Search results for: Phase change material

Authors: Mohamed Jaditager, Julie Lovisa, Nagaratnam Sivakugan

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The Port of Townsville conducts regular annual maintenance dredging to maintain depths of its harbor basin and approach channels for the navigational safety of the vessels against the natural accumulation of marine sediments. In addition to the regular maintenance dredging, the port undertakes emergency dredging in cases where large quantities of sediments are mobilized and deposited in port waters by cyclone or major flood events. The maintenance dredging material derived from the port may be disposed at sea or on land in accordance with relevant state and commonwealth regulations. For the land disposal, the dredged mud slurry is hydraulically placed into containment ponds and left to undergo sedimentation and self-weight consolidation to form fill material for land reclamation. This paper provides an overview of the maintenance dredging at the Port of Townsville and emphasis on maintenance dredging requirements, sediment quality, bathymetry, dredging methods used, and dredged material disposal options.

Keywords: consolidation, dredged material, maintenance dredging, marine sediments, sedimentation

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Authors: Feng-Tsung Cheng, Shu-Li Wang, Mei-Fang Wu, , Hui-Yu Chuang

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Due to the rapid development of modern technology, the widespread usage of the Internet makes business environment changing quickly. In order to be a leader in the global competitive market and to pursuit survive, “changing” becomes an unspoken rules need to follow for the company survival. The purpose of this paper is to build change model by using SWOT, strategy map, and balance scorecard, KPI and change management theory. The research findings indicate that organizational change plan formulated by the case company should require the employee to resist change factors and performance management system issues into consideration and must be set organizational change related programs, such as performance appraisal reward system, consulting and counseling mechanisms programs to improve motivation and reduce staff negative emotions. Then according to the model revised strategy maps and performance indicators proposed in this paper, such as strategy maps add and modify corporate culture, improve internal processes management, increase the growth rate of net income and other strategies. The performance indicators are based on strategy maps new and modified by adding net income growth rate, to achieve target production rate, manpower training achievement rates and other indicators, through amendments to achieve the company’s goal, be a leading brand of precision machinery industry.

Keywords: organizational change, SWOT analysis, strategy maps, performance indicators

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Authors: Sarah Noaman

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Utilizing renewable resources has become extensive solution for most problems in Egypt nowadays. It plays role in environmental issues such as energy crisis, lake of natural resources and climate change. This paper focuses on the importance of working with the key concepts of creating eco-friendly spaces in Egypt by using traditional perennial plants, such as Guadua bamboo as renewable resources in structures manufacture. Egypt is in critical need to search for alternative raw materials. Thus, this paper focuses on studying the usage of neglected yet affordable materials, such as Guadua bamboo in light weight structures and digital fabrication. Guadua bamboo has been cultivated throughout in tropical and subtropical areas. In Egypt, they exist in many rural areas where people try to control their growth by using pesticides as it serves no economic purpose. This paper aims to discuss the usage of Guadua bamboo either in its original state or after fabrication in the context of interior design and architecture. The results will show the applicability of using perennial plants as complementary materials in the manufacturing processes; also the conclusion will focus the lights on the importance of re-forming shallow water plants in interior design and architecture.

Keywords: digital fabrication, Guadua bamboo, zero-waste material, sustainable material, interior architecture

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Authors: Angelica Corcoran, Fredrik Lind, Pavleta Knutsson, Henrik Thunman

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Solid waste volumes are at current predominately deposited on landfill. Furthermore, the impending climate change requires new solutions for a sustainable future energy mix. Currently, solid waste is globally utilized to small extent as fuel during combustion for heat and power production. Due to its variable composition and size, solid waste is considered difficult to combust and requires a technology with high fuel flexibility. One of the commercial technologies used for combustion of such difficult fuels is circulating fluidized beds (CFB). In a CFB boiler, fine particles of a solid material are used as 'bed material', which is accelerated by the incoming combustion air that causes the bed material to fluidize. The chosen bed material has conventionally been silica sand with the main purpose of being a heat carrier, as it transfers heat released by the combustion to the heat-transfer surfaces. However, the release of volatile compounds occurs rapidly in comparison with the lateral mixing in the combustion chamber. To ensure complete combustion a surplus of air is introduced, which decreases the total efficiency of the boiler. In recent years, the concept of partly or entirely replacing the silica sand with an oxygen carrier as bed material has been developed. By introducing an oxygen carrier to the combustion chamber, combustion can be spread out both temporally and spatially in the boiler. Specifically, the oxygen carrier can take up oxygen from the combustion air where it is in abundance and release it to combustible gases where oxygen is in deficit. The concept is referred to as oxygen carrier aided combustion (OCAC) where the natural ore ilmenite (FeTiO3) has been the oxygen carrier used. The authors have validated the oxygen buffering ability of ilmenite during combustion of biomass in Chalmers 12-MWth CFB boiler in previous publications. Furthermore, the concept has been demonstrated on full industrial scale during combustion of municipal solid waste (MSW) in E.ON’s 75 MWth CFB boiler. The experimental campaigns have showed increased mass transfer of oxygen inside the boiler when combustion both biomass and MSW. As a result, a higher degree of burnout is achieved inside the combustion chamber and the plant can be operated at a lower surplus of air. Moreover, the buffer of oxygen provided by the oxygen carrier makes the system less sensitive to disruptions in operation. In conclusion, combusting difficult fuels with OCAC results in higher operation stability and an increase in boiler efficiency.

Keywords: OCAC, ilmenite, combustion, CFB

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Authors: Didik Sugiyanto

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Conditions that often occur in the framework of a particular vehicle at a car is a collision or collision with another object, an example of such damage is to the frame or chassis for the required design framework that is able to absorb impact energy. Characteristics of the material are influenced by the value of the stiffness of the material that need to be considered in choosing the material properties of the material. To obtain material properties that can be adapted to the experimental conditions tested the tensile and compression testing. In this study focused on the chassis at an angle of 150, 300, and 450. It is based on field studies that vehicle primarily for freight cars have a point of order light between 150 to 450. Research methods include design tools, design framework, procurement of materials and experimental tools, tool-making, the manufacture of the test framework, and the testing process, experiment is testing the power of the press to know the order. From this test obtained the maximum force on the corner of 150 was 569.76 kg at a distance of 16 mm, angle 300 is 370.3 kg at a distance of 15 mm, angle 450 is 391.71 kg at a distance of 28 mm. After reaching the maximum force the order will occur collapse, followed by a decrease in the next distance. It can be concluded that the greatest strain energy occurs at an angle of 150. So it is known that the frame at an angle of 150 produces the best level of security.

Keywords: buckling, collapse, body frame, vehicle

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Authors: Vishaka Agarwal

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Fashion is a dynamic entity. With globalisation, fashion is being retailed out to every corner of the world, and people are becoming fashion aware and adapting to the latest trends and look. In this scenario, the role of fashion in providing social change in society is strong. Every product that we use has a design element in it, and consumers prefer to buy those products. The aim of the paper is to look at the ways in which social change can be brought into society through ethical designing by designers taking into consideration the IPR issues. Review of research done by earlier researchers in studying the work done by designers to achieve social change in the society and also discussions with designers to understand the future plans looking at changing world scenario would be done. The paper concludes that fashion has a dynamic role to play in achieving social change in society, and designers are virtually controlling what people buy, wear, and consume globally. This paper would be useful to the social planners and designers in planning the future of society.

Keywords: fashion designers, ethics, intellectual property right, society

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Authors: Caroline Rocco, Feyza Karasu, Céline Croutxé-Barghorn, Xavier Allonas, Maxime Lecompère, Gérard Riess, Yujing Zhang, Catarina Esteves, Leendert van der Ven, Rolf van Benthem Gijsbertus de With

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Acrylates are widely used in UV-curing technology. Their high reactivity can, however, limit their conversion due to early vitrification. In addition, the free radical photopolymerization is known to be sensitive to oxygen inhibition leading to tacky surfaces. Although epoxides can lead to full polymerization, they are sensitive to humidity and exhibit low polymerization rate. To overcome the intrinsic limitations of both classes of monomers, Interpenetrating Polymer Networks (IPNs) can be synthesized. They consist of at least two cross linked polymers which are permanently entangled. They can be achieved under thermal and/or light induced polymerization in one or two steps approach. IPNs can display homogeneous to heterogeneous morphologies with various degrees of phase separation strongly linked to the monomer miscibility and also synthesis parameters. In this presentation, we synthesize UV-cured methacrylate - epoxide based IPNs with different chemical compositions in order to get a better understanding of their formation and phase separation. Miscibility before and during the photopolymerization, reaction kinetics, as well as mechanical properties and morphology have been investigated. The key parameters controlling the morphology and the phase separation, namely monomer miscibility and synthesis parameters have been identified. By monitoring the stiffness changes on the film surface, atomic force acoustic microscopy (AFAM) gave, in conjunction with polymerization kinetic profiles and thermomechanical properties, explanations and corroborated the miscibility predictions. When varying the methacrylate / epoxide ratio, it was possible to move from a miscible and highly-interpenetrated IPN to a totally immiscible and phase-separated one.

Keywords: investigation of properties and morphology, kinetics, phase separation, UV-cured IPNs

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Authors: Alireza Khaloo, Asghar Gholizadeh-Vayghan

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The present work focuses on the characterization of the physicochemical properties of kaolinitic clays in both raw and calcined (i.e., dehydroxylated) states. The properties investigated included the dehydroxylation temperature, chemical composition and crystalline phases, band types, kaolinite content, vitreous phase, and reactive and unreactive silica and alumina. The thermogravimetric analysis, X-ray diffractometry and infrared spectroscopy results suggest that full dehydroxylation takes place at 639°C, converting kaolinite to reactive metakaolinite (Si₂Al₂O₇). Application of higher temperatures up to 800 °C leads to complete decarbonation of the calcite phase, and the kaolinite converts to mullite at temperatures exceeding 957 °C. Calcination at 639°C was found to cause a 50% increase in the vitreous content of kaolin. Statistically meaningful increases in the reactivity of silica, alumina, calcite and sodium carbonate in kaolin were detected as a result of such thermal treatment. Such increases were found to be 11%, 47%, 240% and 10%, respectively. The ferrite phase, however, showed a 36% decline in reactivity. The proposed approach can be used as an analytical method to determine the viability of the source of kaolinite and proper physical and chemical modifications needed to enhance its suitability for geopolymer production.

Keywords: physicochemical properties, dehydroxylation, kaolinitic clays, kaolinite content, vitreous phase, reactivity

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Authors: N. Nowzari-Dalini, S. Sabbaghi

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Phenol is a hazardous material found in many industrial wastewaters. Photocatalytic degradation and furthermore catalyst doping are promising techniques in purpose of effective phenol removal, which have been studied comprehensively in this decade. In this study, Fe, Cr codoped TiO₂ were prepared by sol-gel method, and its photocatalytic activity was investigated through degradation of phenol under visible light. The catalyst was characterized by XRD, SEM, FT-IR, BET, and EDX. The results showed that nanoparticles possess anatase phase, and the average size of nanoparticles was about 21 nm. Also, photocatalyst has significant surface area. Effect of experimental parameters such as pH, irradiation time, pollutant concentration, and catalyst concentration were investigated by using Design-Expert^® software. 98% of phenol degradation was achieved after 6h of irradiation.

Keywords: doping, metals, sol-gel, titanium dioxide, wastewater

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Authors: Chathurika Sewwandi Kannangara, Jerome Carson

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The objective of this research is to identify strengths among the individuals with dyslexia and design a positive psychology intervention to support such individuals. Dyslexia is a combination of abilities and difficulties that affect the learning process in areas as such reading, spelling and writing. It is a persistent condition. The research aims to adapt positive psychology techniques to support individuals with dyslexia. Population of the research will be undergraduate and college level students with dyslexia. First phase of the study will be conducted on a sample of undergraduate and college level students with dyslexia in Bolton, UK. The concept of treatment in positive psychology is not only to fix the component just what is wrong, instead it is also to develop and construct on what is right in the individual. The first phase of the research aims to identify the signature strengths among the individuals with dyslexia using Interviews, Descriptions on personal experiences on ‘My life with Dyslexia’, and Values in Action (VIA) strength survey. In order to conduct the survey for individuals with dyslexia, the VIA survey has been hosted in a website which is solely developed in the form of dyslexia friendly context. Dyslexia friendly website for surveys had designed and developed following the British Dyslexia Association guidelines. The findings of the first phase would be utilized for the second phase of the research to develop the positive psychology intervention.

Keywords: dyslexia, signature strengths, positive psychology, qualitative study, learning difficulties

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Authors: David Halley, Tyra Oseng-Rees, Luca Pagano, Juan A Ferriz-Papi

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Recycled glass material is made from 100% recycled bottle glass and consumes less energy than re-melt technology. It also uses no additives in the manufacturing process allowing the recycled glass material, in principal, to go back to the recycling stream after end-of-use, contributing to the circular economy with a low ecological impact. The aim of this paper is to investigate the procedure for testing the recycled glass material for impact resistance, so it can be applied to pavements and other surfaces which are at risk of impact during service. A review of different impact test procedures for construction materials was undertaken, comparing methodologies and international standards applied to other materials such as natural stone, ceramics and glass. A drop weight impact testing machine was designed and manufactured in-house to perform these tests. As a case study, samples of the recycled glass material were manufactured with two different thicknesses and tested. The impact energy was calculated theoretically, obtaining results with 5 and 10 J. The results on the material were subsequently discussed. Improvements on the procedure can be made using high speed video technology to calculate velocity just before and immediately after the impact to know the absorbed energy. The initial results obtained in this procedure were positive although repeatability needs to be developed to obtain a correlation of results and finally be able to validate the procedure. The experiment with samples showed the practicality of this procedure and application to the recycled glass material impact testing although further research needs to be developed.

Keywords: construction materials, drop weight impact, impact testing, recycled glass

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Authors: Nishi Bhuvandas, P. V. Timbadiya, P. L. Patel, P. D. Porey

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Recent perceived climate variability raises concerns with unprecedented hydrological phenomena and extremes. Distribution and circulation of the waters of the Earth become increasingly difficult to determine because of additional uncertainty related to anthropogenic emissions. According to the sixth Intergovernmental Panel on Climate Change (IPCC) Technical Paper on Climate Change and water, changes in the large-scale hydrological cycle have been related to an increase in the observed temperature over several decades. Although many previous research carried on effect of change in climate on hydrology provides a general picture of possible hydrological global change, new tools and frameworks for modelling hydrological series with nonstationary characteristics at finer scales, are required for assessing climate change impacts. Of the downscaling techniques, dynamic downscaling is usually based on the use of Regional Climate Models (RCMs), which generate finer resolution output based on atmospheric physics over a region using General Circulation Model (GCM) fields as boundary conditions. However, RCMs are not expected to capture the observed spatial precipitation extremes at a fine cell scale or at a basin scale. Statistical downscaling derives a statistical or empirical relationship between the variables simulated by the GCMs, called predictors, and station-scale hydrologic variables, called predictands. The main focus of the paper is on the need for using statistical downscaling techniques for projection of local hydrometeorological variables under climate change scenarios. The projections can be then served as a means of input source to various hydrologic models to obtain streamflow, evapotranspiration, soil moisture and other hydrological variables of interest.

Keywords: climate change, downscaling, GCM, RCM

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Authors: Bhanu Pant, Sanjay H. Upadhyay

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Frequently, the upper stage of high-performance launch vehicles utilizes cryogenic tank-submerged pressurization gas bottles with high volume-to-weight efficiency to achieve a direct gain in the satellite payload. Titanium alloys, owing to their high specific strength coupled with excellent compatibility with various fluids, are the materials of choice for these applications. Amongst the Titanium alloys, there are two alloys suitable for cryogenic applications, namely Ti6Al4V-ELI and Ti5Al2.5Sn-ELI. The two-phase alpha-beta alloy Ti6Al4V-ELI is usable up to LOX temperature of 90K, while the single-phase alpha alloy Ti5Al2.5Sn-ELI can be used down to LHe temperature of 4 K. The high-pressure gas bottles submerged in the LH2 (20K) can store more amount of gas in as compared to those submerged in LOX (90K) bottles the same volume. Thus, the use of these alpha alloy gas bottles stored at 20K gives a distinct advantage with respect to the need for a lesser number of gas bottles to store the same amount of high-pressure gas, which in turn leads to a one-to-one advantage in the payload in the satellite. The cost advantage to the tune of 15000$/ kg of weight is saved in the upper stages, and, thereby, the satellite payload gain is expected by this change. However, the processing of alpha Ti5Al2.5Sn-ELI alloy gas bottles poses challenges due to the lower forgeability of the alloy and mode of qualification for the critical severe application environment. The present paper describes the processing and challenges/ solutions during the development of these advanced gas bottles for LH2 (20K) applications.

Keywords: titanium alloys, cryogenic gas bottles, alpha titanium alloy, alpha-beta titanium alloy

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Authors: Saheli Mitra, Ramesh Karri, Praveen K. Mylapalli, Arka. B. Dey, Gourav Bhattacharya, Gouriprasanna Roy, Syed M. Kamil, Surajit Dhara, Sunil K. Sinha, Sajal K. Ghosh

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The most well-known structures of lyotropic liquid crystalline systems are the two dimensional hexagonal phase of cylindrical micelles with a positive interfacial curvature and the lamellar phase of flat bilayers with zero interfacial curvature. In aqueous solution of surfactants, the concentration dependent phase transitions have been investigated extensively. However, instead of changing the surfactant concentrations, the local curvature of an aggregate can be altered by tuning the electrostatic interactions among the constituent molecules. Intermediate phases with non-uniform interfacial curvature are still unexplored steps to understand the route of phase transition from hexagonal to lamellar. Understanding such structural evolution in lyotropic liquid crystalline systems is important as it decides the complex rheological behavior of the system, which is one of the main interests of the soft matter industry. Sodium dodecyl sulfate (SDS) is an anionic surfactant and can be considered as a unique system to tune the electrostatics by cationic additives. In present study, imidazolium-based ionic liquids (ILs) with different number of carbon atoms in their single hydrocarbon chain were used as the additive in the aqueous solution of SDS. At a fixed concentration of total non-aqueous components (SDS and IL), the molar ratio of these components was changed, which effectively altered the electrostatic interactions between the SDS molecules. As a result, the local curvature is observed to modify, and correspondingly, the structure of the hexagonal liquid crystalline phases are transformed into other phases. Polarizing optical microscopy of SDS and imidazole-based-IL systems have exhibited different textures of the liquid crystalline phases as a function of increasing concentration of the ILs. The small angle synchrotron x-ray diffraction (SAXD) study has indicated the hexagonal phase of direct cylindrical micelles to transform to a rectangular phase at the presence of short (two hydrocarbons) chain IL. However, the hexagonal phase is transformed to a lamellar phase at the presence of long (ten hydrocarbons) chain IL. Interestingly, at the presence of a medium (four hydrocarbons) chain IL, the hexagonal phase is transformed to another hexagonal phase of direct cylindrical micelles through the lamellar phase. To the best of our knowledge, such a phase sequence has not been reported earlier. Even though the small angle x-ray diffraction study has revealed the lattice parameters of these phases to be similar to each other, their rheological behavior has been distinctly different. These rheological studies have shed lights on how these phases differ in their viscoelastic behavior. Finally, the packing parameters, calculated for these phases based on the geometry of the aggregates, have explained the formation of the self-assembled aggregates.

Keywords: lyotropic liquid crystals, polarizing optical microscopy, rheology, surfactants, small angle x-ray diffraction

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Authors: W. M. Ng, O. B. Iskender, L. Simonini, J. M. Gonzalez

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A multitude of factors, including mechanical imperfections of the deployment system and separation instance of satellites from launchers, oftentimes results in highly uncontrolled initial tumbling motion immediately after deployment. In particular, small satellites which are characteristically launched as a piggyback to a large rocket, are generally allocated a large time window to complete detumbling within the early orbit phase. Because of the saturation risk of the actuators, current algorithms are conservative to avoid draining excessive power in the detumbling phase. This work aims to enable time-optimal switching of control modes during the early phase, reducing the time required to transit from launch to sun-pointing mode for power budget conscious satellites. This assumes the usage of B-dot controller for detumbling and PD controller for pointing. Nonlinear Euler's rotation equations are used to represent the attitude dynamics of satellites and Commercial-off-the-shelf (COTS) reaction wheels and magnetorquers are used to perform the manoeuver. Simulation results will be based on a spacecraft attitude simulator and the use case will be for multiple orbits of launch deployment general to Low Earth Orbit (LEO) satellites.

Keywords: attitude control, detumbling, small satellites, spacecraft autonomy, time optimal control

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Authors: Reet Bishnoi

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Climate change poses a pressing global challenge, with far-reaching consequences for the planet's ecosystems and biodiversity. This abstract introduces the research topic, "Assessing the Impact of Climate Change on Biodiversity Hotspots: A Multidisciplinary Study," which delves into the intricate relationship between climate change and biodiversity in the world's most ecologically diverse regions. Biodiversity hotspots, characterized by their exceptionally high species richness and endemism, are under increasing threat due to rising global temperatures, altered precipitation patterns, and other climate-related factors. This research employs a multidisciplinary approach, incorporating ecological, climatological, and conservationist methodologies to comprehensively analyze the effects of climate change on these vital regions. Through a combination of field research, climate modelling, and ecological assessments, this study aims to elucidate the vulnerabilities of biodiversity hotspots and understand how changes in temperature and precipitation are affecting the diverse species and ecosystems that inhabit these areas. The research seeks to identify potential tipping points, assess the resilience of native species, and propose conservation strategies that can mitigate the adverse impacts of climate change on these critical regions. By illuminating the complex interplay between climate change and biodiversity hotspots, this research not only contributes to our scientific understanding of these issues but also informs policymakers, conservationists, and the public about the urgent need for coordinated efforts to safeguard our planet's ecological treasures. The outcomes of this multidisciplinary study are expected to play a pivotal role in shaping future climate policies and conservation practices, emphasizing the importance of protecting biodiversity hotspots for the well-being of the planet and future generations.

Keywords: climate change, biodiversity hotspots, ecological diversity, conservation, multidisciplinary study

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Authors: Zuliziana Suif, Nordila Ahmad, Sengheng Hul

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This paper evaluates the impact of climate change on suspended sediment changes in the Mekong River Basin. In this study, the distributed process-based sediment transport model is used to examine the potential impact of future climate on suspended sediment dynamic changes in the Mekong River Basin. To this end, climate scenarios from two General Circulation Model (GCMs) were considered in the scenario analysis. The simulation results show that the sediment load and concentration shows 0.64% to 69% increase in the near future (2041-2050) and 2.5% to 95% in the far future (2090- 2099). As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in sediment management. Overall, the changes in sediment load and concentration can have a great implication for related sediment management.

Keywords: climate change, suspended sediment, Mekong River Basin, GCMs

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Authors: Stephen Dankwa, Zheng Wenfeng, Xiaolu Li

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Climate change is recently gaining the attention of many countries across the world. Climate change, which is also known as global warming, referring to the increasing in average surface temperature has been a concern to the Environmental Protection Agency of Ghana. Recently, Ghana has become vulnerable to the effect of the climate change as a result of the dependence of the majority of the population on agriculture. The clearing down of trees to grow crops and burning of charcoal in the country has been a contributing factor to the rise in temperature nowadays in the country as a result of releasing of carbon dioxide and greenhouse gases into the air. Recently, petroleum stations across the cities have been on fire due to this climate changes and which have position Ghana in a way not able to withstand this climate event. As a result, the significant of this research paper is to project how the rise in the average surface temperature will be like at the end of the mid-21st century when agriculture and deforestation are allowed to continue for some time in the country. This study uses the Coupled Modeled Intercomparison Project phase 5 (CMIP5) experiment RCP 8.5 model output data to monitor the future climate changes from 2041-2050, at the end of the mid-21st century over the ten (10) major cities (Accra, Bolgatanga, Cape Coast, Koforidua, Kumasi, Sekondi-Takoradi, Sunyani, Ho, Tamale, Wa) in Ghana. In the models, Support Vector Machine and Random forest, where the cities as a function of heat wave metrics (minimum temperature, maximum temperature, mean temperature, heat wave duration and number of heat waves) assisted to provide more than 50% accuracy to predict and monitor the pattern of the surface air temperature. The findings identified were that the near-surface air temperature will rise between 1°C-2°C (degrees Celsius) over the coastal cities (Accra, Cape Coast, Sekondi-Takoradi). The temperature over Kumasi, Ho and Sunyani by the end of 2050 will rise by 1°C. In Koforidua, it will rise between 1°C-2°C. The temperature will rise in Bolgatanga, Tamale and Wa by 0.5°C by 2050. This indicates how the coastal and the southern part of the country are becoming hotter compared with the north, even though the northern part is the hottest. During heat waves from 2041-2050, Bolgatanga, Tamale, and Wa will experience the highest mean daily air temperature between 34°C-36°C. Kumasi, Koforidua, and Sunyani will experience about 34°C. The coastal cities (Accra, Cape Coast, Sekondi-Takoradi) will experience below 32°C. Even though, the coastal cities will experience the lowest mean temperature, they will have the highest number of heat waves about 62. Majority of the heat waves will last between 2 to 10 days with the maximum 30 days. The surface temperature will continue to rise by the end of the mid-21st century (2041-2050) over the major cities in Ghana and so needs to be addressed to the Environmental Protection Agency in Ghana in order to mitigate this problem.

Keywords: climate changes, CMIP5, Ghana, heat waves, random forest, SVM

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Authors: Khalida Douibi, Rodrigo Balp, Solène Le Bars

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In the medical field, applications related to human experiments are frequently linked to reduced samples size, which makes the training of machine learning models quite sensitive and therefore not very robust nor generalizable. This is notably the case in Brain-Computer Interface (BCI) studies, where the sample size rarely exceeds 20 subjects or a few number of trials. To address this problem, several resampling approaches are often used during the data preparation phase, which is an overly critical step in a data science analysis process. One of the naive approaches that is usually applied by data scientists consists in the transformation of the entire database before the resampling phase. However, this can cause model’ s performance to be incorrectly estimated when making predictions on unseen data. In this paper, we explored the effect of data leakage observed during our BCI experiments for device control through the real-time classification of SSVEPs (Steady State Visually Evoked Potentials). We also studied potential ways to ensure optimal validation of the classifiers during the calibration phase to avoid overfitting. The results show that the scaling step is crucial for some algorithms, and it should be applied after the resampling phase to avoid data leackage and improve results.

Keywords: data leackage, data science, machine learning, SSVEP, BCI, overfitting

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Authors: Abram Zoltan

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Over the past hundred years, human activities, particularly the burning of fossil fuels, have released enough carbon dioxide and other greenhouse gases to dissipate additional heat into the lower atmosphere and affect the global climate. Climate change affects many social and environmental determinants of health: clean air, safe drinking water, and adequate food. Our aim is to draw attention to the effects of climate change on the health and health care system. Improving climate awareness and the knowledge related to climate change's health impacts are essential among medical students and practicing medical doctors. Therefore, in their everyday practice, they also need some assistance and up-to-date knowledge of how climate change can endanger human health and deal with these novel health problems. Our activity, based on the cooperation of more universities, aims to develop new curriculum outlines and learning materials on climate change's health impacts for medical schools. Special attention is intended to pay to the possible preventative measures against these impacts. For all of this, the project plans to create new curriculum outlines and learning materials for medical students, elaborate methodological guidelines and create training materials for medical doctors' postgraduate learning programs. The target groups of the project are medical students, educational staff of medical schools and universities, practicing medical doctors with special attention to the general practitioners and family doctors. We had searched various surveys, domestic and international studies about the effects of climate change and statistical estimation of the possible consequences. The health effects of climate change can be measured only approximately by considering only a fraction of the potential health effects and assuming continued economic growth and health progress. We can estimate that climate change is expected to cause about 250,000 more deaths. We conclude that climate change is one of the most serious problems of the 21st century, affecting all populations. In the short- to medium-term, the health effects of climate change will be determined mainly by human vulnerability. In the longer term, the effects depend increasingly on the extent to which transformational action is taken now to reduce emissions. We can contribute to reducing environmental pollution by raising awareness and by educating the population.

Keywords: climate change, health impacts, medical students, education

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Authors: Insiya Bhalloo

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It is quite common in the Muslim faith for non-Arabic speakers to be able to convert written Arabic, especially Quranic Arabic, into a phonological code without significant semantic or syntactic knowledge. This is due to prior experience learning to read the Quran (a religious text written in Classical Arabic), from a very young age such as via enrolment in Quranic Arabic classes. As compared to native speakers of Arabic, these Arabic readers do not have a comprehensive morpho-syntactic knowledge of the Arabic language, nor can understand, or engage in Arabic conversation. The study seeks to investigate whether mere phonological experience (as indicated by the Arabic readers’ experience with Arabic phonology and the sound-system) is sufficient to cause phonological-interference during word recognition of previously-heard words, despite the participants’ non-native status. Both native speakers of Arabic and non-native speakers of Arabic, i.e., those individuals that learned to read the Quran from a young age, will be recruited. Each experimental session will include two phases: An exposure phase and a test phase. During the exposure phase, participants will be presented with Arabic words (n=40) on a computer screen. Half of these words will be common words found in the Quran while the other half will be words commonly found in Modern Standard Arabic (MSA) but either non-existent or prevalent at a significantly lower frequency within the Quran. During the test phase, participants will then be presented with both familiar (n = 20; i.e., those words presented during the exposure phase) and novel Arabic words (n = 20; i.e., words not presented during the exposure phase. ½ of these presented words will be common Quranic Arabic words and the other ½ will be common MSA words but not Quranic words. Moreover, ½ the Quranic Arabic and MSA words presented will be comprised of nouns, while ½ the Quranic Arabic and MSA will be comprised of verbs, thereby eliminating word-processing issues affected by lexical category. Participants will then determine if they had seen that word during the exposure phase. This study seeks to investigate whether long-term phonological memory, such as via childhood exposure to Quranic Arabic orthography, has a differential effect on the word-recognition capacities of native Arabic speakers and Arabic readers; we seek to compare the effects of long-term phonological memory in comparison to short-term phonological exposure (as indicated by the presentation of familiar words from the exposure phase). The researcher’s hypothesis is that, despite the lack of lexical knowledge, early experience with converting written Quranic Arabic text into a phonological code will help participants recall the familiar Quranic words that appeared during the exposure phase more accurately than those that were not presented during the exposure phase. Moreover, it is anticipated that the non-native Arabic readers will also report more false alarms to the unfamiliar Quranic words, due to early childhood phonological exposure to Quranic Arabic script - thereby causing false phonological facilitatory effects.

Keywords: modern standard arabic, phonological facilitation, phonological memory, Quranic arabic, word recognition

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Authors: Alexander N. Pisarchik, Parth Chholak

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Intrinsic brain noise was estimated via magneto-encephalograms (MEG) recorded during perception of flickering visual stimuli with frequencies of 6.67 and 8.57 Hz. First, we measured the mean phase difference between the flicker signal and steady-state event-related field (SSERF) in the occipital area where the brain response at the flicker frequencies and their harmonics appeared in the power spectrum. Then, we calculated the probability distribution of the phase fluctuations in the regions of frequency locking and computed its kurtosis. Since kurtosis is a measure of the distribution’s sharpness, we suppose that inverse kurtosis is related to intrinsic brain noise. In our experiments, the kurtosis value varied among subjects from K = 3 to K = 5 for 6.67 Hz and from 2.6 to 4 for 8.57 Hz. The majority of subjects demonstrated leptokurtic kurtosis (K < 3), i.e., the distribution tails approached zero more slowly than Gaussian. In addition, we found a strong correlation between kurtosis and brain complexity measured as the correlation dimension, so that the MEGs of subjects with higher kurtosis exhibited lower complexity. The obtained results are discussed in the framework of nonlinear dynamics and complex network theories. Specifically, in a network of coupled oscillators, phase synchronization is mainly determined by two antagonistic factors, noise, and the coupling strength. While noise worsens phase synchronization, the coupling improves it. If we assume that each neuron and each synapse contribute to brain noise, the larger neuronal network should have stronger noise, and therefore phase synchronization should be worse, that results in smaller kurtosis. The described method for brain noise estimation can be useful for diagnostics of some brain pathologies associated with abnormal brain noise.

Keywords: brain, flickering, magnetoencephalography, MEG, visual perception, perception time

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Authors: Halima Kilungu, Munishi P. K. T., Happiness Jackson Nko

Abstract:

Wetlands contribute significantly to the national economy. Nevertheless, urban wetlands in Tanzania have been taken for granted; many have been converted into waste disposal areas and settlements despite their substantial role in climate-change flood attenuation and livelihood. This is due to the lacking informing assessments from a socio-economic perspective. This study assesses the contribution of urban wetlands to the livelihood of marginalised communities in Dar es Salaam City, Tanzania. Specifically, the study assesses the an extent and nature of change in wetlands in Dar es Salaam City for the past 30 years using the land-use land-cover change approach and the contribution of wetlands to livelihood using questionnaires. The results show that the loss of wetlands in Dar es Salaam is high to extent that will likely jeopardise their future contributions to livelihood. The results inform decision-makers on the importance of wise use of Urban Wetlands and conservation to improving livelihood for urban dwellers.

Keywords: wetlands, tanzania, dar es salaam, climate-change, and wetlands, livelihood

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Authors: Hannah O'Sullivan, Esther Quinn

Abstract:

Purpose: The Architectural, Engineering, and Construction (AEC) industry has historically struggled to adapt to change. Although the ability to innovate and successfully implement organizational change has been demonstrated to be critical in achieving a sustainable competitive advantage in the industry, many AEC organizations continue to struggle when affecting organizational change. One prominent area of organizational change that presents many challenges in the industry is the adoption of new forms of technology, for example, Building Information Modelling (BIM). Certain Organisational Change Management (OCM) practices have been proven to be effective in supporting organizations to adopt change, but little research has been carried out on diverging employee attitudes to change relative to their roles within the organization. The purpose of this research study is to examine how OCM practices influence employee attitudes to change when adopting new forms of technology and to analyze the diverging employee perspectives within an organization on the importance of different OCM strategies. Methodology: Adopting an interview-based approach, a case study was carried out on a large-sized, prominent Irish construction organization who are currently adopting a new technology platform for its projects. Qualitative methods were used to gain insight into differing perspectives on the utilization of various OCM practices and their efficacy when adopting a new form of technology on projects. Change agents implementing the organizational change gave insight into their intentions with the technology rollout strategy, while other employees were interviewed to understand how this rollout strategy was received and the challenges that were encountered. Findings: The results of this research study are currently being finalized. However, it is expected that employees in different roles will value different OCM practices above others. Findings and conclusions will be determined within the coming weeks. Value: This study will contribute to the body of knowledge relating to the introduction of new technologies, including BIM, to AEC organizations. It will also contribute to the field of organizational change management, providing insight into methods of introducing change that will be most effective for different employees based on their roles and levels of experience within the industry. The focus of this study steers away from traditional studies of the barriers to adopting BIM in its first instance at an organizational level and centers on the direct effect on employees when a company changes the technology platform being used.

Keywords: architectural, engineering, and construction (AEC) industry, Building Information Modelling, case study, challenges, employee perspectives, organisational change management.

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Authors: Karolina Kowalczyk-Skoczylas

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The hybrid SPD process called DRECE (Dual Rolls Equal Channel Extrusion) combines the concepts of ECAP method and CONFORM extrusion, and is intended for processing sheet-metal workpieces. The material in the fоrm оf a metal strip is subjected tо plastic defоrmation by passing thrоugh the shaping tоol at a given angle α. Importantly, in this process the dimensions of the metal strip dо nоt change after the pass is cоmpleted. Subsequent DRECE passes allоw fоr increasing the effective strain in the tested material. The methоd has a significant effect оn the micrоstructure and mechanical prоperties оf the strip. The experimental tests have been conducted on the unconventional DRECE device in VŠB Ostrava, the Czech Republic. The DC03 steel strips have been processed in several passes - up to six. Then, both Erichsen cupping tests as well as static tensile tests have been performed to evaluate the effect of DRECE process on drawability, plastic anisotropy and mechanical properties of the investigated steel. Both yield strength and ultimate tensile strength increase significantly after consecutive passes. Drawability decreases slightly after the first and second pass. Then it stabilizes on a reasonably high level, which means that the steel is characterized by useful drawability for technological processes. It was investigated in the material is characterized by a normal anisotropy. In the microstructure, an intensification of the development of microshear bands and their mutual intersection is observed, which leads to the fragmentation of the grain into smaller volumes and, consequently, to the formation of an ultrafine grained structure. "The project was co-financed by the European Union within the programme "The European Funds for Śląsk (Silesia) 2021-2027".

Keywords: SPD process, low carbon steel, mechanical properties, plastic deformation, microstructure evolution

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Authors: Mina Esmi Jahromi, Mehdi Khiadani

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Vertical water jets discharging into free surface turbulent cross flows result in the ingression of a large amount of air in the body of water and form a region of two-phase air-water flow with a considerable interfacial area. This research presents an experimental study of the two-phase bubbly flow using image processing technique. The air ingression and the trajectories of bubble swarms under different experimental conditions are evaluated. The rate of air entrainment and the bubble characteristics such as penetration depth, and dispersion pattern were found to be affected by the most influential parameters of water jet and cross flow including water jet-to-crossflow velocity ratio, water jet falling height, and cross flow depth. This research improves understanding of the underwater flow structure due to the water jet impingement in crossflow and advances the practical applications of water jets such as artificial aeration, circulation, and mixing where crossflow is present.

Keywords: air entrainment, image processing, jet in cross flow, two-phase flow

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Authors: Solmaz Jahed Shiran, Elizabeth Taylor, John Hearne

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Over the past decade a growing body of research, known as mobility biography approach has emerged that focuses on changes in travel behaviour over the life course of individuals. Mobility biographies suggest that changes in travel behaviour have a certain relation to important key events in life courses such as residential relocation, workplace changes, marriage and the birth of children. Taking this approach as the theoretical background, this study uses data from the Household, Income and Labor Dynamics Survey in Australia (HILDA) to model a set of life course events and their interaction with the commute time. By analysing longitudinal data, it is possible to assign different key events during the life course to change a person’s travel behaviour. Changes in the journey-to-work travel time is used as an indication of travel behaviour change in this study. Results of a linear regression model for change in commute time show a significant influence from socio-demographic factors like income and age, the previous home-to-work commute time and remoteness of the residence. Residential relocation and job change have significant influences on commute time. Other life events such as birth of a child, marriage and divorce or separation have also a strong impact on commute time change. Overall, the research confirms previous studies of links between life course events and travel behaviour.

Keywords: life course events, residential mobility, travel behaviour, commute time, job change

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Authors: Mitchell Gohnert, Ryan Bradley

Abstract:

This paper reviews some fundamental concepts of structural optimization, which are based on the type of materials used in construction and the shape of the structure. The first step in structural optimization is to break down all internal forces in a structure into fundamental stresses, which are tensions and compressions. Knowing the stress patterns directs our selection of structural shapes and the most appropriate type of construction material. In our selection of materials, it is essential to understand all construction materials have flaws, or micro-cracks, which reduce the capacity of the material, especially when subjected to tensions. Because of material defects, many construction materials perform significantly better when subjected to compressive forces. Structures are also more efficient if bending moments are eliminated. Bending stresses produce high peak stresses at each face of the member, and therefore, substantially more material is required to resist bending. The shape of the structure also has a profound effect on stress levels. Stress may be reduced dramatically by simply changing the shape. Catenary, triangular and linear shapes are the fundamental structural forms to achieve optimal stress flow. If the natural flow of stress matches the shape of the structures, the most optimal shape is determined.

Keywords: arches, economy of stresses, material strength, optimization, shells

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Authors: Supattra Kanchanopast

Abstract:

This article presents the process of change for innovation in the Thai public sector in order to create higher client satisfaction. Change management should concern the potentiality of the change agent or leader, the long-term vision or policy (political side) of the organization, the communication within the organization, suitable organizational culture and structure, preparedness of the personnel, and the fitness of the reward system. Sustaining innovation creation is not sophisticated, as traditionally believed. A basic management principle of identifying clarified and motivating goals needs to be followed by creating support systems after implementation and by ensuring the stakeholders’ benefit, derived from the innovation projects. Finally, creating an amiable atmosphere among the practitioners, including effective evaluation and reward schemes, will support the innovation. However, none of these will ever take place unless support is gained from the leaders of those organizations, and from the staff and clients involved also as well.

Keywords: change management, client satisfaction, innovation management, Thai public sector

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Authors: K. Eryilmaz, G. Mercanoglu

Abstract:

Aim: Purification of the final product, which is the last step in the synthesis of lanthanide-labeled peptide compounds, can be accomplished by different methods. Among these methods, the two most commonly used methods are C18 solid phase extraction (SPE) and weak cation exchanger cartridge elution. SPE C18 solid phase extraction method yields high purity final product, while elution from the weak cation exchanger cartridge is pH dependent and ineffective in removing colloidal impurities. The aim of this work is to develop an additional purification method for the lanthanide-labeled peptide compound in cases where the desired radionuclidic and radiochemical purity of the final product can not be achieved because of pH problem or colloidal impurity. Material and Methods: For colloidal impurity formation, 3 mL of water for injection (WFI) was added to 30 mCi of 177LuCl3 solution and allowed to stand for 1 day. 177Lu-DOTATATE was synthesized using EZAG ML-EAZY module (10 mCi/mL). After synthesis, the final product was mixed with the colloidal impurity solution (total volume:13 mL, total activity: 40 mCi). The resulting mixture was trapped in SPE-C18 cartridge. The cartridge was washed with 10 ml saline to remove impurities to the waste vial. The product trapped in the cartridge was eluted with 2 ml of 50% ethanol and collected to the final product vial via passing through a 0.22μm filter. The final product was diluted with 10 mL of saline. Radiochemical purity before and after purification was analysed by HPLC method. (column: ACE C18-100A. 3µm. 150 x 3.0mm, mobile phase: Water-Acetonitrile-Trifluoro acetic acid (75:25:1), flow rate: 0.6 mL/min). Results: UV and radioactivity detector results in HPLC analysis showed that colloidal impurities were completely removed from the 177Lu-DOTATATE/ colloidal impurity mixture by purification method. Conclusion: The improved purification method can be used as an additional method to remove impurities that may result from the lanthanide-peptide synthesis in which the weak cation exchange purification technique is used as the last step. The purification of the final product and the GMP compliance (the final aseptic filtration and the sterile disposable system components) are two major advantages.

Keywords: lanthanide, peptide, labeling, purification, radionuclide, radiopharmaceutical, synthesis

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