Search results for: structural lightweight aggregate concrete

Authors: Sylvain Perrin, Thomas Saillour

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The Grande-Motte port and seafront development project on the French Mediterranean coastline entailed evaluating wave impact loads (pressures and forces) on the new beach seawall and comparing the resulting scour potential at the base of the existing and new seawall. A physical model was built at ARTELIA’s hydraulics laboratory in Grenoble (France) to provide insight into the evolution of scouring overtime at the front of the wall, quasi-static and impulsive wave force intensity and distribution on the wall, and water and sand overtopping discharges over the wall. The beach was constituted of fine sand and approximately 50 m wide above mean sea level (MSL). Seabed slopes were in the range of 0.5% offshore to 1.5% closer to the beach. A smooth concrete structure will replace the existing concrete seawall with an elevated curved crown wall. Prior the start of breaking (at -7 m MSL contour), storm-driven maximum spectral significant wave heights of 2.8 m and 3.2 m were estimated for the benchmark historical storm event dated of 1997 and the 50-year return period storms respectively, resulting in 1 m high waves at the beach. For the wave load assessment, a tensor scale measured wave forces and moments and five piezo / piezo-resistive pressure sensors were placed on the wall. Light-weight sediment physical model and pressure and force measurements were performed with scale 1:18. The polyvinyl chloride light-weight particles used to model the prototype silty sand had a density of approximately 1 400 kg/m3 and a median diameter (d50) of 0.3 mm. Quantitative assessments of the seabed evolution were made using a measuring rod and also a laser scan survey. Testing demonstrated the occurrence of numerous impulsive wave impacts on the reflector (22%), induced not by direct wave breaking but mostly by wave run-up slamming on the top curved part of the wall. Wave forces of up to 264 kilonewtons and impulsive pressure spikes of up to 127 kilonewtons were measured. Maximum scour of -0.9 m was measured for the new seawall versus -0.6 m for the existing seawall, which is imputable to increased wave reflection (coefficient was 25.7 - 30.4% vs 23.4 - 28.6%). This paper presents a methodology for the setup and operation of a physical model in order to assess the hydrodynamic and morphodynamic processes at a beach seawall during storms events. It discusses the pros and cons of such methodology versus others, notably regarding structures peculiarities and model effects.

Keywords: beach, impacts, scour, seawall, waves

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Authors: Hasan Izhar Khan, Naiqiang Zhang, Hong Xu, Zhongliang Zhu, Dongfang Jiang

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Inconel 625 is a nickel-based alloy having outstanding corrosion resistance and developed for use at service temperatures ranging from cryogenic to 980°C. It got a wide range of applications in nuclear, petrochemical, chemical, marine, aeronautical, and aerospace industries. Currently, it is one of the candidate materials to be used as a structural material in ultra-supercritical (USC) power plants. In the high-temperature corrosive medium environment, metallic materials are susceptible to corrosion fatigue (CF). CF is an interaction between cyclic stress and corrosive medium environment that acts on a susceptible material and results in initiation and propagation of cracks. For the application of Inconel 625 as a structural material in USC power plants, CF behavior must be evaluated in steam and supercritical water (SCW) environment. Fatigue crack growth rate (FCGR) curves obtained from CF experiments are required to predict residual life of metallic materials used in power plants. In this study, FCGR tests of Inconel 625 were obtained by using compact tension specimen at 550-650 °C in steam (8 MPa) and SCW (25 MPa). The dissolved oxygen level was kept constant at 8000 ppb for the test conducted in steam and SCW. The tests were performed under sine wave loading waveform, 1 Hz loading frequency, stress ratio of 0.6 and maximum stress intensity factor of 32 MPa√m. Crack growth rate (CGR) was detected by using direct current potential drop technique. Results showed that CGR increased with an increase in temperature in the tested environmental conditions. The mechanism concerning the influence of temperature on FCGR are further discussed.

Keywords: corrosion fatigue, crack growth rate, nickel-based alloy, temperature

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Authors: Karthik K. R, Viswanath V, Asraff A. K

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The first stage of a new-generation launch vehicle of ISRO makes use of large pressure vessels made of Aluminium alloy AA2219 to store fuel and oxidizer. These vessels have many weld joints that may contain cracks or crack-like defects during their fabrication. These defects may propagate across the vessel during pressure testing or while in service under the influence of tensile stresses leading to catastrophe. Though ductile materials exhibit significant stable crack growth prior to failure, it is not generally acceptable for an aerospace component. There is a need to predict the initiation of stable crack growth. The structural integrity of the vessel from fracture considerations can be studied by constructing the Failure Assessment Diagram (FAD) that accounts for both brittle fracture and plastic collapse. Critical crack sizes of the pressure vessel may be highly conservative if it is predicted from FAD alone. If the J-R curve for material under consideration is available apriori, the critical crack sizes can be predicted to a certain degree of accuracy. In this paper, a novel approach is proposed to predict the integrity of a weld in a pressure vessel made of AA2219 material. Fracture parameter ‘J-integral’ at the crack front, evaluated through finite element analyses, is used in the new procedure. Based on the simulation of tension tests carried out on SCT specimens by NASA, a cut-off value of J-integral value (J?ᵤₜ_ₒ??) is finalised. For the pressure vessel, J-integral at the crack front is evaluated through FE simulations incorporating different surface cracks at long seam weld in a cylinder and in dome petal welds. The obtained J-integral, at vessel level, is compared with a value of J?ᵤₜ_ₒ??, and the integrity of vessel weld in the presence of the surface crack is firmed up. The advantage of this methodology is that if SCT test data of any metal is available, the critical crack size in hardware fabricated using that material can be predicted to a better level of accuracy.

Keywords: FAD, j-integral, fracture, surface crack

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Authors: Wu Xiaoguang, Liu Jiaxin, Fang Miaomiao, Wei Saidong

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There are many prestressed concrete prefabricated girder Bridges with small and medium span and the damage is serious. This paper mainly study the effect of prestress loss of prefabricated bridge bearing performance, through the establishment of ANSYS finite element model, from the condition of different prestress loss research, get the stress and strain data, draw curve, finally get the following conclusion: loss of prestress can reduce the ultimate bearing capacity of Bridges, the side span across the deflection value than the influence of times side span, the influence of the deflection in the midspan cross value. Therefore, the prestress loss and the effective prestress should be strictly considered in the design and construction process.

Keywords: across the deflection, loss of prestress, prefabricated girder bridge, the main tensile stress

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Authors: Christian Gaigl, Martin Mensinger

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Once a fire resistance rating is necessary, it has to be proofed that the load bearing behavior of a steel construction under the exposure of fire still fits the static demands. High costs of passive fire protection, which satisfies the requirements, frequently result in a concrete solution. To optimize these expenses, one method is to determine the critical temperature according to the Eurocode DIN EN 1993-1-2. For this purpose, positive effects of hot-dip galvanized surface layers on the temperature development of steel members in the accidental situation of fire exposure has been investigated. The test results show a significant better heating behavior of hot-dip galvanized steel components compared to normal steel specimen. This leads in many cases to a R30 (30 minutes of ISO-fire) fire protection requirement of unprotected steel members and therefore to an economic added value.

Keywords: fire resistance, hot-dip galvanizing, steel constructions, R30 requirement, emissivity

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Authors: Perdana Rakhmana Putra, Hansen Wijaya, Sri Budiyani, Muhamad Natsir, Alexis badai Samudra

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The Palembang Sub-Basin (PSB) located in southern part of South Sumatera basin (SSB) consist of half-graben complex trending N-S to NW-SE. These geometries are believe as an impact of strike-slip regime developed in Eocene-Oligocene. Generally, most of the wells in this area produced hydrocarbon from late stage of syn-rift sequences called Lower Talang Akar (LTAF) and post-rift sequences called Batu Raja Formation (BRF) and drilled to proved hydrocarbon on structural trap; three-way dip anticline, four-way dip anticline, dissected anticline, and stratigraphy trap; carbonate build-up and stratigraphic pinch out. Only a few wells reached the deeper syn-rift sequences called Lahat Formation (LAF) and Lemat Formation (LEF). The new interpretation of subsurface data was done by the tectonostratigraphy concept and focusing on syn-rift sequence. Base on seismic characteristic on basin centre, it divided into four sequences: pre-rift sequence, rift initiation, maximum rift and late rift. These sequences believed as a new exploration target on PSB mature basin. This paper will demonstrate the paleo depositional setting during Paleogene and exploration play concept of syn-rift sequence in PSB. The main play for this area consists of stratigraphic and structure play, where the stratigraphic play is Eocene-Oligocene sediment consist of LAF sandstone, LEF-Benakat formation, and LAF with pinch-out geometry. The pinch-out, lenses geometry and on-lap features can be seen on the seismic reflector and formed at the time of the syn-rift sequence. The structural play is dominated by a 3 Way Dip play related to reverse fault trap.

Keywords: syn-rift, tectono-stratigraphy, exploration play, basin center play, south sumatera basin

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Authors: Kamel Malik Bensafta, Gervasio Bensafta

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The purpose of this paper is to investigate the relationship between oil prices and socks markets. The empirical analysis in this paper is conducted within the context of Multivariate GARCH models, using a transform version of the so-called BEKK parameterization. We show that mean and uncertainty of US market are transmitted to oil market and European market. We also identify an important transmission from WTI prices to Brent Prices.

Keywords: oil volatility, stock markets, MGARCH, transmission, structural break

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Authors: Magu Raam Prasaad R., Venkatramani Jagadish

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Recent studies in the literature have shown that randomly fluctuating wind flows can give rise to a distinct regime of pre-flutter oscillations called intermittency. Intermittency is characterized by the presence of sporadic bursts of high amplitude oscillations interspersed amidst low-amplitude aperiodic fluctuations. The focus of this study is on investigating the energy harvesting potential of these intermittent oscillations. Available literature has by and large devoted its attention on extracting energy from flutter oscillations. The possibility of harvesting energy from pre-flutter regimes have remained largely unexplored. However, extracting energy from violent flutter oscillations can be severely detrimental to the structural integrity of airfoil structures. Consequently, investigating the relatively stable pre-flutter responses for energy extraction applications is of practical importance. The present study is devoted towards addressing these concerns. A pitch-plunge airfoil with cubic hardening nonlinearity in the plunge and pitch degree of freedom is considered. The input flow fluctuations are modelled using a sinusoidal term with randomly perturbed frequencies. An electromagnetic coupling is provided to the pitch-plunge equations, such that, energy from the wind induced vibrations of the structural response are extracted. With the mean flow speed as the bifurcation parameter, a fourth order Runge-Kutta based time marching algorithm is used to solve the governing aeroelastic equations with electro-magnetic coupling. The harnessed energy from the intermittency regime is presented and the results are discussed in comparison to that obtained from the flutter regime. The insights from this study could be useful in health monitoring of aeroelastic structures.

Keywords: aeroelasticity, energy harvesting, intermittency, randomly fluctuating flows

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Authors: Qiuhao Chang, Liangliang Huang, Xingru Wu

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In the United States, over 90% of the roads are paved with asphalt. The aging of asphalt is the most serious problem that causes the deterioration of asphalt pavement. Waste cooking oils (WCOs) have been found they can restore the properties of aged asphalt and promote the reuse of aged asphalt pavement. In our previous study, it was found the optimal WCO concentration to restore the aged asphalt sample should be in the range of 10~15 wt% of the aged asphalt sample. After the WCO concentration exceeds 15 wt%, as the WCO concentration increases, some important properties of the asphalt sample can be weakened by the addition of WCO, such as cohesion energy density, surface free energy density, bulk modulus, shear modulus, etc. However, maximizing the utilization of WCO can create environmental and economic benefits. Therefore, in this study, a new idea about using the waste polymer is another additive to restore the WCO modified asphalt that contains a high concentration of WCO (15-25 wt%) is proposed, which has never been reported before. In this way, both waste polymer and WCO can be utilized. The molecular dynamics simulation is used to study the effect of waste polymer on properties of WCO modified asphalt and understand the corresponding mechanism at the molecular level. The radial distribution function, self-diffusion, cohesion energy density, surface free energy density, bulk modulus, shear modulus, adhesion energy between asphalt and aggregate are analyzed to validate the feasibility of combining the waste polymer and WCO to restore the aged asphalt. Finally, the optimal concentration of waste polymer and WCO are determined.

Keywords: reclaim aged asphalt pavement, waste cooking oil, waste polymer, molecular dynamics simulation

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Authors: Joyce Cruz Ferraz Dutra, Marcele Fonseca Passos, Rubens Maciel Filho, Douglas Fernandes Barbin, Gustavo Mockaitis

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The search for alternatives to control hunger in the world, generated a major environmental problem. Intensive systems of fish production can cause an imbalance in the aquatic environment, triggering the phenomenon of eutrophication. Currently, there are many forms of growth control aquatic plants, such as mechanical withdrawal, however some difficulties arise for their final destination. The Egeria densa is a species of submerged aquatic macrophyte-rich in cellulose and low concentrations of lignin. By applying the concept of second generation energy, which uses lignocellulose for energy production, the reuse of these aquatic macrophytes (Egeria densa) in the biofuels production can turn an interesting alternative. In order to make lignocellulose sugars available for effective fermentation, it is important to use pre-treatments in order to separate the components and modify the structure of the cellulose and thus facilitate the attack of the microorganisms responsible for the fermentation. Therefore, the objective of this research work was to evaluate the structural and morphological transformations occurring in the biomass of aquatic macrophytes (E.densa) submitted to a thermal pretreatment. The samples were collected in an intensive fish growing farm, in the low São Francisco dam, in the northeastern region of Brazil. After collection, the samples were dried in a 65 0C ventilation oven and milled in a 5mm micron knife mill. A duplicate assay was carried, comparing the in natural biomass with the pretreated biomass with heat (MT). The sample (MT) was submitted to an autoclave with a temperature of 1210C and a pressure of 1.1 atm, for 30 minutes. After this procedure, the biomass was characterized in terms of degree of crystallinity and morphology, using X-ray diffraction (XRD) techniques and scanning electron microscopy (SEM), respectively. The results showed that there was a decrease of 11% in the crystallinity index (% CI) of the pretreated biomass, leading to the structural modification in the cellulose and greater presence of amorphous structures. Increases in porosity and surface roughness of the samples were also observed. These results suggest that biomass may become more accessible to the hydrolytic enzymes of fermenting microorganisms. Therefore, the morphological transformations caused by the thermal pretreatment may be favorable for a subsequent fermentation and, consequently, a higher yield of biofuels. Thus, the use of thermally pretreated aquatic macrophytes (E.densa) can be an environmentally, financially and socially sustainable alternative. In addition, it represents a measure of control for the aquatic environment, which can generate income (biogas production) and maintenance of fish farming activities in local communities.

Keywords: aquatics macrophyte, biofuels, crystallinity, morphology, pretreatment thermal

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Authors: Iman Shabanzadeh

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Over the last three decades, the main demands of the Iranian workforce have been focused on three areas: "The right to a decent wage", "The right to organize" and "The right to job security". In order to investigate and analyze this situation, the present study focuses on the component of job security. The purpose of the study is to figure out what mechanisms in Iran's Labor Law have led to the destabilization and undermining of workers' job security. The research method is descriptive-analytical. To collect information, library and document sources in the field of laws related to labor rights in Iran and, semi-structured interviews with experts have been used. In the data analysis stage, the qualitative content analysis method was also used. The trend analysis of the statistics related to the labor force situation in Iran in the last three decades shows that the employment structure has been facing an increase in the active population, but in the last decade, a large part of this population has been mainly active in the service sector, and contract-free enterprises, so a smaller share of this employment has insurance coverage and a larger share has underemployment. In this regard, the results of this study show that four contexts have been proposed as the main legal and executive mechanisms of labor instability in Iran, which are: 1) temporaryization of the labor force by providing different interpretations of labor law, 2) adjustment labor in the public sector and the emergence of manpower contracting companies, 3) the cessation of labor law protection of workers in small workshops and 4) the existence of numerous restrictions on the effective organization of workers. The theoretical conclusion of this article is that the main root of the challenges of the labor society and the destabilized workforce in Iran is the existence of structural inequalities in the field of labor security, whose traces can be seen in the legal provisions and executive regulations of this field.

Keywords: inequality, precariat, temporaryization, labor force, labor law

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Authors: R. S. Malik, S. K. Madan, V. K. Sehgal

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Reinforced concrete (RCC) buildings with dual system consisting of shear walls and moment resisting frames or braces and moment resisting frames have been widely used to resist lateral forces during earthquakes. The two dual systems are designed to resist the total design lateral force in proportion to their lateral stiffness. The response of the combination of braces and shear walls has not yet been studied therefore has practically no work to refer to. The combination may prove to be more effective in lateral load resistance by employing the peculiar advantages of shear walls and braces simultaneously and may also improve the architectural appearance of structures. This concept has been applied to regular RCC buildings provided with shear walls, braces, and their combinations.

Keywords: dynamic analysis, displacement, pushover analysis, dual structures, storey drift

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Authors: Usman A. Usman

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Undeniably, unlike the Classical side, the Keynesian perspective of the aggregate demand side indeed has a significant position in the policy, growth, and welfare of Nigeria due to government involvement and ineffective demand of the population living with poor per capita income. This study seeks to investigate the effect of Government Final Consumption Expenditure, Financial Deepening on Households, and NPISHs Final consumption expenditure using data on Nigeria from 1981 to 2019. This study employed the ADF stationarity test, Johansen Cointegration test, and Vector Error Correction Model. The results of the study revealed that the coefficient of Government final consumption expenditure has a positive effect on household consumption expenditure in the long run. There is a long-run and short-run relationship between gross fixed capital formation and household consumption expenditure. The coefficients cpsgdp financial deepening and gross fixed capital formation posit a negative impact on household final consumption expenditure. The coefficients money supply lm2gdp, which is another proxy for financial deepening, and the coefficient FDI have a positive effect on household final consumption expenditure in the long run. Therefore, this study recommends that Gross fixed capital formation stimulates household consumption expenditure; a legal framework to support investment is a panacea to increasing hoodmold income and consumption and reducing poverty in Nigeria. Therefore, this should be a key central component of policy.

Keywords: household, government expenditures, vector error correction model, johansen test

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Authors: Erfan Niazi, Marianne Fenech

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Red Blood Cells (RBCs) or erythrocytes tend to form chain-like aggregates under low shear rate called rouleaux. This is a reversible process and rouleaux disaggregate in high shear rates. Therefore, RBCs aggregation occurs in the microcirculation where low shear rates are present but does not occur under normal physiological conditions in large arteries. Numerical modeling of RBCs interactions is fundamental in analytical models of a blood flow in microcirculation. Population Balance Modeling (PBM) is particularly useful for studying problems where particles agglomerate and break in a two phase flow systems to find flow characteristics. In this method, the elementary particles lose their individual identity due to continuous destructions and recreations by break-up and agglomeration. The aim of this study is to find RBCs aggregation in a dynamic situation. Simplified PBM was used previously to find the aggregation rate on a static observation of the RBCs aggregation in a drop of blood under the microscope. To find aggregation rate in a dynamic situation we propose an experimental set up testing RBCs sedimentation. In this test, RBCs interact and aggregate to form rouleaux. In this configuration, disaggregation can be neglected due to low shear stress. A high-speed camera is used to acquire video-microscopic pictures of the process. The sizes of the aggregates and velocity of sedimentation are extracted using an image processing techniques. Based on the data collection from 5 healthy human blood samples, the aggregation rate was estimated as 2.7x10³(±0.3 x10³) 1/s.

Keywords: red blood cell, rouleaux, microfluidics, image processing, population balance modeling

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Authors: Ayşin Sev, Meltem Ezel

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Sustainability, being the urgent issue of our time, is closely related with the innovations in technology. Nanotechnology (NT), although not a new science, can be regarded relatively a new science for buildings with brand new materials and applications. This paper tends to give a research review of current and near future applications of nanotechnology (NT) for achieving high-performance and healthy buildings for a sustainable future. In the introduction, the driving forces for the sustainability of construction industry are explained. Then, the term NT is defined, and significance of innovations in NT for a sustainable construction industry is revealed. After presenting the application areas of NT and nanomaterials for buildings with a number of cases, challenges in the adoption of this technology are put forward, and finally the impacts of nanoparticles and nanomaterials on human health and environment are discussed.

Keywords: nanomaterial, self-healing concrete, self cleaning sensor, nanosensor, steel, wood, aerogel, flexible solar panel

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Authors: Fayssal Tayalati

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Although languages use very divergent constructional strategies, all existential constructions appear to invariably involve an implicit or explicit locative constituent. This locative constituent either surface as a true locative phrase or are realized as a possessor noun phrase. However, while much research focuses on the supposed underlying syntactic relation of locative and possessive existential constructions, not much is known about possible semantic factors that could govern the choice between these constructions. The main question that we address in this talk concerns the choice between the two related constructions in Modern Standard Arabic (MAS). Although both are used to express the existence of something somewhere, we can distinguish three contexts: First, for some types of entities, only the EL construction is possible (e.g. (1a) ṯammata raǧulun fī l-ḥadīqati vs. (1b) *(kāna) ladā l-ḥadīqati raǧulun). Second, for other types of entities, only the possessive construction is possible (e.g. (2a) ladā ṭ-ṭawilati aklun dāʾiriyyun vs. (2b) *ṯammata šaklun dāʾiriyyun ladā/fī ṭ-ṭawilati). Finally, for still other entities, both constructions can be found (e.g. (3a) ṯammata ḥubbun lā yūṣafu ladā ǧārī li-zawǧati-hi and (3b) ladā ǧārī ḥubbun lā yūṣafu li-zawǧati-hi). The data covering a range of ontologically different entities (concrete objects, events, body parts, dimensions, essential qualities, feelings, etc.) shows that the choice between the existential locative and the possessive constructions is closely linked to the conceptual autonomy of the existential theme with respect to its location or to the whole that it is a part of. The construction with ṯammata is the only possible one to express the existence of a fully autonomous (i.e. nondependent) entity (concrete objects (e.g.1) and abstract objects such as events, especially the ones that Grimshaw called ‘simple events’). The possessive construction with (kāna) ladā is the only one used to express the existence of fully non-autonomous (i.e. fully dependent on a whole) entities (body parts, dimensions (e.g. 2), essential qualities). The two constructions alternate when the existential theme is conceptually dependent but separable of the whole, either because it has an autonomous (independent) existence of the given whole (spare parts of an object), or because it receives a relative autonomy in the speech through a modifier (accidental qualities, feelings (e.g. 3a, 3b), psychological states, among some other kinds of themes). In this case, the modifier expresses an approximate boundary on a scale, and provides relative autonomy to the entity. Finally, we will show that kinship terms (e.g. son), which at first sight may seem to constitute counterexamples to our hypothesis, are nonetheless supported by it. The ontological (non-)autonomy of located or possessed entities is also reflected by morpho-syntactic properties, among them the use and the choice of determiners, pluralisation and the behavior of entities in the context of associative anaphora.

Keywords: existence, possession, autonomous entities, non-autonomous entities

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Authors: André Jesus, Yanjie Zhu, Irwanda Laory

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Structural health monitoring is one of the most promising technologies concerning aversion of structural risk and economic savings. Analysts often have to deal with a considerable variety of uncertainties that arise during a monitoring process. Namely the widespread application of numerical models (model-based) is accompanied by a widespread concern about quantifying the uncertainties prevailing in their use. Some of these uncertainties are related with the deterministic nature of the model (code uncertainty) others with the variability of its inputs (parameter uncertainty) and the discrepancy between a model/experiment (systematic uncertainty). The actual process always exhibits a random behaviour (observation error) even when conditions are set identically (residual variation). Bayesian inference assumes that parameters of a model are random variables with an associated PDF, which can be inferred from experimental data. However in many Bayesian methods the determination of systematic uncertainty can be problematic. In this work systematic uncertainty is associated with a discrepancy function. The numerical model and discrepancy function are approximated by Gaussian processes (surrogate model). Finally, to avoid the computational burden of a fully Bayesian approach the parameters that characterise the Gaussian processes were estimated in a four stage process (modular Bayesian approach). The proposed methodology has been successfully applied on fields such as geoscience, biomedics, particle physics but never on the SHM context. This approach considerably reduces the computational burden; although the extent of the considered uncertainties is lower (second order effects are neglected). To successfully identify the considered uncertainties this formulation was extended to consider multiple responses. The efficiency of the algorithm has been tested on a small scale aluminium bridge structure, subjected to a thermal expansion due to infrared heaters. Comparison of its performance with responses measured at different points of the structure and associated degrees of identifiability is also carried out. A numerical FEM model of the structure was developed and the stiffness from its supports is considered as a parameter to calibrate. Results show that the modular Bayesian approach performed best when responses of the same type had the lowest spatial correlation. Based on previous literature, using different types of responses (strain, acceleration, and displacement) should also improve the identifiability problem. Uncertainties due to parametric variability, observation error, residual variability, code variability and systematic uncertainty were all recovered. For this example the algorithm performance was stable and considerably quicker than Bayesian methods that account for the full extent of uncertainties. Future research with real-life examples is required to fully access the advantages and limitations of the proposed methodology.

Keywords: bayesian, calibration, numerical model, system identification, systematic uncertainty, Gaussian process

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Authors: S. K. Ashiquer Rahman

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The proper policy handling might not able to attain the target since some of recessions, e.g., pandemic-led crises, the variables shocks of the economics. At the level of this situation, the Central bank implements the monetary policy to choose increase the exogenous expenditure and level of money supply consecutively for booster level economic growth, whether the monetary policy is relatively more effective than fiscal policy in altering real output growth of a country or both stand for relatively effective in the direction of output growth of a country. The dispute with reference to the relationship between the monetary policy and fiscal policy is centered on the inflationary penalty of the shortfall financing by the fiscal authority. The latest variables socks of economics as well as the pandemic-led crises, central banks around the world predicted just about a general dilemma in relation to increase rates to face the or decrease rates to sustain the economic movement. Whether the prices hang about fundamentally unaffected, the aggregate demand has also been hold a significantly negative attitude by the outbreak COVID-19 pandemic. To empirically investigate the effects of economics shocks associated COVID-19 pandemic, the paper considers the effectiveness of the monetary policy and fiscal policy that linked to the adjustment mechanism of different economic variables. To examine the effects of economics shock associated COVID-19 pandemic towards the effectiveness of Monetary Policy and Fiscal Policy in the direction of output growth of a Country, this paper uses the Simultaneous equations model under the estimation of Two-Stage Least Squares (2SLS) and Ordinary Least Squares (OLS) Method.

Keywords: IS-LM framework, pandemic. Economics variables shocks, simultaneous equations model, output growth

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Authors: Musa Akdere, Gunnar Seide, Thomas Gries

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Carbon fibres are fibrous materials with a carbon atom amount of more than 90%. They combine excellent mechanicals properties with a very low density. Thus carbon fibre reinforced plastics (CFRP) are very often used in lightweight design and construction. The precursor material is usually polyacrylonitrile (PAN) based and wet-spun. During the production of carbon fibre, the precursor has to be stabilized thermally to withstand the high temperatures of up to 1500 °C which occur during carbonization. Even though carbon fibre has been used since the late 1970s in aerospace application, there is still no general method available to find the optimal production parameters and the trial-and-error approach is most often the only resolution. To have a much better insight into the process the chemical reactions during stabilization have to be analyzed particularly. Therefore, a model of the chemical reactions (cyclization, dehydration, and oxidation) based on the research of Dunham and Edie has been developed. With the presented model, it is possible to perform a complete simulation of the fibre undergoing all zones of stabilization. The fiber bundle is modeled as several circular fibers with a layer of air in-between. Two thermal mechanisms are considered to be the most important: the exothermic reactions inside the fiber and the convective heat transfer between the fiber and the air. The exothermic reactions inside the fibers are modeled as a heat source. Differential scanning calorimetry measurements have been performed to estimate the amount of heat of the reactions. To shorten the required time of a simulation, the number of fibers is decreased by similitude theory. Experiments were conducted to validate the simulation results of the fibre temperature during stabilization. The experiments for the validation were conducted on a pilot scale stabilization oven. To measure the fibre bundle temperature, a new measuring method is developed. The comparison of the results shows that the developed simulation model gives good approximations for the temperature profile of the fibre bundle during the stabilization process.

Keywords: carbon fibre, coupled simulation, exothermic reactions, fibre-air-interface

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Authors: L. Pavithra, R. Sharmila, Shivani Sridhar

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Columns severe structural damage needs proportioning a significant portion of earthquake energy can be dissipated yielding in the beams. Presence of axial load along with cyclic loading has a significant influence on column. The objective of this paper is to present the analytical results of columns subjected to biaxial cyclic loading.

Keywords: RC column, Seismic behaviour, cyclic behaviour, biaxial testing, ductile behaviour

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Authors: Ana Paula Mousinho, Ronaldo D. Mansano, Nelson Ordonez

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Carbon nanotubes are one of the main elements in nanotechnologies; their applications are in microelectronics, nano-electronics devices (photonics, spintronic), chemical sensors, structural material and currently in clean energy devices (supercapacitors and fuel cells). The use of magnetic particle decorated carbon nanotubes increases the applications in magnetic devices, magnetic memory, and magnetic oriented drug delivery. In this work, single-walled carbon nanotubes (CNTs) forest decorated with chromium were deposited at room temperature by high-density plasma chemical vapor deposition (HDPCVD) system. The CNTs forest was obtained using pure methane plasmas and chromium, as precursor material (seed) and for decorating the CNTs. Magnetron sputtering deposited the chromium on silicon wafers before the CNTs' growth. Scanning electron microscopy, atomic force microscopy, micro-Raman spectroscopy, and X-ray diffraction characterized the single-walled CNTs forest decorated with chromium. In general, the CNTs' spectra show a unique emission band, but due to the presence of the chromium, the spectra obtained in this work showed many bands that are related to the CNTs with different diameters. The CNTs obtained by the HDPCVD system are highly aligned and showed metallic features, and they can be used as photonic material, due to the unique structural and electrical properties. The results of this work proved the possibility of obtaining the controlled deposition of aligned single-walled CNTs forest films decorated with chromium by high-density plasma chemical vapor deposition system.

Keywords: CNTs forest, high density plasma deposition, high-aligned CNTs, nanomaterials

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Authors: Mohammad K. Parvez, Mohammed S. Al-Dosari

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Hepatitis E virus (HEV) is an emerging RNA virus that causes acute and chronic liver disease with a global mortality rate of about 2%. Despite milestone developments in understanding of HEV biology, there is still lack of a robust culture system or animal model. Therefore, in a novel approach, two recombinant-baculoviruses (vBac-ORF2 and vBac-ORF3) that could overexpress HEV ORF2 (structural/capsid) and ORF3 (nonstructural/regulatory) proteins, respectively were constructed. The established HEV-SAR55 (genotype 1) replicon that contained GFP gene, in place of ORF2/ORF3 sequences was in vitro transcribed, and GFP production in RNA transfected S10-3 cells was scored by FACS. Enhanced infectivity, if any, of nascent virions produced by exogenously-supplied ORF2 and viral RNA by co-expression of ORF3 was tested on naïve HepG2 cells. Co-transduction with vBac-ORF2/vBac-ORF3 (108 pfu/microL) produced high amounts of native ORF2/ORF3 in approximately 60% of S10-3 cells, determined by immunofluorescence microscopy and Western analysis. FACS analysis showed about 9% GFP positivity of S10-3 cells on day6 post-transfection (i.e, day5 post-transduction). Further, FACS scoring indicated that lysates from S10-3 cultures receiving the RNA plus vBac-ORF2 were capable of producing HEV particles with about 4% infectivity in HepG2 cells. However, lysates of cultures co-transduced with vBac-ORF3, were found to further enhance virion infectivity by approximately 17%. This supported a previously proposed role of ORF3 as a minor-structural protein in HEV virion assembly and infectivity. In conclusion, the present model for efficient genomic RNA packaging and production of infectious virions could be a valuable tool to study various aspects of HEV molecular biology, in vitro.

Keywords: chronic liver disease, hepatitis E virus, ORF2, ORF3, replicon

Procedia PDF Downloads 251

Authors: Peng Li, Chuanri Li, Tao Li

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Reliability allocation is quite important during early design and development stages for a system to apportion its specified reliability goal to subsystems. This paper improves the reliability fuzzy allocation method and gives concrete processes on determining the factor set, the factor weight set, judgment set, and multi-grade fuzzy comprehensive evaluation. To determine the weight of factor set, the modified trapezoidal numbers are proposed to reduce errors caused by subjective factors. To decrease the fuzziness in the fuzzy division, an approximation method based on linear programming is employed. To compute the explicit values of fuzzy numbers, centroid method of defuzzification is considered. An example is provided to illustrate the application of the proposed reliability allocation method based on fuzzy arithmetic.

Keywords: reliability allocation, fuzzy arithmetic, allocation weight, linear programming

Procedia PDF Downloads 337

Authors: Rony Reátegui, Cesar Chácara, Benjamin Castañeda, Rafael Aguilar

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Nowadays, heritage building information modeling (HBIM) is considered an efficient tool to represent and manage information of cultural heritage (CH). The basis of this tool relies on a 3D model generally obtained from a cloud-to-BIM procedure. There are different methods to create an HBIM model that goes from manual modeling based on the point cloud to the automatic detection of shapes and the creation of objects. The selection of these methods depends on the desired level of development (LOD), level of information (LOI), grade of generation (GOG), as well as on the availability of commercial software. This paper presents the 3D modeling of a stone masonry chapel using Recap Pro, Revit, and Dynamo interface following a three-step methodology. The first step consists of the manual modeling of simple structural (e.g., regular walls, columns, floors, wall openings, etc.) and architectural (e.g., cornices, moldings, and other minor details) elements using the point cloud as reference. Then, Dynamo is used for generative modeling of complex structural elements such as vaults, infills, and domes. Finally, semantic information (e.g., materials, typology, state of conservation, etc.) and pathologies are added within the HBIM model as text parameters and generic models families, respectively. The application of this methodology allows the documentation of CH following a relatively simple to apply process that ensures adequate LOD, LOI, and GOG levels. In addition, the easy implementation of the method as well as the fact of using only one BIM software with its respective plugin for the scan-to-BIM modeling process means that this methodology can be adopted by a larger number of users with intermediate knowledge and limited resources since the BIM software used has a free student license.

Keywords: cloud-to-BIM, cultural heritage, generative modeling, HBIM, parametric modeling, Revit

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Authors: Dhaivat S. Soni, Snehal Thakor, Afroz Bhatti

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The prepare CNTs in bulk quantity by as easiest as possible method with highly pure and small diameter. Prepared CNTs first charactered its structural parameter for the conformation of CNTs and purity. Surface morphology of CNTs stured by using various instruments finally study application of prepared CNTs in various field. Carbon nanotubes (CNTs) were synthesized in large scale by pyrolyzing activated carbon in sealed autoclaves.

Keywords: nanostructures, nanotubes, carbon, pyrolysis

Procedia PDF Downloads 392

Authors: Dineshsingh Thakur, S. Nagesh, J. Basha

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A lightweight High Speed Flexible Coupling (HSFC) is used to connect the Engine Gear Box (EGB) with an Accessory Gear Box (AGB) of the combat aircraft. The HSFC transmits the power at high speeds ranging from 10000 to 18000 rpm from the EGB to AGB. The HSFC is also accommodates larger misalignments resulting from thermal expansion of the aircraft engine and mounting arrangement. The HSFC has the series of metallic contoured annular thin cross-sectioned flexible plates to accommodate the misalignments. The flexible plates are accommodating the misalignment by the elastic material flexure. As the HSFC operates at higher speed, the flexural and axial resonance frequencies are to be kept away from the operating speed and proper prediction is required to prevent failure in the transmission line of a single engine fighter aircraft. To study the influence of flexible plate’s contour on the lateral critical speed (LCS) of HSFC, a mathematical model of HSFC as a elven rotor system is developed. The flexible plate being the bending member of the system, its bending stiffness which results from the contoured governs the LCS. Using transfer matrix method, Influence of various flexible plate contours on critical speed is analyzed. In the above analysis, the support bearing flexibility on critical speed prediction is also considered. Based on the study, a model is built with the optimum contour of flexible plate, for validation by experimental modal analysis. A good correlation between the theoretical prediction and model behavior is observed. From the study, it is found that the flexible plate’s contour is playing vital role in modification of system’s dynamic behavior and the present model can be extended for the development of similar type of flexible couplings for its computational simplicity and reliability.

Keywords: flexible rotor, critical speed, experimental modal analysis, high speed flexible coupling (HSFC), misalignment

Procedia PDF Downloads 207

Authors: Umamaheswara Rao Jada, Susmita Mukhopadhyay

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In the present highly complex, dynamic and interdependent organizational environment, employees' ideas, opinions and suggestions which is technically referred to as ‘constructive employee voice’ is increasingly being recognized and valued. Literature has consistently demonstrated the relevance of leadership in employee voicing behavior, however the new form of leadership, ‘empowering leadership’ has not been given much attention. The study, therefore, devotes itself to the effort to explore the impact of this new form of leadership on employee voice behavior and the interplay with leader member exchange (LMX) and psychological safety as mediators in the same. The study utilizes structural equation modeling for analyzing the data collected from 310 Indian service industry employees through the questionnaire developed for the study. The findings of the study demonstrate the significant impact of empowering form of leadership on employees’ constructive voice behavior. Additionally, supporting results were observed for the mediating impact of leader member exchange (LMX) and psychological safety between empowering leadership and employees’ constructive voice behavior. The results of this study provide insights into the intervening mechanisms by linking leaders’ empowering behavior with employees’ constructive voice, while also highlighting the potential importance of LMX relationship in organizations and psychological safety in the context of constructive voice behavior. The study brings forth the relevance of the new form of leadership, ‘empowering leadership’ for fostering the better exchange of ideas, opinions, and suggestions between leaders and followers which tend to benefit the organization, providing empirical evidence of the sequential mediation of LMX and psychological safety. The piece of work is assumed to benefit the leaders in organizations by providing them the basis for adopting empowering form of leadership in light of results displayed.

Keywords: constructive voice, empowering leadership, leader member exchange (LMX), psychological safety, sequential mediation, structural equation modeling

Procedia PDF Downloads 301

Authors: Mewa Singh

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Nanomedicine, a fusion of nanotechnology and medicine, is an emerging technology ideally suited to the targeted therapies. Nanoparticles overcome the low selectivity of anti-cancer drugs toward the tumor as compared to normal tissue and hence result-in less severe side-effects. Our new technology, HYBRID-NANOENGINEERING™, uses a new molecule (MR007) in the creation of nanoparticles that not only helps in nanonizing the medicine but also provides synergy to the medicine. The simplified manufacturing process will result in reduced manufacturing costs. Treatment is made more convenient because hybrid nanomedicines can be produced in oral, injectable or transdermal formulations. The manufacturing process uses no protein, oil or detergents. The particle size is below 180 nm with a narrow distribution of size. Importantly, these properties confer great stability of the structure. The formulation does not aggregate in plasma and is stable over a wide range of pH. The final hybrid formulation is stable for at least 18 months as a powder. More than 97 drugs, including paclitaxel, docetaxel, tamoxifen, doxorubicinm prednisone, and artemisinin have been nanonized in water soluble formulations. Preclinical studies on cell cultures of tumors show promising results. Our HYBRID-NANOENGINEERING™ platform enables the design and development of hybrid nano-pharmaceuticals that combine efficacy with tolerability, giving patients hope for both extended overall survival and improved quality of life. This study would discuss or present this new discovery of HYBRID-NANOENGINEERING™ which targets drug delivery, synergistic, and potentiating effects, and barriers of drug delivery and advanced drug delivery systems.

Keywords: nano-medicine, nano-particles, drug delivery system, pharmaceuticals

Procedia PDF Downloads 480

Authors: Arámbula-Villa Gerónimo, García-Lara Kenia Y., Figueroa-Cárdenas J. D., Pérez-Robles J. F., Jiménez-Sandoval S., Salazar-López R., Herrera-Corredor J. A.

Abstract:

The nixtamalization process (thermal-alkaline method) improves the nutritional part of the corn grain. In this process, the using of Ca(OH)₂ is basic, although the chemical mechanisms between this alkali and the carbohydrates (starch), proteins, lipids, and fiber have not been fully identified. In this study, the native corn starch was taken as a model, and it was subjected to cooking with different concentrations of lime (nixtamalization process) and specific studies of FTIR and XRD were carried out to identify the formation of chemical compounds, and the physical, physicochemical, rheological (paste) and structural properties of material obtained were determined. The FTIR spectra showed the formation of calcium-starch complexes. The treatments with Ca(OH)₂ showed a band shift towards 1675 cm⁻¹ and a band in 1436 cm⁻¹ (COO⁻), indicating the oxidation of starch. Three bands were identified (1575, 1550, and 1540 cm⁻¹) characteristics of carboxylic acid salts for three types of coordinated structures: monodentate, pseudo-bridged, and bidentate. The XRD spectra of starch treated with Ca(OH)₂ showed a peak corresponding to CaCO₃ (29.40°). The oxidation of starch was favored with low concentrations of Ca(OH)₂, producing carboxyl and carbonyl groups and increasing the residual CaCO₃. The increased concentration of Ca(OH)₂ showed the formation of calcium carboxylates, with a decrease in relative crystallinity and residual CaCO₃. Samples with low concentrations of Ca(OH)₂ slowed the onset of gelatinization and increased the swelling of the granules and the peak viscosity. The higher concentrations of Ca(OH)₂ difficulted the water absorption and decreased the viscosity rate and peak viscosity. These results can be used to improve the quality characteristics of the dough and tortillas and to get better acceptance by consumers.

Keywords: maize starch, nixtamalization, gelatinization, calcium carboxylates

Procedia PDF Downloads 90

Authors: Vivek Hokam, Vishrut Landge

Abstract:

An ideal maintenance program for an industrial road network is one that would maintain all sections at a sufficiently high level of functional and structural conditions. However, due to various constraints such as budget, manpower and equipment, it is not possible to carry out maintenance on all the needy industrial road sections within a given planning period. A rational and systematic priority scheme needs to be employed to select and schedule industrial road sections for maintenance. Priority analysis is a multi-criteria process that determines the best ranking list of sections for maintenance based on several factors. In priority setting, difficult decisions are required to be made for selection of sections for maintenance. It is more important to repair a section with poor functional conditions which includes uncomfortable ride etc. or poor structural conditions i.e. sections those are in danger of becoming structurally unsound. It would seem therefore that any rational priority setting approach must consider the relative importance of functional and structural condition of the section. The maintenance priority index and pavement performance models tend to focus mainly on the pavement condition, traffic criteria etc. There is a need to develop the model which is suitably used with respect to limited budget provisions for maintenance of pavement. Linear programming is one of the most popular and widely used quantitative techniques. A linear programming model provides an efficient method for determining an optimal decision chosen from a large number of possible decisions. The optimum decision is one that meets a specified objective of management, subject to various constraints and restrictions. The objective is mainly minimization of maintenance cost of roads in industrial area. In order to determine the objective function for analysis of distress model it is necessary to fix the realistic data into a formulation. Each type of repair is to be quantified in a number of stretches by considering 1000 m as one stretch. A stretch considered under study is having 3750 m length. The quantity has to be put into an objective function for maximizing the number of repairs in a stretch related to quantity. The distress observed in this stretch are potholes, surface cracks, rutting and ravelling. The distress data is measured manually by observing each distress level on a stretch of 1000 m. The maintenance and rehabilitation measured that are followed currently are based on subjective judgments. Hence, there is a need to adopt a scientific approach in order to effectively use the limited resources. It is also necessary to determine the pavement performance and deterioration prediction relationship with more accurate and economic benefits of road networks with respect to vehicle operating cost. The infrastructure of road network should have best results expected from available funds. In this paper objective function for distress model is determined by linear programming and deterioration model considering overloading is discussed.

Keywords: budget, maintenance, deterioration, priority

Procedia PDF Downloads 204