Search results for: internal heat sources

Authors: Timothy Fwa Yerima

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This paper evaluates the development of human rights jurisprudence in Africa by the ECOWAS Court of Justice. It traces that though ECOWAS was not established with the aim of promoting and protecting human rights as the African Court of Human and Peoples’ Rights, no doubt, the 1991 ECOWAS Court Protocol and the 1993 ECOWAS Revised Treaty give the ECOWAS Court its human rights mandate. The paper, however, points out that despite the availability of these two Laws, the ECOWAS Court had difficulty in its human rights mandate, in view of the twin problems of lack of access to the Court by private parties and personal jurisdiction of the Court to entertain cases filed by private parties. The paper considers the 2005 Supplementary Protocol, not only as an effective legal framework in West African Sub-Region that tackles these problems in human rights cases but also a strong foundation upon which the Court has been developing human rights jurisprudence in Africa through the interpretation and application of this Law and other sources of Law of the Court. After a thorough analysis of some principles laid down by the ECOWAS Court so far, the paper observes that human rights jurisprudence in Africa is growing rapidly; depicting that though the ECOWAS Court initially had difficulty in its human rights mandate, today it has a bright and visionary landing. The paper concludes that West African Sub-Region will witness a more effective performance of the ECOWAS Court if some of its challenges are tackled.

Keywords: access, African human rights, ECOWAS court of justice, jurisprudence, personal jurisdiction

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Authors: Neha Sharma, Kanthi K. Kondepudi, Naveen Gupta

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Phytases are phytate specific phosphatases catalyzing the step-wise dephosphorylation of phytate, which acts as an anti-nutritional factor in food due to its strong binding capacity to minerals. In recent years microbial phytases have been explored for improving nutritional quality of food. But the major limitation is acceptability of phytases from these microorganisms. Therefore, efforts are being made to isolate organisms which are generally regarded as safe for human consumption such as Lactic Acid Bacteria (LAB). Phytases from these organisms will have an edge over other phytase sources due to its probiotic attributes. Only few LAB have been reported to give phytase activity that too is generally seen as intracellular. LAB producing extracellular phytase will be more useful as it can degrade phytate more effectively. Moreover, enzyme from such isolate will have application in food processing also. Only few species of Lactobacillus producing extracellular phytase have been reported so far. This study reports the isolation of a probiotic strain of Lactobacillus fermentum spp KA1 which produces extracellular phytase. Conditions for the optimal production of phytase have been optimized and the enzyme production resulted in an approximately 13-fold increase in yield. The phytate degradation potential of extracellular phytase in rice bran has been explored and conditions for optimal degradation were optimized. Under optimal conditions, there was 43.26% release of inorganic phosphate and 6.45% decrease of phytate content.

Keywords: Lactobacillus, phytase, phytate reduction, rice bran

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Authors: Jerzy Ejsmont, Beata Świeczko-Żurek, Grzegorz Ronowski

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Gas cylinders in general and particularly cylinders containing acetylene constitute a great potential danger for fire and rescue services involved in salvage operations. Experiments show that gas cylinders with acetylene, oxygen, hydrogen, CNG, LPG or CO2 may blow after short exposition to heat with very destructive effect as fragments of blown cylinder may fly even several hundred meters. In the case of acetylene, the explosion may occur also several hours after the cylinder is cooled down. One of the possible neutralization procedures that in many cases may be used to prevent explosions is shooting dangerous cylinders by rifle bullets. This technique is used to neutralize acetylene cylinders in a few European countries with great success. In Poland research project 'BLOW' was launched in 2014 with the aim to investigate phenomena related to fire influence on industrial and home used cylinders and to evaluate usefulness of the shooting technique. All together over 100 gas cylinders with different gases were experimentally tested at the military blasting grounds and in shelters. During the experiments cylinder temperature and pressure were recorded. In the case of acetylene that is subjected to thermal decomposition also concentration of hydrogen was monitored. Some of the cylinders were allowed to blow and others were shot by snipers. It was observed that shooting hot cylinders has never created more dangerous situations than letting the cylinders to explode spontaneously. In a great majority of cases cylinders that were punctured by bullets released gas in a more or less violent but relatively safe way. The paper presents detailed information about experiments and presents particularities of behavior of cylinders containing different gases. Extensive research was also done in order to select bullets that may be safely and efficiently used to puncture different cylinders. The paper shows also results of those experiments as well as gives practical information related to techniques that should be used during shooting.

Keywords: fire, gas cylinders, neutralization, shooting

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Authors: Ravinder Kaur

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Introduction Global cerebrovascular reactivity (CVR) mapping is a promising clinical assessment for stress-testing the brain using physiological challenges, such as CO₂, to elicit changes in perfusion. It enables real-time assessment of cerebrovascular integrity and health. Conventional imaging approaches solely use steady-state parameters, like cerebral blood flow (CBF), to evaluate the integrity of the resting parenchyma and can erroneously show a healthy brain at rest, despite the underlying pathogenesis in the presence of cerebrovascular disease. Conversely, coupling CO₂ inhalation with phase-contrast MRI neuroimaging interrogates the capacity of the vasculature to respond to changes under stress. It shows promise in providing prognostic value as a novel health marker to measure neurovascular function in disease and to detect early brain vasculature dysfunction. Objective This exploratory study was established to:(a) quantify the CBF response to CO₂ in hypocapnia and hypercapnia,(b) evaluate disparities in CVR between internal carotid (ICA) and vertebral artery (VA), and (c) assess sex-specific variation in CVR. Methodology Phase-contrast MRI was employed to measure the cerebrovascular reactivity to CO₂ (±10 mmHg). The respiratory interventions were presented using the prospectively end-tidal targeting RespirActTM Gen3 system. Post-processing and statistical analysis were conducted. Results In 9 young, healthy subjects, the CBF increased from hypocapnia to hypercapnia in all vessels (4.21±0.76 to 7.20±1.83 mL/sec in ICA, 1.36±0.55 to 2.33±1.31 mL/sec in VA, p < 0.05). The CVR was quantitatively higher in ICA than VA (slope of linear regression: 0.23 vs. 0.07 mL/sec/mmHg, p < 0.05). No statistically significant effect was observed in CVR between male and female (0.25 vs 0.20 mL/sec/mmHg in ICA, 0.09 vs 0.11 mL/sec/mmHg in VA, p > 0.05). Conclusions The principal finding in this investigation validated the modulation of CBF by CO₂. Moreover, it has indicated that regional heterogeneity in hemodynamic response exists in the brain. This study provides scope to standardize the quantification of CVR prior to its clinical translation.

Keywords: cerebrovascular disease, neuroimaging, phase contrast MRI, cerebrovascular reactivity, carbon dioxide

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Authors: Moustafa M. S. Sanad

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The worsening of energy supply crisis and the exacerbation of climate change by environmental pollution problems have become the greatest threat to human life. One of the ways to confront these problems is to rely on renewable energy and its storage systems. Nowadays, huge attention has been directed to the development of lithium-ion batteries (LIBs) as efficient tools for storing the clean energy produced by green sources like solar and wind energies. Accordingly, the demand for powerful electrode materials with excellent electrochemical characteristics has been progressively increased to meet fast and continuous growth in the market of energy storage systems. Therefore, the electronic and electrical properties of conversion anode materials for rechargeable lithium-ion batteries (LIBs) can be enhanced by introducing lattice defects and oxygen vacancies in the crystal structure. In this regard, the intended presentation will demonstrate new insights and effective ways for enhancing the electrical conductivity and improving the electrochemical performance of different anode materials such as MgFe₂O₄, CdFe₂O₄, Fe₃O₄, LiNbO₃ and Nb₂O₅. The changes in the physicochemical and morphological properties have been deeply investigated via structural and spectroscopic analyses (e.g., XRD, FESEM, HRTEM, and XPS). Moreover, the enhancement in the electrochemical properties of these anode materials will be discussed through Galvanostatic Cycling (GC), Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) techniques.

Keywords: structure modification, cationic substitution, non-stoichiometric synthesis, plasma treatment, lithium-ion batteries

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Authors: H. Li, W. Qin, Ben Ye

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Friction Push Plug Welding (FPPW) is a solid phase welding suitable for repairing defective welds and filling self-reacting weld keyholes in Friction Stir Welds. In FPPW process, a tapered shaped plug is rotated at high speed and forced into a tapered hole in the substrate. The plug and substrate metal is softened by the increasing temperature generated by friction and material plastic deformation. This paper aims to investigate the effect of process parameters on the quality of the weld. Orthogonal design methods were employed to reduce the amount of experiment. Three values were selected for each process parameter, rotation speed (1500r/min, 2000r/min, 2500r/min), plunge depth (2mm, 3mm, 4mm) and plunge speed (60mm/min, 90mm/min, 120r/min). AA6061aluminum alloy plug and substrate plate was used in the experiment. In a trial test with the plunge depth of 1mm, a noticeable defect appeared due to the short plunge time and insufficient temperature. From the recorded temperature profiles, it was found that the peak temperature increased with the increase of the rotation speed, plunge speed and plunge depth. In the initial stage, the plunge speed was the main factor affecting heat generation, while in the steady state welding stage, the rotation speed played a more important role. The FPPW weld defect includes flash and incomplete penetration in the upper, middle and bottom interface with the substrate. To obtain defect free weld, the higher rotation speed and proper plunge depth were recommended.

Keywords: friction push plug welding, process parameter, weld defect, orthogonal design

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Authors: Geetanjali Sharma

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There are always provincial variations which deserve more detailed treatment. Before the arrival of modern era, geography and cultural homogeneity were determining factors of human habitat and migration. Boundaries as if we see them, did not exist earlier. The connectivity of the world was also different as of now. The reinforcement of the old silk route will improve economic cooperation and connectivity between Asian, European and African countries, but obviously, it is designed to improve China’s geopolitical and geostrategic position in the world. The paper is based on the secondary sources of data. Analytical and historical approach has been used to clarify the ties between the old silk routes and new One-Belt-One-Road initiative China. The paper begins with an explanation of the historical background of the old Silk Route, its origin and development, trailed by an analysis of latest declarations by the Chinese leaders to revive it. It also discusses the impacts of this initiative on India’s economy and cultural exchange between associated regions. Lastly, the paper sums up the findings and suggestions for keeping a balance between the security and economic relationship between the countries. It concludes that the silk route is an effort in commencing a ‘grand strategy’ for global trade and cooperation with hidden objectives of China to increase the investment of China in other continents as well. The revival of silk route may prove to be a very helpful in reinforcing cooperation and raising it to a new level of economic establishments. However, China has yet to promote the much-needed political and strategic trust.

Keywords: OBOR (One-Belt-One-Road), geopolitics, economic relation, security concerns

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Authors: Seungchul Lee, Minjeong Kim, Iman Janghorban Esfahani, Jeong Tai Kim, ChangKyoo Yoo

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It is hard to maintain the effluent quality of the wastewater treatment plants (WWTPs) under with fixed types of operational control because of continuously changed influent flow rate and pollutant load. The aims of this study is development of multi-loop multi-objective control (ML-MOC) strategy in plant-wide scope targeting four objectives: 1) maximization of nutrient removal efficiency, 2) minimization of operational cost, 3) maximization of CH4 production in anaerobic digestion (AD) for CH4 reuse as a heat source and energy source, and 4) minimization of N2O gas emission to cope with global warming. First, benchmark simulation mode is modified to describe N2O dynamic in biological process, namely benchmark simulation model for greenhouse gases (BSM2G). Then, three types of single-loop proportional-integral (PI) controllers for DO controller, NO3 controller, and CH4 controller are implemented. Their optimal set-points of the controllers are found by using multi-objective genetic algorithm (MOGA). Finally, multi loop-MOC in BSM2G is implemented and evaluated in BSM2G. Compared with the reference case, the ML-MOC with the optimal set-points showed best control performances than references with improved performances of 34%, 5% and 79% of effluent quality, CH4 productivity, and N2O emission respectively, with the decrease of 65% in operational cost.

Keywords: Benchmark simulation model for greenhouse gas, multi-loop multi-objective controller, multi-objective genetic algorithm, wastewater treatment plant

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Authors: Mei-Hui Liu

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This study examines the effectiveness of a blended professional development program on preservice EFL (English as a foreign language) teachers’ learning to teach speech acts with the advent of Information and Communication Technology, researchers and scholars underscore the significance of integrating online and face-to-face learning opportunities in the teacher education field. Yet, a paucity of evidence has been documented to investigate the extent to which such a blended professional learning model may impact real classroom practice and student learning outcome. This yearlong project involves various stakeholders, including 25 preservice teachers, 5 English professionals, and 45 secondary school students. Multiple data sources collected are surveys, interviews, reflection journals, online discussion messages, artifacts, and discourse completion tests. Relying on the theoretical lenses of Community of Inquiry, data analysis depicts the nature and process of preservice teachers’ professional development in this blended learning community, which triggers and fosters both face-to-face and synchronous/asynchronous online interactions among preservice teachers and English professionals (i.e., university faculty and in-service teachers). Also included is the student learning outcome after preservice teachers put what they learn from the support community into instructional practice. Pedagogical implications and research suggestions are further provided based on the research findings and limitations.

Keywords: blended professional development, preservice EFL teachers, speech act instruction, student learning outcome

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Authors: A. Ribeiro, N. Pacheco, M. Soares, N. Valério, L. Nascimento, A. Silva, C. Vilarinho, J. Carvalho

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Hydrogen will play a key role in changing the current global energy paradigm, associated with the high use of fossil fuels and the release of greenhouse gases. This work intended to identify and quantify the potential of Solid Recovered Fuels (SFR) existing in Portugal and project the cost of hydrogen, produced through its steam gasification in different scenarios, associated with the size or capacity of the plant and the existence of carbon capture and storage (CCS) systems. Therefore, it was performed a techno-economic analysis simulation using an ASPEN base model, the H2A Hydrogen Production Model Version 3.2018. Regarding the production of SRF, it was possible to verify the annual production of more than 200 thousand tons of SRF in Portugal in 2019. The results of the techno-economic analysis simulations showed that in the scenarios containing a high (200,000 tons/year) and medium (40,000 tons/year) amount of SFR, the cost of hydrogen production was competitive concerning the current prices of hydrogen. The results indicate that scenarios 1 and 2, which use 200,000 tons of SRF per year, have lower hydrogen production values, 1.22 USD/kg H2 and 1.63 USD/kg H2, respectively. The cost of producing hydrogen without carbon capture and storage (CCS) systems in an average amount of SFR (40,000 tons/year) was 1.70 USD/kg H2. In turn, scenarios 5 (without CCS) and 6 (with CCS), which use only 683 tons of SFR from urban sources, have the highest costs, 6.54 USD/kg H2 and 908.97 USD/kg H2, respectively. Therefore, it was possible to conclude that there is a huge potential for the use of SRF for the production of hydrogen through steam gasification in Portugal.

Keywords: gasification, hydrogen, solid recovered fuels, techno-economic analysis, waste-to-energy

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Authors: Aina Barcelona, Carolyn Oldham, Jordi Colomer, Jordi Garcia-Orellana, Teresa Serra

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Seagrass meadows increase the sedimentation within the canopy. However, there is still a lack of knowledge about how seagrasses impact the vertical distribution of sediment coming from external sources and reaches the meadow. This study aims to determine the number of particles retained by a seagrass meadow. Based on the hydrodynamics in the vertical direction, a meadow can be separated into different compartments: the blades, the seabed, within the canopy layer, and the above canopy layer. A set of laboratory experiments were conducted under different hydrodynamic conditions and canopy densities with the purpose to mimic the real field conditions. This study demonstrates and quantifies that seagrass meadows decrease the volume of the suspended sediment by two mechanisms: capturing the suspended sediment by the seagrass blades and promoting the particle sedimentation to the seabed. This study also demonstrates that the number of sediment particles trapped by single seagrass blades decreases with canopy density. However, when considering the trapping by the total number of blades, the sediment captured by all the blades of the meadow increases with canopy density. Furthermore, comparing with the bare seabed, this study demonstrated that there is a reduction in the suspended particles within the canopy, which implies an improvement in the water clarity. In addition, the particle sedimentation on the seabed increases with the canopy density compared with the bare seabed, making evident the contribution of the vegetation in enhancing sedimentation.

Keywords: seagrass, sediment capture, turbulent kinetic energy, oscillatory flow

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Authors: Sunday Sedodo Nupo, Clara Berstien Oguntona, Babatunde Oguntona, Oluseyi Akinloye, P. A. Olunusi Adeboye

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Cardiovascular diseases are now becoming dominant sources of morbidity and mortality worldwide. This study investigated the lipid profile of civil servants. A cross-sectional study was carried out among randomly selected 202 male and 298 female civil servants in Abeokuta Ogun state. A pretested structured questionnaire was used to elicit information on history of non-communicable diseases and physical activity pattern of the respondents. The blood pressures of the subjects were measured and classified using World Health Organization criteria. The total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL). Ethical approval was obtained from Ogun State Ministry of Health. Data collected were analysed using Statistical package for social science version 17.1. Results showed that majority (76%) of the subjects were within the age range of 20 - 40 years, 75% earned between N58,500 - N98,000 monthly and 68% were sedentary. The mean energy intake of men and women were 3942±38 kcal and 2791±3 kcal respectively, while the protein intake for men was 65±49 g/day and 54.28±40 g/day for women. Desirable TC level (<200 mg/dl) was found in 80% of the selected subjects while the normal TG (<150 mg/dl) and LDL (<129 mg/dl) was found in 95% and 90% subjects respectively. The mean TC was 78.91±11 mg/dl and 62.69±9 mg/dl in men and women respectively. The study showed that most of the subjects had normal lipid in terms of serum triglycerides, total cholesterol, HDL cholesterol and LDL cholesterol.

Keywords: high density lipoprotein, morbidity, mortality, triglycerides

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Authors: Abdulrahman Nami Almutairi

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In the face of escalating climate change concerns, the concept of smart cities emerges as a promising approach to mitigate carbon emissions and move towards carbon neutrality. This paper provides a comprehensive review of the role of Natural Gas in achieving carbon neutrality. Natural gas has often been seen as a transitional fuel in the context of reducing carbon emissions. Its main role stems from being cleaner than coal and oil when burned for electricity generation and industrial processes. The urgent need to address this global issue has prompted a global shift towards cleaner energy sources and sustainable practices. In this endeavor, natural gas has emerged as a pivotal player, hailed for its potential to mitigate carbon emissions, and facilitate the transition to a low-carbon economy. With its lower carbon intensity compared to conventional fossil fuels, natural gas presents itself as a promising alternative for meeting energy demands while reducing environmental impact. As the world stands at a critical juncture in the fight against climate change, exploring the potential of natural gas as a transitional fuel offers insights into pathways towards a more sustainable and resilient future. By critically evaluating its opportunities and challenges, we can harness the potential of natural gas as a transitional fuel while advancing towards a cleaner, more resilient energy system. Through collaborative efforts and informed decision-making, we can pave the way for a future where energy is not only abundant but also environmentally sustainable and socially equitable.

Keywords: natural gas, clean fuel, carbon emissions, global warming, environmental protection

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Authors: Anuradha Chug, Sunali Gandhi

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Regression Testing is a very expensive and time-consuming process carried out to ensure the validity of modified software. Due to the availability of insufficient resources to re-execute all the test cases in time constrained environment, efforts are going on to generate test data automatically without human efforts. Many search based techniques have been proposed to generate efficient, effective as well as optimized test data, so that the overall cost of the software testing can be minimized. The generated test data should be able to uncover all potential lapses that exist in the software or product. Inspired from the natural behavior of bat for searching her food sources, current study employed a meta-heuristic, search-based bat algorithm for optimizing the test data on the basis certain parameters without compromising their effectiveness. Mathematical functions are also applied that can effectively filter out the redundant test data. As many as 50 Java programs are used to check the effectiveness of proposed test data generation and it has been found that 86% saving in testing efforts can be achieved using bat algorithm while covering 100% of the software code for testing. Bat algorithm was found to be more efficient in terms of simplicity and flexibility when the results were compared with another nature inspired algorithms such as Firefly Algorithm (FA), Hill Climbing Algorithm (HC) and Ant Colony Optimization (ACO). The output of this study would be useful to testers as they can achieve 100% path coverage for testing with minimum number of test cases.

Keywords: regression testing, test case selection, test case prioritization, genetic algorithm, bat algorithm

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Authors: Y. Ghiassi-Farrokhfal

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The number of electric vehicles (EVs) is increasing worldwide. Replacing gas fueled cars with EVs reduces carbon emission. However, the extensive energy consumption of EVs stresses the energy systems, requiring non-green sources of energy (such as gas turbines) to compensate for the new energy demand caused by EVs in the energy systems. To make EVs even a greener solution for the future energy systems, new EV charging stations are equipped with solar PV panels and batteries. This will help serve the energy demand of EVs through the green energy of solar panels. To ensure energy availability, solar panels are combined with batteries. The energy surplus at any point is stored in batteries and is used when there is not enough solar energy to serve the demand. While EV charging stations equipped with solar panels and batteries are green and ecologically optimal, they might not be financially viable solutions, due to battery prices. To make the system viable, we should size the battery economically and operate the system optimally. This is, in general, a challenging problem because of the stochastic nature of the EV arrivals at the charging station, the available solar energy, and the battery operating system. In this work, we provide a mathematical model for this problem and we compute the return on investment (ROI) of such a system, which is designed to be ecologically and financially optimal. We also quantify the minimum required investment in terms of battery and solar panels along with the operating strategy to ensure that a charging station has enough energy to serve its EV demand at any time.

Keywords: solar energy, battery storage, electric vehicle, charging stations

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Authors: Kimberley K. Whyte-Jones

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Public participation may improve the quality of environmental management decisions. However, the quality of such a decision is strongly dependent on the quality of the process that leads to it. In order to ensure an effective and efficient process, key features of best practice in participation should be carefully observed; this would also combat disillusionment of citizens, decision-makers and practitioners. The overarching aim of this study is to determine what constitutes an effective public participation process relevant to the Newfoundland and Labrador, Canada context, and to discover whether the public participation process that led to the 2014-2024 Provincial Sustainable Forest Management Strategy (PSFMS) met best practices criteria. The research design uses an exploratory case study strategy to consider a specific participatory process in environmental decision-making in Newfoundland and Labrador. Data collection methods include formal semi-structured interviews and the review of secondary data sources. The results of this study will determine the validity of a specific public participation best practice framework. The findings will be useful for informing citizen participation processes in general and will deduce best practices in public participation in environmental management in the province. The study is, therefore, meaningful for guiding future policies and practices in the management of forest resources in the province of Newfoundland and Labrador, and will help in filling a noticeable gap in research compiling best practices for environmentally related public participation processes.

Keywords: best practices, environmental decision-making, forest management, public participation

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Authors: Shao Qi

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The article uses the CiteSpace knowledge graph analysis tool to sort and visualize the journal literature on urban plants and habitats in the Web of Science and China National Knowledge Infrastructure databases. Based on a comprehensive interpretation of the visualization results of various data sources and the description of the intrinsic relationship between high-frequency keywords using knowledge mapping, the research hotspots, processes and evolution trends in this field are analyzed. Relevant case studies are also conducted for the hotspot contents to explore the means of landscape intervention and synthesize the understanding of research theories. The results show that (1) from 1999 to 2022, the research direction of urban plants and habitats gradually changed from focusing on plant and animal extinction and biological invasion to the field of human urban habitat creation, ecological restoration, and ecosystem services. (2) The results of keyword emergence and keyword growth trend analysis show that habitat creation research has shown a rapid and stable growth trend since 2017, and ecological restoration has gained long-term sustained attention since 2004. The hotspots of future research on urban plants and habitats in China may focus on habitat creation and ecological restoration.

Keywords: research trends, visual analysis, habitat creation, ecological restoration

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Authors: Muna Khushaim

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Aluminum-based alloys play a key role in modern engineering, especially in the aerospace industry. Introduction of solute atoms such as Li and Cu is the main approach to improve the strength in age-hardenable Al alloys via the precipitation hardening phenomenon. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Comparing the random binomial frequency distribution and the experimental frequency distribution of concentrations in atom probe tomography data was used to investigate the early stage of decomposition in the different binary and ternary alloys which were experienced different heat treatments. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160 °C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160 °C) induces increasing on the number density of the Li clusters and hence increase number of precipitated δ' particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus, the results contribute to the understanding of Al-alloy design.

Keywords: aluminum alloy, atom probe tomography, early stage, decomposition

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Authors: Onyedikachi Ulelu, Andrew P. Longstaff, Simon Fletcher, Simon Parkinson

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The widespread interest in 'Industry 4.0' or 'digital manufacturing' has led to significant research requiring the acquisition of data from sensors, instruments, and machine signals. In-depth research then identifies methods of analysis of the massive amounts of data generated before and during manufacture to solve a particular problem. The ultimate goal is for industrial Internet of Things (IIoT) data to be processed automatically to assist with either visualisation or autonomous system decision-making. However, the collection and processing of data in an industrial environment come with a cost. Little research has been undertaken on how to specify optimally what data to capture, transmit, process, and store at various levels of an edge-cloud network. The first step in this specification is to categorise IIoT data for efficient and effective use. This paper proposes the required attributes and classification to take manufacturing digital data from various sources to determine the most suitable location for data processing on the edge-cloud network. The proposed classification framework will minimise overhead in terms of network bandwidth/cost and processing time of machine tool data via efficient decision making on which dataset should be processed at the ‘edge’ and what to send to a remote server (cloud). A fast-and-frugal heuristic method is implemented for this decision-making. The framework is tested using case studies from industrial machine tools for machine productivity and maintenance.

Keywords: data classification, decision making, edge computing, industrial IoT, industry 4.0

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Authors: Lara A. Alshawawreh, R. Sean Smith, John B. Wood

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This study focuses on the sheltering response in the Middle East, specifically through reviewing two Syrian refugee camps in Jordan, involving Zaatari and Azraq. Zaatari camp involved the rapid deployment of tents and shelters over a very short period of time and Azraq was purpose built and pre-planned over a longer period. At present, both camps collectively host more than 133,000 occupants. Field visits were taken to both camps and the main issues and problems in the sheltering response were highlighted through focus group discussions with camp occupants and inspection of shelter habitats. This provided both subjective and objective research data sources. While every case has its own significance and deployment to meet humanitarian needs, there are some common requirements irrespective of geographical region. The results suggest that there is a gap in the suitability of the required habitat needs and what has been provided. It is recommended that the global international response and support could be improved in relation to the habitat form, construction type, layout, function and critically the cultural aspects. Services, health and hygiene are key elements to the shelter habitat provision. The study also identified the amendments to shelters undertaken by the beneficiaries providing insight into their key main requirements. The outcomes from this study could provide an important learning opportunity to develop improved habitat response for future shelters.

Keywords: culture, post-disaster, refugees, shelters

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Authors: Sina Mahdavi

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Background and Objective: Multiple sclerosis (MS) is the most common inflammatory autoimmune disease of the central nervous system (CNS) that affects the myelination process in the CNS. Complex interactions of various "environmental or infectious" factors may act as triggers in autoimmunity and disease progression. The association between viral infections, especially Epstein-Barr virus (EBV) and MS, is one potential cause that is not well understood. In this study, we aim to summarize the available data on EBV infection in MS disease progression. Materials and Methods: For this study, the keywords "Multiple sclerosis," "Epstein-Barr virus," and "central nervous system" in the databases PubMed, Google Scholar, Sid, and MagIran between 2016 and 2022 were searched, and 14 articles were chosen, studied, and analyzed. Results: Demyelinated lesions isolated from MS patients contain EBNAs from EBV proteins. The EBNA1 domain contains a pentapeptide fragment identical to B-crystallin, a heat shock peptide, that is increased in peripheral B cells in response to B-crystallin infection, resulting in myelin-directed autoimmunity mediated by proinflammatory T cells. EBNA2, which is involved in the regulation of viral transcription, may enhance transcription from MS risk loci. A 7-fold increase in the risk of MS has been observed in EBV infection with HLA-DR15 synergy. Conclusion: EBV infection along with a variety of specific genetic risk alleles, cause inflammatory cascades in the CNS by infected B cells. There is a high expression of EBV during the course of MS, which indicates the relationship between EBV and MS, that this virus can play a role in the development of MS by creating an inflammatory state. Therefore, measures to modulate the expression of EBV may be effective in reducing inflammatory processes in demyelinated areas of MS patients.

Keywords: multiple sclerosis, Epstein-Barr virus, central nervous system, EBNAs

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Authors: Kai-Wei Huang, Yi-Feng Lin

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The purpose of this study is to have chemical resistance, high heat resistance and mechanical strength of ceramic hollow fiber membrane into a membrane contactor, and the combustion process is applied (Post-combustion capture) of the carbon dioxide absorption device. In this paper, we would investigate the effect of the ceramic membrane hydrophobicity to the flux of the carbon dioxide adsorption. To improve the applicability of the ceramic film. We use the dry-wet spinning method with the high temperature sintering process for preparing a ceramic hollow fiber membranes to increase the filling density per unit volume of the membrane. The PESf/Al2O3 ratio of 1:5 was prepared ceramic hollow fibers membrane precursors and investigate the relationship of the different sintering temperature to the membrane pore size and porosity. It can be found that the membrane via the sintering temperature of 1400 °C prepared with the highest porosity of 70%, while the membrane via the sintering temperature of 1600 °C prepared although has a minimum porosity of about 54%, but also has the smallest average pore size of about 0.2 μm. The hydrophilic ceramic hollow fiber membranes which after high-temperature sintering were changed into hydrophobic successfully via the 0.02M FAS modifier. The hydrophobic ceramic hollow fiber membranes with different sintering temperature, the membrane which was prepared via 1400 °C sintering has the highest carbon dioxide adsorption about 4.2 × 10-4 (mole/m2s). The membrane prepared via 1500 °C sintering has the carbon dioxide adsorption about 3.8 × 10-3 (mole/m2s),and the membrane prepared via 1600 °C sintering has the lowest carbon dioxide adsorption about 2.68 × 10-3 (mole/m2s).All of them have reusability and in long time operation, the membrane which was prepared via 1600 °C sintering has the smallest pores and also could operate for three days. After the test, the 1600 °C sintering ceramic hollow fiber membrane was most suitable for the factory.

Keywords: carbon dioxide capture, membrane contactor, ceramic membrane, ceramic hollow fiber membrane

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Authors: Livhuwani Muthelo

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The health and safety of the miners in the South African mining industry are guided by the regulations and standards which are anticipated to promote a healthy work environment and fatalities. It is of utmost importance for the miners to comply with these regulations/standards to protect themselves from potential occupational health and safety risks, accidents, and fatalities. The purpose of this study was to develop and validate strategies to enhance compliance with the Health and safety standards within the mining industries of Limpopo province in South Africa. A mixed-method exploratory sequential research design was adopted. The population consisted of 5350 miners. Purposive sampling was used to select the participants in the qualitative strand and stratified random sampling in the quantitative strand. Semi-structured interviews were conducted among the occupational health nurse practitioners and the health and safety team. Thematic analysis was used to generate an understanding of the interviews. In the quantitative strand, a survey was conducted using a self-administered questionnaire. Data were analysed using SPSS version 26.0. A descriptive statistical test was used in the analysis of data including frequencies, means, and standard deviation. Cronbach's alpha test was used to measure internal consistency. The integrated results revealed that there are diverse experiences related to health and safety standards compliance among the mineworkers. The main findings were challenges related to leadership compliance and also related to the cost of maintaining safety, Miner's behavior-related challenges; the impact of non-compliance on the overall health of the miners was also described, the conflict between production and safety. Health and safety compliance is not just mere compliance with regulations and standards but a culture that warrants the miners and organization to take responsibility for their behavior and actions towards health and safety. Thus taking responsibility for your well-being and other miners.

Keywords: perceptions, compliance, health and safety, legislation, standards, miners

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Authors: Tatiana A. Pozdniakova, Maria A. P. Cechinel, Luciana P. Mazur, Rui A. R. Boaventura, Vitor J. P. Vilar.

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Two brown macroalgae, Laminaria hyperborea and Pelvetia canaliculata, were employed as natural cation exchangers in a fixed-bed column for Zn(II) removal from a galvanization wastewater. The column (4.8 cm internal diameter) was packed with 30-59 g of previously hydrated algae up to a bed height of 17-27 cm. The wastewater or eluent was percolated using a peristaltic pump at a flow rate of 10 mL/min. The effluent used in each experiment presented similar characteristics: pH of 6.7, 55 mg/L of chemical oxygen demand and about 300, 44, 186 and 244 mg/L of sodium, calcium, chloride and sulphate ions, respectively. The main difference was nitrate concentration: 20 mg/L for the effluent used with L. hyperborean and 341 mg/L for the effluent used with P. canaliculata. The inlet zinc concentration also differed slightly: 11.2 mg/L for L. hyperborean and 8.9 mg/L for P. canaliculata experiments. The breakthrough time was approximately 22.5 hours for both macroalgae, corresponding to a service capacity of 43 bed volumes. This indicates that 30 g of biomass is able to treat 13.5 L of the galvanization wastewater. The uptake capacities at the saturation point were similar to that obtained in batch studies (unpublished data) for both algae. After column exhaustion, desorption with 0.1 M HNO3 was performed. Desorption using 9 and 8 bed volumes of eluent achieved an efficiency of 100 and 91%, respectively for L. hyperborean and P. canaliculata. After elution with nitric acid, the column was regenerated using different strategies: i) convert all the binding sites in the sodium form, by passing a solution of 0.5 M NaCl, until achieve a final pH of 6.0; ii) passing only tap water in order to increase the solution pH inside the column until pH 3.0, and in this case the second sorption cycle was performed using protonated algae. In the first approach, in order to remove the excess of salt inside the column, distilled water was passed through the column, leading to the algae structure destruction and the column collapsed. Using the second approach, the algae remained intact during three consecutive sorption/desorption cycles without loss of performance.

Keywords: biosorption, zinc, galvanization wastewater, packed-bed column

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Authors: Nikita Katyal, Shaurya Uppal

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This paper tackles the significant challenge of accurately classifying customers within a retailer’s customer base. Accurate classification is essential for developing targeted marketing strategies that effectively engage this important demographic. To address this issue, we propose a method that utilizes Large Language Models (LLMs). By employing LLMs, we analyze the metadata associated with product purchases derived from historical data to identify key product categories that act as distinguishing factors. These categories, such as baby food, eldercare products, or family-sized packages, offer valuable insights into the likely household composition of customers, including families with babies, families with kids/teenagers, families with pets, households caring for elders, or mixed households. We segment high-confidence customers into distinct categories by integrating historical purchase behavior with LLM-powered product classification. This paper asserts that life stage segmentation can significantly enhance e-commerce businesses’ ability to target the appropriate customers with tailored products and campaigns, thereby augmenting sales and improving customer retention. Additionally, the paper details the data sources, model architecture, and evaluation metrics employed for the segmentation task.

Keywords: LLMs, segmentation, product tags, fine-tuning, target segments, marketing communication

Procedia PDF Downloads 23

Authors: Ji-Seok Koo, Hee‑Yong Kwon, Hui-Young Yun, Kyung-Hui Wang, Youn-Seo Koo

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This paper presents a forecasting system for PM2.5 levels in Seoul, South Korea, leveraging a combination of chemical transport modeling and ConvLSTM-DNN machine learning technology. Exposure to PM2.5 has known detrimental impacts on public health, making its prediction crucial for establishing preventive measures. Existing forecasting models, like the Community Multiscale Air Quality (CMAQ) and Weather Research and Forecasting (WRF), are hindered by their reliance on uncertain input data, such as anthropogenic emissions and meteorological patterns, as well as certain intrinsic model limitations. The system we've developed specifically addresses these issues by integrating machine learning and using carefully selected input features that account for local and distant sources of PM2.5. In South Korea, the PM2.5 concentration is greatly influenced by both local emissions and long-range transport from China, and our model effectively captures these spatial and temporal dynamics. Our PM2.5 prediction system combines the strengths of advanced hybrid machine learning algorithms, convLSTM and DNN, to improve upon the limitations of the traditional CMAQ model. Data used in the system include forecasted information from CMAQ and WRF models, along with actual PM2.5 concentration and weather variable data from monitoring stations in China and South Korea. The system was implemented specifically for Seoul's PM2.5 forecasting.

Keywords: PM2.5 forecast, machine learning, convLSTM, DNN

Procedia PDF Downloads 54

Authors: Mohamed Ghorab

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Local generated and distributed system for thermal and electrical energy is sighted in the near future to reduce transmission losses instead of the centralized system. Distributed Energy Resources (DER) is designed at different sizes (small and medium) and it is incorporated in energy distribution between the hubs. The energy generated from each technology at each hub should meet the local energy demands. Economic and environmental enhancement can be achieved when there are interaction and energy exchange between the hubs. Network energy system and CO₂ optimization between different six hubs presented Canadian community level are investigated in this study. Three different scenarios of technology systems are studied to meet both thermal and electrical demand loads for the six hubs. The conventional system is used as the first technology system and a reference case study. The conventional system includes boiler to provide the thermal energy, but the electrical energy is imported from the utility grid. The second technology system includes combined heat and power (CHP) system to meet the thermal demand loads and part of the electrical demand load. The third scenario has integration systems of CHP and Organic Rankine Cycle (ORC) where the thermal waste energy from the CHP system is used by ORC to generate electricity. General Algebraic Modeling System (GAMS) is used to model DER system optimization based on energy economics and CO₂ emission analyses. The results are compared with the conventional energy system. The results show that scenarios 2 and 3 provide an annual total cost saving of 21.3% and 32.3 %, respectively compared to the conventional system (scenario 1). Additionally, Scenario 3 (CHP & ORC systems) provides 32.5% saving in CO₂ emission compared to conventional system subsequent case 2 (CHP system) with a value of 9.3%.  

Keywords: distributed energy resources, network energy system, optimization, microgeneration system

Procedia PDF Downloads 190

Authors: I. Szer, J. Szer, K. Czarnocki, E. Błazik-Borowa

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People on construction scaffoldings work in dynamically changing, often unfavourable climate. Additionally, this kind of work is performed on low stiffness structures at high altitude, which increases the risk of accidents. It is therefore desirable to define the parameters of the work environment that contribute to increasing the construction worker occupational safety level. The aim of this article is to present how changes in microclimate parameters on scaffolding can impact the development of dangerous situations and accidents. For this purpose, indicators based on the human thermal balance were used. However, use of this model under construction conditions is often burdened by significant errors or even impossible to implement due to the lack of precise data. Thus, in the target model, the modified parameter was used – apparent environmental temperature. Apparent temperature in the proposed Scaffold Use Risk Assessment Model has been a perceived outdoor temperature, caused by the combined effects of air temperature, radiative temperature, relative humidity and wind speed (wind chill index, heat index). In the paper, correlations between component factors and apparent temperature for facade scaffolding with a width of 24.5 m and a height of 42.3 m, located at south-west side of building are presented. The distribution of factors on the scaffolding has been used to evaluate fitting of the microclimate model. The results of the studies indicate that observed ranges of apparent temperature on the scaffolds frequently results in a worker’s inability to adapt. This leads to reduced concentration and increased fatigue, adversely affects health, and consequently increases the risk of dangerous situations and accidental injuries

Keywords: apparent temperature, health, safety work, scaffoldings

Procedia PDF Downloads 182

Authors: G. Ozturk, B. Demirci

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It is well known that essential oils used for therapeutic purposes for many years. In this study, five different Pharmacopoeia grade essential oils (Achillea millefolium L., Pimpinella anisum L., Matricaria recutita L., Eucalyptus globulus L., Salvia officinalis L.) which obtained from commercial sources were evaluated for chemical compositions, synergistic antimicrobial activities, and lipoxygenase enzyme inhibitions. Volatile components were determined by gas chromatography/flame ionization detector and gas chromatography/mass spectrometer, simultaneously. The potential antimicrobial activity of essential oils was tested against oral pathogenic standard strains such as Streptococcus mutans, Streptococcus sanguinis, Staphylococcus aureus, Corynebacterium striatum, Candida albicans and Candida krusei by broth microdilution methods. Ciprofloxacin and ketoconazole were used positive controls. It has been observed that the essential oils tested have average inhibitory antimicrobial activity against oral pathogens with a Minimum Inhibition Concentration of 20-0.625 mg/mL. The active essential oils have been combined with antibiotics and synergistic effects have been evaluated by Checkerboard method. ƩFIC values were determined. In combination with antibiotics M. recutita essential oil has been shown to have a synergistic effect against S. aureus in combination with tetracycline (ƩFIC 0.46). In addition, 5-LOX inhibitory activity was measured by modifying the spectrophotometric method developed by Baylac and Racine. As a result, 5-LOX % inhibition of S. officinalis, E. globulus and M. recutita were calculated as 34.0 ± 6.66, 72.7 ± 2.78 and 27.7 ± 0.60, respectively.

Keywords: antimicrobial activity, essential oils, synergistic activity, 5-lipoxygenase inhibition

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Authors: A. Roukbi, B. Draoui

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Due to the high cost and the environmental problems caused by the conventional air-conditioning systems, various researches are being increasingly focused on thermal comfort in the building sector integrating renewable energy sources, particularly solar energy. For that purpose, this study aims to present a modeling and performance analysis of a direct air-cooled Water/LiBr absorption chiller. The chiller is considered to be coupled to a small residential building at an arid zone situated in south Algeria. The system is modeled with TRNSYS simulation program. The main objective is to study the feasibility of the chosen system in arid zones and to apply a simplified method to predict the performance of the system by mean of the characteristic equation approach tacking in account the influence of the climatic conditions of the considered site, the collector area and storage volume of the hot water tank on the performance of the installation. First, the results of the system modeling are compared with an experimental data from the open literature and the developed model is then validated. In another hand, a parametric study is performed to analyze the performance of the direct air-cooled absorption chiller at the operating conditions of interest for the present study. Thus, the obtained results has shown that the studied system can present a good alternative for cooling systems in arid zones since the cooling load is roughly in phase with solar availability.

Keywords: absorption chiller, air-cooled, arid zone, thermal comfort

Procedia PDF Downloads 230