Search results for: tidal currents

Authors: Axel Priambodo, Dwiharso Nugroho

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Studies conducted to map the reservoir properties based on facies architecture in which to determine the distribution of the petrophysical properties and calculate hydrocarbon reserves in study interval. Facies Architecture analysis begins with stratigraphic correlation that indicates the area is divided into different system tracts. The analysis of distribution patterns and compiling core analysis with facies architecture model show that there are three estuarine facies appear. Formation evaluation begins with shale volume calculation using Asquith-Krygowski and Volan Triangle Method. Proceed to the calculation of the total and effective porosity using the Bateman-Konen and Volan Triangle Method. After getting the value of the porosity calculation was continued to determine the effective water saturation and non-effective by including parameters of water resistivity and resistivity clay. The results of the research show that the Facies Architecture on the field in divided into three main facies which are Estuarine Channel, Estuarine Sand Bar, and Tidal Flat. The petrophysics analysis are done by comparing different methods also shows that the Volan Triangle Method does not give a better result of the Volume Shale than the Gamma Ray Method, but on the other hand, the Volan Triangle Methode is better on calculating porosity compared to the Bateman-Konen Method. The effective porosity distributions are affected by the distribution of the facies. Estuarine Sand Bar has a low porosity number and Estuarine Channel has a higher number of the porosity. The effective water saturation is controlled by structure where on the closure zone the water saturation is lower than the area beneath it. It caused by the hydrocarbon accumulation on the closure zone.

Keywords: petrophysics, geology, petroleum, reservoir

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Authors: Sapfo A. Mortaki

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This article examines the presence of Greek immigrant artists (painters and sculptors) in Paris during 1970-2010. The aim is to highlight their presence in the French capital through archival research in the daily and periodical press as well as present the impact of their artistic activity on the French intellectual life and society. At the same time, their contribution to the development of cultural life in Greece becomes apparent. The integration of those migrant artists into an environment of cultural coexistence and the understanding of the social phenomenon of their migration, in the context of postmodernity, are being investigated. The cultural relations between the two countries are studied in the context of support mechanisms, such as the Greek community, cultural institutions, museums and galleries. The recognition of the Greek artists by the French society and the social dimension in the context of their activity in Paris, are discussed in terms of the assimilation theory. Since the 1970s, and especially since the fall of the dictatorship in Greece, in opposition to the prior situation, artists' contacts with their homeland have been significantly enhanced, with most of them now travelling to Paris, while others work in parallel in both countries. As a result, not only do the stages of the development of their work through their pursuits become visible, but, most importantly, the artistic world becomes informed about the multifaceted expression of art through the succession of various contemporary currents. Thus, the participation of Greek artists in the international cultural landscape is demonstrated.

Keywords: artistic migration, cultural impact, Greek artists, postmodernity, theory of assimilation

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Authors: Jeet Vijay Sah, Alphonsa Joseph, Pravin Kumari Dwivedi, Ghanshyam Jhala, Subroto Mukherjee

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AISI 304 is known for its corrosion resistance which comes from Cr that forms passive Cr₂O₃ on the surface. But its poor hardness makes it unsuitable for applications where the steel also requires high wear resistance. This can be improved by surface hardening using nitrocarburizing processes, which form ε-Fe2-3N, γ’-Fe4N, nitrides, and carbides of Cr and Fe on the surface and subsurface. These formed phases give the surface greater hardness, but the corrosion resistance drops because of the lack of Cr2O3 passivation as a result. To overcome this problem, plasma nitrocarburizing processes are being developed where the process temperatures are kept below 723 K to avoid Cr-N precipitation. In the presented work, low-temperature pulsed-DC plasma nitrocarburizing utilizing a discharge of N₂-H₂-C₂H₂ at 500 Pa with varying N₂:H₂ ratios was conducted on AISI 304 samples at 673 K. The process durations were also varied, and the samples were characterized by microindentation using Vicker’s hardness tester, corrosion resistances were established from electrochemical impedance studies, and corrosion potentials and corrosion currents were obtained by potentiodynamic polarization testing. XRD revealed S-phase, which is a supersaturated solid solution of N and C in the γ phase. The S-phase was observed to be composed of the expanded phases of γ; γN, γC, and γ’N and ε’N phases. Significant improvement in surface hardness was achieved after every process, which is attributed to the S-phase. Corrosion resistance was also found to improve after the processes. The samples were also characterized by XPS, SEM, and GDOES.

Keywords: AISI 304, surface engineering, nitrocarburizing, S-phase

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Authors: Ahmad Akrad, Rabia Sehab, Fadi Alyoussef

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Nowadays, induction machines are widely used in industry thankful to their advantages comparing to other technologies. Indeed, there is a big demand because of their reliability, robustness and cost. The objective of this paper is to deal with diagnosis, detection and isolation of faults in a three-phase induction machine. Among the faults, Inter-turn short-circuit fault (ITSC), current sensors fault and single-phase open circuit fault are selected to deal with. However, a fault detection method is suggested using residual errors generated by the root mean square (RMS) of phase currents. The application of this method is based on an asymmetric nonlinear model of Induction Machine considering the winding fault of the three axes frame state space. In addition, current sensor redundancy and sensor fault detection and isolation (FDI) are adopted to ensure safety operation of induction machine drive. Finally, a validation is carried out by simulation in healthy and faulty operation modes to show the benefit of the proposed method to detect and to locate with, a high reliability, the three types of faults.

Keywords: induction machine, asymmetric nonlinear model, fault diagnosis, inter-turn short-circuit fault, root mean square, current sensor fault, fault detection and isolation

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Authors: Md. Royhanur Islam, Thomas Cansse, Md. Sahidul Islam, Atiqur Rahman Sunny

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The geographical location of Bangladesh makes it one of the most vulnerable countries to climate change. Climate-induced phenomena mainly affect the south-central region of Bangladesh (Laxmipur district) where they have begun to occur more frequently. The aim of the study was to identify the hydro-climatic factors that lead to weather-related disasters in the coastal areas and analyse the consequences of these factors on coastal livelihoods, with possible adaptation options using participatory rural appraisal (PRA) tools. The present study showed several disasters such as land erosion, depressions and cyclones, coastal flooding, storm surge, and precipitation. The frequency of these disasters is of a noticeable rate. Surveys have also discovered that land erosion is ongoing. Tidal water is being introduced directly into the mainland, and as a result of the salt intrusion, production capacity is declining. The coastal belt is an important area for fishing activities, but due to changed fishing times and a lack of Alternative Income Generating Activities (AIGAs), people have been forced to search for alternative livelihood options by taking both short-term and long-term adaptation options. Therefore, in order to increase awareness and minimize the losses, vulnerable communities must be fully incorporated into disaster response strategies. The government as well as national and international donor organizations should come forward and resolve the present situation of these vulnerable groups since otherwise, they will have to endure endless and miserable suffering due to the effects of climate change ahead in their lives.

Keywords: adaptation, community, fishery development, livelihood

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Authors: Mamidi Ramakrishna Rao

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Doubly-fed induction generators (DFIG) due to their advantages like speed variation and four-quadrant operation, find its application in wind turbines. DFIG besides supplying power to the grid has to support reactive power (kvar) under grid voltage variations, should contribute minimum fault current during faults, have high efficiency, minimum weight, adequate rotor protection during crow-bar-operation from +20% to -20% of rated speed.  To achieve the optimum performance, a good electromagnetic design of DFIG is required. In this paper, a simple and heuristic global optimization – Differential Evolution has been used. Variables considered are lamination details such as slot dimensions, stack diameters, air gap length, and generator stator and rotor stack length. Two operating conditions have been considered - voltage and speed variations. Constraints included were reactive power supplied to the grid and limiting fault current and torque. The optimization has been executed separately for three objective functions - maximum efficiency, weight reduction, and grid fault stator currents. Subsequent calculations led to the conclusion that designs determined through differential evolution help in determining an optimum electrical design for each objective function.

Keywords: design optimization, performance, DFIG, differential evolution

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Authors: Mohammad Reza Zamani Kouhpanji

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Characterizing the fatigue and fracture properties of nanostructures is one of the most challenging tasks in nanoscience and nanotechnology due to lack of a MEMS/NEMS device for generating uniform cyclic loadings at high frequencies. Here, the dynamic response of a recently proposed MEMS/NEMS device under different inputs signals is completely investigated. This MEMS/NEMS device is designed and modeled based on the electromagnetic force induced between paired parallel wires carrying electrical currents, known as Ampere’s Force Law (AFL). Since this MEMS/NEMS device only uses two paired wires for actuation part and sensing part, it represents highly sensitive and linear response for nanostructures with any stiffness and shapes (single or arrays of nanowires, nanotubes, nanosheets or nanowalls). In addition to studying the maximum gains at different resonance frequencies of the MEMS/NEMS device, its dynamical responses are investigated for different inputs and nanostructure properties to demonstrate the capability, usability, and reliability of the device for wide range of nanostructures. This MEMS/NEMS device can be readily integrated into SEM/TEM instruments to provide real time study of the fatigue and fracture properties of nanostructures as well as their softening or hardening behaviors, and initiation and/or propagation of nanocracks in them.

Keywords: MEMS/NEMS devices, paired wire actuators and sensors, dynamical response, fatigue and fracture characterization, Ampere’s force law

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Authors: Saurabh Chaudhury, Sanjeet Kumar Sinha

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The MOSFET has been the main building block in high performance and low power VLSI chips for the last several decades. Device scaling is fundamental to technological advancements, which allows more devices to be integrated on a single die providing greater functionality per chip. Ultimately, the goal of scaling is to build an individual transistor that is smaller, faster, cheaper, and consumes less power. Scaling continued following Moore's law initially and now we see an exponential growth in today's nano scaled chip. However, device scaling to deep nano meter regime leads to exponential increase in leakage currents and excessive heat generation. Moreover, fabrication process variability causing a limitation to further scaling. Researchers believe that with a mix of chemistry, physics, and engineering, nano electronics may provide a solution to increasing fabrication costs and may allow integrated circuits to be scaled beyond the limits of the modern transistor. Carbon nano tube (CNT) and nano wires (NW) based FETs have been analyzed and characterized in laboratory and also been demonstrated as prototypes. This work presents an extensive simulation based study and analysis of CNTFET and NW-FET devices and comparison of the results with conventional MOSFET. From this study, we can conclude that these devices have got some excellent properties and favorable characteristics which will definitely lead the future semiconductor devices in post silicon era.

Keywords: carbon nanotube, nanowire FET, low power, nanoscaled devices, VLSI

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Authors: Yansong Gao, Damith C.Ranasinghe, Siad F. Al-Sarawi, Omid Kavehei, Derek Abbott

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Passive crossbar arrays is in principle the simplest functional electrical circuit, together with memristive device in cross-point, holding great promise in future high-density, non-volatile memories. However, the greatest problem of crossbar array is the sneak path current. In this paper, we investigate one type of memristive device with intrinsic rectification behavior to address the sneak path currents. Firstly, a SPICE behavior model written in Verilog-A language of the memristive device is presented to fit experimental data published in literature. Next, systematic performance simulations including read margin and power consumption of crossbar array, which uses the self-rectifying memristive device as storage element at cross-point, with respect to different crossbar sizes, interconnect resistance, ratio of HRS/LRS (High Resistance State/ Low Resistance State), rectification ratio and different read schemes are conducted. Subsequently, Trade-offs among reading margin, power consumption, and reading schemes are analyzed to provide guidelines for circuit design. Finally, performance comparison between the memristive device with/without intrinsic rectification behavior is given to show the worthiness of this intrinsic rectification behavior.

Keywords: memristive device, memristor, crossbar, RRAM, read margin, power consumption

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Authors: Najib Belhadj Messaoud, Slim Souissi

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The non-linear dynamic behavior of a single stage spur gear reducer is studied in this paper in transient regime. Driving and driver rotors are, respectively, powered by a motor torque Cm and loaded by a resistive torque Cr. They are supported by two identical Active Magnetic Bearings (AMBs). Gear excitation is induced by the motor torque and load variation in addition to the fluctuation of meshing stiff-ness due to the variation of input rotational speed. Three models of AMBs were used with four, six and eight magnets. They are operated by P.D controller and powered by control and bias currents. The dynamic parameters of the AMBs are modeled by stiffness and damping matrices computed by the derivation of the electromagnetic forces. The equations of motion are solved iteratively using Newmark time integration method. In the first part of the study, the model is powered by an electric motor and by a four strokes four cylinders diesel engine in the second part. The numerical results of the dynamic responses of the system come to confirm the significant effect of the transient regime on the dynamic behavior of a gear set, particularly in the case of engine acyclism condition. Results also confirm the influence of the magnet number by AMBs on the dynamic behavior of the system. Indeed, vibrations were more important in the case of gear reducer supported by AMBs with four magnets.

Keywords: motor, stiffness, gear, acyclism, fluctuation, torque

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Authors: Mamidi Ramakrishna Rao, Jagdish Mamidi

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With advancing technology, the market environment for wind power generation systems has become highly competitive. The industry has been moving towards higher wind generator power ratings, in particular, off-shore generator ratings. Current off-shore wind turbine generators are in the power range of 10 to 12 MW. Unlike traditional induction motors, slow-speed permanent magnet surface mounted (PMSM) high-power generators are relatively challenging and designed differently. In this paper, PMSM generator design features have been discussed and analysed. The focus attention is on armature windings, harmonics, and permanent magnet. For the power ratings under consideration, the generator air-gap diameters are in the range of 8 to 10 meters, and active material weigh ~60 tons and above. Therefore, material weight becomes one of the critical parameters. Particle Swarm Optimization (PSO) technique is used for weight reduction and performance improvement. Four independent variables have been considered, which are air gap diameter, stack length, magnet thickness, and winding current density. To account for core and teeth saturation, preventing demagnetization effects due to short circuit armature currents, and maintaining minimum efficiency, suitable penalty functions have been applied. To check for performance satisfaction, a detailed analysis and 2D flux plotting are done for the optimized design.

Keywords: offshore wind generator, PMSM, PSO optimization, design optimization

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Authors: Javier Delgado-Gonzaga, Wilfrido Rivera, David Juárez-Romero

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Cooling and water purification are processes that have contributed to the economic and social development of the modern world. However, these processes require a significant amount of energy globally. Nowadays, absorption heat pumps have been studied with great interest since they are capable of producing cooling and/or purifying water from low-temperature energy sources such as industrial waste heat or renewable energy. In addition, absorption heat pumps require negligible amounts of electricity for their operation and generally use working fluids that do not represent a risk to the environment. The objective of this work is to evaluate a system that integrates an absorption heat transformer and an absorption cooling system to produce fresh water and cooling from a low-temperature heat source. Both cycles operate with the working pair LiBr-H2O. The integration is possible through the interaction of the LiBr-H2O solution streams between both cycles and also by recycling heat from the absorption heat transformer to the absorption cooling system. Mathematical models were developed to compare the performance of four different configurations. The results showed that the configuration in which the hottest streams of LiBr-H2O solution preheated the coldest streams in the economizers of both cycles was one that achieved the best performance. The interaction of the solution currents and the heat recycling analyzed in this work serves as a record of the possibilities of integration between absorption cycles for cogeneration.

Keywords: absorption heat transformer, absorption cooling system, water desalination, integrated system

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Authors: Yves Lacroix, Van Van Than, Didier Léandri, Pierre Liardet

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The western Tombolo of the Giens peninsula in southern France, known as Almanarre beach, is subject to coastal erosion. We are trying to use computer simulation in order to propose solutions to stop this erosion. Our aim was first to determine the main factors for this erosion and successfully apply a coupled hydro-sedimentological numerical model based on observations and measurements that have been performed on the site for decades. We have gathered all available information and data about waves, winds, currents, tides, bathymetry, coastal line, and sediments concerning the site. These have been divided into two sets: one devoted to calibrating a numerical model using Mike 21 software, the other to serve as a reference in order to numerically compare the present situation to what it could be if we implemented different types of underwater constructions. This paper presents the first part of the study: selecting and melting different sources into a coherent data basis, identifying the main erosion factors, and calibrating the coupled software model against the selected reference period. Our results bring calibration of the numerical model with good fitting coefficients. They also show that the winter South-Western storm events conjugated to depressive weather conditions constitute a major factor of erosion, mainly due to wave impact in the northern part of the Almanarre beach. Together, current and wind impact is shown negligible.

Keywords: Almanarre beach, coastal erosion, hydro-sedimentological, numerical model

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Authors: Abdulrazaq Yahaya, Omobola Okoh, Anthony Okoh

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Polychlorinated biphenyls (PCBs) are generated from short emission or leakage from capacitors and electrical transformers, industrial chemicals wastewater discharge and careless disposal of wastes. They are toxic, semi-volatile compounds which can persist in the environment, hence classified as persistent organic pollutants. Their presence in the environmental matrices has become a global concern. In this study, we assessed the concentrations and distribution patterns of 19 polychlorinated biphenyls congeners (PCB 1, 5, 18, 31, 44, 52, 66, 87, 101, 110, 138, 141, 151, 153, 170, 180, 183, 187, and 206) at six sampling points in water along the course of Buffalo River, Eastern Cape, South Africa. Solvent extraction followed by sulphuric acid, potassium permanganate and silica gel cleanup were used in this study. The analysis was done with gas chromatography electron capture detector (GC-ECD). The results of the analysis of all the 19 PCBs congeners ranged from not detectable to 0.52 ppb and 2.5 ppb during summer and autumn periods respectively. These values are generally higher than the World Health Organization (WHO) maximum permissible limit. Their presence in the waterbody suggests an increase in anthropogenic activities over the seasons. In view of their volatility, the compounds are transportable over long distances by air currents away from their point of origin putting the health of the communities at risk, thus suggesting the need for strict regulations on the use as well as save disposal of this group of compounds in the communities.

Keywords: organic pollutants, polychlorinated biphenyls, pollution, solvent extraction

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Authors: Nkwa Agbor Etobi Arreneke

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A well-designed earthing/grounding system will not only provide an effective path for direct dissipation of faulty currents into the earth/soil, but also ensure the safety of personnels withing and around its immediate surrounding perimeter is free from the possibility of fatal electric shock. In order to achieve the latter, it is of paramount importance to ensuring that both the step and touch potentials are kept within the allowable tolerance set by standards IEEE Std-80-2000. In this article, the step and touch potentials of an earthing system are simulated and conformity verified using the Finite Element Method (FEM), and has been found to be 242.4V and 194.80V respectively. The effect of injection current position is also analyzed to observe its effect on a person within or in contact with any active part of the earthing system of the substation. The values obtained closely matches those of other published works which made using different numerical methods and/or simulations Genetic Algorithm (GA). This current study is aimed at throwing more light to the dangers of step and touch potential of earthing systems of substation and electrical facilities as a whole, and the need for further in-dept analysis of these parameters. Observations made on this current paper shows that, the position of contact with an energize earthing system is of paramount important in determining its effect on living organisms in contact with any energized part of the earthing systems.

Keywords: earthing/grounding systems, finite element method (fem), ground/earth resistance, safety, touch and step potentials, generic algorithm

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Authors: Yves Lacroix, Van Van Than, Didier Léandri, Pierre Liardet

Abstract:

The western Tombolo of the Giens peninsula in southern France, known as Almanarre beach, is subject to coastal erosion. We are trying to use computer simulation in order to propose solutions to stop this erosion. Our aim was first to determine the main factors for this erosion and successfully apply a coupled hydro-sedimentological numerical model based on observations and measurements that have been performed on the site for decades. We have gathered all available information and data about waves, winds, currents, tides, bathymetry, coastal line, and sediments concerning the site. These have been divided into two sets: one devoted to calibrating a numerical model using Mike 21 software, the other to serve as a reference in order to numerically compare the present situation to what it could be if we implemented different types of underwater constructions. This paper presents the first part of the study: selecting and melting different sources into a coherent data basis, identifying the main erosion factors, and calibrating the coupled software model against the selected reference period. Our results bring calibration of the numerical model with good fitting coefficients. They also show that the winter South-Western storm events conjugated to depressive weather conditions constitute a major factor of erosion, mainly due to wave impact in the northern part of the Almanarre beach. Together, current and wind impact is shown negligible.

Keywords: Almanarre beach, coastal erosion, hydro-sedimentological, numerical model

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Authors: Sinwook Park, Gilad Yossifon

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The presence of a floating electrode array located within the depletion layer formed due to concentration-polarization (CP) across a microchannel-membrane device, produces not only induced-charge electro-osmosis (ICEO) vortex and but also a bipolar current resulting from faradaic reactions. It has been shown that there exists an optimal SiO2 layer thickness of ~50nm which is sufficient to suppress bipolar currents (at least up to 5V applied voltage) but still enables ICEO vortices that stir the depletion layer, thereby affecting its I-V response. This effect is pronounced beyond the limiting current where the existence of the depletion layer results in increased local electric field due to decreased solution conductivity. This comprehensive study of the interaction of embedded electrodes with the induced CP in microchannel-perm selective medium systems, allows one to choose the thickness of the thin dielectric coating to either enhance the mixing as a means to control the diffuse layer, or suppress it, for example, in the case where electrodes are intended for local measurements of the solution conductivity with minimal invasion. In addition, the use of alternating-current electro-osmosis by activating electrodes results in further enhancement of the fluid stirring and opens new routes for on-demand spatiotemporal control of the CP length. In addition, the use of embedded heaters within the depletion layer generates electro-thermal vortices that in turn also control the CP length.

Keywords: AC electrokinetics, microchannel, concentration-polarization, bipolar current

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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: Anusree Ghosh, Nahid Morshed, Tapas Ranjan Chakraborty, Moniruzzaman Khan, Liakath Ali

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To establish the Bangabandhu Sheikh Mujib Shilpa Nagar in Mirsarai, Chattogram land was reclaimed from the river mouth of the Feni River in the Bay of Bangle. The sandy land has a salinity of 9.5 EC ds/m, and the water of the adjacent Bay was 13.2 EC ds/m during winter, i.e., it has moderate salinity. The selection of plant species for the plantation was following the local practices. Mangrove plantation in a such landscape is not common in the country, and some actions towards the plantation seem ineffective and could be accomplished differently. The aim of this paper is to analyze the trial and develop a strategy for mangrove afforestation in reclaimed land where the tidal effect does not occur year-round. Though the Keora (Sonneratia apetala) is the priority species in a typical mangrove plantation, the success rate is comparatively high for the Baen (Avcennia officinalis) and Sada Baen (Avicennia alba). The natural growth was recorded for Keora, Goran (Ceriops decandra), Lal Jhau (Tamarix dioica) and Baen. Though there was the natural growth of Durba grass (Cynodon dactylon) and Motha Gash (Cyperus rotundus), no growth of climber was reported at the early stage of the natural growth. The transplanted growth of Keora, Gewa (Excoecaria agallocha), and Baen was found not suitable for plantation. The saplings growing from the viviparous germinated bean show no germination failure. Since the plantation site remains dry for 5 months, there was irrigation from the river; though it resulted in an increase in land salinity. To increase fertility, cow dung was used, and green manuring by planting Doincha (Sesbania bispinosa) shows a very insignificant contribution. The plantation of, only one and a half years old, is now a habitat of more than 100 species. The learning from the mangrove plantation from August 2021 to February 2023 assumes that in reclaimed land where there is inundation during monsoon only and salinity is moderate, the plantation from viviparous germinated Baen is better.

Keywords: mangrove plantation, reclaimed land, climate change, habitat restoration

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Authors: Nargiz Ismayilova

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The issue of modernism and the concept of postmodernism has been the focus of world researchers for many years, and there are very few researchers who have come to a common denominator about this term. During the independence period, the expansion of the relations of Azerbaijani literature with the world has led to the spread of many currents and tendencies formed in the West to the literary environment in our country. In this context, the works created in our environment are distinguished by their extreme richness in terms of subject matter and diversity in terms of genre. As an interesting example of contemporary postmodern prose in Azerbaijan, Parviz Jabrayil's novel "In a Foreign Language" pays attention with its more different plotline. The disagreement exists among the critics about the novel. Some are looking for high artistry in work; others are satisfied with the elements of postmodernism in work. Delimitation of the border between modernism and postmodernism can serve to carry out a deep scientific study of the novel. The novel depicts the world in the author's consciousness against the background of water shortage (thirst) in the Old City (Icharishahar). The author deconstructs today's Ichari Shahar mould. Along with modernism, elements of postmodernism occupy a large place in the work. When we look at the general tendencies of postmodernist art, we see that science and individuality are questioned, criticizing the sharp boundaries of modernism and the negativity of these restrictions, and modernism offers alternatives to artistic production by identifying its negatives and shortcomings in the areas of artistic freedom. The novel is extremely interesting in this point of view.

Keywords: concept of postmodernism, modernism, delimitation, political postmodernism, modern postmodern prose, Azerbaijani literature, novel, comparison, world literature, analysis

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Authors: M. A. Motin, M. A. Aziz, M. Hafiz Mia, M. A. Hasem

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The redox behavior of catechol in the presence of nicotinamide as nucleophiles has been studied in aqueous solution with various pH values and different concentration of nicotinamide using cyclic voltammetry and differential pulse voltammetry. Cyclic voltammetry of catechol in buffer solution (3.00 < pH < 9.00) shows one anodic and corresponding cathodic peak which relates to the transformation of catechol to corresponding o-benzoquinone and vice versa within a quasi reversible two electron transfer process. Cyclic voltammogram of catechol in the presence of nicotinamide in buffer solution of pH 7, show one anodic peak in the first cycle of potential and on the reverse scan the corresponding cathodic peak slowly decreases and new peak is observed at less positive potential. In the second cycle of potential a new anodic peak is observed at less positive potential. This indicates that nicotinamide attached with catechol and formed adduct after first cycle of oxidation. The effect of pH of catechol in presence of nicotinamide was studied by varying pH from 3 to 11. The substitution reaction of catechol with nicotimamide is facilitated at pH 7. In buffer solution of higher pH (>9), the CV shows different pattern. The effect of concentration of nicotinamide was studied by 2mM to 100 mM. The maximum substitution reaction has been found for 50 mM of nicotinamide and of pH 7. The proportionality of the first scan anodic and cathodic peak currents with square root of scan rate suggests that the peak current of the species at each redox reaction is controlled by diffusion process. The current functions (1/v-1/2) of the anodic peak decreased with the increasing of scan rate demonstrated that the behavior of the substitution reaction is of ECE type.

Keywords: redox interaction, catechol, nicotinamide, substituion reaction, pH effect

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Authors: Himanshu Dehra

Abstract:

An experimental study was conducted for ascertaining electrical and thermal characteristics of a pair of photovoltaic (PV) modules integrated with solar wall of an outdoor room. A pre-fabricated outdoor room was setup for conducting outdoor experiments on a PV solar wall with passive and active ventilation through the outdoor room. The selective operating conditions for glass coated PV modules were utilized for establishing their electrical and thermal characteristics. The PV solar wall was made up of glass coated PV modules, a ventilated air column, and an insulating layer of polystyrene filled plywood board. The measurements collected were currents, voltages, electric power, air velocities, temperatures, solar intensities, and thermal time constant. The results have demonstrated that: i) a PV solar wall installed on a wooden frame was of more heat generating capacity in comparison to a window glass or a standalone PV module; ii) generation of electric power was affected with operation of vertical PV solar wall; iii) electrical and thermal characteristics were not significantly affected by heat and thermal storage losses; and iv) combined heat and electricity generation were function of volume of thermal and electrical resistances developed across PV solar wall. Finally, a comparison of temperature plots of passive and active ventilation envisaged that fan pressure was necessary to avoid overheating of the PV solar wall. The active ventilation was necessary to avoid over-heating of the PV solar wall and to maintain adequate ventilation of room under mild climate conditions.

Keywords: photovoltaic solar wall, solar energy, passive ventilation, active ventilation

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Authors: Dipti Chand, Riya Saboo

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OBJECTIVES: Early and correct diagnosis may present a significant clinical challenge in diagnosis of patients presenting to Emergency Department with Acute Dyspnoea. The common cause of acute dyspnoea and respiratory distress in Emergency Department are Decompensated Heart Failure (HF), Chronic Obstructive Pulmonary Disease (COPD), Asthma, Pneumonia, Acute Respiratory Distress Syndrome (ARDS), Pulmonary Embolism (PE), and other causes like anaemia. The aim of the study was to measure NT-pro Brain Natriuretic Peptide (BNP) and exhaled End-Tidal Carbon dioxide (ETCO2) in patients presenting with dyspnoea. MATERIAL AND METHODS: This prospective, cross-sectional and observational study was performed at the Government Medical College and Hospital, Nagpur, between October 2019 and October 2021 in patients admitted to the Medicine Intensive Care Unit. Three groups of patients were compared: (1) HFrelated acute dyspnoea group (n = 52), (2) pulmonary (COPD/PE)-related acute dyspnoea group (n = 31) and (3) sepsis with ARDS-related dyspnoea group (n = 13). All patients underwent initial clinical examination with a recording of initial vital parameters along with on-admission ETCO2 measurement, NT-proBNP testing, arterial blood gas analysis, lung ultrasound examination, 2D echocardiography, chest X-rays, and other relevant diagnostic laboratory testing. RESULTS: 96 patients were included in the study. Median NT-proBNP was found to be high for the Heart Failure group (11,480 pg/ml), followed by the sepsis group (780 pg/ml), and pulmonary group had an Nt ProBNP of 231 pg/ml. The mean ETCO2 value was maximum in the pulmonary group (48.610 mmHg) followed by Heart Failure (31.51 mmHg) and the sepsis group (19.46 mmHg). The results were found to be statistically significant (P < 0.05). CONCLUSION: NT-proBNP has high diagnostic accuracy in differentiating acute HF-related dyspnoea from pulmonary (COPD and ARDS)-related acute dyspnoea. The higher levels of ETCO2 help in diagnosing patients with COPD.

Keywords: NT PRO BNP, ETCO2, dyspnoea, lung USG

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Authors: Ying-Pin Chang

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This paper presents a method for combining a particle swarm optimization with nonlinear time-varying evolution and orthogonal arrays (PSO-NTVEOA) in the planning of harmonic filters for the high speed railway traction system with specially connected transformers in unbalanced three-phase power systems. The objective is to minimize the cost of the filter, the filters loss, the total harmonic distortion of currents and voltages at each bus simultaneously. An orthogonal array is first conducted to obtain the initial solution set. The set is then treated as the initial training sample. Next, the PSO-NTVEOA method parameters are determined by using matrix experiments with an orthogonal array, in which a minimal number of experiments would have an effect that approximates the full factorial experiments. This PSO-NTVEOA method is then applied to design optimal harmonic filters in Taiwan High Speed Rail (THSR) traction system, where both rectifiers and inverters with IGBT are used. From the results of the illustrative examples, the feasibility of the PSO-NTVEOA to design an optimal passive harmonic filter of THSR system is verified and the design approach can greatly reduce the harmonic distortion. Three design schemes are compared that V-V connection suppressing the 3rd order harmonic, and Scott and Le Blanc connection for the harmonic improvement is better than the V-V connection.

Keywords: harmonic filters, particle swarm optimization, nonlinear time-varying evolution, orthogonal arrays, specially connected transformers

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Authors: Raheleh Farzanmanesh, Christopher J. Weston

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Mangroves are forest ecosystems located in the inter-tidal regions of tropical and subtropical coastlines that provide many valuable economic and ecological benefits for millions of people, such as preventing coastal erosion, providing breeding, and feeding grounds, improving water quality, and supporting the well-being of local communities. In addition, mangroves capture and store high amounts of carbon in biomass and soils that play an important role in combating climate change. The decline in mangrove area has prompted government and private sector interest in mangrove conservation and restoration projects to achieve multiple Sustainable Development Goals, from reducing poverty to improving life on land. Mangrove aboveground biomass plays an essential role in the global carbon cycle, climate change mitigation and adaptation by reducing CO2 emissions. However, little information is available about the effectiveness of mangrove sustainable management on mangrove change area and aboveground biomass (AGB). Here, we proposed a method for mapping, modeling, and assessing mangrove area and AGB in two Global Environment Facility (GEF) blue forests projects based on Sentinel-2 Level 1C imagery during their conservation lifetime. The SVR regression model was used to estimate AGB in Tahiry Honko project in Madagascar and the Abu Dhabi Blue Carbon Demonstration Project (Abu Dhabi Emirates. The results showed that mangrove forests and AGB declined in the Tahiry Honko project, while in the Abu Dhabi project increased after the conservation initiative was established. The results provide important information on the impact of mangrove conservation activities and contribute to the development of remote sensing applications for mapping and assessing mangrove forests in blue carbon initiatives.

Keywords: blue carbon, mangrove forest, REDD+, aboveground biomass, Sentinel-2

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Authors: Maria Amodeo, Pasquale Arpaia, Marco Buzio, Vincenzo Di Capua, Francesco Donnarumma

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Different deep neural network architectures have been compared and tested to predict magnetic hysteresis in the context of pulsed electromagnets for experimental physics applications. Modelling quasi-static or dynamic major and especially minor hysteresis loops is one of the most challenging topics for computational magnetism. Recent attempts at mathematical prediction in this context using Preisach models could not attain better than percent-level accuracy. Hence, this work explores neural network approaches and shows that the architecture that best fits the measured magnetic field behaviour, including the effects of hysteresis and eddy currents, is the nonlinear autoregressive exogenous neural network (NARX) model. This architecture aims to achieve a relative RMSE of the order of a few 100 ppm for complex magnetic field cycling, including arbitrary sequences of pseudo-random high field and low field cycles. The NARX-based architecture is compared with the state-of-the-art, showing better performance than the classical operator-based and differential models, and is tested on a reference quadrupole magnetic lens used for CERN particle beams, chosen as a case study. The training and test datasets are a representative example of real-world magnet operation; this makes the good result obtained very promising for future applications in this context.

Keywords: deep neural network, magnetic modelling, measurement and empirical software engineering, NARX

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Authors: Aimen Saleh

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The Silurian Lower Acacus sandstone is one of the main reservoirs in North West Libya. Our aim in this study is to grasp a robust understanding of the hydrocarbon potential and distribution in the area. To date, the depositional environment of the Lower Acacus reservoir still open to discussion and contradiction. Henceforth, building three dimensional (3D) property modelling is one way to support the analysis and description of the reservoir, its properties and characterizations, so this will be of great value in this project. The 3D model integrates different data set, these incorporates well logs data, petrophysical reservoir properties and seismic data as well. The finalized depositional environment model of the Lower Acacus concludes that the area is located in a deltaic transitional depositional setting, which ranges from a wave dominated delta into tide dominated delta type. This interpretation carried out through a series of steps of model generation, core description and Formation Microresistivity Image tool (FMI) interpretation. After the analysis of the core data, the Lower Acacus layers shows a strong effect of tidal energy. Whereas these traces found imprinted in different types of sedimentary structures, for examples; presence of some crossbedding, such as herringbones structures, wavy and flaser cross beddings. In spite of recognition of some minor marine transgression events in the area, on the contrary, the coarsening upward cycles of sand and shale layers in the Lower Acacus demonstrate presence of a major regressive phase of the sea level. However, consequently, we produced a final package of this model in a complemented set of facies distribution, porosity and oil presence. And also it shows the record of the petroleum system, and the procedure of Hydrocarbon migration and accumulation. Finally, this model suggests that the area can be outlined into three main segments of hydrocarbon potential, which can be a textbook guide for future exploration and production strategies in the area.

Keywords: Acacus, Ghadames , Libya, Silurian

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Authors: Babak Rezaei, Arash Zargar Shoushtari

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Kangan anticline is located in the Coastal Fars area, southwest of Nar and west of west Assaluyeh anticlines and north of Kangan harbor in Boushehr province. The Kangan anticline is nearly asymmetric and with 55Km long and 6Km wide base on structural map of Kangan Formation. The youngest and the oldest Formations on surface are Bakhtiyari (Pliocene) and Sarvak (Cenomanian) respectively. The highest dip angles of 30 and 40 degree were observed in north and south flanks of Kangan anticline respectively and two reverse faults cut these flanks parallel to structure strike. Existence of sweet gas in Kangan Fm. and Upper Dalan in this structure is confirmed with probable Silurian shales origin. Main facies belts in these formations include super tidal and intertidal flat, lagoon, oolitic-bioclastic shoals and open marine sub environments that expand in a homoclinal and shallow water carbonate ramp under the arid climates. Digenetic processes studies, indicates the influence of all digenetic environments (marine, meteoric, burial) in the reservoir succession. These processes sometimes has led to reservoir quality improvement (such as dolomitization and dissolution) but in many instances reservoir units has been destroyed (such as compaction, anhydrite and calcite cementation). In this study, petrophysical evaluation is made in Kangan and upper Dalan formations by using well log data of five selected wells. Probabilistic method is used for petrophysical evaluation by applying appropriate soft wares. According to this evaluation the lithology of Kangan and upper Dalan Formations mainly consist of limestone and dolomite with thin beds of Shale and evaporates. In these formations 11 Zones with different reservoir characteristic have been identified. Based on wire line data analyses, in some part of these formations, high porosity can be observed. The range of porosity (PHIE) and water saturation (Sw) are estimated around 10-20% and 20-30%, respectively.

Keywords: microfacies, electrofacies, petrophysics, diagenese, gas fields

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Authors: Mohammad Atiqur Rahman

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The study aimed at inventorying the threatened biodiversity of Bangladesh and assessing the rate of loss of biodiversity caused due to environmental degradation for conservation management. The impact assessment of environmental depletion and rate of biodiversity loss determination have been made by a long term field investigation, examination of preserved herbarium specimens and survey of relevant floristic literature following the IUCN’s threatened criteria of assessing Red List Plants under the Flora Bangladesh Project. Biodiversity of Bangladesh, as evaluated, has been affected to a large extent during the last four and half decades due to spontaneous environmental degradation caused by frequent occurrence of cyclonic storms and tidal bores since 1970 and flooding, draught, unilateral diversion of trans-boundary waters by operating Farakka Barrage since 1975, indiscriminate destruction and over exploitation of natural resources, unplanned development and industrialization, overpopulation etc. Depletion of world’s largest mangrove biodiversity in Sundarbans, coastal and island biodiversity in southern part, agro-biodiversity and agro-fisheries all over the country, Haor and wetland biodiversity of plain lands, terrestrial and forest biodiversity in central and eastern hilly part of Bangladesh, as assessed, have greatly been occurred at a higher rate due to environmental degradation which in turn affect directly or indirectly the economy, food security and environmental health of the country. Complete inventory of 30 plant families resulted in the recognition of 45.18% species of Bangladesh as threatened environmentally and 13.23% species as possibly extinct from the flora since these have neither been reported or could be traced in the field for more than 100 years. The rate of extinction is determined to be 2.65% per 20 years. Hence the study indicates that the loss of biodiversity and environmental degradation in Bangladesh occurring at an alarming rate. The study focuses on the issues of environment, the extent of loss of different plant biodiversities in Bangladesh, prioritizing and implementing national conservation strategies for sustainable management of the environment.

Keywords: Bangladesh, biodiversity, conservation, environmental management

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Authors: Julia Zimmerman, Gaurav Savant

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This study aims to evaluate the efficacy of the U.S. Army Corp of Engineers’ River Analysis System (HEC-RAS) application to modeling the hydraulics of estuaries. HEC-RAS has been broadly used for a variety of riverine applications. However, it has not been widely applied to the study of circulation in estuaries. This report details the model development and validation of a combined 1D/2D unsteady flow hydraulic model using HEC-RAS for estuaries and they are associated with tidally influenced rivers. Two estuaries, Galveston Bay and Delaware Bay, were used as case studies. Galveston Bay, a bar-built, vertically mixed estuary, was modeled for the 2005 calendar year. Delaware Bay, a drowned river valley estuary, was modeled from October 22, 2019, to November 5, 2019. Water surface elevation was used to validate both models by comparing simulation results to NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) gauge data. Simulations were run using the Diffusion Wave Equations (DW), the Shallow Water Equations, Eulerian-Lagrangian Method (SWE-ELM), and the Shallow Water Equations Eulerian Method (SWE-EM) and compared for both accuracy and computational resources required. In general, the Diffusion Wave Equations results were found to be comparable to the two Shallow Water equations sets while requiring less computational power. The 1D/2D combined approach was valid for study areas within the 2D flow area, with the 1D flow serving mainly as an inflow boundary condition. Within the Delaware Bay estuary, the HEC-RAS DW model ran in 22 minutes and had an average R² value of 0.94 within the 2-D mesh. The Galveston Bay HEC-RAS DW ran in 6 hours and 47 minutes and had an average R² value of 0.83 within the 2-D mesh. The longer run time and lower R² for Galveston Bay can be attributed to the increased length of the time frame modeled and the greater complexity of the estuarine system. The models did not accurately capture tidal effects within the 1D flow area.

Keywords: Delaware bay, estuarine hydraulics, Galveston bay, HEC-RAS, one-dimensional modeling, two-dimensional modeling

Procedia PDF Downloads 171