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Is the 0.018-inch or the 0.022-inch bracket slot system more effective for the levelling and alignment stage of orthodontic treatment?El-Angbawi, Ahmed M. F. January 2013 (has links)
Aim: To compare the 0.018-inch and 0.022-inch conventional pre-adjusted orthodontic bracket slot systems in terms of the effectiveness of levelling and alignment stage of orthodontic treatment. Design: Prospective, multi-centre randomised clinical trial. Setting: This was undertaken in the secondary care hospital environment in Tayside NHS in the United Kingdom. Subjects and methods: One hundred and five orthodontic patients were randomly allocated to treatment with either the 0.018-inch bracket slot (n= 52) and 0.022-inch bracket slot (n=53) Victory conventional pre-adjusted bracket systems (3M Unitek). The patients were treated in three centres in secondary care hospitals Tayside NHS, United Kingdom. The levelling and alignment stage of treatment was assessed from the start of treatment until the ligation of the working archwire for each bracket slot system (0.016x0.022 stainless steel for the 0.018-inch group and 0.019x0.025 stainless steel for the 0.022-inch group). Periapical radiographs were taken before the start of treatment and after 9 months in treatment for the maxillary central incisors to assess orthodontically-induced inflammatory root resorption (OIIRR). The “Smiles better” questionnaire was completed by the participants at 6 months from the start of treatment. Primary outcome measures: The duration of the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches. Secondary outcome measures: The number of scheduled appointments for the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches, OIIRR at 9 months from the start of treatment using periapical radiographs and patient perception of wearing orthodontic appliances. Results: The data from 92 patients (mean age 19.55 years) were analysed after the completion of their levelling and alignment stage of orthodontic treatment. An ANOVA test showed no statistically significant difference in the duration or number of scheduled appointments for the levelling and alignment stage in the maxillary and mandibular arches between the two appliance groups. Non-parametric statistical test showed no statistically significant difference in the severity of OIIRR and patient perception of wearing orthodontic appliances between the two study groups except for the soreness of teeth, where more patients in the 0.022-inch group experienced significant teeth soreness than the 0.018-inch group. Multiple regression analysis determined that 49.6% of the variance in the duration of levelling and alignment duration for the maxillary arch can be explained by five factors: alignment of ectopic tooth, scheduled appointment intervals, gender, bracket slot size system and the number of failed scheduled visits. For the mandibular arch, 50.8% of the variance in the levelling and duration of alignment can be explained by three factors: scheduled appointment intervals, arch irregularity and the number of debonded brackets. Conclusions: There is no difference in the effectiveness of the levelling and alignment stage of orthodontic treatment between the 0.018-inch or 0.022-inch conventional bracket slot systems except for the soreness of teeth.
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Självkompakterande betong : Ytjämnhet utan efterbehandling / Self-Compacting Concrete : Flat surface without after-treatmentElofsson, Andreas, Hallin, Mikael January 2006 (has links)
<p>Betonggjutning är ett tungt moment inom byggproduktion och entreprenörer har länge använt betong med flyttillsats för att få en mer lättarbetad betong. Ändå har det krävts långa arbetspass och många tungarbetade moment. Efter lasernivellering, vibrering, slodning och glättning har man kunnat uppnå en yta som nästan är helt jämn. Dock ej så jämn att avjämningsmassa kunnat elimineras för att inte få sviktande parkett eller buktande plastmattor.</p><p>Självkompakterande betong (SKB), eller vibreringsfri betong som man först kallade den, forskades fram på 80-talet i Japan och dök upp i Sverige i slutet på 90-talet. Det är en betong som innehåller en flyttillsats och en så kallad filler vars gemensamma egenskaper ger en betong som har bibehållen homogenitet samtidigt som den fyller ut formen och omsluter armering endast genom gravitationskraften. SKB är ca 10-15 % dyrare än traditionell betong men har motiverats med framförallt minskad produktionstid, färre betongarbetare och bättre arbetsmiljö.</p><p>Eftersom SKB mer eller mindre är flytande så blir jämnheten mycket god. Erfarenhetsmässigt har ytorna blivit i det närmaste perfekta efter lasernivellering, slodning och torrslipning. Trots stora konstaterade arbetsmiljövinster och vetskapen om den goda ytjämnheten har AB Färdig Betong i Karlstad endast levererat SKB till 8 projekt sedan 1997.</p><p>Examensarbetets syfte är att fastställa om SKB kan motiveras baserat på den goda ytjämnhet som kan uppnås redan efter gjutning jämfört med normalpresterande betong (NPB).</p><p>Examensarbetet har utförts i samarbete med Skanska Sverige AB i Karlstad, som under våren 2006 genomförde två projekt med SKB. Mätningar av ytor med SKB gjordes på Färjstad i Karlstad och mätningar av referensytor med NPB gjordes i Karlstad med omnejd. Mätningarna kompletteras med intervjuer i form av erfarenhetsåterföring från dem som tillverkat, levererat, mottagit, gjutit och efterbehandlat betongtypen.</p><p>De krav på ytjämnhet av platsgjuten betong som generellt tillämpas återfinns i Hus AMA 98 och definieras som buktighet, lutning och nivåskillnad. Resultaten från mätningarna bedömdes i enlighet med Hus AMA 98, därefter har betongtypernas mätvärden analyserats och jämförts.</p><p>Utifrån resultaten har bland annat följande slutsatser kunnat konstateras:</p><p>Självkompakterande betong kan vid rätt handhavande ge en yta som uppfyller kraven enligt Hus AMA’s krav för undergolv i klass B utan varken vibrering, slipning eller efterbehandling.</p><p>Användandet av SKB i större bostadsprojekt skapar stora förutsättningar för lägre totalekonomi jämfört med användandet av NPB. Detta baseras huvudsakligen på minskat behov av arbetskraft vid gjutning och efterbehandling av den gjutna ytan.</p><p>De bekräftade möjligheterna för förbättrad ytkvalitet redan efter gjutning kommer i framtiden innebära att fler entreprenörer väljer SKB.</p> / <p>Concrete moulding is a heavy moment in the building process and for a long time contractors have used an admixture to create a concrete that is easier to handle. However many hours of work and heavy moments has been required. After laser levelling, vibrating, screeding and troweling a surface that is almost flat has been obtained. Yet not flat enough to eliminate floor levelling and thereby avoiding bending parquet flooring or curved plastic flooring.</p><p>Self-compacting concrete (SCC), or vibrating free concrete as it was named in the beginning, was developed in the eighties in Japan and showed up in Sweden in the late nineties. It is a concrete that contains an admixture and filler that together makes the concrete flow under its own weight, completely filling the formwork and achieving full compaction, even in the presence of congested reinforcement. SCC is approximately 10-15 % more expensive than traditional concrete but is motivated with faster construction times, fewer workers and an improved work environment.</p><p>Since SCC just about flows the resulting surface becomes almost perfect. Experience shows that surfaces are nearly perfect after laser levelling, screeding and dry smoothing. Despite the advantages of the flat surfaces and the established improvement on the work environment, AB Färdig Betong in Karlstad, Sweden has only delivered SCC to eight projects since 1997.</p><p>The aim of this degree thesis is to determine if SCC can be motivated based on the flat surfaces that can be obtained after moulding compared to traditional concrete.</p><p>The degree thesis has been performed in cooperation with Skanska Sverige AB in Karlstad, Sweden at their two projects with SCC in spring 2006. The measurement of SCC surfaces was made in Färjestad, Karlstad and reference measurements of traditional concrete was made in Karlstad and surroundings. The measurement have been complemented with interviews that present experience of producing, delivering, receiving, moulding and after treating SCC.</p><p>The requirements for on site moulding concrete surfaces that are to be followed are found in Hus AMA 98 and is defined as curve, rake and level variance. The result from the measurements are judged on the basis of the requirements.</p><p>Conclusions</p><p>Correctly performed SCC can create a surface that fulfils the requirements in Hus AMA 98 for a class B floor.</p><p>The use of SCC in larger housing constructions makes conditions for a lower total cost. This is based principally on fewer workers, faster construction times and less after treatment of the moulded surfaces.</p><p>The confirmed possibilities of improved surfaces after moulding should mean that more contractors will use SCC in the future.</p>
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Självkompakterande betong : Ytjämnhet utan efterbehandling / Self-Compacting Concrete : Flat surface without after-treatmentElofsson, Andreas, Hallin, Mikael January 2006 (has links)
Betonggjutning är ett tungt moment inom byggproduktion och entreprenörer har länge använt betong med flyttillsats för att få en mer lättarbetad betong. Ändå har det krävts långa arbetspass och många tungarbetade moment. Efter lasernivellering, vibrering, slodning och glättning har man kunnat uppnå en yta som nästan är helt jämn. Dock ej så jämn att avjämningsmassa kunnat elimineras för att inte få sviktande parkett eller buktande plastmattor. Självkompakterande betong (SKB), eller vibreringsfri betong som man först kallade den, forskades fram på 80-talet i Japan och dök upp i Sverige i slutet på 90-talet. Det är en betong som innehåller en flyttillsats och en så kallad filler vars gemensamma egenskaper ger en betong som har bibehållen homogenitet samtidigt som den fyller ut formen och omsluter armering endast genom gravitationskraften. SKB är ca 10-15 % dyrare än traditionell betong men har motiverats med framförallt minskad produktionstid, färre betongarbetare och bättre arbetsmiljö. Eftersom SKB mer eller mindre är flytande så blir jämnheten mycket god. Erfarenhetsmässigt har ytorna blivit i det närmaste perfekta efter lasernivellering, slodning och torrslipning. Trots stora konstaterade arbetsmiljövinster och vetskapen om den goda ytjämnheten har AB Färdig Betong i Karlstad endast levererat SKB till 8 projekt sedan 1997. Examensarbetets syfte är att fastställa om SKB kan motiveras baserat på den goda ytjämnhet som kan uppnås redan efter gjutning jämfört med normalpresterande betong (NPB). Examensarbetet har utförts i samarbete med Skanska Sverige AB i Karlstad, som under våren 2006 genomförde två projekt med SKB. Mätningar av ytor med SKB gjordes på Färjstad i Karlstad och mätningar av referensytor med NPB gjordes i Karlstad med omnejd. Mätningarna kompletteras med intervjuer i form av erfarenhetsåterföring från dem som tillverkat, levererat, mottagit, gjutit och efterbehandlat betongtypen. De krav på ytjämnhet av platsgjuten betong som generellt tillämpas återfinns i Hus AMA 98 och definieras som buktighet, lutning och nivåskillnad. Resultaten från mätningarna bedömdes i enlighet med Hus AMA 98, därefter har betongtypernas mätvärden analyserats och jämförts. Utifrån resultaten har bland annat följande slutsatser kunnat konstateras: Självkompakterande betong kan vid rätt handhavande ge en yta som uppfyller kraven enligt Hus AMA’s krav för undergolv i klass B utan varken vibrering, slipning eller efterbehandling. Användandet av SKB i större bostadsprojekt skapar stora förutsättningar för lägre totalekonomi jämfört med användandet av NPB. Detta baseras huvudsakligen på minskat behov av arbetskraft vid gjutning och efterbehandling av den gjutna ytan. De bekräftade möjligheterna för förbättrad ytkvalitet redan efter gjutning kommer i framtiden innebära att fler entreprenörer väljer SKB. / Concrete moulding is a heavy moment in the building process and for a long time contractors have used an admixture to create a concrete that is easier to handle. However many hours of work and heavy moments has been required. After laser levelling, vibrating, screeding and troweling a surface that is almost flat has been obtained. Yet not flat enough to eliminate floor levelling and thereby avoiding bending parquet flooring or curved plastic flooring. Self-compacting concrete (SCC), or vibrating free concrete as it was named in the beginning, was developed in the eighties in Japan and showed up in Sweden in the late nineties. It is a concrete that contains an admixture and filler that together makes the concrete flow under its own weight, completely filling the formwork and achieving full compaction, even in the presence of congested reinforcement. SCC is approximately 10-15 % more expensive than traditional concrete but is motivated with faster construction times, fewer workers and an improved work environment. Since SCC just about flows the resulting surface becomes almost perfect. Experience shows that surfaces are nearly perfect after laser levelling, screeding and dry smoothing. Despite the advantages of the flat surfaces and the established improvement on the work environment, AB Färdig Betong in Karlstad, Sweden has only delivered SCC to eight projects since 1997. The aim of this degree thesis is to determine if SCC can be motivated based on the flat surfaces that can be obtained after moulding compared to traditional concrete. The degree thesis has been performed in cooperation with Skanska Sverige AB in Karlstad, Sweden at their two projects with SCC in spring 2006. The measurement of SCC surfaces was made in Färjestad, Karlstad and reference measurements of traditional concrete was made in Karlstad and surroundings. The measurement have been complemented with interviews that present experience of producing, delivering, receiving, moulding and after treating SCC. The requirements for on site moulding concrete surfaces that are to be followed are found in Hus AMA 98 and is defined as curve, rake and level variance. The result from the measurements are judged on the basis of the requirements. Conclusions Correctly performed SCC can create a surface that fulfils the requirements in Hus AMA 98 for a class B floor. The use of SCC in larger housing constructions makes conditions for a lower total cost. This is based principally on fewer workers, faster construction times and less after treatment of the moulded surfaces. The confirmed possibilities of improved surfaces after moulding should mean that more contractors will use SCC in the future.
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Transformation av geodetiska höjdnät med flygburen laserskanning : En inledande genomförbarhetsstudieDalheimer, Jan January 2018 (has links)
När kraven på mätosäkerhet är hög vid geodetiska mätningar behövs geodetiska referenssystem realiserade av geodetiska nät av hög kvalitet. Etableringen och transformation till överordnade referenssystem i höjd av dessa nät genomförs idag ofta med terrestra metoder som avvägning, vilket är ett noggrant men tidskrävande arbete. Det finns flera försök att använda sig av andra metoder såsom GNSS, men en möjlighet skulle även vara att använda punktmoln från flygburen laserskanning. Detta arbetes syfte är att undersöka om punktmoln kan användas till transformation av ett geodetiskt höjdnät i Sandvikens kommun. Nätet består av cirka 500 fixpunkter och har 2010 transformerats till RH2000 av Lantmäteriet. Det använda punktmolnet har producerats av Lantmäteriet och har en medelavvikelse om 0,05 m på plana hårdgjorda ytor. Detta är relativt högt då vanligen osäkerheter på millimeternivå önskas vid transformationer. Men eftersom medeltal kan reducera slumpmässiga avvikelser i enskilda mätningar kan en transformation bestående av ett medelhöjdskift möjligen ge ett tillfredsställande resultat. Medelhöjdskiftet är då ett medeltal av flera höjdskift beräknade på olika ställen i punktmolnet. Genom att avväga höjdskillnaden mellan fixpunkterna i nätet och punkter på markytan som med olika metoder höjdbestäms utifrån punktmolnet har höjder för fixpunkterna enligt punktmolnet erhållits. Dessa har jämförts med RH2000 höjder enligt Lantmäteriets transformation för att beräkna en avvikelse, samt med de äldre lokala höjderna för att beräkna ett höjdskift. Genom att beräkna medelvärde och dess osäkerhet för höjdskiftet över hela nätet har en uppfattning om metodens lämplighet erhållits. Höjdskiften låg överlag inom några millimeter från det som Lantmäteriet beräknat, med 3 mm osäkerhet för den överlag bästa metoden. Även om höjdskiftets och därmed transformationens osäkerhet delvis blev något hög jämfört med avvägning så kan punktmoln ändå vara ett lämpligt alternativ. Speciellt i mera avlägsna områden utan bra anknytningar till det överordnade nätet kan det vara intressant. Det finns dock många parametrar som ännu inte utforskats, bland annat vissa eventuella systematiska avvikelser. / When the requirements on accuracy and precision are high for geodetic measurements you need geodetic reference systems realized with geodetic control networks of high quality. Today, establishment and transformation to higher order reference systems for height usually uses terrestrial methods like levelling. While highly accurate these result in time consuming work. There have been a couple attempts at using other methods for this task, for example GNSS, but another possibility might be usage of point clouds from airborne laser scanning. As a starting point for further studies this study attempts to use point clouds to transform a geodetic height network in Sandviken municipality, Sweden. The network consists of around 500 benchmarks and has been transformed to the national reference system for height, RH2000, by the Swedish national geodetic survey (Lantmäteriet) in 2010. The point cloud used is also produced by Lantmäteriet and is said to have a mean error of 0,05 m. This is relatively high since the requirements usually are in the millimeter range when determining transformation parameters, but if the transformation only consist of a single height shift calculated as a mean from several height shifts derived from the point cloud any random errors in the point cloud should be reduced. By measuring the height difference between benchmarks and points on the ground, that through different methods are given heights according to the point cloud, heights of the benchmarks have been determined according according to the point cloud. These can be compared to heights in RH2000 according to the transformation performed by Lantmäteriet to see their deviation from the assumed true value. Further comparisons against the older local heights of the benchmarks give a height shift that can be used as a simple transformation. By calculating a mean and uncertainty an estimation of the suitability of the method can be achieved. The all height shifts deviated a few millimeters from the result Lantmäteriet got, with uncertainties around 3 mm for the overall best method. Even if the uncertainty of the shift and therefore the transformation ended up somewhat high compared to what Lantmäteriet achieved it is still believed that point clouds may be or become a viable alternative. Especially in more remote regions without good connections to the higher order network. There are many parameters that have not yet been explored though, as well as some potential systematic errors that should be further investigated.
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Realizace a zaměření sítě polohových a výškových bodů v povodí Ostřice různými metodami. / Project and surveying of the network for planimetry and hight points in the area of the river Ostřice using several methods.FINK, Miroslav January 2009 (has links)
In this thesis was elaborated the topic: Project and surveying of the network for planimetry and hight points in the area of the river Ostřice using several methods. It{\crq}s purpose was a reconnaissance of the part of a basin of Ostřice, assessment of existing point field, propose and complete the point network for planimetry in sufficient density for further surveying work in the area and survey of location and level by using geodetic methods and GPS. The reconnaissance of the area was conducted due to geodetic and levelling data of the points and maps. A network of 18 points of the detailed point network was built. I located nine of them by using a GPS method and a method of polygonal traverse. The electronic total station Leica TC 407 was used for the point survey by the method of polygonal traverse, for the GPS method was used a GPS apparatus Trimble 4600LS. Altitude of the points was determined by the method of technical levelling. For the altitude determination was used a Topcon AT {--} 24A levelling device.
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Die rol van tolke in onderhoudvoering : ‘n sielkundig-sistemiese perspektief en geldigheidsbepaling (Afrikaans)Barsby, Amanda 17 October 2005 (has links)
Eleven official languages are spoken in South Africa. Misunderstandings during communication seems to be inevitable. The researcher or psychologist often does not speak or have full command of the language of the group that is being investigated, and therefore has to rely on interpreters to understand the internally experienced world of these persons. Trained interpreters are scarce and this study endeavours to determine the extent of the validity of translations done by the available interpreters. This is done by means of a psychological-systemic perspective. The nature of this study is qualitative. Fifteen interviews were conducted with trauma patients at the Maxilla- and Face Surgery Department of the Garankuwa Hospital. Only eleven of these were useable. Mouth injuries etc. affected the quality of the other interviews not used. Four nurses from this department interviewed the patients and wrote up the interpreted answers on a semi-structured interview schedule made available by the researcher. A verbatim translation of the interviews was made from the tape recordings. Units of meaning were assigned and a comparison of the interpreted and the verbatim translations were made. Three perceptual styles were used to identify how much of the meaning the interpreter included (sharpening), excluded (levelling) and changed (assimilation) during the translation. The translation-interpretation process is analysed against the contextual background and paradigms of the participants The results make it clear that South Africa indeed has a problem with the validity of the outputs of interpreters being used as well as the availability of interpreters and their subject-specific training. Copyright 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Barsby, A 2005, Die rol van tolke in onderhoudvoering : ‘n sielkundig-sistemiese perspektief en geldigheidsbepaling (Afrikaans), MA dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-10172005-152643 / > / Dissertation (MA (Research Psychology))--University of Pretoria, 2006. / Psychology / unrestricted
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Gravimetrická měření a opakovaná nivelace na polygonu Tetčice / Gravity measurements at Tetčice polygonBitalová, Katarína January 2014 (has links)
This master's thesis deals with measurements of highs and gravity of points polygon located in village Tetčice, through which is crossing a eastern fault of Boskovice furrow. With repeated measurement should be proved effect to high levels of groundwater. Repeated measurements are realized in the range 2 stages. In thesis is in detail described calculation complete Bouguer gravity anomaly and their quantitative interpretation. From the gravimetric of dates is created map of complete Bouguer gravity anomaly and interpretative profile through Boskovice furrow. Interpretative profile has localized fault, whose tectonic activity belong to possible factors level movement in the village. Level measurements meets the requirement of precise levelling. The results of the measurements are compared and discussed with the previous stages of the research.
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Vývoj nového druhu lehčeného podlahového potěru se samonivelační funkcí / Development of a new type of lightweight self-levelling floor screedŠenk, Josef January 2015 (has links)
This thesis is focused on development of a new type of lightweight self-levelling floor screed. The aim of this thesis is to develop lightweight screed with self-levelling function, which could be stored in a dry mixture in bags or silos, designed for use with only addition of water.
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Determination of a gravimetric geoid model of Kazakhstan using the KTH-methodInerbayeva (Shoganbekova), Daniya January 2010 (has links)
This study work deals with the determination of the gravimetric geoid model for Kazakhstan by using the KTH-method. A number of data sets were collected for this work, such as the gravity anomalies, high-resolution Digital Elevation Model (DEM), Global Geopotential Models (GGMs) and GPS/Levelling data. These data has been optimally combined through the KTH approach, developed at the Royal Institute of Technology (KTH) in Stockholm. According to this stochastic method, Stokes’ formula is being used with the original surface gravity anomaly, which combine with a GGM yields approximate geoid heights. The corrected geoid heights are then obtained by adding the topographic, downward continuation, atmospheric and ellipsoidal corrections to the approximate geoid heights. To compute the geoid model for Kazakhstan as accurately as possible with available data set different numerical tests have been performed: Choice of the best fit geopotential model in the computation area Investigations for the best choice of the initial condition for determination of the least-squares parameters Selection of the best parametric model for reducing the effect of the systematic error and data inconsistencies between computed geoid heights and GPS/Levelling heights. Finally, 5'x5' Kazakh gravimetric geoid (KazGM2010) has been modelled.
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Posouzení fyzikálně-mechanických vlastností a trvanlivosti pojivových koncepcí na bázi účelového vzniku ettringitu / Assessment of physico-mechanical properties and durability of binder concepts based on purposeful creation of ettringituPupíková, Petra January 2012 (has links)
Masters`s thesis deals with study of binder concept based on purposeful creation of ettringite, assessment of physic-mechanical properties and durability. The teoretical part is the mention of ettringite and his function in building materials, are described binder concepts based on purposeful creation of ettringite and self-levelling screed for which the controlled formation ettringite typical. In the practical part are did analysis of raw materials and the composition of the mixture, including types corrosive environment for the assessment of durability. In addition are checked properties of the proposed mixture and evaluated the appropriateness of use of each type of waste materials with regard to the resulting properties.
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