Search results for: carbon capture and utilization (CCU)

Authors: Jana Andzane, Gunta Kunakova, Margarita Baitimirova, Mikelis Marnauza, Floriana Lombardi, Donats Erts

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Bismuth selenide (Bi₂Se₃) is known as a narrow band gap semiconductor with pronounced thermoelectric (TE) and topological insulator (TI) properties. Unique TI properties offer exciting possibilities for fundamental research as observing the exciton condensate and Majorana fermions, as well as practical application in spintronic and quantum information. In turn, TE properties of this material can be applied for wide range of thermoelectric applications, as well as for broadband photodetectors and near-infrared sensors. Nanostructuring of this material results in improvement of TI properties due to suppression of the bulk conductivity, and enhancement of TE properties because of increased phonon scattering at the nanoscale grains and interfaces. Regarding TE properties, crystallographic growth direction, as well as orientation of the nanostructures relative to the growth substrate, play significant role in improvement of TE performance of nanostructured material. For instance, Bi₂Se₃ layers consisting of randomly oriented nanostructures and/or of combination of them with planar nanostructures show significantly enhanced in comparison with bulk and only planar Bi₂Se₃ nanostructures TE properties. In this work, a catalyst-free vapour-solid deposition technique was applied for controlled obtaining of different types of Bi₂Se₃ nanostructures and continuous nanostructured layers for targeted applications. For example, separated Bi₂Se₃ nanoplates, nanobelts and nanowires can be used for investigations of TI properties; consisting from merged planar and/or randomly oriented nanostructures Bi₂Se₃ layers are useful for applications in heat-to-power conversion devices and infrared detectors. The vapour-solid deposition was carried out using quartz tube furnace (MTI Corp), equipped with an inert gas supply and pressure/temperature control system. Bi₂Se₃ nanostructures/nanostructured layers of desired type were obtained by adjustment of synthesis parameters (process temperature, deposition time, pressure, carrier gas flow) and selection of deposition substrate (glass, quartz, mica, indium-tin-oxide, graphene and carbon nanotubes). Morphology, structure and composition of obtained Bi₂Se₃ nanostructures and nanostructured layers were inspected using SEM, AFM, EDX and HRTEM techniques, as well as home-build experimental setup for thermoelectric measurements. It was found that introducing of temporary carrier gas flow into the process tube during the synthesis and deposition substrate choice significantly influence nanostructures formation mechanism. Electrical, thermoelectric, and topological insulator properties of different types of deposited Bi₂Se₃ nanostructures and nanostructured coatings are characterized as a function of thickness and discussed.

Keywords: bismuth seleinde, nanostructures, topological insulator, vapour-solid deposition

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Authors: Jollen Dai, Truman You, Xinyun Du, Katrina Liu

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Transportation is one of the leading sources of greenhouse gas emissions (GHG). Thus, to meet the Paris Agreement 2015, all countries must adopt a different and more sustainable transportation system. From bikes to Maglev, the world is slowly shifting to sustainable transportation. To develop a utility public transit system, a sustainable web of buses must be implemented. As of now, only a handful of cities have adopted a detailed plan to implement a full fleet of e-buses by the 2030s, with Shenzhen in the lead. Every change requires a detailed plan and a focused analysis of the impacts of the change. In this report, the economic implications and financial implications have been taken into consideration to develop a well-rounded 10-year plan for New York City. We also apply the same financial model to the other cities, LA and Chicago. We picked NYC, Chicago, and LA to conduct the comparative NPB analysis since they are all big metropolitan cities and have complex transportation systems. All three cities have started an action plan to achieve a full fleet of e-bus in the decades. Plus, their energy carbon footprint and their energy price are very different, which are the key factors to the benefits of electric buses. Using TCO (Total Cost Ownership) financial analysis, we developed a model to calculate NPB (Net Present Benefit) /and compare EBS (electric buses) to DBS (diesel buses). We have considered all essential aspects in our model: initial investment, including the cost of a bus, charger, and installation, government fund (federal, state, local), labor cost, energy (electricity or diesel) cost, maintenance cost, insurance cost, health and environment benefit, and V2G (vehicle to grid) benefit. We see about $1,400,000 in benefits for a 12-year lifetime of an EBS compared to DBS provided the government fund to offset 50% of EBS purchase cost. With the government subsidy, an EBS starts to make positive cash flow in 5th year and can pay back its investment in 5 years. Please remember that in our model, we consider environmental and health benefits, and every year, $50,000 is counted as health benefits per bus. Besides health benefits, the significant benefits come from the energy cost savings and maintenance savings, which are about $600,000 and $200,000 in 12-year life cycle. Using linear regression, given certain budget limitations, we then designed an optimal three-phase process to replace all NYC electric buses in 10 years, i.e., by 2033. The linear regression process is to minimize the total cost over the years and have the lowest environmental cost. The overall benefits to replace all DBS with EBS for NYC is over $2.1 billion by the year of 2033. For LA, and Chicago, the benefits for electrification of the current bus fleet are $1.04 billion and $634 million by 2033. All NPB analyses and the algorithm to optimize the electrification phase process are implemented in Python code and can be shared.

Keywords: financial modeling, total cost ownership, net present benefits, electric bus, diesel bus, NYC, LA, Chicago

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Authors: Evans V. Mauda, Stefan H. Foord, Thinandavha C. Munyai

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The greatest threat to biodiversity is a loss of habitat through landscape fragmentation and attrition. Land use changes are therefore among the most immediate drivers of species diversity. Urbanization and agriculture are the main drivers of habitat loss and transformation in the Savanna biomes of South Africa. Agricultural expansion and the intensification in particular, take place at the expense of biodiversity and will probably be the primary driver of biodiversity loss in this century. Arthropods show measurable behavioural responses to changing land mosaics at the smallest scale and heterogeneous environments are therefore predicted to support more complex and diverse biological assemblages. Ants are premier soil turners, channelers of energy and dominate insect fauna, while spiders are a mega-diverse group that can regulate other invertebrate populations. This study aims to quantify the response of these two taxa in a rural-urban mosaic of a rapidly developing communal area. The study took place in and around two villages in the north-eastern corner of South Africa. Two replicates for each of the dominant land use categories, viz. urban settlements, dryland cultivation and cattle rangelands, were set out in each of the villages and sampled during the dry and wet seasons for a total of 2 villages × 3 land use categories × 2 seasons = 24 assemblages. Local scale variables measured included vertical and horizontal habitat structure as well as structural and chemical composition of the soil. Ant richness was not affected by land use but local scale variables such as vertical vegetation structure (+) and leaf litter cover (+), although vegetation complexity at lower levels was negatively associated with ant richness. However, ant richness was largely shaped by regional and temporal processes invoking the importance of dispersal and historical processes. Spider species richness was mostly affected by land use and local conditions highlighting their landscape elements. Spider richness did not vary much between villages and across seasons and seems to be less dependent on context or history. There was a considerable amount of variation in spider richness that was not explained and this could be related to factors which were not measured in this study such as temperature and competition. For both ant and spider assemblages the constrained ordination explained 18 % of variation in these taxa. Three environmental variables (leaf litter cover, active carbon and rock cover) were important in explaining ant assemblage structure, while two (sand and leaf litter cover) were important for spider assemblage structure. This study highlights the importance of disturbance (land use activities) and leaf litter with the associated effects on ant and spider assemblages across the study area.

Keywords: ants, assemblages, biosphere, diversity, land use, spiders, urbanization

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Authors: Antonella Falanga, Armando Cartenì

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"Big data" refers to extremely vast and complex sets of data, encompassing extraordinarily large and intricate datasets that require specific tools for meaningful analysis and processing. These datasets can stem from diverse origins like sensors, mobile devices, online transactions, social media platforms, and more. The utilization of big data is pivotal, offering the chance to leverage vast information for substantial advantages across diverse fields, thereby enhancing comprehension, decision-making, efficiency, and fostering innovation in various domains. Big data, distinguished by its remarkable attributes of enormous volume, high velocity, diverse variety, and significant value, represent a transformative force reshaping the industry worldwide. Their pervasive impact continues to unlock new possibilities, driving innovation and advancements in technology, decision-making processes, and societal progress in an increasingly data-centric world. The use of these technologies is becoming more widespread, facilitating and accelerating operations that were once much more complicated. In particular, big data impacts across multiple sectors such as business and commerce, healthcare and science, finance, education, geography, agriculture, media and entertainment and also mobility and logistics. Within the transportation sector, which is the focus of this study, big data applications encompass a wide variety, spanning across optimization in vehicle routing, real-time traffic management and monitoring, logistics efficiency, reduction of travel times and congestion, enhancement of the overall transportation systems, but also mitigation of pollutant emissions contributing to environmental sustainability. Meanwhile, in public administration and the development of smart cities, big data aids in improving public services, urban planning, and decision-making processes, leading to more efficient and sustainable urban environments. Access to vast data reservoirs enables deeper insights, revealing hidden patterns and facilitating more precise and timely decision-making. Additionally, advancements in cloud computing and artificial intelligence (AI) have further amplified the potential of big data, enabling more sophisticated and comprehensive analyses. Certainly, utilizing big data presents various advantages but also entails several challenges regarding data privacy and security, ensuring data quality, managing and storing large volumes of data effectively, integrating data from diverse sources, the need for specialized skills to interpret analysis results, ethical considerations in data use, and evaluating costs against benefits. Addressing these difficulties requires well-structured strategies and policies to balance the benefits of big data with privacy, security, and efficient data management concerns. Building upon these premises, the current research investigates the efficacy and influence of big data by conducting an overview of the primary and recent implementations of big data in transportation systems. Overall, this research allows us to conclude that big data better provide to enhance rational decision-making for mobility choices and is imperative for adeptly planning and allocating investments in transportation infrastructures and services.

Keywords: big data, public transport, sustainable mobility, transport demand, transportation planning

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Authors: Vidar Hepsø

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The energy and oil companies on the Norwegian Continental shelf come from a situation where each asset control and manage their energy supply (island mode) and move towards a situation where the assets need to collaborate and coordinate energy use with others due to increased cost and scarcity of electric energy sharing the energy that is provided. Currently, several areas are electrified either with an onshore grid cable or are receiving intermittent energy from offshore wind-parks. While the onshore grid in Norway is well regulated, the offshore grid is still in the making, with several oil and gas electrification projects and offshore wind development just started. The paper will describe the shift in the mindset that comes with operating this new offshore grid. This transition process heralds an increase in collaboration across boundaries and integration of energy management across companies, businesses, technical disciplines, and engagement with stakeholders in the larger society. This transition will be described as a function of the new challenges with increased complexity of the energy mix (wind, oil/gas, hydrogen and others) coupled with increased technical and organization complexity in energy management. Organizational complexity denotes an increasing integration across boundaries, whether these boundaries are company, vendors, professional disciplines, regulatory regimes/bodies, businesses, and across numerous societal stakeholders. New practices must be developed, made legitimate and institutionalized across these boundaries. Only parts of this complexity can be mitigated technically, e.g.: by use of batteries, mixing energy systems and simulation/ forecasting tools. Many challenges must be mitigated with legitimated societal and institutionalized governance practices on many levels. Offshore electrification supports Norway’s 2030 climate targets but is also controversial since it is exploiting the larger society’s energy resources. This means that new systems and practices must also be transparent, not only for the industry and the authorities, but must also be acceptable and just for the larger society. The paper report from ongoing work in Norway, participant observation and interviews in projects and people working with offshore grid development in Norway. One case presented is the development of an offshore floating windfarm connected to two offshore installations and the second case is an offshore grid development initiative providing six installations electric energy via an onshore cable. The development of the offshore grid is analyzed using a capability platform framework, that describes the technical, competence, work process and governance capabilities that are under development in Norway. A capability platform is a ‘stack’ with the following layers: intelligent infrastructure, information and collaboration, knowledge sharing & analytics and finally business operations. The need for better collaboration and energy forecasting tools/capabilities in this stack will be given a special attention in the two use cases that are presented.

Keywords: capability platform, electrification, carbon footprint, control rooms, energy forecsting, operational model

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Authors: Erik Vassøy Olsen, Hirpa G. Lemu

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Inspired by the Formula-1 competition, IMechE (Institute of Mechanical Engineers) and Formula SAE (Society of Mechanical Engineers) organize annual competitions for University and College students worldwide to compete with a single-seat race car they have designed and built. The design of the chassis or the frame is a key component of the competition because the weight and stiffness properties are directly related with the performance of the car and the safety of the driver. In addition, a reduced weight of the chassis has a direct influence on the design of other components in the car. Among others, it improves the power to weight ratio and the aerodynamic performance. As the power output of the engine or the battery installed in the car is limited to 80 kW, increasing the power to weight ratio demands reduction of the weight of the chassis, which represents the major part of the weight of the car. In order to reduce the weight of the car, ION Racing team from the University of Stavanger, Norway, opted for a monocoque design. To ensure fulfilment of the above-mentioned requirements of the chassis, the monocoque design should provide sufficient torsional stiffness and absorb the impact energy in case of a possible collision. The study reported in this article is based on the requirements for Formula Student competition. As part of this study, diverse mechanical tests were conducted to determine the mechanical properties and performances of the monocoque design. Upon a comprehensive theoretical study of the mechanical properties of sandwich composite materials and the requirements of monocoque design in the competition rules, diverse tests were conducted including 3-point bending test, perimeter shear test and test for absorbed energy. The test panels were homemade and prepared with an equivalent size of the side impact zone of the monocoque, i.e. 275 mm x 500 mm so that the obtained results from the tests can be representative. Different layups of the test panels with identical core material and the same number of layers of carbon fibre were tested and compared. Influence of the core material thickness was also studied. Furthermore, analytical calculations and numerical analysis were conducted to check compliance to the stated rules for Structural Equivalency with steel grade SAE/AISI 1010. The test results were also compared with calculated results with respect to bending and torsional stiffness, energy absorption, buckling, etc. The obtained results demonstrate that the material composition and strength of the composite material selected for the monocoque design has equivalent structural properties as a welded frame and thus comply with the competition requirements. The developed analytical calculation algorithms and relations will be useful for future monocoque designs with different lay-ups and compositions.

Keywords: composite material, Formula student, ION racing, monocoque design, structural equivalence

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Authors: Natia Jalagonia, Jimsher Maisuradze, Karlo Barbakadze, Tinatin Kuchukhidze

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At present intensive scientific researches of ceramics, cermets and metal alloys have been conducted for improving materials physical-mechanical characteristics. In purpose of increasing impact strength of ceramics based on alumina, simple method of graphene homogenization was developed. Homogeneous distribution of graphene (homogenization) in pressing composite became possible through the connection of functional groups of graphene oxide (-OH, -COOH, -O-O- and others) and alumina superficial OH groups with aluminum organic compounds. These two components connect with each other with -O-Al–O- bonds, and by their thermal treatment (300–500°C), graphene and alumina phase are transformed. Thus, choosing of aluminum organic compounds for modification is stipulated by the following opinion: aluminum organic compounds fragments fixed on graphene and alumina finally are transformed into an integral part of the matrix. By using of other elements as modifier on the matrix surface (Al2O3) other phases are transformed, which change sharply physical-mechanical properties of ceramic composites, for this reason, effect caused by the inclusion of graphene will be unknown. Fixing graphene fragments on alumina surface by alumoorganic compounds result in new type graphene-alumina complex, in which these two components are connected by C-O-Al bonds. Part of carbon atoms in graphene oxide are in sp3 hybrid state, so functional groups (-OH, -COOH) are located on both sides of graphene oxide layer. Aluminum organic compound reacts with graphene oxide at the room temperature, and modified graphene oxide is obtained: R2Al-O-[graphene]–COOAlR2. Remaining Al–C bonds also reacts rapidly with surface OH groups of alumina. In a result of these process, pressing powdery composite [Al2O3]-O-Al-O-[graphene]–COO–Al–O–[Al2O3] is obtained. For the purpose, graphene oxide suspension in dry toluene have added alumoorganic compound Al(iC4H9)3 in toluene with equimolecular ratio. Obtained suspension has put in the flask and removed solution in a rotary evaporate presence nitrogen atmosphere. Obtained powdery have been researched and used to consolidation of ceramic materials based on alumina. Ceramic composites are obtained in high temperature vacuum furnace with different temperature and pressure conditions. Received ceramics do not have open pores and their density reaches 99.5 % of TD. During the work, the following devices have been used: High temperature vacuum furnace OXY-GON Industries Inc (USA), device of spark-plasma synthesis, induction furnace, Electronic Scanning Microscopes Nikon Eclipse LV 150, Optical Microscope NMM-800TRF, Planetary mill Pulverisette 7 premium line, Shimadzu Dynamic Ultra Micro Hardness Tester DUH-211S, Analysette 12 Dynasizer and others.

Keywords: graphene oxide, alumo-organic, ceramic

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Authors: Robert Wimmer, Soeren Eikemeier, Michael Berger, Anita Preisler

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A relatively large percentage of energy and resource consumption occurs in the building sector. This concerns the production of building materials, the construction of buildings and also the energy consumption during the use phase. Therefore, the overall objective of this EU LIFE project “LIFE Cycle Habitation” (LIFE13 ENV/AT/000741) is to demonstrate innovative building concepts that significantly reduce CO₂emissions, mitigate climate change and contain a minimum of grey energy over their entire life cycle. The project is being realised with the contribution of the LIFE financial instrument of the European Union. The ultimate goal is to design and build prototypes for carbon-neutral and “LIFE cycle”-oriented residential buildings and make energy-efficient settlements the standard of tomorrow in line with the EU 2020 objectives. To this end, a resource and energy-efficient building compound is being built in Böheimkirchen, Lower Austria, which includes 6 living units and a community area as well as 2 single family houses with a total usable floor surface of approximately 740 m². Different innovative straw bale construction types (load bearing and pre-fabricated non loadbearing modules) together with a highly innovative energy-supply system, which is based on the maximum use of thermal energy for thermal energy services, are going to be implemented. Therefore only renewable resources and alternative energies are used to generate thermal as well as electrical energy. This includes the use of solar energy for space heating, hot water and household appliances like dishwasher or washing machine, but also a cooking place for the community area operated with thermal oil as heat transfer medium on a higher temperature level. Solar collectors in combination with a biomass cogeneration unit and photovoltaic panels are used to provide thermal and electric energy for the living units according to the seasonal demand. The building concepts are optimised by support of dynamic simulations. A particular focus is on the production and use of modular prefabricated components and building parts made of regionally available, highly energy-efficient, CO₂-storing renewable materials like straw bales. The building components will be produced in collaboration by local SMEs that are organised in an efficient way. The whole building process and results are monitored and prepared for knowledge transfer and dissemination including a trial living in the residential units to test and monitor the energy supply system and to involve stakeholders into evaluation and dissemination of the applied technologies and building concepts. The realised building concepts should then be used as templates for a further modular extension of the settlement in a second phase.

Keywords: energy-efficiency, green architecture, renewable resources, sustainable building

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Authors: Peter Kus, Anna Ostroverkh, Yurii Yakovlev, Yevheniia Lobko, Roman Fiala, Ivan Khalakhan, Vladimir Matolin

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Hydrogen economy is a concept of low-emission society which harvests most of its energy from renewable sources (e.g., wind and solar) and in case of overproduction, electrochemically turns the excess amount into hydrogen, which serves as an energy carrier. Proton exchange membrane water electrolyzers (PEMWE) are the backbone of this concept. By fast-response electricity to hydrogen conversion, the PEMWEs will not only stabilize the electrical grid but also provide high-purity hydrogen for variety of fuel cell powered devices, ranging from consumer electronics to vehicles. Wider commercialization of PEMWE technology is however hindered by high prices of noble metals which are necessary for catalyzing the redox reactions within the cell. Namely, platinum for hydrogen evolution reaction (HER), running on cathode, and iridium for oxygen evolution reaction (OER) on anode. Possible way of how to lower the loading of Pt and Ir is by using conductive high-surface nanostructures as catalyst supports in conjunction with thin-film catalyst deposition. The presented study discusses unconventional technique of membrane electron assembly (MEA) preparation. Noble metal catalysts (Pt and Ir) were magnetron sputtered in very low loadings onto the surface of porous sublayers (located on gas diffusion layer or directly on membrane), forming so to say localized three-phase boundary. Ultrasonically sprayed corrosion resistant TiC-based sublayer was used as a support material on anode, whereas magnetron sputtered nanostructured etched nitrogenated carbon (CNx) served the same role on cathode. By using this configuration, we were able to significantly decrease the amount of noble metals (to thickness of just tens of nanometers), while keeping the performance comparable to that of average state-of-the-art catalysts. Complex characterization of prepared supported catalysts includes in-cell performance and durability tests, electrochemical impedance spectroscopy (EIS) as well as scanning electron microscopy (SEM) imaging and X-ray photoelectron spectroscopy (XPS) analysis. Our research proves that magnetron sputtering is a suitable method for thin-film deposition of electrocatalysts. Tested set-up of thin-film supported anode and cathode catalysts with combined loading of just 120 ug.cm⁻² yields remarkable values of specific current. Described approach of thin-film low-loading catalyst deposition might be relevant when noble metal reduction is the topmost priority.

Keywords: hydrogen economy, low-loading catalyst, magnetron sputtering, proton exchange membrane water electrolyzer

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Authors: Vladimir Messerle, Alfred Mosse, Alexandr Ustimenko, Oleg Lavrichshev

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Hygiene and sanitary study of typical medical-biological waste made in Kazakhstan, Russia, Belarus and other countries show that their risk to the environment is much higher than that of most chemical wastes. For example, toxicity of solid waste (SW) containing cytotoxic drugs and antibiotics is comparable to toxicity of radioactive waste of high and medium level activity. This report presents the results of the thermodynamic analysis of thermal processing of SW and experiments at the developed plasma unit for SW processing. Thermodynamic calculations showed that the maximum yield of the synthesis gas at plasma gasification of SW in air and steam mediums is achieved at a temperature of 1600K. At the air plasma gasification of SW high-calorific synthesis gas with a concentration of 82.4% (СO – 31.7%, H2 – 50.7%) can be obtained, and at the steam plasma gasification – with a concentration of 94.5% (СO – 33.6%, H2 – 60.9%). Specific heat of combustion of the synthesis gas produced by air gasification amounts to 14267 kJ/kg, while by steam gasification - 19414 kJ/kg. At the optimal temperature (1600 K), the specific power consumption for air gasification of SW constitutes 1.92 kWh/kg, while for steam gasification - 2.44 kWh/kg. Experimental study was carried out in a plasma reactor. This is device of periodic action. The arc plasma torch of 70 kW electric power is used for SW processing. Consumption of SW was 30 kg/h. Flow of plasma-forming air was 12 kg/h. Under the influence of air plasma flame weight average temperature in the chamber reaches 1800 K. Gaseous products are taken out of the reactor into the flue gas cooling unit, and the condensed products accumulate in the slag formation zone. The cooled gaseous products enter the gas purification unit, after which via gas sampling system is supplied to the analyzer. Ventilation system provides a negative pressure in the reactor up to 10 mm of water column. Condensed products of SW processing are removed from the reactor after its stopping. By the results of experiments on SW plasma gasification the reactor operating conditions were determined, the exhaust gas analysis was performed and the residual carbon content in the slag was determined. Gas analysis showed the following composition of the gas at the exit of gas purification unit, (vol.%): СO – 26.5, H2 – 44.6, N2–28.9. The total concentration of the syngas was 71.1%, which agreed well with the thermodynamic calculations. The discrepancy between experiment and calculation by the yield of the target syngas did not exceed 16%. Specific power consumption for SW gasification in the plasma reactor according to the results of experiments amounted to 2.25 kWh/kg of working substance. No harmful impurities were found in both gas and condensed products of SW plasma gasification. Comparison of experimental results and calculations showed good agreement. Acknowledgement—This work was supported by Ministry of Education and Science of the Republic of Kazakhstan and Ministry of Education and Science of the Russian Federation (Agreement on grant No. 14.607.21.0118, project RFMEF160715X0118).

Keywords: coal, efficiency, ignition, numerical modeling, plasma-fuel system, plasma generator

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Authors: Davide Cocchi, Andrea Zucchelli, Luca Raimondi, Maria Brugo Tommaso

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The increasing attention is given to the issues of environmental pollution and climate change is exponentially stimulating the development of electrically propelled vehicles powered by renewable energy, in particular, the solar one. Given the small amount of solar energy that can be stored and subsequently transformed into propulsive energy, it is necessary to develop vehicles with high mechanical, electrical and aerodynamic efficiencies along with reduced masses. The reduction of the masses is of fundamental relevance especially for the unsprung masses, that is the assembly of those elements that do not undergo a variation of their distance from the ground (wheel, suspension system, hub, upright, braking system). Therefore, the reduction of unsprung masses is fundamental in decreasing the rolling inertia and improving the drivability, comfort, and performance of the vehicle. This principle applies even more in solar propelled vehicles, equipped with an electric motor that is connected directly to the wheel hub. In this solution, the electric motor is integrated inside the wheel. Since the electric motor is part of the unsprung masses, the development of compact and lightweight solutions is of fundamental importance. The purpose of this research is the design development and optimization of a CFRP 16 wheel hub motor for solar propulsion vehicles that can carry up to four people. In addition to trying to maximize aspects of primary importance such as mass, strength, and stiffness, other innovative constructive aspects were explored. One of the main objectives has been to achieve a high geometric packing in order to ensure a reduced lateral dimension, without reducing the power exerted by the electric motor. In the final solution, it was possible to realize a wheel hub motor assembly completely comprised inside the rim width, for a total lateral overall dimension of less than 100 mm. This result was achieved by developing an innovative connection system between the wheel and the rotor with a double purpose: centering and transmission of the driving torque. This solution with appropriate interlocking noses allows the transfer of high torques and at the same time guarantees both the centering and the necessary stiffness of the transmission system. Moreover, to avoid delamination in critical areas, evaluated by means of FEM analysis using 3D Hashin damage criteria, electrospun nanofibrous mats have been interleaved between CFRP critical layers. In order to reduce rolling resistance, the rim has been designed to withstand high inflation pressure. Laboratory tests have been performed on the rim using the Digital Image Correlation technique (DIC). The wheel has been tested for fatigue bending according to E/ECE/324 R124e.

Keywords: composite laminate, delamination, DIC, lightweight vehicle, motor hub wheel, nanofiber

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Authors: Alessandra Swiny, Michalis Georgiou, Yiorgos Hadjichristou

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This paper focuses on the questions raised through the work of Unit 5: ‘In/Out of crisis, emergent and adaptive’; an architectural research-based studio at the University of Nicosia. It focusses on sustainable architectural and urban explorations tackling with the ever growing crises in its various types, phases and locations. ‘Great crisis situations’ are seen as ‘great chances’ that trigger investigations for further development and evolution of the built environment in an ultimate sustainable approach. The crisis is taken as an opportunity to rethink the urban and architectural directions as new forces for inventions leading to emergent and adaptive built environments. The Unit 5’s identity and environment facilitates the students to respond optimistically, alternatively and creatively towards the global current crisis. Mark Wigley’s notion that “crises are ultimately productive” and “They force invention” intrigued and defined the premises of the Unit. ‘Weather and nature are coauthors of the built environment’ Jonathan Hill states in his ‘weather architecture’ discourse. The weather is constantly changing and new environments, the subnatures are created which derived from the human activities David Gissen explains. The above set of premises triggered innovative responses by the Unit’s students. They thoroughly investigated the various kinds of crisis and their causes in relation to their various types of Terrains. The tools used for the research and investigation were chosen in contradictive pairs to generate further crisis situations: The re-used/salvaged competed with the new, the handmade rivalling with the fabrication, the analogue juxtaposed with digital. Students were asked to delve into state of art technologies in order to propose sustainable emergent and adaptive architectures and Urbanities, having though always in mind that the human and the social aspects of the community should be the core of the investigation. The resulting unprecedented spatial conditions and atmospheres of the emergent new ways of living are deemed to be the ultimate aim of the investigation. Students explored a variety of sites and crisis conditions such as: The vague terrain of the Green Line in Nicosia, the lost footprints of the sinking Venice, the endangered Australian coral reefs, the earthquake torn town of Crevalcore, and the decaying concrete urbanscape of Athens. Among other projects, ‘the plume project’ proposes a cloud-like, floating and almost dream-like living environment with unprecedented spatial conditions to the inhabitants of the coal mine of Centralia, USA, not just to enable them to survive but even to prosper in this unbearable environment due to the process of the captured plumes of smoke and heat. Existing water wells inspire inversed vertical structures creating a new living underground network, protecting the nomads from catastrophic sand storms in the Araoune of Mali. “Inverted utopia: Lost things in the sand”, weaves a series of tea-houses and a library holding lost artifacts and transcripts into a complex underground labyrinth by the utilization of the sand solidification technology. Within this methodology, crisis is seen as a mechanism for allowing an emergence of new and fascinating ultimate sustainable future cultures and cities.

Keywords: adaptive built environments, crisis as opportunity, emergent urbanities, forces for inventions

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Authors: Sam Derakhshan Deilami, Iain N. Kings, Lynne E. Macaskie, Brajendra K. Sharma, Anthony V. Bridgwater, Joseph Wood

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This paper reports the application of a bacteria-supported palladium catalyst to the hydrodeoxygenation (HDO) of pyrolysis bio-oil, towards producing an upgraded transport fuel. Biofuels are key to the timely replacement of fossil fuels in order to mitigate the emissions of greenhouse gases and depletion of non-renewable resources. The process is an essential step in the upgrading of bio-oils derived from industrial by-products such as agricultural and forestry wastes, the crude oil from pyrolysis containing a large amount of oxygen that requires to be removed in order to create a fuel resembling fossil-derived hydrocarbons. The bacteria supported catalyst manufacture is a means of utilizing recycled metals and second life bacteria, and the metal can also be easily recovered from the spent catalysts after use. Comparisons are made between bio-Pd, and a conventional activated carbon supported Pd/C catalyst. Bio-oil was produced by fast pyrolysis of beechwood at 500 C at a residence time below 2 seconds, provided by Aston University. 5 wt % BioPd/C was prepared under reducing conditions, exposing cells of E. coli MC4100 to a solution of sodium tetrachloropalladate (Na2PdCl4), followed by rinsing, drying and grinding to form a powder. Pd/C was procured from Sigma-Aldrich. The HDO experiments were carried out in a 100 mL Parr batch autoclave using ~20g bio-crude oil and 0.6 g bio-Pd/C catalyst. Experimental variables investigated for optimization included temperature (160-350C) and reaction times (up to 5 h) at a hydrogen pressure of 100 bar. Most of the experiments resulted in an aqueous phase (~40%) and an organic phase (~50-60%) as well as gas phase (<5%) and coke (<2%). Study of the temperature and time upon the process showed that the degree of deoxygenation increased (from ~20 % up to 60 %) at higher temperatures in the region of 350 C and longer residence times up to 5 h. However minimum viscosity (~0.035 Pa.s) occurred at 250 C and 3 h residence time, indicating that some polymerization of the oil product occurs at the higher temperatures. Bio-Pd showed a similar degree of deoxygenation (~20 %) to Pd/C at lower temperatures of 160 C, but did not rise as steeply with temperature. More coke was formed over bio-Pd/C than Pd/C at temperatures above 250 C, suggesting that bio-Pd/C may be more susceptible to coke formation than Pd/C. Reactions occurring during bio-oil upgrading include catalytic cracking, decarbonylation, decarboxylation, hydrocracking, hydrodeoxygenation and hydrogenation. In conclusion, it was shown that bio-Pd/C displays an acceptable rate of HDO, which increases with residence time and temperature. However some undesirable reactions also occur, leading to a deleterious increase in viscosity at higher temperatures. Comparisons are also drawn with earlier work on the HDO of Chlorella derived bio-oil manufactured from micro-algae via hydrothermal liquefaction. Future work will analyze the kinetics of the reaction and investigate the effect of bi-metallic catalysts.

Keywords: bio-oil, catalyst, palladium, upgrading

Procedia PDF Downloads 175

Authors: Tatiana L. Avalos-Rendon, Elias A. Pasten Chelala, Carlos J. Mendoza EScobedo, Ignacio A. Figueroa, Victor H. Lara, Luis M. Palacios-Romero

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The cement industry is facing cost increments in energy supply, requirements for reduction of CO₂, and insufficient supply of raw materials of good quality. According to all these environmental issues, cement industry must change its consumption patterns and reduce CO₂ emissions to the atmosphere. This can be achieved by generating environmental consciousness, which encourages the use of industrial by-products and/or recycling for the production of cement, as well as alternate, environment-friendly methods of synthesis which reduce CO₂. Calcination is the conventional method for the obtainment of Portland cement clinker. This method consists of grinding and mixing of raw materials (limestone, clay, etc.) in an adequate dosage. Resulting mix has a clinkerization temperature of 1450 °C so that the formation of the main component occur: alite (Ca₃SiO₅, C₃S). Considering that the energy required to produce C₃S is 1810 kJ kg -1, calcination method for the obtainment of clinker represents two major disadvantages: long thermal treatment and elevated temperatures of synthesis, both of which cause high emissions of carbon dioxide (CO₂) to the atmosphere. Belite Portland clinker is characterized by having a low content of calcium oxide (CaO), causing the presence of alite to diminish and favoring the formation of belite (β-Ca₂SiO₄, C₂S), so production of clinker requires a reduced energy consumption (1350 kJ kg-1), releasing less CO₂ to the atmosphere. Conventionally, β-Ca₂SiO₄ is synthetized by the calcination of calcium carbonate (CaCO₃) and silicon dioxide (SiO₂) through the reaction in solid state at temperatures greater than 1300 °C. Resulting belite shows low hydraulic reactivity. Therefore, this study concerns a new simple modified combustion method for the synthesis of two belite cements at low temperatures (1000 °C). Silica fume, as subproduct of metallurgic industry and commercial natural zeolite were utilized as raw materials. These are considered low-cost materials and were utilized with no additional purification process. Belite cements properties were characterized by XRD, SEM, EDS and BET techniques. Hydration capacity of belite cements was calculated while the mechanical strength was determined in ordinary Portland cement specimens (PC) with a 10% partial replacement of the belite cements obtained. Results showed belite cements presented relatively high surface áreas, at early ages mechanical strengths similar to those of alite cement and comparable to strengths of belite cements obtained by different synthesis methods. Cements obtained in this work present good hydraulic reactivity properties.

Keywords: belite, silica fume, zeolite, hydraulic reactivity

Procedia PDF Downloads 346

Authors: P. Serrano-Pérez, M. C. Rodríguez-Molina, C. Palo, E. Palo, A. Lacasa

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Phytophthora nicotianae is the principal causal agent of root and crown rot disease of red pepper plants in Extremadura (Western Spain). There is a need to develop a biologically-based method of soil disinfestation that facilitates profitable and sustainable production without the use of chemical fumigants. Anaerobic Soil Disinfestation (ASD), as well know as biodisinfestation, has been shown to control a wide range of soil-borne pathogens and nematodes in numerous crop production systems. This method implies soil wetting, incorporation of a easily decomposable carbon-rich organic amendment and covering with plastic film for several weeks. ASD with rapeseed cake (var. Tocatta, a glucosinolates-free variety) used as C-source was assayed in spring 2014, before the pepper crop establishment. The field experiment was conducted at the Agricultural Research Centre Finca La Orden (Southwestern Spain) and the treatments were: rapeseed cake (RCP); rapeseed cake without plastic cover (RC); control non-amendment (CP) and control non-amendment without plastic cover (C). The experimental design was a randomized complete block design with four replicates and a plot size of 5 x 5 m. On 26 March, rapeseed cake (1 kg·m-2) was incorporated into the soil with a rotovator. Biological probes with the inoculum were buried at 15 and 30-cm depth (biological probes were previously prepared with 100 g of disinfected soil inoculated with chlamydospores (chlam) of P. nicotianae P13 isolate [100 chlam·g-1 of soil] and wrapped in agryl cloth). Sprinkler irrigation was run until field capacity and the corresponding plots were covered with transparent plastic (PE 0.05 mm). On 6 May plastics were removed, the biological probes were dug out and a bioassay was established. One pepper seedling at the 2 to 4 true-leaves stage was transplanted in the soil from each biological probe. Plants were grown in a climatic chamber and disease symptoms were recorded every week during 2 months. Fragments of roots and crown of symptomatic plants were analyzed on NARPH media and soil from rizospheres was analyzed using carnation petals as baits. Results of “survival” were expressed as the percentage of soil samples where P. nicotianae was detected and results of “infectivity” were expressed as the percentage of diseased plants. No differences were detected in deep effect. Infectivity of P. nicotianae chlamydospores was successfully reduced in RCP treatment (4.2% of infectivity) compared with the controls (41.7% of infectivity). The pattern of survival was similar to infectivity observed by the bioassay: 21% of survival in RCP; 79% in CP; 83% in C and 87% in RC. Although ASD may be an effective alternative to chemical fumigants to pest management, more research is necessary to show their impact on the microbial community and chemistry of the soil.

Keywords: biodisinfestation, BSD, soil fumigant alternatives, organic amendments

Procedia PDF Downloads 216

Authors: Sayed Maeen Badshah, Kuen-Song Lin, Abrar Hussain, Jamshid Hussain

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Liver cancer is a significant global health issue, ranking fifth in incidence and second in mortality. Effective therapeutic strategies are urgently needed to combat this disease, particularly in regions with high prevalence. This study focuses on developing and characterizing fluorescent organometallic frameworks as distinct drug delivery carriers with potential applications in both the treatment and biological imaging of liver cancer. This work introduces two distinct organometallic frameworks: the cake-shaped GQD@NH₂-MIL-125 and the cross-shaped M8U6/FM8U6. The GQD@NH₂-MIL-125 framework is particularly noteworthy for its high fluorescence, making it an effective tool for biological imaging. X-ray diffraction (XRD) analysis revealed specific diffraction peaks at 6.81ᵒ (011), 9.76ᵒ (002), and 11.69ᵒ (121), with an additional significant peak at 26ᵒ (2θ), corresponding to the carbon material. Morphological analysis using Field Emission Scanning Electron Microscopy (FE-SEM), and Transmission Electron Microscopy (TEM) demonstrated that the framework has a front particle size of 680 nm and a side particle size of 55±5 nm. High-resolution TEM (HR-TEM) images confirmed the successful attachment of graphene quantum dots (GQDs) onto the NH2-MIL-125 framework. Fourier-Transform Infrared (FT-IR) spectroscopy identified crucial functional groups within the GQD@NH₂-MIL-125 structure, including O-Ti-O metal bonds within the 500 to 700 cm⁻¹ range, and N-H and C-N bonds at 1,646 cm⁻¹ and 1,164 cm⁻¹, respectively. BET isotherm analysis further revealed a specific surface area of 338.1 m²/g and an average pore size of 46.86 nm. This framework also demonstrated UV-active properties, as identified by UV-visible light spectra, and its photoluminescence (PL) spectra showed an emission peak around 430 nm when excited at 350 nm, indicating its potential as a fluorescent drug delivery carrier. In parallel, the cross-shaped M8U6/FM8U6 frameworks were synthesized and characterized using X-ray diffraction, which identified distinct peaks at 2θ = 7.4 (111), 8.5 (200), 9.2 (002), 10.8 (002), 12.1 (220), 16.7 (103), and 17.1 (400). FE-SEM, HR-TEM, and TEM analyses revealed particle sizes of 350±50 nm for M8U6 and 200±50 nm for FM8U6. These frameworks, synthesized from terephthalic acid (H₂BDC), displayed notable vibrational bonds, such as C=O at 1,650 cm⁻¹, Fe-O in MIL-88 at 520 cm⁻¹, and Zr-O in UIO-66 at 482 cm⁻¹. BET analysis showed specific surface areas of 740.1 m²/g with a pore size of 22.92 nm for M8U6 and 493.9 m²/g with a pore size of 35.44 nm for FM8U6. Extended X-ray Absorption Fine Structure (EXAFS) spectra confirmed the stability of Ti-O bonds in the frameworks, with bond lengths of 2.026 Å for MIL-125, 1.962 Å for NH₂-MIL-125, and 1.817 Å for GQD@NH₂-MIL-125. These findings highlight the potential of these organometallic frameworks for enhanced liver cancer therapy through precise drug delivery and imaging, representing a significant advancement in nanomaterial applications in biomedical science.

Keywords: liver cancer cells, metal organic frameworks, Doxorubicin (DOX), drug release.

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Authors: Angela Cristina Da F. De Oliveira, Salma E. Asmar, Norbert P. Battlori, Yaz Vera, Uriel R. Valencia, Tâmara Duarte Borges, Antoni D. Bueno, Leandro Batista Costa

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As homeothermic animals, pigs manifest maximum performance when kept at comfortable temperature levels, represented by a limit where thermoregulatory processes are minimal (18 - 20°C). In a stress situation where it will have a higher energy demand for thermal maintenance, the energy contribution to the productive functions will be reduced, generating health imbalances, drop in productive rates and welfare problems. The hypothesis of this project is that 5% starch replacement per 5% sunflower oil (SO), in growing and finishing pig’s diet (Iberic x Duroc), is effective as a nutritional strategy to reduce the negative impacts of thermal stress on performance and animal welfare. Seventy-two crossbred males (51± 6,29 kg body weight- BW) were housed according to the initial BW, in climate-controlled rooms, in collective pens, and exposed to heat stress conditions (30 - 32°C; 35% to 50% humidity). The experiment lasted 90 days, and it was carried out in a randomized block design, in a 2 x 2 factorial, composed of two diets (starch or sunflower oil (with or without) and two feed intake management (ad libitum and restriction). The treatments studied were: 1) control diet (5% starch x 0% SO) with ad libitum intake (n = 18); 2) SO diet (replacement of 5% of starch per 5% SO) with ad libitum intake (n = 18); 3) control diet with restriction feed intake (n = 18); or 4) SO diet with restriction feed intake (n = 18). Feed was provided in two phases, 50–100 Kg BW for growing and 100-140 Kg BW for finishing period, respectively. Hematological, biochemical and growth performance parameters were evaluated on all animals at the beginning of the environmental treatment, on the transition of feed (growing to finishing) and in the final of experiment. After the experimental period, when animals reached a live weight of 130-140 kg, they were slaughtered by carbon dioxide (CO2) stunning. Data have shown for the growing phase no statistical interaction between diet (control x SO) and management feed intake (ad libitum x restriction) on animal performance. At finishing phase, pigs fed with SO diet with restriction feed intake had the same average daily gain (ADG) compared with pigs in control diet with ad libitum feed intake. Furthermore, animals fed with the same diet (SO), presented a better feed gain (p < 0,05) due to feed intake reduce (p < 0,05) when compared with control group. To hematological and biochemical parameters, animals under heat stress had an increase in hematocrit, corpuscular volume, urea concentration, creatinine, calcium, alanine aminotransferase and aspartate aminotransferase (p < 0,05) when compared with the beginning of experiment. These parameters were efficient to characterize the heat stress, although the experimental treatments were not able to reduce the hematological and biochemical stress indicators. In addition, the inclusion of SO on pig diets improve feed gain in pigs at finishing phase, even with restriction feed intake.

Keywords: hematological, performance, pigs, welfare

Procedia PDF Downloads 281

Authors: Georgios A. Fragkiadakis, Antonia Psaroudaki, Theodora Mouratidou, Eirini Sfakianaki

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Research: Within the project "Actions for the optimal utilization of the potential of carob in the Region of Crete" which is financed-supervised by the Region, with collaboration of Crete University and Hellenic Mediterranean University, a SWOT (strengths, weaknesses, opportunities, threats) survey was carried out, to evaluate the prospects of carob in human nutrition, in Crete. Results and conclusions: 1). Strengths: There exists a local production of carob for human consumption, based on international reports, and local-product reports. The data on products in the market (over 100 brands of carob food), indicates a sufficiency of carob materials offered in Crete. The variety of carob food products retailed in Crete indicates a strong demand-production-consumption trend. There is a stable number (core) of businesses that invest significantly (Creta carob, Cretan mills, etc.). The great majority of the relevant food stores (bakery, confectionary etc.) do offer carob products. The presence of carob products produced in Crete is strong on the internet (over 20 main professionally designed websites). The promotion of the carob food-products is based on their variety and on a few historical elements connected with the Cretan diet. 2). Weaknesses: The international prices for carob seed affect the sector; the seed had an international price of €20 per kg in 2021-22 and fell to €8 in 2022, causing losses to carob traders. The local producers do not sort the carobs they deliver for processing, causing 30-40% losses of the product in the industry. The occasional high price triggers the collection of degraded raw material; large losses may emerge due to the action of insects. There are many carob trees whose fruits are not collected, e.g. in Apokoronas, Chania. The nutritional and commercial value of the wild carob fruits is very low. Carob trees-production is recorded by Greek statistical services as "other cultures" in combination with prickly pear i.e., creating difficulties in retrieving data. The percentage of carob used for human nutrition, in contrast to animal feeding, is not known. The exact imports of carob are not closely monitored. We have no data on the recycling of carob by-products in Crete. 3). Opportunities: The development of a culture of respect for carob trade may improve professional relations in the sector. Monitoring carob market and connecting production with retailing-industry needs may allow better market-stability. Raw material evaluation procedures may be implemented to maintain carob value-chain. The state agricultural services may be further involved in carob-health protection. The education of farmers on carob cultivation/management, can improve the quality of the product. The selection of local productive varieties, may improve the sustainability of the culture. Connecting the consumption of carob with health-food products, may create added value in the sector. The presence and extent of wild carob threes in Crete, represents, potentially, a target for grafting. 4). Threats: The annual fluctuation of carob yield challenges the programming of local food industry activities. Carob is a forest species also - there is danger of wrong classification of crops as forest areas, where land ownership is not clear.

Keywords: human nutrition, carob food, SWOT analysis, crete, greece

Procedia PDF Downloads 92

Authors: Ahmed Tawfik

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Oxidation of 1,4 dioxane produces metabolites by-products involving glycolaldehyde and acids that have geno- and cytotoxicity impact on microbial degradation. Thereby, the incorporation of algae with bacteria in the treatment system would eliminate and overcome the accumulation of metabolites that are utilized as a carbon source for the build-up of biomass. Therefore, the aim of the present study is to assess the potential of algae/bacteria-based membrane bioreactor (AB-MBR) for biodegradation of 1,4 dioxane-rich wastewater at a high imposed loading rate. Three identical reactors, i.e., AB-MBR1, AB-MBR2, and AB-MBR3, were operated in parallel at 1,4 dioxane loading rates of 641.7, 320.9, and 160.4 mg/L. d., and HRTs of 6.0, 12 and 24 h. respectively. The AB-MBR1 achieved 1,4 dioxane removal rate of 263.7 mg/L.d., where the residual value in the treated effluent amounted to 94.4±22.9 mg/L. Reducing the 1,4 dioxane loading rate (LR) to 320.9 mg/L.d in the AB-MBR2 maximized the removal rate efficiency of 265.9 mg/L.d., with a removal efficiency of 82.8±3.2%. The minimum value of 1,4 dioxane of 17.3±1.8 mg/L in the treated effluent of AB-MBR3 was obtained at an HRT of 24.0 h and loading rate of 160.4 mg/L.d. The mechanism of 1,4 dioxane degradation in AB-MBR was a combination of volatilization (8.03±0.6%), UV oxidation (14.1±0.9%), microbial biodegradation (49.1±3.9%) and absorption/uptake and assimilation by algae (28.8±2.%). Further, the Thioclava, Afipia, and Mycobacterium genera oxidized and produced the required enzymes for hydrolysis and cleavage of the dioxane ring into 2-hydroxy-1,4 dioxane. Moreover, the fungi, i.e., Basidiomycota and Cryptomycota, played a big role in the degradation of the 1,4 dioxane into 2-hydroxy-1,4 dioxane. Xanthobacter and Mesorhizobium were involved in the metabolism process by secreting alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and glycolate oxidase. Bacteria and fungi produced dehydrogenase (DH) for the transformation of 2-hydroxy-1,4 dioxane into 2-hydroxy-ethoxyacetaldehyde. The latter is converted into Ethylene glycol by Aldehyde hydrogenase (ALDH). Ethylene glycol is oxidized into acids using Alcohol hydrogenase (ADH). The Diatomea, Chlorophyta, and Streptophyta utilize the metabolites for biomass assimilation and produce the required oxygen for further oxidation of the dioxane and its metabolites by-products of bacteria and fungi. The major portion of metabolites (ethylene glycol, glycolic acid, and oxalic acid were removed due to uptake and absorption by algae (43±4.3%), followed by adsorption (18.4±0.9%). The volatilization and UV oxidation contribution for the degradation of metabolites were 8.7±0.7% and 12.3±0.8%, respectively. The capabilities of genera Defluviimonas, Thioclava, Luteolibacter, and Afipia. The genera of Defluviimonas, Thioclava, Luteolibacter, and Mycobacterium were grown under a high 1,4 dioxane LR of 641.7 mg/L.d. The Chlorophyta (4.1-43.6%), Streptophyta (2.5-21.7%), and Diatomea (0.8-1.4%) phyla were dominant for degradation of 1,4 dioxane. The results of this study strongly demonstrated that the bioremediation and bioaugmentation process can safely remove 1,4 dioxane from industrial wastewater while minimizing environmental concerns and reducing economic costs.

Keywords: wastewater, membrane bioreactor, bacterial community, algal community

Procedia PDF Downloads 43

Authors: A. D. Rao, Sachiko Mohanty, R. Gayathri, V. Ranga Rao

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Modeling on coupled physical and biogeochemical processes of coastal waters is vital to identify the primary production status under different natural and anthropogenic conditions. About 7, 500 km length of Indian coastline is occupied with number of semi enclosed coastal bodies such as estuaries, inlets, bays, lagoons, and other near shore, offshore shelf waters, etc. This coastline is also rich in wide varieties of ecosystem flora and fauna. Directly/indirectly extensive domestic and industrial sewage enter into these coastal water bodies affecting the ecosystem character and create environment problems such as water quality degradation, hypoxia, anoxia, harmful algal blooms, etc. lead to decline in fishery and other related biological production. The present study is focused on the southeast coast of India, starting from Pulicat to Gulf of Mannar, which is rich in marine diversity such as lagoon, mangrove and coral ecosystem. Three dimensional Massachusetts Institute of Technology general circulation model (MITgcm) along with Darwin biogeochemical module is configured for the western Bay of Bengal (BoB) to study the biogeochemistry over this region. The biogeochemical module resolves the cycling of carbon, phosphorous, nitrogen, silica, iron and oxygen through inorganic, living, dissolved and particulate organic phases. The model domain extends from 4°N-16.5°N and 77°E-86°E with a horizontal resolution of 1 km. The bathymetry is derived from General Bathymetric Chart of the Oceans (GEBCO), which has a resolution of 30 sec. The model is initialized by using the temperature, salinity filed from the World Ocean Atlas (WOA2013) of National Oceanographic Data Centre with a resolution of 0.25°. The model is forced by the surface wind stress from ASCAT and the photosynthetically active radiation from the MODIS-Aqua satellite. Seasonal climatology of nutrients (phosphate, nitrate and silicate) for the southwest BoB region are prepared using available National Institute of Oceanography (NIO) in-situ data sets and compared with the WOA2013 seasonal climatology data. The model simulations with the two different initial conditions viz., WOA2013 and the generated NIO climatology, showed evident changes in the concentration and the evolution of the nutrients in the study region. It is observed that the availability of nutrients is more in NIO data compared to WOA in the model domain. The model simulated primary productivity is compared with the spatially distributed satellite derived chlorophyll data and at various locations with the in-situ data. The seasonal variability of the model simulated primary productivity is also studied.

Keywords: Bay of Bengal, Massachusetts Institute of Technology general circulation model, MITgcm, biogeochemistry, primary productivity

Procedia PDF Downloads 141

Authors: A. Saravanan, B. R. Huang, C. J. Yeh, K. C. Leou, I. N. Lin

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A new class of ultra-nano diamond-graphite nano-hybrid (DGH) composite materials containing nano-sized diamond needles was developed at low temperature process. Such kind of diamond- graphite nano-hybrid composite nanowires exhibit high electrical conductivity and excellent electron field emission (EFE) properties. Few earlier reports mention that addition of N2 gas to the growth plasma requires high growth temperature (800°C) to trigger the dopants to generate the conductivity in the films. High growth temperature is not familiar with the Si-based device fabrications. We have used a novel process such as bias-enhanced-grown (beg) MPECVD process to grow diamond films at low substrate temperature (450°C). We observed that the beg-N/UNCD films thus obtained possess high conductivity of σ=987 S/cm, ever reported for diamond films with excellent Electron field emission (EFE) properties. TEM investigation indicated that these films contain needle-like diamond grains about 5 nm in diameter and hundreds of nanometers in length. Each of the grains was encased in graphitic layers about tens of nano-meters in thickness. These materials properties suitable for more specific applications, such as high conductivity for electron field emitters, high robustness for microplasma cathodes and high electrochemical activity for electro-chemical sensing. Subsequently, other hand, the highly conducting DGH films were coated on vertically aligned ZnO nanorods, there is no prior nucleation or seeding process needed due to the use of BEG method. Such a composite structure provides significant enhancement in the field emission characteristics of the cold cathode was observed with ultralow turn on voltage 1.78 V/μm with high EFE current density of 3.68 mA/ cm2 (at 4.06V/μm) due to decoration of DGH material on ZnO nanorods. The DGH/ZNRs based device get stable emission for longer duration of 562min than bare ZNRs (104min) without any current degradation because the diamond coating protects the ZNRs from ion bombardment when they are used as the cathode for microplasma devices. The potential application of these materials is demonstrated by the plasma illumination measurements that ignited the plasma at the minimum voltage by 290 V. The photoresponse (Iphoto/Idark) behavior of the DGH/ZNRs based photodetectors exhibits a much higher photoresponse (1202) than bare ZNRs (229). During the process the electron transport is easy from ZNRs to DGH through graphitic layers, the EFE properties of these materials comparable to other primarily used field emitters like carbon nanotubes, graphene. The DGH/ZNRs composite also providing a possibility of their use in flat panel, microplasma and vacuum microelectronic devices.

Keywords: bias-enhanced nucleation and growth, ZnO nanorods, electrical conductivity, electron field emission, photo-detectors

Procedia PDF Downloads 370

Authors: Moaawia Abdulgader Gdara

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En -Naga sub - basin considered to be the most southern of the concessions in the Sirte Basin operated by HOO. En Naga Sub – basin have likely been point-sourced of CO₂ accumulations during the last 7 million years from local satellite intrusives associated with the Haruj Al Aswad igneous complex. CO2 occurs in the En Naga Sub-basin as a result of the igneous activity of the Al Harouge Al Aswad complex.Igneous extrusive have been pierced in the subsurface are exposed at the surface. The lower cretaceous Bahi Sandstone facies are recognized in the En Naga Sub-basin. They result from the influence of paleotopography on the processes associated with continental deposition over the Sirt Unconformity and the Cenomanian marine transgression In the Lower Cretaceous Bahi Sandstones, the presence of trapped carbon dioxide is proven within the En Naga Sub-basin. This makes it unique in providing an abundance of CO₂ gas reservoirs with almost pure magmatic CO₂, which can be easily sampled. Huge amounts of CO2 exist in the Lower Cretaceous Bahi Sandstones in the En-Naga sub-basin, where the economic value of CO₂ is related to its use for enhanced oil recovery (EOR) Based on the production tests for the drilled wells that makes Lower Cretaceous Bahi sandstones the principle reservoir rocks for CO2 where large volumes of CO2 gas have been discovered in the Bahi Formation on and near EPSA 120/136(En -Naga sub basin). The Bahi sandstones are generally described as a good reservoir rock. Intergranular porosities and permeabilities are highly variable and can exceed 25% and 100 MD. In the (En Naga sub – basin), three main developed structures (Barrut I, En Naga A and En Naga O) are thought to be prospective for the lower Cretaceous Bahi sandstone reservoir. These structures represents a good example for the deep over pressure potential in (En Naga sub - basin). The very high pressures assumed associated with local igneous intrusives may account for the abnormally high Bahi (and Lidam) reservoir pressures. The best gas tests from this facies are at F1-72 on the (Barrut I structure) from part of a 458 feet+ section having an estimated high value of CO2 as 98% overpressured. Bahi CO) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co₂ generation and migration to the bahi sandstone reservoir generation and migration to the bahi sandstone reservoir generation and migration to the bahi sandstone reservoir generation and migration to the bahi sandstone reservoir prospectivity is thought to be excellent in the central to western areas where At U1-72 (En Naga O structure) a significant CO2 gas kick occurred at 11,971 feet and quickly led to blowout conditions due to uncontrollable leaks in the surface equipment. Which reflects a better reservoir quality sandstones associated with Paleostructural highs. Condensate and gas prospectivity increases to the east as the CO₂) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co₂ generation and migration to the bahi sandstone reservoir generation and migration to the bahi sandstone reservoir prospectivity decreases with distance away from the Al Haruj Al Aswad igneous complex. To date, it has not been possible to accurately determine the volume of these strategically valuable reserves although there are positive indications that they are very large.

Keywords: 1) en naga sub basin, 2)al harouge al aswad igneous complex., 3) lower cretaceous bahi reservoir, 4)co2 generation and migration to the bahi sandstone reservoir

Procedia PDF Downloads 71

Authors: Igor V. Grigoriev

Abstract:

Understanding of biological processes encoded in fungi is instrumental in addressing future food, feed, and energy demands of the growing human population. Genomics is a powerful and quickly evolving tool to understand these processes. The Fungal Genomics Program of the US Department of Energy Joint Genome Institute (JGI) partners with researchers around the world to explore fungi in several large scale genomics projects, changing the fungal genomics landscape. The key trends of these changes include: (i) rapidly increasing scale of sequencing and analysis, (ii) developing approaches to go beyond culturable fungi and explore fungal ‘dark matter,’ or unculturables, and (iii) functional genomics and multi-omics data integration. Power of comparative genomics has been recently demonstrated in several JGI projects targeting mycorrhizae, plant pathogens, wood decay fungi, and sugar fermenting yeasts. The largest JGI project ‘1000 Fungal Genomes’ aims at exploring the diversity across the Fungal Tree of Life in order to better understand fungal evolution and to build a catalogue of genes, enzymes, and pathways for biotechnological applications. At this point, at least 65% of over 700 known families have one or more reference genomes sequenced, enabling metagenomics studies of microbial communities and their interactions with plants. For many of the remaining families no representative species are available from culture collections. To sequence genomes of unculturable fungi two approaches have been developed: (a) sequencing DNA from fruiting bodies of ‘macro’ and (b) single cell genomics using fungal spores. The latter has been tested using zoospores from the early diverging fungi and resulted in several near-complete genomes from underexplored branches of the Fungal Tree, including the first genomes of Zoopagomycotina. Genome sequence serves as a reference for transcriptomics studies, the first step towards functional genomics. In the JGI fungal mini-ENCODE project transcriptomes of the model fungus Neurospora crassa grown on a spectrum of carbon sources have been collected to build regulatory gene networks. Epigenomics is another tool to understand gene regulation and recently introduced single molecule sequencing platforms not only provide better genome assemblies but can also detect DNA modifications. For example, 6mC methylome was surveyed across many diverse fungi and the highest among Eukaryota levels of 6mC methylation has been reported. Finally, data production at such scale requires data integration to enable efficient data analysis. Over 700 fungal genomes and other -omes have been integrated in JGI MycoCosm portal and equipped with comparative genomics tools to enable researchers addressing a broad spectrum of biological questions and applications for bioenergy and biotechnology.

Keywords: fungal genomics, single cell genomics, DNA methylation, comparative genomics

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Authors: Kalaya Sribuddhachart, Mayuree Pumipaiboon, Mayuva Youngsabanant-Areekijseree

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The ultrastructure of 20 species of pheasant eggshells in Thailand, (Simese Fireback, Lophura diardi), (Silver Pheasant, Lophura nycthemera), (Kalij Pheasant, Lophura leucomelanos crawfurdii), (Kalij Pheasant, Lophura leucomelanos lineata), (Red Junglefowl, Gallus gallus spadiceus), (Crested Fireback, Lophura ignita rufa), (Green Peafowl, Pavo muticus), (Indian Peafowl, Pavo cristatus), (Grey Peacock Pheasant, Polyplectron bicalcaratum bicalcaratum), (Lesser Bornean Fireback, Lophura ignita ignita), (Green Junglefowl, Gallus varius), (Hume's Pheasant, Syrmaticus humiae humiae), (Himalayan Monal, Lophophorus impejanus), Golden Pheasant, Chrysolophus pictus, (Ring-Neck Pheasant, Phasianus sp.), (Reeves’s Pheasant, Syrmaticus reevesi), (Polish Chicken, Gallus sp.), (Brahma Chicken, Gallus sp.), (Yellow Golden Pheasant, Chrysolophus pictus luteus), and (Lady Amhersts Pheasant, Chrysolophus amherstiae) were studied by Secondary electron imaging (SEI) and Energy dispersive X-ray analysis (EDX) detectors of scanning electron microscope. Generally, all pheasant eggshells showed 3 layers of cuticle, palisade, and mammillary. The total thickness was ranging from 190.28±5.94-838.96±16.31µm. The palisade layer is the most thickness layer following by mammillary and cuticle layers. The palisade layer in all pheasant eggshells consisted of numerous vesicle holes that were firmly forming as network thorough the layer. The vesicle holes in all pheasant eggshells had difference porosity ranging from 0.44±0.11-0.23±0.05 µm. While the mammillary layer was the most compact layer with a variable shape (broad-base V and U-shape) connect to shell membrane. Elemental analysis by of 20 specie eggshells showed 9 apparent elements including carbon (C), oxygen (O), calcium (Ca), phosphorous (P), sulfur (S), magnesium (Mg), silicon (Si), aluminum (Al), and copper (Cu) at the percentage of 28.90- 8.33%, 60.64-27.61%, 55.30-14.49%, 1.97-0.03%, 0.08-0.03%, 0.50-0.16%, 0.30-0.04%, 0.06-0.02%, and 2.67-1.73%, respectively. It was found that Ca, C, and O showed highest elemental compositions, which essential for pheasant embryonic development, mainly presented as composited structure of calcium carbonate (CaCO3) more than 97%. Meanwhile, Mg, S, Si, Al, and P were major inorganic constituents of the eggshells which directly related to an increase of the shell hardness. Finally, the percentage of heavy metal copper (Cu) has been observed in 4 eggshell species. There are Golden Pheasant (2.67±0.16%), Indian Peafowl (2.61±0.13%), Green Peafowl (1.97±0.74%), and Silver Pheasant (1.73±0.11%), respectively. A non-significant difference was found in the percentages of 9 elements in all pheasant eggshells. This study is useful to provide the information of biology and taxonomic of pheasant study in Thailand for conservation.

Keywords: pheasants eggshells, secondary electron imaging (SEI) and energy dispersive X-ray analysis (EDX), morphology, Thailand

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Authors: Ana Violante, Jodie Maccarrone, Maria Fimiani

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In the United States, over 30 million people are hospitalized annually for conditions that require acute, 24-hour, supervised care. The experience of hospitalization can be traumatic, exposing the patient to loss of control, autonomy, and productivity. Furthermore, 40% of patients admitted to hospitals for general medical illness have a comorbid psychiatric diagnosis. Research suggests individuals admitted with psychiatric comorbidities experience poorer health outcomes, higher utilization rates and increased overall cost of care. Empirical work suggests hospital settings that include a consultation liaison (CL) service report reduced length of stay, lower costs per patient, improved medical staff and patient satisfaction and reduced readmission after 180 days. Despite the overall positive impact CL services can have on patient care, it is estimated that only 1% - 2.8% of hospital admits receive these services, and most research has been conducted by the field of psychiatry. Health psychologists could play an important role in increasing access to this valuable service, though the extent to which health psychologists participate in CL settings is not well known. Objective: Outline the preliminary findings from an empirical study to understand how many APPIC internship training programs offer adult consultation liaison rotations within inpatient hospital settings nationally, as well as describe the specific nature of these training experiences. Research Method/Design: Data was exported into Excel from the 2022-2023 APPIC Directory categorized as “health psychology” sites. It initially returned a total of 537 health training programs out 1518 total programs (35% of all APPIC programs). A full review included a quantitative and qualitative comprehensive review of the APPIC program summary, the site website, and program brochures. The quantitative review extracted the number of training positions; amount of stipend; location or state of program, patient, population, and rotation. The qualitative review examined the nature of the training experience. Results: 29 (5%) of all APPIC health psychology internship training programs (2%) respectively of all APPIC training internship programs offering internship CL training were identified. Of the 29 internship training programs, 16 were exclusively within a pediatric setting (55%), 11 were exclusively within an adult setting (38%), and two were a mix of pediatric and adult settings (7%). CL training sites were located to 19 states, offering a total of 153 positions nationally, with Florida containing the largest number of programs (4). Only six programs offered 12-month training opportunities while the rest offered CL as a major (6 month) to minor (3-4 month) rotation. The program’s stipend for CL training positions ranged from $25,000 to $62,400, with an average of $32,056. Conclusions: These preliminary findings suggest CL training and services are currently limited. Training opportunities that do exist are mostly limited to minor, short rotations and governed by psychiatry. Health psychologists are well-positioned to better define the role of psychology in consultation liaison services and enhance and formalize existing training protocols. Future research should explore in more detail empirical outcomes of CL services that employ psychology and delineate the contributions of psychology from psychiatry and other disciplines within an inpatient hospital setting.

Keywords: consultation liaison, health psychology, hospital setting, training

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Authors: Fabrizio Ascione, Martina Borrelli, Rosa Francesca De Masi, Silvia Ruggiero, Giuseppe Peter Vanoli

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The refurbishment of public buildings is one of the key factors of energy efficiency policy of European States. Educational buildings account for the largest share of the oldest edifice with interesting potentialities for demonstrating best practice with regards to high performance and low and zero-carbon design and for becoming exemplar cases within the community. In this context, this paper discusses the critical issue of dealing the energy refurbishment of a university building in heating dominated climate of South Italy. More in detail, the importance of using validated models will be examined exhaustively by proposing an analysis on uncertainties due to modelling assumptions mainly referring to the adoption of stochastic schedules for occupant behavior and equipment or lighting usage. Indeed, today, the great part of commercial tools provides to designers a library of possible schedules with which thermal zones can be described. Very often, the users do not pay close attention to diversify thermal zones and to modify or to adapt predefined profiles, and results of designing are affected positively or negatively without any alarm about it. Data such as occupancy schedules, internal loads and the interaction between people and windows or plant systems, represent some of the largest variables during the energy modelling and to understand calibration results. This is mainly due to the adoption of discrete standardized and conventional schedules with important consequences on the prevision of the energy consumptions. The problem is surely difficult to examine and to solve. In this paper, a sensitivity analysis is presented, to understand what is the order of magnitude of error that is committed by varying the deterministic schedules used for occupation, internal load, and lighting system. This could be a typical uncertainty for a case study as the presented one where there is not a regulation system for the HVAC system thus the occupant cannot interact with it. More in detail, starting from adopted schedules, created according to questioner’ s responses and that has allowed a good calibration of energy simulation model, several different scenarios are tested. Two type of analysis are presented: the reference building is compared with these scenarios in term of percentage difference on the projected total electric energy need and natural gas request. Then the different entries of consumption are analyzed and for more interesting cases also the comparison between calibration indexes. Moreover, for the optimal refurbishment solution, the same simulations are done. The variation on the provision of energy saving and global cost reduction is evidenced. This parametric study wants to underline the effect on performance indexes evaluation of the modelling assumptions during the description of thermal zones.

Keywords: energy simulation, modelling calibration, occupant behavior, university building

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Authors: Bruna Azzari Puga, Richard Roe, Andre Pagani de Souza

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abstract outlines a proposed study to examine how and to what extent interactive, experiential, learner centered methodology develops learning of basic civic and democratic competencies among young children. It stems from the Literacy and Law course taught at Georgetown University Law Center in Washington, DC, since 1998. Law students, trained in best literacy practices and legal cases affecting literacy development, read “law related” children’s books and engage in interactive and extension activities with emerging readers. The law students write a monthly journal describing their experiences and a final paper: a conventional paper or a children’s book illuminating some aspect of literacy and law. This proposal is based on the recent adaptation of Literacy and Law to Brazil at Mackenzie Presbyterian University in São Paulo in three forms: first, a course similar to the US model, often conducted jointly online with Brazilian and US law students; second, a similar course that combines readings of children’s literature with activity based learning, with law students from a satellite Mackenzie campus, for young children from a vulnerable community near the city; and third, a course taught by law students at the main Mackenzie campus for 4th grade students at the Mackenzie elementary school, that is wholly activity and discourse based. The workings and outcomes of these courses are well documented by photographs, reports, lesson plans, and law student journals. The authors, faculty who teach the above courses at Mackenzie and Georgetown, observe that literacy, broadly defined as cognitive and expressive development through reading and discourse-based activities, can be influential in developing democratic civic skills, identifiable by explicit civic competencies. For example, children experience justice in the classroom through cooperation, creativity, diversity, fairness, systemic thinking, and appreciation for rules and their purposes. Moreover, the learning of civic skills as well as the literacy skills is enhanced through interactive, learner centered practices in which the learners experience literacy and civic development. This study will develop rubrics for individual and classroom teaching and supervision by examining 1) the children’s books and students diaries of participating law students and 2) the collection of photos and videos of classroom activities, and 3) faculty and supervisor observations and reports. These rubrics, and the lesson plans and activities which are employed to advance the higher levels of performance outcomes, will be useful in training and supervision and in further replication and promotion of this form of teaching and learning. Examples of outcomes include helping, cooperating and participating; appreciation of viewpoint diversity; knowledge and utilization of democratic processes, including due process, advocacy, individual and shared decision making, consensus building, and voting; establishing and valuing appropriate rules and a reasoned approach to conflict resolution. In conclusion, further development and replication of the learner centered literacy and law practices outlined here can lead to improved qualities of democratic teaching and learning supporting mutual respect, positivity, deep learning, and the common good – foundation qualities of a sustainable world.

Keywords: democracy, law, learner-centered, literacy

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Authors: Dorottya Guban, Irina Borbath, Istvan Bakos, Peter Nemeth, Andras Tompos

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One of the greatest challenges of the implementation of polymer electrolyte membrane fuel cells (PEMFCs) is to find active and durable electrocatalysts. The cell performance is always limited by the oxygen reduction reaction (ORR) on the cathode since it is at least 6 orders of magnitude slower than the hydrogen oxidation on the anode. Therefore high loading of Pt is required. Catalyst corrosion is also more significant on the cathode, especially in case of mobile applications, where rapid changes of loading have to be tolerated. Pt-Sn bulk alloys and SnO2-decorated Pt3Sn nanostructures are among the most studied bimetallic systems for fuel cell applications. Exclusive formation of supported Sn-Pt alloy phases with different Pt/Sn ratios can be achieved by using controlled surface reactions (CSRs) between hydrogen adsorbed on Pt sites and tetraethyl tin. In this contribution our results for commercial and a home-made 20 wt.% Pt/C catalysts modified by tin anchoring via CSRs are presented. The parent Pt/C catalysts were synthesized by modified NaBH4-assisted ethylene-glycol reduction method using ethanol as a solvent, which resulted either in dispersed and highly stable Pt nanoparticles or evenly distributed raspberry-like agglomerates according to the chosen synthesis parameters. The 20 wt.% Pt/C catalysts prepared that way showed improved electrocatalytic performance in the ORR and stability in comparison to the commercial 20 wt.% Pt/C catalysts. Then, in order to obtain Sn-Pt/C catalysts with Pt/Sn= 3 ratio, the Pt/C catalysts were modified with tetraethyl tin (SnEt4) using three and five consecutive tin anchoring periods. According to in situ XPS studies in case of catalysts with highly dispersed Pt nanoparticles, pre-treatment in hydrogen even at 170°C resulted in complete reduction of the ionic tin to Sn0. No evidence of the presence of SnO2 phase was found by means of the XRD and EDS analysis. These results demonstrate that the method of CSRs is a powerful tool to create Pt-Sn bimetallic nanoparticles exclusively, without tin deposition onto the carbon support. On the contrary, the XPS results revealed that the tin-modified catalysts with raspberry-like Pt agglomerates always contained a fraction of non-reducible tin oxide. At the same time, they showed increased activity and long-term stability in the ORR than Pt/C, which was assigned to the presence of SnO2 in close proximity/contact with Pt-Sn alloy phase. It has been demonstrated that the content and dispersion of the fcc Pt3Sn phase within the electrocatalysts can be controlled by tuning the reaction conditions of CSRs. The bimetallic catalysts displayed an outstanding performance in the ORR. The preparation of a highly dispersed 20Pt/C catalyst permits to decrease the Pt content without relevant decline in the electrocatalytic performance of the catalysts.

Keywords: anode catalyst, cathode catalyst, controlled surface reactions, oxygen reduction reaction, PtSn/C electrocatalyst

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Authors: Valentin Père, Mathieu Milhé, Fabien Baillon, Jean-Louis Dirion

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Microgrids offer potential solutions to meet the need for local grid stability and increase isolated networks autonomy with the integration of intermittent renewable energy production and storage facilities. In such a context, sizing production and storage for a given network is a complex task, highly depending on input data such as power load profile and renewable resource availability. This work aims at developing an operating cost computation methodology for different microgrid designs based on the use of deep reinforcement learning (RL) algorithms to tackle the optimal operation problem in stochastic environments. RL is a data-based sequential decision control method based on Markov decision processes that enable the consideration of random variables for control at a chosen time scale. Agents trained via RL constitute a promising class of Energy Management Systems (EMS) for the operation of microgrids with energy storage. Microgrid sizing (or design) is generally performed by minimizing investment costs and operational costs arising from the EMS behavior. The latter might include economic aspects (power purchase, facilities aging), social aspects (load curtailment), and ecological aspects (carbon emissions). Sizing variables are related to major constraints on the optimal operation of the network by the EMS. In this work, an islanded mode microgrid is considered. Renewable generation is done with photovoltaic panels; an electrochemical battery ensures short-term electricity storage. The controllable unit is a hydrogen tank that is used as a long-term storage unit. The proposed approach focus on the transfer of agent learning for the near-optimal operating cost approximation with deep RL for each microgrid size. Like most data-based algorithms, the training step in RL leads to important computer time. The objective of this work is thus to study the potential of Batch-Constrained Q-learning (BCQ) for the optimal sizing of microgrids and especially to reduce the computation time of operating cost estimation in several microgrid configurations. BCQ is an off-line RL algorithm that is known to be data efficient and can learn better policies than on-line RL algorithms on the same buffer. The general idea is to use the learned policy of agents trained in similar environments to constitute a buffer. The latter is used to train BCQ, and thus the agent learning can be performed without update during interaction sampling. A comparison between online RL and the presented method is performed based on the score by environment and on the computation time.

Keywords: batch-constrained reinforcement learning, control, design, optimal

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Authors: Blanca A. Pichardo, Victor H. Lopez, Melchor Salazar, Rafael Garcia, Alberto Ruiz

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Clad pipes in comparison to plain carbon steel pipes offer the oil and gas industry high corrosion resistance, reduction in economic losses due to pipeline failures and maintenance, lower labor risk, prevent pollution and environmental damage due to hydrocarbons spills caused by deteriorated pipelines. In this context, it is paramount to establish reliable welding procedures to join bimetallic plates or pipes. Thus, the aim of this work is to study the microstructure and mechanical behavior of clad plates welded by the gas metal arc welding (GMAW) process. A clad of 316L stainless steel was deposited onto API 5L X-60 plates by overlay welding with the GMAW process. Welding parameters were, 22.5 V, 271 A, heat input 1,25 kJ/mm, shielding gas 98% Ar + 2% O₂, reverse polarity, torch displacement speed 3.6 mm/s, feed rate 120 mm/s, electrode diameter 1.2 mm and application of an electromagnetic field of 3.5 mT. The overlay welds were subjected to macro-structural and microstructural characterization. After manufacturing the clad plates, a single V groove joint was machined with a 60° bevel and 1 mm root face. GMA welding of the bimetallic plates was performed in four passes with ER316L-Si filler for the root pass and an ER70s-6 electrode for the subsequent welding passes. For joining the clad plates, an electromagnetic field was applied with 2 purposes; to improve the microstructural characteristics and to assist the stability of the electric arc during welding in order to avoid magnetic arc blow. The welds were macro and microstructurally characterized and the mechanical properties were also evaluated. Vickers microhardness (100 g load for 10 s) measurements were made across the welded joints at three levels. The first profile, at the 316L stainless steel cladding, was quite even with a value of approximately 230 HV. The second microhardness profile showed high values in the weld metal, ~400 HV, this was due to the formation of a martensitic microstructure by dilution of the first welding pass with the second. The third profile crossed the third and fourth welding passes and an average value of 240 HV was measured. In the tensile tests, yield strength was between 400 to 450 MPa with a tensile strength of ~512 MPa. In the Charpy impact tests, the results were 86 and 96 J for specimens with the notch in the face and in the root of the weld bead, respectively. The results of the mechanical properties were in the range of the API 5L X-60 base material. The overlap welding process used for cladding is not suitable for large components, however, it guarantees a metallurgical bond, unlike the most commonly used processes such as thermal expansion. For welding bimetallic plates, control of the temperature gradients is key to avoid distortions. Besides, the dissimilar nature of the bimetallic plates gives rise to the formation of a martensitic microstructure during welding.

Keywords: clad pipe, dissimilar welding, gas metal arc welding, magnetic fields

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