Search results for: marine microorganisms
104 Made on Land, Ends Up in the Water "I-Clare" Intelligent Remediation System for Removal of Harmful Contaminants in Water using Modified Reticulated Vitreous Carbon Foam
Authors: Sabina Żołędowska, Tadeusz Ossowski, Robert Bogdanowicz, Jacek Ryl, Paweł Rostkowski, Michał Kruczkowski, Michał Sobaszek, Zofia Cebula, Grzegorz Skowierzak, Paweł Jakóbczyk, Lilit Hovhannisyan, Paweł Ślepski, Iwona Kaczmarczyk, Mattia Pierpaoli, Bartłomiej Dec, Dawid Nidzworski
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The circular economy of water presents a pressing environmental challenge in our society. Water contains various harmful substances, such as drugs, antibiotics, hormones, and dioxides, which can pose silent threats. Water pollution has severe consequences for aquatic ecosystems. It disrupts the balance of ecosystems by harming aquatic plants, animals, and microorganisms. Water pollution poses significant risks to human health. Exposure to toxic chemicals through contaminated water can have long-term health effects, such as cancer, developmental disorders, and hormonal imbalances. However, effective remediation systems can be implemented to remove these contaminants using electrocatalytic processes, which offer an environmentally friendly alternative to other treatment methods, and one of them is the innovative iCLARE system. The project's primary focus revolves around a few main topics: Reactor design and construction, selection of a specific type of reticulated vitreous carbon foams (RVC), analytical studies of harmful contaminants parameters and AI implementation. This high-performance electrochemical reactor will be build based on a novel type of electrode material. The proposed approach utilizes the application of reticulated vitreous carbon foams (RVC) with deposited modified metal oxides (MMO) and diamond thin films. The following setup is characterized by high surface area development and satisfactory mechanical and electrochemical properties, designed for high electrocatalytic process efficiency. The consortium validated electrode modification methods that are the base of the iCLARE product and established the procedures for the detection of chemicals detection: - deposition of metal oxides WO3 and V2O5-deposition of boron-doped diamond/nanowalls structures by CVD process. The chosen electrodes (porous Ferroterm electrodes) were stress tested for various parameters that might occur inside the iCLARE machine–corosis, the long-term structure of the electrode surface during electrochemical processes, and energetic efficacy using cyclic polarization and electrochemical impedance spectroscopy (before and after electrolysis) and dynamic electrochemical impedance spectroscopy (DEIS). This tool allows real-time monitoring of the changes at the electrode/electrolyte interphase. On the other hand, the toxicity of iCLARE chemicals and products of electrolysis are evaluated before and after the treatment using MARA examination (IBMM) and HPLC-MS-MS (NILU), giving us information about the harmfulness of using electrode material and the efficiency of iClare system in the disposal of pollutants. Implementation of data into the system that uses artificial intelligence and the possibility of practical application is in progress (SensDx).Keywords: waste water treatement, RVC, electrocatalysis, paracetamol
Procedia PDF Downloads 88103 The Impact of Climate Change on Sustainable Aquaculture Production
Authors: Peyman Mosberian-Tanha, Mona Rezaei
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Aquaculture sector is the fastest growing food sector with annual growth rate of about 10%. The sustainability of aquaculture production, however, has been debated mainly in relation to the feed ingredients used for farmed fish. The industry has been able to decrease its dependency on marine-based ingredients in line with policies for more sustainable production. As a result, plant-based ingredients have increasingly been incorporated in aquaculture feeds, especially in feeds for popular carnivorous species, salmonids. The effect of these ingredients on salmonids’ health and performance has been widely studied. In most cases, plant-based diets are associated with varying degrees of health and performance issues across salmonids, partly depending on inclusion levels of plant ingredients and the species in question. However, aquaculture sector is facing another challenge of concern. Environmental challenges in association with climate change is another issue the aquaculture sector must deal with. Data from trials in salmonids subjected to environmental challenges of various types show adverse physiological responses, partly in relation to stress. To date, there are only a limited number of studies reporting the interactive effects of adverse environmental conditions and dietary regimens on salmonids. These studies have shown that adverse environmental conditions exacerbate the detrimental effect of plant-based diets on digestive function and health in salmonids. This indicates an additional challenge for the aquaculture sector to grow in a sustainable manner. The adverse environmental conditions often studied in farmed fish is the change in certain water quality parameters such as oxygen and/or temperature that are typically altered in response to climate change and, more specifically, global warming. In a challenge study, we observed that the in the fish fed a plant-based diet, the fish’s ability to absorb dietary energy was further reduced when reared under low oxygen level. In addition, gut health in these fish was severely impaired. Some other studies also confirm the adverse effect of environmental challenge on fish’s gut health. These effects on the digestive function and gut health of salmonids may result in less resistance to diseases and weaker performance with significant economic and ethical implications. Overall, various findings indicate the multidimensional negative effects of climate change, as a major environmental issue, in different sectors, including aquaculture production. Therefore, a comprehensive evaluation of different ways to cope with climate change is essential for planning more sustainable strategies in aquaculture sector.Keywords: aquaculture, climate change, sustainability, salmonids
Procedia PDF Downloads 188102 Optimization Based Design of Decelerating Duct for Pumpjets
Authors: Mustafa Sengul, Enes Sahin, Sertac Arslan
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Pumpjets are one of the marine propulsion systems frequently used in underwater vehicles nowadays. The reasons for frequent use of pumpjet as a propulsion system are that it has higher relative efficiency at high speeds, better cavitation, and acoustic performance than its rivals. Pumpjets are composed of rotor, stator, and duct, and there are two different types of pumpjet configurations depending on the desired hydrodynamic characteristic, which are with accelerating and decelerating duct. Pumpjet with an accelerating channel is used at cargo ships where it works at low speeds and high loading conditions. The working principle of this type of pumpjet is to maximize the thrust by reducing the pressure of the fluid through the channel and throwing the fluid out from the channel with high momentum. On the other hand, for decelerating ducted pumpjets, the main consideration is to prevent the occurrence of the cavitation phenomenon by increasing the pressure of the fluid about the rotor region. By postponing the cavitation, acoustic noise naturally falls down, so decelerating ducted systems are used at noise-sensitive vehicle systems where acoustic performance is vital. Therefore, duct design becomes a crucial step during pumpjet design. This study, it is aimed to optimize the duct geometry of a decelerating ducted pumpjet for a highly speed underwater vehicle by using proper optimization tools. The target output of this optimization process is to obtain a duct design that maximizes fluid pressure around the rotor region to prevent from cavitation and minimizes drag force. There are two main optimization techniques that could be utilized for this process which are parameter-based optimization and gradient-based optimization. While parameter-based algorithm offers more major changes in interested geometry, which makes user to get close desired geometry, gradient-based algorithm deals with minor local changes in geometry. In parameter-based optimization, the geometry should be parameterized first. Then, by defining upper and lower limits for these parameters, design space is created. Finally, by proper optimization code and analysis, optimum geometry is obtained from this design space. For this duct optimization study, a commercial codedparameter-based optimization algorithm is used. To parameterize the geometry, duct is represented with b-spline curves and control points. These control points have x and y coordinates limits. By regarding these limits, design space is generated.Keywords: pumpjet, decelerating duct design, optimization, underwater vehicles, cavitation, drag minimization
Procedia PDF Downloads 209101 The Analysis of Swales Model (Cars Model) in the UMT Final Year Engineering Students
Authors: Kais Amir Kadhim
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Context: The study focuses on the rhetorical structure of chapters in engineering final year projects, specifically the Introduction chapter, written by UMT (University of Marine Technology) engineering students. Existing research has explored the use of genre-based approaches to analyze the writing of final year projects in various disciplines. Research Aim: The aim of this study is to investigate the rhetorical structure of Introduction chapters in engineering final year projects by UMT students. The study aims to identify the frequency of communicative moves and their constituent steps within the Introduction chapters, as well as understand how students justify their research projects. Methodology: The research design will utilize a mixed method approach, combining both quantitative and qualitative methods. Forty Introduction chapters from two different fields in UMT engineering undergraduate programs will be selected for analysis. Findings: The study intends to identify the types of moves present in the Introduction chapters of engineering final year projects by UMT students. Additionally, it aims to determine if these moves and steps are obligatory, conventional, or optional. Theoretical Importance: The study draws upon Bunton's modified CARS (Creating a Research Space) model, which is a conceptual framework used for analyzing the introduction sections of theses. By applying this model, the study contributes to the understanding of the rhetorical structure of Introduction chapters in engineering final year projects. Data Collection: The study will collect data from forty Introduction chapters of engineering final year projects written by UMT engineering students. These chapters will be selected from two different fields within UMT's engineering undergraduate programs. Analysis Procedures: The analysis will involve identifying and categorizing the communicative moves and their constituent steps within the Introduction chapters. The study will utilize both quantitative and qualitative analysis methods to examine the frequency and nature of these moves. Question Addressed: The study aims to address the question of how UMT engineering students structure and justify their research projects within the Introduction chapters of their final year projects. Conclusion: The study aims to contribute to the knowledge of rhetorical structure in engineering final year projects by investigating the Introduction chapters written by UMT engineering students. By using a mixed method research design and applying the modified CARS model, the study intends to identify the types of moves and steps employed by students and explore their justifications for their research projects. The findings have the potential to enhance the understanding of effective academic writing in engineering disciplines.Keywords: cohesive markers, learning, meaning, students
Procedia PDF Downloads 75100 Wave Powered Airlift PUMP for Primarily Artificial Upwelling
Authors: Bruno Cossu, Elio Carlo
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The invention (patent pending) relates to the field of devices aimed to harness wave energy (WEC) especially for artificial upwelling, forced downwelling, production of compressed air. In its basic form, the pump consists of a hydro-pneumatic machine, driven by wave energy, characterised by the fact that it has no moving mechanical parts, and is made up of only two structural components: an hollow body, which is open at the bottom to the sea and partially immersed in sea water, and a tube, both joined together to form a single body. The shape of the hollow body is like a mushroom whose cap and stem are hollow; the stem is open at both ends and the lower part of its surface is crossed by holes; the tube is external and coaxial to the stem and is joined to it so as to form a single body. This shape of the hollow body and the type of connection to the tube allows the pump to operate simultaneously as an air compressor (OWC) on the cap side, and as an airlift on the stem side. The pump can be implemented in four versions, each of which provides different variants and methods of implementation: 1) firstly, for the artificial upwelling of cold, deep ocean water; 2) secondly, for the lifting and transfer of these waters to the place of use (above all, fish farming plants), even if kilometres away; 3) thirdly, for the forced downwelling of surface sea water; 4) fourthly, for the forced downwelling of surface water, its oxygenation, and the simultaneous production of compressed air. The transfer of the deep water or the downwelling of the raised surface water (as for pump versions indicated in points 2 and 3 above), is obtained by making the water raised by the airlift flow into the upper inlet of another pipe, internal or adjoined to the airlift; the downwelling of raised surface water, oxygenation, and the simultaneous production of compressed air (as for the pump version indicated in point 4), is obtained by installing a venturi tube on the upper end of the pipe, whose restricted section is connected to the external atmosphere, so that it also operates like a hydraulic air compressor (trompe). Furthermore, by combining one or more pumps for the upwelling of cold, deep water, with one or more pumps for the downwelling of the warm surface water, the system can be used in an Ocean Thermal Energy Conversion plant to supply the cold and the warm water required for the operation of the same, thus allowing to use, without increased costs, in addition to the mechanical energy of the waves, for the purposes indicated in points 1 to 4, the thermal one of the marine water treated in the process.Keywords: air lifted upwelling, fish farming plant, hydraulic air compressor, wave energy converter
Procedia PDF Downloads 14899 Analysis of Sea Waves Characteristics and Assessment of Potential Wave Power in Egyptian Mediterranean Waters
Authors: Ahmed A. El-Gindy, Elham S. El-Nashar, Abdallah Nafaa, Sameh El-Kafrawy
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The generation of energy from marine energy became one of the most preferable resources since it is a clean source and friendly to environment. Egypt has long shores along Mediterranean with important cities that need energy resources with significant wave energy. No detailed studies have been done on wave energy distribution in the Egyptian waters. The objective of this paper is to assess the energy wave power available in the Egyptian waters for the choice of the most suitable devices to be used in this area. This paper deals the characteristics and power of the offshore waves in the Egyptian waters. Since the field observations of waves are not frequent and need much technical work, the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis data in Mediterranean, with a grid size 0.75 degree, which is a relatively course grid, are considered in the present study for preliminary assessment of sea waves characteristics and power. The used data covers the period from 2012 to 2014. The data used are significant wave height (swh), mean wave period (mwp) and wave direction taken at six hourly intervals, at seven chosen stations, and at grid points covering the Egyptian waters. The wave power (wp) formula was used to calculate energy flux. Descriptive statistical analysis including monthly means and standard deviations of the swh, mwp, and wp. The percentiles of wave heights and their corresponding power are done, as a tool of choice of the best technology suitable for the site. The surfer is used to show spatial distributions of wp. The analysis of data at chosen 7 stations determined the potential of wp off important Egyptian cities. Offshore of Al Saloum and Marsa Matruh, the highest wp occurred in January and February (16.93-18.05) ± (18.08-22.12) kw/m while the lowest occurred in June and October (1.49-1.69) ± (1.45-1.74) kw/m. In front of Alexandria and Rashid, the highest wp occurred in January and February (16.93-18.05) ± (18.08-22.12) kw/m while the lowest occurred in June and September (1.29-2.01) ± (1.31-1.83) kw/m. In front of Damietta and Port Said, the highest wp occurred in February (14.29-17.61) ± (21.61-27.10) kw/m and the lowest occurred in June (0.94-0.96) ± (0.71-0.72) kw/m. In winter, the probabilities of waves higher than 0.8 m in percentage were, at Al Saloum and Marsa Matruh (76.56-80.33) ± (11.62-12.05), at Alexandria and Rashid (73.67-74.79) ± (16.21-18.59) and at Damietta and Port Said (66.28-68.69) ± (17.88-17.90). In spring, the percentiles were, at Al Saloum and Marsa Matruh, (48.17-50.92) ± (5.79-6.56), at Alexandria and Rashid, (39.38-43.59) ± (9.06-9.34) and at Damietta and Port Said, (31.59-33.61) ± (10.72-11.25). In summer, the probabilities were, at Al Saloum and Marsa Matruh (57.70-66.67) ± (4.87-6.83), at Alexandria and Rashid (59.96-65.13) ± (9.14-9.35) and at Damietta and Port Said (46.38-49.28) ± (10.89-11.47). In autumn, the probabilities were, at Al Saloum and Marsa Matruh (58.75-59.56) ± (2.55-5.84), at Alexandria and Rashid (47.78-52.13) ± (3.11-7.08) and at Damietta and Port Said (41.16-42.52) ± (7.52-8.34).Keywords: distribution of sea waves energy, Egyptian Mediterranean waters, waves characteristics, waves power
Procedia PDF Downloads 19198 The Development of Noctiluca scintillans Algal Bloom in Coastal Waters of Muscat, Sulanate of Oman
Authors: Aysha Al Sha'aibi
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Algal blooms of the dinoflagellate species Noctiluca scintillans became frequent events in Omani waters. The current study aims at elucidating the abundance, size variation and observations on the feeding mechanism performed by this species during the winter bloom. An attempt was made, to relate observed biological parameters of the Noctiluca population to environmental factors. Field studies spanned the period from December 2014 to April 2015. Samples were collected from Bandar Rawdah (Muscat region) by Bongo nets, twice per week, from the surface and the integrated upper mixed layer. The measured environmental variables were: temperature, salinity, dissolved oxygen, chlorophyll a, turbidity, nitrite, phosphate, wind speed and rainfall. During the winter bloom (from December 2014 through February 2015), the abundance exhibited the highest concentration on 17 February (640.24×106 cell.L-1) in oblique samples and 83.9x103 cell.L-1 in surface samples, with a subsequent decline up to the end of April. The average number of food vacuoles inside Noctiluca cells was 1.5 per cell; the percentage of feeding Noctiluca compared to the entire population varied from 0.01% to 0.03%. Both the surface area of the Noctiluca symbionts (Pedinomonas noctilucae) and cell diameter were maximal in December. In oblique samples the highest average cell diameter and the surface area of symbiont algae were 751.7 µm and 179.2x103 µm2 respectively. In surface samples, highest average cell diameter and the surface area of symbionts were 760 µm and 284.05x103 µm2 respectively. No significant correlations were detected between Noctiluca’s biological parameters and environmental variables except for the correlation between cell diameter and chlorophyll a, also between symbiotic algae surface area and chlorophyll a. The high correlation of chlorophyll a was as a reason of endosymbiotic algae Pedinomonas noctilucae and green Noctiluca enhanced chlorophyll during bloom. All correlations among biological parameters were significant; they are perhaps one of major factors that mediating high growth rates, generating millions of cell per liter in a short time range. The results gained from this study will provide a beneficial background for understanding deeply the development of coastal algal blooms of Noctiluca scintillans. Moreover, results could be used in different applications related to marine environment.Keywords: abundance, feeding activities, Noctiluca scintillans, Oman
Procedia PDF Downloads 43597 Septic Pulmonary Emboli as a Complication of Peripheral Venous Cannula Insertion
Authors: Ankita Baidya, Vanishri Ganakumar, Ranveer S. Jadon, Piyush Ranjan, Rita Sood
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Septic embolism can have varied presentations and clinical considerations. Infected central venous catheters are commonly associated with septic emboli but peripheral vascular catheters are rarely implicated. We describe a rare case of septic pulmonary emboli related to infected peripheral venous cannulation caused by an unusual etiological agent. A young male presented with complaints of fever, productive cough, sudden onset shortness of breath and cellulitis in both the upper limbs. He was recently hospitalised for dengue fever and administered intravenous fluids through peripheral venous line. The patient was febrile, tachypneic and in respiratory distress, there were multiple pus filled bullae in left hand alongwith swelling and erythema involving right forearm that started at the site of cannulation. Chest examination showed active accessory muscles of respiration, stony dull percussion at the base of right lung and decreased breath sounds at right infrascapular, infraaxillary and mammary area. Other system examination was within normal limits. Chest X-ray revealed bilateral multiple patchy heterogenous peripheral opacities and infiltrates with right-sided pleural effusion. Contrast-enhanced computed tomography (CECT) chest showed feeding vessel sign confirming the diagnosis as septic emboli. Venous Doppler and 2D-echocardiogarm were normal. Laboratory findings showed marked leucocytosis (22000/mm3). Pus aspirate, blood sample, and sputum sample were sent for microbiological testing. The patient was started empirically on ceftriaxone, vancomycin, and clindamycin. The Pus culture and sputum culture showed Klebsiella pneumoniae sensitive to cefoperazone-sulbactum, piperacillin-tazobactum, meropenem and amikacin. The antibiotics were modified accordingly to antimicrobial sensitivity profile to Cefoperazone-sulbactum. Bronchoalveolar lavage (BAL) was done and sent for microbiological investigations. BAL culture showed Klebsiella pneumoniae with same antimicrobial resistance profile. On day 6 of starting cefoperazone-sulbactum, he became afebrile. The skin lesions improved significantly. He was administered 2 weeks of cefoperazone–sulbactum and discharged on oral faropenem for 4 weeks. At the time of discharge, TLC was 11200/mm3 with marked radiological resolution of infection and healed skin lesions. He was kept in regular follow up. Chest X-ray and skin lesions showed complete resolution after 8 weeks. Till date, only couple of case reports of septic emboli through peripheral intravenous line have been reported in English literature. This case highlights that a simple procedure of peripheral intravenous cannulation can lead to catastrophic complication of septic pulmonary emboli and widespread cellulitis if not done with proper care and precautions. Also, the usual pathogens in such clinical settings are gram positive bacteria, but with the history of recent hospitalization, empirical therapy should also cover drug resistant gram negative microorganisms. It also emphasise the importance of appropriate healthcare practices to be taken care during all procedures.Keywords: antibiotics, cannula, Klebsiella pneumoniae, septic emboli
Procedia PDF Downloads 16096 Study on the Use of Manganese-Containing Materials as a Micro Fertilizer Based on the Local Mineral Resources and Industrial Wastes in Hydroponic Systems
Authors: Marine Shavlakadze
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Hydroponic greenhouses systems (production of the artificial substrate without soil) are becoming popular in the world. Mostly the system is used to grow vegetables and berries. Different countries are taking action to participate in the development of hydroponic technology and solutions such as EU members, Turkey, Australia, New Zealand, Israel, Scandinavian countries, etc. Many vegetables and berries are grown by hydroponics in Europe. As a result of our research, we have obtained material containing manganese and nitrogen. It became possible to produce this fertilizer by means of one-stage thermal processing, using industrial waste containing manganese (ores and sludges) and mineral substance (ammonium nitrate) that exist in Georgia. The received material is usable as a micro-fertilizer with economic efficiency. It became possible to turn practically water-insoluble manganese dioxide substance into the soluble condition from industrial waste in an indirect way. The ability to use the material as a fertilizer is predetermined by its chemical and phase composition, as the amount of the active component of the material in relation to manganese is 30%. At the same time, the active component elements presented non-ballast sustained action compounds. The studies implemented in Poland and in Georgia by us have shown that the manganese-containing micro-fertilizer- Mn(NO3)2 can provide the plant with nitrate nitrogen, which is a form that can be used for plants, providing the economy and simplicity of the application of fertilizers. Given the fact that the application of the manganese-containing micro-fertilizers significantly increases the productivity and improves the quality of the big number of agricultural products, it is necessary to mention that it is recommended to introduce the manganese containing fertilizers into the following cultures: sugar beet, corn, potato, vegetables, vine grape, fruit, berries, and other cultures. Also, as a result of the study, it was established that the material obtained is the predominant fertilizer for vegetable cultures in the soil. Based on the positive results of the research, we consider it expedient to conduct research in hydroponic systems, which will enable us to provide plants the required amount of manganese; we also introduce nitrogen in solution and regulate the solution of pH, which is one of the main problems in hydroponic production. The findings of our research will be used in hydroponic greenhouse farms to increase the fertility of vegetable crops and, consequently, to get bountiful and high-quality harvests, which will promote the development of hydroponic greenhouses in Georgia as well as abroad.Keywords: hydroponics, micro-fertilizers, manganese-containing materials, industrial wastes
Procedia PDF Downloads 12995 Magnetic Navigation in Underwater Networks
Authors: Kumar Divyendra
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Underwater Sensor Networks (UWSNs) have wide applications in areas such as water quality monitoring, marine wildlife management etc. A typical UWSN system consists of a set of sensors deployed randomly underwater which communicate with each other using acoustic links. RF communication doesn't work underwater, and GPS too isn't available underwater. Additionally Automated Underwater Vehicles (AUVs) are deployed to collect data from some special nodes called Cluster Heads (CHs). These CHs aggregate data from their neighboring nodes and forward them to the AUVs using optical links when an AUV is in range. This helps reduce the number of hops covered by data packets and helps conserve energy. We consider the three-dimensional model of the UWSN. Nodes are initially deployed randomly underwater. They attach themselves to the surface using a rod and can only move upwards or downwards using a pump and bladder mechanism. We use graph theory concepts to maximize the coverage volume while every node maintaining connectivity with at least one surface node. We treat the surface nodes as landmarks and each node finds out its hop distance from every surface node. We treat these hop-distances as coordinates and use them for AUV navigation. An AUV intending to move closer to a node with given coordinates moves hop by hop through nodes that are closest to it in terms of these coordinates. In absence of GPS, multiple different approaches like Inertial Navigation System (INS), Doppler Velocity Log (DVL), computer vision-based navigation, etc., have been proposed. These systems have their own drawbacks. INS accumulates error with time, vision techniques require prior information about the environment. We propose a method that makes use of the earth's magnetic field values for navigation and combines it with other methods that simultaneously increase the coverage volume under the UWSN. The AUVs are fitted with magnetometers that measure the magnetic intensity (I), horizontal inclination (H), and Declination (D). The International Geomagnetic Reference Field (IGRF) is a mathematical model of the earth's magnetic field, which provides the field values for the geographical coordinateson earth. Researchers have developed an inverse deep learning model that takes the magnetic field values and predicts the location coordinates. We make use of this model within our work. We combine this with with the hop-by-hop movement described earlier so that the AUVs move in such a sequence that the deep learning predictor gets trained as quickly and precisely as possible We run simulations in MATLAB to prove the effectiveness of our model with respect to other methods described in the literature.Keywords: clustering, deep learning, network backbone, parallel computing
Procedia PDF Downloads 9894 Spectroscopic Study of the Anti-Inflammatory Action of Propofol and Its Oxidant Derivatives: Inhibition of the Myeloperoxidase Activity and of the Superoxide Anions Production by Neutrophils
Authors: Pauline Nyssen, Ange Mouithys-Mickalad, Maryse Hoebeke
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Inflammation is a complex physiological phenomenon involving chemical and enzymatic mechanisms. Polymorphonuclear neutrophil leukocytes (PMNs) play an important role by producing reactive oxygen species (ROS) and releasing myeloperoxidase (MPO), a pro-oxidant enzyme. Released both in the phagolysosome and the extracellular medium, MPO produces during its peroxidase and halogenation cycles oxidant species, including hypochlorous acid, involved in the destruction of pathogen agents, like bacteria or viruses. Inflammatory pathologies, like rheumatoid arthritis, atherosclerosis induce an excessive stimulation of the PMNs and, therefore, an uncontrolled release of ROS and MPO in the extracellular medium, causing severe damages to the surrounding tissues and biomolecules such as proteins, lipids, and DNA. The treatment of chronic inflammatory pathologies remains a challenge. For many years, MPO has been used as a target for the development of effective treatments. Numerous studies have been focused on the design of new drugs presenting more efficient MPO inhibitory properties. However, some designed inhibitors can be toxic. An alternative consists of assessing the potential inhibitory action of clinically-known molecules, having antioxidant activity. Propofol, 2,6-diisopropyl phenol, which is used as an intravenous anesthetic agent, meets these requirements. Besides its anesthetic action employed to induce a sedative state during surgery or in intensive care units, propofol and its injectable form Diprivan indeed present antioxidant properties and act as ROS and free radical scavengers. A study has also evidenced the ability of propofol to inhibit the formation of the neutrophil extracellular traps fibers, which are important to trap pathogen microorganisms during the inflammation process. The aim of this study was to investigate the potential inhibitory action mechanism of propofol and Diprivan on MPO activity. To go into the anti-inflammatory action of propofol in-depth, two of its oxidative derivatives, 2,6-diisopropyl-1,4-p-benzoquinone (PPFQ) and 3,5,3’,5’-tetra isopropyl-(4,4’)-diphenoquinone (PPFDQ), were studied regarding their inhibitory action. Specific immunological extraction followed by enzyme detection (SIEFED) and molecular modeling have evidenced the low anti-catalytic action of propofol. Stopped-flow absorption spectroscopy and direct MPO activity analysis have proved that propofol acts as a reversible MPO inhibitor by interacting as a reductive substrate in the peroxidase cycle and promoting the accumulation of redox compound II. Overall, Diprivan exhibited a weaker inhibitory action than the active molecule propofol. In contrast, PPFQ seemed to bind and obstruct the enzyme active site, preventing the trigger of the MPO oxidant cycles. PPFQ induced a better chlorination cycle inhibition at basic and neutral pH in comparison to propofol. PPFDQ did not show any MPO inhibition activity. The three interest molecules have also demonstrated their inhibition ability on an important step of the inflammation pathway, the PMNs superoxide anions production, thanks to EPR spectroscopy and chemiluminescence. In conclusion, propofol presents an interesting immunomodulatory activity by acting as a reductive substrate in the peroxidase cycle of MPO, slowing down its activity, whereas PPFQ acts more as an anti-catalytic substrate. Although PPFDQ has no impact on MPO, it can act on the inflammation process by inhibiting the superoxide anions production by PMNs.Keywords: Diprivan, inhibitor, myeloperoxidase, propofol, spectroscopy
Procedia PDF Downloads 14893 Characterization of the Lytic Bacteriophage VbɸAB-1 against Drug Resistant Acinetobacter baumannii Isolated from Hospitalized Pressure Ulcers Patients
Authors: M. Doudi, M. H. Pazandeh, L. Rahimzadeh Torabi
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Bedsores are pressure ulcers that occur on the skin or tissue due to being immobile and lying in bed for extended periods. Bedsores have the potential to progress into open ulcers, increasing the possibility of variety of bacterial infection. Acinetobacter baumannii, a pathogen of considerable clinical importance, exhibited a significant correlation with Bedsores (pressure ulcers) infections, thereby manifesting a wide spectrum of antibiotic resistance. The emergence of drug resistance has led researchers to focus on alternative methods, particularly phage therapy, for tackling bacterial infections. Phage therapy has emerged as a novel therapeutic approach to regulate the activity of these agents. The management of bacterial infections greatly benefits from the clinical utilization of bacteriophages as a valuable antimicrobial intervention. The primary objective of this investigation consisted of isolating and discerning potent bacteriophage capable of targeting multi drug-resistant (MDR) and extensively drug-resistant (XDR) bacteria obtained from pressure ulcers. In present study, analyzed and isolated A. baumannii strains obtained from a cohort of patients suffering from pressure ulcers at Taleghani Hospital in Ahvaz, Iran. An approach that included biochemical and molecular identification techniques was used to determine the taxonomic classification of bacterial isolates at the genus and species levels. The molecular identification process was facilitated by using the 16S rRNA gene in combination with universal primers 27 F, and 1492 R. Bacteriophage was obtained through the isolation process conducted on treatment plant sewage located in Isfahan, Iran. The main goal of this study was to evaluate different characteristics of phage, such as their appearance, range of hosts they can infect, how quickly they can enter a host, their stability at varying temperatures and pH levels, their effectiveness in killing bacteria, the growth pattern of a single phage stage, mapping of enzymatic digestion, and identification of proteomics patterns. The findings demonstrated that an examination was conducted on a sample of 50 specimens, wherein 15 instances of A. baumannii were identified. These microorganisms are the predominant Gram-negative agents known to cause wound infections in individuals suffering from bedsores. The study's findings indicated a high prevalence of antibiotic resistance in the strains isolated from pressure ulcers, excluding the clinical strains that exhibited responsiveness to colistin.According to the findings obtained from assessments of host range and morphological characteristics of bacteriophage VbɸAB-1, it can be concluded that this phage possesses specificity towards A. Baumannii BAH_Glau1001 was classified as a member of the Plasmaviridae family. The bacteriophage mentioned earlier showed the strongest antibacterial effect at a temperature of 18 °C and a pH of 6.5. Through the utilization of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on protein fragments, it was established that the bacteriophage VbɸAB-1 exhibited a size range between 50 and 75 kilodaltons (KDa). The numerous research findings on the effectiveness of phages and the safety studies conducted suggest that the phages studied in this research can be considered as a practical solution and recommended approach for controlling and treating stubborn pathogens in burn wounds among hospitalized patients.Keywords: acinetobacter baumannii, extremely drug- resistant, phage therapy, surgery wound
Procedia PDF Downloads 9292 Structural and Biochemical Characterization of Red and Green Emitting Luciferase Enzymes
Authors: Wael M. Rabeh, Cesar Carrasco-Lopez, Juliana C. Ferreira, Pance Naumov
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Bioluminescence, the emission of light from a biological process, is found in various living organisms including bacteria, fireflies, beetles, fungus and different marine organisms. Luciferase is an enzyme that catalyzes a two steps oxidation of luciferin in the presence of Mg2+ and ATP to produce oxyluciferin and releases energy in the form of light. The luciferase assay is used in biological research and clinical applications for in vivo imaging, cell proliferation, and protein folding and secretion analysis. The luciferase enzyme consists of two domains, a large N-terminal domain (1-436 residues) that is connected to a small C-terminal domain (440-544) by a flexible loop that functions as a hinge for opening and closing the active site. The two domains are separated by a large cleft housing the active site that closes after binding the substrates, luciferin and ATP. Even though all insect luciferases catalyze the same chemical reaction and share 50% to 90% sequence homology and high structural similarity, they emit light of different colors from green at 560nm to red at 640 nm. Currently, the majority of the structural and biochemical studies have been conducted on green-emitting firefly luciferases. To address the color emission mechanism, we expressed and purified two luciferase enzymes with blue-shifted green and red emission from indigenous Brazilian species Amydetes fanestratus and Phrixothrix, respectively. The two enzymes naturally emit light of different colors and they are an excellent system to study the color-emission mechanism of luciferases, as the current proposed mechanisms are based on mutagenesis studies. Using a vapor-diffusion method and a high-throughput approach, we crystallized and solved the crystal structure of both enzymes, at 1.7 Å and 3.1 Å resolution respectively, using X-ray crystallography. The free enzyme adopted two open conformations in the crystallographic unit cell that are different from the previously characterized firefly luciferase. The blue-shifted green luciferase crystalized as a monomer similar to other luciferases reported in literature, while the red luciferases crystalized as an octamer and was also purified as an octomer in solution. The octomer conformation is the first of its kind for any insect’s luciferase, which might be relate to the red color emission. Structurally designed mutations confirmed the importance of the transition between the open and close conformations in the fine-tuning of the color and the characterization of other interesting mutants is underway.Keywords: bioluminescence, enzymology, structural biology, x-ray crystallography
Procedia PDF Downloads 32691 Geological Characteristics and Hydrocarbon Potential of M’Rar Formation Within NC-210, Atshan Saddle Ghadamis-Murzuq Basins, Libya
Authors: Sadeg M. Ghnia, Mahmud Alghattawi
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The NC-210 study area is located in Atshan Saddle between both Ghadamis and Murzuq basins, west Libya. The preserved Palaeozoic successions are predominantly clastics reaching thickness of more than 20,000 ft in northern Ghadamis Basin depocenter. The Carboniferous series consist of interbedded sandstone, siltstone, shale, claystone and minor limestone deposited in a fluctuating shallow marine to brackish lacustrine/fluviatile environment which attain maximum thickness of over 5,000ft in the area of Atshan Saddle and recorded 3,500 ft. in outcrops of Murzuq Basin flanks. The Carboniferous strata was uplifted and eroded during Late Paleozoic and early Mesozoic time in northern Ghadamis Basin and Atshan Saddle. The M'rar Formation age is Tournaisian to Late Serpukhovian based on palynological markers and contains about 12 cycles of sandstone and shale deposited in shallow to outer neritic deltaic settings. The hydrocarbons in the M'rar reservoirs possibly sourced from the Lower Silurian and possibly Frasinian radioactive hot shales. The M'rar Formation lateral, vertical and thickness distribution is possibly influenced by the reactivation of Tumarline Strik-Slip fault and its conjugate faults. A pronounced structural paleohighs and paleolows, trending SE & NW through the Gargaf Saddle, is possibly indicative of the present of two sub-basins in the area of Atshan Saddle. A number of identified seismic reflectors from existing 2D seismic covering Atshan Saddle reflect M’rar deltaic 12 sandstone cycles. M’rar7, M’rar9, M’rar10 and M’rar12 are characterized by high amplitude reflectors, while M’rar2 and M’rar6 are characterized by medium amplitude reflectors. These horizons are productive reservoirs in the study area. Available seismic data in the study area contributed significantly to the identification of M’rar potential traps, which are prominently 3- way dip closure against fault zone. Also seismic data indicates the presence of a significant strikeslip component with the development of flower-structure. The M'rar Formation hydrocarbon discoveries are concentrated mainly in the Atshan Saddle located in southern Ghadamis Basin, Libya and Illizi Basin in southeast of Algeria. Significant additional hydrocarbons may be present in areas adjacent to the Gargaf Uplift, along structural highs and fringing the Hoggar Uplift, providing suitable migration pathways.Keywords: hydrocarbon potential, stratigraphy, Ghadamis basin, seismic, well data integration
Procedia PDF Downloads 7490 Biomedical Application of Green Biosynthesis Magnetic Iron Oxide (Fe3O4) Nanoparticles Using Seaweed (Sargassum muticum) Aqueous Extract
Authors: Farideh Namvar, Rosfarizan Mohamed
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In the field of nanotechnology, the use of various biological units instead of toxic chemicals for the reduction and stabilization of nanoparticles, has received extensive attention. This use of biological entities to create nanoparticles has designated as “Green” synthesis and it is considered to be far more beneficial due to being economical, eco-friendly and applicable for large-scale synthesis as it operates on low pressure, less input of energy and low temperatures. The lack of toxic byproducts and consequent decrease in degradation of the product renders this technique more preferable over physical and classical chemical methods. The variety of biomass having reduction properties to produce nanoparticles makes them an ideal candidate for fabrication. Metal oxide nanoparticles have been said to represent a "fundamental cornerstone of nanoscience and nanotechnology" due to their variety of properties and potential applications. However, this also provides evidence of the fact that metal oxides include many diverse types of nanoparticles with large differences in chemical composition and behaviour. In this study, iron oxide nanoparticles (Fe3O4-NPs) were synthesized using a rapid, single step and completely green biosynthetic method by reduction of ferric chloride solution with brown seaweed (Sargassum muticum) water extract containing polysaccharides as a main factor which acts as reducing agent and efficient stabilizer. Antimicrobial activity against six microorganisms was tested using well diffusion method. The resulting S-IONPs are crystalline in nature, with a cubic shape. The average particle diameter, as determined by TEM, was found to be 18.01 nm. The S-IONPs were efficiently inhibited the growth of Listeria monocytogenes, Escherichia coli and Candida species. Our favorable results suggest that S-IONPs could be a promising candidate for development of future antimicrobial therapies. The nature of biosynthesis and the therapeutic potential by S-IONPs could pave the way for further research on design of green synthesis therapeutic agents, particularly nanomedicine, to deal with treatment of infections. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial activity of these particles. Antioxidant activity of S-IONPs synthesized by green method was measured by ABTS (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (IC50= 1000µg) radical scavenging activity. Also, with the increasing concentration of S-IONPs, catalase gene expression compared to control gene GAPDH increased. For anti-angiogenesis study the Ross fertilized eggs were divided into four groups; the control and three experimental groups. The gelatin sponges containing albumin were placed on the chorioalantoic membrane and soaked with different concentrations of S-IONPs. All the cases were photographed using a photo stereomicroscope. The number and the lengths of the vessels were measured using Image J software. The crown rump (CR) and weight of the embryo were also recorded. According to the data analysis, the number and length of the blood vessels, as well as the CR and weight of the embryos reduced significantly compared to the control (p < 0.05), dose dependently. The total hemoglobin was quantified as an indicator of the blood vessel formation, and in the treated samples decreased, which showed its inhibitory effect on angiogenesis.Keywords: anti-angiogenesis, antimicrobial, antioxidant, biosynthesis, iron oxide (fe3o4) nanoparticles, sargassum muticum, seaweed
Procedia PDF Downloads 31489 EverPro as the Missing Piece in the Plant Protein Portfolio to Aid the Transformation to Sustainable Food Systems
Authors: Aylin W Sahin, Alice Jaeger, Laura Nyhan, Gregory Belt, Steffen Münch, Elke K. Arendt
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Our current food systems cause an increase in malnutrition resulting in more people being overweight or obese in the Western World. Additionally, our natural resources are under enormous pressure and the greenhouse gas emission increases yearly with a significant contribution to climate change. Hence, transforming our food systems is of highest priority. Plant-based food products have a lower environmental impact compared to their animal-based counterpart, representing a more sustainable protein source. However, most plant-based protein ingredients, such as soy and pea, are lacking indispensable amino acids and extremely limited in their functionality and, thus, in their food application potential. They are known to have a low solubility in water and change their properties during processing. The low solubility displays the biggest challenge in the development of milk alternatives leading to inferior protein content and protein quality in dairy alternatives on the market. Moreover, plant-based protein ingredients often possess an off-flavour, which makes them less attractive to consumers. EverPro, a plant-protein isolate originated from Brewer’s Spent Grain, the most abundant by-product in the brewing industry, represents the missing piece in the plant protein portfolio. With a protein content of >85%, it is of high nutritional value, including all indispensable amino acids which allows closing the protein quality gap of plant proteins. Moreover, it possesses high techno-functional properties. It is fully soluble in water (101.7 ± 2.9%), has a high fat absorption capacity (182.4 ± 1.9%), and a foaming capacity which is superior to soy protein or pea protein. This makes EverPro suitable for a vast range of food applications. Furthermore, it does not cause changes in viscosity during heating and cooling of dispersions, such as beverages. Besides its outstanding nutritional and functional characteristics, the production of EverPro has a much lower environmental impact compared to dairy or other plant protein ingredients. Life cycle assessment analysis showed that EverPro has the lowest impact on global warming compared to soy protein isolate, pea protein isolate, whey protein isolate, and egg white powder. It also contributes significantly less to freshwater eutrophication, marine eutrophication and land use compared the protein sources mentioned above. EverPro is the prime example of sustainable ingredients, and the type of plant protein the food industry was waiting for: nutritious, multi-functional, and environmentally friendly.Keywords: plant-based protein, upcycled, brewers' spent grain, low environmental impact, highly functional ingredient
Procedia PDF Downloads 8088 The Lytic Bacteriophage VbɸAB-1 Against Drug-Resistant Acinetobacter Baumannii Isolated from Hospitalized Pressure Ulcers Patients
Authors: M. Doudi, M. H. Pazandeh, L. Rahimzadeh Torabi
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Bedsores are pressure ulcers that occur on the skin or tissue due to being immobile and lying in bed for extended periods. Bedsores have the potential to progress into open ulcers, increasing the possibility of a variety of bacterial infections. Acinetobacter baumannii, a pathogen of considerable clinical importance, exhibited a significant correlation with Bedsores (pressure ulcers) infections, thereby manifesting a wide spectrum of antibiotic resistance. The emergence of drug resistance has led researchers to focus on alternative methods, particularly phage therapy, for tackling bacterial infections. Phage therapy has emerged as a novel therapeutic approach to regulate the activity of these agents. The management of bacterial infections greatly benefits from the clinical utilization of bacteriophages as a valuable antimicrobial intervention. The primary objective of this investigation consisted of isolating and discerning potent bacteriophage capable of targeting multi-drug-resistant (MDR) and extensively drug-resistant (XDR) bacteria obtained from pressure ulcers. The present study analyzed and isolated A. baumannii strains obtained from a cohort of patients suffering from pressure ulcers at Taleghani Hospital in Ahvaz, Iran. An approach that included biochemical and molecular identification techniques was used to determine the taxonomic classification of bacterial isolates at the genus and species levels. The molecular identification process was facilitated by using the 16S rRNA gene in combination with universal primers 27 F and 1492 R. Bacteriophage was obtained through the isolation process conducted on treatment plant sewage located in Isfahan, Iran. The main goal of this study was to evaluate different characteristics of phage, such as their appearance, the range of hosts they can infect, how quickly they can enter a host, their stability at varying temperatures and pH levels, their effectiveness in killing bacteria, the growth pattern of a single phage stage, mapping of enzymatic digestion, and identification of proteomics patterns. The findings demonstrated that an examination was conducted on a sample of 50 specimens, wherein 15 instances of A. baumannii were identified. These microorganisms are the predominant Gram-negative agents known to cause wound infections in individuals suffering from bedsores. The study's findings indicated a high prevalence of antibiotic resistance in the strains isolated from pressure ulcers, excluding the clinical strains that exhibited responsiveness to colistin. According to the findings obtained from assessments of host range and morphological characteristics of bacteriophage VbɸAB-1, it can be concluded that this phage possesses specificity towards A. Baumannii BAH_Glau1001 was classified as a member of the Podoviridae family. The bacteriophage mentioned earlier showed the strongest antibacterial effect at a temperature of 18 °C and a pH of 6.5. Through the utilization of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis on protein fragments, it was established that the bacteriophage VbɸAB-1 exhibited a size range between 50 and 75 kilodaltons (KDa). The numerous research findings on the effectiveness of phages and the safety studies conducted suggest that the phages studied in this research can be considered as a practical solution and recommended approach for controlling and treating stubborn pathogens in burn wounds among hospitalized patients. The findings of our research indicated that isolated phages could be an effective antimicrobial and an appreciate candidate for prophylaxis against pressure ulcers.Keywords: acinetobacter baumannii, extremely drug-resistant, phage therapy, surgery wound
Procedia PDF Downloads 9087 A Comparison of Tsunami Impact to Sydney Harbour, Australia at Different Tidal Stages
Authors: Olivia A. Wilson, Hannah E. Power, Murray Kendall
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Sydney Harbour is an iconic location with a dense population and low-lying development. On the east coast of Australia, facing the Pacific Ocean, it is exposed to several tsunamigenic trenches. This paper presents a component of the most detailed assessment of the potential for earthquake-generated tsunami impact on Sydney Harbour to date. Models in this study use dynamic tides to account for tide-tsunami interaction. Sydney Harbour’s tidal range is 1.5 m, and the spring tides from January 2015 that are used in the modelling for this study are close to the full tidal range. The tsunami wave trains modelled include hypothetical tsunami generated from earthquakes of magnitude 7.5, 8.0, 8.5, and 9.0 MW from the Puysegur and New Hebrides trenches as well as representations of the historical 1960 Chilean and 2011 Tohoku events. All wave trains are modelled for the peak wave to coincide with both a low tide and a high tide. A single wave train, representing a 9.0 MW earthquake at the Puysegur trench, is modelled for peak waves to coincide with every hour across a 12-hour tidal phase. Using the hydrodynamic model ANUGA, results are compared according to the impact parameters of inundation area, depth variation and current speeds. Results show that both maximum inundation area and depth variation are tide dependent. Maximum inundation area increases when coincident with a higher tide, however, hazardous inundation is only observed for the larger waves modelled: NH90high and P90high. The maximum and minimum depths are deeper on higher tides and shallower on lower tides. The difference between maximum and minimum depths varies across different tidal phases although the differences are slight. Maximum current speeds are shown to be a significant hazard for Sydney Harbour; however, they do not show consistent patterns according to tide-tsunami phasing. The maximum current speed hazard is shown to be greater in specific locations such as Spit Bridge, a narrow channel with extensive marine infrastructure. The results presented for Sydney Harbour are novel, and the conclusions are consistent with previous modelling efforts in the greater area. It is shown that tide must be a consideration for both tsunami modelling and emergency management planning. Modelling with peak tsunami waves coinciding with a high tide would be a conservative approach; however, it must be considered that maximum current speeds may be higher on other tides.Keywords: emergency management, sydney, tide-tsunami interaction, tsunami impact
Procedia PDF Downloads 24286 Modeling Search-And-Rescue Operations by Autonomous Mobile Robots at Sea
Authors: B. Kriheli, E. Levner, T. C. E. Cheng, C. T. Ng
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During the last decades, research interest in planning, scheduling, and control of emergency response operations, especially people rescue and evacuation from the dangerous zone of marine accidents, has increased dramatically. Until the survivors (called ‘targets’) are found and saved, it may cause loss or damage whose extent depends on the location of the targets and the search duration. The problem is to efficiently search for and detect/rescue the targets as soon as possible with the help of intelligent mobile robots so as to maximize the number of saved people and/or minimize the search cost under restrictions on the amount of saved people within the allowable response time. We consider a special situation when the autonomous mobile robots (AMR), e.g., unmanned aerial vehicles and remote-controlled robo-ships have no operator on board as they are guided and completely controlled by on-board sensors and computer programs. We construct a mathematical model for the search process in an uncertain environment and provide a new fast algorithm for scheduling the activities of the autonomous robots during the search-and rescue missions after an accident at sea. We presume that in the unknown environments, the AMR’s search-and-rescue activity is subject to two types of error: (i) a 'false-negative' detection error where a target object is not discovered (‘overlooked') by the AMR’s sensors in spite that the AMR is in a close neighborhood of the latter and (ii) a 'false-positive' detection error, also known as ‘a false alarm’, in which a clean place or area is wrongly classified by the AMR’s sensors as a correct target. As the general resource-constrained discrete search problem is NP-hard, we restrict our study to finding local-optimal strategies. A specificity of the considered operational research problem in comparison with the traditional Kadane-De Groot-Stone search models is that in our model the probability of the successful search outcome depends not only on cost/time/probability parameters assigned to each individual location but, as well, on parameters characterizing the entire history of (unsuccessful) search before selecting any next location. We provide a fast approximation algorithm for finding the AMR route adopting a greedy search strategy in which, in each step, the on-board computer computes a current search effectiveness value for each location in the zone and sequentially searches for a location with the highest search effectiveness value. Extensive experiments with random and real-life data provide strong evidence in favor of the suggested operations research model and corresponding algorithm.Keywords: disaster management, intelligent robots, scheduling algorithm, search-and-rescue at sea
Procedia PDF Downloads 17285 Detailed Ichnofacies and Sedimentological Analysis of the Cambrian Succession (Tal Group) of the Nigalidhar Syncline, Lesser Himalaya, India and the Interpretation of Its Palaeoenvironment
Authors: C. A. Sharma, Birendra P. Singh
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Ichnofacies analysis is considered the best paleontological tool for interpreting ancient depositional environments. Nineteen (19) ichnogenera (namely: Bergaueria, Catenichnus, Cochlichnus, Cruziana, Diplichnites, Dimorphichnus, Diplocraterion, Gordia, Guanshanichnus, Lockeia, Merostomichnites, Monomorphichnus, Palaeophycus, Phycodes, Planolites, Psammichnites, Rusophycus, Skolithos and Treptichnus) are recocered from the Tal Group (Cambrian) of the Nigalidhar Syncline. The stratigraphic occurrences of these ichnogenera represent alternating proximal Cruziana and Skolithos ichnofacies along the contact of Sankholi and Koti-Dhaman formations of the Tal Group. Five ichnogenera namely Catenichnus, Guanshanichnus, Lockeia, Merostomichnites and Psammichnites are recorded for the first time from the Nigalidhar Syncline. Cruziana ichnofacies is found in the upper part of the Sankholi Formation to the lower part of the Koti Dhaman Formation in the NigaliDhar Syncline. The preservational characters here indicate a subtidal environmental condition with poorly sorted, unconsolidated substrate. Depositional condition ranging from moderate to high energy levels below the fair weather base but above the storm wave base under nearshore to foreshore setting in a wave dominated shallow water environment is also indicated. The proximal Cruziana-ichnofacies is interrupted by the Skolithos ichnofacies in the Tal Group of the Nigalidhar Syncline which indicate fluctuating high energy condition which was unfavorable for the opportunistic organism which were dominant during the proximal Cruziana ichnofacies. The excursion of Skolithos ichnofacies (as a pipe rock in the upper part of Sankholi Formation) into the proximal Cruziana ichnofacies in the Tal Group indicate that increased energy and allied parameters attributed to the high rate of sedimentation near the proximal part of the basin. The level bearing the Skolithos ichnofacies in the Nigalidhar Syncline at the juncture of Sankholi and Koti-Dhaman formations can be correlated to the level marked as unconformity in between the Deo-Ka-Tibba and the Dhaulagiri formations by the conglomeratic horizon in the Mussoorie Syncline, Lesser Himalaya, India. Thus, the Tal Group of the Nigalidhar syncline at this stratigraphic level represent slightly deeper water condition than the Mussoorie Syncline, where in the later the aerial exposure dominated which leads to the deposition of conglomeratic horizon and subsequent formation of unconformity. The overall ichnological and sedimentological dataset allow us to infer that the Cambrian successions of Nigalidhar Syncline were deposited in a wave-dominated proximal part of the basin under the foreshore to close to upper shoreface regimes of the shallow marine setting.Keywords: Cambrian, Ichnofacies, Lesser Himalaya, Nigalidhar, Tal Group
Procedia PDF Downloads 25884 Developing Methodology of Constructing the Unified Action Plan for External and Internal Risks in University
Authors: Keiko Tamura, Munenari Inoguchi, Michiyo Tsuji
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When disasters occur, in order to raise the speed of each decision making and response, it is common that delegation of authority is carried out. This tendency is particularly evident when the department or branch of the organization are separated by the physical distance from the main body; however, there are some issues to think about. If the department or branch is too dependent on the head office in the usual condition, they might feel lost in the disaster response operation when they are face to the situation. Avoiding this problem, an organization should decide how to delegate the authority and also who accept the responsibility for what before the disaster. This paper will discuss about the method which presents an approach for executing the delegation of authority process, implementing authorities, management by objectives, and preparedness plans and agreement. The paper will introduce the examples of efforts for the three research centers of Niigata University, Japan to arrange organizations capable of taking necessary actions for disaster response. Each center has a quality all its own. One is the center for carrying out the research in order to conserve the crested ibis (or Toki birds in Japanese), the endangered species. The another is the marine biological laboratory. The third one is very unique because of the old growth forests maintained as the experimental field. Those research centers are in the Sado Island, located off the coast of Niigata Prefecture, is Japan's second largest island after Okinawa and is known for possessing a rich history and culture. It takes 65 minutes jetfoil (high-speed ferry) ride to get to Sado Island from the mainland. The three centers are expected to be easily isolated at the time of a disaster. A sense of urgency encourages 3 centers in the process of organizational restructuring for enhancing resilience. The research team from the risk management headquarters offer those procedures; Step 1: Offer the hazard scenario based on the scientific evidence, Step 2: Design a risk management organization for disaster response function, Step 3: Conduct the participatory approach to make consensus about the overarching objectives, Step 4: Construct the unified operational action plan for 3 centers, Step 5: Simulate how to respond in each phase based on the understanding the various phases of the timeline of a disaster. Step 6: Document results to measure performance and facilitate corrective action. This paper shows the result of verifying the output and effects.Keywords: delegation of authority, disaster response, risk management, unified command
Procedia PDF Downloads 12583 Time to Retire Rubber Crumb: How Soft Fall Playgrounds are Threatening Australia’s Great Barrier Reef
Authors: Michelle Blewitt, Scott P. Wilson, Heidi Tait, Juniper Riordan
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Rubber crumb is a physical and chemical pollutant of concern for the environment and human health, warranting immediate investigations into its pathways to the environment and potential impacts. This emerging microplastic is created by shredding end-of-life tyres into ‘rubber crumb’ particles between 1-5mm used on synthetic turf fields and soft-fall playgrounds as a solution to intensifying tyre waste worldwide. Despite having known toxic and carcinogenic properties, studies into the transportation pathways and movement patterns of rubber crumbs from these surfaces remain in their infancy. To address this deficit, AUSMAP, the Australian Microplastic Assessment Project, in partnership with the Tangaroa Blue Foundation, conducted a study to quantify crumb loss from soft-fall surfaces. To our best knowledge, this is the first of its kind, with funding for the audits being provided by the Australian Government’s Reef Trust. Sampling occurred at 12 soft-fall playgrounds within the Great Barrier Reef Catchment Area on Australia’s North-East coast, in close proximity to the United Nations World Heritage Listed Reef. Samples were collected over a 12-month period using randomized sediment cores at 0, 2 and 4 meters away from the playground edge along a 20-meter transect. This approach facilitated two objectives pertaining to particle movement: to establish that crumb loss is occurring and that it decreases with distance from the soft-fall surface. Rubber crumb abundance was expressed as a total value and used to determine an expected average of rubber crumb loss per m2. An Analysis of Variance (ANOVA) was used to compare the differences in crumb abundance at each interval from the playground. Site characteristics, including surrounding sediment type, playground age, degree of ultra-violet exposure and amount of foot traffic, were additionally recorded for the comparison. Preliminary findings indicate that crumb is being lost at considerable rates from soft-fall playgrounds in the region, emphasizing an urgent need to further examine it as a potential source of aquatic pollution, soil contamination and threat to individuals who regularly utilize these surfaces. Additional implications for the future of rubber crumbs as a fit-for-purpose recycling initiative will be discussed with regard to industry, governments and the economic burden of surface maintenance and/ or replacement.Keywords: microplastics, toxic rubber crumb, litter pathways, marine environment
Procedia PDF Downloads 9182 Harmful Algal Poisoning Symptoms in Coastal Areas of Nigeria
Authors: Medina Kadiri
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Nigeria has an extensive coastline of 853 km long between latitude 4°10′ to 6°20′ N and longitude 2°45′ to 8°35′ E and situated in the Gulf of Guinea within the Guinea Current Large Marine Ecosystem. There is a substantial coastal community relying on this region for their livelihood of fishing, aquaculture, mariculture for various sea foods either for consumption or economic sustenance or both. Socio-economic study was conducted, using questionnaires and interview, to investigate the health symptoms of harmful algae experienced by these communities on consumption of sea foods. Eighteen symptoms were recorded. Of the respondents who experienced symptoms after consumption of sea foods, overall, more people (33.5%) experienced vomiting as a symptom, followed by nausea (14.03%) and then diarrhea (13.57%). Others were headache (9.95%), mouth tingling (8.6%) and tiredness (7.24%).The least were muscle pain, rashes, confusion, chills, burning sensation, breathing difficulty and balance difficulty which represented 0.45% each and the rest (dizziness, digestive tract tumors, itching, memory loss, & stomach pain) were less than 3% each. In terms of frequency, the most frequent symptom was diarrhea with 87.5% occurrence, closely followed by vomiting with 81.3%. Tiredness was 75% while nausea was 62.5% and headache 50%. Others such as dizziness, itching, memory loss, mouth tingling and stomach pain had about 40% occurrence or less. The least occurring symptoms were muscle pain, rashes, confusion, chills and balance difficulty and burning sensation occurring only once i.e 6.3%. Breathing difficulty was last but one with 12.5%. Visible symptom from seafood and the particular seafood consumed that prompted the visible symptoms, shows that 3.5% of the entire respondents who ate crab experienced various symptoms ranging from vomiting (2.4%), itching (0.5%) and headache (0.4%). For periwinkle, vomiting had 1.7%, while 1.2% represented diarrhea and nausea symptom comprised 0.8% of all the respondents who ate periwinkle. Some respondents who consumed fish shows that 0.4% of the respondents had Itching. From the respondents who preferred to consume shrimps/crayfish and crab, shrimps/crayfish, crab and periwinkle, the most common illness was tiredness (1.2%), while 0.5% had experienced diarrhea and many others. However, for most respondents who claimed to have no preference for any seafood, with 55.7% affirming this with vomiting being the highest (6.1%), followed closely by mouth tingling/ burning sensation (5.8%). Examining the seasonal influence on visible symptoms revealed that vomiting occurred more in the month of January with 5.5%, while headache and itching were predominant in October with (2.8%). Nausea has 3.1% in January than any season of the year, 2.6% of the entire respondents opined to have experience diarrhea in October than in any other season of the year. Regular evaluation of harmful algal poisoning symptoms is recommended for coastal communities.Keywords: coastal, harmful algae, human poisoning symptoms, Nigeria, phycotoxins
Procedia PDF Downloads 28681 Antimicrobial and Antioxidant Activities of Actinobacteria Isolated from the Pollen of Pinus sylvestris Grown on the Lake Baikal Shore
Authors: Denis V. Axenov-Gribanov, Irina V. Voytsekhovskaya, Evgenii S. Protasov, Maxim A. Timofeyev
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Isolated ecosystems existing under specific environmental conditions have been shown to be promising sources of new strains of actinobacteria. The taiga forest of Baikal Siberia has not been well studied, and its actinobacterial population remains uncharacterized. The proximity between the huge water mass of Lake Baikal and high mountain ranges influences the structure and diversity of the plant world in Siberia. Here, we report the isolation of eighteen actinobacterial strains from male cones of Pinus sylvestris trees growing on the shore of the ancient Lake Baikal in Siberia. The actinobacterial strains were isolated on solid nutrient MS media and Czapek agar supplemented with cycloheximide and phosphomycin. Identification of actinobacteria was carried out by 16S rRNA gene sequencing and further analysis of the evolutionary history. Four different liquid and solid media (NL19, DNPM, SG and ISP) were tested for metabolite production. The metabolite extracts produced by the isolated strains were tested for antibacterial and antifungal activities. Also, antiradical activity of crude extracts was carried out. Strain Streptomyces sp. IB 2014 I 74-3 that active against Gram-negative bacteria was selected for dereplication analysis with using the high-yield liquid chromatography with mass-spectrometry. Mass detection was performed in both positive and negative modes, with the detection range set to 160–2500 m/z. Data were collected and analyzed using Bruker Compass Data Analysis software, version 4.1. Dereplication was performed using the Dictionary of Natural Products (DNP) database version 6.1 with the following search parameters: accurate molecular mass, absorption spectra and source of compound isolation. Thus, in addition to more common representative strains of Streptomyces, several species belonging to the genera Rhodococcus, Amycolatopsis, and Micromonospora were isolated. Several of the selected strains were deposited in the Russian Collection of Agricultural Microorganisms (RCAM), St. Petersburg, Russia. All isolated strains exhibited antibacterial and antifungal activities. We identified several strains that inhibited the growth of the pathogen Candida albicans but did not hinder the growth of Saccharomyces cerevisiae. Several isolates were active against Gram-positive and Gram-negative bacteria. Moreover, extracts of several strains demonstrated high antioxidant activity. The high proportion of biologically active strains producing antibacterial and specific antifungal compounds may reflect their role in protecting pollen against phytopathogens. Dereplication of the secondary metabolites of the strain Streptomyces sp. IB 2014 I 74-3 was resulted in the fact that a total of 59 major compounds were detected in the culture liquid extract of strain cultivated in ISP medium. Eight compounds were preliminarily identified based on characteristics described in the Dictionary of Natural Products database, using the search parameters Streptomyces sp. IB 2014 I 74-3 was found to produce saframycin A, Y3 and S; 2-amino-3-oxo-3H-phenoxazine-1,8-dicarboxylic acid; galtamycinone; platencin A4-13R and A4-4S; ganefromycin d1; the antibiotic SS 8201B; and streptothricin D, 40-decarbamoyl, 60-carbamoyl. Moreover, forty-nine of the 59 compounds detected in the extract examined in the present study did not result in any positive hits when searching within the DNP database and could not be identified based on available mass-spec data. Thus, these compounds might represent new findings.Keywords: actinobacteria, Baikal Lake, biodiversity, male cones, Pinus sylvestris
Procedia PDF Downloads 23280 [Keynote Talk]: Bioactive Cyclic Dipeptides of Microbial Origin in Discovery of Cytokine Inhibitors
Authors: Sajeli A. Begum, Ameer Basha, Kirti Hira, Rukaiyya Khan
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Cyclic dipeptides are simple diketopiperazine derivatives being investigated by several scientists for their biological effects which include anticancer, antimicrobial, haematological, anticonvulsant, immunomodulatory effect, etc. They are potentially active microbial metabolites having been synthesized too, for developing into drug candidates. Cultures of Pseudomonas species have earlier been reported to produce cyclic dipeptides, helping in quorum sensing signals and bacterial–host colonization phenomena during infections, causing cell anti-proliferation and immunosuppression. Fluorescing Pseudomonas species have been identified to secrete lipid derivatives, peptides, pyrroles, phenazines, indoles, aminoacids, pterines, pseudomonic acids and some antibiotics. In the present work, results of investigation on the cyclic dipeptide metabolites secreted by the culture broth of Pseudomonas species as potent pro-inflammatory cytokine inhibitors are discussed. The bacterial strain was isolated from the rhizospheric soil of groundnut crop and identified as Pseudomonas aeruginosa by 16S rDNA sequence (GenBank Accession No. KT625586). Culture broth of this strain was prepared by inoculating into King’s B broth and incubating at 30 ºC for 7 days. The ethyl acetate extract of culture broth was prepared and lyophilized to get a dry residue (EEPA). Lipopolysaccharide (LPS)-induced ELISA assay proved the inhibition of tumor necrosis factor-alpha (TNF-α) secretion in culture supernatant of RAW 264.7 cells by EEPA (IC50 38.8 μg/mL). The effect of oral administration of EEPA on plasma TNF-α level in rats was tested by ELISA kit. The LPS mediated plasma TNF-α level was reduced to 45% with 125 mg/kg dose of EEPA. Isolation of the chemical constituents of EEPA through column chromatography yielded ten cyclic dipeptides, which were characterized using nuclear magnetic resonance and mass spectroscopic techniques. These cyclic dipeptides are biosynthesized in microorganisms by multifunctional assembly of non-ribosomal peptide synthases and cyclic dipeptide synthase. Cyclo (Gly-L-Pro) was found to be more potentially (IC50 value 4.5 μg/mL) inhibiting TNF-α production followed by cyclo (trans-4-hydroxy-L-Pro-L-Phe) (IC50 value 14.2 μg/mL) and the effect was equal to that of standard immunosuppressant drug, prednisolone. Further, the effect was analyzed by determining mRNA expression of TNF-α in LPS-stimulated RAW 264.7 macrophages using quantitative real-time reverse transcription polymerase chain reaction. EEPA and isolated cyclic dipeptides demonstrated diminution of TNF-α mRNA expression levels in a dose-dependent manner under the tested conditions. Also, they were found to control the expression of other pro-inflammatory cytokines like IL-1β and IL-6, when tested through their mRNA expression levels in LPS-stimulated RAW 264.7 macrophages under LPS-stimulated conditions. In addition, significant inhibition effect was found on Nitric oxide production. Further all the compounds exhibited weak toxicity to LPS-induced RAW 264.7 cells. Thus the outcome of the study disclosed the effectiveness of EEPA and the isolated cyclic dipeptides in down-regulating key cytokines involved in pathophysiology of autoimmune diseases.In another study led by the investigators, microbial cyclic dipeptides were found to exhibit excellent antimicrobial effect against Fusarium moniliforme which is an important causative agent of Sorghum grain mold disease. Thus, cyclic dipeptides are emerging small molecular drug candidates for various autoimmune diseases.Keywords: cyclic dipeptides, cytokines, Fusarium moniliforme, Pseudomonas, TNF-alpha
Procedia PDF Downloads 21179 Plastic Pollution: Analysis of the Current Legal Framework and Perspectives on Future Governance
Authors: Giorgia Carratta
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Since the beginning of mass production, plastic items have been crucial in our daily lives. Thanks to their physical and chemical properties, plastic materials have proven almost irreplaceable in a number of economic sectors such as packaging, automotive, building and construction, textile, and many others. At the same time, the disruptive consequences of plastic pollution have been progressively brought to light in all environmental compartments. The overaccumulation of plastics in the environment, and its adverse effects on habitats, wildlife, and (most likely) human health, represents a call for action to decision-makers around the globe. From a regulatory perspective, plastic production is an unprecedented challenge at all levels of governance. At the international level, the design of new legal instruments, the amendment of existing ones, and the coordination among the several relevant policy areas requires considerable effort. Under the pressure of both increasing scientific evidence and a concerned public opinion, countries seem to slowly move towards the discussion of a new international ‘plastic treaty.’ However, whether, how, and with which scopes such instrument would be adopted is still to be seen. Additionally, governments are establishing regional-basedstrategies, prone to consider the specificities of the plastic issue in a certain geographical area. Thanks to the new Circular Economy Action Plan, approved in March 2020 by the European Commission, EU countries are slowly but steadily shifting to a carbon neutral, circular economy in the attempt to reduce the pressure on natural resources and, parallelly, facilitate sustainable economic growth. In this context, the EU Plastic Strategy is promising to change the way plastic is designed, produced, used, and treated after consumption. In fact, only in the EU27 Member States, almost 26 million tons of plastic waste are generated herein every year, whose 24,9% is still destined to landfill. Positive effects of the Strategy also include a more effective protection of our environment, especially the marine one, the reduction of greenhouse gas emissions, a reduced need for imported fossil energy sources, more sustainable production and consumption patterns. As promising as it may sound, the road ahead is still long. The need to implement these measures in domestic legislations makes their outcome difficult to predict at the moment. An analysis of the current international and European Union legal framework on plastic pollution, binding, and voluntary instruments included, could serve to detect ‘blind spots’ in the current governance as well as to facilitate the development of policy interventions along the plastic value chain, where it appears more needed.Keywords: environmental law, European union, governance, plastic pollution, sustainability
Procedia PDF Downloads 10778 Stochastic Modelling for Mixed Mode Fatigue Delamination Growth of Wind Turbine Composite Blades
Authors: Chi Zhang, Hua-Peng Chen
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With the increasingly demanding resources in the word, renewable and clean energy has been considered as an alternative way to replace traditional ones. Thus, one of practical examples for using wind energy is wind turbine, which has gained more attentions in recent research. Like most offshore structures, the blades, which is the most critical components of the wind turbine, will be subjected to millions of loading cycles during service life. To operate safely in marine environments, the blades are typically made from fibre reinforced composite materials to resist fatigue delamination and harsh environment. The fatigue crack development of blades is uncertain because of indeterminate mechanical properties for composite and uncertainties under offshore environment like wave loads, wind loads, and humid environments. There are three main delamination failure modes for composite blades, and the most common failure type in practices is subjected to mixed mode loading, typically a range of opening (mode 1) and shear (mode 2). However, the fatigue crack development for mixed mode cannot be predicted as deterministic values because of various uncertainties in realistic practical situation. Therefore, selecting an effective stochastic model to evaluate the mixed mode behaviour of wind turbine blades is a critical issue. In previous studies, gamma process has been considered as an appropriate stochastic approach, which simulates the stochastic deterioration process to proceed in one direction such as realistic situation for fatigue damage failure of wind turbine blades. On the basis of existing studies, various Paris Law equations are discussed to simulate the propagation of the fatigue crack growth. This paper develops a Paris model with the stochastic deterioration modelling according to gamma process for predicting fatigue crack performance in design service life. A numerical example of wind turbine composite materials is investigated to predict the mixed mode crack depth by Paris law and the probability of fatigue failure by gamma process. The probability of failure curves under different situations are obtained from the stochastic deterioration model for comparisons. Compared with the results from experiments, the gamma process can take the uncertain values into consideration for crack propagation of mixed mode, and the stochastic deterioration process shows a better agree well with realistic crack process for composite blades. Finally, according to the predicted results from gamma stochastic model, assessment strategies for composite blades are developed to reduce total lifecycle costs and increase resistance for fatigue crack growth.Keywords: Reinforced fibre composite, Wind turbine blades, Fatigue delamination, Mixed failure mode, Stochastic process.
Procedia PDF Downloads 41377 Grain Size Statistics and Depositional Pattern of the Ecca Group Sandstones, Karoo Supergroup in the Eastern Cape Province, South Africa
Authors: Christopher Baiyegunhi, Kuiwu Liu, Oswald Gwavava
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Grain size analysis is a vital sedimentological tool used to unravel the hydrodynamic conditions, mode of transportation and deposition of detrital sediments. In this study, detailed grain-size analysis was carried out on thirty-five sandstone samples from the Ecca Group in the Eastern Cape Province of South Africa. Grain-size statistical parameters, bivariate analysis, linear discriminate functions, Passega diagrams and log-probability curves were used to reveal the depositional processes, sedimentation mechanisms, hydrodynamic energy conditions and to discriminate different depositional environments. The grain-size parameters show that most of the sandstones are very fine to fine grained, moderately well sorted, mostly near-symmetrical and mesokurtic in nature. The abundance of very fine to fine grained sandstones indicates the dominance of low energy environment. The bivariate plots that the samples are mostly grouped, except for the Prince Albert samples that show scattered trend, which is due to the either mixture of two modes in equal proportion in bimodal sediments or good sorting in unimodal sediments. The linear discriminant function (LDF) analysis is dominantly indicative of turbidity current deposits under shallow marine environments for samples from the Prince Albert, Collingham and Ripon Formations, while those samples from the Fort Brown Formation are fluvial (deltaic) deposits. The graphic mean value shows the dominance of fine sand-size particles, which point to relatively low energy conditions of deposition. In addition, the LDF results point to low energy conditions during the deposition of the Prince Albert, Collingham and part of the Ripon Formation (Pluto Vale and Wonderfontein Shale Members), whereas the Trumpeters Member of the Ripon Formation and the overlying Fort Brown Formation accumulated under high energy conditions. The CM pattern shows a clustered distribution of sediments in the PQ and QR segments, indicating that the sediments were deposited mostly by suspension and rolling/saltation, and graded suspension. Furthermore, the plots also show that the sediments are mainly deposited by turbidity currents. Visher diagrams show the variability of hydraulic depositional conditions for the Permian Ecca Group sandstones. Saltation is the major process of transportation, although suspension and traction also played some role during deposition of the sediments. The sediments were mainly in saltation and suspension before being deposited.Keywords: grain size analysis, hydrodynamic condition, depositional environment, Ecca Group, South Africa
Procedia PDF Downloads 48176 Facies Sedimentology and Astronomic Calibration of the Reinech Member (Lutetian)
Authors: Jihede Haj Messaoud, Hamdi Omar, Hela Fakhfakh Ben Jemia, Chokri Yaich
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The Upper Lutetian alternating marl–limestone succession of Reineche Member was deposited over a warm shallow carbonate platform that permits Nummulites proliferation. High-resolution studies of 30 meters thick Nummulites-bearing Reineche Member, cropping out in Central Tunisia (Jebel Siouf), have been undertaken, regarding pronounced cyclical sedimentary sequences, in order to investigate the periodicity of cycles and their related orbital-scale oceanic and climatic changes. The palaeoenvironmental and palaeoclimatic data are preserved in several proxies obtainable through high-resolution sampling and laboratories measurement and analysis as magnetic susceptibility (MS) and carbonates contents in conjunction with a wireline logging tools. The time series analysis of proxies permits to establish cyclicity orders present in the studied intervals which could be linked to the orbital cycles. MS records provide high-resolution proxies for relative sea level change in Late Lutetian strata. The spectral analysis of MS fluctuations confirmed the orbital forcing by the presence of the complete suite of orbital frequencies in the precession of 23 ka, the obliquity of 41 ka, and notably the two modes of eccentricity of 100 and 405 ka. Regarding the two periodic sedimentary cycles detected by wavelet analysis of proxy fluctuations which coincide with the long-term 405 ka eccentricity cycle, the Reineche Member spanned 0,8 Myr. Wireline logging tools as gamma ray and sonic were used as a proxies to decipher cyclicity and trends in sedimentation and contribute to identifying and correlate units. There are used to constraint the highest frequency cyclicity modulated by a long term wavelength cycling apparently controlled by clay content. Interpreted as a result of variations in carbonate productivity, it has been suggested that the marl-limestone couplets, represent the sedimentary response to the orbital forcing. The calculation of cycle durations through Reineche Member, is used as a geochronometer and permit the astronomical calibration of the geologic time scale. Furthermore, MS coupled with carbonate contents, and fossil occurrences provide strong evidence for combined detrital inputs and marine surface carbonate productivity cycles. These two synchronous processes were driven by the precession index and ‘fingerprinted’ in the basic marl–limestone couplets, modulated by orbital eccentricity.Keywords: magnetic susceptibility, cyclostratigraphy, orbital forcing, spectral analysis, Lutetian
Procedia PDF Downloads 29475 Numerical Investigation on Transient Heat Conduction through Brine-Spongy Ice
Authors: S. R. Dehghani, Y. S. Muzychka, G. F. Naterer
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The ice accretion of salt water on cold substrates creates brine-spongy ice. This type of ice is a mixture of pure ice and liquid brine. A real case of creation of this type of ice is superstructure icing which occurs on marine vessels and offshore structures in cold and harsh conditions. Transient heat transfer through this medium causes phase changes between brine pockets and pure ice. Salt rejection during the process of transient heat conduction increases the salinity of brine pockets to reach a local equilibrium state. In this process the only effect of passing heat through the medium is not changing the sensible heat of the ice and brine pockets; latent heat plays an important role and affects the mechanism of heat transfer. In this study, a new analytical model for evaluating heat transfer through brine-spongy ice is suggested. This model considers heat transfer and partial solidification and melting together. Properties of brine-spongy ice are obtained using properties of liquid brine and pure ice. A numerical solution using Method of Lines discretizes the medium to reach a set of ordinary differential equations. Boundary conditions are chosen using one of the applicable cases of this type of ice; one side is considered as a thermally isolated surface, and the other side is assumed to be suddenly affected by a constant temperature boundary. All cases are evaluated in temperatures between -20 C and the freezing point of brine-spongy ice. Solutions are conducted using different salinities from 5 to 60 ppt. Time steps and space intervals are chosen properly to maintain the most stable and fast solution. Variation of temperature, volume fraction of brine and brine salinity versus time are the most important outputs of this study. Results show that transient heat conduction through brine-spongy ice can create a various range of salinity of brine pockets from the initial salinity to that of 180 ppt. The rate of variation of temperature is found to be slower for high salinity cases. The maximum rate of heat transfer occurs at the start of the simulation. This rate decreases as time passes. Brine pockets are smaller at portions closer to the colder side than that of the warmer side. A the start of the solution, the numerical solution tends to increase instabilities. This is because of sharp variation of temperature at the start of the process. Changing the intervals improves the unstable situation. The analytical model using a numerical scheme is capable of predicting thermal behavior of brine spongy ice. This model and numerical solutions are important for modeling the process of freezing of salt water and ice accretion on cold structures.Keywords: method of lines, brine-spongy ice, heat conduction, salt water
Procedia PDF Downloads 217