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134 Uppsatser om Tooth erosion - Sida 2 av 9

Skydd mot yterosion i slänter av finmorän

Slopes in fine till soils are exposed to surface erosion due to rainfall, snowmelt and upland water sources. Large areas of road slopes are therefore covered for surface erosion protection. Preventive methods like ditches and trenches are also being used. Silt tills are particularly troublesome since the water can bring the soil into suspension and cause mudslides. Different methods for erosion protection have been studied in this work, with the emphasis placed on rockfill covering. The need for and the dimensioning of this type of covering has been examined in literature and field studies.

Ätstörningar och oral hälsa : En litteraturstudie

Introduktion: Ätstörningar som Anorexia Nervosa (AN) och Bulimia Nervosa (BN) innebär ett folkhälsoproblem och orsakar oral ohälsa. Vid ätstörningar har individen en störd kroppsupplevelse och försöker kontrollera sin vikt och kroppsform. Under de senaste decennierna har det skett en omfattande ökning i förekomsten av ätstörningar. Syfte: Att beskriva oral hälsa vid ätstörningar.   Frågeställningar: Hur påverkas den orala hälsan av sjukdomen AN? Hur påverkas den orala hälsan av sjukdomen BN? Metod: Designen är en litteraturstudie i området oral hälsa och ätstörningar.

Identifiering av områden med risk för fosforförluster genom ytavrinning : metodutveckling med GIS

The eutrophication of lakes and seas with the algal bloom and deficiency inoxygen that follow, has been given priority by the Swedish government as oneof 16 environmental objectives. The purpose of this project was to develop a toolbased on a simple model, limited amount of data and geographic informationsystem (GIS) to identify areas with risk for phosphorus losses due to surfacerunoff. This tool can act as a decision support to decide where appropriatemeasures should be applied with the aim of reducing phosphorus losses and bythat the eutrophication.The method that has been used is a combination of two models, one calculatingthe potential erosion while the other one identifies areas of erosion (net erosion)or deposition. This ability is of great importance because potential erosionshould be calculated on areas with net erosion. Areas with high potential erosionhave an increased risk for phosphorus losses due to surface runoff.The potential erosion was calculated based on factors which describe how topography(LS), land use (C), soil type (K) and precipitation (R) effect the erosion.All of them have been modified to a greater or lesser extent.

Föräldrars kunskaper om kost och karies

The purpose of this study was to investigate parents' knowledge about diet and dental caries. The survey was conducted using a structured questionnaire consisting of 19 questions regarding knowledge of diet and caries, and preventive measures. The questionnaires were distributed to parents who were visiting a dental hygienist or prophylaxis nurse with their children aged 0-3 years. A total of 88 completed surveys were collected. The study showed that the majority of the parents had knowledge about diet and dental caries.

Predicting spawning bed erosion and longevity : a case study in tributaries to river Vindelälven, northern Sweden

Timber floating operations in Scandinavia during the 19th and 20th centuries has contributed to severe negative impacts on riverine ecosystems. Increase in water velocity and lack of stream bed heterogeneity as a result of stream channelization lead to increased bed load transport. Since availability and recruitment of new suitable spawning substrate in Scandinavian watercourses is sparse, spawning habitats for salmonids has become a scarce commodity. Lately, increasingly more attention has been given to the recreation and improvement of brown trout (Salmo trutta) spawning habitats in restoration projects. While much of the research on spawning habitat has been focused on evaluation of the influence that the constructed spawning grounds have on fish populations, few studies have been conducted to evaluate the persistence of these constructions over time. I evaluate erosion of constructed spawning beds as an effect of sediment transport attributable to water discharge.

Optimering av sintrade kugghjul

Powder Metal (PM) gears are machine element components which operate under the same principle as conventional gears, but, due to their intrinsic material characteristic need to be designed slightly different, and its manufacturing process offers advantages previously unobtainable by conventional steel gear manufacturing methods. The use of PM in similar applications, such as synchronous hubs, makes them a suitable candidate for production in such material. The current master thesis work focuses on gear design using PM by utilizing finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.First a topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume, similar topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. A shape optimization of the topological candidate was performed having as state variables root bending strength, independent for compressive and tensile side of the tooth loading; and tooth deflection, which in concept can be correlated to static transmission error (TE).Another aspect in this thesis analysed is the possibility to incorporate non-trochoid root geometry, a trochoid root is always present when machining with a hob, into the gear root and hence reduce the stress concentration here. Due to the use of PM, a non-symmetric optimized root can be achieved and hence be optimizing compression and tension.Results showed significantly lower inertia, for example certain results showed 40% reduced when compared to solid gear, with adverse effects as increase in tooth deformation and increase in maximum principal stress.

Små skogliga vattendrag i Värmland - Generell beskrivning, förekomst av traktorspår samt spårens inverkan på bottenfaunan :

Modern forestry requires a high degree of machine traffic for clear felling and scarification operations. The machines most frequently used are big and the traffic often results in tracks on the forest ground. There are many small streams running through a forest, in connection to logging operations, machines might cross these frequently. These crossings could result in the erosion of fine particulate inorganic matter, which ends up in the stream. The aim of this thesis was to give a general description of small forest streams of order-one in the county of Värmland and to determine the frequency of machine tracks in small streams.

Tandborstning i förskolan ? en kvalitativ undersökning av ett tandhälsoprojekt på Hässleholmen

Introduction: Dental health globally is not equally distributed as shown by caries prevalence is higher in areas with more immigration outside Scandinavia and Western Europe and areas with lower socioeconomic status. To reduce the health inequalities in Borås, a dental health project was made in five kindergartens in the district Hässleholmen. Purpose: The purpose of the survey was, by interviews with the actors involved (teachers, children, parents and the public dental service) find out the views of the project, and whether the project is relevant and should continue. Method: The method used was qualitative interviews with the actors involved in dental health project. A total of 21 interviews were then consolidated by a qualitative content analysis.

Kost-och munhygienvanor hos en grupp skiftarbetare : Tvärsnittstudie

Introduktion: Erosionsskador är ett växande problem bland barn, ungdomar och unga vuxna. Dental erosion har en multifaktoriell etiologi som består av endogena och exogena orsaker. Att erosionsskador på tänderna ökar kan bero på den höga konsumtionen av sura drycker bland barn, ungdomar och unga vuxna. Personer som idrottar kan löpa risk för dental erosion på grund av frekvent intag av sura sport/energidrycker men även till följd av påverkat salivflöde. Få studier har undersökt fotbollsspelares kunskap om dental erosion och dess konsumtion av sport/energidryck.Syfte: Att studera kunskapen om erosionsskador bland en grupp fotbollsspelande kvinnor och män.Frågeställningar: Vilken kunskap har fotbollsspelande kvinnor om erosionsskador? Vilken kunskap har fotbollsspelande män om erosionsskador? Vilken konsumtion har fotbollsspelarna av energi/sportdryck?Metod: Studien är en kvantitativ, empirisk, tvärsnittsstudie.Resultat: Totalt deltog 44 personer i studien, 29 kvinnor och 15 män.

Studie på beteendeförändringar hos katt efter behandling av Feline Odontoclastic Resorptive Lesion (FORL) :

Feline odontoclastic resorptive lesion (FORL) is a tooth disease affecting both domestic and wild cats. Although FORL was described as early as the 1920´s, the etiology is still unclear. Several hypotheses have been presented but different studies have obtained contradictory results, and today there is no generally accepted etiology. Teeth affected by FORL are characterized by root resorption with progressive destruction of the tooth structure and alveolar bone as a consequence of clast cell activity. The disease is considered very painful when reaching a certain stage.

Erosion

Rosenlunds sandbankar är ett naturskyddsområde mellan Jönköping och Huskvarna som rasar med ungefär 30 cm per år. Platsen tillåts att årligen krympa men inte att användas. Det görs inga större ansatser för att dokumentera den för framtida generationer eller synliggöra den för nu levande generationer.I detta examensarbete undersöks ett naturligt fenomen som kommer att påverka civilisationer i tusentals år. Examensarbetet syftar i första hand till att återintroducera en bortglömd plats och beskriva hur den förändras i tid och rum. Med hjälp av studier om erosion, landhöjning, istid och med hjälp av fältstudier tolkas platsens förgänglighet i fotografier och i en serie ritningar.Därefter föreslås ett promenadstråk där det direkt går att beskåda de geologiska processer som omformar platsen.

Assuandammens påverkan på Nilen, Egypten

Regulation of rivers by dams and reservoirs is a good example where anthropogenic impact could be considerable both in the local environment, but also has major implications upstream and downstream. This study was accomplished as a literature study of the river Nile, which is extremely important for water supply. The purpose of this study was to investigate the consequences of the construction of the Aswan High Dam, to obtain a consistent flow for water supply, irrigation and power generation in Egypt. Since Egypt has a very hot and dry climate large amounts of water in reservoir is lost to the Nubian aquifer system and by evaporation. The consequences from constructing the dam are considerable.

Genetic variation in dairy cattle claw health traits recorded by claw trimmers

Claw health has been recorded by claw trimmers at trimming in Sweden since 1996, but data was then captured at each AI association. From 2003 data was captured by central scanning and entered directly to the national cow data base at the Swedish Dairy Association (SDA). This reporting was introduced because SDA wanted to be able to use these records to improve dairy cow claw health by breeding. It is desirable with cows that have healthy claws, because poor claw health can contribute to impaired production and fertility. The claw health report begins with some information about herd, claw trimmer, date et cetera and continues with the part where the claw health is recorded. Here the ID of each cow is filled in and on the same row the conditions for dermatitis, heel horn erosion, sole haemorrhage and sole ulcer are recorded as no lesion (blank), slight lesion (/) or severe lesion (X).

Opportunities for improved environmental sustainability of a wine producer in South Africa : natural resource management and climate change adaptation and mitigation

South Africa has been among the top ten wine producing countries for at least 20 years. Even though the land under grapevines is decreasing globally it is still increasing in Africa. The awareness of environment has strengthen the last years and South African producers experience a high demand of environmentally friendly produced wine, especially from the European market. This demand was the driving force behind the development of the world unique sustainability certification, Integrated Production of Wine (IPW), which is inscribed in the South African legislation. What makes this certification unique is that consumers can trace their product all the way back to the farming practices owing to the identity number specified on the IPW Integrity & Sustainability seal on certified products.

Upprättande av insatsbeskrivning för kritiska händelser såsom läckage i fyllningsdammar

Sverige har uppskattningsvis 10000 dammar varav 1000 av dessa används inom vattenkraften. För att en damm ska kategoriseras som hög krävs det att den är 15 m eller högre, vilket innebär att det ungefär finns 200 dammar i landet som är 15 m eller högre. Enbart några få dammar i Sverige är över 100 m höga. När det gäller fyllningsdammar finns det två olika typer av dammar och dessa är:1. Homogena fyllningsdammar och 2.

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