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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.
61

Analysis of "Observer Effect" in Logbook Reporting Accuracy for U.S. Pelagic Longline Fishing Vessels in the Atlantic and Gulf of Mexico

Morrell, Thomas J 02 May 2019 (has links)
Commercial pelagic longline fishers within the U.S. Atlantic, Gulf of Mexico, and Caribbean are required to report all fishing interactions per each gear deployment to NOAA’s Vessel Logbook Program of the Southeast Fisheries Science Center to quantify bycatch, increase conservation efforts, and avoid jeopardizing the existence of vulnerable species listed under the Endangered Species Act (ESA). To provide additional accuracy, the Pelagic Observer Program (POP) of the SEFSC deploys professionally trained observers on longline vessels to produce a statistically reliable subset of longline fisheries data. A comparison of self-reported (“unobserved”) datasets versus observer-collected (“observed”) datasets showed a general consistency for most target species but non-reporting or under-reporting for a number of bycatch species and “lesser-valued” target species. These discrepancies between catch compositions and abundancies regarding targeted species, species of bycatch concern, and species of minimum economic value can provide insight into increased fisheries regulations, stricter requirements, or additional observer coverage.
62

Obnova vodní nádrže v obci Žďárná / Renovation of a water reservoir in the village of Žďárná

Pastorková, Nikola January 2022 (has links)
The theme of this diploma thesis is to restore the existing small reservoir in the village Žďárná. A new safety spillway and bottom outlet will be built, the flood will be shaped according to the cross-sections and the dam of the water reservoir will be fortified. The designed objects will be hydraulically verified. Using the HEC-HMS program, a hydrological model of the river basin is created and subsequently a derived flood wave PV20.
63

Flood inundation mapping of the Catalpa Creek Watershed

Poudel, Subodh 08 December 2023 (has links) (PDF)
This study addresses flood risk assessment in the Catalpa Creek watershed, located in northeast Mississippi, USA. Employing the Hydrological Modeling System (HEC-HMS) and the River Analysis System (HEC-RAS), integrated models were developed and calibrated, to predict flood behavior within the watershed. The study conducted flood frequency analyses for return periods ranging from 2 to 100 years and generated flood inundation maps, pinpointing flood-prone areas. Mitigation measures for flood risk management were recommended. The results underscore the effectiveness of the integrated modeling approach for simulating and understanding the complex dynamics of flood events. The research identified critical flood-prone zones, emphasizing the importance of proactive flood risk management. The calibrated hydrological model serves as a valuable tool for stormwater management, water resource planning, and watershed assessment. The study provides insights into flood risk in the Catalpa Creek watershed, offering valuable guidance to regional decision-makers. This study lays the foundation for future investigations in floodplain encroachment, sediment transport, stream restoration, and flood inundation hazard mapping.
64

MonoGenjin : En praktisk undersökning av 2D spelmotors- och spelutveckling

Källberg, Viktor, Källman Andersson, Tobias January 2022 (has links)
Spelindustrin är gigantisk och kontinuerligt växande, där detta inkluderar spelutveckling samt spelande av spel. Detta medför att en betydande mängd akademiker i sina yrkesliv kommer att beröra ämnesområdet spelutveckling. Trots detta faktum finns det en avsaknad av akademisk litteratur som behandlar ämnesområdet spelutveckling, specifikt med ett IS-perspektiv. För att fylla avsaknaden ämnar denna undersökning utöka det specifika konceptet inom spelutveckling som är “skapande av en 2D-spelmotor med tillhörande spel”. Att spela innebär hedonistiska upplevelser. Gäller denna hedonism också vid spelutveckling? Vilka utmaningar och vilken problematik uppstår vid utveckling av en spelmotor? För att utreda detta används en kvalitativ undersökning med en induktiv metodik via forskning genom design (eng. Research through Design, RtD) tillsammans med kollaborativ autoetnografi (Collaborative Autoethnography, CAE). Detta skapar ett unikt perspektiv som används för att producera välmotiverad vägledning för introduktion till ämnesområdet. Datainsamling utgörs av loggbok och dagbok där dessa används för att reflektera kring problem, utmaningar, framgångsfaktorer samt hedonistiska upplevelser inom processen. Undersökningens bakomliggande teori är baserat på Hedonic-motivation system adoption model (HMSAM) samt kriterier för utvärdering av ett lyckat RtD-projekt. Resultaten visar att spelutveckling är en komplicerad process, där egenskaper av spelutveckling identifierats och som bildat riktlinjer som förbereder akademiker inför framtida forskning och arbete. / The gaming industry is gigantic and continuously growing, which includes game development and gaming. This means that a significant number of academics will touch on the subject area of game development during their professional lives. Despite this fact there is a lack of academic literature which deals with the subject area of game development, specifically with an IS perspective. To fill the gap, this study aims to expand the specific concept in game development that is “creation of a 2D game engine with an associated game”. Gaming involves hedonistic experiences. Is this also associated with game development? What challenges and problems arise when developing a game engine? Answering this involves a qualitative study with an inductive methodology via Research through Design (RtD) together with Collaborative Autoethnography (CAE). This creates a unique perspective that is used to produce well-motivated guidance for introduction to the subject area. Data collection consists of a journal and diary where these are used to reflect on problems, challenges, success factors and hedonistic experiences within the process. The study’s underlying theory is based on the Hedonic-motivation system adoption model (HMSAM) and criterias for evaluating successful RtD projects. The results show that game development is a complicated process, where characteristics of game development have been identified which developed guidelines that prepare academics for future research and work.
65

Highly selective mesoporous sorbents for mercury removal from industrial wastewater

Godongwana, Ziboneni Governor January 2011 (has links)
The results of this study show that novel mesoporous carbons were obtained as inverse replica of SBA-15, HMS and MCM-41 silica templates, with a large pore diameter (2-4 nm), a BET surface area of 1867, 874 and 910 m2g –1 respectively for CA_SBA-15_LPG_105, CA_HMS_LPG_80 and CA_MCM- 41_LPG_80 with bimodal pore size distribution (PSD) in the mesopores range. The results obtained show that mesoporous carbon with graphitic structures can be synthesized via the LPG route.
66

Highly selective mesoporous sorbents for mercury removal from industrial wastewater

Godongwana, Ziboneni Governor January 2011 (has links)
The results of this study show that novel mesoporous carbons were obtained as inverse replica of SBA-15, HMS and MCM-41 silica templates, with a large pore diameter (2-4 nm), a BET surface area of 1867, 874 and 910 m2g –1 respectively for CA_SBA-15_LPG_105, CA_HMS_LPG_80 and CA_MCM- 41_LPG_80 with bimodal pore size distribution (PSD) in the mesopores range. The results obtained show that mesoporous carbon with graphitic structures can be synthesized via the LPG route.
67

Accumulation and colloidal mobilization of trace heavy metals in soil irrigated with treated wastewater / Immobilisation et transport colloidal des métaux lourds en concentrations traces dans les sols irrigués par des effluents urbains traités

Pontoni, Ludovico 15 December 2016 (has links)
La réutilisation des eaux usées traitées pour l’irrigation est globalement acceptée et pratiquée pour faire face à la pénurie d'eau et économiser les ressources de haute qualité. Bien que cette pratique présente des avantages indéniables et contribue à un usage plus durable de l'eau douce, elle n’est pas exempt de problèmes liés à l'impact potentiel sur la qualité des sols récepteurs et sur les cultures de micropolluants contenus dans l'eau réutilisée. Parmi ces polluants, les métaux lourds (ML) en concentrations traces jouent un rôle primordial en raison de leur présence systématique dans l'eau utilisée et de leur persistance une fois libéré dans l'environnement. Le devenir des ML dans les sols peut difficilement être prédit parce que les mécanismes de mobilité à travers les sols sont extrêmement variés et liés à des phénomènes simultanés et très complexes impliquant différents équilibres chimiques. Les ML, comme beaucoup d'autres contaminants, ne sont pas seulement partagé entre la phase immobile (le sol) et les phases mobiles présentes dans l'eau. En effet, les colloïdes et les nanoparticules agissent comme une troisième phase mobile, avec leurs propres propriétés rhéologiques et des vitesses de migrations qui leur sont propres. Ce dernier aspect a été l'un des principaux objectifs d’étude de la thèse. Plusieurs essais expérimentaux ont été menés en irriguant un sol standard selon l'Organisation de coopération et de développement économiques (OCDE) avec une eau usés traités réel et / ou synthétiques, contenant des ML en concentrations traces. Pour chaque test, un sol spécifique (avec différentes teneurs en matière organique) et des eaux usées traitées de composition différente (avec différentes concentrations en métaux traces, de salinité, de la teneur en matière organique pour les eaux usées synthétiques, ou des eaux usées traitées réelles) ont été choisi afin d'évaluer les effets des conditions différentes sur le devenir global des ML. L'augmentation de la matière organique du sol de 2,5 à 10% a linéairement amélioré la mobilité des Cd, Cu et Ni avec une augmentation de la mobilité maximum de 35,6, 43,7 et 49,19% pour le Cd, Cu et Ni, respectivement. Pour la plupart des expériences, les ML ont été capturés dans la couche superficielle du sol (0,5 à 1 cm). Néanmoins, des pics de contamination ont été détectés à des profondeurs différentes dans les couches plus profondes du sol. L’étude de la composition des lixiviats montre des variations de concentrations fonction du métal étudié et des caractéristiques du sol et des eaux usées. Des pics de métaux dans le lixiviat sont apparus en même temps que la libération de la matière et / ou la libération de silicates organiques, ce qui démontre l'implication significative des colloïdes dans le transport des métaux. La concentration en sodium (20 mM) a été démontrée un impact fort sur la réduction de la mobilisation colloïdale et que plus de 95% du métal apporté a été détecté dans la couche superficielle du sol en dépit de sa teneur en matière organique. La salinité affiche donc des effets significatifs. L'irrigation avec des eaux usées traitées présentant une très haute teneur en Ca et Mg (111 et 134 mg / L, respectivement) a abouti à la libération moyenne plus élevée de silicium à partir de la matrice inorganique du sol (8,2 mg / L) par rapport à la faible salinité des eaux usées artificielle (1,9 mg / L). Par conséquent, la mobilisation ultérieure de Cd, Cu, Ni et Zn a été observée lorsque le sol a été irrigué avec des eaux usées traitées réelles. Une caractérisation spectroscopique avancée des lixiviats a été réalisée pour identifier les agrégats colloïdaux libérés par le sol dans le but d’en déterminer leur nature, leurs propriétés chimiques et leur état d'agrégation / Reuse of treated wastewater for agricultural purposes is worldwide accepted and practiced to face water scarcity and save high quality resources. Although such practice has undoubtable advantages and is certainly more sustainable respect to the use of fresh water, it is not exempt from severe concerns related to the potential impact on the receiving soil and on the crops of potentially harmful pollutants contained in the reused water at trace levels. Among these pollutants, trace heavy metals (HMs) play a primary role due to their spread presence in the used water and to their persistence once released in the environment. The fate of HMs in the soils can be hardly predicted as mechanisms of mobility through soils are extremely diverse and related to highly complex simultaneous phenomena and chemical equilibria. HMs, in fact, as many other contaminants, are not only partitioned between the solid immobile and the water mobile phases. Indeed, colloids and nanoparticles act as a third mobile phase, with their own rheological properties and velocity. This latter aspect has been one of the main focus of the thesis. In details the thesis describes the results of several experiments conducted irrigating the OECD standard soil with real and/or synthetic wastewater, containing HMs in trace. For each test a specific soil (e.g. varying the organic matter content) and wastewater composition (e.g. varying the metals concentration, the salinity, the organic matter content, or testing real treated wastewaters) has been chosen in order to evaluate the effects of different conditions on the overall HMs fate. The increase of soil organic matter from 2,5 to 10% linearly enhanced the mobility of Cd, Cu and Ni up to a maximum mobility increase of 35.6, 43.7 and 49.19 % for Cd, Cu and Ni, respectively. In most experiments metals accumulated in the top soil layer (0.5 - 1 cm). Nevertheless peaks of contamination were detected at different depths in the soil deeper layers and at different leaching time in the leachates depending on the metal and on the soil and wastewater characteristics. Peaks of metals in the leachate appeared simultaneously with release of organic matter and/or release of silicates, demonstrating outstanding involvement of colloids in metals transport. Sodium concentration (20mM) decidedly reduced colloidal mobilization whereas more than 95 % of the influent metal was detected in the top layer despite the soil organic matter content. Salinity displayed different effects. The irrigation with real treated wastewater with quite high content of Ca and Mg (111 and 134 mg/L, respectively) resulted in higher average release of silicon from the soil inorganic matrix (8.2 mg/L) compared to the low salinity artificial wastewater (1.9 mg/L). Consequently higher mobilization of Cd, Cu, Ni and Zn was observed when the soil was irrigated with real treated wastewater. An advanced spectroscopical characterization of the leachates was performed to identify such colloidal aggregates. The observation of 3D excitation-emission matrix demonstrated in all the leachates samples the presence of fulvic (230-450 nm ex-em fluorescence area) and humic (330-445 nm ex-em) substances. In this context, a novel analytical method was developed to quantify phenolic substances in soil matrices allowing the monitoring of humic matter migration in soil profiles. The novel method was more accurate and more precise respect to the traditional one, allowing to obtain higher recovery of total phenols in peat soil (15.5 % increase) with a decrease of the coefficient of variation (30.1% decrease). Organic water soluble colloids were extracted from the peat used to prepare the OECD standard soil and characterized. Results of size exclusion chromatography highlighted the supramolecular structure of the extracted organic matter. Such structure was further confirmed through fluorescence and 1H-NMR spectroscopy
68

Comparison of Hydrologic Model Performance Statistics Using Thiessen Polygon Rain Gauge and NEXRAD Precipitation Input Methods at Different Watershed Spatial Scales and Rainfall Return Frequencies

Tancreto, Amanda E 01 January 2015 (has links)
As hydrological computer modeling software continues to increase in complexity, the need for further understanding of the value of different model input datasets becomes apparent. Frequently used precipitation model input include rain gauge data and next-generation radar–based (NEXRAD) rainfall data. Rain gauge data are usually interpolated across a model domain using various methods including the Thiessen Polygon methodology, which may be data-sparse in some areas and overly data-dense in others. However, rain gauge data are generally very easy to use in hydrologic model development, often requiring little to no data processing. NEXRAD data have the potential to improve hydrologic runoff estimates due to the increased spatial resolution of the data: but has its own issues regarding accuracy, false precipitation indications, and difficulties due to data processing. Previous studies have investigated the value of NEXRAD input versus traditional rain gauge data inputs for hydrologic studies; however, results are inconclusive as to which precipitation source provides more accurate results. Limited work has been done to compare the value of these datasets at multiple spatial scales, especially in Florida, a study area dominated by low topographic drive and sub-tropical weather. In addition, little to no research has been done regarding the value of NEXRAD versus rain gauge data inputs at different rainfall return frequencies. The proposed research will utilize a hydrological rain-runoff model (HEC-HMS) of the Upper St. Johns River Basin, Florida to compare the performance of the two precipitation data input types at various watershed spatial scales and rainfall return frequencies. Statistical analysis of the hydrological model “goodness-of-fit” results will be utilized to assess the watershed scaling and rainfall frequency requirements to xii which NEXRAD data provide little to no advantage over standard rain gauges using the Thiessen Polygon method for estimating rainfall totals across a model domain.
69

Highly selective mesoporous sorbents for mercury removal from industrial wastewater

Godongwana, Ziboneni Governor January 2011 (has links)
Philosophiae Doctor - PhD / The results of this study show that novel mesoporous carbons were obtained as inverse replica of SBA-15, HMS and MCM-41 silica templates, with a large pore diameter (2-4 nm), a BET surface area of 1867, 874 and 910 m2g–1 respectively for CA_SBA-15_LPG_105, CA_HMS_LPG_80 and CA_MCM- 41_LPG_80 with bimodal pore size distribution (PSD) in the mesopores range. The results obtained show that mesoporous carbon with graphitic structures can be synthesized via the LPG route. / South Africa
70

IMPLEMENTING NETCONF AND YANG ON CUSTOM EMBEDDED SYSTEMS

Georges, Krister, Jahnstedt, Per January 2023 (has links)
Simple Network Management Protocol (SNMP) has been the traditional approach for configuring and monitoring network devices, but its limitations in security and automation have driven the exploration of alternative solutions. The Network Configuration Protocol (NETCONF) and Yet Another Next Generation (YANG) data modeling language significantly improve security and automation capabilities. This thesis aims to investigate the feasibility of implementing a NETCONF server on the Anybus CompactCom (ABCC) Industrial Internet of Things (IIoT) Security module, an embedded device with limited processing power and memory, running on a custom operating system, and using open source projects with MbedTLS as the cryptographic primitive library. The project will assess implementing a YANG model to describe the ABCC’s configurable interface, connecting with a NETCONF client to exchange capabilities, monitoring specific attributes or interfaces on the device, and invoking remote procedure call (RPC) commands to configure the ABCC settings. The goal is to provide a proof of concept and contribute to the growing trend of adopting NETCONF and YANG in the industry, particularly for the Industrial Internet of Things (IIoT) platform of Hardware Meets Software (HMS).

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