• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 13
  • 10
  • 2
  • 1
  • 1
  • Tagged with
  • 29
  • 29
  • 10
  • 9
  • 8
  • 6
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 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.
21

The suitability of estrogen and androgen bioassays for the measurement of endocrine activity in different water matrices

Ngcobo, Silindile January 2017 (has links)
Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and their presence in water bodies is documented. They discharge into surface water (SW) unmonitored, posing a threat to both aquatic and terrestrial lives. This is a challenge as not all populations have access to treated drinking water (TDW). The EDC contaminated serves as a route of exposure, together with ineffective treatment plants. Given the complexity of the endocrine system, EDCs may mimic or antagonise natural hormones or disrupt their synthesis, metabolism and excretion. The associated health effects include testicular dysgenesis syndrome, metabolic disorders and cancers. Policy and internationally standardised test methods are however sti ll limited. This study therefore aimed to assess the suitability of two assays used for screening estrogenic activity and one for androgenic activity in different water sources. The study consisted of two phases. In phase 1, water sample (tap, surface and treated wastewater) were collected from a catchment area in Pretoria. The samples and a spiked MilliQ laboratory water sample were extracted with solid phase extraction (SPE) and sent to Germany for distribution to participating laboratories. Samples (n=24) from six different countries were received to test for androgenic activity in the MDA-kb2 reporter gene assay. In phase 2, SW and TDW samples were collected from April 2015 until March 2016. The samples were filtered, extracted using SPE and assayed with the YES assay, T47D-KBluc reporter gene assay for estrogenic activity and MDA-kb2 reporter gene assay for androgenic activity. In phase 1, androgenic activity was detected in 4 out of 24 (21%) samples and ranged from 0.23 ± 0.040 ng/L to 0.008 ± 0.001 ng/L DHTEqs. In phase 2, estrogenic activity was detected in 16 out of 24 (67%) SW samples in the T47DKBluc reporter gene assay and ranged from 0.31 ± 0.05 pg/L to 10.51 ± 5.74 pg/L EEqs. It was below the detection limit (dl) in the YES assay. Androgenic activity was detected in 4 out of 24 (17%) SW samples, ranging from 0.0033 ± 0.0050 ng/L to 0.090 ± 0.040 ng/L DHTEqs. Androgenic and estrogenic activity was higher i n pretreatment samples compared to post-treatment in both treatment plants. In phase 1, the MDA-kb2 reporter gene assay was successfully applied to water samples from different sources. Androgenic activity was highest in treated wastewater. In phase 2, treatment plants proved to be effective in removing estrogens detected in the SW samples, as the TDW samples were below the dl. Estrogenic activity is within the ranges reported in other studies. Positive samples were below the 0.7 ng/L proposed trigger value for health risk assessments. Detected androgenic activity was lower in TDW samples compared to the SW samples supplying the two treatment plants indicating that they were both effective in removing the androgenic activity detected. Few studies have reported androgenic activity in tap water. This study strengthens the argument for using a battery of assays when monitoring endocrine activity as EDCs occur at low concentrations in mixtures. / Dissertation (MSc)--University of Pretoria, 2017. / School of Health Systems and Public Health (SHSPH) / MSc / Unrestricted
22

IoT Framework for Water Monitoring Using the M-Bus Interface

Asratyan, Albert, Joshi, Mandar January 2019 (has links)
Immense amounts of water are wasted daily, and it is as important as ever to optimize our water consumption, especially considering that today around 850 million people lack access to clean water. With the rise of the Internet of Things, creating a monitoring system for this purpose becomes easier, but there arises a problem of interfacing water meters to IoT capable devices.In this thesis a framework for IoT smart water monitoring is presented. Both short range and long range communication techniques are shown, compared and discussed. Similarly, different smart water meters and their characteristics are compared.The main goal of this thesis was to implement an interface between a sensor node and the water meter, ensuring the transmission of data in an easy way. To achieve this goal, a M-Bus library integrated into Contiki-OS is presented, thereby showing that it is possible to interface a water meter with a sensor node. The implemented library is capable of changing some of the configurations of the water meter, receiving data from the water meter, as well as forwarding the data via MQTT or CoAP protocols for further processing on the server side. / Stora mängder vatten slösas dagligen och det är viktigt nu att vi optimerar vattenförbrukningen, särskilt med tanke på att cirka 850 miljoner människor idag saknar tillgång till rent vatten. Med uppkomst av Sakernas Internet blir det lättare att skapa ett övervakningssystem för detta ändamål, men det finns fortfarande problem med att ansluta vattenmätare till IoT-kompatibla enheter.I detta arbete presenteras ett ramverk för smart vattenmätning med IoT. Både kortdistansoch långdistanskommunikationsteknik presenteras, jämförs och diskuteras. På samma sätt jämförs olika smarta vattenmätare och deras egenskaper.Huvudsyftet med denna arbetet var att implementera ett gränssnitt mellan en sensornod och vattenmätare, vilket säkerställer överföring av data på ett enkelt sätt. För att uppnå detta mål presenteras ett M-Bus-bibliotek integrerat i ContikiOS, vilket visar att det är möjligt att koppla en vattenmätare till en sensornod. Det implementerade biblioteket kan ändra delar av vattenmätarens konfigurering, ta emot data från vattenmätaren, samt vidarebefordra data via MQTT eller CoAP för vidare bearbetning hos servern.
23

Surface Water Quality Assessment Using Phytoplankton and Zoobenthos: A Case Study at Bung Binh Thien, An Giang Province, Vietnam

Nguyen, Thanh Giao 15 May 2020 (has links)
The study aimed to evaluate water quality at Bung Binh Thien Lake, An Giang Province, Vietnam using Shannon-Wiener species diversity index (H’) and associated average score per taxon (ASPT) calculated from composition of phytoplankton and zoobenthos. The water quality index (WQI) was used as the reference for the quality of surface water. The samples of surface water quality, phytoplankton, and zoobenthos were simultaneously collected at 11 sites in the dry season. The results showed that WQI (57-88) classified water quality from good to medium, H’ calculated using phytoplankton species (1.12-2.71) presented water quality from medium to bad whereas, (H'z) calculated (0 to 2.07) and ASPT (2-4.21) calculated from zoobenthos species divided water quality from bad to very bad. The findings revealed that assessing water quality should not totally only relied on diversity indices (H’, ASPT) but also carefully consider compositions of phytoplankton and zooplankton. In addition, interpretation of the biodiversity indices for water quality examination should involve the experts in the relevant fields. / Nghiên cứu nhằm đánh giá chất lượng nước tại hồ Bung Binh Thiên, tỉnh An Giang, Việt Nam sử dụng chỉ số đa dạng loài Shannon-Wiener (H’) và chỉ số tính điểm trung bình bình theo họ (ASPT) được tính từ thành phần của phiêu sinh thực vật và động vật đáy. Chỉ số chất lượng nước (WQI) được sử dụng tham chiếu cho chất lượng nước mặt. Các mẫu chất lượng nước mặt, phiêu sinh thực vật thực vật và động vật đáy được thu đồng thời tại 11 địa điểm trong mùa khô. Kết quả cho thấy WQI (57-88) phân loại chất lượng nước từ tốt đến trung bình, H’p được tính dựa vào các loài phiêu sinh thực vật (1.12-2.71) thể hiện chất lượng nước từ trung bình đến xấu trong khi, H’z (0- 2.07 ) và ASPT (2-4,21) được tính toán từ các loài động vật đáy phân loại chất lượng nước từ xấu đến rất xấu Kết quả nghiên cứu cho thấy đánh giá chất lượng nước không chỉ hoàn toàn dựa vào các chỉ số đa dạng (H’, ASPT) mà còn xem xét cẩn thận thành phần loài của phiêu sinh thực vật và động vật đáy. Ngoài ra, việc giải thích các chỉ số đa dạng sinh học nhằm tra chất lượng nước cần có sự tham gia của các chuyên gia trong các lĩnh vực liên quan.
24

Long-Term Citizen Science Water Monitoring Data: An Exploration of Accuracy over Space and Time

Albus, Kelly 12 1900 (has links)
The Texas Stream Team (TST) is one of an increasing number of citizen science water monitoring programs throughout the US which have been continuously collecting surface water quality data under quality assurance protocols for decades. Volunteer monitoring efforts have generated monitoring datasets that are long-term, continuous, and cover a large geographic area - characteristics shown to be valuable for scientists and professional agencies. However, citizen science data has been of limited use to researchers due to concerns about the accuracy of data collected by volunteers, and the decades of water quality monitoring data collected by TST volunteers is not widely used, if at all. A growing body of studies have attempted to address accuracy concerns by comparing volunteer data to professional data, but this has rarely been done with large-scale, existing datasets like those collected by TST. This study assesses the accuracy of the volunteer water quality data collected across the state of Texas by the TST citizen science program between 1992-2017 by comparing it to professional data from corresponding stations during the same time period, as well as comparing existing and experimental data from a local TST partner agency. The results indicate that even large-scale, existing volunteer and professional data with unpaired samples that may have been taken months apart can show statewide agreement of 80% for all parameters (DO = 77%, pH = 79%, conductivity = 85%) over the 38 years of sampling included in the analyses, across all locations. The local case study using paired datasets for which a greater number of factors were controlled for show an even higher agreement between volunteers and professionals (DO = 91%, pH = 87%, conductivity = 100%) and show no significant difference between experimental and existing sampling data. The results from this study indicate that TST has been collecting water sampling data for decades that is comparable to professional data and provides compelling evidence for researchers and managers to better utilize TST's and other large-scale monitoring datasets already in existence from similar citizen science water monitoring programs across the country.
25

Incorporating Adaptive Management and Translational Ecology into the North Dakota Total Maximum Daily Load Program: A Case Study of the Fordville Dam Nutrient TMDL

Hargiss, Michael John January 2012 (has links)
Translational ecology and adaptive management strategies were incorporated into the Fordville Dam Nutrient Total Maximum Daily Load (TMDL) case study to determine if these two techniques were compatible to the North Dakota TMDL Program. A case study summary of the Fordville Dam Nutrient TMDL was discussed to provide contrast and comparison of the current TMDL program strategy and systematic improvements that could be made with the incorporation of translational ecology and adaptive management. Translational ecology is an effective way to bridge the information barrier through open communication between the stakeholders and scientists while creating a mutual learning experience. Adaptive management is beneficial to a TMDL implementation plan because it allows stakeholders and resource managers to become involved in management decisions and develop a better understanding of the ecosystem. Therefore, combining translational ecology and adaptive management would make the TMDL process more effective, through better communication and a flexible management plan.
26

Proposta de implantação do índice de abrangência espacial de monitoramento - IAEM por meio da análise da evolução da rede de qualidade das águas superficiais do estado de São Paulo / Proposal of implementation for an Spatial Coverage Monitoring Index - SCMI by temporal analysis of the evolution of the inland waters quality network of São Paulo State

Midaglia, Carmen Lucia Vergueiro 04 December 2009 (has links)
Esta pesquisa de doutorado faz uma avaliação correlacional entre a evolução espacial da rede de monitoramento de qualidade das águas interiores do Estado de São Paulo, através do número de pontos de amostragem e sua respectiva densidade espacial ao longo dos 30 anos de existência da mesma e o crescimento populacional, através da densidade populacional dos municípios inseridos nas 22 unidades de gerenciamento de recursos hídricos do Estado de São Paulo. Analisa também se estes pontos mantiveram a capacidade de representar o status da qualidade da água em função do crescimento populacional, e se é necessário expandir ou adensar a rede em determinadas regiões. Esta comparação ficou mais racional com o uso dos recursos das geotecnologias e da análise multicritério aplicada ao planejamento e gerenciamento de recursos hídricos, com a construção do SIG SP_WATERNET e através da criação de um índice de avaliação do monitoramento que relaciona as 22 unidades espacialmente e ao longo do período estudado. Este índice pode ressaltar o grau de abrangência e de vulnerabilidade da rede de monitoramento das águas interiores superficiais no Estado de São Paulo. / This Ph.D. research makes a correlational evaluation between the spatial evolution of the monitoring network of inland surface waters of State of São Paulo, through the number of sampling points and its density throughout the 30 years of existence of same and the population growth (urbanization) and the population density in the 22 units of water management units of the São Paulo State. It also analyzes if these points had kept the capacity to represent the status of the quality of the water in function of the population growth, and if it is necessary to expand or to rearrange the network in some regions. This comparison was more rational with the use of the resources of the geo-information applied for water resources planning and management, with the construction of SIG SP_WATERNET and with the proposal of an multi-criteria evaluation monitoring index concerning the 22 water management units throughout a studied period. This index can point out the coverage or the vulnerability of the monitoring efficiency of the superficial waters network of São Paulo State.
27

Proposta de implantação do índice de abrangência espacial de monitoramento - IAEM por meio da análise da evolução da rede de qualidade das águas superficiais do estado de São Paulo / Proposal of implementation for an Spatial Coverage Monitoring Index - SCMI by temporal analysis of the evolution of the inland waters quality network of São Paulo State

Carmen Lucia Vergueiro Midaglia 04 December 2009 (has links)
Esta pesquisa de doutorado faz uma avaliação correlacional entre a evolução espacial da rede de monitoramento de qualidade das águas interiores do Estado de São Paulo, através do número de pontos de amostragem e sua respectiva densidade espacial ao longo dos 30 anos de existência da mesma e o crescimento populacional, através da densidade populacional dos municípios inseridos nas 22 unidades de gerenciamento de recursos hídricos do Estado de São Paulo. Analisa também se estes pontos mantiveram a capacidade de representar o status da qualidade da água em função do crescimento populacional, e se é necessário expandir ou adensar a rede em determinadas regiões. Esta comparação ficou mais racional com o uso dos recursos das geotecnologias e da análise multicritério aplicada ao planejamento e gerenciamento de recursos hídricos, com a construção do SIG SP_WATERNET e através da criação de um índice de avaliação do monitoramento que relaciona as 22 unidades espacialmente e ao longo do período estudado. Este índice pode ressaltar o grau de abrangência e de vulnerabilidade da rede de monitoramento das águas interiores superficiais no Estado de São Paulo. / This Ph.D. research makes a correlational evaluation between the spatial evolution of the monitoring network of inland surface waters of State of São Paulo, through the number of sampling points and its density throughout the 30 years of existence of same and the population growth (urbanization) and the population density in the 22 units of water management units of the São Paulo State. It also analyzes if these points had kept the capacity to represent the status of the quality of the water in function of the population growth, and if it is necessary to expand or to rearrange the network in some regions. This comparison was more rational with the use of the resources of the geo-information applied for water resources planning and management, with the construction of SIG SP_WATERNET and with the proposal of an multi-criteria evaluation monitoring index concerning the 22 water management units throughout a studied period. This index can point out the coverage or the vulnerability of the monitoring efficiency of the superficial waters network of São Paulo State.
28

Design & Fabrication of Microfluidic DNA Extraction Device for Water Quality Monitoring

Dang, Bo 10 1900 (has links)
<p>Continuous monitoring of pathogens that may be present in water is one of the key preventive measures that can be used in rural areas of developed countries and developing countries to reduce chances of the water borne diseases outbreak. Off-site testing of microbiological contamination of water is conventionally done for monitoring water quality. However, such a process is time consuming and involves using a variety of hazardous reagents. To address these issues, a portable device for rapid detection of unsafe water is needed.</p> <p>One of the key components in this system is to extract DNA from the pathogens. The primary consideration for DNA extraction is to separate DNA from proteins and other cell debris in the lysate solution. The pure population of DNA molecules are then sent downstream for subsequent processing such as real-time PCR (Polymerase Chain Reaction) and BioFET sensors for further identification and analysis.</p> <p>The focus of the thesis will be on the fabrication of a microfluidic DNA extraction system that can achieve high DNA extraction efficiency and a good repeatability. It can also be easily automated, and integrated with other components of the DNA analysis system. The high surface-to-volume macro/mesoporous silica DNA binding column was synthesized using sol-gel silica technology and triblock copolymer F127 was added to form a crack-free mesoporous silica network. Furthermore, a monodispersed polystyrene microspheres soft-template was assembled using a simple but novel technique that employs controlled suction to enhance self-assembly into a periodically patterned structure in the extraction chamber/chambers. In combination of heat annealing treatment of this assembled polystyrene template, one can easily control the size of the macropores in the final macro/mesoporous silica structure to allow a lower pressure resistance for DNA sample flow at elution stage. The final macro/mesoporous silica structure synthesized using heat annealing temperature of 115<sup>o</sup>C for 10 minutes was determined to have a porosity of 83.6%. Mesopores of this silica monolith was determined by BET test to be 3.65 nm and the macroporous ranging from 0.5μm to 0.86μm were observed. In addition, the fabrication of porous silica monolith can be easily integrated with the microfluidic system for achieving DNA extraction purposes</p> / Master of Applied Science (MASc)
29

Monitorovací systém vodních toků s GSM komunikací / River mionitoring system with GSM communication

Pačinek, David January 2014 (has links)
This master thesis is dedicated to system of water monitoring for use of alternative source power supply and GSM communication. The thesis carried out research on the possibilities to take measurements on watercourses, also detailed research of photovoltaic panel, available accumulators and their charging and a synopsis of similar systems. Furthermore, the master thesis also captures design and implementation datalogger device type with possibility to send measured data to the website.

Page generated in 0.1151 seconds