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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Evaluation of AI-method for measuring and characterizing particles on-line in drinking water treatment / Utvärdering av AI-metod för att mäta och karaktärisera partiklar on-line i dricksvattenberedning

Ådén, Lovisa January 2023 (has links)
The municipal association Norrvatten produces drinking water at Görväln WTP for approximately 700,000 residents in 14 member municipalities in the northern Stockholm region. To ensure the drinking water meets quality criteria, the water must be carefully monitored by the WTP. At Norrvatten there are several rapid filters that remove different types of particles, mainly residues from the previous flocculation step. The running time of the filters can be limited by a filter breakthrough, which means that the filter must be regenerated through backwashing. To detect a filter breakthrough, turbidity measurement is used. A new advanced AI method, a particle meter, from the manufacturer Uponor is installed at several locations at Görväln WTP. The particle meter is being evaluated as a possible complement to the standard turbidity measurement. The particle meter is a type of advanced image interpretation software that measures and categorizes particles that may indicate disturbances in the drinking water production.I n this project, particle meters placed on-line in three different rapid filtrates were compared with existing on-line turbidity measurements. The aim was to investigate whether the particle meter could detect a filter breakthrough earlier than a turbidimeter and whether the particle meter added any additional valuable information for drinking water production. Data from the period 1 May 2022–30 April 2023 was evaluated in Acurve and Excel. Periods where filter breakthrough occurred in filters denoted A, B and C were evaluated to see which method indicates a filter breakthrough the fastest. During the studied period, eight filter breakthroughs occurred in filter C (quartz sand), three in filter A (Filtralite NC 0,8-1,6 mm) and none in filter B (Filtralite 70% NC 0,8-1,6 mm and 30% HC 0,5-1 mm. Rapid filter B has a lower flow rate than filter A and C, which contributes to no breakthroughs being found. The particle meter could not detect a filter breakthrough faster than existing turbidimeters. However, total particles correlated with the trend of turbidity between March–June, which could be explained by the higher abundance of B-particles. During the remaining months, turbidity and total particles followed completely different trends. Therefore, the particle meter could potentially be used to detect algal blooms online early during spring, compared to the weekly laboratory analysis of algae. This is also supported by algae in raw water correlating with the trend of B-particles in the rapid filtrate. Periods where the turbidity was below 0,10 FTU and total particles exceeded 100,000 pcs/ml in filters A, B and C were selected to investigate whether the particle meter provided any additional valuable information. Six events for total particles exceeding 100,000 pcs/ml were found in filter C, two in filter A and none in filter B during the examined period. The lower flow rate as well as the material combination in Filter B could contribute to no events being found. The material in Filter A could also contribute to a lower number of events compared to Filter C. The small particle category, 3 𝜇𝑚 , dominated during these periods and is prone to false detections due to fouling of the particle meter. The particle category that correlated with total particles was small particles in filter A and a mixture of B-and F-particles in filter C. B-and F-particles often followed the same trend which could be because particles, mainly algae, have been categorized into both categories at the same time. Events where total particles >100,000 pcs/ml occur means that there are particles in the filtrate periodically which the rapid filters cannot separate, and which are not detected by the turbidimeter. However, these results could be a consequence of false detections. The particle categorization of the particle meter does not seem to be finished, as only a few of the total particles have been categorized as either B-, C-, F- or small particles. This leads to difficulty in interpreting and using the produced data. / Kommunalförbundet Norrvatten producerar dricksvatten på Görvälnverket till ungefär 700 000 invånare i 14 medlemskommuner i norra Stockholmsregionen. För att säkerställa att dricksvattnet uppfyller de kvalitetskriterier som finns måste vattnet noggrant kontrolleras av vattenverket. Hos Norrvatten finns flertalet snabbfilter som avlägsnar olika typer av partiklar, främst rester från den föregående flockningssteget. Filtrets gångtid kan begränsas av ett filtergenombrott, som leder till att filtret måste regenereras genom backspolning. För att upptäcka ett filtergenombrott används turbiditetsmätning. En ny avancerad AI-metod, en partikelmätare, från tillverkaren Uponor är installerad på flertalet platser i Görvälnverket. Partikelmätaren utvärderas som ett möjligt komplement till den vanliga turbiditetsmätningen. Partikelmätaren är en typ av avancerat bildtolkningsprogram som mäter och kategoriserar partiklar som kan indikera störningar i dricksvattenberedningen. I det här arbetet jämfördes partikelmätare placerad on-line i tre olika snabbfiltrat med existerade on-line turbiditetsmätning. Målet var att undersöka om partikelmätaren kunde upptäcka ett filtergenombrott snabbare än en turbidimeter samt om partikelmätaren tillförde någon ytterligare värdefull information för dricksvattenberedningen. Data från perioden 1 maj 2022–30 april 2023 utvärderades i Acurve och Excel. Perioder där filtergenombrott skett i filter benämnda A, B och C utvärderades för att se vilken mätare som indikerar ett filtergenombrott snabbast. Under den studerade perioden inträffade åtta filtergenombrott i snabbfilter C (kvartssand), tre i snabbfilter A (Filtralite NC 0,8–1,6 mm) och inga i snabbfilter B (Filtralite 70% NC 0,8–1,6 mm och 30% HC 0,5–1 mm. Snabbfilter B har lägre flöde än filter A och C, vilket kan vara en orsak till att inga genombrott hittades. Partikelmätaren kunde inte påvisa ett filtergenombrott snabbare än redan existerande turbidimeter. Däremot korrelerade totala partiklar med trenden för turbiditet mellan mars–juni, vilket kan förklaras av den högre förekomsten av B-partiklar. Under resterande månader följde turbiditet och totala partiklar helt olika trender. Därför skulle partikelmätaren potentiellt kunna användas för att upptäcka algblomningar on-line tidigt under våren, jämfört med de veckovisa laboratorieanalyserna av alger. Detta stöds också av alger i råvatten som korrelerar med trenden av B-partiklar i det samlade snabbfiltratet. Perioder där turbiditeten var lägre än 0,10 FTU och totala partiklar översteg 100 000 pcs/ml i filter A, B och C valdes ut i syftet att undersöka om partikelmätaren tillförde någon ytterligare värdefull information för dricksvattenberedningen. I den undersökta perioden hittades sex event där totala partiklar översteg 100 000 pcs/ml i filter C, två i filter A och inga i filter B. Den lägre flödeshastigheten samt materialkombinationen i filter B skulle kunna vara orsaken till att inga event hittades. Materialet i filter A skulle också kunna bidra till det lägre antalet event jämfört med filter C. Små partiklar, <3 μm, dominerade under dessa perioder som är en kategori där felavläsningar är vanligt vid fouling av partikelmätaren. Den partikelkategori som korrelerade med totala partiklar var små partiklar i filter A och en blandning av B-och F-partiklar i filter C. B-och F-partiklar följde ofta samma trend vilket skulle kunna bero på att partiklar, främst alger, har blivit indelade i båda kategorierna samtidigt. Att totala partiklar >100 000 pcs/ml förekommer i perioder innebär att det finns partiklar i filtratet periodvis som snabbfiltren inte kan avskilja och som inte detekteras av turbidimetern. Dessa resultat skulle dock kunna vara en konsekvens av feldetektion. Partikelkategoriseringen hos partikelmätaren verkar inte vara helt färdig hos Norrvatten då endast ett fåtal av de totala partiklarna har blivit kategoriserade som antingen B-, C-, F- eller små partiklar. Detta leder till en svårighet i att tolka och använda framtagna data.
2

O sistema radicular na estruturação do solo avaliada pela argila dispersa em água / The root system in soil structuring evaluated by the clay dispersed in water

Aline Martineli Batista 27 June 2018 (has links)
Tendo em vista o fato de que o sistema radicular das culturas modifica as propriedades do solo ao seu entorno e da praticamente ausência de trabalhos científicos para avaliação das diferenças estruturais entre solo e rizosfera, o objetivo deste estudo foi aprofundar o conhecimento destas diferenças, avaliando a agregação do solo junto às raízes e fora da sua influência, em diferentes rotações culturais. A amostragem foi realizada na camada superficial do solo (0,00 - 0,05 m) em cada sistema de rotação, considerando como rizosfera o solo aderido às raízes e como solo sem influência das raízes, aquele não aderido a elas. Para avaliar a estabilidade estrutural do solo, foram feitas as análises da argila prontamente dispersa em água, da argila mecanicamente dispersa em água e da estabilidade de percolação. As análises granulométrica e química também foram realizadas. Os dados obtidos foram submetidos à análise de variância e, quando significativo, ao teste de médias Tukey (p<=0,05). Posteriormente, foram feitas correlações entre os atributos físicos utilizados como indicadores da estabilidade dos agregados e os demais atributos avaliados. A rizosfera apresentou agregados mais estáveis em água do que o solo fora dela, sendo a argila mecanicamente dispersa em água o indicador mais sensível na detecção desse resultado. Foi evidênciado que o sistema radicular de diferentes culturas influenciaram de forma diferente a agregação das partículas do solo. As correlações mais significativas foram para a argila mecanicamente dispersa em água. / Considering the fact that the crops root system modifies the soil properties around it and in the almost absence of scientific works to evaluate the structural differences between soil and rhizosphere, the objective of this study was to increase the knowledge of these differences by evaluating soil aggregation close to the root and out of its influence, at different crop rotations. Sampling was performed in the soil surface layer (0.00 - 0.05 m) in each rotation system, considering as rhizosphere the soil adhered to the roots and as soil without influence of the roots, that not adhered to them. To evaluate the structural stability of the soil, analyzes of clay readily and mechanically dispersed in water and of the percolation stability were made. The granulometric and chemical analyzes were also made. Data obtained were analysed by the analysis of variance and, when significant, by Tukey test (p<=0.05). Then, the correlations were made between the physical attributes used as indicators of the aggregates stability and the other attributes evaluated. Rhizosphere presented more stable aggregates in water than the soil outside it, being the mechanically clay dispersed in water the most sensitive indicator in the detection of this outcome. It was evidenced that the root system of different crops influenced of different way the soil particles aggregation. The more significant correlations were those for clay mechanically dispersed in water.
3

O sistema radicular na estruturação do solo avaliada pela argila dispersa em água / The root system in soil structuring evaluated by the clay dispersed in water

Batista, Aline Martineli 27 June 2018 (has links)
Tendo em vista o fato de que o sistema radicular das culturas modifica as propriedades do solo ao seu entorno e da praticamente ausência de trabalhos científicos para avaliação das diferenças estruturais entre solo e rizosfera, o objetivo deste estudo foi aprofundar o conhecimento destas diferenças, avaliando a agregação do solo junto às raízes e fora da sua influência, em diferentes rotações culturais. A amostragem foi realizada na camada superficial do solo (0,00 - 0,05 m) em cada sistema de rotação, considerando como rizosfera o solo aderido às raízes e como solo sem influência das raízes, aquele não aderido a elas. Para avaliar a estabilidade estrutural do solo, foram feitas as análises da argila prontamente dispersa em água, da argila mecanicamente dispersa em água e da estabilidade de percolação. As análises granulométrica e química também foram realizadas. Os dados obtidos foram submetidos à análise de variância e, quando significativo, ao teste de médias Tukey (p<=0,05). Posteriormente, foram feitas correlações entre os atributos físicos utilizados como indicadores da estabilidade dos agregados e os demais atributos avaliados. A rizosfera apresentou agregados mais estáveis em água do que o solo fora dela, sendo a argila mecanicamente dispersa em água o indicador mais sensível na detecção desse resultado. Foi evidênciado que o sistema radicular de diferentes culturas influenciaram de forma diferente a agregação das partículas do solo. As correlações mais significativas foram para a argila mecanicamente dispersa em água. / Considering the fact that the crops root system modifies the soil properties around it and in the almost absence of scientific works to evaluate the structural differences between soil and rhizosphere, the objective of this study was to increase the knowledge of these differences by evaluating soil aggregation close to the root and out of its influence, at different crop rotations. Sampling was performed in the soil surface layer (0.00 - 0.05 m) in each rotation system, considering as rhizosphere the soil adhered to the roots and as soil without influence of the roots, that not adhered to them. To evaluate the structural stability of the soil, analyzes of clay readily and mechanically dispersed in water and of the percolation stability were made. The granulometric and chemical analyzes were also made. Data obtained were analysed by the analysis of variance and, when significant, by Tukey test (p<=0.05). Then, the correlations were made between the physical attributes used as indicators of the aggregates stability and the other attributes evaluated. Rhizosphere presented more stable aggregates in water than the soil outside it, being the mechanically clay dispersed in water the most sensitive indicator in the detection of this outcome. It was evidenced that the root system of different crops influenced of different way the soil particles aggregation. The more significant correlations were those for clay mechanically dispersed in water.
4

Une solution optique pour la mesure simultanée in-siut de la salinité et la turbidité de l'eau de mer

Hou, Bo 11 January 2012 (has links) (PDF)
Salinity and turbidity are two important seawater properties for the physical oceanography. The study of physical oceanography requires a compact high-resolution in-situ salino-turbidi-meter. The main objective of this work is to propose, design and implement an optical solution to simultaneously measure the seawater salinity and turbidity. Our first study is carried out to design a high-resolution refractometer based on a laser beam deviation measurement by a Position Sensitive Device (PSD). The refractive index measurements obtained by the voltage value delivered by PSD have been evaluated to quantify the performances of the sensor. According to the obtained results, it is clear that this PSD-based refractometer is attractive for innovative applications in metrology. However, PSD lacks the capability to retrieve the power distribution information of laser beam, which is related to the turbidity measurements. On the contrary, Charge-Coupled Device (CCD) gives much more information of laser beam than PSD. In the second part of the thesis, a performance comparison between PSD and CCD combined with a centroid algorithm are discussed with special attention paid to the CCD-based refractometer. According to the operating principle of CCD-based system, five factors of CCD-based system: image window size, number of processed images, threshold, binning and saturation are evaluated to optimize the CCD-based refractometer. By applying the optimized parameters, the performance of CCD-based refractometer is better than PSD-based refractometer in measuring the refractive index. Furthermore, by applying different post-processing algorithms, CCD-based system possesses the capability of measuring the power distribution sensitive quantities. To show this advantage of CCD-based system, the attenuation measurement method is used to measure turbidity without modifying the refractometer configuration. The turbidity measurement and salinity measurements influence each other in a refractometer. To overcome these influences, a CCD combined with a new location algorithm is used to measure both the refractive index and the attenuation. Several simulations and experiments are carried out to evaluate this new method. According to the results, the way to improve the resolution is discussed as well. Comparing to the nephelometer specified by the NTU standard, our method has been proved as a valid method to measure turbidity. By studying the performances of CCD-based refracto-turbidi-meter, 3 new prototypes are proposed to improve the salinity and turbidity measurement performance at the end of this thesis.
5

Vliv parametrů sýřeniny na vybrané ekonomické ukazatele výroby sýrů s bílou plísní / Cheese curd parameters influence to selected economic factors of production of cheese with white fungus

Pavlíčková, Žaneta January 2008 (has links)
The theme of this diploma thesis is the monitoring of influences on economic aspect of the production of the blue cheese "Hermelín" in the company Pribina. The objective was to specify the dependencies of the deviations of the features of productive cow's milk and of cheese curd made from it and their economics impacts. For this purpose, the analyses of curd grain, whey and cheeses just formed were executed. The samples were taken and analyzed during the manufacturing of cheeses in the factory. Another goal was to try to design a quick operational method for measuring the firmness of curd grain, which is a factor theoretically dependent on renneting qualities of milk and indicating losses of valuable components from cheese curd to whey. The firmness of grain along with these losses may cause negative deviations from required standard of final products, especially at parametres needed for entry of cheeses on sale, such as total solids, weight or content of fat. Concerning productive pasteurize milk, the most attention was focused on the milk coagulation time and its influence on successive phases of manufacturing and on final product. Milk coagulation time is an essential technological quality of milk and it is participant on quantitative and qualitative production of cheese factory. It has been proved that milk coagulation time is notably affected by its titrating acidity, statistic analyse found this influence as very statistically significant (P
6

Polyelectrolytes : Bottle-Brush Architectures and Association with Surfactants

Naderi, Ali January 2008 (has links)
This thesis has the dual purpose of raising awareness of the importance of the mixing protocol on the end products of polyelectrolyte-oppositely charged surfactant systems, and to contribute to a better understanding of the properties of bottle-brush polyelectrolytes when adsorbed onto interfaces. In the first part of this thesis work, the effects of the mixing protocol and the mixing procedure on formed polyelectrolyte-oppositely charged surfactant aggregates were investigated. It was shown that the initial properties of the aggregates were highly dependent on the mixing parameters, and that the difference between the resulting aggregates persisted for long periods of time. The second part of the studies was devoted to the surface properties of a series of bottle-brush polyelectrolytes made of charged segments and segments bearing poly(ethylene oxide) side chains; particular attention was paid to the effect of side chain to charge density ratio of the polyelectrolytes. It was shown that the adsorbed mass of the polyelectrolytes, and the corresponding number of poly(ethylene oxide) bearing segments at the interface, went through a maximum as the charge density of the polyelectrolyte was increased. Also, it was found that bottle-brush polyelectrolyte layers were desorbed quite easily when subjected to salt solutions. This observation was rationalized by the unfavourable excluded volume interactions between the side chains and the entropic penalty of confining them at an interface, which weaken the strength of the binding of the polyelectrolytes to the interface. However, it was shown that the same side chains effectively protect the adsorbed layer against desorption when the layer is exposed to solutions containing an oppositely charged surfactant. Investigation of the lubrication properties of the bottle-brush polyelectrolytes in an asymmetric (mica-silica) system also related the observed favourable frictional properties to the protective nature of the side chains. The decisive factor for achieving very low coefficients of friction was found to be the concentration of the side chains in the gap between the surfaces. Interestingly, it was shown that a brush-like conformation of the bottle-brush polyelectrolyte at the interface has little effect on achieving favourable lubrication properties. However, a brush-like conformation is vital for the resilience of the adsorbed layer against the competitive adsorption of species with a higher surface affinity. / QC 20100830
7

Optické vláknové snímače / Optical Fiber Sensors

Krejsa, Jan January 2016 (has links)
The diploma thesis focuses on optical fiber sensors with detailed preview of the turbidity sensor, its design and testing. The introduction deals with the general theory of fiber sensors and measurement methodology of physical variables. This part is followed by a charter focusing on the possible ways of measuring turbidity. Furthermore, the diploma thesis introduces design of the new turbidity sensor which is realized with consideration of the industrial usage and future application to the automated process of beer production. It also includes a detailed description of the hardware and software sensors created within this thesis. The last section is devoted to a calibration and testing functionality of turbidity sensor.

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