LD2668 .T4 1966 B75 / Master of Science

The use of cleaning products can lead to indoor concentrations of toxic air contaminants above regulatory levels. Studies show that the use of cleaning products is related to adverse respiratory health effects in adults ranging from irritation to asthma. Yet exposure to these chemicals is poorly understood. This thesis summarizes the current state of knowledge of inhalation exposure to toxic chemicals in consumer cleaning products. A new two-compartment model that treats personal air space as distinct from bulk room air is presented. The model accounts for air exchange between the two compartments and fresh air, dynamic source characteristics (i.e., the time-varying liquid concentrations and emission rates of pollutants within a mixture), the characteristics of chemical use (e.g., how frequently a cleaning chemical is applied to a new area), and reactive chemistry with ozone. The model’s applicability is restricted by limited data available for parameterization. Key components that are missing include composition data for consumer cleaning products and activity patterns. Extensive effort went into calculating the air exchange rate between the two zones. Twelve computational fluid dynamic simulations and two model scenarios were completed. The predicted concentration in the inner-zone (Cin) was divided by the room concentration predicted by the traditional well-mixed model (Cwm). Concentration ratios (Cin/Cwm) ranged from 1.1 to 700. In terms of real cleaning events, results indicate that the beginning (where the only emission source is near the person) of events taking place in large indoor environments with high air exchange rates are the situations for which well-mixed models are most likely to fail in predicting actual exposures. / text

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<p>Examensarbetets mål är att rengöra en diamantkomposit med en ytrengöringsmetod. Metoden skulle vara mera effektiv än den manuella sandblästring som används idag för att ytrengöra detaljen.</p><p>Detaljen är liten och har ett vitalt spår som ska rengöras. Detta ställer höga krav på effektiva metoder. De metoder som tas upp teoretiskt i examensarbetet är bland annat blästring, trumling och laserrengöring. Ett urval av metoderna testades. Den metod som utmärkte sig främst I testerna var automatisksandblästring. Det gav lika bra resultat som manuell sandblästring men på en bråkdel av tiden som det tog för manuellsandblästring. Det gjordes även en investeringsberäkning i examensarbetet och den gav att trumling var den billigaste metoden.</p><p>Slutsatsen är att automatisk sandblästring bör användas som metod. Metoden gav ett bättre resultat än övriga metoder och var mindre arbetskrävande än manuell sandblästring.</p> / <p>This goal of the thesis´ is to surface finish a diamond with an appropriate method. The method should be more effective than manual sandblasting, the current method in use. The part is small and it has a vital track that must be surface cleaned. This puts great demands on effective methods. The methods that are mentioned theoretically in the thesis are automatic sandblasting, tumbling and laser cleaning. A couple of methods were tested and evaluated. Automatic sandblasting was found to be most effective. That method gave an equal result compared to the manual sandblasting but with a fraction of the time compared to manual sandblasting. Within the thesis a capital budgeting have been done.</p><p>The conclusion of the thesis was that the automatic sandblasting machine should be used.</p>

Examensarbetets mål är att rengöra en diamantkomposit med en ytrengöringsmetod. Metoden skulle vara mera effektiv än den manuella sandblästring som används idag för att ytrengöra detaljen. Detaljen är liten och har ett vitalt spår som ska rengöras. Detta ställer höga krav på effektiva metoder. De metoder som tas upp teoretiskt i examensarbetet är bland annat blästring, trumling och laserrengöring. Ett urval av metoderna testades. Den metod som utmärkte sig främst I testerna var automatisksandblästring. Det gav lika bra resultat som manuell sandblästring men på en bråkdel av tiden som det tog för manuellsandblästring. Det gjordes även en investeringsberäkning i examensarbetet och den gav att trumling var den billigaste metoden. Slutsatsen är att automatisk sandblästring bör användas som metod. Metoden gav ett bättre resultat än övriga metoder och var mindre arbetskrävande än manuell sandblästring. / This goal of the thesis´ is to surface finish a diamond with an appropriate method. The method should be more effective than manual sandblasting, the current method in use. The part is small and it has a vital track that must be surface cleaned. This puts great demands on effective methods. The methods that are mentioned theoretically in the thesis are automatic sandblasting, tumbling and laser cleaning. A couple of methods were tested and evaluated. Automatic sandblasting was found to be most effective. That method gave an equal result compared to the manual sandblasting but with a fraction of the time compared to manual sandblasting. Within the thesis a capital budgeting have been done. The conclusion of the thesis was that the automatic sandblasting machine should be used.

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