Search results for: subsurface transport

Authors: Yeng Min Yi, Rosli Md Illias, Salehhuddin Hamdan

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Industrial biocatalysis is mainly based on the use of cell free or intracellular enzyme systems. However, the expensive cost and relatively lower operational stability of free enzymes limit practical use in industries. Cell surface display system can be used as a cost-efficient alternative to overcome the laborious purification and substrate transport limitation. In this research, TibA autotransporter from E. coli was used to display Aspergillus fumigatus xylanase (xyn). The amplified xyn was fused in between N-terminal signal peptide and C-terminal β-barrel of TibA. The cloned was transformed and expressed in E. coli BL21 (DE3). Outer membrane localization of TibA-xyn fusion protein was confirmed by SDS PAGE and western blot with expected size of 62.5 kDa. Functional display of xyn was examined by activity assay. Cell surface displayed xyn exhibited the highest activity at 37 °c, 0.3 mM IPTG. As a summary, TibA displaying system has the potential for further industrial applications. Moreover, this is the first report of the display of xylanase using TibA on the surface of E. coli.

Keywords: biocatalysis, cell surface display, Escherichia coli, TibA autotransporter

Procedia PDF Downloads 281

Authors: Andreea Anamaria Anghel, Flaviu Mihai Frigura-Lliasa, Attila Simo

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In recent years, there has been a renewed interest in revitalizing the historical area of Timisoara, a city located in western Romania, with a focus on preserving its architectural heritage while also promoting sustainable urban development. This has led to several initiatives aimed at improving public spaces, promoting sustainable transport, and encouraging the use of green infrastructure, such as green interior courtyards, to enhance the livability and sustainability of the area. A preliminary study regarding history, characteristics and current condition was carried out by the authors regarding these interior courtyards in the historical areas of Timisoara, the European Capital of Culture, in 2023, highlighting their potential to contribute to the sustainable development of the city. Modern interventions in interior historical courtyards should aim to preserve the historic character of these spaces while also promoting their sustainable and functional use in the 21st century. By doing so, these courtyards can continue to serve as vital urban oases and cultural landmarks for generations to come.

Keywords: architectural heritage, green interior courtyards, public spaces, sustainable development

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Authors: A. Kaddour, S. M. A. Bekkouche

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Limiting heat losses during ventilation of indoor building spaces has become a basic aim for architects. Much experience has been gained in terms of ventilation of indoor spaces. Nevertheless, due to the complex applications, attempts to create a theoretical base for solving the problems related to the issue are limited, especially determining the minimum ventilation period required within a designated space. In this paper we have approached this matter, both theoretically and computationally. The conclusion we reached was that controlled ventilation of spaces through vent holes that successively open and close at regular time intervals can limit the excessive circulation of air masses, which in turn limits heat losses. Air change rates through open and tilted windows in rooms of residential buildings driven by atmospheric motions are investigated to evaluate natural ventilation concepts. Model of thermal building simulations is used. A separated sample storey and a sample single room in larger scales were used to measure air transport through window openings under the influence of the external pressure distribution.

Keywords: natural ventilation, temperature factor, air change rates, air circulation

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Authors: R. Chouatah, E. G. Filali, B. Zouzou

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It has been well established that there are no differences between microscale and macroscale flows of incompressible liquids. However, surface roughness has been known to impact the transport phenomena. The effect of structured roughness on the dynamics and heat transfer of water flowing through minichannel was numerically investigated in this study. Our study consists in characterizing the dynamic field and heat transfer aspect of a flow in circular minichannel equipped with structured roughness using CFD software, CFX. The study is performed to understand the effect of various roughness elements (rectangular, triangular), roughness height and roughness pitch on the friction factor and heat transfer coefficient. Our work focuses on a water flow inside a circular mini-channel of 1 mm in diameter and 10 cm in length. The speed entry into the mini-channel varies from 0.1 m/s to 25 m/s. The wall of the mini-channel is submitted to a constant heat flux; q=100,000 W/m². The simulations results are compared to those obtained with smooth minichannel and the existing experimental and numerical results in the literature.

Keywords: heat transfer, laminar and turbulent flow, minichannel, structured roughness

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Authors: T. Poyai, P. Painmanakul, N. Chawaloesphonsiya, P. Dhanasin, C. Getwech, P. Wattana

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Drilling is a key activity in oil and gas exploration and production. Drilling always requires the use of drilling mud for lubricating the drill bit and controlling the subsurface pressure. As drilling proceeds, a considerable amount of cuttings or rock fragments is generated. In general, water or Water Based Mud (WBM) serves as drilling fluid for the top hole section. The cuttings generated from this section is non-hazardous and normally applied as fill materials. On the other hand, drilling the bottom hole to reservoir section uses Synthetic Based Mud (SBM) of which synthetic oils are composed. The bottom-hole cuttings, SBM cuttings, is regarded as a hazardous waste, in accordance with the government regulations, due to the presence of hydrocarbons. Currently, the SBM cuttings are disposed of as an alternative fuel and raw material in cement kiln. Instead of burning, this work aims to propose an alternative for drill cuttings management under two ultimate goals: (1) reduction of hazardous waste volume; and (2) making use of the cleaned cuttings. Soil washing was selected as the major treatment process. The physiochemical properties of drill cuttings were analyzed, such as size fraction, pH, moisture content, and hydrocarbons. The particle size of cuttings was analyzed via light scattering method. Oil present in cuttings was quantified in terms of total petroleum hydrocarbon (TPH) through gas chromatography equipped with flame ionization detector (GC-FID). Other components were measured by the standard methods for soil analysis. Effects of different washing agents, liquid-to-solid (L/S) ratio, washing time, mixing speed, rinse-to-solid (R/S) ratio, and rinsing time were also evaluated. It was found that drill cuttings held the electrical conductivity of 3.84 dS/m, pH of 9.1, and moisture content of 7.5%. The TPH in cuttings existed in the diesel range with the concentration ranging from 20,000 to 30,000 mg/kg dry cuttings. A majority of cuttings particles held a mean diameter of 50 µm, which represented silt fraction. The results also suggested that a green solvent was considered most promising for cuttings treatment regarding occupational health, safety, and environmental benefits. The optimal washing conditions were obtained at L/S of 5, washing time of 15 min, mixing speed of 60 rpm, R/S of 10, and rinsing time of 1 min. After washing process, three fractions including clean cuttings, spent solvent, and wastewater were considered and provided with recommendations. The residual TPH less than 5,000 mg/kg was detected in clean cuttings. The treated cuttings can be then used for various purposes. The spent solvent held the calorific value of higher than 3,000 cal/g, which can be used as an alternative fuel. Otherwise, the recovery of the used solvent can be conducted using distillation or chromatography techniques. Finally, the generated wastewater can be combined with the produced water and simultaneously managed by re-injection into the reservoir.

Keywords: drill cuttings, green solvent, soil washing, total petroleum hydrocarbon (TPH)

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Authors: Kwangho Lee, Joongmyeon Bae

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Fuel cells are spotlighted in the world for being highly efficient and environmentally friendly. A hydrogen fuel for a fuel cell is obtained from a number of sources. Most of fuel cell for APU(Auxiliary power unit) system using diesel fuel as a hydrogen source. Diesel fuel has many advantages, such as high hydrogen storage density, easy to transport and also well-infra structure. However, conventional diesel reforming system for PEMFC(Proton exchange membrane fuel cell) requires a large volume and complex CO removal system for the lower the CO level to less than 10ppm. In addition, the PROX(Preferential Oxidation) reaction cooling load is needed because of the strong exothermic reaction. However, the hydrogen separation membrane that we propose can be eliminated many disadvantages, because the volume is small and permeates only pure hydrogen. In this study, we were conducted to the pressurized diesel reforming and water-gas shift reaction experiment for the hydrogen permeable membrane application.

Keywords: hydrogen, diesel, reforming, ATR, WGS, PROX, membrane, pressure

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Authors: Arlan S. Freitas, Leila M. Carvalho, Adriana L. Soares, Arnoud Neto, Marta S. Madruga, Rafael H. Carvalho, Elza I. Ida, Massami Shimokomaki

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The objective of this work was to evaluate the influence of microclimatic profile of broiler transport trucks and holding time (340) min under commercial conditions over the breast meat quality and DOA (Dead On Arrival) in a tropical Brazilian regions as the NorthEast. In this particular region routinely the season is divided into dry and wet seasons. Three loads of 4,100 forty seven days old broiler were monitored from farm to slaughterhouse in a distance of 273 km (320 min), morning periods of August, September and October 2015 rainy days. Meat qualities were evaluated by determining the occurrence of PSE (pale, soft, exudative) meat and DFD (dark, firm, dry) meat. The percentage of DOA per loaded truck was determined by counting the dead broiler during the hanging step at the slaughtering plant. Results showed the occurrence of 26.30% of PSE and 2.49% of DFD and 0.45% of DOA. By having PSE- and DFD- meat means that the birds were under thermal and cold stress leading as consequence to a relative high DOA index.

Keywords: animal welfare, DFD, microclimatic profile, PSE

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Authors: Abdurrasheed Sa'id, Abubakar Isma'il, Waheed Alayande

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This study focused on carrying out numerical simulations of Kangimi reservoir sedimentation by reviewing different numerical sediment transport models, and GSTARS3 was selected. The model was developed using the 1977 data. It was calibrated by simulating the 2012 profile and sediment deposition and compared with 2012 hydrographic survey results of NWRI. The model was validated by simulating the 2016 deposition and compared the results with NWRI estimates. Also, the performance of the proposed model was tested using statistical parameters such as MSE (Mean Square Error), MAPE (Mean Average Percentage Error) and R2 (Coefficient of determination) with values of 1.32m, 0.17% and 0.914 respectively which shows strong agreement. After the calibration, validation and performance testing the model was used to simulate the 2032 and 2062 profiles and deposition. The results showed that by 2032 the reservoir will be silted by 25.34MCM or 43.3% of the design capacity and 60.7% of the capacity by the year 2062. A number of sedimentation mitigation measures were recommended.

Keywords: NWRI- national water resources institute, sedimentation, GSTARS3, model

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Authors: Juraj Camaj, Anna Dolinayova, Jana Lalinska, Miroslav Bariak

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Planning of infrastructure and processes in logistic center within the frame of various kinds of logistic hubs and technological activities in them represent quite complex problem. The main goal is to design appropriate layout, which enables to realize expected operation on the desired levels. The simulation software represents progressive contemporary experimental technique, which can support complex processes of infrastructure planning and all of activities on it. It means that simulation experiments, reflecting various planned infrastructure variants, investigate and verify their eligibilities in relation with corresponding expected operation. The inducted approach enables to make qualified decisions about infrastructure investments or measures, which derive benefit from simulation-based verifications. The paper represents simulation software for simulation infrastructural layout and technological activities in marshalling yard, intermodal terminal, warehouse and combination between them as the parts of logistic center.

Keywords: marshalling yard, intermodal terminal, warehouse, transport technology, simulation

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Authors: M. Eckert, M. Oliveira

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The intensive use of natural aggregates, near cities and towns, associated to the increase of the global population, leads to its depletion and increases the transport distances. The uncontrolled deposition of construction and demolition waste in landfills and city outskirts, causes pollution and takes up space. The use of recycled aggregates in concrete preparation would contribute to mitigate the problem. However, it arises the problem that the high water absorption of recycled aggregate decreases the bleeding rate of concrete, and when this gets lower than the evaporation rate, plastic shrinkage cracking occurs. This phenomenon can be particularly problematic in hot and windy curing environments. Cracking facilitates the flow of liquid and gas into concrete which attacks the reinforcement and degrades the concrete. These factors reduce the durability of concrete structures and consequently the lifetime of buildings. A ring test was used, cured in a wind tunnel, to evaluate the plastic shrinkage cracking sensitivity of recycled aggregate concrete, in order to implement preventive means to control this phenomenon. The role of several aggregate properties on the concrete segregation and cracking mechanisms were also discussed.

Keywords: recycled aggregate, plastic shrinkage cracking, wind tunnel, durability

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Authors: Gia Surguladze, Nino Topuria, Lily Petriashvili, Giorgi Surguladze

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Modeling of building processes of a multimodal freight transportation support information system is discussed based on modern CASE technologies. Functional efficiencies of ports in the eastern part of the Black Sea are analyzed taking into account their ecological, seasonal, resource usage parameters. By resources, we mean capacities of berths, cranes, automotive transport, as well as work crews and neighbouring airports. For the purpose of designing database of computer support system for Managerial (Logistics) function, using Object-Role Modeling (ORM) tool (NORMA – Natural ORM Architecture) is proposed, after which Entity Relationship Model (ERM) is generated in automated process. The software is developed based on Process-Oriented and Service-Oriented architecture, in Visual Studio.NET environment.

Keywords: seaport resources, business-processes, multimodal transportation, CASE technology, object-role model, entity relationship model, SOA

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Authors: Narayanakumar Somasundaram, Venkat Nihit Chirivella, Venkata Dilip Kumar Pasupuleti

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Ajakool, India, has a multi-span bridge that is constructed for rail transport with a maximum operating speed of 100 km/hr. It is a standard RDSO design of a PSC box girder carrying a single railway track. The Structural Health Monitoring System (SHM) is designed and installed to compare and analyze the vibrations and displacements on the bridge due to different live loads from moving trains. The study is conducted for three different spans of the same bridge to understand the health of the elastomeric bearings. Also, to validate the same, a three-dimensional finite element model is developed, and modal analysis is carried out. The proposed methodology can help in detecting deteriorated elastomeric bearings using only wireless tri-accelerometer sensors. Detailed analysis and results are presented in terms of mode shapes, accelerations, displacements, and their importance to each other. This can be implemented with a lot of ease and can be more accurate.

Keywords: dynamic effects, vibration analysis, accelerometer sensors, finite element analysis, structural health monitoring, elastomeric bearing

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Authors: Jackson Becker

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Transportation produces the largest amount of carbon dioxide emissions in the United States of America. Today, cars are the predominant mode of transportation across the country, and our cities have been reshaped due to them. This was not always the case. Streetcars were seen in almost every American city of the early 1900s. These streetcar systems were viewed as obsolete with the rise of the automobile. With fewer streetcars came lower public transport ridership. Austin, Texas is one of the fastest growing cities in the country, and it used to have an extensive streetcar line. Today, it plans to build a light rail line with less rail mileage than 100 years ago. This research looks at the areas of Austin that are not included in the city’s new transit plan. Transit connectivity is one factor that goes into walkability rates for cities. This study also looks at the correlation between walkability ratings with median household income levels from the 2019 Census. The results showed a correlation between higher income neighborhoods having higher walkability rates, which was influenced by the lack of public transportation options.

Keywords: transportation, walkability, income, austin

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Authors: Minjin Kim, Jihwan Kim, Bongsoo Kim, Junho Suh

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We demonstrate nanomechanical resonators constructed with synthetic nanowires (NWs) and study their electro-mechanical properties at millikelvin temperatures. Nanomechanical resonators are fabricated using single-crystalline Au NWs and InAs NWs. The mechanical resonance signals are acquired by either magnetomotive or capacitive detection methods. The Au NWs are synthesized by chemical vapor transport method at 1100 °C, and they exhibit clean surface and single-crystallinity with little defects. Due to pristine surface quality, these Au NW mechanical resonators could provide an ideal model system for studying surface-related effects on the mechanical systems. The InAs NWs are synthesized by molecular beam epitaxy or metal organic chemical vapor deposition method. The InAs NWs show electronic conductance modulation resembling Coulomb blockade, which also manifests in the mechanical resonance signals in the form of damping and resonance frequency shift. Our result provides an evidence of strong electro-mechanical coupling in synthetic NW nanomechanical resonators.

Keywords: Au nanowire, InAs nanowire, nanomechanical resonator, synthetic nanowires

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Authors: Norbert Magyar, Jozsef Kovacs, Peter Tanos, Balazs Trasy, Tamas Garamhegyi, Istvan Gabor Hatvani

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Water is one of the most important common resources, and as a result of urbanization, agriculture, and industry it is becoming more and more exposed to potential pollutants. The prevention of the deterioration of water quality is a crucial role for environmental scientist. To achieve this aim, the operation of monitoring networks is necessary. In general, these networks have to meet many important requirements, such as representativeness and cost efficiency. However, existing monitoring networks often include sampling sites which are unnecessary. With the elimination of these sites the monitoring network can be optimized, and it can operate more economically. The aim of this study is to illustrate the applicability of the CCDA (Combined Cluster and Discriminant Analysis) to the field of water quality monitoring and optimize the monitoring networks of a river (the Danube), a wetland-lake system (Kis-Balaton & Lake Balaton), and two surface-subsurface water systems on the watershed of Lake Neusiedl/Lake Fertő and on the Szigetköz area over a period of approximately two decades. CCDA combines two multivariate data analysis methods: hierarchical cluster analysis and linear discriminant analysis. Its goal is to determine homogeneous groups of observations, in our case sampling sites, by comparing the goodness of preconceived classifications obtained from hierarchical cluster analysis with random classifications. The main idea behind CCDA is that if the ratio of correctly classified cases for a grouping is higher than at least 95% of the ratios for the random classifications, then at the level of significance (α=0.05) the given sampling sites don’t form a homogeneous group. Due to the fact that the sampling on the Lake Neusiedl/Lake Fertő was conducted at the same time at all sampling sites, it was possible to visualize the differences between the sampling sites belonging to the same or different groups on scatterplots. Based on the results, the monitoring network of the Danube yields redundant information over certain sections, so that of 12 sampling sites, 3 could be eliminated without loss of information. In the case of the wetland (Kis-Balaton) one pair of sampling sites out of 12, and in the case of Lake Balaton, 5 out of 10 could be discarded. For the groundwater system of the catchment area of Lake Neusiedl/Lake Fertő all 50 monitoring wells are necessary, there is no redundant information in the system. The number of the sampling sites on the Lake Neusiedl/Lake Fertő can decrease to approximately the half of the original number of the sites. Furthermore, neighbouring sampling sites were compared pairwise using CCDA and the results were plotted on diagrams or isoline maps showing the location of the greatest differences. These results can help researchers decide where to place new sampling sites. The application of CCDA proved to be a useful tool in the optimization of the monitoring networks regarding different types of water bodies. Based on the results obtained, the monitoring networks can be operated more economically.

Keywords: combined cluster and discriminant analysis, cost efficiency, monitoring network optimization, water quality

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Authors: Yasser M. Saad, Amr A. El Hanafy, Saleh A. Alkarim, Hussein A. Almehdar, Elrashdy M. Redwan

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Camels are substantial providers of transport, milk, sport, meat, shelter, security and capital in many countries, particularly in Saudi Arabia. Inter simple sequence repeat technique was used to detect the genetic variations among some camel breeds (Majaheim, Safra, Wadah, and Hamara). Actual number of alleles, effective number of alleles, gene diversity, Shannon’s information index and polymorphic bands were calculated for each evaluated camel breed. Neighbor-joining tree that re-constructed for evaluated these camel breeds showed that, Hamara breed is distantly related from the other evaluated camels. In addition, the polymorphic sites, haplotypes and nucleotide diversity were identified for some camelidae cox1 gene sequences (obtained from NCBI). The distance value between C. bactrianus and C. dromedarius (0.072) was relatively low. Analysis of genetic diversity is an important way for conserving Camelus dromedarius genetic resources.

Keywords: camel, genetics, ISSR, neighbor-joining

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Authors: Carlos Alberto Carvalho Castro, Nancy Del Ducca Barbedo, Edmilsom Otoni Côrrea

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With increase the production oil and lines transmission gases that are in ample expansion, the industries medium and great transport they had to adapt itself to supply the demand manufacture in this fabrication segment. In this context, two welding processes have been more extensively used: the GMAW (Gas Metal Arc Welding) and the FCAW (Flux Cored Arc Welding). In this work, welds using these processes were carried out in flat position on ASTM A-36 carbon steel plates in order to make a comparative evaluation between them concerning to mechanical and metallurgical properties. A statistical tool based on technical analysis and design of experiments, DOE, from the Minitab software was adopted. For these analyses, the voltage, current, and welding speed, in both processes, were varied. As a result, it was observed that the welds in both processes have different characteristics in relation to the metallurgical properties and performance, but they present good weldability, satisfactory mechanical strength e developed mathematical models.

Keywords: Flux Cored Arc Welding (FCAW), Gas Metal Arc Welding (GMAW), Design of Experiments (DOE), mathematical models

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Authors: Sudhir Kumar Tiwari

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The paper demonstrates a methodology that can be used at an early design stage of any conventional aircraft. This research activity assesses the feasibility derivation of methodology for aircraft loads estimation during the various phases of design for a transport category aircraft by utilizing potential of using commercial finite element analysis software, which may drive significant time saving. Early Design phase have limited data and quick changing configuration results in handling of large number of load cases. It is useful to idealize the aircraft as a connection of beams, which can be very accurately modelled using finite element analysis (beam elements). This research explores the correct approach towards idealizing an aircraft using beam elements. FEM Techniques like inertia relief were studied for implementation during course of work. The correct boundary condition technique envisaged for generation of shear force, bending moment and torque diagrams for the aircraft. The possible applications of this approach are the aircraft design process, which have been investigated.

Keywords: multi-disciplinary optimization, aircraft load, finite element analysis, stick model

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Authors: Mostafa Shahriari, Sergio Rojas, David Pardo, Angel Rodriguez- Rozas, Shaaban A. Bakr, Victor M. Calo, Ignacio Muga

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Logging-While Drilling (LWD) is a technique to record down-hole logging measurements while drilling the well. Nowadays, LWD devices (e.g., nuclear, sonic, resistivity) are mostly used commercially for geo-steering applications. Modern borehole resistivity tools are able to measure all components of the magnetic field by incorporating tilted coils. The depth of investigation of LWD tools is limited compared to the thickness of the geological layers. Thus, it is a common practice to approximate the Earth’s subsurface with a sequence of 1D models. For a 1D model, we can reduce the dimensionality of the problem using a Hankel transform. We can solve the resulting system of ordinary differential equations (ODEs) either (a) analytically, which results in a so-called semi-analytic method after performing a numerical inverse Hankel transform, or (b) numerically. Semi-analytic methods are used by the industry due to their high performance. However, they have major limitations, namely: -The analytical solution of the aforementioned system of ODEs exists only for piecewise constant resistivity distributions. For arbitrary resistivity distributions, the solution of the system of ODEs is unknown by today’s knowledge. -In geo-steering, we need to solve inverse problems with respect to the inversion variables (e.g., the constant resistivity value of each layer and bed boundary positions) using a gradient-based inversion method. Thus, we need to compute the corresponding derivatives. However, the analytical derivatives of cross-bedded formation and the analytical derivatives with respect to the bed boundary positions have not been published to the best of our knowledge. The main contribution of this work is to overcome the aforementioned limitations of semi-analytic methods by solving each 1D model (associated with each Hankel mode) using an efficient multi-scale finite element method. The main idea is to divide our computations into two parts: (a) offline computations, which are independent of the tool positions and we precompute only once and use them for all logging positions, and (b) online computations, which depend upon the logging position. With the above method, (a) we can consider arbitrary resistivity distributions along the 1D model, and (b) we can easily and rapidly compute the derivatives with respect to any inversion variable at a negligible additional cost by using an adjoint state formulation. Although the proposed method is slower than semi-analytic methods, its computational efficiency is still high. In the presentation, we shall derive the mathematical variational formulation, describe the proposed multi-scale finite element method, and verify the accuracy and efficiency of our method by performing a wide range of numerical experiments and comparing the numerical solutions to semi-analytic ones when the latest are available.

Keywords: logging-While-Drilling, resistivity measurements, multi-scale finite elements, Hankel transform

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Authors: Ali Ateş, Ansar B. Mwimbo, Ali H. Abdulkarim

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General transport equation has a wide range of application in Fluid Mechanics and Heat Transfer problems. In this equation, generally when φ variable which represents a flow property is used to represent fluid velocity component, general transport equation turns into momentum equations or with its well known name Navier-Stokes equations. In these non-linear differential equations instead of seeking for analytic solutions, preferring numerical solutions is a more frequently used procedure. Finite difference method is a commonly used numerical solution method. In these equations using velocity and pressure gradients instead of stress tensors decreases the number of unknowns. Also, continuity equation, by integrating the system, number of equations is obtained as number of unknowns. In this situation, velocity and pressure components emerge as two important parameters. In the solution of differential equation system, velocities and pressures must be solved together. However, in the considered grid system, when pressure and velocity values are jointly solved for the same nodal points some problems confront us. To overcome this problem, using staggered grid system is a referred solution method. For the computerized solutions of the staggered grid system various algorithms were developed. From these, two most commonly used are SIMPLE and SIMPLER algorithms. In this study Navier-Stokes equations were numerically solved for Newtonian flow, whose mass or gravitational forces were neglected, for incompressible and laminar fluid, as a hydro dynamically fully developed region and in two dimensional cartesian coordinate system. Finite difference method was chosen as the solution method. This is a parametric study in which varying values of velocity components, pressure and Reynolds numbers were used. Differential equations were discritized using central difference and hybrid scheme. The discritized equation system was solved by Gauss-Siedel iteration method. SIMPLE and SIMPLER were used as solution algorithms. The obtained results, were compared for central difference and hybrid as discritization methods. Also, as solution algorithm, SIMPLE algorithm and SIMPLER algorithm were compared to each other. As a result, it was observed that hybrid discritization method gave better results over a larger area. Furthermore, as computer solution algorithm, besides some disadvantages, it can be said that SIMPLER algorithm is more practical and gave result in short time. For this study, a code was developed in DELPHI programming language. The values obtained in a computer program were converted into graphs and discussed. During sketching, the quality of the graph was increased by adding intermediate values to the obtained result values using Lagrange interpolation formula. For the solution of the system, number of grid and node was found as an estimated. At the same time, to indicate that the obtained results are satisfactory enough, by doing independent analysis from the grid (GCI analysis) for coarse, medium and fine grid system solution domain was obtained. It was observed that when graphs and program outputs were compared with similar studies highly satisfactory results were achieved.

Keywords: finite difference method, GCI analysis, numerical solution of the Navier-Stokes equations, SIMPLE and SIMPLER algoritms

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Authors: Mikhail Gritskevich, Sebastian Hohenstein

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The paper presents the results of a detailed assessment of several modern Reynolds Averaged Navier-Stokes (RANS) turbulence models for prediction of C3X vane film cooling at various injection regimes. Three models are considered, namely the Shear Stress Transport (SST) model, the modification of the SST model accounting for the streamlines curvature (SST-CC), and the Explicit Algebraic Reynolds Stress Model (EARSM). It is shown that all the considered models face with a problem in prediction of the adiabatic effectiveness in the vicinity of the cooling holes; however, accounting for the Reynolds stress anisotropy within the EARSM model noticeably increases the solution accuracy. On the other hand, further downstream all the models provide a reasonable agreement with the experimental data for the adiabatic effectiveness and among the considered models the most accurate results are obtained with the use EARMS.

Keywords: discrete holes film cooling, Reynolds Averaged Navier-Stokes (RANS), Reynolds stress tensor anisotropy, turbulent heat transfer

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Authors: Chattrarat Hotrawaisaya

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This research aims to formulate the logistics collaborative model which is the management tool for orchid flower exporter. The researchers study logistics activities in orchid supply chain that stakeholders can collaborate and develop, including demand forecasting, inventory management, warehouse and storage, order-processing, and transportation management. The research also explores logistics collaboration implementation into orchid’s stakeholders. The researcher collected data before implementation and after model implementation. Consequently, the costs and efficiency were calculated and compared between pre and post period of implementation. The research found that the results of applying the logistics collaborative model to orchid exporter reduces inventory cost and transport cost. The model also improves forecasting accuracy, and synchronizes supply chain of exporter. This research paper contributes the uniqueness logistics collaborative model which value to orchid industry in Thailand. The orchid exporters may use this model as their management tool which aims in competitive advantage.

Keywords: logistics, orchid, supply chain, collaboration

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Authors: Munu Fritz-Austin Ndam

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Although the Cameroonian system of farming is considered as the first generation, the primary actors here involved have not yet understood the meaning of adding value to the product or produce they produce. The challenge here is for everyone who practices agriculture as an income generating activity in Cameroon to be able to understand the concept of value-added products and to know how to go about it. Recent studies have shown that these farmers who depend on agriculture as their main income generation activity make a great loss out of it because they don’t have the means to either transport their produce to the appropriate market, they don’t the knowledge on how to transform it, or they don’t have a means of conserving the product for a longer duration. It is important to note that after a thorough evaluation of the activity carried out, the final added value product sold is of great benefit not only to the producer but the buyer and the population at large. In my proposed prestation, I will discuss how the transformation activity will have a positive impact on the lives of farmers and the buyers and, most importantly, describe the methodology and procedure which is followed before the tubers (banana, Plantain, potato)is transformed into the finished or semi-finished product.

Keywords: transformation, sustainability, development, consumption

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Authors: Piyaporn Buaklang, Narisa Kengtrong Bordeerat

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The use of nanoparticles is increasing worldwide and there are many nanotech-based daily products available in the market. The toxicity of nanoparticles results from their extremely small size which can be transported easily into the blood stream and other organs. We aimed to study the genotoxicity of two nanoparticles, Titanium dioxide (TiO2-NPs) and Zinc oxide (ZnO-NPs), in TK6 cells by micronucleus assay. The cells were tested at 8, 24, and 48 hours after exposed to 0.10, 0.25, 0.50 and 1.00 µg/mL of TiO2-NPs particles size < 25 nm and < 100 nm and to ZnO-NPs at 1, 10, 50, and 100 µg/mL, particles size < 50 nm and < 100 nm. At 24 hours of incubation transmission electron microscope (TEM) revealed that the nanoparticles TiO2-NPs at 1.00 µg/mL and ZnO-NPs at 10 µg/mL were able to be taken into the cells and induced the production of increasing amount of micronucleus in dose-dependent manner. The effect of the two nanoparticles on chromosome aberration indicated that TiO2-NPs and ZnO-NPs are genotoxic. In addition, the toxicity of TiO2-NPs was found to be 10 times more toxic than ZnO-NPs after 24 hours exposure. Analysis showed that the TiO2-NPs induced formation of micronucleus was both time and dose dependent, whereas the genotoxicity of ZnO-NPs was only dose dependent. In conclusion, TiO2-NPs and ZnO-NPs were able to transport through the cells membrane and directly genotoxic to TK6 cells in dose-dependent manner.

Keywords: nanoparticles, genotoxicity, human lymphoblast cells (TK6), micronucleus

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Authors: Aldan A. Sapargaliyev, Yerbol A. Sapargaliyev

Abstract:

Since the invention, the electric machine (EM) can be defined as oEM – one-vector electric machine, as it works due to one-vector inductive coupling with use of one-vector electromagnet. The disadvantages of oEM are large size and limited efficiency at low and medium power applications. This paper describes multi-vector electric machine (mEM) based on multi-vector inductive coupling, which is characterized by the increased surface area of ​​the inductive coupling per EM volume, with a reduced share of inefficient and energy-consuming part of the winding, in comparison with oEM’s. Particularly, it is considered, calculated and compared the performance of three different electrical motors and their power at the same volumes and rotor frequencies. It is also presented the result of calculation of correlation between power density and volume for oEM and mEM. The method of multi-vector inductive coupling enables mEM to possess 1.5-4.0 greater density of power per volume and significantly higher efficiency, in comparison with today’s oEM, especially in low and medium power applications. mEM has distinct advantages, when used in transport vehicles such as electric cars and aircrafts.

Keywords: electric machine, electric motor, electromagnet, efficiency of electric motor

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Authors: Somesh Kumar Sharma, Sunanad Gupta

Abstract:

The contribution of aviation to society and economy is undisputedly significant. The aviation industry drives economic and social progress by contributing prominently to tourism, commerce and improved quality of life. Identifying the amount of fuel consumed by an aircraft while moving in both airspace and ground networks is critical to air transport economics. Aviation fuel is a major operating cost parameter of the aviation industry and at the same time it is prone to various constraints. This article aims to develop a model for fuel consumption of aviation product. The paper tailors the information for the fuel consumption optimization in terms of information development, information evaluation and information refinement. The information is evaluated and refined using statistical package R and Factor Analysis which is further validated with neural networking. The study explores three primary dimensions which are finally summarized into 23 influencing variables in contrast to 96 variables available in literature. The 23 variables explored in this study should be considered as highly influencing variables for fuel consumption which will contribute significantly towards fuel optimization.

Keywords: fuel consumption, civil aviation industry, neural networking, optimization

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Authors: Siamack A. Shirazi, Farzin Darihaki

Abstract:

Solid particles could be found in many multiphase flows, including transport pipelines and pipe fittings. Such particles interact with the pipe material and cause erosion which threats the integrity of the system. Therefore, predicting the erosion rate is an important factor in the design and the monitor of such systems. Mechanistic models can provide reliable predictions for many conditions while demanding only relatively low computational cost. Mechanistic models utilize a representative particle trajectory to predict the impact characteristics of the majority of the particle impacts that cause maximum erosion rate in the domain. The erosion caused by particle impacts is not only due to the direct impacts but also random impingements. In the present study, an alternative model has been introduced to describe the erosion due to random impingement of particles. The present model provides a realistic trend for erosion with changes in the particle size and particle Stokes number. The present model is examined against the experimental data and CFD simulation results and indicates better agreement with the data incomparison to the available models in the literature.

Keywords: erosion, mechanistic modeling, particles, multiphase flow, gas-liquid-solid

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Authors: Hisham Elmouazen, Xiaobing Zhang

Abstract:

In regenerative-cooled rocket engines, understanding the coolant behaviour within cooling channels is essential to enhance engine performance and maintain chamber walls at low temperatures. However, modelling and testing the rocket engine's cooling channels is challenging due to the high temperature of the chamber walls, supercritical flow, and high Reynolds number. Therefore, a numerical analysis of five different V-rib cross-sections to optimize rocket engine cooling channels' performance is developed and validated in this work. Three-dimensional CFD simulations are employed by the Shear Stress Transport (k- ω) turbulent model at Reynolds number 42,500. The study findings illustrate that the V-ribbed channel performance is optimized by 59.5% relative to the plain/flat channel. Additionally, the chamber wall temperature is decreased to 726.4 K, and the right-angle trapezoidal V-rib (Case 4) improves thermal augmentation up to 74.3 % with a slightly high friction factor.

Keywords: computational fluid dynamics CFD, regenerative-cooled system, thermal performance, V-rib cross-sections

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Authors: S. K. Subah, R. Tasnim, M. I. Jahan, M. R. Islam

Abstract:

While talking about how comfortable and convenient Dhaka's bus service is, the minimum emphasis is placed on the female commuters of the Dhaka city. Recognizing the contemporary situation, the supreme focus is to develop experimental model based on statistical methods. SEM has been adopted to quantify passenger satisfaction, which is affected by the perceived service quality. The study deals with 16 observed variables and three latent variables, which were correlated to identify their significance on the regulation of perceived SQ (Service Quality). To calibrate the model, a dataset of 250 responses from female users of local buses has been utilized through survey. A questionnaire structured with SQ variables was prepared in consultation with prevailing literature, practitioners, academicians, and users. The result concludes that the attributes of safe and secured environment have the most significant impact on the overall bus service quality according to the insight of female respondents. The study outcome might be a great help for the policymakers, women's organizations, and NGOs to formulate transport policy that will ensure a women-friendly public bus service.

Keywords: bus service quality, female perception, structural equation modelling, safety-security, women friendly bus

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Authors: Asad Naeem, Minsung Kim, Jinkoo Kim

Abstract:

In this work, the effectiveness of damped cable systems (DCS) on the mitigation of earthquake-induced response of a framed structure is investigated. The seismic performance of DCS is investigated using fragility analysis and life cycle cost evaluation of an existing building retrofitted with DCS, and the results are compared with those of the structure retrofitted with viscous dampers. The comparison of the analysis results reveals that, due to the self-centering capability of the DCS, residual displacement becomes nearly zero in the structure retrofitted with the DCS. According to the fragility analysis, the structure retrofitted with the DCS has smaller probability of reaching a limit states compared to the structure with viscous dampers. It is also observed that both the initial and life cycle costs of the DCS method required for the seismic retrofit is smaller than those of the structure retrofitted with viscous dampers. Acknowledgment: This research was supported by a grant (17CTAP-C132889-01) from Technology Advancement Research Program (TARP) funded by Ministry of Land, Infrastructure, and Transport of Korean government.

Keywords: damped cable system, seismic retrofit, self centering, fragility analysis

Procedia PDF Downloads 453