962 resultados para Marine systems modelling
Resumo:
The bioavailability of metals and their potential for environmental pollution depends not simply on total concentrations, but is to a great extent determined by their chemical form. Consequently, knowledge of aqueous metal species is essential in investigating potential metal toxicity and mobility. The overall aim of this thesis is, thus, to determine the species of major and trace elements and the size distribution among the different forms (e.g. ions, molecules and mineral particles) in selected metal-enriched Boreal river and estuarine systems by utilising filtration techniques and geochemical modelling. On the basis of the spatial physicochemical patterns found, the fractionation and complexation processes of elements (mainly related to input of humic matter and pH-change) were examined. Dissolved (<1 kDa), colloidal (1 kDa-0.45 μm) and particulate (>0.45 μm) size fractions of sulfate, organic carbon (OC) and 44 metals/metalloids were investigated in the extremely acidic Vörå River system and its estuary in W Finland, and in four river systems in SW Finland (Sirppujoki, Laajoki, Mynäjoki and Paimionjoki), largely affected by soil erosion and acid sulfate (AS) soils. In addition, geochemical modelling was used to predict the formation of free ions and complexes in these investigated waters. One of the most important findings of this study is that the very large amounts of metals known to be released from AS soils (including Al, Ca, Cd, Co, Cu, Mg, Mn, Na, Ni, Si, U and the lanthanoids) occur and can prevail mainly in toxic forms throughout acidic river systems; as free ions and/or sulfate-complexes. This has serious effects on the biota and especially dissolved Al is expected to have acute effects on fish and other organisms, but also other potentially toxic dissolved elements (e.g. Cd, Cu, Mn and Ni) can have fatal effects on the biota in these environments. In upstream areas that are generally relatively forested (higher pH and contents of OC) fewer bioavailable elements (including Al, Cu, Ni and U) may be found due to complexation with the more abundantly occurring colloidal OC. In the rivers in SW Finland total metal concentrations were relatively high, but most of the elements occurred largely in a colloidal or particulate form and even elements expected to be very soluble (Ca, K, Mg, Na and Sr) occurred to a large extent in colloidal form. According to geochemical modelling, these patterns may only to a limited extent be explained by in-stream metal complexation/adsorption. Instead there were strong indications that the high metal concentrations and dominant solid fractions were largely caused by erosion of metal bearing phyllosilicates. A strong influence of AS soils, known to exist in the catchment, could be clearly distinguished in the Sirppujoki River as it had very high concentrations of a metal sequence typical of AS soils in a dissolved form (Ba, Br, Ca, Cd, Co, K, Mg, Mn, Na, Ni, Rb and Sr). In the Paimionjoki River, metal concentrations (including Ba, Cs, Fe, Hf, Pb, Rb, Si, Th, Ti, Tl and V; not typical of AS soils in the area) were high, but it was found that the main cause of this was erosion of metal bearing phyllosilicates and thus these metals occurred dominantly in less toxic colloidal and particulate fractions. In the two nearby rivers (Laajoki and Mynäjoki) there was influence of AS soils, but it was largely masked by eroded phyllosilicates. Consequently, rivers draining clay plains sensitive to erosion, like those in SW Finland, have generally high background metal concentrations due to erosion. Thus, relying on only semi-dissolved (<0.45 μm) concentrations obtained in routine monitoring, or geochemical modelling based on such data, can lead to a great overestimation of the water toxicity in this environment. The potentially toxic elements that are of concern in AS soil areas will ultimately be precipitated in the recipient estuary or sea, where the acidic metalrich river water will gradually be diluted/neutralised with brackish seawater. Along such a rising pH gradient Al, Cu and U will precipitate first together with organic matter closest to the river mouth. Manganese is relatively persistent in solution and, thus, precipitates further down the estuary as Mn oxides together with elements such as Ba, Cd, Co, Cu and Ni. Iron oxides, on the contrary, are not important scavengers of metals in the estuary, they are predicted to be associated only with As and PO4.
Resumo:
This paper presents the kinematic study of robotic biped locomotion systems. The main purpose is to determine the kinematic characteristics and the system performance during walking. For that objective, the prescribed motion of the biped is completely characterised in terms of five locomotion variables: step length, hip height, maximum hip ripple, maximum foot clearance and link lengths. In this work, we propose four methods to quantitatively measure the performance of the walking robot: energy analysis, perturbation analysis, lowpass frequency response and locomobility measure. These performance measures are discussed and compared in determining the robustness and effectiveness of the resulting locomotion.
Resumo:
The increasing complexity of controller systems, applied in modern passenger cars, requires adequate simulation tools. The toolset FASIM_C++, described in the following, uses complex vehicle models in three-dimensional vehicle dynamics simulation. The structure of the implemented dynamic models and the generation of the equations of motion applying the method of kinematic differentials is explained briefly. After a short introduction in methods of event handling, several vehicle models and applications like controller development, roll-over simulation and real-time-simulation are explained. Finally some simulation results are presented.
Resumo:
The accuracy of modelling of rotor systems composed of rotors, oil film bearings and a flexible foundation, is evaluated and discussed in this paper. The model validation of different models has been done by comparing experimental results with numerical results by means. The experimental data have been obtained with a fully instrumented four oil film bearing, two shafts test rig. The fault models are then used in the frame of a model based malfunction identification procedure, based on a least square fitting approach applied in the frequency domain. The capability of distinguishing different malfunctions has been investigated, even if they can create similar effects (such as unbalance, rotor bow, coupling misalignment and others) from shaft vibrations measured in correspondence of the bearings.
Resumo:
Transmission system operators and distribution system operators are experiencing new challenges in terms of reliability, power quality, and cost efficiency. Although the potential of energy storages to face those challenges is recognized, the economic implications are still obscure, which introduce the risk into the business models. This thesis aims to investigate the technical and economic value indicators of lithium-ion battery energy storage systems (BESS) in grid-scale applications. In order to do that, a comprehensive performance lithium-ion BESS model with degradation effects estimation is developed. The model development process implies literature review on lifetime modelling, use, and modification of previous study progress, building the additional system parts and integrating it into a complete tool. The constructed model is capable of describing the dynamic behavior of the BESS voltage, state of charge, temperature and capacity loss. Five control strategies for BESS unit providing primary frequency regulation are implemented, in addition to the model. The questions related to BESS dimensioning and the end of life (EoL) criterion are addressed. Simulations are performed with one-month real frequency data acquired from Fingrid. The lifetime and cost-benefit analysis of the simulation results allow to compare and determine the preferable control strategy. Finally, the study performs the sensitivity analysis of economic profitability with variable size, EoL and system price. The research reports that BESS can be profitable in certain cases and presents the recommendations.
Resumo:
The study revealed the potential of marine yeasts as a source of single cell protein and immunostimulant for prawns. Prawns fed with the selected marine yeasts were showing more growth compared to the control feed and commercial feed. Yeasts being rich with proteins, vitamins and carbohydrates serve as a growth promoter for prawns as being evidenced in this study. The better performance of marine yeasts, D. hansenii S8 and S100 and C. tropicalis S186 compared to S. cerevisiae S36 as a feed supplement is worth investigating. Besides being a rich nutritional source, yeasts act as immunostimulants by virtue of its high carbohydrate (Beta, 1-3 glucan) and RNA content. Beta, 1-3 glucan, a cell wall component of yeasts /fungi is the most commonly used immunostimulant in aquaculture. The present study shows that even the whole cell yeast could serve as a good immunostimulant when supplied through diet. Extraction of Beta-1,3 glucan results in the removal of nutrients like proteins, vitamins etc. from the cell biomass.Utilization of the yeast biomass as such in the diet would help perform a dual role as nutritional component and immunostimulant for aquaculture applications.
Resumo:
Sharing of information with those in need of it has always been an idealistic goal of networked environments. With the proliferation of computer networks, information is so widely distributed among systems, that it is imperative to have well-organized schemes for retrieval and also discovery. This thesis attempts to investigate the problems associated with such schemes and suggests a software architecture, which is aimed towards achieving a meaningful discovery. Usage of information elements as a modelling base for efficient information discovery in distributed systems is demonstrated with the aid of a novel conceptual entity called infotron.The investigations are focused on distributed systems and their associated problems. The study was directed towards identifying suitable software architecture and incorporating the same in an environment where information growth is phenomenal and a proper mechanism for carrying out information discovery becomes feasible. An empirical study undertaken with the aid of an election database of constituencies distributed geographically, provided the insights required. This is manifested in the Election Counting and Reporting Software (ECRS) System. ECRS system is a software system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous statutory reports.Most of the distributed systems of the nature of ECRS normally will possess a "fragile architecture" which would make them amenable to collapse, with the occurrence of minor faults. This is resolved with the help of the penta-tier architecture proposed, that contained five different technologies at different tiers of the architecture.The results of experiment conducted and its analysis show that such an architecture would help to maintain different components of the software intact in an impermeable manner from any internal or external faults. The architecture thus evolved needed a mechanism to support information processing and discovery. This necessitated the introduction of the noveI concept of infotrons. Further, when a computing machine has to perform any meaningful extraction of information, it is guided by what is termed an infotron dictionary.The other empirical study was to find out which of the two prominent markup languages namely HTML and XML, is best suited for the incorporation of infotrons. A comparative study of 200 documents in HTML and XML was undertaken. The result was in favor ofXML.The concept of infotron and that of infotron dictionary, which were developed, was applied to implement an Information Discovery System (IDS). IDS is essentially, a system, that starts with the infotron(s) supplied as clue(s), and results in brewing the information required to satisfy the need of the information discoverer by utilizing the documents available at its disposal (as information space). The various components of the system and their interaction follows the penta-tier architectural model and therefore can be considered fault-tolerant. IDS is generic in nature and therefore the characteristics and the specifications were drawn up accordingly. Many subsystems interacted with multiple infotron dictionaries that were maintained in the system.In order to demonstrate the working of the IDS and to discover the information without modification of a typical Library Information System (LIS), an Information Discovery in Library Information System (lDLIS) application was developed. IDLIS is essentially a wrapper for the LIS, which maintains all the databases of the library. The purpose was to demonstrate that the functionality of a legacy system could be enhanced with the augmentation of IDS leading to information discovery service. IDLIS demonstrates IDS in action. IDLIS proves that any legacy system could be augmented with IDS effectively to provide the additional functionality of information discovery service.Possible applications of IDS and scope for further research in the field are covered.
Resumo:
The present study revealed the importance of marine actinomycetes as a potent source of bio active secondary metabolites. The selected isolates were capable of protecting Peaneus monodon against WSSV infection. They also proved to be inhibitory to vibrios and is a rich pool of hydrolytic enzymes. Their capacity to proliferate in saline environments and their property of non-pathogenicity to prawns makes them good candidates to be applied as probionts in penaeid shrimp aquaculture. They also enhanced the immune status of shrimps challenged with WSSV and act as a good source of antioxidants. Exploitation of the potential for the prophylactic and therapeutic measures in aquatic animal health management would be highly rewarding. This work is a preliminary study targeting marine actinomycetes as a source of antiviral compounds and as probionts in Penaeus monodon culture systems. More work is needed to understand the nature and mode of action of the bioactive compound, the various aspects of immune and antioxidant responses under challenge and when exposed to pro active treatments, and the dose and frequency of application of such compounds under rearing conditions.
Resumo:
This thesis Entitled Marine actinomycetes as source of antimicrobial compounds and as probiotics and single cell protein for application in penaeid peawn culture systems. Ocean harbours more than 80% of all life on earth and remains our greatest untapped natural resource. The study revealed the potential of marine actinomycetes as a source of antimicrobial compounds. The selected streptomycetes were found to be capable of inhibiting most of the pathogenic vibrios, whichis a major problem both in hatcheries and grow out systems. The bioactive principle can be incorporated with commercial feeds and applied as medicated diet for the control of vibrios in culture systems.The hydrolytic potential inhibitory property against pathogens and non—pathogenicity to penaeid prawns make the selected Streptomycesspp.an effective probioic in aquaculture. Since there is considerably less inhibition to the natural in pond ecosystem the microbial diversityis being maintained and thereby the water quality. Actinomycetes was found to be a good source of single cell protein as an ingredient inaquaculture feed formulations. Large amount of mycelial waste (actinomycete biomassO is produced from antibiotic industries and this nutrient rich waste can be effectively used as a protein source in aquaculture feeds.This study reveals the importance of marine actinomycetes as a source of antimicrobial compounds and as a probiotic and single cell protein for aquaculture applications.
Resumo:
This thesis attempts to investigate the problems associated with such schemes and suggests a software architecture, which is aimed towards achieving a meaningful discovery. Usage of information elements as a modelling base for efficient information discovery in distributed systems is demonstrated with the aid of a novel conceptual entity called infotron. The investigations are focused on distributed systems and their associated problems. The study was directed towards identifying suitable software architecture and incorporating the same in an environment where information growth is phenomenal and a proper mechanism for carrying out information discovery becomes feasible. An empirical study undertaken with the aid of an election database of constituencies distributed geographically, provided the insights required. This is manifested in the Election Counting and Reporting Software (ECRS) System. ECRS system is a software system, which is essentially distributed in nature designed to prepare reports to district administrators about the election counting process and to generate other miscellaneous statutory reports.
Resumo:
An alkaline protease gene (Eap) was isolated for the first time from a marine fungus, Engyodontium album. Eap consists of an open reading frame of 1,161 bp encoding a prepropeptide consisting of 387 amino acids with a calculated molecular mass of 40.923 kDa. Homology comparison of the deduced amino acid sequence of Eap with other known proteins indicated that Eap encode an extracellular protease that belongs to the subtilase family of serine protease (Family S8). A comparative homology model of the Engyodontium album protease (EAP) was developed using the crystal structure of proteinase K. The model revealed that EAP has broad substrate specificity similar to Proteinase K with preference for bulky hydrophobic residues at P1 and P4. Also, EAP is suggested to have two disulfide bonds and more than two Ca2? binding sites in its 3D structure; both of which are assumed to contribute to the thermostable nature of the protein.
Resumo:
marine bacterium, Micrococcus MCCB 104, isolated from hatchery water, demonstrated extracellular antagonistic properties against Vibrio alginolyticus, V. parahaemolyticus, V. vulnificus, V. fluviallis, V. nereis, V. proteolyticus, V. mediterranei, V. cholerae and Aeromonas sp., bacteria associated with Macrobrachium rosenbergii larval rearing systems. The isolate inhibited the growth of V. alginolyticus during co-culture. The antagonistic component of the extracellular product was heat-stable and insensitive to proteases, lipase, catalase and α-amylase. Micrococcus MCCB 104 was demonstrated to be non-pathogenic to M. rosenbergii larvae
Resumo:
The addition of commercial nitrifying bacterial products has resulted in significant improvement of nitrification efficiency in recirculating aquaculture systems (RAS). We developed two nitrifying bacterial consortia (NBC) from marine and brackish water as start up cultures for immobilizing commercialized nitrifying bioreactors for RAS. In the present study, the community compositions of the NBC were analyzed by universal 16S rRNA gene and bacterial amoA gene sequencing and fluorescence in situ hybridization (FISH). This study demonstrated that both the consortia involved autotrophic nitrifiers, denitrifiers as well as heterotrophs. Abundant taxa of the brackish water heterotrophic bacterial isolates were Paenibacillus and Beijerinckia spp. whereas in the marine consortia they were Flavobacterium, Cytophaga and Gramella species. The bacterial amoA clones were clustered together with high similarity to Nitrosomonas sp. and uncultured beta Proteobacteria. FISH analysis detected ammonia oxidizers belonging to b subclass of proteobacteria and Nitrosospira sp. in both the consortia, and Nitrosococcus mobilis lineage only in the brackish water consortium and the halophilic Nitrosomonas sp. only in the marine consortium. However, nitrite oxidizers, Nitrobacter sp. and phylum Nitrospira were detected in both the consortia. The metabolites from nitrifiers might have been used by heterotrophs as carbon and energy sources making the consortia a stable biofilm.
Resumo:
An alkaline protease gene (Eap) was isolated for the first time from a marine fungus, Engyodontium album. Eap consists of an open reading frame of 1,161 bp encoding a prepropeptide consisting of 387 amino acids with a calculated molecular mass of 40.923 kDa. Homology comparison of the deduced amino acid sequence of Eap with other known proteins indicated that Eap encode an extracellular protease that belongs to the subtilase family of serine protease (Family S8). A comparative homology model of the Engyodontium album protease (EAP) was developed using the crystal structure of proteinase K. The model revealed that EAP has broad substrate specificity similar to Proteinase K with preference for bulky hydrophobic residues at P1 and P4. Also, EAP is suggested to have two disulfide bonds and more than two Ca2? binding sites in its 3D structure; both of which are assumed to contribute to the thermostable nature of the protein.
Resumo:
This lab follows the lecture 'System Design: Using UML Use Cases'http://www.edshare.soton.ac.uk/9619/ It introduces Visual Paradigm as a UML modelling tool. Students work through Visual Paradigm online Tutorials and then create two projects.