Search results for: VPG (Virtual Proving Ground)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3320

Search results for: VPG (Virtual Proving Ground)

2480 Comparison between Ultra-High-Performance Concrete and Ultra-High-Performance-Glass Concrete

Authors: N. A. Soliman, A. F. Omran, A. Tagnit-Hamou

Abstract:

The finely ground waste glass has successfully used by the authors to develop and patent an ecological ultra-high-performance concrete (UHPC), which was named as ultra-high-performance-glass concrete (UHPGC). After the successful development in laboratory, the current research presents a comparison between traditional UHPC and UHPGC produced using large-scale pilot plant mixer, in terms of rheology, mechanical, and durability properties. The rheology of the UHPGCs was improved due to the non-absorptive nature of the glass particles. The mechanical performance of UHPGC was comparable and very close to the traditional UHPC due to the pozzolan reactivity of the amorphous waste glass. The UHPGC has also shown excellent durability: negligible permeability (chloride-ion ≈ 20 Coulombs from the RCPT test), high abrasion resistance (volume loss index less than 1.3), and almost no freeze-thaw deterioration even after 1000 freeze-thaw cycles. The enhancement in the strength and rigidity of the UHPGC mixture can be referred to the inclusions of the glass particles that have very high strength and elastic modulus.

Keywords: ground glass pozzolan, large-scale production, sustainability, ultra-high performance glass concrete

Procedia PDF Downloads 145
2479 Design and Performance Evaluation of Hybrid Corrugated-GFRP Infill Panels

Authors: Woo Young Jung, Sung Min Park, Ho Young Son, Viriyavudh Sim

Abstract:

This study presents a way to reduce earthquake damage and emergency rehabilitation of critical structures such as schools, high-tech factories, and hospitals due to strong ground motions associated with climate changes. Regarding recent trend, a strong earthquake causes serious damage to critical structures and then the critical structure might be influenced by sequence aftershocks (or tsunami) due to fault plane adjustments. Therefore, in order to improve seismic performance of critical structures, retrofitted or strengthening study of the structures under aftershocks sequence after emergency rehabilitation of the structures subjected to strong earthquakes is widely carried out. Consequently, this study used composite material for emergency rehabilitation of the structure rather than concrete and steel materials because of high strength and stiffness, lightweight, rapid manufacturing, and dynamic performance. Also, this study was to develop or improve the seismic performance or seismic retrofit of critical structures subjected to strong ground motions and earthquake aftershocks, by utilizing GFRP-Corrugated Infill Panels (GCIP).

Keywords: aftershock, composite material, GFRP, infill panel

Procedia PDF Downloads 329
2478 Protective Approach of Mentha Piperita against Cadmium Induced Renotoxicity in Albino Rats

Authors: Baby Tabassum, Priya Bajaj

Abstract:

Cadmium is the second most hazardous heavy metal occurring in both elemental as well as compound forms. It is a highly toxic metal with a very high bio-concentration factor (BCF>100). WHO permitted groundwater cadmium concentration is 0.005 mg/L only, but reality is far away from this limit. A number of natural and anthropogenic industrial activities contribute to the spread of cadmium into the environment. The present study had been designated to find out the renal changes at functional level after cadmium intoxication and protection against these changes offered by Mentha piperata. For the purpose, albino rats were selected as the model organism. Cadmium significantly increases the serum level of serum proteins and nitrogenous wastes showing reduced filtration rate of kidneys. Pretreatment with Mentha piperata leaf extract causes significant retention of these levels to normalcy. These findings conclude that Cadmium exposure affects renal functioning but Mentha could prevent it, proving its nephro-protective potential against heavy metal toxicity.

Keywords: albino rat, cadmium, Mentha piperata, nephrotoxicity

Procedia PDF Downloads 384
2477 Study of Strontium Sorption onto Indian Bentonite

Authors: Pankaj Pathak, Susmita Sharma

Abstract:

Incessant industrial growth fulfill the energy demand of present day society, at the same time it produces huge amount of waste which could be hazardous or non-hazardous in nature. These wastes are coming out from different sources viz, nuclear power, thermal power, coal mines which contain different types of contaminants and one of the emergent contaminant is strontium, used in the present study. The isotope of strontium (Sr90) is radioactive in nature with half-life of 28.8 years and permissible limit of strontium in drinking water is 1.5 ppm. Above the permissible limit causes several types of diseases in human being. Therefore, safe disposal of strontium into ground becomes a biggest challenge for the researchers. In this context, bentonite is being used as an efficient material to retain strontium onto ground due to its specific physical, chemical and mineralogical properties which exhibits higher cation exchange capacity and specific surface area. These properties influence the interaction between strontium and bentonite, which is quantified by employing a parameter known as distribution coefficient. Batch test was conducted, and sorption isotherms were modelled at different interaction time. The pseudo first-order and pseudo second order kinetic models have been used to fit experimental data, which helps to determine the sorption rate and mechanism.

Keywords: bentonite, interaction time, sorption, strontium

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2476 A New Direction of Urban Regeneration: Form-Based Urban Reconstruction through the Idea of Bricolage

Authors: Hyejin Song, Jin Baek

Abstract:

Based on the idea of bricolage that a new meaning beyond that of each of objects can be created through combination and juxtaposition of various objets, this study finds a way of morphological-recomposing of urban space through combination and juxtaposition of existing urban fabric and new fabric and suggests this idea as new direction of urban regeneration. This study sets concept of bricolage as a philosophical ground of interpreting contemporary urban situation. In this concept, urban objects such as buildings from various zeitgeists are positively considered as potential textures which can construct meaningful context. Seoul, as the city having long history and experiencing colonization and development, appears dynamic urban structure full of various objects from various periods. However, in contrast with successful plazas and streets in Europe, objects in Seoul do not make a meaningful context as public space due to thoughtless development. This study defines this situation as ‘disorgnized-fabric’. Following the concept of bricolage, to find the way for those existing scattered objects to be organized as a context of meaningful public space, this study firstly researches the case of successful public space by morphological analysis. Secondly, this study carefully explores urban space in Seoul, and draws figure-ground diagram to grasp the form of current urban fabric by various urban-objects. As a result of exploration, a lot of urban spaces from Myeong-dong, one of vibrant commercial district in Seoul, to declining residential area are judged as having potential fabric which can become meaningful context by just small adjustment of relationship between existing objects. This study also confirmed that by inserting a new object with consideration of form of existing fabric, it is possible to accord a new context as plaza to existing void which have broken as several parts. This study defines it as form-based urban reconstruction through the idea of bricolage, and suggests that it could be one of philosophical ground of successful urban regeneration.

Keywords: adjustment of relationship between existing objets, bricolage, morphological analysis of urban fabric, urban regeneration, urban reconstruction

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2475 Bearing Capacity of Sulphuric Acid Content Soil

Authors: R. N. Khare, J. P. Sahu, Rajesh Kumar Tamrakar

Abstract:

Tests were conducted to determine the property of soil with variation of H2SO4 content for soils under different stage. The soils had varying amounts of plasticity’s ranging from low to high plasticity. The unsaturated soil behavior was investigated for different conditions, covering a range of compactive efforts and water contents. The soil characteristic curves were more sensitive to changes in compaction effort than changes in compaction water content. In this research paper two types of water (Ground water Ph =7.9, Turbidity= 13 ppm; Cl =2.1mg/l and surface water Ph =8.65; Turbidity=18.5; Cl=1mg/l) were selected of Bhilai Nagar, State-Chhattisgarh, India which is mixed with a certain type of soil. Results shows that by the presence of ground water day by day the particles are becoming coarser in 7 days thereafter its size reduces; on the other hand by the presence of surface water the courser particles are disintegrating, finer particles are accumulating and also the dry density is reduces. Plasticity soils retained the smallest water content and the highest plasticity soils retained the highest water content at a specified suction. In addition, soil characteristic for soils to be compacted in the laboratory and in the field are still under process for analyzing the bearing capacity. The bearing capacity was reduced 2 to 3 times in the presence of H2SO4.

Keywords: soil compaction, H2SO4, soil water, water conditions

Procedia PDF Downloads 527
2474 Applying Theory of Inventive Problem Solving to Develop Innovative Solutions: A Case Study

Authors: Y. H. Wang, C. C. Hsieh

Abstract:

Good service design can increase organization revenue and consumer satisfaction while reducing labor and time costs. The problems facing consumers in the original serve model for eyewear and optical industry includes the following issues: 1. Insufficient information on eyewear products 2. Passively dependent on recommendations, insufficient selection 3. Incomplete records on progression of vision conditions 4. Lack of complete customer records. This study investigates the case of Kobayashi Optical, applying the Theory of Inventive Problem Solving (TRIZ) to develop innovative solutions for eyewear and optical industry. Analysis results raise the following conclusions and management implications: In order to provide customers with improved professional information and recommendations, Kobayashi Optical is suggested to establish customer purchasing records. Overall service efficiency can be enhanced by applying data mining techniques to analyze past consumer preferences and purchase histories. Furthermore, Kobayashi Optical should continue to develop a 3D virtual trial service which can allow customers for easy browsing of different frame styles and colors. This 3D virtual trial service will save customer waiting times in during peak service times at stores.

Keywords: theory of inventive problem solving (TRIZ), service design, augmented reality (AR), eyewear and optical industry

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2473 Methylation Profiling and Validation of Candidate Tissue-Specific Differentially Methylated Regions for Identification of Human Blood, Saliva, Semen and Vaginal Fluid and Its Application in Forensics

Authors: Meenu Joshi, Natalie Naidoo, Farzeen Kader

Abstract:

Identification of body fluids is an essential step in forensic investigation to aid in crime reconstruction. Tissue-specific differentially methylated regions (tDMRs) of the human genome can be targeted to be used as biomarkers to differentiate between body fluids. The present study was undertaken to establish the methylation status of potential tDMRs in blood, semen, saliva, and vaginal fluid by using methylation-specific PCR (MSP) and bisulfite sequencing (BS). The methylation statuses of 3 potential tDMRS in genes ZNF282, PTPRS, and HPCAL1 were analysed in 10 samples of each body fluid. With MSP analysis, the ZNF282, and PTPRS1 tDMR displayed semen-specific hypomethylation while HPCAL1 tDMR showed saliva-specific hypomethylation. With quantitative analysis by BS, the ZNF282 tDMR showed statistically significant difference in overall methylation between semen and all other body fluids as well as at individual CpG sites (p < 0.05). To evaluate the effect of environmental conditions on the stability of methylation profiles of the ZNF282 tDMR, five samples of each body fluid were subjected to five different forensic simulated conditions (dry at room temperature, wet in an exsiccator, outside on the ground, sprayed with alcohol, and sprayed with bleach) for 50 days. Vaginal fluid showed highest DNA recovery under all conditions while semen had least DNA quantity. Under outside on the ground condition, all body fluids except semen showed a decrease in methylation level; however, a significant decrease in methylation level was observed for saliva. A statistical significant difference was observed for saliva and semen (p < 0.05) for outside on the ground condition. No differences in methylation level were observed for the ZNF282 tDMR under all conditions for vaginal fluid samples. Thus, in the present study ZNF282 tDMR has been identified as a novel and stable semen-specific hypomethylation marker.

Keywords: body fluids, bisulphite sequencing, forensics, tDMRs, MSP

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2472 Research on Sensitivity of Geological Disasters in Road Area Based on Analytic Hierarchy Process

Authors: Li Yongyi

Abstract:

In order to explore the distribution of geological disasters within the expressway area of Shaanxi Province, the Analytic Hierarchy Process theory is applied based on the geographic information system technology platform, and the ground elevation, rainfall, vegetation coverage and other indicators are selected for analysis, and the expressway area is sensitive Sexual evaluation. The results show that the highway area disasters in Shaanxi Province are mainly distributed in the southern mountainous areas and are dominated by landslides; the disaster area ratio basically increases with the increase in ground elevation, surface slope, surface undulation, rainfall, and vegetation coverage. The increase in the distance from the river shows a decreasing trend; after grading the disaster sensitivity within 5km of the expressway, the extremely sensitive area, the highly sensitive area, the medium sensitive area, the low sensitive area, and the extremely low sensitive area respectively account for 8.17%、15.80%、22.99%、26.22%、26.82%. Highly sensitive road areas are mainly distributed in southern Shaanxi.

Keywords: highway engineering, sensitivity, analytic hierarchy process, geological hazard, road area

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2471 Legume Grain as Alternative to Soya Bean Meal in Small Ruminant Diets

Authors: Abidi Sourour, Ben Salem Hichem, Zoghlemi Aziza, Mezni Mejid, Nasri Saida

Abstract:

In Tunisia, there is an urgent need to maintain food security by reversing soil degradation and improving crop and livestock productivity. Conservation Agriculture (CA) can be helpful in enhancing crop productivity and soil health. However, the demand for crop residues as animal feed are among the major constraints for the adoption of CA. Thus, the objective of this trial is to test the nutritional value of new forage mixture hays as alternative to cereal residues. Two tri-specific cereal-legume mixture were studied and compared to the classic Vetch-Oat one. They were implemented at farm level in four regions characterized by sub-humi climatic: V70-A15-T15 (Vetch70% - Oat15% -Triticale15%) installed in two sites (Zhir and safasaf), V60-A7-T33 (Vetch60% - Oat7% -Triticale33%) and V70-A30 (Vetch70%-Oat30%). Results revealed a significant variation between mixtures V70-A15-T15 installed at Safsafa, recorded the highest forage yield with 12t DM ha-1 than V60A7T33 and V70A30 installed, respectively in ksar cheikh and Fernana with 11.6 and 11.2.tMSha-1. The same mixture installed in Safsafa gave 22% less yields than the one installed in Safsafa. In fact, the month of March was dry in Z'hir. Moreover, these yields in DM can be comparable to those observed by Yucel and Avci (2009). The CP contents of the samples studied vary significantly between the mixtures (P<0.0003). V70-A15-T15 installed in Safsaf and V70A30 present higher contents of CP (respectively 14.4 and 13.7% DM) compared to the other mixtures. These contents are explained by the high proportion of vetch in the fourth mixture and by the low proportion of weeds in the second. In all cases, the hay produced from these mixtures is significantly richer in protein than that of oats in pure culture (Abdelraheem et al., 2019). The positive correlation between the CP content and the proportion of vetch explains this superior quality. The NDF and ADF contents were similar for all mixtures. These values were similar to those reported in the literature (Abidi and Benyoussef, 2019; Haj-Ayed and al., 2000). In general, the Land Equivalent Ratio (LER) was significantly greater than 1 for the vetch-oat-triticale mixture at Zhiir and Safsafa and also for the vetch-oat a at Fernana, proving that they are more productive in intercropping than in pure culture. For the Ksar Cheikh site, the LER value of the vetch-oat-triticale mixture is maintained at around 1. Proving the absence of the advantage of mixture culture compared to pure culture. This proves the massive presence of weeds interferes with the two partners of the mixture increases. The LER for the vetch-oat mixture reached its maximum in March 13 and decreases in April but remained above 1. This proves that the tutoring power of oats showed itself in a constant way until an advanced stage since the variety used is characterized by very thick stems, protecting it from the risk of lodging. These forages mixture present a promising option, a high nutritional quality that could reduce the use of concentrate and, therefore, the cost of feed. With such feed value, these mixtures allow good animal performance.

Keywords: soybean, lupine, vetch, lamb-ADG, meat

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2470 Virtual Metrology for Copper Clad Laminate Manufacturing

Authors: Misuk Kim, Seokho Kang, Jehyuk Lee, Hyunchang Cho, Sungzoon Cho

Abstract:

In semiconductor manufacturing, virtual metrology (VM) refers to methods to predict properties of a wafer based on machine parameters and sensor data of the production equipment, without performing the (costly) physical measurement of the wafer properties (Wikipedia). Additional benefits include avoidance of human bias and identification of important factors affecting the quality of the process which allow improving the process quality in the future. It is however rare to find VM applied to other areas of manufacturing. In this work, we propose to use VM to copper clad laminate (CCL) manufacturing. CCL is a core element of a printed circuit board (PCB) which is used in smartphones, tablets, digital cameras, and laptop computers. The manufacturing of CCL consists of three processes: Treating, lay-up, and pressing. Treating, the most important process among the three, puts resin on glass cloth, heat up in a drying oven, then produces prepreg for lay-up process. In this process, three important quality factors are inspected: Treated weight (T/W), Minimum Viscosity (M/V), and Gel Time (G/T). They are manually inspected, incurring heavy cost in terms of time and money, which makes it a good candidate for VM application. We developed prediction models of the three quality factors T/W, M/V, and G/T, respectively, with process variables, raw material, and environment variables. The actual process data was obtained from a CCL manufacturer. A variety of variable selection methods and learning algorithms were employed to find the best prediction model. We obtained prediction models of M/V and G/T with a high enough accuracy. They also provided us with information on “important” predictor variables, some of which the process engineers had been already aware and the rest of which they had not. They were quite excited to find new insights that the model revealed and set out to do further analysis on them to gain process control implications. T/W did not turn out to be possible to predict with a reasonable accuracy with given factors. The very fact indicates that the factors currently monitored may not affect T/W, thus an effort has to be made to find other factors which are not currently monitored in order to understand the process better and improve the quality of it. In conclusion, VM application to CCL’s treating process was quite successful. The newly built quality prediction model allowed one to reduce the cost associated with actual metrology as well as reveal some insights on the factors affecting the important quality factors and on the level of our less than perfect understanding of the treating process.

Keywords: copper clad laminate, predictive modeling, quality control, virtual metrology

Procedia PDF Downloads 345
2469 Topography Effects on Wind Turbines Wake Flow

Authors: H. Daaou Nedjari, O. Guerri, M. Saighi

Abstract:

A numerical study was conducted to optimize the positioning of wind turbines over complex terrains. Thus, a two-dimensional disk model was used to calculate the flow velocity deficit in wind farms for both flat and complex configurations. The wind turbine wake was assessed using the hybrid methods that combine CFD (Computational Fluid Dynamics) with the actuator disc model. The wind turbine rotor has been defined with a thrust force, coupled with the Navier-Stokes equations that were resolved by an open source computational code (Code_Saturne V3.0 developed by EDF) The simulations were conducted in atmospheric boundary layer condition considering a two-dimensional region located at the north of Algeria at 36.74°N longitude, 02.97°E latitude. The topography elevation values were collected according to a longitudinal direction of 1km downwind. The wind turbine sited over topography was simulated for different elevation variations. The main of this study is to determine the topography effect on the behavior of wind farm wake flow. For this, the wake model applied in complex terrain needs to selects the singularity effects of topography on the vertical wind flow without rotor disc first. This step allows to determine the existence of mixing scales and friction forces zone near the ground. So, according to the ground relief the wind flow waS disturbed by turbulence and a significant speed variation. Thus, the singularities of the velocity field were thoroughly collected and thrust coefficient Ct was calculated using the specific speed. In addition, to evaluate the land effect on the wake shape, the flow field was also simulated considering different rotor hub heights. Indeed, the distance between the ground and the hub height of turbine (Hhub) was tested in a flat terrain for different locations as Hhub=1.125D, Hhub = 1.5D and Hhub=2D (D is rotor diameter) considering a roughness value of z0=0.01m. This study has demonstrated that topographical farm induce a significant effect on wind turbines wakes, compared to that on flat terrain.

Keywords: CFD, wind turbine wake, k-epsilon model, turbulence, complex topography

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2468 User Satisfaction Survey Based Facility Performance Evaluation

Authors: Gopikrishnan Seshadhri, V. M. Topkar

Abstract:

Facility management post occupation is a facet that has gained tremendous ground in the recent times. While the efficiency of expenditure and utilization of all types of resources are monitored to ensure timely completion with minimum cost and acceptable quality during construction phase, value for money comes out only when the facility performs satisfactorily post occupation, meeting aspirations and expectations of users of the facility. It is more so for the public facilities. Due to the paradigm shift in focus to outcome based performance evaluation, user satisfaction obtained mainly through questionnaires has become the single important criterion in performance evaluation. Questionnaires presently being used to gauge user satisfaction being subjective, the feedback obtained do not necessarily reflect actual performance. Hence, there is a requirement of developing a survey instrument that can gauge user satisfaction as objectively as possible and truly reflects the ground reality. A near correct picture of actual performance of the built facility from the user point of view will enable facility managers to address pertinent issues. This paper brings out the need for an effective survey instrument that will elicit more objective user response. It also lists steps involved in formulation of such an instrument.

Keywords: facility performance evaluation, attributes, attribute descriptors, user satisfaction surveys, statistical methods, performance indicators

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2467 Finite Element Modeling of Two-Phase Microstructure during Metal Cutting

Authors: Junior Nomani

Abstract:

This paper presents a novel approach to modelling the metal cutting of duplex stainless steels, a two-phase alloy regarded as a difficult-to-machine material. Calculation and control of shear strain and stresses during cutting are essential to achievement of ideal cutting conditions. Too low or too high leads to higher required cutting force or excessive heat generation causing premature tool wear failure. A 2D finite element cutting model was created based on electron backscatter diffraction (EBSD) data imagery of duplex microstructure. A mesh was generated using ‘object-oriented’ software OOF2 version V2.1.11, converting microstructural images to quadrilateral elements. A virtual workpiece was created on ABAQUS modelling software where a rigid body toolpiece advanced towards workpiece simulating chip formation, generating serrated edge chip formation cutting. Model results found calculated stress strain contour plots correlated well with similar finite element models tied with austenite stainless steel alloys. Virtual chip form profile is also similar compared experimental frozen machining chip samples. The output model data provides new insight description of strain behavior of two phase material on how it transitions from workpiece into the chip.

Keywords: Duplex stainless steel, ABAQUS, OOF2, Chip formation

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2466 Study and Conservation of Cultural and Natural Heritages with the Use of Laser Scanner and Processing System for 3D Modeling Spatial Data

Authors: Julia Desiree Velastegui Caceres, Luis Alejandro Velastegui Caceres, Oswaldo Padilla, Eduardo Kirby, Francisco Guerrero, Theofilos Toulkeridis

Abstract:

It is fundamental to conserve sites of natural and cultural heritage with any available technique or existing methodology of preservation in order to sustain them for the following generations. We propose a further skill to protect the actual view of such sites, in which with high technology instrumentation we are able to digitally preserve natural and cultural heritages applied in Ecuador. In this project the use of laser technology is presented for three-dimensional models, with high accuracy in a relatively short period of time. In Ecuador so far, there are not any records on the use and processing of data obtained by this new technological trend. The importance of the project is the description of the methodology of the laser scanner system using the Faro Laser Scanner Focus 3D 120, the method for 3D modeling of geospatial data and the development of virtual environments in the areas of Cultural and Natural Heritage. In order to inform users this trend in technology in which three-dimensional models are generated, the use of such tools has been developed to be able to be displayed in all kinds of digitally formats. The results of the obtained 3D models allows to demonstrate that this technology is extremely useful in these areas, but also indicating that each data campaign needs an individual slightly different proceeding starting with the data capture and processing to obtain finally the chosen virtual environments.

Keywords: laser scanner system, 3D model, cultural heritage, natural heritage

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2465 An ab initioStudy of the Structural, Elastic, Electronic, and Optical Properties of the Perovskite ScRhO3

Authors: L. Foudia, K. Haddadi, M. Reffas

Abstract:

First principles study of structural, elastic, electronic and optical properties of the monoclinic perovskite type ScRhO₃ has been reported using the pseudo-potential plane wave method within the local density approximation. The calculated lattice parameters, including the lattice constants and angle β, are in excellent agreement with the available experimental data, which proving the reliability of the chosen theoretical approach. Pressure dependence up to 20 GPa of the single crystal and polycrystalline elastic constants has been investigated in details using the strain-stress approach. The mechanical stability, ductility, average elastic wave velocity, Debye temperature and elastic anisotropy were also assessed. Electronic band structure and density of states (DOS) demonstrated its semiconducting nature showing a direct band gap of 1.38 eV. Furthermore, several optical properties, such as absorption coefficient, reflectivity, refractive index, dielectric function, optical conductivity and electron energy loss function, have been calculated for radiation up to 40 eV.

Keywords: ab-initio, perovskite, DFT, band gap

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2464 Immersive and Non-Immersive Virtual Reality Applied to the Cervical Spine Assessment

Authors: Pawel Kiper, Alfonc Baba, Mahmoud Alhelou, Giorgia Pregnolato, Michela Agostini, Andrea Turolla

Abstract:

Impairment of cervical spine mobility is often related to pain triggered by musculoskeletal disorders or direct traumatic injuries of the spine. To date, these disorders are assessed with goniometers and inclinometers, which are the most popular devices used in clinical settings. Nevertheless, these technologies usually allow measurement of no more than two-dimensional range of motion (ROM) quotes in static conditions. Conversely, the wide use of motion tracking systems able to measure 3 to 6 degrees of freedom dynamically, while performing standard ROM assessment, are limited due to technical complexities in preparing the setup and high costs. Thus, motion tracking systems are primarily used in research. These systems are an integral part of virtual reality (VR) technologies, which can be used for measuring spine mobility. To our knowledge, the accuracy of VR measure has not yet been studied within virtual environments. Thus, the aim of this study was to test the reliability of a protocol for the assessment of sensorimotor function of the cervical spine in a population of healthy subjects and to compare whether using immersive or non-immersive VR for visualization affects the performance. Both VR assessments consisted of the same five exercises and random sequence determined which of the environments (i.e. immersive or non-immersive) was used as first assessment. Subjects were asked to perform head rotation (right and left), flexion, extension and lateral flexion (right and left side bending). Each movement was executed five times. Moreover, the participants were invited to perform head reaching movements i.e. head movements toward 8 targets placed along a circular perimeter each 45°, visualized one-by-one in random order. Finally, head repositioning movement was obtained by head movement toward the same 8 targets as for reaching and following reposition to the start point. Thus, each participant performed 46 tasks during assessment. Main measures were: ROM of rotation, flexion, extension, lateral flexion and complete kinematics of the cervical spine (i.e. number of completed targets, time of execution (seconds), spatial length (cm), angle distance (°), jerk). Thirty-five healthy participants (i.e. 14 males and 21 females, mean age 28.4±6.47) were recruited for the cervical spine assessment with immersive and non-immersive VR environments. Comparison analysis demonstrated that: head right rotation (p=0.027), extension (p=0.047), flexion (p=0.000), time (p=0.001), spatial length (p=0.004), jerk target (p=0.032), trajectory repositioning (p=0.003), and jerk target repositioning (p=0.007) were significantly better in immersive than non-immersive VR. A regression model showed that assessment in immersive VR was influenced by height, trajectory repositioning (p<0.05), and handedness (p<0.05), whereas in non-immersive VR performance was influenced by height, jerk target (p=0.002), head extension, jerk target repositioning (p=0.002), and by age, head flex/ext, trajectory repositioning, and weight (p=0.040). The results of this study showed higher accuracy of cervical spine assessment when executed in immersive VR. The assessment of ROM and kinematics of the cervical spine can be affected by independent and dependent variables in both immersive and non-immersive VR settings.

Keywords: virtual reality, cervical spine, motion analysis, range of motion, measurement validity

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2463 Trust: The Enabler of Knowledge-Sharing Culture in an Informal Setting

Authors: Emmanuel Ukpe, S. M. F. D. Syed Mustapha

Abstract:

Trust in an organization has been perceived as one of the key factors behind knowledge sharing, mainly in an unstructured work environment. In an informal working environment, to instill trust among individuals is a challenge and even more in the virtual environment. The study has contributed in developing the framework for building trust in an unstructured organization in performing knowledge sharing in a virtual environment. The artifact called KAPE (Knowledge Acquisition, Processing, and Exchange) was developed for knowledge sharing for the informal organization where the framework was incorporated. It applies to Cassava farmers to facilitate knowledge sharing using web-based platform. A survey was conducted; data were collected from 382 farmers from 21 farm communities. Multiple regression technique, Cronbach’s Alpha reliability test; Tukey’s Honestly significant difference (HSD) analysis; one way Analysis of Variance (ANOVA), and all trust acceptable measures (TAM) were used to test the hypothesis and to determine noteworthy relationships. The results show a significant difference when there is a trust in knowledge sharing between farmers, the ones who have high in trust acceptable factors found in the model (M = 3.66 SD = .93) and the ones who have low on trust acceptable factors (M = 2.08 SD = .28), (t (48) = 5.69, p = .00). Furthermore, when applying Cognitive Expectancy Theory, the farmers with cognitive-consonance show higher level of trust and satisfaction with knowledge and information from KAPE, as compared with a low level of cognitive-dissonance. These results imply that the adopted trust model KAPE positively improved knowledge sharing activities in an informal environment amongst rural farmers.

Keywords: trust, knowledge, sharing, knowledge acquisition, processing and exchange, KAPE

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2462 Virtual Reality for Chemical Engineering Unit Operations

Authors: Swee Kun Yap, Sachin Jangam, Suraj Vasudevan

Abstract:

Experiential learning is dubbed as a highly effective way to enhance learning. Virtual reality (VR) is thus a helpful tool in providing a safe, memorable, and interactive learning environment. A class of 49 fluid mechanics students participated in starting up a pump, one of the most used equipment in the chemical industry, in VR. They experience the process in VR to familiarize themselves with the safety training and the standard operating procedure (SOP) in guided mode. Students subsequently observe their peers (in groups of 4 to 5) complete the same training. The training first brings each user through the personal protection equipment (PPE) selection, before guiding the user through a series of steps for pump startup. One of the most common feedback given by industries include the weakness of our graduates in pump design and operation. Traditional fluid mechanics is a highly theoretical module loaded with engineering equations, providing limited opportunity for visualization and operation. With VR pump, students can now learn to startup, shutdown, troubleshoot and observe the intricacies of a centrifugal pump in a safe and controlled environment, thereby bridging the gap between theory and practical application. Following the completion of the guided mode operation, students then individually complete the VR assessment for pump startup on the same day, which requires students to complete the same series of steps, without any cues given in VR to test their recollection rate. While most students miss out a few minor steps such as the checking of lubrication oil and the closing of minor drain valves before pump priming, all the students scored full marks in the PPE selection, and over 80% of the students were able to complete all the critical steps that are required to startup a pump safely. The students were subsequently tested for their recollection rate by means of an online quiz 3 weeks later, and it is again found that over 80% of the students were able to complete the critical steps in the correct order. In the survey conducted, students reported that the VR experience has been enjoyable and enriching, and 79.5% of the students voted to include VR as a positive supplementary exercise in addition to traditional teaching methods. One of the more notable feedback is the higher ease of noticing and learning from mistakes as an observer rather than as a VR participant. Thus, the cycling between being a VR participant and an observer has helped tremendously in their knowledge retention. This reinforces the positive impact VR has on learning.

Keywords: experiential learning, learning by doing, pump, unit operations, virtual reality

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2461 Using GIS and Map Data for the Analysis of the Relationship between Soil and Groundwater Quality at Saline Soil Area of Kham Sakaesaeng District, Nakhon Ratchasima, Thailand

Authors: W. Thongwat, B. Terakulsatit

Abstract:

The study area is Kham Sakaesaeng District in Nakhon Ratchasima Province, the south section of Northeastern Thailand, located in the Lower Khorat-Ubol Basin. This region is the one of saline soil area, located in a dry plateau and regularly experience standing with periods of floods and alternating with periods of drought. Especially, the drought in the summer season causes the major saline soil and saline water problems of this region. The general cause of dry land salting resulted from salting on irrigated land, and an excess of water leading to the rising water table in the aquifer. The purpose of this study is to determine the relationship of physical and chemical properties between the soil and groundwater. The soil and groundwater samples were collected in both rainy and summer seasons. The content of pH, electrical conductivity (EC), total dissolved solids (TDS), chloride and salinity were investigated. The experimental result of soil and groundwater samples show the slightly pH less than 7, EC (186 to 8,156 us/cm and 960 to 10,712 us/cm), TDS (93 to 3,940 ppm and 480 to 5,356 ppm), chloride content (45.58 to 4,177,015 mg/l and 227.90 to 9,216,736 mg/l), and salinity (0.07 to 4.82 ppt and 0.24 to 14.46 ppt) in the rainy and summer seasons, respectively. The distribution of chloride content and salinity content were interpolated and displayed as a map by using ArcMap 10.3 program, according to the season. The result of saline soil and brined groundwater in the study area were related to the low-lying topography, drought area, and salt-source exposure. Especially, the Rock Salt Member of Maha Sarakham Formation was exposed or lies near the ground surface in this study area. During the rainy season, salt was eroded or weathered from the salt-source rock formation and transported by surface flow or leached into the groundwater. In the dry season, the ground surface is dry enough resulting salt precipitates from the brined surface water or rises from the brined groundwater influencing the increasing content of chloride and salinity in the ground surface and groundwater.

Keywords: environmental geology, soil salinity, geochemistry, groundwater hydrology

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2460 Seismic Perimeter Surveillance System (Virtual Fence) for Threat Detection and Characterization Using Multiple ML Based Trained Models in Weighted Ensemble Voting

Authors: Vivek Mahadev, Manoj Kumar, Neelu Mathur, Brahm Dutt Pandey

Abstract:

Perimeter guarding and protection of critical installations require prompt intrusion detection and assessment to take effective countermeasures. Currently, visual and electronic surveillance are the primary methods used for perimeter guarding. These methods can be costly and complicated, requiring careful planning according to the location and terrain. Moreover, these methods often struggle to detect stealthy and camouflaged insurgents. The object of the present work is to devise a surveillance technique using seismic sensors that overcomes the limitations of existing systems. The aim is to improve intrusion detection, assessment, and characterization by utilizing seismic sensors. Most of the similar systems have only two types of intrusion detection capability viz., human or vehicle. In our work we could even categorize further to identify types of intrusion activity such as walking, running, group walking, fence jumping, tunnel digging and vehicular movements. A virtual fence of 60 meters at GCNEP, Bahadurgarh, Haryana, India, was created by installing four underground geophones at a distance of 15 meters each. The signals received from these geophones are then processed to find unique seismic signatures called features. Various feature optimization and selection methodologies, such as LightGBM, Boruta, Random Forest, Logistics, Recursive Feature Elimination, Chi-2 and Pearson Ratio were used to identify the best features for training the machine learning models. The trained models were developed using algorithms such as supervised support vector machine (SVM) classifier, kNN, Decision Tree, Logistic Regression, Naïve Bayes, and Artificial Neural Networks. These models were then used to predict the category of events, employing weighted ensemble voting to analyze and combine their results. The models were trained with 1940 training events and results were evaluated with 831 test events. It was observed that using the weighted ensemble voting increased the efficiency of predictions. In this study we successfully developed and deployed the virtual fence using geophones. Since these sensors are passive, do not radiate any energy and are installed underground, it is impossible for intruders to locate and nullify them. Their flexibility, quick and easy installation, low costs, hidden deployment and unattended surveillance make such systems especially suitable for critical installations and remote facilities with difficult terrain. This work demonstrates the potential of utilizing seismic sensors for creating better perimeter guarding and protection systems using multiple machine learning models in weighted ensemble voting. In this study the virtual fence achieved an intruder detection efficiency of over 97%.

Keywords: geophone, seismic perimeter surveillance, machine learning, weighted ensemble method

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2459 Bridging Minds and Nature: Revolutionizing Elementary Environmental Education Through Artificial Intelligence

Authors: Hoora Beheshti Haradasht, Abooali Golzary

Abstract:

Environmental education plays a pivotal role in shaping the future stewards of our planet. Leveraging the power of artificial intelligence (AI) in this endeavor presents an innovative approach to captivate and educate elementary school children about environmental sustainability. This paper explores the application of AI technologies in designing interactive and personalized learning experiences that foster curiosity, critical thinking, and a deep connection to nature. By harnessing AI-driven tools, virtual simulations, and personalized content delivery, educators can create engaging platforms that empower children to comprehend complex environmental concepts while nurturing a lifelong commitment to protecting the Earth. With the pressing challenges of climate change and biodiversity loss, cultivating an environmentally conscious generation is imperative. Integrating AI in environmental education revolutionizes traditional teaching methods by tailoring content, adapting to individual learning styles, and immersing students in interactive scenarios. This paper delves into the potential of AI technologies to enhance engagement, comprehension, and pro-environmental behaviors among elementary school children. Modern AI technologies, including natural language processing, machine learning, and virtual reality, offer unique tools to craft immersive learning experiences. Adaptive platforms can analyze individual learning patterns and preferences, enabling real-time adjustments in content delivery. Virtual simulations, powered by AI, transport students into dynamic ecosystems, fostering experiential learning that goes beyond textbooks. AI-driven educational platforms provide tailored content, ensuring that environmental lessons resonate with each child's interests and cognitive level. By recognizing patterns in students' interactions, AI algorithms curate customized learning pathways, enhancing comprehension and knowledge retention. Utilizing AI, educators can develop virtual field trips and interactive nature explorations. Children can navigate virtual ecosystems, analyze real-time data, and make informed decisions, cultivating an understanding of the delicate balance between human actions and the environment. While AI offers promising educational opportunities, ethical concerns must be addressed. Safeguarding children's data privacy, ensuring content accuracy, and avoiding biases in AI algorithms are paramount to building a trustworthy learning environment. By merging AI with environmental education, educators can empower children not only with knowledge but also with the tools to become advocates for sustainable practices. As children engage in AI-enhanced learning, they develop a sense of agency and responsibility to address environmental challenges. The application of artificial intelligence in elementary environmental education presents a groundbreaking avenue to cultivate environmentally conscious citizens. By embracing AI-driven tools, educators can create transformative learning experiences that empower children to grasp intricate ecological concepts, forge an intimate connection with nature, and develop a strong commitment to safeguarding our planet for generations to come.

Keywords: artificial intelligence, environmental education, elementary children, personalized learning, sustainability

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2458 Effects of Supplementary Cementitious Materials on Early Age Thermal Properties of Cement Paste

Authors: Maryam Ghareh Chaei, Masuzyo Chilwesa, Ali Akbarnezhad, Arnaud Castel, Redmond Lloyd, Stephen Foster

Abstract:

Cement hydration is an exothermic chemical reaction generally leading to a rise in concrete’s temperature. This internal heating of concrete may, in turn, lead to a temperature difference between the hotter interior and the cooler exterior of concrete and thus differential thermal stresses in early ages which could be particularly significant in mass concrete. Such differential thermal stresses result in early age thermal cracking of concrete when exceeding the concrete’s tensile strength. The extent of temperature rise and thus early age differential thermal stresses is generally a function of hydration heat intensity, thermal properties of concrete and size of the concrete element. Both hydration heat intensity and thermal properties of concrete may vary considerably with variations in the type cementitious materials and other constituents. With this in mind, partial replacement of cement with supplementary cementitious materials including fly ash and ground granulated blast furnace slag has been investigated widely as an effective strategy to moderate the heat generation rate and thus reduce the risk of early age thermal cracking of concrete. However, there is currently a lack of adequate literature on effect of partial replacement of cement with fly ash and/or ground granulated blast furnace slag on the thermal properties of concrete. This paper presents the results of an experimental conducted to evaluate the effect of addition of varying percentages of fly ash (up to 60%) and ground granulated blast furnace slag (up to 50%) on the heat capacity and thermal conductivity of early age cement paste. The water to cementitious materials ratio is kept 0.45 for all the paste samples. The results of the experimental studies were used in a numerical analysis performed using Comsol Multiphysics to highlight the effects of variations in the thermal properties of concrete, due to variations in the type of aggregate and content of supplemenraty cementitious materials, on the risk of early age cracking of a concrete raft.

Keywords: thermal diffusivity, early age thermal cracking, concrete, supplementary cementitious materials

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2457 Using Virtual Reality Exergaming to Improve Health of College Students

Authors: Juanita Wallace, Mark Jackson, Bethany Jurs

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Introduction: Exergames, VR games used as a form of exercise, are being used to reduce sedentary lifestyles in a vast number of populations. However, there is a distinct lack of research comparing the physiological response during VR exergaming to that of traditional exercises. The purpose of this study was to create a foundationary investigation establishing changes in physiological responses resulting from VR exergaming in a college aged population. Methods: In this IRB approved study, college aged students were recruited to play a virtual reality exergame (Beat Saber) on the Oculus Quest 2 (Facebook, 2021) in either a control group (CG) or training group (TG). Both groups consisted of subjects who were not habitual users of virtual reality. The CG played VR one time per week for three weeks and the TG played 150 min/week three weeks. Each group played the same nine Beat Saber songs, in a randomized order, during 30 minute sessions. Song difficulty was increased during play based on song performance. Subjects completed a pre- and posttests at which the following was collected: • Beat Saber Game Metrics: song level played, song score, number of beats completed per song and accuracy (beats completed/total beats) • Physiological Data: heart rate (max and avg.), active calories • Demographics Results: A total of 20 subjects completed the study; nine in the CG (3 males, 6 females) and 11 (5 males, 6 females) in the TG. • Beat Saber Song Metrics: The TG improved performance from a normal/hard difficulty to hard/expert. The CG stayed at the normal/hard difficulty. At the pretest there was no difference in game accuracy between groups. However, at the posttest the CG had a higher accuracy. • Physiological Data (Table 1): Average heart rates were similar between the TG and CG at both the pre- and posttest. However, the TG expended more total calories. Discussion: Due to the lack of peer reviewed literature on c exergaming using Beat Saber, the results of this study cannot be directly compared. However, the results of this study can be compared with the previously established trends for traditional exercise. In traditional exercise, an increase in training volume equates to increased efficiency at the activity. The TG should naturally increase in difficulty at a faster rate than the CG because they played 150 hours per week. Heart rate and caloric responses also increase during traditional exercise as load increases (i.e. speed or resistance). The TG reported an increase in total calories due to a higher difficulty of play. The song accuracy decreases in the TG can be explained by the increased difficulty of play. Conclusion: VR exergaming is comparable to traditional exercise for loads within the 50-70% of maximum heart rate. The ability to use VR for health could motivate individuals who do not engage in traditional exercise. In addition, individuals in health professions can and should promote VR exergaming as a viable way to increase physical activity and improve health in their clients/patients.

Keywords: virtual reality, exergaming, health, heart rate, wellness

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2456 Virtual Reference Service as a Space for Communication and Interaction: Providing Infrastructure for Learning in Times of Crisis at Uppsala University

Authors: Nadja Ylvestedt

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Uppsala University Library is a geographically dispersed research library consisting of nine subject libraries located in different campus areas throughout the city of Uppsala. Despite the geographical dispersion, it is the library's ambition to be perceived as a cohesive library with consistently high service and quality. A key factor to being one cohesive library is the library's online services, especially the virtual reference service. E-mail, chat and phone are answered by a team of specially trained staff under the supervision of a team leader. When covid-19 hit, well-established routines and processes to provide an infrastructure for students and researchers at the university changed radically. The strong connection between services provided at the library locations as well as at the VRS has been one of the key components of the library’s success in providing patrons with the help they need. With radically minimized availability at the physical locations, the infrastructure was at risk of collapsing. Objectives:- The objective of this project has been to evaluate the consequences of the sudden change in the organization of the library. The focus of this evaluation is the library’s VRS as an important space for learning, interaction and communication between the library and the community when other traditional spaces were not available. The goal of this evaluation is to capture the lessons learned from providing infrastructure for learning and research in times of crisis both on a practical, user-centered level but also to stress the importance of leadership in ever-changing environments that supports and creates agile, flexible services and teams instead of rigid processes adhering to obsolete goals. Results:- Reduced availability at the physical library locations was one of the strategies to prevent the spread of the covid-19 virus. The library staff was encouraged to work from home, so student workers staffed the library’s physical locations during that time, leaving the VRS to be the only place where patrons could get expert help. The VRS had an increase of 65% of questions asked between spring term 2019 and spring term 2020. The VRS team had to navigate often complicated and fast-changing new routines depending on national guidelines. The VRS team has a strong emphasis on agility in their approach to the challenges and opportunities, with methods to evaluate decisions regularly with user experience in mind. Fast decision-making, collecting feedback, an open-minded approach to reviewing rules and processes with both a short-term and a long-term focus and providing a healthy work environment have been key factors in managing this crisis and learn from it. This was resting on a strong sense of ownership regarding the VRS, well-working communication tools and agile and active communication between team members, as well as between the team and the rest of the organization who served as a second-line support system to aid the VRS team. Moving forward, the VRS has become an important space for communication, interaction and provider of infrastructure, implementing new routines and more extensive availability due to the lessons learned during crisis. The evaluation shows that the virtual environment has become an important addition to the physical spaces, existing in its own right but always in connection with and in relationship with the library structure as a whole. Thereby showing that the basis of human interaction stays the same while its form morphs and adapts to changes, thus leaving the virtual environment as a space of communication and infrastructure with unique opportunities for outreach and the potential to become a staple in patron’s education and learning.

Keywords: virtual reference service, leadership, digital infrastructure, research library

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2455 Exertainment: Designing Active Video Games to Get Youth Moving

Authors: Geoff Skinner, Ilung Pranata

Abstract:

The advancement of ICT innovations provides us with a comfortable and convenient modern lifestyle. However, this modern easy lifestyle is proving to have some serious health consequences. Such technological advancements that have dramatically increased ones time in front of screens have been a contributing factor to increasing rates of obesity. In particular the youth obesity issue has gained more and more attention from researchers and health institutions around the world. Although technology innovations may lead to a sedate modern life, they also have a potential to solve the obesity issue in children. This paper provides a review of the issues in child obesity and the potential of active video games to mitigate these issues. Additionally, the paper also discusses the key requirements to develop an active video game that hopes to help combat child obesity through motivating youth to exergame. A framework is introduced to meet the requirements, from which a prototype was implemented. Discussion of the simulation and testing that were performed to verify the attainment of objectives is also detailed.

Keywords: e-video games, exergaming, health informatics, human computer interaction

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2454 Representation of Islamophobia on Social Media: Facebook Comments Analysis

Authors: Nadia Syed

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The digital age has inevitably changed the way in which hate crime is committed. The cyber world has become a highly effective means for individuals and groups to be targeted, harmed, and marginalized , largely through online medium. Facebook has become one of the fastest growing social media platforms. At the end of 2013, Facebook had 1,23bn monthly active users and 757 million daily users who log onto Facebook. Within this online space, there are also an increasing number of online virtual communities, and hate groups who are using this freedom to share a violent, Islamophobic and racist description which attempts to create a aggressive virtual environment. This paper is a research on the rise of Islamophobia and the role of media in spreading it. This paper focusing on how the media especially Facebook is portraying Islam as the religion which promotes violence and ultimately playing a significant role in the global rise of Islamophobia against Muslims. It is important to analyse these ‘new’ communities by monitoring the activities they conduct, because the material they post, potentially can have a harmful impact on community cohesion within society. Additionally, as a result of recent figures that shows an increase in online anti-Muslim abuse, there is a pertinent need to address the issue about Islamophobia on social media. On the whole, this study found Muslims being demonized and vilified online which had manifested through negative attitudes, discrimination, stereotypes, physical threats and online harassment which all had the potential to incite violence or prejudicial action because it disparages and intimidates a protected individual or group.

Keywords: Islamophobia, online, social media, facebook, internet, extremism

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2453 Conductivity-Depth Inversion of Large Loop Transient Electromagnetic Sounding Data over Layered Earth Models

Authors: Ravi Ande, Mousumi Hazari

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One of the common geophysical techniques for mapping subsurface geo-electrical structures, extensive hydro-geological research, and engineering and environmental geophysics applications is the use of time domain electromagnetic (TDEM)/transient electromagnetic (TEM) soundings. A large transmitter loop for energising the ground and a small receiver loop or magnetometer for recording the transient voltage or magnetic field in the air or on the surface of the earth, with the receiver at the center of the loop or at any random point inside or outside the source loop, make up a large loop TEM system. In general, one can acquire data using one of the configurations with a large loop source, namely, with the receiver at the center point of the loop (central loop method), at an arbitrary in-loop point (in-loop method), coincident with the transmitter loop (coincidence-loop method), and at an arbitrary offset loop point (offset-loop method), respectively. Because of the mathematical simplicity associated with the expressions of EM fields, as compared to the in-loop and offset-loop systems, the central loop system (for ground surveys) and coincident loop system (for ground as well as airborne surveys) have been developed and used extensively for the exploration of mineral and geothermal resources, for mapping contaminated groundwater caused by hazardous waste and thickness of permafrost layer. Because a proper analytical expression for the TEM response over the layered earth model for the large loop TEM system does not exist, the forward problem used in this inversion scheme is first formulated in the frequency domain and then it is transformed in the time domain using Fourier cosine or sine transforms. Using the EMLCLLER algorithm, the forward computation is initially carried out in the frequency domain. As a result, the EMLCLLER modified the forward calculation scheme in NLSTCI to compute frequency domain answers before converting them to the time domain using Fourier Cosine and/or Sine transforms.

Keywords: time domain electromagnetic (TDEM), TEM system, geoelectrical sounding structure, Fourier cosine

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2452 Numerical Modelling of Prestressed Geogrid Reinforced Soil System

Authors: Soukat Kumar Das

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Rapid industrialization and increase in population has resulted in the scarcity of suitable ground conditions. It has driven the need of ground improvement by means of reinforcement with geosynthetics with the minimum possible settlement and with maximum possible safety. Prestressing the geosynthetics offers an economical yet safe method of gaining the goal. Commercially available software PLAXIS 3D has made the analysis of prestressed geosynthetics simpler with much practical simulations of the ground. Attempts have been made so far to analyse the effect of prestressing geosynthetics and the effect of interference of footing on Unreinforced (UR), Geogrid Reinforced (GR) and Prestressed Geogrid Reinforced (PGR) soil on the load bearing capacity and the settlement characteristics of prestressed geogrid reinforced soil using the numerical analysis by using the software PLAXIS 3D. The results of the numerical analysis have been validated and compared with those given in the referred paper. The results have been found to be in very good agreement with those of the actual field values with very small variation. The GR soil has been found to be improve the bearing pressure 240 % whereas the PGR soil improves it by almost 500 % for 1mm settlement. In fact, the PGR soil has enhanced the bearing pressure of the GR soil by almost 200 %. The settlement reduction has also been found to be very significant as for 100 kPa bearing pressure the settlement reduction of the PGR soil has been found to be about 88 % with respect to UR soil and it reduced to up to 67 % with respect to GR soil. The prestressing force has resulted in enhanced reinforcement mechanism, resulting in the increased bearing pressure. The deformation at the geogrid layer has been found to be 13.62 mm for GR soil whereas it decreased down to mere 3.5 mm for PGR soil which certainly ensures the effect of prestressing on the geogrid layer. The parameter Improvement factor or conventionally known as Bearing Capacity Ratio for different settlements and which depicts the improvement of the PGR with respect to UR and GR soil and the improvement of GR soil with respect to UR soil has been found to vary in the range of 1.66-2.40 in the present analysis for GR soil and was found to be vary between 3.58 and 5.12 for PGR soil with respect to UR soil. The effect of prestressing was also observed in case of two interfering square footings. The centre to centre distance between the two footings (SFD) was taken to be B, 1.5B, 2B, 2.5B and 3B where B is the width of the footing. It was found that for UR soil the improvement of the bearing pressure was up to 1.5B after which it remained almost same. But for GR soil the zone of influence rose up to 2B and for PGR it further went up to 2.5B. So the zone of interference for PGR soil has increased by 67% than Unreinforced (UR) soil and almost 25 % with respect to GR soil.

Keywords: bearing, geogrid, prestressed, reinforced

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2451 NanoSat MO Framework: Simulating a Constellation of Satellites with Docker Containers

Authors: César Coelho, Nikolai Wiegand

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The advancement of nanosatellite technology has opened new avenues for cost-effective and faster space missions. The NanoSat MO Framework (NMF) from the European Space Agency (ESA) provides a modular and simpler approach to the development of flight software and operations of small satellites. This paper presents a methodology using the NMF together with Docker for simulating constellations of satellites. By leveraging Docker containers, the software environment of individual satellites can be easily replicated within a simulated constellation. This containerized approach allows for rapid deployment, isolation, and management of satellite instances, facilitating comprehensive testing and development in a controlled setting. By integrating the NMF lightweight simulator in the container, a comprehensive simulation environment was achieved. A significant advantage of using Docker containers is their inherent scalability, enabling the simulation of hundreds or even thousands of satellites with minimal overhead. Docker's lightweight nature ensures efficient resource utilization, allowing for deployment on a single host or across a cluster of hosts. This capability is crucial for large-scale simulations, such as in the case of mega-constellations, where multiple traditional virtual machines would be impractical due to their higher resource demands. This ability for easy horizontal scaling based on the number of simulated satellites provides tremendous flexibility to different mission scenarios. Our results demonstrate that leveraging Docker containers with the NanoSat MO Framework provides a highly efficient and scalable solution for simulating satellite constellations, offering not only significant benefits in terms of resource utilization and operational flexibility but also enabling testing and validation of ground software for constellations. The findings underscore the importance of taking advantage of already existing technologies in computer science to create new solutions for future satellite constellations in space.

Keywords: containerization, docker containers, NanoSat MO framework, satellite constellation simulation, scalability, small satellites

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