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Temporal And Spatial Changes Of Primary Productivity In The Sea Of Marmara Obtained By Remote SensingIkis, Didem 01 December 2007 (has links) (PDF)
Temporal and spatial variations in the Sea of Marmara based on monthly averages of chlorophyll a, which is the major indicator of phytoplankton biomass and primary production, recorded by SeaWiFS and MODIS-Aqua sensors at nearly 100 stations have been analyzed for the period of 1997-2007. Majority of phytoplankton blooms occur during the winter and spring seasons, followed by a smaller secondary bloom during the fall season. The majority of high magnitude blooms occur at the Eastern part of the Sea which may be attributed to an increase in the amount of discharge of water contaminated with nutrients originating on land where the industries are located.
The correlations between monthly averages of sea surface temperature (SST) and corresponding chlorophyll a values are statistically significant (inverse) at 1% level, where r= -0.53 and the equation of the fitted model is:
Chlorophyll a = 7.09199 &ndash / 0.215402* SST
This correlation is expected because a relative decrease in SST is an indicative of upwelling and vertical mixing which are the primary processes for the formation of phytoplankton blooms.
We have also found that monthly averages of chlorophyll a recorded by SeaWiFS and MODIS-Aqua are nearly identical and either data set can be used in place of the other.
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Recovery of PGM's from Spent Autocatalyst Using Hydrometallurgy and Ultrasound-Assisted Solvent ExtractionHung, Ying-Shiu 02 August 2001 (has links)
In this study, various techniques of hydrometallurgy and ultrasound-assisted solvent extraction were used to recover the platinum group metals (PGM¡¦s) from a composite sample of honeycomb-type autocatalysts. After they were removed from the converter casings, the autocatalyst substrates were first crushed and then ground by a ball mill. The recovery procedures employed are shown as follows: (1) dissolve PGM¡¦s from ground spent autocatalyst by aqua regia leaching; (2) separate PGM¡¦s from base metals in the aqua regia leachate by metal cementation using zinc powder so that PGM¡¦s can be precipitated out; (3) the PGM¡¦s precipitate was first dissolved by aqua regia, then proceed to remove nitrate and hydrochloride within. The residue was further dissolved in hydrochloride acid as a preparation step for solvent extraction; (4) the PGM¡¦s pregnant solution of hydrochloride acid was treated by solvent extraction and stripping to separate and purify each component of PGM¡¦s. Effects of ultrasound agitation on the efficiency of solvent extraction was also evaluated in this work.
Results of aqua regia leaching experiments have shown that the quantity of dissolved PGM¡¦s increased as the solid-to-liquid ratio decreased. The maximum dissolved quantity of PGM¡¦s could be obtained by a 3-hr leaching time. At this stage, the PGM¡¦s recoveries are 80-90% for platinum and rhodium and greater than 99% for palladium. The result of a preliminary test has indicated that acetic acid can not effectively separate the PGM¡¦s and base metals. Thus, the method of cementation by zinc powder was employed to separate PGM¡¦s from base metals. Before cementation, the aqua regia leachate was diluted and pH-adjusted to greater than 2. In so doing, an almost complete cementation (>99%) could be obtained by the least quantity of zinc powder. In addition, the base metals occurred with the PGM¡¦s precipitate have been minimized except lead and zinc.
While palladium was extracted by di-n-octyl sulfide (DOS), ultrasound assistance has rendered a complete extraction within a few minutes. At this stage, the extraction efficiency was found to be independent of the HCl concentration. It was found that platinum and rhodium were not extracted by DOS. When platinum was extracted by tri-n-octylamine (TOA) and assisted by ultrasound, rhodium will be extracted at the HCl concentration higher than 4M. Thus, TOA is not an effective chemical for selective extraction of platinum. TOA was then replaced by tributyl phosphate (TBP). Experimental results have indicated that the extraction of platinum using TBP was affected by the HCl concentration. The best result was obtained when the HCl concentration was 5M. Extraction by TBP was found to be fast. It took only 20-30 seconds to reach the equilibrium even with no ultrasound assistance. But multi-stage extractions are generally required to extract platinum completely. Rhodium was found to be not extracted by TBP. After palladium and platinum were extracted, only rhodium was remained in the reffinate. In summary, solvent extraction using DOS and TBP has made it possible to separate palladium, platinum, and rhodium effectively. In the palladium stripping solution almost no base metals was determined. However, zinc and lead were found in the platinum stripping solution and the rhodium-containing raffinate. These base metals should be removed to achieve a better purity for each precious metal.
The TCLP (i.e., a leaching test for toxicity) result of the autocatalyst substrate after aqua regia leaching has found to be non-hazardous. However, several streams of wastewater and acid gas generated in the recovery process should be properly managed to avoid the secondary pollution.
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The design and optimisation of a bubble pump for an aqua-ammonia diffusion absorption heat pump / Stefan van der Walt.Van der Walt, Stefan January 2012 (has links)
Energy shortages around the world necessitated research into alternative energy sources especially for domestic applications to reduce the load on conventional energy sources. This resulted in research done on the possibility of integrating solar energy with an aqua-ammonia diffusion absorption cycle specifically for domestic applications.
The bubble pump can be seen as the heart of the diffusion absorption cycle, since it is responsible, in the absence of a mechanical pump, to circulate the fluid and to desorb the refrigerant (ammonia) from the mixture. It is thus of paramount importance to ensure that the bubble pump is designed efficiently.
Various bubble pump simulation models have been developed over the years, but it was found that none of the existing models served as a good basis for application-specific design. Most of the models constrained too many parameters from the outset which made the investigation of the effects of certain parameters on the bubble pump’s performance impossible. According to the research, no bubble pump model investigated the effect of such a wide variety of factors including tube diameter, heat flux, mass flux, generator heat input and system pressure on the bubble pump’s lift height.
A simulation model for a bubble pump for integration with a solar-driven aqua-ammonia diffusion absorption cycle was developed. It serves as a versatile design model to optimise the bubble pump for a large variety of conditions as well as changes in parameters. It was achieved by constraining the bubble pump dimensions and parameters as little as possible. A unique feature of this model was the fact that the bubble pump tube was divided into segments of known quality which made the length of the pipe completely dependent on the flow inside the pipe. It also made the demarcation of the flow development inside the tube easier.
The model attempted to incorporate the most appropriate correlations for pressurised two-phase aqua-ammonia flow. The most appropriate void fraction correlation was found to be Abstract
The design and optimisation of a bubble pump for an aqua-ammonia diffusion absorption heat pump the Rouhani-Axelsson (Rouhani I) correlation. It was mainly due to its exclusive use of thermophysical properties and the vapour quality.
The most appropriate heat transfer coefficient that predicted the most realistic wall temperature, was the correlation from Riviera and Best (1999) which was the only correlation found in the literature developed with aqua-ammonia in mind. It was found that the published correlation could not reproduce their experimental results, and a modification of their correlation was made after which the simulation model’s results correlated well with the experimental values of Riviera and Best (1999).
The main goal of the simulation model was to determine the height that the bubble pump was capable of lifting at the slug to churn flow transition under various conditions. The effect of varying a variety of parameters on the bubble pump lift height was also investigated.
The results from Shelton & White Stewart (2002) were compared to the outputs of the simulation model, and it was found that their constraining of the submergence ratio limited their outputs, and that their heat inputs under different conditions was a bit optimistic. The simulation model’s outputs correlated well at higher tube diameters with the results from Shelton & White Stewart (2002), but at the lower diameters which was used in their study it was impossible to compare data, since their diameters was already in mini flow and micro flow regions. The temperatures also correlated well, all within 2% of the results from Shelton & White Stewart (2002).
It was found that there couldn’t be just one set of optimised conditions and values for the bubble pump, but that each cycle with differing specifications and operating conditions would yield a unique set of optimised parameters. It was for that reason very important not to constrain parameters beforehand without investigating its effect on the bubble pump first. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.
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The design and optimisation of a bubble pump for an aqua-ammonia diffusion absorption heat pump / Stefan van der Walt.Van der Walt, Stefan January 2012 (has links)
Energy shortages around the world necessitated research into alternative energy sources especially for domestic applications to reduce the load on conventional energy sources. This resulted in research done on the possibility of integrating solar energy with an aqua-ammonia diffusion absorption cycle specifically for domestic applications.
The bubble pump can be seen as the heart of the diffusion absorption cycle, since it is responsible, in the absence of a mechanical pump, to circulate the fluid and to desorb the refrigerant (ammonia) from the mixture. It is thus of paramount importance to ensure that the bubble pump is designed efficiently.
Various bubble pump simulation models have been developed over the years, but it was found that none of the existing models served as a good basis for application-specific design. Most of the models constrained too many parameters from the outset which made the investigation of the effects of certain parameters on the bubble pump’s performance impossible. According to the research, no bubble pump model investigated the effect of such a wide variety of factors including tube diameter, heat flux, mass flux, generator heat input and system pressure on the bubble pump’s lift height.
A simulation model for a bubble pump for integration with a solar-driven aqua-ammonia diffusion absorption cycle was developed. It serves as a versatile design model to optimise the bubble pump for a large variety of conditions as well as changes in parameters. It was achieved by constraining the bubble pump dimensions and parameters as little as possible. A unique feature of this model was the fact that the bubble pump tube was divided into segments of known quality which made the length of the pipe completely dependent on the flow inside the pipe. It also made the demarcation of the flow development inside the tube easier.
The model attempted to incorporate the most appropriate correlations for pressurised two-phase aqua-ammonia flow. The most appropriate void fraction correlation was found to be Abstract
The design and optimisation of a bubble pump for an aqua-ammonia diffusion absorption heat pump the Rouhani-Axelsson (Rouhani I) correlation. It was mainly due to its exclusive use of thermophysical properties and the vapour quality.
The most appropriate heat transfer coefficient that predicted the most realistic wall temperature, was the correlation from Riviera and Best (1999) which was the only correlation found in the literature developed with aqua-ammonia in mind. It was found that the published correlation could not reproduce their experimental results, and a modification of their correlation was made after which the simulation model’s results correlated well with the experimental values of Riviera and Best (1999).
The main goal of the simulation model was to determine the height that the bubble pump was capable of lifting at the slug to churn flow transition under various conditions. The effect of varying a variety of parameters on the bubble pump lift height was also investigated.
The results from Shelton & White Stewart (2002) were compared to the outputs of the simulation model, and it was found that their constraining of the submergence ratio limited their outputs, and that their heat inputs under different conditions was a bit optimistic. The simulation model’s outputs correlated well at higher tube diameters with the results from Shelton & White Stewart (2002), but at the lower diameters which was used in their study it was impossible to compare data, since their diameters was already in mini flow and micro flow regions. The temperatures also correlated well, all within 2% of the results from Shelton & White Stewart (2002).
It was found that there couldn’t be just one set of optimised conditions and values for the bubble pump, but that each cycle with differing specifications and operating conditions would yield a unique set of optimised parameters. It was for that reason very important not to constrain parameters beforehand without investigating its effect on the bubble pump first. / Thesis (MIng (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2013.
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Řešení mimořádné události v Aquaparku v Uherském Hradišti / Extraordinary events in the Aquapark in Uherské HradištěKUBÍČKOVÁ, Kamila January 2016 (has links)
The thesis deals with the issue of possible chlorine leakage from the Aqua Park in the town of Uherské Hradiště. Chlorine is a toxic substance, widely used in industry. The amount of chlorine used in the aqua park does not comply with the values stipulated under the Major Accident Prevention Act, as it is under the limits set in the act and the object therefore cannot be classified into either group A or group B. Since the aqua park falls between unclassified sources, it is not subject to any obligations under this act, including processing documentation for cases of emergency. Despite that it is necessary to ensure the safety of persons in the aqua park area, as well as in its immediate vicinity in case of leakage of large quantities of the substance. The aim of the thesis is to determine whether the aqua park can ensure preparedness for emergencies, especially for chlorine leakage. Chlorine is a moderately toxic substance which irritates particularly the respiratory system, eyes and mucous membranes, and in high concentrations, it can cause pulmonary edema and death. The thesis defines its basic physical and chemical properties, the method of using and providing first aid in case of exposure to the substance. Furthermore, it presents basic concepts related to emergencies and leakages of hazardous substances as well as basic legislation dealing with the issue. Such legislation includes primarily the Act on Integrated Rescue System, Act on Chemical Substances and Mixtures, as well as the Fire Protection Act. The thesis further includes risk assessment and analysis carried out using the Cause-Consequence Analysis or cause-effect analysis. This method is used for a better understanding of failures which can occur in an enterprise. It tries to deal mainly with the evaluation of the probability of system failures and looks for the causes of such failures. Using the Aloha and Terex software programs, a chlorine leak was simulated into the surrounding areas during the summer and winter seasons. Both programs simulated a chlorine leak in the total amount of 975 kg, under the same meteorological conditions for both seasons. Based on the specified input information, endangered zones in which it is necessary to evacuate the people were determined.
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Applications of DINEOF to satellite-derived chlorophyll-a from a productive coastal regionHilborn, Andrea 10 October 2018 (has links)
A major limitation for remote sensing analyses of oceanographic variables is loss of spatial data. The Data INterpolating Empirical Orthogonal Functions (DINEOF) method has demonstrated effectiveness for filling spatial gaps in remote sensing datasets, making them more easily implemented in further applications. However, dataset reconstructions with this method are sensitive to the characteristics of the input data used. The spatial and temporal coverage of the input imagery can heavily impact the reconstruction outcome, and thus, further metrics derived from these datasets, such as phytoplankton bloom phenology. In this study, the DINEOF method was applied to a three-year time series of MODIS-Aqua chlorophyll-a of the Salish Sea, Canada. Spatial reconstructions were performed on an annual and multi-year basis at daily and week- composite time resolutions, and assessed relative to the original, clouded chla datasets and a set of extracted in situ chla measurements. A sensitivity test was performed to assess stability of the results with variation of cross-validation data and simulated scenarios of lower temporal data coverage. Daily input time series showed greater accuracy reconstructing chla (95.08-97.08% explained variance, RMSExval 1.49 - 1.65 mg m-3) than week-composite counterparts (68.99-76.88% explained variance, RMSExval 1.87 – 2.07 mg m-3), with longer time series of both types producing a better relationship to original chla pixel concentrations (R 0.95 over 0.94, RMSE 1.29 over 1.35 mg m-3, slope 0.88 over 0.84). Original daily chla achieved a better relationship to in situ matchups than DINEOF gap-filled chla, with annual DINEOF-processed data performing better than the multi-year. The results of this study are of interest to those who require spatially continuous satellite-derived products, particularly from short time series, and encourage processing consistency in future DINEOF studies to allow unification for global purposes such as climate change studies (Mélin et al., 2017). / Graduate
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Optimalizace univerzitní bezdrátové sítě pro provoz hlasových služebKonečný, Jakub January 2015 (has links)
This diploma thesis focuses on the issue of evaluation VoIP services (from the perspective of QoE) and their quality in university network. It includes theoretical basics of VoIP testing, principals of QoS, and also overview of QoE/MOS measurement methods. Next part describes the test bed and methodology used for measurements and evaluating of results. Site survey results and VoIP quality measurement are evaluated at the end, followed by recommendations that can lead to better VoIP quality in MENDELU wireless network.
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Analýza společnosti Aqua Angels EUROPE s.r.o / Analysis of the Aqua Angels EUROPE s.r.o. companyBláhová, Kateřina January 2014 (has links)
The aim of this thesis is the real representation of the company's business Auqa Angels EUROPE s.r.o. - a brief description of each area inside the company, know-how, product description, pricing and insight into the distribution system and the importance of sales personnel in the company. The author is concerned with the individual marketing activities of this small company and evaluate their effectiveness. Furthermore, this work aims at a competitive comparison in the Czech market with bottled water and evaluate the awareness of the brand and its positioning among consumers. The basic hypothesis is low Aqua Angels brand awareness among consumers thanks non wholesale marketing activities and narrow target group and pessimistic view of the drinking regime of Czech population. Part of this thesis is also the overall assessment of the current situation of Aqua Angels EUROPE s.r.o. and recommendation of appropriate workable solutions in areas where deficiencies are determined.
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Vliv aerobního pohybového programu ve vodě na úroveň zdravotně orientované tělesné zdatnosti a kvality života seniorek / The effect of water-based exercise program on health related physical fitness and quality of life in elderly womenKramperová, Veronika January 2020 (has links)
Title: Effects of water-based aerobic programme on health-related physical fitness and health-related quality of life level in elderly females Objectives: The aim of this study was to asses the effect of shallow water aerobic programme on changes of health-related physical fitness and health- related quality of life level in elderly females. Methods: 33 women (mean age 67 ± 5,2 years) were eligible for participation for the study. Participants were divided into experimental and control group. The experimental group (n = 17) participated in a 6month shallow water aerobic programme once a week 60 minutes. The control group did not participate in the physical program. Body composition, low-back and hamstring flexibility, hand grip strength, upper body and lower body strength, aerobic capacity, dynamic postural stability and health-related quality of life were determined before and after completion. Results: This study has shown that the training programme caused a significant increase in aerobic capacity (p = 0,01; r = 0,62) and in general health perception (p = 0,04; r = 0,36). Keywords: physical fitness, water exercise programme, ageing, quality of life
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Estudio de la dinámica del espesor óptico de los aerosoles producido por las fuentes naturales y antropogénicas a partir de las imágenes del sensor modis a bordo del satélite terra y aqua sobre américa del Sur (2000-20012)Rojas Benavente, Noelia January 2014 (has links)
El objetivo de este trabajo es estudiar la dinámica de los aerosoles en Perú y América del Sur, a partir de las imágenes promedios mensuales del espesor óptico de aerosoles (AOT) en la longitud de onda de 550 nm estimados por el sensor MODIS (Moderate Resolution Imaging Spectroradiometer) a bordo de los satélites TERRA y AQUA, para un periodo de catorce años (2000-2013). La importancia del estudio de la dinámica de los aerosoles es que vamos a tener en cuenta a la hora de usar los modelos de corrección atmosférica. El área de estudio corresponde a las latitudes 4°N a 24°S y las longitudes 83°W a 33°W (que abarca Perú y parte de América de Sur). Se ha usado datos AOT in-situ horarios de 6 estaciones AERONET de América del Sur (Brasil: Rio Branco, Paraná Ji, Alta Foresta, Campo Grande, Chile: Arica y Bolivia: La Paz). Para cada estación, se han obtenido los promedios mensuales y se ha generado una serie de tiempo AOT mensual de 14 años (168 datos AOT). Se emplearan datos imágenes AOT productos mensuales de nivel L3, 166 datos imágenes AOT procedentes del sensor MODIS abordo del satélite TERRA durante el período del 2000 al 2013, y 138 datos imágenes AOT productos mensuales procedentes del sensor MODIS abordo del satélite AQUA durante el periodo del 2002 al 2013. El software web GIOVANNI es usado para estimar las imágenes productos mensuales AOTMODIS-TERRA y AOT-MODIS-AQUA de 1º x 1º (110 km x 110 km) que abarca un área de aproximadamente 16 940 000 km2 y también para estimar las series de tiempo AOT-MODIS-TERRA y AOT-MODIS-AQUA promedios mensuales y promedios espaciales del área de estudio (166 datos AOT para TERRA y 138 datos AOT para AQUA).
La serie de tiempo AOT-MODIS-TERRA toma valores máximos y mínimos entre 0,0 a 0,499, pudiendo obtener que sus valores máximos se presentan en la temporada seca del hemisferio sur (agosto a noviembre) durante los 14 años. La serie de tiempo AOT-MODIS-AQUA toma valores máximos y mínimos entre 0,0 a 0,493, pudiendo obtener que sus valores máximos se presentan en la temporada seca (agosto a noviembre) durante los 12 años. La serie de tiempo AOT-AERONET para Brasil (cuatro estaciones) muestra una variación estacional con máximos en la estación seca durante los 14 años y para Chile y Bolivia (una estación para Chile y una estación para Bolivia) muestra una variación estacional muy diferente a los datos AOT/MODIS, teniendo pocos registros de datos AOT.
Las gráficas de dispersión de las series de tiempo AOT-MODIS vs AOT-AERONET muestran una alta correlación entre 0.8 y 0.9 en cuatro estaciones de Brasil y una baja correlación de 0.4 en una estación de Chile y 0.6 en una estación de Bolivia. / Tesis
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