Search results for: linear parameter varying (LPV)

Authors: Mario Sandro F. Rocha, Carlos S. Ande, Anderson A. Oliveira, Felipe M. Bersotti, Lucas O. Venzel

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The inertial motion capture systems (mocap) are among the most suitable tools for quantitative clinical analysis in rehabilitation and sports medicine. The inertial measuring units (IMUs), composed by accelerometers, gyroscopes, and magnetometers, are able to measure spatial orientations and calculate displacements with sufficient precision for applications in biomechanical analysis of movement. Furthermore, this type of system is relatively affordable and has the advantages of portability and independence from external references. In this work, we present the last version of our inertial motion capture system, based on the foregoing technology, with a unity interface designed for rehabilitation and sports. In our hardware architecture, only one serial port is required. First, the board client must be connected to the computer by a USB cable. Next, an available serial port is configured and opened to establish the communication between the client and the application, and then the client starts scanning for the active MOCAP_S servers around. The servers play the role of the inertial measuring units that capture the movements of the body and send the data to the client, which in turn create a package composed by the ID of the server, the current timestamp, and the motion capture data defined in the client pre-configuration of the capture session. In the current version, we can measure the game rotation vector (grv) and linear acceleration (lacc), and we also have a step detector that can be abled or disabled. The grv data are processed and directly linked to the bones of the 3D model, and, along with the data of lacc and step detector, they are also used to perform the calculations of displacements and other variables shown on the graphical user interface. Our user interface was designed to calculate and present variables that are important for rehabilitation and sports, such as cadence, speed, total gait cycle, gait cycle length, obliquity and rotation, and center of gravity displacement. Our goal is to present a low-cost portable and wearable system with a friendly interface for application in biomechanics and sports, which also performs as a product of high precision and low consumption of energy.

Keywords: biomechanics, inertial sensors, motion capture, rehabilitation

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Authors: Pawel Martynowicz

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Vibrations are a crucial problem for slender structures such as towers, masts, chimneys, wind turbines, bridges, high buildings, etc., that is why most of them are equipped with vibration attenuation or fatigue reduction solutions. In this work, a slender structure (i.e., wind turbine tower-nacelle model) equipped with nonlinear, semiactive tuned vibration absorber(s) is analyzed. For this study purposes, magnetorheological (MR) dampers are used as semiactive actuators. Several optimal-based approaches to structural vibration attenuation are investigated against the standard ‘ground-hook’ law and passive tuned vibration absorber(s) implementations. The common approach to optimal control of nonlinear systems is offline computation of the optimal solution, however, so determined open loop control suffers from lack of robustness to uncertainties (e.g., unmodelled dynamics, perturbations of external forces or initial conditions), and thus perturbation control techniques are often used. However, proper linearization may be an issue for highly nonlinear systems with implicit relations between state, co-state, and control. The main contribution of the author is the development as well as numerical and experimental verification of the Pontriagin maximum-principle-based vibration control concepts that produce directly actuator control input (not the demanded force), thus force tracking algorithm that results in control inaccuracy is entirely omitted. These concepts, including one-step optimal control, quasi-optimal control, and optimal-based modified ‘ground-hook’ law, can be directly implemented in online and real-time feedback control for periodic (or semi-periodic) disturbances with invariant or time-varying parameters, as well as for non-periodic, transient or random disturbances, what is a limitation for some other known solutions. No offline calculation, excitations/disturbances assumption or vibration frequency determination is necessary, moreover, all of the nonlinear actuator (MR damper) force constraints, i.e., no active forces, lower and upper saturation limits, hysteresis-type dynamics, etc., are embedded in the control technique, thus the solution is optimal or suboptimal for the assumed actuator, respecting its limitations. Depending on the selected method variant, a moderate or decisive reduction in the computational load is possible compared to other methods of nonlinear optimal control, while assuring the quality and robustness of the vibration reduction system, as well as considering multi-pronged operational aspects, such as possible minimization of the amplitude of the deflection and acceleration of the vibrating structure, its potential and/or kinetic energy, required actuator force, control input (e.g. electric current in the MR damper coil) and/or stroke amplitude. The developed solutions are characterized by high vibration reduction efficiency – the obtained maximum values of the dynamic amplification factor are close to 2.0, while for the best of the passive systems, these values exceed 3.5.

Keywords: magnetorheological damper, nonlinear tuned vibration absorber, optimal control, real-time structural vibration attenuation, wind turbines

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Authors: Pulakesh Das, Mukunda Dev Behera, Manchiraju Sri Ramachandra Murthy

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Large numbers of people living in and around the Hindu Kush Himalaya (HKH) region, depends on this diverse mountainous region for ecosystem services. Following the global trend, this region also experiencing rapid population growth, and demand for timber and agriculture land. The eight countries sharing the HKH region have different forest resources utilization and conservation policies that exert varying forces in the forest ecosystem. This created a variable spatial as well altitudinal gradient in rate of deforestation and corresponding forest patch fragmentation. The quantitative relationship between fragmentation and demography has not been established before for HKH vis-à-vis along elevation gradient. This current study was carried out to attribute the overall and different nature in landscape fragmentations along the altitudinal gradient with the demography of each sharing countries. We have used the tree canopy cover data derived from Landsat data to analyze the deforestation and afforestation rate, and corresponding landscape fragmentation observed during 2000 – 2010. Area-weighted mean radius of gyration (AMN radius of gyration) was computed owing to its advantage as spatial indicator of fragmentation over non-spatial fragmentation indices. Using the subtraction method, the change in fragmentation was computed during 2000 – 2010. Using the tree canopy cover data as a surrogate of forest cover, highest forest loss was observed in Myanmar followed by China, India, Bangladesh, Nepal, Pakistan, Bhutan, and Afghanistan. However, the sequence of fragmentation was different after the maximum fragmentation observed in Myanmar followed by India, China, Bangladesh, and Bhutan; whereas increase in fragmentation was seen following the sequence of as Nepal, Pakistan, and Afghanistan. Using SRTM-derived DEM, we observed higher rate of fragmentation up to 2400m that corroborated with high human population for the year 2000 and 2010. To derive the nature of fragmentation along the altitudinal gradients, the Statistica software was used, where the user defined function was utilized for regression applying the Gauss-Newton estimation method with 50 iterations. We observed overall logarithmic decrease in fragmentation change (area-weighted mean radius of gyration), forest cover loss and population growth during 2000-2010 along the elevation gradient with very high R2 values (i.e., 0.889, 0.895, 0.944 respectively). The observed negative logarithmic function with the major contribution in the initial elevation gradients suggest to gap filling afforestation in the lower altitudes to enhance the forest patch connectivity. Our finding on the pattern of forest fragmentation and human population across the elevation gradient in HKH region will have policy level implication for different nations and would help in characterizing hotspots of change. Availability of free satellite derived data products on forest cover and DEM, grid-data on demography, and utility of geospatial tools helped in quick evaluation of the forest fragmentation vis-a-vis human impact pattern along the elevation gradient in HKH.

Keywords: area-weighted mean radius of gyration, fragmentation, human impact, tree canopy cover

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Authors: Giovana Longo-Silva, Risia Cristina Egito de Menezes, Renan Serenini, Márcia de Oliveira Lima, Júlia Souza de Melo, Larissa de Lima Soares

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Introduction: Sleep duration and quality have been increasingly recognized as important factors affecting overall health and well-being, including their potential impact on body weight and composition. Previous research has shown inconsistent results regarding the association between sleep patterns and body mass index (BMI), particularly among diverse populations such as Brazilian adults. Understanding these relationships is crucial for developing targeted interventions to address obesity and related health issues. Objective: This study aimed to investigate the association between sleep duration, insomnia, and BMI among Brazilian adults using data from a large national survey focused on chronic nutrition and sleep habits. Materials and Methods: The study included 2050 participants from a population-based virtual survey. BMI was calculated using self-reported weight and height measurements. Participants also reported usual bedtime and wake time on weekdays and weekends and whether they experienced symptoms of insomnia. The average sleep duration across the entire week was calculated as follows: [(5×sleep duration on weekdays) + (2×sleep duration on weekends)]/7. Linear regression analyses were conducted to assess the association between sleep duration, insomnia, and BMI, adjusting for potential confounding factors, including age, sex, marital status, physical exercise duration, and diet quality. Results: After adjusting for confounding variables, the study found that BMI decreased by 0.19 kg/m² for each additional hour of sleep duration (95% CI = -0.37, -0.02; P = 0.03). Conversely, individuals with insomnia had a higher BMI, with an increase of 0.75 kg/m² (95% CI = 0.28, 1.22; P = 0.002) compared to those without insomnia. Conclusions: The findings suggest a significant association between sleep duration, insomnia, and BMI among Brazilian adults. Longer sleep duration was associated with lower BMI, while insomnia was associated with higher BMI. These results underscore the importance of considering sleep patterns in strategies aimed at preventing and managing obesity in this population. Further research is needed to explore the underlying mechanisms and potential interventions targeting sleep-related factors to promote healthier body weight outcomes.

Keywords: sleep, obesity, chronobiology, nutrition

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Authors: K. S. Poutanen, P. Dussort, A. Erkner, S. Fiszman, K. Karnik, M. Kristensen, C. F. M. Marsaux, S. Miquel-Kergoat, S. Pentikäinen, P. Putz, R. E. Steinert, J. Slavin, D. J. Mela

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Dietary fiber (DF) intake has been associated with lower body weight or less weight gain. These effects are generally attributed to putative effects of DF on appetite. Many intervention studies have tested the effect of DFs on appetite-related measures, with inconsistent results. However, DF includes a wide category of different compounds with diverse chemical and physical characteristics, and correspondingly diverse effects in human digestion. Thus, inconsistent results between DF consumption and appetite are not surprising. The specific contribution of different compounds with varying physico-chemical properties to appetite control and the mediating mechanisms are not well characterized. This systematic review aimed to assess the influence of specific DF characteristics, including viscosity, gel forming capacity, fermentability, and molecular weight, on appetite-related outcomes in healthy humans. Medline and FSTA databases were searched for controlled human intervention trials, testing the effects of well-characterized DFs on subjective satiety/appetite or energy intake outcomes. Studies were included only if they reported: 1) fiber name and origin, and 2) data on viscosity, gelling properties, fermentability, or molecular weight of the DF materials tested. The search generated 3001 unique records, 322 of which were selected for further consideration from title and abstract screening. Of these, 149 were excluded due to insufficient fiber characterization and 124 for other reasons (not original article, not randomized controlled trial, or no appetite related outcome), leaving 49 papers meeting all the inclusion criteria, most of which reported results from acute testing (<1 day). The eligible 49 papers described 90 comparisons of DFs in foods, beverages or supplements. DF-containing material of interest was efficacious for at least one appetite-related outcome in 51/90 comparisons. Gel-forming DF sources were most consistently efficacious but there were no clear associations between viscosity, MW or fermentability and appetite-related outcomes. A considerable number of papers had to be excluded from the review due to shortcomings in fiber characterization. To build understanding about the impact of DF on satiety/appetite specifically there should be clear hypotheses about the mechanisms behind the proposed beneficial effect of DF material on appetite, and sufficient data about the DF properties relevant for the hypothesized mechanisms to justify clinical testing. The hypothesized mechanisms should also guide the decision about relevant duration of exposure in studies, i.e. are the effects expected to occur during acute time frame (related to stomach emptying, digestion rate, etc.) or develop from sustained exposure (gut fermentation mediated mechanisms). More consistent measurement methods and reporting of fiber specifications and characterization are needed to establish reliable structure-function relationships for DF and health outcomes.

Keywords: appetite, dietary fiber, physico-chemical properties, satiety

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Authors: Marcin Zielinski, Marcin Debowski, Paulina Rusanowska, Magda Dudek

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As a result of sonification, the destruction of complex biomass structures results in an increase in the biogas yield from the conditioned material. First, the amount of organic matter released into the solution due to disintegration was determined. This parameter was determined by changes in the carbon content in liquid phase of the conditioned substrate. The amount of carbon in the liquid phase increased with the prolongation of the sonication time to 16 min. Further increase in the duration of sonication did not cause a statistically significant increase in the amount of organic carbon in the liquid phase. The disintegrated material was then used for respirometric measurements for determination of the impact of the conditioning process used on methane fermentation effectiveness. The relationship between the amount of energy introduced into the lignocellulosic substrate and the amount of biogas produced has been demonstrated. Statistically significant increase in the amount of biogas was observed until sonication of 16 min. Further increase in energy in the conditioning process did not significantly increase the production of biogas from the treated substrate. The biogas production from the conditioned substrate was 17% higher than from the reference biomass at that time. The ultrasonic disintegration method did not significantly affect the observed biogas composition. In all series, the methane content in the produced biogas from the conditioned substrate was similar to that obtained with the raw substrate sample (51.1%). Another method of substrate conditioning was hydrothermal depolymerization. This method consists in application of increased temperature and pressure to substrate. These phenomena destroy the structure of the processed material, the release of organic compounds to the solution, which should lead to increase the amount of produced biogas from such treated biomass. The hydrothermal depolymerization was conducted using an innovative microwave heating method. Control measurements were performed using conventional heating. The obtained results indicate the relationship between depolymerization temperature and the amount of biogas. Statistically significant value of the biogas production coefficients increased as the depolymerization temperature increased to 150°C. Further raising the depolymerization temperature to 180°C did not significantly increase the amount of produced biogas in the respirometric tests. As a result of the hydrothermal depolymerization obtained using microwave at 150°C for 20 min, the rate of biogas production from the Sida silage was 780 L/kg VS, which accounted for nearly 50% increase compared to 370 L/kg VS obtained from the same silage but not depolymerised. The study showed that by microwave heating it is possible to effectively depolymerized substrate. Significant differences occurred especially in the temperature range of 130-150ºC. The pre-treatment of Sida hermaphrodita silage (biogas substrate) did not significantly affect the quality of the biogas produced. The methane concentration was about 51.5% on average. The study was carried out in the framework of the project under program BIOSTRATEG funded by the National Centre for Research and Development No. 1/270745/2/NCBR/2015 'Dietary, power, and economic potential of Sida hermaphrodita cultivation on fallow land'.

Keywords: disintegration, biogas, methane fermentation, Virginia fanpetals, biomass

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Authors: Mina Rouhollahi, J. Boland

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Changes in cities’ heat balance due to rapid urbanization and the urban heat island (UHI) have increased energy demands for space cooling and have resulted in uncomfortable living conditions for urban residents. Climate resilience and comfortable living spaces can be addressed through well-designed urban development. The sustainable housing can be more effective in controlling high levels of urban heat. In Australia, to mitigate the effects of UHIs and summer heat waves, one solution to sustainable housing has been the trend to compact housing design and the construction of energy efficient dwellings. This paper analyses whether current housing configurations and orientations are effective in avoiding increased demands for air conditioning and having an energy efficient residential neighborhood. A significant amount of energy is consumed to ensure thermal comfort in houses. This paper reports on the modelling of heat transfer within the homes using the measurements of radiation, convection and conduction between exterior/interior wall surfaces and outdoor/indoor environment respectively. The simulation was tested on selected 7.5-star energy efficient houses constructed of typical material elements and insulation in Adelaide, Australia. The chosen design dwellings were analyzed in extremely hot weather through one year. The data were obtained via a thermal circuit to accurately model the fundamental heat transfer mechanisms on both boundaries of the house and through the multi-layered wall configurations. The formulation of the Lumped capacitance model was considered in discrete time steps by adopting a non-linear model method. The simulation results focused on the effects of orientation of the solar radiation on the dynamic thermal characteristics of the houses orientations. A high star rating did not necessarily coincide with a decrease in peak demands for cooling. A more effective approach to avoid increasing the demands for air conditioning and energy may be to integrate solar–climatic data to evaluate the performance of energy efficient houses.

Keywords: energy-efficient residential building, heat transfer, neighborhood orientation, solar–climatic data

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Authors: Andrzej Szewczak

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Study of the effect of high temperatures on polymer coatings represents an important field of research of their properties. Polymers, as materials with numerous features (chemical resistance, ease of processing and recycling, corrosion resistance, low density and weight) are currently the most widely used modern building materials, among others in the resin concrete, plastic parts, and hydrophobic coatings. Unfortunately, the polymers have also disadvantages, one of which decides about their usage - low resistance to high temperatures and brittleness. This applies in particular thin and flexible polymeric coatings applied to other materials, such a steel and concrete, which degrade under varying thermal conditions. Research about improvement of this state includes methods of modification of the polymer composition, structure, conditioning conditions, and the polymerization reaction. At present, ways are sought to reflect the actual environmental conditions, in which the coating will be operating after it has been applied to other material. These studies are difficult because of the need for adopting a proper model of the polymer operation and the determination of phenomena occurring at the time of temperature fluctuations. For this reason, alternative methods are being developed, taking into account the rapid modeling and the simulation of the actual operating conditions of polymeric coating’s materials in real conditions. The nature of a duration is typical for the temperature influence in the environment. Studies typically involve the measurement of variation one or more physical and mechanical properties of such coating in time. Based on these results it is possible to determine the effects of temperature loading and develop methods affecting in the improvement of coatings’ properties. This paper contains a description of the stability studies of silicone coatings deposited on the surface of a ceramic brick. The brick’s surface was hydrophobized by two types of inorganic polymers: nano-polymer preparation based on dialkyl siloxanes (Series 1 - 5) and an aqueous solution of the silicon (series 6 - 10). In order to enhance the stability of the film formed on the brick’s surface and immunize it to variable temperature and humidity loading, the nano silica was added to the polymer. The right combination of the polymer liquid phase and the solid phase of nano silica was obtained by disintegration of the mixture by the sonification. The changes of viscosity and surface tension of polymers were defined, which are the basic rheological parameters affecting the state and the durability of the polymer coating. The coatings created on the brick’s surfaces were then subjected to a temperature loading of 100° C and moisture by total immersion in water, in order to determine any water absorption changes caused by damages and the degradation of the polymer film. The effect of moisture and temperature was determined by measurement (at specified number of cycles) of changes in the surface hardness (using a Vickers’ method) and the absorption of individual samples. As a result, on the basis of the obtained results, the degradation process of polymer coatings related to their durability changes in time was determined.

Keywords: silicones, siloxanes, surface hardness, temperature, water absorption

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Authors: Yichao Liu, Peter Fransson, Julian Heidecke, Jonas Wallin, Joacim Rockloev

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Dengue, a mosquito-borne viral disease, poses a significant public health challenge in endemic tropical or subtropical countries, including Sri Lanka. To reveal insights into the complexity of the dynamics of this disease and study the drivers, a comprehensive model capable of both robust forecasting and insightful inference of drivers while capturing the co-circulating of several virus strains is essential. However, existing studies mostly focus on only one aspect at a time and do not integrate and carry insights across the siloed approach. While mechanistic models are developed to capture immunity dynamics, they are often oversimplified and lack integration of all the diverse drivers of disease transmission. On the other hand, purely data-driven methods lack constraints imposed by immuno-epidemiological processes, making them prone to overfitting and inference bias. This research presents a hybrid model that combines machine learning techniques with mechanistic modelling to overcome the limitations of existing approaches. Leveraging eight years of newly reported dengue case data, along with socioeconomic factors, such as human mobility, weekly climate data from 2011 to 2018, genetic data detecting the introduction and presence of new strains, and estimates of seropositivity for different districts in Sri Lanka, we derive a data-driven vector (SEI) to human (SEIR) model across 16 regions in Sri Lanka at the weekly time scale. By conducting ablation studies, the lag effects allowing delays up to 12 weeks of time-varying climate factors were determined. The model demonstrates superior predictive performance over a pure machine learning approach when considering lead times of 5 and 10 weeks on data withheld from model fitting. It further reveals several interesting interpretable findings of drivers while adjusting for the dynamics and influences of immunity and introduction of a new strain. The study uncovers strong influences of socioeconomic variables: population density, mobility, household income and rural vs. urban population. The study reveals substantial sensitivity to the diurnal temperature range and precipitation, while mean temperature and humidity appear less important in the study location. Additionally, the model indicated sensitivity to vegetation index, both max and average. Predictions on testing data reveal high model accuracy. Overall, this study advances the knowledge of dengue transmission in Sri Lanka and demonstrates the importance of incorporating hybrid modelling techniques to use biologically informed model structures with flexible data-driven estimates of model parameters. The findings show the potential to both inference of drivers in situations of complex disease dynamics and robust forecasting models.

Keywords: compartmental model, climate, dengue, machine learning, social-economic

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Authors: Lee Yujin, Han Jiye, Oh Jin-Woo

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The adverse effects of endocrine disrupting chemicals (EDCs) has attracted considerable public interests. The benzene-like EDCs structure mimics the mechanisms of hormones naturally occurring in vivo, and alters physiological function of the endocrine system. Although, some of the most representative EDCs such as polychlorinated biphenyls (PCBs) and phthalates compounds already have been prohibited to produce and use in many countries, however, PCBs and phthalates in plastic products as flame retardant and plasticizer are still circulated nowadays. EDCs can be released from products while using and discarding, and it causes serious environmental and health issues. Here, we developed virus-based structurally coloured nanostructure that can detect minute EDCs concentration sensitively and selectively. These structurally coloured nanostructure exhibits characteristic angel-independent colors due to the regular virus bundle structure formation through simple pulling technique. The designed number of different colour bands can be formed through controlling concentration of virus solution and pulling speed. The virus, M-13 bacteriophage, was genetically engineered to react with specific ECDs, typically PCBs and phthalates. M-13 bacteriophage surface (pVIII major coat protein) was decorated with benzene derivative binding peptides (WHW) through phage library method. In the initial assessment, virus-based color sensor was exposed to several organic chemicals including benzene, toluene, phenol, chlorobenzene, and phthalic anhydride. Along with the selectivity evaluation of virus-based colour sensor, it also been tested for sensitivity. 10 to 300 ppm of phthalic anhydride and chlorobenzene were detected by colour sensor, and showed the significant sensitivity with about 90 of dissociation constant. Noteworthy, all measurements were analyzed through principal component analysis (PCA) and linear discrimination analysis (LDA), and exhibited clear discrimination ability upon exposure to 2 categories of EDCs (PCBs and phthalates). Because of its easy fabrication, high sensitivity, and the superior selectivity, M-13 bacteriophage-based color sensor could be a simple and reliable portable sensing system for environmental monitoring, healthcare, social security, and so on.

Keywords: M-13 bacteriophage, colour sensor, genetic engineering, EDCs

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Authors: Julio Jesus Salazar, Julio Jesus De Lama

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the fundamental objective of hydrological studies applied to the engineering field is to determine the statistically consistent volumes or water flows that, in each case, allow us to size or design a series of elements or structures to effectively manage and develop a river basin. To determine these values, there are several ways of working within the framework of traditional hydrology: (1) Study each of the factors that influence the hydrological cycle, (2) Study the historical behavior of the hydrology of the area, (3) Study the historical behavior of hydrologically similar zones, and (4) Other studies (rain simulators or experimental basins). Of course, this range of studies in a certain basin is very varied and complex and presents the difficulty of collecting the data in real time. In this complex space, the study of variables can only be overcome by collecting and transmitting data to decision centers through the Internet of things and artificial intelligence. Thus, this research work implemented the learning project of the sub-basin of the Shullcas river in the Andean basin of the Mantaro river in Peru. The sensor firmware to collect and communicate hydrological parameter data was programmed and tested in similar basins of the European Union. The Machine Learning applications was programmed to choose the algorithms that direct the best solution to the determination of the rainfall-runoff relationship captured in the different polygons of the sub-basin. Tests were carried out in the mountains of Europe, and in the sub-basins of the Shullcas river (Huancayo) and the Yauli river (Jauja) with heights close to 5000 m.a.s.l., giving the following conclusions: to guarantee a correct communication, the distance between devices should not pass the 15 km. It is advisable to minimize the energy consumption of the devices and avoid collisions between packages, the distances oscillate between 5 and 10 km, in this way the transmission power can be reduced and a higher bitrate can be used. In case the communication elements of the devices of the network (internet of things) installed in the basin do not have good visibility between them, the distance should be reduced to the range of 1-3 km. The energy efficiency of the Atmel microcontrollers present in Arduino is not adequate to meet the requirements of system autonomy. To increase the autonomy of the system, it is recommended to use low consumption systems, such as the Ashton Raggatt McDougall or ARM Cortex L (Ultra Low Power) microcontrollers or even the Cortex M; and high-performance direct current (DC) to direct current (DC) converters. The Machine Learning System has initiated the learning of the Shullcas system to generate the best hydrology of the sub-basin. This will improve as machine learning and the data entered in the big data coincide every second. This will provide services to each of the applications of the complex system to return the best data of determined flows.

Keywords: hydrology, internet of things, machine learning, river basin

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Authors: Caixia Gao, Chuanrong Li, Lingli Tang, Lingling Ma, Yonggang Qian, Ning Wang

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Knowledge of land surface temperature (LST) is of crucial important in energy balance studies and environment modeling. Satellite thermal infrared (TIR) imagery is the primary source for retrieving LST at the regional and global scales. Due to the combination of atmosphere and land surface of received radiance by TIR sensors, atmospheric effect correction has to be performed to remove the atmospheric transmittance and upwelling radiance. Spinning Enhanced Visible and Infrared Imager (SEVIRI) onboard Meteosat Second Generation (MSG) provides measurements every 15 minutes in 12 spectral channels covering from visible to infrared spectrum at fixed view angles with 3km pixel size at nadir, offering new and unique capabilities for LST, LSE measurements. However, due to its high temporal resolution, the atmosphere correction could not be performed with radiosonde profiles or reanalysis data since these profiles are not available at all SEVIRI TIR image acquisition times. To solve this problem, a two-part six-parameter semi-empirical diurnal temperature cycle (DTC) model has been applied to the temporal interpolation of ECMWF reanalysis data. Due to the fact that the DTC model is underdetermined with ECMWF data at four synoptic times (UTC times: 00:00, 06:00, 12:00, 18:00) in one day for each location, some approaches are adopted in this study. It is well known that the atmospheric transmittance and upwelling radiance has a relationship with water vapour content (WVC). With the aid of simulated data, the relationship could be determined under each viewing zenith angle for each SEVIRI TIR channel. Thus, the atmospheric transmittance and upwelling radiance are preliminary removed with the aid of instantaneous WVC, which is retrieved from the brightness temperature in the SEVIRI channels 5, 9 and 10, and a group of the brightness temperatures for surface leaving radiance (Tg) are acquired. Subsequently, a group of the six parameters of the DTC model is fitted with these Tg by a Levenberg-Marquardt least squares algorithm (denoted as DTC model 1). Although the retrieval error of WVC and the approximate relationships between WVC and atmospheric parameters would induce some uncertainties, this would not significantly affect the determination of the three parameters, td, ts and β (β is the angular frequency, td is the time where the Tg reaches its maximum, ts is the starting time of attenuation) in DTC model. Furthermore, due to the large fluctuation in temperature and the inaccuracy of the DTC model around sunrise, SEVIRI measurements from two hours before sunrise to two hours after sunrise are excluded. With the knowledge of td , ts, and β, a new DTC model (denoted as DTC model 2) is accurately fitted again with these Tg at UTC times: 05:57, 11:57, 17:57 and 23:57, which is atmospherically corrected with ECMWF data. And then a new group of the six parameters of the DTC model is generated and subsequently, the Tg at any given times are acquired. Finally, this method is applied to SEVIRI data in channel 9 successfully. The result shows that the proposed method could be performed reasonably without assumption and the Tg derived with the improved method is much more consistent with that from radiosonde measurements.

Keywords: atmosphere correction, diurnal temperature cycle model, land surface temperature, SEVIRI

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Authors: Wei Wang, Yannick Liu, Lu Zhen, H. Wang

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Maritime transport plays an important role in global economic development but also inevitably faces increasing pressures from all sides, such as ship operating cost reduction and environmental protection. An ideal innovation to address these pressures is electric ships. The electric ship is in the early stage. Considering the special characteristics of electric ships, i.e., travel range limit, to guarantee the efficient operation of electric ships, the service network needs to be re-designed carefully. This research designs a cost-efficient and environmentally friendly service network for electric ships, including the location of charging stations, charging plan, route planning, ship scheduling, and ship deployment. The problem is formulated as a mixed-integer linear programming model with the objective of minimizing total cost comprised of charging cost, the construction cost of charging stations, and fixed cost of ships. A case study using data of the shipping network along the Yangtze River is conducted to evaluate the performance of the model. Two operating scenarios are used: an electric ship scenario where all the transportation tasks are fulfilled by electric ships and a conventional ship scenario where all the transportation tasks are fulfilled by fuel oil ships. Results unveil that the total cost of using electric ships is only 42.8% of using conventional ships. Using electric ships can reduce 80% SOx, 93.47% NOx, 89.47% PM, and 42.62% CO2, but will consume 2.78% more time to fulfill all the transportation tasks. Extensive sensitivity analyses are also conducted for key operating factors, including battery capacity, charging speed, volume capacity, and a service time limit of transportation task. Implications from the results are as follows: 1) it is necessary to equip the ship with a large capacity battery when the number of charging stations is low; 2) battery capacity will influence the number of ships deployed on each route; 3) increasing battery capacity will make the electric ship more cost-effective; 4) charging speed does not affect charging amount and location of charging station, but will influence the schedule of ships on each route; 5) there exists an optimal volume capacity, at which all costs and total delivery time are lowest; 6) service time limit will influence ship schedule and ship cost.

Keywords: cost reduction, electric ship, environmental protection, sustainable shipping

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Authors: Carly Nesvat, Dominic Jarrett, Colin Thomson, Wilma Coltart, Thelma Bowers, Jan Thomson

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Introduction: Within Scotland, the Same As You strategy committed to moving people with learning disabilities out of long-stay hospital accommodation into homes in the community. Much of the focus of this movement was on the placement of people within individual homes. In order to achieve this, potentially excessive supports were put in place which created dependence, and carried significant ongoing cost primarily for local authorities. The greater focus on empowerment and community participation which has been evident in more recent learning disability strategy, along with the financial pressures being experienced across the public sector, created an imperative to re-examine that provision, particularly in relation to the use of expensive sleepover supports to individuals, and the potential for this to be appropriately scaled back through the use of telecare. Method: As part of a broader programme of redesigning overnight supports within North Ayrshire, a cluster of individuals living in close proximity were identified, who were in receipt of overnight supports, but who were identified as having the capacity to potentially benefit from their removal. In their place, a responder service was established (an individual staying overnight in a nearby service user’s home), and a variety of telecare solutions were placed within individual’s homes. Active and passive technology was connected to an Alarm Receiving Centre, which would alert the local responder service when necessary. Individuals and their families were prepared for the change, and continued to be informed about progress with the pilot. Results: 4 individuals, 2 of whom shared a tenancy, had their sleepover supports removed as part of the pilot. Extensive data collection in relation to alarm activation was combined with feedback from the 4 individuals, their families, and staff involved in their support. Varying perspectives emerged within the feedback. 3 of the individuals were clearly described as benefitting from the change, and the greater sense of independence it brought, while more concerns were evident in relation to the fourth. Some family members expressed a need for greater preparation in relation to the change and ongoing information provision. Some support staff also expressed a need for more information, to help them understand the new support arrangements for an individual, as well as noting concerns in relation to the outcomes for one participant. Conclusion: Developing a telecare response in relation to a cluster of individuals was facilitated by them all being supported by the same care provider. The number of similar clusters of individuals being identified within North Ayrshire is limited. Developing other solutions such as a response service for redesign will potentially require greater collaboration between different providers of home support, as well as continuing to explore the full range of telecare, including digital options. The pilot has highlighted the need for effective preparatory and ongoing engagement with staff and families, as well as the challenges which can accompany making changes to long-standing packages of support.

Keywords: challenges, change, engagement, telecare

Procedia PDF Downloads 162

Authors: Md. Afroz Ansari

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The Bengal basin is a spectacular example of a peripheral foreland basin formed by the convergence of the Indian plate beneath the Eurasian and Burmese plates. The basin is embraced on three sides; north, west and east by different fault-controlled tectonic features whereas released in the south where the rivers are drained into the Bay of Bengal. The Bengal basin in the eastern part of the Indian subcontinent constitutes the largest fluvio-deltaic to shallow marine sedimentary basin in the world today. This continental basin coupled with the offshore Bengal Fan under the Bay of Bengal forms the biggest sediment dispersal system. The continental basin is continuously receiving the sediments by the two major rivers Ganga and Brahmaputra (known as Jamuna in Bengal), and Meghna (emerging from the point of conflux of the Ganga and Brahmaputra) and large number of rain-fed, small tributaries originating from the eastern Indian Shield. The drained sediments are ultimately delivered into the Bengal fan. The significance of the present study is to delineate the variations in thicknesses of the sediments, different crustal structures, and the mantle lithosphere throughout the onshore-offshore Bengal basin. In the present study, the different crustal/geological units and the shallower mantle lithosphere were delineated by analyzing the Bouguer Gravity Anomaly (BGA) data along two long traverses South-North (running from Bengal fan cutting across the transition offshore-onshore of the Bengal basin and intersecting the Main Frontal Thrust of India-Himalaya collision zone in Sikkim-Bhutan Himalaya) and West-East (running from the Peninsular Indian Shield across the Bengal basin to the Chittagong–Tripura Fold Belt). The BGA map was derived from the analysis of topex data after incorporating Bouguer correction and all terrain corrections. The anomaly map was compared with the available ground gravity data in the western Bengal basin and the sub-continents of India for consistency of the data used. Initially, the anisotropy associated with the thicknesses of the different crustal units, crustal interfaces and moho boundary was estimated through spectral analysis of the gravity data with varying window size over the study area. The 2D density sections along the traverses were finalized after a number of iterations with the acceptable root mean square (RMS) errors. The estimated thicknesses of the different crustal units and dips of the Moho boundary along both the profiles are consistent with the earlier results. Further the results were encouraged by examining the earthquake database and focal mechanism solutions for better understanding the geodynamics. The earthquake data were taken from the catalogue of US Geological Survey, and the focal mechanism solutions were compiled from the Harvard Centroid Moment Tensor Catalogue. The concentrations of seismic events at different depth levels are not uncommon. The occurrences of earthquakes may be due to stress accumulation as a result of resistance from three sides.

Keywords: anisotropy, interfaces, seismicity, spectrum analysis

Procedia PDF Downloads 257

Authors: Chiqian Zhang, Kyle D. McIntosh, Nathan Sienkiewicz, Ian Struewing, Erin A. Stelzer, Jennifer L. Graham, Jingrang Lu

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Phytoplankton plays an essential role in freshwater aquatic ecosystems and is the primary group synthesizing organic carbon and providing food sources or energy to ecosystems. Therefore, the identification and quantification of phytoplankton are important for estimating and assessing ecosystem productivity (carbon fixation), water quality, and eutrophication. Microscopy is the current gold standard for identifying and quantifying phytoplankton composition and abundance. However, microscopic analysis of phytoplankton is time-consuming, has a low sample throughput, and requires deep knowledge and rich experience in microbial morphology to implement. To improve this situation, quantitative polymerase chain reaction (qPCR) was considered for phytoplankton identification and quantification. Using qPCR to assess phytoplankton composition and abundance, however, has not been comprehensively evaluated. This study focused on: 1) conducting a comprehensive performance comparison of qPCR and microscopy techniques in identifying and quantifying phytoplankton and 2) examining the use of qPCR as a tool for assessing eutrophication. Twelve large rivers located throughout the United States were evaluated using data collected from 2017 to 2019 to understand the relation between qPCR-based phytoplankton abundance and eutrophication. This study revealed that temporal variation of phytoplankton abundance in the twelve rivers was limited within years (from late spring to late fall) and among different years (2017, 2018, and 2019). Midcontinent rivers had moderately greater phytoplankton abundance than eastern and western rivers, presumably because midcontinent rivers were more eutrophic. The study also showed that qPCR- and microscope-determined phytoplankton abundance had a significant positive linear correlation (adjusted R² 0.772, p-value < 0.001). In addition, phytoplankton abundance assessed via qPCR showed promise as an indicator of the eutrophication status of those rivers, with oligotrophic rivers having low phytoplankton abundance and eutrophic rivers having (relatively) high phytoplankton abundance. This study demonstrated that qPCR could serve as an alternative tool to traditional microscopy for phytoplankton quantification and eutrophication assessment in freshwater rivers.

Keywords: phytoplankton, eutrophication, river, qPCR, microscopy, spatiotemporal variation

Procedia PDF Downloads 87

Authors: Jing Zhang, Yvonne Reinwald, Nick Poulson, Alicia El Haj, Chung See, Mike Somekh, Melissa Mather

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Biomedical imaging of native tissue using light offers the potential to obtain excellent structural and functional information in a non-invasive manner with good temporal resolution. Image contrast can be derived from intrinsic absorption, fluorescence, or scatter, or through the use of extrinsic contrast. A major challenge in applying optical microscopy to in vivo tissue imaging is the effects of light attenuation which limits light penetration depth and achievable imaging resolution. Recently Selective Plane Illumination Microscopy (SPIM) has been used to map the 3D distribution of fluorophores dispersed in biological structures. In this approach, a focused sheet of light is used to illuminate the sample from the side to excite fluorophores within the sample of interest. Images are formed based on detection of fluorescence emission orthogonal to the illumination axis. By scanning the sample along the detection axis and acquiring a stack of images, 3D volumes can be obtained. The combination of rapid image acquisition speeds with the low photon dose to samples optical sectioning provides SPIM is an attractive approach for imaging biological samples in 3D. To date all implementations of SPIM rely on the use of fluorescence reporters be that endogenous or exogenous. This approach has the disadvantage that in the case of exogenous probes the specimens are altered from their native stage rendering them unsuitable for in vivo studies and in general fluorescence emission is weak and transient. Here we present for the first time to our knowledge a label-free implementation of SPIM that has downstream applications in the clinical setting. The experimental set up used in this work incorporates both label-free and fluorescent illumination arms in addition to a high specification camera that can be partitioned for simultaneous imaging of both fluorescent emission and scattered light from intrinsic sources of optical contrast in the sample being studied. This work first involved calibration of the imaging system and validation of the label-free method with well characterised fluorescent microbeads embedded in agarose gel. 3D constructs of mammalian cells cultured in agarose gel with varying cell concentrations were then imaged. A time course study to track cell proliferation in the 3D construct was also carried out and finally a native tissue sample was imaged. For each sample multiple images were obtained by scanning the sample along the axis of detection and 3D maps reconstructed. The results obtained validated label-free SPIM as a viable approach for imaging cells in a 3D gel construct and native tissue. This technique has the potential use in a near-patient environment that can provide results quickly and be implemented in an easy to use manner to provide more information with improved spatial resolution and depth penetration than current approaches.

Keywords: bioimaging, optics, selective plane illumination microscopy, tissue imaging

Procedia PDF Downloads 236

Authors: Marcus Goh Tian Xi, Alicia Chua Si Wen, Eunice Gan Ghee Wu, Helen Bound, Lee Liang Ying, Albert Lee

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The Map of Dialogical Inquiry provides a conceptual look at the underlying nature of future-oriented skills. According to the Map, learning is learner-oriented, with conversational time shifted from teachers to learners, who play a strong role in deciding what and how they learn. For example, in courses operating on the principles of Dialogical Inquiry, learners were able to leave the classroom with a deeper understanding of the topic, broader exposure to differing perspectives, and stronger critical thinking capabilities, compared to traditional approaches to teaching. Despite its contributions to learning, the Map is grounded in a qualitative approach both in its development and its application for providing feedback to learners and educators. Studies hinge on openended responses by Map users, which can be time consuming and resource intensive. The present research is motivated by this gap in practicality by aiming to develop and validate a quantitative measure of the Map. In addition, a quantifiable measure may also strengthen applicability by making learning experiences trackable and comparable. The Map outlines eight learning aspects that learners should holistically engage. This research focuses on the Analysing aspect of learning. According to the Map, Analysing has four key components: liking or engaging in logic, using interpretative lenses, seeking patterns, and critiquing and deconstructing. Existing scales of constructs (e.g., critical thinking, rationality) related to these components were identified so that the current scale could adapt items from. Specifically, items were phrased beginning with an “I”, followed by an action phrase, to fulfil the purpose of assessing learners' engagement with Analysing either in general or in classroom contexts. Paralleling standard scale development procedure, the 26-item Analysing scale was administered to 330 participants alongside existing scales with varying levels of association to Analysing, to establish construct validity. Subsequently, the scale was refined and its dimensionality, reliability, and validity were determined. Confirmatory factor analysis (CFA) revealed if scale items loaded onto the four factors corresponding to the components of Analysing. To refine the scale, items were systematically removed via an iterative procedure, according to their factor loadings and results of likelihood ratio tests at each step. Eight items were removed this way. The Analysing scale is better conceptualised as unidimensional, rather than comprising the four components identified by the Map, for three reasons: 1) the covariance matrix of the model specified for the CFA was not positive definite, 2) correlations among the four factors were high, and 3) exploratory factor analyses did not yield an easily interpretable factor structure of Analysing. Regarding validity, since the Analysing scale had higher correlations with conceptually similar scales than conceptually distinct scales, with minor exceptions, construct validity was largely established. Overall, satisfactory reliability and validity of the scale suggest that the current procedure can result in a valid and easy-touse measure for each aspect of the Map.

Keywords: analytical thinking, dialogical inquiry, education, lifelong learning, pedagogy, scale development

Procedia PDF Downloads 79

Authors: Ekemini M. Okon, Reuben C. Okocha, Babatunde T. Adesina, Judith O. Ehigie, Babatunde M. Falana, Boluwape T. Okikiola

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Antimicrobial resistance (AMR) has evolved to become a significant threat to global public health and food safety. The development of AMR in animals has been associated with antimicrobial overuse. In recent years, the number of antimicrobials used in food animals such as fish and poultry has escalated. It, therefore, becomes imperative to understand the patterns of AMR in fish and poultry and map out future directions for better surveillance efforts. This study used the Preferred Reporting Items for Systematic reviews and Meta-Analyses(PRISMA) to assess the trend, patterns, and spatial distribution for AMR research in Egypt, Nigeria, and South Africa. A literature search was conducted through the Scopus and Web of Science databases in which published studies on AMR between 1989 and 2021 were assessed. A total of 172 articles were relevant for this study. The result showed progressive attention on AMR studies in fish and poultry from 2018 to 2021 across the selected countries. The period between 2018 (23 studies) and 2021 (25 studies) showed a significant increase in AMR publications with a peak in 2019 (28 studies). Egypt was the leading exponent of AMR research (43%, n=74) followed by Nigeria (40%, n=69), then South Africa (17%, n=29). AMR studies in fish received relatively little attention across countries. The majority of the AMR studies were on poultry in Egypt (82%, n=61), Nigeria (87%, n=60), and South Africa (83%, n=24). Further, most of the studies were on Escherichia and Salmonella species. Antimicrobials frequently researched were ampicillin, erythromycin, tetracycline, trimethoprim, chloramphenicol, and sulfamethoxazole groups. Multiple drug resistance was prevalent, as demonstrated by antimicrobial resistance patterns. In poultry, Escherichia coli isolates were resistant to cefotaxime, streptomycin, chloramphenicol, enrofloxacin, gentamycin, ciprofloxacin, oxytetracycline, kanamycin, nalidixic acid, tetracycline, trimethoprim/sulphamethoxazole, erythromycin, and ampicillin. Salmonella enterica serovars were resistant to tetracycline, trimethoprim/sulphamethoxazole, cefotaxime, and ampicillin. Staphylococcusaureus showed high-level resistance to streptomycin, kanamycin, erythromycin, cefoxitin, trimethoprim, vancomycin, ampicillin, and tetracycline. Campylobacter isolates were resistant to ceftriaxone, erythromycin, ciprofloxacin, tetracycline, and nalidixic acid at varying degrees. In fish, Enterococcus isolates showed resistance to penicillin, ampicillin, chloramphenicol, vancomycin, and tetracycline but sensitive to ciprofloxacin, erythromycin, and rifampicin. Isolated strains of Vibrio species showed sensitivity to florfenicol and ciprofloxacin, butresistance to trimethoprim/sulphamethoxazole and erythromycin. Isolates of Aeromonas and Pseudomonas species exhibited resistance to ampicillin and amoxicillin. Specifically, Aeromonashydrophila isolates showed sensitivity to cephradine, doxycycline, erythromycin, and florfenicol. However, resistance was also exhibited against augmentinandtetracycline. The findings constitute public and environmental health threats and suggest the need to promote and advance AMR research in other countries, particularly those on the global hotspot for antimicrobial use.

Keywords: antibiotics, antimicrobial resistance, bacteria, environment, public health

Procedia PDF Downloads 179

Authors: Suliman Al-Fayoumi, Sherri Amberg, Huafeng Zhou, Jack W. Singer, James P. Dean

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Pacritinib is an oral kinase inhibitor with specificity for JAK2, FLT3, IRAK1, and CSF1R. In clinical studies, pacritinib was well tolerated with clinical activity in patients with myelofibrosis. The most frequent adverse events (AEs) observed with pacritinib are gastrointestinal (diarrhea, nausea, and vomiting; mostly grade 1-2 in severity) and typically resolve within 2 weeks. A human ADME mass balance study demonstrated that pacritinib is predominantly cleared via hepatic metabolism and biliary excretion (>85% of administered dose). The major hepatic metabolite identified, M1, is not thought to materially contribute to the pharmacological activity of pacritinib. Hepatic diseases are known to impair hepatic blood flow, drug-metabolizing enzymes, and biliary transport systems and may affect drug absorption, disposition, efficacy, and toxicity. This phase 1 study evaluated the pharmacokinetics (PK) and safety of pacritinib and the M1 metabolite in study subjects with mild, moderate, or severe hepatic impairment (HI) and matched healthy subjects with normal liver function to determine if pacritinib dosage adjustments are necessary for patients with varying degrees of hepatic insufficiency. Study participants (aged 18-85 y) were enrolled into 4 groups based on their degree of HI as defined by Child-Pugh Clinical Assessment Score: mild (n=8), moderate (n=8), severe (n=4), and healthy volunteers (n=8) matched for age, BMI, and sex. Individuals with concomitant renal dysfunction or progressive liver disease were excluded. A single 400 mg dose of pacritinib was administered to all participants. Blood samples were obtained for PK evaluation predose and at multiple time points postdose through 168 h. Key PK parameters evaluated included maximum plasma concentration (Cmax), time to Cmax (Tmax), area under the plasma concentration time curve (AUC) from hour zero to last measurable concentration (AUC0-t), AUC extrapolated to infinity (AUC0-∞), and apparent terminal elimination half-life (t1/2). Following treatment, pacritinib was quantifiable for all study participants at 1 h through 168 h postdose. Systemic pacritinib exposure was similar between healthy volunteers and individuals with mild HI. However, there was a significant difference between those with moderate and severe HI and healthy volunteers with respect to peak concentration (Cmax) and plasma exposure (AUC0-t, AUC0-∞). Mean Cmax decreased by 47% and 57% respectively in participants with moderate and severe HI vs matched healthy volunteers. Similarly, mean AUC0-t decreased by 36% and 45% and mean AUC0-∞ decreased by 46% and 48%, respectively in individuals with moderate and severe HI vs healthy volunteers. Mean t1/2 ranged from 51.5 to 74.9 h across all groups. The variability on exposure ranged from 17.8% to 51.8% across all groups. Systemic exposure of M1 was also significantly decreased in study participants with moderate or severe HI vs. healthy participants and individuals with mild HI. These changes were not significantly dissimilar from the inter-patient variability in these parameters observed in healthy volunteers. All AEs were grade 1-2 in severity. Diarrhea and headache were the only AEs reported in >1 participant (n=4 each). Based on these observations, it is unlikely that dosage adjustments would be warranted in patients with mild, moderate, or severe HI treated with pacritinib.

Keywords: pacritinib, myelofibrosis, hepatic impairment, pharmacokinetics

Procedia PDF Downloads 290

Authors: Shakti S. Acharya, V. R. R. Medicherla, Rajeev Rawat, Komal Bapna, Deepnarayan Biswas, Khadija Ali, K. Maiti

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The discovery of invar effect in 35% Ni concentration Fe1-xNix alloy has stimulated enormous experimental and theoretical research. Elemental Fe and low Ni concentration Fe1-xNix alloys which possess body centred cubic (bcc) crystal structure at ambient temperature and pressure transform to hexagonally close packed (hcp) phase at around 13 GPa. Magnetic order was found to be absent at 11K for Fe92Ni8 alloy when subjected to a high pressure of 26 GPa. The density functional theoretical calculations predicted substantial hyperfine magnetic fields, but were not observed in Mossbaur spectroscopy. The bulk modulus of fcc Fe1-xNix alloys with Ni concentration more than 35%, is found to be independent of pressure. The magnetic moment of Fe is also found be almost same in these alloys from 4 to 10 GPa pressure. Fe1-xNix alloys exhibit a complex microstructure which is formed by a series of complex phase transformations like martensitic transformation, spinodal decomposition, ordering, mono-tectoid reaction, eutectoid reaction at temperatures below 400°C. Despite the existence of several theoretical models the field is still in its infancy lacking full knowledge about the anomalous properties exhibited by these alloys. Fe1-xNix alloys have been prepared by arc melting the high purity constituent metals in argon ambient. These alloys have annealed at around 3000C in vacuum sealed quartz tube for two days to make the samples homogeneous. These alloys have been structurally characterized by x-ray diffraction and were found to exhibit a transition from bcc to fcc for x > 0.3. Ni 2p core levels of the alloys have been measured using high resolution (0.45 eV) x-ray photoelectron spectroscopy. Ni 2p core level shifts to lower binding energy with respect to that of pure Ni metal giving rise to negative core level shifts (CLSs). Measured CLSs exhibit a linear dependence in fcc region (x > 0.3) and were found to deviate slightly in bcc region (x < 0.3). ESCA potential model fails correlate CLSs with site potentials or charges in metallic alloys. CLSs in these alloys occur mainly due to shift in valence bands with composition due to intra atomic charge redistribution.

Keywords: arc melting, core level shift, ESCA potential model, valence band

Procedia PDF Downloads 368

Authors: Mohammad M. Khan, Pankaj Agarwal

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The present investigation deals with the microstructures, mechanical and detailed wear characteristics of in situ TiC particles reinforced zinc aluminum-based metal matrix composites. The composites have been synthesized by liquid metallurgy route using vortex technique. The composite was found to be harder than the matrix alloy due to high hardness of the dispersoid particles therein. The former was also lower in ultimate tensile strength and ductility as compared to the matrix alloy. This could be explained to be due to the use of coarser size dispersoid and larger interparticle spacing. Reasonably uniform distribution of the dispersoid phase in the alloy matrix and good interfacial bonding between the dispersoid and matrix was observed. The composite exhibited predominantly brittle mode of fracture with microcracking in the dispersoid phase indicating effective easy transfer of load from matrix to the dispersoid particles. To study the wear behavior of the samples three different types of tests were performed namely: (i) sliding wear tests using a pin on disc machine under dry condition, (ii) high stress (two-body) abrasive wear tests using different combinations of abrasive media and specimen surfaces under the conditions of varying abrasive size, traversal distance and load, and (iii) low-stress (three-body) abrasion tests using a rubber wheel abrasion tester at various loads and traversal distances using different abrasive media. In sliding wear test, significantly lower wear rates were observed in the case of base alloy over that of the composites. This has been attributed to the poor room temperature strength as a result of increased microcracking tendency of the composite over the matrix alloy. Wear surfaces of the composite revealed the presence of fragmented dispersoid particles and microcracking whereas the wear surface of matrix alloy was observed to be smooth with shallow grooves. During high-stress abrasion, the presence of the reinforcement offered increased resistance to the destructive action of the abrasive particles. Microcracking tendency was also enhanced because of the reinforcement in the matrix. The negative effect of the microcracking tendency was predominant by the abrasion resistance of the dispersoid. As a result, the composite attained improved wear resistance than the matrix alloy. The wear rate increased with load and abrasive size due to a larger depth of cut made by the abrasive medium. The wear surfaces revealed fine grooves, and damaged reinforcement particles while subsurface regions revealed limited plastic deformation and microcracking and fracturing of the dispersoid phase. During low-stress abrasion, the composite experienced significantly less wear rate than the matrix alloy irrespective of the test conditions. This could be explained to be due to wear resistance offered by the hard dispersoid phase thereby protecting the softer matrix against the destructive action of the abrasive medium. Abraded surfaces of the composite showed protrusion of dispersoid phase. The subsurface regions of the composites exhibited decohesion of the dispersoid phase along with its microcracking and limited plastic deformation in the vicinity of the abraded surfaces.

Keywords: abrasive wear, liquid metallurgy, metal martix composite, SEM

Procedia PDF Downloads 140

Authors: Nicolas Bae, Theodore L. Karavasilis

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Increasingly, a large number of new and existing tall buildings are required to improve their resilient performance against strong winds and earthquakes to minimize direct, as well as indirect damages to society. Those advent stationary functions of tall building structures in metropolitan regions can be severely hazardous, in socio-economic terms, which also increase the requirement of advanced seismic performance. To achieve these progressive requirements, the seismic reinforcement for some old, conventional buildings have become enormously costly. The methods of increasing the buildings’ resilience against wind or earthquake loads have also become more advanced. Up to now, vibration control devices, such as the passive damper system, is still regarded as an effective and an easy-to-install option, in improving the seismic resilience of buildings at affordable prices. The main purpose of this paper is to examine 1) the optimization of the shape of visco plastic brace damper (VPBD) system which is one of hybrid damper system so that it can maximize its energy dissipation capacity in tall buildings against wind and earthquake. 2) the verification of the seismic performance of the visco plastic brace damper system in tall buildings; up to forty-storey high steel frame buildings, by comparing the results of Non-Linear Response History Analysis (NLRHA), with and without a damper system. The most significant contribution of this research is to introduce the optimized hybrid damper system that is adequate for high rise buildings. The efficiency of this visco plastic brace damper system and the advantages of its use in tall buildings can be verified since tall buildings tend to be affected by wind load at its normal state and also by earthquake load after yielding of steel plates. The modeling of the prototype tall building will be conducted using the Opensees software. Three types of modeling were used to verify the performance of the damper (MRF, MRF with visco-elastic, MRF with visco-plastic model) 22-set seismic records used and the scaling procedure was followed according to the FEMA code. It is shown that MRF with viscous, visco-elastic damper, it is superior effective to reduce inelastic deformation such as roof displacement, maximum story drift, roof velocity compared to the MRF only.

Keywords: tall steel building, seismic retrofit, viscous, viscoelastic damper, performance based design, resilience based design

Procedia PDF Downloads 182

Authors: Saadet Taşyürek Demirel, Halide Sena Koçyiğit, Rümeysa Fatma Çetin

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Celebrity worship, characterized by excessive admiration and devotion towards public figures, often mirrors elements of religious fervor. This study delves into the intricate connection between celebrity worship and religiosity, particularly within the Turkish cultural context, where Islamic values predominantly shape societal norms. The investigation involves the adaptation of the Celebrity Attitude Scale into Turkish and scrutinizes the interplay between young individuals' religiosity and their extreme adulation of celebrities. Additionally, the study explores potential moderating factors, such as age and gender, that might influence this relationship. A cohort of 197 young adults, aged 19 to 30, participated in this research, responding to self-administered questionnaires that assessed their attitudes towards celebrities using the adapted Celebrity Attitude Scale, along with their self-reported religiosity. The anticipated relationship between religiosity and celebrity worship is hypothesized to exhibit a non-linear pattern. Specifically, we expect religiosity to positively predict celebrity worship tendencies among individuals with minimal to moderate religiosity levels. Conversely, a negative association between religiosity and celebrity worship is expected to manifest among participants exhibiting moderate to high levels of religiosity. The findings of this study will contribute to the comprehension of the intricate dynamics between celebrity worship and religiosity, offering insights specifically within the Turkish cultural context. By shedding light on this relationship, the study aims to enhance our understanding of the multifaceted influences that shape individuals' perceptions and behaviors towards both celebrities and religious inclinations. Methodology of the study: A quantitative research will be conducted, where the factor analysis and correlational method will be used. The factor structure of the scale will be determined with exploratory and confirmatory factor analysis. The reliability, internal consistency, Objectives of the study: This study examines the relationship between religiosity and celebrity worship by young adults in the Turkish context. The other aim of the study is to assess the Turkish validity and reliability of the Celebrity Attitude Scale and contribute it to the literature. Main Contributions of the study: The study aims to introduce celebrity worship to Turkish literature, assess the Celebrity Attitude Scale's reliability in a Turkish sample, explore manifestations of celebrity worship, and examine its link to religiosity. This research addresses the lack of Turkish sources on celebrity worship and extends understanding of the concept.

Keywords: celebrity, worship, religiosity, god

Procedia PDF Downloads 64

Authors: Reza Ziaie Moayed, Saeideh Mohammadi

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Soft soil is used in many of civil engineering projects like coastal, marine and road projects. Because of low shear strength and stiffness of soft soils, large settlement and low bearing capacity will occur under superstructure loads. This will make the civil engineering activities more difficult and costlier. In the case of soft soils, improvement is a suitable method to increase the shear strength and stiffness for engineering purposes. In recent years, the artificial cementation of soil by cement and lime has been extensively used for soft soil improvement. Cement stabilization is a well-established technique for improving soft soils. Artificial cementation increases the shear strength and hardness of the natural soils. On the other hand, in soft soils, the use of piles to transfer loads to the depths of ground is usual. By using cement treated soil around the piles, high bearing capacity and low settlement in piles can be achieved. In the present study, lateral bearing capacity of short piles in cemented soils is investigated by numerical approach. For this purpose, three dimensional (3D) finite difference software, FLAC 3D is used. Cement treated soil has a strain hardening-softening behavior, because of breaking of bonds between cement agent and soil particle. To simulate such behavior, strain hardening-softening soil constitutive model is used for cement treated soft soil. Additionally, conventional elastic-plastic Mohr Coulomb constitutive model and linear elastic model are used for stress-strain behavior of natural soils and pile. To determine the parameters of constitutive models and also for verification of numerical model, the results of available triaxial laboratory tests on and insitu loading of piles in cement treated soft soil are used. Different parameters are considered in parametric study to determine the effective parameters on the bearing of the piles on cemented treated soils. In the present paper, the effect of various length and height of the artificial cemented area, different diameter and length of the pile and the properties of the materials are studied. Also, the effect of choosing a constitutive model for cemented treated soils in the bearing capacity of the pile is investigated.

Keywords: bearing capacity, cement-treated soils, FLAC 3D, pile

Procedia PDF Downloads 113

Authors: Zeenat Rupawalla, Nicole Robinson, Susanne Schmidt, Sijie Li, Selina Carruthers, Elodie Buisset, John Roles, Ben Hankamer, Juliane Wolf

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Agriculture has radically changed the global biogeochemical cycle of nitrogen (N). Fossil fuel-enabled synthetic N-fertiliser is a foundation of modern agriculture but applied to soil crops only use about half of it. To address N-pollution from cropping and the large carbon and energy footprint of N-fertiliser synthesis, new technologies delivering enhanced energy efficiency, decarbonisation, and a circular nutrient economy are needed. We characterised algae fertiliser (AF) as an alternative to synthetic N-fertiliser (SF) using empirical and modelling approaches. We cultivated microalgae in nutrient solution and modelled up-scaled production in nutrient-rich wastewater. Over four weeks, AF released 63.5% of N as ammonium and nitrate, and 25% of phosphorous (P) as phosphate to the growth substrate, while SF released 100% N and 20% P. To maximise crop N-use and minimise N-leaching, we explored AF and SF dose-response-curves with spinach in glasshouse conditions. AF-grown spinach produced 36% less biomass than SF-grown plants due to AF’s slower and linear N-release, while SF resulted in 5-times higher N-leaching loss than AF. Optimised blends of AF and SF boosted crop yield and minimised N-loss due to greater synchrony of N-release and crop uptake. Additional benefits of AF included greener leaves, lower leaf nitrate concentration, and higher microbial diversity and water holding capacity in the growth substrate. Life-cycle-analysis showed that replacing the most effective SF dosage with AF lowered the carbon footprint of fertiliser production from 2.02 g CO₂ (C-producing) to -4.62 g CO₂ (C-sequestering), with a further 12% reduction when AF is produced on wastewater. Embodied energy was lowest for AF-SF blends and could be reduced by 32% when cultivating algae on wastewater. We conclude that (i) microalgae offer a sustainable alternative to synthetic N-fertiliser in spinach production and potentially other crop systems, and (ii) microalgae biofertilisers support the circular nutrient economy and several sustainable development goals.

Keywords: bioeconomy, decarbonisation, energy footprint, microalgae

Procedia PDF Downloads 128

Authors: Yasmine Aridi, Lara Nasreddine, Maya Khalil, Arafat Tfayli, Anas Mugharbel, Farah Naja

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Breast cancer is the most commonly diagnosed cancer site among women worldwide and the second most common cause of cancer mortality. Breast cancer rates differ vastly between geographical areas, countries, and within the same country. In Lebanon, the proportion of breast cancer to all other sites of tumor is 38.2%; these rates are still lower than those observed worldwide, but remain the highest among Arab countries. Studies and evidence based reviews show a strong association between breast cancer development and prognosis and dietary habits, specifically the Mediterranean diet (MD). As such, the aim of this study is to examine dietary patterns and adherence to the MD among a sample of 182 breast cancer female patients in Beirut, Lebanon. Subjects were recruited from two major hospitals; a private medical center and a public hospital. All subjects were administered two questionnaires: socio- demographics and Mediterranean diet adherence. Five Mediterranean scores were calculated: MS, MSDPS, PMDI, PREDIMED and DDS. The mean age of the participants was 53.78 years. The overall adherence to the Mediterranean diet (MD) was low since the sample means of 3 out of the 5 calculated scores were less than the scores’ medians. Given that 4 out of the 5 Mediterranean scores significantly varied between the recruitment sites, women in the private medical center were found to adhere more to the MD. Our results also show that the majority of the sample population’s intakes are exceeding the recommendations for total and saturated fat, while meeting the requirements for fiber, EPA, DHA and Linolenic Acid. Participants in the private medical center were consuming significantly more calories, carbohydrates, fiber, sugar, Lycopene, Calcium, Iron and Folate and less fat. After conducting multivariate linear regression analyses, the following significant results were observed: positive associations between MD (CPMDI, PREDIMED) and monthly income & current state of health, while negative associations between MD (MSDPS, PREDIMED) and age & employment status. Our findings indicated a low overall adherence to the MD and identified factors associated with it; which suggests a need to address dietary habits among BC patients in Lebanon, specifically encouraging them to adhere to their traditional Mediterranean diet.

Keywords: Adherence, Breast cancer, Dietary patterns, Mediterranean diet, Nutrition

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Authors: Lotanna Ezeonu, Jason P. Robbins, Ziyu Tang, Xiaofang Yang, Bruce E. Koel, Simon G. Podkolzin

Abstract:

The interaction of organic molecules with metal surfaces is of interest in numerous technological applications, such as catalysis, bone replacement, and biosensors. Acetic acid is one of the main products of bio-oils produced from the pyrolysis of hemicellulosic feedstocks. However, their high oxygen content makes them unsuitable for use as fuels. Hydrodeoxygenation is a proven technique for catalytic deoxygenation of bio-oils. An understanding of the energetics and control of the bond-breaking sequences of biomass-derived oxygenates on metal surfaces will enable a guided optimization of existing catalysts and the development of more active/selective processes for biomass transformations to fuels. Such investigations have been carried out with the aid of ultrahigh vacuum and its concomitant techniques. The high catalytic activity of platinum in biomass-derived oxygenate transformations has sparked a lot of interest. We herein exploit infrared reflection absorption spectroscopy(IRAS), temperature-programmed desorption(TPD), and density functional theory(DFT) to study the adsorption and decomposition of acetic acid on a Pt(111) surface, which was then compared with Ni(111), a model non-noble metal. We found that acetic acid adsorbs molecularly on the Pt(111) surface, interacting through the lone pair of electrons of one oxygen atomat 90 K. At 140 K, the molecular form is still predominant, with some dissociative adsorption (in the form of acetate and hydrogen). Annealing to 193 K led to complete dehydrogenation of molecular acetic acid species leaving adsorbed acetate. At 440 K, decomposition of the acetate species occurs via decarbonylation and decarboxylation as evidenced by desorption peaks for H₂,CO, CO₂ and CHX fragments (x=1, 2) in theTPD.The assignments for the experimental IR peaks were made using visualization of the DFT-calculated vibrational modes. The results showed that acetate adsorbs in a bridged bidentate (μ²η²(O,O)) configuration. The coexistence of linear and bridge bonded CO was also predicted by the DFT results. Similar molecular acid adsorption energy was predicted in the case of Ni(111) whereas a significant difference was found for acetate adsorption.

Keywords: acetic acid, platinum, nickel, infared-absorption spectrocopy, temperature programmed desorption, density functional theory

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Authors: Navid Mirzaei Varzeghani, Mahmoud Saffarzadeh, Ali Naderan, Amirhossein Taheri

Abstract:

Countries are progressing, and the world's busiest airports see year-on-year increases in travel demand. Passenger acceptability of an airport depends on the airport's appeals, which may include one of these routes between the city and the airport, as well as the facilities to reach them. One of the critical roles of transportation planners is to predict future transportation demand so that an integrated, multi-purpose system can be provided and diverse modes of transportation (rail, air, and land) can be delivered to a destination like an airport. In this study, 356 questionnaires were filled out in person over six days. First, the attraction of business and non-business trips was studied using data and a linear regression model. Lower travel costs, a range of ages more significant than 55, and other factors are essential for business trips. Non-business travelers, on the other hand, have prioritized using personal vehicles to get to the airport and ensuring convenient access to the airport. Business travelers are also less price-sensitive than non-business travelers regarding airport travel. Furthermore, carrying additional luggage (for example, more than one suitcase per person) undoubtedly decreases the attractiveness of public transit. Afterward, based on the manner and purpose of the trip, the locations with the highest trip generation to the airport were identified. The most famous district in Tehran was District 2, with 23 visits, while the most popular mode of transportation was an online taxi, with 12 trips from that location. Then, significant variables in separation and behavior of travel methods to access the airport were investigated for all systems. In this scenario, the most crucial factor is the time it takes to get to the airport, followed by the method's user-friendliness as a component of passenger preference. It has also been demonstrated that enhancing public transportation trip times reduces private transportation's market share, including taxicabs. Based on the responses of personal and semi-public vehicles, the desire of passengers to approach the airport via public transportation systems was explored to enhance present techniques and develop new strategies for providing the most efficient modes of transportation. Using the binary model, it was clear that business travelers and people who had already driven to the airport were the least likely to change.

Keywords: multimodal transportation, demand modeling, travel behavior, statistical models

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Authors: Avadh Bihari

Abstract:

Corporate social responsibility (CSR) has become a global parameter to define corporates' ethical and responsible behaviour. It was a voluntary practice in India till 2013, driven by various guidelines, which has become a mandate since 2014 under the Companies Act, 2013. This has compelled the corporates to redesign their CSR strategies by bringing in structures, planning, accountability, and transparency in their processes with a mandate to 'comply or explain'. Based on the author's M.Phil. dissertation, this paper presents the changes in organisational practices and institutional mechanisms of third-sector organisations (TSOs) with the theoretical frameworks of institutionalism and co-optation. It became an interesting case as India is the only country to have a law on CSR, which is not only mandating the reporting but the spending too. The space of CSR in India is changing rapidly and affecting multiple institutions, in the context of the changing roles of the state, market, and TSOs. Several factors such as stringent regulation on foreign funding, mandatory CSR pushing corporates to look out for NGOs, and dependency of Indian NGOs on CSR funds have come to the fore almost simultaneously, which made it an important area of study. Further, the paper aims at addressing the gap in the literature on the effects of mandated CSR on the functioning of TSOs through the empirical and theoretical findings of this study. The author had adopted an interpretivist position in this study to explore changes in organisational practices from the participants' experiences. Data were collected through in-depth interviews with five corporate officials, eleven officials from six TSOs, and two academicians, located at Mumbai and Delhi, India. The findings of this study show the legislation has institutionalised CSR, and TSOs get co-opted in the process of implementing mandated CSR. Seventy percent of the corporates implement their CSR projects through TSOs in India; this has affected the organisational practices of TSOs to a large extent. They are compelled to recruit expert workforce, create new departments for monitoring & evaluation, communications, and adopt management practices of project implementation from corporates. These are attempts to institutionalise the TSOs so that they can produce calculated results as demanded by corporates. In this process, TSOs get co-opted in a struggle to secure funds and lose their autonomy. The normative, coercive, and mimetic isomorphisms of institutionalism come into play as corporates are mandated to take up CSR, thereby influencing the organisational practices of TSOs. These results suggest that corporates and TSOs require an understanding of each other's work culture to develop mutual respect and work towards the goal of sustainable development of the communities. Further, TSOs need to retain their autonomy and understanding of ground realities without which they become an extension of the corporate-funder. For a successful CSR project, engagement beyond funding is required from corporate, through their involvement and not interference. CSR-led community development can be structured by management practices to an extent, but cannot overshadow the knowledge and experience of TSOs.

Keywords: corporate social responsibility, institutionalism, organisational practices, third-sector organisations

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