Aim: The aim of this study was to examine and explain the various methods available to rate the erosion damage, and on which teeth and tooth surfaces of erosion damage mostly occurs in children and adolescents.Method: A literature review was conducted, based on 15 scientific articles that have been reviewed, evaluated and analyzed. Articles were searched for in the database PubMed.Result: Six of the articles used the TWI (Tooth wear index), which is an index to diagnose the Tooth wear in the primary and permanent dentition. Eight articles used other indices as they considered that the TWI was not sufficiently developed to register the degree of Tooth wear on some teeth. Tooth wear in the primary dentition occurs most often in the canines and incisors. Tooth wear in the permanent dentition was found in the literature to be mostly occurring on the occlusal / incisal surfaces of all teeth and tooth surfaces.LyssnaConclusion: There is no common index in the articles but many of them use the TWI.

This review paper summaries scientific research about horse thermoregulation and the consequences of using a blanket. Horse owners put blankets on their horses to protect them when they are clipped, to protect them from bugs, to keep them clean and so on. This can have consequences for the horse which their owners might be unaware of. I have tried to answer following questions by searching the available scientific literature; ? How can the horse maintain thermoregulation? ? Is there a risk of suffering when horses wear a blanket? ? Is there a risk of suffering when horses do not wear a blanket? ? How can animal inspectors estimate the welfare of horses when they wear or do not wear a blanket? My result shows that horses who wear a blanket have an increased risk of becoming overheated, develop a chafing, have an increased exposure hazard and have a restrained natural behaviour.

This project has as main goal to study the influence of the coating thickness, deposited by arc-PVD- technology, on the wear resistance of coated cemented carbide inserts in three different turning operations. An additional effort has also been made to develop a new test method for evaluating flank wear resistance. Three different coating types (Coating A, Coating B and Coating C) have been studied in three distinctive thicknesses (2, 4 and 6 µm) for each type. For two of the coating types (Coating A and B) special studies has been done with the thickest coating, creating two additional coating versions of the thickest coating, by changing various deposition parameters, with the aim to enhance the cohesive properties of the coating and lower the residual stresses at the cutting edge. The results show increased crater wear resistance with increased coating thickness for all coating types, but the amount of increase changes with coating type (Coating A>B>C).

During this master thesis, wear and friction properties for the high-temperature alloy Kanthal APMT were studied. The results were also compared to 253MA. The initial tests showed, among other things, that the surface fineness of the muffle tubes matters in real applications like conveyor belts. A 253MA-sample wear-tested against a 253MA-tube showed lowest wear at 900°C while a pre-oxidized APMT-sample wear-tested against a APMT-tube had the lowest mean value of the friction force at 1100°C, compared to all other tests..

Coca cola och sportdrycker är båda drycker som idag konsumeras i stora mängder världen över. Erosionskador på tänderna är vanligare än vad många tror eller ens vet om. Både vuxna och tonåringar dricker stora mängder erosiva drycker utan att veta om dess skador på tänderna. Dessa drycker börjar oftast drickas i tonåren men konsumtionen fortsätter sedan långt upp i åldrarna. Tandslitage är tandsubstansförlust som inte är av kariogen påverkan.

The agricultural plantingmachines are used just a few weeks every year. That means that the supply of service and spare parts have to be good to make the timeliness costs low at the agricultural hard working periods. The machines wear down successivly when they are used. The wear is harder on some parts than the others on a machine. Spare parts can be dicided into consumables.

This thesis discusses the dress code during the Pitted Ware culture on the Swedish island of Gotland. Eight Pitted Ware grave-fields have been analyzed; only 74 skeletons have been identified with some sort of ornament that could have been attached to clothes. The grave-fields are rich in finds and in people nearly every age group is present. The analysis has shown that there are clear differences between the genders. The female always has some sort of seal tooth ornament around her waist and thighs.

Feline Odontoclastic Resorptive Lesions (FORL) is a painful disease that affects feline teeth and that is increasing in prevalence. The ethiology is still rather unknown. However, research on the ultra structure of the feline tooth may help us understand why FORL is so prevalent in cats and not in other species. Since the ethiology is still unknown, there is yet no profylaxis. The pathogenesis is rather well known; the hard structure of affected teeth gradually undergo odontoclastic resorption and resorptive lesions are often partly replaced with bone- or cementum-like tissue.

Nowadays naval units are participating in international missions, where new and in many cases tougher conditions will affect their propulsion. This essay deals with some of the now developed nanostructure coatings and gives a presentation of how the coatings could function on some exposed parts of the naval powertrain. The essay investigates the possibility that the coatings can be used as a protective layer that will reduce or prevent wear on selected parts of the naval powertrains. As a basis for the essay, nanotechnology is described, as well as different reasons that wear occurs and application techniques for coatings The conclusion is that nanostructured coatings can be applied and provide a much better result on hardness and wear resistance as of naval powertrains compared to micro-structural coatings, both for manufacturing and renovation. The essay presents a few examples of the military utility of the nanostructure coatings as well as suggestions for further research..

This report discusses questions concerning wear on forest roads. The purpose of the work is to investigate if the wear on the roads will decrease when the speed limit gets lower for the trucks that transport the wood. A normal forest road, class B, was used in the study. In total 5000 m3f timber was transported on the road. Data about the road was measured with a profilograph car before and after the timber transport.

Volvo Cars in Skövde manufacture and assemble Volvo engines. When attaching the ignition coil to all 4-cylinder engines, a special mounting tool is required. This mounting tool is currently manufactured from injection-molded polyoxymethylene (POM), a thermoplastic. It has been noted that the life span of the tool is shortened as a result of abrasive wear that occurs during the attachment process of the ignition coil.An investigation of the possibility of manufacturing the mounting tool with a 3D-printer is undertaken in cooperation with ÅF, a consultant to Volvo Cars. A literature study is first presented to introduce broader knowledge on the subject.

Nowadays naval units are participating in international missions, where new and in many cases tougher conditions will affect their propulsion. This essay deals with some of the now developed nanostructure coatings and gives a presentation of how the coatings could function on some exposed parts of the naval powertrain. The essay investigates the possibility that the coatings can be used as a protective layer that will reduce or prevent wear on selected parts of the naval powertrains. As a basis for the essay, nanotechnology is described, as well as different reasons that wear occurs and application techniques for coatings The conclusion is that nanostructured coatings can be applied and provide a much better result on hardness and wear resistance as of naval powertrains compared to micro-structural coatings, both for manufacturing and renovation. The essay presents a few examples of the military utility of the nanostructure coatings as well as suggestions for further research..

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.

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.

Future emission legislation puts great emphasis on increasing the efficiency of the engine, thereby reducing fuel consumption. The tribological contact between cylinder liner and piston ring is where an great amount of energy is lost due to friction, and by reducing these losses an reduction in fuel consumption can be achieved.The aim of this thesis was to evaluate the tested piston ring coatings against a plasma sprayed cylinder liner and rank these combinations of materials for friction and wear resistance. The coatings that were tested was Cr + Al2O3, (Al,Cr)N, two types of CrN and WC / C.The experimental tests were performed with a so-called pin-plate, where used oil with addition of an acidic mixture of sulfuric and nitric acid to mimic the acidic condensate formed when exhausts recirculate, were added with a continuous flow. The results were then analyzed by weighing, studies by optical microscopy and scanning electron microscopy (SEM) and profile measurements.The results from each material combination were that the plasma coated cylinder liner wears too aggressively in order to yield a ranking of the piston ring coatings based on the parameters of friction and wear resistance. It is therefore proposed that an alternative coating on the cylinder liner should be developed, lacking the large abrasive wear on piston rings and that can withstand the corrosive environment resulting in engines equipped with EGR.