Search results for: irregular steel frames
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2346

Search results for: irregular steel frames

996 Behavior Factors Evaluation for Reinforced Concrete Structures

Authors: Muhammad Rizwan, Naveed Ahmad, Akhtar Naeem Khan

Abstract:

Seismic behavior factors are evaluated for the performance assessment of low rise reinforced concrete RC frame structures based on experimental study of unidirectional dynamic shake table testing of two 1/3rd reduced scaled two storey frames, with a code confirming special moment resisting frame (SMRF) model and a noncompliant model of similar characteristics but built in low strength concrete .The models were subjected to a scaled accelerogram record of 1994 Northridge earthquake to deformed the test models to final collapse stage in order to obtain the structural response parameters. The fully compliant model was observed with more stable beam-sway response, experiencing beam flexure yielding and ground-storey column base yielding upon subjecting to 100% of the record. The response modification factor - R factor obtained for the code complaint and deficient prototype structures were 7.5 and 4.5 respectively, which is about 10% and 40% less than the UBC-97 specified value for special moment resisting reinforced concrete frame structures.

Keywords: Northridge 1994 earthquake, reinforced concrete frame, response modification factor, shake table testing

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995 Experimental and Analytical Design of Rigid Pavement Using Geopolymer Concrete

Authors: J. Joel Bright, P. Peer Mohamed, M. Aswin SAangameshwaran

Abstract:

The increasing usage of concrete produces 80% of carbon dioxide in the atmosphere. Hence, this results in various environmental effects like global warming. The amount of the carbon dioxide released during the manufacture of OPC due to the calcination of limestone and combustion of fossil fuel is in the order of one ton for every ton of OPC produced. Hence, to minimize this Geo Polymer Concrete was introduced. Geo polymer concrete is produced with 0% cement, and hence, it is eco-friendly and it also uses waste product from various industries like thermal power plant, steel manufacturing plant, and paper waste materials. This research is mainly about using Geo polymer concrete for pavement which gives very high strength than conventional concrete and at the same time gives way for sustainable development.

Keywords: activator solution, GGBS, fly ash, metakaolin

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994 Characterization of High Carbon Ash from Pulp and Paper mill for Potential Utilization

Authors: Ruma Rano, Firoza Sultana, Bishal Bhuyan, Nurul Alam Mazumder

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Fly ash collected from Cachar Paper Mill, Assam, India has been thoroughly characterized in respect of its physico-chemical, morphological and mineralogical features were concerned by using density, LOI, FTIR, XRD, SEM-EDS etc. The results reveal that there is a striking difference in the features and properties of the coarser and finer fractions .The high carbon ash consists of large unburnt carbon (chars), irregular carbonaceous particles in the coarser fraction, which appear to be porous and may be used as domestic fuel. The percentage of char albeit the carbon content decreases with decrease in size of particles. The various fractions essentially contain quartz and mullite as the main mineral phases. For suggesting the potential utilization channels, number of experiments were performed correlating the total characteristic features. Water holding capacities of different size classified fractions were determined, the coarser fractions have unexpectedly higher water holding capacities than the finer ones. An attempt has been made to correlate the results obtained with potential use in agriculture. Another potential application of coarser particles is used as adsorbent for effluents containing waste organic materials. Thus thorough characterization leads to not only a definite direction about the uses of the value added components but also gives useful information regarding the prevailing combustion process.

Keywords: chars, porous, water holding capacity, combustion process

Procedia PDF Downloads 356
993 Durability Properties of Foamed Concrete with Fiber Inclusion

Authors: Hanizam Awang, Muhammad Hafiz Ahmad

Abstract:

An experimental study was conducted on foamed concrete with synthetic and natural fibres consisting of AR-glass, polypropylene, steel, kenaf and oil palm fibre. The foamed concrete mixtures produced had a target density of 1000 kg/m3 and a mix ratio of (1:1.5:0.45). The fibres were used as additives. The inclusion of fibre was maintained at a volumetric fraction of 0.25 and 0.4 %. The water absorption, thermal and shrinkage were determined to study the effect of the fibre on the durability properties of foamed concrete. The results showed that AR-glass fibre has the lowest percentage value of drying shrinkage compared to others.

Keywords: foamed concrete, fibres, durability, construction, geological engineering

Procedia PDF Downloads 440
992 Construction of India’s Largest Blast Furnace (4554 cum) Foundation at JSPL, Angul, Odisha: A Qualitative Approach

Authors: N. S. S. Rao, Tapan Kumar Das, Latiful Pasha

Abstract:

Tata Projects Limited (TPL) located in Hyderabad, India has taken up the challenging venture of executing the entire civil works for India’s largest Blast Furnace with a capacity of 4554 cum at Jindal Steel and Power Limited (JSPL), Angul, Odisha, India. The following write-up briefly elaborates the various steps and methodologies involved in the construction of the foundation for this India’s largest blast furnace.

Keywords: blast furnace, construction, qualitative, approach

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991 Design Guidelines for URM Infills and Effect of Construction Sequence on Seismic Performance of Code Compliant RC Frame Buildings

Authors: Putul Haldar, Yogendra Singh, D. K. Paul

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Un-Reinforced Masonry (URM) infilled RC framed buildings are the most common construction practice for modern multi-storey buildings in India like many other parts of the world. Although the behavior and failure pattern of the global structure changes significantly due to infill-frame interaction, the general design practice is to treat them as non-structural elements and their stiffness, strength and interaction with frame is often ignored, as it is difficult to simulate. Indian Standard, like many other major national codes, does not provide any explicit guideline for modeling of infills. This paper takes a stock of controlling design provisions in some of the major national seismic design codes (BIS 2002; CEN 2004; NZS-4230 2004; ASCE-41 2007) to ensure the desired seismic performance of infilled frame. Most of the national codes on seismic design of buildings still lack in adequate guidelines on modeling and design of URM infilled frames results in variable assumption in analysis and design. This paper, using nonlinear pushover analysis, also presents the effect of one of such assumptions of conventional ‘simultaneous’ analysis procedure of infilled frame on the seismic performance of URM infilled RC frame buildings.

Keywords: URM infills, RC frame, seismic design codes, construction sequence of infilled frame

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990 Breast Cancer and BRCA Gene: A Study on Genetic and Environmental Interaction

Authors: Abhishikta Ghosh Roy

Abstract:

Breast cancer is the most common malignancy among women globally, including India. Human breast cancer results from the genetic and environmental interaction. The present study attempts to understand the molecular heterogeneity of BRCA1 and BRCA2 genes, as well as to understand the association of various lifestyle and reproductive variables for the Breast Cancer risk. The study was conducted amongst 110 patients and 128 controls with total DNA sequencing of flanking and coding regions of BRCA1 BRCA2 genes that revealed ten Single Nucleotide Polymorphisms (SNPs) (6 novels). The controls selected for the study were age, sex and ethnic group matched. After written and informed consent biological samples were collected from the subjects. After detailed molecular analysis, significant (p < 0.005) molecular heterogeneity is revealed in terms of SNPs in BRCA1 (4 Exonic & 1 Intronic) and BRCA2 (2exonic and 3 Intronic) genes. The augmentation study investigated significant (p < 0.05) association with positive family history, early age at menarche, irregular menstrual periods, menopause, prolong contraceptive use, nulliparity, history of abortions, consumption of alcohol and smoking for breast cancer risk. To the best of authors knowledge, this study is the first of its kind, envisaged that the identification of the SNPs and modification of the lifestyle factors might aid to minimize the risk among the Bengalee Hindu females.

Keywords: breast cancer, BRCA, lifestyle, India

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989 Observing Teaching Practices Through the Lenses of Self-Regulated Learning: A Study Within the String Instrument Individual Context

Authors: Marija Mihajlovic Pereira

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Teaching and learning a musical instrument is challenging for both teachers and students. Teachers generally use diverse strategies to resolve students' particular issues in a one-to-one context. Considering individual sessions as a supportive educational context, the teacher can play a decisive role in stimulating and promoting self-regulated learning strategies, especially with beginning learners. The teachers who promote self-controlling behaviors, strategic monitoring, and regulation of actions toward goals could expect their students to practice more qualitatively and consciously. When encouraged to adopt self-regulation habits, students' could benefit from greater productivity on a longer path. Founded on Bary Zimmerman's cyclical model that comprehends three phases - forethought, performance, and self-reflection, this work aims to articulate self-regulated and music learning. Self-regulated learning appeals to the individual's attitude in planning, controlling, and reflecting on their performance. Furthermore, this study aimed to present an observation grid for perceiving teaching instructions that encourage students' controlling cognitive behaviors in light of the belief that conscious promotion of self-regulation may motivate strategic actions toward goals in musical performance. The participants, two teachers, and two students have been involved in the social inclusion project in Lisbon (Portugal). The author and one independent inter-observer analyzed six video-recorded string instrument lessons. The data correspond to three sessions per teacher lectured to one (different) student. Violin (f) and violoncello (m) teachers hold a Master's degree in music education and approximately five years of experience. In their second year of learning an instrument, students have acquired reasonable skills in musical reading, posture, and sound quality until then. The students also manifest positive learning behaviors, interest in learning a musical instrument, although their study habits are still inconsistent. According to the grid's four categories (parent codes), in-class rehearsal frames were coded using MaxQda software, version 20, according to the grid's four categories (parent codes): self-regulated learning, teaching verbalizations, teaching strategies, and students' in-class performance. As a result, selected rehearsal frames qualitatively describe teaching instructions that might promote students' body and hearing awareness, such as "close the eyes while playing" or "sing to internalize the pitch." Another analysis type, coding the short video events according to the observation grid's subcategories (child codes), made it possible to perceive the time teachers dedicate to specific verbal or non-verbal strategies. Furthermore, a coding overlay analysis indicated that teachers tend to stimulate. (i) Forethought – explain tasks, offer feedback and ensure that students identify a goal, (ii) Performance – teach study strategies and encourage students to sing and use vocal abilities to ensure inner audition, (iii) Self-reflection – frequent inquiring and encouraging the student to verbalize their perception of performance. Although developed in the context of individual string instrument lessons, this classroom observation grid brings together essential variables in a one-to-one lesson. It may find utility in a broader context of music education due to the possibility to organize, observe and evaluate teaching practices. Besides that, this study contributes to cognitive development by suggesting a practical approach to fostering self-regulated learning.

Keywords: music education, observation grid, self-regulated learning, string instruments, teaching practices

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988 Application of Deep Neural Networks to Assess Corporate Credit Rating

Authors: Parisa Golbayani, Dan Wang, Ionut¸ Florescu

Abstract:

In this work we implement machine learning techniques to financial statement reports in order to asses company’s credit rating. Specifically, the work analyzes the performance of four neural network architectures (MLP, CNN, CNN2D, LSTM) in predicting corporate credit rating as issued by Standard and Poor’s. The paper focuses on companies from the energy, financial, and healthcare sectors in the US. The goal of this analysis is to improve application of machine learning algorithms to credit assessment. To accomplish this, the study investigates three questions. First, we investigate if the algorithms perform better when using a selected subset of important features or whether better performance is obtained by allowing the algorithms to select features themselves. Second, we address the temporal aspect inherent in financial data and study whether it is important for the results obtained by a machine learning algorithm. Third, we aim to answer if one of the four particular neural network architectures considered consistently outperforms the others, and if so under which conditions. This work frames the problem as several case studies to answer these questions and analyze the results using ANOVA and multiple comparison testing procedures.

Keywords: convolutional neural network, long short term memory, multilayer perceptron, credit rating

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987 Challenges and Opportunities in Computing Logistics Cost in E-Commerce Supply Chain

Authors: Pramod Ghadge, Swadesh Srivastava

Abstract:

Revenue generation of a logistics company depends on how the logistics cost of a shipment is calculated. Logistics cost of a shipment is a function of distance & speed of the shipment travel in a particular network, its volumetric size and dead weight. Logistics billing is based mainly on the consumption of the scarce resource (space or weight carrying capacity of a carrier). Shipment’s size or deadweight is a function of product and packaging weight, dimensions and flexibility. Hence, to arrive at a standard methodology to compute accurate cost to bill the customer, the interplay among above mentioned physical attributes along with their measurement plays a key role. This becomes even more complex for an ecommerce company, like Flipkart, which caters to shipments from both warehouse and marketplace in an unorganized non-standard market like India. In this paper, we will explore various methodologies to define a standard way of billing the non-standard shipments across a wide range of size, shape and deadweight. Those will be, usage of historical volumetric/dead weight data to arrive at a factor which can be used to compute the logistics cost of a shipment, also calculating the real/contour volume of a shipment to address the problem of irregular shipment shapes which cannot be solved by conventional bounding box volume measurements. We will also discuss certain key business practices and operational quality considerations needed to bring standardization and drive appropriate ownership in the ecosystem.

Keywords: contour volume, logistics, real volume, volumetric weight

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986 Simulation 2D of Flare Steel Tubes

Authors: B. Daheche, M. T. Hannachi, H. Djebaili

Abstract:

In this approach, we tried to describe the flare test tubes welded by high frequency induction HF, and its experimental application. The test is carried out ENTTPP (National company of pipe mill and processing of flat products). Usually, the final products (tube) undergo a series of destructive testing (CD) in order to see the efficiency of welding. This test performed on sections of pipe with a length defined in the notice is made under a determined effort (pressure), which depends on its share of other parameters namely mechanical (fracture resistance) and geometry (thickness tube, outside diameter), the variation of this effort is well researched and recorded.

Keywords: flare, destructive testing, pressure, drafts tube, tube finished

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985 Morphological and Chemical Characterization of the Surface of Orthopedic Implant Materials

Authors: Bertalan Jillek, Péter Szabó, Judit Kopniczky, István Szabó, Balázs Patczai, Kinga Turzó

Abstract:

Hip and knee prostheses are one of the most frequently used medical implants, that can significantly improve patients’ quality of life. Long term success and biointegration of these prostheses depend on several factors, like bulk and surface characteristics, construction and biocompatibility of the material. The applied surgical technique, the general health condition and life-quality of the patient are also determinant factors. Medical devices used in orthopedic surgeries have different surfaces depending on their function inside the human body. Surface roughness of these implants determines the interaction with the surrounding tissues. Numerous modifications have been applied in the recent decades to improve a specific property of an implant. Our goal was to compare the surface characteristics of typical implant materials used in orthopedic surgery and traumatology. Morphological and chemical structure of Vortex plate anodized titanium, cemented THR (total hip replacement) stem high nitrogen REX steel (SS), uncemented THR stem and cup titanium (Ti) alloy with titanium plasma spray coating (TPS), cemented cup and uncemented acetabular liner HXL and UHMWPE and TKR (total knee replacement) femoral component CoCrMo alloy (Sanatmetal Ltd, Hungary) discs were examined. Visualization and elemental analysis were made by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Surface roughness was determined by atomic force microscopy (AFM) and profilometry. SEM and AFM revealed the morphological and roughness features of the examined materials. TPS Ti presented the highest Ra value (25 ± 2 μm, followed by CoCrMo alloy (535 ± 19 nm), Ti (227 ± 15 nm) and stainless steel (170 ± 11 nm). The roughness of the HXL and UHMWPE surfaces was in the same range, 147 ± 13 nm and 144 ± 15 nm, respectively. EDS confirmed typical elements on the investigated prosthesis materials: Vortex plate Ti (Ti, O, P); TPS Ti (Ti, O, Al); SS (Fe, Cr, Ni, C) CoCrMo (Co, Cr, Mo), HXL (C, Al, Ni) and UHMWPE (C, Al). The results indicate that the surface of prosthesis materials have significantly different features and the applied investigation methods are suitable for their characterization. Contact angle measurements and in vitro cell culture testing are further planned to test their surface energy characteristics and biocompatibility.

Keywords: morphology, PE, roughness, titanium

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984 2D Surface Flow Model in The Biebrza Floodplain

Authors: Dorota Miroslaw-Swiatek, Mateusz Grygoruk, Sylwia Szporak

Abstract:

We applied a two-dimensional surface water flow model with irregular wet boundaries. In this model, flow equations are in the form of a 2-D, non-linear diffusion equations which allows to account spatial variations in flow resistance and topography. Calculation domain to simulate the flow pattern in the floodplain is congruent with a Digital Elevation Model (DEM) grid. The rate and direction of sheet flow in wetlands is affected by vegetation type and density, therefore the developed model take into account spatial distribution vegetation resistance to the water flow. The model was tested in a part of the Biebrza Valley, of an outstanding heterogeneity in the elevation and flow resistance distributions due to various ecohydrological conditions and management measures. In our approach we used the highest-possible quality of the DEM in order to obtain hydraulic slopes and vegetation distribution parameters for the modelling. The DEM was created from the cloud of points measured in the LiDAR technology. The LiDAR reflects both the land surface as well as all objects on top of it such as vegetation. Depending on the density of vegetation cover the ability of laser penetration is variable. Therefore to obtain accurate land surface model the “vegetation effect” was corrected using data collected in the field (mostly the vegetation height) and satellite imagery such as Ikonos (to distinguish different vegetation types of the floodplain and represent them spatially). Model simulation was performed for the spring thaw flood in 2009.

Keywords: floodplain flow, Biebrza valley, model simulation, 2D surface flow model

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983 Criminals not Addicts: Newspaper Framing of Gambling-Related Crimes

Authors: Cameron Brown, Jessica Vanburen, Scott Hunt

Abstract:

This study analyzed 411 international newspaper stories pertaining to gambling-related crimes from January 2013 to December 2014. These stories included accounts of crimes committed to fund gambling or pay gambling debts or that occurred at gambling establishments. Our analysis pays particular attention to those crimes that were imputed to be committed by “problem” or “addictive” gamblers, who commit crimes to fund gambling or pay gambling debts. Previous research on problem/addictive gambling has focused on its etiology or prevalence rates and has not attended to the media portrayals of this behavior and its association with crime. Using frame analysis concepts, the data demonstrate that the newspaper stories typically frame the events as “crimes” and not the result of illness or addiction. The “evidence” of motive that could have indicated psychological problems or additions were rather framed as “criminal motive.” This framing practice advances an identity of a “problem/addictive gambler” as a deviant criminal perpetrator and not a victim of addiction. The paper concludes with a discussion of how these findings can be used to advance research on social portrayals of problem/addictive gamblers. Specifically, we consider how these media frames impede an understanding of problem/addictive gambling as a public health problem.

Keywords: problem gambling, addictive gambling, identity resonace, frame analysis

Procedia PDF Downloads 295
982 High-Production Laser and Plasma Welding Technologies for High-Speed Vessels Production

Authors: V. M. Levshakov, N. A. Steshenkova, N. A. Nosyrev

Abstract:

Application of hulls processing technologies, based on high-concentrated energy sources (laser and plasma technologies), allow improve shipbuilding production. It is typical for high-speed vessels construction using steel and aluminum alloys with high precision hulls required. Report describes high-performance technologies for plasma welding (using direct current of reversed polarity), laser, and hybrid laser-arc welding of hulls structures developed by JSC “SSTC”.

Keywords: flat sections, hybrid laser-arc welding, plasma welding, plasmatron

Procedia PDF Downloads 434
981 The Effect of Symmetrical Presentation of a "Photographic Mind Map" on the Production of Design Solutions

Authors: Pascal Alberti, Mustapha Mouloua

Abstract:

In today’s global market economy, various companies are often confronted with the dynamic and complex nature of current competitive markets. The dynamics of these markets are becoming more and more fluid, often requiring companies to provide competitive, definite advantages, and technological responses within increasingly shorte time frames. To meet these demands, companies must rely on the cognitive abilities of actors of creativity to provide tangible answers to the current contextual problems. Thus, it is important to provide a variety of instruments and design tools to support this particular stage of innovation, and to meet their demand expectations. For a number of years now, we have been extensively conducting experiments on the use of mind maps in the context of innovative projects with collaborative research teams from various nationalities. Our research findings reported a significant difference between a “Word” Mind Map and “Photographic” Mind Map, a correlation between the different uses of iconic tools and certain types of innovation, and a relationship between the different cognitive logics. In this paper, we will present our new results related to the effect of symmetrical presentation of a Photographic Mind Map" on the production of design solutions. Finally, we will conclude by highlighting the importance of our experimental method, and discussing both the theoretical and practical implications of our research.

Keywords: creativity, innovation, management, mind mapping, design product

Procedia PDF Downloads 503
980 Enhancement Effect of Electromagnetic Field on Separation of Edible Oil from Oil-Water Emulsion

Authors: Olfat A. Fadali, Mohamed S. Mahmoud, Omnia H. Abdelraheem, Shimaa G. Mohammed

Abstract:

The effect of electromagnetic field (EMF) on the removal of edible oil from oil-in-water emulsion by means of electrocoagulation was investigated in rectangular batch electrochemical cell with DC current. Iron (Fe) plate anodes and stainless steel cathodes were employed as electrodes. The effect of different magnetic field intensities (1.9, 3.9 and 5.2 tesla), three different positions of EMF (below, perpendicular and parallel to the electrocoagulation cell), as well as operating time; had been investigated. The application of electromagnetic field (5.2 tesla) raises percentage of oil removal from 72.4% for traditional electrocoagulation to 90.8% after 20 min.

Keywords: electrocoagulation, electromagnetic field, Oil-water emulsion, edible oil

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979 Collaborative Economy in Developing Countries: Perspectives from the Philippines

Authors: Ivy Jessen Galvan

Abstract:

Over the past decade, a phenomenon has emerged at the frontier of the digital economy: a wave of ‘disruptive’ technologies that offer digital solutions to variety of everyday problems, challenging the way traditional industries operate. Most of these disruptive technologies are applications ('apps') that rely on the Internet to connect people to people for sharing, selling, renting, or lending, creating a unique economic model wherein users provide for other users’ demand – called 'collaborative economy.' Although collaborative economy is spreading in every part of the world, there may be different ways in which this phenomenon is unfolding throughout the developing countries. In this study, the characteristics of collaborative economy in the Philippines are highlighted and compared from observations in the developed world. The paper looks at two leading collaborative economy ventures in the Philippines – Grab and Shopee – probing into how these smartphone-based platforms place technology into the 'micro-frictions' of the Philippine developing context. Using framing analysis on interviews conducted among Grab and Shopee users in Metro Manila, three frames have been identified: 1) metropolitan solution; 2) financial inclusion and; 3) formalization of labor. This research contextualizes the Fourth Industrial Revolution in ASEAN by analyzing the effect of a digital economy in everyday life.

Keywords: ASEAN Unicorns, collaborative economy, developing countries, fourth industrial revolution

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978 An Optimization Algorithm for Reducing the Liquid Oscillation in the Moving Containers

Authors: Reza Babajanivalashedi, Stefania Lo Feudo, Jean-Luc Dion

Abstract:

Liquid sloshing is a crucial problem for the dynamic of moving containers in the packaging industries. Sloshing issues have been so far mainly modeled within the framework of fluid dynamics or by using equivalent mechanical models with different kinds of movements and shapes of containers. Nevertheless, these approaches do not allow to determinate the shape of the free surface of the liquid in case of the irregular shape of the moving containers, so that experimental measurements may be required. If there is too much slosh in the moving tank, the liquid can be splashed out on the packages. So, the free surface oscillation must be controlled/reduced to eliminate the splashing. The purpose of this research is to propose an optimization algorithm for finding an optimum command law to reduce surface elevation. In the first step, the free surface of the liquid is simulated based on the separation variable and weak formulation models. Then Genetic and Gradient algorithms are developed for finding the optimum command law. The optimum command law is compared with existing command laws, and the results show that there is a significant difference in surface oscillation between optimum and existing command laws. This algorithm is applicable for different varieties of bottles in case of using the camera for detecting the liquid elevation, and it can produce new command laws for different kinds of tanks to reduce the surface oscillation and remove the splashing phenomenon.

Keywords: sloshing phenomenon, separation variables, weak formulation, optimization algorithm, command law

Procedia PDF Downloads 138
977 Influence of Wind Induced Fatigue Damage in the Reliability of Wind Turbines

Authors: Emilio A. Berny-Brandt, Sonia E. Ruiz

Abstract:

Steel tubular towers serving as support structures for large wind turbines are subject to several hundred million stress cycles arising from the turbulent nature of the wind. This causes high-cycle fatigue which can govern tower design. The practice of maintaining the support structure after wind turbines reach its typical 20-year design life have become common, but without quantifying the changes in the reliability on the tower. There are several studies on this topic, but most of them are based on the S-N curve approach using the Miner’s rule damage summation method, the de-facto standard in the wind industry. However, the qualitative nature of Miner’s method makes desirable the use of fracture mechanics to measure the effects of fatigue in the capacity curve of the structure, which is important in order to evaluate the integrity and reliability of these towers. Temporal and spatially varying wind speed time histories are simulated based on power spectral density and coherence functions. Simulations are then applied to a SAP2000 finite element model and step-by-step analysis is used to obtain the stress time histories for a range of representative wind speeds expected during service conditions of the wind turbine. Rainflow method is then used to obtain cycle and stress range information of each of these time histories and a statistical analysis is performed to obtain the distribution parameters of each variable. Monte Carlo simulation is used here to evaluate crack growth over time in the tower base using the Paris-Erdogan equation. A nonlinear static pushover analysis to assess the capacity curve of the structure after a number of years is performed. The capacity curves are then used to evaluate the changes in reliability of a steel tower located in Oaxaca, Mexico, where wind energy facilities are expected to grow in the near future. Results show that fatigue on the tower base can have significant effects on the structural capacity of the wind turbine, especially after the 20-year design life when the crack growth curve starts behaving exponentially.

Keywords: crack growth, fatigue, Monte Carlo simulation, structural reliability, wind turbines

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976 Low-Dose Chest Computed Tomography Can Help in Differential Diagnosis of Asthma–COPD Overlap Syndrome in Children

Authors: Frantisek Kopriva, Kamila Michalkova, Radim Dudek, Jana Volejnikova

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Rationale: Diagnostic criteria of asthma–COPD overlap syndrome (ACOS) are controversial in pediatrics. Emphysema is characteristic of COPD and usually does not occur in typical asthma; its presence in patients with asthma suggests the concurrence with COPD. Low-dose chest computed tomography (CT) allows a non-invasive assessment of the lung tissue structure. Here we present CT findings of emphysematous changes in a child with ACOS. Patient and Methods: In a 6-year-old boy, atopy was confirmed by a skin prick test using common allergen extracts (grass and tree pollen, house dust mite, molds, cat, dog; manufacturer Stallergenes Greer, London, UK), where reactions over 3 mm were considered positive. Treatment with corticosteroids was started during the course of severe asthma. At 12 years of age, his spirometric parameters deteriorated despite treatment adjustment (VC 1.76 L=85%, FEV1 1.13 L=67%, TI%VCmax 64%, MEF25 19%, TLC 144%) and the bronchodilator test became negative. Results: Low-dose chest CT displayed irregular regions with increased radiolucency of pulmonary parenchyma (typical for hyperinflation in emphysematous changes) in both lungs. This was in accordance with the results of spirometric examination. Conclusions: ACOS is infrequent in children. However, low-dose chest CT scan can be considered to confirm this diagnosis or eliminate other diagnoses when the clinical condition is deteriorating and treatment response is poor.

Keywords: child, asthma, low-dose chest CT, ACOS

Procedia PDF Downloads 140
975 Fabric-Reinforced Cementitious Matrix (FRCM)-Repaired Corroded Reinforced Concrete (RC) Beams under Monotonic and Fatigue Loads

Authors: Mohammed Elghazy, Ahmed El Refai, Usama Ebead, Antonio Nanni

Abstract:

Rehabilitating corrosion-damaged reinforced concrete (RC) structures has been accomplished using various techniques such as steel plating, external post-tensioning, and external bonding of fiber reinforced polymer (FRP) composites. This paper reports on the use of an innovative technique to strengthen corrosion-damaged RC structures using fabric-reinforced cementitious matrix (FRCM) composites. FRCM consists of dry-fiber fabric embedded in cement-based matrix. Twelve large-scale RC beams were constructed and tested in flexural monotonic and fatigue loads. Prior to testing, ten specimens were subjected to accelerated corrosion process for 140 days leading to an average mass loss in the tensile steel bars of 18.8 %. Corrosion was restricted to the main reinforcement located in the middle third of the beam span. Eight corroded specimens were repaired and strengthened while two virgin and two corroded-unrepaired/unstrengthened beams were used as benchmarks for comparison purpose. The test parameters included the FRCM materials (Carbon-FRCM, PBO-FRCM), the number of FRCM plies, the strengthening scheme, and the type of loading (monotonic and fatigue). The effects of the pervious parameters on the flexural response, the mode of failure, and the fatigue life were reported. Test results showed that corrosion reduced the yield and ultimate strength of the beams. The corroded-unrepaired specimen failed to meet the provisions of the ACI-318 code for crack width criteria. The use of FRCM significantly increased the ultimate strength of the corroded specimen by 21% and 65% more than that of the corroded-unrepaired specimen. Corrosion significantly decreased the fatigue life of the corroded-unrepaired beam by 77% of that of the virgin beam. The fatigue life of the FRCM repaired-corroded beams increased to 1.5 to 3.8 times that of the corroded-unrepaired beam but was lower than that of the virgin specimen. The specimens repaired with U-wrapped PBO-FRCM strips showed higher fatigue life than those repaired with the end-anchored bottom strips having similar number of PBO-FRCM-layers. PBO-FRCM was more effective than Carbon-FRCM in restoring the fatigue life of the corroded specimens.

Keywords: corrosion, concrete, fabric-reinforced cementitious matrix (FRCM), fatigue, flexure, repair

Procedia PDF Downloads 288
974 A Study of the Replacement of Natural Coarse Aggregate by Spherically-Shaped and Crushed Waste Cathode Ray Tube Glass in Concrete

Authors: N. N. M. Pauzi, M. R. Karim, M. Jamil, R. Hamid, M. F. M. Zain

Abstract:

The aim of this study is to conduct an experimental investigation on the influence of complete replacement of natural coarse aggregate with spherically-shape and crushed waste cathode ray tube (CRT) glass to the aspect of workability, density, and compressive strength of the concrete. After characterizing the glass, a group of concrete mixes was prepared to contain a 40% spherical CRT glass and 60% crushed CRT glass as a complete (100%) replacement of natural coarse aggregates. From a total of 16 types of concrete mixes, the optimum proportion was selected based on its best performance. The test results showed that the use of spherical and crushed glass that possesses a smooth surface, rounded, irregular and elongated shape, and low water absorption affects the workability of concrete. Due to a higher specific gravity of crushed glass, concrete mixes containing CRT glass had a higher density compared to ordinary concrete. Despite the spherical and crushed CRT glass being stronger than gravel, the results revealed a reduction in compressive strength of the concrete. However, using a lower water to binder (w/b) ratio and a higher superplasticizer (SP) dosage, it is found to enhance the compressive strength of 60.97 MPa at 28 days that is lower by 13% than the control specimen. These findings indicate that waste CRT glass in the form of spherical and crushed could be used as an alternative of coarse aggregate that may pave the way for the disposal of hazardous e-waste.

Keywords: cathode ray tube, glass, coarse aggregate, compressive strength

Procedia PDF Downloads 155
973 Creative Art Practice in Response to Climate Change: How Art Transforms and Frames New Approaches to Speculative Ecological and Sustainable Futures

Authors: Wenwen Liu, Robert Burton, Simon McKeown

Abstract:

Climate change is seriously threatening human security and development, leading to global warming and economic, political, and social chaos. Many artists have created visual responses that challenge perceptions on climate change, actively guiding people to think about the climate issues and potential crises after urban industrialization and explore positive solutions. This project is an interdisciplinary and intertextual study where art practice is informed by culture, philosophy, psychology, ecology, and science. By correlating theory and artistic practice, it studies how art practice creates a new way of understanding climate issues and uses art as a way of exploring speculative futures. In the context of practical-based research, arts-based practice as research and creative practice as interdisciplinary research are applied alternately to seek the original solution and new knowledge. Through creative art practice, this project has established new visual ways of looking at climate change and has developed it into a new model to generate more possibilities, an alternative social imagination. It not only encourages people to think and find a sustainable speculative future conducive to all species but also proves that people have the ability to realize positive futures.

Keywords: climate change, creative practice as interdisciplinary research, arts-based practice as research, creative art practice, speculative future

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972 Contrastive Learning for Unsupervised Object Segmentation in Sequential Images

Authors: Tian Zhang

Abstract:

Unsupervised object segmentation aims at segmenting objects in sequential images and obtaining the mask of each object without any manual intervention. Unsupervised segmentation remains a challenging task due to the lack of prior knowledge about these objects. Previous methods often require manually specifying the action of each object, which is often difficult to obtain. Instead, this paper does not need action information of objects and automatically learns the actions and relations among objects from the structured environment. To obtain the object segmentation of sequential images, the relationships between objects and images are extracted to infer the action and interaction of objects based on the multi-head attention mechanism. Three types of objects’ relationships in the object segmentation task are proposed: the relationship between objects in the same frame, the relationship between objects in two frames, and the relationship between objects and historical information. Based on these relationships, the proposed model (1) is effective in multiple objects segmentation tasks, (2) just needs images as input, and (3) produces better segmentation results as more relationships are considered. The experimental results on multiple datasets show that this paper’s method achieves state-of-art performance. The quantitative and qualitative analyses of the result are conducted. The proposed method could be easily extended to other similar applications.

Keywords: unsupervised object segmentation, attention mechanism, contrastive learning, structured environment

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971 Multilevel Two-Phase Structuring in the Nitrogen Supersaturated AISI316 Stainless Steel

Authors: Tatsuhiko Aizawa, Yohei Suzuki, Tomomi Shiratori

Abstract:

The austenitic stainless steel type AISI316 has been widely utilized as structural members and mold die substrates. The low temperature plasma nitriding has been utilized to harden these AISI316 members, parts, and dies without loss of intrinsic corrosion resistance to AISI316 stainless steels. Formation of CrN precipitates by normal plasma nitriding processes resulted in severe deterioration of corrosion toughness. Most previous studies on this low temperature nitriding of AISI316 only described the lattice expansion of original AISI316 lattices by the occupation of nitrogen interstitial solutes into octahedral vacancy sites, the significant hardening by nitrogen solid solution, and the enhancement of corrosion toughness. In addition to those engineering items, this low temperature nitriding process was characterized by the nitrogen supersaturation and nitrogen diffusion processes. The nitrogen supersaturated zones expanded by the nitrogen solute occupation to octahedral vacancy sites, and the un-nitrided surroundings to these zones were plastically strained to compensate for the mismatch strains across these nitrided and nitrided zones. The microstructure of nitrided AISI316 was refined by this plastic straining. The nitrogen diffusion process was enhanced to transport nitrogen solute atoms through the refined zone boundaries. This synergetic collaboration among the nitrogen supersaturation, the lattice expansion, the plastic straining, and the grain refinement yielded a thick nitrogen supersaturated layer. This synergetic relation was also characterized by the multilevel two-phase structuring. In XRD (X-Ray Diffraction) analysis, the nitrided AISI316 layer had - and -phases with the peak shifts from original lattices. After EBSD (Electron Back Scattering Diffraction) analysis, -grains and -grains homogeneously distributed in the nitrided layer. The scanning transmission electron microscopy (STEM) revealed that g-phase zone is N-poor cluster and a-phase zone is N-rich cluster. This proves that nitrogen supersaturated AISI316 stainless steels have multi-level two-phase structure in a very fine granular system.

Keywords: AISI316 stainless steels, chemical affinity to nitrogen solutes, multi-level two-phase structuring, nitrogen supersaturation

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970 Effects of Viscoelastic and Viscous Links on Seismic Pounding Mitigation in Buildings

Authors: Ali Reza Mirzagoltabar Roshan, H. Ahmadi Taleshian, A. Eliasi

Abstract:

This paper examines the effects of viscous and viscoelastic dampers as an efficient technique for seismic pounding mitigation. To aim that, 15 steel frame models with different numbers of stories and bays and also with different types of ductility were analyzed under 10 different earthquake records for assigned values of link damping and stiffness and the most suitable values of damper parameters (damping and stiffness) are presented. Moreover, it is demonstrated that viscous dampers can perform as efficiently as viscoelastic alternative with a more economical aspect for pounding mitigation purposes.

Keywords: adjacent buildings, separation distance, seismic pounding mitigation, viscoelastic link

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969 An Occupational Analysis on Chikankari Industry Workers in Lucknow City, India

Authors: Mahvish Anjum

Abstract:

India is a land of craftsmen and a hub of many popular embroidery clusters. Chikankari is the name given to the delicate art of hand embroidery, traditionally practiced in the city of Lucknow and its environs. Chikankari not only provide employment to 250,000 artisans of different crafts but people from non-craft base also earn their livelihood by associating themselves with this craft. People working in this sector are exploited in term of working hours, low and irregular income, unsatisfactory work conditions, no legal protection and exposed to occupational health hazards. The present paper is an attempt to analyse occupational profile of workers engaged in Chikan embroidery industry. Being an empirical study, the entire work is based upon primary sources of data which have collected through field survey. Purposive random sampling has used for selection of data. Total 150 workers have surveyed through questionnaire technique in Lucknow city during October-November, 2017. For analysis of data Z-score, ANOVA, and Pearson correlation techniques are used. The result of present study indicates that artisans are exploited by the middle man and face the problem of late payment and long working hours because they are not directly associated with the manufacturers. Work conditions of the workers are quite poor such as improper ventilation, poor light and unhygienic conditions that adversely affect the health of workers.

Keywords: artisans, socio-economic status, unorganized industry, work condition

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968 Anxiety and Change in Eating Habits and Health Behaviors among Adult Women during COVID-19 Pandemic Lockdown in Alexandria, Egypt

Authors: Heba Ahmed Abdelaziz, Doaa Tawfik Mohamed Ibrahim

Abstract:

Background: COVID-19 pandemic is the major health problem facing the world recently, causing variable effects on mental health and eating behavior. Aim of the study: Identifying changes in eating patterns and other health behaviors in relation to the anxiety caused by the COVID-19 pandemic lockdown in adult females in Alexandria, Egypt. Method: 344 adult females (20+ years old), were included in online self-administered questionnaire. Results: Severe anxiety symptoms was among 34.6% of the studied females especially; those aged 25-40 years, married, non-working or student females, females who had change in their work routine (half or full time from home). Homemade pastries and bakery product then beverages followed by fresh fruits and vegetables were frequently consumed by the studied females than before lockdown while fast foods were decreased during lockdown. Overweight and obesity were high among most of the participants with different grades of anxiety symptoms. Females with moderate and severe anxiety symptoms reported increase in appetite and body weight with irregular sleeping during lockdown. Conclusion: the current study concluded that stressful situations like lockdown due to COVID-19 pandemic is associated with anxiety (severe, moderate, mild then minimal, respectively) along with changes in eating habits, physical activity, sleeping pattern and smoking.

Keywords: COVID-19, lockdown, females, anxiety, eating, stress, lifestyle

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967 The Effect of Vitamin "E" on the Peripheral Neurotoxicity of Antimony in Adult Male Albino Rat

Authors: Pymaneh Bairami Rad

Abstract:

The present work was planned with the aim to study the histological changes that might occur in the sciatic nerve of adult male albino rat following antimony trioxide exposure and to throw more light on the protective role of vitamin "E" on the peripheral neurotoxicity induced by this environmental toxin Sixty adult male albino rats, weighing 183 - 235 grams, were utilized in this work. The animals were divided into 3 groups; each of 20 rats: animals of group I served as control, animals of group II received antimony trioxide daily for 12 successive weeks , animals of group III received antimony trioxide and vitamin "E" daily for the same duration. Antimony trioxide was given in a daily dose of 500 mg/ kg body weight which represents 1/40 of the known LD50 and vitamin "E" was administered in a daily dose of 300 mg/kg body weight. Both antimony trioxide and vitamin "E" were given to the animals by gastric intubation. This research revealed many histological changes in the sciatic nerve, following exposure to antimony trioxide, including Wallerian degeneration in most myelinated nerve fibers with pleomorphic destruction, fragmentation, loss of normal lamination and rupture of myelin sheaths. The axoplasms of these nerve fibers were irregular, degenerated and contained myelin fragments with loss of neurofibrils. Obvious increase in endoneurium was also observed. Concomitant administration of vitamin "E" with antimony trioxide resulted in marked improvement in the histological changes observed in the sciatic nerve.

Keywords: neurotoxicity, antimony, vitamin e, anatomy, histology

Procedia PDF Downloads 426