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Sample records for forging process parameters

  1. Influence of Processing Parameters on Grain Size Evolution of a Forged Superalloy

    NASA Astrophysics Data System (ADS)

    Reyes, L. A.; Páramo, P.; Salas Zamarripa, A.; de la Garza, M.; Guerrero-Mata, M. P.

    2016-01-01

    The microstructure evolution of nickel-based superalloys has a great influence on the mechanical behavior during service conditions. Microstructure modification and the effect of process variables such as forging temperature, die-speed, and tool heating were evaluated after hot die forging of a heat-resistant nickel-based alloy. Forging sequences in a temperature range from 1253 to 1323 K were considered through experimental trials. An Avrami model was applied using finite element data to evaluate the average grain size and recrystallization at different evolution zones. It was observed that sequential forging at final temperatures below 1273 K provided greater grain refinement through time-dependent recrystallization phenomena. This investigation was aim to explore the influence of forging parameters on grain size evolution in order to design a fully homogenous and refined microstructure after hot die forging.

  2. An Approach to Optimize Size Parameters of Forging by Combining Hot-Processing Map and FEM

    NASA Astrophysics Data System (ADS)

    Hu, H. E.; Wang, X. Y.; Deng, L.

    2014-11-01

    The size parameters of 6061 aluminum alloy rib-web forging were optimized by using hot-processing map and finite element method (FEM) based on high-temperature compression data. The results show that the stress level of the alloy can be represented by a Zener-Holloman parameter in a hyperbolic sine-type equation with the hot deformation activation energy of 343.7 kJ/mol. Dynamic recovery and dynamic recrystallization concurrently preceded during high-temperature deformation of the alloy. Optimal hot-processing parameters for the alloy corresponding to the peak value of 0.42 are 753 K and 0.001 s-1. The instability domain occurs at deformation temperature lower than 653 K. FEM is an available method to validate hot-processing map in actual manufacture by analyzing the effect of corner radius, rib width, and web thickness on workability of rib-web forging of the alloy. Size parameters of die forgings can be optimized conveniently by combining hot-processing map and FEM.

  3. Parameter Optimization During Forging Process of a Novel High-Speed-Steel Cold Work Roll

    NASA Astrophysics Data System (ADS)

    Guo, Jing; Liu, Ligang; Sun, Yanliang; Li, Qiang; Ren, Xuejun; Yang, Qingxiang

    2016-01-01

    The forging of high-speed-steel (HSS) roll has always been a technical problem in manufacturing industry. In this study, the forging process of a novel HSS cold work roll was simulated by deform-3D on the basis of rigid-viscoplastic finite element model. The effect of heating temperature and forging speed on temperature and stress fields during forging process was simulated too. The results show that during forging process, the temperature of the contact region with anvils increases. The stress of the forging region increases and distributes un-uniformly, while that of the non-forging region is almost zero. With increasing forging time, Z load on anvil increases gradually. With increasing heating temperature or decreasing forging speed, the temperature of the whole billet increases, while the stress and Z load on anvil decrease. In order to ensure the high efficiency and safety of the forging process, the heating temperature and the forging speed are chosen as 1160 °C and 16.667 mm/s, respectively.

  4. Effects of Forging Process Parameters on Microstructure Evolution of Aluminum Alloy 7050

    SciTech Connect

    Yi Youping; Shi Yan; Yang Jihui; Lin Yongcheng

    2007-04-07

    The objective of this work is to investigate the behavior of microstructure evolution of aluminum alloy 7050 under the condition of different forging process parameters by means of combining materials physical model with finite element code. For the purpose of establishing constitutive equation and physical model of microstructure evolution, the isothermal compression test were performed by machine Gleeble 1500 on the condition of temperatures ranging from 250 deg. C to 450 deg. C and constant strain rates of 0.01s-1, 0.1s-1, 1s-1 and 10s-1. The behaviors of microstructure evolutions of aluminum alloy 7050 under difference process parameters were studied by metallographic observations. The experiment results showed that recrystallization during forming process occurred at the critical strain and the volume fraction of recrystallization changed with the temperature and strain rate. According to the results of isothermal compression test, a constitutive equation and an empirical model of DRX were obtained. A finite element code DEFORM 3D was used to analyze the influence of different forging process parameters on the behavior of microstructure evolution in details. The present model and simulation method can be served as a useful tool to predict and control the properties and shape of aluminum alloy 7050 components during forging.

  5. Effects of Process Parameters on Deformation and Temperature Uniformity of Forged Ti-6Al-4V Turbine Blade

    NASA Astrophysics Data System (ADS)

    Luo, Shiyuan; Zhu, Dahu; Hua, Lin; Qian, Dongsheng; Yan, Sijie; Yu, Fengping

    2016-09-01

    This work is motivated by the frequent occurrence of macro- and microdefects within forged Ti-6Al-4V turbine blades due to the severely nonuniform strain and temperature distributions. To overcome the problem of nonuniformity during the blade forging operation, firstly, a 2D coupled thermo-mechanical finite element approach using the strain-compensated Arrhenius-type constitutive model is employed to simulate the real movements and processing conditions, and its reliability is verified experimentally. Secondly, two evaluation indexes, standard deviation of equivalent plastic strain and standard deviation of temperature, are proposed to evaluate the uniformity characteristics within the forged blade, and the effects of four process parameters including the forging velocity, friction factor, initial workpiece temperature and dwell time on the uniformity of strain and temperature distributions are carefully studied. Finally, the numerically optimized combination of process parameters is validated by the application in a practical process. The parametric study reveals that a reasonable combination of process parameters considering the flow resistance, flow localization and the effects of deformation and friction heating is crucial for the titanium alloy blade forging with uniformity. This work can provide a significant guidance for the design and optimization of blade forging processes.

  6. Large forging manufacturing process

    DOEpatents

    Thamboo, Samuel V.; Yang, Ling

    2002-01-01

    A process for forging large components of Alloy 718 material so that the components do not exhibit abnormal grain growth includes the steps of: a) providing a billet with an average grain size between ASTM 0 and ASTM 3; b) heating the billet to a temperature of between 1750.degree. F. and 1800.degree. F.; c) upsetting the billet to obtain a component part with a minimum strain of 0.125 in at least selected areas of the part; d) reheating the component part to a temperature between 1750.degree. F. and 1800.degree. F.; e) upsetting the component part to a final configuration such that said selected areas receive no strains between 0.01 and 0.125; f) solution treating the component part at a temperature of between 1725.degree. F. and 1750.degree. F.; and g) aging the component part over predetermined times at different temperatures. A modified process achieves abnormal grain growth in selected areas of a component where desirable.

  7. Forging process design for risk reduction

    NASA Astrophysics Data System (ADS)

    Mao, Yongning

    In this dissertation, forging process design has been investigated with the primary concern on risk reduction. Different forged components have been studied, especially those ones that could cause catastrophic loss if failure occurs. As an effective modeling methodology, finite element analysis is applied extensively in this work. Three examples, titanium compressor disk, superalloy turbine disk, and titanium hip prosthesis, have been discussed to demonstrate this approach. Discrete defects such as hard alpha anomalies are known to cause disastrous failure if they are present in those stress critical components. In this research, hard-alpha inclusion movement during forging of titanium compressor disk is studied by finite element analysis. By combining the results from Finite Element Method (FEM), regression modeling and Monte Carlo simulation, it is shown that changing the forging path is able to mitigate the failure risk of the components during the service. The second example goes with a turbine disk made of superalloy IN 718. The effect of forging on microstructure is the main consideration in this study. Microstructure defines the as-forged disk properties. Considering specific forging conditions, preform has its own effect on the microstructure. Through a sensitivity study it is found that forging temperature and speed have significant influence on the microstructure. In order to choose the processing parameters to optimize the microstructure, the dependence of microstructure on die speed and temperature is thoroughly studied using design of numerical experiments. For various desired goals, optimal solutions are determined. The narrow processing window of titanium alloy makes the isothermal forging a preferred way to produce forged parts without forging defects. However, the cost of isothermal forging (dies at the same temperature as the workpiece) limits its wide application. In this research, it has been demonstrated that with proper process design, the die

  8. Modelling of the radial forging process of a hollow billet with the mandrel on the lever radial forging machine

    NASA Astrophysics Data System (ADS)

    Karamyshev, A. P.; Nekrasov, I. I.; Pugin, A. I.; Fedulov, A. A.

    2016-04-01

    The finite-element method (FEM) has been used in scientific research of forming technological process modelling. Among the others, the process of the multistage radial forging of hollow billets has been modelled. The model includes both the thermal problem, concerning preliminary heating of the billet taking into account thermal expansion, and the deformation problem, when the billet is forged in a special machine. The latter part of the model describes such features of the process as die calibration, die movement, initial die temperature, friction conditions, etc. The results obtained can be used to define the necessary process parameters and die calibration.

  9. Microstructural Evaluation of Forging Parameters for Superalloy Disks

    NASA Technical Reports Server (NTRS)

    Falsey, John R.

    2004-01-01

    Forgings of nickel base superalloy were formed under several different strain rates and forging temperatures. Samples were taken from each forging condition to find the ASTM grain size, and the as large as grain (ALA). The specimens were mounted in bakelite, polished, etched and then optical microscopy was used to determine grain size. The specimens ASTM grain sizes from each forging condition were plotted against strain rate, forging temperature, and presoak time. Grain sizes increased with increasing forging temperature. Grain sizes also increased with decreasing strain rates and increasing forging presoak time. The ALA had been determined from each forging condition using the ASTM standard method. Each ALA was compared with the ASTM grain size of each forging condition to determine if the grain sizes were uniform or not. The forging condition of a strain rate of .03/sec and supersolvus heat treatment produced non uniform grains indicated by critical grain growth. Other anomalies are noted as well.

  10. Improvements in the process of boss bar upset forging into a horizontal forging machine with the aim of joint knuckle forging quality improvement

    NASA Astrophysics Data System (ADS)

    Pankratov, D. L.; Nizamov, R. S.; Kharisov, I. Zh

    2016-06-01

    A new technique for tapered composing transition shaping has been put forward in the process of upset forging with the use of an experimental tool. The results of the upset forging process with the use of a new composing transition has been computer simulated.

  11. Process modelings and simulations of heavy castings and forgings

    NASA Astrophysics Data System (ADS)

    Li, Dianzhong; Sun, Mingyue; Wang, Pei; Kang, Xiuhong; Fu, Paixian; Li, Yiyi

    2013-05-01

    The Materials Process Modeling Division, IMR, CAS has been promoting for more than 10 years research activities on modeling and experimental studies on heavy castings and forgings. In this report, we highlight some selected achievements and impacts in this area: To satisfy domestic strategic requirements, such as nuclear and hydraulic power, marine projects and high speed rail, we have developed a number of casting and forging technologies, which combine advanced computing simulations, X-ray real time observation techniques and industrial-scaled trial experiments. These technologies have been successfully applied in various industrial areas and yielded a series of scientific and technological breakthroughs and innovation. Important examples of this strategic research include the hot-processing technologies of the Three Gorge water turbine runner, marine crankshaft manufacturers, backup rolls for hot rolling mills and the production of hundreds-ton steel ingot.

  12. Numerical simulation and experimental study for the die forging process of a high-speed railway brake disc hub

    NASA Astrophysics Data System (ADS)

    Sun, Mingyue; Xu, Bin; Zhang, Long; LI, Dianzhong

    2013-05-01

    With the aim of manufacturing a near-net shape forging product of a brake disk hub for the high-speed railway, the die forging process was designed and optimized in this study. Firstly, based on the measured stress-strain curves at different strain rates and the thermal-physical parameters of 40Cr A steel, a finite element model for the forging process of a high-speed railway brake disc hub was established. Then, the temperature, stress and strain fields were studied and analyzed at the pre-forging and the finial-forging stages. Besides, in order to trace the stress and strain evolution, five points at different positions were chosen on the billet, and the comparison of the state conditions was made among these points. The results have demonstrated that the product can be well formed by an elaborately designed three-stage forging process, which may reduce the metal machine allowance and the producing cost effectively. Finally, an industrial trial was made and a machined product with sound quality was obtained.

  13. First Results of Energy Saving at Process Redesign of Die Forging Al-Alloys

    SciTech Connect

    Pepelnjak, Tomaz; Kuzman, Karl; Kokol, Anton

    2011-05-04

    The contribution deals with eco-friendly solutions for shortened production chains of forging light alloys. During the die forging operations a remarkable amount of material goes into the flash and later on into chips during finish machining. These low value side products are rich with embedded energy therefore recycling or reprocessing could be very energy saving procedure.In cooperation with a die forging company a shortened reprocessing cycle has been studied starting from re-melting the forging flash and without additional heating to cast preforms for subsequent die forging. As such preforms have not as good formability characteristics as those done from extruded billets the isothermal forging process has been adopted. First results showed that without cracks and other defects the formability is sufficient for a broad spectrum of forgings.To improve the formability a homogenization process of cast preforms has been implemented. As the process started immediately after casting, amount of additional energy for heating was minimized. To reduce voids forging process was redesigned in a way to assure greater hydrostatic pressures in parts during forging. First results were promising therefore research is going towards improving processes without adding significantly more energy as it is needed for casting with homogenization and die forging.

  14. Microstructure Modeling of a Ni-Fe-Based Superalloy During the Rotary Forging Process

    NASA Astrophysics Data System (ADS)

    Loyda, A.; Hernández-Muñoz, G. M.; Reyes, L. A.; Zambrano-Robledo, P.

    2016-06-01

    The microstructure evolution of Ni-Fe superalloys has a great influence on the mechanical behavior during service conditions. The rotary forging process offers an alternative to conventional bulk forming processes where the parts can be rotary forged with a fraction of the force commonly needed by conventional forging techniques. In this investigation, a numerical modeling of microstructure evolution for design and optimization of the hot forging operations has been used to manufacture a heat-resistant nickel-based superalloy. An Avrami model was implemented into finite element commercial platform DEFORM 3D to evaluate the average grain size and recrystallization during the rotary forging process. The simulations were carried out considering three initial temperatures, 980, 1000, and 1050 °C, to obtain the microstructure behavior after rotary forging. The final average grain size of one case was validated by comparing with results of previous experimental work of disk forging operation. This investigation was aimed to explore the influence of the rotary forging process on microstructure evolution in order to obtain a homogenous and refined grain size in the final component.

  15. Forging Advisor

    SciTech Connect

    Kerry Barnett

    2003-03-01

    Many mechanical designs demand components produced to a near net shape condition to minimize subsequent process steps. Rough machining from slab or bar stock can quickly and economically produce simple prismatic or cylindrical shapes. More complex shapes can be produced by laser engineered net shaping (LENS), casting , or forging. But for components that require great strength in mission critical applications, forging may be the best or even the only option. However, designers of these parts may and often do lack the detailed forging process knowledge necessary to understand the impact of process details such as grain flow or parting line placement on both the forging process and the characteristics of the forged part. Economics and scheduling requirements must also be considered. Sometimes the only viable answer to a difficult problem is to re-design the assembly to reduce loading and enable use of other alternatives.

  16. 3D Finite Element Analysis of Spider Non-isothermal Forging Process

    NASA Astrophysics Data System (ADS)

    Niu, Ling; Wei, Wei; Wei, Kun Xia; Alexandrov, Igor V.; Hu, Jing

    2016-06-01

    The differences of effective stress, effective strain, velocity field, and the load-time curves between the spider isothermal and non-isothermal forging processes are investigated by making full use of 3D FEA, and verified by the production experiment of spider forging. Effective stress is mainly concentrated on the pin, and becomes lower closer to the front of the pin. The maximum effective strain in the non-isothermal forging is lower than that in the isothermal. The great majority of strain in the non-isothermal forging process is 1.76, which is larger than the strain of 1.31 in the isothermal forging. The maximum load required in the isothermal forging is higher than that in the non-isothermal. The maximum experimental load and deformation temperature in the spider production are in good agreement with those in the non-isothermal FEA. The results indicate that the non-isothermal 3D FEA results can guide the design of the spider forging process.

  17. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-10-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  18. FEM Analysis and Experimental Verification of the Integral Forging Process for AP1000 Primary Coolant Pipe

    NASA Astrophysics Data System (ADS)

    Wang, Shenglong; Yu, Xiaoyi; Yang, Bin; Zhang, Mingxian; Wu, Huanchun

    2016-08-01

    AP1000 primary coolant pipes must be manufactured by integral forging technology according to the designer—Westinghouse Electric Co. The characteristics of these large, special-shaped pipes create nonuniform temperatures, effective stress, and effective strain during shaping of the pipes. This paper presents a three-dimensional finite element simulation (3D FEM) of the integral forging process, and qualitatively evaluates the likelihood of forging defects. By analyzing the evolution histories of the three field variables, we concluded that the initial forging temperature should be strictly controlled within the interval 1123 K to 1423 K (850 °C to 1150 °C) to avoid second-phase precipitation. In the hard deformation zones, small strains do not contribute to recrystallization resulting in coarse grains. Conversely, in the free deformation zone, the large strains can contribute to the dynamic recrystallization, favoring grain refinement and closure of voids. Cracks are likely to appear, however, on the workpiece surface when forging leads to large deformations. Based on the simulation results, an eligible workpiece with good mechanical properties, few macroscopic defects, and favorable grain size has been successfully forged by experiments at an industrial scale, which validates the FEM simulation.

  19. Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys

    SciTech Connect

    Kim, H. H.; Kang, C. G.

    2010-06-15

    Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.

  20. Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys

    NASA Astrophysics Data System (ADS)

    Kim, H. H.; Kang, C. G.

    2010-06-01

    Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.

  1. Manufacturing of Precision Forgings by Radial Forging

    SciTech Connect

    Wallner, S.; Harrer, O.; Buchmayr, B.; Hofer, F.

    2011-01-17

    Radial forging is a multi purpose incremental forging process using four tools on the same plane. It is widely used for the forming of tool steels, super alloys as well as titanium- and refractory metals. The range of application goes from reducing the diameters of shafts, tubes, stepped shafts and axels, as well as for creating internal profiles for tubes in Near-Net-Shape and Net-Shape quality. Based on actual development of a weight optimized transmission input shaft, the specific features of radial forging technology is demonstrated. Also a Finite Element Model for the simulation of the process is shown which leads to reduced pre-processing effort and reduced computing time compared to other published simulation methods for radial forging. The finite element model can be applied to quantify the effects of different forging strategies.

  2. Experimental and Numerical Investigation of Forging Process to Reproduce a 3D Aluminium Foam Complex Shape

    NASA Astrophysics Data System (ADS)

    Filice, Luigino; Gagliardi, Francesco; Shivpuri, Rajiv; Umbrello, Domenico

    2007-05-01

    Metallic foams represent one of the most exciting materials introduced in the manufacturing scenario in the last years. In the study here addressed, the experimental and numerical investigations on the forging process of a simple foam billet shaped into complex sculptured parts were carried out. In particular, the deformation behavior of metallic foams and the development of density gradients were investigated through a series of experimental forging tests in order to produce a selected portion of a hip prosthesis. The human bone replacement was chosen as case study due to its industrial demand and for its particular 3D complex shape. A finite element code (Deform 3D®) was utilized for modeling the foam behavior during the forging process and an accurate material rheology description was used based on a porous material model which includes the measured local density. Once the effectiveness of the utilized Finite Element model was verified through the comparison with the experimental evidences, a numerical study of the influence of the foam density was investigated. The obtained numerical results shown as the initial billet density plays an important role on the prediction of the final shape, the optimization of the flash as well as the estimation of the punch load.

  3. Experimental and Numerical Investigation of Forging Process to Reproduce a 3D Aluminium Foam Complex Shape

    SciTech Connect

    Filice, Luigino; Gagliardi, Francesco; Umbrello, Domenico; Shivpuri, Rajiv

    2007-05-17

    Metallic foams represent one of the most exciting materials introduced in the manufacturing scenario in the last years. In the study here addressed, the experimental and numerical investigations on the forging process of a simple foam billet shaped into complex sculptured parts were carried out. In particular, the deformation behavior of metallic foams and the development of density gradients were investigated through a series of experimental forging tests in order to produce a selected portion of a hip prosthesis. The human bone replacement was chosen as case study due to its industrial demand and for its particular 3D complex shape. A finite element code (Deform 3D) was utilized for modeling the foam behavior during the forging process and an accurate material rheology description was used based on a porous material model which includes the measured local density. Once the effectiveness of the utilized Finite Element model was verified through the comparison with the experimental evidences, a numerical study of the influence of the foam density was investigated. The obtained numerical results shown as the initial billet density plays an important role on the prediction of the final shape, the optimization of the flash as well as the estimation of the punch load.

  4. Simulations and Experiments of the Nonisothermal Forging Process of a Ti-6Al-4V Impeller

    NASA Astrophysics Data System (ADS)

    Prabhu, T. Ram

    2016-09-01

    In the present study, a nonisothermal precision forging process of a Ti-6Al-4V first-stage impeller for the gas turbine engine was simulated using the finite element software. The simulation results such as load requirements, damage, velocity field, stress, strain, and temperature distributions are discussed in detail. Simulations predicted the maximum load requirement of about 80 MN. The maximum temperature loss was observed at the contour surface regions. The center and contour regions are the high-strained regions in the part. To validate the model, forging experiments mimicking simulations were performed in the α + β phases region (930 °C). The selected locations of the part were characterized for tensile properties at 27 and 200 °C, hardness, microstructure, grain size, and the amount of primary α phase based on the strain distribution results. The soundness of the forged part was verified using fluorescent penetrant test (Mil Std 2175 Grade A) and ultrasonic test (AMS 2630 class A1). From the experimental results, it was found that the variations in the hardness, tensile properties at room, and elevated temperature are not significant. The microstructure, grain size, and primary α phase content are nearly same.

  5. Simulations and Experiments of the Nonisothermal Forging Process of a Ti-6Al-4V Impeller

    NASA Astrophysics Data System (ADS)

    Prabhu, T. Ram

    2016-06-01

    In the present study, a nonisothermal precision forging process of a Ti-6Al-4V first-stage impeller for the gas turbine engine was simulated using the finite element software. The simulation results such as load requirements, damage, velocity field, stress, strain, and temperature distributions are discussed in detail. Simulations predicted the maximum load requirement of about 80 MN. The maximum temperature loss was observed at the contour surface regions. The center and contour regions are the high-strained regions in the part. To validate the model, forging experiments mimicking simulations were performed in the α + β phases region (930 °C). The selected locations of the part were characterized for tensile properties at 27 and 200 °C, hardness, microstructure, grain size, and the amount of primary α phase based on the strain distribution results. The soundness of the forged part was verified using fluorescent penetrant test (Mil Std 2175 Grade A) and ultrasonic test (AMS 2630 class A1). From the experimental results, it was found that the variations in the hardness, tensile properties at room, and elevated temperature are not significant. The microstructure, grain size, and primary α phase content are nearly same.

  6. Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

    NASA Astrophysics Data System (ADS)

    Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

    This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

  7. Development of Replacements for Phoscoating Used in Forging, Extrusion and Metal Forming Processes

    SciTech Connect

    Kerry Barnett

    2003-03-01

    Many forging, extrusion, heading and other metal forming processes use graphite-based lubricants, phosphate coatings, and other potentially hazardous or harmful substances to improve the tribology of the metal forming process. The application of phosphate-based coatings has long been studied to determine if other synthetic ''clean'' lubricants could provide the same degree of protection afforded by phoscoatings and its formulations. So far, none meets the cost and performance objectives provided by phoscoatings as a general aid to the metal forming industry. In as much as phoscoatings and graphite have replaced lead-based lubricants, the metal forming industry has had previous experience with a legislated requirement to change processes. However, without a proactive approach to phoscoating replacement, many metal forming processes could find themselves without a cost effective tribology material necessary for the metal forming process

  8. Modeling of Closed-Die Forging for Estimating Forging Load

    NASA Astrophysics Data System (ADS)

    Sheth, Debashish; Das, Santanu; Chatterjee, Avik; Bhattacharya, Anirban

    2016-05-01

    Closed die forging is one common metal forming process used for making a range of products. Enough load is to exert on the billet for deforming the material. This forging load is dependent on work material property and frictional characteristics of the work material with the punch and die. Several researchers worked on estimation of forging load for specific products under different process variables. Experimental data on deformation resistance and friction were used to calculate the load. In this work, theoretical estimation of forging load is made to compare this value with that obtained through LS-DYNA model facilitating the finite element analysis. Theoretical work uses slab method to assess forging load for an axi-symmetric upsetting job made of lead. Theoretical forging load estimate shows slightly higher value than the experimental one; however, simulation shows quite close matching with experimental forging load, indicating possibility of wide use of this simulation software.

  9. Forging; Heat Treating and Testing; Technically Oriented Industrial Materials and Process 1: 5898.05.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course provides students with advanced and exploratory experience in the area of plastic deformation of metals and in the changing of the physical characteristics of metals by the controlled application and timed removal of heat. Course content includes goals, specific objectives, safety in forge work, forging tools and equipment, industrial…

  10. Processing and properties of superclean ASTM A508 Cl. 4 forgings

    SciTech Connect

    Hinkel, A.V.; Handerhan, K.J.; Manzo, G.J.; Simkins, G.P.

    1988-12-31

    Steels with improved resistance to temper embrittlement are now being produced using ``superclean`` steelmaking technology. This technology involves the use of scrap control, proper electric arc furnace and ladle refining furnace practices to produce steel with very low Mn, Si, P, S and other residual impurities such as Sn, As and Sb. This technology has been applied on a production basis to modified ASTM A508 Cl- 4 material intended for high temperature pressure vessel forgings. Processing and properties of this superclean material are reviewed. In addition, the cleanliness and mechanical properties are compared to conventionally melted A508 Cl. 4 material. The ``superclean`` A508 Cl. 4 mod. was found to meet all specification requirements. In addition, the superclean material was found to possess superior upper shelf CVN properties, a lower FATT{sub 50} and NDTT, along with superior microcleanliness compared to conventional material. Finally, the superclean material was found to be immune to temper embrittlement based on the short-term embrittlement treatments examined.

  11. Effect of Forging Parameters on Low Cycle Fatigue Behaviour of Al/Basalt Short Fiber Metal Matrix Composites

    PubMed Central

    Karthigeyan, R.; Ranganath, G.

    2013-01-01

    This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface. PMID:24298207

  12. Effect of forging parameters on low cycle fatigue behaviour of Al/basalt short fiber metal matrix composites.

    PubMed

    Karthigeyan, R; Ranganath, G

    2013-01-01

    This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface.

  13. Formation and Microstructure of Ultrafine-Grained Titanium Processed by Multi-Directional Forging

    NASA Astrophysics Data System (ADS)

    Wang, Bingfeng; Wang, Xiaoyan; Li, Juan

    2016-06-01

    Ultrafine-grained titanium with uniform grain size for medical applications is obtained by multi-directional forging at 773 K in air. The microstructures and microtextures in the deformed titanium specimens are investigated by optical microscopy, electron backscattered diffraction technique, and transmission electron microscopy. Titanium specimen experience the recrystallization softening at cumulative strain about 1.2. After six passes with the cumulative strains of 2.4, the coarse grain sizes are gradually refined from about 25 μm to about 0.2 μm. New microtextures with recrystallized features generate in the specimens after multi-directional forgings. Grain boundaries in the specimens are geometrical necessary boundaries aiming to accommodate the imposed strain. It is suggested that the continuous dynamic recrystallization induced by deformation bands is responsible for the formation of ultrafine-grained titanium during multi-directional forging. Meanwhile the subdivision of grains by the mechanical twinning dramatically enhanced grain refinement to develop ultrafine-grained microstructure.

  14. Bioresorbable composite screws manufactured via forging process: pull-out, shear, flexural and degradation characteristics.

    PubMed

    Felfel, R M; Ahmed, I; Parsons, A J; Rudd, C D

    2013-02-01

    Bioresorbable screws have the potential to overcome some of the complications associated with metallic screws currently in use. Removal of metallic screws after bone has healed is a serious issue which can lead to refracture due to the presence of screw holes. Poly lactic acid (PLA), fully 40 mol% P(2)O(5) containing phosphate unidirectional (P40UD) and a mixture of UD and short chopped strand random fibre mats (P40 70%UD/30%RM) composite screws were prepared via forging composite bars. Water uptake and mass loss for the composite screws manufactured increased significantly to ∼1.25% (P=0.0002) and ∼1.1% (P<0.0001), respectively, after 42 days of immersion in PBS at 37 °C. The initial maximum flexural load for P40 UD/RM and P40 UD composite screws was ∼60% (P=0.0047) and ∼100% (P=0.0037) higher than for the PLA screws (∼190 N), whilst the shear load was slightly higher in comparison to PLA (∼2.2 kN). The initial pull-out strengths for the P40 UD/RM and PLA screws were similar whereas that for P40 UD screws was ∼75% higher (P=0.022). Mechanical properties for the composite screws decreased initially after 3 days of immersion and this reduction was ascribed to the degradation of the fibre/matrix interface. After 3 days interval the mechanical properties (flexural, shear and pull-out) maintained their integrity for the duration of the study (at 42 days). This property retention was attributed to the chemical durability of the fibres used and stability of the matrix properties during the degradation process. It was also deemed necessary to enhance the fibre/matrix interface via use of a coupling agent in order to maintain the initial mechanical properties acquired for the required period of time. Lastly, it is also suggested that the degrading reinforcement fibres may have the potential to buffer any acidic products released from the PLA matrix. PMID:23262309

  15. Process Modeling In Cold Forging Considering The Process-Tool-Machine Interactions

    NASA Astrophysics Data System (ADS)

    Kroiss, Thomas; Engel, Ulf; Merklein, Marion

    2010-06-01

    In this paper, a methodic approach is presented for the determination and modeling of the axial deflection characteristic for the whole system of stroke-controlled press and tooling system. This is realized by a combination of experiment and FE simulation. The press characteristic is uniquely measured in experiment. The tooling system characteristic is determined in FE simulation to avoid experimental investigations on various tooling systems. The stiffnesses of press and tooling system are combined to a substitute stiffness that is integrated into the FE process simulation as a spring element. Non-linear initial effects of the press are modeled with a constant shift factor. The approach was applied to a full forward extrusion process on a press with C-frame. A comparison between experiments and results of the integrated FE simulation model showed a high accuracy of the FE model. The simulation model with integrated deflection characteristic represents the entire process behavior and can be used for the calculation of a mathematical process model based on variant simulations and response surfaces. In a subsequent optimization step, an adjusted process and tool design can be determined, that compensates the influence of the deflections on the workpiece dimensions leading to high workpiece accuracy. Using knowledge on the process behavior, the required number of variant simulations was reduced.

  16. New Trends in Forging Technologies

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Hagen, T.; Knigge, J.; Elgaly, I.; Hadifi, T.; Bouguecha, A.

    2011-05-01

    Limited natural resources increase the demand on highly efficient machinery and transportation means. New energy-saving mobility concepts call for design optimisation through downsizing of components and choice of corrosion resistant materials possessing high strength to density ratios. Component downsizing can be performed either by constructive structural optimisation or by substituting heavy materials with lighter high-strength ones. In this context, forging plays an important role in manufacturing load-optimised structural components. At the Institute of Metal Forming and Metal-Forming Machines (IFUM) various innovative forging technologies have been developed. With regard to structural optimisation, different strategies for localised reinforcement of components were investigated. Locally induced strain hardening by means of cold forging under a superimposed hydrostatic pressure could be realised. In addition, controlled martensitic zones could be created through forming induced phase conversion in metastable austenitic steels. Other research focused on the replacement of heavy steel parts with high-strength nonferrous alloys or hybrid material compounds. Several forging processes of magnesium, aluminium and titanium alloys for different aeronautical and automotive applications were developed. The whole process chain from material characterisation via simulation-based process design to the production of the parts has been considered. The feasibility of forging complex shaped geometries using these alloys was confirmed. In spite of the difficulties encountered due to machine noise and high temperature, acoustic emission (AE) technique has been successfully applied for online monitoring of forging defects. New AE analysis algorithm has been developed, so that different signal patterns due to various events such as product/die cracking or die wear could be detected and classified. Further, the feasibility of the mentioned forging technologies was proven by means

  17. Design and Analysis of a Forging Die for Manufacturing of Multiple Connecting Rods

    NASA Astrophysics Data System (ADS)

    Megharaj, C. E.; Nagaraj, P. M.; Jeelan Pasha, K.

    2016-09-01

    This paper demonstrates to utilize the hammer capacity by modifying the die design such that forging hammer can manufacture more than one connecting rod in a given forging cycle time. To modify the die design study is carried out to understand the parameters that are required for forging die design. By considering these parameters, forging die is designed using design modelling tool solid edge. This new design now can produce two connecting rods in same capacity hammer. The new design is required to validate by verifying complete filing of metal in die cavities without any defects in it. To verify this, analysis tool DEFORM 3D is used in this project. Before start of validation process it is require to convert 3D generated models in to. STL file format to import the models into the analysis tool DEFORM 3D. After importing these designs they are analysed for material flow into the cavities and energy required to produce two connecting rods in new forging die design. It is found that the forging die design is proper without any defects and also energy graph shows that the forging energy required to produce two connecting rods is within the limit of that hammer capacity. Implementation of this project increases the production of connecting rods by 200% in less than previous cycle time.

  18. High-energy rate forgings of wedges :

    SciTech Connect

    Reynolds, Thomas Bither; Everhart, Wesley; Switzner, Nathan T; Balch, Dorian K.; San Marchi, Christopher W.

    2014-05-01

    The wedge geometry is a simple geometry for establishing a relatively constant gradient of strain in a forged part. The geometry is used to establish gradients in microstructure and strength as a function of strain, forging temperature, and quenching time after forging. This geometry has previously been used to benchmark predictions of strength and recrystallization using Sandias materials model for type 304L austenitic stainless steel. In this report, the processing conditions, in particular the times to forge and quench the forged parts, are summarized based on information recorded during forging on June 18, 2013 of the so-called wedge geometry from type 316L and 21Cr-6Ni-9Mn austenitic stainless steels.

  19. Initial billet and forging dies shape optimization: Application on an axisymetrical forging with a hammer

    NASA Astrophysics Data System (ADS)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal

    2011-05-01

    In metal forming process, the forging die design is the most important step for products quality control. Reasonable dies shape can not only reduce raw material cost but also improving material flow and eliminating defects. The main objective of this paper is to obtain some optimal parameters of the initial billet and forging dies shape according to the simulation results of a two-step metal forming process (platting step and forging step). To develop this metal forming process optimization system several numerical tools are required: geometric modelling (CATIA V5™), FEM analysis (ABAQUS®), work-flow control and optimization computation (MODEFRONTIER®). This study is done in three stages: simulating the two-step metal forming process, building surrogate meta-models to relate response and variables and optimizing the process by using advanced optimization algorithms. In this paper, a two-step axisymmetric metal forming project was studied as an example. By using our simulation model, we get 581 correct real simulation results totally. According to all these real values, we build the surrogate meta-models and obtain Pareto points for a two-objective optimization process. The choice of a solution in all Pareto points will be done by the engineer who can choose his best values according to their criterions of project.

  20. Forging of Advanced Disk Alloy LSHR

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; Gayda, John; Falsey, John

    2005-01-01

    The powder metallurgy disk alloy LSHR was designed with a relatively low gamma precipitate solvus temperature and high refractory element content to allow versatile heat treatment processing combined with high tensile, creep and fatigue properties. Grain size can be chiefly controlled through proper selection of solution heat treatment temperatures relative to the gamma precipitate solvus temperature. However, forging process conditions can also significantly influence solution heat treatment-grain size response. Therefore, it is necessary to understand the relationships between forging process conditions and the eventual grain size of solution heat treated material. A series of forging experiments were performed with subsequent subsolvus and supersolvus heat treatments, in search of suitable forging conditions for producing uniform fine grain and coarse grain microstructures. Subsolvus, supersolvus, and combined subsolvus plus supersolvus heat treatments were then applied. Forging and subsequent heat treatment conditions were identified allowing uniform fine and coarse grain microstructures.

  1. Simulation of 7050 Wrought Aluminum Alloy Wheel Die Forging and its Defects Analysis based on DEFORM

    SciTech Connect

    Huang Shiquan; Yi Youping; Zhang Yuxun

    2010-06-15

    Defects such as folding, intercrystalline cracking and flow lines outcrop are very likely to occur in the forging of aluminum alloy. Moreover, it is difficult to achieve the optimal set of process parameters just by trial and error within an industrial environment. In producing 7050 wrought aluminum alloy wheel, a rigid-plastic finite element method (FEM) analysis has been performed to optimize die forging process. Processing parameters were analyzed, focusing on the effects of punch speed, friction factor and temperature. Meanwhile, mechanism as well as the evolution with respect to the defects of the wrought wheel was studied in details. From an analysis of the results, isothermal die forging was proposed for producing 7050 aluminum alloy wheel with good mechanical properties. Finally, verification experiment was carried out on hydropress.

  2. Phased Array Ultrasonic Inspection of Titanium Forgings

    SciTech Connect

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; Fromont, F. de

    2007-03-21

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed.

  3. Phased Array Ultrasonic Inspection of Titanium Forgings

    NASA Astrophysics Data System (ADS)

    Howard, P.; Klaassen, R.; Kurkcu, N.; Barshinger, J.; Chalek, C.; Nieters, E.; Sun, Zongqi; deFromont, F.

    2007-03-01

    Aerospace forging inspections typically use multiple, subsurface-focused sound beams in combination with digital C-scan image acquisition and display. Traditionally, forging inspections have been implemented using multiple single element, fixed focused transducers. Recent advances in phased array technology have made it possible to perform an equivalent inspection using a single phased array transducer. General Electric has developed a system to perform titanium forging inspection based on medical phased array technology and advanced image processing techniques. The components of that system and system performance for titanium inspection will be discussed.

  4. Superplastic forging nitride ceramics

    DOEpatents

    Panda, P.C.; Seydel, E.R.; Raj, R.

    1988-03-22

    A process is disclosed for preparing silicon nitride ceramic parts which are relatively flaw free and which need little or no machining, said process comprising the steps of: (a) preparing a starting powder by wet or dry mixing ingredients comprising by weight from about 70% to about 99% silicon nitride, from about 1% to about 30% of liquid phase forming additive and from 1% to about 7% free silicon; (b) cold pressing to obtain a preform of green density ranging from about 30% to about 75% of theoretical density; (c) sintering at atmospheric pressure in a nitrogen atmosphere at a temperature ranging from about 1,400 C to about 2,200 C to obtain a density which ranges from about 50% to about 100% of theoretical density and which is higher than said preform green density, and (d) press forging workpiece resulting from step (c) by isothermally uniaxially pressing said workpiece in an open die without initial contact between said workpiece and die wall perpendicular to the direction of pressing and so that pressed workpiece does not contact die wall perpendicular to the direction of pressing, to substantially final shape in a nitrogen atmosphere utilizing a temperature within the range of from about 1,400 C to essentially 1,750 C and strain rate within the range of about 10[sup [minus]7] to about 10[sup [minus]1] seconds[sup [minus]1], the temperature and strain rate being such that surface cracks do not occur, said pressing being carried out to obtain a shear deformation greater than 30% whereby superplastic forging is effected.

  5. Effect of Process Parameters on Microstructure and Hardness of Oxide Dispersion Strengthened 18Cr Ferritic Steel

    NASA Astrophysics Data System (ADS)

    Nagini, M.; Vijay, R.; Rajulapati, Koteswararao V.; Rao, K. Bhanu Sankara; Ramakrishna, M.; Reddy, A. V.; Sundararajan, G.

    2016-08-01

    Pre-alloyed ferritic 18Cr steel (Fe-18Cr-2.3W-0.3Ti) powder was milled with and without nano-yttria in high-energy ball mill for varying times until steady-state is reached. The milled powders were consolidated by upset forging followed by hot extrusion. Microstructural changes were examined at all stages of processing (milling, upset forging, and extrusion). In milled powders, crystallite size decreases and hardness increases with increasing milling time reaching a steady-state beyond 5 hours. The size of Y2O3 particles in powders decreases with milling time and under steady-state milling conditions; the particles either dissolve in matrix or form atomic clusters. Upset forged sample consists of unrecrystallized grain structure with few pockets of fine recrystallized grains and dispersoids of 2 to 4 nm. In extruded and annealed rods, the particles are of cuboidal Y2Ti2O7 at all sizes and their size decreased from 15 nm to 5 nm along with significant increase in number density. The oxide particles in ODS6 are of cuboidal Y2Ti2O7 with diamond cubic crystal structure ( Fd bar{3} m) having a lattice parameter of 10.1 Å and are semicoherent with the matrix. The hardness values of extruded and annealed samples predicted by linear summation model compare well with measured values.

  6. Enhancement of Aluminum Alloy Forgings through Rapid Billet Heating

    SciTech Connect

    Kervick, R.; Blue, C. A.; Kadolkar, P. B.; Ando, T.; Lu, H.; Nakazawa, K.; Mayer, H.; Mochnal, G.

    2006-06-01

    Forging is a manufacturing process in which metal is pressed, pounded or squeezed under great pressure and, often, under high strain rates into high-strength parts known as forgings. The process is typically performed hot by preheating the metal to a desired temperature before it is worked. The forging process can create parts that are stronger than those manufactured by any other metal working process. Forgings are almost always used where reliability and human safety are critical. Forgings are normally component parts contained inside assembled items such airplanes, automobiles, tractors, ships, oil drilling equipment, engines missiles, and all kinds of capital equipment Forgings are stronger than castings and surpass them in predictable strength properties, producing superior strength that is assured, part to part.

  7. Forging of FeAl intermetallic compounds

    SciTech Connect

    Flores, O.; Juarez, J.; Campillo, B.; Martinez, L.; Schneibel, J.H.

    1994-09-01

    Much activity has been concentrated on the development of intermetallic compounds with the aim of improving tensile ductility, fracture toughness and high notch sensitivity in order to develop an attractive combination of properties for high and low temperature applications. This paper reports experience in processing and forging of FeAl intermetallic of B2 type. During the experiments two different temperatures were employed, and the specimens were forged after annealing in air, 10{sup {minus}2} torr vacuum and argon. From the results it was learned that annealing FeAl in argon atmosphere prior to forging resulted in better deformation behavior than for the other two environments. For the higher forging temperature used in the experiments (700C), the as-cast microstructure becomes partially recrystallized.

  8. Mechanical Testing Development for Reservoir Forgings

    SciTech Connect

    Wenski, E.G.

    2000-05-22

    The goal of this project was to determine the machining techniques and testing capabilities required for mechanical property evaluation of commercially procured reservoir forgings. Due to the small size of these specific forgings, specialized methods are required to adequately machine and test these sub-miniature samples in accordance with the requirements of ASTM-E8 and ASTM-E9. At the time of project initiation, no capability existed at Federal Manufacturing & Technologies (FM&T) to verify the physical properties of these reservoirs as required on the drawing specifications. The project determined the sample definitions, machining processes, and testing procedures to verify the physical properties of the reservoir forgings; specifically, tensile strength, yield strength, reduction of area, and elongation. In addition, a compression test method was also developed to minimize sample preparation time and provide a more easily machined test sample while maintaining the physical validation of the forging.

  9. Fallon FORGE Well Lithologies

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    x,y,z text file of the downhole lithologic interpretations in the wells in and around the Fallon FORGE site. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  10. Near-Net Forging Technology Demonstration Program

    NASA Technical Reports Server (NTRS)

    Hall, I. Keith

    1996-01-01

    Significant advantages in specific mechanical properties, when compared to conventional aluminum (Al) alloys, make aluminum-lithium (Al-Li) alloys attractive candidate materials for use in cryogenic propellant tanks and dry bay structures. However, the cost of Al-Li alloys is typically five times that of 2219 aluminum. If conventional fabrication processes are employed to fabricate launch vehicle structure, the material costs will restrict their utilization. In order to fully exploit the potential cost and performance benefits of Al-Li alloys, it is necessary that near-net manufacturing methods be developed to off-set or reduce raw material costs. Near-net forging is an advanced manufacturing method that uses elevated temperature metal movement (forging) to fabricate a single piece, near-net shape, structure. This process is termed 'near-net' because only a minimal amount of post-forge machining is required. The near-net forging process was developed to reduce the material scrap rate (buy-to-fly ratio) and fabrication costs associated with conventional manufacturing methods. The goal for the near-net forging process, when mature, is to achieve an overall cost reduction of approximately 50 percent compared with conventional manufacturing options for producing structures fabricated from Al-Li alloys. This NASA Marshall Space Flight Center (MSFC) sponsored program has been a part of a unique government / industry partnership, coordinated to develop and demonstrate near-net forging technology. The objective of this program was to demonstrate scale-up of the near-net forging process. This objective was successfully achieved by fabricating four integrally stiffened, 170- inch diameter by 20-inch tall, Al-Li alloy 2195, Y-ring adapters. Initially, two 2195 Al-Li ingots were converted and back extruded to produce four cylindrical blockers. Conventional ring rolling of the blockers was performed to produce ring preforms, which were then contour ring rolled to produce

  11. Friction and wear in hot forging of steels

    SciTech Connect

    Daouben, E.; Dubar, L.; Dubar, M.; Deltombe, R.; Dubois, A.; Truong-Dinh, N.; Lazzarotto, L.

    2007-04-07

    In the field of hot forging of steels, the mastering of wear phenomena enables to save cost production, especially concerning tools. Surfaces of tools are protected thanks to graphite. The existing lubrication processes are not very well known: amount and quality of lubricant, lubrication techniques have to be strongly optimized to delay wear phenomena occurrence. This optimization is linked with hot forging processes, the lubricant layers must be tested according to representative friction conditions. This paper presents the first part of a global study focused on wear phenomena encountered in hot forging of steels. The goal is the identification of reliable parameters, in order to bring knowledge and models of wear. A prototype testing stand developed in the authors' laboratory is involved in this experimental analysis. This test is called Warm and Hot Upsetting Sliding Test (WHUST). The stand is composed of a heating induction system and a servo-hydraulic system. Workpieces taken from production can be heated until 1200 deg. C. A nitrided contactor representing the tool is heated at 200 deg. C. The contactor is then coated with graphite and rubs against the workpiece, leaving a residual track on it. Friction coefficient and surface parameters on the contactor and the workpiece are the most representative test results. The surface parameters are mainly the sliding length before defects occurrence, and the amplitude of surface profile of the contactor. The developed methodology will be first presented followed by the different parts of the experimental prototype. The results of experiment show clearly different levels of performance according to different lubricants.

  12. Hot Cutting of Real-Time Cast-Forged GS Ductile Iron for Automotive Rods

    NASA Astrophysics Data System (ADS)

    Fouilland, Laurence; Mansori, Mohamed El

    2011-01-01

    In the global economy context, automotive industry suppliers have to keep a constant advance on products design and manufacturing process. Concerning automotive rods, the substitution of forged steel by spherical graphite iron (SG iron) with high mechanical properties constitutes a valid economic alternative. Such rods are produced using a complex coupled process: casting and forging followed by an austempered heat treatment. The forging operation is capable to shape the cast rod which introduces hot deformation to increase mechanical properties of net-shape SG iron rod. However, the intermediate re-heating between casting and forging must be avoided to keep competitive manufacturing costs. A major concern of this new process development is the cracks produced in rod's surface which are consecutive to hot spruing involved after casting operations. This issue is addressed in this paper which discusses the physical mechanisms involved in the hot ductile damage of SG iron. Hot cutting tests were performed to simulate the spruing operation which shows the close interactions between microstructure, machining parameters and resulting damages. The damage mechanisms in terms of crack initiation and its growth have been studied with respect to the constituent phases (austenite+graphite nodules), the cut surface morphology and the hot cutting performance.

  13. Superplastic forging nitride ceramics

    DOEpatents

    Panda, Prakash C.; Seydel, Edgar R.; Raj, Rishi

    1988-03-22

    The invention relates to producing relatively flaw free silicon nitride ceramic shapes requiring little or no machining by superplastic forging This invention herein was made in part under Department of Energy Grant DE-AC01-84ER80167, creating certain rights in the United States Government. The invention was also made in part under New York State Science and Technology Grant SB1R 1985-10.

  14. A material based approach to creating wear resistant surfaces for hot forging

    NASA Astrophysics Data System (ADS)

    Babu, Sailesh

    . Dissertation outlines development of a new cyclic contact test design to recreate intermittent tempering seen in hot forging. This test has been used to validate the use of tempering parameters in modeling of in-service softening of tool steel surfaces. The dissertation also outlines an industrial case study, conducted at a forging company, to validate the wear model. This dissertation also outlines efforts at Ohio State University, to deposit Nickel Aluminide on AISI H13 substrate, using Laser Engineered Net Shaping (LENS). Dissertation reports results from an array of experiments conducted using LENS 750 machine, at various power levels, table speeds and hatch spacing. Results pertaining to bond quality, surface finish, compositional gradients and hardness are provided. Also, a thermal-based finite element numerical model that was used to simulate the LENS process is presented, along with some demonstrated results.

  15. Surveillance of industrial processes with correlated parameters

    DOEpatents

    White, A.M.; Gross, K.C.; Kubic, W.L.; Wigeland, R.A.

    1996-12-17

    A system and method for surveillance of an industrial process are disclosed. The system and method includes a plurality of sensors monitoring industrial process parameters, devices to convert the sensed data to computer compatible information and a computer which executes computer software directed to analyzing the sensor data to discern statistically reliable alarm conditions. The computer software is executed to remove serial correlation information and then calculate Mahalanobis distribution data to carry out a probability ratio test to determine alarm conditions. 10 figs.

  16. Surveillance of industrial processes with correlated parameters

    DOEpatents

    White, Andrew M.; Gross, Kenny C.; Kubic, William L.; Wigeland, Roald A.

    1996-01-01

    A system and method for surveillance of an industrial process. The system and method includes a plurality of sensors monitoring industrial process parameters, devices to convert the sensed data to computer compatible information and a computer which executes computer software directed to analyzing the sensor data to discern statistically reliable alarm conditions. The computer software is executed to remove serial correlation information and then calculate Mahalanobis distribution data to carry out a probability ratio test to determine alarm conditions.

  17. Parameter adaptive estimation of random processes

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Vanlandingham, H. F.

    1975-01-01

    This paper is concerned with the parameter adaptive least squares estimation of random processes. The main result is a general representation theorem for the conditional expectation of a random variable on a product probability space. Using this theorem along with the general likelihood ratio expression, the least squares estimate of the process is found in terms of the parameter conditioned estimates. The stochastic differential for the a posteriori probability and the stochastic differential equation for the a posteriori density are found by using simple stochastic calculus on the representations obtained. The results are specialized to the case when the parameter has a discrete distribution. The results can be used to construct an implementable recursive estimator for certain types of nonlinear filtering problems. This is illustrated by some simple examples.

  18. Computer-Aided Design of Manufacturing Chain Based on Closed Die Forging for Hardly Deformable Cu-Based Alloys

    NASA Astrophysics Data System (ADS)

    Pietrzyk, Maciej; Kuziak, Roman; Pidvysots'kyy, Valeriy; Nowak, Jarosław; Węglarczyk, Stanisław; Drozdowski, Krzysztof

    2013-07-01

    Two copper-based alloys were considered, Cu-1 pct Cr and Cu-0.7 pct Cr-1 pct Si-2 pct Ni. The thermal, electrical, and mechanical properties of these alloys are given in the paper and compared to pure copper and steel. The role of aging and precipitation kinetics in hardening of the alloys is discussed based upon the developed model. Results of plastometric tests performed at various temperatures and various strain rates are presented. The effect of the initial microstructure on the flow stress was investigated. Rheologic models for the alloys were developed. A finite element (FE) model based on the Norton-Hoff visco-plastic flow rule was applied to the simulation of forging of the alloys. Analysis of the die wear for various processes of hot and cold forging is presented as well. A microstructure evolution model was implemented into the FE code, and the microstructure and mechanical properties of final products were predicted. Various variants of the manufacturing cycles were considered. These include different preheating schedules, hot forging, cold forging, and aging. All variants were simulated using the FE method and loads, die filling, tool wear, and mechanical properties of products were predicted. Three variants giving the best combination of forging parameters were selected and industrial trials were performed. The best manufacturing technology for the copper-based alloys is proposed.

  19. Effect of Variants of Thermomechanical Working and Annealing Treatment on Titanium Alloy Ti6Al4V Closed Die Forgings

    NASA Astrophysics Data System (ADS)

    Gupta, R. K.; Kumar, V. Anil; Kumar, P. Ram

    2016-06-01

    Performance of titanium alloy Ti6Al4V pressure vessels made of closed die forged domes of route `B' (multiple step forged and mill annealed) is reported to be better than route `A' (single/two step forged and mill annealed). Analysis revealed that forgings processed through route `B' have uniformity in microstructure and yield strength at various locations within the forging, as compared to that of route `A.' It is attributed to in-process recrystallization (dynamic as well as static) of route `B' forgings as compared to limited recrystallization of route `A' forgings. Further, post-forging recrystallization annealing (RA) effect is found to be more significant for route `A' forgings in achieving uniform microstructure and mechanical properties, since route `B' forgings have already undergone similar phenomenon during the thermomechanical working process itself. Considering prime importance of yield strength, statistical scatter in yield strength values within the forgings have been evaluated for forgings of both the routes. Standard deviation in the yield strength of route `B' forgings was lower (<10 MPa) as compared to route `A' (>15 MPa), which later became lower (~10 MPa) after RA with a minor decrease in yield strength. The present work discusses these variants of thermomechanical processing along with annealing to achieve better uniformity in properties and microstructure.

  20. Visual parameter optimisation for biomedical image processing

    PubMed Central

    2015-01-01

    Background Biomedical image processing methods require users to optimise input parameters to ensure high-quality output. This presents two challenges. First, it is difficult to optimise multiple input parameters for multiple input images. Second, it is difficult to achieve an understanding of underlying algorithms, in particular, relationships between input and output. Results We present a visualisation method that transforms users' ability to understand algorithm behaviour by integrating input and output, and by supporting exploration of their relationships. We discuss its application to a colour deconvolution technique for stained histology images and show how it enabled a domain expert to identify suitable parameter values for the deconvolution of two types of images, and metrics to quantify deconvolution performance. It also enabled a breakthrough in understanding by invalidating an underlying assumption about the algorithm. Conclusions The visualisation method presented here provides analysis capability for multiple inputs and outputs in biomedical image processing that is not supported by previous analysis software. The analysis supported by our method is not feasible with conventional trial-and-error approaches. PMID:26329538

  1. Effects of process parameters on hydrothermal carbonization

    NASA Astrophysics Data System (ADS)

    Uddin, Md. Helal

    In recent years there has been increased research activity in renewable energy, especially upgrading widely available lignicellulosic biomass, in a bid to counter the increasing environmental concerns related with the use of fossil fuels. Hydrothermal carbonization (HTC), also known as wet torrefaction or hot water pretreatment, is a process for pretreatment of diverse lignocellulosic biomass feedstocks, where biomass is treated under subcritical water conditions in short contact time to produce high-value products. The products of this process are: a solid mass characterized as biochar/biocoal/biocarbon, which is homogeneous, energy dense, and hydrophobic; a liquid stream composed of five and six carbon sugars, various organic acids, and 5-HMF; and a gaseous stream, mainly CO2. A number of process parameters are considered important for the extensive application of the HTC process. Primarily, reaction temperature determines the characteristics of the products. In the solid product, the oxygen carbon ratio decreases with increasing reaction temperature and as a result, HTC biochar has the similar characteristics to low rank coal. However, liquid and gaseous stream compositions are largely correlated with the residence time. Biomass particle size can also limit the reaction kinetics due to the mass transfer effect. Recycling of process water can help to minimize the utility consumption and reduce the waste treatment cost as a result of less environmental impact. Loblolly pine was treated in hot compressed water at 200 °C, 230 °C, and 260 °C with 5:1 water:biomass mass ratio to investigate the effects of process parameters on HTC. The solid product were characterized by their mass yields, higher heating values (HHV), and equilibrium moisture content (EMC), while the liquid were characterized by their total organic carbon content and pH value.

  2. Tool Path Design of Incremental Open-Die Disk Forging Using Physical Modeling

    NASA Astrophysics Data System (ADS)

    Lee, Sung-Uk; Yang, Dong-Yol

    A small-batch product of large-sized parts is usually manufactured using incremental open-die forging. In order to control the overall change in the shape of a part, it is essential to be able to predict the shape changes that occur during each step. This paper addresses shape changes of a material according to the forging path. Rapid prediction of metal flows for continuing incremental deformation using theoretical methods is difficult. Accordingly, instead of a theoretical approach, an experiment that tests the tendency of the metal flow for development of forming processes is required. For the sake of convenience, simulative experiments are carried out using plasticine at room temperature. In present study, the tool movement is dominant parameters to with respect to changing the shape of the workpiece.

  3. Research on the Microstructure and Mechanical Property of Ti-7Cu Alloy after Semi-Solid Forging

    NASA Astrophysics Data System (ADS)

    Chen, Yongnan; Huo, Yazhou; Zhao, Yongqing; Sun, Zhiping; Bai, Fan

    2016-06-01

    The present work is focused on the development of microstructure of Ti-7Cu alloy as a function of forging temperature and forging ratio in semi-solid state and the influence of resulting microstructure on the mechanical properties. The experimental results showed that the dynamic recrystallization occurred during semi-solid forging and the grain refinement was attained which is considered to be favorable for improving the semi-solid formability. The grain size increased with forging temperature and decreased with forging ratio. Forging temperature has a significant effect on the precipitation behavior in grain boundary regions during the semi-solid processing. More acicular-Ti2Cu tended to precipitate in grain boundary regions with higher forging temperature and finally formed precipitates zones adjacent to grain boundaries after forged at 1,100°C. High ultimate tensile strengths and low elongation have been achieved after semi-solid forging. The strength and hardness decreased with increase of forging temperature, while the ductility increased with increase of forging ratio. The relative contributions of tensile properties were attributed to the varieties of grain size and the distribution of Ti2Cu precipitates obtained by semi-solid forging.

  4. Prediction of Microstructure in High-Strength Ductile Forging Parts

    SciTech Connect

    Urban, M.; Back, A.; Hirt, G.; Keul, C.; Bleck, W.

    2010-06-15

    Governmental, environmental and economic demands call for lighter, stiffer and at the same time cheaper products in the vehicle industry. Especially safety relevant parts have to be stiff and at the same time ductile. The strategy of this project was to improve the mechanical properties of forging steel alloys by employing a high-strength and ductile bainitic microstructure in the parts while maintaining cost effective process chains to reach these goals for high stressed forged parts. Therefore, a new steel alloy combined with an optimized process chain has been developed. To optimize the process chain with a minimum of expensive experiments, a numerical approach was developed to predict the microstructure of the steel alloy after the process chain based on FEM simulations of the forging and cooling combined with deformation-time-temperature-transformation-diagrams.

  5. West Flank Coso, CA FORGE Seismic Reflection

    DOE Data Explorer

    Doug Blankenship

    2016-05-16

    PDFs of seismic reflection profiles 101,110, 111 local to the West Flank FORGE site. 45 line kilometers of seismic reflection data are processed data collected in 2001 through the use of vibroseis trucks. The initial analysis and interpretation of these data was performed by Unruh et al. (2001). Optim processed these data by inverting the P-wave first arrivals to create a 2-D velocity structure. Kirchhoff images were then created for each line using velocity tomograms (Unruh et al., 2001).

  6. Investigations on Forging Dies with Ceramic Inserts by means of Finite-Element-Analysis

    NASA Astrophysics Data System (ADS)

    Behrens, B.-A.; Schäfer, F.; Bistron, M.

    2007-05-01

    The tools in hot forging processes are exposed to high thermal and mechanical loadings. Tempering of the tool edge layer occurs as a result of thermal loadings. This leads to a gradual hardness loss of the tool material and increase of wear over forging cycles. Hence, the tool life in hot forging is mainly limited by wear. An extension of the die service life can be achieved by the use of ceramic inserts. The integration of ceramics into the die base plate made of hot-work steel is realised by active brazing, whereby it possible to apply ceramic in region with high wear. It has to be ensured in the design process of ceramic inserts for forging dies that no critical tensile stresses occur in the ceramics. A reliable design of the ceramic inserts is possible only through consideration of brazing and forming process. The development of a Finite-Element-model for the design of forging dies with ceramic inserts is the intention of the work presented in this paper. At first the forging process with a conventional die is analyzed concerning abrasive die wear to identify regions with high wear risk applying a modified Archard model. Based on the results of wear calculation, a forging die with ceramic inserts is investigated in terms of joint stresses at the end of the active brazing process. Subsequently, the forging process considering the residual stresses caused by joining is simulated in order to obtain the die stress in use.

  7. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  8. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  9. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Forging machines. 1910.218 Section 1910.218 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.218 Forging machines. (a... other identifier, for the forging machine which was inspected. (ii) Scheduling and recording...

  10. Development of high purity large forgings for nuclear power plants

    NASA Astrophysics Data System (ADS)

    Tanaka, Yasuhiko; Sato, Ikuo

    2011-10-01

    The recent increase in the size of energy plants has been supported by the development of manufacturing technology for high purity large forgings for the key components of the plant. To assure the reliability and performance of the large forgings, refining technology to make high purity steels, casting technology for gigantic ingots, forging technology to homogenize the material and consolidate porosity are essential, together with the required heat treatment and machining technologies. To meet these needs, the double degassing method to reduce impurities, multi-pouring methods to cast the gigantic ingots, vacuum carbon deoxidization, the warm forging process and related technologies have been developed and further improved. Furthermore, melting facilities including vacuum induction melting and electro slag re-melting furnaces have been installed. By using these technologies and equipment, large forgings have been manufactured and shipped to customers. These technologies have also been applied to the manufacture of austenitic steel vessel components of the fast breeder reactors and components for fusion experiments.

  11. Evaluation of Control Parameters for the Activated Sludge Process

    ERIC Educational Resources Information Center

    Stall, T. Ray; Sherrard, Josephy H.

    1978-01-01

    An evaluation of the use of the parameters currently being used to design and operate the activated sludge process is presented. The advantages and disadvantages for the use of each parameter are discussed. (MR)

  12. HYDROGEN-ASSISTED FRACTURE IN FORGED TYPE 304L AUSTENITIC STAINLESS STEEL

    SciTech Connect

    Switzner, Nathan; Neidt, Ted; Hollenbeck, John; Knutson, J.; Everhart, Wes; Hanlin, R.; Bergen, R.; Balch, D. K.

    2012-09-06

    Austenitic stainless steels generally have good resistance to hydrogen-assisted fracture; however, structural designs for high-pressure gaseous hydrogen are constrained by the low strength of this class of material. Forging is used to increase the low strength of austenitic stainless steels, thus improving the efficiency of structural designs. Hydrogen-assisted racture, however, depends on microstructural details associated with manufacturing. In this study, hydrogen-assisted fracture of forged type 304L austenitic stainless steel is investigated. Microstructural variation in multi-step forged 304L was achieved by forging at different rates and temperatures, and by process annealing. High internal hydrogen content in forged type 304L austenitic stainless steel is achieved by thermal precharging in gaseous hydrogen and results in as much as 50% reduction of tensile ductility.

  13. Fallon FORGE Well Temp data

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    x,y,z downhole temperature data for wells in and around the Fallon FORGE site. Data for the following wells are included: 82-36, 82-19, 84.31, 61-36, 88-24, FOH-3D, FDU-1, and FDU-2. Data are formatted in txt format and in columns for importing into Earthvision Software. Column headers and coordinate system information is stored in the file header.

  14. Study on the Hot Processing Parameters-Impact Toughness Correlation of Ti-6Al-4V Alloy

    NASA Astrophysics Data System (ADS)

    Shi, Xiaohui; Zeng, Weidong; Sun, Yu; Han, Yuanfei; Zhao, Yongqing

    2016-05-01

    In this research, the hot processing parameters-impact toughness correlation of Ti-6Al-4V titanium alloy is studied. Fifty-four groups of hot processing treatments with different forging temperatures (930, 950, 970 °C), deformation degrees (20, 50, 80%), annealing temperatures (600, 700, 800 °C), and annealing time (1 and 5 h) were conducted. The orthogonal design was used to find the primary hot processing parameters influencing the impact toughness of Ti-6Al-4V alloy. The results show that the annealing temperature can exert the biggest influence on impact toughness. Low annealing temperature is essential to achieve high impact toughness value. In addition, the BP neural network was used to describe the quantitative correlation between hot processing parameters and impact toughness. The results show that the BP neural network exhibits good performance in predicting the impact toughness of Ti-6Al-4V alloy. The prediction error is within 5%. The BP neural network and the orthogonal design method are mutually confirmed in the present work. Finally, based on the microstructure analysis, the reasons responsible for above experimental results are explained.

  15. Industrial forging applications of shaping simulation using modeling clay

    NASA Astrophysics Data System (ADS)

    Ravassard, P.; Bournicon, C.

    1982-09-01

    The use of Plasticine and similar modeling materials to simulate forgings is advocated. It permits low cost studies of complex processes for manufacturing or training purposes without interfering with work schedules of real machines. Criteria for choosing a clay, construction of dies, equipment, and laboratory procedures are described.

  16. Thermo-mechanical modeling of the electrically-assisted manufacturing (EAM) technique during open die forging

    NASA Astrophysics Data System (ADS)

    Salandro, Wesley A.

    This thesis contains all of the steps which allow the Electrically-Assisted Manufacturing (EAM) technique to be experimentally explored and analytically modeled for an electrically-assisted forging operation. Chapter 1 includes the problem statement, proposed solution, and literature reviews on EAM. Chapter 2 describes a thorough background on the EAM technique, highlights prior EAM research, and explains the research approach taken for this thesis. The coupled thermo-mechanical modeling strategy, along with the introduction of the Electroplastic Effect Coefficient (EEC) is provided in Chapter 3. Chapter 4 explains the two different approaches to determine the EEC profiles when modeling a particular metal. The simplified EAF mechanical model for electrically-assisted forging is presented in Chapter 5. Also in this chapter, the same modeling methodology (i.e. thermo-mechanical, EEC, etc.) is used to predict loads for an electrically-assisted bending (EAB) process. The following chapters explore how different material- and process-based parameters affect the EAF technique. Chapter 6 examines how different workpiece contact areas affect EAF effectiveness, along with an exploration of how well different metal forming lubricants perform with EAF. Chapter 7 explores if there is a difference in the thermal or mechanical profiles of specimens undergoing EAF forging tests with different average grain sizes. Chapter 8 examines the same effects as the previous chapter on specimens with varying levels of prior cold work. The materials- and process-based simplifications and sensitivities of the proposed modeling strategy are outlined in Chapter 9. Chapters 10-14 include the science behind the electroplastic effect, conclusions, future work, broader impacts, and intellectual merit, respectively. The overall intention of this thesis is to show the candidate's ability to take an idea for a new manufacturing process, prove that it works, and then understand and model the process

  17. Structure and Mechanical Properties of Nitrogen Austenitic Steel after Ultrasonic Forging

    NASA Astrophysics Data System (ADS)

    Narkevich, N. A.; Tolmachev, A. I.; Vlasov, I. V.; Surikova, N. S.

    2016-03-01

    Electron microscopy and X-ray diffraction have been used to investigate a nitrogen 07Kh17AG18 steel with an austenitic structure after the surface deformation treatment—ultrasonic forging. During ultrasonic forging, an austenitic structure transforms into a new structure with an elevated concentration of deformation-induced stacking faults, a lot of deformation microtwins, ɛ-martensite crystals. The austenite lattice parameter is found to be decreased in the surface layer. After ultrasonic forging, nitrided steel exhibits enhanced strength properties with retained high plasticity.

  18. Assessment of NASA Dual Microstructure Heat Treatment Method for Multiple Forging Batch Heat Treatment

    NASA Technical Reports Server (NTRS)

    Gayda, John (Technical Monitor); Lemsky, Joe

    2004-01-01

    NASA dual microstructure heat treatment technology previously demonstrated on single forging heat treat batches of a generic disk shape was successfully demonstrated on a multiple disk batch of a production shape component. A group of four Rolls-Royce Corporation 3rd Stage AE2100 forgings produced from alloy ME209 were successfully dual microstructure heat treated as a single heat treat batch. The forgings responded uniformly as evidenced by part-to-part consistent thermocouple recordings and resultant macrostructures, and from ultrasonic examination. Multiple disk DMHT processing offers a low cost alternative to other published dual microstructure processing techniques.

  19. Reactor pressure vessel with forged nozzles

    DOEpatents

    Desai, Dilip R.

    1993-01-01

    Inlet nozzles for a gravity-driven cooling system (GDCS) are forged with a cylindrical reactor pressure vessel (RPV) section to which a support skirt for the RPV is attached. The forging provides enhanced RPV integrity around the nozzle and substantial reduction of in-service inspection costs by eliminating GDCS nozzle-to-RPV welds.

  20. Combining Noise Factors and Process Parameters in a Response Surface

    SciTech Connect

    Wyckoff, J.J.

    1998-03-19

    This presentation covers the strategy and analysis of an experiment to characterize a gas tungsten arc welding process. The experiment combined four uncontrolled noise factors and four controlled process parameters. A nontraditional response surface design was employed. Multiple responses were modeled. Optimal settings for the process parameters to successfully weld the widest range of the pertinent product features were identified. Thus, the process was made ''robust'' against ''noise'' factors. Comparisons are made between the experimental and analytical approach taken versus the Taguchi style of experimentation and analysis. This comparison is mainly done with respect to the information gained, such as product design criteria, incoming material specifications, and process adjustments for nonconforming material.

  1. Deformation Mechanisms in Tube Billets from Zr-1%Nb Alloy under Radial Forging

    SciTech Connect

    Perlovich, Yuriy; Isaenkova, Margarita; Fesenko, Vladimir; Krymskaya, Olga; Zavodchikov, Alexander

    2011-05-04

    Features of the deformation process by cold radial forging of tube billets from Zr-1%Nb alloy were reconstructed on the basis of X-ray data concerning their structure and texture. The cold radial forging intensifies grain fragmentation in the bulk of billet and increases significantly the latent hardening of potentially active slip systems, so that operation only of the single slip system becomes possible. As a result, in radially-forged billets unusual deformation and recrystallization textures arise. These textures differ from usual textures of {alpha}-Zr by the mutual inversion of crystallographic axes, aligned along the axis of tube.

  2. Deformation Mechanisms in Tube Billets from Zr-1%Nb Alloy under Radial Forging

    NASA Astrophysics Data System (ADS)

    Perlovich, Yuriy; Isaenkova, Margarita; Fesenko, Vladimir; Krymskaya, Olga; Zavodchikov, Alexander

    2011-05-01

    Features of the deformation process by cold radial forging of tube billets from Zr-1%Nb alloy were reconstructed on the basis of X-ray data concerning their structure and texture. The cold radial forging intensifies grain fragmentation in the bulk of billet and increases significantly the latent hardening of potentially active slip systems, so that operation only of the single slip system becomes possible. As a result, in radially-forged billets unusual deformation and recrystallization textures arise. These textures differ from usual textures of α-Zr by the mutual inversion of crystallographic axes, aligned along the axis of tube.

  3. Forging of eccentric co-extruded Al-Mg compounds and analysis of the interface strength

    NASA Astrophysics Data System (ADS)

    Förster, W.; Binotsch, C.; Awiszus, B.; Lehmann, T.; Müller, J.; Kirbach, C.; Stockmann, M.; Ihlemann, J.

    2016-03-01

    Within the subproject B3 of the Collaborative Research Center 692 it has been shown that Al-Mg compounds with a good bonding quality can be produced by hydrostatic coextrusion. During processing by forging, the aluminum sleeve is thinned in areas of high strains depending on the component geometry. To solve this problem an eccentric core arrangement during co-extrusion was investigated. Based on the results of FE-simulations, the experimental validation is presented in this work. Rods with an offset of 0.25, 0.5 and 0.75 mm were produced by eccentric hydrostatic co-extrusion. Ultrasonic testing was used to evaluate the bonding quality across the entire rods. For the forging investigations the basic process Rising was chosen. The still good bonding quality after forging was examined by dye penetrant testing and optical microscopy. For an optimal stress transfer between the materials across the entire component, a sufficient bonding between the materials is essential. To evaluate the interface strength, a special bending test was developed. For the conception of the bending specimens it was required to analyze the Rising specimens geometry. These analyses were performed using a reconstruction of the geometrical data based on computer tomography (CT) investigations. The comparison with the numerically deter-mined Rising specimen geometry shows good correlation. Parametric Finite Element Analyses of the bending test were used to develop the load case and the specimen geometry. By means of iterative adaption of load application, bearing and specimen geometry parameters, an advantageous stress state and experimentally applicable configuration were found. Based on this conception, the experimental setup was configured and bending tests were performed. The interface strength was deter-mined by the calculation of the maximum interlaminar interfacial tension stress using the experimental interface failure force and the bending FE model.

  4. Fuzzy control of the production environment process parameters

    NASA Astrophysics Data System (ADS)

    Izvekov, V. N.

    2015-04-01

    The fuzzy control process for support of given microclimatic production environment process parameters with loss of one from values, regulating regime of process was shown. The structural schematic decisions with algorithm of functioning and oriented to existing apparatus (means of realization) was presented.

  5. Parameter tuning of PVD process based on artificial intelligence technique

    NASA Astrophysics Data System (ADS)

    Norlina, M. S.; Diyana, M. S. Nor; Mazidah, P.; Rusop, M.

    2016-07-01

    In this study, an artificial intelligence technique is proposed to be implemented in the parameter tuning of a PVD process. Due to its previous adaptation in similar optimization problems, genetic algorithm (GA) is selected to optimize the parameter tuning of the RF magnetron sputtering process. The most optimized parameter combination obtained from GA's optimization result is expected to produce the desirable zinc oxide (ZnO) thin film from the sputtering process. The parameters involved in this study were RF power, deposition time and substrate temperature. The algorithm was tested to optimize the 25 datasets of parameter combinations. The results from the computational experiment were then compared with the actual result from the laboratory experiment. Based on the comparison, GA had shown that the algorithm was reliable to optimize the parameter combination before the parameter tuning could be done to the RF magnetron sputtering machine. In order to verify the result of GA, the algorithm was also been compared to other well known optimization algorithms, which were, particle swarm optimization (PSO) and gravitational search algorithm (GSA). The results had shown that GA was reliable in solving this RF magnetron sputtering process parameter tuning problem. GA had shown better accuracy in the optimization based on the fitness evaluation.

  6. Effect of processing parameters on reaction bonding of silicon nitride

    NASA Technical Reports Server (NTRS)

    Richman, M. H.; Gregory, O. J.; Magida, M. B.

    1980-01-01

    Reaction bonded silicon nitride was developed. The relationship between the various processing parameters and the resulting microstructures was to design and synthesize reaction bonded materials with improved room temperature mechanical properties.

  7. Life Detection System DTIVA for Monitoring Parameter in Fossilization Process

    NASA Astrophysics Data System (ADS)

    Gómez, F.; Garcia-Descalzo, L.; Cockell, C. S.; Schwendner, P.; Rettberg, P.; Beblo-Vranesevic, K.; Bohmeier, M.; Rabbow, E.; Westall, F.; Gaboyer, F.; Walter, N.; Moissl-Eichinger, M.; Perras, A.; Amils, R.; Malki, M.; Ehrenfreund, P.; Monaghan, E.; Marteinsson, V.; Vannier, P.

    2016-05-01

    Using Life Detection System LDS we followed the physicochemical parameter in a growth culture under fossilization/mineralization-induced process with the objectives of biomarkers detection. Biomarkers study is crucial for the search for life on Mars.

  8. Metal cutting analogy for establishing Friction Stir Welding process parameters

    NASA Astrophysics Data System (ADS)

    Stafford, Sylvester Allen

    A friction stir weld (FSW) is a solid state joining operation whose processing parameters are currently determined by lengthy trial and error methods. To implement FSWing rapidly in various applications will require an approach for predicting process parameters based on the physics of the process. Based on hot working conditions for metals, a kinematic model has been proposed for calculating the shear strain and shear strain rates during the FSW process, validation of the proposed model with direct measuring is difficult however. Since the shear strain and shear strain rates predicted for the FSW process, are similar to those predicted in metal cutting, validation of the FSW algorithms with microstructural studies of metal chips may be possible leading to the ability to predict FSW processing parameters.

  9. Analysis of the thermo-mechanical deformations in a hot forging tool by numerical simulation

    NASA Astrophysics Data System (ADS)

    L-Cancelos, R.; Varas, F.; Martín, E.; Viéitez, I.

    2016-03-01

    Although programs have been developed for the design of tools for hot forging, its design is still largely based on the experience of the tool maker. This obliges to build some test matrices and correct their errors to minimize distortions in the forged piece. This phase prior to mass production consumes time and material resources, which makes the final product more expensive. The forging tools are usually constituted by various parts made of different grades of steel, which in turn have different mechanical properties and therefore suffer different degrees of strain. Furthermore, the tools used in the hot forging are exposed to a thermal field that also induces strain or stress based on the degree of confinement of the piece. Therefore, the mechanical behaviour of the assembly is determined by the contact between the different pieces. The numerical simulation allows to analyse different configurations and anticipate possible defects before tool making, thus, reducing the costs of this preliminary phase. In order to improve the dimensional quality of the manufactured parts, the work presented here focuses on the application of a numerical model to a hot forging manufacturing process in order to predict the areas of the forging die subjected to large deformations. The thermo-mechanical model developed and implemented with free software (Code-Aster) includes the strains of thermal origin, strains during forge impact and contact effects. The numerical results are validated with experimental measurements in a tooling set that produces forged crankshafts for the automotive industry. The numerical results show good agreement with the experimental tests. Thereby, a very useful tool for the design of tooling sets for hot forging is achieved.

  10. Time parameters and Lorentz transformations of relativistic stochastic processes.

    PubMed

    Dunkel, Jörn; Hänggi, Peter; Weber, Stefan

    2009-01-01

    Rules for the transformation of time parameters in relativistic Langevin equations are derived and discussed. In particular, it is shown that, if a coordinate-time-parametrized process approaches the relativistic Jüttner-Maxwell distribution, the associated proper-time-parametrized process converges to a modified momentum distribution, differing by a factor proportional to the inverse energy. PMID:19256987

  11. Optimization of Gas Metal Arc Welding Process Parameters

    NASA Astrophysics Data System (ADS)

    Kumar, Amit; Khurana, M. K.; Yadav, Pradeep K.

    2016-09-01

    This study presents the application of Taguchi method combined with grey relational analysis to optimize the process parameters of gas metal arc welding (GMAW) of AISI 1020 carbon steels for multiple quality characteristics (bead width, bead height, weld penetration and heat affected zone). An orthogonal array of L9 has been implemented to fabrication of joints. The experiments have been conducted according to the combination of voltage (V), current (A) and welding speed (Ws). The results revealed that the welding speed is most significant process parameter. By analyzing the grey relational grades, optimal parameters are obtained and significant factors are known using ANOVA analysis. The welding parameters such as speed, welding current and voltage have been optimized for material AISI 1020 using GMAW process. To fortify the robustness of experimental design, a confirmation test was performed at selected optimal process parameter setting. Observations from this method may be useful for automotive sub-assemblies, shipbuilding and vessel fabricators and operators to obtain optimal welding conditions.

  12. Image processing method for multicore fiber geometric parameters

    NASA Astrophysics Data System (ADS)

    Zhang, Chuanbiao; Ning, Tigang; Li, Jing; Li, Chao; Ma, Shaoshuo

    2016-05-01

    An image processing method has been developed to obtain multicore fiber geometric parameters. According to the characteristics of multicore fiber, we using MATLAB to processing the sectional view of the multicore fiber (MCF), and the algorithm mainly concludes the following steps: filter out image noise, edge detection, use an appropriate threshold for boundary extraction and an improved curve-fitting algorithm for reconstruction the cross section, then we get the relative geometric parameters of the MCF in pixels. We also compares different edge detection operator and analyzes each detection results, which can provide a meaningful reference for edge detection.

  13. The optimization of operating parameters on microalgae upscaling process planning.

    PubMed

    Ma, Yu-An; Huang, Hsin-Fu; Yu, Chung-Chyi

    2016-03-01

    The upscaling process planning developed in this study primarily involved optimizing operating parameters, i.e., dilution ratios, during process designs. Minimal variable cost was used as an indicator for selecting the optimal combination of dilution ratios. The upper and lower mean confidence intervals obtained from the actual cultured cell density data were used as the final cell density stability indicator after the operating parameters or dilution ratios were selected. The process planning method and results were demonstrated through three case studies of batch culture simulation. They are (1) final objective cell densities were adjusted, (2) high and low light intensities were used for intermediate-scale cultures, and (3) the number of culture days was expressed as integers for the intermediate-scale culture.

  14. Stellar atmospheric parameter estimation using Gaussian process regression

    NASA Astrophysics Data System (ADS)

    Bu, Yude; Pan, Jingchang

    2015-02-01

    As is well known, it is necessary to derive stellar parameters from massive amounts of spectral data automatically and efficiently. However, in traditional automatic methods such as artificial neural networks (ANNs) and kernel regression (KR), it is often difficult to optimize the algorithm structure and determine the optimal algorithm parameters. Gaussian process regression (GPR) is a recently developed method that has been proven to be capable of overcoming these difficulties. Here we apply GPR to derive stellar atmospheric parameters from spectra. Through evaluating the performance of GPR on Sloan Digital Sky Survey (SDSS) spectra, Medium resolution Isaac Newton Telescope Library of Empirical Spectra (MILES) spectra, ELODIE spectra and the spectra of member stars of galactic globular clusters, we conclude that GPR can derive stellar parameters accurately and precisely, especially when we use data preprocessed with principal component analysis (PCA). We then compare the performance of GPR with that of several widely used regression methods (ANNs, support-vector regression and KR) and find that with GPR it is easier to optimize structures and parameters and more efficient and accurate to extract atmospheric parameters.

  15. Process Parameters Optimization in Single Point Incremental Forming

    NASA Astrophysics Data System (ADS)

    Gulati, Vishal; Aryal, Ashmin; Katyal, Puneet; Goswami, Amitesh

    2016-04-01

    This work aims to optimize the formability and surface roughness of parts formed by the single-point incremental forming process for an Aluminium-6063 alloy. The tests are based on Taguchi's L18 orthogonal array selected on the basis of DOF. The tests have been carried out on vertical machining center (DMC70V); using CAD/CAM software (SolidWorks V5/MasterCAM). Two levels of tool radius, three levels of sheet thickness, step size, tool rotational speed, feed rate and lubrication have been considered as the input process parameters. Wall angle and surface roughness have been considered process responses. The influential process parameters for the formability and surface roughness have been identified with the help of statistical tool (response table, main effect plot and ANOVA). The parameter that has the utmost influence on formability and surface roughness is lubrication. In the case of formability, lubrication followed by the tool rotational speed, feed rate, sheet thickness, step size and tool radius have the influence in descending order. Whereas in surface roughness, lubrication followed by feed rate, step size, tool radius, sheet thickness and tool rotational speed have the influence in descending order. The predicted optimal values for the wall angle and surface roughness are found to be 88.29° and 1.03225 µm. The confirmation experiments were conducted thrice and the value of wall angle and surface roughness were found to be 85.76° and 1.15 µm respectively.

  16. Processing parameters matching effects upon Rhizobium tropici biopolymers' rheological properties.

    PubMed

    Pimenta, Flávia Duta; Lopes, Léa Maria de Almeida; de França, Francisca Pessôa

    2008-07-01

    The combined effects of the processing parameters upon rheological properties of biopolymers produced by Rhizobium tropici were studied as a function of the Ca(+2) ions' concentration variation, yeast extract concentration added to the medium, aeration, and agitation, maintaining the mannitol concentration in 10 g/L. The experiments were carried out using a fermenter with 20-L capacity as a reactor. All processing parameters were monitored online. The temperature [(30 +/- 1) degrees C] and pH values (7.0) were kept constant throughout the experimental time. As a statistical tool, a complete 2(3) factorial design with central point and response surface was used to investigate the interactions between relevant variables of the fermentation process: calcium carbonate concentration, yeast extract concentration, aeration, and agitation. The processing parameter setup for reaching the maximum response for rheological propriety production was obtained when applying mannitol concentration of 10.0 g/L, calcium carbonate concentration 1.0 g/L, yeast extract concentration 1.0 g/L, aeration 1.30 vvm, and agitation 800 rpm. The viscosimetric investigation of polysaccharide solutions exposed their shear-thinning behavior and polyelectrolytic feature.

  17. Processing parameters matching effects upon Rhizobium tropici biopolymers' rheological properties.

    PubMed

    Pimenta, Flávia Duta; Lopes, Léa Maria de Almeida; de França, Francisca Pessôa

    2008-07-01

    The combined effects of the processing parameters upon rheological properties of biopolymers produced by Rhizobium tropici were studied as a function of the Ca(+2) ions' concentration variation, yeast extract concentration added to the medium, aeration, and agitation, maintaining the mannitol concentration in 10 g/L. The experiments were carried out using a fermenter with 20-L capacity as a reactor. All processing parameters were monitored online. The temperature [(30 +/- 1) degrees C] and pH values (7.0) were kept constant throughout the experimental time. As a statistical tool, a complete 2(3) factorial design with central point and response surface was used to investigate the interactions between relevant variables of the fermentation process: calcium carbonate concentration, yeast extract concentration, aeration, and agitation. The processing parameter setup for reaching the maximum response for rheological propriety production was obtained when applying mannitol concentration of 10.0 g/L, calcium carbonate concentration 1.0 g/L, yeast extract concentration 1.0 g/L, aeration 1.30 vvm, and agitation 800 rpm. The viscosimetric investigation of polysaccharide solutions exposed their shear-thinning behavior and polyelectrolytic feature. PMID:18437296

  18. Making randomised trials more efficient: report of the first meeting to discuss the Trial Forge platform.

    PubMed

    Treweek, Shaun; Altman, Doug G; Bower, Peter; Campbell, Marion; Chalmers, Iain; Cotton, Seonaidh; Craig, Peter; Crosby, David; Davidson, Peter; Devane, Declan; Duley, Lelia; Dunn, Janet; Elbourne, Diana; Farrell, Barbara; Gamble, Carrol; Gillies, Katie; Hood, Kerry; Lang, Trudie; Littleford, Roberta; Loudon, Kirsty; McDonald, Alison; McPherson, Gladys; Nelson, Annmarie; Norrie, John; Ramsay, Craig; Sandercock, Peter; Shanahan, Daniel R; Summerskill, William; Sydes, Matt; Williamson, Paula; Clarke, Mike

    2015-06-05

    Randomised trials are at the heart of evidence-based healthcare, but the methods and infrastructure for conducting these sometimes complex studies are largely evidence free. Trial Forge ( www.trialforge.org ) is an initiative that aims to increase the evidence base for trial decision making and, in doing so, to improve trial efficiency.This paper summarises a one-day workshop held in Edinburgh on 10 July 2014 to discuss Trial Forge and how to advance this initiative. We first outline the problem of inefficiency in randomised trials and go on to describe Trial Forge. We present participants' views on the processes in the life of a randomised trial that should be covered by Trial Forge.General support existed at the workshop for the Trial Forge approach to increase the evidence base for making randomised trial decisions and for improving trial efficiency. Agreed upon key processes included choosing the right research question; logistical planning for delivery, training of staff, recruitment, and retention; data management and dissemination; and close down. The process of linking to existing initiatives where possible was considered crucial. Trial Forge will not be a guideline or a checklist but a 'go to' website for research on randomised trials methods, with a linked programme of applied methodology research, coupled to an effective evidence-dissemination process. Moreover, it will support an informal network of interested trialists who meet virtually (online) and occasionally in person to build capacity and knowledge in the design and conduct of efficient randomised trials.Some of the resources invested in randomised trials are wasted because of limited evidence upon which to base many aspects of design, conduct, analysis, and reporting of clinical trials. Trial Forge will help to address this lack of evidence.

  19. Making randomised trials more efficient: report of the first meeting to discuss the Trial Forge platform.

    PubMed

    Treweek, Shaun; Altman, Doug G; Bower, Peter; Campbell, Marion; Chalmers, Iain; Cotton, Seonaidh; Craig, Peter; Crosby, David; Davidson, Peter; Devane, Declan; Duley, Lelia; Dunn, Janet; Elbourne, Diana; Farrell, Barbara; Gamble, Carrol; Gillies, Katie; Hood, Kerry; Lang, Trudie; Littleford, Roberta; Loudon, Kirsty; McDonald, Alison; McPherson, Gladys; Nelson, Annmarie; Norrie, John; Ramsay, Craig; Sandercock, Peter; Shanahan, Daniel R; Summerskill, William; Sydes, Matt; Williamson, Paula; Clarke, Mike

    2015-01-01

    Randomised trials are at the heart of evidence-based healthcare, but the methods and infrastructure for conducting these sometimes complex studies are largely evidence free. Trial Forge ( www.trialforge.org ) is an initiative that aims to increase the evidence base for trial decision making and, in doing so, to improve trial efficiency.This paper summarises a one-day workshop held in Edinburgh on 10 July 2014 to discuss Trial Forge and how to advance this initiative. We first outline the problem of inefficiency in randomised trials and go on to describe Trial Forge. We present participants' views on the processes in the life of a randomised trial that should be covered by Trial Forge.General support existed at the workshop for the Trial Forge approach to increase the evidence base for making randomised trial decisions and for improving trial efficiency. Agreed upon key processes included choosing the right research question; logistical planning for delivery, training of staff, recruitment, and retention; data management and dissemination; and close down. The process of linking to existing initiatives where possible was considered crucial. Trial Forge will not be a guideline or a checklist but a 'go to' website for research on randomised trials methods, with a linked programme of applied methodology research, coupled to an effective evidence-dissemination process. Moreover, it will support an informal network of interested trialists who meet virtually (online) and occasionally in person to build capacity and knowledge in the design and conduct of efficient randomised trials.Some of the resources invested in randomised trials are wasted because of limited evidence upon which to base many aspects of design, conduct, analysis, and reporting of clinical trials. Trial Forge will help to address this lack of evidence. PMID:26044814

  20. Forging of Naval Brass (ASTM B16) - Finite Element Analysis using Ls Dyna

    NASA Astrophysics Data System (ADS)

    Subha Sankari, T.; Sangavi, S.; Paneerselvam, T.; Venkatraman, R.; Venkatesan, M.

    2016-09-01

    Forging is one of the important manufacturing process in which products like connecting rod, transmission shaft, clutch hubs and gears are produced. Finite element analysis (FEA) in forming techniques is of recent interest for the optimal design and determination of right manufacturing forming process. The data from the numerical results can help in providing the information for selecting the ideal process conditions. Thus aside from experimental values, simulation by the finite element analysis software's such as LS DYNA can be used for the analysis of strain distribution in forging processes. In the present work, Finite element simulation of open die forging of naval brass (ASTM B16) is done at an optimal temperature. An advanced multi physics simulation software package by the Livermore software technology cooperation LSTC - LS DYNA is utilized for the simulation of forging process. For the forging validation, experiment is conducted with a cylindrical billet having height 45 mm and diameter of 40mm. The numerical results are compared with that of experimental results carried out at the same temperature and dimensions for validation. The distribution of strain is analyzed. Energy analysis due to impact load is detailed. The simulation results are found to be in good agreement with the experimental results.

  1. West Flank Coso, CA FORGE Magnetotelluric Inversion

    DOE Data Explorer

    Doug Blankenship

    2016-05-16

    The Coso Magnetotelluric (MT) dataset of which the West Flank FORGE MT data is a subset, was collected by Schlumberger / WesternGeco and initially processed by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy. The 2011 data was based on 99 soundings that were centered on the West Flank geothermal prospect. The new soundings along with previous data from 2003 and 2006 were incorporated into a 3D inversion. Full impedance tensor data were inverted in the 1-3000 Hz range. The modelling report notes several noise sources, specifically the DC powerline that is 20,000 feet west of the survey area, and may have affected data in the 0.02 to 10 Hz range. Model cell dimensions of 450 x 450 x 65 feet were used to avoid computational instability in the 3D model. The fit between calculated and observed MT values for the final model run had an RMS value of 1.807. The included figure from the WesternGeco report shows the sounding locations from the 2011, 2006 and 2003 surveys.

  2. Parameters in selective laser melting for processing metallic powders

    NASA Astrophysics Data System (ADS)

    Kurzynowski, Tomasz; Chlebus, Edward; Kuźnicka, Bogumiła; Reiner, Jacek

    2012-03-01

    The paper presents results of studies on Selective Laser Melting. SLM is an additive manufacturing technology which may be used to process almost all metallic materials in the form of powder. Types of energy emission sources, mainly fiber lasers and/or Nd:YAG laser with similar characteristics and the wavelength of 1,06 - 1,08 microns, are provided primarily for processing metallic powder materials with high absorption of laser radiation. The paper presents results of selected variable parameters (laser power, scanning time, scanning strategy) and fixed parameters such as the protective atmosphere (argon, nitrogen, helium), temperature, type and shape of the powder material. The thematic scope is very broad, so the work was focused on optimizing the process of selective laser micrometallurgy for producing fully dense parts. The density is closely linked with other two conditions: discontinuity of the microstructure (microcracks) and stability (repeatability) of the process. Materials used for the research were stainless steel 316L (AISI), tool steel H13 (AISI), and titanium alloy Ti6Al7Nb (ISO 5832-11). Studies were performed with a scanning electron microscope, a light microscopes, a confocal microscope and a μCT scanner.

  3. Influence of processing parameters on the quality of soycurd (tofu).

    PubMed

    Rekha, C R; Vijayalakshmi, G

    2013-02-01

    Tofu, a non-fermented soybean curd is a nutritious and digestible product with a high quality protein. Tofu making procedure includes soaking of beans, grinding, filtering, boiling, coagulating and moulding. The flavour, quality and the texture of tofu produced is significantly influenced by its processing parameters. Studies were carried out on the processing parameters like solid content of milk, thermal treatment of soybeans with sodium bicarbonate, stirring time after adding coagulant and moulding of tofu on the texture and quality of tofu. Our studies showed that the texture of the final product depended on the solid content of milk before coagulation. Pretreatment of soybeans with sodium bicarbonate, for 10 min and milk obtained with low solid content of 7° Brix resulted in regular, smooth textured tofu with less beany flavour. Duration of stirring during coagulation and moulding parameters had a significant effect on the yield of tofu. Stirring the milk after adding the coagulant for 5 s before settling and pressing the tofu with a load of 1,000 g initially for 15 min followed by 500 g for another 15 min, yielded (22.6 g/100 ml of milk) soft textured firm tofu.

  4. Thermo-Mechanical Processing Parameters for the INCONEL ALLOY 740

    SciTech Connect

    Ludtka, G.M.; Smith, G.

    2007-11-19

    In 2000, a Cooperative Research and Development Agreement (CRADA) was undertaken between the Oak Ridge National Laboratory (ORNL) and the Special Metals Corporation (SMC) to determine the mechanical property response of the IN740 alloy to help establish thermo-mechanical processing parameters for the use of this alloy in supercritical and ultra-critical boiler tubes with the potential for other end uses. SMC had developed an alloy, commercially known as INCONEL alloy 740, which exhibited various beneficial physical, mechanical, and chemical properties. As part of SMC's on-going efforts to optimize this alloy for targeted boiler applications there was a need to develop an understanding of the thermo-mechanical response of the material, characterize the resulting microstructure from this processing, and possibly, utilize models to develop the appropriate processing scheme for this product.

  5. 1. MIDDLE FORGE DISPLAY, ACROSS FROM BUILDING NO. 114 on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. MIDDLE FORGE DISPLAY, ACROSS FROM BUILDING NO. 114 on FARLEY AVE. MARKER ON DISPLAY ITSELF READS: FORGE AND TOOLS, USED AT MIDDLE FORGE LOCATED AT PICATINNY LAKE OUTLETS 1749 TO 1880. NEARBY MARKER READS: THE MIDDLE FORGE. THE MT. HOPE IRONWORKS INCLUDING A TRACT CALLED THE MIDDLE FORGE, SUPPLIED ORDNANCE MATERIAL TO THE CONTINENTAL ARMY IN THE AMERICAN REVOLUTION. GENERAL WASHINGTON INSPECTED THE FACILITY. THE WAR DEPARTMENT PURCHASED THE MIDDLE FORGE PORPERTY FOR AN ARMY POWDER DEPOT IN 1879-80. THE FORGE AND TOOLS WERE RECOVERED AT THE ACTUAL SITE NEAR PICATINNY PEAK. THROUGH THE YEARS, THE MIDDLE FORGE DISPLAY CAME TO BE THE UNOFFICIAL SYMBOL OF PICATINNY ARSENAL. -- HISTORICAL OFFICE NO DATE - Picatinny Arsenal, State Route 15 near I-80, Dover, Morris County, NJ

  6. 4. FORGE, ANVIL, PEDESTAL GRINDER, AND BELT DRIVES. NOTE WATERWHEEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. FORGE, ANVIL, PEDESTAL GRINDER, AND BELT DRIVES. NOTE WATERWHEEL NEEDLE VALVE CASTING HANGING ON THE WALL ABOVE THE FORGE. VIEW TO NORTH. - Santa Ana River Hydroelectric System, SAR-1 Machine Shop, Redlands, San Bernardino County, CA

  7. Impact of Temperature on Cooling Structural Variation of Forging Dies

    NASA Astrophysics Data System (ADS)

    Piesova, Marianna; Czan, Andrej

    2014-12-01

    The article is focused on the issue of die forging in the automotive industry. The cooling effect of temperature on the structure of forged die are under review. In the article, there is elaborated the analysis of theoretical knowledge in the field, focusing on die forging and experimentally proven effect of the cooling rate on the final structure of forged dies made of hypoeutectic carbon steel C56E2.

  8. Estimating demographic parameters using hidden process dynamic models.

    PubMed

    Gimenez, Olivier; Lebreton, Jean-Dominique; Gaillard, Jean-Michel; Choquet, Rémi; Pradel, Roger

    2012-12-01

    Structured population models are widely used in plant and animal demographic studies to assess population dynamics. In matrix population models, populations are described with discrete classes of individuals (age, life history stage or size). To calibrate these models, longitudinal data are collected at the individual level to estimate demographic parameters. However, several sources of uncertainty can complicate parameter estimation, such as imperfect detection of individuals inherent to monitoring in the wild and uncertainty in assigning a state to an individual. Here, we show how recent statistical models can help overcome these issues. We focus on hidden process models that run two time series in parallel, one capturing the dynamics of the true states and the other consisting of observations arising from these underlying possibly unknown states. In a first case study, we illustrate hidden Markov models with an example of how to accommodate state uncertainty using Frequentist theory and maximum likelihood estimation. In a second case study, we illustrate state-space models with an example of how to estimate lifetime reproductive success despite imperfect detection, using a Bayesian framework and Markov Chain Monte Carlo simulation. Hidden process models are a promising tool as they allow population biologists to cope with process variation while simultaneously accounting for observation error. PMID:22373775

  9. Unraveling the Processing Parameters in Friction Stir Welding

    NASA Technical Reports Server (NTRS)

    Schneider, Judy; Nunes, Arthur C., Jr.

    2005-01-01

    In friction stir welding (FSW), a rotating threaded pin tool is translated along a weld seam, literally stirring the edges of the seam together. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path or paths is required. In this study, various markers are used to trace the flow paths of the metal. X-ray radiographs record the segmentation and position of the wire. Several variations in the trajectories can be differentiated within the weld zone.

  10. Achieving Fine Beta Grain Structure in a Metastable Beta Titanium Alloy Through Multiple Forging-Annealing Cycles

    NASA Astrophysics Data System (ADS)

    Zafari, Ahmad; Ding, Yunpeng; Cui, Jianzhong; Xia, Kenong

    2016-07-01

    A coarse-grained (order of 1 mm) Ti-5553 metastable beta alloy was subjected to multiple passes of low-temperature forging and multiple forging plus annealing cycles, respectively. In the forging only processing, strain was concentrated in the shear bands formed and accumulated with each forging pass, resulting in a heterogeneous microstructure and eventual cracking along the shear bands. In contrast, the introduction of a short beta annealing after each forging step led to fine recrystallized grains (50 to 100 µm) formed in the shear bands, and a uniformly refined beta grain structure after four cycles. This is attributed to the strengthening effect of the fine grains, causing redistribution of most severe strains to the coarse grain region in the subsequent forging, consistent with the simulated results by finite element analysis. The analyses of the microstructures and simulated strain distributions revealed that the critical strain for recrystallization is between 0.2 and 0.5 and the strain to fracture to be ~0.8 to 0.9. The fine-grained (50 to 100 µm) beta alloy, however, fractured at a much smaller strain of <0.4 during the next forging step, owing to the formation of stress-induced martensitic α″ which is more prevalent in fine grains than in coarse ones.

  11. 22 CFR 121.10 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Forgings, castings, and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings, and machined bodies. The U.S. Munitions List controls as defense articles those forgings, castings, and other unfinished products, such...

  12. Co-Operative Training in the Sheffield Forging Industry

    ERIC Educational Resources Information Center

    Duncan, R.

    2008-01-01

    Purpose: The purpose of this paper is to give details of an operation carried out in Sheffield to increase the recruitment of young men into the steel forging industry. Design/methodology/approach: The Sheffield Forges Co-operative Training Scheme was designed to encourage boys to enter the forging industry and to provide them with training and…

  13. On-line estimation of concentration parameters in fermentation processes.

    PubMed

    Xiong, Zhi-hua; Huang, Guo-hong; Shao, Hui-he

    2005-06-01

    It has long been thought that bioprocess, with their inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers. A novel software sensor is proposed to make more effective use of those measurements that are already available, which enable improvement in fermentation process control. The proposed method is based on mixtures of Gaussian processes (GP) with expectation maximization (EM) algorithm employed for parameter estimation of mixture of models. The mixture model can alleviate computational complexity of GP and also accord with changes of operating condition in fermentation processes, i.e., it would certainly be able to examine what types of process-knowledge would be most relevant for local models' specific operating points of the process and then combine them into a global one. Demonstrated by on-line estimate of yeast concentration in fermentation industry as an example, it is shown that soft sensor based state estimation is a powerful technique for both enhancing automatic control performance of biological systems and implementing on-line monitoring and optimization.

  14. Characteristics, Process Parameters, and Inner Components of Anaerobic Bioreactors

    PubMed Central

    Abdelgadir, Awad; Chen, Xiaoguang; Liu, Jianshe; Xie, Xuehui; Zhang, Jian; Zhang, Kai; Wang, Heng; Liu, Na

    2014-01-01

    The anaerobic bioreactor applies the principles of biotechnology and microbiology, and nowadays it has been used widely in the wastewater treatment plants due to their high efficiency, low energy use, and green energy generation. Advantages and disadvantages of anaerobic process were shown, and three main characteristics of anaerobic bioreactor (AB), namely, inhomogeneous system, time instability, and space instability were also discussed in this work. For high efficiency of wastewater treatment, the process parameters of anaerobic digestion, such as temperature, pH, Hydraulic retention time (HRT), Organic Loading Rate (OLR), and sludge retention time (SRT) were introduced to take into account the optimum conditions for living, growth, and multiplication of bacteria. The inner components, which can improve SRT, and even enhance mass transfer, were also explained and have been divided into transverse inner components, longitudinal inner components, and biofilm-packing material. At last, the newly developed special inner components were discussed and found more efficient and productive. PMID:24672798

  15. Parameter and Process Significance in Mechanistic Modeling of Cellulose Hydrolysis

    NASA Astrophysics Data System (ADS)

    Rotter, B.; Barry, A.; Gerhard, J.; Small, J.; Tahar, B.

    2005-12-01

    The rate of cellulose hydrolysis, and of associated microbial processes, is important in determining the stability of landfills and their potential impact on the environment, as well as associated time scales. To permit further exploration in this field, a process-based model of cellulose hydrolysis was developed. The model, which is relevant to both landfill and anaerobic digesters, includes a novel approach to biomass transfer between a cellulose-bound biofilm and biomass in the surrounding liquid. Model results highlight the significance of the bacterial colonization of cellulose particles by attachment through contact in solution. Simulations revealed that enhanced colonization, and therefore cellulose degradation, was associated with reduced cellulose particle size, higher biomass populations in solution, and increased cellulose-binding ability of the biomass. A sensitivity analysis of the system parameters revealed different sensitivities to model parameters for a typical landfill scenario versus that for an anaerobic digester. The results indicate that relative surface area of cellulose and proximity of hydrolyzing bacteria are key factors determining the cellulose degradation rate.

  16. Optimization of drying process parameters for cauliflower drying.

    PubMed

    Gupta, Manoj Kumar; Sehgal, V K; Arora, Sadhna

    2013-02-01

    The different sizes (3, 4 and 5 cm) of hybrid variety of cauliflower (variety no. 71) were dehydrated in thin layer at three temperatures of 55, 60 and 65 °C with velocities of 40, 50 and 60 m/min. Dehydrated samples were analyzed for vitamin C, rehydration ratio and browning. Statistical analysis indicated that drying time was dependent on initial size of cauliflower, drying air temperature and velocity, but rehydration ratio was significantly affected by the combined effect of temperature and airflow velocity. Vitamin C content of the dried cauliflower samples were significantly affected by temperature only and non enzymatic browning was function of temperature, airflow velocity, and combined effect of temperature and airflow velocity. Optimization of the drying process parameters for the given constraints resulted in 60.10(0)C, 59.28 m/min, 3.35 cm. The predicted responses for the optimized combination of process parameters were time, vitamin C content, rehydration ratio, and browning values of 491.22 min (time), 289.86 mg/100 g (Vitamin C), 6.91 ( rehydration ratio), and 0.14 (browning), respectively with the desirability factor of 0.787. PMID:24425888

  17. Optimization of polyetherimide processing parameters for optical interconnect applications

    NASA Astrophysics Data System (ADS)

    Zhao, Wei; Johnson, Peter; Wall, Christopher

    2015-10-01

    ULTEM® polyetherimide (PEI) resins have been used in opto-electronic markets since the optical properties of these materials enable the design of critical components under tight tolerances. PEI resins are the material of choice for injection molded integrated lens applications due to good dimensional stability, near infrared (IR) optical transparency, low moisture uptake and high heat performance. In most applications, parts must be produced consistently with minimal deviations to insure compatibility throughout the lifetime of the part. With the large number of lenses needed for this market, injection molding has been optimized to maximize the production rate. These optimized parameters for high throughput may or may not translate to an optimized optical performance. In this paper, we evaluate and optimize PEI injection molding processes with a focus on optical property performance. A commonly used commercial grade was studied to determine factors and conditions which contribute to optical transparency, color, and birefringence. Melt temperature, mold temperature, injection speed and cycle time were varied to develop optimization trials and evaluate optical properties. These parameters could be optimized to reduce in-plane birefringence from 0.0148 to 0.0006 in this study. In addition, we have studied an optically smooth, sub-10nm roughness mold to re-evaluate material properties with minimal influence from mold quality and further refine resin and process effects for the best optical performance.

  18. Analysis Of Potentiometric Methods Used For Crack Detection In Forging Tools

    NASA Astrophysics Data System (ADS)

    Pilc, Jozef; Drbúl, Mário; Stančeková, Dana; Varga, Daniel; Martinček, Juraj; Kuždák, Viktor

    2015-12-01

    Increased use of forging tools in mass production causes their increased wear and creates pressure to design more efficient renovation process. Renovation is complicated because of the identification of cracks expanding from the surface to the core material. Given that the production of forging tools is expensive, caused by the cost of tool steels and the thermo-chemical treatment, it is important to design forging tool with its easy renovation in mind. It is important to choose the right renovation technology, which will be able to restore the instrument to its original state while maintaining financial rentability. Choosing the right technology is difficult because of nitrided and heat-treated surface for high hardness and wear resistance. Article discusses the use of non-destructive method of detecting cracks taking into account the size of the cracks formed during working process.

  19. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-08-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group quantity factors (PFGs) during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunch grasses to rhizome plexus and dense plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by Sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  20. Predicting parameters of degradation succession processes of Tibetan Kobresia grasslands

    NASA Astrophysics Data System (ADS)

    Lin, L.; Li, Y. K.; Xu, X. L.; Zhang, F. W.; Du, Y. G.; Liu, S. L.; Guo, X. W.; Cao, G. M.

    2015-11-01

    In the past two decades, increasing human activity (i.e., overgrazing) in the Tibetan Plateau has strongly influenced plant succession processes, resulting in the degradation of alpine grasslands. Therefore, it is necessary to diagnose the degree of degradation to enable implementation of appropriate management for sustainable exploitation and protection of alpine grasslands. Here, we investigated environmental factors and plant functional group (PFG) quantity factors during the alpine grassland succession processes. Principal component analysis (PCA) was used to identify the parameters indicative of degradation. We divided the entire degradation process into six stages. PFG types shifted from rhizome bunchgrasses to rhizome plexus and dense-plexus grasses during the degradation process. Leguminosae and Gramineae plants were replaced by sedges during the advanced stages of degradation. The PFGs were classified into two reaction groups: the grazing-sensitive group, containing Kobresia humilis Mey, and Gramineae and Leguminosae plants, and the grazing-insensitive group, containing Kobresia pygmaea Clarke. The first group was correlated with live root biomass in the surface soil (0-10 cm), whereas the second group was strongly correlated with mattic epipedon thickness and K. pygmaea characteristics. The degree of degradation of alpine meadows may be delineated by development of mattic epipedon and PFG composition. Thus, meadows could be easily graded and their use adjusted based on our scaling system, which would help prevent irreversible degradation of important grasslands. Because relatively few environmental factors are investigated, this approach can save time and labor to formulate a conservation management plan for degraded alpine meadows.

  1. A comparative method for processing immunological parameters: developing an "Immunogram"

    PubMed Central

    Ortolani, Riccardo; Bellavite, Paolo; Paiola, Fiorenza; Martini, Morena; Marchesini, Martina; Veneri, Dino; Franchini, Massimo; Chirumbolo, Salvatore; Tridente, Giuseppe; Vella, Antonio

    2010-01-01

    Background The immune system is a network of numerous cells that communicate both directly and indirectly with each other. The system is very sensitive to antigenic stimuli, which are memorised, and is closely connected with the endocrine and nervous systems. Therefore, in order to study the immune system correctly, it must be considered in all its complexity by analysing its components with multiparametric tools that take its dynamic characteristic into account. Methods We analysed lymphocyte subpopulations by using monoclonal antibodies with six different fluorochromes; the monoclonal panel employed included CD45, CD3, CD4, CD8, CD16, CD56, CD57, CD19, CD23, CD27, CD5, and HLA-DR. This panel has enabled us to measure many lymphocyte subsets in different states and with different functions: helper, suppressor, activated, effector, naïve, memory, and regulatory. A database was created to collect the values of immunological parameters of approximately 8,000 subjects who have undergone testing since 2000. When the distributions of the values for these parameters were compared with the medians of reference values published in the literature, we found that most of the values from the subjects included in the database were close to the medians in the literature. To process the data we used a comparative method that calculates the percentile rank of the values of a subject by comparing them with the values for others subjects of the same age. Results From this data processing we obtained a set of percentile ranks that represent the positions of the various parameters with regard to the data for other age-matched subjects included in the database. These positions, relative to both the absolute values and percentages, are plotted in a graph. We have called the final plot, which can be likened to that subject’s immunological fingerprint, an “Immunogram”. In order to perform the necessary calculations automatically, we developed dedicated software (Immunogramma) which

  2. Forging Collaborative Partnerships: The Waterloo Neighborhood Project.

    ERIC Educational Resources Information Center

    Gruenewald, Anne

    The Forging Collaborative Partnerships Project in Waterloo, Iowa is a collaborative venture to assist voluntary agencies in developing tools and strategies to strengthen collaborative relationships among public and nonprofit child welfare agencies and other key stakeholders as they adopt a family-focused philosophy. This monograph details how the…

  3. Forging Inclusive Solutions: Experiential Earth Charter Education

    ERIC Educational Resources Information Center

    Hill, Linda D.

    2010-01-01

    Forging Inclusive Solutions describes the aims, methodology and outcomes of Inclusive Leadership Adventures, an experiential education curriculum for exploring the Earth Charter. Experiential education builds meaningful relationships, skills, awareness and an inclusive community based on the Earth Charter principles. When we meet people where they…

  4. 29 CFR 1910.218 - Forging machines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specifications or dimensions shown in Table O-11. (2) Hydraulic forging presses. When dies are being changed or maintenance is being performed on the press, the following shall be accomplished: (i) The hydraulic pumps and... a manner that they will not fly off or fall in event of failure. (3) Hammers and presses. (i)...

  5. Effect of forging strain rate and deformation temperature on the mechanical properties of warm-worked 304L stainless steel

    SciTech Connect

    Switzner, N. T.; Van Tyne, C. J.; Mataya, M. C.

    2010-01-25

    Stainless steel 304L forgings were produced with four different types of production forging equipment – hydraulic press, mechanical press, screw press, and high-energy rate forging (HERF). Each machine imparted a different nominal strain rate during the deformation. The final forgings were done at the warm working (low hot working) temperatures of 816 °C, 843°C, and 871°C. The objectives of the study were to characterize and understand the effect of industrial strain rates (i.e. processing equipment), and deformation temperature on the mechanical properties for the final component. Some of the components were produced with an anneal prior to the final forging while others were deformed without the anneal. The results indicate that lower strain rates produced lower strength and higher ductility components, but the lower strain rate processes were more sensitive to deformation temperature variation and resulted in more within-part property variation. The highest strain rate process, HERF, resulted in slightly lower yield strength due to internal heating. Lower processing temperatures increased strength, decreased ductility but decreased within-part property variation. The anneal prior to the final forging produced a decrease in strength, a small increase in ductility, and a small decrease of within-part property variation.

  6. Effect of processing parameters on coconut oil expression efficiencies.

    PubMed

    Mpagalile, Joseph Jeremiah; Clarke, Brian

    2005-03-01

    The effect of process parameters on oil expression efficiency from freshly dried coconut gratings was investigated. The range of parameters investigated were: pressing time, 4 and 8 min; particle size, fine (0.6 - 1.18 mm) and coarse (1.18 - 2.36 mm); pressure, 3-33 MPa; moisture content, 3%, 7%, 11% and 15%; and temperature, 30 degrees C, 60 degrees C and 90 degrees C. Results showed that 8 min of pressing and finer particles both led to significantly (P < 0.05) higher oil expression efficiency. The pressure increase within the range 3-13 MPa led to significantly higher oil yields, with yields leveling off thereafter. The effect of pressure increase was highly associated with the moisture content of the gratings, and the optimum moisture content under low-pressure pressing was found to be 11%. A pressing temperature of 60 degrees C led to higher oil expression efficiency, whereas a further increase of temperature to 90 degrees C did not lead to a significant increase in oil yield.

  7. Distributed parameter approach to the dynamics of complex biological processes

    SciTech Connect

    Lee, T.T.; Wang, F.Y.; Newell, R.B.

    1999-10-01

    Modeling and simulation of a complex biological process for the removal of nutrients (nitrogen and phosphorus) from municipal wastewater are addressed. The model developed in this work employs a distributed-parameter approach to describe the behavior of components within three different bioreaction zones and the behavior of sludge in the anaerobic zone and soluble phosphate in the aerobic zone in two experiments. Good results are achieved despite the apparent plant-model mismatch, such as uncertainties with the behavior of phosphorus-accumulating organisms. Validation of the proposed secondary-settler model shows that it is superior to two state-of-the-art models in terms of the sum of the square relative errors.

  8. Characterization of a Viking Blade Fabricated by Traditional Forging Techniques

    NASA Astrophysics Data System (ADS)

    Vo, H.; Frazer, D.; Bailey, N.; Traylor, R.; Austin, J.; Pringle, J.; Bickel, J.; Connick, R.; Connick, W.; Hosemann, P.

    2016-09-01

    A team of students from the University of California, Berkeley, participated in a blade-smithing competition hosted by the Minerals, Metals, and Materials Society at the TMS 2015 144th annual meeting and exhibition. Motivated by ancient forging methods, the UC Berkeley team chose to fabricate our blade from historical smithing techniques utilizing naturally-occurring deposits of iron ore. This approach resulted in receiving the "Best Example of a Traditional Blade Process/Ore Smelting Technique" award for our blade named "Berkelium." First, iron-enriched sand was collected from local beaches. Magnetite (Fe3O4) was then extracted from the sand and smelted into individual high- and low-carbon steel ingots. Layers of high- and low-carbon steels were forge-welded together, predominantly by hand, to form a composite material. Optical microscopy, energy dispersive spectroscopy, and Vickers hardness mechanical testing were conducted at different stages throughout the blade-making process to evaluate the microstructure and hardness evolution during formation. It was found that the pre-heat-treated blade microstructure was composed of ferrite and pearlite, and contained many nonmetallic inclusions. A final heat treatment was performed, which caused the average hardness of the blade edge to increase by more than a factor of two, indicating a martensitic transformation.

  9. Optimisation of shock absorber process parameters using failure mode and effect analysis and genetic algorithm

    NASA Astrophysics Data System (ADS)

    Mariajayaprakash, Arokiasamy; Senthilvelan, Thiyagarajan; Vivekananthan, Krishnapillai Ponnambal

    2013-07-01

    The various process parameters affecting the quality characteristics of the shock absorber during the process were identified using the Ishikawa diagram and by failure mode and effect analysis. The identified process parameters are welding process parameters (squeeze, heat control, wheel speed, and air pressure), damper sealing process parameters (load, hydraulic pressure, air pressure, and fixture height), washing process parameters (total alkalinity, temperature, pH value of rinsing water, and timing), and painting process parameters (flowability, coating thickness, pointage, and temperature). In this paper, the process parameters, namely, painting and washing process parameters, are optimized by Taguchi method. Though the defects are reasonably minimized by Taguchi method, in order to achieve zero defects during the processes, genetic algorithm technique is applied on the optimized parameters obtained by Taguchi method.

  10. Technical bases for precipitate hydrolysis process operating parameters

    SciTech Connect

    Bannochie, C.J.

    1992-10-05

    This report provides the experimental data and rationale in support of the operating parameters for precipitate hydrolysis specified in WSRC-RP-92737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF).

  11. Effects of process parameters in plastic, metal, and ceramic injection molding processes

    NASA Astrophysics Data System (ADS)

    Lee, Shi W.; Ahn, Seokyoung; Whang, Chul Jin; Park, Seong Jin; Atre, Sundar V.; Kim, Jookwon; German, Randall M.

    2011-09-01

    Plastic injection molding has been widely used in the past and is a dominant forming approach today. As the customer demands require materials with better engineering properties that were not feasible with polymers, powder injection molding with metal and ceramic powders has received considerable attention in recent decades. To better understand the differences in the plastic injection molding, metal injection molding, and ceramic injection molding, the effects of the core process parameters on the process performances has been studied using the state-of-the-art computer-aided engineering (CAE) design tool, PIMSolver® The design of experiments has been conducted using the Taguchi method to obtain the relative contributions of various process parameters onto the successful operations.

  12. Snake River Plain FORGE Well Data for INEL-1

    DOE Data Explorer

    Robert Podgorney

    1979-03-01

    Well data for the INEL-1 well located in eastern Snake River Plain, Idaho. This data collection includes caliper logs, lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, full color logs, fracture analysis, photos, and rock strength parameters for the INEL-1 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  13. Snake River Plain FORGE Well Data for WO-2

    DOE Data Explorer

    Robert Podgorney

    1991-07-29

    Well data for the WO-2 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, temperature at depth data, neutron density and gamma data, and rock strength parameters for the WO-2 well. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  14. Optimized process parameters for fabricating metal particles reinforced 5083 Al composite by friction stir processing

    PubMed Central

    Bauri, Ranjit; Yadav, Devinder; Shyam Kumar, C.N.; Janaki Ram, G.D.

    2015-01-01

    Metal matrix composites (MMCs) exhibit improved strength but suffer from low ductility. Metal particles reinforcement can be an alternative to retain the ductility in MMCs (Bauri and Yadav, 2010; Thakur and Gupta, 2007) [1,2]. However, processing such composites by conventional routes is difficult. The data presented here relates to friction stir processing (FSP) that was used to process metal particles reinforced aluminum matrix composites. The data is the processing parameters, rotation and traverse speeds, which were optimized to incorporate Ni particles. A wide range of parameters covering tool rotation speeds from 1000 rpm to 1800 rpm and a range of traverse speeds from 6 mm/min to 24 mm/min were explored in order to get a defect free stir zone and uniform distribution of particles. The right combination of rotation and traverse speed was found from these experiments. Both as-received coarse particles (70 μm) and ball-milled finer particles (10 μm) were incorporated in the Al matrix using the optimized parameters. PMID:26566541

  15. Technical bases for precipitate hydrolysis process operating parameters. Revision 1

    SciTech Connect

    Bannochie, C.J.; Lambert, D.P.

    1992-11-09

    This report provides the experimental data and rationale in support of the operating parameters for tetraphenylborate precipitate hydrolysis specified in WSRC-RP-92-737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF). The program was in conjunction with reducing the nitrite ion level in DWPF feed.

  16. Technical bases for precipitate hydrolysis process operating parameters

    SciTech Connect

    Bannochie, C.J.; Lambert, D.P.

    1992-11-09

    This report provides the experimental data and rationale in support of the operating parameters for tetraphenylborate precipitate hydrolysis specified in WSRC-RP-92-737. The report is divided into two sections, the first dealing with lab-scale precipitate hydrolysis experimentation while the second part addresses large-scale runs conducted to demonstrate the revised operating parameters in the Precipitate Hydrolysis Experimental Facility (PHEF). The program was in conjunction with reducing the nitrite ion level in DWPF feed.

  17. TRITIUM AGING EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEEL

    SciTech Connect

    Morgan, M

    2008-04-14

    The fracture toughness properties of Type 21-6-9 stainless steel were measured for forgings in the unexposed, hydrogen-exposed, and tritium-exposed-and-aged conditions. Fracture toughness samples were cut from conventionally-forged and high-energy-rate-forged forward-extruded cylinders and mechanically tested at room temperature using ASTM fracture-toughness testing procedures. Some of the samples were exposed to either hydrogen or tritium gas (340 MPa, 623 K) prior to testing. Tritium-exposed samples were aged for up to seven years and tested periodically in order to measure the effect on fracture toughness of {sup 3}He from radioactive tritium decay. The results show that hydrogen-exposed and tritium-exposed samples had lower fracture- toughness values than unexposed samples and that fracture toughness decreased with increasing decay {sup 3}He content. Forged steels were more resistant to the embrittling effects of tritium and decay {sup 3}He than annealed steels, although their fracture-toughness properties depended on the degree of sensitization that occurred during processing. The fracture process was dominated by microvoid nucleation, growth and coalescence; however, the size and spacing of microvoids on the fracture surfaces were affected by hydrogen and tritium with the lowest-toughness samples having the smallest microvoids and finest spacing.

  18. Influence of Process Parameter on Grit Blasting as a Pretreatment Process for Thermal Spraying

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Linke, T. F.; Sommer, J.; Liao, X.

    2016-01-01

    In thermal spraying, uncoated substrates usually require roughening. As the most common roughening method, grit blasting increases the surface area and produces undercuts in almost all cases, which facilitate mechanical interlocking and thus promote the bonding between the substrate and coating. The effects of grit blasting parameters, i.e., the particle size, the blasting angle, the stand-off distance, and the pressure, on the resulting surface topography are investigated. Furthermore, the efficiency and wear behavior of the blasting media are analyzed. Influences of three different blasting media, corundum, alumina zirconia, and steel shot, on the surface roughening, are compared. By varying adjusted blasting parameters, different initial conditions (surface topography) are created. Subsequently, the substrate is coated, and the coating bond strength is measured. One of the main results of this publication is that alumina zirconia and steel grit show a longer lifetime than pure alumina as a blasting media. Moreover, it has been shown that the blasting parameters such as grain size, working pressure, and history (wear status) of the abrasive particles have a significant effect on the resulting surface topography. Additionally, systematical analysis in this study shows that the blasting parameters such as stand-off distance and blasting angle have a small influence on the results of the blasting process. Another important conclusion of this study is that the conventional surface parameters that have been analyzed in this study did not turn out to be suitable for describing the relationship between the surface topography of the substrate and resulting bond strength.

  19. 77 FR 23496 - Boundary Revision of Valley Forge National Historical Park

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-19

    ... National Park Service Boundary Revision of Valley Forge National Historical Park AGENCY: National Park... to the boundary of Valley Forge National Historical Park, pursuant to the authority specified below... ``Valley Forge National Historical Park Proposed Boundary Expansion, Montgomery County,...

  20. Sensor Data Acquisition and Processing Parameters for Human Activity Classification

    PubMed Central

    Bersch, Sebastian D.; Azzi, Djamel; Khusainov, Rinat; Achumba, Ifeyinwa E.; Ries, Jana

    2014-01-01

    It is known that parameter selection for data sampling frequency and segmentation techniques (including different methods and window sizes) has an impact on the classification accuracy. For Ambient Assisted Living (AAL), no clear information to select these parameters exists, hence a wide variety and inconsistency across today's literature is observed. This paper presents the empirical investigation of different data sampling rates, segmentation techniques and segmentation window sizes and their effect on the accuracy of Activity of Daily Living (ADL) event classification and computational load for two different accelerometer sensor datasets. The study is conducted using an ANalysis Of VAriance (ANOVA) based on 32 different window sizes, three different segmentation algorithm (with and without overlap, totaling in six different parameters) and six sampling frequencies for nine common classification algorithms. The classification accuracy is based on a feature vector consisting of Root Mean Square (RMS), Mean, Signal Magnitude Area (SMA), Signal Vector Magnitude (here SMV), Energy, Entropy, FFTPeak, Standard Deviation (STD). The results are presented alongside recommendations for the parameter selection on the basis of the best performing parameter combinations that are identified by means of the corresponding Pareto curve. PMID:24599189

  1. A study of selected parameters in solid propellant processing

    NASA Technical Reports Server (NTRS)

    Mckay, R. A.

    1986-01-01

    A propellant processing study to identify and control unplanned variation in composite solid propellant properties has shown that burning rate increases with process mixing but is not sensitve to process temperature. Different vertical propellant mixes of the same type were shown to provide different conditions of mixing at the pot wall because of differences in gearing, sometimes resulting in a stagnant wall film. Poor propellant produced in the stagnant wall film was attributed to poor mixing because of viscosity effects and wall film geometry. A control strategy based on briefly heating the wall was demonstrated. The study showed the need for improved process controls, good process instruments, and good propellant testing.

  2. Fallon FORGE 3D Geologic Model

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  3. Protostars: Forges of cosmic rays?

    NASA Astrophysics Data System (ADS)

    Padovani, M.; Marcowith, A.; Hennebelle, P.; Ferrière, K.

    2016-05-01

    processes, and on the formation of pre-biotic molecules.

  4. Roll compaction process modeling: transfer between equipment and impact of process parameters.

    PubMed

    Souihi, Nabil; Reynolds, Gavin; Tajarobi, Pirjo; Wikström, Håkan; Haeffler, Gunnar; Josefson, Mats; Trygg, Johan

    2015-04-30

    In this study, the roll compaction of an intermediate drug load formulation was performed using horizontally and vertically force fed roll compactors. The horizontally fed roll compactor was equipped with an instrumented roll technology allowing the direct measurement of normal stress at the roll surface, while the vertically fed roll compactor was equipped with a force gauge between the roll axes. Furthermore, characterization of ribbons, granules and tablets was also performed. Ribbon porosity was primarily found to be a function of normal stress, exhibiting a quadratic relationship thereof. A similar quadratic relationship was also observed between roll force and ribbon porosity of the vertically fed roll compactor. The predicted peak pressure (Pmax) using the Johanson model was found to be higher than the measured normal stress, however, the predicted Pmax correlated well with the ribbon relative density/porosity and the majority of downstream properties of granules and tablets, demonstrating its use as a scale-independent parameter. A latent variable model was developed for both the horizontal and vertical fed roll compactors to express ribbon porosity as a function of geometric and process parameters. The model validation, performed with new data, resulted in overall good predictions. This study successfully demonstrated the scale up/transfer between two different roll compactors and revealed that the combined use of design of experiments, latent variable models and in silico predictions result in better understanding of the critical process parameters in roll compaction.

  5. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2014-04-01 2014-04-01 false Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are...

  6. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles..., castings, extrusions and machined bodies) which have reached a stage in manufacture where they are...

  7. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2012-04-01 2010-04-01 true Forgings, castings, and... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are...

  8. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles..., castings, extrusions and machined bodies) which have reached a stage in manufacture where they are...

  9. 22 CFR 121.10 - Forgings, castings and machined bodies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Forgings, castings and machined bodies. 121.10... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings and machined bodies. Articles..., castings, extrusions and machined bodies) which have reached a stage in manufacture where they are...

  10. 76 FR 168 - Heavy Forged Hand Tools From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-03

    ... antidumping duty order on imports of heavy forged hand tools from China (65 FR 48962). Following second five... continuation of the antidumping duty orders on imports of heavy forged hand tools from China (71 FR 8276). The... part 207), as most recently amended at 74 FR 2847 (January 16, 2009). \\1\\ No response to this...

  11. 17. Forge building, fuel storage shed, and foundry, 1906 Photocopied ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. Forge building, fuel storage shed, and foundry, 1906 Photocopied from a photograph by Thomas S. Bronson, 'Group at Whitney Factory, 5 November 1906,' NHCHSL. The most reliable view of the fuel storage sheds and foundry, together with a view of the forge building. - Eli Whitney Armory, West of Whitney Avenue, Armory Street Vicinity, Hamden, New Haven County, CT

  12. Construction of a test bench for closed die forging

    NASA Astrophysics Data System (ADS)

    Batit, G.; Kaczmarek, B.; Ravassard, P.

    1984-03-01

    A swan neck press was equipped with hydraulic jacks to enable it to press and forge complex shapes in closed dies in one operation without wasting metal. Maximum closing stress is 250 kN, maximum pressing stress is 250 kN, maximum forging stress is 70 kN.

  13. 76 FR 50755 - Heavy Forged Hand Tools From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-16

    ... determined on April 8, 2011 that it would conduct expedited reviews (76 FR 31631, June 1, 2011). The... COMMISSION Heavy Forged Hand Tools From China Determinations On the basis of the record \\1\\ developed in the... antidumping duty orders on heavy forged hand tools from China would be likely to lead to continuation...

  14. View west of small tooling and forging dies in Blacksmith ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View west of small tooling and forging dies in Blacksmith Shop, Boilermakers Department, east side of building 57; during World War II approximately forty women were employed as blacksmith's forging a variety of small tools; these may be the tools they used. - Naval Base Philadelphia-Philadelphia Naval Shipyard, Structure Shop, League Island, Philadelphia, Philadelphia County, PA

  15. online Surveillance of Industrial Processes with Correlated Parameters

    1996-12-18

    SMP is a system for online surveillance of industrial processes or machinery for determination of the incipience or onset of abnormal operating conditions. SMP exploits the cross correlation between all of the sensors that are available on the system under surveillance to provide an extremely high sensitivity for annunciation of subtle disturbances in process variables.

  16. Physics and Technological Training in Bulgarian Forge Craft

    NASA Astrophysics Data System (ADS)

    Petkova, Petya N.; Velcheva, Keranka G.

    2010-01-01

    The contemporary world regenerates and preserves the traditions of decorative—applied art and the national crafts. This brings up young generation and helps them to uncover the sources of national culture. In the commonly educational system the technological training realizes succession of new methods for national and applied art. The aim is examination of the national crafts as technological processes for cultivation of different metal constructions. There are enforced physical laws here. Seven basic groups of forging methods consider in Bulgarian tradition craft as heat treatment, plastic deformation and applying of different tensions. This gives information about morphology of construction after applying of stress, enlarging or decreasing of the linear sizes, structure change and the change of physical and mechanical properties.

  17. Quench-Induced Stresses in AA2618 Forgings for Impellers: A Multiphysics and Multiscale Problem

    NASA Astrophysics Data System (ADS)

    Chobaut, Nicolas; Saelzle, Peter; Michel, Gilles; Carron, Denis; Drezet, Jean-Marie

    2015-05-01

    In the fabrication of heat-treatable aluminum parts such as AA2618 compressor impellers for turbochargers, solutionizing and quenching are key steps to obtain the required mechanical characteristics. Fast quenching is necessary to avoid coarse precipitation as it reduces the mechanical properties obtained after heat treatment. However, fast quenching induces residual stresses that can cause unacceptable distortions during machining. Furthermore, the remaining residual stresses after final machining can lead to unfavorable stresses in service. Predicting and controlling internal stresses during the whole processing from heat treatment to final machining is therefore of particular interest to prevent negative impacts of residual stresses. This problem is multiphysics because processes such as heat transfer during quenching, precipitation phenomena, thermally induced deformations, and stress generation are interacting and need to be taken into account. The problem is also multiscale as precipitates of nanosize form during quenching at locations where the cooling rate is too low. This precipitation affects the local yield strength of the material and thus impacts the level of macroscale residual stresses. A thermomechanical model accounting for precipitation in a simple but realistic way is presented. Instead of modelling precipitation that occurs during quenching, the model parameters are identified using a limited number of tensile tests achieved after representative interrupted cooling paths in a Gleeble machine. The simulation results are compared with as-quenched residual stresses in a forging measured by neutron diffraction.

  18. Effect of some process parameters in enzymatic dyeing of wool.

    PubMed

    Tzanov, Tzanko; Silva, Carla Joana; Zille, Andrea; Oliveira, Jovita; Cavaco-Paulo, Artur

    2003-10-01

    This article reports on the dyeing of wool using an enzymatic system comprising laccase; dye precursor, 2,5-diaminobenzenesulfonic acid; and dye modifiers, catechol and resorcinol. Enzymatic dyeing was performed as a batchwise process at the temperature and pH of maximum enzyme activity. The effects of the process variables reaction time, enzyme, and modifier concentration on fabric color were studied, according to an appropriate experimental design. Different hues and depths of shades could be achieved by varying the concentration of the modifiers and the time of laccase treatment. The duration of the enzymatic reaction appeared to be the most important factor in the dyeing process. Thus, the dyeing process, performed at low temperature and mild pH, was advantageous in terms of reduced enzyme and chemical dosage.

  19. Dimensionless Numbers Expressed in Terms of Common CVD Process Parameters

    NASA Technical Reports Server (NTRS)

    Kuczmarski, Maria A.

    1999-01-01

    A variety of dimensionless numbers related to momentum and heat transfer are useful in Chemical Vapor Deposition (CVD) analysis. These numbers are not traditionally calculated by directly using reactor operating parameters, such as temperature and pressure. In this paper, these numbers have been expressed in a form that explicitly shows their dependence upon the carrier gas, reactor geometry, and reactor operation conditions. These expressions were derived for both monatomic and diatomic gases using estimation techniques for viscosity, thermal conductivity, and heat capacity. Values calculated from these expressions compared well to previously published values. These expressions provide a relatively quick method for predicting changes in the flow patterns resulting from changes in the reactor operating conditions.

  20. Implant for in-vivo parameter monitoring, processing and transmitting

    SciTech Connect

    Ericson, Milton N.; McKnight, Timothy E.; Smith, Stephen F.; Hylton, James O.

    2009-11-24

    The present invention relates to a completely implantable intracranial pressure monitor, which can couple to existing fluid shunting systems as well as other internal monitoring probes. The implant sensor produces an analog data signal which is then converted electronically to a digital pulse by generation of a spreading code signal and then transmitted to a location outside the patient by a radio-frequency transmitter to an external receiver. The implanted device can receive power from an internal source as well as an inductive external source. Remote control of the implant is also provided by a control receiver which passes commands from an external source to the implant system logic. Alarm parameters can be programmed into the device which are capable of producing an audible or visual alarm signal. The utility of the monitor can be greatly expanded by using multiple pressure sensors simultaneously or by combining sensors of various physiological types.

  1. Hot Superplastic Powder Forging for Transparent nanocrystalline Ceramics

    SciTech Connect

    Cannon, W. Roger

    2006-05-22

    The program explored a completely new, economical method of manufacturing nanocrystalline ceramics, Hot Superplastic Powder Forging (HSPF). The goal of the work was the development of nanocrystalline/low porosity optically transparent zirconia/alumina. The high optical transparency should result from lack of grain boundary scattering since grains will be smaller than one tenth the wavelength of light and from elimination of porosity. An important technological potential for this process is manufacturing of envelopes for high-pressure sodium vapor lamps. The technique for fabricating monolithic nanocrystalline material does not begin with powder whose particle diameter is <100 nm as is commonly done. Instead it begins with powder whose particle diameter is on the order of 10-100 microns but contains nanocrystalline crystallites <<100 nm. Spherical particles are quenched from a melt and heat treated to achieve the desired microstructure. Under a moderate pressure within a die or a mold at temperatures of 1100C to 1300C densification is by plastic flow of superplastic particles. A nanocrystalline microstructure results, though some features are greater than 100nm. It was found, for instance, that in the fully dense Al2O3-ZrO2 eutectic specimens that a bicontinuous microstructure exists containing <100 nm ZrO2 particles in a matrix of Al2O3 grains extending over 1-2 microns. Crystallization, growth, phase development and creep during hot pressing and forging were studied for several compositions and so provided some details on development of polycrystalline microstructure from heating quenched ceramics.

  2. Meta-Model Based Optimisation Algorithms for Robust Optimization of 3D Forging Sequences

    SciTech Connect

    Fourment, Lionel

    2007-04-07

    In order to handle costly and complex 3D metal forming optimization problems, we develop a new optimization algorithm that allows finding satisfactory solutions within less than 50 iterations (/function evaluation) in the presence of local extrema. It is based on the sequential approximation of the problem objective function by the Meshless Finite Difference Method (MFDM). This changing meta-model allows taking into account the gradient information, if available, or not. It can be easily extended to take into account uncertainties on the optimization parameters. This new algorithm is first evaluated on analytic functions, before being applied to a 3D forging benchmark, the preform tool shape optimization that allows minimizing the potential of fold formation during the two-stepped forging sequence.

  3. The effects of forming parameters on conical ring rolling process.

    PubMed

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

  4. The Effects of Forming Parameters on Conical Ring Rolling Process

    PubMed Central

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the “obtuse angle zone” of ring's cross-section are higher than those at “acute angle zone”; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained. PMID:25202716

  5. A stochastic process approach of the drake equation parameters

    NASA Astrophysics Data System (ADS)

    Glade, Nicolas; Ballet, Pascal; Bastien, Olivier

    2012-04-01

    The number N of detectable (i.e. communicating) extraterrestrial civilizations in the Milky Way galaxy is usually calculated by using the Drake equation. This equation was established in 1961 by Frank Drake and was the first step to quantifying the Search for ExtraTerrestrial Intelligence (SETI) field. Practically, this equation is rather a simple algebraic expression and its simplistic nature leaves it open to frequent re-expression. An additional problem of the Drake equation is the time-independence of its terms, which for example excludes the effects of the physico-chemical history of the galaxy. Recently, it has been demonstrated that the main shortcoming of the Drake equation is its lack of temporal structure, i.e., it fails to take into account various evolutionary processes. In particular, the Drake equation does not provides any error estimation about the measured quantity. Here, we propose a first treatment of these evolutionary aspects by constructing a simple stochastic process that will be able to provide both a temporal structure to the Drake equation (i.e. introduce time in the Drake formula in order to obtain something like N(t)) and a first standard error measure.

  6. Parameter Optimization of Nitriding Process Using Chemical Kinetics

    NASA Astrophysics Data System (ADS)

    Özdemir, İ. Bedii; Akar, Firat; Lippmann, Nils

    2016-09-01

    Using the dynamics of chemical kinetics, an investigation to search for an optimum condition for a gas nitriding process is performed over the solution space spanned by the initial temperature and gas composition of the furnace. For a two-component furnace atmosphere, the results are presented in temporal variations of gas concentrations and the nitrogen coverage on the surface. It seems that the exploitation of the nitriding kinetics can provide important feedback for setting the model-based control algorithms. The present work shows that when the nitrogen gas concentration is not allowed to exceed 6 pct, the Nad coverage can attain maximum values as high as 0.97. The time evolution of the Nad coverage also reveals that, as long as the temperature is above the value where nitrogen poisoning of the surface due to the low-temperature adsorption of excess nitrogen occurs, the initial ammonia content in the furnace atmosphere is much more important in the nitriding process than is the initial temperature.

  7. Factors Affecting Scale Adhesion on Steel Forgings

    NASA Astrophysics Data System (ADS)

    Zitterman, J. A.; Bacco, R. P.; Boggs, W. E.

    1982-04-01

    Occasionally, undesirable "sticky" adherent scale forms on low-carbon steel during reheating for hot forging. The mechanical abrading or chemical pickling required to remove this scale adds appreciably to the fabrication cost. Characterization of the steel-scale system by metallographic examination, x-ray diffraction, and electron-probe microanalysis revealed that nickel, silicon, and/or sulfur might be involved in the mechanism of sticky-scale formation. Laboratory reheating tests were conducted on steels with varied concentrations of nickel and silicon in atmospheres simulating those resulting from burning natural gas or sulfur-bearing fuels. Subsequent characterization of the scale formed during the tests tends to confirm that the composition of the steel, especially increased nickel and silicon contents, and the presence of the sulfur in the furnace atmosphere cause the formation of this undesirable scale.

  8. Parallel investigation of double forged pure tungsten samples irradiated in three DPF devices

    NASA Astrophysics Data System (ADS)

    Gribkov, V. A.; Paduch, M.; Zielinska, E.; Laas, T.; Shirokova, V.; Väli, B.; Paju, J.; Pimenov, V. N.; Demina, E. V.; Latyshev, S. V.; Niemela, J.; Crespo, M.-L.; Cicuttin, A.; Talab, A. A.; Pokatilov, A.; Parker, M.

    2015-08-01

    The double forged pure tungsten (W) samples (supplied by IAEA CRP from the FZJ team in Juelich, Germany) were irradiated in DPF (dense plasma focus) devices PF-12, "Bora" and PF-1000 by hot plasma and fast ion streams. We have used the following analytical methods: microscopy (optical and scanning electron), X-ray photoelectron spectroscopy, electrical conductivity and microroughness measurements. The damage dependence of the tungsten grades on irradiation conditions and power flux densities of irradiation processes is discussed.

  9. A Comparison between the Properties of Solid Cylinders and Tube Products in Multi-Pass Hot Radial Forging Using Finite Element Method

    NASA Astrophysics Data System (ADS)

    Abedian, A.; Poursina, M.; Golestanian, H.

    2007-05-01

    Radial forging is an open die forging process used for reducing the diameter of shafts, tubes, stepped shafts and axels, and creating internal profiles for tubes such as rifling of gun barrels. In this work, a comprehensive study of multi-pass hot radial forging of short hollow and solid products are presented using 2-D axisymmetric finite element simulation. The workpiece is modeled as an elastic-viscoplastic material. A mixture of Coulomb law and constant limit shear is used to model the die-workpiece and mandrel-workpiece contacts. Thermal effects are also taken in to account. Three-pass radial forging of solid cylinders and tube products are considered. Temperature, stress, strain and metal flow distribution are obtained in each pass through thermo-mechanical simulation. The numerical results are compared with available experimental data and are in good agreement with them.

  10. Optimization of process parameters for the manufacturing of rocket casings: A study using processing maps

    NASA Astrophysics Data System (ADS)

    Avadhani, G. S.

    2003-12-01

    Maraging steels possess ultrahigh strength combined with ductility and toughness and could be easily fabricated and heat-treated. Bulk metalworking of maraging steels is an important step in the component manufacture. To optimize the hot-working parameters (temperature and strain rate) for the ring rolling process of maraging steel used for the manufacture of rocket casings, a systematic study was conducted to characterize the hot working behavior by developing processing maps for γ-iron and an indigenous 250 grade maraging steel. The hot deformation behavior of binary alloys of iron with Ni, Co, and Mo, which are major constituents of maraging steel, is also studied. Results from the investigation suggest that all the materials tested exhibit a domain of dynamic recrystallization (DRX). From the instability maps, it was revealed that strain rates above 10 s-1 are not suitable for hot working of these materials. An important result from the stress-strain behavior is that while Co strengthens γ-iron, Ni and Mo cause flow softening. Temperatures around 1125 °C and strain rate range between 0.001 and 0.1 s-1 are suitable for the hot working of maraging steel in the DRX domain. Also, higher strain rates may be used in the meta-dynamic recrystallization domain above 1075 °C for high strain rate applications such as ring rolling. The microstructural mechanisms identified from the processing maps along with grain size analyses and hot ductility measurements could be used to design hot-working schedules for maraging steel.

  11. 6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. NORTH END OF MACHINE SHOP. FORGE SHOP (HAER No. CA-326-K) ON LEFT, FORD PLANT IN DISTANCE, NE BY 60. - Rosie the Riveter National Historical Park, Machine Shop, 1311 Canal Boulevard, Richmond, Contra Costa County, CA

  12. DETAIL VIEW OF BLACKSMITH'S FORGE AND WORK AREA ON WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF BLACKSMITH'S FORGE AND WORK AREA ON WEST SIDE OF UPPER TRAM TERMINAL, LOOKING EAST. FORGE IS IN FOREGROUND, WITH THE ANVIL BLOCK JUST TO THE RIGHT AND BEHIND IT. A TRAM CAR IS UPSIDE DOWN TO THE LEFT OF THE FORGE. THE PIPE GOING INTO THE FORGE ON THE RIGHT CARRIED COMPRESSED AIR TO BLOW THE COALS. AT CENTER RIGHT ON THE TRAM TERMINAL ARE THE OPENING AND CLOSING MECHANISMS FOR THE ORE BUCKETS. AT CENTER LEFT IS A BRAKE WHEEL. THE ANCHOR POINTS FOR THE STATIONARY TRAM CABLES ARE JUST BELOW THIS WHEEL. THE FRONT END OF THE TERMINAL IS JUST OFF FRAME ON THE RIGHT. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  13. View facing east of top of quarry wall with forge ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View facing east of top of quarry wall with forge site in foreground - Granite Hill Plantation, Quarry No. 4, South side of State Route 16, 1.3 miles northeast east of Sparta, Sparta, Hancock County, GA

  14. Relationships Between Process Parameters, Microstructure, and Adhesion Strength of HVOF Sprayed IN718 Coatings

    NASA Astrophysics Data System (ADS)

    Lyphout, Christophe; Nylén, Per; Östergren, Lars

    2011-01-01

    Fundamental understanding of relationships between process parameters, particle in-flight characteristics, and adhesion strength of HVOF sprayed coatings is important to achieve the high coating adhesion that is needed in aeronautic repair applications. In this study, statistical Design of Experiments (DoE) was used to identify the most important process parameters that influence adhesion strength of IN718 coatings sprayed on IN718 substrates. Special attention was given to the parameters combustion ratio, total gas mass flow, stand-off distance and external cooling, since these parameters were assumed to have a significant influence on particle temperature and velocity. Relationships between these parameters and coating microstructure were evaluated to fundamentally understand the relationships between process parameters and adhesion strength.

  15. Quenching and Cold-Work Residual Stresses in Aluminum Hand Forgings : Contour Method Measurement and FEM Prediction

    SciTech Connect

    Prime, M. B.; Newborn, M. A.; Balog, J. A.

    2003-01-01

    The cold-compression stress relief process used to reduce the quench-induced stresses in high-strength aerospace aluminum alloy forgings does not fully relieve the stresses. This study measured and predicted the residual stress in 7050-T74 (solution heat treated, quenched, and artificially overaged) and 7050-T7452 (cold compressed prior to aging) hand forgings. The manufacturing process was simulated by finite element analysis. First, a thermal analysis simulated the quench using appropriate thermal boundary conditions and temperature dependent material properties. Second, a structural analysis used the thermal history and a temperature and strain-rate dependent constitutive model to predict the stresses after quenching. Third, the structural analysis was continued to simulate the multiple cold compressions of the stress relief process. Experimentally, the residual stresses in the forgings were mapped using the contour method, which involved cutting the forgings using wire EDM and then measuring the contour of the cut surface using a CMM. Multiple cuts were used to map different stress components. The results show a spatially periodic variation of stresses that results from the periodic nature of the cold work stress relief process. The results compare favorably with the finite element prediction of the stresses.

  16. An Advanced User Interface Approach for Complex Parameter Study Process Specification in the Information Power Grid

    NASA Technical Reports Server (NTRS)

    Yarrow, Maurice; McCann, Karen M.; Biswas, Rupak; VanderWijngaart, Rob; Yan, Jerry C. (Technical Monitor)

    2000-01-01

    The creation of parameter study suites has recently become a more challenging problem as the parameter studies have now become multi-tiered and the computational environment has become a supercomputer grid. The parameter spaces are vast, the individual problem sizes are getting larger, and researchers are now seeking to combine several successive stages of parameterization and computation. Simultaneously, grid-based computing offers great resource opportunity but at the expense of great difficulty of use. We present an approach to this problem which stresses intuitive visual design tools for parameter study creation and complex process specification, and also offers programming-free access to grid-based supercomputer resources and process automation.

  17. T3PS v1.0: Tool for Parallel Processing in Parameter Scans

    NASA Astrophysics Data System (ADS)

    Maurer, Vinzenz

    2016-01-01

    T3PS is a program that can be used to quickly design and perform parameter scans while easily taking advantage of the multi-core architecture of current processors. It takes an easy to read and write parameter scan definition file format as input. Based on the parameter ranges and other options contained therein, it distributes the calculation of the parameter space over multiple processes and possibly computers. The derived data is saved in a plain text file format readable by most plotting software. The supported scanning strategies include: grid scan, random scan, Markov Chain Monte Carlo, numerical optimization. Several example parameter scans are shown and compared with results in the literature.

  18. Snake River Plain FORGE Site Characterization Data

    DOE Data Explorer

    Robert Podgorney

    2016-04-18

    The site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. This collection includes data on seismic events, groundwater, geomechanical models, gravity surveys, magnetics, resistivity, magnetotellurics (MT), rock physics, stress, the geologic setting, and supporting documentation, including several papers. Also included are 3D models (Petrel and Jewelsuite) of the proposed site. Data for wells INEL-1, WO-2, and USGS-142 have been included as links to separate data collections. These data have been assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL). Other contributors include the National Renewable Energy Laboratory (NREL), Lawrence Livermore National Laboratory (LLNL), the Center for Advanced Energy Studies (CEAS), the University of Idaho, Idaho State University, Boise State University, University of Wyoming, University of Oklahoma, Energy and Geoscience Institute-University of Utah, US Geothermal, Baker Hughes Campbell Scientific Inc., Chena Power, US Geological Survey (USGS), Idaho Department of Water Resources, Idaho Geological Survey, and Mink GeoHydro.

  19. A split-optimization approach for obtaining multiple solutions in single-objective process parameter optimization.

    PubMed

    Rajora, Manik; Zou, Pan; Yang, Yao Guang; Fan, Zhi Wen; Chen, Hung Yi; Wu, Wen Chieh; Li, Beizhi; Liang, Steven Y

    2016-01-01

    It can be observed from the experimental data of different processes that different process parameter combinations can lead to the same performance indicators, but during the optimization of process parameters, using current techniques, only one of these combinations can be found when a given objective function is specified. The combination of process parameters obtained after optimization may not always be applicable in actual production or may lead to undesired experimental conditions. In this paper, a split-optimization approach is proposed for obtaining multiple solutions in a single-objective process parameter optimization problem. This is accomplished by splitting the original search space into smaller sub-search spaces and using GA in each sub-search space to optimize the process parameters. Two different methods, i.e., cluster centers and hill and valley splitting strategy, were used to split the original search space, and their efficiency was measured against a method in which the original search space is split into equal smaller sub-search spaces. The proposed approach was used to obtain multiple optimal process parameter combinations for electrochemical micro-machining. The result obtained from the case study showed that the cluster centers and hill and valley splitting strategies were more efficient in splitting the original search space than the method in which the original search space is divided into smaller equal sub-search spaces.

  20. A split-optimization approach for obtaining multiple solutions in single-objective process parameter optimization.

    PubMed

    Rajora, Manik; Zou, Pan; Yang, Yao Guang; Fan, Zhi Wen; Chen, Hung Yi; Wu, Wen Chieh; Li, Beizhi; Liang, Steven Y

    2016-01-01

    It can be observed from the experimental data of different processes that different process parameter combinations can lead to the same performance indicators, but during the optimization of process parameters, using current techniques, only one of these combinations can be found when a given objective function is specified. The combination of process parameters obtained after optimization may not always be applicable in actual production or may lead to undesired experimental conditions. In this paper, a split-optimization approach is proposed for obtaining multiple solutions in a single-objective process parameter optimization problem. This is accomplished by splitting the original search space into smaller sub-search spaces and using GA in each sub-search space to optimize the process parameters. Two different methods, i.e., cluster centers and hill and valley splitting strategy, were used to split the original search space, and their efficiency was measured against a method in which the original search space is split into equal smaller sub-search spaces. The proposed approach was used to obtain multiple optimal process parameter combinations for electrochemical micro-machining. The result obtained from the case study showed that the cluster centers and hill and valley splitting strategies were more efficient in splitting the original search space than the method in which the original search space is divided into smaller equal sub-search spaces. PMID:27625978

  1. Multiresponse Optimization of Process Parameters in Turning of GFRP Using TOPSIS Method

    PubMed Central

    Parida, Arun Kumar; Routara, Bharat Chandra

    2014-01-01

    Taguchi's design of experiment is utilized to optimize the process parameters in turning operation with dry environment. Three parameters, cutting speed (v), feed (f), and depth of cut (d), with three different levels are taken for the responses like material removal rate (MRR) and surface roughness (Ra). The machining is conducted with Taguchi L9 orthogonal array, and based on the S/N analysis, the optimal process parameters for surface roughness and MRR are calculated separately. Considering the larger-the-better approach, optimal process parameters for material removal rate are cutting speed at level 3, feed at level 2, and depth of cut at level 3, that is, v3-f2-d3. Similarly for surface roughness, considering smaller-the-better approach, the optimal process parameters are cutting speed at level 1, feed at level 1, and depth of cut at level 3, that is, v1-f1-d3. Results of the main effects plot indicate that depth of cut is the most influencing parameter for MRR but cutting speed is the most influencing parameter for surface roughness and feed is found to be the least influencing parameter for both the responses. The confirmation test is conducted for both MRR and surface roughness separately. Finally, an attempt has been made to optimize the multiresponses using technique for order preference by similarity to ideal solution (TOPSIS) with Taguchi approach. PMID:27437503

  2. A Study on the Influence of Process Parameters on the Viscoelastic Properties of ABS Components Manufactured by FDM Process

    NASA Astrophysics Data System (ADS)

    Dakshinamurthy, Devika; Gupta, Srinivasa

    2016-06-01

    Fused Deposition Modelling (FDM) is a fast growing Rapid Prototyping (RP) technology due to its ability to build parts having complex geometrical shape in reasonable time period. The quality of built parts depends on many process variables. In this study, the influence of three FDM process parameters namely, slice height, raster angle and raster width on viscoelastic properties of Acrylonitrile Butadiene Styrene (ABS) RP-specimen is studied. Statistically designed experiments have been conducted for finding the optimum process parameter setting for enhancing the storage modulus. Dynamic Mechanical Analysis has been used to understand the viscoelastic properties at various parameter settings. At the optimal parameter setting the storage modulus and loss modulus of the ABS-RP specimen was 1008 and 259.9 MPa respectively. The relative percentage contribution of slice height and raster width on the viscoelastic properties of the FDM-RP components was found to be 55 and 31 % respectively.

  3. Effects of Processing Parameters on the Forming Quality of C-Shaped Thermosetting Composite Laminates in Hot Diaphragm Forming Process

    NASA Astrophysics Data System (ADS)

    Bian, X. X.; Gu, Y. Z.; Sun, J.; Li, M.; Liu, W. P.; Zhang, Z. G.

    2013-10-01

    In this study, the effects of processing temperature and vacuum applying rate on the forming quality of C-shaped carbon fiber reinforced epoxy resin matrix composite laminates during hot diaphragm forming process were investigated. C-shaped prepreg preforms were produced using a home-made hot diaphragm forming equipment. The thickness variations of the preforms and the manufacturing defects after diaphragm forming process, including fiber wrinkling and voids, were evaluated to understand the forming mechanism. Furthermore, both interlaminar slipping friction and compaction behavior of the prepreg stacks were experimentally analyzed for showing the importance of the processing parameters. In addition, autoclave processing was used to cure the C-shaped preforms to investigate the changes of the defects before and after cure process. The results show that the C-shaped prepreg preforms with good forming quality can be achieved through increasing processing temperature and reducing vacuum applying rate, which obviously promote prepreg interlaminar slipping process. The process temperature and forming rate in hot diaphragm forming process strongly influence prepreg interply frictional force, and the maximum interlaminar frictional force can be taken as a key parameter for processing parameter optimization. Autoclave process is effective in eliminating voids in the preforms and can alleviate fiber wrinkles to a certain extent.

  4. Roles of the influential parameters in the incineration process using centrality concept of graph theory

    NASA Astrophysics Data System (ADS)

    Awatif, W. A.; Sabariah, B.; Rashid, M.; Normah, M.

    2014-06-01

    The dioxin furan is byproducts of the incineration process in which becomes a major concern to the public. In this paper, the role of the influential parameters affecting the Dioxin Furan Emission (DFE) in the incineration process was discussed. A total of seven selected incinerators in Malaysia were considered in the study. The incineration plant was categorized into the type of waste incinerated during the process, i.e. sludge and biomedical waste. Six parameters comprise of temperature, nitrogen oxide, sulphur dioxide, carbon dioxide, oxygen and moisture content were identified as the influential parameters affecting the DFE of the incineration process. Multiple Linear Regression (MLR) models were initially developed to relate the DFE and the influential parameters in each category of incinerators. These models served as the basis for the construction of the graphical models representing the interaction of the influential parameters in the process. Centrality concept was then used on these graphical models to describe the role of the parameters in the process.

  5. Optimizing Friction Stir Welding via Statistical Design of Tool Geometry and Process Parameters

    NASA Astrophysics Data System (ADS)

    Blignault, C.; Hattingh, D. G.; James, M. N.

    2012-06-01

    This article considers optimization procedures for friction stir welding (FSW) in 5083-H321 aluminum alloy, via control of weld process parameters and tool design modifications. It demonstrates the potential utility of the "force footprint" (FF) diagram in providing a real-time graphical user interface (GUI) for process optimization of FSW. Multiple force, torque, and temperature responses were recorded during FS welding using 24 different tool pin geometries, and these data were statistically analyzed to determine the relative influence of a number of combinations of important process and tool geometry parameters on tensile strength. Desirability profile charts are presented, which show the influence of seven key combinations of weld process variables on tensile strength. The model developed in this study allows the weld tensile strength to be predicted for other combinations of tool geometry and process parameters to fall within an average error of 13%. General guidelines for tool profile selection and the likelihood of influencing weld tensile strength are also provided.

  6. High Temperature, Slow Strain Rate Forging of Advanced Disk Alloy ME3

    NASA Technical Reports Server (NTRS)

    Gabb, Timothy P.; OConnor, Kenneth

    2001-01-01

    The advanced disk alloy ME3 was designed in the HSR/EPM disk program to have extended durability at 1150 to 1250 F in large disks. This was achieved by designing a disk alloy and process producing balanced monotonic, cyclic, and time-dependent mechanical properties. combined with robust processing and manufacturing characteristics. The resulting baseline alloy, processing, and supersolvus heat treatment produces a uniform, relatively fine mean grain size of about ASTM 7, with as-large-as (ALA) grain size of about ASTM 3. There is a long term need for disks with higher rim temperature capabilities than 1250 F. This would allow higher compressor exit (T3) temperatures and allow the full utilization of advanced combustor and airfoil concepts under development. Several approaches are being studied that modify the processing and chemistry of ME3, to possibly improve high temperature properties. Promising approaches would be applied to subscale material, for screening the resulting mechanical properties at these high temperatures. n obvious path traditionally employed to improve the high temperature and time-dependent capabilities of disk alloys is to coarsen the grain size. A coarser grain size than ASTM 7 could potentially be achieved by varying the forging conditions and supersolvus heat treatment. The objective of this study was to perform forging and heat treatment experiments ("thermomechanical processing experiments") on small compression test specimens of the baseline ME3 composition, to identify a viable forging process allowing significantly coarser grain size targeted at ASTM 3-5, than that of the baseline, ASTM 7.

  7. Modelling of Viscoplastic Behaviour of IN718 Under Hot Forging Conditions

    SciTech Connect

    Lin, Y. P.; Lin, J.; Dean, T. A.; Brown, P. D.

    2007-04-07

    The mechanical properties of IN718 are directly related to microstructure such as grain size and the hardening mechanisms, which are effective during thermomechanical processing and subsequent heat treatment. In this study a set of unified viscoplastic constitutive equations were determined for IN718 from experimental data of hot forging conditions. Techniques were developed to analyse the reliability and consistency of the experimental data derived from different previous publications. In addition to viscoplastic flow of the material, the determined material model can be used to predict the evolution of dislocations, recrystallisation and grain size occurring during thermomechanical processing.

  8. Effect of spray drying processing parameters on the insecticidal activity of two encapsulated formulations of baculovirus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this work was to evaluate the effect of spray dryer processing parameters on the process yield and insecticidal activity of baculovirus to support the development of this beneficial group of microbes as biopesticides. For each of two baculoviruses [granulovirus (GV) from Pieris rapae (L....

  9. Effects of the Deslagging Process on some Physicochemical Parameters of Honey

    PubMed Central

    Ranjbar, Ali Mohammad; Sadeghpour, Omid; Khanavi, Mahnaz; Shams Ardekani, Mohammad Reza; Moloudian, Hamid; Hajimahmoodi, Mannan

    2015-01-01

    Some physicochemical parameters of honey have been introduced by the International Honey Commission to evaluate its quality and origin but processes such as heating and filtering can affect these parameters. In traditional Iranian medicine, deslagging process involves boiling honey in an equal volume of water and removing the slag formed during process. The aim of this study was to determine the effects of deslagging process on parameters of color intensity, diastase evaluation, electrical conductivity, pH, free acidity, refractive index, hydroxy methyl furfural (HMF), proline and water contents according to the International Honey Committee (IHC) standards. The results showed that deslagged honey was significantly different from control honey in terms of color intensity, pH, diastase number, HMF and proline content. It can be concluded that the new standards are needed to regulate deslagged honey. PMID:25901175

  10. West Flank Coso FORGE Magnetotelluric 3D Data

    DOE Data Explorer

    Doug Blankenship

    2016-01-01

    This is the 3D version of the MT data for the West Flank FORGE area.The Coso geothermal field has had three Magnetotelluric (MT) datasets collected including surveys in 2003, 2006, and 2011. The final collection, in 2011, expanded the survey to the west and covers the West Flank of FORGE area.This most recent data set was collected by Schlumberger/WesternGeco and inverted by the WesternGeco GeoSolutions Integrated EM Center of Excellence in Milan, Italy; the 2003 and 2006 data were integrated for these inversions in the present study.

  11. Mechanistic basis for the effects of process parameters on quality attributes in high shear wet granulation.

    PubMed

    Badawy, Sherif I F; Narang, Ajit S; LaMarche, Keirnan; Subramanian, Ganeshkumar; Varia, Sailesh A

    2012-12-15

    Three model compounds were used to study the effect of process parameters on in-process critical material attributes and a final product critical quality attribute. The effect of four process parameters was evaluated using design of experiment approach. Batches were characterized for particle size distribution, density (porosity), flow, compaction, and dissolution rate. The mechanisms of the effect of process parameters on primary granule properties (size and density) were proposed. Water amount showed significant effect on granule size and density. The effect of impeller speed was dependent on the granule mechanical properties and efficiency of liquid distribution in the granulator. Blend density was found to increase rapidly during wet massing. Liquid addition rate was the least consequential factor and showed minimal impact on granule density and growth. Correlations of primary properties with granulation bulk powder properties (compaction and flow) and tablet dissolution were also identified. The effects of the process parameters on the bulk powder properties and tablet dissolution were consistent with their proposed link to primary granule properties. Understanding the impact of primary granule properties on bulk powder properties and final product critical quality attributes provides the basis for modulating granulation parameters in order to optimize product performance. PMID:22981985

  12. On selecting a prior for the precision parameter of Dirichlet process mixture models

    USGS Publications Warehouse

    Dorazio, R.M.

    2009-01-01

    In hierarchical mixture models the Dirichlet process is used to specify latent patterns of heterogeneity, particularly when the distribution of latent parameters is thought to be clustered (multimodal). The parameters of a Dirichlet process include a precision parameter ?? and a base probability measure G0. In problems where ?? is unknown and must be estimated, inferences about the level of clustering can be sensitive to the choice of prior assumed for ??. In this paper an approach is developed for computing a prior for the precision parameter ?? that can be used in the presence or absence of prior information about the level of clustering. This approach is illustrated in an analysis of counts of stream fishes. The results of this fully Bayesian analysis are compared with an empirical Bayes analysis of the same data and with a Bayesian analysis based on an alternative commonly used prior.

  13. Physical parameters for proton induced K-, L-, and M-shell ionization processes

    NASA Astrophysics Data System (ADS)

    Shehla; Puri, Sanjiv

    2016-10-01

    The proton induced atomic inner-shell ionization processes comprising radiative and non-radiative transitions are characterized by physical parameters, namely, the proton ionization cross sections, X-ray emission rates, fluorescence yields and Coster-Kronig (CK) transition probabilities. These parameters are required to calculate the K/L/M shell X-ray production (XRP) cross sections and relative X-ray intensity ratios, which in turn are required for different analytical applications. The current status of different physical parameters is presented in this report for use in various applications.

  14. Applications and perspectives of multi-parameter flow cytometry to microbial biofuels production processes.

    PubMed

    da Silva, Teresa Lopes; Roseiro, José Carlos; Reis, Alberto

    2012-04-01

    Conventional microbiology methods used to monitor microbial biofuels production are based on off-line analyses. The analyses are, unfortunately, insufficient for bioprocess optimization. Real time process control strategies, such as flow cytometry (FC), can be used to monitor bioprocess development (at-line) by providing single cell information that improves process model formulation and validation. This paper reviews the current uses and potential applications of FC in biodiesel, bioethanol, biomethane, biohydrogen and fuel cell processes. By highlighting the inherent accuracy and robustness of the technique for a range of biofuel processing parameters, more robust monitoring and control may be implemented to enhance process efficiency.

  15. Mammalian Cell Culture Process for Monoclonal Antibody Production: Nonlinear Modelling and Parameter Estimation

    PubMed Central

    Selişteanu, Dan; Șendrescu, Dorin; Georgeanu, Vlad

    2015-01-01

    Monoclonal antibodies (mAbs) are at present one of the fastest growing products of pharmaceutical industry, with widespread applications in biochemistry, biology, and medicine. The operation of mAbs production processes is predominantly based on empirical knowledge, the improvements being achieved by using trial-and-error experiments and precedent practices. The nonlinearity of these processes and the absence of suitable instrumentation require an enhanced modelling effort and modern kinetic parameter estimation strategies. The present work is dedicated to nonlinear dynamic modelling and parameter estimation for a mammalian cell culture process used for mAb production. By using a dynamical model of such kind of processes, an optimization-based technique for estimation of kinetic parameters in the model of mammalian cell culture process is developed. The estimation is achieved as a result of minimizing an error function by a particle swarm optimization (PSO) algorithm. The proposed estimation approach is analyzed in this work by using a particular model of mammalian cell culture, as a case study, but is generic for this class of bioprocesses. The presented case study shows that the proposed parameter estimation technique provides a more accurate simulation of the experimentally observed process behaviour than reported in previous studies. PMID:25685797

  16. Mammalian cell culture process for monoclonal antibody production: nonlinear modelling and parameter estimation.

    PubMed

    Selişteanu, Dan; Șendrescu, Dorin; Georgeanu, Vlad; Roman, Monica

    2015-01-01

    Monoclonal antibodies (mAbs) are at present one of the fastest growing products of pharmaceutical industry, with widespread applications in biochemistry, biology, and medicine. The operation of mAbs production processes is predominantly based on empirical knowledge, the improvements being achieved by using trial-and-error experiments and precedent practices. The nonlinearity of these processes and the absence of suitable instrumentation require an enhanced modelling effort and modern kinetic parameter estimation strategies. The present work is dedicated to nonlinear dynamic modelling and parameter estimation for a mammalian cell culture process used for mAb production. By using a dynamical model of such kind of processes, an optimization-based technique for estimation of kinetic parameters in the model of mammalian cell culture process is developed. The estimation is achieved as a result of minimizing an error function by a particle swarm optimization (PSO) algorithm. The proposed estimation approach is analyzed in this work by using a particular model of mammalian cell culture, as a case study, but is generic for this class of bioprocesses. The presented case study shows that the proposed parameter estimation technique provides a more accurate simulation of the experimentally observed process behaviour than reported in previous studies. PMID:25685797

  17. Mammalian cell culture process for monoclonal antibody production: nonlinear modelling and parameter estimation.

    PubMed

    Selişteanu, Dan; Șendrescu, Dorin; Georgeanu, Vlad; Roman, Monica

    2015-01-01

    Monoclonal antibodies (mAbs) are at present one of the fastest growing products of pharmaceutical industry, with widespread applications in biochemistry, biology, and medicine. The operation of mAbs production processes is predominantly based on empirical knowledge, the improvements being achieved by using trial-and-error experiments and precedent practices. The nonlinearity of these processes and the absence of suitable instrumentation require an enhanced modelling effort and modern kinetic parameter estimation strategies. The present work is dedicated to nonlinear dynamic modelling and parameter estimation for a mammalian cell culture process used for mAb production. By using a dynamical model of such kind of processes, an optimization-based technique for estimation of kinetic parameters in the model of mammalian cell culture process is developed. The estimation is achieved as a result of minimizing an error function by a particle swarm optimization (PSO) algorithm. The proposed estimation approach is analyzed in this work by using a particular model of mammalian cell culture, as a case study, but is generic for this class of bioprocesses. The presented case study shows that the proposed parameter estimation technique provides a more accurate simulation of the experimentally observed process behaviour than reported in previous studies.

  18. Effects of process parameters on the molding quality of the micro-needle array

    NASA Astrophysics Data System (ADS)

    Qiu, Z. J.; Ma, Z.; Gao, S.

    2016-07-01

    Micro-needle array, which is used in medical applications, is a kind of typical injection molded products with microstructures. Due to its tiny micro-features size and high aspect ratios, it is more likely to produce short shots defects, leading to poor molding quality. The injection molding process of the micro-needle array was studied in this paper to find the effects of the process parameters on the molding quality of the micro-needle array and to provide theoretical guidance for practical production of high-quality products. With the shrinkage ratio and warpage of micro needles as the evaluation indices of the molding quality, the orthogonal experiment was conducted and the analysis of variance was carried out. According to the results, the contribution rates were calculated to determine the influence of various process parameters on molding quality. The single parameter method was used to analyse the main process parameter. It was found that the contribution rate of the holding pressure on shrinkage ratio and warpage reached 83.55% and 94.71% respectively, far higher than that of the other parameters. The study revealed that the holding pressure is the main factor which affects the molding quality of micro-needle array so that it should be focused on in order to obtain plastic parts with high quality in the practical production.

  19. Intelligent Modeling Combining Adaptive Neuro Fuzzy Inference System and Genetic Algorithm for Optimizing Welding Process Parameters

    NASA Astrophysics Data System (ADS)

    Gowtham, K. N.; Vasudevan, M.; Maduraimuthu, V.; Jayakumar, T.

    2011-04-01

    Modified 9Cr-1Mo ferritic steel is used as a structural material for steam generator components of power plants. Generally, tungsten inert gas (TIG) welding is preferred for welding of these steels in which the depth of penetration achievable during autogenous welding is limited. Therefore, activated flux TIG (A-TIG) welding, a novel welding technique, has been developed in-house to increase the depth of penetration. In modified 9Cr-1Mo steel joints produced by the A-TIG welding process, weld bead width, depth of penetration, and heat-affected zone (HAZ) width play an important role in determining the mechanical properties as well as the performance of the weld joints during service. To obtain the desired weld bead geometry and HAZ width, it becomes important to set the welding process parameters. In this work, adaptative neuro fuzzy inference system is used to develop independent models correlating the welding process parameters like current, voltage, and torch speed with weld bead shape parameters like depth of penetration, bead width, and HAZ width. Then a genetic algorithm is employed to determine the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width.

  20. Experiments for practical education in process parameter optimization for selective laser sintering to increase workpiece quality

    NASA Astrophysics Data System (ADS)

    Reutterer, Bernd; Traxler, Lukas; Bayer, Natascha; Drauschke, Andreas

    2016-04-01

    Selective Laser Sintering (SLS) is considered as one of the most important additive manufacturing processes due to component stability and its broad range of usable materials. However the influence of the different process parameters on mechanical workpiece properties is still poorly studied, leading to the fact that further optimization is necessary to increase workpiece quality. In order to investigate the impact of various process parameters, laboratory experiments are implemented to improve the understanding of the SLS limitations and advantages on an educational level. Experiments are based on two different workstations, used to teach students the fundamentals of SLS. First of all a 50 W CO2 laser workstation is used to investigate the interaction of the laser beam with the used material in accordance with varied process parameters to analyze a single-layered test piece. Second of all the FORMIGA P110 laser sintering system from EOS is used to print different 3D test pieces in dependence on various process parameters. Finally quality attributes are tested including warpage, dimension accuracy or tensile strength. For dimension measurements and evaluation of the surface structure a telecentric lens in combination with a camera is used. A tensile test machine allows testing of the tensile strength and the interpreting of stress-strain curves. The developed laboratory experiments are suitable to teach students the influence of processing parameters. In this context they will be able to optimize the input parameters depending on the component which has to be manufactured and to increase the overall quality of the final workpiece.

  1. Processing Parameters Optimization for Material Deposition Efficiency in Laser Metal Deposited Titanium Alloy

    NASA Astrophysics Data System (ADS)

    Mahamood, Rasheedat M.; Akinlabi, Esther T.

    2016-03-01

    Ti6Al4V is an important Titanium alloy that is mostly used in many applications such as: aerospace, petrochemical and medicine. The excellent corrosion resistance property, the high strength to weight ratio and the retention of properties at high temperature makes them to be favoured in most applications. The high cost of Titanium and its alloys makes their use to be prohibitive in some applications. Ti6Al4V can be cladded on a less expensive material such as steel, thereby reducing cost and providing excellent properties. Laser Metal Deposition (LMD) process, an additive manufacturing process is capable of producing complex part directly from the 3-D CAD model of the part and it also has the capability of handling multiple materials. Processing parameters play an important role in LMD process and in order to achieve desired results at a minimum cost, then the processing parameters need to be properly controlled. This paper investigates the role of processing parameters: laser power, scanning speed, powder flow rate and gas flow rate, on the material utilization efficiency in laser metal deposited Ti6Al4V. A two-level full factorial design of experiment was used in this investigation, to be able to understand the processing parameters that are most significant as well as the interactions among these processing parameters. Four process parameters were used, each with upper and lower settings which results in a combination of sixteen experiments. The laser power settings used was 1.8 and 3 kW, the scanning speed was 0.05 and 0.1 m/s, the powder flow rate was 2 and 4 g/min and the gas flow rate was 2 and 4 l/min. The experiments were designed and analyzed using Design Expert 8 software. The software was used to generate the optimized process parameters which were found to be laser power of 3.2 kW, scanning speed of 0.06 m/s, powder flow rate of 2 g/min and gas flow rate of 3 l/min.

  2. The effects of process parameters on injection-molded PZT ceramics part fabrication- compounding process rheology.

    SciTech Connect

    Halbleib, Laura L.; Yang, Pin; Mondy, Lisa Ann; Burns, George Robert

    2005-05-01

    Solid solutions of lead-based perovskites are the backbone materials of the piezoelectric components for transducer, actuator, and resonator applications. These components, typically small in size, are fabricated from large sintered ceramic slugs using grinding and lapping processes. These operations increase manufacturing costs and produce a large hazardous waste stream, especially when component size decreases. To reduce costs and hazardous wastes associated with the production of these components, an injection molding technique is being investigated to replace the machining processes. The first step in the new technique is to compound an organic carrier with a ceramic powder. The organic carrier is a thermoplastic based system composed of a main carrier, a binder, and a surfactant. Understanding the rheology of the compounded material is necessary to minimize the creation of defects such as voids or cavities during the injection-molding process. An experiment was performed to model the effects of changes in the composition and processing of the material on the rheological behavior. Factors studied included: the surfactant of the organic carrier system, the solid loading of the compounded material, and compounding time. The effects of these factors on the viscosity of the material were investigated.

  3. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... machined bodies. 447.22 Section 447.22 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are...

  4. 27 CFR 447.22 - Forgings, castings, and machined bodies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... machined bodies. 447.22 Section 447.22 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO... IMPLEMENTS OF WAR The U.S. Munitions Import List § 447.22 Forgings, castings, and machined bodies. Articles..., castings, extrusions, and machined bodies) which have reached a stage in manufacture where they are...

  5. Forging an Identity over the Life-Course

    ERIC Educational Resources Information Center

    Spiteri, Damian

    2009-01-01

    Using a social constructionist approach, this study explores the self-perceptions of young men who, when at school, were classed as boys with social, emotional and behavioural difficulties (SEBD). The aim is to understand how these perceptions were forged throughout the young men's life-courses resulting in changing self-identities. The study also…

  6. Family Health and Financial Literacy--Forging the Connection

    ERIC Educational Resources Information Center

    Braun, Bonnie; Kim, Jinhee; Anderson, Elaine A.

    2009-01-01

    Families are at-risk of or experiencing a diminished quality of living and life in current economic times and difficult decisions are required. Health and financial literacy are the basis for wise personal and public decision making. Family and consumer sciences (FCS) professionals can forge connections between health and financial literacy to…

  7. Electronic Portfolios in Teacher Education: Forging a Middle Ground

    ERIC Educational Resources Information Center

    Strudler, Neal; Wetzel, Keith

    2012-01-01

    At a time when implementation of electronic portfolios (EPs) is expanding, the issues of clarifying their purposes continue to plague teacher education programs. Are student-centered uses of EPs compatible with program assessment and accreditation efforts? Is this an either/or situation, or can a productive middle ground be forged? This article…

  8. 16. Forge building and fuel storage shed from the southwest, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Forge building and fuel storage shed from the southwest, c.1918 Photocopied from a photograph in the collection of William F. Applegate, 43 Grandview Avenue, Wallingford, Connecticut. - Eli Whitney Armory, West of Whitney Avenue, Armory Street Vicinity, Hamden, New Haven County, CT

  9. Forging Consensus for Implementing Youth Socialization Policy in Northwest China

    ERIC Educational Resources Information Center

    Fairbrother, Gregory P.

    2011-01-01

    The goal of this article is to examine how the provincial education media in China play a role of forging consensus among local actors responsible for the implementation of new centrally-promulgated youth socialization policy. In doing so, it also explores the tension among three of the Chinese state's claims to legitimacy: economic development,…

  10. The Valley Forge Encampment: Epic on the Schuylkill.

    ERIC Educational Resources Information Center

    Trussell, John B. B., Jr.

    Valley Forge, outside Philadelphia (Pennsylvania), has long been recognized as the site of a great victory of the human spirit. Eleven thousand men including Blacks and Indians resided there during the winter of 1777-78 and triumphed over cold, starvation, nakedness, disease, and uncertainty. The encampment site was unprepared for the tattered,…

  11. Variational estimation of process parameters in a simplified atmospheric general circulation model

    NASA Astrophysics Data System (ADS)

    Lv, Guokun; Koehl, Armin; Stammer, Detlef

    2016-04-01

    Parameterizations are used to simulate effects of unresolved sub-grid-scale processes in current state-of-the-art climate model. The values of the process parameters, which determine the model's climatology, are usually manually adjusted to reduce the difference of model mean state to the observed climatology. This process requires detailed knowledge of the model and its parameterizations. In this work, a variational method was used to estimate process parameters in the Planet Simulator (PlaSim). The adjoint code was generated using automatic differentiation of the source code. Some hydrological processes were switched off to remove the influence of zero-order discontinuities. In addition, the nonlinearity of the model limits the feasible assimilation window to about 1day, which is too short to tune the model's climatology. To extend the feasible assimilation window, nudging terms for all state variables were added to the model's equations, which essentially suppress all unstable directions. In identical twin experiments, we found that the feasible assimilation window could be extended to over 1-year and accurate parameters could be retrieved. Although the nudging terms transform to a damping of the adjoint variables and therefore tend to erases the information of the data over time, assimilating climatological information is shown to provide sufficient information on the parameters. Moreover, the mechanism of this regularization is discussed.

  12. Influence of Processing Parameters on the Flow Path in Friction Stir Welding

    NASA Technical Reports Server (NTRS)

    Schneider, J. A.; Nunes, A. C., Jr.

    2006-01-01

    Friction stir welding (FSW) is a solid phase welding process that unites thermal and mechanical aspects to produce a high quality joint. The process variables are rpm, translational weld speed, and downward plunge force. The strain-temperature history of a metal element at each point on the cross-section of the weld is determined by the individual flow path taken by the particular filament of metal flowing around the tool as influenced by the process variables. The resulting properties of the weld are determined by the strain-temperature history. Thus to control FSW properties, improved understanding of the processing parameters on the metal flow path is necessary.

  13. A New Feedback-Based Method for Parameter Adaptation in Image Processing Routines

    PubMed Central

    Mikut, Ralf; Reischl, Markus

    2016-01-01

    The parametrization of automatic image processing routines is time-consuming if a lot of image processing parameters are involved. An expert can tune parameters sequentially to get desired results. This may not be productive for applications with difficult image analysis tasks, e.g. when high noise and shading levels in an image are present or images vary in their characteristics due to different acquisition conditions. Parameters are required to be tuned simultaneously. We propose a framework to improve standard image segmentation methods by using feedback-based automatic parameter adaptation. Moreover, we compare algorithms by implementing them in a feedforward fashion and then adapting their parameters. This comparison is proposed to be evaluated by a benchmark data set that contains challenging image distortions in an increasing fashion. This promptly enables us to compare different standard image segmentation algorithms in a feedback vs. feedforward implementation by evaluating their segmentation quality and robustness. We also propose an efficient way of performing automatic image analysis when only abstract ground truth is present. Such a framework evaluates robustness of different image processing pipelines using a graded data set. This is useful for both end-users and experts. PMID:27764213

  14. A Study on Reactive Spray Deposition Technology Processing Parameters in the Context of Pt Nanoparticle Formation

    NASA Astrophysics Data System (ADS)

    Roller, Justin M.; Maric, Radenka

    2015-12-01

    Catalytic materials are complex systems in which achieving the desired properties (i.e., activity, selectivity and stability) depends on exploiting the many degrees of freedom in surface and bulk composition, geometry, and defects. Flame aerosol synthesis is a process for producing nanoparticles with ample processing parameter space to tune the desired properties. Flame dynamics inside the reactor are determined by the input process variables such as solubility of precursor in the fuel; solvent boiling point; reactant flow rate and concentration; flow rates of air, fuel and the carrier gas; and the burner geometry. In this study, the processing parameters for reactive spray deposition technology, a flame-based synthesis method, are systematically evaluated to understand the residence times, reactant mixing, and temperature profiles of flames used in the synthesis of Pt nanoparticles. This provides a framework for further study and modeling. The flame temperature and length are also studied as a function of O2 and fuel flow rates.

  15. Effects of process parameters on solid self-microemulsifying particles in a laboratory scale fluid bed.

    PubMed

    Mukherjee, Tusharmouli; Plakogiannis, Fotios M

    2012-01-01

    The purpose of this study was to select the critical process parameters of the fluid bed processes impacting the quality attribute of a solid self-microemulsifying (SME) system of albendazole (ABZ). A fractional factorial design (2(4-1)) with four parameters (spray rate, inlet air temperature, inlet air flow, and atomization air pressure) was created by MINITAB software. Batches were manufactured in a laboratory top-spray fluid bed at 625-g scale. Loss on drying (LOD) samples were taken throughout each batch to build the entire moisture profiles. All dried granulation were sieved using mesh 20 and analyzed for particle size distribution (PSD), morphology, density, and flow. It was found that as spray rate increased, sauter-mean diameter (D(s)) also increased. The effect of inlet air temperature on the peak moisture which is directly related to the mean particle size was found to be significant. There were two-way interactions between studied process parameters. The main effects of inlet air flow rate and atomization air pressure could not be found as the data were inconclusive. The partial least square (PLS) regression model was found significant (P < 0.01) and predictive for optimization. This study established a design space for the parameters for solid SME manufacturing process.

  16. Effect of processing parameters on surface finish for fused deposition machinable wax patterns

    NASA Technical Reports Server (NTRS)

    Roberts, F. E., III

    1995-01-01

    This report presents a study on the effect of material processing parameters used in layer-by-layer material construction on the surface finish of a model to be used as an investment casting pattern. The data presented relate specifically to fused deposition modeling using a machinable wax.

  17. Orthogonal experiment and analysis on process parameters of bowl feed polishing (BFP)

    NASA Astrophysics Data System (ADS)

    Meng, Kai; Wan, Yongjian; Xu, Qinglan; Yang, Yang

    2013-08-01

    With the development of science and technology, the demand for high-precision product is increasing continuously. Ultra-smooth surface with sub-nanometer roughness has extensive applications in the field of soft X-ray optics, high power laser and laser gyro. Bowl feed polishing (BFP) technology is an effective ultra-smooth surface processing method, but the polishing process of BFP which is affected by a lot of factors is extremely complex and difficult to control. It is important to understand the effect of the process variables such as abrasive particle size, concentration of abrasive particle, speed of polishing pad, acidity and polishing time in the process of BFP. They are very important parameters that must be carefully formulated to achieve desired material removal rates and surface roughness. Using a design of experiment (DOE) approach, this study was performed investigating the main effect of the each parameter during K9 BFP. A better understanding of the interaction behavior between the various parameters and the effect on removal rate and surface roughness is achieved by using the statistical analysis techniques. In the experimental tests, the optimized parameters combination for BFP which were derived from the statistical analysis could be found for material removal rate and better surface roughness through the above experiment results.

  18. Development of process parameters for 22 nm PMOS using 2-D analytical modeling

    SciTech Connect

    Maheran, A. H. Afifah; Menon, P. S.; Shaari, S.; Ahmad, I.; Faizah, Z. A. Noor

    2015-04-24

    The complementary metal-oxide-semiconductor field effect transistor (CMOSFET) has become major challenge to scaling and integration. Innovation in transistor structures and integration of novel materials are necessary to sustain this performance trend. CMOS variability in the scaling technology becoming very important concern due to limitation of process control; over statistically variability related to the fundamental discreteness and materials. Minimizing the transistor variation through technology optimization and ensuring robust product functionality and performance is the major issue.In this article, the continuation study on process parameters variations is extended and delivered thoroughly in order to achieve a minimum leakage current (I{sub LEAK}) on PMOS planar transistor at 22 nm gate length. Several device parameters are varies significantly using Taguchi method to predict the optimum combination of process parameters fabrication. A combination of high permittivity material (high-k) and metal gate are utilized accordingly as gate structure where the materials include titanium dioxide (TiO{sub 2}) and tungsten silicide (WSi{sub x}). Then the L9 of the Taguchi Orthogonal array is used to analyze the device simulation where the results of signal-to-noise ratio (SNR) of Smaller-the-Better (STB) scheme are studied through the percentage influences of the process parameters. This is to achieve a minimum I{sub LEAK} where the maximum predicted I{sub LEAK} value by International Technology Roadmap for Semiconductors (ITRS) 2011 is said to should not above 100 nA/µm. Final results shows that the compensation implantation dose acts as the dominant factor with 68.49% contribution in lowering the device’s leakage current. The absolute process parameters combination results in I{sub LEAK} mean value of 3.96821 nA/µm where is far lower than the predicted value.

  19. Development of process parameters for 22 nm PMOS using 2-D analytical modeling

    NASA Astrophysics Data System (ADS)

    Maheran, A. H. Afifah; Menon, P. S.; Ahmad, I.; Shaari, S.; Faizah, Z. A. Noor

    2015-04-01

    The complementary metal-oxide-semiconductor field effect transistor (CMOSFET) has become major challenge to scaling and integration. Innovation in transistor structures and integration of novel materials are necessary to sustain this performance trend. CMOS variability in the scaling technology becoming very important concern due to limitation of process control; over statistically variability related to the fundamental discreteness and materials. Minimizing the transistor variation through technology optimization and ensuring robust product functionality and performance is the major issue.In this article, the continuation study on process parameters variations is extended and delivered thoroughly in order to achieve a minimum leakage current (ILEAK) on PMOS planar transistor at 22 nm gate length. Several device parameters are varies significantly using Taguchi method to predict the optimum combination of process parameters fabrication. A combination of high permittivity material (high-k) and metal gate are utilized accordingly as gate structure where the materials include titanium dioxide (TiO2) and tungsten silicide (WSix). Then the L9 of the Taguchi Orthogonal array is used to analyze the device simulation where the results of signal-to-noise ratio (SNR) of Smaller-the-Better (STB) scheme are studied through the percentage influences of the process parameters. This is to achieve a minimum ILEAK where the maximum predicted ILEAK value by International Technology Roadmap for Semiconductors (ITRS) 2011 is said to should not above 100 nA/µm. Final results shows that the compensation implantation dose acts as the dominant factor with 68.49% contribution in lowering the device's leakage current. The absolute process parameters combination results in ILEAK mean value of 3.96821 nA/µm where is far lower than the predicted value.

  20. Gas separation using membranes. 1: Optimization of the separation process using new cost parameters

    SciTech Connect

    Hinchliffe, A.B.; Porter, K.E.

    1997-03-01

    This is the first in a series of papers presenting new concepts for the development of membranes for gas separation. In this paper two new cost parameters, which are useful for costing and optimization of membrane gas separation systems, are described. The new parameters, cost permeability and effective selectivity, can be used to show the direction to be taken in membrane research and development. The new parameters are shown to predict accurately the cost of membrane separation plant by correlating bids from membrane plant suppliers using the new parameters with cross-flow design equations. The parameters are used to optimize the membrane gas separation of hydrogen and carbon monoxide for two commercially available membrane systems. The membrane separation is compared with the currently used method, cryogenic flash distillation. Economic evaluation methods are developed to compare different separation methods so that the process as a whole can be optimized. The evaluation shows that, for membrane gas separation, it is important to find the optimum degree of separation; when membrane separation is evaluated at the separation specification for the established cryogenic method, membranes are not competitive; however, when the process is optimized for membrane separation, the cost of separation reduces to less than 60% of the cryogenic separation.

  1. Recommended direct simulation Monte Carlo collision model parameters for modeling ionized air transport processes

    NASA Astrophysics Data System (ADS)

    Swaminathan-Gopalan, Krishnan; Stephani, Kelly A.

    2016-02-01

    A systematic approach for calibrating the direct simulation Monte Carlo (DSMC) collision model parameters to achieve consistency in the transport processes is presented. The DSMC collision cross section model parameters are calibrated for high temperature atmospheric conditions by matching the collision integrals from DSMC against ab initio based collision integrals that are currently employed in the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA) and Data Parallel Line Relaxation (DPLR) high temperature computational fluid dynamics solvers. The DSMC parameter values are computed for the widely used Variable Hard Sphere (VHS) and the Variable Soft Sphere (VSS) models using the collision-specific pairing approach. The recommended best-fit VHS/VSS parameter values are provided over a temperature range of 1000-20 000 K for a thirteen-species ionized air mixture. Use of the VSS model is necessary to achieve consistency in transport processes of ionized gases. The agreement of the VSS model transport properties with the transport properties as determined by the ab initio collision integral fits was found to be within 6% in the entire temperature range, regardless of the composition of the mixture. The recommended model parameter values can be readily applied to any gas mixture involving binary collisional interactions between the chemical species presented for the specified temperature range.

  2. Identification of sensitive parameters in the modeling of SVOC reemission processes from soil to atmosphere.

    PubMed

    Loizeau, Vincent; Ciffroy, Philippe; Roustan, Yelva; Musson-Genon, Luc

    2014-09-15

    Semi-volatile organic compounds (SVOCs) are subject to Long-Range Atmospheric Transport because of transport-deposition-reemission successive processes. Several experimental data available in the literature suggest that soil is a non-negligible contributor of SVOCs to atmosphere. Then coupling soil and atmosphere in integrated coupled models and simulating reemission processes can be essential for estimating atmospheric concentration of several pollutants. However, the sources of uncertainty and variability are multiple (soil properties, meteorological conditions, chemical-specific parameters) and can significantly influence the determination of reemissions. In order to identify the key parameters in reemission modeling and their effect on global modeling uncertainty, we conducted a sensitivity analysis targeted on the 'reemission' output variable. Different parameters were tested, including soil properties, partition coefficients and meteorological conditions. We performed EFAST sensitivity analysis for four chemicals (benzo-a-pyrene, hexachlorobenzene, PCB-28 and lindane) and different spatial scenari (regional and continental scales). Partition coefficients between air, solid and water phases are influent, depending on the precision of data and global behavior of the chemical. Reemissions showed a lower variability to soil parameters (soil organic matter and water contents at field capacity and wilting point). A mapping of these parameters at a regional scale is sufficient to correctly estimate reemissions when compared to other sources of uncertainty.

  3. Application of CBR method for adding the process of cutting tools and parameters selection

    NASA Astrophysics Data System (ADS)

    Ociepka, P.; Herbus, K.

    2015-11-01

    Modem enterprises must face with the dynamically changing market demand what influences the designing process. It is possible by linking computer tools with information gathered by experienced designers teams. The article describes the method basing on engineering knowledge and experience to adding the process of tools selection and cutting parameters determination for a turning operation. The method, proposed by the authors, is based on the CBR (Case Based Reasoning) method. CBR is a method of problem solving that involves searching for an analogy (similarity) between the current task to be solved, and the earlier cases that properly described, are stored in a computer memory. This article presents an algorithm and a formalized description of the developed method. It was discussed the range of its utilization, as well as it was illustrated the method of its functioning on the example of the tools and cutting parameters selection with respect to the turning process.

  4. Phases' characteristics of poultry litter hydrothermal carbonization under a range of process parameters.

    PubMed

    Mau, Vivian; Quance, Julie; Posmanik, Roy; Gross, Amit

    2016-11-01

    The aim of this work was to study the hydrothermal carbonization of poultry litter under a range of process parameters. Experiments were conducted to investigate the effect of HTC of poultry litter under a range of operational parameters (temperature, reaction time, and solids concentration) on the formation and characteristics of its phases. Results showed production of a hydrochar with caloric value of 24.4MJ/kg, similar to sub-bituminous coal. The gaseous phase consisted mainly of CO2. However, significant amounts of H2S dictate the need for (further) treatment. The process also produced an aqueous phase with chemical characteristics suggesting its possible use as a liquid fertilizer. Temperature had the most significant effect on processes and product formation. Solids concentration was not a significant factor once dilution effects were considered. PMID:27544913

  5. Optimization of process parameters for production of volatile fatty acid, biohydrogen and methane from anaerobic digestion.

    PubMed

    Khan, M A; Ngo, H H; Guo, W S; Liu, Y; Nghiem, L D; Hai, F I; Deng, L J; Wang, J; Wu, Y

    2016-11-01

    The anaerobic digestion process has been primarily utilized for methane containing biogas production over the past few years. However, the digestion process could also be optimized for producing volatile fatty acids (VFAs) and biohydrogen. This is the first review article that combines the optimization approaches for all three possible products from the anaerobic digestion. In this review study, the types and configurations of the bioreactor are discussed for each type of product. This is followed by a review on optimization of common process parameters (e.g. temperature, pH, retention time and organic loading rate) separately for the production of VFA, biohydrogen and methane. This review also includes additional parameters, treatment methods or special additives that wield a significant and positive effect on production rate and these products' yield.

  6. Computerized Optimization of the Process Parameters in Laser-Assisted Milling

    NASA Astrophysics Data System (ADS)

    Wiedenmann, R.; Langhorst, M.; Zaeh, M. F.

    Machining advanced materials, e.g. titanium alloys, usually results in a short tool life. Laser-assisted milling represents an innovative method to enhance machinability with less tool wear and an increased material removal rate. The material is heated locally and thereby softened before machining. This paper describes a thermo-mechanical simulation of a laser-assisted milling process in order to achieve a controlled heat impact. For that purpose the influence of different material parameters on the temperature field was analyzed computationally. The penetration depth of the laser induced heat and the thermally induced internal loads were investigated considering the loss of material and thus of heat during the milling process. Finally, the laser and the milling parameters were adapted for a real laser-assisted process.

  7. Analysis and optimization of process parameters in Al-SiCp laser cladding

    NASA Astrophysics Data System (ADS)

    Riquelme, Ainhoa; Rodrigo, Pilar; Escalera-Rodríguez, María Dolores; Rams, Joaquín

    2016-03-01

    The laser cladding process parameters have great effect on the clad geometry and on dilution in the single and multi-pass aluminum matrix composite reinforced with SiC particles (Al/SiCp) coatings on ZE41 magnesium alloys deposited using a high-power diode laser (HPLD). The influence of the laser power (500-700 W), scan speed (3-17 mm/s) and laser beam focal position (focus, positive and negative defocus) on the shape factor, cladding-bead geometry, cladding-bead microstructure (including the presence of pores and cracks), and hardness has been evaluated. The correlation of these process parameters and their influence on the properties and ultimately, on the feasibility of the cladding process, is demonstrated. The importance of focal position is demonstrated. The different energy distribution of the laser beam cross section in focus plane or in positive and negative defocus plane affect on the cladding-bead properties.

  8. Optimization of process parameters for production of volatile fatty acid, biohydrogen and methane from anaerobic digestion.

    PubMed

    Khan, M A; Ngo, H H; Guo, W S; Liu, Y; Nghiem, L D; Hai, F I; Deng, L J; Wang, J; Wu, Y

    2016-11-01

    The anaerobic digestion process has been primarily utilized for methane containing biogas production over the past few years. However, the digestion process could also be optimized for producing volatile fatty acids (VFAs) and biohydrogen. This is the first review article that combines the optimization approaches for all three possible products from the anaerobic digestion. In this review study, the types and configurations of the bioreactor are discussed for each type of product. This is followed by a review on optimization of common process parameters (e.g. temperature, pH, retention time and organic loading rate) separately for the production of VFA, biohydrogen and methane. This review also includes additional parameters, treatment methods or special additives that wield a significant and positive effect on production rate and these products' yield. PMID:27570139

  9. Fault detection in heavy duty wheels by advanced vibration processing techniques and lumped parameter modeling

    NASA Astrophysics Data System (ADS)

    Malago`, M.; Mucchi, E.; Dalpiaz, G.

    2016-03-01

    Heavy duty wheels are used in applications such as automatic vehicles and are mainly composed of a polyurethane tread glued to a cast iron hub. In the manufacturing process, the adhesive application between tread and hub is a critical assembly phase, since it is completely made by an operator and a contamination of the bond area may happen. Furthermore, the presence of rust on the hub surface can contribute to worsen the adherence interface, reducing the operating life. In this scenario, a quality control procedure for fault detection to be used at the end of the manufacturing process has been developed. This procedure is based on vibration processing techniques and takes advantages of the results of a lumped parameter model. Indicators based on cyclostationarity can be considered as key parameters to be adopted in a monitoring test station at the end of the production line due to their not deterministic characteristics.

  10. Parameter identification of process simulation models as a means for knowledge acquisition and technology transfer

    NASA Astrophysics Data System (ADS)

    Batzias, Dimitris F.; Ifanti, Konstantina

    2012-12-01

    Process simulation models are usually empirical, therefore there is an inherent difficulty in serving as carriers for knowledge acquisition and technology transfer, since their parameters have no physical meaning to facilitate verification of the dependence on the production conditions; in such a case, a 'black box' regression model or a neural network might be used to simply connect input-output characteristics. In several cases, scientific/mechanismic models may be proved valid, in which case parameter identification is required to find out the independent/explanatory variables and parameters, which each parameter depends on. This is a difficult task, since the phenomenological level at which each parameter is defined is different. In this paper, we have developed a methodological framework under the form of an algorithmic procedure to solve this problem. The main parts of this procedure are: (i) stratification of relevant knowledge in discrete layers immediately adjacent to the layer that the initial model under investigation belongs to, (ii) design of the ontology corresponding to these layers, (iii) elimination of the less relevant parts of the ontology by thinning, (iv) retrieval of the stronger interrelations between the remaining nodes within the revised ontological network, and (v) parameter identification taking into account the most influential interrelations revealed in (iv). The functionality of this methodology is demonstrated by quoting two representative case examples on wastewater treatment.

  11. The influence of process parameters on the laser-induced coloring of titanium

    NASA Astrophysics Data System (ADS)

    Antończak, Arkadiusz J.; Stępak, Bogusz; Kozioł, Paweł E.; Abramski, Krzysztof M.

    2014-06-01

    This paper presents the results of the measurements and analysis of the influence of laser process parameters on the color obtained. The study was conducted for titanium (Grade 2) using a commercially available industrial pulsed fiber laser. It was determined how a variety of different laser process parameters, such as laser power, the scanning speed of the material, the temperature of the material, the size of the marked area, and the position of the sample, relative to both the focal plane and the center of the working field of the system, affect the repeatability of the colors created. For an objective assessment of color changes, an optical spectrometer and the CIE color difference parameter were used. Our paper explains why the tolerance of process parameters highly depends on the specific color. Additionally, a comparison of the results for titanium with those obtained for stainless steel in a previous study is presented. Based on this analysis, a number of necessary modifications are proposed to laser systems commonly used for monochrome marking in order to improve repeatability in color marking.

  12. Estimation of Temperature Dependent Parameters of a Batch Alcoholic Fermentation Process

    NASA Astrophysics Data System (ADS)

    de Andrade, Rafael Ramos; Rivera, Elmer Ccopa; Costa, Aline C.; Atala, Daniel I. P.; Filho, Francisco Maugeri; Filho, Rubens Maciel

    In this work, a procedure was established to develop a mathematical model considering the effect of temperature on reaction kinetics. Experiments were performed in batch mode in temperatures from 30 to 38°C. The microorganism used was Saccharomyces cerevisiae and the culture media, sugarcane molasses. The objective is to assess the difficulty in updating the kinetic parameters when there are changes in fermentation conditions. We conclude that, although the re-estimation is a time-consuming task, it is possible to accurately describe the process when there are changes in raw material composition if a re-estimation of parameters is performed.

  13. Optimization of the Solution and Processing Parameters for Strontium Titanate Thin Films for Electronic Devices

    NASA Astrophysics Data System (ADS)

    Weiss, Claire Victoria

    Metallo-organic solution deposition (MOSD) and spin-coating were used to deposit strontium titanate (SrTiO3 or STO) thin films on Si and metalized Si substrates. In addition, a thermodynamic model was constructed based on the Landau polynomial for the free energy. Using this model, the thin film strain due to the difference in thermal expansion coefficients (TECs) of the film and substrate was calculated, as well as its effect on the permittivity and tunability. It was found that a large tensile thermal strain develops in the STO/Si material system, and this strain significantly lowers the dielectric response as compared to bulk STO. A multi-dimensional parameter optimization process was used to systematically vary the solution, deposition, and processing parameters of the STO thin films. These parameters include the precursor solution heating, solution molarity/concentration, solution aging, spin-coating recipe, pyrolysis procedure/temperature, annealing temperature, and annealing oxygen environment. X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), and dielectric/insulating measurements were used to characterize the STO thin film devices. By optimizing various deposition parameters, such as the solution molarity and the pyrolysis temperature, the tensile stress induced from the difference in TECs of the film and substrate, which was predicted by the thermodynamic theory, can be reduced or completely eliminated. This stress relaxation is achieved through the tailoring of compressive "growth stresses" by optimizing the precursor solution molarity as well as the post-deposition heat treatment processing. By utilizing the multi-dimensional parameter optimization process, high-quality, electronic-grade thin film STO can be deposited via the affordable, simple, and industry-standard MOSD technique.

  14. Hydrothermal carbonization of biomass from landscape management - Influence of process parameters on soil properties of hydrochars.

    PubMed

    Röhrdanz, Michael; Rebling, Tammo; Ohlert, Jan; Jasper, Jan; Greve, Thomas; Buchwald, Rainer; von Frieling, Petra; Wark, Michael

    2016-05-15

    Besides pyrolysis the technology of hydrothermal carbonization (HTC) is tested to produce hydrochars for soil improvement. The chemical and physical properties of the hydrochars mainly depend on the feedstock and the process parameters reaction time and process temperature. Systematic investigations on the influences of these process parameters on soil properties of hydrochars like water holding capacity (WHC) and cation exchange capacity (CEC) are missing. In this study, a rush-rich biomass was carbonized within defined HTC process conditions under variation of reaction time and process temperature to produce hydrochars. Analysis of WHC, CEC, the elemental composition and Fourier-transform infrared spectroscopy (FT-IR) were performed to evaluate the influence of HTC process conditions on the pedological hydrochar properties. The results indicated that at increasing reaction severity (reaction time and process temperature) WHC and CEC decreased as well as the elemental O/C ratio. The decrease of WHC and CEC is based on the decrease of the hydrochar surface polarity. However, even the lowest WHC and CEC of investigated hydrochars still exceeded those of pure quartz sand by factors of 5-10. An application of hydrochars produced at severe HTC conditions could improve WHC and CEC of sandy soils. This has to be investigated in further studies. PMID:26974240

  15. Meltlets® of Soy Isoflavones: Process Optimization and the Effect of Extrusion Spheronization Process Parameters on Antioxidant Activity

    PubMed Central

    Deshmukh, Ketkee; Amin, Purnima

    2013-01-01

    In the current research work an attempt was made to develop “Melt in mouth pellets” (Meltlets®) containing 40% herbal extract of soy isoflavones that served to provide antioxidants activity in menopausal women. The process of extrusion–spheronization was optimized for extruder speed, extruder screen size, spheronization speed, and time. While doing so the herbal extract incorporated in the pellet matrix was subjected to various processing conditions such as the effect of the presence of other excipients, mixing or kneading to prepare wet mass, heat generated during the process of extrusion, spheronization, and drying. Thus, the work further investigates the effect of these processing parameters on the antioxidant activity of the soy isoflavone herbal extract incorporated in the formula. Thereby, the antioxidant activity of the soya bean herbal extract, Meltlets® and of the placebo pellets was evaluated using DPPH free radical scavenging assay and total reduction capacity. PMID:24302800

  16. A preliminary evaluation of an F100 engine parameter estimation process using flight data

    NASA Technical Reports Server (NTRS)

    Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

    1990-01-01

    The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the compact engine model (CEM). In this step, the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion control law development.

  17. A preliminary evaluation of an F100 engine parameter estimation process using flight data

    NASA Technical Reports Server (NTRS)

    Maine, Trindel A.; Gilyard, Glenn B.; Lambert, Heather H.

    1990-01-01

    The parameter estimation algorithm developed for the F100 engine is described. The algorithm is a two-step process. The first step consists of a Kalman filter estimation of five deterioration parameters, which model the off-nominal behavior of the engine during flight. The second step is based on a simplified steady-state model of the 'compact engine model' (CEM). In this step the control vector in the CEM is augmented by the deterioration parameters estimated in the first step. The results of an evaluation made using flight data from the F-15 aircraft are presented, indicating that the algorithm can provide reasonable estimates of engine variables for an advanced propulsion-control-law development.

  18. Simulation of Electromagnetic and Thermal Processes in Fastcycling Magnets for Calculation Parameters of Stability

    NASA Astrophysics Data System (ADS)

    Zubko, V.; Kozub, S.; Tkachenko, L.

    SIS300 fast-cycling superconducting quadrupole magnet is developed at IHEP. Temperature margin and minimum quench energy are main parameters of stability of superconducting magnets. These parameters are important for the design and safe operation of superconducting magnets. But additional understanding for fast-cycling superconducting magnets is needed. To calculate the temperature margin one needs coupled numerical transient simulation of electromagnetic and thermal processes in the coil because critical temperature, operating temperature and AC losses are nonuniform over turns and their magnitudes vary in time during accelerator cycles. For calculation of the minimum quench energy the combination of the network model with thermal analysis is necessary, which allows one to model quench dynamics, including the effects of a current redistribution between strands of cable and spatial inhomogeneity of cable. Results for the temperature margin and the minimum quench energy for the magnet are presented and theirs dependence on various parameters is discussed.

  19. Optimization of process parameters in CNC turning of aluminium alloy using hybrid RSM cum TLBO approach

    NASA Astrophysics Data System (ADS)

    Rudrapati, R.; Sahoo, P.; Bandyopadhyay, A.

    2016-09-01

    The main aim of the present work is to analyse the significance of turning parameters on surface roughness in computer numerically controlled (CNC) turning operation while machining of aluminium alloy material. Spindle speed, feed rate and depth of cut have been considered as machining parameters. Experimental runs have been conducted as per Box-Behnken design method. After experimentation, surface roughness is measured by using stylus profile meter. Factor effects have been studied through analysis of variance. Mathematical modelling has been done by response surface methodology, to made relationships between the input parameters and output response. Finally, process optimization has been made by teaching learning based optimization (TLBO) algorithm. Predicted turning condition has been validated through confirmatory experiment.

  20. Identification of sorption processes and parameters for radionuclide transport in fractured rock

    NASA Astrophysics Data System (ADS)

    Dai, Zhenxue; Wolfsberg, Andrew; Reimus, Paul; Deng, Hailin; Kwicklis, Edward; Ding, Mei; Ware, Doug; Ye, Ming

    2012-01-01

    SummaryIdentification of chemical reaction processes in subsurface environments is a key issue for reactive transport modeling because simulating different processes requires developing different chemical-mathematical models. In this paper, two sorption processes (equilibrium and kinetics) are considered for modeling neptunium and uranium sorption in fractured rock. Based on different conceptualizations of the two processes occurring in fracture and/or matrix media, seven dual-porosity, multi-component reactive transport models are developed. The process models are identified with a stepwise strategy by using multi-tracer concentration data obtained from a series of transport experiments. In the first step, breakthrough data of a conservative tracer (tritium) obtained from four experiments are used to estimate the flow and non-reactive transport parameters (i.e., mean fluid residence time in fracture, fracture aperture, and matrix tortuosity) common to all the reactive transport models. In the second and third steps, by fixing the common non-reactive flow and transport parameters, the sorption parameters (retardation factor, sorption coefficient, and kinetic rate constant) of each model are estimated using the breakthrough data of reactive tracers, neptunium and uranium, respectively. Based on the inverse modeling results, the seven sorption-process models are discriminated using four model discrimination (or selection) criteria, Akaike information criterion ( AIC), modified Akaike information criterion ( AICc), Bayesian information criterion ( BIC) and Kashyap information criterion ( KIC). These criteria suggest the kinetic sorption process for modeling reactive transport of neptunium and uranium transport in both fracture and matrix. This conclusion is confirmed by two chemical criteria, the half reaction time and Damköhler number criterion.

  1. Reduced iron parameters and cognitive processes in children and adolescents with DM1 compared to those with standard parameters.

    PubMed

    Mojs, Ewa; Stanisławska-Kubiak, Maia; Wójciak, Rafał W; Wojciechowska, Julita; Przewoźniak, Sabina

    2016-03-01

    Anemia in patients with diabetes is not scarce and may contribute to the complications of the disease. The risk of iron deficiency parameters in child sufferers of diabetes type 1, observed in studies, can lead to cognitive impairment. The aim of the study was to determine whether children and adolescents with diabetes type 1, in whom reduced ferric parameters are observed in control tests, may also show reduced cognitive performance. The study included 100 children with diabetes type 1 at the age of 6-17 years. During control tests, patients' morphological blood parameters were measured: red blood cells (RBC), hemoglobin, glycosylated hemoglobin, hematocrit, RBC volume, the molar mass of hemoglobin in RBC (MCH), mean corpuscular hemoglobin in RBC and iron concentrations in serum using flame atomic absorption spectroscopy and the Wechsler Intelligence Scale for Children (WISC-R). Results in the group of children with a diabetes type 1 significantly lower concentration of three ferric parameters affect the non-verbal intelligence measured with WISC-R. The prevalence of reduced ferric parameters justifies further screening in all children with diabetes type 1 and taking up appropriate preventive measures to reduce the risk of their occurrence. PMID:26912011

  2. Post-processing of seismic parameter data based on valid seismic event determination

    DOEpatents

    McEvilly, Thomas V.

    1985-01-01

    An automated seismic processing system and method are disclosed, including an array of CMOS microprocessors for unattended battery-powered processing of a multi-station network. According to a characterizing feature of the invention, each channel of the network is independently operable to automatically detect, measure times and amplitudes, and compute and fit Fast Fourier transforms (FFT's) for both P- and S- waves on analog seismic data after it has been sampled at a given rate. The measured parameter data from each channel are then reviewed for event validity by a central controlling microprocessor and if determined by preset criteria to constitute a valid event, the parameter data are passed to an analysis computer for calculation of hypocenter location, running b-values, source parameters, event count, P- wave polarities, moment-tensor inversion, and Vp/Vs ratios. The in-field real-time analysis of data maximizes the efficiency of microearthquake surveys allowing flexibility in experimental procedures, with a minimum of traditional labor-intensive postprocessing. A unique consequence of the system is that none of the original data (i.e., the sensor analog output signals) are necessarily saved after computation, but rather, the numerical parameters generated by the automatic analysis are the sole output of the automated seismic processor.

  3. Optimization of process parameters of pulsed TIG welded maraging steel C300

    NASA Astrophysics Data System (ADS)

    Deepak, P.; Jualeash, M. J.; Jishnu, J.; Srinivasan, P.; Arivarasu, M.; Padmanaban, R.; Thirumalini, S.

    2016-09-01

    Pulsed TIG welding technology provides excellent welding performance on thin sections which helps to increase productivity, enhance weld quality, minimize weld costs, and boost operator efficiency and this has drawn the attention of the welding society. Maraging C300 steel is extensively used in defence and aerospace industry and thus its welding becomes an area of paramount importance. In pulsed TIG welding, weld quality depends on the process parameters used. In this work, Pulsed TIG bead-on-plate welding is performed on a 5mm thick maraging C300 plate at different combinations of input parameters: peak current (Ip), base current (Ib) and pulsing frequency (HZ) as per box behnken design with three-levels for each factor. Response surface methodology is utilized for establishing a mathematical model for predicting the weld bead depth. The effect of Ip, Ib and HZ on the weld bead depth is investigated using the developed model. The weld bead depth is found to be affected by all the three parameters. Surface and contour plots developed from regression equation are used to optimize the processing parameters for maximizing the weld bead depth. Optimum values of Ip, Ib and HZ are obtained as 259 A, 120 A and 8 Hz respectively. Using this optimum condition, maximum bead depth of the weld is predicted to be 4.325 mm.

  4. Subsonic flight test evaluation of a propulsion system parameter estimation process for the F100 engine

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Gilyard, Glenn B.

    1992-01-01

    Integrated engine-airframe optimal control technology may significantly improve aircraft performance. This technology requires a reliable and accurate parameter estimator to predict unmeasured variables. To develop this technology base, NASA Dryden Flight Research Facility (Edwards, CA), McDonnell Aircraft Company (St. Louis, MO), and Pratt & Whitney (West Palm Beach, FL) have developed and flight-tested an adaptive performance seeking control system which optimizes the quasi-steady-state performance of the F-15 propulsion system. This paper presents flight and ground test evaluations of the propulsion system parameter estimation process used by the performance seeking control system. The estimator consists of a compact propulsion system model and an extended Kalman filter. The extended Laman filter estimates five engine component deviation parameters from measured inputs. The compact model uses measurements and Kalman-filter estimates as inputs to predict unmeasured propulsion parameters such as net propulsive force and fan stall margin. The ability to track trends and estimate absolute values of propulsion system parameters was demonstrated. For example, thrust stand results show a good correlation, especially in trends, between the performance seeking control estimated and measured thrust.

  5. The Effects of Operational Parameters on a Mono-wire Cutting System: Efficiency in Marble Processing

    NASA Astrophysics Data System (ADS)

    Yilmazkaya, Emre; Ozcelik, Yilmaz

    2016-02-01

    Mono-wire block cutting machines that cut with a diamond wire can be used for squaring natural stone blocks and the slab-cutting process. The efficient use of these machines reduces operating costs by ensuring less diamond wire wear and longer wire life at high speeds. The high investment costs of these machines will lead to their efficient use and reduce production costs by increasing plant efficiency. Therefore, there is a need to investigate the cutting performance parameters of mono-wire cutting machines in terms of rock properties and operating parameters. This study aims to investigate the effects of the wire rotational speed (peripheral speed) and wire descending speed (cutting speed), which are the operating parameters of a mono-wire cutting machine, on unit wear and unit energy, which are the performance parameters in mono-wire cutting. By using the obtained results, cuttability charts for each natural stone were created on the basis of unit wear and unit energy values, cutting optimizations were performed, and the relationships between some physical and mechanical properties of rocks and the optimum cutting parameters obtained as a result of the optimization were investigated.

  6. Applying an interferometric exposure model to analyze the influences of process parameters on the linewidth

    NASA Astrophysics Data System (ADS)

    Chien, Cheng-Wei; Chen, Jyh-Chen; Lee, Ju-Yi

    2006-11-01

    We utilize a modified interferometric exposure model, enhanced with the Beer-Lambert law, to study how some process parameters influence the structural dimensions within the whole exposure area. An experimental apparatus is built to verify the accuracy of this model. The simulation results indicate that when the incident angle is larger than 15°, the effect of the beam deformation cannot be neglected. One cannot readily obtain periodic structures with the same dimensions during static exposure because of the Gaussian distribution of the light intensity. The theoretical results match the experimental ones quite well. The variation of Dill's parameter A has a greater influence on the transmittance and the linewidth when A is decreasing. If a poor contrast fringe is exposed in the photoresist, it will not only cause a greater nonuniformity of the structural dimensions but also a decreased aspect ratio in the structure after the development process.

  7. Modelling of sensory and instrumental texture parameters in processed cheese by near infrared reflectance spectroscopy.

    PubMed

    Blazquez, Carmen; Downey, Gerard; O'Callaghan, Donal; Howard, Vincent; Delahunty, Conor; Sheehan, Elizabeth; Everard, Colm; O'Donnell, Colm P

    2006-02-01

    This study investigated the application of near infrared (NIR) reflectance spectroscopy to the measurement of texture (sensory and instrumental) in experimental processed cheese samples. Spectra (750 to 2498 nm) of cheeses were recorded after 2 and 4 weeks storage at 4 degrees C. Trained assessors evaluated 9 sensory properties, a texture profile analyser (TPA) was used to record 5 instrumental parameters and cheese 'meltability' was measured by computer vision. Predictive models for sensory and instrumental texture parameters were developed using partial least squares regression on raw or pre-treated spectral data. Sensory attributes and instrumental texture measurements were modelled with sufficient accuracy to recommend the use of NIR reflectance spectroscopy for routine quality assessment of processed cheese. PMID:16433962

  8. Modelling of influential parameters on a continuous evaporation process by Doehlert shells

    PubMed Central

    Porte, Catherine; Havet, Jean-Louis; Daguet, David

    2003-01-01

    The modelling of the parameters that influence the continuous evaporation of an alcoholic extract was considered using Doehlert matrices. The work was performed with a wiped falling film evaporator that allowed us to study the influence of the pressure, temperature, feed flow and dry matter of the feed solution on the dry matter contents of the resulting concentrate, and the productivity of the process. The Doehlert shells were used to model the influential parameters. The pattern obtained from the experimental results was checked allowing for some dysfunction in the unit. The evaporator was modified and a new model applied; the experimental results were then in agreement with the equations. The model was finally determined and successfully checked in order to obtain an 8% dry matter concentrate with the best productivity; the results fit in with the industrial constraints of subsequent processes. PMID:18924887

  9. Influence of Hot forging on Tribological behavior of Al6061-TiB2 In-situ composites

    NASA Astrophysics Data System (ADS)

    Pradeep kumar, G. S.; Keshavamurthy, R.; kuppahalli, Prabhakar; kumari, Prachi

    2016-09-01

    Al6061-TiB2 metal matrix composite was fabricated by stir casting technique via in-situ reaction, using mixture of Al6061 alloy, Potassium tetraflouroborate salt (KBF4) and tetraflourotitanate (K2TiF6). The cast composites were processed to hot forging, SEM studies; X- ray Diffraction studies (XRD), Microhardness and Dry friction and wear tests. Pin on disc type machine was used to perform tribological tests over a load range of 20-100N and sliding velocities of 0.314-1.57m/s. SEM and XRD studies confirms formation of fine in-situ TiB2 particles. Composites exhibit higher Microhardness, improved wear resistance and Lower COF with formation of TiB2 particles when compared with the unreinforced alloy. Compared to cast alloy and its Composites, forged alloy and its composites show superior Tribological behavior under similar test conditions.

  10. Ergodicity and Parameter Estimates for Infinite-Dimensional Fractional Ornstein-Uhlenbeck Process

    SciTech Connect

    Maslowski, Bohdan Pospisil, Jan

    2008-06-15

    Existence and ergodicity of a strictly stationary solution for linear stochastic evolution equations driven by cylindrical fractional Brownian motion are proved. Ergodic behavior of non-stationary infinite-dimensional fractional Ornstein-Uhlenbeck processes is also studied. Based on these results, strong consistency of suitably defined families of parameter estimators is shown. The general results are applied to linear parabolic and hyperbolic equations perturbed by a fractional noise.

  11. Influence of processing parameters on long lasting hybrid phosphor for LED applications

    NASA Astrophysics Data System (ADS)

    Jain, Abhilasha; Kumar, Ashwini; Dhoble, S. J.; Peshwe, D. R.

    2016-05-01

    Rare earth activated hybrid phosphors have made significant progress in terms of better light output, color properties and potential for long life. All these features coupled with low cost production and reduced maintenance have offered phosphor converted LEDs for diverse optoelectronic applications including signal lighting in advanced aviation. The present paper explores the effect of various processing parameters on luminescent hybrid phosphors fabricated through combustion synthesis.

  12. Continuous melt granulation: Influence of process and formulation parameters upon granule and tablet properties.

    PubMed

    Monteyne, Tinne; Vancoillie, Jochem; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-10-01

    The pharmaceutical industry has a growing interest in alternative manufacturing models allowing automation and continuous production in order to improve process efficiency and reduce costs. Implementing a switch from batch to continuous processing requires fundamental process understanding and the implementation of quality-by-design (QbD) principles. The aim of this study was to examine the relationship between formulation-parameters (type binder, binder concentration, drug-binder miscibility), process-parameters (screw speed, powder feed rate and granulation temperature), granule properties (size, size distribution, shape, friability, true density, flowability) and tablet properties (tensile strength, friability, dissolution rate) of four different drug-binder formulations using Design of experiments (DOE). Two binders (polyethylene glycol (PEG) and Soluplus®) with a different solid state, semi-crystalline vs amorphous respectively, were combined with two model-drugs, metoprolol tartrate (MPT) and caffeine anhydrous (CAF), both having a contrasting miscibility with the binders. This research revealed that the granule properties of miscible drug-binder systems depended on the powder feed rate and barrel filling degree of the granulator whereas the granule properties of immiscible systems were mainly influenced by binder concentration. Using an amorphous binder, the tablet tensile strength depended on the granule size. In contrast, granule friability was more important for tablet quality using a brittle binder. However, this was not the case for caffeine-containing blends, since these phenomena were dominated by the enhanced compression properties of caffeine Form I, which was formed during granulation. Hence, it is important to gain knowledge about formulation behavior during processing since this influences the effect of process parameters onto the granule and tablet properties. PMID:27449628

  13. Continuous melt granulation: Influence of process and formulation parameters upon granule and tablet properties.

    PubMed

    Monteyne, Tinne; Vancoillie, Jochem; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-10-01

    The pharmaceutical industry has a growing interest in alternative manufacturing models allowing automation and continuous production in order to improve process efficiency and reduce costs. Implementing a switch from batch to continuous processing requires fundamental process understanding and the implementation of quality-by-design (QbD) principles. The aim of this study was to examine the relationship between formulation-parameters (type binder, binder concentration, drug-binder miscibility), process-parameters (screw speed, powder feed rate and granulation temperature), granule properties (size, size distribution, shape, friability, true density, flowability) and tablet properties (tensile strength, friability, dissolution rate) of four different drug-binder formulations using Design of experiments (DOE). Two binders (polyethylene glycol (PEG) and Soluplus®) with a different solid state, semi-crystalline vs amorphous respectively, were combined with two model-drugs, metoprolol tartrate (MPT) and caffeine anhydrous (CAF), both having a contrasting miscibility with the binders. This research revealed that the granule properties of miscible drug-binder systems depended on the powder feed rate and barrel filling degree of the granulator whereas the granule properties of immiscible systems were mainly influenced by binder concentration. Using an amorphous binder, the tablet tensile strength depended on the granule size. In contrast, granule friability was more important for tablet quality using a brittle binder. However, this was not the case for caffeine-containing blends, since these phenomena were dominated by the enhanced compression properties of caffeine Form I, which was formed during granulation. Hence, it is important to gain knowledge about formulation behavior during processing since this influences the effect of process parameters onto the granule and tablet properties.

  14. Performance Assessment Method for a Forged Fingerprint Detection Algorithm

    NASA Astrophysics Data System (ADS)

    Shin, Yong Nyuo; Jun, In-Kyung; Kim, Hyun; Shin, Woochang

    The threat of invasion of privacy and of the illegal appropriation of information both increase with the expansion of the biometrics service environment to open systems. However, while certificates or smart cards can easily be cancelled and reissued if found to be missing, there is no way to recover the unique biometric information of an individual following a security breach. With the recognition that this threat factor may disrupt the large-scale civil service operations approaching implementation, such as electronic ID cards and e-Government systems, many agencies and vendors around the world continue to develop forged fingerprint detection technology, but no objective performance assessment method has, to date, been reported. Therefore, in this paper, we propose a methodology designed to evaluate the objective performance of the forged fingerprint detection technology that is currently attracting a great deal of attention.

  15. Crack toughness evaluation of hot pressed and forged beryllium.

    NASA Technical Reports Server (NTRS)

    Jones, M. H.; Bubsey, R. T.; Brown, W. F., Jr.

    1973-01-01

    Fracture toughness tests at room temperature were made on three-point loaded beryllium bend specimens cut from hot pressed block and a forged disk. These specimens had plane proportions conforming to ASTM E 399 and covered a thickness range of from 1/32 to 1/2 in. Two sets of bend specimens were tested, one having fatigue cracks and the other 0.5 mil radius notches. One objective of the investigation was the development of techniques to produce fatigue cracks in accordance with the procedures specified in ASTM E 399. This objective was achieved for the hot pressed material. In plane cracks were not consistently produced in the specimens cut from forged stock.

  16. West Flank Coso, CA FORGE ArcGIS data 2

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    archive of ArcGIS data from the West Flank FORGE site located in Coso, California. Archive contains: 8 shapefiles polygon of the 3D geologic model polylines of the traces 3D modeled faults polylines of the fault traces from Duffield and Bacon, 1980 polygon of the West Flank FORGE site polylines of the traces of the geologic cross-sections (cross-sections in a separate archive in the GDR) polylines of the traces of the seismic reflection profiles through and adjacent to the West Flank site (seismic reflection profiles in a separate archive in the GDR) points of the well collars in and around the West Flank site polylines of the surface expression of the West Flank well paths

  17. Using experimental design to evaluate processing parameters in soft ferrite manufacture

    SciTech Connect

    Taylor, J.A.T.; Reczek, S.T.; Rosen, A.

    1995-09-01

    The manufacture of soft ferrites is a complex process that involves multitudinous, interrelated steps. Seldom can one variable, such as the effect of the particle size of a raw material, be evaluated without considering other parameters. The particle size of hematite, for example, may affect reaction rate during calcination and consequently the spinel formation. Spinel content affects hardness and is reflected in grinding time. Grinding time affects the amount of iron introduced from the milling media, and so on. To optimize a process, the primary effect of a parameter and the interactions of that affect with other variables should be evaluated. This can be accomplished by using an experimental design that maximizes the information that can be obtained from each set of samples. The purpose of this study was to investigate the impact of several processing parameters on the magnetic properties of MnZn spinels. An experimental design using an orthogonal array of three variables at two levels was used to examine sintering time, atmosphere containment and part size effects. Four and eight hours at the maximum firing temperature were used for this investigation. Atmosphere containment was achieved by covering saggers with shielding of the same composition as the cores. Size effects, which could result from surface to volume ratio differences, were addressed by comparing the data for large and small cores. The surface to volume ratio of small cores was 1.4 times that of large cores.

  18. Influence of process parameters and equipment on dry foam formulation properties using indomethacin as model drug.

    PubMed

    Sprunk, Angela; Page, Susanne; Kleinebudde, Peter

    2013-10-15

    Dry foam technology was developed to overcome insufficient oral bioavailability of poorly soluble and wettable active pharmaceutical ingredients (APIs). It is intended to enable a faster and more efficient dissolution by avoiding API agglomeration and floating of non-wetted API particles. The aim of this study was to investigate the influence of process parameters, such as paste water content and type of equipment used on dry foam morphology, granule characteristics and dissolution behavior of the corresponding tablets using indomethacin as model compound. Multiple analytical methods, namely scanning electron microscopy, X-ray micro-computed tomography and mercury porosimetry, specific surface area analysis and sieve analysis were employed. Dissolution of dry foam formulation tablets was compared to a reference formulation in biorelevant media. Process parameters proved to have a distinct influence on dry foam morphology and granule characteristics, correlations between paste viscosity and pore size distribution could be observed. Dissolution behavior of indomethacin was improved by dry foam technology compared to the reference formulation. Variation of process parameters within the studied ranges did not alter the characteristics of the dry foam formulation dissolution behavior. Therefore, dry foam technology seems a promising future technology with the option of continuous manufacturing. PMID:23891743

  19. Influence of in line monitored fluid bed granulation process parameters on the stability of Ethinylestradiol.

    PubMed

    Roßteuscher-Carl, Katrin; Fricke, Sabine; Hacker, Michael C; Schulz-Siegmund, Michaela

    2015-12-30

    Ethinylestradiol (EE) as a highly active and low dosed compound is prone to oxidative degradation. The stability of the drug substance is therefore a critical parameter that has to be considered during drug formulation. Beside the stability of the drug substance, granule particle size and moisture are critical quality attributes (CQA) of the fluid bed granulation process which influence the tableting ability of the resulting granules. Both CQA should therefore be monitored during the production process by process analytic technology (PAT) according to ICH Q8. This work focusses on the effects of drying conditions on the stability of EE in a fluid-bed granulation process. We quantified EE degradation products 6-alpha-hydroxy-EE, 6-beta-hydroxy-EE, 9(11)-dehydro-EE and 6-oxo-EE during long time storage and accelerated conditions. PAT-tools that monitor granule particle size (Spatial filtering technology) and granule moisture (Microwave resonance technology) were applied and compared with off-line methods. We found a relevant influence of residual granule moisture and thermic stress applied during granulation on the storage stability of EE, whereas no degradation was found immediately after processing. Hence we conclude that drying parameters have a relevant influence on long term EE stability.

  20. Deep silicon etch for biology MEMS fabrication: review of process parameters influence versus chip design

    NASA Astrophysics Data System (ADS)

    Magis, T.; Ballerand, S.; Bellemin Comte, A.; Pollet, Olivier

    2013-03-01

    Micro-system for biology is a growing market, especially for micro-fluidic applications (environment and health). Key part for the manufacturing of biology MEMS is the deep silicon etching by plasma to create microstructures. Usual etching process as an alternation of etching and passivation steps is a well-known method for MEMS fabrication, nowadays used in high volume production for devices like sensors and actuators. MEMS for biology applications are very different in design compared to more common micro-systems like accelerometers for instance. Indeed, their design includes on the same chip structures of very diverse size like narrow pillars, large trenches and wide cavities. This makes biology MEMS fabrication very challenging for DRIE, since each type of feature considered individually would require a specific etch process. Furthermore process parameters suited to match specifications on small size features (vertical profile, low sidewall roughness) induce issues and defects on bigger structures (undercut, micro-masking) and vice versa. Thus the process window is constrained leading to trade-offs in process development. In this paper process parameters such as source and platen powers, pressure, etching and passivation gas flows and steps duration were investigated to achieve all requirements. As well interactions between those different factors were characterized at different levels, from individual critical feature up to chip scale and to wafer scale. We will show the plasma process development and tuning to reach all these specifications. We also compared different chambers configurations of our ICP tool (source wafer distance, plasma diffusion) in order to obtain a good combination of hardware and process. With optimized etching we successfully fabricate micro-fluidic devices like micro-pumps.

  1. Impact of soil parameter and physical process on reproducibility of hydrological processes by land surface model in semiarid grassland

    NASA Astrophysics Data System (ADS)

    Miyazaki, S.; Yorozu, K.; Asanuma, J.; Kondo, M.; Saito, K.

    2014-12-01

    The land surface model (LSM) takes part in the land-atmosphere interaction on the earth system model for the climate change research. In this study, we evaluated the impact of soil parameters and physical process on reproducibility of hydrological process by LSM Minimal Advanced Treatments of Surface Interaction and RunOff (MATSIRO; Takata et al, 2003, GPC) forced by the meteorological data observed at grassland in semiarid climate in China and Mongolia. The testing of MATSIRO was carried out offline mode over the semiarid grassland sites at Tongyu (44.42 deg. N, 122.87 deg. E, altitude: 184m) in China, Kherlen Bayan Ulaan (KBU; 47.21 deg. N, 108.74 deg. E, altitude: 1235m) and Arvaikheer (46.23 N, 102.82E, altitude: 1,813m) in Mongolia. Although all sites locate semiarid grassland, the climate condition is different among sites, which the annual air temperature and precipitation are 5.7 deg. C and 388mm (Tongyu), 1.2 deg.C and 180mm (KBU), and 0.4 deg. C and 245mm(Arvaikheer). We can evaluate the effect of climate condition on the model performance. Three kinds of experiments have been carried out, which was run with the default parameters (CTL), the observed parameters (OBS) for soil physics and hydrology, and vegetation, and refined MATSIRO with the effect of ice in thermal parameters and unfrozen water below the freezing with same parameters as OBS run (OBSr). The validation data has been provided by CEOP(http://www.ceop.net/) , RAISE(http://raise.suiri.tsukuba.ac.jp/), GAME-AAN (Miyazaki et al., 2004, JGR) for Tongyu, KBU, and Arvaikheer, respectively. The reproducibility of the net radiation, the soil temperature (Ts), and latent heat flux (LE) were well reproduced by OBS and OBSr run. The change of soil physical and hydraulic parameter affected the reproducibility of soil temperature (Ts) and soil moisture (SM) as well as energy flux component especially for the sensible heat flux (H) and soil heat flux (G). The reason for the great improvement on the

  2. Quantitative analysis of beam delivery parameters and treatment process time for proton beam therapy

    SciTech Connect

    Suzuki, Kazumichi; Gillin, Michael T.; Sahoo, Narayan; Zhu, X. Ronald; Lee, Andrew K.; Lippy, Denise

    2011-07-15

    Purpose: To evaluate patient census, equipment clinical availability, maximum daily treatment capacity, use factor for major beam delivery parameters, and treatment process time for actual treatments delivered by proton therapy systems. Methods: The authors have been recording all beam delivery parameters, including delivered dose, energy, range, spread-out Bragg peak widths, gantry angles, and couch angles for every treatment field in an electronic medical record system. We analyzed delivery system downtimes that had been recorded for every equipment failure and associated incidents. These data were used to evaluate the use factor of beam delivery parameters, the size of the patient census, and the equipment clinical availability of the facility. The duration of each treatment session from patient walk-in and to patient walk-out of the treatment room was measured for 82 patients with cancers at various sites. Results: The yearly average equipment clinical availability in the last 3 yrs (June 2007-August 2010) was 97%, which exceeded the target of 95%. Approximately 2200 patients had been treated as of August 2010. The major disease sites were genitourinary (49%), thoracic (25%), central nervous system (22%), and gastrointestinal (2%). Beams have been delivered in approximately 8300 treatment fields. The use factor for six beam delivery parameters was also evaluated. Analysis of the treatment process times indicated that approximately 80% of this time was spent for patient and equipment setup. The other 20% was spent waiting for beam delivery and beam on. The total treatment process time can be expressed by a quadratic polynomial of the number of fields per session. The maximum daily treatment capacity of our facility using the current treatment processes was estimated to be 133 {+-} 35 patients. Conclusions: This analysis shows that the facility has operated at a high performance level and has treated a large number of patients with a variety of diseases. The use

  3. Process optimization in high-average-power ultrashort pulse laser microfabrication: how laser process parameters influence efficiency, throughput and quality

    NASA Astrophysics Data System (ADS)

    Schille, Joerg; Schneider, Lutz; Loeschner, Udo

    2015-09-01

    In this paper, laser processing of technical grade stainless steel and copper using high-average-power ultrashort pulse lasers is studied in order to gain deeper insight into material removal for microfabrication. A high-pulse repetition frequency picosecond and femtosecond laser is used in conjunction with high-performance galvanometer scanners and an in-house developed two-axis polygon scanner system. By varying the processing parameters such as wavelength, pulse length, fluence and repetition rate, cavities of standardized geometry are fabricated and analyzed. From the depths of the cavities produced, the ablation rate and removal efficiency are estimated. In addition, the quality of the cavities is evaluated by means of scanning electron microscope micrographs or rather surface roughness measurements. From the results obtained, the influence of the machining parameters on material removal and machining quality is discussed. In addition, it is shown that both material removal rate and quality increase by using femtosecond compared to picosecond laser pulses. On stainless steel, a maximum throughput of 6.81 mm3/min is achieved with 32 W femtosecond laser powers; if using 187 W picosecond laser powers, the maximum is 15.04 mm3/min, respectively. On copper, the maximum throughputs are 6.1 mm3/min and 21.4 mm3/min, obtained with 32 W femtosecond and 187 W picosecond laser powers. The findings indicate that ultrashort pulses in the mid-fluence regime yield most efficient material removal. In conclusion, from the results of this analysis, a range of optimum processing parameters are derived feasible to enhance machining efficiency, throughput and quality in high-rate micromachining. The work carried out here clearly opens the way to significant industrial applications.

  4. Forging And Milling Contribution On Residual Stresses For A Textured Biphasic Titanium Alloy

    SciTech Connect

    Deleuze, C.; Fabre, A.; Barrallier, L.; Molinas, O.

    2011-01-17

    Ti-10V-2Fe-3Al is a biphasic titanium alloy ({alpha}+{beta}) used in aeronautical applications for its mechanical properties, such as its yield strength of 1200 MPa and it weighs 40% less than steel. This alloy is particularly useful for vital parts with complex geometry, because of its high forging capability. In order to predict the capability for fatigue lifetime, the designers need to know the residual stresses. X-Ray diffraction is the main experimental technique used to determine residual stresses on the surface. In this case, stress levels are primarily influenced by the complex forging and milling process. On this alloy in particular, it may be difficult to characterize stress due to modification of the microstructure close to the surface. Results obtained by x-ray analysis depend on the correct definition of the shape of the diffraction peaks. The more precisely defined the position of the peak, the more accurately the stresses are evaluated. This paper presents a method to detect if residual stresses can be characterized by x-ray diffraction. The characterization of hardness seems to be a relevant technique to quickly analyze the capability of x-ray diffraction to determine residual stresses.

  5. Display device for indicating the value of a parameter in a process plant

    DOEpatents

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1993-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system (72) which is nuclear qualified for rapid response to changes in plant parameters and a component control system (64) which together provide a discrete monitoring and control capability at a panel (14-22, 26, 28) in the control room (10). A separate data processing system (70), which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs (84) and a large, overhead integrated process status overview board (24). The discrete indicator and alarm system (72) and the data processing system (70) receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board (24) is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof.

  6. Estimation of the soil strength parameters in Tertiary volcanic regolith (NE Turkey) using analytical hierarchy process

    NASA Astrophysics Data System (ADS)

    Ersoy, Hakan; Karsli, Melek Betül; Çellek, Seda; Kul, Bilgehan; Baykan, İdris; Parsons, Robert L.

    2013-12-01

    Costly and time consuming testing techniques and the difficulties in providing undisturbed samples for these tests have led researchers to estimate strength parameters of soils with simple index tests. However, the paper focuses on estimation of strength parameters of soils as a function of the index properties. Analytical hierarchy process and multiple regression analysis based methodology were performed on datasets obtained from soil tests on 41 samples in Tertiary volcanic regolith. While the hierarchy model focused on determining the most important index properties affecting on strength parameters, regression analysis established meaningful relationships between strength parameters and index properties. The negative polynomial correlations between the friction angle and plasticity properties, and the positive exponential relations between the cohesion and plasticity properties were determined. These relations are characterized by a regression coefficient of 0.80. However, Terzaghi bearing capacity formulas were used to test the model. It is important to see whether there is any statistically significant relation between the calculated and the observed bearing capacity values for model testing. Based on the model, the positive linear correlation characterized by the regression coefficient of 0.86 were determined between bearing capacity values obtained by direct and indirect methods.

  7. Development of optimization model for sputtering process parameter based on gravitational search algorithm

    NASA Astrophysics Data System (ADS)

    Norlina, M. S.; Diyana, M. S. Nor; Mazidah, P.; Rusop, M.

    2016-07-01

    In the RF magnetron sputtering process, the desirable layer properties are largely influenced by the process parameters and conditions. If the quality of the thin film has not reached up to its intended level, the experiments have to be repeated until the desirable quality has been met. This research is proposing Gravitational Search Algorithm (GSA) as the optimization model to reduce the time and cost to be spent in the thin film fabrication. The optimization model's engine has been developed using Java. The model is developed based on GSA concept, which is inspired by the Newtonian laws of gravity and motion. In this research, the model is expected to optimize four deposition parameters which are RF power, deposition time, oxygen flow rate and substrate temperature. The results have turned out to be promising and it could be concluded that the performance of the model is satisfying in this parameter optimization problem. Future work could compare GSA with other nature based algorithms and test them with various set of data.

  8. Production of furfural from pentosan-rich biomass: analysis of process parameters during simultaneous furfural stripping.

    PubMed

    Agirrezabal-Telleria, I; Gandarias, I; Arias, P L

    2013-09-01

    Among the furan-based compounds, furfural (FUR) shows interesting properties as building-block or industrial solvent. It is produced from pentosan-rich biomass via xylose cyclodehydration. The current FUR production makes use of homogeneous catalysts and excessive amounts of steam. The development of greener furfural production and separation techniques implies the use of heterogeneous catalysts and innovative separation processes. This work deals with the conversion of corncobs as xylose source to be dehydrated to furfural. The results reveal differences between the use of direct corncob hydrolysis and dehydration to furfural and the prehydrolysis and dehydration procedures. Moreover, this work focuses on an economical analysis of the main process parameters during N2-stripping and its economical comparison to the current steam-stripping process. The results show a considerable reduction of the annual utility costs due to use of recyclable nitrogen and the reduction of the furfural purification stages. PMID:23810948

  9. Production of furfural from pentosan-rich biomass: analysis of process parameters during simultaneous furfural stripping.

    PubMed

    Agirrezabal-Telleria, I; Gandarias, I; Arias, P L

    2013-09-01

    Among the furan-based compounds, furfural (FUR) shows interesting properties as building-block or industrial solvent. It is produced from pentosan-rich biomass via xylose cyclodehydration. The current FUR production makes use of homogeneous catalysts and excessive amounts of steam. The development of greener furfural production and separation techniques implies the use of heterogeneous catalysts and innovative separation processes. This work deals with the conversion of corncobs as xylose source to be dehydrated to furfural. The results reveal differences between the use of direct corncob hydrolysis and dehydration to furfural and the prehydrolysis and dehydration procedures. Moreover, this work focuses on an economical analysis of the main process parameters during N2-stripping and its economical comparison to the current steam-stripping process. The results show a considerable reduction of the annual utility costs due to use of recyclable nitrogen and the reduction of the furfural purification stages.

  10. Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production

    PubMed Central

    Patel, Vinay R.; Dumancas, Gerard G.; Kasi Viswanath, Lakshmi C.; Maples, Randall; Subong, Bryan John J.

    2016-01-01

    Castor oil, produced from castor beans, has long been considered to be of important commercial value primarily for the manufacturing of soaps, lubricants, and coatings, among others. Global castor oil production is concentrated primarily in a small geographic region of Gujarat in Western India. This region is favorable due to its labor-intensive cultivation method and subtropical climate conditions. Entrepreneurs and castor processors in the United States and South America also cultivate castor beans but are faced with the challenge of achieving high castor oil production efficiency, as well as obtaining the desired oil quality. In this manuscript, we provide a detailed analysis of novel processing methods involved in castor oil production. We discuss novel processing methods by explaining specific processing parameters involved in castor oil production. PMID:27656091

  11. Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production.

    PubMed

    Patel, Vinay R; Dumancas, Gerard G; Kasi Viswanath, Lakshmi C; Maples, Randall; Subong, Bryan John J

    2016-01-01

    Castor oil, produced from castor beans, has long been considered to be of important commercial value primarily for the manufacturing of soaps, lubricants, and coatings, among others. Global castor oil production is concentrated primarily in a small geographic region of Gujarat in Western India. This region is favorable due to its labor-intensive cultivation method and subtropical climate conditions. Entrepreneurs and castor processors in the United States and South America also cultivate castor beans but are faced with the challenge of achieving high castor oil production efficiency, as well as obtaining the desired oil quality. In this manuscript, we provide a detailed analysis of novel processing methods involved in castor oil production. We discuss novel processing methods by explaining specific processing parameters involved in castor oil production.

  12. Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production.

    PubMed

    Patel, Vinay R; Dumancas, Gerard G; Kasi Viswanath, Lakshmi C; Maples, Randall; Subong, Bryan John J

    2016-01-01

    Castor oil, produced from castor beans, has long been considered to be of important commercial value primarily for the manufacturing of soaps, lubricants, and coatings, among others. Global castor oil production is concentrated primarily in a small geographic region of Gujarat in Western India. This region is favorable due to its labor-intensive cultivation method and subtropical climate conditions. Entrepreneurs and castor processors in the United States and South America also cultivate castor beans but are faced with the challenge of achieving high castor oil production efficiency, as well as obtaining the desired oil quality. In this manuscript, we provide a detailed analysis of novel processing methods involved in castor oil production. We discuss novel processing methods by explaining specific processing parameters involved in castor oil production. PMID:27656091

  13. Castor Oil: Properties, Uses, and Optimization of Processing Parameters in Commercial Production

    PubMed Central

    Patel, Vinay R.; Dumancas, Gerard G.; Kasi Viswanath, Lakshmi C.; Maples, Randall; Subong, Bryan John J.

    2016-01-01

    Castor oil, produced from castor beans, has long been considered to be of important commercial value primarily for the manufacturing of soaps, lubricants, and coatings, among others. Global castor oil production is concentrated primarily in a small geographic region of Gujarat in Western India. This region is favorable due to its labor-intensive cultivation method and subtropical climate conditions. Entrepreneurs and castor processors in the United States and South America also cultivate castor beans but are faced with the challenge of achieving high castor oil production efficiency, as well as obtaining the desired oil quality. In this manuscript, we provide a detailed analysis of novel processing methods involved in castor oil production. We discuss novel processing methods by explaining specific processing parameters involved in castor oil production.

  14. Effect of Geometric Parameters on Formability and Strain Path During Tube Hydrforming Process

    NASA Astrophysics Data System (ADS)

    Omar, A.; Harisankar, K. R.; Tewari, Asim; Narasimhan, K.

    2016-08-01

    Forming limit diagram (FLD) is an important tool to measure the material's formability for metal forming processes. In order to successfully manufacture a component through tube hydroforming process it is very important to know the effect of material properties, process and geometrical parameters on the outcome of finished product. This can be obtained by running a finite element code which not only saves time and money but also gives a result with considerable accuracy. Therefore, in this paper the mutual effect of diameter as well as thickness has been studied. Firstly the finite element based prediction is carried out to assess the formability of seamless and welded tubes with varying thickness. Later on, effect of varying diameter and thickness on strain path is predicted using statistical based regression analysis. Finally, the mutual effect of varying material property alongwith varying thickness and diameter on constraint factor is studied.

  15. Simulations and Experiments of Hot Forging Design and Evaluation of the Aircraft Landing Gear Barrel Al Alloy Structure

    NASA Astrophysics Data System (ADS)

    Ram Prabhu, T.

    2016-04-01

    In the present study, the hot forging design of a typical landing gear barrel was evolved using finite element simulations and validated with experiments. A DEFORM3D software was used to evolve the forging steps to obtain the sound quality part free of defects with minimum press force requirements. The hot forging trial of a barrel structure was carried out in a 30 MN hydraulic press based on the simulation outputs. The tensile properties of the part were evaluated by taking samples from all three orientations (longitudinal, long transverse, short transverse). The hardness and microstructure of the part were also investigated. To study the soundness of the product, fluorescent penetrant inspection and ultrasonic testing were performed in order to identify any potential surface or internal defects in the part. From experiments, it was found that the part was formed successfully without any forging defects such as under filling, laps, or folds that validated the effectiveness of the process simulation. The tensile properties of the part were well above the specification limit (>10%) and the properties variation with respect to the orientation was less than 2.5%. The part has qualified the surface defects level of Mil Std 1907 Grade C and the internal defects level of AMS 2630 Class A (2 mm FBh). The microstructure shows mean grain length and width of 167 and 66 µm in the longitudinal direction. However, microstructure results revealed that the coarse grain structure was observed on the flat surface near the lug region due to the dead zone formation. An innovative and simple method of milling the surface layer after each pressing operation was applied to solve the problem of the surface coarse grain structure.

  16. Forging Colloidal Nanostructures via Cation Exchange Reactions

    PubMed Central

    2016-01-01

    Among the various postsynthesis treatments of colloidal nanocrystals that have been developed to date, transformations by cation exchange have recently emerged as an extremely versatile tool that has given access to a wide variety of materials and nanostructures. One notable example in this direction is represented by partial cation exchange, by which preformed nanocrystals can be either transformed to alloy nanocrystals or to various types of nanoheterostructures possessing core/shell, segmented, or striped architectures. In this review, we provide an up to date overview of the complex colloidal nanostructures that could be prepared so far by cation exchange. At the same time, the review gives an account of the fundamental thermodynamic and kinetic parameters governing these types of reactions, as they are currently understood, and outlines the main open issues and possible future developments in the field. PMID:26891471

  17. A GRAPHICS PROCESSING UNIT-ENABLED, HIGH-RESOLUTION COSMOLOGICAL MICROLENSING PARAMETER SURVEY

    SciTech Connect

    Bate, N. F.; Fluke, C. J.

    2012-01-10

    In the era of synoptic surveys, the number of known gravitationally lensed quasars is set to increase by over an order of magnitude. These new discoveries will enable a move from single-quasar studies to investigations of statistical samples, presenting new opportunities to test theoretical models for the structure of quasar accretion disks and broad emission line regions (BELRs). As one crucial step in preparing for this influx of new lensed systems, a large-scale exploration of microlensing convergence-shear parameter space is warranted, requiring the computation of O(10{sup 5}) high-resolution magnification maps. Based on properties of known lensed quasars, and expectations from accretion disk/BELR modeling, we identify regions of convergence-shear parameter space, map sizes, smooth matter fractions, and pixel resolutions that should be covered. We describe how the computationally time-consuming task of producing {approx}290,000 magnification maps with sufficient resolution (10,000{sup 2} pixel map{sup -1}) to probe scales from the inner edge of the accretion disk to the BELR can be achieved in {approx}400 days on a 100 teraflop s{sup -1} high-performance computing facility, where the processing performance is achieved with graphics processing units. We illustrate a use-case for the parameter survey by investigating the effects of varying the lens macro-model on accretion disk constraints in the lensed quasar Q2237+0305. We find that although all constraints are consistent within their current error bars, models with more densely packed microlenses tend to predict shallower accretion disk radial temperature profiles. With a large parameter survey such as the one described here, such systematics on microlensing measurements could be fully explored.

  18. Consolidation processing parameters and alternative processing methods for powder metallurgy Al-Cu-Mg-X-X alloys

    NASA Technical Reports Server (NTRS)

    Sankaran, K. K.

    1987-01-01

    The effects of varying the vacuum degassing parameters on the microstructure and properties of Al-4Cu-1Mg-X-X (X-X = 1.5Li-0.2Zr or 1.5Fe-0.75Ce) alloys processed from either prealloyed (PA) or mechanically alloyed (M) powder, and consolidated by either using sealed aluminum containers or containerless vacuum hot pressing were studied. The consolidated billets were hot extruded to evaluate microstructure and properties. The MA Li-containing alloy did not include Zr, and the MA Fe- and Ce-containing alloy was made from both elemental and partially prealloyed powder. The alloys were vacuum degassed both above and below the solution heat treatment temperature. While vacuum degassing lowered the hydrogen content of these alloys, the range over which the vacuum degassing parameters were varied was not large enough to cause significant changes in degassing efficiency, and the observed variations in the mechanical properties of the heat treated alloys were attributed to varying contributions to strengthening by the sub-structure and the dispersoids. Mechanical alloying increased the strength over that of alloys of similar composition made from PA powder. The inferior properties in the transverse orientation, especially in the Li-containing alloys, suggested deficiencies in degassing. Among all of the alloys processed for this study, the Fe- and Ce-containing alloys made from MA powder possessed better combinations of strength and toughness.

  19. Mathematical modeling and analysis of EDM process parameters based on Taguchi design of experiments

    NASA Astrophysics Data System (ADS)

    Laxman, J.; Raj, K. Guru

    2015-12-01

    Electro Discharge Machining is a process used for machining very hard metals, deep and complex shapes by metal erosion in all types of electro conductive materials. The metal is removed through the action of an electric discharge of short duration and high current density between the tool and the work piece. The eroded metal on the surface of both work piece and the tool is flushed away by the dielectric fluid. The objective of this work is to develop a mathematical model for an Electro Discharge Machining process which provides the necessary equations to predict the metal removal rate, electrode wear rate and surface roughness. Regression analysis is used to investigate the relationship between various process parameters. The input parameters are taken as peak current, pulse on time, pulse off time, tool lift time. and the Metal removal rate, electrode wear rate and surface roughness are as responses. Experiments are conducted on Titanium super alloy based on the Taguchi design of experiments i.e. L27 orthogonal experiments.

  20. Beer fermentation: monitoring of process parameters by FT-NIR and multivariate data analysis.

    PubMed

    Grassi, Silvia; Amigo, José Manuel; Lyndgaard, Christian Bøge; Foschino, Roberto; Casiraghi, Ernestina

    2014-07-15

    This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor and assess process parameters in beer fermentation at different operative conditions. For this purpose, the fermentation of wort with two different yeast strains and at different temperatures was monitored for nine days by FT-NIR. To correlate the collected spectra with °Brix, pH and biomass, different multivariate data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the abovementioned process parameters that define the beer fermentation. The accuracy and robustness of the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in the production of beer. PMID:24594186

  1. Beer fermentation: monitoring of process parameters by FT-NIR and multivariate data analysis.

    PubMed

    Grassi, Silvia; Amigo, José Manuel; Lyndgaard, Christian Bøge; Foschino, Roberto; Casiraghi, Ernestina

    2014-07-15

    This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor and assess process parameters in beer fermentation at different operative conditions. For this purpose, the fermentation of wort with two different yeast strains and at different temperatures was monitored for nine days by FT-NIR. To correlate the collected spectra with °Brix, pH and biomass, different multivariate data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the abovementioned process parameters that define the beer fermentation. The accuracy and robustness of the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in the production of beer.

  2. Sensitivity analysis of a dry-processed Candu fuel pellet's design parameters

    SciTech Connect

    Choi, Hangbok; Ryu, Ho Jin

    2007-07-01

    Sensitivity analysis was carried out in order to investigate the effect of a fuel pellet's design parameters on the performance of a dry-processed Canada deuterium uranium (CANDU) fuel and to suggest the optimum design modifications. Under a normal operating condition, a dry-processed fuel has a higher internal pressure and plastic strain due to a higher fuel centerline temperature when compared with a standard natural uranium CANDU fuel. Under a condition that the fuel bundle dimensions do not change, sensitivity calculations were performed on a fuel's design parameters such as the axial gap, dish depth, gap clearance and plenum volume. The results showed that the internal pressure and plastic strain of the cladding were most effectively reduced if a fuel's element plenum volume was increased. More specifically, the internal pressure and plastic strain of the dry-processed fuel satisfied the design limits of a standard CANDU fuel when the plenum volume was increased by one half a pellet, 0.5 mm{sup 3}/K. (authors)

  3. Mechanical properties and microstructure of Al-Li-Cu-Mg-Zr die forgings

    NASA Astrophysics Data System (ADS)

    Webster, Donald; Kirkbride, Richard

    1986-11-01

    Four forgings of Al 8090 alloy were evaluated for strength, toughness, and stress corrosion resistance. A microstructural evaluation was also conducted. The forgings easily met the strength requirements for Al 7075-T73 but only just met the 7 pct minimum elongation requirement. The stress corrosion threshold was less than 35 MPa in the short transverse orientation, a value that is far below the 310 MPa minimum often required for Al 7075-T73. Fracture in areas which received low forging reductions was intergranular, while fracture in more heavily forged areas was also along subgrain boundaries. Possible mechanisms for the low toughness and stress corrosion resistance of Al-Li alloys are discussed.

  4. Residual Stresses in 21-6-9 Stainless Steel Warm Forgings

    SciTech Connect

    Everhart, Wesley A.; Lee, Jordan D.; Broecker, Daniel J.; Bartow, John P.; McQueen, Jamie M.; Switzner, Nathan T.; Neidt, Tod M.; Sisneros, Thomas A.; Brown, Donald W.

    2012-11-14

    Forging residual stresses are detrimental to the production and performance of derived machined parts due to machining distortions, corrosion drivers and fatigue crack drivers. Residual strains in a 21-6-9 stainless steel warm High Energy Rate Forging (HERF) were measured via neutron diffraction. The finite element analysis (FEA) method was used to predict the residual stresses that occur during forging and water quenching. The experimentally measured residual strains were used to calibrate simulations of the three-dimensional residual stress state of the forging. ABAQUS simulation tools predicted residual strains that tend to match with experimental results when varying yield strength is considered.

  5. Effect of design and process parameters on nip width of soft calendering

    NASA Astrophysics Data System (ADS)

    Kanth, Neel; Ray, A. K.; Dang, Riti

    2016-07-01

    Calendering is a well-known operation in which a material is run between rolls to thin it into sheets or to produce smooth or glossy finish. An attempt has been made in this investigation to remove the drawbacks in the model of Meijers and applicable directly to soft calendering, also to make nip mechanics model generalized and applicable, so that it can be applicable where there is roll to roll or roll to plate contact. Also, the effect of various design and process parameters on results of soft calendering has been discussed using the data taken from paper industry.

  6. Influence of Process Parameters on Forming of Arched Aircraft Skin with Aluminum Alloy 2024

    NASA Astrophysics Data System (ADS)

    Yan, Huajun; Zhang, Shuangjie; Gao, Ying

    To solve these problems such as easily springback and hardly controlling the loading direction when arched aircraft skin is formed, stretch forming of steel plate with aluminium alloy 2024 was simulated by the finite element software Abaqus, and the shape of the stretch forming die was the arc with radius 350mm. The influence of process parameters, such as stretch forming track and dangling length on forming of arched aircraft skin was researched, and the reasonable range of stretch forming length track and dangling length was given. The results have significance for research the forming law of arched aircraft skin.

  7. Formulation and implementation of a practical algorithm for parameter estimation with process and measurement noise

    NASA Technical Reports Server (NTRS)

    Maine, R. E.; Iliff, K. W.

    1980-01-01

    A new formulation is proposed for the problem of parameter estimation of dynamic systems with both process and measurement noise. The formulation gives estimates that are maximum likelihood asymptotically in time. The means used to overcome the difficulties encountered by previous formulations are discussed. It is then shown how the proposed formulation can be efficiently implemented in a computer program. A computer program using the proposed formulation is available in a form suitable for routine application. Examples with simulated and real data are given to illustrate that the program works well.

  8. Binaural processing model based on contralateral inhibition. II. Dependence on spectral parameters.

    PubMed

    Breebaart, J; van de Par, S; Kohlrausch, A

    2001-08-01

    This and two accompanying articles [Breebaart et al., J. Acoust. Soc. Am. 110, 1074-1088 (2001); 110, 1105-1117 (2001)] describe a computational model for the signal processing in the binaural auditory system. The model consists of several stages of monaural and binaural preprocessing combined with an optimal detector. In the present article the model is tested and validated by comparing its predictions with experimental data for binaural discrimination and masking conditions as a function of the spectral parameters of both masker and signal. For this purpose, the model is used as an artificial observer in a three-interval, forced-choice adaptive procedure. All model parameters were kept constant for all simulations described in this and the subsequent article. The effects of the following experimental parameters were investigated: center frequency of both masker and target, bandwidth of masker and target, the interaural phase relations of masker and target, and the level of the masker. Several phenomena that occur in binaural listening conditions can be accounted for. These include the wider effective binaural critical bandwidth observed in band-widening NoS(pi) conditions, the different masker-level dependence of binaural detection thresholds for narrow- and for wide-band maskers, the unification of IID and ITD sensitivity with binaural detection data, and the dependence of binaural thresholds on frequency. PMID:11519577

  9. Bioreactor process parameter screening utilizing a Plackett-Burman design for a model monoclonal antibody.

    PubMed

    Agarabi, Cyrus D; Schiel, John E; Lute, Scott C; Chavez, Brittany K; Boyne, Michael T; Brorson, Kurt A; Khan, Mansoor A; Read, Erik K

    2015-06-01

    Consistent high-quality antibody yield is a key goal for cell culture bioprocessing. This endpoint is typically achieved in commercial settings through product and process engineering of bioreactor parameters during development. When the process is complex and not optimized, small changes in composition and control may yield a finished product of less desirable quality. Therefore, changes proposed to currently validated processes usually require justification and are reported to the US FDA for approval. Recently, design-of-experiments-based approaches have been explored to rapidly and efficiently achieve this goal of optimized yield with a better understanding of product and process variables that affect a product's critical quality attributes. Here, we present a laboratory-scale model culture where we apply a Plackett-Burman screening design to parallel cultures to study the main effects of 11 process variables. This exercise allowed us to determine the relative importance of these variables and identify the most important factors to be further optimized in order to control both desirable and undesirable glycan profiles. We found engineering changes relating to culture temperature and nonessential amino acid supplementation significantly impacted glycan profiles associated with fucosylation, β-galactosylation, and sialylation. All of these are important for monoclonal antibody product quality.

  10. Analysis of Operational Parameters Affecting the Sulfur Content in Hot Metal of the COREX Process

    NASA Astrophysics Data System (ADS)

    Wu, Shengli; Wang, Laixin; Kou, Mingyin; Wang, Yujue; Zhang, Jiacong

    2016-10-01

    The COREX process, which has obvious advantages in environment protection, still has some disadvantages. It has a higher sulfur content in hot metal (HM) than the blast furnace has. In the present work, the distribution and transfer of sulfur in the COREX have been analyzed and several operational parameters related to the sulfur content in HM ([pct S]) have been obtained. Based on this, the effects of the coal rate, slag ratio, temperature of HM, melting rate, binary basicity (R 2), the ratio of MgO/Al2O3, utilization of reducing gas, top gas consumption per ton burden solid, metallization rate, oxidation degree of reducing gas, and coal and DRI distribution index on the sulfur content in HM are investigated. What's more, a linear model has been developed and subsequently used for predicting and controlling the S content in HM of the COREX process.

  11. Employment of the covariance matrix in parameter estimation for stochastic processes in cell biology

    NASA Astrophysics Data System (ADS)

    Preuss, R.; Dieterich, P.

    2013-08-01

    The dynamics of movements of biological cells can be described with models from correlated stochastic processes. In order to overcome problems from correlated and insufficient data in the determination of the model parameters of such processes we employ the covariance matrix of the data. Since the covariance suffers itself from statistical uncertainty it is corrected by a renormalization treatment [1]. For the example of normal and fractional Brownian motion, which allows both to access all quantities on full theoretical grounds and to generate data similar to experiment, we discuss our results and those of previous works by Gregory [2] and Sivia [3]. The presented approach has the potential to estimate the aging correlation function of observed cell paths and can be applied to more complicated models.

  12. Low-dose capsule filling of inhalation products: critical material attributes and process parameters.

    PubMed

    Faulhammer, Eva; Fink, Marlies; Llusa, Marcos; Lawrence, Simon M; Biserni, Stefano; Calzolari, Vittorio; Khinast, Johannes G

    2014-10-01

    The aim of the present work was to identify the material attributes and process parameters of a dosator-nozzle capsule filling machine that are critical in low-fill weight capsule filling for inhalation therapies via hard-gelatin capsules. Twelve powders, mostly inhalation carriers, some fines and one proprietary active pharmaceutical ingredient (API), were carefully characterized and filled into size 3 capsules. Since different process conditions are required to fill capsules with powders that have very different material attributes, the powders were divided into two groups. A design of experiments (DOE) based exclusively on process parameters was developed for each group, to identify the critical material attributes (CMA) and critical process parameters (CPP). The fill weight (4-45 mg) of the group I powders (larger particles, higher density, better flowability and less cohesion) correlated with the nozzle diameter (1.9-3.4mm), the dosing chamber length (2.5-5mm), the powder layer depth (5-12.5mm) and the powder density (bulk and tapped density). The RSDs were acceptable in most cases, even for very low doses. The fill weight (1.5-21 mg) of group II powders (very fine and low dense particles with a particle size <10 μm, poor flowability and higher cohesion) depended also on the nozzle diameter (1.9-2.8mm), the dosing chamber length (2.5-5mm) and the powder layer depth (5-10mm), albeit in a different way, indicating that for these powders dosator filling was not volumetric. Moreover, frictional (wall friction angle) and powder-flow characteristics (bulk density and basic flowability energy) have an influence on the mass. Thus, in summary, group I and group II powders can be filled successfully via dosator systems at low fill weights. However, the group II powders were more challenging to fill, especially without automated process control. This study is the first scientific qualification of dosator nozzles for low-fill weight (1-45 mg) capsule filling.

  13. Comparison between 2D and 3D Numerical Modelling of a hot forging simulative test

    SciTech Connect

    Croin, M.; Ghiotti, A.; Bruschi, S.

    2007-04-07

    The paper presents the comparative analysis between 2D and 3D modelling of a simulative experiment, performed in laboratory environment, in which operating conditions approximate hot forging of a turbine aerofoil section. The plane strain deformation was chosen as an ideal case to analyze the process because of the thickness variations in the final section and the consequent distributions of contact pressure and sliding velocity at the interface that are closed to the conditions of the real industrial process. In order to compare the performances of 2D and 3D approaches, two different analyses were performed and compared with the experiments in terms of loads and temperatures peaks at the interface between the dies and the workpiece.

  14. Physiological description of multivariate interdependencies between process parameters, morphology and physiology during fed-batch penicillin production.

    PubMed

    Posch, Andreas E; Herwig, Christoph

    2014-01-01

    Optimization of productivity and economics of industrial bioprocesses requires characterization of interdependencies between process parameters and process performance. In the case of penicillin production, as in other processes, process performance is often closely interlinked with the physiology and morphology of the organism used for production. This study presents a systematic approach to efficiently characterize the physiological effects of multivariate interdependencies between bioprocess design parameters (spore inoculum concentration, pO2 control level and substrate feed rate), morphology, and physiology. Method development and application was performed using the industrial model process of penicillin production. Applying traditional, statistical bioprocess analysis, multivariate correlations of raw bioprocess design parameters (high spore inoculum concentration, low pO2 control as well as reduced glucose feeding) and pellet morphology were identified. A major drawback of raw design parameter correlation models; however, is the lack of transferability across different process scales and regimes. In this context, morphological and physiological bioprocess modeling based on scalable physiological parameters is introduced. In this study, raw parameter effects on pellet morphology were efficiently summarized by the physiological parameter of the biomass yield per substrate. Finally, for the first time to our knowledge, the specific growth rate per spore was described as time-independent determinant for switching from pellet to disperse growth during penicillin production and thus introduced as a novel, scalable key process parameter for pellet morphology and process performance.

  15. Setting the process parameters for the coating process in order to assure tablet appearance based on multivariate analysis of prior data.

    PubMed

    Tanabe, Shuichi; Nakagawa, Hiroshi; Watanabe, Tomoyuki; Minami, Hidemi; Kano, Manabu; Urbanetz, Nora A

    2016-09-10

    Designing efficient, robust process parameters in drug product manufacturing is important to assure a drug's critical quality attributes. In this research, an efficient, novel procedure for a coating process parameter setting was developed, which establishes a prediction model for setting suitable input process parameters by utilizing prior manufacturing knowledge for partial least squares regression (PLSR). In the proposed procedure, target values or ranges of the output parameters are first determined, including tablet moisture content, spray mist condition, and mechanical stress on tablets. Following the preparation of predictive models relating input process parameters to corresponding output parameters, optimal input process parameters are determined using these models so that the output parameters hold within the target ranges. In predicting the exhaust air temperature output parameter, which reflects the tablets' moisture content, PLSR was employed based on prior measured data (such as batch records of other products rather than design of experiments), leading to minimal new experiments. The PLSR model was revealed to be more accurate at predicting the exhaust air temperature than a conventional semi-empirical thermodynamic model. A commercial scale verification demonstrated that the proposed process parameter setting procedure enabled assurance of the quality of tablet appearance without any trial-and-error experiments.

  16. Analysis of parameter and interaction between parameter of the microwave assisted transesterification process of coconut oil using response surface methodology

    NASA Astrophysics Data System (ADS)

    Hidayanti, Nur; Suryanto, A.; Qadariyah, L.; Prihatini, P.; Mahfud, Mahfud

    2015-12-01

    A simple batch process was designed for the transesterification of coconut oil to alkyl esters using microwave assisted method. The product with yield above 93.225% of alkyl ester is called the biodiesel fuel. Response surface methodology was used to design the experiment and obtain the maximum possible yield of biodiesel in the microwave-assisted reaction from coconut oil with KOH as the catalyst. The results showed that the time reaction and concentration of KOH catalyst have significant effects on yield of alkyl ester. Based on the response surface methodology using the selected operating conditions, the time of reaction and concentration of KOH catalyst in transesterification process were 150 second and 0.25%w/w, respectively. The largest predicted and experimental yield of alkyl esters (biodiesel) under the optimal conditions are 101.385% and 93.225%, respectively. Our findings confirmed the successful development of process for the transesterification reaction of coconut oil by microwave-assisted heating, which is effective and time-saving for alkyl ester production.

  17. Describing the catchment-averaged precipitation as a stochastic process improves parameter and input estimation

    NASA Astrophysics Data System (ADS)

    Del Giudice, Dario; Albert, Carlo; Rieckermann, Jörg; Reichert, Peter

    2016-04-01

    Rainfall input uncertainty is one of the major concerns in hydrological modeling. Unfortunately, during inference, input errors are usually neglected, which can lead to biased parameters and implausible predictions. Rainfall multipliers can reduce this problem but still fail when the observed input (precipitation) has a different temporal pattern from the true one or if the true nonzero input is not detected. In this study, we propose an improved input error model which is able to overcome these challenges and to assess and reduce input uncertainty. We formulate the average precipitation over the watershed as a stochastic input process (SIP) and, together with a model of the hydrosystem, include it in the likelihood function. During statistical inference, we use "noisy" input (rainfall) and output (runoff) data to learn about the "true" rainfall, model parameters, and runoff. We test the methodology with the rainfall-discharge dynamics of a small urban catchment. To assess its advantages, we compare SIP with simpler methods of describing uncertainty within statistical inference: (i) standard least squares (LS), (ii) bias description (BD), and (iii) rainfall multipliers (RM). We also compare two scenarios: accurate versus inaccurate forcing data. Results show that when inferring the input with SIP and using inaccurate forcing data, the whole-catchment precipitation can still be realistically estimated and thus physical parameters can be "protected" from the corrupting impact of input errors. While correcting the output rather than the input, BD inferred similarly unbiased parameters. This is not the case with LS and RM. During validation, SIP also delivers realistic uncertainty intervals for both rainfall and runoff. Thus, the technique presented is a significant step toward better quantifying input uncertainty in hydrological inference. As a next step, SIP will have to be combined with a technique addressing model structure uncertainty.

  18. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations

    PubMed Central

    Heidari, Ali; Forouzan, Mohammad R.

    2012-01-01

    Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed. PMID:25685398

  19. Data processing in subspace identification and modal parameter identification of an arch bridge

    NASA Astrophysics Data System (ADS)

    Fan, Jiangling; Zhang, Zhiyi; Hua, Hongxing

    2007-05-01

    A data-processing method concerning subspace identification is presented to improve the identification of modal parameters from measured response data only. The identification procedure of this method consists of two phases, first estimating frequencies and damping ratios and then extracting mode shapes. Elements of Hankel matrices are specially rearranged to enhance the identifiability of weak characteristics and the robustness to noise contamination. Furthermore, an alternative stabilisation diagram in combination with component energy index is adopted to effectively separate spurious and physical modes. On the basis of identified frequencies, mode shapes are extracted from the signals obtained by filtering measured data with a series of band-pass filters. The proposed method was tested with a concrete-filled steel tubular arch bridge, which was subjected to ambient excitation. Gabor representation was also employed to process measured signals before conducting parameter identification. Identified results show that the proposed method can give a reliable separation of spurious and physical modes as well as accurate estimates of weak modes only from response signals.

  20. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations.

    PubMed

    Heidari, Ali; Forouzan, Mohammad R

    2013-01-01

    Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed.

  1. Sensitivity study and parameter optimization of OCD tool for 14nm finFET process

    NASA Astrophysics Data System (ADS)

    Zhang, Zhensheng; Chen, Huiping; Cheng, Shiqiu; Zhan, Yunkun; Huang, Kun; Shi, Yaoming; Xu, Yiping

    2016-03-01

    Optical critical dimension (OCD) measurement has been widely demonstrated as an essential metrology method for monitoring advanced IC process in the technology node of 90 nm and beyond. However, the rapidly shrunk critical dimensions of the semiconductor devices and the increasing complexity of the manufacturing process bring more challenges to OCD. The measurement precision of OCD technology highly relies on the optical hardware configuration, spectral types, and inherently interactions between the incidence of light and various materials with various topological structures, therefore sensitivity analysis and parameter optimization are very critical in the OCD applications. This paper presents a method for seeking the optimum sensitive measurement configuration to enhance the metrology precision and reduce the noise impact to the greatest extent. In this work, the sensitivity of different types of spectra with a series of hardware configurations of incidence angles and azimuth angles were investigated. The optimum hardware measurement configuration and spectrum parameter can be identified. The FinFET structures in the technology node of 14 nm were constructed to validate the algorithm. This method provides guidance to estimate the measurement precision before measuring actual device features and will be beneficial for OCD hardware configuration.

  2. Optimization of pretreatments and process parameters for sorghum popping in microwave oven using response surface methodology.

    PubMed

    Mishra, Gayatri; Joshi, Dinesh C; Mohapatra, Debabandya

    2015-12-01

    Sorghum is a popular healthy snack food. Popped sorghum was prepared in a domestic microwave oven. A 3 factor 3 level Box and Behneken design was used to optimize the pretreatment conditions. Grains were preconditioned to 12-20 % moisture content by the addition of 0-2 % salt solutions. Oil was applied (0-10 % w/w) to the preconditioned grains. Optimization of the pretreatments was based on popping yield, volume expansion ratio, and sensory score. The optimized condition was found at 16.62 % (wb), 0.55 % salt and 10 % oil with popping yield of 82.228 %, volume expansion ratio of 14.564 and overall acceptability of 8.495. Further, the microwave process parameters were optimized using a 2 factor 3 level design having microwave power density ranging from 9 to 18 W/g and residence time ranging from 100 to 180 s. For the production of superior quality pop sorghum, the optimized microwave process parameters were microwave power density of 18 Wg(-1) and residence time of 140 s. PMID:26604356

  3. Micropollutant biotransformation kinetics associate with WWTP process parameters and microbial community characteristics.

    PubMed

    Helbling, Damian E; Johnson, David R; Honti, Mark; Fenner, Kathrin

    2012-10-01

    The objective of this work was to identify relevant wastewater treatment plant (WWTP) parameters and underlying microbial processes that influence the biotransformation of a diverse set of micropollutants. To do this, we determined biotransformation rate constants for ten organic micropollutants in batch reactors seeded with activated sludge from ten diverse WWTPs. The estimated biotransformation rate constants for each compound ranged between one and four orders of magnitude among the ten WWTPs. The biotransformation rate constants were tested for statistical associations with various WWTP process parameters, amoA transcript abundance, and acetylene-inhibited monooxygenase activity. We determined that (i) ammonia removal associates with oxidative micropollutant biotransformation reaction rates; (ii) archaeal but not bacterial amoA transcripts associate with both ammonia removal and oxidative micropollutant biotransformation reaction rates; and (iii) the activity of acetylene-inhibited monooxygenases (including ammonia monooxygenase) associates with ammonia removal and the biotransformation rate of isoproturon, but does not associate with all oxidative micropollutant biotransformations. In combination, these results lead to the conclusion that ammonia removal and amoA transcript abundance can potentially be predictors of oxidative micropollutant biotransformation reactions, but that the biochemical mechanism is not necessarily linked to ammonia monooxygenase activity. PMID:22938719

  4. Statistical inference methods for recurrent event processes with shape and size parameters

    PubMed Central

    WANG, MEI-CHENG; HUANG, CHIUNG-YU

    2015-01-01

    Summary This paper proposes a unified framework to characterize the rate function of a recurrent event process through shape and size parameters. In contrast to the intensity function, which is the event occurrence rate conditional on the event history, the rate function is the occurrence rate unconditional on the event history, and thus it can be interpreted as a population-averaged count of events in unit time. In this paper, shape and size parameters are introduced and used to characterize the association between the rate function λ(·) and a random variable X. Measures of association between X and λ(·) are defined via shape- and size-based coefficients. Rate-independence of X and λ(·) is studied through tests of shape-independence and size-independence, where the shape-and size-based test statistics can be used separately or in combination. These tests can be applied when X is a covariable possibly correlated with the recurrent event process through λ(·) or, in the one-sample setting, when X is the censoring time at which the observation of N(·) is terminated. The proposed tests are shape- and size-based, so when a null hypothesis is rejected, the test results can serve to distinguish the source of violation. PMID:26412863

  5. Performance of respiratory pattern parameters in classifiers for predict weaning process.

    PubMed

    Chaparro, Javier A; Giraldo, Beatriz F; Caminal, Pere; Benito, Salvador

    2012-01-01

    Weaning trials process of patients in intensive care units is a complex clinical procedure. 153 patients under extubation process (T-tube test) were studied: 94 patients with successful trials (group S), 38 patients who failed to maintain spontaneous breathing and were reconnected (group F), and 21 patients with successful test but that had to be reintubated before 48 hours (group R). The respiratory pattern of each patient was characterized through the following time series: inspiratory time (T(I)), expiratory time (T(E)), breathing cycle duration (T(Tot)), tidal volume (V(T)), inspiratory fraction (T(I)/T(Tot)), half inspired flow (V(T)/T(I)), and rapid shallow index (f/V(T)), where ƒ is respiratory rate. Using techniques as autoregressive models (AR), autoregressive moving average models (ARMA) and autoregressive models with exogenous input (ARX), the most relevant parameters of the respiratory pattern were obtained. We proposed the evaluation of these parameters using classifiers as logistic regression (LR), linear discriminant analysis (LDA), support vector machines (SVM) and classification and regression tree (CART) to discriminate between patients from groups S, F and R. An accuracy of 93% (98% sensitivity and 82% specificity) has been obtained using CART classification. PMID:23366890

  6. The role of interior watershed processes in improving parameter estimation and performance of watershed models.

    PubMed

    Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

    2014-09-01

    Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation.

  7. Optimization of processing parameters for the preparation of phytosterol microemulsions by the solvent displacement method.

    PubMed

    Leong, Wai Fun; Che Man, Yaakob B; Lai, Oi Ming; Long, Kamariah; Misran, Misni; Tan, Chin Ping

    2009-09-23

    The purpose of this study was to optimize the parameters involved in the production of water-soluble phytosterol microemulsions for use in the food industry. In this study, response surface methodology (RSM) was employed to model and optimize four of the processing parameters, namely, the number of cycles of high-pressure homogenization (1-9 cycles), the pressure used for high-pressure homogenization (100-500 bar), the evaporation temperature (30-70 degrees C), and the concentration ratio of microemulsions (1-5). All responses-particle size (PS), polydispersity index (PDI), and percent ethanol residual (%ER)-were well fit by a reduced cubic model obtained by multiple regression after manual elimination. The coefficient of determination (R(2)) and absolute average deviation (AAD) value for PS, PDI, and %ER were 0.9628 and 0.5398%, 0.9953 and 0.7077%, and 0.9989 and 1.0457%, respectively. The optimized processing parameters were 4.88 (approximately 5) homogenization cycles, homogenization pressure of 400 bar, evaporation temperature of 44.5 degrees C, and concentration ratio of microemulsions of 2.34 cycles (approximately 2 cycles) of high-pressure homogenization. The corresponding responses for the optimized preparation condition were a minimal particle size of 328 nm, minimal polydispersity index of 0.159, and <0.1% of ethanol residual. The chi-square test verified the model, whereby the experimental values of PS, PDI, and %ER agreed with the predicted values at a 0.05 level of significance. PMID:19694442

  8. Optimization of HTST process parameters for production of ready-to-eat potato-soy snack.

    PubMed

    Nath, A; Chattopadhyay, P K; Majumdar, G C

    2012-08-01

    Ready-to-eat (RTE) potato-soy snacks were developed using high temperature short time (HTST) air puffing process and the process was found to be very useful for production of highly porous and light texture snack. The process parameters considered viz. puffing temperature (185-255 °C) and puffing time (20-60 s) with constant initial moisture content of 36.74% and air velocity of 3.99 m.s(-1) for potato-soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology following central composite rotatable design (CCRD). The optimum product in terms of minimum moisture content (11.03% db), maximum expansion ratio (3.71), minimum hardness (2,749.4 g), minimum ascorbic acid loss (9.24% db) and maximum overall acceptability (7.35) were obtained with 10.0% soy flour blend in potato flour at the process conditions of puffing temperature (231.0 °C) and puffing time (25.0 s).

  9. Translational Research: Forging a New Cultural Identity

    PubMed Central

    Coller, Barry S.

    2009-01-01

    More than a decade ago, Dr. Joseph Goldstein called attention to the increasing dissociation between scientific advances and their translation into improved health with his pithy analysis of the biotechnology industry: “1 new gene per day, 1 new company per week, 1 new drug per year.”1 Unfortunately, the gap continues to grow, with increasing concerns about whether the enormous increase in knowledge brought about by the sequencing of the human genome and other scientific advances are being matched by the translational effort. For example, a recent review by the Congressional Budget Office found that the dramatic increase in inflation-adjusted funding of biomedical research since 1970 by the pharmaceutical industry and the National Institutes of Health (NIH), in addition to the influx of capital from the biotechnology industry, has had only a minor impact on the number of truly new drugs approved by the Food and Drug Administration each year.2 The outlook for the immediate future does not appear to be much brighter, with declining numbers of new drugs being submitted for regulatory approval3 and the investment community expressing grave concerns about the prospects for both the biotechnology and pharmaceutical industries.4,5 It is not surprising, therefore, that there has been intense focus on how to successfully bridge the gap between scientific discovery and the development of new strategies to diagnose, treat, and prevent disease; this process is now commonly called translational research. PMID:18828172

  10. The effect of selected parameters of the honing process on cylinder liner surface topography

    NASA Astrophysics Data System (ADS)

    Pawlus, P.; Dzierwa, A.; Michalski, J.; Reizer, R.; Wieczorowski, M.; Majchrowski, R.

    2014-04-01

    Many truck cylinder liners made from gray cast iron were machined. Ceramic and diamond honing stones were used in the last stages of operation: coarse honing and plateau honing. The effect of honing parameters on the cylinder liner surface topography was studied. Selected surface topography parameters were response variables. It was found that parameters from the Sq group were sensitive to honing parameter change. When plateau honing time varied, the Smq parameter increased, while the other parameters, Spq and Svq, were stable.

  11. West Flank Coso, CA FORGE 3D geologic model

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  12. Snake River Plain FORGE Well Data for USGS-142

    SciTech Connect

    Robert Podgorney

    2015-11-23

    Well data for the USGS-142 well located in eastern Snake River Plain, Idaho. This data collection includes lithology reports, borehole logs, and photos of rhyolite core samples. This collection of data has been assembled as part of the site characterization data used to develop the conceptual geologic model for the Snake River Plain site in Idaho, as part of phase 1 of the Frontier Observatory for Research in Geothermal Energy (FORGE) initiative. They were assembled by the Snake River Geothermal Consortium (SRGC), a team of collaborators that includes members from national laboratories, universities, industry, and federal agencies, lead by the Idaho National Laboratory (INL).

  13. Influence of process parameters on properties of Nanostructured Lipid Carriers (NLC) formulation.

    PubMed

    Lasoń, Elwira; Sikora, Elżbieta; Ogonowski, Jan

    2013-01-01

    Nanostructured lipid carriers (NLC) are stable colloidal formulations with notable advantages for drug delivery systems. Thanks to their physicochemical stability, biocompatibility, biodegradability and controlled drug release, they have received increasing attention for the last several years. The aim of the study was to prepare and characterize nanostructured lipid carriers (NLC). Both, the effect of the process parameters and the effect of the preemulsion composition on the NLC properties were investigated. In the work, different type of surfactants (i.e. decyl glucoside, Poloxamer188, Tween 80, sodium cholate) and their combinations were used to stabilize NLC dispersions. Moreover, several kinds of solid lipids (modified beeswax, gliceryl behenate, cetyl palmitate and berry wax) and liquid lipids (caprilic/capric triglyceride and decyl oleate) were applied. An ultrasonication method using a probe type sonicator was used to obtain NLC, and the time and energy of the process were modified throuhout. The physicochemical properties of the formulations, such as particle size, size distribution, polidispersity index were studied using the dynamic light scattering (DLS) method. The electrophoretic mobility of obtained particles was also measured, using the Zetasizer Nano ZS Malvern Instrument based on the Laser Doppler Velocimetry (LDV) technique. Knowing the value of electrophoretic mobility of particles for given conditions, the zeta potential was determined. The obtained results showed that the process parameters and the composition of the preemulsion had significant impact on the nanoparticles structure. The optimal formulations size ranged between 60 and 80 nm, and the value of their zeta potential was up to -30mV. The stability of these systems was further confirmed by macroscopic observation. PMID:24432330

  14. Functional relationships for the estimation of van Genuchten parameter values in landfill processes models.

    PubMed

    White, Jim; Zardava, Kiriaki; Nayagum, Dharumarajen; Powrie, William

    2015-04-01

    Numerical models of landfill processes need to be able to estimate the capillary pressure and relative permeability of waste as a function of moisture content using analytical equations such as the van Genuchten equations. The paper identifies the range of van Genuchten parameter values for use in models and proposes a formulaic relationship between these parameter values and saturated moisture content. The concept of porous material, its behaviour under unsaturated conditions and Mualem's integral transform equation that estimates relative permeability from capillary pressure are reviewed. The application of the algebraic form of the capillary pressure function proposed by van Genuchten and its application using Mualem's transform to obtain the van Genuchten algebraic functions for relative permeability are discussed. Functional relationships are identified between saturated moisture content and the van Genuchten parameters using a database of results from other sources. These relationships may be used in numerical modelling of unsaturated flow in landfilled waste where the saturated moisture content varies significantly as the result of compression, settlement and degradation. A 2D numerical model simulation of leachate recirculation is used to investigate the sensitivity of the simulation to the introduction of these functional relationships. It is found that the transient liquid and gas flows across the model boundaries appear to be insensitive to whether or not the functions are incorporated into the model algorithm. However it is observed that using the relationships does have some impact on the distribution of the degree of saturation throughout the model and on the transient behaviour of the way in which the recirculation recharges the waste. However it is not thought that this impact would be sufficient to influence the design of a leachate recirculation system.

  15. Scalable Hyper-parameter Estimation for Gaussian Process Based Time Series Analysis

    SciTech Connect

    Chandola, Varun; Vatsavai, Raju

    2010-01-01

    Gaussian process (GP) is increasingly becoming popular as a kernel machine learning tool for non-parametric data analysis. Recently, GP has been applied to model non-linear dependencies in time series data. GP based analysis can be used to solve problems of time series prediction, forecasting, missing data imputation, change point detection, anomaly detection, etc. But the use of GP to handle massive scientific time series data sets has been limited, owing to its expensive computational complexity. The primary bottleneck is the handling of the covariance matrix whose size is quadratic in the length of the time series. In this paper we propose a scalable method that exploit the special structure of the covariance matrix for hyper-parameter estimation in GP based learning. The proposed method allows estimation of hyper parameters associated with GP in quadratic time, which is an order of magnitude improvement over standard methods with cubic complexity. Moreover, the proposed method does not require explicit computation of the covariance matrix and hence has memory requirement linear to the length of the time series as opposed to the quadratic memory requirement of standard methods. To further improve the computational complexity of the proposed method, we provide a parallel version to concurrently estimate the log likelihood for a set of time series which is the key step in the hyper-parameter estimation. Performance results on a multi-core system show that our proposed method provides significant speedups as high as 1000, even when running in serial mode, while maintaining a small memory footprint. The parallel version exploits the natural parallelization potential of the serial algorithm and is shown to perform significantly better than the serial faster algorithm, with speedups as high as 10.

  16. Functional relationships for the estimation of van Genuchten parameter values in landfill processes models.

    PubMed

    White, Jim; Zardava, Kiriaki; Nayagum, Dharumarajen; Powrie, William

    2015-04-01

    Numerical models of landfill processes need to be able to estimate the capillary pressure and relative permeability of waste as a function of moisture content using analytical equations such as the van Genuchten equations. The paper identifies the range of van Genuchten parameter values for use in models and proposes a formulaic relationship between these parameter values and saturated moisture content. The concept of porous material, its behaviour under unsaturated conditions and Mualem's integral transform equation that estimates relative permeability from capillary pressure are reviewed. The application of the algebraic form of the capillary pressure function proposed by van Genuchten and its application using Mualem's transform to obtain the van Genuchten algebraic functions for relative permeability are discussed. Functional relationships are identified between saturated moisture content and the van Genuchten parameters using a database of results from other sources. These relationships may be used in numerical modelling of unsaturated flow in landfilled waste where the saturated moisture content varies significantly as the result of compression, settlement and degradation. A 2D numerical model simulation of leachate recirculation is used to investigate the sensitivity of the simulation to the introduction of these functional relationships. It is found that the transient liquid and gas flows across the model boundaries appear to be insensitive to whether or not the functions are incorporated into the model algorithm. However it is observed that using the relationships does have some impact on the distribution of the degree of saturation throughout the model and on the transient behaviour of the way in which the recirculation recharges the waste. However it is not thought that this impact would be sufficient to influence the design of a leachate recirculation system. PMID:25573738

  17. Diets of differentially processed wheat alter ruminal fermentation parameters and microbial populations in beef cattle.

    PubMed

    Jiang, S Z; Yang, Z B; Yang, W R; Li, Z; Zhang, C Y; Liu, X M; Wan, F C

    2015-11-01

    The influences of differently processed wheat products on rumen fermentation, microbial populations, and serum biochemistry profiles in beef cattle were studied. Four ruminally cannulated Limousin × Luxi beef cattle (400 ± 10 kg) were used in the experiment with a 4 × 4 Latin square design. The experimental diets contained (on a DM basis) 60% corn silage as a forage source and 40% concentrate with 4 differently processed wheat products (extruded, pulverized, crushed, and rolled wheat). Concentrations of ruminal NH-N and microbial protein (MCP) in cattle fed crushed and rolled wheat were greater ( < 0.05) than the corresponding values in cattle fed pulverized and extruded wheat. Ruminal concentrations of total VFA and acetate and the ratio of acetate to propionate decreased ( < 0.05) with increased geometric mean particle size (geometric mean diameter) of processed wheat, except for extruded wheat; cattle fed extruded wheat had the lowest concentrations of total VFA and acetate among all treatments. The relative abundance of , , ciliated protozoa, and was lower in cattle fed the pulverized wheat diet than in the other 3 diets ( < 0.05), whereas the relative abundance of was decreased in cattle fed extruded wheat compared with cattle fed crushed and rolled wheat ( < 0.05). No treatment effect was obtained for serum enzyme activity and protein concentration ( > 0.05). Our findings suggest that the method of wheat processing could have a significant effect on ruminal fermentation parameters and microbial populations in beef cattle and that crushed and rolled processing is better in terms of ruminal NH-N and MCP content, acetate-to-propionate ratio, and relative abundance of rumen microorganisms.

  18. Optimising Drug Solubilisation in Amorphous Polymer Dispersions: Rational Selection of Hot-melt Extrusion Processing Parameters.

    PubMed

    Li, Shu; Tian, Yiwei; Jones, David S; Andrews, Gavin P

    2016-02-01

    The aim of this article was to construct a T-ϕ phase diagram for a model drug (FD) and amorphous polymer (Eudragit® EPO) and to use this information to understand the impact of how temperature-composition coordinates influenced the final properties of the extrudate. Defining process boundaries and understanding drug solubility in polymeric carriers is of utmost importance and will help in the successful manufacture of new delivery platforms for BCS class II drugs. Physically mixed felodipine (FD)-Eudragit(®) EPO (EPO) binary mixtures with pre-determined weight fractions were analysed using DSC to measure the endset of melting and glass transition temperature. Extrudates of 10 wt% FD-EPO were processed using temperatures (110°C, 126°C, 140°C and 150°C) selected from the temperature-composition (T-ϕ) phase diagrams and processing screw speed of 20, 100 and 200rpm. Extrudates were characterised using powder X-ray diffraction (PXRD), optical, polarised light and Raman microscopy. To ensure formation of a binary amorphous drug dispersion (ADD) at a specific composition, HME processing temperatures should at least be equal to, or exceed, the corresponding temperature value on the liquid-solid curve in a F-H T-ϕ phase diagram. If extruded between the spinodal and liquid-solid curve, the lack of thermodynamic forces to attain complete drug amorphisation may be compensated for through the use of an increased screw speed. Constructing F-H T-ϕ phase diagrams are valuable not only in the understanding drug-polymer miscibility behaviour but also in rationalising the selection of important processing parameters for HME to ensure miscibility of drug and polymer.

  19. Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

    PubMed

    Loaiza, Vanessa M; Camos, Valérie

    2016-01-01

    The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects. PMID:27152126

  20. Optimizing the equal channel angular pressing process (ECAP) operation parameters to produce bulk nanostructure materials

    SciTech Connect

    Abushgair, K.

    2015-03-30

    In this work we were interested in doing simulation using finite elements analysis (FEA) to study the equal channel angular pressing process (ECAP), which is currently one of the most popular methods of severe plastic deformation Processes (SPD). for fabricating Ultra-Fine Grained (UFG) materials, because it allows very high strains to be imposed leading to extreme work hardening and microstructural refinement. The main object of this study is to establish the influence of main parameters which effect ECAP process which are magnitude of the die angle and the friction coefficient. The angle studied between (90-135°) degree, and magnitude of the friction coefficient μ between (0.12-0.6), and number of pass. The samples were made from aluminum alloy at room temperature with (15X 15) mm cross section and 150 mm length. The simulation result shows that normal elastic strain, shears elastic strain, and max. shear elastic strain increased, when changing the angle from 90° to 100°. and decrease between the angle 110° to 135°. Also the total deformation increased when we change die angle from 90° to 135°. By studding the friction effect on the die and sample we noted that increasing the friction coefficient from 0.12 to 0.6, normal elastic strain, and shear elastic strain increased and increasing the friction coefficient from 0.1 to 0.6 decrease the normal and shear stress.

  1. Enzymatic Production of Bioxylitol from Sawdust Hydrolysate: Screening of Process Parameters.

    PubMed

    Rafiqul, I S M; Sakinah, A M M; Zularisam, A W

    2015-06-01

    Xylose-rich sawdust hydrolysate can be an economic substrate for the enzymatic production of xylitol, a specialty product. It is important to identify the process factors influencing xylitol production. This research aimed to screen the parameters significantly affecting bioxylitol synthesis from wood sawdust by xylose reductase (XR). Enzymatic bioxylitol production was conducted to estimate the effect of different variables reaction time (2-18 h), temperature (20-70 °C), pH (4.0-9.0), NADPH (1.17-5.32 g/L), and enzyme concentration (2-6 %) on the yield of xylitol. Fractional factorial design was followed to identify the key process factors. The screening design identified that time, temperature, and pH are the most significant factors influencing bioxylitol production among the variables with the values of 12 h, 35 °C, and 7.0, respectively. These conditions led to a xylitol yield of 71 % (w/w). This is the first report on the statistical screening of process variables influencing enzyme-based bioxylitol production from lignocellulosic biomass.

  2. Image processing analysis of nuclear track parameters for CR-39 detector irradiated by thermal neutron

    NASA Astrophysics Data System (ADS)

    Al-Jobouri, Hussain A.; Rajab, Mustafa Y.

    2016-03-01

    CR-39 detector which covered with boric acid (H3Bo3) pellet was irradiated by thermal neutrons from (241Am - 9Be) source with activity 12Ci and neutron flux 105 n. cm-2. s-1. The irradiation times -TD for detector were 4h, 8h, 16h and 24h. Chemical etching solution for detector was sodium hydroxide NaOH, 6.25N with 45 min etching time and 60 C˚ temperature. Images of CR-39 detector after chemical etching were taken from digital camera which connected from optical microscope. MATLAB software version 7.0 was used to image processing. The outputs of image processing of MATLAB software were analyzed and found the following relationships: (a) The irradiation time -TD has behavior linear relationships with following nuclear track parameters: i) total track number - NT ii) maximum track number - MRD (relative to track diameter - DT) at response region range 2.5 µm to 4 µm iii) maximum track number - MD (without depending on track diameter - DT). (b) The irradiation time -TD has behavior logarithmic relationship with maximum track number - MA (without depending on track area - AT). The image processing technique principally track diameter - DT can be take into account to classification of α-particle emitters, In addition to the contribution of these technique in preparation of nano- filters and nano-membrane in nanotechnology fields.

  3. 77 FR 14445 - Application for a License To Export Steel Forging

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ... FR 49139 (Aug. 28, 2007). Information about filing electronically is available on the NRC's public... Spain. December 15, 2011 head steel head steel February 7, 2012 forging. forging will be XR175 machined into the 11005983 finished vessel head at ENSA Equipos Nucleares, S.A. in Spain, for use in...

  4. Binaural processing model based on contralateral inhibition. III. Dependence on temporal parameters.

    PubMed

    Breebaart, J; van de Par, S; Kohlrausch, A

    2001-08-01

    This paper and two accompanying papers [Breebaart et al., J. Acoust. Soc. Am. 110, 1074-1088 (2001); 110, 1089-1104 (2001)] describe a computational model for the signal processing of the binaural auditory system. The model consists of several stages of monaural and binaural preprocessing combined with an optimal detector. Simulations of binaural masking experiments were performed as a function of temporal stimulus parameters and compared to psychophysical data adapted from literature. For this purpose, the model was used as an artificial observer in a three-interval, forced-choice procedure. All model parameters were kept constant for all simulations. Model predictions were obtained as a function of the interaural correlation of a masking noise and as a function of both masker and signal duration. Furthermore, maskers with a time-varying interaural correlation were used. Predictions were also obtained for stimuli with time-varying interaural time or intensity differences. Finally, binaural forward-masking conditions were simulated. The results show that the combination of a temporal integrator followed by an optimal detector in the time domain can account for all conditions that were tested, except for those using periodically varying interaural time differences (ITDs) and those measuring interaural correlation just-noticeable differences (jnd's) as a function of bandwidth. PMID:11519578

  5. Assessment of PEM4PIT parameters by analyzing catchment form and processes

    NASA Astrophysics Data System (ADS)

    Santini, M.; Grimaldi, S.; Nardi, F.; Petroselli, A.

    2008-12-01

    A physically based approach (PEM4PIT, Physical Erosion Model for PIT removal) was recently introduced to correct hydrologic spurious depressions (pits) and flat areas in Digital Elevation Models. Despite PEM4PIT proved to be more suitable than commonly used geometric methods to reconstruct hydrologically connected topography and reliable stream network metrics, fundamental in rainfall/runoff modeling, the best choice of the three model parameters (slope-area exponent, (theta) erodibility (beta), and diffusivity (D)) remained an open issue to be investigated. In this work a methodology to select the optimal set of parameters is described. In particular two methods are illustrated for theta estimation, the former using Horton ratios (Flint, 1974) and the latter analyzing the "approximate characteristic form" of slope profile (Kirkby, 1971). Regarding beta and D, they are estimated applying separately a simplified topographic equilibrium equation for the basin domains interested by the fluvial erosion and diffusion processes, respectively. ASTER DEMs of several case studies watersheds are used as input dataset; finally PEM4PIT results are compared, in terms of extracted network, with the results of standard approaches and with the digitized bluelines.

  6. Consequences of Continuity: The Hunt for Intrinsic Properties within Parameters of Dynamics in Psychological Processes.

    PubMed

    Boker, Steven M

    2002-07-01

    A little over three hundred years ago Sir Isaac Newton wrote of a simple set of relations that could be used to predict the motions of objects relative to one another. The main advantage of this insight was that the relationship between the movements of the planets and stars could be predicted much more simply than with the accurate, but cumbersome Ptolemaic calculations. But perhaps the most important consequence of the acceptance of Newton's insight was that intrinsic properties such as mass could be distinguished from measurements such as weight. The success of Newtonian mechanics led directly to the widespread use of parameters such as force, relative speed, and momentum as a way of understanding the dynamics of moving objects. A similar revolution in thinking appears to be underway in the behavioral sciences. It is likely that intensive longitudinal measurement coupled with dynamical systems analyses will lead to simplified but powerful models of the evolution of psychological processes. In this case, it is reasonable to expect that a set of intrinsic psychological properties may be able to be extracted from the parameters of successful dynamical systems models. The purpose of this article is to issue an invitation to the hunt, to provide a tentative map as to where the game might likely be found, and blow a call on the hunting horn.

  7. Tailoring wet explosion process parameters for the pretreatment of cocksfoot grass for high sugar yields.

    PubMed

    Njoku, S I; Ahring, B K; Uellendahl, H

    2013-08-01

    The pretreatment of lignocellulosic biomass is crucial for efficient subsequent enzymatic hydrolysis and ethanol fermentation. In this study, wet explosion (WEx) pretreatment was applied to cocksfoot grass and pretreatment conditions were tailored for maximizing the sugar yields using response surface methodology. The WEx process parameters studied were temperature (160-210 °C), retention time (5-20 min), and dilute sulfuric acid concentration (0.2-0.5 %). The pretreatment parameter set E, applying 210 °C for 5 min and 0.5 % dilute sulfuric acid, was found most suitable for achieving a high glucose release with low formation of by-products. Under these conditions, the cellulose and hemicellulose sugar recovery was 94 % and 70 %, respectively. The efficiency of the enzymatic hydrolysis of cellulose under these conditions was 91 %. On the other hand, the release of pentose sugars was higher when applying less severe pretreatment conditions C (160 °C, 5 min, 0.2 % dilute sulfuric acid). Therefore, the choice of the most suitable pretreatment conditions is depending on the main target product, i.e., hexose or pentose sugars.

  8. Self-sustaining smoldering combustion for NAPL remediation: laboratory evaluation of process sensitivity to key parameters.

    PubMed

    Pironi, Paolo; Switzer, Christine; Gerhard, Jason I; Rein, Guillermo; Torero, Jose L

    2011-04-01

    Smoldering combustion has been introduced recently as a potential remediation strategy for soil contaminated by nonaqueous phase liquids (NAPLs). Published proof-of-concept experiments demonstrated that the process can be self-sustaining (i.e., requires energy input only to start the process) and achieve essentially complete remediation of the contaminated soil. Those initial experiments indicated that the process may be applicable across a broad range of NAPLs and soils. This work presents the results of a series of bench-scale experiments that examine in detail the sensitivity of the process to a range of key parameters, including contaminant concentration, water saturation, soil type, and air flow rates for two contaminants, coal tar and crude oil. Smoldering combustion was observed to be self-sustaining in the range 28,400 to 142,000 mg/kg for coal tar and in the range 31,200 to 104,000 mg/kg for crude oil, for the base case air flux. The process remained self-sustaining and achieved effective remediation across a range of initial water concentrations (0 to 177,000 mg/kg water) despite extended ignition times and decreased temperatures and velocities of the reaction front. The process also exhibited self-sustaining and effective remediation behavior across a range of fine to coarse sand grain sizes up to a threshold maximum value between 6 mm and 10 mm. Propagation velocity is observed to be highly dependent on air flux, and smoldering was observed to be self-sustaining down to an air Darcy flux of at least 0.5 cm/s for both contaminants. The extent of remediation in these cases was determined to be at least 99.5% and 99.9% for crude oil and coal tar, respectively. Moreover, no physical evidence of contamination was detected in the treatment zone for any case where a self-sustaining reaction was achieved. Lateral heat losses to the external environment were observed to significantly affect the smoldering process at the bench scale, suggesting that the field

  9. Effect of Electron Beam Freeform Fabrication (EBF3) Processing Parameters on Composition of Ti-6-4

    NASA Technical Reports Server (NTRS)

    Lach, Cynthia L.; Taminger, Karen; Schuszler, A. Bud, II; Sankaran, Sankara; Ehlers, Helen; Nasserrafi, Rahbar; Woods, Bryan

    2007-01-01

    The Electron Beam Freeform Fabrication (EBF3) process developed at NASA Langley Research Center was evaluated using a design of experiments approach to determine the effect of processing parameters on the composition and geometry of Ti-6-4 deposits. The effects of three processing parameters: beam power, translation speed, and wire feed rate, were investigated by varying one while keeping the remaining parameters constant. A three-factorial, three-level, fully balanced mutually orthogonal array (L27) design of experiments approach was used to examine the effects of low, medium, and high settings for the processing parameters on the chemistry, geometry, and quality of the resulting deposits. Single bead high deposits were fabricated and evaluated for 27 experimental conditions. Loss of aluminum in Ti-6-4 was observed in EBF3 processing due to selective vaporization of the aluminum from the sustained molten pool in the vacuum environment; therefore, the chemistries of the deposits were measured and compared with the composition of the initial wire and base plate to determine if the loss of aluminum could be minimized through careful selection of processing parameters. The influence of processing parameters and coupling between these parameters on bulk composition, measured by Direct Current Plasma (DCP), local microchemistries determined by Wavelength Dispersive Spectrometry (WDS), and deposit geometry will also be discussed.

  10. HESS Opinions: Advocating process modeling and de-emphasizing parameter estimation

    NASA Astrophysics Data System (ADS)

    Bahremand, Abdolreza

    2016-04-01

    Since its origins as an engineering discipline, with its widespread use of "black box" (empirical) modeling approaches, hydrology has evolved into a scientific discipline that seeks a more "white box" (physics-based) modeling approach to solving problems such as the description and simulation of the rainfall-runoff responses of a watershed. There has been much recent debate regarding the future of the hydrological sciences, and several publications have voiced opinions on this subject. This opinion paper seeks to comment and expand upon some recent publications that have advocated an increased focus on process-based modeling while de-emphasizing the focus on detailed attention to parameter estimation. In particular, it offers a perspective that emphasizes a more hydraulic (more physics-based and less empirical) approach to development and implementation of hydrological models.

  11. The effect of processing parameters on plasma sprayed beryllium for fusion applications

    SciTech Connect

    Castro, R.G.; Stanek, P.W.; Jacobson, L.A.; Cowgill, D.F.; Snead, L.L.

    1993-10-01

    Plasma spraying is being investigated as a potential coating technique for applying thin (0.1--5mm) layers of beryllium on plasma facing surfaces of blanket modules in ITER and also as an in-situ repair technique for repairing eroded beryllium surfaces in high heat flux divertor regions. High density spray deposits (>98% of theoretical density) of beryllium will be required in order to maximize the thermal conductivity of the beryllium coatings. A preliminary investigation was done to determine the effect of various processing parameters (particle size, particle morphology, secondary gas additions and reduced chamber pressure) on the as-deposited density of beryllium. The deposits were made using spherical beryllium feedstock powder which was produced by centrifugal atomization at Los Alamos National Laboratory (LANL). Improvements in the as-deposited densities and deposit efficiencies of the beryllium spray deposits will be discussed along with the corresponding thermal conductivity and outgassing behavior of these deposits.

  12. Narrow size distributed Ag nanoparticles grown by spin coating and thermal reduction: effect of processing parameters

    NASA Astrophysics Data System (ADS)

    Ansari, A. A.; Sartale, S. D.

    2016-08-01

    A simple method to grow uniform sized Ag nanoparticles with narrow size distribution on flat support (glass and Si substrates) via spin coating of Ag+ ions (AgNO3) solution followed by thermal reduction in H2 is presented. These grown nanoparticles can be used as model catalytic system to study size dependent oxygen reduction reaction (ORR) activity. Ag nanoparticles formation was confirmed by local surface plasmon resonance and x-ray photoelectron spectroscopy measurements. Influences of process parameters (revolution per minute (rpm), ramp and salt concentration) on grown Ag nanoparticles size, density and size uniformity are studied. With increase in rpm and ramp the size decreases and the particle number density increases, whereas the size dispersion improves. The catalytic activity of the grown Ag particles for ORR is studied and it is found that the catalytic performance is dependent on the size as well as the number density of the grown Ag nanoparticles.

  13. Application of the CBR method for adding the process of cutting tools and parameters selection

    NASA Astrophysics Data System (ADS)

    Ociepka, P.; Herbuś, K.

    2016-08-01

    The paper presents a method, basing on engineering knowledge and experience, designated to aid the selection of tools and machining parameters for the processes of turning. In this method, the informatics system is built basing on a Case Based Reasoning (CBR) method. This is a method of problems solving based on experience. It consists in finding analogies between the currently being solved task, and earlier realized tasks that have been stored in the database of the CBR system. The article presents the structure of the developed software, as well as the functioning of the CBR method. It also presents the possibility of integrating the developed method with the CAM module of the SIEMENS PLM NX program.

  14. Effects of process parameters on sheet resistance uniformity of fluorine-doped tin oxide thin films

    PubMed Central

    2012-01-01

    An alternative indium-free material for transparent conducting oxides of fluorine-doped tin oxide [FTO] thin films deposited on polyethylene terephthalate [PET] was prepared by electron cyclotron resonance - metal organic chemical vapor deposition [ECR-MOCVD]. One of the essential issues regarding metal oxide film deposition is the sheet resistance uniformity of the film. Variations in process parameters, in this case, working and bubbler pressures of ECR-MOCVD, can lead to a change in resistance uniformity. Both the optical transmittance and electrical resistance uniformity of FTO film-coated PET were investigated. The result shows that sheet resistance uniformity and the transmittance of the film are affected significantly by the changes in bubbler pressure but are less influenced by the working pressure of the ECR-MOCVD system. PMID:22221518

  15. Combustion synthesis and effects of processing parameters on physical properties of {alpha}-alumina

    SciTech Connect

    Collins, M.V.; Hirschfeld, D.A.; Shea, L.E.

    2000-01-04

    Fine particle porous {alpha}-alumina has been prepared by a wet chemical method of combustion synthesis using an aqueous precursor containing aluminum nitrate (oxidizer) and carbohydrazide, an organic fuel as starting materials. The aluminum nitrate and carbohydrazide were reacted exothermically at 400--600 C. The synthesis of {alpha}-alumina ({alpha}-Al{sub 2}O{sub 3}) was used as a model for understanding the effects of processing parameters on physical properties such as surface area, average pore size, and residual carbon content. The porous powders were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area analysis and elemental analysis. The decomposition of the starting materials was investigated using differential thermal and thermogravimetric analyses (DTA/TGA). It has been shown that the furnace temperature, fuel/oxidizer ratio, and precursor water content can be tailored to produce powders with different physical properties.

  16. Friction and Adhesion in Dry Warm Forging of Magnesium Alloy with Coated Tools

    NASA Astrophysics Data System (ADS)

    Matsumoto, Ryo; Kawashima, Hiroaki; Osakada, Kozo

    In order to develop forging process of magnesium alloys without lubrication, frictional behavior of magnesium alloy AZ31B (Mg-3%Al-1%Zn) is evaluated by a tapered plug penetration test under dry condition. The cemented tungsten carbide (WC) plugs polished to be a mirror-like surface are coated with diamond-like carbon (DLC) and TiAlN by physical vapor deposition (PVD). The cylindrical hollow billets of AZ31B are penetrated by the tapered plugs at a temperature of 200°C. The surface roughness of the hole of the billet, the adhesion length of AZ31B on the plug surface and the penetration load are measured. Compared with WC and TiAlN coating, it is found that DLC coating is effective in preventing AZ31B from adhering to the tool surface and reducing the penetration load.

  17. Optimization of residual stresses in MMC's through the variation of interfacial layer architectures and processing parameters

    NASA Technical Reports Server (NTRS)

    Pindera, Marek-Jerzy; Salzar, Robert S.

    1996-01-01

    The objective of this work was the development of efficient, user-friendly computer codes for optimizing fabrication-induced residual stresses in metal matrix composites through the use of homogeneous and heterogeneous interfacial layer architectures and processing parameter variation. To satisfy this objective, three major computer codes have been developed and delivered to the NASA-Lewis Research Center, namely MCCM, OPTCOMP, and OPTCOMP2. MCCM is a general research-oriented code for investigating the effects of microstructural details, such as layered morphology of SCS-6 SiC fibers and multiple homogeneous interfacial layers, on the inelastic response of unidirectional metal matrix composites under axisymmetric thermomechanical loading. OPTCOMP and OPTCOMP2 combine the major analysis module resident in MCCM with a commercially-available optimization algorithm and are driven by user-friendly interfaces which facilitate input data construction and program execution. OPTCOMP enables the user to identify those dimensions, geometric arrangements and thermoelastoplastic properties of homogeneous interfacial layers that minimize thermal residual stresses for the specified set of constraints. OPTCOMP2 provides additional flexibility in the residual stress optimization through variation of the processing parameters (time, temperature, external pressure and axial load) as well as the microstructure of the interfacial region which is treated as a heterogeneous two-phase composite. Overviews of the capabilities of these codes are provided together with a summary of results that addresses the effects of various microstructural details of the fiber, interfacial layers and matrix region on the optimization of fabrication-induced residual stresses in metal matrix composites.

  18. Hypertension and hematologic parameters in a community near a uranium processing facility

    SciTech Connect

    Wagner, Sara E.; Burch, James B.; Bottai, Matteo; Pinney, Susan M.; Puett, Robin; Porter, Dwayne; Vena, John E.; Hebert, James R.

    2010-11-15

    Background: Environmental uranium exposure originating as a byproduct of uranium processing can impact human health. The Fernald Feed Materials Production Center functioned as a uranium processing facility from 1951 to 1989, and potential health effects among residents living near this plant were investigated via the Fernald Medical Monitoring Program (FMMP). Methods: Data from 8216 adult FMMP participants were used to test the hypothesis that elevated uranium exposure was associated with indicators of hypertension or changes in hematologic parameters at entry into the program. A cumulative uranium exposure estimate, developed by FMMP investigators, was used to classify exposure. Systolic and diastolic blood pressure and physician diagnoses were used to assess hypertension; and red blood cells, platelets, and white blood cell differential counts were used to characterize hematology. The relationship between uranium exposure and hypertension or hematologic parameters was evaluated using generalized linear models and quantile regression for continuous outcomes, and logistic regression or ordinal logistic regression for categorical outcomes, after adjustment for potential confounding factors. Results: Of 8216 adult FMMP participants 4187 (51%) had low cumulative uranium exposure, 1273 (15%) had moderate exposure, and 2756 (34%) were in the high (>0.50 Sievert) cumulative lifetime uranium exposure category. Participants with elevated uranium exposure had decreased white blood cell and lymphocyte counts and increased eosinophil counts. Female participants with higher uranium exposures had elevated systolic blood pressure compared to women with lower exposures. However, no exposure-related changes were observed in diastolic blood pressure or hypertension diagnoses among female or male participants. Conclusions: Results from this investigation suggest that residents in the vicinity of the Fernald plant with elevated exposure to uranium primarily via inhalation exhibited

  19. Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes.

    PubMed

    Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J; McKinney, Walter; Jackson, Mark; Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L; Roberts, Jenny R; Frazer, David G; Antonini, James M

    2015-02-01

    Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson's disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m(3); 3h/day × 5 d/week × 2 weeks) to fumes generated by gas-metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. PMID:25549921

  20. Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes.

    PubMed

    Sriram, Krishnan; Lin, Gary X; Jefferson, Amy M; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J; McKinney, Walter; Jackson, Mark; Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L; Roberts, Jenny R; Frazer, David G; Antonini, James M

    2015-02-01

    Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson's disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m(3); 3h/day × 5 d/week × 2 weeks) to fumes generated by gas-metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their fine counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks.

  1. Modifying welding process parameters can reduce the neurotoxic potential of manganese-containing welding fumes

    PubMed Central

    Sriram, Krishnan; Lin, Gary X.; Jefferson, Amy M.; Stone, Samuel; Afshari, Aliakbar; Keane, Michael J.; McKinney, Walter; Jackson, Mark; Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared L.; Roberts, Jenny R.; Frazer, David G.; Antonini, James M.

    2015-01-01

    Welding fumes (WF) are a complex mixture of toxic metals and gases, inhalation of which can lead to adverse health effects among welders. The presence of manganese (Mn) in welding electrodes is cause for concern about the potential development of Parkinson’s disease (PD)-like neurological disorder. Consequently, from an occupational safety perspective, there is a critical need to prevent adverse exposures to WF. As the fume generation rate and physicochemical characteristics of welding aerosols are influenced by welding process parameters like voltage, current or shielding gas, we sought to determine if changing such parameters can alter the fume profile and consequently its neurotoxic potential. Specifically, we evaluated the influence of voltage on fume composition and neurotoxic outcome. Rats were exposed by whole-body inhalation (40 mg/m3; 3 h/day × 5 d/week × 2 weeks) to fumes generated by gas–metal arc welding using stainless steel electrodes (GMA-SS) at standard/regular voltage (25 V; RVSS) or high voltage (30 V; HVSS). Fumes generated under these conditions exhibited similar particulate morphology, appearing as chain-like aggregates; however, HVSS fumes comprised of a larger fraction of ultrafine particulates that are generally considered to be more toxic than their ne counterparts. Paradoxically, exposure to HVSS fumes did not elicit dopaminergic neurotoxicity, as monitored by the expression of dopaminergic and PD-related markers. We show that the lack of neurotoxicity is due to reduced solubility of Mn in HVSS fumes. Our findings show promise for process control procedures in developing prevention strategies for Mn-related neurotoxicity during welding; however, it warrants additional investigations to determine if such modifications can be suitably adapted at the workplace to avert or reduce adverse neurological risks. PMID:25549921

  2. FEM simulation for cold press forging forming of the round-fin heat sink

    NASA Astrophysics Data System (ADS)

    Wang, Kesheng; Han, Yu; Zhang, Haiyan; Zhang, Lihan

    2013-05-01

    In this paper, the finite element method is used to investigate the forming process of cold press forging for the round-fin heat sink in the automotive lighting. A series of simulations on the round-fin heat sink forming using the program DEFORM were carried out. The blank thickness and friction coefficient on the formation of round-fin were studied, and the tooling structure with counterpressure on the heat sink formation was also investigated. The results show that the blank thickness is very good for the round-fin formation, and the thicker the blank is, the better the round-fin can be formed; and also When both the punch-blank interface and the die-blank interface have the same value of friction factor, the larger value of friction factor is in favor of round-fin forming, the further investigation reveals that the friction at the punch-blank interface has more significant effect on preventing the initiation of flow-through compared with the friction at the die-blank interface, which implies that the punch-blank interface has more significant effect on the material flow in the formation of round-fin. Meanwhile, The tooling structure with counterpressure is helpful to the formation of round-fin heat sink, which not only ensures the height of each round-fin on the heat sink is uniform but also retards the initiation of flow-through on the reverse side of round-fin. In addition, the experiments of press forging process were conducted to validate the finite element analysis, and the simulation results are in good agreement with the experimental data.

  3. Topographic study of sputter-deposited film with different process parameters

    NASA Astrophysics Data System (ADS)

    Ju, Shin-Pon; Weng, Cheng-I.; Chang, Jee-Gong; Hwang, Chi-Chuan

    2001-06-01

    In this study, molecular dynamics simulation is employed to investigate the surface topography of thin films produced by the sputtering process for different parameters such as substrate temperature, incident energy, and incident angle. Interface width is used to quantify the quality of the deposited film. The Morse potential is used to model the atomic interaction between atoms. From the results of this study, it is found that for lower substrate temperature, lower incident energy, and larger incident angle, the growing film structure tends toward a three-dimensional columnar structure, and a rougher film is produced. Conversely, for higher substrate temperature, higher incident energy, and smaller incident angle, the growing film structure tends toward a two-dimensional (Frank-van der Merwe) quasi-layer-by-layer structure, and a smoother film is produced. Finally, average surface kinetic energy is found to be an important factor in determining the surface properties produced in the process. Generally, the produced film is smoother when the average surface kinetic energy is larger.

  4. Optimization of process parameters for drilled hole quality characteristics during cortical bone drilling using Taguchi method.

    PubMed

    Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj; Ghai, Aman

    2016-09-01

    Orthopaedic surgery involves drilling of bones to get them fixed at their original position. The drilling process used in orthopaedic surgery is most likely to the mechanical drilling process and there is all likelihood that it may harm the already damaged bone, the surrounding bone tissue and nerves, and the peril is not limited at that. It is very much feared that the recovery of that part may be impeded so that it may not be able to sustain life long. To achieve sustainable orthopaedic surgery, a surgeon must try to control the drilling damage at the time of bone drilling. The area around the holes decides the life of bone joint and so, the contiguous area of drilled hole must be intact and retain its properties even after drilling. This study mainly focuses on optimization of drilling parameters like rotational speed, feed rate and the type of tool at three levels each used by Taguchi optimization for surface roughness and material removal rate. The confirmation experiments were also carried out and results found with the confidence interval. Scanning electrode microscopy (SEM) images assisted in getting the micro level information of bone damage.

  5. Mathematical model of solid food pasteurization by ohmic heating: influence of process parameters.

    PubMed

    Marra, Francesco

    2014-01-01

    Pasteurization of a solid food undergoing ohmic heating has been analysed by means of a mathematical model, involving the simultaneous solution of Laplace's equation, which describes the distribution of electrical potential within a food, the heat transfer equation, using a source term involving the displacement of electrical potential, the kinetics of inactivation of microorganisms likely to be contaminating the product. In the model, thermophysical and electrical properties as function of temperature are used. Previous works have shown the occurrence of heat loss from food products to the external environment during ohmic heating. The current model predicts that, when temperature gradients are established in the proximity of the outer ohmic cell surface, more cold areas are present at junctions of electrodes with lateral sample surface. For these reasons, colder external shells are the critical areas to be monitored, instead of internal points (typically geometrical center) as in classical pure conductive heat transfer. Analysis is carried out in order to understand the influence of pasteurisation process parameters on this temperature distribution. A successful model helps to improve understanding of these processing phenomenon, which in turn will help to reduce the magnitude of the temperature differential within the product and ultimately provide a more uniformly pasteurized product.

  6. Parameter study of r-process lanthanide production and heating rates in kilonovae

    NASA Astrophysics Data System (ADS)

    Lippuner, Jonas; Roberts, Luke F.

    2015-04-01

    Explosive r-process nucleosynthesis in material ejected during compact object mergers may lead to radioactively powered transients called kilonovae. The timescale and peak luminosity of these transients are sensitive to the composition of the material after nuclear burning ceases, as the composition determines the local heating rate from nuclear decays and the opacity. The presence of lanthanides in the ejecta can drastically increase the opacity. We use the new general-purpose nuclear reaction network SkyNet to run a parameter study of r-process nucleosynthesis for a range of initial electron fractions Ye, initial entropies s, and density decay timescales τ. We find that the ejecta is lanthanide-free for Ye >~ 0 . 22 - 0 . 3 , depending on s and τ. The heating rate is insensitive to s and τ, but certain, larger values of Ye lead to reduced heating rates, because single nuclides dominate the heating. With a simple model we estimate the luminosity, time, and effective temperature at the peak of the light curve. Since the opacity is much lower in the lanthanide-free case, we find the luminosity peaks much earlier at ~ 1 day vs. ~ 15 days in the lanthanide-rich cases. Although there is significant variation in the heating rate with Ye, changes in the heating rate do not mitigate the effect of the lanthanides. This research is partially supported by NSF under Award Numbers AST-1333520 and AST-1205732.

  7. Optimization of processing parameters and metrology for novel NCA negative resists for NGL

    NASA Astrophysics Data System (ADS)

    Singh, Vikram; Satyanarayana, V. S. V.; Kessler, Felipe; Scheffer, Francine R.; Weibel, Daniel E.; Sharma, Satinder K.; Ghosh, Subrata; Gonsalves, Kenneth E.

    2014-04-01

    It is expected that EUV resists must simultaneously pattern 20-nm half-pitch and below, with an LWR of <1.8 nm, and a sensitivity of 5-20 mJ/cm2. In order to make a resist perform optimally, new resist chemistry is required. One such approach being investigated by us is the development of polymeric non-CAR negative photo resists for sub 16 nm technology which is directly sensitive to radiation without utilizing the concept of chemical amplification (CARs). These resist designs are accomplished by homopolymers which are prepared from monomers containing sulfonium groups. We have achieved 20 nm patterns by e-beam lithography using this system. Here we will discuss in detail process parameters such as: spinning conditions for film thicknesses <50 nm and resulting surface topographies, baking regimes, exposure conditions and protocols on sensitivity, contrast, resolution and LER/LWR. Etch resistance data on these thin films will also be provided. Our results are aimed to provide a clear understanding of how these critical steps in the lithographic imaging process will affect extendibility of the non-CAR resist concept to sub 20 nanoscale features. Photodynamics and EUV exposure data will be covered.

  8. Variation in biochemical parameters in different parts of potato tubers for processing purposes.

    PubMed

    Bandana; Sharma, Vineet; Kaushik, S K; Singh, Brajesh; Raigond, Pinky

    2016-04-01

    The present study was conducted to estimate the variation in bio-chemical parameters among eight different parts viz. bud end cortex, bud end medulla, central cortex, central medulla, pith, stem end cortex, stem end medulla and peel of potato tuber of processing varieties. Concentration of dry matter, reducing sugar, sucrose and starch content were higher in cortical region than in medullar region of stem end, bud end and central portion. Variety Kufri Chipsona-1 had maximum dry matter content in stem end cortex (SEC 30.34 %), followed by Kufri Frysona (SEC 27.71 %). Mean reducing sugar values were comparatively more in bud end cortex (BEC 111.3 mg/100 g Fresh Weight) and lowest in stem end medulla (SEM 44.05 mg/100 g FW). Bio-chemical contents varied considerably within different parts of tuber as well as in different genotypes. The information generated in this study can help processors for effective utilization of potato for various types of processing products viz., chips and French fries. PMID:27413232

  9. Characterization Of An EBL System: The Influence Of Process Parameters On Thickness Resist And Engraving Shapes

    SciTech Connect

    D'Urso, G.; Longo, M.; Ravasio, C.; Maccarini, G.

    2011-01-17

    In LIGA process, the low flexibility due to the use of masks might be overcome using the electron beam of a scansion electron microscope (SEM) instead of the synchrotron radiation. In this way, through the vector control of the beam, it is possible to irradiate a specific path on the resist without using any mask. Anyway, it is important to remark that the Electron Beam Lithography (EBL) can not include all the applications of the X-ray LIGA technique but it could be a valid alternative only for some specific uses. In particular, some limits concerning the impression of high thickness resists are expected. An EBL system based on a SEM was recently implemented by the authors and some tests were carried out to characterize the device performances. Aim of this work is to asses the system performances in terms of maximum impressible thickness resist and shape of the engraved entities. Several tests were carried out by varying the resist thickness and the process parameters.

  10. Optimization of process parameters for drilled hole quality characteristics during cortical bone drilling using Taguchi method.

    PubMed

    Singh, Gurmeet; Jain, Vivek; Gupta, Dheeraj; Ghai, Aman

    2016-09-01

    Orthopaedic surgery involves drilling of bones to get them fixed at their original position. The drilling process used in orthopaedic surgery is most likely to the mechanical drilling process and there is all likelihood that it may harm the already damaged bone, the surrounding bone tissue and nerves, and the peril is not limited at that. It is very much feared that the recovery of that part may be impeded so that it may not be able to sustain life long. To achieve sustainable orthopaedic surgery, a surgeon must try to control the drilling damage at the time of bone drilling. The area around the holes decides the life of bone joint and so, the contiguous area of drilled hole must be intact and retain its properties even after drilling. This study mainly focuses on optimization of drilling parameters like rotational speed, feed rate and the type of tool at three levels each used by Taguchi optimization for surface roughness and material removal rate. The confirmation experiments were also carried out and results found with the confidence interval. Scanning electrode microscopy (SEM) images assisted in getting the micro level information of bone damage. PMID:27254280

  11. Sensitive parameters in predicting exposure contaminants concentration in a risk assessment process.

    PubMed

    Avagliano, Salvatore; Vecchio, Antonella; Belgiorno, Vincenzo

    2005-12-01

    A sensitivity analysis (SA) was conducted on the analytical models considered in the risk-based corrective-action (RBCA) methodology of risk analysis, as developed by the American Society for Testing of Materials (ASTM), to predict a contaminant's concentration in the affected medium at the point of human exposure. These models are of interest because evaluations regarding the best approach to contaminated site remediation are shifting toward increased use of risk-based decision, and the ASTM RBCA methodology represents the most effective and internationally widely used standardized guide for risk assessment process. This paper identifies key physical and chemical parameters that need additional precision and accuracy consideration in order to reduce uncertainty in models prediction, thereby saving time, money and engineering effort in the data collection process. SA was performed applying a variance-based method to organic contaminants migration models with reference to soil-to-groundwater leaching ingestion exposure scenario. Results indicate that model output strongly depends on the organic-carbon partition coefficient, organic-carbon content, net infiltration, Darcy velocity, source-receptor distance, and first-order decay constant.

  12. Effects of Flux Precoating and Process Parameter on Welding Performance of Inconel 718 Alloy TIG Welds

    NASA Astrophysics Data System (ADS)

    Lin, Hsuan-Liang; Wu, Tong-Min; Cheng, Ching-Min

    2014-01-01

    The purpose of this study is to investigate the effect of activating flux on the depth-to-width ratio (DWR) and hot cracking susceptibility of Inconel 718 alloy tungsten inert gas (TIG) welds. The Taguchi method is employed to investigate the welding parameters that affect the DWR of weld bead and to achieve optimal conditions in the TIG welds that are coated with activating flux in TIG (A-TIG) process. There are eight single-component fluxes used in the initial experiment to evaluate the penetration capability of A-TIG welds. The experimental results show that the Inconel 718 alloy welds precoated with 50% SiO2 and 50% MoO3 flux were provided with better welding performance such as DWR and hot cracking susceptibility. The experimental procedure of TIG welding process using mixed-component flux and optimal conditions not only produces a significant increase in DWR of weld bead, but also decreases the hot cracking susceptibility of Inconel 718 alloy welds.

  13. Variation in biochemical parameters in different parts of potato tubers for processing purposes.

    PubMed

    Bandana; Sharma, Vineet; Kaushik, S K; Singh, Brajesh; Raigond, Pinky

    2016-04-01

    The present study was conducted to estimate the variation in bio-chemical parameters among eight different parts viz. bud end cortex, bud end medulla, central cortex, central medulla, pith, stem end cortex, stem end medulla and peel of potato tuber of processing varieties. Concentration of dry matter, reducing sugar, sucrose and starch content were higher in cortical region than in medullar region of stem end, bud end and central portion. Variety Kufri Chipsona-1 had maximum dry matter content in stem end cortex (SEC 30.34 %), followed by Kufri Frysona (SEC 27.71 %). Mean reducing sugar values were comparatively more in bud end cortex (BEC 111.3 mg/100 g Fresh Weight) and lowest in stem end medulla (SEM 44.05 mg/100 g FW). Bio-chemical contents varied considerably within different parts of tuber as well as in different genotypes. The information generated in this study can help processors for effective utilization of potato for various types of processing products viz., chips and French fries.

  14. Effects of Process Parameters on Ultrasonic Micro-Hole Drilling in Glass and Ruby

    SciTech Connect

    Schorderet, Alain; Deghilage, Emmanuel; Agbeviade, Kossi

    2011-05-04

    Brittle materials such as ceramics, glasses and oxide single crystals find increasing applications in advanced micro-engineering products. Machining small features in such materials represents a manufacturing challenge. Ultrasonic drilling constitutes a promising technique for realizing simple micro-holes of high diameter-to-depth ratio. The process involves impacting abrasive particles in suspension in a liquid slurry between tool and work piece. Among the process performance criteria, the drilling time (productivity) is one of the most important quantities to evaluate the suitability of the process for industrial applications.This paper summarizes recent results pertaining to the ultrasonic micro-drilling process obtained with a semi-industrial 3-axis machine. The workpiece is vibrated at 40 kHz frequency with an amplitude of several micrometers. A voice-coil actuator and a control loop based on the drilling force impose the tool feed. In addition, the tool is rotated at a prescribed speed to improve the drilling speed as well as the hole geometry. Typically, a WC wire serves as tool to bore 200 {mu}m diameter micro-holes of 300 to 1,000 {mu}m depth in glass and ruby. The abrasive slurry contains B4C particles of 1 {mu}m to 5 {mu}m diameter in various concentrations.This paper discusses, on the basis of the experimental results, the influence of several parameters on the drilling time. First, the results show that the control strategy based on the drilling force allows to reach higher feed rates (avoiding tool breakage). Typically, a 8 um/s feed rate is achieved with glass and 0.9 {mu}m/s with ruby. Tool rotation, even for values as low as 50 rpm, increases productivity and improves holes geometry. Drilling with 1 {mu}m and 5 {mu}m B4C particles yields similar productivity results. Our future research will focus on using the presented results to develop a model that can serve to optimize the process for different applications.

  15. Power ultrasound-assisted cleaner leather dyeing technique: influence of process parameters.

    PubMed

    Sivakumar, Venkatasubramanian; Rao, Paruchuri Gangadhar

    2004-03-01

    The application of power ultrasound to leather processing has a significant role in the concept of "clean technology" for leather production. The effect of power ultrasound in leather dyeing has been compared with dyeing in the absence of ultrasound and conventional drumming. The power ultrasound source used in these experiments was ultrasonic cleaner (150 W and 33 kHz). The effect of various process parameters such as amount of dye offer, temperature, and type of dye has been experimentally found out. The effect of presonication of dye solution as well as leather has been studied. Experiments at ultrasonic bath temperature were carried out to find out the combined thermal as well as stirring effects of ultrasound. Dyeing in the presence of ultrasound affords about 37.5 (1.8 times) difference as increase in % dye exhaustion or about 50% decrease in the time required for dyeing compared to dyeing in the absence of ultrasound for 4% acid red dye. About 29 (1.55 times) increase in % dye exhaustion or 30% reduction in time required for dyeing was observed using ultrasound at stationary condition compared with conventional dynamic drumming conditions. The effect of ultrasound at constant temperature conditions with a control experiment has also been studied. The dye exhaustion increases as the temperature increases (30-60 degrees C) and better results are observed at higher temperature due to the use of ultrasound. Presonication of dye solution or crust leather prior to the dyeing process has no significant improvement in dye exhaustion, suggesting ultrasound effect is realized when it is applied during the dyeing process. The results indicate that 1697 and 1416 ppm of dye can be reduced in the spent liquor due to the use of ultrasound for acid red (for 100 min) and acid black (for 3 h) dyes, respectively, thereby reducing the pollution load in the effluent stream. The color yield of the leather as inferred from the reflectance measurement indicates that dye offer can

  16. POD of ultrasonic detection of synthetic hard alpha inclusions in titanium aircraft engine forgings

    SciTech Connect

    Thompson, R. B.; Meeker, W. Q.; Brasche, L. J. H.

    2011-06-23

    The probability of detection (POD) of inspection techniques is a key input to estimating the lives of structural components such as aircraft engines. This paper describes work conducted as a part of the development of POD curves for the ultrasonic detection of synthetic hard alpha (SHA) inclusions in titanium aircraft engine forgings. The sample upon which the POD curves are to be based contains four types of right circular SHAs that have been embedded in a representative titanium forging, as well as a number of flat bottomed holes (FBHs). The SHAs were of two sizes, number 3 and number 5, with each size including seeds with nominal nitrogen concentrations of both 3 and 17 wt. %. The FBHs included sizes of number 1, number 3, and number 5. This discreteness of the data poses a number of challenges to standard processes for determining POD. For example, at each concentration of nitrogen, there are only two sizes, with 10 inspection opportunities each. Fully empirical, standard methodologies such as a circumflex versus a provide less than an ideal framework for such an analysis. For example, there is no way to describe the beam limiting effect whereby the signal no longer increases the flaw grows larger than the beam, one can only determine POD at the two concentration levels present in the block, and confidence bounds tend to be broad because of the limited data available for each case. In this paper, we will describe strategies involving the use of physics-based models to overcome these difficulties by allowing the data from all reflectors to be analyzed by a single statistical model. Included will be a discussion of the development of the physics-based model, its comparison to the experimental data (obtained at multiple sites with multiple operators) and its implications regarding the statistical analysis, whose details will be given in a separate article by Li et al. in this volume.

  17. Effect of Process Parameters on Dynamic Mechanical Performance of FDM PC/ABS Printed Parts Through Design of Experiment

    NASA Astrophysics Data System (ADS)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal; Nikzad, Mostafa; Azadmanjiri, Jalal

    2016-07-01

    In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values.

  18. Influence of the process parameters on the replication of microstructured freeform surfaces

    NASA Astrophysics Data System (ADS)

    Burgsteiner, M.; Müller, F.; Lucyshyn, T.; Kukla, C.; Holzer, C.

    2014-05-01

    Surfaces of technical parts are getting more and more attention in terms of functionalization. By modification, additional functionality is given to the part, e.g. self-cleaning effect or antireflection behavior. Nowadays mainly flat surfaces are structured which is a consequence of the available production methods. However, the demand of micro structured free form surfaces is increasing, enabling novel products. A major problem in the mass production (e.g. injection molding) of structured freeform surfaces is to demold these structures without ripping or deforming them due to occurring undercuts. Recently a novel concept was developed which overcomes this limitation. A nickel substrate containing a structure composed of lines orientated in two different directions, one orientated in melt flow direction, the other one perpendicular to that, but both with a cross-section of approximately 45 μm × 55 μm (w × h) was used as a premaster to cast a flexible master. This master made of poly(dimethylsiloxane) (PDMS) was mounted on a bending edge in an injection mold cavity. Within this paper the influence of process parameters on the replication grade of the structure lines depending on the structure orientation was evaluated, varying the holding pressure, melt and mold temperature using statistical design of experiment methods. The replication grade was evaluated by characterizing the shape of the structure lines along the entire process chain, using an infinite focus system. The results show, that the melt temperature has the biggest influence on the dimensions of the structures, the mold temperature only a slight one.

  19. Spray granulation: importance of process parameters on in vitro and in vivo behavior of dried nanosuspensions.

    PubMed

    Figueroa, Carlos E; Bose, Sonali

    2013-11-01

    The use of fluid bed granulation for drying of pharmaceutical nanoparticulates on micron-sized granule substrates is a relatively new technique, with limited understanding in the current literature of the effects of process parameters on the physical properties of the dried nanoparticle powders. This work evaluated the effects of spray mode, spray rate and atomizing pressure for spray granulation of drug nanosuspensions through a systematic study. Naproxen and a proprietary Novartis compound were converted into nanosuspensions through wet media milling and dried onto a mannitol based substrate using spray granulation. For naproxen, various physical properties of the granules, as well as the in vitro re-dispersion and dissolution characteristics of the nano-crystals, were measured. It was found that the spray mode had the most drastic effect, where top spray yielded smaller re-dispersed particle sizes and faster release rates of drug from granules than bottom spray. This was attributed to the co-current spraying in bottom spray resulting in denser, homogenous films on the substrate. Similar in vitro results were obtained for the proprietary molecule, Compound A. In vivo studies in beagle dogs with Compound A showed no significant difference between the liquid and the dried forms of the nanosuspension in terms of overall AUC, differences were observed in the tmax which correlated with the rank ordering observed from the in vitro dissolution profiles. These findings make spray granulation amenable to the production of powders with desired processing and handling properties, without compromising the overall exposure of the compound under investigation.

  20. Effect of process design and operating parameters on aerobic methane oxidation in municipal WWTPs.

    PubMed

    Daelman, Matthijs R J; Van Eynde, Tamara; van Loosdrecht, Mark C M; Volcke, Eveline I P

    2014-12-01

    Methane is a potent greenhouse gas and its emission from municipal wastewater treatment plants (WWTPs) should be prevented. One way to do this is to promote the biological conversion of dissolved methane over stripping in aeration tanks. In this study, the well-established Activated Sludge Model n°1 (ASM1) and Benchmark Simulation Model n°1 (BSM1) were extended to study the influence of process design and operating parameters on biological methane oxidation. The aeration function used in BSM 1 was upgraded to more accurately describe gas-liquid transfer of oxygen and methane in aeration tanks equipped with subsurface aeration. Dissolved methane could be effectively removed in an aeration tank at an aeration rate that is in agreement with optimal effluent quality. Subsurface bubble aeration proved to be better than surface aeration, while a CSTR configuration was superior to plug flow conditions in avoiding methane emissions. The conversion of methane in the activated sludge tank benefits from higher methane concentrations in the WWTP's influent. Finally, if an activated sludge tank is aerated with methane containing off-gas, a limited amount of methane is absorbed and converted in the mixed liquor. This knowledge helps to stimulate the methane oxidizing capacity of activated sludge in order to abate methane emissions from wastewater treatment to the atmosphere. PMID:25225767

  1. Statistical optimization of process parameters on biohydrogen production from glucose by Clostridium sp. Fanp2.

    PubMed

    Pan, C M; Fan, Y T; Xing, Y; Hou, H W; Zhang, M L

    2008-05-01

    Statistically based experimental designs were applied to optimizing process parameters for hydrogen production from glucose by Clostridium sp. Fanp2 which was isolated from effluent sludge of anaerobic hydrogen-producing bioreactor. The important factors influencing hydrogen production, which identified by initial screening method of Plackett-Burman, were glucose, phosphate buffer and vitamin solution. The path of steepest ascent was undertaken to approach the optimal region of the three significant factors. Box-Behnken design and response surface analysis were adopted to further investigate the mutual interaction between the variables and identify optimal values that bring maximum hydrogen production. Experimental results showed that glucose, vitamin solution and phosphate buffer concentration all had an individual significant influence on the specific hydrogen production potential (Ps). Simultaneously, glucose and vitamin solution, glucose and phosphate buffer were interdependent. The optimal conditions for the maximal Ps were: glucose 23.75 g/l, phosphate buffer 0.159 M and vitamin solution 13.3 ml/l. Using this statistical optimization method, the hydrogen production from glucose was increased from 2248.5 to 4165.9 ml H2/l.

  2. Production of polyols via direct hydrolysis of kraft lignin: effect of process parameters.

    PubMed

    Mahmood, Nubla; Yuan, Zhongshun; Schmidt, John; Charles Xu, Chunbao

    2013-07-01

    Kraft lignin (KL) was successfully depolymerized into polyols of moderately high hydroxyl number and yield with moderately low weight-average molecular weight (Mw) via direct hydrolysis using NaOH as a catalyst, without any organic solvent/capping agent. The effects of process parameters including reaction temperature, reaction time, NaOH/lignin ratio (w/w) and substrate concentration were investigated and the polyols/depolymerized lignins (DLs) obtained were characterized with GPC-UV, FTIR-ATR, (1)H NMR, Elemental & TOC analyzer. The best operating conditions appeared to be at 250°C, 1h, and NaOH/lignin ratio ≈0.28 with 20 wt.% substrate concentration, leading to <0.5% solid residues and ∼92% yield of DL (aliphatic-hydroxyl number ≈352 mg KOH/mg and Mw≈3310 g/mole), suitable for replacement of polyols in polyurethane foam synthesis. The overall % carbon recovery under the above best conditions was ∼90%. A higher temperature favored reduced Mw of the polyols while a longer reaction time promoted dehydration/condensation reactions. PMID:23644065

  3. The influence of VAR processes and parameters on white spot formation in Alloy 718

    SciTech Connect

    Damkroger, B.K.; Kelley, J.B.; Schlienger, M.E.; Van Den Avyle, J.A.; Williamson, R.L.; Zanner, F.J.

    1994-05-01

    Significant progress has occurred lately regarding the classification, characterization, and formation of white spots during vacuum arc remelting (VAR). White spots have been generally split into three categories: discrete white spots, which are believed to be associated with undissolved material which has fallen in from the shelf, crown, or torus regions; dendritic white spots, usually associated with dendrite clusters having fallen from the electrode; and solidification white spots, believed to be caused by local perturbations in the solidifications conditions. Characteristics and proposed formation mechanisms of white spots are reviewed and discussed in context of physical processes occurring during VAR, such as fluid flow and arc behavior. Where possible, their formation mechanisms will be considered with respect to specific operating parameters. In order to more fully understand the formation of solidification white spots, an experimental program has been begun to characterize the solidification stability of Alloy 718 and variants with respect to changes in growth rate and thermal environment. A description of the experimental program and preliminary results are included.

  4. Effect of process design and operating parameters on aerobic methane oxidation in municipal WWTPs.

    PubMed

    Daelman, Matthijs R J; Van Eynde, Tamara; van Loosdrecht, Mark C M; Volcke, Eveline I P

    2014-12-01

    Methane is a potent greenhouse gas and its emission from municipal wastewater treatment plants (WWTPs) should be prevented. One way to do this is to promote the biological conversion of dissolved methane over stripping in aeration tanks. In this study, the well-established Activated Sludge Model n°1 (ASM1) and Benchmark Simulation Model n°1 (BSM1) were extended to study the influence of process design and operating parameters on biological methane oxidation. The aeration function used in BSM 1 was upgraded to more accurately describe gas-liquid transfer of oxygen and methane in aeration tanks equipped with subsurface aeration. Dissolved methane could be effectively removed in an aeration tank at an aeration rate that is in agreement with optimal effluent quality. Subsurface bubble aeration proved to be better than surface aeration, while a CSTR configuration was superior to plug flow conditions in avoiding methane emissions. The conversion of methane in the activated sludge tank benefits from higher methane concentrations in the WWTP's influent. Finally, if an activated sludge tank is aerated with methane containing off-gas, a limited amount of methane is absorbed and converted in the mixed liquor. This knowledge helps to stimulate the methane oxidizing capacity of activated sludge in order to abate methane emissions from wastewater treatment to the atmosphere.

  5. Method of validating measurement data of a process parameter from a plurality of individual sensor inputs

    DOEpatents

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1998-01-01

    A method for generating a validated measurement of a process parameter at a point in time by using a plurality of individual sensor inputs from a scan of said sensors at said point in time. The sensor inputs from said scan are stored and a first validation pass is initiated by computing an initial average of all stored sensor inputs. Each sensor input is deviation checked by comparing each input including a preset tolerance against the initial average input. If the first deviation check is unsatisfactory, the sensor which produced the unsatisfactory input is flagged as suspect. It is then determined whether at least two of the inputs have not been flagged as suspect and are therefore considered good inputs. If two or more inputs are good, a second validation pass is initiated by computing a second average of all the good sensor inputs, and deviation checking the good inputs by comparing each good input including a present tolerance against the second average. If the second deviation check is satisfactory, the second average is displayed as the validated measurement and the suspect sensor as flagged as bad. A validation fault occurs if at least two inputs are not considered good, or if the second deviation check is not satisfactory. In the latter situation the inputs from each of all the sensors are compared against the last validated measurement and the value from the sensor input that deviates the least from the last valid measurement is displayed.

  6. Crack toughness evaluation of hot pressed and forged beryllium

    NASA Technical Reports Server (NTRS)

    Jones, M. H.; Bubsey, R. T.; Brown, W. F., Jr.

    1971-01-01

    Beryllium fracture toughness test specimens were fatigue cracked using reversed cycling with a compression load two to three times the tension load. In worked beryllium, textures may be produced which result in fatigue cracks that are out of plane with the starter notch. Specimens of hot pressed stock exhibited load displacement records which were nonlinear throughout their course. Fracture specimens of both hot pressed and forged stock showed essentially no reduction of thickness and the fracture surfaces were flat and normal to the load axis. However, the stress intensity factor at maximum load increased with decreasing thickness. Load-displacement and electric potential records for the hot pressed beryllium specimens exhibited several anomalies such as negative residual crack mouth displacements and a decrease in electrical potential with increasing load.

  7. Follow-up of hearing thresholds among forge hammering workers

    SciTech Connect

    Kamal, A.A.; Mikael, R.A.; Faris, R. )

    1989-01-01

    Hearing threshold was reexamined in a group of forge hammering workers investigated 8 years ago with consideration of the age effect and of auditory symptoms. Workers were exposed to impact noise that ranged from 112 to 139 dB(A)--at an irregular rate of 20 to 50 drop/minute--and a continuous background noise that ranged from 90 to 94 dB(A). Similar to what was observed 8 years ago, the present permanent threshold shift (PTS) showed a maximum notch at the frequency of 6 kHz and considerable elevations at the frequencies of 0.25-1 kHz. The age-corrected PTS and the postexposure hearing threshold were significantly higher than the corresponding previous values at the frequencies 0.25, 0.5, 1, and 8 kHz only. The rise was more evident at the low than at the high frequencies. Temporary threshold shift (TTS) values were significantly less than those 8 years ago. Contrary to the previous TTS, the present TTS were higher at low than at high frequencies. Although progression of PTS at the frequencies 0.25 and 0.5 kHz was continuous throughout the observed durations of exposure, progression at higher frequencies occurred essentially in the first 10 to 15 years of exposure. Thereafter, it followed a much slower rate. Tinnitus was significantly associated with difficulty in hearing the human voice and with elevation of PTS at all the tested frequencies, while acoustic after-image was significantly associated with increment of PTS at the frequencies 0.25-2 kHz. No relation between PTS and smoking was found. PTS at low frequencies may provide an indication of progression of hearing damage when the sensitivity at 6 and 4 kHz diminishes after prolonged years of exposure. Tinnitus and acoustic after-image are related to the auditory effect of forge hammering noise.

  8. Impact of kinetic parameters on heat transfer modeling for a pultrusion process

    NASA Astrophysics Data System (ADS)

    Gorthala, R.; Roux, J. A.; Vaughan, J. G.; Donti, R. P.; Hassouneh, A.

    An examination is conducted of pultrusion heat model predictions for various parameters of resin chemical kinetics; these parameters' values affect model heat-transfer results and model predictions. Attention is given to the applicability of DSC kinetic parameters to resin cure modeling, by comparing the predicted product cure temperature profiles and resin degree-of-cure values with pultrusion experiment results obtained for both carbon and glass reinforcements, different pull speeds and fiber volumes, and various die temperature profiles.

  9. Development of Processing Parameters for Organic Binders Using Selective Laser Sintering

    NASA Technical Reports Server (NTRS)

    Mobasher, Amir A.

    2003-01-01

    This document describes rapid prototyping, its relation to Computer Aided Design (CAD), and the application of these techniques to choosing parameters for Selective Laser Sintering (SLS). The document reviews the parameters selected by its author for his project, the SLS machine used, and its software.

  10. Do fattening process and biological parameters affect the accumulation of metals in Atlantic bluefin tuna?

    PubMed

    Milatou, Niki; Dassenakis, Manos; Megalofonou, Persefoni

    2015-01-01

    The objective of this study was to determine the current levels of heavy metals and trace elements in Atlantic bluefin tuna muscle tissues and how they are influenced by the fattening process and various life history parameters to ascertain whether the concentrations in muscle tissue exceed the maximum levels defined by the European Commission Decision and to evaluate the health risk posed by fish consumption. A total of 20 bluefin tuna reared in sea cages, ranging from 160 to 295 cm in length and from 80 to 540 kg in weight, were sampled from a bluefin tuna farm in the Ionian Sea. The condition factor K of each specimen was calculated and their age was estimated. Heavy metal and trace element (Hg, Zn, Fe and Cu) contents were determined in muscle tissue using cold vapour atomic absorption spectrometry and flame and graphite furnace atomic absorption spectrometry. The total Hg concentrations ranged from 0.28 to 1.28 mg kg(-1) w/w, Zn from 5.81 to 76.37 mg kg(-1) w/w, Fe from 12.14 to 39.58 mg kg(-1) w/w, and Cu from 0.36 to 0.94 mg kg(-1) w/w. Only 5% of the muscle samples of tuna contained Hg above the maximum level laid down by the European Commission Decision. Moreover, 15% of the muscle samples contained Zn above the maximum level, while Fe and Cu concentrations were within the acceptable tolerable guideline values. The reared bluefin tuna had lower concentrations of Hg than the wild ones from the Mediterranean Sea. Hg and Fe concentrations showed a positive relationship with size and age of bluefin tuna, whereas negative relationships were found for the concentrations of Zn and Cu. The estimated dietary intake values of the analysed metals were mostly below the derived guidelines.

  11. Predicting trace organic compound attenuation with spectroscopic parameters in powdered activated carbon processes.

    PubMed

    Ziska, Austin D; Park, Minkyu; Anumol, Tarun; Snyder, Shane A

    2016-08-01

    The removal of trace organic compounds (TOrCs) is of growing interest in water research and society. Powdered activated carbon (PAC) has been proven to be an effective method of removal for TOrCs in water, with the degree of effectiveness depending on dosage, contact time, and activated carbon type. In this study, the attenuation of TOrCs in three different secondary wastewater effluents using four PAC materials was studied in order to elucidate the effectiveness and efficacy of PAC for TOrC removal. With the notable exception of hydrochlorothiazide, all 14 TOrC indicators tested in this study exhibited a positive correlation of removal rate with their log Dow values, demonstrating that the main adsorption mechanism was hydrophobic interaction. As a predictive model, the modified Chick-Watson model, often used for the prediction of microorganism inactivation by disinfectants, was applied. The applied model exhibited good predictive power for TOrC attenuation by PAC in wastewater. In addition, surrogate models based upon spectroscopic measurements including UV absorbance at 254 nm and total fluorescence were applied to predict TOrC removal by PAC. The surrogate model was found to provide an excellent prediction of TOrC attenuation for all combinations of water quality and PAC type included in this study. The success of spectrometric parameters as surrogates in predicting TOrC attenuation by PAC are particularly useful because of their potential application in real-time on-line sensor monitoring and process control at full-scale water treatment plants, which could lead to significantly reduced operator response times and PAC operational optimization. PMID:27174829

  12. Optimization of Process Parameters and Kinetic Model of Enzymatic Extraction of Polyphenols from Lonicerae Flos

    PubMed Central

    Kong, Fansheng; Yu, Shujuan; Bi, Yongguang; Huang, Xiaojun; Huang, Mengqian

    2016-01-01

    Objective: To optimize and verify the cellulase extraction of polyphenols from honeysuckle and provide a reference for enzymatic extracting polyphenols from honeysuckle. Materials and Methods: The uniform design was used According to Fick's first law and kinetic model, fitting analysis of the dynamic process of enzymatic extracting polyphenols was conducted. Results: The optimum enzymatic extraction parameters for polyphenols from honeysuckle are found to be 80% (v/v) of alcohol, 35:1 (mL/g) of liquid-solid ratio, 80°C of extraction temperature, 8.5 of pH, 6.0 mg of enzyme levels, and 130 min of extraction time. Under the optimal conditions, the extraction rate of polyphenols was 3.03%. The kinetic experiments indicated kinetic equation had a good linear relationship with t even under the conditions of different levels of enzyme and temperature, which means fitting curve tallies well with the experimental values. Conclusion: The results of quantification showed that the results provide a reference for enzymatic extracting polyphenols from honeysuckle. SUMMARY Lonicerae flos (Lonicera japonica Thunb.) is a material of traditional Chinese medicine and healthy drinks, of which active compounds mainly is polyphenols. At present, plant polyphenols are the hotspots centents of food, cosmetic and medicine, because it has strong bioactivity. Several traditional methods are available for the extraction of plant polyphenols including impregnation, solvent extraction, ultrasonic extraction, hot-water extraction, alkaline dilute alcohol or alkaline water extraction, microwave extraction and Supercritical CO2 extraction. But now, an increasing number of research on using cellulase to extract active ingredients from plants. Enzymatic method is widely used for enzyme have excellent properties of high reaction efficiency and specificity, moderate reaction conditions, shorter extraction time and easier to control, less damage to the active ingredient. At present, the enzymatic

  13. The combined effect of wet granulation process parameters and dried granule moisture content on tablet quality attributes.

    PubMed

    Gabbott, Ian P; Al Husban, Farhan; Reynolds, Gavin K

    2016-09-01

    A pharmaceutical compound was used to study the effect of batch wet granulation process parameters in combination with the residual moisture content remaining after drying on granule and tablet quality attributes. The effect of three batch wet granulation process parameters was evaluated using a multivariate experimental design, with a novel constrained design space. Batches were characterised for moisture content, granule density, crushing strength, porosity, disintegration time and dissolution. Mechanisms of the effect of the process parameters on the granule and tablet quality attributes are proposed. Water quantity added during granulation showed a significant effect on granule density and tablet dissolution rate. Mixing time showed a significant effect on tablet crushing strength, and mixing speed showed a significant effect on the distribution of tablet crushing strengths obtained. The residual moisture content remaining after granule drying showed a significant effect on tablet crushing strength. The effect of moisture on tablet tensile strength has been reported before, but not in combination with granulation parameters and granule properties, and the impact on tablet dissolution was not assessed. Correlations between the energy input during granulation, the density of granules produced, and the quality attributes of the final tablets were also identified. Understanding the impact of the granulation and drying process parameters on granule and tablet properties provides a basis for process optimisation and scaling. PMID:27016211

  14. The combined effect of wet granulation process parameters and dried granule moisture content on tablet quality attributes.

    PubMed

    Gabbott, Ian P; Al Husban, Farhan; Reynolds, Gavin K

    2016-09-01

    A pharmaceutical compound was used to study the effect of batch wet granulation process parameters in combination with the residual moisture content remaining after drying on granule and tablet quality attributes. The effect of three batch wet granulation process parameters was evaluated using a multivariate experimental design, with a novel constrained design space. Batches were characterised for moisture content, granule density, crushing strength, porosity, disintegration time and dissolution. Mechanisms of the effect of the process parameters on the granule and tablet quality attributes are proposed. Water quantity added during granulation showed a significant effect on granule density and tablet dissolution rate. Mixing time showed a significant effect on tablet crushing strength, and mixing speed showed a significant effect on the distribution of tablet crushing strengths obtained. The residual moisture content remaining after granule drying showed a significant effect on tablet crushing strength. The effect of moisture on tablet tensile strength has been reported before, but not in combination with granulation parameters and granule properties, and the impact on tablet dissolution was not assessed. Correlations between the energy input during granulation, the density of granules produced, and the quality attributes of the final tablets were also identified. Understanding the impact of the granulation and drying process parameters on granule and tablet properties provides a basis for process optimisation and scaling.

  15. Modeling the X-ray Process, and X-ray Flaw Size Parameter for POD Studies

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M.

    2014-01-01

    Nondestructive evaluation (NDE) method reliability can be determined by a statistical flaw detection study called probability of detection (POD) study. In many instances, the NDE flaw detectability is given as a flaw size such as crack length. The flaw is either a crack or behaving like a crack in terms of affecting the structural integrity of the material. An alternate approach is to use a more complex flaw size parameter. The X-ray flaw size parameter, given here, takes into account many setup and geometric factors. The flaw size parameter relates to X-ray image contrast and is intended to have a monotonic correlation with the POD. Some factors such as set-up parameters, including X-ray energy, exposure, detector sensitivity, and material type that are not accounted for in the flaw size parameter may be accounted for in the technique calibration and controlled to meet certain quality requirements. The proposed flaw size parameter and the computer application described here give an alternate approach to conduct the POD studies. Results of the POD study can be applied to reliably detect small flaws through better assessment of effect of interaction between various geometric parameters on the flaw detectability. Moreover, a contrast simulation algorithm for a simple part-source-detector geometry using calibration data is also provided for the POD estimation.

  16. 75 FR 20859 - Notice of Realty Action, Independence National Historical Park, Pennsylvania and Valley Forge...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... National Park Service Notice of Realty Action, Independence National Historical Park, Pennsylvania and Valley Forge National Historical Park, Pennsylvania AGENCY: National Park Service, Department of the... is located within the boundary of Independence National Historical Park (INDE). The privately...

  17. A Design of Experiment approach to predict product and process parameters for a spray dried influenza vaccine.

    PubMed

    Kanojia, Gaurav; Willems, Geert-Jan; Frijlink, Henderik W; Kersten, Gideon F A; Soema, Peter C; Amorij, Jean-Pierre

    2016-09-25

    Spray dried vaccine formulations might be an alternative to traditional lyophilized vaccines. Compared to lyophilization, spray drying is a fast and cheap process extensively used for drying biologicals. The current study provides an approach that utilizes Design of Experiments for spray drying process to stabilize whole inactivated influenza virus (WIV) vaccine. The approach included systematically screening and optimizing the spray drying process variables, determining the desired process parameters and predicting product quality parameters. The process parameters inlet air temperature, nozzle gas flow rate and feed flow rate and their effect on WIV vaccine powder characteristics such as particle size, residual moisture content (RMC) and powder yield were investigated. Vaccine powders with a broad range of physical characteristics (RMC 1.2-4.9%, particle size 2.4-8.5μm and powder yield 42-82%) were obtained. WIV showed no significant loss in antigenicity as revealed by hemagglutination test. Furthermore, descriptive models generated by DoE software could be used to determine and select (set) spray drying process parameter. This was used to generate a dried WIV powder with predefined (predicted) characteristics. Moreover, the spray dried vaccine powders retained their antigenic stability even after storage for 3 months at 60°C. The approach used here enabled the generation of a thermostable, antigenic WIV vaccine powder with desired physical characteristics that could be potentially used for pulmonary administration. PMID:27523619

  18. A Design of Experiment approach to predict product and process parameters for a spray dried influenza vaccine.

    PubMed

    Kanojia, Gaurav; Willems, Geert-Jan; Frijlink, Henderik W; Kersten, Gideon F A; Soema, Peter C; Amorij, Jean-Pierre

    2016-09-25

    Spray dried vaccine formulations might be an alternative to traditional lyophilized vaccines. Compared to lyophilization, spray drying is a fast and cheap process extensively used for drying biologicals. The current study provides an approach that utilizes Design of Experiments for spray drying process to stabilize whole inactivated influenza virus (WIV) vaccine. The approach included systematically screening and optimizing the spray drying process variables, determining the desired process parameters and predicting product quality parameters. The process parameters inlet air temperature, nozzle gas flow rate and feed flow rate and their effect on WIV vaccine powder characteristics such as particle size, residual moisture content (RMC) and powder yield were investigated. Vaccine powders with a broad range of physical characteristics (RMC 1.2-4.9%, particle size 2.4-8.5μm and powder yield 42-82%) were obtained. WIV showed no significant loss in antigenicity as revealed by hemagglutination test. Furthermore, descriptive models generated by DoE software could be used to determine and select (set) spray drying process parameter. This was used to generate a dried WIV powder with predefined (predicted) characteristics. Moreover, the spray dried vaccine powders retained their antigenic stability even after storage for 3 months at 60°C. The approach used here enabled the generation of a thermostable, antigenic WIV vaccine powder with desired physical characteristics that could be potentially used for pulmonary administration.

  19. Parametric appraisal of process parameters for adhesion of plasma sprayed nanostructured YSZ coatings using Taguchi experimental design.

    PubMed

    Mantry, Sisir; Mishra, Barada K; Chakraborty, Madhusudan

    2013-01-01

    This paper presents the application of the Taguchi experimental design in developing nanostructured yittria stabilized zirconia (YSZ) coatings by plasma spraying process. This paper depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on various process parameters, and effect of those process parameters on performance output has been studied using Taguchi's L16 orthogonal array design. Particle velocities prior to impacting the substrate, stand-off-distance, and particle temperature are found to be the most significant parameter affecting the bond strength. To achieve retention of nanostructure, molten state of nanoagglomerates (temperature and velocity) has been monitored using particle diagnostics tool. Maximum adhesion strength of 40.56 MPa has been experimentally found out by selecting optimum levels of selected factors. The enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nanozones.

  20. Effect of some process parameters on geometric errors in twopoint incremental forming for Al-Cu-Mg Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Li, Xiaoqiang; Han, Kai; Yu, Honghan; Zhang, Yongsheng; Li, Dongsheng

    2016-08-01

    Two point incremental forming receives widespread study with its advantages of economy and flexibility in small batch products, such as aircraft parts. Aircraft parts, however, are rigorous in their shape errors. In this paper, one real airplane part is selected and formed with different process parameters to investigate the shape error level of part. Comparing the geometric errors caused by different process parameters, such as tool diameter, step size, feed rate and tool path, it is found that the geometric errors reduce as tool diameter increases. Meanwhile, the effect of step size is not linear. Influence law of feed rate is various with different other parameters. The bidirectional tool path, having opposite processing direction at adjacent layer, reduces the errors.

  1. Parametric Appraisal of Process Parameters for Adhesion of Plasma Sprayed Nanostructured YSZ Coatings Using Taguchi Experimental Design

    PubMed Central

    Mantry, Sisir; Mishra, Barada K.; Chakraborty, Madhusudan

    2013-01-01

    This paper presents the application of the Taguchi experimental design in developing nanostructured yittria stabilized zirconia (YSZ) coatings by plasma spraying process. This paper depicts dependence of adhesion strength of as-sprayed nanostructured YSZ coatings on various process parameters, and effect of those process parameters on performance output has been studied using Taguchi's L16 orthogonal array design. Particle velocities prior to impacting the substrate, stand-off-distance, and particle temperature are found to be the most significant parameter affecting the bond strength. To achieve retention of nanostructure, molten state of nanoagglomerates (temperature and velocity) has been monitored using particle diagnostics tool. Maximum adhesion strength of 40.56 MPa has been experimentally found out by selecting optimum levels of selected factors. The enhanced bond strength of nano-YSZ coating may be attributed to higher interfacial toughness due to cracks being interrupted by adherent nanozones. PMID:24288490

  2. On the Estimation of Process Parameters in the Taguchi's Approach to the On-line Control Procedure for Attributes

    NASA Astrophysics Data System (ADS)

    Borges, Wagner S.; Esteves, Luis Gustavo; Wechsler, Sergio

    2008-11-01

    Under the model proposed by Nayebpour and Woodall [5] for Taguchi's on-line control procedure for attributes, estimators for the process parameter vector are derived both from the Classical (maximum likelihood) and Bayesian standpoints. The likelihood function is generated by the detection time of the first defective item under the control procedure. Under the Classical standpoint, a case of nonidentifiability is disclosed. Under the Bayesian standpoint, posterior probability distributions for the process parameters are determined by taking into account independent beta prior distributions.

  3. Effect of the parameters of a wide-aperture acousto-optic filter on the image processing quality

    SciTech Connect

    Voloshinov, V B; Bogomolov, D V

    2006-05-31

    The properties of wide-aperture paratellurite crystal acousto-optic filters used for optical image processing are studied. The influence of parameters of these filters on the quality of optical imaging in laser and nonmonochromatic light is studied. The spatial resolution of filters is measured upon laser and nonmonochromatic illumination of objects. Filtration is performed in a broad wavelength range at different powers of a control electric signal. The optimisation of the filter parameters for improving its spatial resolution is discussed. (optical image processing)

  4. Influence of Process Parameters on the Quality of Aluminium Alloy EN AW 7075 Using Selective Laser Melting (SLM)

    NASA Astrophysics Data System (ADS)

    Kaufmann, N.; Imran, M.; Wischeropp, T. M.; Emmelmann, C.; Siddique, S.; Walther, F.

    Selective laser melting (SLM) is an additive manufacturing process, forming the desired geometry by selective layer fusion of powder material. Unlike conventional manufacturing processes, highly complex parts can be manufactured with high accuracy and little post processing. Currently, different steel, aluminium, titanium and nickel-based alloys have been successfully processed; however, high strength aluminium alloy EN AW 7075 has not been processed with satisfying quality. The main focus of the investigation is to develop the SLM process for the wide used aluminium alloy EN AW 7075. Before process development, the gas-atomized powder material was characterized in terms of statistical distribution: size and shape. A wide range of process parameters were selected to optimize the process in terms of optimum volume density. The investigations resulted in a relative density of over 99%. However, all laser-melted parts exhibit hot cracks which typically appear in aluminium alloy EN AW 7075 during the welding process. Furthermore the influence of processing parameters on the chemical composition of the selected alloy was determined.

  5. Deformation, recrystallization, strength, and fracture of press-forged ceramic crystals.

    NASA Technical Reports Server (NTRS)

    Rice, R. W.

    1972-01-01

    Sapphire and ruby were very difficult to press-forge because they deformed without cracking only in a limited temperature range before they melted. Spinel crystals were somewhat easier and MgO, CaO, and TiC crystals much easier to forge. The degree of recrystallization that occurred during forging (which was related to the ease and type of slip intersections) varied from essentially zero in Al2O3 to complete (i.e., random polycrystalline bodies were produced) in CaO. Forging of bi- and polycrystalline bodies produced incoherent bodies as a result of grain-boundary sliding. Strengths of the forged crystals were comparable to those of dense polycrystalline bodies of similar grain size. However, forged and recrystallized CaO crystals were ductile at lower temperatures than dense hot-pressed CaO. This behavior is attributed to reduced grain-boundary impurities and porosity. Fracture origins could be located, indicating that fracture in the CaO occurs internally as a result of surface work hardening caused by machining.-

  6. West Flank Coso, CA FORGE 3D temperature model

    DOE Data Explorer

    Doug Blankenship

    2016-03-01

    x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104˚C was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20˚C was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73˚C/km (4˚F/100’) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20˚C surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6˚C (20˚F), or one contour interval, of the

  7. A Computational approach in optimizing process parameters of GTAW for SA 106 Grade B steel pipes using Response surface methodology

    NASA Astrophysics Data System (ADS)

    Sumesh, A.; Sai Ramnadh, L. V.; Manish, P.; Harnath, V.; Lakshman, V.

    2016-09-01

    Welding is one of the most common metal joining techniques used in industry for decades. As in the global manufacturing scenario the products should be more cost effective. Therefore the selection of right process with optimal parameters will help the industry in minimizing their cost of production. SA 106 Grade B steel has a wide application in Automobile chassis structure, Boiler tubes and pressure vessels industries. Employing central composite design the process parameters for Gas Tungsten Arc Welding was optimized. The input parameters chosen were weld current, peak current and frequency. The joint tensile strength was the response considered in this study. Analysis of variance was performed to determine the statistical significance of the parameters and a Regression analysis was performed to determine the effect of input parameters over the response. From the experiment the maximum tensile strength obtained was 95 KN reported for a weld current of 95 Amp, frequency of 50 Hz and peak current of 100 Amp. With an aim of maximizing the joint strength using Response optimizer a target value of 100 KN is selected and regression models were optimized. The output results are achievable with a Weld current of 62.6148 Amp, Frequency of 23.1821 Hz, and Peak current of 65.9104 Amp. Using Die penetration test the weld joints were also classified in to 2 categories as good weld and weld with defect. This will also help in getting a defect free joint when welding is performed using GTAW process.

  8. Visualization and processing of computed solid-state NMR parameters: MagresView and MagresPython.

    PubMed

    Sturniolo, Simone; Green, Timothy F G; Hanson, Robert M; Zilka, Miri; Refson, Keith; Hodgkinson, Paul; Brown, Steven P; Yates, Jonathan R

    2016-09-01

    We introduce two open source tools to aid the processing and visualisation of ab-initio computed solid-state NMR parameters. The Magres file format for computed NMR parameters (as implemented in CASTEP v8.0 and QuantumEspresso v5.0.0) is implemented. MagresView is built upon the widely used Jmol crystal viewer, and provides an intuitive environment to display computed NMR parameters. It can provide simple pictorial representation of one- and two-dimensional NMR spectra as well as output a selected spin-system for exact simulations with dedicated spin-dynamics software. MagresPython provides a simple scripting environment to manipulate large numbers of computed NMR parameters to search for structural correlations. PMID:27435606

  9. Visualization and processing of computed solid-state NMR parameters: MagresView and MagresPython.

    PubMed

    Sturniolo, Simone; Green, Timothy F G; Hanson, Robert M; Zilka, Miri; Refson, Keith; Hodgkinson, Paul; Brown, Steven P; Yates, Jonathan R

    2016-09-01

    We introduce two open source tools to aid the processing and visualisation of ab-initio computed solid-state NMR parameters. The Magres file format for computed NMR parameters (as implemented in CASTEP v8.0 and QuantumEspresso v5.0.0) is implemented. MagresView is built upon the widely used Jmol crystal viewer, and provides an intuitive environment to display computed NMR parameters. It can provide simple pictorial representation of one- and two-dimensional NMR spectra as well as output a selected spin-system for exact simulations with dedicated spin-dynamics software. MagresPython provides a simple scripting environment to manipulate large numbers of computed NMR parameters to search for structural correlations.

  10. Brief Report: Coherent Motion Processing in Autism: Is Dot Lifetime an Important Parameter?

    ERIC Educational Resources Information Center

    Manning, Catherine; Charman, Tony; Pellicano, Elizabeth

    2015-01-01

    Contrasting reports of "reduced" and "intact" sensitivity to coherent motion in autistic individuals may be attributable to stimulus parameters. Here, we investigated whether dot lifetime contributes to elevated thresholds in children with autism. We presented a standard motion coherence task to 31 children with autism and 31…

  11. Mechanization of the Grit Blasting Process for Thermal Spray Coating Applications: A Parameter Study

    NASA Astrophysics Data System (ADS)

    Begg, Henry; Riley, Melissa; de Villiers Lovelock, Heidi

    2016-01-01

    The bond strength between a thermal spray coating and substrate is critical for many applications and is dependent on good substrate surface preparation and optimized spray parameters. While spray parameters are usually carefully monitored and controlled, most surface preparation is carried out by manual grit blasting, with little or no calibration of blast parameters. Blasting is currently highly dependent on operator skill and often surface finish is only assessed visually, meaning a consistent, reproducible surface profile cannot be guaranteed. This paper presents investigations on the effect of blast parameters (including blast pressure, standoff distance, media feed rate, blast angle, traverse speed, and media size) on surface profile for seven different metallic substrates using a mechanized, robotic blasting system and employing a brown fused alumina blast medium. Substrates were characterized using non-contact focus variation microscopy. Average surface roughness was found to be most affected by blast pressure, media size, and traverse speed, while changes to media feed rate and standoff distance had a limited effect on surface profile. Changes to blast angle resulted in limited change to average roughness, but microscopy examinations suggested a change in the mechanism of material removal.

  12. Model-based analysis of coupled equilibrium-kinetic processes: indirect kinetic studies of thermodynamic parameters using the dynamic data.

    PubMed

    Emami, Fereshteh; Maeder, Marcel; Abdollahi, Hamid

    2015-05-01

    Thermodynamic studies of equilibrium chemical reactions linked with kinetic procedures are mostly impossible by traditional approaches. In this work, the new concept of generalized kinetic study of thermodynamic parameters is introduced for dynamic data. The examples of equilibria intertwined with kinetic chemical mechanisms include molecular charge transfer complex formation reactions, pH-dependent degradation of chemical compounds and tautomerization kinetics in micellar solutions. Model-based global analysis with the possibility of calculating and embedding the equilibrium and kinetic parameters into the fitting algorithm has allowed the complete analysis of the complex reaction mechanisms. After the fitting process, the optimal equilibrium and kinetic parameters together with an estimate of their standard deviations have been obtained. This work opens up a promising new avenue for obtaining equilibrium constants through the kinetic data analysis for the kinetic reactions that involve equilibrium processes.

  13. Optimization of the EMS process parameters in compocasting of high-wear-resistant Al-nano-TiC composites

    NASA Astrophysics Data System (ADS)

    Shamsipour, Majid; Pahlevani, Zahra; Shabani, Mohsen Ostad; Mazahery, Ali

    2016-04-01

    Understanding of the electromagnetic stirrer (EMS) process parameters-wear relation in nanocomposite is required for further creation of tailored modifications of process in accordance with the demands for various applications. This study depicts the performance of hybrid algorithm for optimization of the parameters in EMS compocasting of nano-TiC-reinforced Al-Si alloys. Adaptive neuro-fuzzy inference system (ANFIS) coupled with particle swarm optimization (PSO) was applied to find the optimum combination of the inputs including mold temperature, mix time, impeller speed, powder temperature, cast temperature and average particle size. The optimized condition was obtained in minimization of objective function. The objective function is calculated by ANFIS and then minimized by PSO. The optimized parameters were used to produce semisolid cast aluminum matrix composites reinforced with nano-TiC particles. The optimized nanocomposites were then studied for their tribological properties.

  14. The effect of hydrodynamic dispersion parameters on process optimization of S-109 partial waste retrieval

    SciTech Connect

    Tachiev, F.; Yaari, G.; Foster, N.; Blaine, B.

    2007-07-01

    The removal of cesium by draining the supernate and interstitial salt solution from the salt-cake while fresh water is continuously being added at the top of the tank requires modeling of the transport in variably saturated porous media, and possibly includes a diffusion component. The uncertainties in this method are based on the highly inhomogeneous properties of the salt-cake and limited knowledge of the drainage and transport parameters, more specifically, its hydraulic constraints and hydrodynamic dispersion properties. The hydraulic parameters of the salt-cake (hydraulic conductivity and van Genuchten parameters) have significance with respect to tank drainage and re-saturation and determine the kinetics of the flow through the salt waste. The unsaturated properties are needed in order to assess not only the time frame of tank drainage but also the equilibrium conditions. One of the most important parameters for determining the transport properties of the porous media is the hydrodynamic dispersion tensor. The hydrodynamic dispersion can be applied to describe the spreading of cesium mass spatially and temporally. It combines effects from local variations in pore fluid velocity dispersion and molecular diffusion. In this study, the hydrodynamic dispersion parameters, the Peclet number for molecular diffusion, and the resulting uncertainties have been estimated from pilot scale column experiments using S-109 salt-cake simulant. A 2-D axisymmetric finite element model has been developed to couple the flow in variably saturated regime with transport of non-reacting cesium. The model used unsaturated hydraulic properties as determined from previous experimental work. The study performed sensitivity analysis of the hydrodynamic dispersion factor and provided information about its significance with respect to cesium temporal and spatial distribution. The model was used to compare relevant operating parameters during the replacement of cesium rich supernatant with

  15. The Flow Behavior and Microstructural Evolution of Ti-5Al-5Mo-5V-3Cr during Subtransus Isothermal Forging

    NASA Astrophysics Data System (ADS)

    Jones, N. G.; Dashwood, R. J.; Dye, D.; Jackson, M.

    2009-08-01

    High-strength metastable β alloys, for example, Ti-5Al-5Mo-5V-3Cr, have replaced steel as the material of choice for large components, such as the main truck beam on the latest generation of airframes. The production of these components is carried out by hot near-net-shape forging, during which process variable control is essential to achieve the desired microstructural condition and subsequent mechanical properties. The flow behavior and microstructural evolution during subtransus isothermal forging of Ti-5Al-5Mo-5V-3Cr has been investigated for two different starting microstructures and analysis has incorporated previously published results. The flow behavior, irrespective of initial microstructural condition, is found to be very similar at strains ≥0.35. It is thought that this is due to a common microstructural state being reached, where dynamic recovery of the β phase is the dominating deformation mechanism. At strains <0.35, the flow behavior is believed to be dominated by the morphology and volume fraction of the α phase. Small globular α particles are thought to have little effect on the flow behavior, while the observed flow softening is directly linked to the fragmentation of acicular α precipitates.

  16. Numerical simulation of multi-mini-pot pouring process of a 13-ton steel ingot

    NASA Astrophysics Data System (ADS)

    Li, Jun; Ge, Honghao; Wang, Bin; Wu, Menghuai; Li, Jianguo

    2015-06-01

    Heavy ingots up to several hundred tons for power plant forgings exhibit large scale grain size and morphology differences, which are harmful to the design of forging parameters, and severe macrosegregation, which could not be eliminated during the subsequent forging and heat treatment processing. To cast these ingots with more homogeneity, a multi-mini-pot (MMP) poring technique is proposed, in which liquid metal is poured by multi-mini-pot (MMP) with intermission between each pot and solidification occurs step by step. In this paper, we are focus on the prediction of macrosegregation in MMP pouring process. A three-phase model is employed to study the MMP pouring process for a 13-ton heavy ingot. The main features of this three-phases model in such a heavy ingot can be quantitatively modelled: growth of columnar dendrite trunks; nucleation, growth and sedimentation of equiaxed crystals; thermosolutal convection of the melt; solute transport by both convection and crystal sedimentation; and the columnar-to-equiaxed transition (CET). The results shown that the MMP pouring technique tend to decrease the macrosegregation significantly by compared with the conventional method.

  17. Optimization of Process Parameters of Hybrid Laser-Arc Welding onto 316L Using Ensemble of Metamodels

    NASA Astrophysics Data System (ADS)

    Zhou, Qi; Jiang, Ping; Shao, Xinyu; Gao, Zhongmei; Cao, Longchao; Yue, Chen; Li, Xiongbin

    2016-08-01

    Hybrid laser-arc welding (LAW) provides an effective way to overcome problems commonly encountered during either laser or arc welding such as brittle phase formation, cracking, and porosity. The process parameters of LAW have significant effects on the bead profile and hence the quality of joint. This paper proposes an optimization methodology by combining non-dominated sorting genetic algorithm (NSGA-II) and ensemble of metamodels (EMs) to address multi-objective process parameter optimization in LAW onto 316L. Firstly, Taguchi experimental design is adopted to generate the experimental samples. Secondly, the relationships between process parameters ( i.e., laser power ( P), welding current ( A), distance between laser and arc ( D), and welding speed ( V)) and the bead geometries are fitted using EMs. The comparative results show that the EMs can take advantage of the prediction ability of each stand-alone metamodel and thus decrease the risk of adopting inappropriate metamodels. Then, the NSGA-II is used to facilitate design space exploration. Besides, the main effects and contribution rates of process parameters on bead profile are analyzed. Eventually, the verification experiments of the obtained optima are carried out and compared with the un-optimized weld seam for bead geometries, weld appearances, and welding defects. Results illustrate that the proposed hybrid approach exhibits great capability of improving welding quality in LAW.

  18. Optimisation of Lime-Soda process parameters for reduction of hardness in aqua-hatchery practices using Taguchi methods.

    PubMed

    Yavalkar, S P; Bhole, A G; Babu, P V Vijay; Prakash, Chandra

    2012-04-01

    This paper presents the optimisation of Lime-Soda process parameters for the reduction of hardness in aqua-hatchery practices in the context of M. rosenbergii. The fresh water in the development of fisheries needs to be of suitable quality. Lack of desirable quality in available fresh water is generally the confronting restraint. On the Indian subcontinent, groundwater is the only source of raw water, having varying degree of hardness and thus is unsuitable for the fresh water prawn hatchery practices (M. rosenbergii). In order to make use of hard water in the context of aqua-hatchery, Lime-Soda process has been recommended. The efficacy of the various process parameters like lime, soda ash and detention time, on the reduction of hardness needs to be examined. This paper proposes to determine the parameter settings for the CIFE well water, which is pretty hard by using Taguchi experimental design method. Orthogonal Arrays of Taguchi, Signal-to-Noise Ratio, the analysis of variance (ANOVA) have been applied to determine their dosage and analysed for their effect on hardness reduction. The tests carried out with optimal levels of Lime-Soda process parameters confirmed the efficacy of the Taguchi optimisation method. Emphasis has been placed on optimisation of chemical doses required to reduce the total hardness using Taguchi method and ANOVA, to suit the available raw water quality for aqua-hatchery practices, especially for fresh water prawn M. rosenbergii.

  19. [Parameters of physical and mental development of children and adolescents residing near enterprise for radioactive waste processing and stationary storage].

    PubMed

    Kirillov, V F; Popova, O L; Mikhaĭlov, A I; Kuznetsova, A I; Prokazova, L P; Pronina, T K; Varfolomeeva, I G

    2005-01-01

    Operation of enterprise for radioactive waste processing and disposal does not influence negatively physical and mental development of children and adolescents residing in the area under observation. In some parameters, physical and mental development of children and adolescents residing in the area under observation surpasses that in reference area--that could be due to social and economic peculiarities. PMID:16381481

  20. Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

    NASA Astrophysics Data System (ADS)

    Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

    2016-07-01

    In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.

  1. Movement Synchrony Forges Social Bonds across Group Divides

    PubMed Central

    Tunçgenç, Bahar; Cohen, Emma

    2016-01-01

    Group dynamics play an important role in the social interactions of both children and adults. A large amount of research has shown that merely being allocated to arbitrarily defined groups can evoke disproportionately positive attitudes toward one's in-group and negative attitudes toward out-groups, and that these biases emerge in early childhood. This prompts important empirical questions with far-reaching theoretical and applied significance. How robust are these inter-group biases? Can biases be mitigated by behaviors known to bond individuals and groups together? How can bonds be forged across existing group divides? To explore these questions, we examined the bonding effects of interpersonal synchrony on minimally constructed groups in a controlled experiment. In-group and out-group bonding were assessed using questionnaires administered before and after a task in which groups performed movements either synchronously or non-synchronously in a between-participants design. We also developed an implicit behavioral measure, the Island Game, in which physical proximity was used as an indirect measure of interpersonal closeness. Self-report and behavioral measures showed increased bonding between groups after synchronous movement. Bonding with the out-group was significantly higher in the condition in which movements were performed synchronously than when movements were performed non-synchronously between groups. The findings are discussed in terms of their importance for the developmental social psychology of group dynamics as well as their implications for applied intervention programs. PMID:27303341

  2. Comparison of pitting fatigue life of ausforged and standard forged AISI M-50 and AISI 9310 spur gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Bamberger, E. N.; Zaretsky, E. V.

    1975-01-01

    Standard forged and ausforged spur gears made of vacuum-induction-melted, consumable-electrode, vacuum-arc-remelted AISI M-50 steel were tested under conditions that produced fatigue pitting. The gears were 8.89 cm (3.5 in.) in pitch diameter and had tip relief. The M-50 standard forged and ausforged test results were compared with each other. They were then compared with results for machined vacuum-arc-remelted AISI 9310 gears tested under identical conditions. Both types of M-50 gears had lives approximately five times that of the 9310 gears. The life at which 10 percent of the M-50 ausforged gears failed was slightly less than that at which the M-50 standard forged gears failed. The ausforged gears had a slightly greater tendency to fail by tooth fracture than did the standard forged gears, most likely because of the better forging and grain flow pattern of standard forged gears.

  3. A real-time measurement system for parameters of live biology metabolism process with fiber optics

    NASA Astrophysics Data System (ADS)

    Tao, Wei; Zhao, Hui; Liu, Zemin; Cheng, Jinke; Cai, Rong

    2010-08-01

    Energy metabolism is one of the basic life activities of cellular in which lactate, O2 and CO2 will be released into the extracellular environment. By monitoring the quantity of these parameters, the mitochondrial performance will be got. A continuous measurement system for the concentration of O2, CO2 and PH value is introduced in this paper. The system is made up of several small-sized fiber optics biosensors corresponding to the container. The setup of the system and the principle of measurement of several parameters are explained. The setup of the fiber PH sensor based on principle of light absorption is also introduced in detail and some experimental results are given. From the results we can see that the system can measure the PH value precisely suitable for cell cultivation. The linear and repeatable accuracies are 3.6% and 6.7% respectively, which can fulfill the measurement task.

  4. Isentrope Parameter Effect in the Compression Process of the Fusion Advanced Fuel

    NASA Astrophysics Data System (ADS)

    Mahdavi, M.; Azadboni, F. Khodadadi

    2013-02-01

    In inertial confinement fusion, Fermi degeneracy plays an important role in reducing the cost of driver energy. In this research, based on recent progresses in the laser electron accelerators research, we have physically designed a D/3 He target and examine the isentropic parameter of a D/3 He fuel to achieve the goal of gains of order 500. The design target significantly depends on the isentrope parameter and the pressure of the D/3 He fuel. In during the compression, If the D/3 He fuel stays in the degeneracy state, the compression energy is smaller than the ignition energy for the same amount of fuel. The energy requirement to compress a D/3 He fuel with density 2.9 × 104 g/cm3 is 4.2 × 107 J/g. Also, the driver energy needed to achieve these gains is estimated to be 1000 MJ when the coupling efficiency is 10 % and isentropic parameter is 1.5.

  5. Real-time digital processing of Doppler ultrasound signals and calculation of flow parameters.

    PubMed

    Schlindwein, F S; Vieira, M H; Vasconcelos, C F; Simpson, D M

    1994-01-01

    Vascular diseases and their complications are responsible for around 27% of deaths in Brazil. Doppler ultrasound is a non-invasive technique that has been used to study blood flow in intact blood vessels since Satomura first reported the potential of the technique in 1959. Because it is non-invasive it makes sequential studies and those in normals feasible. Whereas in contrast angiography only vessel anatomy is displayed, Doppler ultrasound produces dynamic information on blood-flow. It may be used to estimate flow-rates, to image regions of blood flow (colour Doppler), and to help in locating sites of arterial disease, thus complementing X-ray examinations. This paper describes a system based on a Digital Signal Processor for real-time spectrum analysis of Doppler ultrasound signals, real-time display of sonograms, and calculation and analysis of three parameters of clinical interest derived from the Doppler signal. The system comprises a TMS320C25 development board, which acquires the signal and performs spectrum analysis, and a microcomputer, which reads the spectral estimates, displays them as a sonogram in real-time and calculates a set of spectral parameters proposed in the literature. The system permits a maximum sampling frequency of 40.96 kHz, and in the sonogram, 80 power spectra per second (each with 128 frequency bins) are displayed. In a preliminary study, the stability of the haemodynamic parameters and their dependence on a user-defined threshold value is investigated.

  6. Metastable region of phase diagram: optimum parameter range for processing ultrahigh molecular weight polyethylene blends.

    PubMed

    Gai, Jing-Gang; Zuo, Yuan

    2012-06-01

    Numerous studies suggest that two-phase morphology and thick interface are separately beneficial to the viscosity reduction and mechanical property maintainence of the matrix when normal molecular weight polymer (NMWP) is used for modification of ultrahigh molecular weight polyethylene (UHMWPE). Nevertheless, it is very difficult to obtain a UHMWPE/NMWP blend which may demonstrate both two-phase morphology and thick interface. In this work, dissipative particle dynamics simulations and Flory-Huggins theory are applied in predicting the optimum NMWP and the corresponding conditions, wherein the melt flowability of UHMWPE can be improved while its mechanical properties can also be retained. As is indicated by dissipative particle dynamics simulations and phase diagram calculated from Flory-Huggins theory, too small Flory-Huggins interaction parameter (χ) and molecular chain length of NMWP (N(NMWP)) may lead to the formation of a homogeneous phase, whereas very large interfacial tension and thin interfaces might also appear when parameters N(NMWP) and χ are too large. When these parameters are located in the metastable region of the phase diagram, however, two-phase morphology occurs and interfaces of the blends are extremely thick. Therefore, metastable state is found to be advisable for both the viscosity reduction and mechanical property improvement of the UHMWPE/NMWP blends.

  7. Effect of process parameters on properties of argon–nitrogen plasma for titanium nitride film deposition

    SciTech Connect

    Saikia, Partha; Kakati, Bharat

    2013-11-15

    In this study, the effect of working pressure and input power on the physical properties and sputtering efficiencies of argon–nitrogen (Ar/N{sub 2}) plasma in direct current magnetron discharge is investigated. The discharge in Ar/N{sub 2} is used to deposit TiN films on high speed steel substrate. The physical plasma parameters are determined by using Langmuir probe and optical emission spectroscopy. On the basis of the different reactions in the gas phase, the variation of plasma parameters and sputtering rate are explained. A prominent change of electron temperature, electron density, ion density, and degree of ionization of Ar is found as a function of working pressure and input power. The results also show that increasing working pressure exerts a negative effect on film deposition rate while increasing input power has a positive impact on the same. To confirm the observed physical properties and evaluate the texture growth as a function of deposition parameters, x-ray diffraction study of deposited TiN films is also done.

  8. A pass planning method for multi-hit stretching of heavy forgings by integration of a semi-analytical technique and degrees-reduced finite element

    NASA Astrophysics Data System (ADS)

    Cui, Zhenshan; Chen, Wen; Sui, Dashan; Liu, Juan

    2013-05-01

    A pass planning method for multi-pass and multi-hit stretching of heavy forgings is proposed, which composes of a semi-analytical procedure and a degrees-reduced finite element code. The semi-analytical procedure is based on a kinematically admissible velocity and Markov variational principle, and can be applied to roughly calculate the deformed shape and working force for stretch forging process for work-piece which has vertical and lateral symmetrical lines in cross-section. Meanwhile, in order to obtain the distributions of metal flow, temperature, strain and stress in detail, a degrees-reduced thermo-mechanical coupled rigid finite element code is developed. In this code, the instantaneous deformation zone is specially extracted from the total domain and simulated for metal flow, while the total domain is used to simulate the evolution of thermal field. Taking the semi-analytical method as a solver, the pass planning procedure for stretch forging is developed, and the degrees-reduced finite element code is used as a supplement to check the rationality of the planed pass schedule. An example is implemented to demonstrate the application of the proposed technique.

  9. Impact of Process Parameters on the Laser-induced Nanoparticle Formation During Keyhole Welding under Remote Conditions

    NASA Astrophysics Data System (ADS)

    Scholz, Tobias; Dickmann, Klaus; Ostendorf, Andreas

    The interaction between the vapor plume and the incident laser radiation affects remote laser welding. Relating to laser systems with an emitted wavelength around 1 μm, a significant loss mechanism can be traced back to the extinction by laser-induced particle formation. Due to the tight coupling between the particle formation and the evaporation rate inside the keyhole, the particle formation shows a strong dependence on the keyhole geometry and thus on process parameters (e.g. feed rate and laser beam power). In order to verify the relationship between particle formation and process parameters, the beam of a broadband LED was guided through the vapor plume during the welding processes with a fiber laser. The attenuated probe beam was analyzed in dependence on the wavelength. In addition, the propagation of the vapor plume was investigated by using high speed imaging.

  10. Optimization of Surface Roughness Parameters of Al-6351 Alloy in EDC Process: A Taguchi Coupled Fuzzy Logic Approach

    NASA Astrophysics Data System (ADS)

    Kar, Siddhartha; Chakraborty, Sujoy; Dey, Vidyut; Ghosh, Subrata Kumar

    2016-06-01

    This paper investigates the application of Taguchi method with fuzzy logic for multi objective optimization of roughness parameters in electro discharge coating process of Al-6351 alloy with powder metallurgical compacted SiC/Cu tool. A Taguchi L16 orthogonal array was employed to investigate the roughness parameters by varying tool parameters like composition and compaction load and electro discharge machining parameters like pulse-on time and peak current. Crucial roughness parameters like Centre line average roughness, Average maximum height of the profile and Mean spacing of local peaks of the profile were measured on the coated specimen. The signal to noise ratios were fuzzified to optimize the roughness parameters through a single comprehensive output measure (COM). Best COM obtained with lower values of compaction load, pulse-on time and current and 30:70 (SiC:Cu) composition of tool. Analysis of variance is carried out and a significant COM model is observed with peak current yielding highest contribution followed by pulse-on time, compaction load and composition. The deposited layer is characterised by X-Ray Diffraction analysis which confirmed the presence of tool materials on the work piece surface.

  11. [Variations in fatty acids, tocopherol and other quality parameters of virgin olive oil subjected to refining process].

    PubMed

    Bonilla Polo, A; Murillo Ramos, J J; González Bonillo, J; Sanz Pérez, B

    1997-01-01

    In the refining process of the oil, this is subjected to extreme conditions, and there is an interest in knowing the comparative variation in the contents of fatty acids, alpha tocopherol and other quality indicating parameters during the refining process carried out under the same conditions as in industry, but in the laboratory. Refined oil is a product which meets the characteristics of the food regulations, but which, due to the decrease in the alpha tocopherol content and in polyunsaturated fatty acids, has decreased some of its excellent nutritional properties. The process with the greatest influence is saponification.

  12. [Variations in fatty acids, tocopherol and other quality parameters of virgin olive oil subjected to refining process].

    PubMed

    Bonilla Polo, A; Murillo Ramos, J J; González Bonillo, J; Sanz Pérez, B

    1997-01-01

    In the refining process of the oil, this is subjected to extreme conditions, and there is an interest in knowing the comparative variation in the contents of fatty acids, alpha tocopherol and other quality indicating parameters during the refining process carried out under the same conditions as in industry, but in the laboratory. Refined oil is a product which meets the characteristics of the food regulations, but which, due to the decrease in the alpha tocopherol content and in polyunsaturated fatty acids, has decreased some of its excellent nutritional properties. The process with the greatest influence is saponification. PMID:9477657

  13. Effect of processing parameter and filler content on tensile properties of multi-walled carbon nanotubes reinforced polylactic acid nanocomposite

    NASA Astrophysics Data System (ADS)

    Ali, Adilah Mat; Ahmad, Sahrim Hj.

    2013-05-01

    Polymer nanocomposite of multi-walled carbon nanotubes (MWCNT) nanoparticles incorporated with polylactic acid (PLA) and liquid natural rubber (LNR) as compatibilizer were prepared via melt blending method using the Haake Rheomix internal mixer. In order to obtain the optimal processing parameter, the nanocomposite with 89 wt % of PLA was blended with 10 wt % of LNR and 1 wt % of MWCNTs were mixed with various mixing parameter condition; mixing temperature, mixing speed and mixing time. The optimum processing parameter of the composites was obtained at temperature of 190°C, rotation speed of 90 rpm and mixing time of 14 min. Next, the effect of MWCNTs loading on the tensile properties of nanocomposites was investigated. The nanocomposites were melt blended using the optimal processing parameter with MWCNTs loading of 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4 wt %. The result showed that the sample with 3.5 wt % of MWCNTs gave higher tensile strength and Young's modulus. The SEM micrographs confirmed the effect of good dispersion of MWCNTs and their interfacial bonding in PLA nanocomposites. However, the elongation at break decreased with increasing the percentage of MWCNTs.

  14. A review of signal processing used in the implementation of the pulse oximetry photoplethysmographic fluid responsiveness parameter.

    PubMed

    Addison, Paul S

    2014-12-01

    ΔPOP is a physiological parameter derived from the respiration-induced change in the pulse oximetry plethysmographic (POP) waveform or "pleth." It has been proposed as a proxy for pulse pressure variation used in the determination of the response to intravascular volume expansion in hypovolemic patients. Many studies have now reported on the parameter, and many research groups have constructed algorithms for its computation from the first principles where the implementation details have been described. This review focuses on the signal processing aspects of ΔPOP, as reported in the literature, and aims to provide a comprehensive summary of the wide-ranging algorithmic strategies that have been attempted in its computation. A search was conducted for articles concerning the use of ΔPOP as a fluid responsiveness parameter. In particular, articles concerning the correlation between ΔPOP and pulse pressure variation were targeted. Comments and replies to comments by the authors in which signal processing aspects were discussed were also included in the review. The parameter is first defined, and a history of the early work surrounding pleth-based fluid responsiveness parameters is presented. This is followed by an overview of the signal processing methods used in the reported studies, including details of exclusion criteria, manual filtering (preprocessing), gain change issues, acquisition details, selection of registration periods, averaging methods, physiological influences on the pleth, and comments by the investigators themselves. It is concluded that to develop a robust, fully automated ΔPOP algorithm for use in the clinical environment, more rigorous signal processing is required. Specifically, signals should be evaluated over significant periods of time, with emphasis on the quality and temporal relevance of the information.

  15. Powder metallurgy processing of high strength turbine disk alloys

    NASA Technical Reports Server (NTRS)

    Evans, D. J.

    1976-01-01

    Using vacuum-atomized AF2-1DA and Mar-M432 powders, full-scale gas turbine engine disks were fabricated by hot isostatically pressing (HIP) billets which were then isothermally forged using the Pratt & Whitney Aircraft GATORIZING forging process. While a sound forging was produced in the AF2-1DA, a container leak had occurred in the Mar-M432 billet during HIP. This resulted in billet cracking during forging. In-process control procedures were developed to identify such leaks. The AF2-1DA forging was heat treated and metallographic and mechanical property evaluation was performed. Mechanical properties exceeded those of Astroloy, one of the highest temperature capability turbine disk alloys presently used.

  16. The effect of process parameters on the thermal conditions during moving mold ESR

    SciTech Connect

    Heilman, J.E.; Damkroger, B.K.

    1994-09-01

    Several experimental melts were conducted using a moving mold electroslag remelting furnace. The conditions of electrode immersion depth, slag cap thickness, and melt current were varied. Mold wall temperatures and slag pool temperatures were measured and the heat flux through the mold wall was calculated. The relationships between varying ESR melt parameters and the resultant thermal conditions were examined. The thermal profile of the mold, the heat transfer to the mold coolant total and fractional, and the formation of a slag skin were studied.

  17. A new topological parameter for monitoring subtle aggregation events in host-guest inclusion processes

    NASA Astrophysics Data System (ADS)

    Novato, Willian T. G.; De Almeida, Wagner B.; Dos Santos, Hélio F.

    2012-02-01

    Supramolecular complexes with cyclodextrin (CD) have been the subject of considerable research in the material and life sciences. The dynamics of systems are difficult to characterise, therefore, knowledge of the molecular features governing the host-guest equilibrium might aid in the design and practical application of the resulting inclusion complexes. In this Letter, we present a new topological parameter based on simple trigonometric considerations to be used to monitor subtle host-guest inclusion events along the molecular dynamics trajectory. The new topological descriptor, called vector-μ, was applied to amphetamine@α/β-CD inclusion complexes, providing interesting insights on the host-guest equilibrium.

  18. Statistical Investigation of the Effect of Process Parameters on the Shear Strength of Metal Adhesive Joints

    NASA Astrophysics Data System (ADS)

    Rajkumar, Goribidanur Rangappa; Krishna, Munishamaih; Narasimhamurthy, Hebbale Narayanrao; Keshavamurthy, Yalanabhalli Channegowda

    2016-03-01

    The objective of the work was to optimize sheet metal joining parameters such as adhesive material, adhesive thickness, adhesive overlap length and surface roughness for single lap joint of aluminium sheet shear strength using robust design. An orthogonal array, main effect plot, signal-to-noise ratio and analysis of variance were employed to investigate the shear strength of the joints. The statistical result shows vinyl ester is best candidate among other two polymers viz. epoxy and polyester due to its low viscosity value compared to other two polymers. The experiment results shows that the adhesive thickness 0.6 mm, overlap length 50 mm and surface roughness 2.12 µm for obtained maximum shear strength of Al sheet joints. The ANOVA result shows one of the most significant factors is overlap length which affect joint strength in addition to adhesive thickness, adhesive material, and surface roughness. A confirmation test was carried out as the optimal combination of parameters will not match with the any of the experiments in the orthogonal array.

  19. Process modeling and parameter optimization using radial basis function neural network and genetic algorithm for laser welding of dissimilar materials

    NASA Astrophysics Data System (ADS)

    Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Yue, Chen

    2015-11-01

    The welded joints of dissimilar materials have been widely used in automotive, ship and space industries. The joint quality is often evaluated by weld seam geometry, microstructures and mechanical properties. To obtain the desired weld seam geometry and improve the quality of welded joints, this paper proposes a process modeling and parameter optimization method to obtain the weld seam with minimum width and desired depth of penetration for laser butt welding of dissimilar materials. During the process, Taguchi experiments are conducted on the laser welding of the low carbon steel (Q235) and stainless steel (SUS301L-HT). The experimental results are used to develop the radial basis function neural network model, and the process parameters are optimized by genetic algorithm. The proposed method is validated by a confirmation experiment. Simultaneously, the microstructures and mechanical properties of the weld seam generated from optimal process parameters are further studied by optical microscopy and tensile strength test. Compared with the unoptimized weld seam, the welding defects are eliminated in the optimized weld seam and the mechanical properties are improved. The results show that the proposed method is effective and reliable for improving the quality of welded joints in practical production.

  20. Improved Warm-Working Process For An Iron-Base Alloy

    NASA Technical Reports Server (NTRS)

    Cone, Fred P.; Cryns, Brendan J.; Miller, John A.; Zanoni, Robert

    1992-01-01

    Warm-working process produces predominantly unrecrystallized grain structure in forgings of iron-base alloy A286 (PWA 1052 composition). Yield strength and ultimate strength increased, and elongation and reduction of area at break decreased. Improved process used on forgings up to 10 in. thick and weighing up to 900 lb.

  1. Real-Time Parameter Estimation Method Applied to a MIMO Process and its Comparison with an Offline Identification Method

    SciTech Connect

    Kaplanoglu, Erkan; Safak, Koray K.; Varol, H. Selcuk

    2009-01-12

    An experiment based method is proposed for parameter estimation of a class of linear multivariable systems. The method was applied to a pressure-level control process. Experimental time domain input/output data was utilized in a gray-box modeling approach. Prior knowledge of the form of the system transfer function matrix elements is assumed to be known. Continuous-time system transfer function matrix parameters were estimated in real-time by the least-squares method. Simulation results of experimentally determined system transfer function matrix compare very well with the experimental results. For comparison and as an alternative to the proposed real-time estimation method, we also implemented an offline identification method using artificial neural networks and obtained fairly good results. The proposed methods can be implemented conveniently on a desktop PC equipped with a data acquisition board for parameter estimation of moderately complex linear multivariable systems.

  2. Femtosecond laser ablation properties of transparent materials: impact of the laser process parameters on the machining throughput

    NASA Astrophysics Data System (ADS)

    Matylitsky, V. V.; Hendricks, F.; Aus der Au, J.

    2013-03-01

    High average power, high repetition rate femtosecond lasers with μJ pulse energies are increasingly used for bio-medical and material processing applications. With the introduction of femtosecond laser systems such as the SpiritTM platform developed by High Q Lasers and Spectra-Physics, micro-processing of solid targets with femtosecond laser pulses have obtained new perspectives for industrial applications [1]. The unique advantage of material processing with subpicosecond lasers is efficient, fast and localized energy deposition, which leads to high ablation efficiency and accuracy in nearly all kinds of solid materials. The study on the impact of the laser processing parameters on the removal rate for transparent substrate using femtosecond laser pulses will be presented. In particular, examples of micro-processing of poly-L-lactic acid (PLLA) - bio-degradable polyester and XensationTM glass (Schott) machined with SpiritTM ultrafast laser will be shown.

  3. Effect of Thermo-Mechanical Processing and Heat Treatment on the Tribological Characteristics of Al Based MMC's

    NASA Astrophysics Data System (ADS)

    Keshavamurthy, R.; Madhu Sudhan, J.; Gowda, Narasimhe; Krishna, R. Ananda

    2016-09-01

    This paper reports on effect of forging and Heat Treatment on Tribological characteristics of aluminium alloy-silicon nitride. Cast aluminium alloy and composite were subjected to open die hot forging process. Alloy and its composites were examined to characteristics hardness and wear test under both primary and secondary processing conditions. Effect of heat treatment on hardness and tribological behaviour were also studied. Microstructure shows even spreading of particles in cast & forged conditions. hot forged alloy and composite shows a noticeable improvement in wear resistance and COF compare to their primary counter parts. Heat treatment has a considerable effect on hardness, friction and wear characteristics of composites.

  4. Effect of isothermal forging on the fracture properties of binary [gamma]-base titanium aluminides at room temperature

    SciTech Connect

    Gnanamoorthy, R.; Mutoh, Y. ); Masahashi, N.; Mizuhara, Y. )

    1994-07-15

    Gamma base titanium aluminides are light in weight and possess excellent high temperature properties such as strength, stiffness and oxidation resistance. Mechanical properties of [gamma]-base titanium aluminides depend on the microstructure, alloying addition and processing route. Influences of microstructure and alloying addition on the fracture properties have been investigated. However, the influence of processing route on fracture properties is not clear at present. In the present study, the flexural strength, the flexural strength, fracture toughness and fatigue crack growth properties of (a) cast and heat treated and (b) cast, heat treated and subsequently isothermal forged binary Ti-50Al (compositions are mentioned in atomic percent) with equiaxed microstructures are investigated. Fracture surface and crack growth path investigations are performed.

  5. Forging Hispanic communities in new destinations: A case study of Durham, NC1

    PubMed Central

    Flippen, Chenoa A.; Parrado, Emilio A.

    2013-01-01

    The Chicago School of urban sociology and its extension in the spatial assimilation model have provided the dominant framework for understanding the interplay between immigrant social and spatial mobility. However, the main tenets of the theory were derived from the experience of pre-war, centralized cities; scholars falling under the umbrella of the Los Angeles school have recently challenged the extent to which they are applicable to the contemporary urban form, which is characterized by sprawling, decentralized, and multi-nucleated development. Indeed, new immigrant destinations, such as those scattered throughout the American Southeast, are both decentralized and lack prior experience with large scale immigration. Informed by this debate this paper traces the formation and early evolution of Hispanic neighborhoods in Durham, NC, a new immigrant destination. Using qualitative data we construct a social history of immigrant neighborhoods and apply survey and census information to examine the spatial pattern of neighborhood succession. We also model the sorting of immigrants across neighborhoods according to personal characteristics. Despite the many differences in urban form and experience with immigration, the main processes forging the early development of Hispanic neighborhoods in Durham are remarkably consistent with the spatial expectations from the Chicago School, though the sorting of immigrants across neighborhoods is more closely connected to family dynamics and political economy considerations than purely human capital attributes. PMID:24482612

  6. Forging School-Scientist Partnerships: A Case of Easier Said than Done?

    NASA Astrophysics Data System (ADS)

    Falloon, Garry

    2013-12-01

    Since the early 1980s, a number of initiatives have been undertaken worldwide which have involved scientists and teachers working together in projects designed to support the science learning of students. Many of these have attempted to establish school-scientist partnerships. In these, scientists, teachers, and students formed teams engaged in mutually beneficial science-based activities founded on principles such as equal recognition and input, and shared vision, responsibility and risk. This article uses two partnership programmes run by a New Zealand Science Research Institute, to illustrate the challenges faced by scientists and teachers as they attempted to forge meaningful and effective partnerships. It argues that achieving the theorised position of a shared partnership space at the intersection of the worlds of scientists and teachers is problematic, and that scientists must instead be prepared to penetrate deeply into the world of the classroom when undertaking any such interactions. Findings indicate epistemological differences, curriculum and school systems and issues, and teacher efficacy and science knowledge significantly affect the process of partnership formation. Furthermore, it is argued that a re-thinking of partnerships is needed to reflect present economic and education environments, which are very different to those in which they were originally conceived nearly 30 years ago. It suggests that technology has an important role to play in future partnership interactions.

  7. Closed Die Deformation Behavior of Cylindrical Iron-Alumina Metal Matrix Composites During Cold Sinter Forging

    NASA Astrophysics Data System (ADS)

    Prasanna Kumar, Undeti Jacob; Gupta, Pallav; Jha, Arun Kant; Kumar, Devendra

    2015-09-01

    The present paper aims to study the closed die deformation behavior of cylindrical Fe-Al2O3 metal matrix composites (MMCs). Closed die was manufactured by machining the high carbon steel block followed by oil quenching and then finishing. Samples sintered at a temperature of 1100 °C for 1 h were characterized with X-ray diffraction and scanning electron microscopy, which showed the formation of Fe, Al2O3 and nano size FeAl2O4 phases respectively. Density and hardness of the composite samples were determined after sintering. Closed die deformation studies of the prepared composite samples were carried under three different interfacial frictional conditions i.e. dry, solid lubricating and liquid lubricating. Hardness, density and metallographic characterizations were also done for the deformed samples. On comparing the micrographs of the samples before and after deformation it was revealed that in deformed specimens recrystallization has taken place due to the difference in the energy between the strained iron matrix and unstrained alumina reinforcement during closed die forging process. Experimental density of the samples was also verified with the theoretical density using the standard equations. It is expected that the results of the present investigations will be helpful in developing quality MMC components for wide industrial applications.

  8. The effect of process parameters on Twin Wire Arc spray pattern shape

    SciTech Connect

    Hall, Aaron Christopher; McCloskey, James Francis; Horner, Allison Lynne

    2015-04-20

    A design of experiments approach was used to describe process parameter—spray pattern relationships in the Twin Wire Arc process using zinc feed stock in a TAFA 8835 (Praxair, Concord, NH, USA) spray torch. Specifically, the effects of arc current, primary atomizing gas pressure, and secondary atomizing gas pressure on spray pattern size, spray pattern flatness, spray pattern eccentricity, and coating deposition rate were investigated. Process relationships were investigated with the intent of maximizing or minimizing each coating property. It was determined that spray pattern area was most affected by primary gas pressure and secondary gas pressure. Pattern eccentricity was most affected by secondary gas pressure. Pattern flatness was most affected by primary gas pressure. Lastly, coating deposition rate was most affected by arc current.

  9. The effect of process parameters on Twin Wire Arc spray pattern shape

    DOE PAGES

    Hall, Aaron Christopher; McCloskey, James Francis; Horner, Allison Lynne

    2015-04-20

    A design of experiments approach was used to describe process parameter—spray pattern relationships in the Twin Wire Arc process using zinc feed stock in a TAFA 8835 (Praxair, Concord, NH, USA) spray torch. Specifically, the effects of arc current, primary atomizing gas pressure, and secondary atomizing gas pressure on spray pattern size, spray pattern flatness, spray pattern eccentricity, and coating deposition rate were investigated. Process relationships were investigated with the intent of maximizing or minimizing each coating property. It was determined that spray pattern area was most affected by primary gas pressure and secondary gas pressure. Pattern eccentricity was mostmore » affected by secondary gas pressure. Pattern flatness was most affected by primary gas pressure. Lastly, coating deposition rate was most affected by arc current.« less

  10. Induction hardening: Differences to a conventional heat treatment process and optimization of its parameters

    NASA Astrophysics Data System (ADS)

    Vieweg, A.; Ressel, G.; Prevedel, P.; Raninger, P.; Panzenböck, M.; Marsoner, S.; Ebner, R.

    2016-03-01

    The possibility of obtaining similar mechanical properties with faster heating processes than the conventional ones has been of interest for several years. In the present study, investigations were performed in terms of the influences of such fast heat-treatments on the microstructure and mechanical properties of the material. This investigation compares an inductive with a conventional furnace heat treating process of a 50CrMo4 steel, however only the austenitizing treatment was changed and subsequent quenching and tempering was done in the same way. To this end experiments with a middle frequency generator, using different heating rates and austenitizing temperatures, were conducted and followed by oil quenching of the workpieces. The resulting structures were characterized regarding their microstructures and mechanical properties in order to gather a better understanding of the differences between the inductive and the conventional heat treating process. As a main result it was found, that the fast austenitized samples exhibited worse ductility than the conventional treated material.

  11. Genome-Wide QTL Mapping for Wheat Processing Quality Parameters in a Gaocheng 8901/Zhoumai 16 Recombinant Inbred Line Population

    PubMed Central

    Jin, Hui; Wen, Weie; Liu, Jindong; Zhai, Shengnan; Zhang, Yan; Yan, Jun; Liu, Zhiyong; Xia, Xianchun; He, Zhonghu

    2016-01-01

    Dough rheological and starch pasting properties play an important role in determining processing quality in bread wheat (Triticum aestivum L.). In the present study, a recombinant inbred line (RIL) population derived from a Gaocheng 8901/Zhoumai 16 cross grown in three environments was used to identify quantitative trait loci (QTLs) for dough rheological and starch pasting properties evaluated by Mixograph, Rapid Visco-Analyzer (RVA), and Mixolab parameters using the wheat 90 and 660 K single nucleotide polymorphism (SNP) chip assays. A high-density linkage map constructed with 46,961 polymorphic SNP markers from the wheat 90 and 660 K SNP assays spanned a total length of 4121 cM, with an average chromosome length of 196.2 cM and marker density of 0.09 cM/marker; 6596 new SNP markers were anchored to the bread wheat linkage map, with 1046 and 5550 markers from the 90 and 660 K SNP assays, respectively. Composite interval mapping identified 119 additive QTLs on 20 chromosomes except 4D; among them, 15 accounted for more than 10% of the phenotypic variation across two or three environments. Twelve QTLs for Mixograph parameters, 17 for RVA parameters and 55 for Mixolab parameters were new. Eleven QTL clusters were identified. The closely linked SNP markers can be used in marker-assisted wheat breeding in combination with the Kompetitive Allele Specific PCR (KASP) technique for improvement of processing quality in bread wheat. PMID:27486464

  12. Genome-Wide QTL Mapping for Wheat Processing Quality Parameters in a Gaocheng 8901/Zhoumai 16 Recombinant Inbred Line Population.

    PubMed

    Jin, Hui; Wen, Weie; Liu, Jindong; Zhai, Shengnan; Zhang, Yan; Yan, Jun; Liu, Zhiyong; Xia, Xianchun; He, Zhonghu

    2016-01-01

    Dough rheological and starch pasting properties play an important role in determining processing quality in bread wheat (Triticum aestivum L.). In the present study, a recombinant inbred line (RIL) population derived from a Gaocheng 8901/Zhoumai 16 cross grown in three environments was used to identify quantitative trait loci (QTLs) for dough rheological and starch pasting properties evaluated by Mixograph, Rapid Visco-Analyzer (RVA), and Mixolab parameters using the wheat 90 and 660 K single nucleotide polymorphism (SNP) chip assays. A high-density linkage map constructed with 46,961 polymorphic SNP markers from the wheat 90 and 660 K SNP assays spanned a total length of 4121 cM, with an average chromosome length of 196.2 cM and marker density of 0.09 cM/marker; 6596 new SNP markers were anchored to the bread wheat linkage map, with 1046 and 5550 markers from the 90 and 660 K SNP assays, respectively. Composite interval mapping identified 119 additive QTLs on 20 chromosomes except 4D; among them, 15 accounted for more than 10% of the phenotypic variation across two or three environments. Twelve QTLs for Mixograph parameters, 17 for RVA parameters and 55 for Mixolab parameters were new. Eleven QTL clusters were identified. The closely linked SNP markers can be used in marker-assisted wheat breeding in combination with the Kompetitive Allele Specific PCR (KASP) technique for improvement of processing quality in bread wheat. PMID:27486464

  13. Effect of Die Strength and Work Piece Strength on the Wear of Hot Forging Dies

    NASA Astrophysics Data System (ADS)

    Levy, B. S.; Van Tyne, C. J.

    2015-01-01

    The effect of the strength ratio extracted from an Archard model for wear is used to describe the wear rates expected in hot forging dies. In the current study, the strength ratio is the strength of the hot forging die to the strength of the work piece. Three hot forging die steels are evaluated. The three die steels are FX, 2714, and WF. To determine the strength of the forging die, a continuous function has been developed that describes the yield strength of three die steels for temperatures from 600 to 700 °C and for times up to 20 h (i.e., tempering times of up to 20 h). The work piece material is assumed to be AISI 1045. Based on the analysis, the wear resistance of WF should be superior and FX should be slightly better than 2714. Decreasing the forging temperature increases the strength ratio, because the strength of the die surface increases faster than the flow strength of AISI 1045. The increase in the strength ratio indicates a decrease in the expected wear rate.

  14. Identification of forged Bank of England £20 banknotes using IR spectroscopy

    NASA Astrophysics Data System (ADS)

    Sonnex, Emily; Almond, Matthew J.; Baum, John V.; Bond, John W.

    2014-01-01

    Bank of England notes of £20 denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. An aim of this work was to develop a non-destructive method so that a small, compact Fourier transform infrared spectrometer (FT-IR) instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 cm-1 arising from νasym (CO32-) from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine £20 notes were observed in the ν(OH) (ca. 3500 cm-1), ν(Csbnd H) (ca. 2900 cm-1) and ν(Cdbnd O) (ca. 1750 cm-1) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper.

  15. Identification of Forged Bank of England 20 Gbp Banknotes Using IR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Sonnex, Emily

    2014-06-01

    Bank of England notes of 20 GBP denomination have been studied using infrared spectroscopy in order to generate a method to identify forged notes. A principal aim of this work was to develop a method so that a small, compact ATR FTIR instrument could be used by bank workers, police departments or others such as shop assistants to identify forged notes in a non-lab setting. The ease of use of the instrument is the key to this method, as well as the relatively low cost. The presence of a peak at 1400 wn from the blank paper section of a forged note proved to be a successful indicator of the note's illegality for the notes that we studied. Moreover, differences between the spectra of forged and genuine 20 GBP notes were observed in the ν(OH) (ca. 3500 wn), ν(C-H) (ca. 2900 wn) and ν(C=O) (ca. 1750 wn) regions of the IR spectrum recorded for the polymer film covering the holographic strip. In cases where these simple tests fail, we have shown how an infrared microscope can be used to further differentiate genuine and forged banknotes by producing infrared maps of selected areas of the note contrasting inks with background paper. Further to this, with an announcement by the Bank of England to produce polymer banknotes in the future, the work has been extended using Australian polymer banknotes to show that the method would be transferable.

  16. TDNiCr (ni-20Cr-2ThO2) forging studies

    NASA Technical Reports Server (NTRS)

    Filippi, A. M.

    1974-01-01

    Elevated temperature tensile and stress rupture properties were evaluated for forged TDNiCr (Ni-20Cr-2ThO2) and related to thermomechanical history and microstructure. Forging temperature and final annealed condition had pronounced influences on grain size which, in turn, was related to high temperature strength. Tensile strength improved by a factor of 8 as grain size changed from 1 to 150 microns. Stress-rupture strength was improved by a factor of 3 to 5 by a grain size increase from 10 to 1000 microns. Some contributions to the elevated temperature strength of very large grain material may also occur from the development of a strong texture and a preponderance of small twins. Other conditions promoting the improvement of high temperature strength were: an increase of total reduction, forging which continued the metal deformation inherent in the starting material, a low forging speed, and prior deformation by extrusion. The mechanical properties of optimally forged TDNiCr compared favorably to those of high strength sheet developed for space shuttle application.

  17. Optimization of processing parameters and ingredients for development of low-fat fibre-supplemented paneer.

    PubMed

    Singh, G; Kumar, A; Kumbhar, B K; Dar, B N

    2015-02-01

    Increasing demand of low calorie and high fibre containing products give impetus to dairy industry for development of a well palatable low calorie dairy products like paneer. The objective of the present study was to develop low-fat fibre-supplemented paneer. The ingredients were chosen for low-fat fibre- supplemented paneer to reduce the cost and calorie content besides providing the functional benefits. Optimization of ingredients was carried out in terms of independent variables viz wheat bran (0.4-0.8 %), maltodextrin (1-5 %), coagulation temperature (60-80 °C) and amount of citric acid solution (150-210 ml). Response Surface Methodology (RSM) was used to design the experiments and to select the optimum levels of ingredients. Paneer was made by using different levels of ingredients by coagulating hot milk using citric acid solution followed by pressing and dipping in chilled water for texturization. These parameters were evaluated in terms of physico-chemical parameters viz water activity, pH and acidity. Instrumental texture profile analysis (TPA) of paneer during optimization trials was done using TAXT 2i Texture Analyzer. The textural responses namely hardness, adhesiveness, springiness, cohesiveness, gumminess and chewiness were measured via Texture Analyzer. The sensory properties namely flavor, appearance, body and texture, mouth feel and overall acceptability of paneer samples were evaluated by a semi-trained panel of judges using 9-point hedonic scale. Full second order polynomial was developed to predict each response. All the textural and sensory responses were statistically analysed.

  18. Effect of Processing Parameters on Plasma Jet and In-flight Particles Characters in Supersonic Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Wei, Pei; Wei, Zhengying; Zhao, Guangxi; Bai, Y.; Tan, Chao

    2016-09-01

    In supersonic plasma spraying system (SAPS), heat transfer from arc plasma is characterized by several distinct features, such as transport of dissociation and ionization energy and of electrical charges in addition to mass transport. The thermodynamic and transport properties of plasma jet were influenced by several main parameters such as primary gas flow rate, the H2 vol.% and current intensity A. This paper first analyzes the effect of these parameters on the temperature and velocity of plasma jet theoretically. Further, the loading particles were melted and accelerated by plasma jet. Effects of several main parameters such as carrier gas flow rate, the H2 vol.%, the current intensity, the voltage and the spraying distance on temperature and velocity of in-flight particle were studied experimentally. The average maximum temperature and velocity of in-flight particle at any given parameters were systematically quantified. Optimal SAPS process parameters were given in this paper. In general, increasing the particles impacting velocity and surface temperature can improve the maximum spreading factor and decrease the coating porosity.

  19. Taguchi's off line method and Multivariate loss function approach for quality management and optimization of process parameters -A review

    NASA Astrophysics Data System (ADS)

    Bharti, P. K.; Khan, M. I.; Singh, Harbinder

    2010-10-01

    Off-line quality control is considered to be an effective approach to improve product quality at a relatively low cost. The Taguchi method is one of the conventional approaches for this purpose. Through this approach, engineers can determine a feasible combination of design parameters such that the variability of a product's response can be reduced and the mean is close to the desired target. The traditional Taguchi method was focused on ensuring good performance at the parameter design stage with one quality characteristic, but most products and processes have multiple quality characteristics. The optimal parameter design minimizes the total quality loss for multiple quality characteristics. Several studies have presented approaches addressing multiple quality characteristics. Most of these papers were concerned with maximizing the parameter combination of signal to noise (SN) ratios. The results reveal the advantages of this approach are that the optimal parameter design is the same as the traditional Taguchi method for the single quality characteristic; the optimal design maximizes the amount of reduction of total quality loss for multiple quality characteristics. This paper presents a literature review on solving multi-response problems in the Taguchi method and its successful implementation in various industries.

  20. Forming a lutein nanodispersion via solvent displacement method: the effects of processing parameters and emulsifiers with different stabilizing mechanisms.

    PubMed

    Tan, Tai Boon; Yussof, Nor Shariffa; Abas, Faridah; Mirhosseini, Hamed; Nehdi, Imededdine Arbi; Tan, Chin Ping

    2016-03-01

    A solvent displacement method was used to prepare lutein nanodispersions. The effects of processing parameters (addition method, addition rate, stirring time and stirring speed) and emulsifiers with different stabilizing mechanisms (steric, electrostatic, electrosteric and combined electrostatic-steric) on the particle size and particle size distribution (PSD) of the nanodispersions were investigated. Among the processing parameters, only the addition method and stirring time had significant effects (p<0.05) on the particle size and PSD. For steric emulsifiers, Tween 20, 40, 60 and 80 were used to produce nanodispersions successfully with particle sizes below 100nm. Tween 80 (steric) was then chosen for further comparison against sodium dodecyl sulfate (SDS) (electrostatic), sodium caseinate (electrosteric) and SDS-Tween 80 (combined electrostatic-steric) emulsifiers. At the lowest emulsifier concentration of 0.1%, all the emulsifiers invariably produced stable nanodispersions with small particle sizes (72.88-142.85nm) and narrow PSDs (polydispersity index<0.40). PMID:26471574

  1. Testing of New Materials and Computer Aided Optimization of Process Parameters and Clamping Device During Predevelopment of Laser Welding Processes

    NASA Astrophysics Data System (ADS)

    Weidinger, Peter; Günther, Kay; Fitzel, Martin; Logvinov, Ruslan; Ilin, Alexander; Ploshikhin, Vasily; Hugger, Florian; Mann, Vincent; Roth, Stephan; Schmidt, Michael

    The necessity for weight reduction in motor vehicles in order to save fuel consumption pushes automotive suppliers to use materials of higher strength. Due to their excellent crash behavior high strength steels are increasingly applied in various structures. In this paper some predevelopment steps for a material change from a micro alloyed to dual phase and complex phase steels of a T-joint assembly are displayed. Initially the general weldability of the materials regarding pore formation, hardening in the heat affected zone and hot cracking susceptibility is discussed. After this basic investigation, the computer aided design optimization of a clamping device is shown, in which influences of the clamping jaw, the welding position and the clamping forces upon weld quality are presented. Finally experimental results of the welding process are displayed, which validate the numerical simulation.

  2. Study on parameters affecting the mechanical properties of dry fiber bundles during continuous composite manufacturing processes

    NASA Astrophysics Data System (ADS)

    Maier, A.; Schledjewski, R.

    2016-07-01

    For continuous manufacturing processes mechanical preloading of the fibers occurs during the delivery of the fibers from the spool creel to the actual manufacturing process step. Moreover preloading of the dry roving bundles might be mandatory, e.g. during winding, to be able to produce high quality components. On the one hand too high tensile loads within dry roving bundles might result in a catastrophic failure and on the other hand the part produced under too low pre-tension might have low quality and mechanical properties. In this work, load conditions influencing mechanical properties of dry glass fiber bundles during continuous composite manufacturing processes were analyzed. Load conditions, i.e. fiber delivery speed, necessary pre-tension and other effects of the delivery system during continuous fiber winding, were chosen in process typical ranges. First, the strain rate dependency under static tensile load conditions was investigated. Furthermore different free gauge lengths up to 1.2 m, interactions between fiber points of contact regarding influence of sizing as well as impregnation were tested and the effect of twisting on the mechanical behavior of dry glass fiber bundles during the fiber delivery was studied.

  3. The impact of material attributes and process parameters on the micronisation of lactose monohydrate.

    PubMed

    Shariare, M H; de Matas, M; York, P; Shao, Q

    2011-04-15

    Dry powder inhalers (DPIs), which are important medicines for drug delivery to the lungs, require drug particles in the respirable size range of 1-6 μm for optimal lung deposition. Drugs administered by the oral route also derive benefit from particles in this size range owing to their large surface area to volume ratio, which provides potential for rapid dissolution. Micronisation used in the production of particles, however often leads to heterogeneous product containing mechanically activated surfaces with amorphous content. This study was therefore carried out to evaluate the effect of particle properties of three grades of lactose monohydrate, with sizes above and below the brittle-ductile transition (dcrit) and their interaction with process variables on the quality of micronised material. Following an experimental design, the impact of three factors (grinding pressure, injector pressure and feed rate) on the particulate attributes of micronised powders produced from the different size grades was assessed. Processing conditions were shown to be important determinants of powder properties only for the coarsest starting material. Ultrafine material was achieved by processing finer grade feed stock below dcrit. However the resultant product was more crystalline and transformed on heating to the anhydrous state with markedly reduced onset temperature with lower energy surfaces than powders produced from larger sized starting material. Thus the propensity for micronisation of lactose monohydrate can be altered through control of starting materials and optimal settings for process variables. PMID:21295125

  4. Mitochondrial DNA Fragmentation to Monitor Processing Parameters in High Acid, Plant-Derived Foods.

    PubMed

    Caldwell, Jane M; Pérez-Díaz, Ilenys M; Harris, Keith; Hassan, Hosni M; Simunovic, Josip; Sandeep, K P

    2015-12-01

    Mitochondrial DNA (mtDNA) fragmentation was assessed in acidified foods. Using quantitative polymerase chain reaction, Ct values measured from fresh, fermented, pasteurized, and stored cucumber mtDNA were determined to be significantly different (P > 0.05) based on processing and shelf-life. This indicated that the combination of lower temperature thermal processes (hot-fill at 75 °C for 15 min) and acidified conditions (pH = 3.8) was sufficient to cause mtDNA fragmentation. In studies modeling high acid juices, pasteurization (96 °C, 0 to 24 min) of tomato serum produced Ct values which had high correlation to time-temperature treatment. Primers producing longer amplicons (approximately 1 kb) targeting the same mitochondrial gene gave greater sensitivity in correlating time-temperature treatments to Ct values. Lab-scale pasteurization studies using Ct values derived from the longer amplicon differentiated between heat treatments of tomato serum (95 °C for <2 min). MtDNA fragmentation was shown to be a potential new tool to characterize low temperature (<100 °C) high acid processes (pH < 4.6), nonthermal processes such as vegetable fermentation and holding times of acidified, plant-derived products. PMID:26556214

  5. Motion compensated image processing and optimal parameters for egg crack detection using modified pressure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shell eggs with microcracks are often undetected during egg grading processes. In the past, a modified pressure imaging system was developed to detect eggs with microcracks without adversely affecting the quality of normal intact eggs. The basic idea of the modified pressure imaging system was to ap...

  6. Influence of process parameter on Campylobacter spp. counts on poultry meat in a slaughterhouse environment.

    PubMed

    Lehner, Y; Reich, F; Klein, G

    2014-09-01

    Campylobacter spp. are the most important food-borne pathogens in broilers. Exposure of the consumer can be influenced by the reduction of contaminated broiler meat at various steps along the production line. This study was performed at a poultry slaughterhouse in Germany. Steps within the slaughter process were defined by the slaughterhouse quality control for potential Campylobacter reduction. Their impact was tested for two process variations. The first process variation was the increase of the temperature of the scalding water from 53.0 to 53.9 °C. The second step was the application of an additional outside sprayer which was placed after plucking. The increase of the scalding water temperature was the most effective measure (>2 log reduction), but resulted in defects to the broiler skin. This would limit marketing of fresh broiler meat with skin. The additional water spray after plucking had no additional effect. In fact, numbers of Campylobacter were lower before introduction of the sprayer. In conclusion, modifications of the processing technology have to be evaluated carefully, but can have additional effects for Campylobacter reduction. PMID:24715049

  7. Mitochondrial DNA Fragmentation to Monitor Processing Parameters in High Acid, Plant-Derived Foods.

    PubMed

    Caldwell, Jane M; Pérez-Díaz, Ilenys M; Harris, Keith; Hassan, Hosni M; Simunovic, Josip; Sandeep, K P

    2015-12-01

    Mitochondrial DNA (mtDNA) fragmentation was assessed in acidified foods. Using quantitative polymerase chain reaction, Ct values measured from fresh, fermented, pasteurized, and stored cucumber mtDNA were determined to be significantly different (P > 0.05) based on processing and shelf-life. This indicated that the combination of lower temperature thermal processes (hot-fill at 75 °C for 15 min) and acidified conditions (pH = 3.8) was sufficient to cause mtDNA fragmentation. In studies modeling high acid juices, pasteurization (96 °C, 0 to 24 min) of tomato serum produced Ct values which had high correlation to time-temperature treatment. Primers producing longer amplicons (approximately 1 kb) targeting the same mitochondrial gene gave greater sensitivity in correlating time-temperature treatments to Ct values. Lab-scale pasteurization studies using Ct values derived from the longer amplicon differentiated between heat treatments of tomato serum (95 °C for <2 min). MtDNA fragmentation was shown to be a potential new tool to characterize low temperature (<100 °C) high acid processes (pH < 4.6), nonthermal processes such as vegetable fermentation and holding times of acidified, plant-derived products.

  8. Optimizing Technological Parameters of the Reduction Processes in Treating Steels in a Ladle Furnace

    NASA Astrophysics Data System (ADS)

    Gizatulin, R. A.; Valuev, D. V.; Valueva, A. V.; Serikbol, A.; Borovikov, I. F.

    2015-09-01

    This work reports the possible development of reduction processes when treating the molten metal and slag using a ladle furnace under conditions of intensive stirring with an inert gas. The industrial data have been received, confirming the possibility of decreasing the concentration of ferrous and manganese oxides in the slag and stabilizing the contents of manganese and silicon in the metal.

  9. Electrochemical machining of super-hydrophobic Al surfaces and effect of processing parameters on wettability

    NASA Astrophysics Data System (ADS)

    Song, Jin-long; Xu, Wen-ji; Liu, Xin; Lu, Yao; Sun, Jing

    2012-09-01

    Super-hydrophobic aluminum (Al) surfaces were successfully fabricated via electrochemical machining in neutral NaClO3 electrolyte and subsequent fluoroalkylsilane (FAS) modification. The effects of the processing time, processing current density, and electrolyte concentration on the wettability, morphology, and roughness were studied. The surface morphology, chemical composition, and wettability of the Al surfaces were investigated using scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), white-light interferometry, roughness measurements, X-ray diffraction (XRD), Fourier-transform infrared spectrometry (FTIR), and optical contact angle measurements. The results show that hierarchical rough structures and low surface energy films were present on the Al surfaces after electrochemical machining and FAS modification. The combination of the rough structures and the low surface energy materials plays a crucial role in achieving super-hydrophobicity. Compared with the anodic oxidation and chemical etching method, the method proposed in our work does not require strong acid or alkali, and causes less harm to the environment and operators but with high processing efficiency. The rough structures required by the super-hydrophobic surfaces were obtained at 30-s processing time and the best super-hydrophobicity with 164.6∘ water contact angle and 2∘ tilting angle was obtained at 360 s. The resulting super-hydrophobic Al surfaces have a long-time stability in air and an excellent resistance to corrosive liquids.

  10. Effect of Process Parameters on the Size and Shape of Nano- and Micrometric Zinc Oxide.

    PubMed

    Pulit-Prociak, Jolanta; Banach, Marcin

    2016-01-01

    The paper presents a method of obtaining zinc oxide nano- and microparticles. In these studies microwave reactor and laboratory pressure reactor were used. Since microwave radiation accelerates proceeding of reactions, this way was found to be an effective method in the process of obtaining nanocrystallines of zinc oxide. The size of prepared particles rarely exceeded 500 nm. PMID:27333554

  11. Features of thermal processes of plasma deposition and hardening of coatings with external modulation parameters of the arc

    NASA Astrophysics Data System (ADS)

    Kadyrmetov, A. M.; Sharifullin, S. N.; Maltsev, A. F.

    2016-06-01

    In the work on the basis of mathematical modeling analysis of processes of plasma deposition of coatings with modulation of the electrical parameters of the extension arc. The effect of modulation on the temperature field in the system "coating-basis" on a local scale, proportionate to the diameter of the spot attachment of the arc to the surface, and at the macrolevel of evaporation surface. It justifies the preconditions of the improvement of plasma deposition and hardening coatings.

  12. Development of a controlled release formulation by continuous twin screw granulation: Influence of process and formulation parameters.

    PubMed

    Vanhoorne, V; Vanbillemont, B; Vercruysse, J; De Leersnyder, F; Gomes, P; Beer, T De; Remon, J P; Vervaet, C

    2016-05-30

    The aim of this study was to evaluate the potential of twin screw granulation for the continuous production of controlled release formulations with hydroxypropylmethylcellulose as hydrophilic matrix former. Metoprolol tartrate was included in the formulation as very water soluble model drug. A premix of metoprolol tartrate, hydroxypropylmethylcellulose and filler (ratio 20/20/60, w/w) was granulated with demineralized water via twin screw granulation. After oven drying and milling, tablets were produced on a rotary Modul™ P tablet press. A D-optimal design (29 experiments) was used to assess the influence of process (screw speed, throughput, barrel temperature and screw design) and formulation parameters (starch content of the filler) on the process (torque), granule (size distribution, shape, friability, density) and tablet (hardness, friability and dissolution) critical quality attributes. The torque was dominated by the number of kneading elements and throughput, whereas screw speed and filling degree only showed a minor influence on torque. Addition of screw mixing elements after a block of kneading elements improved the yield of the process before milling as it resulted in less oversized granules and also after milling as less fines were present. Temperature was also an important parameter to optimize as a higher temperature yielded less fines and positively influenced the aspect ratio. The shape of hydroxypropylmethylcellulose granules was comparable to that of immediate release formulations. Tensile strength and friability of tablets were not dependent on the process parameters. The use of starch as filler was not beneficial with regard to granule and tablet properties. Complete drug release was obtained after 16-20h and was independent of the design's parameters. PMID:27041123

  13. Degradation of carbofuran in aqueous solution by ultrasound and Fenton processes: Effect of system parameters and kinetic study.

    PubMed

    Ma, Ying-Shih; Sung, Chi-Fanga; Lin, Jih-Gaw

    2010-06-15

    To establish an efficient oxidation process for carbofuran degradation, the effects of some operating parameters such as dosages of H(2)O(2), Fe(2+) and initial carbofuran concentrations were observed during carbofuran degradation by the ultrasound process, Fenton process and a combined ultrasound/Fenton process. The degradation kinetics of carbofuran was also examined based on the experimental data. The results show that more than 99% of the carbofuran was degraded by the ultrasound/Fenton process within short reaction time periods. Increased dosages of H(2)O(2) and Fe(2+) enhanced the degradation of carbofuran in the ultrasound and Fenton oxidation processes, but initial carbofuran concentrations decreased carbofuran degradation in both the Fenton and ultrasound/Fenton processes. The degradation kinetics of carbofuran by the three oxidation processes was found to be in accordance with first-order reaction kinetics. The results provide fundamental information about the treatment of carbofuran wastewater and/or other pesticides by the ultrasound/Fenton oxidation process.

  14. Temporal variations in parameters reflecting terminal-electron-accepting processes in an aquifer contaminated with waste fuel and chlorinated solvents

    USGS Publications Warehouse

    McGuire, Jennifer T.; Smith, Erik W.; Long, David T.; Hyndman, David W.; Haack, Sheridan K.; Klug, Michael J.; Velbel, Michael A.

    2000-01-01

    A fundamental issue in aquifer biogeochemistry is the means by which solute transport, geochemical processes, and microbiological activity combine to produce spatial and temporal variations in redox zonation. In this paper, we describe the temporal variability of TEAP conditions in shallow groundwater contaminated with both waste fuel and chlorinated solvents. TEAP parameters (including methane, dissolved iron, and dissolved hydrogen) were measured to characterize the contaminant plume over a 3-year period. We observed that concentrations of TEAP parameters changed on different time scales and appear to be related, in part, to recharge events. Changes in all TEAP parameters were observed on short time scales (months), and over a longer 3-year period. The results indicate that (1) interpretations of TEAP conditions in aquifers contaminated with a variety of organic chemicals, such as those with petroleum hydrocarbons and chlorinated solvents, must consider additional hydrogen-consuming reactions (e.g., dehalogenation); (2) interpretations must consider the roles of both in situ (at the sampling point) biogeochemical and solute transport processes; and (3) determinations of microbial communities are often necessary to confirm the interpretations made from geochemical and hydrogeological measurements on these processes.

  15. Hyperspectral Data Processing and Mapping of Soil Parameters: Preliminary Data from Tuscany (Italy)

    NASA Astrophysics Data System (ADS)

    Garfagnoli, F.; Moretti, S.; Catani, F.; Innocenti, L.; Chiarantini, L.

    2010-12-01

    -sensor radiance values, where calibration coefficients and parameters from laboratory measurements are applied to non-georeferred VNIR/SWIR DN values. Then, geocoded products are retrieved for each flight line by using a procedure developed in IDL Language and PARGE (PARametric Geocoding) software. When all compensation parameters are applied to hyperspectral data or to the final thematic map, orthorectified, georeferred and coregistered VNIR to SWIR images or maps are available for GIS application and 3D view. Airborne imagery has to be corrected for the influence of the atmosphere, solar illumination, sensor viewing geometry and terrain geometry information, for the retrieval of inherent surface reflectance properties. Then, different geophysical parameters can be investigated and retrieved by means of inversion algorithms. The experimental fitting of laboratory data on mineral content is used for airborne data inversion, whose results are in agreement with laboratory records, demonstrating the possibility to use this methodology for digital mapping of soil properties.

  16. Application of physicochemical properties and process parameters in the development of a neural network model for prediction of tablet characteristics.

    PubMed

    Sovány, Tamás; Papós, Kitti; Kása, Péter; Ilič, Ilija; Srčič, Stane; Pintye-Hódi, Klára

    2013-06-01

    The importance of in silico modeling in the pharmaceutical industry is continuously increasing. The aim of the present study was the development of a neural network model for prediction of the postcompressional properties of scored tablets based on the application of existing data sets from our previous studies. Some important process parameters and physicochemical characteristics of the powder mixtures were used as training factors to achieve the best applicability in a wide range of possible compositions. The results demonstrated that, after some pre-processing of the factors, an appropriate prediction performance could be achieved. However, because of the poor extrapolation capacity, broadening of the training data range appears necessary. PMID:23413109

  17. Determination of thermodynamic and transport parameters of naphthenic acids and organic process chemicals in oil sand tailings pond water.

    PubMed

    Wang, Xiaomeng; Robinson, Lisa; Wen, Qing; Kasperski, Kim L

    2013-07-01

    Oil sand tailings pond water contains naphthenic acids and process chemicals (e.g., alkyl sulphates, quaternary ammonium compounds, and alkylphenol ethoxylates). These chemicals are toxic and can seep through the foundation of the tailings pond to the subsurface, potentially affecting the quality of groundwater. As a result, it is important to measure the thermodynamic and transport parameters of these chemicals in order to study the transport behavior of contaminants through the foundation as well as underground. In this study, batch adsorption studies and column experiments were performed. It was found that the transport parameters of these chemicals are related to their molecular structures and other properties. The computer program (CXTFIT) was used to further evaluate the transport process in the column experiments. The results from this study show that the transport of naphthenic acids in a glass column is an equilibrium process while the transport of process chemicals seems to be a non-equilibrium process. At the end of this paper we present a real-world case study in which the transport of the contaminants through the foundation of an external tailings pond is calculated using the lab-measured data. The results show that long-term groundwater monitoring of contaminant transport at the oil sand mining site may be necessary to avoid chemicals from reaching any nearby receptors. PMID:23736740

  18. Determination of thermodynamic and transport parameters of naphthenic acids and organic process chemicals in oil sand tailings pond water.

    PubMed

    Wang, Xiaomeng; Robinson, Lisa; Wen, Qing; Kasperski, Kim L

    2013-07-01

    Oil sand tailings pond water contains naphthenic acids and process chemicals (e.g., alkyl sulphates, quaternary ammonium compounds, and alkylphenol ethoxylates). These chemicals are toxic and can seep through the foundation of the tailings pond to the subsurface, potentially affecting the quality of groundwater. As a result, it is important to measure the thermodynamic and transport parameters of these chemicals in order to study the transport behavior of contaminants through the foundation as well as underground. In this study, batch adsorption studies and column experiments were performed. It was found that the transport parameters of these chemicals are related to their molecular structures and other properties. The computer program (CXTFIT) was used to further evaluate the transport process in the column experiments. The results from this study show that the transport of naphthenic acids in a glass column is an equilibrium process while the transport of process chemicals seems to be a non-equilibrium process. At the end of this paper we present a real-world case study in which the transport of the contaminants through the foundation of an external tailings pond is calculated using the lab-measured data. The results show that long-term groundwater monitoring of contaminant transport at the oil sand mining site may be necessary to avoid chemicals from reaching any nearby receptors.

  19. Relationships Between LRI Process Parameters and Impact and Post-Impact Behaviour of Stitched and Unstitched NCF Laminates

    NASA Astrophysics Data System (ADS)

    Njionhou, Alvine; Berthet, Florentin; Castanié, Bruno; Bouvet, Christophe

    2012-12-01

    The general context of the development of out-of-autoclave processes in the aeronautics industry raises the question of the possible links between these new processes and impact behaviour. In this study, a Taguchi table was used in a design of experiment approach to establish possible links. The study focused on the liquid resin infusion process applied to laminates made with stitched or unstitched quadri-axial carbon Non-Crimp Fabric (NCF). On the basis of previous studies and an analysis of the literature, five process parameters were selected (stitching, curing temperature, preform position, number of highly porous media, vacuum level). The impact energy was set at 35 J in order to obtain enough residual dent depth. The parameters analysed during and after impact were: maximum displacement of the impactor, energy absorbed, permanent indentation depth, and delaminated surface. Then, compression after impact tests were performed and the corresponding average stress was measured. The interactions found by statistical analysis show a very high sensitivity to stitching, which was, of course, expected. A very significant influence of curing temperature and a significant influence of preform position were also found on the permanent indentation depth and a physical explanation is provided. Globally, it was demonstrated that the resin infusion process itself did not influence the impact behaviour.

  20. Developing LBM Process Parameters for Ti-6Al-4V Thin Wall Structures and Determining the Corresponding Mechanical Characteristics

    NASA Astrophysics Data System (ADS)

    Ahuja, Bhrigu; Schaub, Adam; Karg, Michael; Lechner, Michael; Merklein, Marion; Schmidt, Michael

    The Laser Beam Melting (LBM) process technology within the family of Additive Manufacturing technology is characterized by its ability to fabricate fully dense 3D structures directly from micro-sized metal powder. With the current state of the art, Ti-6Al-4V has been processed using LBM machine systems constituting a laser with a beam diameter of about 100 μm. In order to fabricate structures with smaller wall thicknesses, processing of Ti-6Al-4V is attempted on the LBM machine system, Realizer SLM 50 consisting of a laser with a beam diameter 10 μm. The proposed paper presents the development of process parameters for fabricating fully dense Ti-6Al-4V 3D structures using the LBM machine system, Realizer SLM 50. Further experiments are carried out to determine the wall thickness and mechanical properties achievable using the selected process parameters. Analysis and scientific arguments are presented to explain the influence of building direction and heat treatment on mechanical properties.

  1. Stevia rebaudiana Bertoni as a natural antioxidant/antimicrobial for high pressure processed fruit extract: processing parameter optimization.

    PubMed

    Barba, Francisco José; Criado, María Nieves; Belda-Galbis, Clara Miracle; Esteve, María José; Rodrigo, Dolores

    2014-04-01

    Response surface methodology was used to evaluate the optimal high pressure processing treatment (300-500 MPa, 5-15 min) combined with Stevia rebaudiana (Stevia) addition (0-2.5% (w/v)) to guarantee food safety while maintaining maximum retention of nutritional properties. A fruit extract matrix was selected and Listeria monocytogenes inactivation was followed from the food safety point of view while polyphenoloxidase (PPO) and peroxidase (POD) activities, total phenolic content (TPC) and antioxidant capacity (TEAC and ORAC) were studied from the food quality point of view. A combination of treatments achieved higher levels of inactivation of L. monocytogenes and of the oxidative enzymes, succeeding in completely inactivating POD and also increasing the levels of TPC, TEAC and ORAC. A treatment of 453 MPa for 5 min with a 2.5% (w/v) of Stevia succeeded in inactivating over 5 log cycles of L. monocytogenes and maximizing inactivation of PPO and POD, with the greatest retention of bioactive components.

  2. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    SciTech Connect

    Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  3. Some Working Parameters and Energy Use in a Pistachio Nut Processing Plant: A Case Study

    NASA Astrophysics Data System (ADS)

    Polat, Refik; Erol Ak, Bekir; Acar, Izzet

    This study was performed with the objective to investigate the work process, work capacity, work effectiveness, energy consumption and labor force requirements of basic units such as washing, dehulling, sorting, separating, roasting and packing in a pistachio processing plant which has been mechanized in the last years. As a result of this study, the work capacity in washing, sorting, breaking, drying, separating units was found to be 1.5, 1.5, 2, 1, 1.6 t h-1, respectively. The work effectiveness in sorting and breaking units was found to be 95% and that of separating unit was 99%. The total energy consumption of the units was found to be 20.42 kW h-1 and the total labor force requirement was found to be five workers.

  4. Site-specific analysis of radiological and physical parameters for cobbly soils at the Gunnison, Colorado, processing site. Revision 1

    SciTech Connect

    Not Available

    1994-01-01

    The remedial action at the Gunnison, Colorado, processing site is being performed under the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978. Under UMTRCA, the US Environmental Protection Agency (EPA) is charged with the responsibility of developing appropriate and applicable standards for the cleanup of radiologically contaminated land and buildings at 24 designated sites, including the Gunnison, Colorado, inactive processing site. Section 108 of Public Law 95-604 states that the US Department of Energy (DOE) shall ``select and perform remedial actions at the designated processing sites and disposal sites in accordance with the general standards`` prescribed by the EPA. Regulations governing the required remedial action at inactive uranium processing sites were promulgated by the EPA in 1983 and are contained in 40 CFR Part 192 (1993), Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings. This document describes the radiological and physical parameters for the remedial action of the soil.

  5. Microbiological, physicochemical and sensory parameters of dry fermented sausages manufactured with high hydrostatic pressure processed raw meat.

    PubMed

    Omer, M K; Prieto, B; Rendueles, E; Alvarez-Ordoñez, A; Lunde, K; Alvseike, O; Prieto, M

    2015-10-01

    The aim of this trial was to describe physicochemical, microbiological and organoleptic characteristics of dry fermented sausages produced from high hydrostatic pressure (HHP) pre-processed trimmings. During ripening of the meat products pH, weight, water activity (aw), and several microbiological parameters were measured at zero, eight, fifteen days and after 6weeks. Sensory characteristics were estimated at day 15 and after six weeks by a test panel by using several sensory tests. Enterobacteriaceae were not detected in sausages from HHP-processed trimmings. Fermentation was little affected, but weight and aw of the HHP-processed sausages decreased faster during ripening. HHP-treated sausages were consistently less favoured than non HHP-treated sausages, but the strategy may be an alternative approach if the process is optimized.

  6. Liquefaction of lignocellulosic biomass: solvent, process parameter, and recycle oil screening.

    PubMed

    van Rossum, Guus; Zhao, Wei; Castellvi Barnes, Maria; Lange, Jean-Paul; Kersten, Sascha R A

    2014-01-01

    The liquefaction of lignocellulosic biomass is studied for the production of liquid (transportation) fuels. The process concept uses a product recycle as a liquefaction medium and produces a bio-oil that can be co-processed in a conventional oil refinery. This all is done at medium temperature (≈ 300 °C) and pressure (≈ 60 bar). Solvent-screening experiments showed that oxygenated solvents are preferred as they allow high oil (up to 93% on carbon basis) and low solid yields (≈ 1-2% on carbon basis) and thereby outperform the liquefaction of biomass in compressed water and biomass pyrolysis. The following solvent ranking was obtained: guaiacol>hexanoic acid ≫ n-undecane. The use of wet biomass results in higher oil yields than dry biomass. However, it also results in a higher operating pressure, which would make the process more expensive. Refill experiments were also performed to evaluate the possibility to recycle the oil as the liquefaction medium. The recycled oil appeared to be very effective to liquefy the biomass and even surpassed the start-up solvent guaiacol, but became increasingly heavy and more viscous after each refill and eventually showed a molecular weight distribution that resembles that of refinery vacuum residue. PMID:24265195

  7. Study of the Influence of Key Process Parameters on Furfural Production.

    PubMed

    Fele Žilnik, Ljudmila; Grilc, Viktor; Mirt, Ivan; Cerovečki, Željko

    2016-01-01

    The present work reports the influence of key process variables on the furfural formation from leached chestnut-wood chips in a pressurized reactor. Effect of temperature, pressure, type and concentration of the catalyst solution, the steam flow rate or stripping module, the moisture content of the wood particles and geometric characteristics such as size and type of the reactor, particle size and bed height were considered systematically. One stage process was only taken into consideration. Lab-scale and pilot-scale studies were performed. The results of the non-catalysed laboratory experiments were compared with an actual non-catalysed (auto-catalysed) industrial process and with experiments on the pilot scale, the latter with 28% higher furfural yield compared to the others. Application of sulphuric acid as catalyst, in an amount of 0.03-0.05 g (H2SO4 100%)/g d.m. (dry material), enables a higher production of furfural at lower temperature and pressure of steam in a shorter reaction time. Pilot scale catalysed experiments have revealed very good performance for furfural formation under less severe operating conditions, with a maximum furfural yield as much as 88% of the theoretical value.

  8. Influence of the process parameters on osmotic dehydration of mapara (Hypophthalmus edentatus) fillet.

    PubMed

    de Almeida Maciel, Renan; da Cruz Rodrigues, Antonio Manoel; da Silva Pena, Rosinelson

    2016-01-01

    The effects of temperature, time, pressure and brine concentration were assessed during osmotic dehydration (OD) of H. edentatus fillet. The response surface methodology (RSM) showed that using vacuum during the OD process did not cause a statistically significant change (p > 0.05) on the water loss (WL), solid gain (SG) and water activity (aw). The other factors showed a statistically significant effect (p ≤ 0.05) on at least one of these responses. Through RSM, the following condition could be defined for the OD process: brine concentration at 25 % NaCl, 25 °C, 120 min and atmospheric pressure. The Azuara model was shown to be effective in predicting the WL and SG kinetics during the OD process. The simplified solution of Fick's second law of diffusion for a slab geometry was used to calculate the average values of apparent diffusion coefficient (Deff), namely 4.73 × 10(-10) m(2)/s for WL and 1.33 × 10(-9) m(2)/s for SG.

  9. Liquefaction of lignocellulosic biomass: solvent, process parameter, and recycle oil screening.

    PubMed

    van Rossum, Guus; Zhao, Wei; Castellvi Barnes, Maria; Lange, Jean-Paul; Kersten, Sascha R A

    2014-01-01

    The liquefaction of lignocellulosic biomass is studied for the production of liquid (transportation) fuels. The process concept uses a product recycle as a liquefaction medium and produces a bio-oil that can be co-processed in a conventional oil refinery. This all is done at medium temperature (≈ 300 °C) and pressure (≈ 60 bar). Solvent-screening experiments showed that oxygenated solvents are preferred as they allow high oil (up to 93% on carbon basis) and low solid yields (≈ 1-2% on carbon basis) and thereby outperform the liquefaction of biomass in compressed water and biomass pyrolysis. The following solvent ranking was obtained: guaiacol>hexanoic acid ≫ n-undecane. The use of wet biomass results in higher oil yields than dry biomass. However, it also results in a higher operating pressure, which would make the process more expensive. Refill experiments were also performed to evaluate the possibility to recycle the oil as the liquefaction medium. The recycled oil appeared to be very effective to liquefy the biomass and even surpassed the start-up solvent guaiacol, but became increasingly heavy and more viscous after each refill and eventually showed a molecular weight distribution that resembles that of refinery vacuum residue.

  10. Study of the Influence of Key Process Parameters on Furfural Production.

    PubMed

    Fele Žilnik, Ljudmila; Grilc, Viktor; Mirt, Ivan; Cerovečki, Željko

    2016-01-01

    The present work reports the influence of key process variables on the furfural formation from leached chestnut-wood chips in a pressurized reactor. Effect of temperature, pressure, type and concentration of the catalyst solution, the steam flow rate or stripping module, the moisture content of the wood particles and geometric characteristics such as size and type of the reactor, particle size and bed height were considered systematically. One stage process was only taken into consideration. Lab-scale and pilot-scale studies were performed. The results of the non-catalysed laboratory experiments were compared with an actual non-catalysed (auto-catalysed) industrial process and with experiments on the pilot scale, the latter with 28% higher furfural yield compared to the others. Application of sulphuric acid as catalyst, in an amount of 0.03-0.05 g (H2SO4 100%)/g d.m. (dry material), enables a higher production of furfural at lower temperature and pressure of steam in a shorter reaction time. Pilot scale catalysed experiments have revealed very good performance for furfural formation under less severe operating conditions, with a maximum furfural yield as much as 88% of the theoretical value. PMID:27333552

  11. Effect of food components and processing parameters on DNA degradation in food.

    PubMed

    Bauer, Torsten; Hammes, Walter P; Haase, Norbert U; Hertel, Christian

    2004-01-01

    The effect of food components on degradation of DNA by DNase I (EC 3.1.21.1) was monitored by electrotransformation of Escherichia coil, making it possible to determine the number of plasmid molecules capable of giving rise to transformed cells. The transformation frequency increased linearly with the plasmid number within the range of 2 x 10(6) to 2 x 10(10). DNA degradation was reduced by one order of magnitude in the presence of 0.05% (w.v(-1)) maltol or 1 mM putrescine. Complete inhibition of degradation was observed with > or = 0.2% (w.v(-1)) maltol, > or = 0.01% (w.v(-1)) octyl gallate or > or = 0.5 mM of spermine. To monitor degradation of plant DNA during food processing, a real-time PCR system was established. The ratio of copy numbers of a potato gbss DNA fragment of 325 bp and a nested 96 bp fragment was determined. The latter served as internal reference for normalization. The system made it possible to exclude process-dependent changes of DNA concentration in the food matrix. Processing of genetically modified potatoes to dried potato sticks, crisps or flakes was studied and drying steps were shown to exert the strongest effect on DNA degradation, resulting in a drop of the ratio from 0.73 to 0.16.

  12. Preparation of hydroxyapatite nanoparticles by sol-gel method with optimum processing parameters

    SciTech Connect

    Yusoff, Yusriha Mohd; Salimi, Midhat Nabil Ahmad; Anuar, Adilah

    2015-05-15

    Many studies have been carried out in order to prepare hydroxyapatite (HAp) by various methods. In this study, we focused on the preparation of HAp nanoparticles by using sol-gel technique in which few parameters are optimized which were stirring rate, aging time and sintering temperature. HAp nanoparticles were prepared by using precursors of calcium nitrate tetrahydrate, Ca(NO{sub 3}){sub 2}.4H{sub 2}O and phosphorous pentoxide, P{sub 2}O{sub 5}. Both precursors are mixed in ethanol respectively before they were mixed together in which it formed a stable sol. Fourier transform infrared (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) were used for its characterization in terms of functional group, phase composition, crystallite size and morphology of the nanoparticles produced. FTIR spectra showed that the functional groups that present in all five samples were corresponding to the formation of HAp. Besides, XRD shows that only one phase was formed which was hydroxyapatite. Meanwhile, SEM shows that the small particles combine together to form agglomeration.

  13. Validation of cresis synthetic aperture radar processor and optimal processing parameters

    NASA Astrophysics Data System (ADS)

    Smith, Logan Sanders

    Sounding the ice sheets of Greenland and Antarctica is a vital component in determining the effect of global warming on sea level rise. Of particular importance are measurements of the bedrock topography of the outlet glaciers that transport ice from the ice sheet's interior to the margin where it calves into icebergs, contributing to sea level rise. These outlet glaciers are difficult to sound due to crevassing caused by the relatively fast movement of the ice in the glacial channel and higher signal attenuation caused by warmer ice. The Center for Remote Sensing of Ice Sheets (CReSIS) uses multi-channel airborne radars which employ methods for achieving better resolution and signal-to-noise ratio (SNR) to better sound outlet glaciers. Synthetic aperture radar (SAR) techniques are used in the along-track dimension, pulse compression in the range dimension, and an antenna array in the cross-track dimension. CReSIS has developed the CReSIS SAR processor (CSARP) to effectively and efficiently process the data collected by these radars in each dimension. To validate the performance of this processor a SAR simulator was developed with the functionality to test the implementation of the processing algorithms in CSARP. In addition to the implementation of this simulator for validation of processing the data in the along-track, cross-track and range dimensions, there are a number of data-dependent processing steps that can affect the quality of the final data product. CSARP was tested with an ideal simulated point target in white Gaussian noise. The SNR change achieved by range compression, azimuth compression, array combination with and without matched filtering, and lever arm application were all within .2 dB of the theoretical expectation. Channel equalization, when paired with noise-based matched filtering, provided 1-2 dB of gain on average but significantly less than the expected gain. Extending the SAR aperture length to sound bedrock will improve the along

  14. EVOLUTION OF BRIGHTEST CLUSTER GALAXY STRUCTURAL PARAMETERS IN THE LAST {approx}6 Gyr: FEEDBACK PROCESSES VERSUS MERGER EVENTS

    SciTech Connect

    Ascaso, B.; Aguerri, J. A. L.; Varela, J.; Cava, A.; Moles, M.

    2011-01-10

    We present results on the evolution of the structural parameters of two samples of brightest cluster galaxies (BCGs) in the last 6 Gyr. The nearby sample of BCGs consists of 69 galaxies from the WINGS survey spanning a redshift range of 0.04 < z < 0.07. The intermediate-redshift (0.3 < z < 0.6) sample is formed by 20 BCGs extracted from the Hubble Space Telescope archive. Both samples have similar spatial resolution and their host clusters have similar X-ray luminosities. We report an increase in the size of the BCGs from intermediate to local redshift. However, we do not detect any variation in the Sersic shape parameter in both samples. These results prove to be robust since the observed tendencies are model independent. We also obtain significant correlations between some of the BCG parameters and the main properties of the host clusters. More luminous, larger, and centrally located BCGs are located in more massive and dominant galaxy clusters. These facts indicate that the host galaxy cluster has played an important role in the formation of their BCGs. We discuss the possible mechanisms that can explain the observed evolution of the structural parameters of the BCGs. We conclude that the main mechanisms that can explain the increase in size and the non-evolution in the Sersic shape parameter of the BCGs in the last 6 Gyr are feedback processes. This result disagrees with semi-analytical simulation results supporting the idea that merging processes are the main mechanism responsible for the evolution of the BCGs up until the present epoch.

  15. Estimating leaf-level parameters for ecosystem process models: a study in mixed conifer canopies on complex terrain.

    PubMed

    Duursma, Remko A; Marshall, John D; Nippert, Jesse B; Chambers, Chris C; Robinson, Andrew P

    2005-11-01

    Ecosystem process models are often used to predict carbon flux on a landscape or on a global scale. Such models must be aggregate and canopies are often treated as a uniform unit of foliage. Parameters that are known to vary within the canopy, e.g., nitrogen content and leaf mass per area, are often estimated by a mean value for the canopy. Estimating appropriate means is complicated, especially in mixed-species stands and in complex terrain. We analyzed sources of variation in specific parameters with the goal of testing various simplifying assumptions. The measurements came from mixed-species forests in the northern Rocky Mountains. We found that, for three important parameters (nitrogen concentration and content, and leaf mass per area), a sample taken near the vertical center of the crown provided a good estimate of the mean values for the crown. Altitude (700-1700 m), solar insolation (4200-5400 MJ m(-2) year(-1)) and leaf area index (1-11) had negligible effects on the parameters; only species differences were consistently detected. The correlation between mass-based photosynthetic rates and mass-based nitrogen concentrations was much weaker than the correlation between area-based photosynthetic rates and area-based nitrogen concentration. Comparison of photosynthesis-nitrogen relationships for a wide variety of conifer species and sites revealed a broad general trend that can be used in models. These results suggest important potential simplifications in model parameterization, most notably that canopy means can be estimated with ease, that complex terrain is a minor source of variation in these parameters and that use of one photosynthesis-nitrogen relationship for conifer species does not result in large errors. Species-to-species variation, however, was large and needs to be accounted for when parameterizing process models. PMID:16105802

  16. Development of forging and heat treating practices for AMS 5737 for use at liquid helium temperatures

    SciTech Connect

    Dalder, E.N.C.; Greenlee, M.

    1981-08-10

    To achieve a combination of high yield-strength (sigma y), plane-strain fracture-toughness (K/sub IC/) and resistance to galling when turned against austenitic stainless steels in highly-loaded threaded turnbuckles in the M.F.T.F.-B (Mirror Fusion Test Facility), AMS 5737 (Fe-15Cr-25Ni-1Mo-V-Ti-Al-B), a heat-treatable Fe-base superalloy that is slightly-ferromagnetic under high magnetic fields at 4K, was chosen for large (approx. 340 kg) forged turn buckles. This report describes the forging and heat-treatment optimization program that resulted in good sigma y and K/sub IC/ over the 4 to 300K range of service-temperatures and the verification tests run on a pre-production forging and actual production parts.

  17. Evaluation of Die Chilling Effects during Forging of Nimonic-80A Superalloy

    SciTech Connect

    Shahriari, D.; Sadeghi, M. H.; Amiri, A.; Cheraghzadeh, M.

    2010-06-15

    Nimonic-80A is a kind of nickel-based superalloys which is used in high temperature components of land gas turbines. In this paper, the influence of four design factors: die temperature, strain rate, friction coefficient and geometry size of ring sample over the variation of internal diameters (VID) and forging load (FL) was studied. It was done by means of design methodology based on DOE-designated full factorial and FE simulations. FEM and experimental results showed that the variation of internal diameters and forging load had inverse proportion to the die temperature. Regression models were developed by using the response surface methodology (RSM) for VID and FL. Rate of the dynamic recrystallization varied depending on different amounts of die temperature. The results can be used in the semi-isothermal forging of complex part of the Nimonic-80A.

  18. Effect of Breadmaking Process on In Vitro Gut Microbiota Parameters in Irritable Bowel Syndrome

    PubMed Central

    Costabile, Adele; Santarelli, Sara; Claus, Sandrine P.; Sanderson, Jeremy; Hudspith, Barry N.; Brostoff, Jonathan; Ward, Jane L.; Lovegrove, Alison; Shewry, Peter R.; Jones, Hannah E.; Whitley, Andrew M.; Gibson, Glenn R.

    2014-01-01

    A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria–mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small -molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of δ-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process. PMID:25356771

  19. Effect of breadmaking process on in vitro gut microbiota parameters in irritable bowel syndrome.

    PubMed

    Costabile, Adele; Santarelli, Sara; Claus, Sandrine P; Sanderson, Jeremy; Hudspith, Barry N; Brostoff, Jonathan; Ward, Jane L; Lovegrove, Alison; Shewry, Peter R; Jones, Hannah E; Whitley, Andrew M; Gibson, Glenn R

    2014-01-01

    A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria-mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small-molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of δ-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process.

  20. Effect of breadmaking process on in vitro gut microbiota parameters in irritable bowel syndrome.

    PubMed

    Costabile, Adele; Santarelli, Sara; Claus, Sandrine P; Sanderson, Jeremy; Hudspith, Barry N; Brostoff, Jonathan; Ward, Jane L; Lovegrove, Alison; Shewry, Peter R; Jones, Hannah E; Whitley, Andrew M; Gibson, Glenn R

    2014-01-01

    A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria-mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small-molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of δ-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process. PMID:25356771

  1. Improving Processes of Mechanized Pulsed Arc Welding of Low-Frequency Range Variation of Mode Parameters

    NASA Astrophysics Data System (ADS)

    Saraev, Yu N.; Solodskiy, S. A.; Ulyanova, O. V.

    2016-04-01

    A new technology of low-frequency modulation of the arc current in MAG and MIG welding is presented. The technology provides control of thermal and crystallization processes, stabilizes the time of formation and crystallization of the weld pool. Conducting theoretical studies allowed formulating the basic criteria for obtaining strong permanent joints for high-duty structures, providing conditions for more equilibrium structure of the deposited metal and the smaller width of the HAZ. The stabilization of time of the formation and crystallization of the weld pool improves the formation of the weld and increases productivity in welding thin sheet metal.

  2. Optimization of Processing Parameters in ECM of Die Tool Steel Using Nanofluid by Multiobjective Genetic Algorithm

    PubMed Central

    Sathiyamoorthy, V.; Sekar, T.; Elango, N.

    2015-01-01

    Formation of spikes prevents achievement of the better material removal rate (MRR) and surface finish while using plain NaNO3 aqueous electrolyte in electrochemical machining (ECM) of die tool steel. Hence this research work attempts to minimize the formation of spikes in the selected workpiece of high carbon high chromium die tool steel using copper nanoparticles suspended in NaNO3 aqueous electrolyte, that is, nanofluid. The selected influencing parameters are applied voltage and electrolyte discharge rate with three levels and tool feed rate with four levels. Thirty-six experiments were designed using Design Expert 7.0 software and optimization was done using multiobjective genetic algorithm (MOGA). This tool identified the best possible combination for achieving the better MRR and surface roughness. The results reveal that voltage of 18 V, tool feed rate of 0.54 mm/min, and nanofluid discharge rate of 12 lit/min would be the optimum values in ECM of HCHCr die tool steel. For checking the optimality obtained from the MOGA in MATLAB software, the maximum MRR of 375.78277 mm3/min and respective surface roughness Ra of 2.339779 μm were predicted at applied voltage of 17.688986 V, tool feed rate of 0.5399705 mm/min, and nanofluid discharge rate of 11.998816 lit/min. Confirmatory tests showed that the actual performance at the optimum conditions was 361.214 mm3/min and 2.41 μm; the deviation from the predicted performance is less than 4% which proves the composite desirability of the developed models. PMID:26167538

  3. Optimization of Processing Parameters in ECM of Die Tool Steel Using Nanofluid by Multiobjective Genetic Algorithm.

    PubMed

    Sathiyamoorthy, V; Sekar, T; Elango, N

    2015-01-01

    Formation of spikes prevents achievement of the better material removal rate (MRR) and surface finish while using plain NaNO3 aqueous electrolyte in electrochemical machining (ECM) of die tool steel. Hence this research work attempts to minimize the formation of spikes in the selected workpiece of high carbon high chromium die tool steel using copper nanoparticles suspended in NaNO3 aqueous electrolyte, that is, nanofluid. The selected influencing parameters are applied voltage and electrolyte discharge rate with three levels and tool feed rate with four levels. Thirty-six experiments were designed using Design Expert 7.0 software and optimization was done using multiobjective genetic algorithm (MOGA). This tool identified the best possible combination for achieving the better MRR and surface roughness. The results reveal that voltage of 18 V, tool feed rate of 0.54 mm/min, and nanofluid discharge rate of 12 lit/min would be the optimum values in ECM of HCHCr die tool steel. For checking the optimality obtained from the MOGA in MATLAB software, the maximum MRR of 375.78277 mm(3)/min and respective surface roughness Ra of 2.339779 μm were predicted at applied voltage of 17.688986 V, tool feed rate of 0.5399705 mm/min, and nanofluid discharge rate of 11.998816 lit/min. Confirmatory tests showed that the actual performance at the optimum conditions was 361.214 mm(3)/min and 2.41 μm; the deviation from the predicted performance is less than 4% which proves the composite desirability of the developed models.

  4. Influence of process parameters on properties of reactively sputtered tungsten nitride thin films

    SciTech Connect

    Addonizio, Maria L.; Castaldo, Anna; Antonaia, Alessandro; Gambale, Emilia; Iemmo, Laura

    2012-05-15

    Tungsten nitride (WN{sub x}) thin films were produced by reactive dc magnetron sputtering of tungsten in an Ar-N{sub 2} gas mixture. The influence of the deposition power on the properties of tungsten nitride has been analyzed and compared with that induced by nitrogen content variation in the sputtering gas. A combined analysis of structural, electrical and optical properties on thin WN{sub x} films obtained at different deposition conditions has been performed. It was found that at an N{sub 2} content of 14% a single phase structure of W{sub 2}N films was formed with the highest crystalline content. This sputtering gas composition was subsequently used for fabricating films at different deposition powers. Optical analysis showed that increasing the deposition power created tungsten nitride films with a more metallic character, which is confirmed with resistivity measurements. At low sputtering powers the resulting films were crystalline whereas, with an increase of power, an amorphous phase was also present. The incorporation of an excess of nitrogen atoms resulted in an expansion of the W{sub 2}N lattice and this effect was more pronounced at low deposition powers. Infrared analysis revealed that in WN{sub x} films deposited at low power, chemisorbed N{sub 2} molecules did not behave as ligands whereas at high deposition power they clearly appeared as ligands around metallic tungsten. In this study, the influence of the most meaningful deposition parameters on the phase transformation reaction path was established and deposition conditions suitable for producing thermally stable and highly crystalline W{sub 2}N films were found.

  5. Optimization of Processing Parameters in ECM of Die Tool Steel Using Nanofluid by Multiobjective Genetic Algorithm.

    PubMed

    Sathiyamoorthy, V; Sekar, T; Elango, N

    2015-01-01

    Formation of spikes prevents achievement of the better material removal rate (MRR) and surface finish while using plain NaNO3 aqueous electrolyte in electrochemical machining (ECM) of die tool steel. Hence this research work attempts to minimize the formation of spikes in the selected workpiece of high carbon high chromium die tool steel using copper nanoparticles suspended in NaNO3 aqueous electrolyte, that is, nanofluid. The selected influencing parameters are applied voltage and electrolyte discharge rate with three levels and tool feed rate with four levels. Thirty-six experiments were designed using Design Expert 7.0 software and optimization was done using multiobjective genetic algorithm (MOGA). This tool identified the best possible combination for achieving the better MRR and surface roughness. The results reveal that voltage of 18 V, tool feed rate of 0.54 mm/min, and nanofluid discharge rate of 12 lit/min would be the optimum values in ECM of HCHCr die tool steel. For checking the optimality obtained from the MOGA in MATLAB software, the maximum MRR of 375.78277 mm(3)/min and respective surface roughness Ra of 2.339779 μm were predicted at applied voltage of 17.688986 V, tool feed rate of 0.5399705 mm/min, and nanofluid discharge rate of 11.998816 lit/min. Confirmatory tests showed that the actual performance at the optimum conditions was 361.214 mm(3)/min and 2.41 μm; the deviation from the predicted performance is less than 4% which proves the composite desirability of the developed models. PMID:26167538

  6. Effect of process parameters on metal transfer of hyperbaric GMAW of duplex stainless steels

    SciTech Connect

    Olsen, J.M.; Dos Santos, J.F.; Richardson, I.M.

    1994-12-31

    This work presents the preliminary results of a comprehensive and systematic evaluation of current rise and fall rates as well as shielding gas composition and their affect on the metal transfer, when duplex stainless steels are GMA welded under hyperbaric conditions using the short circuit metal transfer mode. The evaluation of the test results are based on an examination of the welding process signals recorded on a transient recorder. Over a time period of 500 ms, the signal was measured to assess the process instability, current rise and fall rates and their inter-relationship. The results presented in this study indicate that for a given welding condition, the appropriate selection of current rise and fall rates can minimize the effect of instabilities caused by high ambient pressure. The presence of active gases in the shielding did not significantly affect the metal transfer behavior. All the experiments described in this work have been carried out in the hyperbaric test facilities of the GKSS-Forschungszentrum in Germany.

  7. Association of coliform bacteria with wastewater particles: impact of operational parameters of the activated sludge process.

    PubMed

    Loge, Frank J; Emerick, Robert W; Ginn, Tim R; Darby, Jeannie L

    2002-01-01

    The fraction of particles with associated coliform bacteria (PAC) in the activated sludge process was evaluated using a 16S rRNA oligonucleotide probe specific to the family Enterobacteriaceae. The PAC was found to decline exponentially with increasing mean cell residence times (MCRTs). The factors influencing the formation of PAC, identified with simplified mass balance relationships. are the concentration of particles, the concentration of dispersed (non-particle associated) coliform bacteria, and the MCRT. The concentration of dispersed coliform bacteria was found to decline with increasing MCRTs. The rate of decline was greater than the typical half-life attributed to endogenous decay, suggesting that other factors (e.g., predation by protozoa) influence the concentration of dispersed coliform bacteria, and subsequently the formation of PAC. Given that the association of targeted organisms with particles adversely impacts the performance of a disinfection system, studies targeted at the fate of organisms other than coliform bacteria in the activated sludge process are of paramount importance in assessing the health risks of post-disinfected effluents. PMID:11766816

  8. 76 FR 5331 - Forged Stainless Steel Flanges From India and Taiwan: Final Results of Sunset Reviews and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    .... See Initiation of Five-Year (``Sunset'') Review, 75 FR 67082 (November 1, 2010). We did not receive a... Forged Stainless Steel Flanges From India, 59 FR 5994 (February 9, 1994) and Antidumping Duty Order: Certain Forged Stainless Steel Flanges From Taiwan, 59 FR 5995 (February 9, 1994). On January 23,...

  9. 76 FR 31631 - Heavy Forged Hand Tools From China; Scheduling of Expedited Five-Year Reviews Concerning the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-01

    ... of institution (76 FR 168, January 3, 2011) of the subject five-year reviews was adequate and that... COMMISSION Heavy Forged Hand Tools From China; Scheduling of Expedited Five- Year Reviews Concerning the Antidumping Duty Orders on Heavy Forged Hand Tools From China. AGENCY: United States International...

  10. The effect of GASAR processing parameters on porosity and properties in aluminum alloy

    SciTech Connect

    Paradies, C.J.; Tobin, A.; Wolla, J.

    1998-12-31

    The GASAR process involves the dissolution of hydrogen in a molten metal or alloy by controlling the hydrogen pressure and the temperature in a high pressure chamber. The difference between the hydrogen solubility in the melt and the solid is used to control the growth of hydrogen pores within the solidifying structure. Designed experiments have been performed to determine the relative effects of the saturation pressure, temperature, casting pressure, mold temperature and cooling rate on the total porosity, pore size, distribution and shape in pure nickel and aluminum alloys. The shape and distribution of pores was found to depend upon the structure of the primary solid pore nucleation and growth. Reducing the casting pressure had the strongest effect on increasing the total porosity and pore size.

  11. Development of an ideal observer that incorporates nuisance parameters and processes list-mode data

    DOE PAGES

    MacGahan, Christopher Jonathan; Kupinski, Matthew Alan; Hilton, Nathan R.; Brubaker, Erik M.; Johnson, William C.

    2016-02-01

    Observer models were developed to process data in list-mode format in order to perform binary discrimination tasks for use in an arms-control-treaty context. Data used in this study was generated using GEANT4 Monte Carlo simulations for photons using custom models of plutonium inspection objects and a radiation imaging system. We evaluated observer model performance and then presented using the area under the receiver operating characteristic curve. Lastly, we studied the ideal observer under both signal-known-exactly conditions and in the presence of unknowns such as object orientation and absolute count-rate variability; when these additional sources of randomness were present, their incorporationmore » into the observer yielded superior performance.« less

  12. Development of an ideal observer that incorporates nuisance parameters and processes list-mode data.

    PubMed

    MacGahan, Christopher J; Kupinski, Matthew A; Hilton, Nathan R; Brubaker, Erik M; Johnson, William C

    2016-04-01

    Observer models were developed to process data in list-mode format in order to perform binary discrimination tasks for use in an arms-control-treaty context. Data used in this study was generated using GEANT4 Monte Carlo simulations for photons using custom models of plutonium inspection objects and a radiation imaging system. Observer model performance was evaluated and presented using the area under the receiver operating characteristic curve. The ideal observer was studied under both signal-known-exactly conditions and in the presence of unknowns such as object orientation and absolute count-rate variability; when these additional sources of randomness were present, their incorporation into the observer yielded superior performance. PMID:27140781

  13. On psychobiology in psychoanalysis - salivary cortisol and secretory IgA as psychoanalytic process parameters

    PubMed Central

    Euler, Sebastian; Schimpf, Heinrich; Hennig, Jürgen; Brosig, Burkhard

    2005-01-01

    This study investigates the psychobiological impact of psychoanalysis in its four-hour setting. During a period of five weeks, 20 subsequent hours of psychoanalysis were evaluated, involving two patients and their analysts. Before and after each session, saliva samples were taken and analysed for cortisol (sCortisol) and secretory immunoglobuline A (sIgA). Four time-series (n=80 observations) resulted and were evaluated by "Pooled Time Series Analysis" (PTSA) for significant level changes and setting-mediated rhythms. Over all sessions, sCortisol levels were reduced and sIgA secretion augmented parallel to the analytic work. In one analytic dyad a significant rhythm within the four-hour setting was observed with an increase of sCortisol in sessions 2 and 3 of the week. Psychoanalysis may, therefore, have some psychobiological impact on patients and analysts alike and may modulate immunological and endocrinological processes. PMID:19742067

  14. Disentangling fluxes of energy and matter in plasma-surface interactions: Effect of process parameters

    SciTech Connect

    Wolter, M.; Levchenko, I.; Ostrikov, K.; Kersten, H.; Kumar, S.

    2010-09-15

    The possibility to discriminate between the relative importance of the fluxes of energy and matter in plasma-surface interaction is demonstrated by the energy flux measurements in low-temperature plasmas ignited by the radio frequency discharge (power and pressure ranges 50-250 W and 8-11.5 Pa) in Ar, Ar+H{sub 2}, and Ar+H{sub 2}+CH{sub 4} gas mixtures typically used in nanoscale synthesis and processing of silicon- and carbon-based nanostructures. It is shown that by varying the gas composition and pressure, the discharge power, and the surface bias one can effectively control the surface temperature and the matter supply rates. The experimental findings are explained in terms of the plasma-specific reactions in the plasma bulk and on the surface.

  15. On psychobiology in psychoanalysis - salivary cortisol and secretory IgA as psychoanalytic process parameters.

    PubMed

    Euler, Sebastian; Schimpf, Heinrich; Hennig, Jürgen; Brosig, Burkhard

    2005-01-01

    This study investigates the psychobiological impact of psychoanalysis in its four-hour setting. During a period of five weeks, 20 subsequent hours of psychoanalysis were evaluated, involving two patients and their analysts. Before and after each session, saliva samples were taken and analysed for cortisol (sCortisol) and secretory immunoglobuline A (sIgA). Four time-series (n=80 observations) resulted and were evaluated by "Pooled Time Series Analysis" (PTSA) for significant level changes and setting-mediated rhythms. Over all sessions, sCortisol levels were reduced and sIgA secretion augmented parallel to the analytic work. In one analytic dyad a significant rhythm within the four-hour setting was observed with an increase of sCortisol in sessions 2 and 3 of the week. Psychoanalysis may, therefore, have some psychobiological impact on patients and analysts alike and may modulate immunological and endocrinological processes.

  16. Effect of process parameters on production of a biopolymer by Rhizobium sp.

    PubMed

    Duta, Flávia Pereira; De França, Francisca Pessôa; Sérvulo, Eliana Flávia Camporese; De Almeida Lopes, Léa Maria; Da Costa, Antonio Carlos Augusto; Barros, Ana

    2004-01-01

    The production of biopolymers by a Rhizobium strain was studied under batch and bioreactor conditions. The best viscosity levels were obtained under low mannitol concentrations as well as low agitation and aeration conditions. Infrared spectra indicated the presence of chemical groups characteristic of microbially produced biopolymers, including C = O and O-acetyl groups. Thermogravimetric analysis showed the characteristic degradation profiles of the exopolysaccharide produced (T(onset) = 290degreesC). The experimental design showed that a low substrate concentration (10.0 g/L), and low aeration (0.2 vvm) and agitation (200 rpm) levels should be used. The maximum yield of the process was a Yp/s (g/g) of 0.19 +/- 0.1, obtained under optimized conditions.

  17. Characteristic parameters in combustion processes and their accessibility to current and future diagnostics. Annual report

    SciTech Connect

    Goulard, R.

    1980-05-01

    A review of current combustion research shows a growing awareness of the potential offered by the new high speed three-dimensional techniques. Some of the recent advances in the fluid dynamics of jet mixing are discussed, with an emphasis on the 10 kHz range (especially vortex shedding). Also the very fast subnanosecond range of radical kinetics is investigated, as well as the comparably fast scattering and fluorescence processes. High speed diagnostics are discussed in these two ranges of time resolution, with an emphasis on optical tomography for the fluid dynamic time range (10/sup -4/ s) and on picosecond techniques for the physical chemistry range (10/sup -9/ s). This work was carried out during the period June 1, 1979 to May 31, 1980.

  18. Artificial Intelligence Based Selection of Optimal Cutting Tool and Process Parameters for Effective Turning and Milling Operations

    NASA Astrophysics Data System (ADS)

    Saranya, Kunaparaju; John Rozario Jegaraj, J.; Ramesh Kumar, Katta; Venkateshwara Rao, Ghanta

    2016-06-01

    With the increased trend in automation of modern manufacturing industry, the human intervention in routine, repetitive and data specific activities of manufacturing is greatly reduced. In this paper, an attempt has been made to reduce the human intervention in selection of optimal cutting tool and process parameters for metal cutting applications, using Artificial Intelligence techniques. Generally, the selection of appropriate cutting tool and parameters in metal cutting is carried out by experienced technician/cutting tool expert based on his knowledge base or extensive search from huge cutting tool database. The present proposed approach replaces the existing practice of physical search for tools from the databooks/tool catalogues with intelligent knowledge-based selection system. This system employs artificial intelligence based techniques such as artificial neural networks, fuzzy logic and genetic algorithm for decision making and optimization. This intelligence based optimal tool selection strategy is developed using Mathworks Matlab Version 7.11.0 and implemented. The cutting tool database was obtained from the tool catalogues of different tool manufacturers. This paper discusses in detail, the methodology and strategies employed for selection of appropriate cutting tool and optimization of process parameters based on multi-objective optimization criteria considering material removal rate, tool life and tool cost.

  19. The effects of process parameters on yield and properties of iron nanoparticles from ferrocene in a low-pressure plasma

    NASA Astrophysics Data System (ADS)

    Panchal, V.; Lahoti, G.; Bhandarkar, U.; Neergat, M.

    2011-08-01

    The effects of process parameters on iron nanoparticle formation and properties while using ferrocene as a precursor in a low-pressure capacitively coupled plasma are investigated. The L18 array of the Taguchi method, followed by the L4 array, is used with the notional objective of increasing the yield of nanoparticles. A study of the size, shape and composition of the particles (using transmission electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, x-ray diffraction, CHON and inductively coupled plasma-atomic emission spectroscopy analysis) gives an insight into the role played by various process parameters. Pressure is the most critical parameter in increasing nanoparticle yield, whereas hydrogen flow plays a key role in determining the nanoparticle size and composition. Atomic hydrogen helps in removing amorphous carbon and reducing the nanoparticle size. RF power plays an important role in the dissociation of ferrocene thus also affecting the composition. Nanoparticles obtained using optimized conditions are a mixture of Fe3O4 and Fe2O3 with cluster size 25-40 nm in diameter that are further made up of 2-4 nm crystallites. Magnetic property measurements indicate that the nanoparticles are super-paramagnetic in nature.

  20. Phased Array Inspection of Titanium Disk Forgings Targeting no. 1/2 FBH Sensitivity

    SciTech Connect

    Roberts, R.A.; Friedl, J.

    2005-04-09

    The phased array implementation of a focused zoned ultrasonic inspection to achieve a >3dB signal-to-noise for no. 1/2 flat bottom holes (FBH) in titanium is reported. Previous work established the ultrasound focusing required to achieve the targeted sensitivity. This work reports on the design of a phased array transducer capable of maintaining the needed focus to the depths required in the forging inspection. The performance of the phased array inspection is verified by examining signal-to-noise of no. 1/2 FBHs contained in coupons cut from actual forgings.