Search results for: aeolian sand deposition

Authors: M. Amparo Núñez-Andrés, Felipe Buill, Albert Prades

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More and more frequently, geomatics techniques such as terrestrial laser scanning or digital photogrammetry, either terrestrial or from drones, are being used to obtain digital terrain models (DTM) used for the monitoring of geological phenomena that cause natural disasters, such as landslides, rockfalls, debris-flow. One of the main multitemporal analyses developed from these models is the quantification of volume changes in the slopes and hillsides, either caused by erosion, fall, or land movement in the source area or sedimentation in the deposition zone. To carry out this task, it is necessary to filter the point clouds of all those elements that do not belong to the slopes. Among these elements, vegetation stands out as it is the one we find with the greatest presence and its constant change, both seasonal and daily, as it is affected by factors such as wind. One of the best-known indexes to detect vegetation on the image is the NVDI (Normalized Difference Vegetation Index), which is obtained from the combination of the infrared and red channels. Therefore it is necessary to have a multispectral camera. These cameras are generally of lower resolution than conventional RGB cameras, while their cost is much higher. Therefore we have to look for alternative indices based on RGB. In this communication, we present the results obtained in Georisk project (PID2019‐103974RB‐I00/MCIN/AEI/10.13039/501100011033) by using the GLI (Green Leaf Index) and ExG (Excessive Greenness), as well as the change to the Hue-Saturation-Value (HSV) color space being the H coordinate the one that gives us the most information for vegetation filtering. These filters are applied both to the images, creating binary masks to be used when applying the SfM algorithms, and to the point cloud obtained directly by the photogrammetric process without any previous filter or the one obtained by TLS (Terrestrial Laser Scanning). In this last case, we have also tried to work with a Riegl VZ400i sensor that allows the reception, as in the aerial LiDAR, of several returns of the signal. Information to be used for the classification on the point cloud. After applying all the techniques in different locations, the results show that the color-based filters allow correct filtering in those areas where the presence of shadows is not excessive and there is a contrast between the color of the slope lithology and the vegetation. As we have advanced in the case of using the HSV color space, it is the H coordinate that responds best for this filtering. Finally, the use of the various returns of the TLS signal allows filtering with some limitations.

Keywords: RGB index, TLS, photogrammetry, multispectral camera, point cloud

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Authors: G. Ghamrawi, Y. Abunnasr, M. Fawaz, S. Yazigi

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Coastal cities are constantly exposed to environmental degradation and economic regression fueled by rapid and uncontrolled urban growth as well as continuous resource depletion. This is the case of the City of Mina in Tripoli (Lebanon), where lack of awareness to preserve social, ecological, and historical assets, coupled with the increasing development pressures, are threatening the socioeconomic status of the city residents, the quality of life and accessibility to the coast. To address these challenges, a holistic coastal urban design and planning approach was developed to analyze the environmental, political, legal, and socioeconomic context of the city. This approach aims to investigate the potential of balancing urban development with the protection and enhancement of cultural, ecological, and environmental assets under an integrated coastal zone management approach (ICZM). The analysis of Mina's different sectors adopted several tools that include direct field observation, interviews with stakeholders, analysis of available data, historical maps, and previously proposed projects. The findings from the analysis were mapped and graphically represented, allowing the recognition of character zones that become the design intervention units. Consequently, the thesis proposes an urban, city-scale intervention that identifies 6 different character zones (the historical fishing port, Abdul Wahab island, the abandoned Port Said, Hammam el Makloub, the sand beach, and the new developable area) and proposes context-specific design interventions that capitalize on the main characteristics of each zone. Moreover, the intervention builds on the institutional framework of ICZM as well as other studies previously conducted for the coast and adopts nature-based solutions with hybrid systems for providing better environmental design solutions for developing the coast. This enables the realization of an all-inclusive, well-connected shoreline with easy and free access towards the sea; a developed shoreline with an active local economy, and an improved urban environment.

Keywords: blue green infrastructure, coastal cities, hybrid solutions, integrated coastal zone management, sustainable development, urban planning

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Authors: Esmael Makarian, Ayub Elyasi, Fatemeh Saberi, Olusegun Stanley Tomomewo

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Geothermal reservoirs (GTRs) have garnered global recognition as a sustainable energy source. The Thermo-Hydro-Mechanical-Chemical (THMC) integration coupling proves to be a practical and effective method for optimizing production in GTRs. The study outcomes demonstrate that THMC coupling serves as a versatile and valuable tool, offering in-depth insights into GTRs and enhancing their operational efficiency. This is achieved through temperature analysis and pressure changes and their impacts on mechanical properties, structural integrity, fracture aperture, permeability, and heat extraction efficiency. Moreover, THMC coupling facilitates potential benefits assessment and risks associated with different geothermal technologies, considering the complex thermal, hydraulic, mechanical, and chemical interactions within the reservoirs. However, THMC-coupling utilization in GTRs presents a multitude of challenges. These challenges include accurately modeling and predicting behavior due to the interconnected nature of processes, limited data availability leading to uncertainties, induced seismic events risks to nearby communities, scaling and mineral deposition reducing operational efficiency, and reservoirs' long-term sustainability. In addition, material degradation, environmental impacts, technical challenges in monitoring and control, accurate assessment of resource potential, and regulatory and social acceptance further complicate geothermal projects. Addressing these multifaceted challenges is crucial for successful geothermal energy resources sustainable utilization. This paper aims to illuminate the challenges and opportunities associated with THMC coupling in enhanced geothermal systems. Practical solutions and strategies for mitigating these challenges are discussed, emphasizing the need for interdisciplinary approaches, improved data collection and modeling techniques, and advanced monitoring and control systems. Overcoming these challenges is imperative for unlocking the full potential of geothermal energy making a substantial contribution to the global energy transition and sustainable development.

Keywords: geothermal reservoirs, THMC coupling, interdisciplinary approaches, challenges and opportunities, sustainable utilization

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Authors: Alka Jakhar, Harmanpreet Kaur Sandhu, Samaresh Das

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The Terahertz (THz) technology-based devices are heightening at an alarming rate on account of the wide range of applications in imaging, security, communication, and spectroscopic field. The various available room operational THz detectors, including Golay cell, pyroelectric detector, field-effect transistors, and photoconductive antennas, have some limitations such as narrow-band response, slow response speed, transit time limits, and complex fabrication process. There is an urgent demand to explore new materials and device structures to accomplish efficient THz detection systems. Recently, TMDs including topological semimetals and topological insulators such as PtSe₂, MoTe₂, WSe₂, and PtTe₂ provide novel feasibility for photonic and optical devices. The peculiar properties of these materials, such as Dirac cone, fermions presence, nonlinear optical response, high conductivity, and ambient stability, make them worthy for the development of the THz devices. Here, the platinum telluride (PtTe₂) based devices have been demonstrated for THz detection in the frequency range of 0.1-1 THz. The PtTe₂ is synthesized by direct selenization of the sputtered platinum film on the high-resistivity silicon substrate by using the chemical vapor deposition (CVD) method. The Raman spectra, XRD, and XPS spectra confirm the formation of the thin PtTe₂ film. The PtTe₂ channel length is 5µm and it is connected with a bow-tie antenna for strong THz electric field confinement in the channel. The characterization of the devices has been carried out in a wide frequency range from 0.1-1 THz. The induced THz photocurrent is measured by using lock-in-amplifier after preamplifier. The maximum responsivity is achieved up to 1 A/W under self-biased mode. Further, this responsivity has been increased by applying biasing voltage. This photo response corresponds to low energy THz photons is mainly due to the photo galvanic effect in PtTe₂. The DC current is induced along the PtTe₂ channel, which is directly proportional to the amplitude of the incident THz electric field. Thus, these new topological semimetal materials provide new pathways for sensitive detection and sensing applications in the THz domain.

Keywords: terahertz, detector, responsivity, topological-semimetals

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Authors: Lei Zhao, Yi Song, Tim Dunne, Jiaxiang (Jason) Ren, Wenhan Yue, Lei Yang, Li Wen, Yu Liu

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Fasting dissolving magnesium (DM) alloy technology has contributed significantly to the “Shale Revolution” in oil and gas industry. This application requires DM downhole tools dissolving initially at a slow rate, rapidly accelerating to a high rate after certain period of operation time (typically 8 h to 2 days), a contradicting requirement that can hardly be addressed by traditional Mg alloying or processing itself. Premature disintegration has been broadly reported in downhole DM tool from field trials. To address this issue, “temporary” thin polymers of various formulations are currently coated onto DM surface to delay its initial dissolving. Due to conveying parts, harsh downhole condition, and high dissolving rate of the base material, the current delay coatings relying on pure polymers are found to perform well only at low temperature (typical < 100 ℃) and parts without sharp edges or corners, as severe geometries prevent high quality thin film coatings from forming effectively. In this study, a coating technology combining Plasma Electrolytic Oxide (PEO) coatings with advanced thin film deposition has been developed, which can delay DM complex parts (with sharp corners) in corrosive fluid at 150 ℃ for over 2 days. Synergistic effects between porous hard PEO coating and chemical inert elastic-polymer sealing leads to its delaying dissolution improvement, and strong chemical/physical bonding between these two layers has been found to play essential role. Microstructure of this advanced coating and compatibility between PEO and various polymer selections has been thoroughly investigated and a model is also proposed to explain its delaying performance. This study could not only benefit oil and gas industry to unplug their High Temperature High Pressure (HTHP) unconventional resources inaccessible before, but also potentially provides a technical route for other industries (e.g., bio-medical, automobile, aerospace) where primer anti-corrosive protection on light Mg alloy is highly demanded.

Keywords: dissolvable magnesium, coating, plasma electrolytic oxide, sealer

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Authors: Christopher Baiyegunhi, Kuiwu Liu, Oswald Gwavava

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Petrography of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa have been investigated on composition, provenance and influence of weathering conditions. Petrographic studies based on quantitative analysis of the detrital minerals revealed that the sandstones are composed mostly of quartz, feldspar and lithic fragments of metamorphic and sedimentary rocks. The sandstones have an average framework composition of 24.3% quartz, 19.3% feldspar, 26.1% rock fragments, and 81.33% of the quartz grains are monocrystalline. These sandstones are generally very fine to fine grained, moderate to well sorted, and subangular to subrounded in shape. In addition, they are compositionally immature and can be classified as feldspathic wacke and lithic wacke. The absence of major petrographically distinctive compositional variations in the sandstones perhaps indicate homogeneity of their source. As a result of this, it is inferred that the transportation distance from the source area was quite short and the main mechanism of transportation was by river systems to the basin. The QFL ternary diagrams revealed dissected and transitional arc provenance pointing to an active margin and uplifted basement preserving the signature of a recycled provenance. This is an indication that the sandstones were derived from a magmatic arc provenance. Since magmatic provenance includes transitional arc and dissected arc, it also shows that the source area of the Ecca sediments had a secondary sedimentary and metasedimentary rocks from a marginal belt that developed as a result of rifting. The weathering diagrams and semi-quantitative weathering index indicate that the Ecca sandstones are mostly from a plutonic source area, with climatic conditions ranging from arid to humid. The compositional immaturity of the sandstones is suggested to be due to weathering or recycling and low relief or short transport from the source area. The detrital modal compositions of these sandstones are related to back arc to island and continental margin arc. The origin and deposition of the Ecca sandstones are due to low-moderate weathering, recycling of pre-existing rocks, erosion and transportation of debris from the orogeny of the Cape Fold Belt.

Keywords: petrography, tectonic setting, provenance, Ecca Group, Karoo Basin

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Authors: Thomas Arink, Isam Janajreh

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The petroleum industry generates significant amounts of waste in the form of drill cuttings, contaminated soil and oily sludge. Drill cuttings are a product of the off-shore drilling rigs, containing wet soil and total petroleum hydrocarbons (TPH). Contaminated soil comes from different on-shore sites and also contains TPH. The oily sludge is mainly residue or tank bottom sludge from storage tanks. The two main treatment methods currently used are incineration and thermal desorption (TD). Thermal desorption is a method where the waste material is heated to 450ºC in an anaerobic environment to release volatiles, the condensed volatiles can be used as a liquid fuel. For the thermal desorption unit dry contaminated soil is mixed with moist drill cuttings to generate a suitable mixture. By thermo gravimetric analysis (TGA) of the TD feedstock it was found that less than 50% of the TPH are released, the discharged material is stored in landfill. This study proposes co-gasification of petroleum waste with waste tires as an alternative to thermal desorption. Co-gasification with a high-calorific material is necessary since the petroleum waste consists of more than 60 wt% ash (soil/sand), causing its calorific value to be too low for gasification. Since the gasification process occurs at 900ºC and higher, close to 100% of the TPH can be released, according to the TGA. This work consists of three parts: 1. a mathematical gasification model, 2. a reactive flow CFD model and 3. experimental work on a drop tube reactor. Extensive material characterization was done by means of proximate analysis (TGA), ultimate analysis (CHNOS flash analysis) and calorific value measurements (Bomb calorimeter) for the input parameters of the mathematical and CFD model. The mathematical model is a zero dimensional model based on Gibbs energy minimization together with Lagrange multiplier; it is used to find the product species composition (molar fractions of CO, H2, CH4 etc.) for different tire/petroleum feedstock mixtures and equivalence ratios. The results of the mathematical model act as a reference for the CFD model of the drop-tube reactor. With the CFD model the efficiency and product species composition can be predicted for different mixtures and particle sizes. Finally both models are verified by experiments on a drop tube reactor (1540 mm long, 66 mm inner diameter, 1400 K maximum temperature).

Keywords: computational fluid dynamics (CFD), drop tube reactor, gasification, Gibbs energy minimization, petroleum waste, waste tires

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Authors: A. Kouloumpis, P. Zygouri, G. Potsi, K. Spyrou, D. Gournis

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Much of the research effort on graphene focuses on its use as building block for the development of new hybrid nanostructures with well-defined dimensions and behavior suitable for applications among else in gas storage, heterogeneous catalysis, gas/liquid separations, nanosensing and biology. Towards this aim, here we describe a new bottom-up approach, which combines the self-assembly with the Langmuir Schaefer technique, for the production of fullerene-intercalated graphene hybrid materials. This new method uses graphene nanosheets as a template for the grafting of various fullerene C60 molecules (pure C60, bromo-fullerenes, C60Br24, and fullerols, C60(OH)24) in a bi-dimensional array, and allows for perfect layer-by-layer growth with control at the molecular level. Our film preparation approach involves a bottom-up layer-by-layer process that includes the formation of a hybrid organo-graphene Langmuir film hosting fullerene molecules within its interlayer spacing. A dilute water solution of chemically oxidized graphene (GO) was used as subphase on the Langmuir-Blodgett deposition system while an appropriate amino surfactant (that binds covalently with the GO) was applied for the formation of hybridized organo-GO. After the horizontal lift of a hydrophobic substrate, a surface modification of the GO platelets was performed by bringing the surface of the transferred Langmuir film in contact with a second amino surfactant solution (capable to interact strongly with the fullerene derivatives). In the final step, the hybrid organo-graphene film was lowered in the solution of the appropriate fullerene derivative. Multilayer films were constructed by repeating this procedure. Hybrid fullerene-based thin films deposited on various hydrophobic substrates were characterized by X-ray diffraction (XRD) and X-ray reflectivity (XRR), FTIR, and Raman spectroscopies, Atomic Force Microscopy, and optical measurements. Acknowledgments. This research has been co‐financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF)‐Research Funding Program: THALES. Investing in knowledge society through the European Social Fund (no. 377285).

Keywords: hybrids, graphene oxide, fullerenes, langmuir-blodgett, intercalated structures

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Authors: L. Alejandro Cárdenas, Fernando Herrera, David Nova, Juan Ballesteros

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This paper presents a methodology to optimize the maintenance of grid-connected photovoltaic systems, considering the cleaning and module replacement periods based on an asset management strategy. The methodology is based on the analysis of the energy production of the PV plant, the energy feed-in tariff, and the cost of cleaning and replacement of the PV modules, with the overall revenue received being the optimization variable. The methodology is evaluated as a case study of a 5.6 kWp solar PV plant located on the Bogotá campus of the Universidad Nacional de Colombia. The asset management strategy implemented consists of assessing the PV modules through visual inspection, energy performance analysis, pollution, and degradation. Within the visual inspection of the plant, the general condition of the modules and the structure is assessed, identifying dust deposition, visible fractures, and water accumulation on the bottom. The energy performance analysis is performed with the energy production reported by the monitoring systems and compared with the values estimated in the simulation. The pollution analysis is performed using the soiling rate due to dust accumulation, which can be modelled by a black box with an exponential function dependent on historical pollution values. The pollution rate is calculated with data collected from the energy generated during two years in a photovoltaic plant on the campus of the National University of Colombia. Additionally, the alternative of assessing the temperature degradation of the PV modules is evaluated by estimating the cell temperature with parameters such as ambient temperature and wind speed. The medium-term energy decrease of the PV modules is assessed with the asset management strategy by calculating the health index to determine the replacement period of the modules due to degradation. This study proposes a tool for decision making related to the maintenance of photovoltaic systems. The above, projecting the increase in the installation of solar photovoltaic systems in power systems associated with the commitments made in the Paris Agreement for the reduction of CO2 emissions. In the Colombian context, it is estimated that by 2030, 12% of the installed power capacity will be solar PV.

Keywords: asset management, PV module, optimization, maintenance

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Authors: Ane Escobar, Paula Angelomé, Mihaela Delcea, Marek Grzelczak, Sergio Enrique Moya

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The antibacterial capacity of bone-anchoring implants can be improved by the use of antibiotics that can be delivered to the media after the surgery. Mesoporous films have shown great potential in drug delivery for orthopedic applications, since pore size and thickness can be tuned to produce different surface area and free volume inside the material. This work shows the synthesis of mesoporous titania films (MTF) by sol-gel chemistry and evaporation-induced self-assembly (EISA) on top of glass substrates. Pores with a diameter of 12nm were observed by Transmission Electron Microscopy (TEM). A film thickness of 100 nm was measured by Scanning Electron Microscopy (SEM). Gentamicin was used to study the antibiotic delivery from the film by means of High-performance liquid chromatography (HPLC). The Staphilococcus aureus strand was used to evaluate the effectiveness of the penicillin loaded films toward inhibiting bacterial colonization. MC3T3-E1 pre-osteoblast cell proliferation experiments proved that MTFs have a good biocompatibility and are a suitable surface for MC3T3-E1 cell proliferation. Moreover, images taken by Confocal Fluorescence Microscopy using labeled vinculin, showed good adhesion of the MC3T3-E1 cells to the MTFs, as well as complex actin filaments arrangement. In order to improve cell proliferation Bone Morphogenetic Protein-2 (BMP-2) was adsorbed on top of the mesoporous film. The deposition of the protein was proved by measurements in the contact angle, showing an increment in the hydrophobicity while the protein concentration is higher. By measuring the dehydrogenase activity in MC3T3-E1 cells cultured in dually functionalized mesoporous titatina films with gentamicin and BMP-2 is possible to find an improvement in cell proliferation. For this purpose, the absorption of a yellow-color formazan dye, product of a water-soluble salt (WST-8) reduction by the dehydrogenases, is measured. In summary, this study proves that by means of the surface modification of MTFs with proteins and loading of gentamicin is possible to achieve an antibacterial effect and a cell growth improvement.

Keywords: antibacterial, biocompatibility, bone morphogenetic protein-2, cell proliferation, gentamicin, implants, mesoporous titania films, osteoblasts

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Authors: Wasan Ismail Khalil, Hisham Khalid Ahmed, Zainab Ali

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Structural Lightweight Aggregate Concrete (SLWAC) has been developed in recent years because it reduces the dead load, cost, thermal conductivity and coefficient of thermal expansion of the structure. So SLWAC has the advantage of being a relatively green building material. Lightweight Aggregate (LWA) is either occurs as natural material such as pumice, scoria, etc. or as artificial material produced from different raw materials such as expanded shale, clay, slate, etc. The use of SLWAC in Iraq is limited due to the lack in natural LWA. The existence of Iraqi clay deposit with different types and characteristics leads to the idea of producing artificial expanded clay aggregate. The main aim in this work is to present of the properties of artificial LWA produced in the laboratory. Available local bentonite clay which occurs in the Western region of Iraq was used as raw material to produce the LWA. Sodium silicate as liquid industrial waste material from glass plant was mixed with bentonite clay in mix proportion 1:1 by weight. The manufacturing method of the lightweight aggregate including, preparation and mixing of clay and sodium silicate, burning of the mixture in the furnace at the temperature between 750-800˚C for two hours, and finally gradually cooling process. The produced LWA was then crushed to small pieces then screened on standard sieve series and prepared with grading which conforms to the specifications of LWA. The maximum aggregate size used in this investigation is 10 mm. The chemical composition and the physical properties of the produced LWA are investigated. The results indicate that the specific gravity of the produced LWA is 1.5 with the density of 543kg/m3 and water absorption of 20.7% which is in conformity with the international standard of LWA. Many trail mixes were carried out in order to produce LWAC containing the artificial LWA produced in this research. The selected mix proportion is 1:1.5:2 (cement: sand: aggregate) by weight with water to cement ratio of 0.45. The experimental results show that LWAC has oven dry density of 1720 kg/m3, water absorption of 8.5%, the thermal conductivity of 0.723 W/m.K and compressive strength of 23 N/mm2. The SLWAC produced in this research can be used in the construction of different thermal insulated buildings and masonry units. It can be concluded that the SLWA produced in this study contributes to sustainable development by, using industrial waste materials, conserving energy, enhancing the thermal and structural efficiency of concrete.

Keywords: expanded clay, lightweight aggregate, structural lightweight aggregate concrete, sustainable

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Authors: Moawia Abulgader Gdara

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En -Naga sub - basin considered to be the most southern of the concessions in the Sirte Basin operated by HOO. En Naga Sub – basin have likely been point-sourced of CO2 accumulations during the last 7 million years from local satellite intrusives associated with the Haruj Al Aswad igneous complex. CO2 occurs in the En Naga Sub-basin as a result of the igneous activity of the Al Harouge Al Aswad complex. Igneous extrusive have been pierced in the subsurface are exposed at the surface. The lower cretaceous Bahi Sandstone facies are recognized in the En Naga Sub-basin. They result from the influence of paleotopography on the processes associated with continental deposition over the Sirt Unconformity and the Cenomanian marine transgression In the Lower Cretaceous Bahi Sandstones, the presence of trapped carbon dioxide is proven within the En Naga Sub-basin. This makes it unique in providing an abundance of CO2 gas reservoirs with almost pure magmatic CO2, which can be easily sampled. Huge amounts of CO2 exist in the Lower Cretaceous Bahi Sandstones in the En-Naga sub-basin, where the economic value of CO2 is related to its use for enhanced oil recovery (EOR) Based on the production tests for the drilled wells that makes Lower Cretaceous Bahi sandstones the principle reservoir rocks for CO2 where large volumes of CO2 gas have been discovered in the Bahi Formation on and near EPSA 120/136(En -Naga sub basin). The Bahi sandstones are generally described as a good reservoir rock. Intergranular porosities and permeabilities are highly variable and can exceed 25% and 100 MD.In the (En Naga sub – basin), The very high pressures assumed associated with local igneous intrusives may account for the abnormally high Bahi (and Lidam Formation) reservoir pressures. The best gas tests from this facies are at F1-72 on the (Barrut I structure) from part of a 458 feet+ section having an estimated high value of CO2 as 98% overpressured. Bahi CO2 prospectivity is thought to be excellent in the central to western areas where At U1-72 (En Naga O structure) a significant CO2 gas kick occurred at 11,971 feet and quickly led to blowout conditions due to uncontrollable leaks in the surface equipment. Which reflects a better reservoir quality sandstones associated with Paleostructural highs. Condensate and gas prospectivity increases to the east as the CO2 prospectivity decreases with distance away from the Al Haruj Al Aswad igneous complex. To date, it has not been possible to accurately determine the volume of these strategically valuable reserves although there are positive indications that they are very large.

Keywords: 1)en naga sub basin, 2)alharouge al aswad igneous complex, 3)co2 generation and migration, 4)lower cretaceous bahi sandstone

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Authors: Byeongcheol Kang, Junyi Kim, Hyungsik Jung, Hyungjun Yang, Jaewoo An, Jonggeun Choe

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It is important to figure out reservoir properties for better production management. Due to the limited information, there are geological uncertainties on very heterogeneous or channel reservoir. One of the solutions is to generate multiple equi-probable realizations using geostatistical methods. However, some models have wrong properties, which need to be excluded for simulation efficiency and reliability. We propose a novel method of model selection scheme, based on distance-based clustering for reliable application of production optimization algorithm. Distance is defined as a degree of dissimilarity between the data. We calculate Hausdorff distance to classify the models based on their similarity. Hausdorff distance is useful for shape matching of the reservoir models. We use multi-dimensional scaling (MDS) to describe the models on two dimensional space and group them by K-means clustering. Rather than simulating all models, we choose one representative model from each cluster and find out the best model, which has the similar production rates with the true values. From the process, we can select good reservoir models near the best model with high confidence. We make 100 channel reservoir models using single normal equation simulation (SNESIM). Since oil and gas prefer to flow through the sand facies, it is critical to characterize pattern and connectivity of the channels in the reservoir. After calculating Hausdorff distances and projecting the models by MDS, we can see that the models assemble depending on their channel patterns. These channel distributions affect operation controls of each production well so that the model selection scheme improves management optimization process. We use one of useful global search algorithms, particle swarm optimization (PSO), for our production optimization. PSO is good to find global optimum of objective function, but it takes too much time due to its usage of many particles and iterations. In addition, if we use multiple reservoir models, the simulation time for PSO will be soared. By using the proposed method, we can select good and reliable models that already matches production data. Considering geological uncertainty of the reservoir, we can get well-optimized production controls for maximum net present value. The proposed method shows one of novel solutions to select good cases among the various probabilities. The model selection schemes can be applied to not only production optimization but also history matching or other ensemble-based methods for efficient simulations.

Keywords: distance-based clustering, geological uncertainty, particle swarm optimization (PSO), production optimization

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Authors: Seyedahmad Hosseini, Mohammadjavad Sotoudeheian

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Introduction: Allergic asthma is a heterogeneous immuno-inflammatory disease based on Th-2-mediated inflammation. Histopathologic abnormalities of the airways characteristic of asthma include epithelial damage and subepithelial collagen deposition. Objectives: Human bronchial epithelial cell genome expression of TNF‑α, IL‑6, ICAM‑1, VCAM‑1, nuclear factor (NF)‑κB signaling pathways up-regulate during inflammatory cascades. Moreover, immunofluorescence assays confirmed the nuclear translocation of NF‑κB p65 during inflammatory responses. An absolute LDH leakage assays suggestedLPS-inducedcells injury, and the associated mechanisms are co-incident events. LPS-induced phosphorylation of ERKand JNK causes inflammation in epithelial cells through inhibition of ERK and JNK activation and NF-κB signaling pathway. Furthermore, the inhibition of NF-κB mRNA expression and the nuclear translocation of NF-κB lead to anti-inflammatory events. Likewise, activation of SUMF2 which inhibits IL-13 and reduces Th2-cytokines, NF-κB, and IgE levels to ameliorate asthma. On the other hand, TNFα-induced mucus production reduced NF-κB activation through inhibition of the activation status of Rac1 and IκBα phosphorylation. In addition, bradykinin B2 receptor (B2R), which mediates airway remodeling, regulates through NF-κB. Bronchial B2R expression is constitutively elevated in allergic asthma. In addition, certain NF-κB -dependent chemokines function to recruit eosinophils in the airway. Besides, bromodomain containing 4 (BRD4) plays a significant role in mediating innate immune response in human small airway epithelial cells as well as transglutaminase 2 (TG2), which is detectable in saliva. So, the guanine nucleotide-binding regulatory protein α-subunit, Gα16, expresses a κB-driven luciferase reporter. This response was accompanied by phosphorylation of IκBα. Furthermore, expression of Gα16 in saliva markedly enhanced TNF-α-induced κB reporter activity. Methods: The applied method to form NF-κB activation is the electromobility shift assay (EMSA). Also, B2R-BRD4-TG2 complex detection by immunoassay method within saliva with EMSA of NF-κB activation may be a novel biomarker for asthma diagnosis and follow up. Conclusion: This concept introduces NF-κB signaling pathway as potential asthma biomarkers and promising targets for the development of new therapeutic strategies against asthma.

Keywords: NF-κB, asthma, saliva, T-helper

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Authors: Mokgadi Miranda Hlongwane, Ntebogeng Sharon Mokgalaka, Felix Dapare Dakora

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Lessertia (L.) frutescens (syn. Sutherlandia frutescens) is a leguminous medicinal plant indigenous to South Africa. Traditionally, L. frutescens has been used to treat cancer, diabetes, epilepsy, fever, HIV, stomach problems, wounds and other ailments. This legume is endemic to the Cape fynbos, with large populations occurring wild and cultivated in the Cape Florist Region. Its widespread distribution in the Western Cape, Northern Cape, Eastern Cape and Kwazulu-Natal is linked to its increased use as a phytomedicine in the treatment of various diseases by traditional healers. The frequent harvesting of field plants for use as a medicine has made it necessary to undertake studies towards the conservation of Lessertia frutescens. As a legume, this species can form root nodules and fix atmospheric N₂ when in symbiosis with soil bacteria called rhizobia. So far, however, few studies (if any) have been done on the efficacy and diversity of native bacterial symbionts nodulating L. frutescens in South Africa. The aim of this project was to isolate and characterize L. frutescens-nodulating bacteria from five different locations in the Western Cape Province. This was done by trapping soil rhizobia using rhizosphere soil suspension to inoculate L. frutescens seedlings growing in sterilized sand and receiving sterile N-free Hoagland nutrient solution under glasshouse conditions. At 60 days after planting, root nodules were harvested from L. frutescens plants, surface-sterilized, macerated, and streaked on yeast mannitol agar (YMA) plates and incubated at 28 ˚C for observation of bacterial growth. The majority of isolates were slow-growers that took 6-14 days to appear on YMA plates. However, seven isolates were fast-growers, taking 2-4 days to appear on YMA plates. Single-colony cultures of the isolates were assessed for their ability to nodulate L. frutescens as a homologous host under glasshouse conditions. Of the 92 bacterial isolates tested, 63 elicited nodule formation on L. frutescens. Symbiotic effectiveness varied markedly between and among test isolates. There were also significant (p≤0.005) differences in nodulation, shoot biomass, photosynthetic rates, leaf transpiration and stomatal conductance of L. frutescens plants inoculated with the test isolates, which is an indication of their functional diversity.

Keywords: lessertia frutescens, nodulating, rhizobia, symbiotic effectiveness

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Authors: Said Cheto, Khawla Oukaltouma, Imane Chamkhi, Ammar Ibn Yasser, Bouchra Benmrid, Ahmed Qaddoury, Lamfeddal Kouisni, Joerg Geistlinger, Youssef Zeroual, Adnane Bargaz, Cherki Ghoulam

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Our study aimed to assess, the role of inoculation of faba bean/wheat intercrops with selected rhizobacteria consortia gathering one rhizobia and two phosphate solubilizing bacteria “PSB” to alleviate the effects of combined water deficit and P limitation on Faba bean/ wheat intercrops versus monocrops under greenhouse conditions. One Vicia faba L variety (Aguadulce “Ag”), and one Triticum durum L. variety (Karim “K”) were grown as sole crops or intercrop in pots containing sterilized substrate (sand: peat 4:1v/v) added either with rock phosphate (RP) as the alone P source (P limitation) or with KH₂PO₄ in nutrient solution (P sufficient control). Plant inoculation was done using rhizobacterial consortia composed; C1(Rhizobium laguerreae, Kocuria sp, and Pseudomonas sp) and C2 (R. laguerreae, Rahnella sp, and Kocuria sp). Two weeks after inoculation, the plants were submitted to water deficit consisting of 40% of substrate water holding Capacity (WHC) versus 80% WHC for well-watered plants. At the flowering stage, the trial was assessed, and the results showed that inoculation with both consortia (C1 and C2) improved faba bean biomass in terms of shoots, roots, and nodules compared to inoculation with rhizobia alone, particularly C2 improved these parametres by 19.03, 78.99, and 72.73%, respectively. Leaf relative water content decreased under combined stress, particularly in response to C1 with a significant improvement of this parameter in wheat intercrops. For faba bean under P limitation, inoculation with C2 increased stomatal conductance (gs) by 35.73% compared to plants inoculated with rhizobia alone. Furthermore, the same inoculum C2 improved membrane stability by 44,33% versus 16,16% for C1 compared to inoculation with rhizobia alone under P deficit. For sole cropped faba bean plants, inoculation with both consortia improved N accumulation compared to inoculation with rhizobia alone with an increase of 70.75% under P limitation. Moreover, under the combined stress, intercropping inoculation with C2 improved plant biomass and N content (112.98%) in wheat plants, compared to the sole crop. Our finding revealed that consortium C2 might offer an agronomic advantage under water and P deficit and could be used as inoculum for enhancing faba bean and wheat production under both monocropping and intercropping systems.

Keywords: drought, phosphorus, intercropping, PSB, rhizobia, vicia faba, Triticum durum

Procedia PDF Downloads 67

Authors: G. Barański, P. Kacejko, M. Wendeker

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The impact of the ignition advance control algorithms of the ASz-62IR-16X aircraft piston engine on a combustion process has been presented in this paper. This aircraft engine is a nine-cylinder 1000 hp engine with a special electronic control ignition system. This engine has two spark plugs per cylinder with an ignition advance angle dependent on load and the rotational speed of the crankshaft. Accordingly, in most cases, these angles are not optimal for power generated. The scope of this paper is focused on developing algorithms to control the ignition advance angle in an electronic ignition control system of an engine. For this type of engine, i.e. radial engine, an ignition advance angle should be controlled independently for each cylinder because of the design of such an engine and its crankshaft system. The ignition advance angle is controlled in an open-loop way, which means that the control signal (i.e. ignition advance angle) is determined according to the previously developed maps, i.e. recorded tables of the correlation between the ignition advance angle and engine speed and load. Load can be measured by engine crankshaft speed or intake manifold pressure. Due to a limited memory of a controller, the impact of other independent variables (such as cylinder head temperature or knock) on the ignition advance angle is given as a series of one-dimensional arrays known as corrective characteristics. The value of the ignition advance angle specified combines the value calculated from the primary characteristics and several correction factors calculated from correction characteristics. Individual cylinder control can proceed in line with certain indicators determined from pressure registered in a combustion chamber. Control is assumed to be based on the following indicators: maximum pressure, maximum pressure angle, indicated mean effective pressure. Additionally, a knocking combustion indicator was defined. Individual control can be applied to a single set of spark plugs only, which results from two fundamental ideas behind designing a control system. Independent operation of two ignition control systems – if two control systems operate simultaneously. It is assumed that the entire individual control should be performed for a front spark plug only and a rear spark plug shall be controlled with a fixed (or specific) offset relative to the front one or from a reference map. The developed algorithms will be verified by simulation and engine test sand experiments. This work has been financed by the Polish National Centre for Research and Development, INNOLOT, under Grant Agreement No. INNOLOT/I/1/NCBR/2013.

Keywords: algorithm, combustion process, radial engine, spark plug

Procedia PDF Downloads 287

Authors: Kirill M. Dubovikov, Ekaterina S. Marchenko, Gulsharat A. Baigonakova

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NiTi alloys are widely used as implants in medicine due to their unique properties such as superelasticity, shape memory effect and biocompatibility. However, despite these properties, one of the major problems is the release of nickel after prolonged use in the human body under dynamic stress. This occurs due to oxidation and cracking of NiTi implants, which provokes nickel segregation from the matrix to the surface and release into living tissues. As we know, nickel is a toxic element and can cause cancer, allergies, etc. One of the most popular ways to solve this problem is to create a corrosion resistant coating on NiTi. There are many coatings of this type, but not all of them have good biocompatibility, which is very important for medical implants. Coatings based on calcium phosphate phases have excellent biocompatibility because Ca and P are the main constituents of the mineral part of human bone. This fact suggests that a Ca-P coating on NiTi can enhance osteogenesis and accelerate the healing process. Therefore, the aim of this study is to investigate the structure of Ca-P coating on NiTi substrate. Plasma assisted radio frequency (RF) sputtering was used to obtain this film. This method was chosen because it allows the crystallinity and morphology of the Ca-P coating to be controlled by the sputtering parameters. It allows us to obtain three different NiTi samples with Ca-P coating. XRD, AFM, SEM and EDS were used to study the composition, structure and morphology of the coating phase. Scratch tests were carried out to evaluate the adhesion of the coating to the substrate. Wettability tests were used to investigate the hydrophilicity of the different coatings and to suggest which of them had better biocompatibility. XRD showed that the coatings of all samples were hydroxyapatite, but the matrix was represented by TiNi intermetallic compounds such as B2, Ti2Ni and Ni3Ti. The SEM shows that the densest and defect-free coating has only one sample after three hours of sputtering. Wettability tests show that the sample with the densest coating has the lowest contact angle of 40.2° and the largest free surface area of 57.17 mJ/m2, which is mostly disperse. A scratch test was carried out to investigate the adhesion of the coating to the surface and it was shown that all coatings were removed by a cohesive mechanism. However, at a load of 30N, the indenter reached the substrate in two out of three samples, except for the sample with the densest coating. It was concluded that the most promising sputtering mode was the third, which consisted of three hours of deposition. This mode produced a defect-free Ca-P coating with good wettability and adhesion.

Keywords: biocompatibility, calcium phosphate coating, NiTi alloy, radio frequency sputtering.

Procedia PDF Downloads 68

Authors: V. P. Ramani, K. P. Patel, S. B. Patel

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It is necessary to dispose of generated industrial wastes in the proper way to overcome the further pollution for a safe environment. Waste can be used in agriculture for good quality higher food production. In order to evaluate the effect and rate of processed industrial biomass on yield, contents, uptake and soil status in maize, a field experiment was conducted during 2009 - 2011 at Anand on loamy sand soil for two years. The treatments of different levels of NPK i.e. 100% RD, 75% RD and 50% RD were kept to study the possibility of reduction in fertilizer application with the use of processed biomass (BM) in different proportion with FYM. (Where, RD= Recommended dose, FYM= Farm Yard Manure, BM= Processed Biomass.) The significantly highest grain yield of maize was recorded under the treatment of 75% NPK + BM application @ 10t ha-1. The higher (10t ha-1) and lower (5t ha-1) application rate of BM with full dose of NPK was found beneficial being at par with the treatment 75% NPK along with BM application @ 10t ha-1. There is saving of 25% recommended dose of NPK when combined with BM application @ 10.0t ha-1 or 50% saving of organics when applied with full dose (100%) of NPK. The highest straw yield (7734 kg ha-1) of maize on pooled basis was observed under the treatment of recommended dose of NPK along with FYM application at 7.5t ha-1 coupled with BM application at 2.5t ha-1. It was also observed that highest straw yield was at par under all the treatments except control and application of 100% recommended dose of NPK coupled with BM application at 7.5t ha-1. The Fe content of maize straw were found altered significantly due to different treatments on pooled basis and it was noticed that biomass application at 7.5t ha-1 along with recommended dose of NPK showed significant enhancement in Fe content of straw over other treatments. Among heavy metals, Co, Pb and Cr contents of grain were found significantly altered due to application of different treatments variably during the pooled. While, Ni content of maize grain was not altered significantly due to application of different organics. However, at higher rate of BM application i.e. of 10t ha-1, there was slight increase in heavy metal content of grain/ straw as well as DTPA heavy metals in soil; although the increase was not alarming Thus, the overall results indicated that the application of BM at 5t ha-1 along with full dose of NPK is beneficial to get higher yield of maize without affecting soil / plant health adversely. It also indicated that the 5t BM ha-1 could be utilized in place of 10t FYM ha-1 where FYM availability is scarce. The 10t BM ha-1 helps to reduce a load of chemical fertilizer up to 25 percent in agriculture. The lower use of agro-chemicals always favors safe environment. However, the continuous use of biomass needs periodical monitoring to check any buildup of heavy metals in soil/ plant over the years.

Keywords: alternate use of industrial waste, heavy metals, maize, processed industrial biomass

Procedia PDF Downloads 315

Authors: Srinivasa Reddy Mallampati, Min Hee Park, Soo Mim Cho, Sung Hyeon Yoon

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One of the issues of End of Life Vehicles (ELVs) recycling promotion is technology for the appropriate treatment of automotive shredder residue (ASR). Owing to its high heterogeneity and variable composition (plastic (23–41%), rubber/elastomers (9–21%), metals (6–13%), glass (10–20%) and dust (soil/sand) etc.), ASR can be classified as ‘hazardous waste’, on the basis of the presence of heavy metals (HMs), PCBs, BFRs, mineral oils, etc. Considering their relevant concentrations, these metals and plastics should be properly recovered for recycling purposes before ASR residues are disposed of. Brominated flame retardant additives in ABS/HIPS and PVC may generate dioxins and furans at elevated temperatures. Moreover, these BFRs additives present in plastic materials may leach into the environment during landfilling operations. ASR thermal process removes some of the organic material but concentrates, the heavy metals and POPs present in the ASR residues. In the present study, Fe/Ca/CaO nanoparticle assisted ozone treatment has been found to selectively hydrophilize the surface of ABS/HIPS and PVC plastics, enhancing its wettability and thereby promoting its separation from ASR plastics by means of froth flotation. The water contact angles, of ABS/HIPS and PVC decreased, about 18.7°, 18.3°, and 17.9° in ASR respectively. Under froth flotation conditions at 50 rpm, about 99.5% and 99.5% of HIPS in ASR samples sank, resulting in a purity of 98% and 99%. Furthermore, at 150 rpm a 100% PVC separation in the settled fraction, with 98% of purity in ASR, respectively. Total recovery of non-ABS/HIPS and PVC plastics reached nearly 100% in the floating fraction. This process improved the quality of recycled ASR plastics by removing surface contaminants or impurities. Further, a hybrid ball-milling and with Fe/Ca/CaO nanoparticle froth flotation process was established for the recovery of HMs from ASR. After ball-milling with Fe/Ca/CaO nanoparticle additives, the flotation efficiency increased to about 55 wt% and the HMs recovery were also increased about 90% for the 0.25 mm size fractions of ASR. Coating with Fe/Ca/CaO nanoparticles associated with subsequent microbubble froth flotation allowed the air bubbles to attach firmly on the HMs. SEM–EDS maps showed that the amounts of HMs were significant on the surface of the floating ASR fraction. This result, along with the low HM concentration in the settled fraction, was confirmed by elemental spectra and semi-quantitative SEM–EDS analysis. Developed hybrid preferential hazardous plastics and metals separation process from ASR is a simple, highly efficient, and sustainable procedure.

Keywords: end of life vehicles shredder residue, hazardous plastics, nanoparticle froth flotation, separation process

Procedia PDF Downloads 274

Authors: Himani Sharma, Amit Agrawal

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Stability of the Cassie and Wenzel wetting states depends on intrinsic contact angle and geometric features on a surface that was exploited in capturing biofluids in microwells. However, the mechanism of imbibition of biofluids in the microwells is not well implied in terms of wettability of a substrate. In this work, we experimentally demonstrated filling dynamics in hydrophilic and hydrophobic microwells by protein solutions. Towards this, we utilized lotus leaf as a mold to fabricate microwells on a Polydimethylsiloxane (PDMS) surface. Lotus leaf containing micrometer-sized blunt-conical shaped pillars with a height of 8-15 µm and diameter of 3-8 µm were transferred on to PDMS. Furthermore, PDMS surface was treated with oxygen plasma to render the hydrophilic nature. A 10µL droplets containing fluorescein isothiocyanate (FITC) - labelled bovine serum albumin (BSA) were rested on both hydrophobic (θa = 108o, where θa is the apparent contact angle) and hydrophilic (θa = 60o) PDMS surfaces. A time-dependent fluorescence microscopy was conducted on these modified PDMS surfaces by recording the fluorescent intensity over a 5 minute period. It was observed that, initially (at t=1 min) FITC-BSA was accumulated on the periphery of both hydrophilic and hydrophobic microwells due to incomplete penetration of liquid-gas meniscus. This deposition of FITC-BSA on periphery of microwell was not changed with time for hydrophobic surfaces, whereas, a complete filling was occurred in hydrophilic microwells (at t=5 mins). This attributes to a gradual movement of three-phase contact line along the vertical surface of the hydrophilic microwells as compared to stable pinning in the hydrophobic microwells as confirmed by Surface Evolver simulations. In addition, if the cavities are presented on hydrophobic surfaces, air bubbles will be trapped inside the cavities once the aqueous solution is placed over these surfaces, resulting in the Cassie-Baxter wetting state. This condition hinders trapping of proteins inside the microwells. Thus, it is necessary to impart hydrophilicity to the microwell surfaces so as to induce the Wenzel state, such that, an entire solution will be fully in contact with the walls of microwells. Imbibition of microwells by protein solutions was analyzed in terms fluorescent intensity versus time. The present work underlines the importance of geometry of microwells and surface wettability of substrate in wetting and effective capturing of solid sub-phases in biofluids.

Keywords: BSA, microwells, surface evolver, wettability

Procedia PDF Downloads 193

Authors: T. B. Karu Jayasundara

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The Earth’s gravity is not uniform. The satellite imageries of the Earth’s surface from NASA reveal a number of different gravity anomaly regions all over the globe. When the moon rotates around the earth, its gravity has a major physical influence on a number of regions on the earth. This physical change can be seen by the tides. The tides make sea levels high and low in coastal regions. During high tide, the gravitational force of the Moon pulls the Earth’s gravity so that the total gravitational intensity of Earth is reduced; it is further reduced in the low gravity regions of Earth. This reduction in gravity helps keep the suspended particles such as dust in the atmosphere, sand grains in the sea water for longer. Dramatic differences can be seen from the floating dust in the low gravity regions when compared with other regions. The above phenomena can be demonstrated from experiments. The experiments have to be done in high and low gravity regions of the earth during high and low tide, which will assist in comparing the final results. One of the experiments that can be done is by using a water filled cylinder about 80 cm tall, a few particles, which have the same density and same diameter (about 1 mm) and a stop watch. The selected particles were dropped from the surface of the water in the cylinder and the time taken for the particles to reach the bottom of the cylinder was measured using the stop watch. The times of high and low tide charts can be obtained from the regional government authorities. This concept is demonstrated by the particle drop times taken at high and low tides. The result of the experiment shows that the particle settlement time is less in low tide and high in high tide. The experiment for dust particles in air can be collected on filters, which are cellulose ester membranes and using a vacuum pump. The dust on filters can be used to make slides according to the NOHSC method. Counting the dust particles on the slides can be done using a phase contrast microscope. The results show that the concentration of dust is high at high tide and low in low tide. As a result of the high tides, a high concentration of heavy minerals deposit on placer deposits and dust particles retain in the atmosphere for longer in low gravity regions. These conditions are remarkably exhibited in the lowest low gravity region of the earth, mainly in the regions of India, Sri Lanka and in the middle part of the Indian Ocean. The biggest heavy mineral placer deposits are found in coastal regions of India and Sri Lanka and heavy dust particles are found in the atmosphere of India, particularly in the Delhi region.

Keywords: gravity, minerals, tides, moon, costal, atmosphere

Procedia PDF Downloads 123

Authors: Maryam Hajibaba, Mohsen Soltanpour, Mehrnoosh Abbasian, S. Abbas Haghshenas

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This paper aims to evaluate the main role of mangroves forests on the unique hydrodynamic characteristics of the Khuran Strait (KS) in the Persian Gulf. Investigation of hydrodynamic conditions of KS is vital to predict and estimate sedimentation and erosion all over the protected areas north of Qeshm Island. KS (or Tang-e-Khuran) is located between Qeshm Island and the Iranian mother land and has a minimum width of approximately two kilometers. Hydrodynamics of the strait is dominated by strong tidal currents of up to 2 m/s. The bathymetry of the area is dynamic and complicated as 1) strong currents do exist in the area which lead to seemingly sand dune movements in the middle and southern parts of the strait, and 2) existence a vast area with mangrove coverage next to the narrowest part of the strait. This is why ordinary modeling schemes with normal mesh resolutions are not capable for high accuracy estimations of current fields in the KS. A comprehensive set of measurements were carried out with several components, to investigate the hydrodynamics and morpho-dynamics of the study area, including 1) vertical current profiling at six stations, 2) directional wave measurements at four stations, 3) water level measurements at six stations, 4) wind measurements at one station, and 5) sediment grab sampling at 100 locations. Additionally, a set of periodic hydrographic surveys was included in the program. The numerical simulation was carried out by using Delft3D – Flow Module. Model calibration was done by comparing water levels and depth averaged velocity of currents against available observational data. The results clearly indicate that observed data and simulations only fit together if a realistic perspective of the mangrove area is well captured by the model bathymetry data. Generating unstructured grid by using RGFGRID and QUICKIN, the flow model was driven with water level time-series at open boundaries. Adopting the available field data, the key role of mangrove area on the hydrodynamics of the study area can be studied. The results show that including the accurate geometry of the mangrove area and consideration of its sponge-like behavior are the key aspects through which a realistic current field can be simulated in the KS.

Keywords: Khuran Strait, Persian Gulf, tide, current, Delft3D

Procedia PDF Downloads 195

Authors: Kulin Dave, Kapil Mohan

Abstract:

Earthquakes are considered to be the most destructive rapid-onset disasters human beings are exposed to. The amount of loss it brings in is sufficient to take careful considerations for designing of structures and facilities. Seismic Hazard Analysis is one such tool which can be used for earthquake resistant design. Ground Response Analysis is one of the most crucial and decisive steps for seismic hazard analysis. Rapar district of Kutch, Gujarat falls in Zone 5 of earthquake zone map of India and thus has high seismicity because of which it is selected for analysis. In total 8 bore-log data were studied at different locations in and around Rapar district. Different soil engineering properties were analyzed and relevant empirical correlations were used to calculate maximum shear modulus (Gmax) and shear wave velocity (Vs) for the soil layers. The soil was modeled using Pressure-Dependent Modified Kodner Zelasko (MKZ) model and the reference curve used for fitting was Seed and Idriss (1970) for sand and Darendeli (2001) for clay. Both Equivalent linear (EL), as well as Non-linear (NL) ground response analysis, has been carried out with Masing Hysteretic Re/Unloading formulation for comparison. Commercially available DEEPSOIL v. 7.0 software is used for this analysis. In this study an attempt is made to quantify ground response regarding generated acceleration time-history at top of the soil column, Response spectra calculation at 5 % damping and Fourier amplitude spectrum calculation. Moreover, the variation of Peak Ground Acceleration (PGA), Maximum Displacement, Maximum Strain (in %), Maximum Stress Ratio, Mobilized Shear Stress with depth is also calculated. From the study, PGA values estimated in rocky strata are nearly same as bedrock motion and marginal amplification is observed in sandy silt and silty clays by both analyses. The NL analysis gives conservative results of maximum displacement as compared to EL analysis. Maximum strain predicted by both studies is very close to each other. And overall NL analysis is more efficient and realistic because it follows the actual hyperbolic stress-strain relationship, considers stiffness degradation and mobilizes stresses generated due to pore water pressure.

Keywords: DEEPSOIL v 7.0, ground response analysis, pressure-dependent modified Kodner Zelasko model, MKZ model, response spectra, shear wave velocity

Procedia PDF Downloads 132

Authors: M. Ghali, M. Elnimr, G. F. Ali, A. M. Eissa, H. Talaat

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CuIn₃Se₅ material is indexed as ordered vacancy compounds having excellent matching properties with CuInGaSe (CIGS) solar absorber layer. For example, the valence band offset of CuIn₃Se₅ with CIGS is nearly 0.3 eV, and the lattice mismatch is less than 1%, besides the absence of discontinuity in their conduction bands. Thus, CuIn₃Se₅ can work as a passivation layer for repelling holes from CIGS/CdS interface and hence to reduce the interface carriers recombination and consequently enhancing the efficiency of CIGS/CdS solar cells. Theoretically, it was reported earlier that an improvement in the efficiency of p-CIGS-based solar cell with a thin ~100 nm of n-CuIn₃Se₅ layer is expected. Recently, a reported experiment demonstrated significant improvement in the efficiency of Molecular Beam Epitaxy (MBE) grown CIGS solar cells from 13.4 to 14.5% via inserting a thin layer of MBE-grown Cu(In,Ga)₃Se₅ layer at the CdS/CIGS interface. It should be mentioned that CuIn₃Se₅ material in either bulk or thin film form, are usually fabricated by high vacuum physical vapor deposition techniques (e.g., three-source co-evaporation, RF sputtering, flash evaporation, and molecular beam epitaxy). In addition, achieving photosensitive films of n-CuIn₃Se₅ material is important for new hybrid organic/inorganic structures, where inorganic photo-absorber layer, with n-type conductivity, can form n–p junction with organic p-type material (e.g., conductive polymers). A detailed study of the physical properties of CuIn₃Se₅ is still necessary for better understanding of device operation and further improvement of solar cells performance. Here, we report on the low-cost synthesis of CuIn₃Se₅ material in nano-scale size, with an average diameter ~10nm, using simple solution-based colloidal chemistry. In contrast to traditionally grown bulk tetragonal CuIn₃Se₅ crystals using high Vacuum-based technology, our colloidal CuIn₃Se₅ nanocrystals show cubic crystal structure with a shape of nanoparticles and band gap ~1.33 eV. Ink-coated thin films prepared from these nanocrystals colloids; display n-type character, 1.26 eV band gap and strong photo-responsive behavior with incident white light. This suggests the potential use of colloidal CuIn₃Se₅ as an active layer in all-solution-processed thin film solar cells.

Keywords: nanocrystals, CuInSe, thin film, optical properties

Procedia PDF Downloads 152

Authors: I. Poot-Ocejo, H. Silva-Poot, J. C. Cruz, A. Yeladaqui-Tello

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Mexico has remarkable archaeological remains mainly in the Maya area, which are critical to the preservation of our cultural heritage, so the authorities have an interest in preserving and restoring these vestiges of the most original way, by employing techniques traditional, which has advantages such as compatibility, durability, strength, uniformity and chemical composition. Recent studies have confirmed the addition of natural resins extracted from the bark of trees, of which Brosium alicastrum (Ramon) has been the most evaluated, besides being one of the most abundant species in the vicinity of the archaeological sites, like that Manilkara Zapota (Chicozapote). Therefore, the objective is to determine if these resins are capable of being employed in archaeological restoration. This study shows the results of the chemical composition and physical-mechanical behavior of mortar mixtures eight made with commercial lime and off by hand, calcium sand, resins added with Brosium alicastrum (Ramon) and Manilkara zapota (Chicozapote), where determined and quantified properties and chemical composition of the resins by X-Ray Fluorescence (XRF), the pH of the material was determined, indicating that both resins are acidic (3.78 and 4.02), and the addition rate maximum was obtained from resins in water by means of ultrasonic baths pulses, being in the case of 10% Manilkara zapota, because it contains up to 40% rubber and for 40% alicastrum Brosium contain less rubber. Through quantitative methodology, the compressive strength 96 specimens of 5 cm x 5 cm x 5 cm of mortar binding, 72 with partial substitution of water mixed with natural resins in proportions 5 to 10% in the case was evaluated of Manilkara Zapota, for Brosium alicastrum 20 and 40%, and 12 artificial resin and 12 without additive (mortars witnesses). 24 specimens likewise glued brick with mortar, for testing shear adhesion was found where, then the microstructure more conducive additions was determined by SEM analysis were prepared sweep. The test results indicate that the addition Manilkara zapota resin in the proportion of 10% 1.5% increase in compressive strength and 1% with respect to adhesion, compared to the control without addition mortar; In the case of Brosium alicastrum results show that compressive strengths and adhesion were insignificant compared to those made with registered by Manilkara zapota mixtures. Mortars containing the natural resins have improvements in physical properties and increase the mechanical strength and adhesion, compared to those who do not, in addition to the components are chemically compatible, therefore have considered that can be employed in Archaeological restoration.

Keywords: lime, mortar, natural resins, Manilkara zapota mixtures, Brosium alicastrum

Procedia PDF Downloads 366

Authors: Siyamak Sarafraz, Reza Esmaeil Pour, Saeed Jamshidi, Asghar Molaei Dehkordi

Abstract:

Cutting transport is one of the major problems in directional and extended reach oil and gas wells. Lack of sufficient attention to this issue may bring some troubles such as casing running, stuck pipe, excessive torque and drag, hole pack off, bit wear, decreased the rate of penetration (ROP), increased equivalent circulation density (ECD) and logging. Since it is practically impossible to directly observe the behavior of deep wells, a test setup was designed to investigate cutting transport phenomena. This experimental work carried out to scrutiny behavior of the effective variables in cutting transport. The test setup contained a test section with 17 feet long that made of a 3.28 feet long transparent glass pipe with 3 inch diameter, a storage tank with 100 liters capacity, drill pipe rotation which made of stainless steel with 1.25 inches diameter, pump to circulate drilling fluid, valve to adjust flow rate, bit and a camera to record all events which then converted to RGB images via the Image Processing Toolbox. After preparation of test process, each test performed separately, and weights of the output particles were measured and compared with each other. Observation charts were plotted to assess the behavior of viscosity, flow rate and RPM in inclinations of 0°, 30°, 60° and 90°. RPM was explored with other variables such as flow rate and viscosity in different angles. Also, effect of different flow rate was investigated in directional conditions. To access the precise results, captured image were analyzed to find out bed thickening and particles behave in the annulus. The results of this experimental study demonstrate that drill string rotation helps particles to be suspension and reduce the particle deposition cutting movement increased significantly. By raising fluid velocity, laminar flow converted to turbulence flow in the annulus. Increases in flow rate in horizontal section by considering a lower range of viscosity is more effective and improved cuttings transport performance.

Keywords: cutting transport, directional drilling, flow rate, hole cleaning, pipe rotation

Procedia PDF Downloads 279

Authors: Yin-Hsuan Wu, Perng-Jy Tsai, Ying-Fang Wang, Shun-Hui Chung

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The present study was conducted to characterize exposure concentrations, concentrations deposited on the different respiratory regions, and resultant health risks associated with heavy metal exposures for road marking workers. Road marking workers of three similar exposure groups (SEGs) were selected, including the paint pouring worker, marking worker, and preparing worker. Personal exposure samples were collected using an inhalable dust sampler (IOM), and the involved particle size distribution samples were estimated using an eight-stage Marple personal cascade impactor during five working days. In total, 25 IOM samples and 20 Marple samples were collected. All collected samples were analyzed for their heavy metal contents using the ICP/MS. The resultant heavy metal particle size distributions were also used to estimate the fractions of particle deposited on the head airways (Chead), tracheobronchial (Cthorac) and alveolar regions (Cresp) of the exposed workers. In addition, Pb and Cr were selected to estimate the incremental cancer risk, and Zn, Ti, and Mo were selected to estimate the corresponding non-cancer risk in the present study. Results show that three heavy metals, including Pb, Cr, and Ti, were found with the highest concentrations for the SEG of the paint pouring worker (=0.585±2.98, 0.307±1.71, 0.902±2.99 μg/m³, respectively). For the fraction of heavy metal particle deposited on the respiratory tract, both alveolar and head regions were found with the highest values (=23-43% and 39-61%, respectively). For both SEGs of the paint pouring and marking, 51% of Cr, 59-61% of Zn, and 48-51% of Ti were found to be deposited on the alveolar region, and 41-43% of Pb was deposited on the head region. Finally, the incremental cancer risk for the SEGs of the paint pouring, marking, and preparing were found as 1.08×10⁻⁵, 2.78×10⁻⁶, and 2.20×10⁻⁶, respectively. In addition, the estimated non-cancer risk for the above three SEGs was found to be consistently less than unity. In conclusion, though the estimated non-cancer risk was less than unity, all resultant incremental cancer risk was greater than 10⁻⁶ indicating the abatement of workers’ exposure is necessary. It is suggested that strategies, including placing on the molten kettle, substitution the currently used paints for less heavy metal containing paints, and wearing fume protecting personal protective equipment can be considered in the future from reducing the worker’s exposure aspect.

Keywords: health risk assessment, heavy metal, respiratory track deposition, road marking

Procedia PDF Downloads 158

Authors: Mercedes Del Rio Merino, Jaime Santacruz Astorqui, Paola Villoria Saez, Carmen Viñas Arrebola

Abstract:

The lack of treatment of the waste from construction and demolition waste (CDW) is a problem that must be solved immediately. It is estimated that in the world not to use CDW generates an increase in the use of new materials close to 20% of the total value of the materials used. The problem is even greater in case these wastes are considered hazardous because the final deposition of them may also generate significant contamination. Therefore, the possibility of including CDW in the manufacturing of building materials, represents an interesting alternative to ensure their use and to reduce their possible risk. In this context and in the last years, many researches are being carried out in order to analyze the viability of using CDW as a substitute for the traditional raw material of high environmental impact. Even though it is true, much remains to be done, because these works generally characterize materials but not specific applications that allow the agents of the construction to have the guarantees required by the projects. Therefore, it is necessary the involvement of all the actors included in the life cycle of these new construction materials, and also to promote its use for, for example, definition of standards, tax advantages or market intervention is necessary. This paper presents the main findings reached in "Waste to resources (W2R)" project since it began in October 2014. The main goal of the project is to develop new materials, elements and construction systems, manufactured from CDW, to be used in improving the energy efficiency of buildings. Other objectives of the project are: to quantify the CDW generated in the energy rehabilitation works, specifically wastes from the building envelope; and to study the traceability of CDW generated and promote CDW reuse and recycle in order to get close to the life cycle of buildings, generating zero waste and reducing the ecological footprint of the construction sector. This paper determines the most important aspects to consider during the design of new constructive solutions, which improve the energy efficiency of buildings and what materials made with CDW would be the most suitable for that. Also, a survey to select best practices for reducing "close to zero waste" in refurbishment was done. Finally, several pilot rehabilitation works conform the parameters analyzed in the project were selected, in order to apply the results and thus compare the theoretical with reality. Acknowledgements: This research was supported by the Spanish State Secretariat for Research, Development and Innovation of the Ministry of Economy and Competitiveness under "Waste 2 Resources" Project (BIA2013-43061-R).

Keywords: building waste, construction and demolition waste, recycling, resources

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Authors: Esmeralda Chávez Vargas, M. de la L. Olvera, A. Maldonado

Abstract:

The doping it is believed as follows, at high concentration fluorine in ZnO: F films is incorporated to the lattice by substitution of O-2 ions by F-1 ions; at middle fluorine concentrations, F ions may form interstitials, whereas for low concentrations it is increased the carriers and mobility could be explained by the surface passivation effect of fluorine. ZnO:F thin films were deposited on sodocalcic glass substratesat 425 °C , 450°C, 475 during 8, 12, 15 min from a 0.2 M solution. Doping concentration in the starting solutions was varied, namely, [F]/[F+Zn] = 0, 5, 15, 30, 45, 60, and 90 at. %; solvent composition was varied as well, 100:100; 50:50; 100:50(acetic acid: water: methanol ratios, in volume). In this work it is reported the characterization results of fluorine doped zinc oxide (ZnO:F) thin films deposited by the ultrasonic spray pyrolysis technique, using zinc acetate and ammonium fluorine as Zn an F precursors, respectively. The effect of varying the fluorine concentration in the starting solutions, the solvent composition, and the ageing time of the starting solutions, on the electrical resistivity, optical transmittance, structure and surface morphology was analyzed. In order to have a quantitative evaluation of the ZnO:F thin films for its application as transparent electrodes, the Figure of Merit was estimated from the Haacke´s formula. After a thoroughly study, it can be found that optimal conditions for the deposition of transparent and conductive ZnO:F thin films on sodocalcic substrates, were as follows; substrate temperature: solution molar concentration 0.2, doping concentration in the starting solution of [F]/[Zn]= 60 at. %, (water content)/(acetic acid) in starting solution: [H2O/ CH3OH]= 50:50, substrate temperature: 450 °C. The effects of aging of the starting solution has also been analyzed thoroughly and it has been found a dramatic effect on the electric resistivity of the material, aged by 40 days, show an electrical resitivity as low as 120 Ω/□, with a transmittance around 80% in the visible range. X-ray diffraction spectra show a polycrystalline of ZnO (wurtzite structure) where the amount of fluorine doping affects to preferential orientation (002 plane). Therefore, F introduction in lattice is by the substitution of O-2 ions by F-1 ions. The results show that ZnO:F thin films are potentially adequate for application as transparent conductive oxide in thin film solar cells.

Keywords: TCOs, transparent electrodes, ultrasonic spray pyrolysis, zinc oxide, ZnO:F

Procedia PDF Downloads 494