bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-Scale Thermo-Crystal Plasticity Finite Element Analysis of Dynamic-Recrystallization Texture Evolution
Authors: Ueda Yuhei , Goto Yu , Yamaguchi Toshihiko , Tomita Yoshihiro , Morita Yusuke , Nakamachi Eiji 
Published: February 2017

In order to predict dynamic recrystallization (DRX) texture evolution during the forming processes of aluminum alloy, we propose a hypothesis to predict DRX evolution and develop a comprehensive computational tool for the thermal process metallurgy simulation. It consists of the two-scale finite element method based on the thermo-coupled elasto-crystalline plasticity analysis and the dynamic-explicit finite element procedure. It can predict the heat generation and diffusion, and plastic anisotropy at the macro-scale, and the crystal texture evolution including DRX due to the plastic deformation and heat generation at the micro-scale.
The computationally evaluated texture evolution, which includes DRX texture, under the severe compression at high temperature is compared against the experimental results of pole figures and orientation distribution function (ODF) analyses. The results predict the evolution of the cube component which is observed in the experiments. Therefore, our proposed method is approved to have a potential predicting DRX texture evolution. Furthermore, we clarify the effect of DRX texture on the onset of such instabilities as necking, surface instability and shear bands which are closely related to the formability or failure of the materials.
Measurement and Evaluation of Temperature Change of Water Driven Spindle
Authors: Hayashi Akio , Nakao Yohichi 
Published: February 2017

Recently, various precision products such as lenses or mirrors are produced by the ultra-precision machine tools. Then, the single-point diamond cutting is mainly carried out using the ultra-precision machine tool. In order to generate the high accuracy and high quality machined surfaces, the high stiffness and precise rotational accuracy of the spindle is required for the ultra-precision machining tools.
The water driven spindle had been developed for the precision machine tool spindle. This spindle is driven by the generated torque due to the water flow power. Then, the rotational speed can be controlled by the supplied flow rate of water. In addition, the spindle has the water hydrostatic bearings that achieve the high bearing stiffness and precise motion accuracy. Furthermore, it is expected that the water driven spindle has the high thermal stability since the water with low viscosity is used as a coolant media.
If the thermal deformation of the spindle is caused during the machining process, the deformation degrades the machining accuracy, accordingly. Thus, it is desirable that the thermal deformation and the temperature change of each part of the spindle and machine tool structure can be controlled and minimized during machining process.
In this paper, in order to investigate the thermal stability of the water driven spindle, the measurement tests of the temperature of the water driven spindle were carried out. In addition, the power loss due to the water viscosity between the rotor and the casing of the spindle is calculated.
As a result, this paper considers the temperature change and considers the thermal stability of the water driven spindle from the results of experiments.
A Simplified Exact Compliance Normal-Directional Contact Model
Authors: Banerjee Arnab , Chanda Avishek , Das Raj 
Published: February 2017

Contact is the most abundant phenomena in the field of multi-body dynamics, experienced when two or more bodies come in close vicinity to each other. During contact, one body virtually penetrates within other and therefore is subjected to a large impulsive force due to the deformation; this is the essence of the compliance based models. Subsequently, different compliance models were proposed, each having a different formulation for the impulsive force variation, which is always a function of time and deformation. A novel multi-linear compliance model, calculated on the basis of the Poisson’s law, is introduced in this work. The responses of all the available compliance models have been critically reviewed in previous studies and using the same study and the observed significant models, a comparative study is presented in this work for establishing the proposed model. A few significant models were selected according to the minimum amount of error induced by each while estimating the coefficient of restitution, impulse, and dissipating energy.
The contact force-penetration relationship in the compression phase and restitution phase are assumed to be linear with a sharp jump at their transition. The slope of the compression phase of the force-displacement diagram of the non-dimensional system is exactly as desired (1+coefficient of restitution) and moreover, the slope of the restitution phase is equal to the coefficient of restitution helping in retrieving the exact coefficient of restitution pertaining in the pre-impact condition. Also, the post-impact coefficient of restitution, impulse, and dissipating energy are exactly accurate, having 0% error, in accordance with that of the stereo-mechanical model, for the full range of the co-efficient of restitution.
Experimental Investigation of a Spark Ignited Engine Using Magnetic Air Conditioner (MAC) for Improved Performance and Reduced Emissions
Authors: Hargude N. V. , Sawant S. M. 
Published: February 2017

In 21st century, to cope up with exponential technological development, use of eco-friendly conventional energy system is a critical issue. Saving of energy is nothing but production of energy. Conventional fuel used in stationary power plant an IC engine is bulk in quantity, which will not be last longer and will exhaust very soon. Stationary power plants and Automobile propelled by I.C. engines have a problem of pollutant emission in environment which mainly depends on combustion process occurs in power plant and I.C. engines. Incomplete combustion of hydro-carbon fuel/s produce very large amount of harmful emission gases resulting into smog in cities & reduces performance of the system. These systems, equipped with Internal Combustion or External combustion produces large amount of exhaust gases CO, HC and NOx like monoxides etc. Since hazardous emissions which are harmful to human life and ecosystem resulting in many types of diseases of human especially in urban areas where automobile vehicle equipped with IC engine density is very high. These emissions have effect on result in environmental cycles also. In today’s globalised world, many attempts are made to reduce intensity of hazardous emissions of an IC engine through pre processing of fuels and post processing combustion exhaust gases in IC engine by many means like MPFI, PCV, EGR, catalytic converter, supercharger, turbocharger, etc. In order to handle, these issues, additional attempt is made. This attempt uses Air conditioner/Energizer for Pre-processing air and unit developed called as Magnetic air Conditioner (MAC).
A permanent magnet, magnetic air conditioner (MAC) is mounted in path of air lines. Mounting MAC in air line enhances quality of air and air molecules properties like it aligns and orientations, especially in an oxygen molecule. Better atomization of an oxygen molecule which further enters into combustion chambers of SI engine along with air. In a conventional four stroke spark Ignited engine, oxygen molecules reacts with hydro -carbon, which assist for complete combustion of hydro-carbon. Use of such Magnetic air conditioners improves performance of SI engine. The specific fuel consumption also decreases, resulting in to decrease in BSFC with increase in load. Use of MAC in engine also reduces emissions like CO, HC, ultimately resulting into reduction in smog in urban areas. The present article describes the mechanism of MAC, objectives and its effect on SI engine, such as enhanced performance parameter, various efficiencies like mechanical, brake thermal, volumetric saving in fuel, and reduced emission. One case study is presented in which ferrite magnets are used as MAC which improves performance and reduces emissions.
Development of an Empirical Model to Predict Sulfuric Acid Condensate Formation in Air Handling System of Medium Speed Diesel Engines
Authors: Raina Pranav , Primus Roy J. , Jayakar Vijayaselvan , T. Harish Dayanand , Kalavara Aravind 
Published: February 2017

One of the biggest challenges for engines used in Marine industry is to burn fuels of varied compositions, since the vessels often move from regions with highly regulated fuels to regions with no regulations, unlike their on-road and other stationary counterparts. This poses an enormous risk to the performance, reliability, durability and service life of engines that employ exhaust gas recirculation (EGR) as a prime technology to meet stringent emission regulations, laid out by various regulating bodies across the globe like the United States (U.S.) Environmental Protection Agency (EPA) and International Maritime Organization (IMO).
Operating on fuels with higher Sulfur content poses a risk of reduced engine component life, due to the formation of concentrated Sulfuric acid (H2SO4), which, if not handled carefully, would lead to higher rates of corrosion on engine parts. Hence, the ability to predict the potential for H2SO4 formation as well its quantity to be handled is essential.
This research paper focuses on the development of an empirical model to predict the amount of H2SO4 condensate that can be formed in the air handling system of medium speed diesel engines. The model utilizes a combination of fundamental physics, chemistry, thermodynamics and chemical kinetics. The H2SO4 prediction calculation employs basic measurable parameters from a running engine, such as engine speed, load, EGR flow rate, fuel flow rate, fuel Sulfur concentration to compute a molar balance of hydrocarbon fuel and combustion air quantities along the entire range of engine operation, providing the amount of H2SO4 condensate formed. This is done primarily at EGR cooler, where the recycled exhaust gas gets cooled primarily and the EGR mixer, where it gets cooled further after coming in contact with the charge air and are identified as critical locations.
Analysis of Fracture Mechanism on Paper Tubes and Relationship Between Paperboard Property and Property of Paper Tubes
Authors: Suda Mitsunori , Kitamura Takanori , Zhang Zhiyuan , Hamada Hiroyuki 
Published: February 2017

According to the report in May, 2015 by Japan Paper Recycling Promotion Center, quantity of paper and paperboard product in Japan decreases is about 18% from 2007 to 2014. Japanese quantity of waste paper in 2014 is 21750000ton, the rate of collected waste paper is 80.8%. Nevertheless Japanese consumption of waste paper is 17190000ton, the rate of utilizing waste paper is 63.9%. It means that quantity of collected waste paper become bigger than quantity of utilizing waste paper, a lot of waste-paper is exported to East Asia (especially China). Balance of waste paper demand and supply in Japan has already broken. It could be expected that waste paper will be collected more and more, but it is difficult to solve the problem that all domestic collected waste paper is used, in order to increasing phenomenon of helpful to recycle, energy saving, environmental protection movement. It is considered that the usage of paper tube need to be expanded which is produced by waste paper. Paper tube has been widely applied in many areas, such as packaging industry, film rolls, adhesive-tape industry, furniture decoration, temporary structures in building and so on. For example churches could be made from paper. The mechanical property of paper tube need to be investigated to get wide application.
At current study, the mechanical property of 8 kinds of paperboards for paper tubes fabrication were investigated included tension, compression and peeling properties combining with anisotropic property. These kinds of paperboards have different mechanical properties but same dimension. By this method, the effects of different properties including tension, compression and peeling on mechanical property of paper tubes could be evaluated. A series of paper tubes with different layers was fabricated and the lateral compression test was carried out and evaluated. The fracture form of paper tubes and fracture position on paper tubes were discussed together with paperboards properties. The cause of delamination behavior of laminated paper was analysis based on the detailed observation and finite element analysis. From fracture process, it was found that the main fracture of paper tube is delamination during lateral compression action which was considered peeling action has a big influence. According to this phenomenon, acoustic emission (AE) and observation of peeling paperboard were conducted.
Applicability of Heat Mirrors in Reducing Thermal Losses in Concentrating Solar Collectors
Authors: Mahendra Prashant , Khullar Vikrant , Mittal Madhup 
Published: February 2017

Flux distribution around the parabolic trough receiver being typically non-uniform, only a certain portion of the receiver circumference receives the concentrated solar irradiance. However, radiative and convective losses occur across the entire receiver circumference. This paper attempts to introduce the idea employing transparent heat mirror to effectively reduce the heat loss area and thus improve the thermal efficiency of the solar collector. Transparent heat mirror essentially has high transmissivity in the solar irradiance wavelength band and high reflectivity in the mid-infrared region thus it allows the solar irradiance to pass through but reflects the infrared radiation back to the solar selective metal tube. Practically, this could be realized if certain portion of the conventional low iron glass envelope is coated with Sn-In2O3 so that its acts as a heat mirror.
In the present study, a parabolic receiver design employing the aforesaid concept has been proposed. Detailed heat transfer model has been formulated. The results of the model were compared with the experimental results of conventional concentrating parabolic trough solar collectors in the literature. It was observed that while maintaining the same external conditions (such as ambient/initial temperatures, wind speed, solar insolation, flow rate, concentration ratio etc.) the heat mirror-based parabolic trough concentrating solar collector has about 3–12% higher thermal efficiency as compared to the conventional parabolic solar collector. Furthermore, steady state heat transfer analysis reveals that depending on the solar flux distribution there is an optimum circumferential angle (θ = θoptimum, where θ is the heat mirror circumferential angle) up to which the glass envelope should be coated with Sn-In2O3. For angles higher than the optimum angle, the collector efficiency tends to decrease owing to increase in optical losses.
A Search Space Reduction Method for Optimizing Sequential Control by Hypothetically Achievable Bound Estimation of the Objective Function
Authors: Tokuda Yuya , Yoshida Yasuhiro , Sekiai Takaaki , Yamanaka Kazunori , Yamashita Atsushi , Iyanaga Norihiro , Katagiri Yukinori , Yoshida Takuya 
Published: February 2017

Metaheuristic methods such as genetic algorithm, simulated annealing, and artificial bee colony algorithm methods take much time to obtain an optimal solution, particularly when a large scale simulator is employed for estimating the state of the environment.
In this paper, a search space reduction method for accelerating the optimization of sequential control systems is proposed. The proposed method estimates a hypothetical achievable bound of the objective function and uses it as the prior knowledge to reduce the search space. The hypothetical achievable bound is estimated using the fact that large scale plants consisting of multiple components are in many cases controlled in a sequential manner.
The size of the search space reduction obtained by the proposed method is evaluated by an example problem that minimizes the start-up time of a thermal power plant. As a result, the size of the search space is reduced by 65%. The proposed method does not lose the optimality of the optimization method to be accelerated. In addition, this method is also applicable to optimization problems other than sequential control if the hypothetical achievable bound of the objective function is estimable without measuring the state of the environment or using the simulator.
Compressed Sensing Techniques for Ultrasonic Imaging of Cargo Containers
Authors: Martínez Lorenzo José Á. , Álvarez López Yuri 
Published: February 2017

This contribution presents a compressed sensing (CS)-based ultrasonic imaging system for fast, low-cost inspection of metallic cargo containers. The idea is to detect the footprint of metallic objects within the container that can be used to conceal smuggling goods. This ultrasonic technology can complement currently deployed X-ray-based radiographic systems and millimeter-wave scanners, thus increasing the probability of detection.
The proposed hardware consists of an array of acoustic transceivers that is attached to the metallic structure of the metallic cargo container to create a guided acoustic wave. Variations in the thickness of the metallic structure create reflections that can be located by backpropagating the measured reflected wave.
Aiming to reduce the number of acoustic transceivers, this contribution evaluates the feasibility of applying CS techniques in the proposed acoustic imaging system. It has been observed that in the majority of the cases, the acoustic images retrieved by the cargo inspection system are sparse, that is, only those image pixels corresponding to discontinuities in the metallic plate (due to gaps, joints, placement of a metallic object on it) are different from zero. Thus, sparsity condition, which is one of the CS requirements, is satisfied for this particular application.
A simulation-based example resembling a real case of cargo inspection is considered for validation purposes. A comparison between standard backpropagation and CS for different number of samples is presented, proving that CS is able to recover the acoustic image with as few as 10% of the samples required by Nyquist sampling rate.
Active Control of Rear Sub-Frame Vibration in Rear and All-Wheel Drive Vehicles
Authors: Deng J. , Kashani A. R. 
Published: February 2017

Feedback control of the rear sub-frame structure is used to abate its gear mesh induced vibration. The goal of the active control is to absorb vibration at a location close to the perturbation source, i.e., the rear differential. Proof mass actuators (PMAs) are used in this active vibration control application. A tuned absorption-based as well as a linear quadratic active vibration control schemes, each with its own advantages and disadvantages, were developed for this application. Following to the synthesis and numerical simulation of the two active vibration control strategies, they were first evaluated on a test structure in the laboratory.
Following the laboratory evaluation, one of the active vibration control strategies was implemented on an all-wheel drive vehicle. Two small PMAs, mounted on the rear sub-frame of the vehicle, were used as the active elements in this vibration control application. An accelerometer placed next to each actuator was used as the feedback sensor.
The effectiveness of active vibration control in absorbing the shaker induced vibration of the sub-frame was successfully demonstrated. In addition, rolling dynamometer tests showed effective vibration reduction of rear differential induced vibration of the sub-frame. As expected, lowering the sub-frame vibration resulted in lower vibration and noise in the cabin.
Analytical Investigation on the Rotational Speed Dependence of the Rotordynamic Fluid Force: The Case of Concentric Circular Whirl in the Annular Plain Seal
Authors: Ikemoto Atsushi , Sakamoto Kazukiyo , Inoue Tsuyoshi , Uchiumi Masaharu 
Published: February 2017

Rotordynamic (RD) fluid forces of various kinds of seals has been investigated and reported by Childs [1], Iwatsusbo [2][3] and so on, because it has significant influence on the stability of rotating machinery. Those studies were carried out at lower speeds than the actual machines because of various restrictions such as the limitations of the experimental unit. Then, extrapolation approximations using the obtained results were used to predict the RD fluid force of the actual machines. However, when the rotor vibration is analyzed for the high speed rotating shaft such as a rocket turbopump, a more accurate evaluation of the rotational speed dependence of the derived RD fluid force is desired.
In this study, the rotational speed dependence of RD fluid forces in the case of the concentric circular whirl in the annular plain seal is investigated. As a result, the characteristics of these fluid forces vary with the rotational speed significantly. In addition, the strong dependencies of RD fluid force coefficients calculated from these fluid forces on the rotational speed are observed. It is revealed that the changes of the RD fluid force coefficients to rotational speed were modeled by using the quadratic function.
Integrated Process for Textile Cotton Waste (TCW) Valorization: Waste-to-Energy and Wastewater Decontamination
Authors: Ribeiro A. , Vilarinho C. , Araújo J. , Carvalho J. 
Published: February 2017

The increasing of world population, industrialization and global consuming, existing market products existed in the along with diversification of raw materials, are responsible for an exponential increase of wastes. This scenario represents loss of resources and ultimately causes air, soils and water pollution. Therefore, proper waste management is currently one of the major challenges faced by modern societies.
Textile industries represents, in Portugal, almost 10% of total productive transforming sector and 19% of total employments in the sector composed by almost 7.000 companies. One of the main environmental problems of textile industries is the production of significant quantities of wastes from its different processing steps. According to the Portuguese Institute of Statistics (INE) these industries produce almost 500.000 tons of wastes each year, with the textile cotton waste (TCW) being the most expressive. It was estimated that 4.000 tons of TCW are produced each year in Portugal.
In this work an integrated TCW valorisation procedure was evaluated, firstly by its thermal and energetic valorisation with slow pyrolysis followed by the utilization of biochar by-product, in lead and chromium synthetic wastewater decontamination.
Pyrolysis experiments were conducted in a small scale rotating pyrolysis reactor with 0.1 m3 of total capacity. Results of pyrolysis experiments showed the formation of 0,241 m3 of biogas for each kilogram of TCW. Results also demonstrated that the biogas is mostly composed by hydrogen (22%), methane (14 %), carbon monoxide (20%) and carbon dioxide (12%), which represents a total high calorific value of 12.3 MJ/Nm3.
Regarding biochar, results of elemental analysis demonstrated a high percentage of carbon driving its use as low cost adsorbent. Adsorption experiments were conducted with lead and chromium synthetic wastewaters (25, 50 and 100 mg L−1) in batch vessels with controlled pH. It was evaluated the behaviour of adsorption capacity and removal rate of each metal during 120 minutes of contact time using 5, 10 and 50 g L−1 of adsorbent dosage. Results indicated high affinity of adsorbent with each tested metal with 78% of removal rate in chromium and 95% in lead experiments. This suggests that biochar from TCW pyrolysis may be appropriated to wastewaters treatment, with high contents of heavy metals and it can be an effective alternative to activated carbon.