Search results for: Industrial engineering
519 Occupational Health Programs for Artisanal and Small-Scale Gold Mining: A Systematic Review for the WHO Global Plan of Action for Workers' Health
Authors: Vivian W. L. Tsang, Karen Lockhart, Samuel Spiegel, Annalee Yassi
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Background: Workers in the informal economy often incur exposure to well-documented occupational health hazards. Insufficient attention has been afforded to rigorously evaluating intervention programs to reduce the risks, especially in artisanal and small-scale gold mining (ASGM). Objectives: This systematic review, conducted as part of the World Health Organization’s Global Plan of Action for Workers’ Health, sought to assess the state of knowledge on occupational health programs and interventions for the informal artisanal and small-scale gold mining (ASGM) sector, an occupation which directly employs at least 50 million people. Methods: We used a comprehensive search strategy for four well-known databases relevant to health outcomes: PubMed, Engineering Village, OVID Medline, and Web of Science, and employed the PRISMA framework for our analysis. Findings: Ten studies met the inclusion criteria of a primary study focused on assessing the impact of interventions addressing occupational health concerns in ASGM. There were no studies evaluating or even identifying comprehensive occupational health and safety programs for this sector, although target interventions addressing specific hazards exist. Major areas of intervention –education and introduction of mercury-reducing/eliminating technology were identified, and the challenges and limitations of each intervention taken into the assessment. Even for these, however, there was a lack of standardization for measuring outcome or impact, let alone long-term health outcomes for miners and mining communities. Conclusion: There is an urgent need for research on comprehensive occupational health programs addressing the array of hazards faced by artisanal and small-scale miners.Keywords: informal economy, artisanal and small-scale gold mining, occupational health, health and safety, workplace safety
Procedia PDF Downloads 152518 Using Variation Theory in a Design-based Approach to Improve Learning Outcomes of Teachers Use of Video and Live Experiments in Swedish Upper Secondary School
Authors: Andreas Johansson
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Conceptual understanding needs to be grounded on observation of physical phenomena, experiences or metaphors. Observation of physical phenomena using demonstration experiments has a long tradition within physics education and students need to develop mental models to relate the observations to concepts from scientific theories. This study investigates how live and video experiments involving an acoustic trap to visualize particle-field interaction, field properties and particle properties can help develop students' mental models and how they can be used differently to realize their potential as teaching tools. Initially, they were treated as analogs and the lesson designs were kept identical. With a design-based approach, the experimental and video designs, as well as best practices for a respective teaching tool, were then developed in iterations. Variation theory was used as a theoretical framework to analyze the planned respective realized pattern of variation and invariance in order to explain learning outcomes as measured by a pre-posttest consisting of conceptual multiple-choice questions inspired by the Force Concept Inventory and the Force and Motion Conceptual Evaluation. Interviews with students and teachers were used to inform the design of experiments and videos in each iteration. The lesson designs and the live and video experiments has been developed to help teachers improve student learning and make school physics more interesting by involving experimental setups that usually are out of reach and to bridge the gap between what happens in classrooms and in science research. As students’ conceptual knowledge also rises their interest in physics the aim is to increase their chances of pursuing careers within science, technology, engineering or mathematics.Keywords: acoustic trap, design-based research, experiments, variation theory
Procedia PDF Downloads 83517 Streamlining Coastal Defense: Investigating the Impact of Seawall Geometry on Wave Loads
Authors: Ahmadreza Ebadati, Asaad Y. Shamseldin, Amin Ghadirian
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Seawall geometry plays a crucial role in mitigating wave impacts, though detailed exploration of its manipulation is limited. This study delves into the effects of varying cross-shore seawall geometry on the dynamics of wave impacts, with a particular focus on vertical seawalls. Inspired by foundational insights linking seawall shape to hydraulic efficiency, this investigation centres on how alterations in seawall geometry can influence wave energy dissipation and subsequent wave impacts. The study investigates the 2D interaction of regular waves with a period of 2.1s with a vertical seawall and berm featuring small-scale cross-shore protrusions and recesses. Utilising OpenFOAM® simulations and a k-ω SST turbulence model, this investigation compares results to a base case simulation, which is partially calibrated with experimental data from a flume study. The analysis evaluates various geometric modifications, specifically interchanged protrusions and recesses at different heights and orientations along the seawall. Findings suggest that specific configurations, such as interchanged protrusions and recesses, can mitigate initial impact forces, while certain arrangements may intensify subsequent impacts. Key insights include the identification of geometry configurations that can effectively reduce the force impulse of slamming waves on coastal structures and potentially decrease the frequency and cost of seawall maintenance. This research contributes to the field by advancing the understanding of how seawall geometry influences wave forces and by providing actionable insights for the design of more resilient seawall structures. Further exploration of seawall geometry variation is recommended, advocating additional case studies to optimise designs tailored to specific coastal environments.Keywords: seawall geometry, wave impact loads, numerical simulation, coastal engineering, wave-structure interaction
Procedia PDF Downloads 50516 Coupled Exciton - Surface Plasmon Polariton Enhanced Photoresponse of Two-Dimensional Hydrogenated Honeycomb Silicon Boride
Authors: Farzaneh Shayeganfar, Ali Ramazani
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Exciton (strong electronic interaction of electron-hole) and hot carriers created by surface plasmon polaritons has been demonstrated in nanoscale optoelectronic devices, enhancing the photoresponse of the system. Herein, we employ a quantum framework to consider coupled exciton- hot carriers effects on photovoltaiv energy distribution, scattering process, polarizability and light emission of 2D-semicnductor. We use density functional theory (DFT) to design computationally a semi-functionalized 2D honeycomb silicon boride (SiB) monolayer with H atoms, suitable for photovoltaics. The dynamical stability, electronic and optical properties of SiB and semi-hydrogenated SiB structures were investigated utilizing the Tran-Blaha modified Becke-Johnson (TB-mBJ) potential. The calculated phonon dispersion shows that while an unhydrogenated SiB monolayer is dynamically unstable, surface semi-hydrogenation improves the stability of the structure and leads to a transition from metallic to semiconducting conductivity with a direct band gap of about 1.57 eV, appropriate for photovoltaic applications. The optical conductivity of this H-SiB structure, determined using the random phase approximation (RPA), shows that light adsorption should begin at the boundary of the visible range of light. Additionally, due to hydrogenation, the reflectivity spectrum declines sharply with respect to the unhydrogenated reflectivity spectrum in the IR and visible ranges of light. The energy band gap remains direct, increasing from 0.9 to 1.8 eV, upon increasing the strain from -6% (compressive) to +6% (tensile). Additionally, compressive and tensile strains lead, respectively, to red and blue shifts of optical the conductivity threshold around the visible range of light. Overall, this study suggests that H-SiB monolayers are suitable as two-dimensional solar cell materials.Keywords: surface plasmon, hot carrier, strain engineering, valley polariton
Procedia PDF Downloads 109515 Critique of the City-Machine: Dismantling the Scientific Socialist Utopia of Soviet Territorialization
Authors: Rachel P. Vasconcellos
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The Russian constructivism is usually enshrined in history as another ''modernist ism'', that is, as an artistic phenomenon related to the early twentieth century‘s zeitgeist. What we aim in this essay is to analyze the constructivist movement not over the Art History field neither through the aesthetic debate, but through a geographical critical theory, taking the main idea of construction in the concrete sense of production of space. Seen from the perspective of the critique of space, the constructivist production is presented as a plan of totality, designed as socialist society‘s spatiality, contemplating and articulating all its scalar levels: the objects of everyday life, the building, the city and the territory. The constructivist avant-garde manifests a geographical ideology, launching the foundation‘s basis of modern planning ideology. Taken in its political sense, the artistic avant-garde of the Russian Revolution intended to anticipate the forms of a social future already put in progress: their plastic research pointed to new formal expressions to revolutionary contents. With the foundation of new institutions under a new State, it was given to the specialized labor of artists, architects, and planners the task of designing the socialist society, based on the thesis of scientific socialism. Their projects were developed under the politico-economics imperatives to the Soviet modernization – that is: the structural needs of industrialization and inclusion of all people in the productive work universe. This context shapes the creative atmosphere of the constructivist avant-garde, which uses the methods of engineering to the transform everyday life. Architecture, urban planning, and state planning integrated must then operate as spatial arrangement morphologically able to produce socialist life. But due to the intrinsic contradictions of the process, the rational and geometric aesthetic of the City-Machine appears, finally, as an image of a scientific socialist utopia.Keywords: city-machine, critique of space, production of space, soviet territorialization
Procedia PDF Downloads 277514 Lexical Semantic Analysis to Support Ontology Modeling of Maintenance Activities– Case Study of Offshore Riser Integrity
Authors: Vahid Ebrahimipour
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Word representation and context meaning of text-based documents play an essential role in knowledge modeling. Business procedures written in natural language are meant to store technical and engineering information, management decision and operation experience during the production system life cycle. Context meaning representation is highly dependent upon word sense, lexical relativity, and sematic features of the argument. This paper proposes a method for lexical semantic analysis and context meaning representation of maintenance activity in a mass production system. Our approach constructs a straightforward lexical semantic approach to analyze facilitates semantic and syntactic features of context structure of maintenance report to facilitate translation, interpretation, and conversion of human-readable interpretation into computer-readable representation and understandable with less heterogeneity and ambiguity. The methodology will enable users to obtain a representation format that maximizes shareability and accessibility for multi-purpose usage. It provides a contextualized structure to obtain a generic context model that can be utilized during the system life cycle. At first, it employs a co-occurrence-based clustering framework to recognize a group of highly frequent contextual features that correspond to a maintenance report text. Then the keywords are identified for syntactic and semantic extraction analysis. The analysis exercises causality-driven logic of keywords’ senses to divulge the structural and meaning dependency relationships between the words in a context. The output is a word contextualized representation of maintenance activity accommodating computer-based representation and inference using OWL/RDF.Keywords: lexical semantic analysis, metadata modeling, contextual meaning extraction, ontology modeling, knowledge representation
Procedia PDF Downloads 105513 The Effect of the Adhesive Ductility on Bond Characteristics of CFRP/Steel Double Strap Joints Subjected to Dynamic Tensile Loadings
Authors: Haider Al-Zubaidy, Xiao-Ling Zhao, Riadh Al-Mahaidi
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In recent years, the technique adhesively-bonded fibre reinforced polymer (FRP) composites has found its way into civil engineering applications and it has attracted a widespread attention as a viable alternative strategy for the retrofitting of civil infrastructure such as bridges and buildings. When adopting this method, adhesive has a significant role and controls the general performance and degree of enhancement of the strengthened and/or upgraded structures. This is because the ultimate member strength is highly affected by the failure mode which is considerably dependent on the utilised adhesive. This paper concerns with experimental investigations on the effect of the adhesive used on the bond between CFRP patch and steel plate under medium impact tensile loading. Experiment were conducted using double strap joints and these samples were prepared using two different types of adhesives, Araldite 420 and MBrace saturant. Drop mass rig was used to carry out dynamic tests at impact speeds of 3.35, 4.43 and m/s while quasi-static tests were implemented at 2mm/min using Instrone machine. In this test program, ultimate load-carrying capacity and failure modes were examined for all loading speeds. For both static and dynamic tests, the adhesive type has a significant effect on ultimate joint strength. It was found that the double strap joints prepared using Araldite 420 showed higher strength than those prepared utilising MBrace saturant adhesive. Failure mechanism for joints prepared using Araldite 420 is completely different from those samples prepared utilising MBrace saturant. CFRP failure is the most common failure pattern for joints with Araldite 420, whereas the dominant failure for joints with MBrace saturant adhesive is adhesive failure.Keywords: CFRP/steel double strap joints, adhesives of different ductility, dynamic tensile loading, bond between CFRP and steel
Procedia PDF Downloads 236512 A Comprehensive Study of a Hybrid System Integrated Solid Oxide Fuel cell, Gas Turbine, Organic Rankine Cycle with Compressed air Energy Storage
Authors: Taiheng Zhang, Hongbin Zhao
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Compressed air energy storage become increasingly vital for solving intermittency problem of some renewable energies. In this study, a new hybrid system on a combination of compressed air energy storage (CAES), solid oxide fuel cell (SOFC), gas turbine (GT), and organic Rankine cycle (ORC) is proposed. In the new system, excess electricity during off-peak time is utilized to compress air. Then, the compressed air is stored in compressed air storage tank. During peak time, the compressed air enters the cathode of SOFC directly instead of combustion chamber of traditional CAES. There is no air compressor consumption of SOFC-GT in peak demand, so SOFC- GT can generate power with high-efficiency. In addition, the waste heat of exhaust from GT is recovered by applying an ORC. Three different organic working fluid (R123, R601, R601a) of ORC are chosen to evaluate system performance. Based on Aspen plus and Engineering Equation Solver (EES) software, energy and exergoeconomic analysis are used to access the viability of the combined system. Besides, the effect of two parameters (fuel flow and ORC turbine inlet pressure) on energy efficiency is studied. The effect of low-price electricity at off-peak hours on thermodynamic criteria (total unit exergy cost of products and total cost rate) is also investigated. Furthermore, for three different organic working fluids, the results of round-trip efficiency, exergy efficiency, and exergoeconomic factors are calculated and compared. Based on thermodynamic performance and exergoeconomic performance of different organic working fluids, the best suitable working fluid will be chosen. In conclusion, this study can provide important guidance for system efficiency improvement and viability.Keywords: CAES, SOFC, ORC, energy and exergoeconomic analysis, organic working fluids
Procedia PDF Downloads 123511 Project Marayum: Creating a Community Built Mobile Phone Based, Online Web Dictionary for Endangered Philippine Languages
Authors: Samantha Jade Sadural, Kathleen Gay Figueroa, Noel Nicanor Sison II, Francis Miguel Quilab, Samuel Edric Solis, Kiel Gonzales, Alain Andrew Boquiren, Janelle Tan, Mario Carreon
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Of the 185 languages in the Philippines, 28 are endangered, 11 are dying off, and 4 are extinct. Language documentation, as a prerequisite to language education, can be one of the ways languages can be preserved. Project Marayum is envisioned to be a collaboratively built, mobile phone-based, online dictionary platform for Philippine languages. Although there are many online language dictionaries available on the Internet, Project Marayum aims to give a sense of ownership to the language community's dictionary as it is built and maintained by the community for the community. From a seed dictionary, members of a language community can suggest changes, add new entries, and provide language examples. Going beyond word definitions, the platform can be used to gather sample sentences and even audio samples of word usage. These changes are reviewed by language experts of the community, sourced from the local state universities or local government units. Approved changes are then added to the dictionary and can be viewed instantly through the Marayum website. A companion mobile phone application allows users to browse the dictionary in remote areas where Internet connectivity is nonexistent. The dictionary will automatically be updated once the user regains Internet access. Project Marayum is still a work in progress. At the time of this abstract's writing, the Project has just entered its second year. Prototypes are currently being tested with the Asi language of Romblon island as its initial language testbed. In October 2020, Project Marayum will have both a webpage and mobile application with Asi, Ilocano, and Cebuano language dictionaries available for use online or for download. In addition, the Marayum platform would be then easily expandable for use of the more endangered language communities. Project Marayum is funded by the Philippines Department of Science and Technology.Keywords: collaborative language dictionary, community-centered lexicography, content management system, software engineering
Procedia PDF Downloads 163510 Study on the Wave Dissipation Performance of Double-Cylinder and Double-Plate Floating Breakwater
Authors: Liu Bijin
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Floating breakwaters have several advantages, including being environmentally friendly, easy to construct, and cost-effective regardless of water depth. They have a broad range of applications in coastal engineering. However, they face significant challenges due to the unstable effect of wave dissipation, structural vulnerability, and high mooring system requirements. This paper investigates the wave dissipation performance of a floating breakwater structure. The structure consists of double cylinders, double vertical plates, and horizontal connecting plates. The investigation is carried out using physical model tests and numerical simulation methods based on STAR-CCM+. This paper discusses the impact of wave elements, relative vertical plate heights, and relative horizontal connecting plate widths on the wave dissipation performance of the double-cylinder, double-plate floating breakwater (DCDPFB). The study also analyses the changes in local vorticity and velocity fields around the DCDPFB to determine the optimal structural dimensions. The study found that the relative width of the horizontal connecting plate, the relative height of the vertical plate, and the size of the semi-cylinder are the key factors affecting the wave dissipation performance of the DCDPFB. The transmittance coefficient is minimally affected by the wave height and the depth of water entry. The local vortex and velocity field formed around the DCDPFB are important factors for dissipating wave energy. The test section of the DCDPFB, constructed according to the relative optimal structural dimensions, showed good wave dissipation performance during offshore prototype tests. The test section of DCDPFB, constructed with optimal structural dimensions, exhibits excellent wave dissipation performance in offshore prototype tests.Keywords: floating breakwater, wave dissipation performance, transmittance coefficient, model test
Procedia PDF Downloads 56509 Problems and Prospects of Agricultural Biotechnology in Nigeria’s Developing Economy
Authors: Samson Abayomi Olasoju, Olufemi Adekunle, Titilope Edun, Johnson Owoseni
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Science offers opportunities for revolutionizing human activities, enriched by input from scientific research and technology. Biotechnology is a major force for development in developing countries such as Nigeria. It is found to contribute to solving human problems like water and food insecurity that impede national development and threaten peace wherever it is applied. This review identified the problems of agricultural biotechnology in Nigeria. On the part of rural farmers, there is a lack of adequate knowledge or awareness of biotechnology despite the fact that they constitute the bulk of Nigerian farmers. On part of the government, the problems include: lack of adequate implementation of government policy on bio-safety and genetically modified products, inadequate funding of education as well as research and development of products related to biotechnology. Other problems include: inadequate infrastructures (including laboratory), poor funding and lack of national strategies needed for development and running of agricultural biotechnology. In spite of all the challenges associated with agricultural biotechnology, its prospects still remain great if Nigeria is to meet with the food needs of the country’s ever increasing population. The introduction of genetically engineered products will lead to the high productivity needed for commercialization and food security. Insect, virus and other related diseases resistant crops and livestock are another viable area of contribution of biotechnology to agricultural production. In conclusion, agricultural biotechnology will not only ensure food security, but, in addition, will ensure that the local farmers utilize appropriate technology needed for large production, leading to the prosperity of the farmers and national economic growth, provided government plays its role of adequate funding and good policy implementation.Keywords: biosafety, biotechnology, food security, genetic engineering, genetic modification
Procedia PDF Downloads 174508 Prediction of Seismic Damage Using Scalar Intensity Measures Based on Integration of Spectral Values
Authors: Konstantinos G. Kostinakis, Asimina M. Athanatopoulou
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A key issue in seismic risk analysis within the context of Performance-Based Earthquake Engineering is the evaluation of the expected seismic damage of structures under a specific earthquake ground motion. The assessment of the seismic performance strongly depends on the choice of the seismic Intensity Measure (IM), which quantifies the characteristics of a ground motion that are important to the nonlinear structural response. Several conventional IMs of ground motion have been used to estimate their damage potential to structures. Yet, none of them has been proved to be able to predict adequately the seismic damage. Therefore, alternative, scalar intensity measures, which take into account not only ground motion characteristics but also structural information have been proposed. Some of these IMs are based on integration of spectral values over a range of periods, in an attempt to account for the information that the shape of the acceleration, velocity or displacement spectrum provides. The adequacy of a number of these IMs in predicting the structural damage of 3D R/C buildings is investigated in the present paper. The investigated IMs, some of which are structure specific and some are nonstructure-specific, are defined via integration of spectral values. To achieve this purpose three symmetric in plan R/C buildings are studied. The buildings are subjected to 59 bidirectional earthquake ground motions. The two horizontal accelerograms of each ground motion are applied along the structural axes. The response is determined by nonlinear time history analysis. The structural damage is expressed in terms of the maximum interstory drift as well as the overall structural damage index. The values of the aforementioned seismic damage measures are correlated with seven scalar ground motion IMs. The comparative assessment of the results revealed that the structure-specific IMs present higher correlation with the seismic damage of the three buildings. However, the adequacy of the IMs for estimation of the structural damage depends on the response parameter adopted. Furthermore, it was confirmed that the widely used spectral acceleration at the fundamental period of the structure is a good indicator of the expected earthquake damage level.Keywords: damage measures, bidirectional excitation, spectral based IMs, R/C buildings
Procedia PDF Downloads 328507 Similarity Solutions of Nonlinear Stretched Biomagnetic Flow and Heat Transfer with Signum Function and Temperature Power Law Geometries
Authors: M. G. Murtaza, E. E. Tzirtzilakis, M. Ferdows
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Biomagnetic fluid dynamics is an interdisciplinary field comprising engineering, medicine, and biology. Bio fluid dynamics is directed towards finding and developing the solutions to some of the human body related diseases and disorders. This article describes the flow and heat transfer of two dimensional, steady, laminar, viscous and incompressible biomagnetic fluid over a non-linear stretching sheet in the presence of magnetic dipole. Our model is consistent with blood fluid namely biomagnetic fluid dynamics (BFD). This model based on the principles of ferrohydrodynamic (FHD). The temperature at the stretching surface is assumed to follow a power law variation, and stretching velocity is assumed to have a nonlinear form with signum function or sign function. The governing boundary layer equations with boundary conditions are simplified to couple higher order equations using usual transformations. Numerical solutions for the governing momentum and energy equations are obtained by efficient numerical techniques based on the common finite difference method with central differencing, on a tridiagonal matrix manipulation and on an iterative procedure. Computations are performed for a wide range of the governing parameters such as magnetic field parameter, power law exponent temperature parameter, and other involved parameters and the effect of these parameters on the velocity and temperature field is presented. It is observed that for different values of the magnetic parameter, the velocity distribution decreases while temperature distribution increases. Besides, the finite difference solutions results for skin-friction coefficient and rate of heat transfer are discussed. This study will have an important bearing on a high targeting efficiency, a high magnetic field is required in the targeted body compartment.Keywords: biomagnetic fluid, FHD, MHD, nonlinear stretching sheet
Procedia PDF Downloads 161506 Revolutionizing Project Management: A Comprehensive Review of Artificial Intelligence and Machine Learning Applications for Smarter Project Execution
Authors: Wenzheng Fu, Yue Fu, Zhijiang Dong, Yujian Fu
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The integration of artificial intelligence (AI) and machine learning (ML) into project management is transforming how engineering projects are executed, monitored, and controlled. This paper provides a comprehensive survey of AI and ML applications in project management, systematically categorizing their use in key areas such as project data analytics, monitoring, tracking, scheduling, and reporting. As project management becomes increasingly data-driven, AI and ML offer powerful tools for improving decision-making, optimizing resource allocation, and predicting risks, leading to enhanced project outcomes. The review highlights recent research that demonstrates the ability of AI and ML to automate routine tasks, provide predictive insights, and support dynamic decision-making, which in turn increases project efficiency and reduces the likelihood of costly delays. This paper also examines the emerging trends and future opportunities in AI-driven project management, such as the growing emphasis on transparency, ethical governance, and data privacy concerns. The research suggests that AI and ML will continue to shape the future of project management by driving further automation and offering intelligent solutions for real-time project control. Additionally, the review underscores the need for ongoing innovation and the development of governance frameworks to ensure responsible AI deployment in project management. The significance of this review lies in its comprehensive analysis of AI and ML’s current contributions to project management, providing valuable insights for both researchers and practitioners. By offering a structured overview of AI applications across various project phases, this paper serves as a guide for the adoption of intelligent systems, helping organizations achieve greater efficiency, adaptability, and resilience in an increasingly complex project management landscape.Keywords: artificial intelligence, decision support systems, machine learning, project management, resource optimization, risk prediction
Procedia PDF Downloads 21505 The Core Obstacles of Continuous Improvement Implementation: Some Key Findings from Health and Education Sectors
Authors: Abdullah Alhaqbani
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Purpose: Implementing continuous improvement is a challenge that public sector organisations face in becoming successful. Many obstacles hinder public organisations from successfully implementing continuous improvement. This paper aims to highlight the key core obstacles that face public organisations to implement continuous improvement programmes. Approach: Based on the literature, this paper reviews 66 papers that were published between 2000 and 2013 and that focused on the concept of continuous improvement and improvement methodologies in the context of public sector organisations. The methodologies for continuous improvement covered in these papers include Total Quality Management, Six Sigma, process re-engineering, lean thinking and Kaizen. Findings: Of the 24 obstacles found in the literature, 11 barriers were seen as core barriers that frequently occurred in public sector organisations. The findings indicate that lack of top management commitment; organisational culture and political issues and resistance to change are significant obstacles for improvement programmes. Moreover, this review found that improvement methodologies share some core barriers to successful implementation within public organisations. These barriers as well are common in the different geographic area. For instance lack of top management commitment and training that found in the education sector in Albanian are common barriers of improvement studies in Kuwait, Saudi Arabia, Spain, UK and US. Practical implications: Understanding these core issues and barriers will help managers of public organisations to improve their strategies with respect to continuous improvement. Thus, this review highlights the core issues that prevent a successful continuous improvement journey within the public sector. Value: Identifying and understanding the common obstacles to successfully implementing continuous improvement in the public sector will help public organisations to learn how to improve in launching and successfully sustaining such programmes. However, this is not the end; rather, it is just the beginning of a longer improvement journey. Thus, it is intended that this review will identify key learning opportunities for public sector organisations in developing nations which will then be tested via further research.Keywords: continuous improvement, total quality management, obstacles, public sector
Procedia PDF Downloads 348504 Investigation of Shear Strength, and Dilative Behavior of Coarse-grained Samples Using Laboratory Test and Machine Learning Technique
Authors: Ehsan Mehryaar, Seyed Armin Motahari Tabari
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Coarse-grained soils are known and commonly used in a wide range of geotechnical projects, including high earth dams or embankments for their high shear strength. The most important engineering property of these soils is friction angle which represents the interlocking between soil particles and can be applied widely in designing and constructing these earth structures. Friction angle and dilative behavior of coarse-grained soils can be estimated from empirical correlations with in-situ testing and physical properties of the soil or measured directly in the laboratory performing direct shear or triaxial tests. Unfortunately, large-scale testing is difficult, challenging, and expensive and is not possible in most soil mechanic laboratories. So, it is common to remove the large particles and do the tests, which cannot be counted as an exact estimation of the parameters and behavior of the original soil. This paper describes a new methodology to simulate particles grading distribution of a well-graded gravel sample to a smaller scale sample as it can be tested in an ordinary direct shear apparatus to estimate the stress-strain behavior, friction angle, and dilative behavior of the original coarse-grained soil considering its confining pressure, and relative density using a machine learning method. A total number of 72 direct shear tests are performed in 6 different sizes, 3 different confining pressures, and 4 different relative densities. Multivariate Adaptive Regression Spline (MARS) technique was used to develop an equation in order to predict shear strength and dilative behavior based on the size distribution of coarse-grained soil particles. Also, an uncertainty analysis was performed in order to examine the reliability of the proposed equation.Keywords: MARS, coarse-grained soil, shear strength, uncertainty analysis
Procedia PDF Downloads 162503 Surface Tension and Bulk Density of Ammonium Nitrate Solutions: A Molecular Dynamics Study
Authors: Sara Mosallanejad, Bogdan Z. Dlugogorski, Jeff Gore, Mohammednoor Altarawneh
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Ammonium nitrate (NH₄NO₃, AN) is commonly used as the main component of AN emulsion and fuel oil (ANFO) explosives, that use extensively in civilian and mining operations for underground development and tunneling applications. The emulsion formulation and wettability of AN prills, which affect the physical stability and detonation of ANFO, highly depend on the surface tension, density, viscosity of the used liquid. Therefore, for engineering applications of this material, the determination of density and surface tension of concentrated aqueous solutions of AN is essential. The molecular dynamics (MD) simulation method have been used to investigate the density and the surface tension of high concentrated ammonium nitrate solutions; up to its solubility limit in water. Non-polarisable models for water and ions have carried out the simulations, and the electronic continuum correction model (ECC) uses a scaling of the charges of the ions to apply the polarisation implicitly into the non-polarisable model. The results of calculated density and the surface tension of the solutions have been compared to available experimental values. Our MD simulations show that the non-polarisable model with full-charge ions overestimates the experimental results while the reduce-charge model for the ions fits very well with the experimental data. Ions in the solutions show repulsion from the interface using the non-polarisable force fields. However, when charges of the ions in the original model are scaled in line with the scaling factor of the ECC model, the ions create a double ionic layer near the interface by the migration of anions toward the interface while cations stay in the bulk of the solutions. Similar ions orientations near the interface were observed when polarisable models were used in simulations. In conclusion, applying the ECC model to the non-polarisable force field yields the density and surface tension of the AN solutions with high accuracy in comparison to the experimental measurements.Keywords: ammonium nitrate, electronic continuum correction, non-polarisable force field, surface tension
Procedia PDF Downloads 231502 Indian Premier League (IPL) Score Prediction: Comparative Analysis of Machine Learning Models
Authors: Rohini Hariharan, Yazhini R, Bhamidipati Naga Shrikarti
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In the realm of cricket, particularly within the context of the Indian Premier League (IPL), the ability to predict team scores accurately holds significant importance for both cricket enthusiasts and stakeholders alike. This paper presents a comprehensive study on IPL score prediction utilizing various machine learning algorithms, including Support Vector Machines (SVM), XGBoost, Multiple Regression, Linear Regression, K-nearest neighbors (KNN), and Random Forest. Through meticulous data preprocessing, feature engineering, and model selection, we aimed to develop a robust predictive framework capable of forecasting team scores with high precision. Our experimentation involved the analysis of historical IPL match data encompassing diverse match and player statistics. Leveraging this data, we employed state-of-the-art machine learning techniques to train and evaluate the performance of each model. Notably, Multiple Regression emerged as the top-performing algorithm, achieving an impressive accuracy of 77.19% and a precision of 54.05% (within a threshold of +/- 10 runs). This research contributes to the advancement of sports analytics by demonstrating the efficacy of machine learning in predicting IPL team scores. The findings underscore the potential of advanced predictive modeling techniques to provide valuable insights for cricket enthusiasts, team management, and betting agencies. Additionally, this study serves as a benchmark for future research endeavors aimed at enhancing the accuracy and interpretability of IPL score prediction models.Keywords: indian premier league (IPL), cricket, score prediction, machine learning, support vector machines (SVM), xgboost, multiple regression, linear regression, k-nearest neighbors (KNN), random forest, sports analytics
Procedia PDF Downloads 53501 The Effects of Damping Devices on Displacements, Velocities and Accelerations of Structures
Authors: Radhwane Boudjelthia
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The most recent earthquakes that occurred in the world and particularly in Algeria, have killed thousands of people and severe damage. The example that is etched in our memory is the last earthquake in the regions of Boumerdes and Algiers (Boumerdes earthquake of May 21, 2003). For all the actors involved in the building process, the earthquake is the litmus test for construction. The goal we set ourselves is to contribute to the implementation of a thoughtful approach to the seismic protection of structures. For many engineers, the most conventional approach protection works (buildings and bridges) the effects of earthquakes is to increase rigidity. This approach is not always effective, especially when there is a context that favors the phenomenon of resonance and amplification of seismic forces. Therefore, the field of earthquake engineering has made significant inroads among others catalyzed by the development of computational techniques in computer form and the use of powerful test facilities. This has led to the emergence of several innovative technologies, such as the introduction of special devices insulation between infrastructure and superstructure. This approach, commonly known as "seismic isolation" to absorb the significant efforts without the structure is damaged and thus ensuring the protection of lives and property. In addition, the restraints to the construction by the ground shaking are located mainly at the supports. With these moves, the natural period of construction is increasing, and seismic loads are reduced. Thus, there is an attenuation of the seismic movement. Likewise, the insulation of the base mechanism may be used in combination with earthquake dampers in order to control the deformation of the insulation system and the absolute displacement of the superstructure located above the isolation interface. On the other hand, only can use these earthquake dampers to reduce the oscillation amplitudes and thus reduce seismic loads. The use of damping devices represents an effective solution for the rehabilitation of existing structures. Given all these acceleration reducing means considered passive, much research has been conducted for several years to develop an active control system of the response of buildings to earthquakes.Keywords: earthquake, building, seismic forces, displacement, resonance, response
Procedia PDF Downloads 127500 E4D-MP: Time-Lapse Multiphysics Simulation and Joint Inversion Toolset for Large-Scale Subsurface Imaging
Authors: Zhuanfang Fred Zhang, Tim C. Johnson, Yilin Fang, Chris E. Strickland
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A variety of geophysical techniques are available to image the opaque subsurface with little or no contact with the soil. It is common to conduct time-lapse surveys of different types for a given site for improved results of subsurface imaging. Regardless of the chosen survey methods, it is often a challenge to process the massive amount of survey data. The currently available software applications are generally based on the one-dimensional assumption for a desktop personal computer. Hence, they are usually incapable of imaging the three-dimensional (3D) processes/variables in the subsurface of reasonable spatial scales; the maximum amount of data that can be inverted simultaneously is often very small due to the capability limitation of personal computers. Presently, high-performance or integrating software that enables real-time integration of multi-process geophysical methods is needed. E4D-MP enables the integration and inversion of time-lapsed large-scale data surveys from geophysical methods. Using the supercomputing capability and parallel computation algorithm, E4D-MP is capable of processing data across vast spatiotemporal scales and in near real time. The main code and the modules of E4D-MP for inverting individual or combined data sets of time-lapse 3D electrical resistivity, spectral induced polarization, and gravity surveys have been developed and demonstrated for sub-surface imaging. E4D-MP provides capability of imaging the processes (e.g., liquid or gas flow, solute transport, cavity development) and subsurface properties (e.g., rock/soil density, conductivity) critical for successful control of environmental engineering related efforts such as environmental remediation, carbon sequestration, geothermal exploration, and mine land reclamation, among others.Keywords: gravity survey, high-performance computing, sub-surface monitoring, electrical resistivity tomography
Procedia PDF Downloads 157499 Robust Numerical Solution for Flow Problems
Authors: Gregor Kosec
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Simple and robust numerical approach for solving flow problems is presented, where involved physical fields are represented through the local approximation functions, i.e., the considered field is approximated over a local support domain. The approximation functions are then used to evaluate the partial differential operators. The type of approximation, the size of support domain, and the type and number of basis function can be general. The solution procedure is formulated completely through local computational operations. Besides local numerical method also the pressure velocity is performed locally with retaining the correct temporal transient. The complete locality of the introduced numerical scheme has several beneficial effects. One of the most attractive is the simplicity since it could be understood as a generalized Finite Differences Method, however, much more powerful. Presented methodology offers many possibilities for treating challenging cases, e.g. nodal adaptivity to address regions with sharp discontinuities or p-adaptivity to treat obscure anomalies in physical field. The stability versus computation complexity and accuracy can be regulated by changing number of support nodes, etc. All these features can be controlled on the fly during the simulation. The presented methodology is relatively simple to understand and implement, which makes it potentially powerful tool for engineering simulations. Besides simplicity and straightforward implementation, there are many opportunities to fully exploit modern computer architectures through different parallel computing strategies. The performance of the method is presented on the lid driven cavity problem, backward facing step problem, de Vahl Davis natural convection test, extended also to low Prandtl fluid and Darcy porous flow. Results are presented in terms of velocity profiles, convergence plots, and stability analyses. Results of all cases are also compared against published data.Keywords: fluid flow, meshless, low Pr problem, natural convection
Procedia PDF Downloads 233498 The Effect of Increased Tip Area of Suction Caissons on the Penetration Resistance Coefficients
Authors: Ghaem Zamani, Farveh Aghaye Nezhad, Amin Barari
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The installation process of caissons has usually been a challenging step in the design phase, especially in the case of suction-assisted installation. The engineering practice for estimating the caisson penetration resistance is primarily controlled by the resistance governed by inner and outer skirt friction and the tip resistance. Different methods have been proposed in the literature to evaluate the above components, while the CPT-based methodology has attained notable popularity among others. In this method, two empirical coefficients are suggested, k𝒻 and kp, which relate the frictional resistance and tip resistance to the cone penetration resistance (q𝒸), respectively. A series of jacking installation and uninstallation experiments for different soil densities were carried out in the offshore geotechnical laboratory of Aalborg University, Denmark. The main goal of these tests was to find appropriate values for empirical coefficients of the CPT-based method for the buckets with large embedment ratio (i.e., d/D=1, where d is the skirt length and D is the diameter) and increased tip area penetrated into dense sand deposits. The friction resistance effects were isolated during the pullout experiments; hence, the k𝒻 was back-measured from the tests in the absence of tip resistance. The actuator force during jacking installation equals the sum of frictional resistance and tip resistance. Therefore, the tip resistance of the bucket is calculated by subtracting the back-measured frictional resistance from penetration resistance; hence the relevant coefficient kp would be achieved. The cone penetration test was operated at different points before and after each installation attempt to measure the cone penetration resistance (q𝒸), and the average value of q𝒸 is used for calculations. The experimental results of the jacking installation tests indicated that a larger friction area considerably increased the penetration resistance; however, this effect was completely diminished when foundation suction-assisted penetration was used. Finally, the values measured for the empirical coefficient of the CPT-based method are compared with the highest expected and most probable values suggested by DNV(1992) for uniform thickness buckets.Keywords: suction caisson, offshore geotechnics, cone penetration test, wind turbine foundation
Procedia PDF Downloads 84497 DNA-Polycation Condensation by Coarse-Grained Molecular Dynamics
Authors: Titus A. Beu
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Many modern gene-delivery protocols rely on condensed complexes of DNA with polycations to introduce the genetic payload into cells by endocytosis. In particular, polyethyleneimine (PEI) stands out by a high buffering capacity (enabling the efficient condensation of DNA) and relatively simple fabrication. Realistic computational studies can offer essential insights into the formation process of DNA-PEI polyplexes, providing hints on efficient designs and engineering routes. We present comprehensive computational investigations of solvated PEI and DNA-PEI polyplexes involving calculations at three levels: ab initio, all-atom (AA), and coarse-grained (CG) molecular mechanics. In the first stage, we developed a rigorous AA CHARMM (Chemistry at Harvard Macromolecular Mechanics) force field (FF) for PEI on the basis of accurate ab initio calculations on protonated model pentamers. We validated this atomistic FF by matching the results of extensive molecular dynamics (MD) simulations of structural and dynamical properties of PEI with experimental data. In a second stage, we developed a CG MARTINI FF for PEI by Boltzmann inversion techniques from bead-based probability distributions obtained from AA simulations and ensuring an optimal match between the AA and CG structural and dynamical properties. In a third stage, we combined the developed CG FF for PEI with the standard MARTINI FF for DNA and performed comprehensive CG simulations of DNA-PEI complex formation and condensation. Various technical aspects which are crucial for the realistic modeling of DNA-PEI polyplexes, such as options of treating electrostatics and the relevance of polarizable water models, are discussed in detail. Massive CG simulations (with up to 500 000 beads) shed light on the mechanism and provide time scales for DNA polyplex formation independence of PEI chain size and protonation pattern. The DNA-PEI condensation mechanism is shown to primarily rely on the formation of DNA bundles, rather than by changes of the DNA-strand curvature. The gained insights are expected to be of significant help for designing effective gene-delivery applications.Keywords: DNA condensation, gene-delivery, polyethylene-imine, molecular dynamics.
Procedia PDF Downloads 120496 Promoting Students' Worldview Through Integrative Education in the Process of Teaching Biology in Grades 11 and 12 of High School
Authors: Saule Shazhanbayeva, Denise van der Merwe
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Study hypothesis: Nazarbayev Intellectual School of Kyzylorda’s Biology teachers can use STEM-integrated learning to improve students' problem-solving ability and responsibility as global citizens. The significance of this study is to indicate how the use of STEM integrative learning during Biology lessons could contribute to forming globally-minded students who are responsible community members. For the purposes of this study, worldview is defined as a view that is broader than the country of Kazakhstan, allowing students to see the significance of their scientific contributions to the world as global citizens. The context of worldview specifically indicates that most students have never traveled outside of their city or region within Kazakhstan. In order to broaden student understanding, it is imperative that students are exposed to different world views and contrasting ideas within the educational setting of Biology as the science being used for the research. This exposure promulgates students understanding of the significance they have as global citizens alongside the obligations which would rest on them as scientifically minded global citizens. Integrative learning should be Biological Science - with Technology and engineering in the form of problem-solving, and Mathematics to allow improved problem-solving skills to develop within the students of Nazarbayev Intellectual School (NIS) of Kyzylorda. The school's vision is to allow students to realise their role as global citizens and become responsible community members. STEM allows integrations by combining four subject skills to solve topical problems designed by educators. The methods used are based on qualitative analysis: for students’ performance during a problem-solution scenario; and Biology teacher interviews to ascertain their understanding of STEM implementation and willingness to integrate it into current lessons. The research indicated that NIS is ready for a shift into STEM lessons to promote globally responsible students. The only additional need is for proper STEM integrative lesson method training for teachers.Keywords: global citizen, STEM, Biology, high-school
Procedia PDF Downloads 72495 A Gold-Based Nanoformulation for Delivery of the CRISPR/Cas9 Ribonucleoprotein for Genome Editing
Authors: Soultana Konstantinidou, Tiziana Schmidt, Elena Landi, Alessandro De Carli, Giovanni Maltinti, Darius Witt, Alicja Dziadosz, Agnieszka Lindstaedt, Michele Lai, Mauro Pistello, Valentina Cappello, Luciana Dente, Chiara Gabellini, Piotr Barski, Vittoria Raffa
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CRISPR/Cas9 technology has gained the interest of researchers in the field of biotechnology for genome editing. Since its discovery as a microbial adaptive immune defense, this system has been widely adopted and is acknowledged for having a variety of applications. However, critical barriers related to safety and delivery are persisting. Here, we propose a new concept of genome engineering, which is based on a nano-formulation of Cas9. The Cas9 enzyme was conjugated to a gold nanoparticle (AuNP-Cas9). The AuNP-Cas9 maintained its cleavage efficiency in vitro, to the same extent as the ribonucleoprotein, including non-conjugated Cas9 enzyme, and showed high gene editing efficiency in vivo in zebrafish embryos. Since CRISPR/Cas9 technology is extensively used in cancer research, melanoma was selected as a validation target. Cell studies were performed in A375 human melanoma cells. Particles per se had no impact on cell metabolism and proliferation. Intriguingly, the AuNP-Cas9 internalized spontaneously in cells and localized as a single particle in the cytoplasm and organelles. More importantly, the AuNP-Cas9 showed a high nuclear localization signal. The AuNP-Cas9, overcoming the delivery difficulties of Cas9, could be used in cellular biology and localization studies. Taking advantage of the plasmonic properties of gold nanoparticles, this technology could potentially be a bio-tool for combining gene editing and photothermal therapy in cancer cells. Further work will be focused on intracellular interactions of the nano-formulation and characterization of the optical properties.Keywords: CRISPR/Cas9, gene editing, gold nanoparticles, nanotechnology
Procedia PDF Downloads 101494 Applying Multiple Kinect on the Development of a Rapid 3D Mannequin Scan Platform
Authors: Shih-Wen Hsiao, Yi-Cheng Tsao
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In the field of reverse engineering and creative industries, applying 3D scanning process to obtain geometric forms of the objects is a mature and common technique. For instance, organic objects such as faces and nonorganic objects such as products could be scanned to acquire the geometric information for further application. However, although the data resolution of 3D scanning device is increasing and there are more and more abundant complementary applications, the penetration rate of 3D scanning for the public is still limited by the relative high price of the devices. On the other hand, Kinect, released by Microsoft, is known for its powerful functions, considerably low price, and complete technology and database support. Therefore, related studies can be done with the applying of Kinect under acceptable cost and data precision. Due to the fact that Kinect utilizes optical mechanism to extracting depth information, limitations are found due to the reason of the straight path of the light. Thus, various angles are required sequentially to obtain the complete 3D information of the object when applying a single Kinect for 3D scanning. The integration process which combines the 3D data from different angles by certain algorithms is also required. This sequential scanning process costs much time and the complex integration process often encounter some technical problems. Therefore, this paper aimed to apply multiple Kinects simultaneously on the field of developing a rapid 3D mannequin scan platform and proposed suggestions on the number and angles of Kinects. In the content, a method of establishing the coordination based on the relation between mannequin and the specifications of Kinect is proposed, and a suggestion of angles and number of Kinects is also described. An experiment of applying multiple Kinect on the scanning of 3D mannequin is constructed by Microsoft API, and the results show that the time required for scanning and technical threshold can be reduced in the industries of fashion and garment design.Keywords: 3D scan, depth sensor, fashion and garment design, mannequin, multiple Kinect sensor
Procedia PDF Downloads 366493 Collagen Hydrogels Cross-Linked by Squaric Acid
Authors: Joanna Skopinska-Wisniewska, Anna Bajek, Marta Ziegler-Borowska, Alina Sionkowska
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Hydrogels are a class of materials widely used in medicine for many years. Proteins, such as collagen, due to the presence of a large number of functional groups are easily wettable by polar solvents and can create hydrogels. The supramolecular network capable to swelling is created by cross-linking of the biopolymers using various reagents. Many cross-linking agents has been tested for last years, however, researchers still are looking for a new, more secure reactants. Squaric acid, 3,4-dihydroxy 3-cyclobutene 1,2- dione, is a very strong acid, which possess flat and rigid structure. Due to the presence of two carboxyl groups the squaric acid willingly reacts with amino groups of collagen. The main purpose of this study was to investigate the influence of addition of squaric acid on the chemical, physical and biological properties of collagen materials. The collagen type I was extracted from rat tail tendons and 1% solution in 0.1M acetic acid was prepared. The samples were cross-linked by the addition of 5%, 10% and 20% of squaric acid. The mixtures of all reagents were incubated 30 min on magnetic stirrer and then dialyzed against deionized water. The FTIR spectra show that the collagen structure is not changed by cross-linking by squaric acid. Although the mechanical properties of the collagen material deteriorate, the temperature of thermal denaturation of collagen increases after cross-linking, what indicates that the protein network was created. The lyophilized collagen gels exhibit porous structure and the pore size decreases with the higher addition of squaric acid. Also the swelling ability is lower after the cross-linking. The in vitro study demonstrates that the materials are attractive for 3T3 cells. The addition of squaric acid causes formation of cross-ling bonds in the collagen materials and the transparent, stiff hydrogels are obtained. The changes of physicochemical properties of the material are typical for cross-linking process, except mechanical properties – it requires further experiments. However, the results let us to conclude that squaric acid is a suitable cross-linker for protein materials for medicine and tissue engineering.Keywords: collagen, squaric acid, cross-linking, hydrogel
Procedia PDF Downloads 388492 Projects and Limits of Memory Engineering: A Case of Lithuanian Partisan War
Authors: Mingaile Jurkute, Vilnius University
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The memory of the Lithuanian partisan war (1944-1953) underwent extremely dramatic transformations. During this war, the image of the resistance and a partisan was one of the key elements of Lithuanian identity. Its importance is evidenced by the extremely large legacy of songs about partisans, no other topic has collected so much folklore in Lithuania. In the Soviet years, this resistance was practically forced to be forgotten. Terror and Soviet laws have forced people to stop talking about the events, even in the family circle. In addition, the Soviets created their own propaganda story, reinterpreting the Lithuanian partisan war, presenting partisans as bandits who brutally tortured and murdered locals. But even in the Soviet years, the memory could neither be completely suppressed, nor completely transformed into wishful shape. The analysis of fiction and cinema shows that the traumatic memory of real events rushed to the surface, thus transforming the very propagandistic narrative. After the restoration of the Republic of Lithuania in 1990, the Lithuanian partisan war was gradually returned to the central place of Lithuanian history. After 2014 the nationalist heroic narrative about Lithuanian partisans became the central narrative of modern Lithuanian history. Nevertheless, interviews I conducted in Lithuanian villages reveal that the memory of local communities and families preserves quite different experiences that do not fit into neither the Soviet narrative nor the heroic one. Such experiences include, for example, partisan violence against local families. This paper is about the efforts of two political ideologies (the Soviet and the Lithuanian patriotic) to use the history of the Lithuanian partisans for their own needs, and the attempts of small communities (mostly families) to resist these efforts. The research reveals that family memory, even when opposed to aggressive state memory policies, can preserve counter-narratives by exploiting unexpected objects beyond the control of the state, such as nature and wildlife. Basically, the paper analyses the limits of the instrumentalization of memory, even by extremely aggressive political regimes.Keywords: collective memory, post-memory, violence, military conflict, family memory
Procedia PDF Downloads 92491 Evaluation of the Gasification Process for the Generation of Syngas Using Solid Waste at the Autónoma de Colombia University
Authors: Yeraldin Galindo, Soraida Mora
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Solid urban waste represents one of the largest sources of global environmental pollution due to the large quantities of these that are produced every day; thus, the elimination of such waste is a major problem for the environmental authorities who must look for alternatives to reduce the volume of waste with the possibility of obtaining an energy recovery. At the Autónoma de Colombia University, approximately 423.27 kg/d of solid waste are generated mainly paper, cardboard, and plastic. A large amount of these solid wastes has as final disposition the sanitary landfill of the city, wasting the energy potential that these could have, this, added to the emissions generated by the collection and transport of the same, has as consequence the increase of atmospheric pollutants. One of the alternative process used in the last years to generate electrical energy from solid waste such as paper, cardboard, plastic and, mainly, organic waste or biomass to replace the use of fossil fuels is the gasification. This is a thermal conversion process of biomass. The objective of it is to generate a combustible gas as the result of a series of chemical reactions propitiated by the addition of heat and the reaction agents. This project was developed with the intention of giving an energetic use to the waste (paper, cardboard, and plastic) produced inside the university, using them to generate a synthesis gas with a gasifier prototype. The gas produced was evaluated to determine their benefits in terms of electricity generation or raw material for the chemical industry. In this process, air was used as gasifying agent. The characterization of the synthesis gas was carried out by a gas chromatography carried out by the Chemical Engineering Laboratory of the National University of Colombia. Taking into account the results obtained, it was concluded that the gas generated is of acceptable quality in terms of the concentration of its components, but it is a gas of low calorific value. For this reason, the syngas generated in this project is not viable for the production of electrical energy but for the production of methanol transformed by the Fischer-Tropsch cycle.Keywords: alternative energies, gasification, gasifying agent, solid urban waste, syngas
Procedia PDF Downloads 258490 Best Combination of Design Parameters for Buildings with Buckling-Restrained Braces
Authors: Ángel de J. López-Pérez, Sonia E. Ruiz, Vanessa A. Segovia
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Buildings vulnerability due to seismic activity has been highly studied since the middle of last century. As a solution to the structural and non-structural damage caused by intense ground motions, several seismic energy dissipating devices, such as buckling-restrained braces (BRB), have been proposed. BRB have shown to be effective in concentrating a large portion of the energy transmitted to the structure by the seismic ground motion. A design approach for buildings with BRB elements, which is based on a seismic Displacement-Based formulation, has recently been proposed by the coauthors in this paper. It is a practical and easy design method which simplifies the work of structural engineers. The method is used here for the design of the structure-BRB damper system. The objective of the present study is to extend and apply a methodology to find the best combination of design parameters on multiple-degree-of-freedom (MDOF) structural frame – BRB systems, taking into account simultaneously: 1) initial costs and 2) an adequate engineering demand parameter. The design parameters considered here are: the stiffness ratio (α = Kframe/Ktotal), and the strength ratio (γ = Vdamper/Vtotal); where K represents structural stiffness and V structural strength; and the subscripts "frame", "damper" and "total" represent: the structure without dampers, the BRB dampers and the total frame-damper system, respectively. The selection of the best combination of design parameters α and γ is based on an initial costs analysis and on the structural dynamic response of the structural frame-damper system. The methodology is applied to a 12-story 5-bay steel building with BRB, which is located on the intermediate soil of Mexico City. It is found the best combination of design parameters α and γ for the building with BRB under study.Keywords: best combination of design parameters, BRB, buildings with energy dissipating devices, buckling-restrained braces, initial costs
Procedia PDF Downloads 258