionsdelarna. Alternativt när byggnaden inte har gasledningar så kan man beräkna för okända laster genom att dimensionera via värdet som uppkommer från en gasexplosion, 34 kN/m2. Dimensioneringen anpassas efter ett verkligt projekt konstruerat av Structor. Tidigare problem har uppstått vid tolkning av eurokodens beräkningsgång och därför har eks 11 kommit med förtydliganden och med mer triviala lösningar kring olyckslaster. Beräkningsgången för de olika olyckslasterna ser olika ut beroende på om man följer eks 11:s metod eller eurokodens metod. Målet med arbetet är att förtydliga skillnaderna mellan de olika beräkningsgångarna och se vad som ligger till grund för dom. För att kunna skapa en bredare förståelse kring olyckslaster har eurokoden, EKS 11, litteratur och Structor varit till stor hjälp. Examensarbetet är avgränsat till olyckslaster när det bara finns ett trapphus som enda utrymningsväg där det sker en jämförelse mellan EKS 11 och SS-EN 19911-7. Resultatet visar att de två olika beräkningsgångarna ger två olika svar vid beräkning av både kända- och okända laster. Ekvationerna för att räkna fram olyckslaster i de olika standarderna tar hänsyn till olika saker vilket leder till olika resultat. Slutsatsen som går att dra är att det alltid finns olika förutsättningar för varje projekt. Därför bör det göras en riskanalys i projekteringsskedet för att avgöra vilken standard som ska användas för det aktuella projektet. / This dissertation is based on a comparison between the two different procedures on accidental actions in the Swedish norm EKS 11 and SS-EN 1991-1-7. If a construction only has a stairwell as the only emergency exit it requires that accidental actions determines. These accidental actions are categorized mainly to known and unknown accidental actions. Known accidental actions are for example collision by a vehicle or a gas leak from a gas pipe in the building. Unknown accidental actions are those loads that cannot be completely determined. Instead an analyze how to decrease the damage by accidental actions are used. The main approach is to value members as key elements, in effect making them strong enough to withstand a prescribed hazard loading. An alternative if the construction does not have any gas pipes is to use the pressure of 34 kN/m2 to represent the static equivalent from a notional gas explosion. The values in the work are based from a project constructed by the Swedish company Structor. Previously difficulties have occurred while comprehending the Eurocode’s calculation procedures therefore the new Swedish norm EKS have clarified a lot about accidental actions. The calculation procedures results in two different answers between the Eurocode and the Swedish norm EKS. The aim with this dissertation is too clarify the differences between them and perceive the reasons behind it. To be able to have a wider understanding of the subject accidental actions a screening has occurred of the Eurocode, the Swedish norm EKS and literature. The Swedish company Structor has also shared a lot of knowledge on the subject. The dissertation has been limited to accidental actions on stairwells as the only emergency exit and a comparison between the Swedish norm EKS 11 and SS-EN1-7. The outcome of the two different calculations shows two different results of the known and unknown accidental actions. The equations for calculating accidental action in the different standards considerate different things which leads to different results. The conclusion is that there always are different conditions in every project. Therefor a risk assessment should be done before the construction begins to determine which standard is the most suitable for the project.
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MÄTNING AV LUFTTÄTHET I FLERBOSTADSHUS : <em>Gällande krav, praktiskt genomförda mätningar samt en tillämpbar metod</em>Sörensen, Ida January 2009 (has links)
<p>Stor förvirring råder kring hur lufttätheten ska mätas i flerbostadshus. De metoder som finns och de resultat som erhålls vid täthetsprovning av småhus är inte alltid applicerbara på flerbostadshus även om mätenheterna är de samma. Detta föranleder problemställningen för detta examensarbete:</p><p><em>Varför och hur kontrolleras lufttätheten i ett flerbostadshus på ett praktiskt tillämpbart sätt, som också gör det möjligt att jämföra resultat från olika objekt?</em></p><p>Metoderna som används för att undersöka detta är litteraturstudier och samtal med erfarna personer, samt demonstration av en mätmetod i fullskala. En diskussion med initiativtagarna till detta examensarbete leder fram till en rekommenderad metod och en mall för hur detta ska utföras.</p><p>Byggnadsskalets luft-, diffusions- och vindtätning har stor betydelse för en byggnads energianvändning, fuktsäkerhet, termiska komfort och hygien, luftkvalitet, ljudmiljö, spridning av brand samt spridning av luftföroreningar utifrån och in. Lufttätheten är en avgörande faktor både för konstruktionens beständighet och för en god innemiljö i moderna byggnader. Lufttäta hus är dessutom lönsamma i längden för de inblandade aktörerna. På lång sikt även för miljön. Studier som gjorts visar att en byggnads energiåtgång för uppvärmning minskar med nästan 30 % om lufttätheten (egentligen luftgenomsläppligheten) förbättras från 0,8 l/s·m<sup>2</sup> till 0,4 l/s·m<sup>2</sup>. En så stor minskning av energianvändningen kunde inte åstadkommas med andra energiförbättringsåtgärder som undersöktes.</p><p>I Boverkets Regelsamling för byggande, BBR 2008 har kravet på lufttäthet tagits bort till förmån för ett funktionskrav för energianvändningen, under vilken lufttätheten faller in. Regelsamlingens allmänna råd hänvisar till standarden, SS-EN 13829 för bestämning av luftläckage.</p><p>De metoder som idag finns att tillgå för att mäta lufttätheten hos byggnader är spårgasmetoden, täthetsprovning med provisorisk vägg, det egna ventilationssystemet, med mottryck i angränsande utrymmen samt med tryckdörr. Den sistnämnda metoden provades på flerbostadshus i Umeå med goda resultat.</p><p>Observera att resultatet för denna rapport är en mall för mätningsförfarandet och den rekommenderade metoden för att mäta lufttäthet inom NCC i Umeå. Den beskriver en praktiskt tillämpbar metod där resultatet går att jämföra mellan olika objekt. Även en intern mätstorhet som beskriver ytterväggens täthet är framtagen.</p><p>Mätstorheten och standardens relevans diskuteras. Ändringen i BBR från specificerade krav till funktionskrav anses vara kunskapsdrivande. Det förfarande som beskrivs i resultatet har bedömts vara det mest optimala under rådande förhållanden med den standard som finns. En förändring av standarden skulle kunna leda till en bättre metod som ger mer informativt resultat.</p> / <p>There is a great perplexity about how air permeability should be measured in multiple-unit dwellings. The methods available and the obtained results for determination of air permeability in single-dwelling houses are not applicable for multiple-unit dwellings, even if the derived quantities are the same. This causes the problem for this report:</p><p><em>Why and how should the air permeability be determined for a multiple-unit dwelling in a functional and applicable way, which also makes it possible to compare the obtained results from different dwelling units?</em></p><p>The methods used to explore solutions are literature studies, conversation with professionals and a full-scale demonstration of one of the methods. A discussion with the initiators of this report leads to the recommended method and a model for how it should be performed.</p><p>The air-, diffusion- and windtightness of the building envelope are of big importance to the building. The use of energy, moisture transfer, thermal comfort and hygiene, air quality, noise, spreading of fire and spreading of air pollutions are all affected by it. The air tightness is a crucial element for the durability of the building and to secure a good indoor environment. Air tight buildings are also cost-effective in the long run for the involved participants. They are also good for the environment. A study that have been made show that the energy-use for heating buildings will be reduced with almost 30 % if the air permeability improves from 0,8 l/s·m<sup>2</sup> to 0,4 l/s·m<sup>2</sup>. Such a big reduction of the energy use could not be accomplished with any other energy improvement-move that was investigated in the study.</p><p>The Swedish building regulations, Boverkets Regelsamling för byggande BBR, used to have a demand for the air tightness of buildings. It has been removed in favor of a demand of the function for the energy use, which also include the air tightness. The common advices in BBR refer to the standard, SS-EN 13829 for determination of air permeability.</p><p>The methods available for determination of air permeability in buildings are the tracer-gas method, determination with a temporary wall, the ventilation system, with corresponding pressure in adjacent spaces and determination with a Blower Door. The last method was demonstrated in multiple-unit dwellings in Umeå, Sweden, with good results.</p><p>Note that the result of this report is a methodology and how the method should be performed within buildings erected by NCC in Umeå. It describes a functional and applicable method where the results can be compared between different objects. An internal quantity which describes the air permeability of the external wall has been developed.</p><p>A discussion of the relevance if the derived quantity and the standard has been made. The change in BBR to demands of the function for the energy use has been considered to be a driving force for knowledge. The procedure described in the results has been considered to be the optimum procedure for existing conditions with the standard available. A change in the standard would lead to a better method which would give more informative results.</p>
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Mechanism of regulation of the RPL30 pre-mRNA splicing in yeastMacías Ribela, Sara 13 June 2008 (has links)
The mechanisms of pre-mRNA splicing regulation are poorly understood. Here we dissect how the Saccharomyces cerevisiae ribosomal L30 protein blocks splicing of its pre-mRNA upon binding a kink-turn structure including the 5' splice site. We show that L30 binds the nascent RPL30 transcript without preventing recognition of the 5' splice site by U1 snRNP but blocking U2 snRNP association with the branch site. Interaction of the factors BBP and Mud2p with the intron, relevant for U2 snRNP recruitment, is not affected by L30. Furthermore, the functions of neither the DEAD-box protein Sub2p in the incipient spliceosome, nor of the U2 snRNP factor Cus2p on branch site recognition, are required for L30 inhibition. These findings contrast with the effects caused by binding a heterologous protein to the same region, completely blocking intron recognition. Collectively, our data suggest that L30 represses a spliceosomal rearrangement required for U2 snRNP association with the nascent RPL30 transcript.
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