Search results for: forest transition savannah zones
2790 Access to the Forest Ecosystem Services: Understanding the Interaction between Livelihood Capitals and Access
Authors: Abu S. M. G. Kibria, Alison M. Behie, Robert Costanza, Colin Groves, Tracy Farrell
Abstract:
This study is aimed to understand the level of access and the influence of livelihood capitals in maintaining access and control of ecosystem services (ESS) in the Sundarbans, Bangladesh. Besides the villagers, we consider other stakeholders including the forest department, coast guard, police, merchants, pirates and villagers who ‘controlled’ or ‘maintained’ access to ESS (crab catching, shrimp fry, honey, shrimp, mixed fish, fuel wood) in this region. Villagers used human, physical, natural and social capitals to gain access to ESS. The highest level of access was observed in crab catching and the lowest was found in honey collection, both of which were done when balancing the costs and benefits of accessing one ESS against another. The outcomes of these ongoing access negotiations were determined by livelihood capitals of the households. In addition, it was often found that the certain variables could have a positive effect on one ESS and a negative effect on another. For instance, human, social and natural capitals (eldest daughter’s education and No. of livelihood group membership and) had significant positive effects on honey collection while two components of human and social capitals including ‘eldest son’s education’ and ‘severity of pirate problem’ had exactly the opposite impact. These complex interactions were also observed in access to other ESS. It thus seems that access to ESS is not anything which is provided, but rather it is achieved by using livelihood capitals. Protecting any ecosystem from over exploitation and improve wellbeing can be achieved by properly balancing the livelihood capital-access nexus.Keywords: provisioning services, access level, livelihood capital, interaction, access gain
Procedia PDF Downloads 2822789 Development of Tools for Multi Vehicles Simulation with Robot Operating System and ArduPilot
Authors: Pierre Kancir, Jean-Philippe Diguet, Marc Sevaux
Abstract:
One of the main difficulties in developing multi-robot systems (MRS) is related to the simulation and testing tools available. Indeed, if the differences between simulations and real robots are too significant, the transition from the simulation to the robot won’t be possible without another long development phase and won’t permit to validate the simulation. Moreover, the testing of different algorithmic solutions or modifications of robots requires a strong knowledge of current tools and a significant development time. Therefore, the availability of tools for MRS, mainly with flying drones, is crucial to enable the industrial emergence of these systems. This research aims to present the most commonly used tools for MRS simulations and their main shortcomings and presents complementary tools to improve the productivity of designers in the development of multi-vehicle solutions focused on a fast learning curve and rapid transition from simulations to real usage. The proposed contributions are based on existing open source tools as Gazebo simulator combined with ROS (Robot Operating System) and the open-source multi-platform autopilot ArduPilot to bring them to a broad audience.Keywords: ROS, ArduPilot, MRS, simulation, drones, Gazebo
Procedia PDF Downloads 2102788 Quercetin and INT3 Inhibits Endocrine Therapy Resistance and Epithelial to Mesenchymal Transition in MCF7 Breast Cancer Cells
Authors: S. Pradhan, D. Pradhan, G. Tripathy
Abstract:
Anti-estrogen treatment resistant is a noteworthy reason for disease relapse and mortality in estrogen receptor alpha (ERα)- positive breast cancers. Tamoxifen or estrogen withdrawal increases the dependance of breast malignancy cells on INT3 signaling. Here, we researched the contribution of Quercetin and INT3 signaling in endocrine resistant breast cancer cells. Methods: We utilized two models of endocrine therapies resistant (ETR-) breast cancer: tamoxifen-resistant (TamR) and long term estrogen-deprived (LTED) MCF7 cells. We assessed the migratory and invasive limit of these cells by Transwell assay. Expression of epithelial to mesenchymal transition (EMT) controllers and in addition INT3 receptors and targets were assessed by real-time PCR and western blot analysis. Besides, we tried in vitro anti-Quercetin monoclonal antibodies (mAbs) and gamma secretase inhibitors (GSIs) as potential EMT reversal therapeutic agents. At last, we created stable Quercetin over expessing MCF7 cells and assessed their EMT features and response to tamoxifen. Results:We found that ETR cells acquired an epithelial to mesenchymal transition (EMT) phenotype and showed expanded levels of Quercetin and INT3 targets. Interestingly, we detected higher level of INT3 however lower levels of INT31 and INT32 proposing a switch to targeting through distinctive INT3 receptors after obtaining of resistance. Anti-Quercetin monoclonal antibodies and the GSI PF03084014 were effective in obstructing the Quercetin/INT3 axis and in part inhibiting the EMT process. As a consequence of this, cell migration and invasion were weakened and the stem cell like population was considerably decreased. Genetic hushing of Quercetin and INT3 prompted proportionate impacts. Finally, stable overexpression of Quercetin was adequate to make MCF7 lethargic to tamoxifen by INT3 activation. Conclusions: ETR cells express abnormal amounts of Quercetin and INT3, whose actuation eventually drives invasive conduct. Anti-Quercetin mAbs and GSI PF03084014 lessen expression of EMT molecules decreasing cellular invasiveness. Quercetin overexpression instigates tamoxifen resistance connected to obtaining of EMT phenotype. Our discovering propose that focusing on Quercetin and/or INT3 warrants further clinical assessment as substantial therapeutic methodologies in endocrine-resistant breast cancer.Keywords: quercetin, INT3, mesenchymal transition, MCF7 breast cancer cells
Procedia PDF Downloads 3112787 Stabilization of Metastable Skyrmion Phase in Polycrystalline Chiral β-Mn Type Co₇Zn₇Mn₆ Alloy
Authors: Pardeep, Yugandhar Bitla, A. K. Patra, G. A. Basheed
Abstract:
The topological protected nanosized particle-like swirling spin textures, “skyrmion,” has been observed in various ferromagnets with chiral crystal structures like MnSi, FeGe, Cu₂OSeO₃ alloys, however the magnetic ordering in these systems takes place at very low temperatures. For skyrmion-based spintronics devices, the skyrmion phase is required to stabilize in a wide temperature – field (T - H) region. The equilibrium skyrmion phase (SkX) in Co₇Zn₇Mn₆ alloy exists in a narrow T – H region just below transition temperature (TC ~ 215 K) and can be quenched by field cooling as a metastable skyrmion phase (MSkX) below SkX region. To realize robust MSkX at 110 K, field sweep ac susceptibility χ(H) measurements were performed after the zero field cooling (ZFC) and field cooling (FC) process. In ZFC process, the sample was cooled from 320 K to 110 K in zero applied magnetic field and then field sweep measurement was performed (up to 2 T) in positive direction (black curve). The real part of ac susceptibility (χ′(H)) at 110 K in positive field direction after ZFC confirms helical to conical phase transition at low field HC₁ (= 42 mT) and conical to ferromagnetic (FM) transition at higher field HC₂ (= 300 mT). After ZFC, FC measurements were performed i.e., sample was initially cooled in zero fields from 320 to 206 K and then a sample was field cooled in the presence of 15 mT field down to the temperature 110 K. After FC process, isothermal χ(H) was measured in positive (+H, red curve) and negative (-H, blue curve) field direction with increasing and decreasing field upto 2 T. Hysteresis behavior in χ′(H), measured after ZFC and FC process, indicates the stabilization of MSkX at 110 K which is in close agreement with literature. Also, the asymmetry between field-increasing curves measured after FC process in both sides confirm the stabilization of MSkX. In the returning process from the high field polarized FM state, helical state below HC₁ is destroyed and only the conical state is observed. Thus, the robust MSkX state is stabilized below its SkX phase over a much wider T - H region by FC in polycrystalline Co₇Zn₇Mn₆ alloy.Keywords: skyrmions, magnetic susceptibility, metastable phases, topological phases
Procedia PDF Downloads 1032786 Structural, Magnetic, Electrical and Dielectric Properties of Pr0.8Na0.2MnO3 Manganite
Authors: H. Ben Khlifa, W. Cheikhrouhou, R. M'nassri
Abstract:
The Orthorhombic Pr0.8Na0.2MnO3 ceramic was prepared in Polycrystalline form by a Pechini sol–gel method and its structural, magnetic, electrical, and dielectric properties were investigated experimentally. A structural study confirms that the sample is a single phase. Magnetic measurements show that the sample is a charge ordered Manganite. The sample undergoes two successive magnetic phase transitions with the variation of temperature: a charge ordering transition occurred at TCO = 212 K followed by a Paramagnetic (PM) to ferromagnetic (FM) transition around TC = 115 K. From an electrical point of view, a saturation region was marked in the conductivity as a function of Temperature s(T) curves at a specific temperature. The dc-conductivity (sdc) reaches a maximum value at 240 K. The obtained results are in good agreement with the temperature dependence of the average normalized change (ANC). We found that the conduction mechanism was governed by small polaron hopping (SPH) in the high-temperature region and by variable range hopping (VRH) in the low-temperature region. Complex impedance analysis indicates the presence of a non-Debye relaxation phenomenon in the system. Also, the compound was modeled by an electrical equivalent circuit. Then, the contribution of the grain boundary in the transport properties was confirmed.Keywords: manganites, preparation methods, magnetization, magnetocaloric effect, electrical and dielectric
Procedia PDF Downloads 1732785 Contribution of Foraminifers in Biostratigraphy and Paleoecology Interpretations of the Basal Eocene From the Phosphatic Sra Ouertaine Basin, in the Southern Tethys(Tunisia)
Authors: Oum Elkhir Mahmoudi, Nebiha Ben Haj Ali
Abstract:
Micropaleontological, sedimentological and statistical studies were carried out on the late Paleoceneearly Eocene succession of Sra Ouertaine and Dyr El Kef in Northern open phosphatic Basin of Tunisia. Based on the abundance and stratigraphic distribution of planktic foraminiferal species, five planktic zones have been recognized from the base to the top of the phosphatic layers. The El Acarinina sibaiyaensis Zone, the E2 Pseudohastigerina wilcoxensis Zone, the E3 Morozovella marginodentata Zone, the E4 Morozovella formosa Zones and the E5 Morozovella subbotinae Zone. The placement of Paleocene-Eocene boundary (PETM) is just below the base of the phosphatic interval. The ETM-2 event may be detectable in the analyzed biotic record of Sra Ouertaine. Based on benthic assemblages, abundances, cluster and multivariate statistical analyses, two biofacies were recognized for each section. The recognized ecozones are typical of warm and shallow water inner neritic setting (dominance of epifaunal fauna Anomalinoides, Dentalina and Cibicidoides associated with Frondicularia phosphatica, Trochamminoides globigeriniformis and Eponides elevatus). The paleoenvironment is eutrophic (presence of several bolivinitids and verneuilinids). For the Dyr El Kef section and P5 and E2 of Sra Ouertaine section, our records indicate that paleoenvironment is influenced by coastal upwelling without oxygen-deficiency, the paleodepth is estimated to be around 50 m. The paleoecosystem is diversified and balanced with a general tendency to stressed condition. While the upper part of Sra Ouertaine section is more eutrophic, influenced by coastal upwelling with oxygen-deficiency, the paleodepth is estimated to be less than 50 m and the ecosystem is unsettled.Keywords: Tunisia, early Eocene, foraminifera, chronostratigraphy
Procedia PDF Downloads 262784 Geophysical Exploration of Aquifer Zones by (Ves) Method at Ayma-Kharagpur, District Paschim Midnapore, West Bengal
Authors: Mayank Sharma
Abstract:
Groundwater has been a matter of great concern in the past years due to the depletion in the water table. This has resulted from the over-exploitation of groundwater resources. Sub-surface exploration of groundwater is a great way to identify the groundwater potential of an area. Thus, in order to meet the water needs for irrigation in the study area, there was a need for a tube well to be installed. Therefore, a Geophysical investigation was carried out to find the most suitable point of drilling and sinking of tube well that encounters an aquifer. Hence, an electrical resistivity survey of geophysical exploration was used to know the aquifer zones of the area. The Vertical Electrical Sounding (VES) method was employed to know the subsurface geology of the area. Seven vertical electrical soundings using Schlumberger electrode array were carried out, having the maximum AB electrode separation of 700m at selected points in Ayma, Kharagpur-1 block of Paschim Midnapore district, West Bengal. The VES was done using an IGIS DDR3 Resistivity meter up to an approximate depth of 160-180m. The data was interpreted, processed and analyzed. Based on all the interpretations using the direct method, the geology of the area at the points of sounding was interpreted. It was established that two deeper clay-sand sections exist in the area at a depth of 50-70m (having resistivity range of 40-60ohm-m) and 70-160m (having resistivity range of 25-35ohm-m). These aquifers will provide a high yield of water which would be sufficient for the desired irrigation in the study area.Keywords: VES method, Schlumberger method, electrical resistivity survey, geophysical exploration
Procedia PDF Downloads 1962783 Transition towards a Market Society: Commodification of Public Health in India and Pakistan
Authors: Mayank Mishra
Abstract:
Market Economy can be broadly defined as economic system where supply and demand regulate the economy and in which decisions pertaining to production, consumption, allocation of resources, price and competition are made by collective actions of individuals or organisations with limited government intervention. On the other hand Market Society is one where instead of the economy being embedded in social relations, social relations are embedded in the economy. A market economy becomes a market society when all of land, labour and capital are commodified. This transition also has effect on people’s attitude and values. Such a transition commence impacting the non-material aspect of life such as public education, public health and the like. The inception of neoliberal policies in non-market norms altered the nature of social goods like public health that raised the following questions. What impact would the transition to a market society make on people in terms of accessibility to public health? Is healthcare a commodity that can be subjected to a competitive market place? What kind of private investments are being made in public health and how do private investments alter the nature of a public good like healthcare? This research problem will employ empirical-analytical approach that includes deductive reasoning which will be using the existing concept of market economy and market society as a foundation for the analytical framework and the hypotheses to be examined. The research also intends to inculcate the naturalistic elements of qualitative methodology which refers to studying of real world situations as they unfold. The research will analyse the existing literature available on the subject. Concomitantly the research intends to access the primary literature which includes reports from the World Bank, World Health Organisation (WHO) and the different departments of respective ministries of the countries for the analysis. This paper endeavours to highlight how the issue of commodification of public health would lead to perpetual increase in its inaccessibility leading to stratification of healthcare services where one can avail the better services depending on the extent of one’s ability to pay. Since the fundamental maxim of private investments is to churn out profits, these kinds of trends would pose a detrimental effect on the society at large perpetuating the lacuna between the have and the have-nots.The increasing private investments, both, domestic and foreign, in public health sector are leading to increasing inaccessibility of public health services. Despite the increase in various public health schemes the quality and impact of government public health services are on a continuous decline.Keywords: commodity, India and Pakistan, market society, public health
Procedia PDF Downloads 3122782 Interpretation and Prediction of Geotechnical Soil Parameters Using Ensemble Machine Learning
Authors: Goudjil kamel, Boukhatem Ghania, Jlailia Djihene
Abstract:
This paper delves into the development of a sophisticated desktop application designed to calculate soil bearing capacity and predict limit pressure. Drawing from an extensive review of existing methodologies, the study meticulously examines various approaches employed in soil bearing capacity calculations, elucidating their theoretical foundations and practical applications. Furthermore, the study explores the burgeoning intersection of artificial intelligence (AI) and geotechnical engineering, underscoring the transformative potential of AI- driven solutions in enhancing predictive accuracy and efficiency.Central to the research is the utilization of cutting-edge machine learning techniques, including Artificial Neural Networks (ANN), XGBoost, and Random Forest, for predictive modeling. Through comprehensive experimentation and rigorous analysis, the efficacy and performance of each method are rigorously evaluated, with XGBoost emerging as the preeminent algorithm, showcasing superior predictive capabilities compared to its counterparts. The study culminates in a nuanced understanding of the intricate dynamics at play in geotechnical analysis, offering valuable insights into optimizing soil bearing capacity calculations and limit pressure predictions. By harnessing the power of advanced computational techniques and AI-driven algorithms, the paper presents a paradigm shift in the realm of geotechnical engineering, promising enhanced precision and reliability in civil engineering projects.Keywords: limit pressure of soil, xgboost, random forest, bearing capacity
Procedia PDF Downloads 222781 Flood Risk Assessment and Adapted to the Climate Change by a Trade-Off Process in Land Use Planning
Authors: Nien-Ming Hong, Kuei-Fang Huang
Abstract:
Climate change is an important issue in future, which seriously affects water resources for a long term planning and management. Flood assessment is highly related with climate and land use. Increasing rainfall and urbanization will induce the inundated area in future. For adapting the impacts of climate change, a land use planning is a good strategy for reducing flood damage. The study is to build a trade-off process with different land use types. The Ta-Liao watershed is the study area with three types of land uses that are build-up, farm and forest. The build-up area is concentrated in the downstream of the watershed. Different rainfall amounts are applied for assessing the land use in 1996, 2005 and 2013. The adapted strategies are based on retarding the development of urban and a trade-off process. When a land changes from farm area to built-up area in downstream, this study is to search for a farm area and change it to forest/grass area or building a retention area in the upstream. For assessing the effects of the strategy, the inundation area is simulated by the Flo-2D model with different rainfall conditions and land uses. The results show inundation maps of several cases with land use change planning. The results also show the trade-off strategies and retention areas can decrease the inundated area and divide the inundated area, which are better than retarding urban development. The land use change is usually non-reverse and the planning should be constructed before the climate change.Keywords: climate change, land use change, flood risk assessment, land use planning
Procedia PDF Downloads 3382780 Modeling and Implementation of a Hierarchical Safety Controller for Human Machine Collaboration
Authors: Damtew Samson Zerihun
Abstract:
This paper primarily describes the concept of a hierarchical safety control (HSC) in discrete manufacturing to up-hold productivity with human intervention and machine failures using a systematic approach, through increasing the system availability and using additional knowledge on machines so as to improve the human machine collaboration (HMC). It also highlights the implemented PLC safety algorithm, in applying this generic concept to a concrete pro-duction line using a lab demonstrator called FATIE (Factory Automation Test and Integration Environment). Furthermore, the paper describes a model and provide a systematic representation of human-machine collabora-tion in discrete manufacturing and to this end, the Hierarchical Safety Control concept is proposed. This offers a ge-neric description of human-machine collaboration based on Finite State Machines (FSM) that can be applied to vari-ous discrete manufacturing lines instead of using ad-hoc solutions for each line. With its reusability, flexibility, and extendibility, the Hierarchical Safety Control scheme allows upholding productivity while maintaining safety with reduced engineering effort compared to existing solutions. The approach to the solution begins with a successful partitioning of different zones around the Integrated Manufacturing System (IMS), which are defined by operator tasks and the risk assessment, used to describe the location of the human operator and thus to identify the related po-tential hazards and trigger the corresponding safety functions to mitigate it. This includes selective reduced speed zones and stop zones, and in addition with the hierarchical safety control scheme and advanced safety functions such as safe standstill and safe reduced speed are used to achieve the main goals in improving the safe Human Ma-chine Collaboration and increasing the productivity. In a sample scenarios, It is shown that an increase of productivity in the order of 2.5% is already possible with a hi-erarchical safety control, which consequently under a given assumptions, a total sum of 213 € could be saved for each intervention, compared to a protective stop reaction. Thereby the loss is reduced by 22.8%, if occasional haz-ard can be refined in a hierarchical way. Furthermore, production downtime due to temporary unavailability of safety devices can be avoided with safety failover that can save millions per year. Moreover, the paper highlights the proof of the development, implementation and application of the concept on the lab demonstrator (FATIE), where it is realized on the new safety PLCs, Drive Units, HMI as well as Safety devices in addition to the main components of the IMS.Keywords: discrete automation, hierarchical safety controller, human machine collaboration, programmable logical controller
Procedia PDF Downloads 3692779 An Analysis of Fertility Decline in India: Evidences from Tamil Nadu and Uttar Pradesh
Authors: Ajay Kumar
Abstract:
Using data from census of India, sample registration system and national family health survey (NFHS-3), this paper traces spatial pattern, trends and the factors which have played their role differently in fertility transition in Uttar Pradesh and Tamil Nadu. For the purpose spatial variation analysis, trend line and binary logistic regression analysis has been carried out. There exist considerable regional disparities in terms of fertility decline in northern and southern states. The pace of fertility decline has been faster in southern and coastal regions, and at a slow pace in backward northern state. In Tamil Nadu fertility declined substantially among the women of lower and higher age groups in comparison to Uttar Pradesh characterized by low literacy, low female age at marriage, poor health infrastructure and low status of women. The Study shows that Fertility rates have been higher among the most vulnerable and deprived sections of the society like Illiterate women, women belong to scheduled caste, scheduled tribe and women residing in rural areas.Keywords: age specific fertility rate, fertility transition, replacement level, total fertility rate
Procedia PDF Downloads 2852778 Chemical Reaction Method for Growing Uniform Photomechanical Organic Crystlas
Authors: Rabih O. Al-Kaysi, Lingyan Zhu, Muhannah K. Al-Muhannah, Christopher J. Bardeen
Abstract:
(E)-3-(Anthracen-9-yl)acrylic acid (9-AYAA) 1 exhibits a strong photomechanical response in bulk crystals but is challenging to grow in microcrystalline form. High quality microcrystals of this molecule could not be grown using techniques like sublimation, reprecipitation, and the floating drop method. If the tertbutyl ester of 9-AYAA is used as a starting material, however, high quality, size-uniform microwires could be grown via acid catalyzed hydrolysis. 9-AYAA microwires with uniform length and thickness were produced after a suspension of (E)-tert-butyl 3-(anthracen-9-yl)acrylate ester 2 microparticles was tumble-mixed in a mixture of phosphoric acid and sodium dodecyl sulfate at 35 °C. The dependence of the results on temperature, surfactant and precursor concentration, and mixing mode was investigated. This chemical reaction-growth method was extended to grow microplates of 9-anthraldehyde 3 using the corresponding acylal 4 as the starting material. Under 475 nm irradiation, the 9-AYAA microwires undergo a photoinduced coiling–uncoiling transition, while the 9-anthraldehyde microplates undergo a folding–unfolding transition.Keywords: photomechanical, surfactant, organic crystals, uniform
Procedia PDF Downloads 4022777 Accelerating Sustainable Urban Transition Through Green Technology Innovation and Clean Energy to Achieve Net Zero Emissions
Authors: Emma Serwaa Obobisa
Abstract:
Urbanization has become the focus for challenging goals relating to environmental performance, such as carbon neutrality. Green technological innovation and clean energy are considered the prominent factors in reducing emissions and achieving sustainable cities. Through the application of a fixed effect model, generalized method of moments, and quantile-on-quantile regression, this study explores the role of green technology innovation and clean energy in accelerating the sustainable urban transition towards net zero emissions in developing countries while controlling for nonrenewable energy consumption, and economic growth. The long-run results show that green technology innovation and renewable energy consumption reduce CO₂ emissions from urban residential buildings. In contrast, economic growth and nonrenewable energy consumption increase CO₂ emissions. This study proposes a consistent technique for encouraging green technological innovation and renewable energy projects in developing countries where the role of innovation in achieving carbon neutrality is still understudied.Keywords: green technology innovation, renewable energy, urbanization, net zero emissions
Procedia PDF Downloads 342776 Analytic Hierarchy Process and Multi-Criteria Decision-Making Approach for Selecting the Most Effective Soil Erosion Zone in Gomati River Basin
Authors: Rajesh Chakraborty, Dibyendu Das, Rabindra Nath Barman, Uttam Kumar Mandal
Abstract:
In the present study, the objective is to find out the most effective zone causing soil erosion in the Gumati river basin located in the state of Tripura, a north eastern state of India using analytical hierarchy process (AHP) and multi-objective optimization on the basis of ratio analysis (MOORA).The watershed is segmented into 20 zones based on Area. The watershed is considered by pointing the maximum elevation from sea lever from Google earth. The soil erosion is determined using the universal soil loss equation. The different independent variables of soil loss equation bear different weightage for different soil zones. And therefore, to find the weightage factor for all the variables of soil loss equation like rainfall runoff erosivity index, soil erodibility factor etc, analytical hierarchy process (AHP) is used. And thereafter, multi-objective optimization on the basis of ratio analysis (MOORA) approach is used to select the most effective zone causing soil erosion. The MCDM technique concludes that the maximum soil erosion is occurring in the zone 14.Keywords: soil erosion, analytic hierarchy process (AHP), multi criteria decision making (MCDM), universal soil loss equation (USLE), multi-objective optimization on the basis of ratio analysis (MOORA)
Procedia PDF Downloads 5382775 Unlocking Green Hydrogen Potential: A Machine Learning-Based Assessment
Authors: Said Alshukri, Mazhar Hussain Malik
Abstract:
Green hydrogen is hydrogen produced using renewable energy sources. In the last few years, Oman aimed to reduce its dependency on fossil fuels. Recently, the hydrogen economy has become a global trend, and many countries have started to investigate the feasibility of implementing this sector. Oman created an alliance to establish the policy and rules for this sector. With motivation coming from both global and local interest in green hydrogen, this paper investigates the potential of producing hydrogen from wind and solar energies in three different locations in Oman, namely Duqm, Salalah, and Sohar. By using machine learning-based software “WEKA” and local metrological data, the project was designed to figure out which location has the highest wind and solar energy potential. First, various supervised models were tested to obtain their prediction accuracy, and it was found that the Random Forest (RF) model has the best prediction performance. The RF model was applied to 2021 metrological data for each location, and the results indicated that Duqm has the highest wind and solar energy potential. The system of one wind turbine in Duqm can produce 8335 MWh/year, which could be utilized in the water electrolysis process to produce 88847 kg of hydrogen mass, while a solar system consisting of 2820 solar cells is estimated to produce 1666.223 MWh/ year which is capable of producing 177591 kg of hydrogen mass.Keywords: green hydrogen, machine learning, wind and solar energies, WEKA, supervised models, random forest
Procedia PDF Downloads 792774 Rural Territorial Sustainable Development: Interinstitutional Dialogue and Transition to Sustainable Livelihoods
Authors: Aico Nogueira
Abstract:
This paper examines the interinstitutional dialogues within the Brazilian federal structures, which comprises federal, state and local levels, around the themes of new approaches and interventions aimed to promote sustainable rural development, particularly rural development as part of a territorial approach. The work seeks to understand to what extent the various levels of the state interact with these strategies, particularly with the locally constituted powers, focusing on the importance of the transition of traditional agriculture methods to more sustainable agroecological systems and its effects on food security and sustainable rural development. The research analyses as case studies the Sustainable Rural Territories Development Program (PRONAT) of the Ministry of Agrarian Development at the federal level, as well as the State of São Paulo and the Vale do Ribeira Territory, an area characterized by environmental and social vulnerability, restrictive environmental laws and attempts to promote sustainable development. In order to examine how the interrelationships between different levels of governance and civil society, in addition to the neo-institutionalist polity centered literature, the research uses an adaptation of the concept of arena in Ostrom and Hannigan, produced at different scales of decision-making processes, as well as the multilevel governance literature. Document analysis, interviews, focus groups and direct observation techniques are also used. The main findings of this study are that how different levels of governance understand and organize themselves for this work and have a direct impact on the actions taken. Consequently, programs formulated for this purpose are not associated with the creation of institutions capable of breaking with a traditional sectoral view that has historically prevailed in policymaking. And the transition from traditional agriculture to agroecological production systems is hampered by a sectorial foundation, based on large-scale production and the strengthening of the traditional country's land concentration model.Keywords: agroecology, food security, inter-institutional dialogue, rural poverty, sustainable rural development, territorial development
Procedia PDF Downloads 2022773 Characterization of the State of Pollution by Nitrates in the Groundwater in Arid Zones Case of Eloued District (South-East of Algeria)
Authors: Zair Nadje, Attoui Badra, Miloudi Abdelmonem
Abstract:
This study aims to assess sensitivity to nitrate pollution and monitor the temporal evolution of nitrate contents in groundwater using statistical models and map their spatial distribution. The nitrate levels observed in the waters of the town of El-Oued differ from one aquifer to another. Indeed, the waters of the Quaternary aquifer are the richest in nitrates, with average annual contents varying from 6 mg/l to 85 mg/l, for an average of 37 mg/l. These levels are higher than the WHO standard (50 mg/l) for drinking water. At the water level of the Terminal Complex (CT) aquifer, the annual average nitrate levels vary from 14 mg/l to 37 mg/l, with an average of 18 mg/l. In the Terminal Complex, excessive nitrate levels are observed in the central localities of the study area. The spatial distribution of nitrates in the waters of the Quaternary aquifer shows that the majority of the catchment points of this aquifer are subject to nitrate pollution. This study shows that in the waters of the Terminal Complex aquifer, nitrate pollution evolves in two major areas. The first focus is South-North, following the direction of underground flow. The second is West-East, progressing towards the East zone. The temporal distribution of nitrate contents in the water of the Terminal Complex aquifer in the city of El-Oued showed that for decades, nitrate contents have suffered a decline after an increase. This evolution of nitrate levels is linked to demographic growth and the rapid urbanization of the city of El-Oued.Keywords: anthropogenic activities, groundwater, nitrates, pollution, arid zones city of El-Oued, Algeria
Procedia PDF Downloads 562772 Geographical Information System and Multi-Criteria Based Approach to Locate Suitable Sites for Industries to Minimize Agriculture Land Use Changes in Bangladesh
Authors: Nazia Muhsin, Tofael Ahamed, Ryozo Noguchi, Tomohiro Takigawa
Abstract:
One of the most challenging issues to achieve sustainable development on food security is land use changes. The crisis of lands for agricultural production mainly arises from the unplanned transformation of agricultural lands to infrastructure development i.e. urbanization and industrialization. Land use without sustainability assessment could have impact on the food security and environmental protections. Bangladesh, as the densely populated country with limited arable lands is now facing challenges to meet sustainable food security. Agricultural lands are using for economic growth by establishing industries. The industries are spreading from urban areas to the suburban areas and using the agricultural lands. To minimize the agricultural land losses for unplanned industrialization, compact economic zones should be find out in a scientific approach. Therefore, the purpose of the study was to find out suitable sites for industrial growth by land suitability analysis (LSA) by using Geographical Information System (GIS) and multi-criteria analysis (MCA). The goal of the study was to emphases both agricultural lands and industries for sustainable development in land use. The study also attempted to analysis the agricultural land use changes in a suburban area by statistical data of agricultural lands and primary data of the existing industries of the study place. The criteria were selected as proximity to major roads, and proximity to local roads, distant to rivers, waterbodies, settlements, flood-flow zones, agricultural lands for the LSA. The spatial dataset for the criteria were collected from the respective departments of Bangladesh. In addition, the elevation spatial dataset were used from the SRTM (Shuttle Radar Topography Mission) data source. The criteria were further analyzed with factors and constraints in ArcGIS®. Expert’s opinion were applied for weighting the criteria according to the analytical hierarchy process (AHP), a multi-criteria technique. The decision rule was set by using ‘weighted overlay’ tool to aggregate the factors and constraints with the weights of the criteria. The LSA found only 5% of land was most suitable for industrial sites and few compact lands for industrial zones. The developed LSA are expected to help policy makers of land use and urban developers to ensure the sustainability of land uses and agricultural production.Keywords: AHP (analytical hierarchy process), GIS (geographic information system), LSA (land suitability analysis), MCA (multi-criteria analysis)
Procedia PDF Downloads 2632771 Laser Paint Stripping on Large Zones on AA 2024 Based Substrates
Authors: Selen Unaldi, Emmanuel Richaud, Matthieu Gervais, Laurent Berthe
Abstract:
Aircrafts are painted with several layers to guarantee their protection from external attacks. For aluminum AA 2024-T3 (metallic structural part of the plane), a protective primer is applied to ensure its corrosion protection. On top of this layer, the top coat is applied for aesthetic aspects. During the lifetime of an aircraft, top coat stripping has an essential role which should be operated as an average of every four years. However, since conventional stripping processes create hazardous disposals and need long hours of labor work, alternative methods have been investigated. Amongst them, laser stripping appears as one of the most promising techniques not only because of the reasons mentioned above but also its controllable and monitorable aspects. The application of a laser beam from the coated side provides stripping, but the depth of the process should be well controlled in order to prevent damage to a substrate and the anticorrosion primer. Apart from that, thermal effects should be taken into account on the painted layers. As an alternative, we worked on developing a process that includes the usage of shock wave propagation to create the stripping via mechanical effects with the application of the beam from the substrate side (back face) of the samples. Laser stripping was applied on thickness-specified samples with a thickness deviation of 10-20%. First, the stripping threshold is determined as a function of power density which is the first flight off of the top coats. After obtaining threshold values, the same power densities were applied to specimens to create large stripping zones with a spot overlap of 10-40%. Layer characteristics were determined on specimens in terms of physicochemical properties and thickness range both before and after laser stripping in order to validate the substrate material health and coating properties. The substrate health is monitored by measuring the roughness of the laser-impacted zones and free surface energy tests (both before and after laser stripping). Also, Hugoniot Elastic Limit (HEL) is determined from VISAR diagnostic on AA 2024-T3 substrates (for the back face surface deformations). In addition, the coating properties are investigated as a function of adhesion levels and anticorrosion properties (neutral salt spray test). The influence of polyurethane top-coat thickness is studied in order to verify the laser stripping process window for industrial aircraft applications.Keywords: aircraft coatings, laser stripping, laser adhesion tests, epoxy, polyurethane
Procedia PDF Downloads 782770 An Interactive Voice Response Storytelling Model for Learning Entrepreneurial Mindsets in Media Dark Zones
Authors: Vineesh Amin, Ananya Agrawal
Abstract:
In a prolonged period of uncertainty and disruptions in the pre-said normal order, non-cognitive skills, especially entrepreneurial mindsets, have become a pillar that can reform the educational models to inform the economy. Dreamverse Learning Lab’s IVR-based storytelling program -Call-a-Kahaani- is an evolving experiment with an aim to kindle entrepreneurial mindsets in the remotest locations of India in an accessible and engaging manner. At the heart of this experiment is the belief that at every phase in our life’s story, we have a choice which brings us closer to achieving our true potential. This interactive program is thus designed using real-time storytelling principles to empower learners, ages 24 and below, to make choices and take decisions as they become more self-aware, practice grit, try new things through stories, guided activities, and interactions, simply over a phone call. This research paper highlights the framework behind an ongoing scalable, data-oriented, low-tech program to kindle entrepreneurial mindsets in media dark zones supported by iterative design and prototyping to reach 13700+ unique learners who made 59000+ calls for 183900+min listening duration to listen to content pieces of around 3 to 4 min, with the last monitored (March 2022) record of 34% serious listenership, within one and a half years of its inception. The paper provides an in-depth account of the technical development, content creation, learning, and assessment frameworks, as well as mobilization models which have been leveraged to build this end-to-end system.Keywords: non-cognitive skills, entrepreneurial mindsets, speech interface, remote learning, storytelling
Procedia PDF Downloads 2092769 A Low Order Thermal Envelope Model for Heat Transfer Characteristics of Low-Rise Residential Buildings
Authors: Nadish Anand, Richard D. Gould
Abstract:
A simplistic model is introduced for determining the thermal characteristics of a Low-rise Residential (LRR) building and then predicts the energy usage by its Heating Ventilation & Air Conditioning (HVAC) system according to changes in weather conditions which are reflected in the Ambient Temperature (Outside Air Temperature). The LRR buildings are treated as a simple lump for solving the heat transfer problem and the model is derived using the lumped capacitance model of transient conduction heat transfer from bodies. Since most contemporary HVAC systems have a thermostat control which will have an offset temperature and user defined set point temperatures which define when the HVAC system will switch on and off. The aim is to predict without any error the Body Temperature (i.e. the Inside Air Temperature) which will estimate the switching on and off of the HVAC system. To validate the mathematical model derived from lumped capacitance we have used EnergyPlus simulation engine, which simulates Buildings with considerable accuracy. We have predicted through the low order model the Inside Air Temperature of a single house kept in three different climate zones (Detroit, Raleigh & Austin) and different orientations for summer and winter seasons. The prediction error from the model for the same day as that of model parameter calculation has showed an error of < 10% in winter for almost all the orientations and climate zones. Whereas the prediction error is only <10% for all the orientations in the summer season for climate zone at higher latitudes (Raleigh & Detroit). Possible factors responsible for the large variations are also noted in the work, paving way for future research.Keywords: building energy, energy consumption, energy+, HVAC, low order model, lumped capacitance
Procedia PDF Downloads 2662768 Count of Trees in East Africa with Deep Learning
Authors: Nubwimana Rachel, Mugabowindekwe Maurice
Abstract:
Trees play a crucial role in maintaining biodiversity and providing various ecological services. Traditional methods of counting trees are time-consuming, and there is a need for more efficient techniques. However, deep learning makes it feasible to identify the multi-scale elements hidden in aerial imagery. This research focuses on the application of deep learning techniques for tree detection and counting in both forest and non-forest areas through the exploration of the deep learning application for automated tree detection and counting using satellite imagery. The objective is to identify the most effective model for automated tree counting. We used different deep learning models such as YOLOV7, SSD, and UNET, along with Generative Adversarial Networks to generate synthetic samples for training and other augmentation techniques, including Random Resized Crop, AutoAugment, and Linear Contrast Enhancement. These models were trained and fine-tuned using satellite imagery to identify and count trees. The performance of the models was assessed through multiple trials; after training and fine-tuning the models, UNET demonstrated the best performance with a validation loss of 0.1211, validation accuracy of 0.9509, and validation precision of 0.9799. This research showcases the success of deep learning in accurate tree counting through remote sensing, particularly with the UNET model. It represents a significant contribution to the field by offering an efficient and precise alternative to conventional tree-counting methods.Keywords: remote sensing, deep learning, tree counting, image segmentation, object detection, visualization
Procedia PDF Downloads 712767 Land Suitability Prediction Modelling for Agricultural Crops Using Machine Learning Approach: A Case Study of Khuzestan Province, Iran
Authors: Saba Gachpaz, Hamid Reza Heidari
Abstract:
The sharp increase in population growth leads to more pressure on agricultural areas to satisfy the food supply. To achieve this, more resources should be consumed and, besides other environmental concerns, highlight sustainable agricultural development. Land-use management is a crucial factor in obtaining optimum productivity. Machine learning is a widely used technique in the agricultural sector, from yield prediction to customer behavior. This method focuses on learning and provides patterns and correlations from our data set. In this study, nine physical control factors, namely, soil classification, electrical conductivity, normalized difference water index (NDWI), groundwater level, elevation, annual precipitation, pH of water, annual mean temperature, and slope in the alluvial plain in Khuzestan (an agricultural hotspot in Iran) are used to decide the best agricultural land use for both rainfed and irrigated agriculture for ten different crops. For this purpose, each variable was imported into Arc GIS, and a raster layer was obtained. In the next level, by using training samples, all layers were imported into the python environment. A random forest model was applied, and the weight of each variable was specified. In the final step, results were visualized using a digital elevation model, and the importance of all factors for each one of the crops was obtained. Our results show that despite 62% of the study area being allocated to agricultural purposes, only 42.9% of these areas can be defined as a suitable class for cultivation purposes.Keywords: land suitability, machine learning, random forest, sustainable agriculture
Procedia PDF Downloads 842766 Prevalence and Intensity of Soil Transmitted Helminth Infections among the School Children in the State of Uttar Pradesh, India
Authors: Prasanta Saini, Junaid Jibran Jawed, Subrata Majumdar
Abstract:
Infections caused by soil-transmitted helminths (STH) are the major problem in all the nations of the world. The major focus of STH research is to study the prevalence of three major helminths, such as Ascaris, Trituris and hookworm. Here we are reporting the prevalence and intensity of the STH in the school children of the state of Uttar Pradesh, India. The aim of the study is to assess the prevalence and risk factors of STH infection among the school children, aged between 5-10 years in 27 districts randomly selected districts with covering nine agro-climatic zones of Uttar Pradesh, India. For this cross-sectional survey, we have selected the populations of government primary school going children in Uttar Pradesh. The sampling was performed in the nine different agro-climatic zones. Every individual of the study populations filled their daily information in the questioner's form and then the sample was collected and processed by kato-katz methods by following the guidelines of WHO. In this method, the sampling was performed in total of 6421 populations. A total of 6,421 children from 130 schools were surveyed. Infection with any soil-transmitted helminths was detected among 4,578 children with an overall prevalence of 75.6% (95% CI: 65.3-83.6). Among the 6421 population, the prevalence of Ascaris is 69.6% (95% CL 57.97-79.11), hookworm is 22.7% (95%CL 19.3-26.3) and Trichuris sp is 4.6% (95% CL 0.8-21.6), so the predicted prevalence map indicates that the STH infection was hyperendemic in this state. The findings of our survey in 130 schools covering 9 agro-climatic with one or more soil transmitted helminths. Majority of STH infections were of light intensity. STH infection was hyper-endemic in entire state, except three zones in western Uttar Pradesh. High prevalence ( > 75%) in all age groups also indicate little impact of existing deworming initiatives, including those among pre-school aged children. WHO recommends annual treatment in areas where STH prevalence is between 20% and 50%, and, a bi-annual treatment in areas with prevalence rates of over 50%. In view of high prevalence of STH infection in Uttar Pradesh, it is strongly recommended to initiate a deworming programme for school children in the state. Although our survey was among primary school children, high prevalence among children aged 4-6 years also indicates the need to strengthen the existing deworming programs for pre-school children. Extending the benefits of deworming to pre-school children through deworming in Anganwadi schools would further reduce to decrease the load of infection in community. As a long-term solution for control STH infection, it is also necessary to improve the sanitation levels in the area, as majority of the houses did not have latrines and most of the children were defecating in open fields, a factor that was found to be significantly associated with STH infection.Keywords: prevalence, school going children, soil transmitted helminthes, Uttar Pradesh-India
Procedia PDF Downloads 2732765 Ganoderma Infection in Acacia mangium: Difference of Plant Hosts to Virulency of Ganoderma
Authors: Rosa Suryantini, Reine S. Wulandari, Slamet Rifanjani
Abstract:
Acacia (Acacia mangium) is a forest plant species which is produced to pulp and paper. The high demand for pulp and paper increase the acacia plantation forest area. However, the outbreak of Ganoderma (root rot pathogen) infection becomes obstacles for the development of acacia plantations. This is due to the extent of host range and species of Ganoderma. Ganoderma has also the ability to survive the long-term without hosts. The diversity of the host and Ganoderma species affects its virulence. Therefore, this study aimed to determine the virulence of Ganoderma from different hosts (acacia, palm oil (Elaeis guineensis) and rubber (Hevea brasiliensis)). The methods were isolation and morphology identification of Ganoderma, and inoculation of Ganoderma isolates on acacia seedlings. The results showed that the three isolates of Ganoderma from different hosts had a morphological similarity with G. Lucidum (according to Ganoderma isolated from acacia or G1), G. boninense (according to Ganoderma isolated from palm oil or G2) and G. applanatum (according to Ganoderma isolated from rubber or G3). Symptoms of infection in acacia were seen at 3 months of age. The symptoms were begun with chlorosis, necrosis and death of seedlings (such as burning). Necrosis was started from the tip of the leaf. Based on this visible symptoms, G1 was moderate virulence isolate and G2 was low virulence isolate while G3 was avirulen isolate. The symptoms were still growing in accordance with the development of plant so it affected the value of diseases severity index. Ganoderma infection decreased the dry weight of seedlings, ie. 3.82 g (seedlings that were inoculated by G1), 4.01 g (seedlings that were inoculated by G2); and 5.02 g (seedlings that were inoculated by G3) when the dry weight of seedlings control was 10,02 g. These results provide information for early control of Ganoderma diseases on acacia especially those planted near rubber and oil palm crops.Keywords: Acacia, Ganoderma, infection, virulence
Procedia PDF Downloads 1922764 Identification Algorithm of Critical Interface, Modelling Perils on Critical Infrastructure Subjects
Authors: Jiří. J. Urbánek, Hana Malachová, Josef Krahulec, Jitka Johanidisová
Abstract:
The paper deals with crisis situations investigation and modelling within the organizations of critical infrastructure. Every crisis situation has an origin in the emergency event occurrence in the organizations of energetic critical infrastructure especially. Here, the emergency events can be both the expected events, then crisis scenarios can be pre-prepared by pertinent organizational crisis management authorities towards their coping or the unexpected event (Black Swan effect) – without pre-prepared scenario, but it needs operational coping of crisis situations as well. The forms, characteristics, behaviour and utilization of crisis scenarios have various qualities, depending on real critical infrastructure organization prevention and training processes. An aim is always better organizational security and continuity obtainment. This paper objective is to find and investigate critical/ crisis zones and functions in critical situations models of critical infrastructure organization. The DYVELOP (Dynamic Vector Logistics of Processes) method is able to identify problematic critical zones and functions, displaying critical interfaces among actors of crisis situations on the DYVELOP maps named Blazons. Firstly, for realization of this ability is necessary to derive and create identification algorithm of critical interfaces. The locations of critical interfaces are the flags of crisis situation in real organization of critical infrastructure. Conclusive, the model of critical interface will be displayed at real organization of Czech energetic crisis infrastructure subject in Black Out peril environment. The Blazons need live power Point presentation for better comprehension of this paper mission.Keywords: algorithm, crisis, DYVELOP, infrastructure
Procedia PDF Downloads 4092763 A Robust and Efficient Segmentation Method Applied for Cardiac Left Ventricle with Abnormal Shapes
Authors: Peifei Zhu, Zisheng Li, Yasuki Kakishita, Mayumi Suzuki, Tomoaki Chono
Abstract:
Segmentation of left ventricle (LV) from cardiac ultrasound images provides a quantitative functional analysis of the heart to diagnose disease. Active Shape Model (ASM) is a widely used approach for LV segmentation but suffers from the drawback that initialization of the shape model is not sufficiently close to the target, especially when dealing with abnormal shapes in disease. In this work, a two-step framework is proposed to improve the accuracy and speed of the model-based segmentation. Firstly, a robust and efficient detector based on Hough forest is proposed to localize cardiac feature points, and such points are used to predict the initial fitting of the LV shape model. Secondly, to achieve more accurate and detailed segmentation, ASM is applied to further fit the LV shape model to the cardiac ultrasound image. The performance of the proposed method is evaluated on a dataset of 800 cardiac ultrasound images that are mostly of abnormal shapes. The proposed method is compared to several combinations of ASM and existing initialization methods. The experiment results demonstrate that the accuracy of feature point detection for initialization was improved by 40% compared to the existing methods. Moreover, the proposed method significantly reduces the number of necessary ASM fitting loops, thus speeding up the whole segmentation process. Therefore, the proposed method is able to achieve more accurate and efficient segmentation results and is applicable to unusual shapes of heart with cardiac diseases, such as left atrial enlargement.Keywords: hough forest, active shape model, segmentation, cardiac left ventricle
Procedia PDF Downloads 3392762 The Influence of Salt Body of J. Ech Cheid on the Maturity History of the Cenomanian: Turonian Source Rock
Authors: Mohamed Malek Khenissi, Mohamed Montassar Ben Slama, Anis Belhaj Mohamed, Moncef Saidi
Abstract:
Northern Tunisia is well known by its different and complex structural and geological zones that have been the result of a geodynamic history that extends from the early Mesozoic era to the actual period. One of these zones is the salt province, where the Halokinesis process is manifested by a number of NE/SW salt structures such as Jebel Ech-Cheid which represents masses of materials characterized by a high plasticity and low density. The salt masses extrusions that have been developed due to an extension that started from the late Triassic to late Cretaceous. The evolution of salt bodies within sedimentary basins have not only contributed to modify the architecture of the basin, but it also has certain geochemical effects which touch mainly source rocks that surround it. It has been demonstrated that the presence of salt structures within sedimentary basins can influence its temperature distribution and thermal history. Moreover, it has been creating heat flux anomalies that may affect the maturity of organic matter and the timing of hydrocarbon generation. Field samples of the Bahloul source rock (Cenomanan-Tunonian) were collected from different sights from all around Ech Cheid salt structure and evaluated using Rock-eval pyrolysis and GC/MS techniques in order to assess the degree of maturity evolution and the heat flux anomalies in the different zones analyze. The Total organic Carbon (TOC) values range between 1 to 9% and the (Tmax) ranges between 424 and 445°C, also the distribution of the source rock biomarkers both saturated and aromatic changes in a regular fashions with increasing maturity and this are shown in the chromatography results such as Ts/(Ts+Tm) ratios, 22S/(22S+22R) values for C31 homohopanes, ββ/(ββ+αα)20R and 20S/(20S+20R) ratios for C29 steranes which gives a consistent maturity indications and assessment of the field samples. These analyses are carried to interpret the maturity evolution and the heat flux around Ech Cheid salt structure through the geological history. These analyses also aim to demonstrate that the salt structure can have a direct effect on the geothermal gradient of the basin and on the maturity of the Bahloul Formation source rock. The organic matter has reached different stages of thermal maturity, but delineate a general increasing maturity trend. Our study confirms that the J. Ech Cheid salt body have on the first hand: a huge influence on the local distribution of anoxic depocentre at least within Cenomanian-Turonian time. In the second hand, the thermal anomaly near the salt mass has affected the maturity of Bahloul Formation.Keywords: Bahloul formation, depocentre, GC/MS, rock-eval
Procedia PDF Downloads 2402761 Microscopic Analysis of Interfacial Transition Zone of Cementitious Composites Prepared by Various Mixing Procedures
Authors: Josef Fládr, Jiří Němeček, Veronika Koudelková, Petr Bílý
Abstract:
Mechanical parameters of cementitious composites differ quite significantly based on the composition of cement matrix. They are also influenced by mixing times and procedure. The research presented in this paper was aimed at identification of differences in microstructure of normal strength (NSC) and differently mixed high strength (HSC) cementitious composites. Scanning electron microscopy (SEM) investigation together with energy dispersive X-ray spectroscopy (EDX) phase analysis of NSC and HSC samples was conducted. Evaluation of interfacial transition zone (ITZ) between the aggregate and cement matrix was performed. Volume share, thickness, porosity and composition of ITZ were studied. In case of HSC, samples obtained by several different mixing procedures were compared in order to find the most suitable procedure. In case of NSC, ITZ was identified around 40-50% of aggregate grains and its thickness typically ranged between 10 and 40 µm. Higher porosity and lower share of clinker was observed in this area as a result of increased water-to-cement ratio (w/c) and the lack of fine particles improving the grading curve of the aggregate. Typical ITZ with lower content of Ca was observed only in one HSC sample, where it was developed around less than 15% of aggregate grains. The typical thickness of ITZ in this sample was similar to ITZ in NSC (between 5 and 40 µm). In the remaining four HSC samples, no ITZ was observed. In general, the share of ITZ in HSC samples was found to be significantly smaller than in NSC samples. As ITZ is the weakest part of the material, this result explains to large extent the improved mechanical properties of HSC compared to NSC. Based on the comparison of characteristics of ITZ in HSC samples prepared by different mixing procedures, the most suitable mixing procedure from the point of view of properties of ITZ was identified.Keywords: electron diffraction spectroscopy, high strength concrete, interfacial transition zone, normal strength concrete, scanning electron microscopy
Procedia PDF Downloads 292