Search results for: terminal maneuvering area

Authors: Mohamed A. Baba, Gazy Rodowan, Brigita Abakevičienė, Sigitas Tamulevičius, Bartlomiej Lemieszek, Sebastian Molin, Tomas Tamulevičius

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Solid oxide fuel cells (SOFC) efficiently convert hydrogen to energy without producing any disturbances or contaminants. The core of the cell is electrolyte. For improving the performance of electrolyte-supported cells, it is desirable to extend the available exchange surface area by micro-structuring of the electrolyte with laser-based micromachining. This study investigated the electrochemical performance of cells micro machined using a femtosecond laser. Commercial ceramic SOFC (Elcogen, AS) with a total thickness of 400 μm was structured by 1030 nm wavelength Yb: KGW fs-laser Pharos (Light Conversion) using 100 kHz repetition frequency and 290 fs pulse length light by scanning with the galvanometer scanner (ScanLab) and focused with a f-Theta telecentric lens (SillOptics). The sample height was positioned using a motorized z-stage. The microstructures were formed using a laser spiral trepanning in Ni/YSZ anode supported membrane at the central part of the ceramic piece of 5.5 mm diameter at active area of the cell. All surface was drilled with 275 µm diameter holes spaced by 275 µm. The machining processes were carried out under ambient conditions. The microstructural effects of the femtosecond laser treatment on the electrolyte surface were investigated prior to the electrochemical characterisation using a scanning electron microscope (SEM) Quanta 200 FEG (FEI). The Novo control Alpha-A was used for electrochemical impedance spectroscopy on a symmetrical cell configuration with an excitation amplitude of 25 mV and a frequency range of 1 MHz to 0.1 Hz. The fuel cell characterization of the cell was examined on open flanges test setup by Fiaxell. Using nickel mesh on the anode side and au mesh on the cathode side, the cell was electrically linked. The cell was placed in a Kittec furnace with a Process IDentifier temperature controller. The wires were connected to a Solartron 1260/1287 frequency analyzer for the impedance and current-voltage characterization. In order to determine the impact of the anode's microstructure on the performance of the commercial cells, the acquired results were compared to cells with unstructured anode. Geometrical studies verified that the depth of the -holes increased linearly according to laser energy and scanning times. On the other hand, it reduced as the scanning speed increased. The electrochemical analysis demonstrates that the open circuit voltage OCV values of the two cells are equal. Further, the modified cell's initial slope reduces to 0.209 from 0.253 of the unmodified cell, revealing that the surface modification considerably decreases energy loss. Plus, the maximum power density for the cell with the microstructure and the reference cell respectively, are 1.45 and 1.16 Wcm⁻².

Keywords: electrochemical performance, electrolyte-supported cells, laser micro-structuring, solid oxide fuel cells

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Authors: Yousra Zakaria Ahmed, Ahmed El Gendy, Salah El Haggar

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In this paper, our methodology to assess sustainability of wastewater treatment technologies in Egypt is presented. The preliminary list of factors to be considered, as well as their ranking listed. The factors include, but are not limited to pollutants removal efficiency and energy consumption under the environmental dimension, construction cost, operation and maintenance costs and required land area cost under the economic dimension and public acceptance, noise and generating job opportunities for local residents. This methodology is intended to be a user-friendly screening tool to support the decision making process when investigating different wastewater treatment technologies in Egypt. Based on the research work results presented in this paper, it can be generally concluded that the categorization of some of the social and environmental aspects of sustainability is subjective and highly dependent on the local conditions and researchers’ background.

Keywords: sustainability, wastewater treatment, sustainability assessment, Egypt

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Authors: Subarna Ferdous, Mitsuru Ikeda

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For the shrimp companies to remain relevant to its local and international consumers, they must offer new shrimp product and services. It must work actively not just to create value for the consumer, but to involve the consumer in co-creating value for shrimp product innovation in the market. In this theoretical work, we conceptualize the business concept of value co-creation in the context of shrimp products, and propose a framework of value co-creation for shrimp product innovation in shrimp industries. With guidance on value co-creation in in shrimp industry, and shrimp value chain actors mapped to the co-creation cycle, companies can use the framework to offer new shrimp product to consumer communities. Although customer co-creation is known approach in the world, it is not commonly used by the companies in Bangladesh. This paper makes an original contribution by conceptualizing co-creation and set the examples of best co-creation practices in food sector. The results of the study provide management with guidelines for successful co-creation projects with an innovation- and market-oriented approach. The framework also provides a basis for further research in this area.

Keywords: bangladesh, shrimp industry, value co-creation, shrimp product

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Authors: Jingjing Li, Shifu Wang

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After the irreversible consequences of the traditional renewal mode of ‘function first and then beautification’, such as the constructive destruction, social differentiation, and cultural, ecological imbalance, the renewal of the historical urban area began to pay attention to the excavation of cultural connotation, and entered a new stage from the pursuit of ‘quantity’ growth to the promotion of ‘quality’, expecting to rejuvenate the old city through the intervention of public art. This paper interprets the cases at home and abroad, summarizes the different forms of expression and application strategies of public art in the renewal of historical urban areas, and combs the limitations of the existing practice in Guangzhou through observation. Finally, it puts forward suggestions from three aspects of the system, implementation strategy, and implementation path, respectively, and explores the path of simultaneous rejuvenation of material space and cultural space in historical urban areas under the intervention of public art.

Keywords: public art, historic city, public space, renewal activation

Procedia PDF Downloads 135

Authors: Levent Seyfi, Ertan Akman, Tuğrul C. Topak

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In this study, irrigation automation with electronic sensors and its control with smartphones were aimed. In this context, temperature and soil humidity measurements of the area irrigated were obtained by temperature and humidity sensors. A micro controller (Arduino) was utilized for accessing values of these parameters and controlling the proposed irrigation system. The irrigation system could automatically be worked according to obtained measurement values. Besides, a GSM module used together with Arduino provided that the irrigation system was in connection to smartphones. Thus, the irrigation system can be remotely controlled. Not only can we observe whether the irrigation system is working or not via developed special android application but also we can see temperature and humidity measurement values. In addition to this, if desired, the irrigation system can be remotely and manually started or stopped regardless of measured sensor vales thanks to the developed android application. In addition to smartphones, the irrigation system can be alternatively controlled via the designed website (www.sulamadenetim.com).

Keywords: smartphone, Android Operating System, sensors, irrigation System, arduino

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Authors: L. Belkhiri, L. Mouni, A. Tiri, T.S. Narany

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In the present study, the self-organizing map (SOM) clustering technique was applied to identify homogeneous clusters of hydrochemical parameters in El Milia plain, Algeria, to assess the quality of groundwater for potable and agricultural purposes. The visualization of SOM-analysis indicated that 35 groundwater samples collected in the study area were classified into three clusters, which showed progressive increase in electrical conductivity from cluster one to cluster three. Samples belonging to cluster one are mostly located in the recharge zone showing hard fresh water type, however, water type gradually changed to hard-brackish type in the discharge zone, including clusters two and three. Ionic ratio studies indicated the role of carbonate rock dissolution in increases on groundwater hardness, especially in cluster one. However, evaporation and evapotranspiration are the main processes increasing salinity in cluster two and three.

Keywords: groundwater quality, self-organizing maps, drinking water, irrigation water

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Authors: R. F. Louh, Cathy Chou, Victor Wang, Howard Yan

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The aim of this study is to manufacture titania and reduced graphene oxide (TiO2/rGO) composite nanofibers via electrospinning (ESP) of precursor fluid consisted of titania sol containing polyvinylpyrrolidone (PVP) and titanium isopropoxide (TTIP) and GO solution. The GO nanoparticles were derived from Hummers’ method. A metal grid ring was used to provide the bias voltage to reach higher ESP yield and nonwoven fabric with dense network of TiO2/GO composite nanofibers. The ESP product was heat treated at 500°C for 2 h in nitrogen atmosphere to acquire TiO2/rGO nanofibers by thermal reduction of GO and phase transformation into anatase TiO2. The TiO2/rGO nanofibers made from various volume fractions of GO solution by ESP were analyzed by FE-SEM, TEM, XRD, EDS, BET and FTIR. Such TiO2/rGO fibers having photocatalytic property, high specific surface area and electrical conductivity can be used for photovoltaics and chemical sensing applications.

Keywords: electrospinning process, titanium oxide, thermally reduced graphene oxide, composite nanofibers

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Authors: Wahid Dianbudiyanto, Shou Heng Liu

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Capacitive deionization (CDI) is a prospective desalination technology, which can be operated at low voltage, low temperature and potentially consume low energy for brackish water desalination. To obtain the optimal electrosorption, an electrode should possess high electrical conductivity, large surface area, good wettability, highly mesoporous structure which provide efficient pathways for ion distribution. In this work, a 3D structure graphene was fabricated using hydrothermal method which is assisted with microwave treatments to form 3D rGO (3DG-Mw-Hyd). The prepared samples have excellent specific capacitance (189.2 F / g) and ultrahigh electrosorption capacity (30 mg/g) for the desalination of 500 mg / l NaCl. These results are superior to the electrode which is fabricated only using the hydrothermal method without microwave assistance (3DG-Hyd) and traditional reflux method. Physical characterizations such as SEM, TEM, and XRD have been used to study the property difference of the materials. The preliminary results show that 3DG-Mw-Hyd is one of the promising electrodes for CDI in the practical applications.

Keywords: capacitive deionization, graphene, microwave, hydrothermal, electrosorption

Procedia PDF Downloads 294

Authors: To Quyen Le, Oswald Devisch, Tu Anh Trinh, Els Hannes

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Urban centres worldwide are affected differently by flooding. In Vietnam this impact is increasingly negative caused by a process of rapid urbanisation. Traditional spatial planning and flood mitigation planning are not able to deal with this growing threat. This article therefore proposes to focus on increasing the participation of local communities in flood control and management. It explores, on the basis of a design studio exercise, how lay knowledge on flooding can be integrated within planning processes. The article presents a theoretical basis for the structured criterion for site selection for a flood resilient urban park from the perspective of science, then discloses the tacit and explicit knowledge of the flood-prone area and finally integrates this knowledge into the design strategies for flood resilient urban park design.

Keywords: analytic hierarchy process, AHP, design resilience, flood resilient urban park, knowledge integration

Procedia PDF Downloads 179

Authors: S. Olyaee, M. Seifouri, A. Nikoosohbat, M. Shams Esfand Abadi

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Photonic Crystal Fibers (PCFs) can be used in optical communications as transmission lines. For this reason, the PCFs with low confinement loss, low chromatic dispersion, and low nonlinear effects are highly suitable transmission media. In this paper, we introduce a new design of index-guiding photonic crystal fiber (IG-PCF) with ultra-low chromatic dispersion, low nonlinearity effects, and low confinement loss. Relatively low dispersion is achieved in the wavelength range of 1200 to 1600 nm using the proposed design. According to the new structure of IG-PCF presented in this study, the chromatic dispersion slope is -30(ps/km.nm) and the confinement loss reaches below 10-7 dB/km. While in the wavelength range mentioned above at the same time an effective area of more than 50.2μm2 is obtained.

Keywords: optical communication systems, index-guiding, dispersion, confinement loss, photonic crystal fiber

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Authors: Siti Rahmah Shamsuri, Eiichiro Matsubara, Shohei Shiomi

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The 1D nanomaterial is far surpassed the 0D nanomaterial. It does not just offer most of the benefit of the 0D nanomaterial such as the large surface area, a great number of active site and an efficient interfacial charge transfer but also can assemble into free-standing and flexible electrode due to their high aspect ratio. Thus, it is essential to develop a simple and ease synthesis of this 1D nanomaterial for the practical application. Here, nickel nanowire/cellulose hybrid has been successfully fabricated via a simple liquid-phase method with the assist of the magnetic field. A finer nickel nanowire was heterogeneously nucleated on the surface of the cellulose fiber, which demonstrated the effect of the hydroxyl group on the cellulose structure. The result of the nickel nanowire size was found to vary from 66-114 nm. A detailed discussion on the mechanism of the nickel nanowire/ cellulose hybrid formation is also shown in this paper.

Keywords: cellulose nanofiber, liquid-phase reduction, metal nanowire, nano hybrid material

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Authors: Abdelghani Leghouchi

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This study aims to predict the consequences associated with the propagation of the flood wave that may occur after the failure of the Taksebt dam and suggest an efficient emergency action plan (EAP) for mitigation purposes. To achieve the objectives of this study, the hydrodynamic model HEC-RAS 2D was used for the flood routing of the dam break wave, which gave an estimate of the hydraulic characteristics downstream the Taksebt dam. Geospatial analysis of the simulation results conducted in a Geographic information system (GIS) environment showed that many residential areas are considered to be in danger in case of the Taksebt dam break event. Based on the obtained results, an emergency actions plan was suggested to moderate the causalities in the downstream area at risk. Overall, the present study showed that the integration of 2D hydraulic modeling and GIS provides great capabilities in providing realistic view of the dam break wave propagation that enhances assessing the associated risks and proposing appropriate mitigation measures.

Keywords: taksebt dam, dam break, wave propagation time, HEC-RAS 2D

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Authors: Mehrdad Mahmudizad, Roya Ahmadi Ahangar

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This paper presents the method of designing the type 2 fuzzy PID controllers in order to solve the problem of Load Frequency Control (LFC). The Harmony Search (HS) algorithm is used to regulate the measurement factors and the effect of uncertainty of membership functions of Interval Type 2 Fuzzy Proportional Integral Differential (IT2FPID) controllers in order to reduce the frequency deviation resulted from the load oscillations. The simulation results implicitly show that the performance of the proposed IT2FPID LFC in terms of error, settling time and resistance against different load oscillations is more appropriate and preferred than PID and Type 1 Fuzzy Proportional Integral Differential (T1FPID) controllers.

Keywords: load frequency control, fuzzy-pid controller, type 2 fuzzy system, harmony search algorithm

Procedia PDF Downloads 278

Authors: A. Ardianto, M. A. Putera Agung, S. Pramusandi

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Power waterway is one of dam structures and as an intake vertical tunnel or well function for hydroelectric power plants in Jatigede area, Sumedang, West Java. Gate shaft is also one of parts the power waterway system. The paper concerns some consideration in determining a critical state parameter on the back stability analysis of gate shaft or excavation wall stability during excavation. Study analysis was carried out using without and with reinforcement system. Results study showed that reinforcement shaft could reduce the total displacement and safety factor could increases significantly. Based on the back calculation results, it was recommended to install some reinforcement materials and drainage system to reduce pore water pressure.

Keywords: power waterway, reinforcement, displacement, safety

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Authors: Devineni Vijay Bhaskar, Yendluri Raja

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We recommend a model for traffic sign detection stranded on Convolutional Neural Networks (CNN). We first renovate the unique image into the gray scale image through with support vector machines, then use convolutional neural networks with fixed and learnable layers for revealing and understanding. The permanent layer can reduction the amount of attention areas to notice and crop the limits very close to the boundaries of traffic signs. The learnable coverings can rise the accuracy of detection significantly. Besides, we use bootstrap procedures to progress the accuracy and avoid overfitting problem. In the German Traffic Sign Detection Benchmark, we obtained modest results, with an area under the precision-recall curve (AUC) of 99.49% in the group “Risk”, and an AUC of 96.62% in the group “Obligatory”.

Keywords: convolutional neural network, support vector machine, detection, traffic signs, bootstrap procedures, precision-recall curve

Procedia PDF Downloads 122

Authors: Jiří Kugl

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Typology and specific opportunities of brownfield revitalization are already largely described. Challenges and opportunities that brownfields represent have been adequately studied and presented, as well as specific ways in which these areas can be used or how they are used abroad. In other words, the questions why (revitalize brownfields) and what (we should do with them) are satisfactorily answered, but the question how (we can work with them) is not. This work will focus on answering this question, which will deal with tools that enable the revitalization and rehabilitation projects in the area. Tools can be divided, for example in terms of spatial planning and urban design, from an environmental perspective, from the perspective of cultural heritage protection and from the perspective of investment opportunities. The result is that the issue of brownfields is handled by numerous institutions and instruments. The aim of this paper is to identify, classify and analyze these instruments. Paper will study instruments from other countries with long-term experience with this issue (eg. France, Great Britain, USA, Germany, Denmark, Czech Republic) and analyse their contribution and the feasibility of their implementation in other countries.

Keywords: brownfields, revitalization, rehabilitation, tools, urban planning

Procedia PDF Downloads 240

Authors: Oluwagbenga O. Isaac Orimoogunje, Omolola Helen Oshosanya

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The study examined land management in a typical watershed in southwestern Nigeria with a view to ascertaining its impact on land suitability analysis for rice cultivation and production. The study applied the analytical hierarchy process (AHP), weighted overlay analysis (WOA), multi-criteria decision-making techniques, and suitability map calculations within a Geographic Information System environment. Five main criteria were used, and these include climate, topography, soil fertility, macronutrients, and micronutrients. A consistency ratio (CR) of 0.067 was obtained for rice cultivation. The results showed that 95% of the land area is suitable for rice cultivation, with pH units ranging between 4.6 and 6.0, organic matter of 1.4–2.5 g kg-1 and base saturation of more than 80%. The study concluded that the Ofiki watershed is a potential site for large-scale rice cultivation in a sustainable capacity.

Keywords: land management, land characteristics, land suitability, rice production, watershed

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Authors: Shahriyar Keshtgar, Mahmoud Reza Heyhat, Sasan Bagheri, Ebrahim Gholami, Seyed Naser Raiisosadat

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The eastern Iranian range is a Z-shaped sigmoidal outcrop appearing with a NS-trending general strike on the satellite images, has already been known as the Sistan suture zone, recently identified as the product of an orogenic event introduced either by the Paleogene or Sistan orogen names. The flysch sedimentary basin of eastern Iran was filled by a huge volume of fine-grained Eocene turbiditic sediments, smaller amounts of pelagic deposits and Cretaceous ophiolitic slices, which are entirely remnants of older accretionary prisms appeared in a fold-thrust belt developed onto a subduction zone under the Lut/Afghan block, portions of the Cimmerian superterrane. In these ranges, there are Triassic sedimentary and carbonate sequences (equivalent to Nayband and Shotori Formations) along with scattered outcrops of Permian limestones (equivalent to Jamal limestone) and greenschist-facies metamorphic rocks, probably belonging to the basement of the Lut block, which have tectonic contacts with younger rocks. Moreover, the younger Eocene detrital-volcanic rocks were also thrusted onto the Cretaceous or younger turbiditic deposits. The first generation folds (parallel folds) and thrusts with slaty cleavage appeared parallel to the NE edge of the Lut block. Structural analysis shows that the most vergence of thrusts is toward the southeast so that the Permo-Triassic units in Lut have been thrusted on the younger rocks, including older (probably Jurassic) granites. Additional structural studies show that the regional transport direction in this deformation event is from northwest to the southeast where, from the outside to the inside of the orogen in the Sechengi area. Younger thrusts of the second deformation event were either directly formed as a result of the second deformation event, or they were older thrusts that reactivated and folded so that often, two sets or more slickenlines can be recognized on the thrust planes. The recent thrusts have been redistributed in directions nearly perpendicular to the edge of the Lut block and parallel to the axial surfaces of the northwest second generation large-scale folds (radial folds). Some of these younger thrusts follow the out-of-the-syncline thrust system. The both axial planes of these folds and associated penetrative shear cleavage extended towards northwest appeared with both northeast and southwest dips parallel to the younger thrusts. The large-scale buckling with the layer-parallel stress field has created this deformation event. Such consecutive deformation events perpendicular to each other cannot be basically explained by the simple linear orogen models presented for eastern Iran so far and are more consistent with the oroclinal buckling model.

Keywords: thrust, tectonic vergence, orocline buckling, sechangi, eastern iranian ranges

Procedia PDF Downloads 78

Authors: S. Olyaee, M. Seifouri, A. Nikoosohbat, M. Shams Esfand Abadi

Abstract:

Photonic Crystal Fibers (PCFs) can be used in optical communications as transmission lines. For this reason, the PCFs with low confinement loss, low chromatic dispersion, and low nonlinear effects are highly suitable transmission media. In this paper, we introduce a new design of index-guiding nanostructured photonic crystal fiber (IG-NPCF) with ultra-low chromatic dispersion, low nonlinearity effects, and low confinement loss. Relatively low dispersion is achieved in the wavelength range of 1200 to 1600nm using the proposed design. According to the new structure of nanostructured PCF presented in this study, the chromatic dispersion slope is -30(ps/km.nm) and the confinement loss reaches below 10-7 dB/km. While in the wavelength range mentioned above at the same time an effective area of more than 50.2μm2 is obtained.

Keywords: optical communication systems, nanostructured, index-guiding, dispersion, confinement loss, photonic crystal fiber

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Authors: P. Brinks, O. Kornadt, R. Oly

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This research focuses on the optimization of glazed surfaces and the assessment of possible solar gains in industrial buildings. Existing window rating methods for single windows were evaluated and a new method for a simple analysis of energy gains and losses by single windows was introduced. Furthermore extensive transient building simulations were carried out to appraise the performance of low cost polycarbonate multi-cell sheets in interaction with typical buildings for industrial applications. Mainly, energy-saving potential was determined by optimizing the orientation and area of such glazing systems in dependency on their thermal qualities. Moreover the impact on critical aspects such as summer overheating and daylight illumination was considered to ensure the user comfort and avoid additional energy demand for lighting or cooling. Hereby the simulated heating demand could be reduced by up to 1/3 compared to traditional architecture of industrial halls using mainly skylights.

Keywords: solar architecture, Passive Solar Building Design, glazing, Low-Energy Buildings, industrial buildings

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Authors: A. Sengouga, Y. Imessaoudene, A. Semar, B. Mouhouche, M. Kadir

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Biskra or Zibans, is located in a structural transition zone between the chain of the Saharan Atlas Mountains and the Sahara. It is an arid region where the superficial water resource is the mild, hence the importance of the lithological description and the evaluation of aquifers rock’s volumes, which are highly dependent on the mobilized water contained in the various reservoirs (Quaternary, Mio-Pliocene, Eocene and Continental intercalary). Through a data synthesis which is particularly based on stratigraphic logs of drilling, the description of aquifers heterogeneity and the determining of the spatial variability of aquifer appearance became possible, by using geostatistical analysis, which allowed the representation of the aquifer thicknesses mapping and their space variation. The different thematic maps realized focus on drilling position, the substratum shape and finally the aquifers thicknesses of the region. It is found that the high density of water points especially these of drilling points are superposed on the hydrologic reservoirs with significant thicknesses.

Keywords: log stratigraphic ArcGIS 10, geometry of aquifers, rocks reservoir volume, Biskra

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Authors: Wu Yiqun, Weng Jiantao

Abstract:

The human settlements of China are picked up from the land use vector map by interpreting the Thematic Map of 2014. This paper established the sustainable human settlements geographical division evaluation system and division model using GIS. The results show that: The density of human residential areas in China is different, and the density of sustainable human areas is higher, and the west is lower than that in the West. The regional differences of sustainable human settlements are obvious: the north is larger than that the south, the plain regions are larger than those of the hilly regions, and the developed regions are larger than the economically developed regions. The geographical distribution of the sustainable human settlements is measured by the degree of porosity. The degree of porosity correlates with the sustainable human settlement density. In the area where the sustainable human settlement density is high the porosity is low, the distribution is even and the gap between the settlements is low.

Keywords: GIS, geographical division, sustainable human settlements, China

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Authors: M. T. Becerra, F. Martín, P. Gutiérrez, S. Cubo, E. Iglesias, A. A. Sáenz del Castillo, P. Cañamero

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The consolidation of the European Higher Education Area (EHEA) in universities has led to significant changes in student training. This paper, part of a Teaching Innovation Project, starts from new training requirements that are fit within Undergraduate Thesis Project, a subject that culminate student learning. Undergraduate Thesis Project is current assessment system that weigh the student acquired training in university education. Students should develop a range of cross curricular competences such as public presentation of ideas, problems and solutions both orally and writing in Undergraduate Thesis Project. Specifically, we intend with our innovation proposal to provide resources that enable university students from Teacher Degree in Education Faculty of University of Extremadura (Spain) to develop the cross curricular competence of public speaking.

Keywords: interaction, public speaking, student, university

Procedia PDF Downloads 439

Authors: Ikah Ning Prasetiowati Permanasari, Gunawan Handayani, Lilik Hendrajaya

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Landslide occurence at Mukapayung, Cililin West Java with material movement downward slope as far as 500m and hit residential areas of the village Nagrog cause eighteen people died and ten homes were destroyed and twenty-three heads of families evacuated. In order to test the hypothesis that soil at the landslides area is prone to landslides, we do drilling and the following tests were taken: particle size distribution, atterberg limits, shear strength, density, shringkage limits and triaxial unconsolidated and consolidated undrained test. Factor of safety was calculated to find out the possibility of subsequent landslides. The value of FOS of three layers is 1,05 which means that the soil in a critical condition and would be imminent to slide if there is disruption from the outside.

Keywords: atterberg limits, particle size distribution, shear strength parameters, slope geometry, factor of safety

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Authors: S. Sulaiman, M. A. Razak, M. R. Ibrahim, A. A. Khan

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An experimental work on the effect of different current and pulse duration on performance of EDM process of Allegheny Ludlum D2 Tool Steel (UNS T30402). The effect of varying the machining parameters on the machining responses such as material removal rate (MRR), electrode wear rate (EWR), and surface roughness (Ra) have been investigated. In this study, triangular shape and circular shape of copper was used as an electrode with surface area of 100 mm². The experiments were repeated for three different values of pulse duration (100 µs, 200 µs and 400 µs) with combination of three different values of discharge current (12 A, 16 A and 24 A). It was found that the pulse duration and current have significant effect on MRR, EWR and Ra. An increase in the pulse durations causes an increase in the MRR and Ra, but a decrease in the EWR. Meanwhile, the effect of currents on EDM performance shows that the increasing currents lead to an increase in the MRR, EWR and Ra.

Keywords: allegheny ludlum D2 tool steel, current, EDM, surface roughness, pulse duration

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Authors: H. Majour, L. Djabri

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Many methods in the groundwater vulnerability have been developed in the world (methods like PRAST, DRIST, APRON/ARAA, PRASTCHIM, GOD). In this study, our choice dealt with two recent complementary methods using category mapping of index with weighting criteria (Point County Systems Model MSCP) namely the standard DRASTIC method and SI (Susceptibility Index). At present, these two methods are the most used for the mapping of the intrinsic vulnerability of groundwater. Two classes of groundwater vulnerability in the Biskra sandy aquifer were identified by the DRASTIC method (average and high) and the SI method (very high and high). Integrated analysis has revealed that the high class is predominant for the DRASTIC method whereas for that of SI the preponderance is for the very high class. Furthermore, we notice that the method SI estimates better the vulnerability for the pollution in nitrates, with a rate of 85 % between the concentrations in nitrates of groundwater and the various established classes of vulnerability, against 75 % for the DRASTIC method. By including the land use parameter, the SI method produced more realistic results.

Keywords: DRASTIC, SI, GIS, Biskra sandy aquifer, Algeria

Procedia PDF Downloads 487

Authors: Andrzej Wałęga, Marta Cebulska, Agnieszka Ziernicka-Wojtaszek, Wojciech Młocek, Agnieszka Wałęga, Tommaso Caloiero

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Drought is one of the natural phenomena influencing many aspects of human activities like food production, agriculture, industry, and the ecological conditions of the environment. In the area of the Polish Carpathians, there are periods with a deficit of rainwater and an increasing frequency in dry months, especially in the cold half of the year. The aim of this work is a spatial and temporal analysis of drought, expressed as SPI in a heterogenous area of the Polish Carpathian and of the highland Region in the Central part of Europe based on long-term precipitation data. Also, to our best knowledge, for the first time in this work, drought characteristics analyzed via the SPI were discussed based on the atmospheric circulation calendar. The study region is the Upper Vistula Basin, located in the southern and south-eastern part of Poland. In this work, monthly precipitation from 56 rainfall stations was analysed from 1961 to 2022. The 3-, 6-, 9-, and 12-month Standardized Precipitation Index (SPI) were used as indicators of meteorological drought. For the 3-month SPI, the main climatic mechanisms determining extreme droughts were defined based on the calendar of synoptic circulations. The Mann-Kendall test was used to detect the trend of extreme droughts. Statistically significant trends of SPI were observed on 52.7% of all analyzed stations, and in most cases, a positive trend was observed. Statistically significant trends were more frequently observed in stations located in the western part of the analyzed region. Long-term droughts, represented by the 12-month SPI, occurred in all stations but not in all years. Short-term droughts (3-month SPI) were most frequent in the winter season, 6 and 9-month SPI in winter and spring, and 12-month SPI in winter and autumn, respectively. The spatial distribution of drought was highly diverse. The most intensive drought occurred in 1984, with the 6-month SPI covering 98% of the analyzed region and the 9 and 12-month SPI covering 90% of the entire region. Droughts exhibit a seasonal pattern, with a dominant 10-year periodicity for all analyzed variants of SPI. Additionally, Fourier analysis revealed a 2-year periodicity for the 3-, 6-, and 9-month SPI and a 31-year periodicity for the 12-month SPI. The results provide insights into the typical climatic conditions in Poland, with strong seasonality in precipitation. The study highlighted that short-term extreme droughts, represented by the 3-month SPI, are often caused by anticyclonic situations with high-pressure wedges Ka and Wa, and anticyclonic West as observed in 52.3% of cases. These findings are crucial for understanding the spatial and temporal variability of short and long-term extreme droughts in Central Europe, particularly for the agriculture sector dominant in the northern part of the analyzed region, where drought frequency is highest.

Keywords: atmospheric circulation, drought, precipitation, SPI, the Upper Vistula Basin

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Authors: R. Abd-Rahman, M. M. Isa, H. H. Goh

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A compound parabolic concentrator (CPC) is a well known non-imaging concentrator that will concentrate the solar radiation onto receiver (PV cell). One of disadvantage of CPC is has tall and narrow height compared to its diameter entry aperture area. Therefore, for economic reason, a truncation had been done by removed from the top of the full height CPC. This is also will lead to the decreases of concentration ratio but it will be negligible. In this paper, the flux distribution of untruncated and truncated 2-D hollow compound parabolic trough concentrator (hCPTC) design is presented. The untruncated design has initial height, H=193.4mm with concentration ratio, C_(2-D)=4. This paper presents the optical simulation of compound parabolic trough concentrator using ray-tracing software TracePro. Results showed that, after the truncation, the height of CPC reduced 45% from initial height with the geometrical concentration ratio only decrease 10%. Thus, the cost of reflector and material dielectric usage can be saved especially at manufacturing site.

Keywords: compound parabolic trough concentrator, optical modelling, ray-tracing analysis, improved performance

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Authors: Sallama Resen, Celal Öztürk

Abstract:

Distance estimation between tow nodes has wide scope of surveillance and tracking applications. This paper suggests a Bluetooth Low Energy (BLE) technology as a media for transceiver and receiver signal in small indoor areas. As an example, BLE communication technologies used in child safety domains. Local network is designed to detect child position in indoor school area consisting Mobile Beacons (MB), Access Points (AP) and Smart Phones (SP) where MBs stuck in children’s shoes as wearable sensors. This paper presents a technique that can detect mobile beacons’ position and help finding children’s location within dynamic environment. By means of bluetooth beacons that are attached to child’s shoes, the distance between the MB and teachers SP is estimated with an accuracy of less than one meter. From the simulation results, it is shown that high accuracy of position coordinates are achieved for multi-mobile beacons in different environments.

Keywords: bluetooth low energy, child safety, mobile beacons, received signal strength

Procedia PDF Downloads 346

Authors: Lisa Listiana

Abstract:

ASEAN leader agreed to accelerate ASEAN Economic Community (AEC) implementation by 2015. The AEC Blueprint has set up obligations for its members to follow which include the establishment of (a) free trade in goods, according to ASEAN Free Trade Area: AFTA, (b) free trade in services, according to ASEAN Framework Agreement on Services: AFAS, (c) free trade in investment, according to ASEAN Comprehensive Investment Agreement: ACIA, (d) free capital flow, and (e) free flow of skilled labors. Consequently, these obligations bring both challenges and opportunities for its members. As accountant is included in the coverage of 8 skilled labors, the readiness of accounting profession to embrace AEC 2015 is pivotal. If Indonesian accountants do not accelerate their learning effort, the knowledge gap between Indonesian accountants and their international colleagues will only be worsened. This paper aims to analyze the current progress of AEC preparation and its challenges and opportunities for Indonesian accountants, and also to propose recommendation as necessary.

Keywords: AEC, ASEAN, readiness, Indonesian accountants

Procedia PDF Downloads 436