Abstract — Among the priority issues that the modern society has to be solved, include also the energy and environmental issues. The notion of control (process control) has expanded in recent years, encompassing new areas such as automatic control of quality, the data processing with decisional purpose for one strategic leadership, ensuring uninterrupted of the system maintainability and thus, security and viability of the entire ensemble. In this context are part and the simplified simulation methods of the energetic installations from the power plants. The paper expose, in the first part, the importance of the steam generator in the operation of power plants, presents the energy processes complexity, emphasizing the importance of their management and automation to increase energy efficiency of each link in the chain. Then, taking as its starting point the real operational aspects, the mathematical modeling, the simulation and automatic control of steam generator, the paper proposes the development of a mathematical model in absolute units and the simulation the operation of a convective heat exchange surface of the steam generator in steady and dynamic regime.
Keywords — Mathematical model, modeling, power plant, simulation, steam generator.
A Correlative Analysis of Machining Parameters with Surface Roughness for Ferrous and Non- Ferrous Alloy Materials
Abstract— Average Surface Roughness (Ra) is one of the most frequently used texture parameters to define the quality of turned components. The roughness values of a turned surface much depends on cutting parameters such as cutting speed, feed rate and depth of cut. Optimization of these parameters is very important in relation to surface roughness as they reveal the best suitable conditions for the turning operation. In this project, a correlative study of machining parameters and the surface roughness for ferrous (stainless steel 304) and non–ferrous alloy (Aluminium) material is carried out. Response Surface Methodology (RSM) and Analysis of Variance (ANOVA) techniques are employed in this analysis to explain the influence of different cutting parameters on surface roughness values. The combination of optimum experimental parameters can be found by machining these ferrous and non-ferrous materials in CNC turning center and finding the least surface roughness parameters. ANOVA analysis, integrated with Design Expert software, is used to determine effective ratios of the parameters and subsequently the relationships between input parameters and their responses relationship are established. The minimum surface roughness results in reference to spindle rpm, feed rate, and depth of cut are determined and estimation of the optimal surface roughness values (Ra) for least surface roughness are the results obtained in the study. In case of stainless steel 304, optimal values of cutting speed, feed and depth of cut against the least surface roughness value of 1.33 microns are found to be 220 m. min-1, 0.2 mm. rev-1 and 0.3 mm respectively. In case of Aluminium, optimal values of cutting speed, feed and depth of cut against the least surface roughness value of 2.8 microns are 200 m. min-1, 0.2 mm. rev-1 and 1.15 mm respectively. These results reaffirm that RSM and ANOVA techniques are useful and efficient in achieving optimal set of machining parameters for select ferrous and non-ferrous materials in correlating the surface finish values.
Keywords— Response Surface Methodology, Analysis of Variance, Computer Numerical Control, Surface Roughness, Machining Parameters.
Appropriate algorithm method for Petrophysical properties to construct 3D modeling for Mishrif formation in Amara oil field
Abstract— Geostatistical modeling technicality hasutilized to build the geological models before scaling-up. Possible images of the area under investigation have provided from these methods that honor the well data and have the same variability computed from the original data. Property modeling is the process of filling the cells of the grid with discrete (facies) or continuous (petrophysics) properties. When interpolation between data points, propagate property values along the grid layers have executed. The main branch in the modeling algorithms obtainable is between Deterministic and Stochastic methods in Petrel. Both kinds of algorithms are available in the Facies and Petrophysical modeling processes.The process of well log up scaling is required to post values in each cell of the 3D grid where each of the wells is situated; to achieve these averages well properties are used to populate each of the cells. Three Dimension modeling has built depending to 12 wells for Mishrif formation in Amara oil field. All wells have PHIE and Water Saturation logs, which exported from interactive petrophysics software. Thereafter, scale up well logs has carried out for these wells. To building the model, there are different methods of distribution of petrophysical properties. Eight methods have executed in order to propagate property values through construct Porosity and Water Saturation Models. Depending on the results, there are not data from the modeling corresponding exactly to the true data from the log interpretation for the same well, but it approximate from the true data in different percentage .Sequential Gaussian Simulation suitable algorithm method to build the 3D modeling for Mishrif formation.
Keywords— Deterministic algorithms, Mishrif Formation, Petrophysical properties, Reservoir modeling, stochastic algorithm.
Abstract— Investigations of the effect Gorbunova possible to determine the localization of the defect contactless microwave sensor from a distance of 70-180 mm. the possibility of indexing latent defect by comparing results before and after heating.
Keywords— Microwave imaging method non-destructive testing of metals, the «Gorbunov» effect reactivation of samples, the indication of defects in the metal.
Abstract—The article describes the procedure for the determination of heat loss through a mathematical model, which was processed through a dimensional analysis. The output of this model is a simple relationship where, based on the locating constant and the regression coefficient, it is possible to determine the loss of the piping system. Subsequently, this method was applied to calculate the heat loss of a pre-insulating pipe buried underground.
Keywords—heat loss, heat network, model, dimensional analysis.
Abstract—The proposed article describes a compressor design for using the heat generated in the hydrogen absorption process into the metal alloy during compression. The absorption of hydrogen into the alloy occurs after the desired pressure has been achieved, whereby the catalytic effect of the used metals to dissociate the hydrogen molecule and the subsequent diffusion of the hydrogen atoms into the intermetallic space of the lattice occur. The absorption process is accompanied by a gradual increase in pressure up to the total saturation value of the metal. The equilibrium pressure at which the absorption occurs is highly dependent on the temperature of the alloy. The difference in the equilibrium pressures of MH materials at an acceptable temperature change has led to efforts of creating a hydrogen compressor that would use MH heating and refrigeration heat cycle.
Keywords—hydrogen, alloy, compressor, compression, absorption.
Abstract – The article provides an analysis of the stress and deformation conditions of NACA blade at wind speed of 3-12 m/s and in a parking position (over 20 m/s). The wind speed of 9 m/s and Poisson’s glass-epoxy laminate with a value of 0.43 initiates yaw of the blade tip from the axis of rotation by 651 mm. Von Mises stress reaches a value of 75.58 MPa. Visualization of airflow around the blade demonstrates that flow separation occurs at the point of blade mounting in the hub and the speed is higher than airflow speed around the blade tip.
Keywords – the finite element method, visualization of air-flow, stress of the blade.
Abstract— Upto date, many experiments have been carried out successfully in producing and using essential oil-treated biodegradable polylactid acid (PLA), but the examinations revealed. That essential oils, theoretically consisting the same composition, (like cinnamonoil, majoram oil, orclaryoil) crystallize differently in the PLA base, weakening its mechanical, optical, and thermal properties. The aim of the experiment is to define the exact components with a Gas-Chromatography instrument with MS-detector. It has been found that among the compounds detected in different cinnamon oil samples, there are indeed other potentially harmful components, such as serpentines, alcoholic derivatives, mineral oils and phthalic acid esters, which have caused the condition to deteriorate.
Keywords— biopolymer, essential oils, GC-MS, phtalic acid esters, PLA.
Waste Management Protocols for Iridium-192 Sources Production Laboratory Used in Cancer Treatment in Brazil
Abstract—Objective: The iridium-192 wired sources production results in radioactive waste that needs to follow the guidelines. The aim of this study is to do a radioactive waste management of wastes from iridium-192 sources production laboratory used in cancer treatment in Brazil. Methods: The wire is acquired in an alloy form with 80% platinum and 20% iridium encapsulated with 100%. Electronic microscopy, X-ray fluorescence, and posterior iridium neutron activation (to determine contaminants) are performed to ensure quality. A 50-cm twisted wire is placed in an aluminum tube. The tube is sealed and place inside the reactor irradiator system and is left for decay during 30 hours to wait for the others undesired activation products to decay. The wire is prepared for treatment with 48 cm length with 192 mCi maximum activity. All the equipment use inside the hot cell must be calibrated every four months. All the waste must be removed from the hot cell. Results: The solid waste is previously characterized in the analysis phase. The contaminants are already known and they are insignificant due to their fast half-life. The iridium-192 half-life is 74.2 days, classified as very short half-life waste. The reminiscent activity is 8mCi. Conclusion: The radioactive waste generated during the I192 wires production is solid, was a short half-life and a weakly activity of 9.7 GBq.g-1. According to the standards, this activity is too high to be discarded into the environment (limit 10 Bq.g-1). The waste must be managed by the R&R (retain e retard) system.
Keywords— Iridium-192, Radioactive waste, Sealed sources, Sources production, Waste management.
Abstract— In the real world, many influenced factors or criteria should be considered in the multiple criteria decision-making (MCDM) process. Face to the uncertain environment, the decision makers or experts always cannot express their opinions exactly in the decision-making process. Under this situation, interval-valued fuzzy sets are suitable used to represent the subjective judgments of decision makers. In this paper, the fuzzy AHP method is applied to compute the fuzzy weights of each criterion based on the interval-valued fuzzy sets. The proposed method can provide a more flexible way for decision makers to express their subjective opinions. A systematic method is presented here to compute the fuzzy weights of criteria for dealing with a MCDM problem. An example is presented to illustrate the computational procedure of the proposed method. Conclusions and future research direction will be discussed at the end of this paper.
Keywords— MCDM, Interval-valued fuzzy set, Fuzzy AHP.
Theory of Dipole-Exchange Spin Excitations in a Spherical Ferromagnetic Nanoshell, consideration of the Boundary Conditions
Abstract— The paper continues study of dipole-exchange spin excitations in a spherical ferromagnetic nanoshell started by the author in the previous paper. The proposed model considers the magnetic dipole-dipole interaction, the exchange interaction, the anisotropy effects and the damping effects. A new method of obtaining the values’ spectrum of the wavenumbers for the investigated excitations – the method based on the application of general boundary conditions – is proposed. Consequently, the values’ spectra of the wavenumbers and the frequencies of the investigated excitations are obtained in addition to the previously obtained dispersion law. Exploitation of the above-mentioned method essentially extends the area of application of the obtained results compared to the previous paper. The obtained dependence of the wavenumber on the angular mode number is shown to be weak and close to linear. On the other hand, the obtained dependence of the wavenumber on the radial mode number is shown to be essential. The obtained spectrum of wavenumbers’ values is shown to transform to a quasi-one-dimensional form once specific conditions are satisfied; these conditions are found.
Keywords— Magnetic dynamics, Spin excitation, Dipole-exchange theory, Ferromagnetic nanosystem, Spherical nanoshell.
Abstract—Several techniques are used in data analysis, where frequent itemset mining and association rule mining are very popular among them. The motivation for ‘Data Mining as a Service’ (DMaaS) paradigm is that when the data owners are not capable of doing mining tasks internally they have to outsource the mining work to a trusted third party. Multiple data owners can also collaboratively mine by combining their databases. In such cases the privacy of outsourced data is a major issue. Here the context includes necessity of ‘corporate privacy’ which means other than the data, the result of mining should also preserve privacy requirements. The system proposed uses Advanced Encryption Standard (AES) to encrypt the data items before outsourcing in order to prevent the vulnerability of ‘Known Plaintext’ attack in the existing system. Fictitious transactions are inserted to the databases using k-anonymity method to counter the frequency analysis attack. A symmetric homomorphic encryption scheme is applied in the databases for performing the mining securely. Based on the experiments and findings, though the running time of proposed solution is slightly greater than the existing system, it provides better security to the data items. Since the computations tasks are performed by the third party server, consumption of resources at the data owners’ side is very less.
Keywords—privacy preserving, association rule mining, data mining, vertically partitioned databases, homomorphic encryption.