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Sample records for increasing milling time

  1. Effect of milling time on microstructure and properties of Nano-titanium polymer by high-energy ball milling

    Science.gov (United States)

    Wang, Bo; Wei, Shicheng; Wang, Yujiang; Liang, Yi; Guo, Lei; Xue, Junfeng; Pan, Fusheng; Tang, Aitao; Chen, Xianhua; Xu, Binshi

    2018-03-01

    Nano-titanium (Nano-Ti) was prepared by high-energy ball milling from pure Ti power and grinding agents (Epoxy resin) at room temperature. The effect of milling time on structure and properties of Nano-Ti polymer were investigated systematically. The results show that high-energy ball milling is an effective way to produce Nano-Ti polymer. The dispersion stability and compatibility between Ti power and grinding agents are improved by prolonging the milling time at a certain degree, that is to say, the optimization milling time is 240 min. The particle size of Ti powder and the diffraction peaks intensity of Ti decrease obviously as the milling time increases due to the compression stress, shear friction and other mechanical forces are formed during ball milling. FT-IR result displays that the wavenumber of all the bands move to lower wavenumber after ball milling, and the epoxy ring is open. The system internal energy rises owing to the broken epoxy group and much more Nano-Ti is formed to promote the grafting reaction between Nano-Ti and epoxy resin. The results from TEM and XPS also prove that. And the grafting ration is maximum as the milling time is 240 min, the mass loss ratio is 17.53%.

  2. Effect of ball milling time on thermoelectric properties of bismuth telluride nanomaterials

    Science.gov (United States)

    Khade, Poonam; Bagwaiya, Toshi; Bhattacharaya, Shovit; Singh, Ajay; Jha, Purushottam; Shelke, Vilas

    2018-04-01

    The effect of different milling time on thermoelectric properties of bismuth telluride (Bi2Te3) was investigated. The nanomaterial was prepared by varying the ball milling time and followed by hot press sintering. The crystal structure and phase formation were verified by X-ray diffraction and Raman Spectroscopy. The experimental results show that electrical conductivity increases whereas thermal conductivity decreases with increasing milling time. The negative sign of seebeck coefficient indicate the n-type nature with majority charge carriers of electrons. A maximum figure of merit about 0.55 is achieved for l5hr ball milled Bi2Te3 sample. The present study demonstrates the simple and cost-effective method for synthesis of Bi2Te3 thermoelectric material at large scale thermoelectric applications.

  3. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al₂O₃ Nanocomposite Synthesized by Ball Milling and Powder Metallurgy.

    Science.gov (United States)

    Toozandehjani, Meysam; Matori, Khamirul Amin; Ostovan, Farhad; Abdul Aziz, Sidek; Mamat, Md Shuhazlly

    2017-10-26

    The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al₂O₃ (Al-5Al₂O₃) has been investigated. Al-5Al₂O₃ nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al₂O₃ nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD) analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness ( HV ), nano-hardness ( HN ), and Young's modulus ( E ) of Al-5Al₂O₃ nanocomposites. HV , HN , and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively.

  4. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al2O3 Nanocomposite Synthesized by Ball Milling and Powder Metallurgy

    Science.gov (United States)

    Matori, Khamirul Amin; Ostovan, Farhad; Abdul Aziz, Sidek; Mamat, Md Shuhazlly

    2017-01-01

    The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al2O3 (Al-5Al2O3) has been investigated. Al-5Al2O3 nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al2O3 nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD) analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness (HV), nano-hardness (HN), and Young’s modulus (E) of Al-5Al2O3 nanocomposites. HV, HN, and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively. PMID:29072632

  5. Effect of Milling Time on the Microstructure, Physical and Mechanical Properties of Al-Al2O3 Nanocomposite Synthesized by Ball Milling and Powder Metallurgy

    Directory of Open Access Journals (Sweden)

    Meysam Toozandehjani

    2017-10-01

    Full Text Available The effect of milling time on the morphology, microstructure, physical and mechanical properties of pure Al-5 wt % Al2O3 (Al-5Al2O3 has been investigated. Al-5Al2O3 nanocomposites were fabricated using ball milling in a powder metallurgy route. The increase in the milling time resulted in the homogenous dispersion of 5 wt % Al2O3 nanoparticles, the reduction of particle clustering, and the reduction of distances between the composite particles. The significant grain refining during milling was revealed which showed as a reduction of particle size resulting from longer milling time. X-Ray diffraction (XRD analysis of the nanocomposite powders also showed that designated ball milling contributes to the crystalline refining and accumulation of internal stress due to induced severe plastic deformation of the particles. It can be argued that these morphological and microstructural variations of nanocomposite powders induced by designated ball milling time was found to contribute to an improvement in the density, densification, micro-hardness (HV, nano-hardness (HN, and Young’s modulus (E of Al-5Al2O3 nanocomposites. HV, HN, and E values of nanocomposites were increased by ~48%, 46%, and 40%, after 12 h of milling, respectively.

  6. Synthesis behavior of nanocrystalline Al-Al2O3 composite during low time mechanical milling process

    International Nuclear Information System (INIS)

    Alizadeh, Mostafa; Aliabadi, Morteza Mirzaei

    2011-01-01

    Research highlights: → In the low time milling the effect of Al 2 O 3 amount is investigated → Al 2 O 3 particles are distributed uniformly in the Al matrix → In the low time milling it is possible to produce nanostructured composite powder → Median size and bulk density measurements demonstrate reaching the steady state. - Abstract: In this work, four different volume fractions of Al 2 O 3 (10, 20, 30 and 40 vol.%) were mixed with the fine Al powder and the powder blends were milled for 5 h. Scanning electron microscopy analysis, particle size analysis and bulk density measurements were used to investigate the morphological changes and achieving the steady state conditions. The results showed that increasing the Al 2 O 3 content can provide the steady state particle size in 5 h milling process. It was found that increasing the volume fraction of Al 2 O 3 leads to increasing the uniformity of Al 2 O 3 . Standard deviations of microhardness measurements confirmed this result. The XRD pattern and XRF investigations depicted that increasing the Al 2 O 3 content causes an increase in the crystal defects, micro-strain and Fe contamination during 5 h milling process of nanocrystalline composite powders while the grain size is decreased. To investigate the effect of milling time, Al-30 vol.% Al 2 O 3 (which achieved steady state during 5 h milling process) was milled for 1-4 h. The results depicted that the milling time lower than 5 h, do not achieve to steady state conditions.

  7. The influence of the long time milling on the structure and magnetic properties of the Fe-Cu-Nb-Si-B powder

    International Nuclear Information System (INIS)

    Fechova, E.; Kollar, P.; Fuezer, J.; Kovac, J.; Petrovic, P.; Kavecansky, V.

    2004-01-01

    We have studied the influence of milling on the structure and magnetic properties of Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 powder prepared in a vibratory micro-mill as a function of long milling time. Three powder samples have been prepared and investigated (the first one was prepared by the milling of amorphous ribbon, the second one by milling of the same ribbon in a partially nanocrystallized state and the third one by milling of pure elements). Structural analysis shows the decrease of the grain size with the increasing time of milling. The coercivity of the samples prepared from pure elements increases almost linearly up to 1700 h of milling while further milling leads to the saturation at 25 kA/m (at the milling time of 3500 h). The coercivity of the samples milled from ribbons increases to its maximum of 8 kA/m for the milling time of 800 h and then decreases

  8. Effect of milling time on the structure, particle size, and morphology of montmorillonite

    International Nuclear Information System (INIS)

    Abareshi, M.

    2017-01-01

    In the current research, effect of milling on the structure, particle size and morphology of montmorillonite was investigated. For this purpose, the montmorillonite was analyzed by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. Then the montmorillonite was milled using high energy planetary ball mill at different milling times (1-60 hours). After that, the structure, particle size and morphology of all samples were investigated by XRD, FTIR, SEM, and transmission electron microscopy. Results showed that the ball milling causes the particle size reduction of clay and separation of the clay layers. Moreover, ball milling increases the overall structural disorder and transforms the crystalline structure into an amorphous phase. Also, the morphology of clay particle changes from layered to aggregates of almost rounded particles after 60 hours of milling.

  9. Study on the bonding state for carbon-boron nitrogen with different ball milling time

    International Nuclear Information System (INIS)

    Xiong, Y.H.; Xiong, C.S.; Wei, S.Q.; Yang, H.W.; Mai, Y.T.; Xu, W.; Yang, S.; Dai, G.H.; Song, S.J.; Xiong, J.; Ren, Z.M.; Zhang, J.; Pi, H.L.; Xia, Z.C.; Yuan, S.L.

    2006-01-01

    The varied bonding state and microstructure characterization were discussed for carbon-boron nitrogen (CBN) with abundant phase structure and nanostructure, which were synthesized directly by mechanical alloying technique at room temperature. According to the results of SEM and X-ray photoelectron spectroscopy (XPS) of CBN with different ball milling time, it is substantiated that the bonding state and microstructure for CBN were closely related to the ball milling time. With the increase of the ball milling time, some new chemical bonding states of CBN were observed, which implies that some new bonding state and microstructures have been formed. The results of XPS are accordance with that of X-ray diffraction of CBN

  10. Influence of the milling time in the microstructural parameters of TA2O5-Al powder refined by Rietveld method

    International Nuclear Information System (INIS)

    Brito, R.A.; Mendes, M.W.D.; Alves Junior, C.; Costa, F.A. da; Gomes, U.U.

    2009-01-01

    Mechanical alloying (MA) is a solid-state powder processing technique involving repeated welding, fracturing, and re-welding of powder particles in a high energy mill. This process is used for producing of fine powders containing unique microstructures. The process starts with mixing of the powders in the desired proportion. Then, the mixture is milled using the established time in the high-energy mill. The powder particles are submitted to repeated cycles of cold working and fracture, and the final product correspond to a composite powder, containing characteristics different of the initial constituents. Ta 2 O 5 -Al powders were milled in a planetary ball mill for different times in order to evaluate the influence of the milling time in their microstructural parameters like crystallite size and micro deformation. The microstructural parameters were obtained by the Rietveld Method. The results showed that the microstructural parameters were influenced by the increase of the milling time. (author)

  11. Microstructure and phase analysis of Zirconia-ODS (Oxide Dispersion Strengthen) alloy sintered by APS with milling time variation

    Science.gov (United States)

    Sugeng, Bambang; Bandriyana, B.; Sugeng, Bambang; Salam, Rohmad; Sumariyo; Sujatno, Agus; Dimyati, Arbi

    2018-03-01

    Investigation on the relationship between the process conditions of milling time and the microstructure on the synthesis of the zirconia-ODS steel alloy has been performed. The elemental composition of the alloy was determined on 20 wt% Cr and zirconia dispersoid of 0.50 wt%. The synthesis was carried out by powder metallurgy method with milling time of 3, 5 and 7 hours, static compression of 20 Ton and sintering process for 4 minutes using the APS (Arc Plasma Sintering) equipment. SEM-EDX and XRD test was carried out to characterize the phase and morphology of the alloy and the effect to the mechanical properties was evaluated by the Vickers Hardness testing. The synthesis produced sample of ODS steel with good dense and very little porous with the Fe-Cr phase that clearly observed in the XRD peak pattern. In addition milling time increased the homogeneously of Fe-Cr phase formulation, enhanced the grain refinement of the structure and increase the hardness of the alloy.

  12. Particle deformation during stirred media milling

    Science.gov (United States)

    Hamey, Rhye Garrett

    Production of high aspect ratio metal flakes is an important part of the paint and coating industry. The United States Army also uses high aspect ratio metal flakes of a specific dimension in obscurant clouds to attenuate infrared radiation. The most common method for their production is by milling a metal powder. Ductile metal particles are initially flattened in the process increasing the aspect ratio. As the process continues, coldwelding of metal flakes can take place increasing the particle size and decreasing the aspect ratio. Extended milling times may also result in fracture leading to a further decrease in the particle size and aspect ratio. Both the coldwelding of the particles and the breakage of the particles are ultimately detrimental to the materials performance. This study utilized characterization techniques, such as, light scattering and image analysis to determine the change in particle size as a function of milling time and parameters. This study proved that a fundamental relationship between the milling parameters and particle deformation could be established by using Hertz's theory to calculate the stress acting on the aluminum particles. The study also demonstrated a method by which milling efficiency could be calculated, based on the amount of energy required to cause particle deformation. The study found that the particle deformation process could be an energy efficient process at short milling times with milling efficiency as high as 80%. Finally, statistical design of experiment was used to obtain a model that related particle deformation to milling parameters, such as, rotation rate and milling media size.

  13. Effect of milling time on the structure, micro-hardness, and thermal behavior of amorphous/nanocrystalline TiNiCu shape memory alloys developed by mechanical alloying

    International Nuclear Information System (INIS)

    Alijani, Fatemeh; Amini, Rasool; Ghaffari, Mohammad; Alizadeh, Morteza; Okyay, Ali Kemal

    2014-01-01

    Highlights: • Potential to produce B1′ (thermal- and stress-induced) and B2 was established. • Martensitic transformation occurred without the formation of intermediate R-phase. • Formation of unwanted intermetallics during heating was hindered by milling. • During milling, microhardness was increased, then reduced, and afterward re-increased. • By milling evolution, thermal crystallization steps changed from 3 to 2. - Abstract: In the present paper, the effect of milling process on the chemical composition, structure, microhardness, and thermal behavior of Ti–41Ni–9Cu compounds developed by mechanical alloying was evaluated. The structural characteristic of the alloyed powders was evaluated by X-ray diffraction (XRD). The chemical composition homogeneity and the powder morphology and size were studied by scanning electron microscopy coupled with electron dispersive X-ray spectroscopy. Moreover, the Vickers micro-indentation hardness of the powders milled for different milling times was determined. Finally, the thermal behavior of the as-milled powders was studied by differential scanning calorimetery. According to the results, at the initial stages of milling (typically 0–12 h), the structure consisted of a Ni solid solution and amorphous phase, and by the milling evolution, nanocrystalline martensite (B19′) and austenite (B2) phases were initially formed from the initial materials and then from the amorphous phase. It was found that by the milling development, the composition uniformity is increased, the inter-layer thickness is reduced, and the powders microhardness is initially increased, then reduced, and afterward re-increased. It was also realized that the thermal behavior of the alloyed powders and the structure of heat treated samples is considerably affected by the milling time

  14. Simulation of Vibrations in Real Time Plane Milling with Spindle Speed Correction

    Directory of Open Access Journals (Sweden)

    I. I. Ivanov

    2017-01-01

    Full Text Available In milling the hard-to-machine materials vibrations (chatter often arise from the high cutting forces if a technological system is insufficiently rigid.The main way to suppress these vibrations is to increase a stiffness of the mounting system of the tool and the work-piece to be machined. However, sometimes this method doesn’t lead to desirable result because of high values of intrinsic pliability of the tool and the work-piece. Currently, there are more complicated methods to ensure milling process quality. Among them there are three main groups:mathematical simulation of milling process dynamics and computation of processing parameters which provide high quality of machined surface, low level of vibrations and static deflections of a tool and a work-piece;introduction of the active vibration suppression devices into machine tool design; such devices include a vibration sensor, a feedback circuit, and an actuator which induces kinematic or force action on the oscillatory system;control of processing parameters, mainly of rotation frequency for minimizing the amplitudes of vibrations.The paper studies one of the 3rd group methods. There is a suggestion to process a signal of vibrational accelerations in real time and detect a chatter onset. If the chatter has been detected its frequency is to be identified, and the new value of rotation speed is set:where Ω – rotation frequency, rot/s; p – the tool eigenfrequency value identified during processing, Hz; z – mill tooth number; i – positive integer number; ε<1 – small positive parameter. In the current research it is assumed that ε = 0,2.The formula has been chosen because at the rotation frequency axis where tooth pass frequency is slightly less than the eigenfrequency divided by the integer value there are stable zones of dynamics in the milling process.The study shows a developed model of the plane milling dynamics. It includes a dynamic model of the tool, a model of cutting

  15. Response to Thermal Exposure of Ball-Milled Aluminum-Borax Powder Blends

    Science.gov (United States)

    Birol, Yucel

    2013-04-01

    Aluminum-borax powder mixtures were ball milled and heated above 873 K (600 °C) to produce Al-B master alloys. Ball-milled powder blends reveal interpenetrating layers of deformed aluminum and borax grains that are increasingly refined with increasing milling time. Thermal exposure of the ball-milled powder blends facilitates a series of thermite reactions between these layers. Borax, dehydrated during heating, is reduced by Al, and B thus generated reacts with excess Al to produce AlB2 particles dispersed across the aluminum grains starting at 873 K (600 °C). AlB2 particles start to form along the interface of the aluminum and borax layers. Once nucleated, these particles grow readily to become hexagonal-shaped crystals that traverse the aluminum grains with increasing temperatures as evidenced by the increase in the size as well as in the number of the AlB2 particles. Ball milling for 1 hour suffices to achieve a thermite reaction between borax and aluminum. Ball milling further does not impact the response of the powder blend to thermal exposure. The nucleation-reaction sites are multiplied, however, with increasing milling time and thus insure a higher number of smaller AlB2 particles. The size of the AlB2 platelets may be adjusted with the ball milling time.

  16. Mechanical alloying and reactive milling in a high energy planetary mill

    International Nuclear Information System (INIS)

    Jiang Xianjin; Trunov, Mikhaylo A.; Schoenitz, Mirko; Dave, Rajesh N.; Dreizin, Edward L.

    2009-01-01

    Powder refinement in a planetary mill (Retsch PM 400-MA) is investigated experimentally and analyzed using discrete element modeling (DEM). Refinement is defined as the average size of the individual components in a composite powder. The specific milling dose, defined as the product of charge ratio and milling time, is used as an experimental parameter tracking the progress of the material refinement. This parameter is determined experimentally for milling of boron and titanium powders, for which the time of initiation of a self-sustained reaction is measured under different milling conditions. It is assumed that the reaction becomes self-sustaining when the same powder refinement is achieved. The DEM calculations established that the milling balls primarily roll along the milling container's perimeter. The inverse of the rate of energy dissipation resulting from this rolling motion is used as the DEM analog of the specific milling dose. The results correlate well with experimental observations.

  17. Non-integrability of time-dependent spherically symmetric Yang-Mills equations

    Energy Technology Data Exchange (ETDEWEB)

    Matinyan, S G; Prokhorenko, E B; Savvidy, G K

    1988-03-07

    The integrability of time-dependent spherically symmetric Yang-Mills equations is studied using the Fermi-Pasta-Ulam method. It is shown that the motion of this system is ergodic, while the system itself is non-integrable, i.e. manifests dynamical chaos.

  18. Properties and sinterability of wet and dry attrition-milled OREOXed powder

    International Nuclear Information System (INIS)

    Lee, J. W.; Kim, J. H.; Kim, W. K.; Park, K. I.; Lee, J. W.

    2001-01-01

    The powder properties and sinterability were investigated with the powder prepared by wet and dry attrition milling of OREOX-treated powder. The OREOX-treated powder was prepared from the simulated spent fuel. Powder having less than 1 μm of average particle size could be obtained by dry milling, but not be obtained by wet milling. Thus, specific surface area of dry milled powder was higher than that of wet milled powder. With increasing of milling time, dry milled powder formed dense agglomerate while wet milled powder showed loose agglomerate. The pellets with higher than 95% T.D. of sintered density and larger than 7 μm of grain size were made with the milled powder regardless of milling method. The milling time in wet milling has greatly improved the sinterability. The pellets produced with dry milled powder have higher sintered density and larger grain size

  19. Structural and magnetic properties of ball milled copper ferrite

    DEFF Research Database (Denmark)

    Goya, G.F.; Rechenberg, H.R.; Jiang, Jianzhong

    1998-01-01

    The structural and magnetic evolution in copper ferrite (CuFe2O4) caused by high-energy ball milling are investigated by x-ray diffraction, Mössbauer spectroscopy, and magnetization measurements. Initially, the milling process reduces the average grain size of CuFe2O4 to about 6 nm and induces....... The canted spin configuration is also suggested by the observed reduction in magnetization of particles in the blocked state. Upon increasing the milling time, nanometer-sized CuFe2O4 particles decompose, forming alpha-Fe2O3 and other phases, causing a further decrease of magnetization. After a milling time...... of 98 h, alpha-Fe2O3 is reduced to Fe3O4, and magnetization increases accordingly to the higher saturation magnetization value of magnetite. Three sequential processes during high-energy ball milling are established: (a) the synthesis of partially inverted CuFe2O4 particles with a noncollinear spin...

  20. Controlling the number of walls in multi walled carbon nanotubes/alumina hybrid compound via ball milling of precipitate catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Nosbi, Norlin [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang (Malaysia); Akil, Hazizan Md, E-mail: hazizan@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang (Malaysia); Cluster for Polymer Composite (CPC), Science and Engineering Research Centre, Engineering Campus, Universiti Sains Malaysia (USM), 14300 Nibong Tebal, Seberang Perai Selatan, Pulau Pinang (Malaysia)

    2015-06-15

    Graphical abstract: - Highlights: • We report that, to manipulate carbon nanotubes geometry and number of walls are by controlling the precipitate catalyst size. • Number of walls and geometry effects depend on the milling time of the precipitate catalyst. • Increasing milling of time will decrease the carbon nanotubes number of walls. • Increasing milling of time will increase the carbon nanotubes thermal conductivity. - Abstract: This paper reports the influence of milling time on the structure and properties of the precipitate catalyst of multi walled carbon nanotubes (MWCNT)/alumina hybrid compound, produced through the chemical vapour deposition (CVD) process. For this purpose, light green precipitate consisted of aluminium, nickel(II) nitrate hexahydrate and sodium hydroxide mixture was placed in a planetary mill equipped with alumina vials using alumina balls at 300 rpm rotation speed for various milling time (5–15 h) prior to calcinations and CVD process. The compound was characterized using various techniques. Based on high-resolution transmission electron microscopy analysis, increasing the milling time up to 15 h decreased the diameter of MWCNT from 32.3 to 13.1 nm. It was noticed that the milling time had a significant effect on MWCNT wall thickness, whereby increasing the milling time from 0 to 15 h reduced the number of walls from 29 to 12. It was also interesting to note that the carbon content increased from 23.29 wt.% to 36.37 wt.% with increasing milling time.

  1. Evaluation of End Mill Coatings

    Energy Technology Data Exchange (ETDEWEB)

    L. J. Lazarus; R. L. Hester,

    2005-08-01

    Milling tests were run on families of High Speed Steel (HSS) end mills to determine their lives while machining 304 Stainless Steel. The end mills tested were made from M7, M42 and T15-CPM High Speed Steels. The end mills were also evaluated with no coatings as well as with Titanium Nitride (TiN) and Titanium Carbo-Nitride (TiCN) coatings to determine which combination of HSS and coating provided the highest increase in end mill life while increasing the cost of the tool the least. We found end mill made from M42 gave us the largest increase in tool life with the least increase in cost. The results of this study will be used by Cutting Tool Engineering in determining which end mill descriptions will be dropped from our tool catalog.

  2. Ferromagnetic behavior of nanocrystalline Cu–Mn alloy prepared by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, B.N., E-mail: bholanath_mondal@yahoo.co.in [Department of Central Scientific Services, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Sardar, G. [Department of Zoology, Baruipur College, South 24 parganas 743 610 (India); Nath, D.N. [Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Chattopadhyay, P.P. [Department of Metallurgy and Materials Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711 103 (India)

    2014-12-15

    50Cu–50Mn (wt%) alloy was produced by ball milling. The milling was continued up to 30 h followed by isothermal annealing over a four interval of temperature from 350 to 650 °C held for 1 h. Crystallite size, lattice strain, lattice parameter were determined by Rietveld refinement structure analysis of X-ray diffraction data. The amount of dissolved/precipitated Mn (wt%) after ball milling/milling followed by annealing was calculated by quantative phase analysis (QPA). The increase of coercivity could be attributed to the introduction of lattice strain and reduction of crystallite size as a function of milling time. Electron paramagnetic resonance and superconducting quantum interface device analysis indicate that soft ferromagnetic behavior has been achieved by ball milled and annealed Cu–Mn alloy. The maximum coercivity value of Cu–Mn alloy obtained after annealing at 350 °C for 1 h is 277 Oe. - Highlights: • A small amount of Mn has dissolved in Cu after ball milling for 30 h. • Coercivity of the Cu–Mn alloy has increased with an increase in milling time. • Substantial MnO has formed after annealing at 650 °C for 1 h. • The ball milled and annealed alloy have revealed soft ferromagnetic behavior. • The alloy annealed at 350 °C shows the maximum value of coercivity.

  3. Fabrication of Al-20 wt%Si powder using scrap Si by ultra high-energy milling process

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Won-Kyung [Division of Advanced Materials Engineering and Institute for Rare Metals, Kongju National University, 275, Budae-dong, Cheonan, Chungnam 330-717 (Korea, Republic of); Y Latin-Small-Letter-Dotless-I lmaz, Fikret [Department of Physics, Faculty of Art and Science, Gaziosmanpasa University, Tasliciftlik Campus, 60240 Tokat (Turkey); Kim, Hyo-Seob; Koo, Jar-Myung [Division of Advanced Materials Engineering and Institute for Rare Metals, Kongju National University, 275, Budae-dong, Cheonan, Chungnam 330-717 (Korea, Republic of); Hong, Soon-Jik, E-mail: hongsj@kongju.ac.kr [Division of Advanced Materials Engineering and Institute for Rare Metals, Kongju National University, 275, Budae-dong, Cheonan, Chungnam 330-717 (Korea, Republic of)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer High energy ball milling process has been successfully employed to produce Al-20Si alloy using scrap Si powders. Black-Right-Pointing-Pointer Fully finer and homogenous structure could be achieved after 60 min of milling time. Black-Right-Pointing-Pointer Si particles were not dissolved but uniformly dispersed in the Al matrix in a milled state. Black-Right-Pointing-Pointer The hardness of as-milled Al-20Si powder increased steadily with the increase of milling time. Black-Right-Pointing-Pointer Grain size and dispersion strengthening are two mechanisms being responsible for hardness increment. - Abstract: In this study, microstructural evolution and mechanical properties of Al-20 wt%Si and pure Al powders fabricated by ultra high-energy ball milling technique were investigated as a function of milling time. The microstructure and mechanical properties of the as-milled powders were examined by scanning electron microscope (SEM), energy dispersive spectrometry (EDS), X-ray diffractometer (XRD) and Vickers hardness tester. SEM observation showed that the particle size increased at an early stage of milling, and then decreased drastically with further milling. XRD and cross-sectional EDS-mapping analyses revealed that Si particles were not dissolved but uniformly dispersed in the Al matrix in a milled state. Vickers hardness of both pure Al and Al-Si powder increases with milling time, which attributes to the grain size strengthening and dispersion strengthening.

  4. Superfine powdered activated carbon (S-PAC) coatings on microfiltration membranes: Effects of milling time on contaminant removal and flux.

    Science.gov (United States)

    Amaral, Pauline; Partlan, Erin; Li, Mengfei; Lapolli, Flavio; Mefford, O Thompson; Karanfil, Tanju; Ladner, David A

    2016-09-01

    In microfiltration processes for drinking water treatment, one method of removing trace contaminants is to add powdered activated carbon (PAC). Recently, a version of PAC called superfine PAC (S-PAC) has been under development. S-PAC has a smaller particle size and thus faster adsorption kinetics than conventionally sized PAC. Membrane coating performance of various S-PAC samples was evaluated by measuring adsorption of atrazine, a model micropollutant. S-PACs were created in-house from PACs of three different materials: coal, wood, and coconut shell. Milling time was varied to produce S-PACs pulverized with different amounts of energy. These had different particles sizes, but other properties (e.g. oxygen content), also differed. In pure water the coal based S-PACs showed superior atrazine adsorption; all milled carbons had over 90% removal while the PAC had only 45% removal. With addition of calcium and/or NOM, removal rates decreased, but milled carbons still removed more atrazine than PAC. Oxygen content and specific external surface area (both of which increased with longer milling times) were the most significant predictors of atrazine removal. S-PAC coatings resulted in loss of filtration flux compared to an uncoated membrane and smaller particles caused more flux decline than larger particles; however, the data suggest that NOM fouling is still more of a concern than S-PAC fouling. The addition of calcium improved the flux, especially for the longer-milled carbons. Overall the data show that when milling S-PAC with different levels of energy there is a tradeoff: smaller particles adsorb contaminants better, but cause greater flux decline. Fortunately, an acceptable balance may be possible; for example, in these experiments the coal-based S-PAC after 30 min of milling achieved a fairly high atrazine removal (overall 80%) with a fairly low flux reduction (under 30%) even in the presence of NOM. This suggests that relatively short duration (low energy

  5. Investigation of the milling-induced thermal behavior of crystalline and amorphous griseofulvin.

    Science.gov (United States)

    Trasi, Niraj S; Boerrigter, Stephan X M; Byrn, Stephen Robert

    2010-07-01

    To gain a better understanding of the physical state and the unusual thermal behavior of milled griseofulvin. Griseofulvin crystals and amorphous melt quench samples were milled in a vibrating ball mill for different times and then analyzed using differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Modulated DSC (mDSC) and annealing studies were done for the milled amorphous samples to further probe the effects of milling. Milling of griseofulvin crystals results in decrease in crystallinity and amorphization of the compound. A double peak is seen for crystallization in the DSC, which is also seen for the milled melt quench sample. Both enthalpy and temperature of crystallization decrease for the milled melt quenched sample. Tg is visible under the first peak with the mDSC, and annealing shows that increasing milling time results in faster crystallization upon storage. Milling of griseofulvin results in the formation of an amorphous form and not a mesophase. It increases the amount of surface created and the overall energy of the amorphous griseofulvin, which leads to a decreased temperature of crystallization. The two exotherms in the DSC are due to some particles having nuclei on the surface.

  6. Synthesis of Ni-YSZ cermet for an electrode of high temperature electrolysis by high energy ball milling

    International Nuclear Information System (INIS)

    Hong, H.S.; Chae, U.S.; Park, K.M.; Choo, S.T.

    2005-01-01

    Ni/YSZ composites for a cathode that can be used in high temperature electrolysis were prepared by ball milling of Ni and YSZ powder. Ball milling was performed in a dry process and in ethanol. The microstructure and electrical conductivity of the composites were examined by XRD, SEM, TEM and a 4-point probe. XRD patterns for both the dry and wet ball-milled powders showed that the composites were composed of crystalline Ni and YSZ particles. The patterns did not change with increases in the milling time up to 48 h. Dry-milling slightly increased the average particle size compared to starting Ni particles, but little change in the particle size was observed with the increase in milling time. On the other hand, the wet-milling reduced the average size and the increasing milling time induced a further decrease in the particle size. After cold-pressing and annealing at 900 C for 2 h, the dry-milled powder exhibited high stability against Ni sintering so that the particle size changed little, but the particle size increased in the wet-milled powder. The electrical conductivity increased after sintering at 900 C. Particles from the dry and wet process became denser and contacted closer after sintering, providing better electron migration paths. (orig.)

  7. Machinability Evaluation in Hard Milling of AISI D2 Steel

    OpenAIRE

    Gaitonde, Vinayak Neelakanth; Karnik, Sulse Ramesh; Maciel, Caio Henrique Alves; Rubio, Juan Carlos Campos; Abrão, Alexandre Mendes

    2016-01-01

    Milling of hardened steel components provides considerable benefits in terms of reduced manufacturing cost and time compared to traditional machining. Temperature variation in milling is an important factor affecting the wear of cutting tools. The poor selection of milling parameters may cause excessive tool wear and increased work surface roughness. Hence, there is a need to study the machinability aspects during milling of hardened steel components. In the present work, influence of cutting...

  8. Synthesis of ferrite nanoparticle by milling process for preparation of single domain magnet

    International Nuclear Information System (INIS)

    Suryadi; Hasbiyallah; Agus S W; Nurul TR; Budhy Kurniawan

    2009-01-01

    Study of ferrite nanoparticle synthesis for preparation of single domain magnet by milling of scrap magnet material have been done. Sample preparation were done using disk mill continued with high energy milling (HEM). Some powder were taken after 5, 10 dan 20 hours milling using HEM-E3D. The powder were then characterized using X-Ray Fluorescence (XRF), X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). XRF characterization result, confirmed by XRD analysis result, showed that the sample are of Strontium ferrite phase. Microstructure analysis result showed the occurrence of grain refining process of ferrite particle with increasing of milling time. Particle having size of nanometers successfully obtained, although in unhomogeneous distribution. Magnetic properties characterization result showed the increasing of hysteresis curve area of sample for longer milling time and sintering process. (author)

  9. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Science.gov (United States)

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J.; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-01-01

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process. PMID:28772747

  10. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2017-04-01

    Full Text Available A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS NiMo-based alloys containing varying amounts of SiC (0.5–2.5 wt % were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA route followed by spark plasma sintering (SPS and rapid cooling. Neutron Powder Diffraction (NPD, Electron Back Scattering Diffraction (EBSD, and Transmission Electron Microscopy (TEM were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni3Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo2C particles during sintering. The amount of grain boundaries greatly increases the Hall–Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  11. The Effect of Milling Time on the Microstructural Characteristics and Strengthening Mechanisms of NiMo-SiC Alloys Prepared via Powder Metallurgy.

    Science.gov (United States)

    Yang, Chao; Muránsky, Ondrej; Zhu, Hanliang; Thorogood, Gordon J; Avdeev, Maxim; Huang, Hefei; Zhou, Xingtai

    2017-04-06

    A new generation of alloys, which rely on a combination of various strengthening mechanisms, has been developed for application in molten salt nuclear reactors. In the current study, a battery of dispersion and precipitation-strengthened (DPS) NiMo-based alloys containing varying amounts of SiC (0.5-2.5 wt %) were prepared from Ni-Mo-SiC powder mixture via a mechanical alloying (MA) route followed by spark plasma sintering (SPS) and rapid cooling. Neutron Powder Diffraction (NPD), Electron Back Scattering Diffraction (EBSD), and Transmission Electron Microscopy (TEM) were employed in the characterization of the microstructural properties of these in-house prepared NiMo-SiC DPS alloys. The study showed that uniformly-dispersed SiC particles provide dispersion strengthening, the precipitation of nano-scale Ni₃Si particles provides precipitation strengthening, and the solid-solution of Mo in the Ni matrix provides solid-solution strengthening. It was further shown that the milling time has significant effects on the microstructural characteristics of these alloys. Increased milling time seems to limit the grain growth of the NiMo matrix by producing well-dispersed Mo₂C particles during sintering. The amount of grain boundaries greatly increases the Hall-Petch strengthening, resulting in significantly higher strength in the case of 48-h-milled NiMo-SiC DPS alloys compared with the 8-h-milled alloys. However, it was also shown that the total elongation is considerably reduced in the 48-h-milled NiMo-SiC DPS alloy due to high porosity. The porosity is a result of cold welding of the powder mixture during the extended milling process.

  12. Soil Carbon 4 per mille

    Science.gov (United States)

    Minasny, Budiman; van Wesemael, Bas

    2017-04-01

    The '4 per mille Soils for Food Security and Climate' was launched at the COP21 aiming to increase global soil organic matter stocks by 4 per mille (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil organic carbon (SOC) stock estimates and sequestration potentials from 20 regions in the world (New Zealand, Chile, South Africa, Australia, Tanzania, Indonesia, Kenya, Nigeria, India, China Taiwan, South Korea, China Mainland, United States of America, France, Canada, Belgium, England & Wales, Ireland, Scotland, and Russia) and asked whether the 4 per mille initiative is feasible. This study highlights region specific efforts and scopes for soil carbon sequestration. Reported soil C sequestration rates generally show that under best management practices, 4 per mille or even higher sequestration rates can be accomplished. High C sequestration rates (up to 10 per mille) can be achieved for soils with low initial SOC stock (topsoil less than 30 t C ha-1), and at the first twenty years after implementation of best management practices. In addition, areas that have reached equilibrium but not at their saturation level will not be able to further increase their sequestration. We found that most studies on SOC sequestration globally only consider topsoil (up to 0.3 m depth), as it is considered to be most affected by management techniques. The 4 per mille initiative was based on a blanket calculation of the whole global soil profile C stock, however the potential to increase SOC is mostly on managed agricultural lands. If we consider 4 per mille on global topsoil of agricultural land, SOC sequestration is about 3.6 Gt C per year, which effectively offset 40% of global anthropogenic greenhouse gas emissions. As a strategy for climate change mitigation, soil carbon sequestration buys time over the next ten to twenty years while other effective sequestration and low carbon technologies become

  13. Non-integrability of time-dependent spherically symmetric Yang-Mills equations

    International Nuclear Information System (INIS)

    Matinyan, S.G.; Prokhorenko, E.V.; Savvidy, G.K.

    1986-01-01

    The integrability of time-dependent spherically symmetric Yang-Mills equations is studied using the Fermi-Pasta-Ulam method. The phase space of this system is shown to have no quasi-periodic motion specific for integrable systems. In particular, the well-known Wu-Yang static solution is unstable, so its vicinity in phase is the stochasticity region

  14. Structure change of soda-silicate glass by mechanical milling

    International Nuclear Information System (INIS)

    Iwao, M; Okuno, M

    2010-01-01

    Structure change of ground soda-silicate glass (SiO 2 -Na 2 O binary systems) was investigated using X-ray diffraction (XRD) and infrared spectroscopy. The measurement results were discussed comparison to that of SiO 2 glass. With increasing Na 2 O concentrations, the XRD intensity around 2θ = 22 0 decreased and the intensity around 32 0 increased. The intensity around 22 0 and 32 0 maybe attributed to SiO 2 glass structure unit and soda-silicate glass unit, respectively. The peaks of Na 2 CO 3 crystal for 2SiO 2 -Na 2 O glass were observed with increasing milling time. This crystallization was suggested that Na + ion on 2SiO 2 -Na 2 O glass surface connected CO 2 in air. The intensity around 22 0 and 32 0 decreased and the intensity around 30 0 increased with increasing milling time. These may indicate that SiO 2 glass structure unit and soda-silicate glass structure unit were mixed by milling. In addition, IR absorption band near v = 1100 cm -1 was separated to two bands near 940 cm -1 and 1070 cm -1 with increasing Na 2 O concentrations. The band near 940 cm -1 decreased and the band near 1070 cm -1 increased with increasing milling time. These spectra changes were suggested due to decrease of Na 2 O concentrations in 2SiO 2 -Na 2 O glass with Na 2 CO 3 crystallization.

  15. Effect of milling on morphology of molten salt synthesized Sr3Ti2O7 crystals

    Directory of Open Access Journals (Sweden)

    Kijamnajsuk, S.

    2007-07-01

    Full Text Available Effect of milling liquid (acetone and ethanol, and milling times on morphology of Sr3Ti2O7 (ST7 crystals grow in molten potassium chloride salt at 1250oC for 4 h was investigated. Two kinds of crystals with different morphologies were found: ST7 crystals having a tabular shape of less than 20 μm diameter and small secondary-phase crystals having high symmetry. Milling starting materials in ethanol yielded ST7 crystals that were up to 3 times thinner than those milled with acetone, increasing the (00l Lotgering factor almost twice that when prepared with acetone. Large crystals become a bit smaller and the number of small crystals increased when the milling time increased.

  16. A study on rheological characteristics of roller milled fenugreek fractions.

    Science.gov (United States)

    Sakhare, Suresh D; Inamdar, Aashitosh A; Prabhasankar, P

    2016-01-01

    Fenugreek seeds were fractionated by roller milling to get various fractions. The roller milled fractions and whole fenugreek flour (WFF) were evaluated for the flow behavior and time-dependent flow properties using a rotational viscometer at the temperatures of 10-60 (0)C. The samples subjected to a programmed shear rate increase linearly from 0 to 300 s(-1) in 3 min and successive decrease linearly shear rate from 300 s(-1) to 0 in 3 min. The roller milled fractions and WFF paste exhibited non-Newtonian pseudoplastic behavior. Difference in hysteresis loop area was observed among the roller milled fractions and WFF, being more noticeable at lower temperatures. Power law and Casson models were used to predict flow properties of samples. The power law model described well the flow behavior of the roller milled fractions and WFF at temperatures tested. Except flour (FL) fraction, consistency coefficient, m, increased with the temperature both in the forward and backward measurements. The roller milled fractions and WFF exhibited rheopectic behavior that increased viscosity with increasing the shear speed and the temperature. For all the sample tested, initial shear stress increased with increase in shear rate and temperature.

  17. Study of effect of dynamic mill treatment on the compaction and sintering of UO2-5wt%CeO2

    International Nuclear Information System (INIS)

    Na, S. H.; Kim, S. H.; Kim, Y. K.; Lee, Y. W.; Yoo, M. J.

    2002-01-01

    Some properties (apparent density, green density, sintered density and grain size) of the simulated mixed oxide(UO 2 -5wt%CeO 2 ) prepared by using the dynamic mill newly developed were investigated. As the dynamic milling time increases, these properties increase. However, the increases of sintered density and grain size were saturated above 2 hrs and 4 hrs of dynamic milling treatment, respectively. It appeared that the dynamic mill has a similar capability to that of other milling methods, and hence can manufacture the pellets having desired properties by controlling milling time

  18. 40 CFR 23.8 - Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. 23.8 Section 23.8 Protection of Environment... Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. Unless the Administrator...

  19. Effect of ball milling time on the hydrogen storage properties of TiF{sub 3}-doped LiAlH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shu-Sheng [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Sun, Li-Xian; Zhang, Yao; Zhang, Jian; Chu, Hai-Liang; Fan, Mei-Qiang; Zhang, Tao [Materials and Thermochemistry Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, Liaoning 116023 (China); Xu, Fen [Faculty of Chemistry and Chemical Engineering, Liaoning Normal University, Dalian 116029 (China); Song, Xiao-Yan [College of Materials Science and Engineering, Key Laboratory of Advanced Functional Materials, Chinese Education Ministry, Beijing University of Technology, Beijing 100124 (China); Grolier, Jean Pierre [Laboratory of Thermodynamics of Solutions and Polymers, Blaise Pascal University, 24 Avenue des Landais, 63177-Aubiere Cedex (France)

    2009-10-15

    In the present work, the catalytic effect of TiF{sub 3} on the dehydrogenation properties of LiAlH{sub 4} has been investigated. Decomposition of LiAlH{sub 4} occurs during ball milling in the presence of 4 mol% TiF{sub 3}. Different ball milling times have been used, from 0.5 h to 18 h. With ball milling time increasing, the crystallite sizes of LiAlH{sub 4} get smaller (from 69 nm to 43 nm) and the dehydrogenation temperature becomes lower (from 80 C to 60 C). Half an hour ball milling makes the initial dehydrogenation temperature of doped LiAlH{sub 4} reduce to 80 C, which is 70 C lower than as-received LiAlH{sub 4}. About 5.0 wt.% H{sub 2} can be released from TiF{sub 3}-doped LiAlH{sub 4} after 18 h ball milling in the range of 60 C-145 C (heating rate 2 C min{sup -1}). TiF{sub 3} probably reacts with LiAlH{sub 4} to form the catalyst, TiAl{sub 3}. The mechanochemical and thermochemical reactions have been clarified. However, the rehydrogenation of LiAlH{sub 4}/Li{sub 3}AlH{sub 6} can not be realized under 95 bar H{sub 2} in the presence of TiF{sub 3} because of their thermodynamic properties. (author)

  20. Effect of ball-milling time on the structural characteristics of biomedical porous Ti-Sn-Nb alloy

    Energy Technology Data Exchange (ETDEWEB)

    Nouri, Alireza, E-mail: alireza_nouri@yahoo.com [CQM-Centro de Quimica da Madeira, MMRG, Universidade da Madeira, Campus Universitario da Penteada, 9000-390 Funchal (Portugal); Institute for Technology Research and Innovation, Deakin University, Geelong, Victoria 3217 (Australia); Hodgson, Peter D. [Institute for Technology Research and Innovation, Deakin University, Geelong, Victoria 3217 (Australia); Wen Cuie [IRIS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, 543-454 Burwood Road, Hawthorn, Victoria 3122 Australia (Australia)

    2011-07-20

    The structural characteristics of biomedical porous materials are crucial for bone tissue to grow into a porous structure and can also influence the fixation and remodeling between the implant and the human tissues. The current study has been investigating the effect of the ball-milling variable of time on the structural characteristics and pore morphology of a biomedical porous Ti-16Sn-4Nb (wt.%) alloy. The alloy was synthesized using high-energy ball milling for different periods of time, and the porous Ti-16Sn-4Nb alloy was fabricated by using a space holder sintering process. The resultant powder particles, bulk, and porous samples were characterized using a scanning electron microscope (SEM), laser particle-size analyzer, chemical analysis, X-ray diffraction analysis (XRD), and the Vickers hardness test. The results indicated that the inner pore surface, pore wall architecture, degree of porosity, pore size and the inter-pore connectivity of the sintered porous alloy are all considerably affected by ball-milling time.

  1. Perovskite nanoparticles: Preparation by reactive milling and magnetic characteristics

    International Nuclear Information System (INIS)

    Phuc, N.X.; Nguyen, Ha M.; Manh, D.H.; Hung, L.T.; Tuong, L.T.C.; Hong, L.V.; Yao, Yeong-Der

    2006-01-01

    La 0.7 Sr 0.3 MnO 3 and La 0.7 Ca 0.3 MnO 3 nanoparticles were synthesized by reactive milling method. Grain size determined from XRD, TEM, and magnetization measurements show an average diameter ≤18 nm and decreasing with increasing milling time. DC and AC magnetic measurements evidenced an interacting superparamagnetism due to clustering of perovskite nanoferromagnets with spin dynamic time in range of 10 -9 -10 -10 s

  2. Space-time symmetry and quantum Yang-Mills gravity how space-time translational gauge symmetry enables the unification of gravity with other forces

    CERN Document Server

    Hsu, Jong-Ping

    2013-01-01

    Yang-Mills gravity is a new theory, consistent with experiments, that brings gravity back to the arena of gauge field theory and quantum mechanics in flat space-time. It provides solutions to long-standing difficulties in physics, such as the incompatibility between Einstein's principle of general coordinate invariance and modern schemes for a quantum mechanical description of nature, and Noether's 'Theorem II' which showed that the principle of general coordinate invariance in general relativity leads to the failure of the law of conservation of energy. Yang-Mills gravity in flat space-time a

  3. Influence of milling time on microstructure and magnetic properties of Fe{sub 80}P{sub 11}C{sub 9} alloy produced by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Taghvaei, A.H. [Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz (Iran, Islamic Republic of); Ghajari, F., E-mail: fati.ghajari@gmail.com [Department of Materials Science and Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of); Markó, D. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Prashanth, K.G. [IFW Dresden, Institute for Complex Materials, Helmholtzstr. 20, 01069 Dresden (Germany); Additive manufacturing Center, Sandvik AB, 81181 Sandviken (Sweden)

    2015-12-01

    Fe{sub 80}P{sub 11}C{sub 9} alloy with amorphous/nanocrytalline microstructure has been synthesized by mechanical alloying of the elemental powders. The microstructure, thermal behavior and morphology of the produced powders have been studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. The crystallite size, lattice strain and fraction of the amorphous phase have been calculated by Rietveld refinement method. The results indicate that the powders microstructure consists of α-Fe(P,C) nanocrystals with an average diameter of 9 nm±1 nm dispersed in the amorphous matrix after 90 h of milling. Moreover, the fraction of amorphous phase initially increases up to 90 h of milling and then decreases after 120 h of milling, as a result of mechanical crystallization and formation of Fe{sub 2}P phase. The magnetic measurements show that while the saturation magnetization decreases continuously with the milling time, the coercivity exhibits a complicated trend. The correlation between microstructural changes and magnetic properties has been discussed in detail. - Highlights: • Glass formation was investigated in Fe{sub 80}P{sub 11}C{sub 9} by mechanical alloying. • Structural parameters were calculated by Rietveld refinement method. • Milling first increased and then decreased the fraction of amorphous phase. • Magnetic properties were significantly changed upon milling.

  4. Preparation of glibenclamide nanocrystals by a simple laboratory scale ultra cryo-milling

    Energy Technology Data Exchange (ETDEWEB)

    Martena, Valentina; Censi, Roberta [University of Camerino, School of Pharmacy (Italy); Hoti, Ela; Malaj, Ledjan [University of Tirana, Department of Pharmacy (Albania); Martino, Piera Di, E-mail: piera.dimartino@unicam.it [University of Camerino, School of Pharmacy (Italy)

    2013-06-15

    The objective of this study is to evaluate the ability to reduce the particle size of glibenclamide (GBC) to the nanometric scale through a very simple and well-known laboratory scale method, the laboratory scale ultra cryo-milling. The effect of milling on GBC crystalline properties and dissolution behaviour was deliberately evaluated in the absence of any surfactants as stabilizers. The milling procedure consisted in adding particles to liquid nitrogen and milling them by hand in a mortar with a pestle for different time intervals (15, 30, 40 min). For comparison, the same milling procedure was also applied without liquid nitrogen. The particle size reduction was evaluated for the coarsest samples (>3 {mu}m) by measuring the particle Ferret's diameter through scanning electron microscopy, while for the smallest one (<3 {mu}m) by dynamic light scattering. A time grinding of 40 min in the presence of liquid nitrogen was revealed highly efficacious to obtain particles of nanodimensions, with a geometric mean particle size of 0.55 {+-} 0.23 {mu}m and more than the 80 % of particles lower than 1,000 nm. Interestingly, non-agglomerated particles were obtained. Differential scanning calorimetry and X-ray powder diffractometry allowed to assess that under mechanical treatment no polymorphic transitions were observed, while a decrease in crystallinity degree occurred depending on the milling procedure (presence or absence of liquid nitrogen) and the milling time (crystallinity decreases at increasing milling time from 15 to 40 min). A comparison of the intrinsic dissolution rate and the dissolution from particles revealed an interesting improvement of particle dissolution particularly for particles milled in the presence of liquid nitrogen due to an increase in particle surface area and concentration gradient, according to the Noyes-Whitney equation.

  5. Processing of magnetically anisotropic MnBi particles by surfactant assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Kanari, K. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Sarafidis, C., E-mail: hsara@physics.auth.gr [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Gjoka, M.; Niarchos, D. [INN, NCSR Demokritos, Athens 15310 (Greece); Kalogirou, O. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2017-03-15

    MnBi particles are obtained from bulk MnBi using mechanochemical processing. The structure and magnetic properties of the MnBi particles are investigated by means of X-ray diffraction analysis, scanning electron microscopy and magnetometry. Surfactant assisted high energy ball milling results to the samples’ degradation even after one hour of milling. In the case of surfactant assisted low energy ball milling the increase of ball milling duration decreases the average particle size while the particles seem to be more separated. The saturation magnetization (M{sub s}) was found to decrease for large milling times beginning from 61 Am{sup 2}/kg, while the coercivity (μ{sub 0}H{sub c}) increases with the increase of ball milling duration up to 35 min where it reaches 1.62 T and thereafter it decreases. - Highlights: • Effect of surfactants in processing of MnBi. • Magnetization degradation due to air storage and due to processing. • Coercivity of 1.6 T in epoxy resin oriented material.

  6. Effect of milling parameters on sinterability, mechanical and electrical properties of Cu-4 wt.% ZrO{sub 2} nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Taha, Mohammed A., E-mail: mtahanrc@gmail.com [Solid-State Physics Department, National Research Centre, El-Buhooth St., 12622, Dokki, Cairo (Egypt); Nassar, Amira H. [Solid-State Physics Department, National Research Centre, El-Buhooth St., 12622, Dokki, Cairo (Egypt); Zawrah, M.F. [Ceramics Department, National Research Centre, El-Buhooth St., 12622, Dokki, Cairo (Egypt)

    2016-09-15

    Mechanical alloying was used to produce Cu matrix nanocomposite reinforced by 4 wt.% ZrO{sub 2} nanoparticles with different milling time up to 16 h and ball-to-powder ratios (BPRs) up to 40:1. The milled nanocomposite powders were investigated by X-ray diffraction (XRD) technique and transmission electron microscopy (TEM). To study the sinterability, the milled powders were cold pressed and sintered at 800 °C for 1 h in argon atmosphere. In order to investigate the relative density and microstructures of the sintered nanocomposites, scanning electron microscopy (SEM) as well as energy dispersive spectrometer (EDS) were employed. The electrical and mechanical properties of the sintered nanocomposites were also examined. The results revealed that a uniform distribution of ZrO{sub 2} reinforcement in Cu matrix was successfully obtained and the agglomeration, crystal and particle sizes were decreased after either milling times and/or BPRs. The results also pointed out that the relative density, microhardness, compressive strength and electrical conductivity of the sintered nanocomposite samples were increased with the increasing of milling time and/or BPRs while apparent porosity was decreased. The maximum values of microhardness, compressive strength and electrical conductivity were 872 MPa, 304 MPa and 45.9% IACS, respectively for the milled sample for 16 h and BRP 40:1. - Highlights: • Cu-4 wt.% ZrO{sub 2} nanoparticles with different parameter by mechanical alloying. • The increased milling times and/or BPRs led to a decrease in the particle size. • Microhardness is increased with increasing ball-to-powder weight ratios. • Compressive strength is increased with increasing milling time. • Electrical conductivity of the samples was increasing with increase milling time.

  7. Preliminary Test of Upgraded Conventional Milling Machine into PC Based CNC Milling Machine

    International Nuclear Information System (INIS)

    Abdul Hafid

    2008-01-01

    CNC (Computerized Numerical Control) milling machine yields a challenge to make an innovation in the field of machining. With an action job is machining quality equivalent to CNC milling machine, the conventional milling machine ability was improved to be based on PC CNC milling machine. Mechanically and instrumentally change. As a control replacing was conducted by servo drive and proximity were used. Computer programme was constructed to give instruction into milling machine. The program structure of consists GUI model and ladder diagram. Program was put on programming systems called RTX software. The result of up-grade is computer programming and CNC instruction job. The result was beginning step and it will be continued in next time. With upgrading ability milling machine becomes user can be done safe and optimal from accident risk. By improving performance of milling machine, the user will be more working optimal and safely against accident risk. (author)

  8. Effect of temperature, time, and milling process on yield, flavonoid, and total phenolic content of Zingiber officinale water extract

    Science.gov (United States)

    Andriyani, R.; Kosasih, W.; Ningrum, D. R.; Pudjiraharti, S.

    2017-03-01

    Several parameters such as temperature, time of extraction, and size of simplicia play significant role in medicinal herb extraction. This study aimed to investigate the effect of those parameters on yield extract, flavonoid, and total phenolic content in water extract of Zingiber officinale. The temperatures used were 50, 70 and 90°C and the extraction times were 30, 60 and 90 min. Z. officinale in the form of powder and chips were used to study the effect of milling treatment. The correlation among those variables was analysed using ANOVA two-way factors without replication. The result showed that time and temperature did not influence the yield of extract of Powder simplicia. However, time of extraction influenced the extract of simplicia treated without milling process. On the other hand, flavonoid and total phenolic content were not influenced by temperature, time, and milling treatment.

  9. FM Interviews: Stephanie Mills

    OpenAIRE

    Valauskas, Edward

    2002-01-01

    Stephanie Mills is an author, editor, lecturer and ecological activist who has concerned herself with the fate of the earth and humanity since 1969, when her commencement address at Mills College in Oakland, Calif., drew the attention of a nation. Her speech, which the New York Times called "perhaps the most anguished statement" of the year's crop of valedictory speeches, predicted a bleak future. According to Mills, humanity was destined for suicide, the result of overpopulation and overuse ...

  10. Properties induced by mechanical milling in the system Sr1-xCaxCuO2

    International Nuclear Information System (INIS)

    Herrero, E.; Gonzalez-Calbet, J.M.; Alonso, J.; Vallet-Regi, M.; Hernando, A.

    1998-01-01

    The Sr 1-x Ca x CuO 2 system has been prepared by a mechanical milling process. The X-ray diffraction study shows that the orthorhombic structure characteristic of SrCuO 2 is preserved in the compositional range 0≤x≤0.7 but a decreasing of crystallinity is observed as the milling time increases. The substitution of Sr by Ca and the milling time plays an important role on the magnetic properties. A superconducting transition is observed for x=0 and 280 h of milling. For x=0.4, an extraordinarily high value of diamagnetic susceptibility is observed between 450 and 500 h of milling. (orig.)

  11. Design and Testing of UMM Vertical Ball Mill (UVBM) for producing Aluminium Powder

    Science.gov (United States)

    Aisyah, I. S.; Caesarendra, Wahyu; Suprihanto, Agus

    2018-04-01

    UMM Vertical Ball Mill (UVBM) was intended to be the apparatus to produce metal powder with superior characteristic in production rate while retaining good quality of metal powder. The concept of design was adopting design theory of Phal and Beitz with emphasis on increasing of probability of success in engineering and economy aspects.Since it was designed as vertical ball mill, a new way to produce powder, then it need to be tested for the performance after manufactured. The test on UVBM was carried out by milling of aluminium chip for 5 (five) different milling time of 0.5 hours, 1 hour, 3 hours, 5 hours and 7 hours, and the powder product then be characterized for it morphology and size using Scanning Electron Microscope (SEM) and Sieve.The results of the study were the longer of the milling time, the finer of the powder. From the test results of SEM, the morphology of the powder with 5 variations of milling time were most of the powder in form of flake (flat), small round and angular (irregular). The distribution of powder size was best obtained on the variation of milling time 3 hours, 5 hours, and 7 hours with percentage of 200 mesh in size of 22.14 %, 64 % and 91.25 % respectively.

  12. Effect of high energy milling time of the aluminum bronze alloy obtained by powder metallurgy with niobium carbide addition

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Alexandre Nogueira Ottoboni; Silva, Aline da; Rodrigues, Carlos Alberto; Melo, Mirian de Lourdes Noronha Motta; Rodrigues, Geovani; Silva, Gilbert, E-mail: aottoboni@yahoo.com.br [Universidade Federal de Itajuba (UNIFEI), Itajuba, MG (Brazil)

    2017-05-15

    The aluminum bronze alloy is part of a class of highly reliable materials due to high mechanical strength and corrosion resistance being used in the aerospace and shipbuilding industry. It's machined to produce parts and after its use cycle, it's discarded, but third process is considered expensive and besides not being correct for environment reasons. Thus, reusing this material through the powder metallurgy (PM) route is considered advantageous. The aluminum bronze chips were submitted to high energy ball milling process with 3% of niobium carbide (NbC) addition. The NbC is a metal-ceramic composite with a ductile-brittle behaviour. It was analyzed the morphology of powders by scanning electron microscopy as well as particle size it was determined. X ray diffraction identified the phases and the influence of milling time in the diffractogram patterns. Results indicates that milling time and NbC addition improves the milling efficiency significantly and being possible to obtain nanoparticles. (author)

  13. Characterization of prealloyed copper powders treated in high energy ball mill

    International Nuclear Information System (INIS)

    Rajkovic, Viseslava; Bozic, Dusan; Jovanovic, Milan T.

    2006-01-01

    The inert gas atomised prealloyed copper powders containing 3.5 wt.% Al were milled up to 20 h in the planetary ball mill in order to oxidize aluminium in situ with oxygen from the air. In the next procedure compacts from milled powder were synthesized by hot-pressing in argon atmosphere. Compacts from as-received Cu-3.5 wt.% Al powder and electrolytic copper powder were also prepared under the same conditions. Microstructural and morphological changes of high energy milled powder as well as changes of thermal stability and electrical conductivity of compacts were studied as a function of milling time and high temperature exposure at 800 deg. C. Optical, scanning electron microscopy (SEM) and X-ray diffraction analysis were performed for microstructural characterization, whereas thermal stability and electrical conductivity were evaluated by microhardness measurements and conductometer Sigmatest, respectively. The prealloyed 5 h-milled and compacted powder showed a significant increase in microhardness reaching the value of 2600 MPa, about 4 times greater than that of compacts synthesized from as-received electrolytic copper powder (670 MPa). The electrical conductivity of compacts from 5 h-milled powder was 52% IACS. The results were discussed in terms of the effect of small grain size and finely distributed alumina dispersoids on hardening and thermal stability of compacts

  14. Contamination risk of stable isotope samples during milling.

    Science.gov (United States)

    Isaac-Renton, M; Schneider, L; Treydte, K

    2016-07-15

    Isotope analysis of wood is an important tool in dendrochronology and ecophysiology. Prior to mass spectrometry analysis, wood must be homogenized, and a convenient method involves a ball mill capable of milling samples directly in sample tubes. However, sample-tube plastic can contaminate wood during milling, which could lead to biological misinterpretations. We tested possible contamination of whole wood and cellulose samples during ball-mill homogenization for carbon and oxygen isotope measurements. We used a multi-factorial design with two/three steel milling balls, two sample amounts (10 mg, 40 mg), and two milling times (5 min, 10 min). We further analyzed abrasion by milling empty tubes, and measured the isotope ratios of pure contaminants. A strong risk exists for carbon isotope bias through plastic contamination: the δ(13) C value of polypropylene deviated from the control by -6.77‰. Small fibers from PTFE filter bags used during cellulose extraction also present a risk as the δ(13) C value of this plastic deviated by -5.02‰. Low sample amounts (10 mg) showed highest contamination due to increased abrasion during milling (-1.34‰), which is further concentrated by cellulose extraction (-3.38‰). Oxygen isotope measurements were unaffected. A ball mill can be used to homogenize samples within test tubes prior to oxygen isotope analysis, but not prior to carbon or radiocarbon isotope analysis. There is still a need for a fast, simple and contamination-free sample preparation procedure. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Hydrogen storage performances of LaMg{sub 11}Ni + x wt% Ni (x = 100, 200) alloys prepared by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yanghuan, E-mail: zhangyh59@sina.com [Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Wang, Haitao [Key Laboratory of Integrated Exploitation of Baiyun Obo Multi-Metal Resources, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China); Zhai, Tingting; Yang, Tai; Yuan, Zeming; Zhao, Dongliang [Department of Functional Material Research, Central Iron and Steel Research Institute, Beijing 100081 (China)

    2015-10-05

    Highlights: • Amorphous and nanostructured alloys were prepared by mechanical milling. • The maximum discharge capacity of ball milled alloys reaches to 1053.5 mA h/g. • The addition of Ni significantly increases the discharge capacity. • Increasing milling time reduces the kinetic performances of ball milled alloys. - Abstract: In order to improve the hydrogen storage performances of Mg-based materials, LaMg{sub 11}Ni alloy was prepared by vacuum induction melting. Then the nanocrystalline/amorphous LaMg{sub 11}Ni + x wt% Ni (x = 100, 200) hydrogen storage alloys were synthesized by ball milling technology. The structure characterizations of the alloys were carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical hydrogen storage characteristics were tested by using programmed control battery testing system. The electrochemical impedance spectra (EIS), potentiodynamic polarization curves and potential-step curves were also plotted by an electrochemical workstation (PARSTAT 2273). The results indicate that the as-milled alloys exhibit a nanocrystalline and amorphous structure, and the amorphization degree of the alloys visibly increases with extending milling time. Prolonging the milling duration markedly enhances the electrochemical discharge capacity and cyclic stability of the alloys. The electrochemical kinetics, including high rate discharge ability (HRD), charge transfer rate, limiting current density (I{sub L}), hydrogen diffusion coefficient (D), monotonously decrease with milling time prolonging.

  16. Transforming from paramagnetism to room temperature ferromagnetism in CuO by ball milling

    Directory of Open Access Journals (Sweden)

    Daqiang Gao

    2011-12-01

    Full Text Available In this work, we experimentally demonstrate that it is possible to induce ferromagnetism in CuO by ball milling without any ferromagnetic dopant. The magnetic measurements indicate that paramagnetic CuO is driven to the ferromagnetic state at room temperature by ball milling gradually. The saturation magnetization of the milled powders is found to increase with expanding the milling time and then decrease by annealing under atmosphere. The fitted X-ray photoelectron spectroscopy results indicate that the observed induction and weaken of the ferromagnetism shows close relationship with the valence charged oxygen vacancies (Cu1+-VO in CuO.

  17. Effect of the milling conditions on the degree of amorphization of selenium by milling in a planetary ball mill

    International Nuclear Information System (INIS)

    Ksiazek, K; Wacke, S; Gorecki, T; Gorecki, Cz

    2007-01-01

    The effect of the milling parameters (rotation speed of the milling device and duration of milling) on the phase composition of the products of milling of fully crystalline selenium has been investigated. The milling was conducted using a planetary micromill and the phase composition of the milling products was determined by differential thermal analysis. It has been found that ball milling leads to the partial amorphization of the starting crystalline material. The content of amorphous phase in the milling products depends, in a rather complicated way, on the milling parameters. At the milling parameters adopted in the present study, the milling product was never fully amorphous. The complicated way the milling parameters affect the content of amorphous phase in the milling products is a result of competition of two processes: amorphization due to deformation and refinement of grains of milled material and crystallization of the already produced amorphous material at the cost of heat evolved in the milling vial during the milling process

  18. Optimization of FIB milling for rapid NEMS prototyping

    DEFF Research Database (Denmark)

    Malm, Bjarke; Petersen, Dirch Hjorth; Lei, Anders

    2011-01-01

    We demonstrate an optimized milling technique to focused ion beam (FIB) milling in template silicon membranes for fast prototyping of nanoelectromechanical systems (NEMS). Using a single-pass milling strategy the highly topology dependent sputtering rate is boosted and shorter milling time...... is achieved. Drift independence is obtained for small critical features using a radial scan strategy, and a back scan routine ensures minimal line width deviation removing redeposited material. Milling a design similar to a nano four-point probe with a pitch down to 400nm we display what optimized FIB milling...

  19. Influence of starting powder milling on magnetic properties of Mn-Zn ferrite

    Directory of Open Access Journals (Sweden)

    Miodrag M. Milutinov

    2017-06-01

    Full Text Available In this paper, the influence of additional sieving and milling of starting industrial Mn-Zn powders on magnetic properties was investigated. The starting powder was milled for 60 minutes, followed by sieving through 325 and 400 meshes. The starting and milled powders were used to fabricate toroid shaped samples sintered at 1200°C for 2 hours. Structural parameters of the fabricated samples were analysed by X-ray diffraction and scanning electron microscopy. Complex permeability, core loss density, and hysteresis were measured using the modified watt-meter method. The complex permeability and hysteresis loop were modelled with a new model proposed in the paper. The core loss density was modelled with the Steinmetz empirical equation. The experimental results and calculations show the significance of the additional milling and sieving process on magnetic properties of Mn-Zn ferrite in the frequency range 0.1-10MHz. These processes increase the relative permeability about 3 times and decrease the core loss 4 times by milling of the starting powder.

  20. Effect of mechanical milling on barium titanate (BaTiO3) perovskite

    Science.gov (United States)

    Singh, Rajan Kumar; Sanodia, Sagar; Jain, Neha; Kumar, Ranveer

    2018-05-01

    Commercial Barium Titanate BaTiO3 (BT) is milled by planetary ball mill in acetone medium using stainless steel bowl & ball for different hours. BT is an important perovskite oxide with structure ABO3. BT has applications in electro-optic devices, energy storing devices such as photovoltaic cells, thermistors, multiceramic capacitors & DRAMs etc. BT is non-toxic & environment friendly ceramic with high dielectric and piezoelectric property so it can be used as the substitute of PZT & PbTiO3. Here, we have investigated the effect of milling time and temperature on particle size and phase transition of BT powder. We used use Raman spectroscopy for studying the spectra of BT; XRD is used for structural study. Intensity (height) of Raman spectra and XRD spectra continuously decrease with increasing the milling hours and width if these spectra increases which indicates, decrease in BT size.

  1. FePt magnetic particles prepared by surfactant-assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, V., E-mail: vvjimeno@fis.ucm.es [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, P.O. Box 155, Las Rozas 28230 (Spain); Departamento de Física de Materiales, Universidad Complutense de Madrid, Madrid 28040 (Spain); Hernando, A.; Crespo, P. [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, P.O. Box 155, Las Rozas 28230 (Spain); Departamento de Física de Materiales, Universidad Complutense de Madrid, Madrid 28040 (Spain)

    2013-10-15

    High-energy ball milling of Fe and Pt elemental powders has been carried out under dry and wet (in presence of solvent and surfactants) conditions. Dry milling leads to the formation of the disordered FCC-FePt alloy whereas by the wet milling procedure the main process is the decrease of Fe and Pt particle size, although some dissolution of Pt into Fe grains cannot be ruled out, and no hint of the formation of the FCC-FePt phase is observed even to milling times up to 20 h, as X-ray diffraction, electron microscopy and Mössbauer spectroscopy indicates. The as-milled particles were annealed at 600 °C for 2 h under Ar atmosphere. It is noticed that the disordered fcc-FePt phase observed in particles milled under dry conditions transform to ordered fct phase characterized by a hard magnetic behavior with a coercive field up to 10,000 Oe. However, those particles milled in the surfactant/solvent medium exhibit a soft magnetic behavior with a coercive field of 600 Oe. These results indicate that wet high-energy ball milling is not an adequate technique for obtaining single-phase FePt particles. - Highlights: • FePt particles have been obtained by high-energy ball milling. • In the presence of surfactants and solvents, almost no alloying process takes place. • After annealing, the coercive field of the FePt alloy particles increases from 150 Oe to 10,000 Oe.

  2. Ball-milling-induced crystallization and ball-milling effect on thermal crystallization kinetics in an amorphous FeMoSiB alloy

    International Nuclear Information System (INIS)

    Guo, F.Q.; Lu, K.

    1997-01-01

    Microstructure evolution in a melt-spun amorphous Fe 77.2 Mo 0.8 Si 9 B 13 alloy subjected to high-energy ball milling was investigated by means of X-ray diffraction (XRD), a transmission electron microscope (TEM), and a differential scanning calorimeter (DSC). It was found that during ball milling, crystallization occurs in the amorphous ribbon sample with precipitation of an α-Fe solid solution, and the amorphous sample crystallizes completely into a single α-Fe nanostructure (rather than α-Fe and borides as in the usual thermal crystallization products) when the milling time exceeds 135 hours. The volume fraction of material crystallized was found to be approximately proportional to the milling time. The fully crystallized sample with a single α-Fe nanophase exhibits an intrinsic thermal stability against phase separation upon annealing at high temperatures. The ball-milling effect on the subsequent thermal crystallization of the amorphous phase in an as-milled sample was studied by comparison of the crystallization products and kinetic parameters between the as-quenched amorphous sample and the as-milled sample was studied by comparison of the crystallization products and kinetic parameters between the as-quenched amorphous sample and the as-milled partially crystallized samples. The crystallization temperatures and activation energies for the crystallization processes of the residual amorphous phase were considerably decreased due to ball milling, indicating that ball milling has a significant effect on the depression of thermal stability of the residual amorphous phase

  3. Microstructural characteristics and mechanical properties of carbon nanotube reinforced aluminum alloy composites produced by ball milling

    International Nuclear Information System (INIS)

    Raviathul Basariya, M.; Srivastava, V.C.; Mukhopadhyay, N.K.

    2014-01-01

    Highlights: • 6082 Al alloy composite with 2 wt% multiwalled carbon nanotubes prepared by milling. • Effect of milling time on structure and property evolution has been studied. • The reinforced composite powders showed a drastic crystallite size refinement. • The presence of carbon nanotube led to a two fold increase in the hardness and modulus. • The composite powder showed good thermal stability studied by DTA. - Abstract: The influence of milling time on the structure, morphology and thermal stability of multi-walled carbon nanotubes (MWCNTs) reinforced EN AW6082 aluminum alloy powders has been studied. After structural and microstructural characterization of the mechanically milled powders micro- and nano-hardness of the composite powder particles were evaluated. The morphological and X-ray diffraction studies on the milled powders revealed that the carbon nanotubes (CNTs) were uniformly distributed and embedded within the aluminum matrix. No reaction products were detected even after long milling up to 50 h. Nanotubes became shorter in length as they fractured under the impact and shearing action during the milling process. A high hardness of about 436 ± 52 HV is achieved for the milled powders, due to the addition of MWCNTs, after milling for 50 h. The increased elastic modulus and nanohardness can be attributed to the finer grain size evolved during high energy ball milling and to the uniform distribution of hard CNTs in the Al-alloy matrix. The hardness values of the composite as well as the matrix alloy compares well with that predicted by the Hall–Petch relationship

  4. Effect of the Milling Time of the Precursors on the Physical Properties of Sprayed Aluminum-Doped Zinc Oxide (ZnO:Al Thin Films

    Directory of Open Access Journals (Sweden)

    María De La Luz Olvera

    2012-08-01

    Full Text Available Aluminum doped zinc oxide (ZnO:Al thin films were deposited on soda-lime glass substrates by the chemical spray technique. The atomization of the solution was carried out by ultrasonic excitation. Six different starting solutions from both unmilled and milled Zn and Al precursors, dissolved in a mix of methanol and acetic acid, were prepared. The milling process was carried out using a planetary ball mill at a speed of 300 rpm, and different milling times, namely, 15, 25, 35, 45, and 60 min. Molar concentration, [Al]/[Zn] atomic ratio, deposition temperature and time, were kept at constant values; 0.2 M, 3 at.%, 475 °C, and 10 min, respectively. Results show that, under the same deposition conditions, electrical resistivities of ZnO:Al thin films deposited from milled precursors are lower than those obtained for films deposited from unmilled precursors. X-ray diffraction analysis revealed that all films display a polycrystalline structure, fitting well with the hexagonal wurtzite structure. Changes in surface morphology were observed by scanning electron microscopy (SEM as well, since films deposited from unmilled precursors show triangular shaped grains, in contrast to films deposited from 15 and 35 min milled precursors that display thin slices with hexagonal shapes. The use of milled precursors to prepare starting solutions for depositing ZnO:Al thin films by ultrasonic pyrolysis influences their physical properties.

  5. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  6. Hybrid ABC Optimized MARS-Based Modeling of the Milling Tool Wear from Milling Run Experimental Data.

    Science.gov (United States)

    García Nieto, Paulino José; García-Gonzalo, Esperanza; Ordóñez Galán, Celestino; Bernardo Sánchez, Antonio

    2016-01-28

    Milling cutters are important cutting tools used in milling machines to perform milling operations, which are prone to wear and subsequent failure. In this paper, a practical new hybrid model to predict the milling tool wear in a regular cut, as well as entry cut and exit cut, of a milling tool is proposed. The model was based on the optimization tool termed artificial bee colony (ABC) in combination with multivariate adaptive regression splines (MARS) technique. This optimization mechanism involved the parameter setting in the MARS training procedure, which significantly influences the regression accuracy. Therefore, an ABC-MARS-based model was successfully used here to predict the milling tool flank wear (output variable) as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc . Regression with optimal hyperparameters was performed and a determination coefficient of 0.94 was obtained. The ABC-MARS-based model's goodness of fit to experimental data confirmed the good performance of this model. This new model also allowed us to ascertain the most influential parameters on the milling tool flank wear with a view to proposing milling machine's improvements. Finally, conclusions of this study are exposed.

  7. Hybrid ABC Optimized MARS-Based Modeling of the Milling Tool Wear from Milling Run Experimental Data

    Directory of Open Access Journals (Sweden)

    Paulino José García Nieto

    2016-01-01

    Full Text Available Milling cutters are important cutting tools used in milling machines to perform milling operations, which are prone to wear and subsequent failure. In this paper, a practical new hybrid model to predict the milling tool wear in a regular cut, as well as entry cut and exit cut, of a milling tool is proposed. The model was based on the optimization tool termed artificial bee colony (ABC in combination with multivariate adaptive regression splines (MARS technique. This optimization mechanism involved the parameter setting in the MARS training procedure, which significantly influences the regression accuracy. Therefore, an ABC–MARS-based model was successfully used here to predict the milling tool flank wear (output variable as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc. Regression with optimal hyperparameters was performed and a determination coefficient of 0.94 was obtained. The ABC–MARS-based model's goodness of fit to experimental data confirmed the good performance of this model. This new model also allowed us to ascertain the most influential parameters on the milling tool flank wear with a view to proposing milling machine's improvements. Finally, conclusions of this study are exposed.

  8. Hybrid ABC Optimized MARS-Based Modeling of the Milling Tool Wear from Milling Run Experimental Data

    Science.gov (United States)

    García Nieto, Paulino José; García-Gonzalo, Esperanza; Ordóñez Galán, Celestino; Bernardo Sánchez, Antonio

    2016-01-01

    Milling cutters are important cutting tools used in milling machines to perform milling operations, which are prone to wear and subsequent failure. In this paper, a practical new hybrid model to predict the milling tool wear in a regular cut, as well as entry cut and exit cut, of a milling tool is proposed. The model was based on the optimization tool termed artificial bee colony (ABC) in combination with multivariate adaptive regression splines (MARS) technique. This optimization mechanism involved the parameter setting in the MARS training procedure, which significantly influences the regression accuracy. Therefore, an ABC–MARS-based model was successfully used here to predict the milling tool flank wear (output variable) as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc. Regression with optimal hyperparameters was performed and a determination coefficient of 0.94 was obtained. The ABC–MARS-based model's goodness of fit to experimental data confirmed the good performance of this model. This new model also allowed us to ascertain the most influential parameters on the milling tool flank wear with a view to proposing milling machine's improvements. Finally, conclusions of this study are exposed. PMID:28787882

  9. Microstructural changes and effect of variation of lattice strain on positron annihilation lifetime parameters of zinc ferrite nanocomposites prepared by high enegy ball-milling

    Directory of Open Access Journals (Sweden)

    Abhijit Banerjee

    2012-12-01

    Full Text Available Zn-ferrite nanoparticles were synthesized at room temperature by mechanical alloying the stoichiometric (1:1 mol% mixture of ZnO and α-Fe2O3 powder under open air. Formation of both normal and inverse spinel ferrite phases was noticed after 30 minutes and 2.5 hours ball milling respectively and the content of inverse spinel phase increased with increasing milling time. The phase transformation kinetics towards formation of ferrite phases and microstructure characterization of ball milled ZnFe2O4 phases was primarily investigated by X-ray powder diffraction pattern analysis. The relative phase abundances of different phases, crystallite size, r.m.s. strain, lattice parameter change etc. were estimated from the Rietveld powder structure refinement analysis of XRD data. Positron annihilation lifetime spectra of all ball milled samples were deconvoluted with three lifetime parameters and their variation with milling time duration was explained with microstructural changes and formation of different phases with increase of milling time duration.

  10. Cryogenic milling for the fabrication of high J{sub c} MgB{sub 2} bulk superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. N.; Kang, M. O.; Park, H. W. [Korea University of Technology and Education, Cheonan (Korea, Republic of); Jun, B. H.; Kim, C. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    Cryogenic milling which is a combined process of low-temperature treatment and mechanical milling was applied to fabricate high critical current density (J{sub c}) MgB{sub 2} bulk superconductors. Liquid nitrogen was used as a coolant, and no solvent or lubricant was used. Spherical Mg (6-12 μm, 99.9 % purity) and plate-like B powder (⁓ 1 μm, 97 % purity) were milled simultaneously for various time periods (0, 2, 4, 6 h) at a rotating speed of 500 rpm using ZrO{sub 2} balls. The (Mg{sup +2B}) powders milled were pressed into pellets and heat-treated at 700°C for 1 h in flowing argon. The use of cryomilled powders as raw materials promoted the formation reaction of superconducting MgB{sub 2}, reduced the grain size of MgB{sub 2}, and suppressed the formation of impurity MgO. The superconducting critical temperature (T{sub c}) of MgB{sub 2} was not influenced as the milling time (t) increased up to 6 h. Meanwhile, the critical current density (J{sub c}) of MgB{sub 2} increased significantly when t increased to 4 h. When t increased further to 6 h, however, Jc decreased. The J{sub c} enhancement of MgB{sub 2} by cryogenic milling is attributed to the formation of the fine grain MgB{sub 2} and a suppression of the MgO formation.

  11. Characterization of tin selenides synthesized by high-energy milling

    Directory of Open Access Journals (Sweden)

    Marcela Achimovičová

    2011-12-01

    Full Text Available Tin selenides SnSeX (x=1,2 were synthesized from tin and selenium powder precursors by high-energy milling in the planetary ballmill Pulverisette 6 (Fritsch, Germany. The orthorhombic tin selenide SnSe and the hexagonal tin diselenide SnSe2 phases were formed after4 min and 5 min of milling, respectively. Specific surface area of both selenides increased with increasing time of mechanochemicalsynthesis. The particle size distribution analysis demonstrated that the synthesized products contain agglomerated selenide particlesconsisting of numerous idiomorphic tin selenide crystals, measuring from 2 to more than 100 nm in diameter, which were also documentedby TEM. UV-Vis spectrophotometry confirmed that tin selenide particles do not behave as quantum dots.

  12. Influence of high-energy milling on structure and microstructure of asbestos-cement materials

    Science.gov (United States)

    Iwaszko, Józef; Zawada, Anna; Lubas, Małgorzata

    2018-03-01

    Asbestos-Containing Waste (ACW) in the form of a fragment from an asbestos-cement board was subjected to high-energy milling in a planetary mill at a constant rotational speed of 650 rpm and for variable milling times: 1, 2, and 3 h. The initial and the milled materials were subjected to infrared spectroscopic examination to identify the asbestos variety and to evaluate changes in the structure caused by high-energy milling. FT-IR (Fourier Transform Infrared Spectroscopy) examinations followed optical microscopy and SEM (Scanning Electron Microscopy) studies as well as X-ray analysis of the phase composition. It was found that the asbestos fibres present in the asbestos-cement board were respirable fibres with pathogenic properties. Identifying asbestos using the spectroscopic method showed that chrysotile asbestos was present in the as-received ACW while no characteristics of absorption bands from crocidolite or amosite were found. The results of the spectroscopic examinations were confirmed by the X-ray phase analysis. During SEM investigations of the milled ACW, complete loss of the fibrous structure of chrysotile was observed. The FT-IR examinations of the milled material showed that with an increased milling time, the characteristic absorption bands characteristic for chrysotile diminished and already after 2 h of milling their almost complete decay was observed. Thereby, it was confirmed that high-energy milling results in destruction of the crystalline structure of the asbestos phase. The conducted studies have shown that the treatment of asbestos-cement materials using high-energy milling is an effective method for asbestos disposal, capable of competing with other technologies and solutions. Moreover, FT-IR spectroscopy was found to be useful to identify asbestos phases and to assess changes caused by high-energy milling.

  13. Characterization of structures and novel magnetic response of Fe87.5Si7Al5.5 alloy processed by ball milling

    International Nuclear Information System (INIS)

    Duan, Yuping; Gu, Shuchao; Zhang, Zhonglun; Wen, Ming

    2012-01-01

    Highlights: ► The water atomized Fe 87.5 Si 7 Al 5.5 (Wt.%) alloy was processed by ball-milling. ► The microstructure and magnetic properties of alloy changed following milling. ► The powders milled for 10 h have the largest M s and strongest reflection loss. ► The permeability of the powders milled for 2 h is the largest. ► The charge exchange between Fe and Si is discussed base on first-principles. - Abstract: The water atomized Fe 87.5 Si 7 Al 5.5 (Wt.%) alloy was processed by a high-energy planetary ball-milling. The characterization of morphology, microstructure, and electromagnetic properties were measured by scanning electron microscope (SEM), X-ray diffractometer, vibrating sample magnetometer (VSM), vector network analyzer and the first principle method. The analysis results showed that the powders shape became flaky from fusiform. The powders showed a reduction of the average grain size and the increase of the internal strain, and then presented an adverse variation trend after 55 h milling. The powders that milled 10 h had the largest saturation magnetization M S (131 emu/g). The value μ′ of the powders decreased with increasing milling time at relatively lower frequency (2–8 GHz), but opposite variation tendency happened at higher frequency (8–18 GHz). Also, only short time milling can enhance the value of μ″ in the test frequency. The powders after 10 h milling showed excellent microwave absorption (RL < −10 dB) at the frequency 9.0–15.6 GHz and the absorption peak shifted regularly to the high frequency as the increased milling time. Furthermore, the effect of charge exchange between the Fe and Si on the saturation magnetization in the ball-milling process was also investigated by using density functional theory (DFT) of first principle.

  14. Characterization of Al–Al4C3 nanocomposites produced by mechanical milling

    International Nuclear Information System (INIS)

    Santos-Beltrán, A.; Goytia-Reyes, R.; Morales-Rodriguez, H.; Gallegos-Orozco, V.; Santos-Beltrán, M.; Baldenebro-Lopez, F.; Martínez-Sánchez, R.

    2015-01-01

    In this work, a mixture of Al–C–Al 4 C 3 nanopowder previously synthesized by mechanical milling and subsequent thermal treatment was used to reinforce the Al matrix. The nanocomposites were fabricated via high-energy ball milling and subsequent sintering process for different periods of time at 550 °C. Hardness and compression tests were performed to evaluate the mechanical properties of the nanocomposites in the as-milled and sintered conditions. According to the results the reinforcement located in the grain boundaries is responsible for the brittle behavior observed in the nanocomposites during the compression test. The combined effect of sintering and precipitation mechanisms produced an evident increase of the strength of the Al matrix at a relatively short sintering time. By using the Rietveld method the crystallite size and microstrain measurements were determined and correlated with the microhardness values. For the proper characterization of the nanoparticles present in the Al matrix, atomic force microscopy and high resolution electron microscopy were used. - Highlights: • Nanostructured Al 4 C 3 reinforcement was fabricated via mechanical milling and heat treatment. • We found a significant increase of the mechanical properties at short sintering times. • The formation of Al 4 C 3 with during sintering time restricted the excessive growth of the crystallite. • Al 4 C 3 located in the grain boundaries causes brittle fracture observed in compression tests. • There is a correlation between, crystallite size and microstrain values with microhardness

  15. Moessbauer analysis of high-energy mechanical-milled sand fraction of a magnetic soil developing on basalt

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Jose Flavio Marcelino; Hneda, Marlon Luiz; Brinatti, Andre Mauricio [State University of Ponta Grossa, Department of Physics (Brazil); Cunha, Joao Batista Marimon da [Federal University of Rio Grande do Sul, Institute of Physics (Brazil); Rosa, Jadir Aparecido [Polo Regional de Ponta Grossa, Agronomy Institute of Parana (Brazil); Fabris, Jose Domingos, E-mail: jdfabris@ufmg.br [Federal University of Jequitinhonha and Mucuri Valleys (UFVJM) (Brazil)

    2011-11-15

    A sample of the coarse sand fraction from the soil material of the A-horizon (0-0.2 m from the soil surface) of a dusky red magnetic Oxisol was submitted to high-energy mechanical milling for different times. This assay aimed mainly at (a) monitoring the individualization of strongly aggregated mineral particles, and (b) measuring the effect of the milling pressure on the mineralogy changes of the material. These data are also intended to experimentally subside any physical model describing the mechanical behavior of the superficial soil layer that is subjected to intensive machine management, in agriculture fields. Powder X-ray data reveal that some mineralogical phases, notably gibbsite, disappear soon after the first few hours milling. The 298 K-transmission Moessbauer spectrum for the non-milled sand sample shows a qualitatively typical pattern for the sand fraction of basalt derived soils, with magnetically ordered sextets, assignable mainly to hematite and maghemite, and an intense central (super)paramagnetic Fe{sup 3 + } doublet. For the milled samples, spectra revealed progressive spectral reduction of the magnetic hyperfine structure, with concomitant increase of relative subspectral areas due to (super)paramagnetic phases, as the milling time increased. This result is consistent with the reduction of measured saturation magnetization, from 4.96(8) J T{sup - 1} kg{sup - 1}, for the non-milled sample, to 3.26(7) J T{sup - 1} kg{sup - 1}, for the sample milled for 8 hours.

  16. Uranium milling costs

    International Nuclear Information System (INIS)

    Coleman, R.B.

    1980-01-01

    Basic process flowsheets are reviewed for conventional milling of US ores. Capital costs are presented for various mill capacities for one of the basic processes. Operating costs are shown for various mill capacities for all of the basic process flowsheets. The number of mills using, or planning to use, a particular process is reviewed. A summary of the estimated average milling costs for all operating US mills is shown

  17. Interior drains for open pit disposal of uranium mill tailings

    International Nuclear Information System (INIS)

    Staub, W.P.

    1978-01-01

    A conceptualized interior drainage system is presented for reducing the environmental impact on natural groundwater by disposal of uranium mill tailings in the mined-out open pit. The evaporation/seepage ratio can be increased through the use of interior drains, long-term monitoring of groundwater quality can be eliminated, and the open pit will not require an extensive liner. Other advantages not related to groundwater are: control of fugitive dust and radon emanation during mill operations and timely reclamation after the impoundment is filled with tailings

  18. Behaviour of CaO coating of gas atomized Mg powders using mechanical milling process

    International Nuclear Information System (INIS)

    Kim, Sun-Mi; Kim, Yong Hwan; Kim, Young Do; Kim, Taek-Soo

    2011-01-01

    Highlights: → This work is very new, since behaviour of CaO coating with milling time as desulfurizer is not frequently reported. → The manuscript reports the new manner of Mg powders desulfurizer development by the innovative process. - Abstract: In order to synthesize a thermally stable Mg powder as a desulfurizer of iron, pure Mg was gas atomized to powders and coated by CaO powders, to produce a thermally stable desulfurizer using a mechanical milling process. Since the effect of desulfurization is dependent on the degree of surface modification, coating behaviours such as the size, morphology and layer thickness were investigated as a function of milling condition. As the milling conducted from 10 min to 30 min, 1 h, 3 h, 6 h, 12 h, CaO particles began to stick on the surface of Mg powders. The layer of CaO formed from 1 h milling was about 17 μm thick and gradually thickened to be 28 μm, 32 μm and 37 μm with increasing the milling time to 3 h, 6 h and 12 h, respectively. The shape of coated powder became more spherical after 1 h milling, being mostly spherical after 6 h. Desulfurization rate and uniformity were evaluated for the various thickness of the coating layer.

  19. Free volume changes in mechanically milled PS and PC studied by positron annihilation lifetime spectroscopy (PALS)

    NARCIS (Netherlands)

    Günther-Schade, K.; Castricum, H.L.; Ziegler, H.J.; Bakker, H.; Faupel, F.

    2004-01-01

    The effect of mechanical milling on free volume was studied by means of positron annihilation lifetime spectroscopy (PALS) in polystyrene (PS) as a typical brittle polymer and in polycarbonate (PC) as a tough representative. Long-time milling increases the free volume, while a decrease is observed

  20. Discrete element method based scale-up model for material synthesis using ball milling

    Science.gov (United States)

    Santhanam, Priya Radhi

    Mechanical milling is a widely used technique for powder processing in various areas. In this work, a scale-up model for describing this ball milling process is developed. The thesis is a combination of experimental and modeling efforts. Initially, Discrete Element Model (DEM) is used to describe energy transfer from milling tools to the milled powder for shaker, planetary, and attritor mills. The rolling and static friction coefficients are determined experimentally. Computations predict a quasisteady rate of energy dissipation, E d, for each experimental configuration. It is proposed that the milling dose defined as a product of Ed and milling time, t, divided by the mass of milled powder, mp characterizes the milling progress independently of the milling device or milling conditions used. Once the milling dose is determined for one experimental configuration, it can be used to predict the milling time required to prepare the same material in any milling configuration, for which Ed is calculated. The concept is validated experimentally for DEM describing planetary and shaker mills. For attritor, the predicted Ed includes substantial contribution from milling tool interaction events with abnormally high forces (>103 N). The energy in such events is likely dissipated to heat or plastically deform milling tools rather than refine material. Indeed, DEM predictions for the attritor correlate with experiments when such events are ignored in the analysis. With an objective of obtaining real-time indicators of milling progress, power, torque, and rotation speed of the impeller of an attritor mill are measured during preparation of metal matrix composite powders in the subsequent portion of this thesis. Two material systems are selected and comparisons made between in-situ parameters and experimental milling progress indicators. It is established that real-time measurements can certainly be used to describe milling progress. However, they need to be interpreted carefully

  1. Tool Wear Analysis on Five-Axis Flank Milling for Curved Shape Part – Full Flute and Ground Shank End Mill

    Directory of Open Access Journals (Sweden)

    Syahrul Azwan Sundi

    2017-01-01

    Full Text Available This paper is a study on full flute (extra-long tool and ground shank end mill wear analysis by utilizing five-axis CNC to implement flank milling strategy on curved shape part. Five-axis machining eases the user to implement variations of strategy such as flank milling. Flank milling is different from point milling. Point milling cuts materials by using the tip of the tool whereas the flank milling uses the cutting tool body to cut material. The type of cutting tool used was end mill 10 mm diameter with High Speed Steel (HSS material. One factor at a time was utilized to analyze the overall data. Feed rate and spindle speed were the two main factors that been set up equally for both full flute and ground shank end mill. At the end of this research, the qualitative analysis based on tool wear between full flute and ground shank end mill is observed. Generally, both types of cutting tools showed almost the same failure indication such as broken edge or chipped off edge, formation of pinned hole on the surface and serration formation or built-up edge (BUE on the primary flute. However, the results obtained from the enlarged images which were captured by Optical Microscope indicated that, the ground shank end mill is better than the full flute end mill.

  2. Partial amorphization of an α-FeCr alloy by ball-milling

    International Nuclear Information System (INIS)

    Loureiro, J. M.; Costa, B. F. O.; Caer, G. Le; Delcroix, P.

    2008-01-01

    The structural changes of near-equiatomic α-FeCr alloys, ground in a vibratory mill in vacuum and in argon, were followed as a function of milling time. An amorphous phase forms in both cases but at a much faster rate when milling in argon than when milling in vacuum. Amorphisation by ball-milling of α-FeCr alloys is deduced to be an intrinsic phenomenon which is however speeded-up by oxygen. The amorphous phase crystallizes into a bcc Cr-rich phase and a bcc Fe-rich phase when annealed for short times.

  3. Nanocrystalline TiAl powders synthesized by high-energy ball milling: effects of milling parameters on yield and contamination

    International Nuclear Information System (INIS)

    Bhattacharya, Prajina; Bellon, Pascal; Averback, Robert S.; Hales, Stephen J.

    2004-01-01

    High-energy ball milling was employed to produce nanocrystalline Ti-Al powders. As sticking of the powders can be sufficiently severe to result in a near zero yield, emphasis was placed on varying milling conditions so as to increase the yield, while avoiding contamination of the powders. The effects of milling parameters such as milling tools, initial state of the powders and addition of process control agents (PCA's) were investigated. Cyclohexane, stearic acid and titanium hydride were used as PCA's. Milling was conducted either in a Cr-steel vial with C-steel balls, or in a tungsten carbide (WC) vial with WC balls, using either elemental or pre-alloyed powders. Powder samples were characterized using X-ray diffraction, scanning and transmission electron microscopy. In the absence of PCA's mechanical alloying in a WC vial and attrition milling in a Cr-steel vial were shown to lead to satisfactory yields, about 65-80%, without inducing any significant contamination of the powders. The results suggest that sticking of the powders on to the milling tools is correlated with the phase evolution occurring in these powders during milling

  4. Effect of milling on the magnetic properties of Al–Mn obtained by mechanical alloying

    International Nuclear Information System (INIS)

    Betancourt, Mirna; Silva, Pedro; Gonzalez, Gema

    2012-01-01

    Highlights: ► Al–42 at.% Mn transforms to α-Mn(Al) by mechanical milling after 5 h of milling. ► Transformation to nano β-Mn is reached after 50 h of milling with 6 nm grain size. ► Milling strongly affects magnetic behavior. - Abstract: Al–Mn powders were prepared to obtain the compound Mn 42 Al 58 by mechanical alloying. The powders were milled during different periods (1 h, 5 h, 11.5 h, 15 h, 20 h and 50 h) using a SPEX 8000 mixer mill in nitrogen atmosphere. The materials were characterized by X-ray diffraction (XRD) and magnetic properties at room temperature, using a vibrating sample magnetometer (VSM). XRD shows partial transformation to α-Mn after only 1 h of milling and a mixture of α-Mn and β-Mn after 11.5 h of milling and further milling resulted in transformation to β-Mn phase with a grain size of 6 nm after 50 h. The change in magnetic properties with milling time is quite dramatic, from a ferromagnetic behavior for α-Mn(Al) to paramagnetic after 11.5 h of milling and showing again ferromagnetic behavior, with a strong increase of magnetization values of 5.5 emu/g, after 50 h of milling with formation of β-Mn(Al).

  5. Dependence of hydrogen storage characteristics of mechanically milled carbon materials on their host structures

    International Nuclear Information System (INIS)

    Shindo, K.; Kondo, T.; Sakurai, Y.

    2004-01-01

    We investigated whether the hydrogen storage characteristics of carbon materials prepared by mechanical milling in an H 2 atmosphere were dependent on their host structures. We used natural graphite (NG) and activated carbon fibers (ACF) and compared them with activated carbon (AC) powders. The XRD patterns of NG and ACF milled for over 20 h and SEM images of these samples milled for 80 h were almost the same as those of AC. The hydrogen storage capacities of NG and ACF estimated by the inert gas fusion-thermal conductivity method increased with the mechanical milling time up to 10 h and showed little milling time dependence thereafter. The capacities of NG and ACF reached about 3.0 wt.% and were similar to that of AC. However, it should be noted that the hydrogen storage mechanism of NG and ACF mechanically milled in an H 2 atmosphere might be different because the changes in their specific surface areas with milling time were opposite. Thermal desorption mass spectroscopy (TDS) revealed that the desorption spectra of the hydrogen molecules (mass number=2) of NG and ACF milled for 10 h in the same way as AC contained two peaks at about 500 and 800 deg. C. The desorption activation energies of hydrogenated NG and ACF at these peaks calculated from a Kissinger plot were almost with the same as those of hydrogenated AC. This suggests that the state of the hydrogen trapped in the structural defects in NG introduced by the mechanical milling may be almost the same as that of AC. In addition, we assumed the possibility that the state of the hydrogen in ACF hydrogenated by mechanical milling could be almost the same as that in hydrogenated AC. We considered that the nanocarbon materials hydrogenated under our milling conditions had very similar physical shapes and hydrogen storage capacities, independent of their host structures

  6. Effect of polishing time and pressure on quality characteristics of rice grain

    International Nuclear Information System (INIS)

    Karim, M.A.

    2002-01-01

    Since totally unpolished rice has poor cooking quality, a certain amount of polishing for the removal of the outermost bran layers is essential. To determine the best combination of polishing time and pressure with respect to obtaining optimum quantity/quality, the brown rice (head grains) of a rice strain 4048 was milled for 10, 20, 30 and 40 seconds against 1,2,3,4 and 5 lbs pressure in a Burrows McGill Polisher No. 3. the quality characteristics studied were: total milling recovery, head rice recovery, whiteness of milled rice, protein content of grain, grain length and bursting upon cooking. Both, total milled rice and head rice reduced while the whiteness of milled rice improved significantly with an increase in polishing time and or pressure. The protein content decreased gradually with an increase in time and pressure of milling but the effect was non significant. The cooked grain length increased with an increase in milling degree up to a stage, beyond which it declined. The increase in bursting of grains on cooking. A combination of 20 seconds polishing time with 2 lbs pressure or 20 seconds polishing time with 3 lbs pressure was found to be the best combination of obtaining the optimum quality as well as the quality of milled rice.(author)

  7. Influence of milling process on efavirenz solubility

    Directory of Open Access Journals (Sweden)

    Erizal Zaini

    2017-01-01

    Full Text Available Introduction: The aim of this study was to investigate the influence of the milling process on the solubility of efavirenz. Materials and Methods: Milling process was done using Nanomilling for 30, 60, and 180 min. Intact and milled efavirenz were characterized by powder X-ray diffraction, scanning electron microscopy (SEM, spectroscopy infrared (IR, differential scanning calorimetry (DSC, and solubility test. Results: The X-ray diffractogram showed a decline on peak intensity of milled efavirenz compared to intact efavirenz. The SEM graph depicted the change from crystalline to amorphous habit after milling process. The IR spectrum showed there was no difference between intact and milled efavirenz. Thermal analysis which performed by DSC showed a reduction on endothermic peak after milling process which related to decreasing of crystallinity. Solubility test of intact and milled efavirenz was conducted in distilled water free CO2with 0.25% sodium lauryl sulfate media and measured using high-performance liquid chromatography method with acetonitrile: distilled water (80:20 as mobile phases. The solubility was significantly increased (P < 0.05 after milling processes, which the intact efavirenz was 27.12 ± 2.05, while the milled efavirenz for 30, 60, and 180 min were 75.53 ± 1.59, 82.34 ± 1.23, and 104.75 ± 0.96 μg/mL, respectively. Conclusions: Based on the results, the solubility of efavirenz improved after milling process.

  8. Depreciation of bearing blocks of rollers of roller conveyers of rolling mills

    Science.gov (United States)

    Artiukh, Viktor; Belyaev, Michael; Ignatovich, Igor; Miloradova, Nadezda

    2017-10-01

    Essential increase in functional durability of a node of a roller of the roller conveyer of the rolling mill by the rational choice of parameters of the small-size shock-absorber (buffer adapter) is shown. At the same time dimensions of a node don’t change, costs of reconstruction are small. The possibility of management of loadings in a bearing node without change of technology parameters of the process which is carried out by the rolling mill is confirmed.

  9. Refinement of Crystalline Boron and the Superconducting Properties of MgB2 by Attrition Ball Milling

    International Nuclear Information System (INIS)

    Lee, J. H.; Shin, S. Y.; Park, H. W.; Jun, B. H.; Kim, C. J.

    2008-01-01

    We report refinement of crystalline boron by an attrition ball milling system and the superconducting properties of the MgB 2 pellets prepared from the refined boron. In this work, we have conducted the ball milling with only crystalline boron powder, in order to improve homogeneity and control the grain size of the MgB 2 that is formed from it. We observed that the crystalline responses in the ball-milled boron became broader and weaker when the ball-milling time was further increased. On the other hand, the B 2 O 3 peak became stronger in the powders, resulting in an increase in the amount of MgO within the MgB 2 volume. The main reason for this is a greater oxygen uptake. From the perspective of the superconducting properties, however, the sample prepared from boron that was ball milled for 5 hours showed an improvement of critical current density (J c ), even with increased MgO phase, under an external magnetic field at 5 and 20 K.

  10. Model Predictive Control for an Industrial SAG Mill

    DEFF Research Database (Denmark)

    Ohan, Valeriu; Steinke, Florian; Metzger, Michael

    2012-01-01

    identication. When applied to MIMO systems we call this controller a MIMO-ARX based MPC. We use an industrial Semi-Autogenous Grinding (SAG) mill to illustrate the performance of this controller. SAG mills are the primary units in a grinding chain and also the most power consuming units. Therefore, improved...... control of SAG mills has the potential to signicantly improve eciency and reduce the specic energy consumption for mineral processes. Grinding circuits involving SAG mills are multivariate processes. Commissioning of a control system based on a classical single-loop controllers with logic is time...

  11. Influence of octanoic acid on SmCo{sub 5} nanoflakes prepared by surfactant-assisted high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Liyun, E-mail: zheng@udel.ed [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); College of Electromechanical Engineering, Hebei University of Engineering, Handan, Hebei 056038 (China); Cui Baozhi; Akdogan, Nilay G.; Li Wanfeng; Hadjipanayis, George C. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)

    2010-08-20

    High-energy ball milling (HEBM) of magnetically hard SmCo{sub 5} was conducted in heptane with octanoic acid as the surfactant. The effects of octanoic acid on the morphology and magnetic properties of the powders were investigated by scanning electron microscopy, X-ray diffraction and vibrating sample magnetometry. The results show an interesting unexpected fact that the SmCo{sub 5} powders processed by octanoic acid-assisted HEBM were in form of nanoflakes with aspect-ratio of 10{sup 2}-10{sup 3} without the presence of nanoparticles. The thickness of nanoflakes decreases with increasing milling time. X-ray diffraction patterns did not show the sign of oxidation and the diffraction peaks of SmCo{sub 5} were getting broader with the increase of milling time. The nanoflakes were magnetically anisotropic and had a higher coercivity than the micro-particles prepared by HEBM without surfactant. The coercivity of SmCo{sub 5} increased initially with the milling time and then it decreased after reaching the maximum value of 15.2 kOe. High-resolution transmission electron microscopy image showed that the SmCo{sub 5} nanoflakes are nanocrystalline with an average crystallite size approximately 12 nm.

  12. Alloying and microstructural changes in platinum–titanium milled and annealed powders

    International Nuclear Information System (INIS)

    Maweja, Kasonde; Phasha, M.J.; Yamabe-Mitarai, Y.

    2012-01-01

    Graphical abstract: (a) SE-SEM micrographs of PtTi martensite formed in powder milled for short time annealed at 1500 °C and quenched in helium gas flow (b) BSE-SEM of structure formed after slow cooling. Highlights: ► A disordered metastable FCC Pt(Ti) solid solution was formed after longer milling period. ► HCP Ti crystals were first deformed and then the atoms were dissolved in strained FCC Pt lattices. ► Longer milling time suppressed the occurrence of martensitic transformation after annealing. ► Martensite phase was formed in products that went through a short milling time then annealed and quenched. ► The width of the martensite features formed was smaller at higher cooling rates. - Abstract: Equiatomic platinum–titanium powder mixtures were processed by high energy ball milling under argon atmosphere and sintered under vacuum. Evolution of the crystal structures and microstructures of the products formed were investigated by XRD and SEM techniques, respectively. The HCP crystals of Ti were first deformed and then a disordered metastable FCC Pt(Ti) solid solution was formed during milling due to semi-coherency of FCC lattices. A nanostructured Pt(Ti) product was formed after long milling time, which contained 44–47 at.% Ti and 53–56 at.% Pt. An ordered PtTi intermetallic was formed by annealing the metastable Pt(Ti) at temperature above 1300 °C. The crystal structure and microstructure of the TiPt phase depended on the milling time, annealing temperature and the cooling rate. The B19 PtTi plate martensite was formed after annealing at 1500 °C and quenching at a cooling rate of 23 °C/min to 200 °C/min for short time milled products. The width of martensite features was smaller at high cooling rate. In PtTi products milled for longer time, no martensitic transformation was observed on cooling the annealed samples. Small amounts of Pt 5 Ti 3 were formed in the powders milled for 16 h or more, followed by annealing at 1500 °C and furnace

  13. Nanograin formation in milled MoO3 powders

    International Nuclear Information System (INIS)

    Guerrero-Paz, J; Dorantes-Rosales, H; Aguilar-Martínez, J A; Garibay-Febles, V

    2013-01-01

    Powder of Molybdenum trioxide was milled for different times in horizontal ball mills. Such powder was characterized by TEM and XRD. Powder was rapidly de-agglomerated and fragmented up to attain nanoplates of two types, amorphous and crystalline. Finally, cold-welding of nanoplates occurred permitting some relaxation process to obtain a more stable energized structure consisting of equiaxial crystalline nanograins after 16 hours of milling.

  14. Swedish Pulp Mill Biorefineries. A vision of future possibilities

    Energy Technology Data Exchange (ETDEWEB)

    Berntsson, Thore (Chamers Univ. of Technology, Goeteborg (Sweden)); Axegaard, Peter; Backlund, Birgit; Samuelsson, Aasa; Berglin, Niklas; Lindgren, Karin (STFI-Packforsk, Stockholm (Sweden))

    2008-07-01

    Today, modern science could make it possible to develop techniques for refining almost the whole wood-matter, pulp mill side streams and bark compounds into platform chemicals, electricity, high quality fuels and structured feed-stock for chemicals and materials. The major challenge is to convert the state of basic scientific knowledge into industrial practise. Our definition of an integrated biorefinery is: 'Full utilization of the incoming biomass and other raw materials for simultaneous and economically optimized production of fibres, chemicals and energy'. Examples of products from a pulp mill biorefinery are: Chemicals and Materials (Phenols, adhesives, carbon fibres, activated carbon, binders, barriers, adhesives, antioxidants, surfactants, chelants, solvents, adhesives surfactants, descaling agents, specialty polymers, pharmaceuticals, nutraceuticals, cosmetics etc., Biofuels (pellets, lignin fuel, methanol, DME, ethanol etc), Electricity (BLGCC, condensing power etc.). The new or increased amounts of traditional products can be made from internal and/or external biomass. Three different levels can be identified: A high degree of energy saving in future mills, especially chemical pulp mills, will lead to large amounts of excess internal biomass which can be transferred to products mentioned above, Components in e.g. the black liquor, forest residues and bark can be upgraded to more valuable ones and the energy balance of the mill is kept through fuel import, wholly or partly depending on the level of mill energy efficiency. This imported fuel can be biomass or other types. External (imported) biomass (in some cases together with excess internal biomass) can be upgraded using synergy effects of docking this upgrading to a pulp mill. Electricity has been included as one of the possible biorefinery products. The electricity production in a mill can be increased in several ways which cannot be directly considered as biorefineries, e.g. recovery boiler

  15. Phase Transitions in Mechanically Milled Mn-Al-C Permanent Magnets

    Directory of Open Access Journals (Sweden)

    Michael J. Lucis

    2014-04-01

    Full Text Available Mn-Al powders were prepared by rapid solidification followed by high-energy mechanical milling. The rapid solidification resulted in single-phase ε. The milling was performed in both the ε phase and the τ phase, with the τ-phase formation accomplished through a heat treatment at 500 °C for 10 min. For the ε-milled samples, the conversion of the ε to the τ phase was accomplished after milling via the same heat treatment. Mechanical milling induced a significant increase in coercivity in both cases, reaching 4.5 kOe and 4.1 kOe, respectively, followed by a decrease upon further milling. The increase in coercivity was the result of grain refinement induced by the high-energy mechanical milling. Additionally, in both cases a loss in magnetization was observed. Milling in the ε phase showed a smaller decrease in the magnetization due to a higher content of the τ phase. The loss in magnetization was attributed to a stress-induced transition to the equilibrium phases, as no site disorder or oxidation was observed. Surfactant-assisted milling in oleic acid also improved coercivity, but in this case values reached >4 kOe and remained stable at least through 32 h of milling.

  16. Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Spencer M.; Yao, Tiankai [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Lu, Fengyuan [Department of Mechanical & Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803 (United States); Xin, Guoqing; Zhu, Weiguang [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States); Lian, Jie, E-mail: lianj@rpi.edu [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180 (United States)

    2017-03-15

    Abstract: High-energy ball milling was used to synthesize Th{sub 1-x}La{sub x}O{sub 2-0.5x} (x = 0.09, 0.23) solid solutions, as well as improve the sinterability of ThO{sub 2} powders. Dense La-doped ThO{sub 2} pellets with theoretical density above 94% were consolidated by spark plasma sintering at temperatures above 1400 °C for 20 min, and the densification behavior and the non-equilibrium effects on phase and structure were investigated. A lattice contraction of the SPS-densified pellets occurred with increasing ball milling duration, and a secondary phase with increased La-content was observed in La-doped pellets. A dependence on the La-content and sintering duration for the onset of localized phase segregation has been proposed. The effects of high-energy ball milling, La-content, and phase formation on the thermal diffusivity were also studied for La-doped ThO{sub 2} pellets by laser flash measurement. Increasing La-content and high energy ball milling time decreases thermal diffusivity; while the sintering peak temperature and holding time beyond 1600 °C dramatically altered the temperature dependence of the thermal diffusivity beyond 600 °C. - Highlights: • Lanthanum incorporation into ThO{sub 2} by high energy ball milling and rapid consolidation by spark plasma sintering. • Elucidation of phase behavior of the La-doped ThO{sub 2} and the contributions of La incorporation and SPS sintering conditions. • Investigation of the effects of La incorporation and high energy ball milling on the thermal behavior of La-doped ThO{sub 2}.

  17. Milling and dispersion of multi-walled carbon nanotubes in texanol

    Science.gov (United States)

    Darsono, Nono; Yoon, Dang-Hyok; Kim, Jaemyung

    2008-03-01

    Rheological results were used to determine the optimum type of dispersant and its concentration for six commercial dispersants for the dispersion of multi-walled carbon nanotube (MWCNT) agglomerates in texanol. An unsaturated polycarboxylic acid copolymer (BYK P-104) exhibited the optimum performance with the lowest MWCNT slurry viscosity in texanol. The cutting and dispersion efficiencies of MWCNTs with 20 wt.% of BYK P-104 dispersant were compared using conventional ball milling and high energy milling, whereby the latter was found to be more effective. High energy milling for 2 h produced a large portion of MWCNT agglomerates smaller than 150 nm, showing a drastic increase in slurry viscosity due to the dispersion into individual CNTs. On the other hand, 120 h ball milling was required to achieve the agglomerate size of 300 nm with less viscosity increase upon milling. Decrease in the degree of MWCNT crystallinity was observed by both milling, even though 2 h high energy milling showed slightly less damage than 120 h ball milling based on XRD and Raman spectroscopy results.

  18. Degree of Milling Effect on Cold Water Rice Quality

    Directory of Open Access Journals (Sweden)

    Ujjwol Subedi

    2018-05-01

    Full Text Available The aim of this study was to examine the effects of degree of milling on various rice parameters such as proximate composition, and cooking properties using mathematical model. The experiments were performed in the laboratory of Food Research Division, Nepal Agricultural Research Council. The three different medium type rice varieties of Nepal (Lumle-2, Chhomrong and Machhapuchre-3 were exposed to five different degrees of milling (0%, 6%, 8%, 10% and 12%. The degree of milling (DM level significantly (P≤0.05 affected the milling recovery; head rice yield, nutrient content as well as cooking properties of the rice. Increase in DM resulted in further reduction of protein content, fat content, minerals, milled rice and head rice yield after bran layer was further removed. A positive correlation between DM used in present model, amylose content, kernel elongation and gruel solid loss was observed, however, with an increase in DM; amylose content, kernel elongation and gruel solid loss were found to be increased. Adopting 6 to 8% DM for commercial milling of rice might help to prevent quantitative, qualitative and nutritional loss along with retention of good cooking characteristics.

  19. Structural and Mössbauer studies of nanocrystalline Mn{sup 4+}-doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} particles prepared by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Widatallah, H. M., E-mail: hishammw@squ.edu.om; Al-Mabsali, F. N.; Al-Hajri, F. S. [Sultan Qaboos University, Physics Department, College of Science (Oman); Khalifa, N. O. [University of Khartoum, Physics Department, Faculty of Science (Sudan); Gismelseed, A. M.; Al-Rawas, A. D.; Elzain, M.; Yousif, A. [Sultan Qaboos University, Physics Department, College of Science (Oman)

    2016-12-15

    The structure and magnetic properties of spinel-related Mn{sup 4+}-doped Li{sub 0.5}Fe{sub 2.5}O{sub 4} nanocrystalline particles of the composition Li{sub 0.5}Fe{sub 2.25}Mn{sub 0.1875}O{sub 4}, prepared by milling a pristine sample for different times, were investigated. The average crystallite and particle size, respectively, decreased form ∼40 nm to ∼10 nm and ∼2.5 μm to ∼10 nm with increasing milling time from 0 h to 70 h. Rietveld refinement of the XRD data of the non-milled sample show the Mn{sup 4+} dopant ions to substitute for Fe{sup 3+} at the octahedral B-sites of the spinel-related structure. The Mössbauer spectra of the milled ferrites indicate that more particles turn superparamagnetic with increasing milling time. The Mössbauer data collected at 78 K suggest that while in the non-milled sample the Mn{sup 4+} ions substitute for Fe{sup 3+} at the octahedral B-sites, this is reversed as milling proceeds with doped Mn{sup 4+} ions, balancing Fe{sup 3+} vacancies and possibly Li{sup +} ions progressively migrate to the tetrahedral A-sites. This is supported by the slight increase observed in the magnetization of the milled samples relative to that of the non-milled one. The magnetic data suggest that in addition to the increasing superparamagentic component of the milled particles, thermal spin reversal and/or spin canting effects are possible at the surface layers of the nanoparticles.

  20. The dispersion of fine chitosan particles by beads-milling

    Science.gov (United States)

    Rochima, Emma; Utami, Safira; Hamdani, Herman; Azhary, Sundoro Yoga; Praseptiangga, Danar; Joni, I. Made; Panatarani, Camellia

    2018-02-01

    This research aimed to produce fine chitosan particles from a crab shell waste by beads-milling method by two different concentration of PEG as dispersing agent (150 and 300 wt. %). The characterization was performed to obtain the size and size distribution, the characteristics of functional groups and the degree of deacetylation. The results showed that the chitosan fine particles was obtained with a milling time 120 minutes with the best concentration of PEG 400 150 wt. %. The average particle size of the as-prepared suspension is 584 nm after addition of acetic acid solution (1%, v/v). Beads milling process did not change the glucosamine and N-acetylglucosamine content on chitosan structure which is indicated by degree of deacetylation higher than 70%. It was concluded that beads milling process can be applied to prepare chitosan fineparticles by proper adjustment in the milling time, pH and dosage of dispersing agent.

  1. Milling uranium silicide powder for dispersion nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, E.; Silva, D.G.; Souza, J.A.B.; Durazzo, M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Riella, H.G. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2009-07-01

    Full text: Uranium silicide (U3Si2) is presently considered the best fuel qualified so far in terms of uranium loading and performance. Stability of the U3Si2 fuel with uranium density of 4.8 g/cm3 was confirmed by burnup stability tests performed during the Reduced Enrichment for Research and Test Reactors (RERTR) program. This fuel was chosen to compose the first core of the new Brazilian Multipurpose Research Reactor (RMB), planned to be constructed in the next years. This new reactor will consume bigger quantities of U3Si2 powder, when compared with the small consumption of the IEA-R1 research reactor of IPEN-CNEN/SP, the unique MTR type research reactor operating in the country. At the present time, the milling operation of U3Si2 ingots is made manually. In order to increase the powder production capacity, the manual milling must be replaced by an automated procedure. This paper describes a new milling machine and procedure developed to produce U3Si2 powder with higher efficiency. (author)

  2. Jaduguda uranium mill : rich experiences for future challenges

    International Nuclear Information System (INIS)

    Beri, K.K.

    1991-01-01

    India's only uranium milling plant at Jaduguda was commissioned in 1967-68 utilising low grade uranium ore. The flowsheet of the mill and controlling parameters were based on studies done on laboratory and pilot plant scale tests at the Bhabha Atomic Research Centre, Bombay. The mill has worked upto expectation except in few areas where modifications had to be done for smooth production. Apart from this improvements in operating practices have been done based on experience gained in operating the mill, incorporating the recent technological advances. In the recent past, the mill was expanded to increase the installed capacity by 40% and was commissioned in October 1987. The expanded mill has given the desired capacity and is working smoothly. The present paper deals with the experience gained in running the plant for the last 20 years and changes incorporated (author). 4 figs

  3. Does wastewater from olive mills induce toxicity and water repellency in soil?

    Science.gov (United States)

    Peikert, B.; Bandow, N.; Schaumann, G. E.

    2012-04-01

    Olive oil mill wastewater is the effluent generated by the olive oil extraction process. It is the main waste product of this industry mainly being produced in the Mediterranean Basin. Because proper treatment options are rare it is often disposed into the environment, e.g. fields or wadies. Due to its high concentration of fatty acids and phytotoxic phenolic compounds and its high chemical and biological oxygen demand, olive oil mill wastewater becomes a serious environmental problem. In this screening study we investigated long-term effects of olive oil mill wastewater application on soil properties in several locations in the West Bank and Israel. We determined wettability via water drop penetration time and the contact angle as well as general soil properties including pH, EC, carbon content, and we conducted thermogravimetrical analyses in order to characterize the impact of the waste water on the quality of soil organic matter. Our results show that application of olive oil mill wastewater has various effects. We determined contact angles between 110 and 120° and water drop penetration times up to 1367 s indicating significant reduction in wettability. Furthermore, soil carbon and nitrogen content and water extractable organic matter increased as well as electric conductivity, which could be pointed out as a fertilizing effect. In contrast soil pH was significantly reduced. Conducting thermal analyses we observed an increase in the labile and refractory carbon fraction. Probably first one is responsible for induced water repellency. As a consequence the reduced wettability negatively affects soil quality. It would therefore be promising to minimize the hydrophobizing impacts without losing fertilizing effects of the olive oil mill wastewater.

  4. One step conversion of wheat straw to sugars by simultaneous ball milling, mild acid, and fungus Penicillium simplicissimum treatment.

    Science.gov (United States)

    Yuan, Li; Chen, Zhenhua; Zhu, Yonghua; Liu, Xuanming; Liao, Hongdong; Chen, Ding

    2012-05-01

    Wheat straw is one of the major lignocellulosic plant residues in many countries including China. An attractive alternative is the utilization of wheat straw for bioethanol production. This article mainly studies a simple one-step wet milling with Penicillium simplicissimum and weak acid to hydrolysis of wheat straw. The optimal condition for hydrolysis was ball milling 48 h in citrate solvent (pH = 4) with P. simplicissimum H5 at the speed of 500 rpm and the yield of sugar increased with increased milling time. Corresponding structure transformations before and after milling analyzed by X-ray diffraction, transmission Fourier transform infrared spectroscopy, and environmental scanning electron microscopy clearly indicated that this combined treatment could be attributed to the crystalline and chemical structure changes of cellulose in wheat straw during ball milling. This combined treatment of ball milling, mild acid, and fungus hydrolysis enabled the conversion of the wheat straw. Compared with traditional method of ball milling, this work showed a more simple, novel, and environmentally friendly way in mechanochemical treatment of wheat straw.

  5. VOC Control in Kraft Mills; FINAL

    International Nuclear Information System (INIS)

    Zhu, J.Y.; Chai, X.-S.; Edwards, L.L.; Gu, Y.; Teja, A.S.; Kirkman, A.G.; Pfromm, P.H.; Rezac, M.E.

    2001-01-01

    The formation of volatile organic compounds (VOCs), such as methanol, in kraft mills has been an environmental concern. Methanol is soluble in water and can increase the biochemical oxygen demand. Furthermore, it can also be released into atmosphere at the process temperatures of kraft mill-streams. The Cluster Rule of the EPA now requires the control of the release of methanol in pulp and paper mills. This research program was conducted to develop a computer simulation tool for mills to predict VOC air emissions. To achieve the objective of the research program, much effort was made in the development of analytical techniques for the analysis of VOC and determination of vapor liquid partitioning coefficient of VOCs in kraft mill-streams using headspace gas chromatography. With the developed analytical tool, methanol formation in alkaline pulping was studied in laboratory to provide benchmark data of the amount of methanol formation in pulping in kraft mills and for the validation of VOC formation and vapor-liquid equilibrium submodels. Several millwide air and liquid samplings were conducted using the analytical tools developed to validate the simulation tool. The VOC predictive simulation model was developed based on the basic chemical engineering concepts, i.e., reaction kinetics, vapor liquid equilibrium, combined with computerized mass and energy balances. Four kraft mill case studies (a continuous digester, two brownstock washing lines, and a pre-evaporator system) are presented and compared with mill measurements. These case studies provide valuable, technical information for issues related to MACT I and MACT II compliance, such as condensate collection and Clean-Condensate-Alternatives (CCA)

  6. Hydrogen storage thermodynamics and kinetics of LaMg11Ni + x wt.% Ni (x = 100, 200) alloys synthesized by mechanical milling

    International Nuclear Information System (INIS)

    Zhang, Yanghuan; Jia, Zhichao; Central Iron and Steel Research Institute, Beijing; Yuan, Zeming; Qi, Yan; Zhao, Dongliang; Hou, Zhonghui

    2016-01-01

    LaMg 11 Ni + x wt.% Ni (x = 100, 200) composite hydrogen storage alloys with a nanocrystalline/amorphous structure were synthesized using ball milling technology. The effects of Ni content and milling time on hydrogen storage thermodynamics and dynamics of the alloys were investigated systematically. The hydrogen desorption properties were assessed using a Sieverts apparatus and differential scanning calorimetry. The thermodynamic parameters for the hydrogen absorption and desorption were calculated using the Van't Hoff equation. The hydrogen desorption activation energies of the hydrogenated alloys were also estimated by Arrhenius and Kissinger methods. Results indicate that the amount of Ni added has no effect on the thermodynamics of the alloys, but it significantly improves their absorption and desorption kinetics. Furthermore, the milling time has a great influence on the hydrogen storage properties. To be specific, the hydrogen absorption capacities reach the maximum values with the variation of milling time, and the hydrogen desorption activation energy obviously decreases with increasing milling time.

  7. Recycling of mill scale in sintering process

    Directory of Open Access Journals (Sweden)

    El-Hussiny N.A.

    2011-01-01

    Full Text Available This investigation deals with the effect of replacing some amount of Baharia high barite iron ore concentrate by mill scale waste which was characterized by high iron oxide content on the parameters of the sintering process., and investigation the effect of different amount of coke breeze added on sintering process parameters when using 5% mill scale waste with 95% iron ore concentrate. The results of this work show that, replacement of iron ore concentrate with mill scale increases the amount of ready made sinter, sinter strength and productivity of the sinter machine and productivity at blast furnace yard. Also, the increase of coke breeze leads to an increase the ready made sinter and productivity of the sintering machine at blast furnace yard. The productivity of the sintering machine after 5% decreased slightly due to the decrease of vertical velocity.

  8. The Influence of Milling on the Dissolution Performance of Simvastatin

    Directory of Open Access Journals (Sweden)

    Thomas Rades

    2010-12-01

    Full Text Available Particle size reduction is a simple means to enhance the dissolution rate of poorly water soluble BCS-class II and IV drugs. However, the major drawback of this process is the possible introduction of process induced disorder. Drugs with different molecular arrangements may exhibit altered properties such as solubility and dissolution rate and, therefore, process induced solid state modifications need to be monitored. The aim of this study was two-fold: firstly, to investigate the dissolution rates of milled and unmilled simvastatin; and secondly, to screen for the main milling factors, as well as factor interactions in a dry ball milling process using simvastatin as model drug, and to optimize the milling procedure with regard to the opposing responses particle size and process induced disorder by application of a central composite face centered design. Particle size was assessed by scanning electron microscopy (SEM and image analysis. Process induced disorder was determined by partial least squares (PLS regression modeling of respective X-ray powder diffractograms (XRPD and Raman spectra. Valid and significant quadratic models were built. The investigated milling factors were milling frequency, milling time and ball quantity at a set drug load, out of which milling frequency was found to be the most important factor for particle size as well as process induced disorder. Milling frequency and milling time exhibited an interaction effect on the responses. The optimum milling settings using the maximum number of milling balls (60 balls with 4 mm diameter was determined to be at a milling frequency of 21 Hz and a milling time of 36 min with a resulting primary particle size of 1.4 μm and a process induced disorder of 6.1% (assessed by Raman spectroscopy and 8.4% (assessed by XRPD, at a set optimization limit of < 2 μm for particle size and < 10% for process induced disorder. This optimum was tested experimentally and the process induced disorder

  9. Preparation of iron sulphides by high energy ball milling

    DEFF Research Database (Denmark)

    Lin, R.; Jiang, Jianzhong; Larsen, R.K.

    1998-01-01

    The reaction of a powder mixture consisting of 50 a.% Fe and 50 a.% S during high energy ball milling has been studied by x-ray diffraction and Mossbauer spectroscopy. After around 19 h of milling FeS2 and FeS havebeen formed. By further milling the FeS compound becomes dominating and only Fe......S with an average crystallite size of about 10 nm was observed after milling times longer than 67 h. Mossbauer spectra obtained with applied fields show that the particles are antiferromagnetic or have a strongly canted spin structure....

  10. An ambitwistor Yang-Mills Lagrangian

    International Nuclear Information System (INIS)

    Mason, L.J.; Skinner, D.

    2006-01-01

    We introduce a Chern-Simons Lagrangian for Yang-Mills theory as formulated on ambitwistor space via the Ward, Isenberg, Yasskin, Green, Witten construction. The Lagrangian requires the selection of a codimension-2 Cauchy-Riemann submanifold which is naturally picked out by the choice of space-time reality structure and we focus on the choice of Euclidean signature. The action is shown to give rise to a space-time action that is equivalent to the standard one, but has just cubic vertices. We identify the ambitwistor propagators and vertices and work out their corresponding expressions on space-time and momentum space. It is proposed that this formulation of Yang-Mills theory underlies the recursion relations of Britto, Cachazo, Feng and Witten and provides the generating principle for twistor diagrams for gauge theory

  11. Ball Milling Assisted Solvent and Catalyst Free Synthesis of Benzimidazoles and Their Derivatives.

    Science.gov (United States)

    El-Sayed, Taghreed H; Aboelnaga, Asmaa; Hagar, Mohamed

    2016-08-24

    Benzoic acid and o-phenylenediamine efficiently reacted under the green solvent-free Ball Milling method. Several reaction parameters were investigated such as rotation frequency; milling balls weight and milling time. The optimum reaction condition was milling with 56.6 g weight of balls at 20 Hz frequency for one hour milling time. The study was extended for synthesis of a series of benzimidazol-2-one or benzimidazol-2-thione using different aldehydes; carboxylic acids; urea; thiourea or ammonium thiocyanate with o-phenylenediamine. Moreover; the alkylation of benzimidazolone or benzimidazolthione using ethyl chloroacetate was also studied.

  12. Characterization of Al–Al{sub 4}C{sub 3} nanocomposites produced by mechanical milling

    Energy Technology Data Exchange (ETDEWEB)

    Santos-Beltrán, A., E-mail: asantos@utchsur.edu.mx [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Goytia-Reyes, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Morales-Rodriguez, H.; Gallegos-Orozco, V. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Santos-Beltrán, M. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico); Baldenebro-Lopez, F. [Universidad Tecnológica de Chihuahua Sur, Carr. Chihuahua a Aldama km. 3 S/N, Col. Colinas del León, CP. 31313 Chihuahua, Chih. (Mexico); Martínez-Sánchez, R. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109 Chihuahua, Chih. (Mexico)

    2015-08-15

    In this work, a mixture of Al–C–Al{sub 4}C{sub 3} nanopowder previously synthesized by mechanical milling and subsequent thermal treatment was used to reinforce the Al matrix. The nanocomposites were fabricated via high-energy ball milling and subsequent sintering process for different periods of time at 550 °C. Hardness and compression tests were performed to evaluate the mechanical properties of the nanocomposites in the as-milled and sintered conditions. According to the results the reinforcement located in the grain boundaries is responsible for the brittle behavior observed in the nanocomposites during the compression test. The combined effect of sintering and precipitation mechanisms produced an evident increase of the strength of the Al matrix at a relatively short sintering time. By using the Rietveld method the crystallite size and microstrain measurements were determined and correlated with the microhardness values. For the proper characterization of the nanoparticles present in the Al matrix, atomic force microscopy and high resolution electron microscopy were used. - Highlights: • Nanostructured Al{sub 4}C{sub 3} reinforcement was fabricated via mechanical milling and heat treatment. • We found a significant increase of the mechanical properties at short sintering times. • The formation of Al{sub 4}C{sub 3} with during sintering time restricted the excessive growth of the crystallite. • Al{sub 4}C{sub 3} located in the grain boundaries causes brittle fracture observed in compression tests. • There is a correlation between, crystallite size and microstrain values with microhardness.

  13. Einstein-Yang-Mills-Lorentz black holes

    Energy Technology Data Exchange (ETDEWEB)

    Cembranos, Jose A.R.; Gigante Valcarcel, Jorge [Universidad Complutense de Madrid, Departamento de Fisica Teorica I, Madrid (Spain)

    2017-12-15

    Different black hole solutions of the coupled Einstein-Yang-Mills equations have been well known for a long time. They have attracted much attention from mathematicians and physicists since their discovery. In this work, we analyze black holes associated with the gauge Lorentz group. In particular, we study solutions which identify the gauge connection with the spin connection. This ansatz allows one to find exact solutions to the complete system of equations. By using this procedure, we show the equivalence between the Yang-Mills-Lorentz model in curved space-time and a particular set of extended gravitational theories. (orig.)

  14. Reduced graphene oxide synthesis by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, O. [Department of Physics, M.U.C Women' s College, Burdwan 713104 (India); Mitra, S. [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India); Pal, M. [CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Datta, A. [University School of Basic and Applied Science (USBAS), Guru Gobind Singh Indraprastha University, New Delhi 110075 (India); Dhara, S. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chakravorty, D., E-mail: mlsdc@iacs.res.in [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India)

    2015-07-01

    Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. The process of ball milling introduces defects and removes oxygen functional groups, thereby creating the possibility of fine tuning the band gap of all intermediate stages of the structural evolution. A limit of the backbone sp{sup 2} network structure has been found which should be able to accommodate defects, before amorphization sets in. The amorphization of graphene oxide is achieved rather quickly in comparison to that of graphite. From thermogravimetric and differential scanning calorimetric analysis along with Fourier transform infrared (FTIR) and Raman spectroscopic studies, it is found that the number of oxygen-containing groups decreases at a faster rate than that of aromatic double bonds with increasing ball milling time with a maximum limit of 3 h. Several characterization techniques (FTIR, Raman, UV–Visible and X-ray photoelectron spectroscopy) have confirmed that the material synthesized is, indeed, reduced graphene oxide. - Highlights: • Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. • Fine tuning the band gap by introducing defects and removing oxygen functional groups. • Introduction of excess defects leads to amorphization. • Photoluminescence has been observed in the UV-blue region.

  15. Modeling the milling tool wear by using an evolutionary SVM-based model from milling runs experimental data

    Science.gov (United States)

    Nieto, Paulino José García; García-Gonzalo, Esperanza; Vilán, José Antonio Vilán; Robleda, Abraham Segade

    2015-12-01

    The main aim of this research work is to build a new practical hybrid regression model to predict the milling tool wear in a regular cut as well as entry cut and exit cut of a milling tool. The model was based on Particle Swarm Optimization (PSO) in combination with support vector machines (SVMs). This optimization mechanism involved kernel parameter setting in the SVM training procedure, which significantly influences the regression accuracy. Bearing this in mind, a PSO-SVM-based model, which is based on the statistical learning theory, was successfully used here to predict the milling tool flank wear (output variable) as a function of the following input variables: the time duration of experiment, depth of cut, feed, type of material, etc. To accomplish the objective of this study, the experimental dataset represents experiments from runs on a milling machine under various operating conditions. In this way, data sampled by three different types of sensors (acoustic emission sensor, vibration sensor and current sensor) were acquired at several positions. A second aim is to determine the factors with the greatest bearing on the milling tool flank wear with a view to proposing milling machine's improvements. Firstly, this hybrid PSO-SVM-based regression model captures the main perception of statistical learning theory in order to obtain a good prediction of the dependence among the flank wear (output variable) and input variables (time, depth of cut, feed, etc.). Indeed, regression with optimal hyperparameters was performed and a determination coefficient of 0.95 was obtained. The agreement of this model with experimental data confirmed its good performance. Secondly, the main advantages of this PSO-SVM-based model are its capacity to produce a simple, easy-to-interpret model, its ability to estimate the contributions of the input variables, and its computational efficiency. Finally, the main conclusions of this study are exposed.

  16. Fabrication of Ti-Ni-Cu shape memory alloy powders by ball milling method

    International Nuclear Information System (INIS)

    Kang, S.; Nam, T.

    2001-01-01

    Ti-Ni and Ti-Ni-Cu shape memory alloy powders have been fabricated by ball milling method, and then alloying behavior and transformation behavior were investigated by means of optical microscopy, electron microscopy, X-ray diffraction and differential scanning calorimetry. As milled Ti-Ni powders fabricated with milling time less than 20 hrs was a mixture of pure elemental Ti and Ni, and therefore it was unable to obtain alloy powders because the combustion reaction between Ti and Ni occurred during heat treatment. Since those fabricated with milling time more than 20 hrs was a mixture of Ti-rich and Ni-rich Ti-Ni solid solution, however, it was possible to obtain alloy powders without the combustion reaction during heat treatment. Clear exothermic and endothermic peaks appeared in the cooling and heating curves, respectively in DSC curves of 20 hrs and 30 hrs milled Ti-Ni powders. On the other hand, in DSC curves of 1 hr, 10 hrs, 50 hrs and 100 hrs, the thermal peaks were almost discernible. The most optimum ball milling time for fabricating Ti-Ni alloy powders was 30 hrs. Ti-40Ni-10Cu(at%) alloy powders were fabricated successfully by ball milling conditions with rotating speed of 100 rpm and milling time of 30 hrs. (author)

  17. Microstructural Evolution, Thermodynamics, and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

    Directory of Open Access Journals (Sweden)

    Yong Luo

    2016-10-01

    Full Text Available The microstructural evolution, thermodynamics, and kinetics of Mo (21 wt % Tm2O3 powder mixtures during ball milling were investigated using X-ray diffraction and transmission electron microscopy. Ball milling induced Tm2O3 to be decomposed and then dissolved into Mo crystal. After 96 h of ball milling, Tm2O3 was dissolved completely and the supersaturated nanocrystalline solid solution of Mo (Tm, O was obtained. The Mo lattice parameter increased with increasing ball-milling time, opposite for the Mo grain size. The size and lattice parameter of Mo grains was about 8 nm and 0.31564 nm after 96 h of ball milling, respectively. Ball milling induced the elements of Mo, Tm, and O to be distributed uniformly in the ball-milled particles. Based on the semi-experimental theory of Miedema, a thermodynamic model was developed to calculate the driving force of phase evolution. There was no chemical driving force to form a crystal solid solution of Tm atoms in Mo crystal or an amorphous phase because the Gibbs free energy for both processes was higher than zero. For Mo (21 wt % Tm2O3, it was mechanical work, not the negative heat of mixing, which provided the driving force to form a supersaturated nanocrystalline Mo (Tm, O solid solution.

  18. USE OF HIGH SPEED STEEL WORK ROLLS (HSS ON APERAM STECKEL MILL

    Directory of Open Access Journals (Sweden)

    Arísio de Abreu Barbosa

    2013-12-01

    Full Text Available This paper outlines the main actions taken to reinforce the decision to use HSS work rolls on the Aperam Steckel Mill. These are: work roll cooling improvements, systematically analyzing Eddy Current and Ultrasonic non destructive tests, mechanical adjustment of work roll crown and critically examining the rolling process. These actions applied together have contributed to the success of HSS rolls state of the art application, and provide the Steckel Mill with a much improved performance. Significant results have been achieved, such as: increasing of work roll change intervals, increasing of the available production time, a yield gain, a product quality improvement, less working hours needed for the roll grinding operation, etc

  19. Improvements in nanoscale zero-valent iron production by milling through the addition of alumina

    Energy Technology Data Exchange (ETDEWEB)

    Ribas, D. [Fundació CTM Centre Tecnològic de Manresa (Spain); Cernik, M. [Technical University of Liberec, Institute for Nanomaterials, Advanced Technologies and Innovation (Czech Republic); Martí, V.; Benito, J. A., E-mail: josep.a.benito@upc.edu [Fundació CTM Centre Tecnològic de Manresa (Spain)

    2016-07-15

    A new milling procedure for a cost-effective production of nanoscale zero-valent iron for environmental remediation is presented. Conventional ball milling of iron in an organic solvent as Mono Ethylene Glycol produces flattened iron particles that are unlikely to break even after very long milling times. With the aim of breaking down these iron flakes, in this new procedure, further milling is carried out by adding an amount of fine alumina powder to the previously milled solution. As the amount of added alumina increases from 9 to 54 g l{sup −1}, a progressive decrease of the presence of flakes is observed. In the latter case, the appearance of the particles formed by fragments of former flakes is rather homogeneous, with most of the final nanoparticles having an equivalent diameter well below 1 µm and with an average particle size in solution of around 400 nm. An additional increase of alumina content results in a highly viscous solution showing worse particle size distribution. Milled particles, in the case of alumina concentrations of 54 g l{sup −1}, have a fairly large specific surface area and high Fe(0) content. These new particles show a very good Cr(VI) removal efficiency compared with other commercial products available. This good reactivity is related to the absence of an oxide layer, the large amount of superficial irregularities generated by the repetitive fracture process during milling and the presence of a fine nanostructure within the iron nanoparticles.

  20. Uranium-mill appraisal program

    International Nuclear Information System (INIS)

    Everett, R.J.; Cain, C.L.

    1982-08-01

    The results of special team appraisals at NRC-licensed uranium mills in the period May to November 1981 are reported. Since the Three Mile Island accident, NRC management has instituted a program of special team appraisals of radiation protection programs at certain NRC-licensed facilities. These appraisals were designed to identify weaknesses and strengths in NRC-licensed programs, including those areas not covered by explicit regulatory requirements. The regulatory requirements related to occupational radiation protection and environmental monitoring at uranium mills have been extensively upgraded in the past few years. In addition, there was some NRC staff concern with respect to the effectiveness of NRC licensing and inspection programs. In response to this concern and to changes in mill requirements, the NRC staff recommended that team appraisals be conducted at mills to determine the adequacy of mill programs, the effectiveness of the new requirements, and mill management implementation of programs and requirements. This report describes the appraisal scope and methodology as well as summary findings and conclusions. Significant weaknesses identified during the mill appraisals are discussed as well as recommendations for improvements in uranium mill programs and mill licensing and inspection

  1. Residual stresses analysis in ball end milling of nickel-based superalloy Inconel 718

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junteng; Zhang, Dinghua; Wu, Baohai; Luo, Ming [Key Laboratory of Contemporary Design and Integrated Manufacturing Technology, Northwestern Polytechnical University (China)

    2017-11-15

    Inconel 718 is widely used in the aviation, space, automotive and biomedical industries because of its outstanding properties. Near-surface residual stresses that are induced by ball end milling in Inconel 718 can be crucial for the performance and service time of the machined parts. In this paper, the influences of cutting conditions, including the use of cutting parameters, cutting fluid and spindle angles, on the residual stresses in the ball end milling process of Inconel 718 alloy were investigated experimentally. X-ray diffraction measurements reveal that residual stress distributions are highly influenced by cutting parameters, especially the depth of cut and cutting speed. The milling operation with cooling induces more compressive stresses trend and the magnitude of the residual stresses increases in the tensile direction with the increase of spindle angles. These cutting induced effects were further discussed with respect to thermal- mechanical coupling theory and some observations made by optical microscopy. From this investigation, it is suggested that the machining process parameters are not the smaller the better for the control of residual stresses in the ball end milling process of Inconel 718. (author)

  2. Raman spectroscopy fingerprint of stainless steel-MWCNTs nanocomposite processed by ball-milling

    Directory of Open Access Journals (Sweden)

    Marcos Allan Leite dos Reis

    2018-01-01

    Full Text Available Stainless steel 304L alloy powder and multiwalled carbon nanotubes were mixed by ball-milling under ambient atmosphere and in a broad range of milling times, which spans from 0 to 120 min. Here, we provided spectroscopic signatures for several distinct composites produced, to show that the Raman spectra present interesting splittings of the D-band feature into two main sub-bands, D-left and D-right, together with several other secondary features. The G-band feature also presents multiple splittings that are related to the outer and inner diameter distributions intrinsic to the multiwalled carbon nanotube samples. A discussion about the second order 2D-band (also known as G′-band is also provided. The results reveal that the multiple spectral features observed in the D-band are related to an increased chemical functionalization. A lower content of amorphous carbon at 60 and 90 min of milling time is verified and the G-band frequencies associated to the tubes in the outer diameters distribution is upshifted, which suggests that doping induced by strain is taking place in the milled samples. The results indicate that Raman spectroscopy can be a powerful tool for a fast and non-destructive characterization of carbon nanocomposites used in powder metallurgy manufacturing processes.

  3. Raman spectroscopy fingerprint of stainless steel-MWCNTs nanocomposite processed by ball-milling

    Science.gov (United States)

    dos Reis, Marcos Allan Leite; Barbosa Neto, Newton Martins; de Sousa, Mário Edson Santos; Araujo, Paulo T.; Simões, Sónia; Vieira, Manuel F.; Viana, Filomena; Loayza, Cristhian R. L.; Borges, Diego J. A.; Cardoso, Danyella C. S.; Assunção, Paulo D. C.; Braga, Eduardo M.

    2018-01-01

    Stainless steel 304L alloy powder and multiwalled carbon nanotubes were mixed by ball-milling under ambient atmosphere and in a broad range of milling times, which spans from 0 to 120 min. Here, we provided spectroscopic signatures for several distinct composites produced, to show that the Raman spectra present interesting splittings of the D-band feature into two main sub-bands, D-left and D-right, together with several other secondary features. The G-band feature also presents multiple splittings that are related to the outer and inner diameter distributions intrinsic to the multiwalled carbon nanotube samples. A discussion about the second order 2D-band (also known as G'-band) is also provided. The results reveal that the multiple spectral features observed in the D-band are related to an increased chemical functionalization. A lower content of amorphous carbon at 60 and 90 min of milling time is verified and the G-band frequencies associated to the tubes in the outer diameters distribution is upshifted, which suggests that doping induced by strain is taking place in the milled samples. The results indicate that Raman spectroscopy can be a powerful tool for a fast and non-destructive characterization of carbon nanocomposites used in powder metallurgy manufacturing processes.

  4. Effects of Milling Atmosphere and Increasing Sintering Temperature on the Magnetic Properties of Nanocrystalline Ni0.36Zn0.64Fe2O4

    Directory of Open Access Journals (Sweden)

    Abdollah Hajalilou

    2015-01-01

    Full Text Available Nanocrystalline Ni0.36Zn0.64Fe2O4 was synthesized by milling a powder mixture of Zn, NiO, and Fe2O3 in a high-energy ball mill for 30 h under three different atmospheres of air, argon, and oxygen. After sintering the 30 h milled samples at 500°C, the XRD patterns suggested the formation of a single phase of Ni-Zn ferrite. The XRD results indicated the average crystallite sizes to be 15, 14, and 16 nm, respectively, for the 30 h milled samples in air, argon, and oxygen atmospheres sintered at 500°C. From the FeSEM micrographs, the average grain sizes of the mentioned samples were 83, 75, and 105 nm, respectively, which grew to 284, 243, and 302 nm after sintering to 900°C. A density of all the samples increased while a porosity decreased by elevating sintering temperature. The parallel evolution of changes in magnetic properties, due to microstructural variations with changes in the milling atmosphere and sintering temperature in the rage of 500–900°C with 100°C increments, is also studied in this work.

  5. Improved oral bioavailability of probucol by dry media-milling.

    Science.gov (United States)

    Li, Jia; Yang, Yan; Zhao, Meihui; Xu, Hui; Ma, Junyuan; Wang, Shaoning

    2017-09-01

    The polymer/probucol co-milled mixtures were prepared to improve drug dissolution rate and oral bioavailability. Probucol, a BCS II drug, was co-milled together with Copovidone (Kollidon VA64, VA64), Soluplus, or MCC using the dry media-milling process with planetary ball-milling equipment. The properties of the milled mixtures including morphology, crystal form, vitro drug dissolution and in vivo oral bioavailability in rats were evaluated. Probucol existed as an amorphous in the matrix of the co-milled mixtures containing VA64, which helped to enhance drug dissolution. The ternary mixture composed of VA64, RH40, and probucol showed increased dissolution rates in both sink and non-sink conditions. It also had a higher oral bioavailability compared to the reference formulation. Dry-media milling of binary or ternary mixtures composed of drug, polymer and surfactant possibly have wide applications to improve dissolution rate and oral bioavailability of water-insoluble drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Towards the effective tool wear control in micro-EDM milling

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Valentincic, J.; Hansen, Hans Nørgaard

    2010-01-01

    The electrode wear in micro-electrical discharge milling (micro-EDM milling) is one of the main problems to be solved in order to improve machining accuracy. This paper presents an investigation on wear and material removal in micro-EDM milling for selected process parameter combinations typical...... of the accuracy of volume measurements on the electrode wear per discharge and on the material removal per discharge are discussed, and the issues limiting the applicability of real time wear sensing in micro-EDM milling are presented....

  7. Environmental activities in uranium mining and milling. A Joint NEA/IAEA report

    International Nuclear Information System (INIS)

    1999-01-01

    This report on 'Environmental Activities in Uranium Mining and Milling' presents an overview of environmental activities related to uranium production. The profile of activities and concerns are based on survey responses from 29 countries and a review of relevant activities of the International Atomic Energy Agency and the OECD Nuclear Energy Agency. It also provides an overview of the reported interests of specialists working in the field, including environmental impact assessment, emissions to air and water, work environment, radiation safety, waste handling and disposal, mine and mill decommissioning and site restoration, and the regulation of these activities. The report reflects the increasing awareness in all countries of the need for environmental protection. For several years large programmes have been underway in several countries to clean up wastes from closed mines and mills. Many of these sites, particularly the older ones, were brought into production, operated and closed when little was known about environmental effects. At the time, little concern was given to the resulting environmental impacts. Currently, planning for and conducting uranium mine closure and mill decommissioning, together with site clean-up and restoration, are of almost universal concern. Mine closure and mill decommissioning activities have been or are being conducted in most of the countries with a history of uranium production. Information about several mine closures and mill decommissioning projects is included in this report

  8. Feed supplemented with byproducts from olive oil mill wastewater processing increases antioxidant capacity in broiler chickens.

    Science.gov (United States)

    Gerasopoulos, Konstantinos; Stagos, Dimitrios; Kokkas, Stylianos; Petrotos, Konstantinos; Kantas, Dimitrios; Goulas, Panagiotis; Kouretas, Dimitrios

    2015-08-01

    In the present study, a ceramic membrane microfiltration method was used for the separation of two liquid products, the downstream permeate and the upstream retentate, from olive mill wastewater (OMWW). These liquid products were examined for their antioxidant activity by incorporating them into broilers' feed. Twenty four broilers 13 d old were divided into two feeding groups receiving supplementation with OMWW retentate or permeate for 37 d. Blood was drawn at 17, 27 and 37 d, while tissues (muscle, heart, liver) were collected at 37 d. The antioxidant effects were assessed by measuring oxidative stress biomarkers in blood and tissues. The results showed that broilers given feed supplemented with OMWW retentate or permeate had significantly lower protein oxidation and lipid peroxidation levels and higher total antioxidant capacity in plasma and tissues compared to control group. In both OMWW groups, catalase activity in erythrocytes and tissues was significantly increased compared to control group. OMWW retentate administration increased significantly GSH in erythrocytes in broilers with low GSH, although both OMWW products significantly reduced GSH in broilers with high GSH. Thus, it has been demonstrated for the first time that supplementation with OMWW processing residues could be used for enhancing broilers' redox status. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. On the bistable zone of milling processes.

    Science.gov (United States)

    Dombovari, Zoltan; Stepan, Gabor

    2015-09-28

    A modal-based model of milling machine tools subjected to time-periodic nonlinear cutting forces is introduced. The model describes the phenomenon of bistability for certain cutting parameters. In engineering, these parameter domains are referred to as unsafe zones, where steady-state milling may switch to chatter for certain perturbations. In mathematical terms, these are the parameter domains where the periodic solution of the corresponding nonlinear, time-periodic delay differential equation is linearly stable, but its domain of attraction is limited due to the existence of an unstable quasi-periodic solution emerging from a secondary Hopf bifurcation. A semi-numerical method is presented to identify the borders of these bistable zones by tracking the motion of the milling tool edges as they might leave the surface of the workpiece during the cutting operation. This requires the tracking of unstable quasi-periodic solutions and the checking of their grazing to a time-periodic switching surface in the infinite-dimensional phase space. As the parameters of the linear structural behaviour of the tool/machine tool system can be obtained by means of standard modal testing, the developed numerical algorithm provides efficient support for the design of milling processes with quick estimates of those parameter domains where chatter can still appear in spite of setting the parameters into linearly stable domains. © 2015 The Authors.

  10. Tungsten-nanodiamond composite powders produced by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, D., E-mail: daniela.nunes@ist.utl.pt [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Livramento, V. [Associacao Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Mardolcar, U.V. [Departamento de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Centro de Ciencias Moleculares e Materiais, Faculdade de Ciencias da Universidade de Lisboa, Campo Grande, 1749-016 Lisboa (Portugal); Correia, J.B. [LNEG, Estrada do Paco do Lumiar, 1649-038 Lisboa (Portugal); Carvalho, P.A. [ICEMS, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Departamento de Bioengenharia, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2012-07-15

    The major challenge in producing tungsten-nanodiamond composites by ball milling lies in successfully dispersing carbon nanoparticles in the metallic matrix while keeping carbide formation at a minimum. Processing windows for carbide minimization have been established through systematic variation of the nanodiamond fraction, milling energy and milling time. Materials characterization has been carried out by X-ray diffraction, scanning and transmission electron microscopy and microhardness testing. Nanostructured matrices with homogeneously dispersed particles that preserved the diamond structure have been produced. Differential thermal analysis has been used to evaluate the composites thermal stability.

  11. Development of an electromechanical principle for wet and dry milling

    Science.gov (United States)

    Halbedel, Bernd; Kazak, Oleg

    2018-05-01

    The paper presents a novel electromechanical principle for wet and dry milling of different materials, in which the milling beads are moved under a time- and local-variable magnetic field. A possibility to optimize the milling process in such a milling machine by simulation of the vector gradient distribution of the electromagnetic field in the process room is presented. The mathematical model and simulation methods based on standard software packages are worked out. The results of numerical simulations and experimental measurements of the electromagnetic field in the working chamber of a developed and manufactured laboratory plant correlate well with each other. Using the obtained operating parameters, dry milling experiments with crushed cement clinker and wet milling experiments of organic agents in the laboratory plant are performed and the results are discussed here.

  12. Determination of the Tapping Part Diameter of the Thread Mill

    Directory of Open Access Journals (Sweden)

    A. E. Dreval'

    2015-01-01

    Full Text Available Currently, there is a tendency to increase the proportion of thread milling operations, among other ways of tapping, which is associated with increasing number of CNC machines, flexibility and versatility of the process.Developments presently existing in the RF and used in the thread mills deal, mainly, with the thread milling cutter designs, to process internal and external thread with straight flutes made from high-speed steel.The paper presents a technique to calculate and select the initial design parameters, i.e. the external diameter of the tapping part of thread milling cutter, which is chosen as a basic computational design. The analysis of directories of tool companies containing foreign de-signs of solid thread end-milling cutters has shown that most of them rep-resent the thread cutter designs made of solid carbide. There are solid and interlocking side milling cutters, which use a tapping part both as a single-disk and as a multi-disk one; chip flutes are made to be both as direct and as screw; solid designs of cutters are made from carbide with a diameter of up to 20 ... 25 mm; thread cutters can be left- and right-hand cutting; Designs of the combined thread mills are proposed; internal channels are used for coolant supply.It is shown that the purpose of the external diameter of the tapping part of the thread mill should take into account the effect of the thread mill diameter on the milling process performance, precision of thread profile received, taper thread, tool strength, and the volume of flutes.The analysis has shown that when choosing the external diameter of the thread mill it worth taking its maximum diameter to improve the char-acteristics of the process under the restrictions imposed on the accuracy of the formed thread.

  13. Magnetic and structural properties of Fe{sub 65}Co{sub 35} alloys obtained by melting, high-energy milling and heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Trifu, A.V.; Dorolti, E. [Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca (Romania); Takacs, A.F., E-mail: albert.takacs@phys.ubbcluj.ro [Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca (Romania); Chicinaş, I. [Materials Sciences and Engineering Department, Technical University of Cluj-Napoca, 103-105 Muncii Avenue, 400641 Cluj-Napoca (Romania); Isnard, O. [Institut Néel, CNRS, Université Joseph Fourier, BP 166X, 38042 Grenoble Cédex 9 (France); Pop, V. [Faculty of Physics, Babes-Bolyai University, 400084 Cluj-Napoca (Romania)

    2013-11-20

    The influence of milling and annealing conditions on the structural and magnetic behaviour of mechanically milled Fe{sub 65}Co{sub 35} alloys has been studied. By differential scanning calorimetry measurements we determined the internal stress relaxation temperature, recrystallisation temperature and structural order/disorder transition temperature of bulk and mechanical milled Fe{sub 65}Co{sub 35}. The width of the X-ray diffraction peaks was found to increase with the milling time. Two types of annealing were performed: a conventional heat treatment at 500, 550 and 600 °C for 2 h and a rapid annealing for a maximum of 2 min at 700, 750 or 800 °C followed by quenching. Crystallite size increases with increasing heat treatment temperature and time, as both are parameters that influence the magnetic properties of the sample. Magnetic permeability variations result from internal stress evolution, changes in crystallite size, supposing that the crystallite size of the annealed samples is at the border between viability of the Herzer model and the classical behaviour of the permeability vs. crystallite size.

  14. Integration of micro milling highspeed spindle on a microEDM-milling machine set-up

    DEFF Research Database (Denmark)

    De Grave, Arnaud; Hansen, Hans Nørgaard; Andolfatto, Loic

    2009-01-01

    In order to cope with repositioning errors and to combine the fast removal rate of micro milling with the precision and small feature size achievable with micro EDM milling, a hybrid micro-milling and micro-EDM milling centre was built and tested. The aim was to build an affordable set-up, easy...... by micro milling. Examples of test parts are shown and used as an experimental validation....

  15. Uranium Mill Tailings Management

    International Nuclear Information System (INIS)

    Nelson, J.D.

    1982-01-01

    This book presents the papers given at the Fifth Symposium on Uranium Mill Tailings Management. Advances made with regard to uranium mill tailings management, environmental effects, regulations, and reclamation are reviewed. Topics considered include tailings management and design (e.g., the Uranium Mill Tailings Remedial Action Project, environmental standards for uranium mill tailings disposal), surface stabilization (e.g., the long-term stability of tailings, long-term rock durability), radiological aspects (e.g. the radioactive composition of airborne particulates), contaminant migration (e.g., chemical transport beneath a uranium mill tailings pile, the interaction of acidic leachate with soils), radon control and covers (e.g., radon emanation characteristics, designing surface covers for inactive uranium mill tailings), and seepage and liners (e.g., hydrologic observations, liner requirements)

  16. Optimisation of milling parameters using neural network

    Directory of Open Access Journals (Sweden)

    Lipski Jerzy

    2017-01-01

    Full Text Available The purpose of this study was to design and test an intelligent computer software developed with the purpose of increasing average productivity of milling not compromising the design features of the final product. The developed system generates optimal milling parameters based on the extent of tool wear. The introduced optimisation algorithm employs a multilayer model of a milling process developed in the artificial neural network. The input parameters for model training are the following: cutting speed vc, feed per tooth fz and the degree of tool wear measured by means of localised flank wear (VB3. The output parameter is the surface roughness of a machined surface Ra. Since the model in the neural network exhibits good approximation of functional relationships, it was applied to determine optimal milling parameters in changeable tool wear conditions (VB3 and stabilisation of surface roughness parameter Ra. Our solution enables constant control over surface roughness parameters and productivity of milling process after each assessment of tool condition. The recommended parameters, i.e. those which applied in milling ensure desired surface roughness and maximal productivity, are selected from all the parameters generated by the model. The developed software may constitute an expert system supporting a milling machine operator. In addition, the application may be installed on a mobile device (smartphone, connected to a tool wear diagnostics instrument and the machine tool controller in order to supply updated optimal parameters of milling. The presented solution facilitates tool life optimisation and decreasing tool change costs, particularly during prolonged operation.

  17. Application of RVA and Time-Lapse Photography to Explore Effects of Extent of Chlorination, Milling Extraction Rate, and Particle-Size Reduction of Flour on Cake-Baking Functionality

    Science.gov (United States)

    Three factors (extent of chlorination, milling extraction rate and particle-size reduction) in the cake-bakeing functionality of Croplan 594W flour were explored by Rapid Visco-Analyzer (RVA) and time-lapse photography. The extent of chlorination and milling extraction rate showed dramatic effects,...

  18. Ball-milling effect on Indonesian natural bentonite for manganese removal from acid mine drainage

    Directory of Open Access Journals (Sweden)

    Prastistho Widyawanto

    2018-01-01

    Full Text Available The influences of mechanical milling on Indonesian Natural Bentonite (INB characteristics and manganese (Mn removal from acid mine drainage (AMD were investigated. The INB characteristics were observed by scanning electron microscope (SEM, X-ray diffraction (XRD, nitrogen adsorption-desorption for specific surface area (SSA and microporosity measurement, cation exchange capacity (CEC and particle size distribution (PSD analyzer. Four minutes milling with frequency 20 Hz on INB caused morphological change which showed more crumbled and destructed particle, lost the (001 peak but still retained the (100 peak that indicated delamination of montmorillonite mineral without breaking the tetrahedral-octahedral-tetrahedral (T-O-T structure, rose the CEC from 28.49 meq/100g to 35.51 meq/100g, increase in the SSA from 60.63 m2/g to 104.88 m2/g, significant increase in microporosity which described in the t plots and decrease in the mean particle size distribution peak from 49.28 μm to 38.84 μm. The effect of contact time and effect of adsorbent dosage on Mn sorption was studied. Both unmilled and milled samples reached equilibrium at 24 hours and the pH rose from 4 to 7 in first 30 minutes. The Mn removal percentage increased significantly after milling. Using Langmuir isotherm, the maximum adsorbed metals (qmax also increased from 0.570 to 4.219 mg/g.

  19. Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

    Energy Technology Data Exchange (ETDEWEB)

    Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

    1980-03-01

    High surface soil concentrations of /sup 226/Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer.

  20. Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

    International Nuclear Information System (INIS)

    Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

    1980-03-01

    High surface soil concentrations of 226 Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer

  1. Fabrication of CNT Dispersion Fluid by Wet-Jet Milling Method for Coating on Bipolar Plate of Fuel Cell

    Directory of Open Access Journals (Sweden)

    Anas Almowarai

    2015-01-01

    Full Text Available Water based carbon nanotube (CNT dispersion was produced by wet-jet milling method. Commercial CNT was originally agglomerated at the particle size of less than 1 mm. The wet-jet milling process exfoliated CNTs from the agglomerates and dispersed them into water. Sedimentation of the CNTs in the dispersion fluid was not observed for more than a month. The produced CNT dispersion was characterized by the SEM and the viscometer. CNT/PTFE composite film was formed with the CNT dispersion in this study. The electrical conductivity of the composite film increased to 10 times when the CNT dispersion, which was produced by the wet-jet milling method, was used as a constituent of the film. Moreover, the composite film was applied to bipolar plate of fuel cell and increased the output power of the fuel cell to 1.3 times.

  2. Instability of higher dimensional Yang-Mills systems

    International Nuclear Information System (INIS)

    Randjbar-Daemi, S.; Strathdee, J.

    1983-01-01

    We investigate the stability of Poincare xO(3) invariant solutions for a pure semi-simple Yang-Mills, as well as Yang-Mills coupled to gravity in 6-dimensional space-time compactified over M 4 xS 2 . In contrast to the Maxwell U(1) theory (IC-82/208) in six dimensions coupled with gravity and investigated previously, the present theory exhibits tachyonic excitations and is unstable. (author)

  3. Aluminum-graphite composite produced by mechanical milling and hot extrusion

    International Nuclear Information System (INIS)

    Flores-Zamora, M.I.; Estrada-Guel, I.; Gonzalez-Hernandez, J.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2007-01-01

    Aluminum-graphite composites were produced by mechanical milling followed by hot extrusion. Graphite content was varied between 0 and 1 wt.%. Al-graphite mixtures were initially mixed in a shaker mill without ball, followed by mechanical milling in a High-energy simoloyer mill for 2 h under argon atmosphere. Milled powders were subsequently pressed at ∼950 MPa for 2 min, and next sintered under vacuum for 3 h at 823 K. Finally, sintered products were held for 0.5 h at 823 K and hot extruded using indirect extrusion. Tension and compression tests were carried out to determine the yield stress and maximum stress of the materials. We found that the mechanical resistance increased as the graphite content increased. Microstructural characterization was done by transmission electron microscopy. Al-O-C nanofibers and graphite nanoparticles were observed in extruded samples by transmission electron microscopy. These nanoparticles and nanofibers seemed to be responsible of the reinforcement phenomenon

  4. Effects of Dry-Milling and Wet-Milling on Chemical, Physical and Gelatinization Properties of Rice Flour

    Directory of Open Access Journals (Sweden)

    Jitranut Leewatchararongjaroen

    2016-09-01

    Full Text Available Rice flour from nine varieties, subjected to dry- and wet-milling processes, was determined for its physical and chemical properties. The results revealed that milling method had an effect on properties of flour. Wet-milling process resulted in flour with significantly lower protein and ash contents and higher carbohydrate content. Wet-milled flour also tended to have lower lipid content and higher amylose content. In addition, wet-milled rice flour contained granules with smaller average size compared to dry-milled samples. Swelling power at 90 °C of wet-milled samples was higher while solubility was significantly lower than those of dry-milled flour. Dry milling process caused the destruction of the crystalline structure and yielded flour with lower crystallinity compared to wet-milling process, which resulted in significantly lower gelatinization enthalpy.

  5. Integrated chemical plants at the pulp mill

    Energy Technology Data Exchange (ETDEWEB)

    Ehtonen, P.; Hurme, M.; Jaervelaeinen, M.

    1995-12-31

    The goal of this paper is to present how the chemical plants can be integrated to the pulp mill. The integration renders possible to balance the chemical consumptions. The total mass balance of a pulp mill with the incoming fuel material and the outgoing waste and flue gases are discussed. The balance figures are presented for the chemicals of the modern fibre line, which will produce fully bleached softwood pulp with an improved effluent quality. The main benefits are lower chemical and transportation costs. The principal over-all plant process block diagrams and process descriptions are presented. The presented info system provides real time information on process and production status at overall mill and department levels. (author)

  6. Crystallographic alignment evolution and magnetic properties of anisotropic Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes prepared by surfactant-assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Xu, M.L.; Wu, Q.; Li, Y.Q.; Liu, W.Q.; Lu, Q.M.; Yue, M., E-mail: yueming@bjut.edu.cn

    2015-08-01

    The microstructure, crystal structure and magnetic properties were studied for Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes prepared by surfactant-assisted high-energy ball milling (SAHEBM). Effect of ball-milling time on the c-axis crystallographic alignment, morphology and magnetic properties of Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes was systematically investigated. With increasing milling time from 1 h to 7 h, the intensity ratio between (002) and (111) reflection peaks indicating degree of c-axis crystal texture of the (Sm, Pr)Co{sub 5} phase increases first, peaks at 3 h, then drops again, revealing that the strongest c-axis crystal texture was obtained in the nanoflakes milled for 3 h. On the other hand, the coercivity (H{sub ci}) of the flakes increases gradually from 1.71 to 14.65 kOe with the increase of ball milling time. As a result, an optimal magnetic properties of M{sub r} of 10.23 kGs, H{sub ci} of 11.45 kOe and (BH){sub max} of 24.40 MGOe was obtained in Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes milled for 3 h, which also displayed a high aspect ratio, small in-plane size, pronounced (001) out-of-plane texture. - Highlights: • Anisotropic Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes with strong c-axis texture were prepared. • Effects of ball-milling time on structure and magnetic properties were studied. • (BH){sub max} value of Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes is larger than that of SmCo{sub 5} nanoflakes.

  7. Investigation of the milling capabilities of the F10 Fine Grind mill using Box-Behnken designs.

    Science.gov (United States)

    Tan, Bernice Mei Jin; Tay, Justin Yong Soon; Wong, Poh Mun; Chan, Lai Wah; Heng, Paul Wan Sia

    2015-01-01

    Size reduction or milling of the active is often the first processing step in the design of a dosage form. The ability of a mill to convert coarse crystals into the target size and size distribution efficiently is highly desirable as the quality of the final pharmaceutical product after processing is often still dependent on the dimensional attributes of its component constituents. The F10 Fine Grind mill is a mechanical impact mill designed to produce unimodal mid-size particles by utilizing a single-pass two-stage size reduction process for fine grinding of raw materials needed in secondary processing. Box-Behnken designs were used to investigate the effects of various mill variables (impeller, blower and feeder speeds and screen aperture size) on the milling of coarse crystals. Response variables included the particle size parameters (D10, D50 and D90), span and milling rate. Milled particles in the size range of 5-200 μm, with D50 ranging from 15 to 60 μm, were produced. The impeller and feeder speeds were the most critical factors influencing the particle size and milling rate, respectively. Size distributions of milled particles were better described by their goodness-of-fit to a log-normal distribution (i.e. unimodality) rather than span. Milled particles with symmetrical unimodal distributions were obtained when the screen aperture size was close to the median diameter of coarse particles employed. The capacity for high throughput milling of particles to a mid-size range, which is intermediate between conventional mechanical impact mills and air jet mills, was demonstrated in the F10 mill. Prediction models from the Box-Behnken designs will aid in providing a better guide to the milling process and milled product characteristics. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. NMR measurements in milled GdCo2 and GdFe2 intermetallic compounds

    International Nuclear Information System (INIS)

    Tribuzy, C.V.B.; Guimaraes, A.P.; Biondo, A.; Larica, C.; Alves, K.M.B.

    1998-12-01

    We have used the nuclear magnetic resonance technique to study the magnetic and structural properties of the Gd-Co and Gd-Fe metallic systems, starting with the C15 laves phase intermetallic compounds, and submitting them to a high energy milling process. This leads to the amorphization of the samples, as determined by the X-ray diffraction spectra. For the Gd-Co system the NMR study used the 59 Co nucleus; in the Gd-Fe system, 155,157 Gd and 57 Fe were used. Both systems showed segregation of the pure elements, after a few hours of milling. In the Gd-Co system, a single line, of increasing width, was observed in the 59 Co spectrum. In the Gd-Fe system, the 155 Gd and 157 Gd resonances show three lines, arising from electrical quadrupole interaction. With increasing milling time, the lines broaden, and extra lines appear attributed to a cubic phase of Gd; this interpretation is supported by the X-ray analysis of the samples. The 57 Fe NMR spectrum of this system also informs on the direction of magnetization of the samples in the early stages of milling. From 1 h to 7 h of milling, a spectrum of α-Fe was observed. The study of the NMR line intensity as a function of radio frequency (r.f.) power in Gd Co 2 suggests the existence of regions of the samples with different degrees of disorder. We have observed the persistence of NMR signals from the original intermetallic compounds in the samples with up to 10 h and 7 h of milling, respectively, for Gd Co 2 and Gd Fe 2 . (author)

  9. A survey of present levels of radiocesium in Swedish pulp mill liquors and the implications for wood radiocesium transfer factors. Using Kraft mill liquors as an indicator of wood radiocesium contamination

    International Nuclear Information System (INIS)

    Ravila, A.; Holm, E.

    2000-01-01

    A survey was initiated to depict and compare the present activity levels in pulp mill liquors from various mill locations. The 137 Cs levels in pulp mill liquors were compared with the mill location and the deposition pattern of the Chernobyl fallout and nuclear weapons fallout. The large input of wood (about 2500 m 3 per day) to an average Nordic Kraft mill and the relatively long-term retention time for radiocesium in the Kraft mill recovery cycle enables representative sampling of substances directly related to the activity concentration in wood. (author)

  10. Getting nanometric MoO3 through chemical synthesis and high energy milling

    International Nuclear Information System (INIS)

    Santos-Beltrán, M.; Paraguay-Delgado, F.; Santos-Beltrán, A.; Fuentes, L.

    2015-01-01

    The effects of high energy mechanical milling (HEMM) were studied on the microstructure and optical properties of MoO 3 for hexagonal and orthorhombic phases. Employing HEMM was possible change particle size as a function of mechanical milling time, as well as the small quantity transformation percentage from hexagonal to orthorhombic phase. The relationship between microstrain and optical properties generated was studied. The electronic structures were calculated using the Density Functional Theory (DFT); to determinate partial density of state (PDOS). Band gap structure calculations show a good correlation between experimental and simulated data. The approximated values of microstrain, particle size, lattice parameters and oxygen vacancies were obtained employing the Rietveld refinement of X-ray diffraction patterns. Samples were characterized by electron microscopy techniques, surface area analysis (BET), thermal-gravimetric analysis (TGA), differential scanning calorimetry (DSC) and ultraviolet–visible spectroscopy (UV–Vis). It was possible, obtain particles with size below 40 nm by 30 min milling. - Graphical abstract: Orthorhombic phase, SEM image, SAED before milling, milling NPs, Particle size and band gap variation by milling time. - Highlights: • MoO 3 with hexagonal and orthorhombic structures was synthesized selectively. • By milling short time (30 m), it was possible get 40 nm diameter particles. • The band gap decrease for nanoparticles, then corroborated by simulation. • MoO 3 nanoparticles get high surface area for new technologic applications

  11. Thermogravimetric and Differential Scanning Calorimetric Behavior of Ball-Milled Nuclear Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eung Seon; Kim, Min Hwan; Kim, Yong Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi Hyun; Cho, Seung Yon [National Fusion Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    An examination was made to characterize the oxidation behavior of ball-milled nuclear graphite powder through a TG-DSC analysis. With the ball milling time, the BET surface area increased with the reduction of particle size, but decreased with the chemisorptions of O{sub 2} on the activated surface. The enhancement of the oxidation after the ball milling is attributed to both increases in the specific surface area and atomic scale defects in the graphite structure. In a high temperature gas-cooled reactor, nuclear graphite has been widely used as fuel elements, moderator or reflector blocks, and core support structures owing to its excellent moderating power, mechanical properties and machinability. For the same reason, it will be used in a helium cooled ceramic reflector test blanket module for the ITER. Each submodule has a seven-layer breeding zone, including three neutron multiplier layers packed with beryllium pebbles, three lithium ceramic pebbles packed tritium breeder layers, and a reflector layer packed with 1 mm diameter graphite pebbles to reduce the volume of beryllium. The abrasion of graphite structures owing to relative motion or thermal cycle during operation may produce graphite dust. It is expected that graphite dust will be more oxidative than bulk graphite, and thus the oxidation behavior of graphite dust must be examined to analyze the safety of the reactors during an air ingress accident. In this study, the thermal stability of ball-milled graphite powder was investigated using a simultaneous thermogravimeter-differential scanning calorimeter.

  12. Anisotropic bonded Sm2.3Fe16.8Zr0.2Ny magnets prepared by milling of as cast material

    International Nuclear Information System (INIS)

    Gebel, B.; Kubis, M.; Roessler, U.K.; Mueller, K.H.

    2001-01-01

    As cast Sm 2.3 Fe 16.8 Zr 0.2 material was milled for 100 min ≤ t ≤ 900 min. After annealing at 800 C for 1 h and subsequent nitrogenation, the samples were cold compacted in a magnetic field and resin bonded. The coercivity μ 0J H C of the samples increased from 0.59 T (t = 100 min) to 2.18 T (t = 900 min). On the other hand, the remanence along the texture axis decreased monotonically with increasing milling time due to the decrease of the degree of texture of the aligned powders. Prolonged milling leads finally to the formation of a soft magnetic phase as indicated by a shoulder in the demagnetization curve for t > 600 min. The highest energy product (BH) max of 50 kJm -3 (136 kJm -3 for the theoretical density of 7.7 gcm -3 ) was obtained for an intermediate milling time of 400 min. Zn bonding of the powders resulted in magnets with lower energy products but improved coercivities. (orig.)

  13. The effect of milling and postmilling procedures on the surface roughness of CAD/CAM materials.

    Science.gov (United States)

    Mota, Eduardo Gonçalves; Smidt, Laura Nunes; Fracasso, Lisiane Martins; Burnett, Luiz Henrique; Spohr, Ana Maria

    2017-11-12

    The aim of this study was to evaluate the surface roughness and analyze the surface topography of five different CAD/CAM ceramics and one CAD/CAM composite resin for CEREC after milling and postmilling procedures. Blocks of the ceramics Mark II, IPS Empress CAD, IPS e.max CAD, Suprinity and Enamic, and blocks of the composite resin Lava Ultimate were milled at CEREC MCXL. Ten flat samples of each material were obtained. The surface roughness (Ra) test was performed before and after milling, crystallization, polishing, and glaze when indicated, followed by SEM and AFM analysis. Data were submitted to one-way ANOVA with repeated measures and the Tukey HSD test (α = 0.05). The milling step significantly increased the roughness of all the tested materials (P CAD and Suprinity) were more suitable to roughness than the other tested materials (P CAD/CAM materials, that is, fully sintered, should be only hand polished. The glaze step can be suppressed resulting in time saving. However, the glaze step in soft-milling lithium disilicate is imperative. © 2017 Wiley Periodicals, Inc.

  14. Einstein-Yang-Mills from pure Yang-Mills amplitudes

    Energy Technology Data Exchange (ETDEWEB)

    Nandan, Dhritiman; Plefka, Jan [Institut für Physik and IRIS Adlershof, Humboldt-Universität zu Berlin,Zum Großen Windkanal 6, D-12489 Berlin (Germany); Schlotterer, Oliver [Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut,Am Mühlenberg 1, D-14476 Potsdam (Germany); Wen, Congkao [I.N.F.N. Sezione di Roma Tor Vergata,Via della Ricerca Scientifica, 00133 Roma (Italy)

    2016-10-14

    We present new relations for scattering amplitudes of color ordered gluons and gravitons in Einstein-Yang-Mills theory. Tree-level amplitudes of arbitrary multiplicities and polarizations involving up to three gravitons and up to two color traces are reduced to partial amplitudes of pure Yang-Mills theory. In fact, the double-trace identities apply to Einstein-Yang-Mills extended by a dilaton and a B-field. Our results generalize recent work of Stieberger and Taylor for the single graviton case with a single color trace. As the derivation is made in the dimension-agnostic Cachazo-He-Yuan formalism, our results are valid for external bosons in any number of spacetime dimensions. Moreover, they generalize to the superamplitudes in theories with 16 supercharges.

  15. An Experiment Study on Surface Roughness in High Speed Milling NAK80 Die Steel

    Directory of Open Access Journals (Sweden)

    Su Fa

    2016-01-01

    Full Text Available The paper introduces that the high speed milling experiments on NAK80 die steel was carried out on the DMU 60 mono BLOCK five axis linkage high speed CNC machining center tool by the TiAlN coated tools, in order to research the effect of milling parameters on surface roughness Ra. The results showed that the Ra value increased with the decrease of milling speed vc, increased with the axial depth of milling ap, and feed per tooth fz and radial depth of milling ae. On the basis of the single factor experiment results, the mathematics model for between surface roughness and milling parameters were established by linear regression analysis.

  16. The investigation of paper mill industry wastewater treatment and activated sludge properties in a submerged membrane bioreactor.

    Science.gov (United States)

    Erkan, Hanife Sari; Engin, Guleda Onkal

    2017-10-01

    The paper mill industry produces high amounts of wastewater and, for this reason, stringent discharge limits are applied for sustainable reclamation and reuse of paper mill industry wastewater in many countries. Submerged membrane bioreactor (sMBR) systems can create new opportunities to eliminate dissolved substances present in paper mill wastewater including. In this study, a sMBR was operated for the treatment of paper mill industry wastewater at 35 h of hydraulic retention time (HRT) and 40 d of sludge retention time (SRT). The chemical oxygen demand (COD), NH 3 -N and total phosphorus (TP) removal efficiencies were found to be 98%, 92.99% and 96.36%. The results demonstrated that sMBR was a suitable treatment for the removal of organic matter and nutrients for treating paper mill wastewater except for the problem of calcium accumulation. During the experimental studies, it was noted that the inorganic fraction of the sludge increased as a result of calcium accumulation in the reactor and increased membrane fouling was observed on the membrane surface due to the calcification problem encountered. The properties of the sludge, such as extracellular polymeric substances (EPS) and soluble microbial products (SMP), relative hydrophobicity, zeta potential and floc size distribution were also monitored. According to the obtained results, the total EPS was found to be 43.93 mg/gMLSS and the average total SMP rejection by the membrane was determined as 66.2%.

  17. 7 CFR 868.310 - Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice...

    Science.gov (United States)

    2010-01-01

    ... Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice. (See also Â... Milled Rice Principles Governing Application of Standards § 868.310 Grades and grade requirements for the classes Long Grain Milled Rice, Medium Grain Milled Rice, Short Grain Milled Rice, and Mixed Milled Rice...

  18. 75 FR 71463 - Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration

    Science.gov (United States)

    2010-11-23

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-73,695] Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration By application dated July 22... regarding the eligibility of workers and former workers of Woodland Mills Corporation, Mill Spring, North...

  19. Bifurcation and stability analysis of a nonlinear milling process

    Science.gov (United States)

    Weremczuk, Andrzej; Rusinek, Rafal; Warminski, Jerzy

    2018-01-01

    Numerical investigations of milling operations dynamics are presented in this paper. A two degree of freedom nonlinear model is used to study workpiece-tool vibrations. The analyzed model takes into account both flexibility of the tool and the workpiece. The dynamics of the milling process is described by the discontinuous ordinary differential equation with time delay, which can cause process instability. First, stability lobes diagrams are created on the basis of the parameters determined in impact test of an end mill and workpiece. Next, the bifurcations diagrams are performed for different values of rotational speeds.

  20. Crystallization degree change of expanded graphite by milling and annealing

    International Nuclear Information System (INIS)

    Tang Qunwei; Wu Jihuai; Sun Hui; Fang Shijun

    2009-01-01

    Expanded graphite was ball milled with a planetary mill in air atmosphere, and subsequently thermal annealed. The samples were characterized by using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). It was found that in the milling initial stage (less than 12 h), the crystallization degree of the expanded graphite declined gradually, but after milling more than 16 h, a recrystallization of the expanded graphite toke place, and ordered nanoscale expanded graphite was formed gradually. In the annealing initial stage, the non-crystallization of the graphite occurred, but, beyond an annealing time, recrystallizations of the graphite arise. Higher annealing temperature supported the recrystallization. The milled and annealed expanded graphite still preserved the crystalline structure as raw material and hold high thermal stability.

  1. Understanding dental CAD/CAM for restorations--dental milling machines from a mechanical engineering viewpoint. Part B: labside milling machines.

    Science.gov (United States)

    Lebon, Nicolas; Tapie, Laurent; Duret, Francois; Attal, Jean-Pierre

    2016-01-01

    Nowadays, dental numerical controlled (NC) milling machines are available for dental laboratories (labside solution) and dental production centers. This article provides a mechanical engineering approach to NC milling machines to help dental technicians understand the involvement of technology in digital dentistry practice. The technical and economic criteria are described for four labside and two production center dental NC milling machines available on the market. The technical criteria are focused on the capacities of the embedded technologies of milling machines to mill prosthetic materials and various restoration shapes. The economic criteria are focused on investment cost and interoperability with third-party software. The clinical relevance of the technology is discussed through the accuracy and integrity of the restoration. It can be asserted that dental production center milling machines offer a wider range of materials and types of restoration shapes than labside solutions, while labside solutions offer a wider range than chairside solutions. The accuracy and integrity of restorations may be improved as a function of the embedded technologies provided. However, the more complex the technical solutions available, the more skilled the user must be. Investment cost and interoperability with third-party software increase according to the quality of the embedded technologies implemented. Each private dental practice may decide which fabrication option to use depending on the scope of the practice.

  2. Effect of the milling time on thermal stability of mechanically alloyed Mg{sub 5}0 Ni{sub 5}0 amorphous alloy; Efecto del tiempo de molienda sobre la estabilidad termica del amorfo Mg{sub 5}0 Ni:50 producido mediante aleado mecanico

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, D.; Ordonez, S.; Serafini, D.; Rojas, P.; Aguilar, C.; Santander, M.; Navea, L.

    2009-07-01

    In order to study the relationship between the milling time used in the production of Mg{sub 5}0Ni{sub 5}0 amorphous alloy and its thermal stability, seven amorphous alloys were produced by milling for 20, 25, 30, 35, 40, 50 and 60 h each sample. The obtained powders were morphological and structurally characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The thermal stability of amorphous alloys was study by differential scanning calorimetry (DSC). Based on the obtained results, it can be concluded that the increase in the added energy when milling for longer time causes the homogenization of the microstructure with an increase in amorphous phase, which dissolves a large amount of nickel in its structure. Therefore, the simultaneous crystallization of the Mg{sub 2}Ni and MgNi{sub 2} intermetallic compounds at 345 degree centigrade can be explained. (Author) 19 refs.

  3. Characterization of Tool Wear in High-Speed Milling of Hardened Powder Metallurgical Steels

    Directory of Open Access Journals (Sweden)

    Fritz Klocke

    2011-01-01

    Full Text Available In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC. The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill (0 = 6, TiAlN coating. It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.

  4. Bioassay for uranium mill tailings

    International Nuclear Information System (INIS)

    Tschaeche, A.N.

    1986-01-01

    Uranium mill tailings are composed of fine sand that contains, among other things, some uranium (U/sup 238/ primarily), and all of the uranium daughters starting with /sup 230/Th that are left behind after the usable uranium is removed in the milling process. Millions of pounds of tailings are and continue to be generated at uranium mills around the United States. Discrete uranium mill tailings piles exist near the mills. In addition, the tailings materials were used in communities situated near mill sites for such purposes as building materials, foundations for buildings, pipe runs, sand boxes, gardens, etc. The Uranium Mill Tailings Remedial Action Project (UMTRAP) is a U.S. Department of Energy Program designed with the intention of removing or stabilizing the mill tailings piles and the tailings used to communities so that individuals are not exposed above the EPA limits established for such tailings materials. This paper discusses the bioassay programs that are established for workers who remove tailings from the communities in which they are placed

  5. Biomass torrefaction mill

    Science.gov (United States)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  6. Distribution of uranium-238 in environmental samples from a residential area impacted by mining and milling activities

    International Nuclear Information System (INIS)

    McConnell, M.A.; Ramanujam, V.M.S.; Alcock, N.W.; Gabehart, G.J.; Au, W.W.

    1998-01-01

    The northern region of Karnes County, Texas, USA, has been the site of extensive mining/milling of uranium for over 30 years. A previous study in their laboratory indicates that residents living near these facilities have increased chromosomal aberrations and a reduced DNA repair capacity. In this study, the long-lived radionuclides uranium-238 ( 238 U) and thorium-232 ( 232 Th) were measured in order to evaluate the extent of contamination from mining/milling facilities. 232 Th was quantified simultaneously and served as a reference. Soil samples were collected from the yards of previously studied households and adjacent areas near former mining and mining/milling sites at the surface and 30 cm subsurface. Additionally, samples from drinking water wells were collected from selected households. Sites located over 14 km from the study area with no known history of mining/milling served as the control. In the control area, 238 U concentrations in soil were consistent between surface (0.13--0.26 mg/kg) and subsurface samples. Near mining/milling sites, 238 U in surface soil was found to be consistently and statistically higher than corresponding subsurface samples. Near mining-only areas, 238 U in surface soil, however, was not significantly increased over subsurface soil. As expected, 238 U was much higher overall in the mining/milling and mining-only areas compared to the control sites. No trends were detected in the distribution of 232 Th. The concentration of 238 U was up to six times higher in a drinking water well near a former mining/milling operation, indicating possible leaching into the groundwater, while 232 Th concentrations were low and uniform. Furthermore, lead isotope ratio analysis indicates contamination from the interstate shipping of ore by rail to and from a mining/milling facility. These data indicate contamination of the environment by the mining/milling activities in a residential area

  7. DEVELOPMENT OF A METHOD OF IMPROVEMENT OF QUALITY OF MILL PRODUCTS AND WEAR RESISTANCE OF THE TOOL AT THE ROLLING MILL 150 JSC «BSW – MANAGING COMPANY OF HOLDING «BMC»

    Directory of Open Access Journals (Sweden)

    I. A. Zuyeu

    2016-01-01

    Full Text Available Enhancement of calibration of mill rolls of the rolling mill 150, to improve of the mill products quality characteristics and to increase efficiency of the whole production is described in the article.

  8. Industrial recovered-materials-utilization targets for the textile-mill-products industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The Congress, in the National Energy Conservation and Policy Act of 1978 (NECPA), directed the Department of Energy to establish materials recovery targets for the metals and metal products, paper and allied products, rubber, and textile-mill-products industries. The targets were developed to provide incentives for using energy-saving recorded materials and to provied a yardstick for measuring progress and improvement in this endeavor. The NECPA indicates that the targets should represent the maximum technically and economically feasible increase in the use of energy-saving recovered materials that each industry can achieve progressively by January 1, 1987. Materials affected by recovered-materials targets include and are limited to aluminum, copper, lead, zinc, iron, steel, paper and associated products, textile-mill, products, and rubber. Using information gathered from the textile-mill-products industry and from other textile-relaed sources, DOE has developed recovered materials targets for that industry. This report presents those targets and their basis and justification. Following an overview of the textile industry, the chapters are: Textile-Mill-Products Industry Operations; Economic Analysis of the Textile-Mill-Products Industry; Governmental and Regulatory Influence on the US Textile Industry; Current Mill Use of Recovered Materials in the Textile-Mill-Products Industry; Limitations on the Use of Recovered Materials in the US Textile-Mill-Products Industry; Materials-Recovery Targets; and Government and Industry Actions That Could Increase the Use of Recovered Materials.

  9. Processing of palm oil mill wastes based on zero waste technology

    Science.gov (United States)

    Irvan

    2018-02-01

    Indonesia is currently the main producer of palm oil in the world with a total production reached 33.5 million tons per year. In the processing of fresh fruit bunches (FFB) besides producing palm oil and kernel oil, palm oil mills also produce liquid and solid wastes. The increase of palm oil production will be followed by an increase in the production of waste generated. It will give rise to major environmental issues especially the discharge of liquid waste to the rivers, the emission of methane from digestion pond and the incineration of empty fruit bunches (EFB). This paper describes a zero waste technology in processing palm oil mill waste after the milling process. The technology involves fermentation of palm oil mill effluent (POME) to biogas by using continuous stirred tank reactor (CSTR) in the presence of thermophilic microbes, producing activated liquid organic fertilizer (ALOF) from discharge of treated waste effluent from biogas digester, composting EFB by spraying ALOF on the EFB in the composter, and producing pellet or biochar from EFB by pyrolysis process. This concept can be considered as a promising technology for palm oil mills with the main objective of eliminating the effluent from their mills.

  10. Magnetic properties of La0.7Ca0.3MnO3 nanoparticles prepared by reactive milling

    International Nuclear Information System (INIS)

    Do Hung Manh; Nguyen Chi Thuan; Pham Thanh Phong; Le Van Hong; Nguyen Xuan Phuc

    2009-01-01

    La 0.7 Ca 0.3 MnO 3 (LCMO) nanoparticles were synthesized by reactive milling in ambient conditions. Magnetic properties of LCMO single-phase nanocrystalline particles were studied. LCMO nanoparticles exhibit superparamagnetism with blocking temperature that decreases in the logarithmic function as increasing applied magnetic field. Besides, the blocking temperature decreases as increasing milling time from 8 h to 16 h. The temperature dependence of the saturation magnetization shows a strong collective excitation due to the spin wave that depends on temperature in form T α with α = 1.7, which slightly deviates from the Bloch law.

  11. Microstructure-sensitive flow stress modeling for force prediction in laser assisted milling of Inconel 718

    Directory of Open Access Journals (Sweden)

    Pan Zhipeng

    2017-01-01

    Full Text Available Inconel 718 is a typical hard-to-machine material that requires thermally enhanced machining technology such as laser-assisted milling. Based upon finite element analysis, this study simulates the forces in the laser-assisted milling process of Inconel 718 considering the effects of grain growth due to γ' and γ" phases. The γ" phase is unstable and becomes the δ phase, which is likely to precipitate at a temperature over 750 °C. The temperature around the center of spot in the experiments is 850 °C, so the phase transformation and grain growth happen throughout the milling process. In the analysis, this study includes the microstructure evolution while accounting for the effects of dynamic recrystallization and grain growth through the Avrami model. The grain growth reduces the yield stress and flow stress, which improves the machinability. In finite element analysis (FEA, several boundary conditions of temperature varying with time are defined to simulate the movement of laser spot, and the constitutive model is described by Johnson-Cook equation. In experiments, this study collects three sets of cutting forces and finds that the predicted values are in close agreements with measurements especially in feed direction, in which the smallest error is around 5%. In another three simulations, this study also examines the effect of laser preheating on the cutting forces by comparison with a traditional milling process without laser assist. When the laser is off, the forces increase in all cases, which prove the softening effect of laser-assisted milling. In addition, when the axial depth of milling increases, the laser has a more significant influence, especially in axial direction, in which the force with laser is more than 18% smaller than the one without laser. Overall, this study validates the influence of laser-assisted milling on Inconel 718 by predicting the cutting forces in FEA.

  12. In situ production of tantalum carbide nanodispersoids in a copper matrix by reactive milling and hot extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Manotas-Albor, Milton, E-mail: manotasm@uninorte.edu.co [Grupo de Investigación en Física Aplicada, Departamento de Física, Universidad del Norte, Km. 5 vía a Puerto Colombia, Barranquilla (Colombia); Departamento de Ingeniería Mecánica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago (Chile); Vargas-Uscategui, Alejandro [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile); Palma, Rodrigo [Departamento de Ingeniería Mecánica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Beauchef 850, Santiago (Chile); Mosquera, Edgar [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Tupper Av. 2069, Santiago (Chile)

    2014-06-15

    Highlights: • Tantalum carbide nanodispersoids were obtained in a copper matrix. • Nanodispersoids were obtained by means of reactive milling followed by hot extrusion. • Hexane was used as the liquid medium for the reactive mechanical alloying process. • Hexane provides the carbon (C) needed for the process. • The reaction of tantalum carbide formation takes place in the hot extrusion. - Abstract: This paper presents a study of the in situ production of tantalum carbide nanodispersoids in a copper matrix. The copper matrix composites were produced by means of reactive milling in hexane (C{sub 6}H{sub 14}) followed by hot extrusion. The composite materials were characterized by means of optical emission spectroscopy (OES), X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Vickers micro-hardness. The effect of milling time was analyzed in 10, 20 and 30 h in a composite with a nominal composition Cu–5 vol.% TaC. A systematic increase of the dislocations density and the carbon concentration were observed when the milling time was increased, whereas the crystallite size of the composite matrix decreased. The material milled for 30 h and hot-extruded showed a density of 9037 kg m{sup −3} (98.2% densification) and a softening resistance of 204 HV; however the latter value showed an abrupt drop after an annealing treatment at 923 K for 1 h. Finally, the TEM analysis showed the presence of tantalum carbide (Ta{sub 4}C{sub 3}) nanodispersoids.

  13. Preparation of tungsten-iron carbide by ball milling

    International Nuclear Information System (INIS)

    Wang, G.M.; Campbell, S.J.; Calka, A.; Kaczmarek, W.A.

    1996-01-01

    Several sets of elemental powder mixtures of Fe-W-C (W 46 Fe 46 C 8 , W 60 Fe 20 C 20 and W 34 Fe 33 C 33 ) were ball milled using Uni-Ball mill for periods of up to 550 h in vacuum with a ball - to - powder ratio of about 35:1. Depending on the milling time, the main component of the as-milled materials was found to be solid solutions of Fe-W-C or Fe-C. Ternary phase W 3 Fe 3 C was obtained on annealing the as-milled materials at about 700 deg C. This product was then found to transfer to (FeW) 6 C on heat treatment at about 800 deg C. The resultant products of the annealing processes were found to depend not only on the annealing temperature, but also the starting composition, especially the initial carbon concentration. Detailed information on the structural and phase evolution during thermal treatment as measured using x-ray diffraction, Moessbauer spectroscopy and thermal analysis is presented. Special interest is focused on the competition for formation in this system between the Fe-C, W-Fe and W-C phases

  14. Decontamination effect of milling by a jet mill on bacteria in rice flour.

    Science.gov (United States)

    Sotome, Itaru; Nei, Daisuke; Tsuda, Masuko; Mohammed, Sharif Hossen; Takenaka, Makiko; Okadome, Hiroshi; Isobe, Seiichiro

    2011-06-01

    The decontamination effect of milling by a jet mill was investigated by counting the number of bacteria in brown and white rice flour with mean particle diameters of 3, 20, and 40µm prepared by the jet mill. In the jet mill, the particles are crushed and reduced in size by the mechanical impact caused by their collision. Although the brown and white rice grains were contaminated with approximately 10(6) and 10(5) CFU/g bacteria, the microbial load of the rice flour decreased as the mean particle diameter decreased, ultimately decreasing to approximately 104 and 103 CFU/g in the brown and white rice flour. The temperature and pressure changes of the sample were not considered to have an effect on reducing the bacterial count during the milling. Hence, it was thought that the rice flour was decontaminated by other effects.

  15. Cleaning up commingled uranium mill tailings: is Federal assistance necessary

    International Nuclear Information System (INIS)

    1979-01-01

    GAO was asked to determine whether Federal assistance should be given to operating mill owners that have processed uranium for sale to both government and industry and, thus, generated residual radioactive wastes. The wastes generated for both government and commercial use are called commingled uranium mill tailings. GAO recommends that the Congress provide assistance to active mill owners to share in the cost of cleaning up that portion of the tailings which were produced under Federal contract. Further, GAO believes that the Congress should also consider having the Federal government assist those mills who acted in good faith in meeting all legal requirements pertaining to controlling the mill tailings that were generated for commercial purposes and for which the Federal government is now requiring retroactive remedial action. At the same time, the Congress should make sure that this action establishes no precedent for the Federal government assuming the financial responsibility of cleaning up other non-Federal nuclear facilities and wastes, including those mill tailings generated after the date when the Federal government notified industry that the failings should be controlled

  16. Hybrid ABC Optimized MARS-Based Modeling of the Milling Tool Wear from Milling Run Experimental Data

    OpenAIRE

    Garc?a Nieto, Paulino Jos?; Garc?a-Gonzalo, Esperanza; Ord??ez Gal?n, Celestino; Bernardo S?nchez, Antonio

    2016-01-01

    Milling cutters are important cutting tools used in milling machines to perform milling operations, which are prone to wear and subsequent failure. In this paper, a practical new hybrid model to predict the milling tool wear in a regular cut, as well as entry cut and exit cut, of a milling tool is proposed. The model was based on the optimization tool termed artificial bee colony (ABC) in combination with multivariate adaptive regression splines (MARS) technique. This optimization mechanism i...

  17. Magnetic properties of nanocrystalline Fe–10%Ni alloy obtained by planetary ball mills

    International Nuclear Information System (INIS)

    Hamzaoui, Rabah; Elkedim, Omar

    2013-01-01

    Highlights: •Solid solution formation accompanied by a grain refinement for nanocrystalline Fe-Ni. •The shock mode process (SMP) prevails when Ω > >ω. •The friction mode process (FMP) is stronger when Ω < <ω. •The FMP leads to the formation of alloys exhibiting a soft magnetic behavior. -- Abstract: Planetary ball mill PM 400 from Retsch (with different milling times for Ω = 400 rpm, ω = 800 rpm) and P4 vario ball mill from Fritsch (with different milling conditions (Ω/ω), Ω and ω being the disc and the vial rotation speeds, respectively) are used for obtaining nanocrystalline Fe–10wt% Ni. The structure and magnetic properties are studied by using X-ray diffraction, SEM and hysteresis measurements, respectively. The bcc-Fe(Ni) phase formation is identified by X-ray diffraction. The higher the shock power and the higher milling time are, the larger the bcc lattice parameter and the lower the grain size. The highest value of the coercivity is 1600 A/m for Fe–10 wt.%Ni (with shock mode (424 rpm/100 rpm) after 36 h of milling), while the lowest value is 189 A/m for (400 rpm/800 rpm) after 72 h of milling. The milling performed in the friction mode has been found to lead the formation of alloys exhibiting a soft magnetic behavior for nanocrystalline Fe–10%Ni

  18. Scale up of ethanol production using pulp mill wastewater sludge by cellulase and saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Kunchada Sangasintu; Petchporn Chawakitchareon

    2010-01-01

    This study aimed to evaluate the potential use of pulp mill wastewater sludge as substrate in ethanol production. The simultaneous saccharification and fermentation process was conducted by using Saccharomyces cerevisiae TISTR 5339 under optimum proportion of cellulase and pulp mill wastewater sludge. The ethanol production from cellulosic materials in simultaneous saccharification and fermentation needs cooperation between cellulase and yeast. The cellulase hydrolyzes cellulose to sugar while yeast utilizes sugar to produce ethanol. The pulp mill wastewater sludge has an average content of 73.3 % hemi cellulose, 67.1 % alpha cellulose, 4.7 % beta cellulose and 1.4 % gamma cellulose. The experimental results indicated that the volume of the ethanol tend to increase with time, providing the maximum ethanol yield of 0.69 g/g on the 7"t"h day, the last day of the experiment. The ethanol production was scaled up in 5 L fermentor under optimum proportion and increased the fermentation period. It was found that the ethanol production gave the maximum ethanol yield of 1.14 g/g on the 9"t"h day of the totally 13 days experimentation. These results showed that the cellulose from pulp mill wastewater sludge was as effective substrate for ethanol production and alternative energy for the future. (author)

  19. Milling properties of low temperature sintered zirconia blocks for dental use

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Ting-Hsun; Wang, Chau-Hsiang [Department of Prosthodontics, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan (China); School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 80728, Taiwan (China); Chen, Ker-Kong [Department of Conservation, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan (China); School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 80728, Taiwan (China); Wang, Moo-Chin, E-mail: mcwang@kmu.edu.tw [Department of Fragrance and Cosmetic Science, Kaohsiung Medical University, 100 Shih-Chuan 1st Road, Kaohsiung 80728, Taiwan (China); Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, 80756, Taiwan (China); Lee, Huey-Er, E-mail: huerle@kmu.edu.tw [Department of Prosthodontics, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan (China); School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 80728, Taiwan (China)

    2017-04-01

    To investigate the milling properties of different yttria-tetragonal zirconia polycrystalline (Y-TZP) block materials by applying a dental computer numerical control (CNC) milling center. Low temperature sintering zirconia block denoted by KMUZ (experimental) with two commercial zirconia blocks for T block made in Taiwan and a G block made in Germany were compared for the milling properties. Seventy-two specimens were milled using the same CNC milling center, and properties were evaluated by measuring the weight loss (g), milling time (s), margin integrity (%) and broken diameter (μm). The crystalline phases contents were identified by X-ray diffraction and the microstructures of the sintering specimens were observed by scanning electron microscopy and transmission electron microscopy. The mean milling time of G and KMUZ were significantly shorter than T (P < 0.05). The KMUZ samples exhibited the least weight loss among the three kinds of blocks (P < 0.05). The percentages of marginal integrity after milling were high in G and KMUZ but low in T (P < 0.05). The mean broken diameters were from 90 μm to 120 μm. The phase transformation of t-ZrO{sub 2} (KMUZ: 7.4%, G: 5.9%, T: 3.2%) to m-ZrO{sub 2} when facing the milling pressure in ZrO{sub 2} blocks was observed by XRD. The result of TEM microstructure of KMUZ revealed that Y and Si were soluble in grain boundaries. The results show that the milling properties of KMUZ were better than one commercial T and near the G. The hindered grain growth, as a result of the Y{sup 3+} content in the grain boundaries, also plays a role in promoting the abnormal grain growth of 3Y-TZP. - Highlights: • The phase transformation of t-ZrO{sub 2} to m-ZrO{sub 2} affects the milling properties. • The phase content of t-ZrO2 was 100% when sintering at 1350 °C for 2 h. • The Y{sup 3+} content in the grain boundaries that hinders grain growth. • The Y{sup 3+} content in boundaries also promotes the abnormal grain growth of 3Y-TZP.

  20. Defect induced electronic states and magnetism in ball-milled graphite.

    Science.gov (United States)

    Milev, Adriyan; Dissanayake, D M A S; Kannangara, G S K; Kumarasinghe, A R

    2013-10-14

    The electronic structure and magnetism of nanocrystalline graphite prepared by ball milling of graphite in an inert atmosphere have been investigated using valence band spectroscopy (VB), core level near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and magnetic measurements as a function of the milling time. The NEXAFS spectroscopy of graphite milled for 30 hours shows simultaneous evolution of new states at ~284.0 eV and at ~290.5 eV superimposed upon the characteristic transitions at 285.4 eV and 291.6 eV, respectively. The modulation of the density of states is explained by evolution of discontinuities within the sheets and along the fracture lines in the milled graphite. The magnetic measurements in the temperature interval 2-300-2 K at constant magnetic field strength show a correlation between magnetic properties and evolution of the new electronic states. With the reduction of the crystallite sizes of the graphite fragments, the milled material progressively changes its magnetic properties from diamagnetic to paramagnetic with contributions from both Pauli and Curie paramagnetism due to the evolution of new states at ~284 and ~290.5 eV, respectively. These results indicate that the magnetic behaviour of ball-milled graphite can be manipulated by changing the milling conditions.

  1. Milles Iles River : study of solutions to address critically low water levels; Riviere des Milles Iles : etude des solutions de soutien des etiages critiques

    Energy Technology Data Exchange (ETDEWEB)

    Cyr, J F; Fontin, M [Centre d' Expertise Hydrique du Quebec, Quebec, PQ (Canada). Service de la Securite des Barrages

    2006-07-01

    Water management for the Mille Iles River, which supplies drinking water to 400,000 people, was discussed with reference to solutions for critically low water flow which was experienced in 2001 and 2002. The river is part of the Lac des Deux Montagnes watershed in the region of Montreal which is characterized as a high population growth area. In the summer of 2001, municipalities served by the Mille Iles River were faced with problems in the supply of drinking water when the river flow reached only 13 cubic metres per second. The minimal values of flow observed for this time of year have rarely been under 20 cubic metres per second since 1970. The quality of water was reduced under such conditions of flow because the dilution of wastewater discharged into the river became so weak that the aging water treatment facilities had to work beyond their capacity. Quebec's Center of Water Expertise (CEHQ) intervened in an emergency measure to ensure water quality. This study investigated the following 3 possible scenarios for a solution to this problem: (1) to increase the Mille Iles River capacity at the Lac des Deux Montagnes outlet, (2) to reduce the flow discharged by the 3 other outlets of Lac des Deux Montagnes, and (3) to increase the inflow to Lac des Deux Montagnes from reservoirs located in the Ottawa River watershed. The first solution was favoured. 2 refs., 1 tab., 8 figs.

  2. Milles Iles River : study of solutions to address critically low water levels; Riviere des Milles Iles : etude des solutions de soutien des etiages critiques

    Energy Technology Data Exchange (ETDEWEB)

    Cyr, J.F.; Fontin, M. [Centre d' Expertise Hydrique du Quebec, Quebec, PQ (Canada). Service de la Securite des Barrages

    2006-07-01

    Water management for the Mille Iles River, which supplies drinking water to 400,000 people, was discussed with reference to solutions for critically low water flow which was experienced in 2001 and 2002. The river is part of the Lac des Deux Montagnes watershed in the region of Montreal which is characterized as a high population growth area. In the summer of 2001, municipalities served by the Mille Iles River were faced with problems in the supply of drinking water when the river flow reached only 13 cubic metres per second. The minimal values of flow observed for this time of year have rarely been under 20 cubic metres per second since 1970. The quality of water was reduced under such conditions of flow because the dilution of wastewater discharged into the river became so weak that the aging water treatment facilities had to work beyond their capacity. Quebec's Center of Water Expertise (CEHQ) intervened in an emergency measure to ensure water quality. This study investigated the following 3 possible scenarios for a solution to this problem: (1) to increase the Mille Iles River capacity at the Lac des Deux Montagnes outlet, (2) to reduce the flow discharged by the 3 other outlets of Lac des Deux Montagnes, and (3) to increase the inflow to Lac des Deux Montagnes from reservoirs located in the Ottawa River watershed. The first solution was favoured. 2 refs., 1 tab., 8 figs.

  3. A study on thermal and mechanical properties of mechanically milled HDPE and PP

    International Nuclear Information System (INIS)

    Can, S.; Tan, S.

    2003-01-01

    In this study, mechanical mixing of HDPE and PP was performed via ball milling. Prepared compositions were 75/25 , 50/50 , 25/75 w/w HDPE/PP. Milling time and ball to powder ratio (B/P) were kept constant and system was cooled by adding solid CO 2 to improve the milling efficiency. To compare these systems with traditional methods, mixtures were also melt mixed by Brabender Plasti-Corder. Both milled and melt mixed systems were examined with DSC for thermal properties and tensile testing for mechanical properties Results are discussed by comparing milled , melt mixed and as-received polymers. It is observed that, unlike ball milled systems' in melt mixed systems mechanical properties are composition dependent. In addition , ball milling results in amorphization of both polymers and very high amounts of PP (75wt %) creates very amorphous HDPE structure. (Original)

  4. Superspace gauge fixing of topological Yang-Mills theories

    Energy Technology Data Exchange (ETDEWEB)

    Constantinidis, Clisthenis P; Piguet, Olivier [Universidade Federal do Espirito Santo (UFES) (Brazil); Spalenza, Wesley [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro (Brazil)

    2004-03-01

    We revisit the construction of topological Yang-Mills theories of the Witten type with arbitrary space-time dimension and number of ''shift supersymmetry'' generators, using a superspace formalism. The super-BF structure of these theories is exploited in order to determine their actions uniquely, up to the ambiguities due to the fixing of the Yang-Mills and BF gauge invariance. UV finiteness to all orders of perturbation theory is proved in a gauge of the Landau type. (orig.)

  5. Superspace gauge fixing of topological Yang-Mills theories

    International Nuclear Information System (INIS)

    Constantinidis, Clisthenis P.; Piguet, Olivier; Spalenza, Wesley

    2004-01-01

    We revisit the construction of topological Yang-Mills theories of the Witten type with arbitrary space-time dimension and number of ''shift supersymmetry'' generators, using a superspace formalism. The super-BF structure of these theories is exploited in order to determine their actions uniquely, up to the ambiguities due to the fixing of the Yang-Mills and BF gauge invariance. UV finiteness to all orders of perturbation theory is proved in a gauge of the Landau type. (orig.)

  6. Beneficial uses of paper mill residuals for New York State`s recycled-paper mills. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This report evaluates the New York paper mill industry in terms of the productive management and treatment of solid wastes. It identifies current efforts by recycling mills to beneficially use paper mill residuals (often called sludge) and suggests additional options that should be considered by the industry in general and individual mills in particular. It also examines the regulations and economics affecting the mills and suggests actions that could improve the industry`s ability to convert wastes to value-added products. The report recommends that the mills should continue measures to reduce fiber and filler clay losses, promote the transfer of usable fiber and clay to mills able to use them, upgrade sludge dewatering capabilities, and take a more regional approach to solid waste disposal problems. State agencies are urged to support these efforts, encourage the development and commercialization of new beneficial use technologies, and reduce regulatory barriers whenever possible.

  7. Production of nanocrystalline cermet thermal spray powders for wear resistant coatings by high-energy milling

    International Nuclear Information System (INIS)

    Eigen, N.; Klassen, T.; Aust, E.; Bormann, R.; Gaertner, F.

    2003-01-01

    TiC-Ni based nanocrystalline cermet powders for thermal spraying were produced by high-energy milling. Milling experiments were performed in an attrition mill and a vibration mill in kilogram scale, and powder morphologies and microstructures were characterized using scanning electron microscopy, X-ray diffraction, and laser scattering for particle size analysis. Milling time and powder input were optimized with respect to the desired microstructure and particle sizes, and the results using both types of mill were compared. Powders with homogeneously dispersed hard phase particles below 300 nm could be produced in both mills. Additional processes for the refinement of powder morphology and particle size distribution are discussed

  8. Machining Chatter Analysis for High Speed Milling Operations

    Science.gov (United States)

    Sekar, M.; Kantharaj, I.; Amit Siddhappa, Savale

    2017-10-01

    Chatter in high speed milling is characterized by time delay differential equations (DDE). Since closed form solution exists only for simple cases, the governing non-linear DDEs of chatter problems are solved by various numerical methods. Custom codes to solve DDEs are tedious to build, implement and not error free and robust. On the other hand, software packages provide solution to DDEs, however they are not straight forward to implement. In this paper an easy way to solve DDE of chatter in milling is proposed and implemented with MATLAB. Time domain solution permits the study and model of non-linear effects of chatter vibration with ease. Time domain results are presented for various stable and unstable conditions of cut and compared with stability lobe diagrams.

  9. Effect of Milling Condition on the Microstructure and the Properties of Nano structured Copper Tungsten Carbide Composite

    International Nuclear Information System (INIS)

    Mahani Yusoff; Zuhailawati Hussain

    2011-01-01

    In this work, in-situ Cu-WC composite has been fabricated by high energy milling followed by sintering. Cu, W and C mixture were mechanically alloyed in a planetary ball mill for 40 h at various milling speeds. Cu-W-C composite powders were cold compacted and sintered in argon ambient. Milled powder and sintered Cu-W-C composite were characterized in terms of Xray diffraction (XRD), field emission scanning electron microscopy (FESEM) and its properties. The result showed that carbide phases are only detected after sintering process. Greater amount of grain refinement during milling generates very high internal strain which reduced Cu crystallite size. It was found that formation of metastable, W 2 C has taken place before the formation of WC. With the presence of WC, the composite become increasingly harden with the increased of milling speed. Increasing milling speed also found to lower the electrical conductivity. (author)

  10. Waste fatty acid addition to black liquor to decrease tall oil soap solubility and increase skimming efficiency in kraft mills pulping mountain pine beetle-infested wood

    Energy Technology Data Exchange (ETDEWEB)

    Uloth, V.; Guy, E. [FPInnovations, Prince George, BC (Canada). PAPRICAN Div.; Shewchuk, D. [Cariboo Pulp and Paper, Quesnel, BC (Canada); Van Heek, R. [Aker Kvaerner, Vancouver, BC (Canada)

    2009-07-01

    This paper presented the results of tests conducted to determine if the addition of waste fatty acids from vegetable oil processing might decrease tall oil soap solubility in pine-beetle impacted wood from British Columbia (BC). The soap recovery and tall oil production at BC mills has fallen by 30 to 40 percent in recent years due to the pulping of high proportions of grey-stage beetle-impacted wood. Full-scale mill tests were conducted over a 4-day period. The study showed that the addition of tall oil fatty acids or waste fatty acids from vegetable oil processing could decrease tall oil soap solubility and increase the soup skimming efficiency in mills pulping a large percentage of grey stage beetle-infested wood. The addition of fatty acids increased tall oil soap skimming efficiency from 50.2 percent in the baseline tests to 71.8 percent based on the total soap available, and from 76.7 percent in the baseline tests to 87.5 percent based on insoluble soap only. The economic analyses indicated that waste fatty acid addition could be economical when natural gas and oil prices are high. 4 tabs., 9 figs.

  11. Understanding milling induced changes: Some results

    Indian Academy of Sciences (India)

    Unknown

    simple model systems. ... times in a planetary mill are shown in figure 2. ... dynamics (CD) model, based on Martin's model for driven systems,21 along with an ... feature of the phase diagram is the self closing miscibility gap at low temperature.

  12. Effects of milling on the extraction efficiency of incurred pesticides in cereals

    DEFF Research Database (Denmark)

    Herrmann, Susan Strange; Hajeb, Parvaneh; Andersen, Gitte

    2017-01-01

    This study investigated the effects of particle size and milling temperature on the extraction efficiencies of pesticide residues from cereal flour. Samples of cereal grains (barley, oat, rye and wheat) were milled using a centrifugal mill with four different sieves (0.2, 1.0, 3.0 and 5.0 mm......) or a knife mill both at room temperature and after freezing of the grain at –80°C overnight. The incurred pesticides in the test materials were extracted by the QuEChERS method and analysed by LC-MS/MS and GC-MS/MS. The particle size distribution for the milled samples was determined using a vibratory sieve...... shaker. Based on the pesticide levels recovered from each of the different millings and the corresponding particle size distributions, it was confirmed that smaller average particle sizes increase the extraction efficiency up to 31%, with all other factors equal. The cereals milled at room temperature...

  13. Seasonal Patterns of Stored-Product Insects at a Rice Mill.

    Science.gov (United States)

    McKay, Tanja; White, Amanda L; Starkus, Laura A; Arthur, Frank H; Campbell, James F

    2017-06-01

    The temporal and spatial patterns in flight activity outside of a rice mill were evaluated for the lesser grain borer [Rhyzopertha dominica (F.)], warehouse beetle [Trogoderma variabile Ballion], cigarette beetle [Lasioderma serricorne (F.)], and Indian meal moth [Plodia interpunctella (Hüϋbner)] to determine critical times of year when the mill would be vulnerable to invasion. Insect activity was monitored using pheromone-baited glue traps (N = 99) from June 2008 to October 2010. Traps were placed along exterior walls of all major buildings and along the fence around the perimeter of the facility. Trogoderma variabile was the most abundant species, with flight activity between mid-March and November. No activity of T. variabile was observed during December through March. Rhyzopertha dominica was also abundant, with activity in mid-April through October. A few adult R. dominica were captured in traps during winter months in the first year of study. Trap captures for all four species increased with an increase in temperature and can be described by linear equations. Knowing seasonal patterns in insect activity allows rice facilities to better understand when facilities are most vulnerable to pest activity. However, this study demonstrates that more research is needed to address how insects are immigrating and emigrating within and around a rice mill. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Yang-Mills-Vlasov system in the temporal gauge

    International Nuclear Information System (INIS)

    Choquet-Bruhat, Y.; Noutchegueme, N.

    1991-01-01

    We prove a local in time existence theorem of a solution of the Cauchy problem for the Yang-Mills-Vlasov integrodifferential system. Such equations govern the evolution of plasmas, for instance of quarks and gluons (quagmas), where non abelian gauge fields and Yang-Mills charges replace the usual electromagnetic field and electric charge. We work with the temporal gauge and use functional spaces with appropriate weight on the momenta, but no fall off is required in the space direction [fr

  15. Superspace gauge fixing of topological Yang-Mills theories

    International Nuclear Information System (INIS)

    Constantinidis, Clisthenis P.; Piguet, Olivier; Spalenza, Wesley

    2003-10-01

    We revisit the construction of topological Yang-Mills theories of the Witten type with arbitrary space-time dimension and number of 'shift supersymmetry' generators, using a superspace formalism. The super-B F structure of these theories is exploited in order to determine their actions uniquely, up to the ambiguities due to the fixing of the Yang-Mills and B F gauge invariance. UV finiteness to all orders of perturbation theory is proved in a gauge of the Landau type. (author)

  16. Superspace gauge fixing of topological Yang-Mills theories

    Energy Technology Data Exchange (ETDEWEB)

    Constantinidis, Clisthenis P; Piguet, Olivier [Espirito Santo Univ. (UFES), Vitoria, ES (Brazil); Spalenza, Wesley

    2003-10-15

    We revisit the construction of topological Yang-Mills theories of the Witten type with arbitrary space-time dimension and number of 'shift supersymmetry' generators, using a superspace formalism. The super-B F structure of these theories is exploited in order to determine their actions uniquely, up to the ambiguities due to the fixing of the Yang-Mills and B F gauge invariance. UV finiteness to all orders of perturbation theory is proved in a gauge of the Landau type. (author)

  17. Women’s participation in rice mills in Sherpur sadar upazila of Bangladesh

    Directory of Open Access Journals (Sweden)

    Naima Sultana

    2014-06-01

    Full Text Available The main purpose of this study was to determine women’s participation in rice mills of Sherpur sadar upazila of Bangladesh. Ninety respondents were selected using cluster random sampling method. The researchers personally collected data from August to September 2012. Aimed at explaining the assessment of the present status of women worker of rice mills and explored the relationship between their selected characteristics and extent of participation. Majority of the respondents had long experience in working in the rice mill and almost everybody had participation around the year. Women were mostly involved in drying and on an average spent time for helping in husking machine operating (3.02 hours followed by final drying of paddy (2.05 hours, drying the paddy before boiling (1.25 hours, piling the paddy (1.12 hours, cleaning the threshing floor (1.05 hours, packing the rice (1.02 hours per day. They worked about 8-10 hours per day. Results show that the women worker’s performance decreased with the increase of their age.

  18. Optimasi Parameter Permesinan Terhadap Waktu Proses Pada Pemrograman Cnc Milling Dengan Berbasis Cad/cam

    OpenAIRE

    Yudhyadi, IGNK; Rachmanto, Tri; Ramadan, Adnan Dedy

    2016-01-01

    The milling process is one of many machining processes for manufacturing component. The length of time in the process of milling machining is influenced by selection and design of machining parameters including cutting speed, feed rate and depth of cut. The purpose of this study to know the influence of cutting speed, feed rate and depth of cut as independent variables versus operation time at CNC milling process as dependent variables. Each independent variable consists of three level of fac...

  19. Magnetic properties of ball-milled Fe0.6Mn0.1Al0.3 alloys

    International Nuclear Information System (INIS)

    Rebolledo, A.F.; Romero, J.J.; Cuadrado, R.; Gonzalez, J.M.; Pigazo, F.; Palomares, F.J.; Medina, M.H.; Perez Alcazar, G.A.

    2007-01-01

    The FeMnAl-disordered alloy system exhibits, depending on the composition and the temperature, a rich variety of magnetic phases including the occurrence of ferromagnetism, antiferromagnetism, paramagnetism and spin-glass and reentrant spin glass behaviors. These latter phases result from the presence of atomic disorder and magnetic dilution and from the competing exchange interactions taking place between an Fe atom and its Mn and Fe first neighbors. The use of mechanical alloying in order to prepare these alloys is specially interesting since it allows to introduce in a progressive way large amounts of disorder. In this work, we describe the evolution with the milling time of the temperature dependence of the magnetic properties of mechanically alloyed Fe 0.6 Mn 0.1 Al 0.3 samples. The materials were prepared in a planetary ball mill using a balls-to-powder mass ratio of 15:1 and pure (99.95 at%) Fe, Mn and Al powders for times up to 19 h. The X-rays diffraction (XRD) spectra show the coexistence of three phases at short milling times. For milling times over 6 h, only the FeMnAl ternary alloy BCC phase is observed. Moesbauer spectroscopy reveals the complete formation of the FeMnAl alloy after 9 h milling time. The magnetic characterization showed that all the samples were ferromagnetic at room temperature with coercivities decreasing from 105 Oe (3 h milled sample) down to 5 Oe in the case of the sample milled for 19 h

  20. Airborne effluent control at uranium mills

    International Nuclear Information System (INIS)

    Sears, M.B.

    1976-01-01

    The Oak Ridge National Laboratory has made an engineering cost--environmental benefit study of radioactive waste treatment systems for decreasing the amount of radioactive materials released from uranium ore processing mills. This paper summarizes the results of the study which pertain to the control and/or abatement of airborne radioactive materials from the mill processes. The tailings area is not included. Present practices in the uranium milling industry, with particular emphasis on effluent control and waste management, have been surveyed. A questionnaire was distributed to each active mill in the United States. Replies were received from about 75 percent of the mill operators. Visits were made to six operating uranium mills that were selected because they represented the different processes in use today and the newest, most modern in mill designs. Discussions were held with members of the Region IV Office of NRC and the Grand Junction Office of ERDA. Nuclear Science Abstracts, as well as other sources, were searched for literature pertinent to uranium mill processes, effluent control, and waste management

  1. Microstructure and properties of copper composite containing in situ NbC reinforcement: Effects of milling speed

    International Nuclear Information System (INIS)

    Zuhailawati, Hussain; Salihin, Hassin Mohd; Mahani, Yusoff

    2010-01-01

    This paper presents a study on the effects of milling speed on the properties of in situ copper-based composite produced by mechanical alloying followed by cold pressing and sintering. A powdered mixture of copper, niobium and graphite with the composition of Cu-30%NbC was milled at various speeds (100, 200, 300 and 400 rpm). The NbC phase started to precipitate in the as-milled powder after 30 h milling at 400 rpm and the formation was completed after sintering at 950 o C. Enhancements of NbC phase formation with a reduction in Cu crystallite size were observed with the increase of milling speed. Density, hardness and electrical conductivity of the sintered composite were evaluated. An increase in milling speed resulted in an increase in sintered density and hardness but a reduction of electrical conductivity. The changes in the properties were correlated to the formation of NbC phase and refinement of copper and niobium carbide crystallite size since higher milling speed is associated with higher kinetic energy per hit.

  2. Rough mill simulator version 3.0: an analysis tool for refining rough mill operations

    Science.gov (United States)

    Edward Thomas; Joel Weiss

    2006-01-01

    ROMI-3 is a rough mill computer simulation package designed to be used by both rip-first and chop-first rough mill operators and researchers. ROMI-3 allows users to model and examine the complex relationships among cutting bill, lumber grade mix, processing options, and their impact on rough mill yield and efficiency. Integrated into the ROMI-3 software is a new least-...

  3. Media milling process optimization for manufacture of drug nanoparticles using design of experiments (DOE).

    Science.gov (United States)

    Nekkanti, Vijaykumar; Marwah, Ashwani; Pillai, Raviraj

    2015-01-01

    Design of experiments (DOE), a component of Quality by Design (QbD), is systematic and simultaneous evaluation of process variables to develop a product with predetermined quality attributes. This article presents a case study to understand the effects of process variables in a bead milling process used for manufacture of drug nanoparticles. Experiments were designed and results were computed according to a 3-factor, 3-level face-centered central composite design (CCD). The factors investigated were motor speed, pump speed and bead volume. Responses analyzed for evaluating these effects and interactions were milling time, particle size and process yield. Process validation batches were executed using the optimum process conditions obtained from software Design-Expert® to evaluate both the repeatability and reproducibility of bead milling technique. Milling time was optimized to process variables by applying DOE resulted in considerable decrease in milling time to achieve the desired particle size. The study indicates the applicability of DOE approach to optimize critical process parameters in the manufacture of drug nanoparticles.

  4. Cutting force and wear evaluation in peripheral milling by CVD diamond dental tools

    International Nuclear Information System (INIS)

    Polini, R.; Allegri, A.; Guarino, S.; Quadrini, F.; Sein, H.; Ahmed, W.

    2004-01-01

    Co-cemented tungsten carbide (WC-Co) tools are currently employed in dental application for prosthesis fabrication. The deposition of a diamond coating onto WC-Co tools could allow both to increase the tool life and tool performance at higher speeds. However, at present it is very difficult to quantify the effective advantage of the application of a diamond coating onto dental tools compared to traditional uncoated tools. Therefore, in this work, we have deposited diamond coatings onto WC-Co dental tools having different geometries by Hot Filament Chemical Vapour Deposition (HFCVD). Prior to deposition, the WC-Co tools were pre-treated in order to roughen the surface and to modify the chemical surface composition. The use of the HFCVD process enabled the deposition of a uniform coating despite the complex geometries of the dental mills. For the first time, in accordance to the knowledge of the authors, we have studied and compared the cutting behaviour of both virgin and diamond-coated dental tools by measuring both wear and cutting force time evolution under milling a very hard Co-Cr-Mo dental alloy. To ensure constant cutting rate (20,000-r.p.m. cutting rate, 0.01-m/min feed rate and 0.5-mm depth of cut), a proper experimental apparatus was used. Three different mill geometries were considered in both coated and uncoated conditions. The results showed that, under the high-speed conditions employed, uncoated tools underwent to catastrophic failure within a few seconds of machining. Diamond-coated tools exhibited much longer tool lives. Lower forces were measured when the coated tool was employed due to the much lower material-mill friction. The best behaviour was observed for coated mills with the presence of a chip-breaker

  5. Agglomeration during wet milling of LAST (lead-antimony-silver-tellurium) powders

    International Nuclear Information System (INIS)

    Hall, B.D.; Case, E.D.; Ren, F.; Johnson, J.R.; Timm, E.J.

    2009-01-01

    LAST (lead-antimony-silver-tellurium) compounds comprise a family of semiconducting materials with good thermoelectric properties. However, the as-cast form of LAST exhibits large grain size and hence low mechanical strength. Powder processing can produce a fine powder particle size that enhances fracture strength, however the powders tend to agglomerate if the individual powder diameters are less than a few microns across. Dry milling or wet milling (hexane additions of 0 cm 3 and 10 cm 3 ) produced hard agglomerates roughly 40 μm in diameter while wet milling with hexane additions of 25 cm 3 , 30 cm 3 or 50 cm 3 resulted in small, porous agglomerates roughly 20 μm in diameter. Thus, by adjusting the amount of milling liquid used while milling LAST powders, one can shift from hard to soft agglomerates, where the literature shows that soft agglomerates are less harmful to the final, sintered product. Also, in agreement with the results from the literature on other materials, wet milling of LAST powders produced smaller particle sizes but required longer times to reach the grindability limit

  6. Dependence of rates of breakage on fines content in wet ball mill grinding

    Science.gov (United States)

    Bhattacharyya, Anirban

    that breakage rates were being influenced by the milling environment as a whole. Primarily, there was always an increase in the breakage rates of coarser fractions with an increase in the amount of fines in the particle population. Consequently, the breakage rates of the finer size fractions were observed to decrease with an increase in grind time. Similar trends were noticed for 2nd order specific selection functions, where incremental inputs of specific energy were provided to observe realtime trends in the nonlinearity of breakage rates closely. Although the breakage rates for coarser size fractions increase with an increase in the amount of fines, the nature of nonlinearities varied with extended grind times. 1st order and 2nd order energy-specific breakage rates were observed to notice the variation in trends with extended grind times. Implications of such nonlinearities in specific breakage rates of various materials were tested on predictive simulation techniques, using the normalized linear population balance model and compared with an incremental methodology of specific energy input.

  7. Milling of rice grains. The degradation on three structural levels of starch in rice flour can be independently controlled during grinding.

    Science.gov (United States)

    Tran, Thuy T B; Shelat, Kinnari J; Tang, Daniel; Li, Enpeng; Gilbert, Robert G; Hasjim, Jovin

    2011-04-27

    Whole polished rice grains were ground using cryogenic and hammer milling to understand the mechanisms of degradation of starch granule structure, whole (branched) molecular structure, and individual branches of the molecules during particle size reduction (grinding). Hammer milling caused greater degradation to starch granules than cryogenic milling when the grains were ground to a similar volume-median diameter. Molecular degradation of starch was not evident in the cryogenically milled flours, but it was observed in the hammer-milled flours with preferential cleavage of longer (amylose) branches. This can be attributed to the increased grain brittleness and fracturability at cryogenic temperatures, reducing the mechanical energy required to diminish the grain size and thus reducing the probability of chain scission. The results indicate, for the first time, that branching, whole molecule, and granule structures of starch can be independently altered by varying grinding conditions, such as grinding force and temperature.

  8. Low-temperature magnetic behavior of ball-milled copper ferrite

    DEFF Research Database (Denmark)

    Goya, G.F.; Rechenberg, H.R.; Jiang, Jianzhong

    1999-01-01

    We present a study on magnetic properties of CuFe2O4 nanoparticles, produced by high-energy ball milling. The series of samples obtained, with average particle sizes LFAN alpha d RTAN ranging from 61 nm to 9 nm, display increasing relaxation effects at room temperature. Irreversibility of the mag......We present a study on magnetic properties of CuFe2O4 nanoparticles, produced by high-energy ball milling. The series of samples obtained, with average particle sizes LFAN alpha d RTAN ranging from 61 nm to 9 nm, display increasing relaxation effects at room temperature. Irreversibility...... of the magnetization and shifts to negative fields in the hysteresis loops are observed below T-f APEQ 55 K, indicating unidirectional magnetic anisotropy in milled samples. These features could be explained by assuming the formation of a spin-disordered surface layer, which is exchange-coupled to the ferrimagnetic...

  9. Focused ion beam milling of carbon fibres

    International Nuclear Information System (INIS)

    Huson, Mickey G.; Church, Jeffrey S.; Hillbrick, Linda K.; Woodhead, Andrea L.; Sridhar, Manoj; Van De Meene, Allison M.L.

    2015-01-01

    A focused ion beam has been used to mill both individual carbon fibres as well as fibres in an epoxy composite, with a view to preparing flat surfaces for nano-indentation. The milled surfaces have been assessed for damage using scanning probe microscopy nano-indentation and Raman micro-probe analysis, revealing that FIB milling damages the carbon fibre surface and covers surrounding areas with debris of disordered carbon. The debris is detected as far as 100 μm from the milling site. The energy of milling as well as the orientation of the beam was varied and shown to have an effect when assessed by Raman spectroscopy. - Highlights: • Focused ion beam (FIB) milling was used to mill flat surfaces on carbon fibres. • Raman spectroscopy showed amorphous carbon was generated during FIB milling. • The amorphous debris is detected as far as 100 μm from the milling site. • This surface degradation was confirmed by nano-indentation experiments.

  10. An experimental and theoretical approach on the effect of presence of oxygen in milled graphite as lithium storage material

    International Nuclear Information System (INIS)

    Robledo, C.B.; Thomas, J.E.; Luque, G.; Leiva, E.P.M.; Cámara, O.; Barraco, D.; Visintin, A.

    2014-01-01

    The effect of milling time on the morphology of graphite is characterized by XRD, SEM, BET, FTIR and XPS and the electrochemical response of the resulting materials upon lithium-ion absorption is analyzed using different techniques. As milling time is increased, the particle size diminishes and the amount of oxygen content increases. Concomitantly, the capacity for lithium adsorption also increases because new adsorption sites become available due to more surface area and oxygen functional groups. These effects are interpreted using first-principles calculations, which show that the presence of oxygenated species promotes lithium adsorption at higher potentials. This capacity increase is probably not relevant for lithium-ion batteries since there is no intercalation process but rather an adsorption one, but may be of interest for supercapacitive applications. Diffusion coefficients of lithium for different graphite particle sizes are evaluated. The effects of diffusion, particle size and oxygen content are discussed

  11. Mill and mental phenomena: critical contributions to a science of cognition.

    Science.gov (United States)

    Bistricky, Steven L

    2013-06-01

    Attempts to define cognition preceded John Stuart Mill's life and continue to this day. John Stuart Mill envisioned a science of mental phenomena informed by associationism, empirical introspection, and neurophysiology, and he advanced specific ideas that still influence modern conceptions of cognition. The present article briefly reviews Mill's personal history and the times in which he lived, and it traces the evolution of ideas that have run through him to contemporary cognitive concepts. The article also highlights contemporary problems in defining cognition and supports specific criteria regarding what constitutes cognition.

  12. Consolidation of mechanically milled powder mixture of aluminum and quasicrystalline particle; Mechanical milling shita junkessho ryushi / aluminium gokin funmatsu no koka seikeisei

    Energy Technology Data Exchange (ETDEWEB)

    Yuasa, E.; Kawamura, C.; Sugiyama, T. [Musashi Institute of Technology, Tokyo (Japan)

    1998-10-15

    A quasi-crystalline Al65Cu20Fe15 powder prepared from alloy cast rapidly solidified by metal-mold casting, and then it was mixed to aluminum powder with various volume fractions by mechanical milling. The powder milled for above 50ks made homogeneous dispersion of quasi-crystalline phase with particle size less than 1{mu}m. The powder was hot-pressed under various conditions and then its features of consolidation were examined by the observation of microstructure and fracture strength in 3-point-bending of the compacts. When the milled powder was hot-pressed at higher compacting temperature than 673K for 3.6ks under pressure of 600MPa, the compact became to dense. Hardness of the obtained compact increases and its fracture strength decreases with increasing volume fraction of quasi-crystalline particles. Intermetallic compound Al7Cu2Fe forms in the interface of aluminum matrix and quasi-crystalline particle. 11 refs., 10 figs.

  13. A case-referent study of cancer mortality among sulfate mill workers in Sweden.

    Science.gov (United States)

    Andersson, E; Hagberg, S; Nilsson, T; Persson, B; Wingren, G; Torén, K

    2001-05-01

    To investigate whether workers in Swedish sulfate mills have an increased risk of death from certain malignancies that have previously been linked to the pulping process. Subjects of the study (n=2480) were men aged 40-75 at death during 1960-89 in the parishes surrounding four sulfate mills. Exposure assessment was based on information from the personnel files in the mills- 35% of the subjects were recognised there, and work categories were created. Among all sulfate mill workers, the odds ratio (OR) (90% confidence interval (90% CI)) for death from lung cancer was 1.6 (1.1 to 2.3), pleural mesotheliomas 9.5 (1.9 to 48), brain tumours 2.6 (1.2 to 5.3), and liver or biliary tract cancer 2.3 (1.0 to 5.2). There was an increased mortality from leukaemia among workers in the soda recovery plant (5.9 (2.6 to 13)) and bleaching plant and digester house (2.8 (1.0 to 7.5)). Sulfate mill workers were at increased risk of dying from lung cancer and pleural mesotheliomas, probably due to exposure to asbestos. Increased risks of brain tumours and cancers of the liver or biliary tract were also found but the aetiology is not obvious.

  14. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

    Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

  15. Effect of milling on DSC thermogram of excipient adipic acid.

    Science.gov (United States)

    Ng, Wai Kiong; Kwek, Jin Wang; Yuen, Aaron; Tan, Chin Lee; Tan, Reginald

    2010-03-01

    The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (Delta(fus)H) and melting point (T(m)) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of Delta(fus)H and T(m) were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

  16. Anisotropic bonded Sm{sub 2.3}Fe{sub 16.8}Zr{sub 0.2}N{sub y} magnets prepared by milling of as cast material

    Energy Technology Data Exchange (ETDEWEB)

    Gebel, B.; Kubis, M.; Roessler, U.K.; Mueller, K.H. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany). Inst. fuer Metallische Werkstoffe

    2001-07-01

    As cast Sm{sub 2.3}Fe{sub 16.8}Zr{sub 0.2} material was milled for 100 min {<=} t {<=} 900 min. After annealing at 800 C for 1 h and subsequent nitrogenation, the samples were cold compacted in a magnetic field and resin bonded. The coercivity {mu}{sub 0J}H{sub C} of the samples increased from 0.59 T (t = 100 min) to 2.18 T (t = 900 min). On the other hand, the remanence along the texture axis decreased monotonically with increasing milling time due to the decrease of the degree of texture of the aligned powders. Prolonged milling leads finally to the formation of a soft magnetic phase as indicated by a shoulder in the demagnetization curve for t > 600 min. The highest energy product (BH){sub max} of 50 kJm{sup -3} (136 kJm{sup -3} for the theoretical density of 7.7 gcm{sup -3}) was obtained for an intermediate milling time of 400 min. Zn bonding of the powders resulted in magnets with lower energy products but improved coercivities. (orig.)

  17. Surface Quality of Staggered PCD End Mill in Milling of Carbon Fiber Reinforced Plastics

    Directory of Open Access Journals (Sweden)

    Guangjun Liu

    2017-02-01

    Full Text Available Machined surface quality determines the reliability, wear resistance and service life of carbon fiber reinforced plastic (CFRP workpieces. In this work, the formation mechanism of the surface topography and the machining defects of CFRPs are proposed, and the influence of milling parameters and fiber cutting angles on the surface quality of CFRPs is obtained, which can provide a reference for extended tool life and good surface quality. Trimming and slot milling tests of unidirectional CFRP laminates are performed. The surface roughness of the machined surface is measured, and the influence of milling parameters on the surface roughness is analyzed. A regression model for the surface roughness of CFRP milling is established. A significance test of the regression model is conducted. The machined surface topography of milling CFRP unidirectional laminates with different fiber orientations is analyzed, and the effect of fiber cutting angle on the surface topography of the machined surface is presented by using a digital super depth-of-field microscope and scanning electron microscope (SEM. To study the influence of fiber cutting angle on machining defects, the machined topography under different fiber orientations is analyzed. The slot milling defects and their formation mechanism under different fiber cutting angles are investigated.

  18. Unique specification of Yang-Mills solutions

    International Nuclear Information System (INIS)

    Campbell, W.B.; Joseph, D.W.; Morgan, T.A.

    1980-01-01

    Screened time-independent cylindrically-symmetric solutions of Yang-Mills equations are given which show that the source does not uniquely determine the field. However, these particular solutions suggest a natural way of uniquely specifying solutions in terms of a physical realization of a symmetry group. (orig.)

  19. PERSPECTIVES OF MODERNIZATION OF WIRE MILL OF HOT ROLLING 150 AT RUP “BMZ”

    Directory of Open Access Journals (Sweden)

    A. V. Gontarj

    2004-01-01

    Full Text Available The offered modernization of the mill presumes the increase of capacity of the small-sort wire mill of hot milling 150 approximately till 40% at reduction of cost of the produced on it rolled wire by 15%, that will allow in future as well to grow the volumes of hardware production.

  20. Two-step milling on the carbonyl iron particles and optimizing on the composite absorption

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yonggang, E-mail: xuyonggang221@163.com [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Yuan, Liming; Wang, Xiaobing [Science and Technology on Electromagnetic Scattering Laboratory, Shanghai 200438 (China); Zhang, Deyuan [Bionic and Micro/Nano/Bio Manufacturing Technology Research Center, School of Mechanical Engineering and Automation, Beihang University, Beijing 100191 (China)

    2016-08-15

    The flaky carbonyl iron particles (CIPs) were prepared using a two-step milling process. The surface morphology was characterized by the scanning electron microscopy, the static magnetic property was evaluated on a vibrating sample magnetometer and X-ray diffraction (XRD) patterns were done to analyze the particle crystal grain structure. The complex permittivity and permeability were measured using a vector network analyzer in the frequency range of 2–18 GHz. Then Hermite interpolation based on the calculated scattering parameters of the tested composite was used to derive the permittivity and permeability of the composite with random volume content. The results showed that the saturation magnetization value of the flaky CIPs decreased as the CIPs was changed to the flakes by high and low speeding milling. The diffraction peaks of the single α-Fe existed in the XRD pattern of CIPs, and the characteristic peaks was broad and the intensity of the diffraction pattern was lower as the high-speeding milling time increased. The sample H2L20 had the largest particle size, the average diameter was 8.64 μm, the thickness was 0.59 μm according to the fitted aspect ratio 14.65. The derived permittivity and permeability using the Hermite interpolation was accurate compared with the tested result, the deviation was about 0.39 + j0.45 and 2.5 + j0.51. Finally, the genetic algorithm was used to optimize the thickness of the CIPs composite of a wide absorbing band of 8–18 GHz. The optimized reflection loss (RL) result showed that the absorbing composites with thickness 1.47 mm had an excellent absorbing property (RL < −10 dB) in 8–18 GHz. - Graphical abstract: The property of absorber added two speeding milling CIPs could be enhanced using the genetic algorithm. - Highlights: • Flaky CIPs were prepared using a two-step milling process. • The permeability increased during the low speeding milling. • The aspect ratio of flaky CIPs increased in the optimized process

  1. Yang-Mills gravity in biconformal space

    International Nuclear Information System (INIS)

    Anderson, Lara B; Wheeler, James T

    2007-01-01

    We write a gravity theory with Yang-Mills-type action using the biconformal gauging of the conformal group. We show that the resulting biconformal Yang-Mills gravity theories describe 4-dim, scale-invariant general relativity in the case of slowly changing fields. In addition, we systematically extend arbitrary 4-dim Yang-Mills theories to biconformal space, providing a new arena for studying flat-space Yang-Mills theories. By applying the biconformal extension to a 4-dim pure Yang-Mills theory with conformal symmetry, we establish a 1-1, onto mapping between a set of gravitational gauge theories and 4-dim, flat-space gauge theories

  2. Releases of radioactivity from uranium mills and effluent treatment costs

    International Nuclear Information System (INIS)

    Witherspoon, J.P.; Sears, M.B.; Blanco, R.E.

    1977-01-01

    Airborne releases of radioactive materials from uranium milling to the environment consist of ore dust, yellowcake dust, tailings dust, and radon gas while the mill is active. After a mill has ceased operations, tailings may be stabilized to minimize or prevent airborne releases of radioactive particulates. However, radon gas will continue to be released in amounts inversely proportional to the degree of stabilization treatment (and expense). Liquid waste disposal is by evaporation and natural seepage to the ground beneath the tailings impoundment area. The release of radioactive materials (and potential radiation exposures) determines the majority of costs associated with minimizing the environmental impact of uranium milling. Radwaste treatments to reduce estimated radiation doses to individuals to 3 to 5% of those received with current milling practices are equivalent to $0.66 per pounds of U 3 O 8 and 0.032 mill per kWhr of electricity. This cost would cover a high efficiency reverse jet bag filter and high energy venturi scrubbers for dusts, neutralization of liquids, and an asphalt-lined tailings basin with a clay core dam to reduce seepage. In addition, this increased cost would cover stabilization of tailings, after mill closure, with a 1-in. asphalt membrane topped by 2 ft of earth and 0.5 ft of crushed rock to provide protection against future leaching and wind erosion. The cost of reducing the radiological hazards associated with uranium milling to this degree would contribute about 0.4% to the current total cost of nuclear power

  3. Magnetic properties of La{sub 0.7}Ca{sub 0.3}MnO{sub 3} nanoparticles prepared by reactive milling

    Energy Technology Data Exchange (ETDEWEB)

    Do Hung Manh [Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam)], E-mail: manhdh@ims.vast.ac.vn; Nguyen Chi Thuan [Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Pham Thanh Phong [Nha Trang Pedagogic College, Khanh Hoa Province (Viet Nam); Le Van Hong; Nguyen Xuan Phuc [Institute of Materials Science, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam)

    2009-06-24

    La{sub 0.7}Ca{sub 0.3}MnO{sub 3} (LCMO) nanoparticles were synthesized by reactive milling in ambient conditions. Magnetic properties of LCMO single-phase nanocrystalline particles were studied. LCMO nanoparticles exhibit superparamagnetism with blocking temperature that decreases in the logarithmic function as increasing applied magnetic field. Besides, the blocking temperature decreases as increasing milling time from 8 h to 16 h. The temperature dependence of the saturation magnetization shows a strong collective excitation due to the spin wave that depends on temperature in form T{sup {alpha}} with {alpha} = 1.7, which slightly deviates from the Bloch law.

  4. FAILURE ANALYSIS IN TUBING OF AIR PREHEATER OF BOILER FROM A SUGARCANE MILL

    Directory of Open Access Journals (Sweden)

    Joner Oliveira Alves

    2014-10-01

    Full Text Available The increased demand for energy from sugarcane bagasse has made the sugar and alcohol mills search alternatives to reduce maintenance of the boilers, releasing more time to the production. The stainless steel use has become one of the main tools for such reduction. However, specification errors can lead to premature failures. This work reports the factors that led tubes of AISI 409 stainless steel fail after half season when applied in a air preheater of boiler from a sugarcane mill. In such application, the AISI 304 lasts about 15 seasons and the carbon steel about 3. A tube sent by the sugar mill was characterized by wet chemical analysis, optical microscopy and EDS. Results indicated chloride formation on the internal walls of the tube, which combined with the environment, accelerated the corrosion process. The carbon steel showed high lifetime due to a 70% higher thickness. Due to the work condictions is recommended the use of stainless steels with higher corrosion resistance, such as the traditional AISI 304 or the ferritic AISI 444, the last presents better thermal exchange.

  5. Heat generation ability in AC magnetic field of nano MgFe2O4-based ferrite powder prepared by bead milling

    International Nuclear Information System (INIS)

    Hirazawa, Hideyuki; Aono, Hiromichi; Naohara, Takashi; Maehara, Tsunehiro; Sato, Mitsunori; Watanabe, Yuji

    2011-01-01

    Nanosized MgFe 2 O 4 -based ferrite powder having heat generation ability in an AC magnetic field was prepared by bead milling and studied for thermal coagulation therapy applications. The crystal size and the particle size significantly decreased by bead milling. The heat generation ability in an AC magnetic field improved with the milling time, i.e. a decrease in crystal size. However, the heat generation ability decreased for excessively milled samples with crystal sizes of less than 5.5 nm. The highest heat ability (ΔT=34 o C) in the AC magnetic field (370 kHz, 1.77 kA/m) was obtained for fine MgFe 2 O 4 powder having a ca. 6 nm crystal size (the samples were milled for 6-8 h using 0.1 mm φ beads). The heat generation of the samples was closely related to hysteresis loss, a B-H magnetic property. The reason for the high heat generation properties of the samples milled for 6-8 h using 0.1 mm φ beads was ascribed to the increase in hysteresis loss by the formation of a single domain. Moreover, the improvement in heating ability was obtained by calcination of the bead-milled sample at low temperature. In this case, the maximum heat generation (ΔT=41 o C) ability was obtained for a ca. 11 nm crystal size sample was prepared by crystal growth during the sample calcination. On the other hand, the ΔT value for Mg 0.5 Ca 0.5 Fe 2 O 4 was synthesized using a reverse precipitation method decreased by bead milling. - Research Highlights: →The crystal and particle size for MgFe 2 O 4 based ferrite were decreased by bead milling. →The highest heat ability was obtained for MgFe 2 O 4 having a ca. 6 nm crystal size. →This high heat generation ability was ascribed to the increase in hysteresis loss. →Hysteresis loss was increased by the formation of a single domain.

  6. Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments.

    Science.gov (United States)

    Belenguer, Ana M; Lampronti, Giulio I; Sanders, Jeremy K M

    2018-01-23

    The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the presence of very small amounts of added solvent. To reproducibly and accurately capture this sensitivity, the experimentalist needs to carefully consider every single factor that can affect the ball mill grinding reaction under investigation, from ensuring the grinding jars are clean and dry before use, to accurately adding the stoichiometry of the starting materials, to validating that the delivery of solvent volume is accurate, to ensuring that the interaction between the solvent and the powder is well understood and, if necessary, a specific soaking time is added to the procedure. Preliminary kinetic studies are essential to determine the necessary milling time to achieve equilibrium. Only then can exquisite phase composition curves be obtained as a function of the solvent concentration under ball mill liquid assisted grinding (LAG). By using strict and careful procedures analogous to the ones here presented, such milling equilibrium curves can be obtained for virtually all milling systems. The system we use to demonstrate these procedures is a disulfide exchange reaction starting from the equimolar mixture of two homodimers to obtain at equilibrium quantitative heterodimer. The latter is formed by ball mill grinding as two different polymorphs, Form A and Form B. The ratio R = [Form B] / ([Form A] + [Form B]) at milling equilibrium depends on the nature and concentration of the solvent in the milling jar.

  7. Influence of rice sample preparation and milling procedures on milling quality appraisals

    Science.gov (United States)

    The objective of this research was to investigate the effect of sample preparation and milling procedure on milling quality appraisals of rough rice. Samples of freshly harvested medium-grain rice (M202) with different initial moisture contents (MCs) ranging from 20.2% to 25.1% (w.b.) were used for...

  8. Delamination of hexagonal boron nitride in a stirred media mill

    International Nuclear Information System (INIS)

    Damm, C.; Körner, J.; Peukert, W.

    2013-01-01

    A scalable process for delamination of hexagonal boron nitride in an aqueous solution of the non-ionic surfactant TWEEN85 using a stirred media mill is presented. The size of the ZrO 2 beads used as grinding media governs the dimensions of the ground boron nitride particles as atomic force microscopic investigations (AFM) reveal: the mean flakes thickness decreases from 3.5 to 1.5 nm and the ratio between mean flake area and mean flake thickness increases from 2,200 to 5,800 nm if the grinding media size is reduced from 0.8 to 0.1 mm. This result shows that a high number of stress events in combination with low stress energy (small grinding media) facilitate delamination of the layered material whereas at high stress energies in combination with a low number of stress events (large grinding media) breakage of the layers dominates over delamination. The results of particle height analyses by AFM show that few-layer structures have been formed by stirred media milling. This result is in agreement with the layer thickness dependence of the delamination energy for hexagonal boron nitride. The concentration of nanoparticles remaining dispersed after centrifugation of the ground suspension increases with grinding time and with decreasing grinding media size. After 5 h of grinding using 0.1 mm ZrO 2 grinding media the yield of nanoparticle formation is about 5 wt%. The nanoparticles exhibit the typical Raman peak for hexagonal boron nitride at 1,366 cm −1 showing that the in-plane order in the milled platelets is remained.

  9. Soil carbon 4 per mille

    NARCIS (Netherlands)

    Mulder, V.L.

    2017-01-01

    The ‘4 per mille Soils for Food Security and Climate’ was launched at the COP21 with an aspiration to increase global soil organic matter stocks by 4 per 1000 (or 0.4 %) per year as a compensation for the global emissions of greenhouse gases by anthropogenic sources. This paper surveyed the soil

  10. Microstructural analysis of sinterized aluminum powder obtained by the high energy milling of beverage cans

    International Nuclear Information System (INIS)

    Souza, Jose Raelson Pereira de; Peres, Mauricio Mhirdaui

    2016-01-01

    The objective is the study of the effect of high energy milling on the sintering of aluminum from beverage cans. The selected aluminum cans were cut and subjected to high energy milling under a common atmosphere (in the air). In milling, three grams of aluminum was used to maintain the ratio of 10/1 between the mass of the beads and the material. The milling time was varied in 1h, 1.5h and 2h, keeping the other variables constant. The particle size distribution was measured by laser granulometry, for further compaction and sintering at a temperature of 600 ° C for 2 h. The samples were characterized by scanning electron microscopy (SEM). The granulometric analysis of the powders found that higher milling times produced finer particles. Powders with granulometry of less than 45 μm were obtained at 1 h, 1.5 h and 2 h times. The times of 1.5h and 2h promoted finer particles with better distribution of size. The SEM analyzes showed little variation in the shape of the particles as a function of the variation of the grinding times, presenting irregularities in the platelet geometry. The sintering time and temperature were effective in the densification of the powder particles, which were influenced by the average particle size

  11. Increasing instruction time in school does increase learning

    DEFF Research Database (Denmark)

    Andersen, Simon Calmar; Humlum, Maria; Nandrup, Anne Brink

    2016-01-01

    Increasing instruction time in school is a central element in the attempts of many governments to improve student learning, but prior research—mainly based on observational data—disputes the effect of this approach and points out the potential negative effects on student behavior. Based on a large......-scale, cluster-randomized trial, we find that increasing instruction time increases student learning and that a general increase in instruction time is at least as efficient as an expert-developed, detailed teaching program that increases instruction with the same amount of time. These findings support the value...... of increased instruction time....

  12. Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li

    2011-05-04

    In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

  13. Learning Activity Packets for Milling Machines. Unit I--Introduction to Milling Machines.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This learning activity packet (LAP) outlines the study activities and performance tasks covered in a related curriculum guide on milling machines. The course of study in this LAP is intended to help students learn to identify parts and attachments of vertical and horizontal milling machines, identify work-holding devices, state safety rules, and…

  14. Influence of milling process in the surface energy of glass tile frits

    International Nuclear Information System (INIS)

    Tamayo, A.; Rubio, F.; Otero, J. L.; Rubio, J.

    2013-01-01

    In this work has been studied the influence of the milling process of two ceramic frits used in the ceramic tile industry. Both glass frits were of similar chemical composition changing SiO 2 by 5% of B 2 O 3 and both of them were water or dry milled. Glass frit surfaces were characterized by FT-IR, Karl-Fischer (K-F) titration and Inverse Gas Chromatography at Infinite Dilution (IGC-ID). By K-F titration it was observed that water milled frits presented 28 and 26 OH groups for 100 A 2 if they do not contain or contain boron, respectively. These surface changes are also observed by IGC-ID. Thus, the glass frit without boron and dry milled presented the highest dispersive surface energy (44 mJ.m - 2) and the less acidic constant (0.13 kJ.mol - 1). Both glass frits are amphoteric with acidic and base surface active sites, and that frit without boron presents the higher basicity. Milling process influences in the acid-base surface characteristics of both frits by increasing the basicity for the one without boron and increasing for the other one. This has been assigned to the different location of hydroxyl groups where the higher interaction is the one that does not contain boron and dry milled as K-F results. (Author)

  15. Dead time and recovery time investigations on grinding plants with the aid of radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Roetzer, H; Hagspiel, W

    1977-02-01

    With the aid of the radionuclides Mn 56 and Na 24 as tracers, respectively, the following characteristics were investigated for a roller mill and for a tandem air-swept grinding plant: the time of passage of the mill feed material, the retention time distribution in the grinding system (most frequent and mean retention time), and the time required for, respectively, 50%, 90% and 95% of the material to pass, in some instances separately for the three raw material components limestone, clay and sand. In addition, in the case of the air-swept grinding plant the time required for conveying the raw meal sample from the sampling point to the X-ray fluorescence analysis apparatus was determined. The mean retention time of the material in the two roller mills IV and V was 2.93 and 2.55 minutes respectively; for the tandem air-swept grinding plant it was 8 minutes. The time taken for 90% of the mill feed to pass through the mill was 5.5 and 5 minutes for the roller mills respectively and was about 18.3 minutes for the air-swept plant. The dead time vor conveying the raw meal sample to the X-ray fluorescence apparatus, including further grinding of the sample in a vibratory mill, was 12 minutes.

  16. Surface topography and roughness of high-speed milled AlMn1Cu

    Science.gov (United States)

    Wang, Zhenhua; Yuan, Juntang; Yin, Zengbin; Hu, Xiaoqiu

    2016-10-01

    The aluminum alloy AlMn1Cu has been broadly applied for functional parts production because of its good properties. But few researches about the machining mechanism and the surface roughness were reported. The high-speed milling experiments are carried out in order to improve the machining quality and reveal the machining mechanism. The typical topography features of machined surface are observed by scan electron microscope(SEM). The results show that the milled surface topography is mainly characterized by the plastic shearing deformation surface and material piling zone. The material flows plastically along the end cutting edge of the flat-end milling tool and meanwhile is extruded by the end cutting edge, resulting in that materials partly adhere to the machined surface and form the material piling zone. As the depth of cut and the feed per tooth increase, the plastic flow of materials is strengthened and the machined surface becomes rougher. However, as the cutting speed increases, the plastic flow of materials is weakened and the milled surface becomes smoother. The cutting parameters (e.g. cutting speed, feed per tooth and depth of cut) influencing the surface roughness are analyzed. It can be concluded that the roughness of the machined surface formed by the end cutting edge is less than that by the cylindrical cutting edge when a cylindrical flat-end mill tool is used for milling. The proposed research provides the typical topography features of machined surface of the anti-rust aluminum alloy AlMn1Cu in high speed milling.

  17. Neglecting rice milling yield and quality underestimates economic losses from high-temperature stress.

    Directory of Open Access Journals (Sweden)

    Nathaniel B Lyman

    Full Text Available Future increases in global surface temperature threaten those worldwide who depend on rice production for their livelihoods and food security. Past analyses of high-temperature stress on rice production have focused on paddy yield and have failed to account for the detrimental impact of high temperatures on milling quality outcomes, which ultimately determine edible (marketable rice yield and market value. Using genotype specific rice yield and milling quality data on six common rice varieties from Arkansas, USA, combined with on-site, half-hourly and daily temperature observations, we show a nonlinear effect of high-temperature stress exposure on yield and milling quality. A 1 °C increase in average growing season temperature reduces paddy yield by 6.2%, total milled rice yield by 7.1% to 8.0%, head rice yield by 9.0% to 13.8%, and total milling revenue by 8.1% to 11.0%, across genotypes. Our results indicate that failure to account for changes in milling quality leads to understatement of the impacts of high temperatures on rice production outcomes. These dramatic losses result from reduced paddy yield and increased percentages of chalky and broken kernels, which together decrease the quantity and market value of milled rice. Recently published estimates show paddy yield reductions of up to 10% across the major rice-producing regions of South and Southeast Asia due to rising temperatures. The results of our study suggest that the often-cited 10% figure underestimates the economic implications of climate change for rice producers, thus potentially threatening future food security for global rice producers and consumers.

  18. Pulp-mill related polychlorinated organic compounds in Baltic Sea sediments

    Energy Technology Data Exchange (ETDEWEB)

    Jonsson, Per (Swedish Environmental Protection Agency, Solna (Sweden)); Rappe, C.; Kjeller, L.O. (Umeaa Univ. (Sweden). Inst. of Environmental Chemistry); Kierkegaard, A. (Stockholm Univ. (Sweden). Inst. of Applied Environmental Research); Haakansson, L. (Uppsala Univ. (Sweden). Inst. of Earth Sciences); Jonsson, Bjoern (County Adm. Board, Umeaa (Sweden))

    1993-01-01

    Sediment samples from the Baltic basin were analyzed for PCDD/Fs, alkyl-CDFs, chloroguaiacols and EOCl. The EOCl distribution pattern in the Iggesund pulp-mill area shows high sediment concentrations close to the mill, and decreasing concentrations with increasing distance from the mill. Two series of alkyl-CDFs have been identified. The PCDD/Fs in offshore surficial sediments from the Baltic proper show a typical incineration pattern, while sediments collected in the vicinity of the mill show enhanced levels of 2,3,7,8-tetraCDD, 2,3,7,8- and 1,2,7,8-tetraCDF, and 1,2,3,7,8-pentaCDD. These PCDD/F congeners are statistically correlated to di-, tri-, and tetrachloroguaiacols, alkyl-CDFs, EOCl, and to the distance from the pulp mill, indicating the same source and transportation regime. Principal component analysis of the data set supports this conclusion. The three 2,3,7,8-tetrachloro-substituted PCDD/F congeners have formerly been found in high concentrations in sediments and crab hepatopancreas close to a pulp mill on the Swedish west coast. Our results from a pulp mill on the Swedish east coast support the conclusion that these congeners are typically associated with pulp bleaching. Deep layer sediments have significantly lower levels of PCDD/Fs. The isomer profiles are different in the surficial and the deep sediments, indicating a more natural preindustrial production of PCDD/Fs. (53 refs., 7 figs.).

  19. Experimental Investigation on Ductile Mode Micro-Milling of ZrO2 Ceramics with Diamond-Coated End Mills

    Directory of Open Access Journals (Sweden)

    Rong Bian

    2018-03-01

    Full Text Available ZrO2 ceramics are currently used in a broad range of industrial applications. However, the machining of post-sintered ZrO2 ceramic is a difficult task, due to its high hardness and brittleness. In this study, micro-milling of ZrO2 with two kinds of diamond-coated end mills has been conducted on a Kern MMP 2522 micro-milling center (Kern Microtechnik GmbH, Eschenlohe, Germany. To achieve a ductile mode machining of ZrO2, the feed per tooth and depth of cut was set in the range of a few micrometers. Cutting force and machined surface roughness have been measured by a Kistler MiniDynamometer (Kistler Group, Winterthur, Switzerland and a Talysurf 120 L profilometer (Taylor Hobson Ltd., Leicester, UK, respectively. Machined surface topography and tool wear have been examined under SEM. Experiment results show that the material can be removed in ductile mode, and mirror quality surface with Ra low as 0.02 μm can be achieved. Curled and smooth chips have been collected and observed. The axial cutting force Fz is always bigger than Fx and Fy, and presents a rising trend with increasing of milling length. Tool wear includes delamination of diamond coating and wear of tungsten carbide substrate. Without the protection of diamond coating, the tungsten carbide substrate was worn out quickly, resulting a change of tool tip geometry.

  20. The progress in the researches for uranium mill tailings cleaning treatment and no-waste uranium ore milling processes

    International Nuclear Information System (INIS)

    Wang Jintang

    1990-01-01

    The production of uranium mill tailings and their risk assessment are described. The moethods of uranium mill tailings disposal and management are criticized and the necessity of the researches for uranium mill tailings cleaning treatment and no-wasle uranium ore milling process are demonstrated. The progress for these researches in China and other countries with uranium production is reviewed, and the corresponding conclusions are reported

  1. Effect of high-energy ball milling in the structural and textural properties of kaolinite

    Directory of Open Access Journals (Sweden)

    E. C. Leonel

    2014-06-01

    Full Text Available Through the process of high-energy ball milling it is possible to obtain solid materials with higher surface area and different particle sizes. These characteristics are very important for some application such as adsorption. Besides, applications of some clays depend on the functionalization which, for kaolinite, takes place in the aluminol groups. Modification in the structural and textural properties of kaolinite by high-energy milling can improve functionalization of kaolinite due to the exposure of aluminol groups. In this work studies were done on the influence of high-energy ball milling on the morphological properties of kaolinite, taking into account parameters such as filling of the miller, number of balls and amount of mass to be milled. Moreover, studies involving milling kinetics of purified kaolinite were carried out to verify modification in the morphology of kaolinite with milling time.

  2. Impact Load Behavior between Different Charge and Lifter in a Laboratory-Scale Mill.

    Science.gov (United States)

    Yin, Zixin; Peng, Yuxing; Zhu, Zhencai; Yu, Zhangfa; Li, Tongqing

    2017-07-31

    The impact behavior between the charge and lifter has significant effect to address the mill processing, and is affected by various factors including mill speed, mill filling, lifter height and media shape. To investigate the multi-body impact load behavior, a series of experiments and Discrete Element Method (DEM) simulations were performed on a laboratory-scale mill, in order to improve the grinding efficiency and prolong the life of the lifter. DEM simulation hitherto has been extensively applied as a leading tool to describe diverse issues in granular processes. The research results shown as follows: The semi-empirical power draw of Bond model in this paper does not apply very satisfactorily for the ball mills, while the power draw determined by DEM simulation show a good approximation for the measured power draw. Besides, the impact force on the lifter was affected by mill speed, grinding media filling, lifter height and iron ore particle. The maximum percent of the impact force between 600 and 1400 N is at 70-80% of critical speed. The impact force can be only above 1400 N at the grinding media filling of 20%, and the maximum percent of impact force between 200 and 1400 N is obtained at the grinding media filling of 20%. The percent of impact force ranging from 0 to 200 N decreases with the increase of lifter height. However, this perfect will increase above 200 N. The impact force will decrease when the iron ore particles are added. Additionally, for the 80% of critical speed, the measured power draw has a maximum value. Increasing the grinding media filling increases the power draw and increasing the lifter height does not lead to any variation in power draw.

  3. Continued care of uranium mill sites: some economic considerations

    International Nuclear Information System (INIS)

    Harrington, W.; Sawyer, J.W. Jr.

    1978-01-01

    A critique of recently enacted legislation authorizing the New Mexico Environmental Improvement Agency to regulate uranium mills in the state is presented. Under this new legislation, the Agency is authorized to require payment of up to 10 cents per pound of yellowcake from each licensed mill in the state until a total of $1 million has been deposited by that mill. The continued care fund thus created will provide for maintenance in perpetuity of mill sites after being decommissioned. Arguments are presented, based on calculations for a typical 5,000 ton per day mill, that even the maximum amount is not likely to generate sufficient income to support an adequate maintenance program. The matter is further aggravated by the rate of inflation which will increase costs beyond the coverage provided by a fixed funding system. To correct this situation, it is proposed that (1) the fund should generate an income stream sufficient to meet all maintenance costs based on currently available information on costs, interest, and inflation rates, and (2) the terms of the continued care contribution should be readily alterable as new information becomes available. The latter condition should be coupled with removal of the upper statutory limit now established for the fund

  4. 75 FR 49524 - Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding...

    Science.gov (United States)

    2010-08-13

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-73,695] Woodland Mills Corporation, Mill Spring, NC; Notice of Affirmative Determination Regarding Application for Reconsideration By application dated July 22, 2010, petitioners requested administrative [[Page 49525

  5. RESEARCH ON THE STUDY OF MATERIAL DEFECTS AND SOMECOAL MILLS SUBASSEMBLIES LIFE TIME

    Directory of Open Access Journals (Sweden)

    Cristina LAPADUSI

    2013-05-01

    Full Text Available The defectsfrom the structureof metallic materials of whichare manufactured the pieces, canbeputoutbyNDT. One ofNDTmethods, commonly usedin practiceisultrasonicmethod.In this paper are rendered the results of the determinations by the effects of coal mills bars by type DGS 100,obtained with ultrasound devices by type PHASOR XS.

  6. Microstructural evolution of nanostructured Ti0.9Al0.1N prepared by reactive ball-milling

    International Nuclear Information System (INIS)

    Bhaskar, U.K.; Bid, S.; Pradhan, S.K.

    2011-01-01

    Research highlights: → Nanocrystalline stoichiometric Ti 0.9 Al 0.1 N powder has been prepared by ball-milling the 0.9 mol fraction of α-Ti (hcp) and 0.1 mol fraction of aluminum (fcc) powders under N 2 at room temperature. Initially, α-Ti phase partially transformed to the transient β-Ti phase and Ti 0.9 Al 0.1 N (fcc) phase is noticed to form after 3 h of milling. Nanocrystalline stoichiometric Ti 0.9 Al 0.1 N phase is formed after 7 h of milling. The main features which are observed in the present study are stated below: 1.During ball-milling of α-Ti, the α-Ti phase partially converted to transient cubic β-Ti phase within 1 h of milling. 2.Ti 0.9 Al 0.1 N (fcc) phase is noticed to form after 3 h of milling. Complete formation of Ti 0.9 Al 0.1 N (fcc) is obtained at 7 h of milling which is lesser than complete formation time (9 h) of TiN. Doping Al atoms accelerates the formation of (TiAl)N phase. 3.The particle size of Ti 0.9 Al 0.1 N decrease rapidly up to 3 h and then increase slightly due to agglomeration effect. 4.The particle size of Ti 0.9 Al 0.1 N estimated from X-ray is in good agreement with that measured from HRTEM. - Abstract: Nanocrystalline stoichiometric Ti 0.9 Al 0.1 N powder has been prepared by ball-milling the α-Ti (hcp) and aluminum (fcc) powders under N 2 at room temperature. Initially, α-Ti phase partially transformed to the transient cubic β-Ti phase and Ti 0.9 Al 0.1 N (fcc) phase is noticed to form after 3 h of milling. Nanocrystalline stoichiometric Ti 0.9 Al 0.1 N phase is formed after 7 h of milling. After 1 h of milling, all Al atoms are diffused into the α-Ti matrix. The transient β-Ti phase is noticed to form after 1 h of milling and disappears completely after 7 h of milling. Microstructure characterization of unmilled and ball-milled powders by analyzing XRD patterns employing the Rietveld structure refinement reveals the inclusion of Al and nitrogen atoms into the Ti lattice on the way to formation of Ti 0.9 Al 0.1 N

  7. Process intensification effect of ball milling on the hydrothermal pretreatment for corn straw enzymolysis

    International Nuclear Information System (INIS)

    Yuan, Zhengqiu; Long, Jinxing; Wang, Tiejun; Shu, Riyang; Zhang, Qi; Ma, Longlong

    2015-01-01

    Highlights: • Novel pretreatment of ball milling combined with hydrothermal method was presented. • Intensification effect of ball milling was significant for corn straw enzymolysis. • Ball milling destroyed the physical structure of corn straw. • Chemical (liquid mixture) method removed lignin and hemicellulose. • Glucose yield increased from 0.41 to 13.86 mg mL −1 under the optimized condition. - Abstract: Enhancement of the cellulose accessibility is significant for biomass enzymatic hydrolysis. Here, we reported an efficient combined pretreatment for corn straw enzymolysis using ball milling and dilute acid hydrothermal method (a mixture solvent of H 2 O/ethanol/sulfuric acid/hydrogen peroxide liquid). The process intensification effect of ball milling on the pretreatment of the corn straw was studied through the comparative characterization of the physical–chemical properties of the raw and pretreated corn straw using FT-IR, BET, XRD, SEM, and HPLC analysis. The effect of the pretreatment temperature was also investigated. Furthermore, various pretreatment methods were compared as well. Moreover, the pretreatment performance was measured by enzymolysis. The results showed that ball milling had a significant process intensification effect on the corn straw enzymolysis. The glucose concentration was dramatically increased from 0.41 to 13.86 mg mL −1 after the combined treatment of ball milling and hydrothermal. The efficient removal of lignin and hemicellulose and the enlargement of the surface area were considered to be responsible for this significant increase based on the intensive analysis on the main components and the physical–chemical properties of the raw and pretreated corn straw

  8. Biotechnological applications for the utilisation of wastes from palm oil mills

    Energy Technology Data Exchange (ETDEWEB)

    Cheah, S C; Ma, A N; Ooi, L C.L.; Ong, A S.H.

    1988-05-01

    The milling of oil palm fruits produces about two-and-a-half to three times as much effluent as oil does. It also generates a large amount of lignocellulosic wastes, mainly in the form of empty fruit bunches, press cake fibres and nut shell. Research efforts at PORIM have been directed towards the utilisation of these wastes as a means to solve the problem of environmental pollution as well as for the generation of economic returns for the mills. We have studied a thermophilic contact process for the anaerobic digestion of palm oil mill effluent and its potential for generating biogas for energy uses. Our work has also shown that the condensate derived from the fruit sterilisation process during milling is amenable to fermentation for the production of single cell protein (SCP) and exo-enzymes. The enzymes produced have been applied for oil clarification, oil recovery from press cake fibers and saccharification of the fibers for the production of sugar feedstocks. This paper will also introduce the concept of integrated waste management for the palm oil mill through the implementation of these technologies.

  9. Effects of surfactant addition and high-speed ball milling on magnetic powders based on Pr-Fe-B obtained by HDDR

    International Nuclear Information System (INIS)

    Santos, Patricia Brissi

    2011-01-01

    This work verified the effect caused by adding the surfactant in the high speed/energy milling in order to obtain Pr 12 Fe 65.9 Co 16 B 6 Nb 0.1 magnetic nano powders. The first part of this work involved the magnetic powder obtainment through the process of hydrogenation, disproportionation, desorption and recombination (HDDR). The pressure of H2 during the hydrogenation and disproportion steps was 930 mbar and the temperature of desorption and recombination was 840 deg C. Initially, the HDDR powders were subjected a high speed milling process at 900 rpm, with quantity variations of the milling medium (cyclohexane) and without the addition of oleic acid. Then, the HDDR powders were subjected to the milling process with the addition of oleic acid and with milling time variations. After the milling process, heat treatments of the powder were carried out at 700 deg C or 800 deg C for 30 minutes in order to obtain the crystallization of the powder. By performing the procedures, it was verified that the milling efficiency improved with the addition of 6.6 ml of cyclohexane as the milling medium and with the addition of oleic acid. It was determined that for the surfactant additions of 0.02 ml to 0.05 ml, with a milling time of up to 360 minutes, powder agglomeration does not occur in the milling pot and the milling efficiency is higher than 90%. The second stage of this work involved the magnetic powder's characterization obtained by using vibrating sample magnetometer, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Through the characterizations it was found that the powder's magnetic properties improved when the addition of oleic acid in a high-speed /energy milling occurred. It was also verified that the α-Fe phase, present in the powder, shows a crystallite size decrease (from 35 nm to ∼ 10 nm) when the time milling variation occurred; meanwhile, the crystallinity degree was lower in the Pr 2 Fe 14 B phase when the time

  10. Black holes with Yang-Mills hair

    International Nuclear Information System (INIS)

    Kleihaus, B.; Kunz, J.; Sood, A.; Wirschins, M.

    1998-01-01

    In Einstein-Maxwell theory black holes are uniquely determined by their mass, their charge and their angular momentum. This is no longer true in Einstein-Yang-Mills theory. We discuss sequences of neutral and charged SU(N) Einstein-Yang-Mills black holes, which are static spherically symmetric and asymptotically flat, and which carry Yang-Mills hair. Furthermore, in Einstein-Maxwell theory static black holes are spherically symmetric. We demonstrate that, in contrast, SU(2) Einstein-Yang-Mills theory possesses a sequence of black holes, which are static and only axially symmetric

  11. Moessbauer Study of the Ball Milling Disordering Process of FeAl Intermetallic Compounds

    International Nuclear Information System (INIS)

    Oleszak, Dariusz; Bruna, Pere; Crespo, Daniel; Pradell, Trinitat

    2005-01-01

    Structural changes during ball milling of ordered Fe50Al50 intermetallic compounds were studied. X-Ray diffraction allowed the computation of a Long Range Order parameter (LRO) which dropped to zero after a short milling time. The initial B2 ordered structure gradually transforms into a disordered BCC structure, with a final crystallite size of about 25 nm. Moessbauer spectroscopy was used for obtaining a Chemical Short Range Order parameter (CSRO). Using a semiempirical n-body noncentral potential a model of the partially disordered B2 structure was built allowing computing the distribution of Quadrupole Splitting during the disordering process. Comparison between experimental and simulated Moessbauer spectra shows a maximum of disorder in the system for 5h milling, related to the highest value of the lattice spacing and the broader quadrupole hyperfine distribution. However, after milling for times longer than 5h, there is a change on the behavior of the experimental data that cannot be explained by the simple disordering process

  12. Pulp mill as an energy producer

    International Nuclear Information System (INIS)

    Kaulamo, O.

    1998-01-01

    The recovery boilers of pulp mills are today the most significant producers of wood energy. The power-to-heat ratio of the power plant process, i.e., power yield, is poor in existing applications. In the study, an alternative of improving the power yield of conventional pulp mills significantly was studied by applying solutions used in power plants to a pulp mill. Extensive conversion of wood energy into electricity is possible only in the recovery boiler of the pulp mill and in a large combustion boiler of bark, wood waste and wood chips integrated to this boiler. Hence, the harvest and transports of wood raw materials, i.e. pulp wood and energy wood, are integrated, and the fraction going to cook and the energy wood fraction are separated at the pulp mill. The method guarantees competitive supply of energy wood. As a result a SELLUPOWER mill was designed, where the recovery boiler combusting black liquor and the large power plant boiler combusting energy wood are integrated to one unit and constructed to a power plant process with a high power-to-heat ratio. Necessary technical solutions, project costs and economical feasibility compared to a conventional pulp mill were determined, and the effect of different production-economical parameters was also studied. (orig.)

  13. Colorado's prospectus on uranium milling

    International Nuclear Information System (INIS)

    Hazle, A.J.; Franz, G.A.; Gamewell, R.

    1982-01-01

    The first part of this paper will discuss Colorado's control of uranium mill tailings under Titles I and II of the Uranium Mill Tailings Radiation Control Act of 1978. Colorado has a legacy of nine inactive mill sites requiring reclamation under Title I, and two presently active plus a number of new mill proposals which must be regulated in accordance with Title II. Past failures in siting and control on the part of federal jurisdictions have left the state with a heavy legacy requiring extensive effort to address impacts to the state's environment and population. The second part of this paper will discuss the remedial action programme authorized under Public Law 92-314 for Mesa Country, where lack of federal control led to the dispersal of several hundred thousand tons of uranium mill tailings on thousands of properties, including hundreds of homes, schools and other structures. Successful completion of the State efforts under both programmes will depend on a high level of funding and on the maintenance of adequate regulatory standards. (author)

  14. Understanding dental CAD/CAM for restorations - dental milling machines from a mechanical engineering viewpoint. Part A: chairside milling machines.

    Science.gov (United States)

    Lebon, Nicolas; Tapie, Laurent; Duret, Francois; Attal, Jean-Pierre

    2016-01-01

    The dental milling machine is an important device in the dental CAD/CAM chain. Nowadays, dental numerical controlled (NC) milling machines are available for dental surgeries (chairside solution). This article provides a mechanical engineering approach to NC milling machines to help dentists understand the involvement of technology in digital dentistry practice. First, some technical concepts and definitions associated with NC milling machines are described from a mechanical engineering viewpoint. The technical and economic criteria of four chairside dental NC milling machines that are available on the market are then described. The technical criteria are focused on the capacities of the embedded technologies of these milling machines to mill both prosthetic materials and types of shape restorations. The economic criteria are focused on investment costs and interoperability with third-party software. The clinical relevance of the technology is assessed in terms of the accuracy and integrity of the restoration.

  15. Effect of milling time and annealing temperature on nanoparticles evolution for 13.5% Cr ODS ferritic steel powders by joint application of XAFS and TEM

    Science.gov (United States)

    He, P.; Hoffmann, J.; Möslang, A.

    2018-04-01

    The characteristics of strengthening nanoparticles have a major influence on the mechanical property and irradiation resistance of oxide dispersion strengthened (ODS) steels. To determine how to control nanoparticles evolution, 0.3% Ti with 0.3% Y2O3 were added in 13.5%Cr pre-alloyed steel powders via different milling and consolidation conditions, then characterized by transmission electron microscopy (TEM) and X-ray absorption fine structure (XAFS) at synchrotron irradiation facility. The dissolution of Y2O3 is greatly dependent on the milling time at fixed milling speeds. After 24 h of milling, only minor amounts of the initially added Y2O3 dissolve into the steel matrix whereas TEM results reveal nearly complete dissolution of Y2O3 in 80-h-milled powder. The annealed powder FT-A800 (at 800 °C for 1 h) exhibits a structure near to the initially added Y2O3. The slightly deviation may be accounted for considerable lattice distortion related to the presence of atomic vacancies or formation of Y-Ti-O nucleus. The annealed powders FT-A1000 and FT-A1100 contain complex mixtures of Y-O/Y-Ti-O oxides, which cannot be fitted by any single thermally stable compounds. The coordination numbers of these first two shells in the annealed powders significantly raise as a function of the annealing temperature, indicating the formation of more ordered Y-O or Y-Ti-O particles. The extended X-ray absorption fine structure (EXAFS) spectrum could not necessarily distinguish the dominant oxide species.

  16. Magnetic properties of Ni nanoparticles dispersed in silica prepared by high-energy ball milling

    Science.gov (United States)

    González, E. M.; Montero, M. I.; Cebollada, F.; de Julián, C.; Vicent, J. L.; González, J. M.

    1998-04-01

    We analyze the magnetic properties of mechanically ground nanosized Ni particles dispersed in a SiO2 matrix. Our magnetic characterization of the as-milled samples show the occurrence of two blocking processes and that of non-monotonic milling time evolutions of the magnetic-order temperature, the high-field magnetization and the saturation coercivity. The measured coercivities exhibit giant values and a uniaxial-type temperature dependence. Thermal treatment carried out in the as-prepared samples result in a remarkable coercivity reduction and in an increase of the high-field magnetization. We conclude, on the basis of the consideration of a core (pure Ni) and shell (Ni-Si inhomogeneous alloy) particle structure, that the magnetoelastic anisotropy plays the dominant role in determining the magnetic properties of our particles.

  17. Effects of uranium mining and milling on surface water in New Mexico

    International Nuclear Information System (INIS)

    Brandvold, L.L.; Brandvold, D.K.; Popp, C.J.

    1980-01-01

    Currently, there are 35 active mines, 5 mills and 4 ion exchange plants in the Grants area. There was a general increase in uranium and vanadium with time over the San Jose and Puerco System. This doesn't appear to be related to any individual discharge but most likely reflects the general increase in activity in the area. As mining continues, this increase is expected to continue. The project reported here involved determining physical and chemical parameters of the water in the San Jose-Puerco system in New Mexico between March 1978 and September 1980. 14 refs

  18. John Stuart Mill: utilitarismo e liberalismo = John Stuart Mill: utilitarianism and liberalism

    Directory of Open Access Journals (Sweden)

    Simões, Mauro Cardoso

    2013-01-01

    Full Text Available Meu objetivo, neste trabalho, é investigar a compatibilidade das teses utilitaristas e liberais de John Stuart Mill. Apresentarei, inicialmente, os principais críticos da filosofia moral e política de Mill, para os quais o discípulo de Bentham teria abandonado o utilitarismo ou, ainda, não esclarecido suficientemente seu princípio da liberdade, o que o tornaria um pensador assistemático e inconsistente. Minha tese é contrária a tais interpretações, uma vez que sustenta ser Mill consistente. Em seguida, defenderei uma interpretação do princípio da liberdade e da individualidade, procurando demonstrar que seu utilitarismo é compatível com seu liberalismo

  19. Atomic disorder and amorphization of B2-structure CoZr by ball milling

    International Nuclear Information System (INIS)

    Zhou, G.F.; Bakker, H.

    1996-01-01

    For a considerable number of intermetallic compounds it has been found that ball milling introduces atomic (chemical) disorder. Disorder due to milling was demonstrated by x-ray diffraction in AlRu, crystallizing in the B2 structure (ordered b.c.c.) by a decrease of the intensity of superlattice reflections relative to fundamental reflections. The same technique was used to investigate disordering by milling in Ni 3 Al, crystallizing in the L1 2 structure (ordered f.c.c.). In both cases the disorder is anti-site disorder of both components, i.e. both atomic species substitute on the wrong sublattices. Besides x-ray diffraction measurements of magnetic properties turned out to be useful in monitoring structural changes due to milling. The change in the superconducting transition temperature, measured by magnetic a.c. susceptibility, was used to demonstrate atomic disordering by milling in Nb 3 Sn and Nb 3 Au. The type of disorder turned out to be anti-site disorder. Such a type of disorder occurs in the same materials also at high temperatures or after irradiation by neutrons. The disordering was accompanied by an increase of the lattice parameter. An increase in high-field magnetization accompanied by a decrease of the lattice parameter during milling was found in B2 CoGa and B2 CoAl. In principle in the completely ordered state both compounds are non-magnetic, because the CO atoms are shielded from one another by Ga and Al atoms, respectively. However, when a Co atom is transferred to the wrong sublattice, it is surrounded by Co atoms as nearest neighbors and bears a magnetic moment. This explains the strong increase of the magnetization due to milling

  20. Scale-up of organic reactions in ball mills: process intensification with regard to energy efficiency and economy of scale.

    Science.gov (United States)

    Stolle, Achim; Schmidt, Robert; Jacob, Katharina

    2014-01-01

    The scale-up of the Knoevenagel-condensation between vanillin and barbituric acid carried out in planetary ball mills is investigated from an engineering perspective. Generally, the reaction proceeded in the solid state without intermediate melting and afforded selectively only one product. The reaction has been used as a model to analyze the influence and relationship of different parameters related to operation in planetary ball mills. From the viewpoint of technological parameters the milling ball diameter, dMB, the filling degree with respect to the milling balls' packing, ΦMB,packing, and the filling degree of the substrates with respect to the void volume of the milling balls' packing, ΦGS, have been investigated at different reaction scales. It was found that milling balls with small dMB lead to higher yields within shorter reaction time, treaction, or lower rotation frequency, rpm. Thus, the lower limit is set considering the technology which is available for the separation of the milling balls from the product after the reaction. Regarding ΦMB,packing, results indicate that the optimal value is roughly 50% of the total milling beakers' volume, VB,total, independent of the reaction scale or reaction conditions. Thus, 30% of VB,total are taken by the milling balls. Increase of the initial batch sizes changes ΦGS significantly. However, within the investigated parameter range no negative influence on the yield was observed. Up to 50% of VB,total can be taken over by the substrates in addition to 30% for the total milling ball volume. Scale-up factors of 15 and 11 were realized considering the amount of substrates and the reactor volume, respectively. Beside technological parameters, variables which influence the process itself, treaction and rpm, were investigated also. Variation of those allowed to fine-tune the reaction conditions in order to maximize the yield and minimize the energy intensity.

  1. Direct measures of mechanical energy for knife mill size reduction of switchgrass, wheat straw, and corn stover.

    Science.gov (United States)

    Bitra, Venkata S P; Womac, Alvin R; Igathinathane, C; Miu, Petre I; Yang, Yuechuan T; Smith, David R; Chevanan, Nehru; Sokhansanj, Shahab

    2009-12-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be +/-0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  2. Grain dust and respiratory health in South African milling workers.

    Science.gov (United States)

    Bachmann, M; Myers, J E

    1991-01-01

    Respiratory health was investigated in 224 grain milling workers. The likelihood of respiratory symptoms and chronic airflow limitation was raised for workers exposed to dust independent of the effects of smoking. Smokers were more likely than non-smokers to respond to a bronchodilator at the end of the working week. Dust was more strongly associated with most abnormal outcomes than was smoking. Subjective categories of exposure to dust were more strongly associated with most abnormal outcomes than were objective categories. The prevalence of all symptoms at the time of a survey conducted at the mill six years before was higher in workers who subsequently left the mill than in those who remained employed although the differences were not significant. PMID:1931723

  3. Observer Based Fault Detection and Moisture Estimating in Coal Mill

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Mataji, Babak

    2008-01-01

    In this paper an observer-based method for detecting faults and estimating moisture content in the coal in coal mills is presented. Handling of faults and operation under special conditions, such as high moisture content in the coal, are of growing importance due to the increasing...... requirements to the general performance of power plants. Detection  of faults and moisture content estimation are consequently of high interest in the handling of the problems caused by faults and moisture content. The coal flow out of the mill is the obvious variable to monitor, when detecting non-intended drops in the coal...... flow out of the coal mill. However, this variable is not measurable. Another estimated variable is the moisture content, which is only "measurable" during steady-state operations of the coal mill. Instead, this paper suggests a method where these unknown variables are estimated based on a simple energy...

  4. Yang-Mills theory for non-semisimple groups

    CERN Document Server

    Nuyts, J; Nuyts, Jean; Wu, Tai Tsun

    2003-01-01

    For semisimple groups, possibly multiplied by U(1)'s, the number of Yang-Mills gauge fields is equal to the number of generators of the group. In this paper, it is shown that, for non-semisimple groups, the number of Yang-Mills fields can be larger. These additional Yang-Mills fields are not irrelevant because they appear in the gauge transformations of the original Yang-Mills fields. Such non-semisimple Yang-Mills theories may lead to physical consequences worth studying. The non-semisimple group with only two generators that do not commute is studied in detail.

  5. Observables in topological Yang-Mills theories with extended shift supersymmetry

    Energy Technology Data Exchange (ETDEWEB)

    Constantinidis, Clisthenis P; Piguet, Olivier [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil); Spalenza, Wesley [Scuola Internazionale Superiore di Studi Avanzati (SISSA), Trieste (Italy); Centro Brasileiro de Pesquisas Fsicas (CBPF), Rio de Janeiro (Brazil)

    2006-01-01

    We present a complete classification, at the classical level, of the observables of topological Yang-Mills theories with an extended shift supersymmetry of N generators, in any space-time dimension. The observables are defined as the Yang-Mills BRST cohomology classes of shift supersymmetry invariants. These cohomology classes turn out to be solutions of an N-extension of Witten's equivariant cohomology. This work generalizes results known in the case of shift supersymmetry with a single generator. (orig.)

  6. Chevron's Panna Maria mill process description

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    Key features of Chevron's Uranium Mill located near Panna Maria, Texas, are described. The mill is designed to process a nominal 2500 dry tons/day of uranium bearing ore containing 15% uncombined moisture. The following operations at the mill are highlighted: ore receiving, grinding, leaching, countercurrent decantation and tailings disposal, filtering, solvent extraction, solvent stripping, precipitation, drying, and packaging

  7. Semiclassical scattering in Yang-Mills theory

    International Nuclear Information System (INIS)

    Gould, T.M.; Poppitz, E.R.

    1994-01-01

    A classical solution to the Yang-Mills theory is given a semiclassical interpretation. The boundary value problem on a complex time contour which arises from the semiclassical approximation to multiparticle scattering amplitudes is reviewed and applied to the case of Yang-Mills theory. The solution describes a classically forbidden transition between states with a large average number of particles in the limit g→0. It dominates a transition probability with a semiclassical suppression factor equal to twice the action of the well-known BPST instanton. Hence, it is relevant to the problem of high-energy tunnelling. It describes transitions of unit topological charge for an appropriate time contour. Therefore, it may have a direct interpretation in terms of fermion-number violating processes in electroweak theory. The solution describes a transition between an initial state with parametrically fewer particles than the final state. Thus, it may be relevant to the study of semiclassical initial-state corrections in the limit of a small number of initial particles. The implications of these results for multiparticle production in electroweak theory are also discussed. (orig.)

  8. Galilean Yang-Mills theory

    Energy Technology Data Exchange (ETDEWEB)

    Bagchi, Arjun [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Basu, Rudranil [Saha Institute of Nuclear Physics,Block AF, Sector 1, Bidhannagar, Kolkata 700068 (India); Kakkar, Ashish [Indian Institute of Science Education and Research,Dr Homi Bhabha Road, Pashan. Pune 411008 (India); Mehra, Aditya [Indian Institute of Science Education and Research,Dr Homi Bhabha Road, Pashan. Pune 411008 (India); Van Swinderen Institute for Particle Physics and Gravity, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands)

    2016-04-11

    We investigate the symmetry structure of the non-relativistic limit of Yang-Mills theories. Generalising previous results in the Galilean limit of electrodynamics, we discover that for Yang-Mills theories there are a variety of limits inside the Galilean regime. We first explicitly work with the SU(2) theory and then generalise to SU(N) for all N, systematising our notation and analysis. We discover that the whole family of limits lead to different sectors of Galilean Yang-Mills theories and the equations of motion in each sector exhibit hitherto undiscovered infinite dimensional symmetries, viz. infinite Galilean Conformal symmetries in D=4. These provide the first examples of interacting Galilean Conformal Field Theories (GCFTs) in D>2.

  9. Galilean Yang-Mills theory

    International Nuclear Information System (INIS)

    Bagchi, Arjun; Basu, Rudranil; Kakkar, Ashish; Mehra, Aditya

    2016-01-01

    We investigate the symmetry structure of the non-relativistic limit of Yang-Mills theories. Generalising previous results in the Galilean limit of electrodynamics, we discover that for Yang-Mills theories there are a variety of limits inside the Galilean regime. We first explicitly work with the SU(2) theory and then generalise to SU(N) for all N, systematising our notation and analysis. We discover that the whole family of limits lead to different sectors of Galilean Yang-Mills theories and the equations of motion in each sector exhibit hitherto undiscovered infinite dimensional symmetries, viz. infinite Galilean Conformal symmetries in D=4. These provide the first examples of interacting Galilean Conformal Field Theories (GCFTs) in D>2.

  10. Fabrication of Al2O3–20 vol.% Al nanocomposite powders using high energy milling and their sinterability

    International Nuclear Information System (INIS)

    Zawrah, M.F.; Abdel-kader, H.; Elbaly, N.E.

    2012-01-01

    Highlights: ► Al 2 O 3 /Al nanocomposite powders were prepared via high energy ball milling. After 20 h milling, the size of Al 2 O 3 –20 vol.% Al nanocomposite particles was in the range of 23–29 nm. A uniform distribution of nanosized Al reinforcement throughout the Al 2 O 3 matrix, coating the particles was successfully obtained. ► There was no any sign of phase changes during the milling. A competition between the cold welding mechanism and the fracturing mechanism were found during milling and finally the above two mechanisms reached an equilibrium. ► The highest value of relative density was obtained for the sintered bodies at 1500 °C. ► The harness of the sintered composite was decreased while the fracture toughness was improved after addition Al into alumina. -- Abstract: In this study, alumina-based matrix nanocomposite powders reinforced with Al particles were fabricated and investigated. The sinterability of the prepared nanocomposite powder at different firing temperature was also conducted. Their mechanical properties in terms of hardness and toughness were tested. Alumina and aluminum powder mixtures were milled in a planetary ball mill for various times up to 30 h in order to produce Al 2 O 3 –20% Al nanocomposite. The phase composition, morphological and microstructural changes during mechanical milling of the nanocomposite particles were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM) techniques, respectively. The crystallite size and internal strain were evaluated by XRD patterns using Scherrer methods. A uniform distribution of the Al reinforcement in the Al 2 O 3 matrix was successfully obtained after milling the powders. The results revealed that there was no any sign of phase changes during the milling. The crystal size decreased with the prolongation of milling times, while the internal strain increased. A simple model is presented to illustrate the mechanical

  11. Radiation hazards of uranium mining and milling

    International Nuclear Information System (INIS)

    Fry, R.M.

    1975-09-01

    This paper examines each of the radiological problems that arise in these processes and explains their scientific background. The major operational requirement is to ensure that exposure of miners over their working lives to radon and its daughter products does not lead to an unacceptable increase in their chance of contracting lung cancer. Studies on the incidence of lung cancer amongst underground uranium miners indicate that this risk will be small if lifetime exposures are kept below about 120 'working level months', even amongst underground miners who smoke cigarettes. The risk is much smaller again for miners who do not smoke cigarettes. Other hazards that must be controlled are exposure of miners and mill workers to external radiation and to dusts containing long-lived radioactive alpha emitting isotopes. Finally, the solid waste products from the mill (the tailings) which contain most of the naturally occurring radioactivity, must be properly impounded and after closure of the mill, stabilized to ensure long-term containment. Access by the public to the stabilized tailings must be controlled and habitation within the controlled area prohibited. (author)

  12. Texture formation in iron particles using mechanical milling with graphite as a milling aid

    Energy Technology Data Exchange (ETDEWEB)

    Motozuka, S.; Hayashi, K. [Department of Mechanical Engineering, Gifu National College of Technology, 2236-2 Kamimakuwa, Motosu, Gifu 501-0495 (Japan); Tagaya, M. [Department of Materials Science and Technology, Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan); Morinaga, M. [Toyota Physical and Chemical Research Institute, 41-1, Yokomichi, Nagakute, Aichi 480-1192 (Japan)

    2015-09-15

    Crystallographically anisotropic platelet iron particles were successfully prepared using a conventional ball mill with addition of graphite (Gp) particles. The morphological and structural changes resulting from the milling were investigated using scanning electron microscopy and X-ray diffraction. The spherical iron particles were plastically deformed into platelet shapes during the milling. Simultaneously, it is suggested that the size of the Gp particles decreased and adhered as nanoparticles on the surface of the iron particles. The adhered Gp particles affected the plastic deformation behavior of the iron particles: the (001) planes of α-iron were oriented parallel to the particle face, and no preferred in-plane orientation was observed. This study not only details the preparation of soft magnetic metal particles that crystallographically oriented to enhance their magnetic properties but also provides new insight into the activities of the well-established and extensively studied mechanical milling method.

  13. Texture formation in iron particles using mechanical milling with graphite as a milling aid

    International Nuclear Information System (INIS)

    Motozuka, S.; Hayashi, K.; Tagaya, M.; Morinaga, M.

    2015-01-01

    Crystallographically anisotropic platelet iron particles were successfully prepared using a conventional ball mill with addition of graphite (Gp) particles. The morphological and structural changes resulting from the milling were investigated using scanning electron microscopy and X-ray diffraction. The spherical iron particles were plastically deformed into platelet shapes during the milling. Simultaneously, it is suggested that the size of the Gp particles decreased and adhered as nanoparticles on the surface of the iron particles. The adhered Gp particles affected the plastic deformation behavior of the iron particles: the (001) planes of α-iron were oriented parallel to the particle face, and no preferred in-plane orientation was observed. This study not only details the preparation of soft magnetic metal particles that crystallographically oriented to enhance their magnetic properties but also provides new insight into the activities of the well-established and extensively studied mechanical milling method

  14. Co-composting of two-phase olive-mill pomace and poultry manure with tomato harvest stalks.

    Science.gov (United States)

    Sülük, Kemal; Tosun, İsmail; Ekinci, Kamil

    2017-04-01

    In this study, two-phase olive-mill pomace with poultry manure and chopped tomato harvest stalks were composted at different initial carbon/nitrogen (C/N) ratios with fixed free air space of 35%. Composting experiment was carried out in the 15 aerobic reactors made of stainless steel and was monitored for 28 days. During the composting process, temperature, moisture content, organic matter (OM), pH, electrical conductivity, oxygen and carbon dioxide concentrations, total carbon, total nitrogen, ammonium nitrogen ([Formula: see text]), nitrate nitrogen ([Formula: see text]), and total phosphorus were monitored. Compost mass and volume changes were determined at the beginning, during remixings, and at the end of composting. While the stabilization period took less time for the mixtures containing a high amount of poultry manure, the mixtures having the high portion of two-phase olive-mill pomace took a longer time due to the structure of olive stone and its lignin content. Dry matter loss (range: 18.1-34.0%.) in the mixtures increased with an increase in the share of poultry manure and tomato stalks in the initial mixture. OM loss (range: 21.7-46.1%) for tomato stalks (measured separately) during composting increased due to an increase in the ratio of poultry manure in the initial mixtures.

  15. CNTs/Al5083 Composites of High-performance Uniform and Dispersion Fabricated by High-energy Ball-milling

    Directory of Open Access Journals (Sweden)

    GUO Li

    2017-11-01

    Full Text Available Carbon nanotubes (CNTs, mass fraction of 0%-2% reinforced Al5083 composites were fabricated by horizontal high-energy ball milling. The effects of ball milling time and CNTs contents on the properties of composite materials were studied. The micro morphology of CNTs/Al5083 composites was characterized by scanning electron microscopy(SEM and transmission electron microscopy(TEM, the tensile strength and microhardness of the composites were tested. The results indicate that after high-energy ball milling for 1.5h, the carbon nanotubes are dispersed homogeneously in the Al5083 matrix, and good interfacial bonding strength between CNTs and Al5083 is obtained at the addition of 1.5%CNTs. Under these conditions, the tensile strength and microhardness of CNTs/Al5083 composites are 188.8MPa and 136HV, respectively. Compared to Al5083 matrix without CNTs reinforcement, tensile strength and microhardness of CNTs/Al5083 composites are increased by 32.2% and 36%, respectively.

  16. Analysis of potential radiation-induced genetic and somatic effects to man from milling of uranium

    International Nuclear Information System (INIS)

    Momeni, M.H.

    1984-01-01

    Potential mortality from natural causes and from radiation exposure conditions typical of those in the vicinity of uranium mills in the western USA was calculated. The exposure conditions were those assumed to exist in the vicinity of a hypothetical model mill. Dose rates to organs at risk were calculated as a function of time using the Uranium Dispersion and Dosimetry Code (Momeni et al. 1979). The changes in population size, birth rates, and radiation-induced and natural mortalities were calculated using the PRIM code (Momeni 1983). The population of the region within a radius of 80 km from the model mill is projected to increase from 57 428 to 75 638.6 during the 85 years of this analysis. Within the same period, the average birth rates for five-year periods increase from 5067.8 to 7436.1. The cumulative deaths within the five-year periods increase from 724 and 3501.8 from spontaneously induced neoplasms and all causes, respectively, to 1538.2 and 6718.2. In comparison to natural causes, radiation-induced mortality is negligible. The highest rate of death from radiation in any five-year period is only 0.2, compared with 1538.2 deaths attributable to spontaneous incidence. The total radiation-induced genetic disorders were much less than unity for the 85-year period of analysis, in contrast with the 10.7% natural incidence of these disorders

  17. Effects of ball milling on microstructures and thermoelectric properties of higher manganese silicides

    International Nuclear Information System (INIS)

    Chen, Xi; Shi, Li; Zhou, Jianshi; Goodenough, John B.

    2015-01-01

    Highlights: • The already low κ L of HMS can be suppressed further by decreasing the grain size. • The ball milling process can lead to the formation of secondary MnSi and W/C-rich phases. • The formation of the MnSi ad W/C rich phases is found to suppress the thermoelectric power factor. - Abstract: Bulk nanostructured higher manganese silicide (HMS) samples with different grain size are prepared by melting, subsequent ball milling (BM), and followed by spark plasma sintering (SPS). The effects of BM time on the microstructures and thermoelectric properties of these samples are investigated. It is found that BM effectively reduces the grain size to about 90 nm in the sample after SPS, which leads to a decrease in both the thermal conductivity and electrical conductivity. By prolonging the BM time, MnSi and tungsten/carbon-rich impurity phases are formed due to the impact-induced decomposition of HMS and contamination from the tungsten carbide jar and balls during the BM, respectively. These impurities result in a reduced Seebeck coefficient and increased thermal conductivity above room temperature. The measured size-dependent lattice thermal conductivities agree qualitatively with the reported calculation results based on a combined phonon and diffuson model. The size effects are found to be increasingly significant as temperature decreases. Because of the formation of the impurity phases and a relatively large grain size, the ZT values are not improved in the ball-milled HMS samples. These findings suggest the need of alternative approaches for the synthesis of pure HMS with further reduced grain size and controlled impurity doping in order to enhance the thermoelectric figure-of-merit of HMS via nanostructuring

  18. Surplus electricity production in sugarcane mills using residual bagasse and straw as fuel

    International Nuclear Information System (INIS)

    Alves, Moises; Ponce, Gustavo H.S.F.; Silva, Maria Aparecida; Ensinas, Adriano V.

    2015-01-01

    The cogeneration system is one of the most important parts of sugarcane mills which use the bagasse as fuel. In the recent years, modern equipments and energy efficiency measures made possible to the sugarcane industry, the production of surplus electricity which become, besides the sugar and ethanol, a third product from the same renewable source, the sugarcane. This work analyses the surplus electric power systems for three different schemes of cogeneration system in the sugarcane industry through the simulator Thermoflow"®. The analysis is made considering both the available bagasse and sugarcane straw recovery as fuel in three different scenarios for the industrial process energy requirements. The results show that the CEST (Condensing Extraction Steam Turbine) system can have a surplus of electricity of up to four times higher than the BPST (Backpressure Steam Turbine) system. The system CEST can have an increase in surplus power above 23% and 102% for the rate of 10% and 50% of cane straw recovery in the field respectively. The BPST-C (Backpressure and Condensing Turbines) system can produce similar values of surplus electricity when compared with the system CEST, but may represent an opportunity of flexible operation of the cogeneration systems in harvest and off-seasons. - Highlights: • At least three cogeneration system options are available in sugarcane mills. • Nowadays, only steam-based cycle cogeneration systems are used in sugarcane mills. • BPST system is limited to 70 e kWh/t cane of surplus electricity production. • CEST system increases the surplus electricity up to four times than the BPST. • Operation during off-season of the BPST-C system is an advantage for this option.

  19. Current practices and options for confinement of uranium mill tailings

    International Nuclear Information System (INIS)

    1981-01-01

    At the United Nations Conference on the Human Environment, which took place in Stockholm from 4 to 6 June 1972, national governments were asked to explore, with the International Atomic Energy Agency and other appropriate international organizations, international co-operation on radioactive waste matters including those of mining and tailings disposal. Since that time the IAEA has been active in the field of uranium and thorium mill tailings management. As part of this activity, the present report describes current practices and options for confinement of uranium mill tailings. It is addressed to technical and administrative personnel who are involved in planning and implementing national and industrial programmes on the management of such tailings. In 1974 and 1975 the IAEA convened meetings of experts to review matters of interest and importance in the management of uranium and thorium mine and mill tailings. These activities led to the publication in 1976 of Management of Wastes from the Mining and Milling of Uranium and Thorium Ores, a Code of Practice and Guide to the Code, IAEA Safety Series No. 44. As a continuation of this activity, the IAEA is here dealing more specifically with the design and siting considerations for the management of uranium mill tailings

  20. Research kinetic of motion of milling bodies in ball mill, outfit heat-exchange unit and calculation of its energy performance

    Science.gov (United States)

    Romanovich, A. A.; Romanovich, M. A.; Apukhtina, I. V.

    2018-03-01

    The article considers topical issues of energy saving in cement production with the use of a technological grinding complex, which includes a press roller grinder and a ball mill. Rational conditions of grinding are proposed for pre-shredded material through the installation of blade energy exchange devices (BEED) in the mill drum. The loading level in the first chamber varies periodically depending on the drum rotation angle, equipped with BEED. In the zone of BEED’s active action, there is a “scooping” of a part of grinding bodies together with crushed material, raising them to a height and giving them a longitudinally transverse movement, which is different from movement created in the mill without BEED. At the same time, additional work that consumes engine power is being done. A technique is proposed for calculating the additional engine power consumption of a mill, equipped with a BEED. This power is spent on creating a longitudinal-transverse motion of grinding bodies and its first and second chambers in areas of active influence of the BEED. Comparative analysis of results obtained experimentally and calculations of proposed equations show a high convergence of results. These analytical dependencies may be interest to Russian and foreign organizations that carry out their activities in the field of design and manufacture of cement equipment, as well as to cement producers.

  1. Application of Odor Sensors to Ore Sorting and Mill Feed Control

    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Nelson

    2005-08-01

    Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modeling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing that will allow optimization of the mill processes on an almost real-time basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. An investigation was conducted to assess the suitability of odor sensors for maintaining traceability in ore production and processing. Commercially available sensors are now used in food processing, environmental monitoring, and other applications and can detect the presence of very small amounts (0.1-500 ppm) of some molecules. An assortment of such molecules could be used to ''tag'' blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ''electronic noses'' could be used to assess its characteristics in real time. It was found that the Cyranose 320{trademark}, a commercially available odor sensor, can easily distinguish among samples of rock marked with almond, cinnamon, citronella, lemon, and orange oils. Further, the sensor could detect mixtures of rocks marked with various combinations of these oils. Treatment of mixtures of galena and silica with odorant compounds showed no detrimental effects on flotation response in laboratory tests. Additional work is recommended to determine how this concept can be extended to the marking of large volumes of materials.

  2. Selective enrichment of a methanol-utilizing consortium using pulp & paper mill waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Gregory R. Mockos; William A. Smith; Frank J. Loge; David N. Thompson

    2007-04-01

    Efficient utilization of carbon inputs is critical to the economic viability of the current forest products sector. Input carbon losses occur in various locations within a pulp mill, including losses as volatile organics and wastewater . Opportunities exist to capture this carbon in the form of value-added products such as biodegradable polymers. Waste activated sludge from a pulp mill wastewater facility was enriched for 80 days for a methanol-utilizing consortium with the goal of using this consortium to produce biopolymers from methanol-rich pulp mill waste streams. Five enrichment conditions were utilized: three high-methanol streams from the kraft mill foul condensate system, one methanol-amended stream from the mill wastewater plant, and one methanol-only enrichment. Enrichment reactors were operated aerobically in sequencing batch mode at neutral pH and 25°C with a hydraulic residence time and a solids retention time of four days. Non-enriched waste activated sludge did not consume methanol or reduce chemical oxygen demand. With enrichment, however, the chemical oxygen demand reduction over 24 hour feed/decant cycles ranged from 79 to 89 %, and methanol concentrations dropped below method detection limits. Neither the non-enriched waste activated sludge nor any of the enrichment cultures accumulated polyhydroxyalkanoates (PHAs) under conditions of nitrogen sufficiency. Similarly, the non-enriched waste activated sludge did not accumulate PHAs under nitrogen limited conditions. By contrast, enriched cultures accumulated PHAs to nearly 14% on a dry weight basis under nitrogen limited conditions. This indicates that selectively-enriched pulp mill waste activated sludge can serve as an inoculum for PHA production from methanol-rich pulp mill effluents.

  3. Current uranium mill licensing issues

    International Nuclear Information System (INIS)

    Scarano, R.A.

    1977-01-01

    The problems encountered to insure environmentally safe mining and milling of uranium ores are reviewed. Emphasis is placed on the management of tailings resulting from milling operations. It is pointed out that although the concentration of radioactivity in the tailings is relatively low, control measures are necessary because of the large quantities involved and because of the long half-life of the parent radionuclides present. The major concerns with mill tailings are radon release to the atmosphere and isolation of the tailings from the human environment. Since it is anticipated that the amount of tailings created by the year 2000 will be more than an order of magnitude greater than the quantities that have been generated during the past 30 years, it is recommended that all mill tailings storage areas be located remote from public contact and in areas such that disruption and dispersion by natural forces and seepage of toxic materials into ground water systems are reduced to the maximum extent achievable. Technical issues that receive attention during the NRC licensing process for uranium mills and the preparation of environmental impact statements are discussed briefly

  4. Would John Stuart Mill have regulated pornography?

    OpenAIRE

    McGlynn, C.; Ward, I.

    2014-01-01

    John Stuart Mill dominates contemporary pornography debates where he is routinely invoked as an authoritative defence against regulation. This article, by contrast, argues that a broader understanding of Mill's ethical liberalism, his utilitarianism, and his feminism casts doubt over such an assumption. New insights into Mill's approach to sex, sexual activity, and the regulation of prostitution reveal an altogether more nuanced and activist approach. We conclude that John Stuart Mill would a...

  5. Substrate milling pretreatment as a key parameter for Solid-State Anaerobic Digestion optimization.

    Science.gov (United States)

    Motte, J-C; Escudié, R; Hamelin, J; Steyer, J-P; Bernet, N; Delgenes, J-P; Dumas, C

    2014-12-01

    The effect of milling pretreatment on performances of Solid-State Anaerobic Digestion (SS-AD) of raw lignocellulosic residue is still controverted. Three batch reactors treating different straw particle sizes (milled 0.25 mm, 1 mm and 10 mm) were followed during 62 days (6 sampling dates). Although a fine milling improves substrate accessibility and conversion rate (up to 30% compared to coarse milling), it also increases the risk of media acidification because of rapid and high acids production during fermentation of the substrate soluble fraction. Meanwhile, a gradual adaptation of microbial communities, were observed according to both reaction progress and methanogenic performances. The study concluded that particle size reduction affected strongly the performances of the reaction due to an increase of substrate bioaccessibility. An optimization of SS-AD processes thanks to particle size reduction could therefore be applied at farm or industrial scale only if a specific management of the soluble compounds is established. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Uranium Mill Tailings Radiation Control Act of 1978

    International Nuclear Information System (INIS)

    Magee, J.

    1980-01-01

    The long-term environmental effects of the Uranium Mill Tailings Radiation Control Act of 1978 address the public health hazards of radioactive wastes and recognize the significance of this issue to public acceptance of nuclear energy. Title I of the Act deals with stabilizing and controlling mill tailings at inactive sites and classifies the sites by priority. It represents a major Federal commitment. Title II changes and strengthens Nuclear Regulatory Commission authority, but it will have little overall impact. It is not possible to assess the Act's effect because there is no way to know if current technology will be adequate for the length of time required. 76 references

  7. Improving milling and production of a dust-producing unit equipped with hammer mills

    Energy Technology Data Exchange (ETDEWEB)

    Vorotnikov, Ye.G.; Nikiforov, A.A.; Rasputin, O.V.; Sukhunin, V.I.

    1982-01-01

    This paper presents generalized experience for deriving coarse ground coal dust in hammer mills by providing comparison data on improving efficiency of operation of the unit when switching to a coarser-type grind of the fuel. Need to have more precise formulas to calculate grinding potential of hammer mills when using a coarser grind is shown.

  8. Wear of micro end mills

    DEFF Research Database (Denmark)

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo

    2005-01-01

    This paper addresses the important issue of wear on micro end mills considering relevant metrological tools for its characterization and quantification. Investigation of wear on micro end mills is particularly difficult and no data are available in the literature. Small worn volumes cause large...... part. For this investigation 200 microns end mills are considered. Visual inspection of the micro tools requires high magnification and depth of focus. 3D reconstruction based on scanning electron microscope (SEM) images and stereo-pair technique is foreseen as a possible method for quantification...

  9. Transformation of Goethite to Hematite Nanocrystallines by High Energy Ball Milling

    Directory of Open Access Journals (Sweden)

    O. M. Lemine

    2014-01-01

    Full Text Available α-Fe2O3 nanocrystallines were prepared by direct transformation via high energy ball milling treatment for α-FeOOH powder. X-ray diffraction, Rietveld analysis, TEM, and vibrating sample magnetometer (VSM are used to characterize the samples obtained after several milling times. Phase identification using Rietveld analysis showed that the goethite is transformed to hematite nanocrystalline after 40 hours of milling. HRTEM confirm that the obtained phase is mostly a single-crystal structure. This result suggested that the mechanochemical reaction is an efficient way to prepare some iron oxides nanocrystallines from raw materials which are abundant in the nature. The mechanism of the formation of hematite is discussed in text.

  10. Dopants incorporation in ZnO mechanical milled powders sensed by positrons

    International Nuclear Information System (INIS)

    Damonte, L. C.; Donderis, V.; Hernandez Fenollosa, M. A.

    2007-01-01

    M-doped ZnO (M: Cd, Mg) powders obtained by mechanical milling were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and positron lifetime annihilation spectroscopy (PALS). The mixing of the oxides is followed by means of XRD and SEM. As milling proceeds, a clear reduction of grain size and homogenization are observed. The evolution of annihilation parameters with milling time and cation content were analyzed and related with the kind of mechanical induced defect involved. Ternary oxides Zn 1-x M x O were efficiency obtained for certain compositions. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice.

  11. Dopants incorporation in ZnO mechanical milled powders sensed by positrons

    Energy Technology Data Exchange (ETDEWEB)

    Damonte, L. C., E-mail: damonte@fisica.unlp.edu.ar; Donderis, V.; Hernandez Fenollosa, M. A. [Universidad Politecnica de Valencia, Departamento de Fisica Aplicada (Spain)

    2007-09-15

    M-doped ZnO (M: Cd, Mg) powders obtained by mechanical milling were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and positron lifetime annihilation spectroscopy (PALS). The mixing of the oxides is followed by means of XRD and SEM. As milling proceeds, a clear reduction of grain size and homogenization are observed. The evolution of annihilation parameters with milling time and cation content were analyzed and related with the kind of mechanical induced defect involved. Ternary oxides Zn{sub 1-x}M{sub x}O were efficiency obtained for certain compositions. The results showed that positrons constitute a well suited probe to characterize the cation substitution in the ZnO oxide lattice.

  12. Effects of milling on functional properties of rice flour.

    Science.gov (United States)

    Kadan, R S; Bryant, R J; Miller, J A

    2008-05-01

    A commercial long-grain rice flour (CRF) and the flours made by using a pin mill and the Udy mill from the same batch of broken second-head white long-grain rice were evaluated for their particle size and functional properties. The purpose of this study was to compare the commercial rice flour milling method to the pin and Udy milling methods used in our laboratory and pilot plant. The results showed that pin milled flour had more uniform particle size than the other 2 milled flours. The chalky kernels found in broken white milled rice were pulverized more into fines in both Udy milled flour and CRF than in the pin milled flour. The excessive amount of fines in flours affected their functional properties, for example, WSI and their potential usage in the novel foods such as rice breads (RB). The RB made from CRF collapsed more than loaves made from pin milled Cypress long-grain flours.

  13. Effect of the milling energy on the production and thermal stability of amorphous Mg50Ni50

    International Nuclear Information System (INIS)

    Guzman, D.; Ordonez, S.; Serafini, D.; Rojas, P.; Bustos, O.

    2009-01-01

    The effect of milling energy on the amorphisation process and subsequent thermal crystallization of Mg 50 Ni 50 was investigated. The amorphous Mg 50 Ni 50 was produced using a planetary mill (medium energy) with a ball to material weight ratio of 13:1, and a SPEX mill (high energy) with a ball to material weight ratio of 20:1. The results obtained by means of X-ray diffraction showed that it is possible to obtain an amorphous Mg 50 Ni 50 alloy, through both milling processes, starting of Ni powders and Mg turnings. However, the amorphisation process requires more time in the planetary mill (80-90 h) than in the SPEX mill (15-20 h), due to the difference in energy level and milling mechanism between these mills. The phase evolution during the amorphisation process is practically independent of the mill energy. In this way, it was observed that the mill conditions promoted an extensive refinement of the microstructure during the first hours of milling. The defects produced during this time led to the amorphisation of part of the system. This amorphous precursor suffers a mechanically induced crystallization into Mg 2 Ni, which is subsequently destabilized into amorphous Mg 50 Ni 50 . Based on the results obtained, it is proposed that the formation of amorphous precursor during mechanical milling of Mg and Ni is a characteristic of the Mg-Ni system, over a wide composition range, rather than of a particular composition. In relation to the thermal crystallization of the amorphous produced, the results of the differential thermal analysis applied to the amorphous samples showed that the formation enthalpy for both amorphous is the same, however, the amorphous produced in a planetary mill presented higher crystallization temperatures and apparent activation energies than the amorphous produced in a SPEX mill. The last behavior would be related with iron contamination coming from the erosion of the milling media. Finally, it is possible to conclude, that under the

  14. Efek Waktu Wet Milling dan Suhu Annealing Terhadap Sifat Fisis, Mikrostruktur dan Magnet dari Flakes NdFeB

    OpenAIRE

    Sipahutar, Wahyu Solafide

    2015-01-01

    Had made research manufacture NdFeB magnets of flakes of wet milling process using a ball mill to the physic properties, microstructure, and magnetic properties with variations milling time is 16 hours, 24 hours, 48 hours, 72 hours. Powder result of mechanical milling using a ball mill and then analyzed the resulting particle size by using PSA and XRD. Then do the manufacture of test samples in the form of pellets by compaction process through print isotropy. Having obtained a sample of pelle...

  15. Structural and magnetic properties of Fe60Al40 alloys prepared by means of a magnetic mill

    International Nuclear Information System (INIS)

    Bernal-Correa, R.; Rosales-Rivera, A.; Pineda-Gomez, P.; Salazar, N.A.

    2010-01-01

    A study on synthesis, structural and magnetic characterization of Fe 60 Al 40 (at.%) alloys prepared by means of mechanical alloying process is presented. The mechanical alloying was performed using a milling device with magnetically controlled ball movement (Uni-Ball-Mill 5 equipment) at several milling times. The characterization was carried out via X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The effects of milling time on the structural state, morphological evolution and magnetic behaviour of the Fe 60 Al 40 (at.%) alloys are discussed. Besides, in this current study we emphasize the result that indicating a ferro-para-ferromagnetic transition from a correlation between X-ray diffraction and magnetization data.

  16. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    Energy Technology Data Exchange (ETDEWEB)

    1979-02-01

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment.

  17. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    International Nuclear Information System (INIS)

    1979-02-01

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment

  18. Comprehensive characterization of ball-milled powders simulating a tribofilm system

    Energy Technology Data Exchange (ETDEWEB)

    Häusler, I., E-mail: ines.haeusler@bam.de; Dörfel, I., E-mail: Ilona.doerfel@bam.de; Peplinski, B., E-mail: Burkhard.peplinski@bam.de; Dietrich, P.M., E-mail: Paul.dietrich@yahoo.de; Unger, W.E.S., E-mail: Wolfgang.Unger@bam.de; Österle, W., E-mail: Werner.Oesterle@bam.de

    2016-01-15

    A model system was used to simulate the properties of tribofilms which form during automotive braking. The model system was prepared by ball milling of a blend of 70 vol.% iron oxides, 15 vol.% molybdenum disulfide and 15 vol.% graphite. The resulting mixture was characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and various transmission electron microscopic (TEM) methods, including energy dispersive X-ray spectroscopy (EDXS), high resolution investigations (HRTEM) with corresponding simulation of the HRTEM images, diffraction methods such as scanning nano-beam electron diffraction (SNBED) and selected area electron diffraction (SAED). It could be shown that the ball milling caused a reduction of the grain size of the initial components to the nanometer range. Sometimes even amorphization or partial break-down of the crystal structure was observed for MoS{sub 2} and graphite. Moreover, chemical reactions lead to a formation of surface coverings of the nanoparticles by amorphous material, molybdenum oxides, and iron sulfates as derived from XPS. - Highlights: • Ball milling of iron oxides, MoS{sub 2}, and graphite to simulate a tribofilm • Increasing coefficient of friction after ball milling of the model blend • Drastically change of the diffraction pattern of the powder mixture • TEM & XPS showed the components of the milled mixture and the process during milling. • MoS{sub 2} and graphite suffered a loss in translation symmetry or became amorphous.

  19. 77 FR 14837 - Bioassay at Uranium Mills

    Science.gov (United States)

    2012-03-13

    ... NUCLEAR REGULATORY COMMISSION [NRC-2012-0057] Bioassay at Uranium Mills AGENCY: Nuclear Regulatory..., ``Bioassay at Uranium Mills.'' This guide describes a bioassay program acceptable to the NRC staff for uranium mills and applicable portions of uranium conversion facilities where the possibility of exposure...

  20. Source terms for airborne radioactivity arising from uranium mill wastes

    International Nuclear Information System (INIS)

    O'Riordan, M.C.; Downing, A.L.

    1978-01-01

    One of the problems in assessing the radiological impact of uranium milling is to determine the rates of release to the air of material from the various sources of radioactivity. Such source terms are required for modelling the transport of radioactive material in the atmosphere. Activity arises from various point and area sources in the mill itself and from the mill tailings. The state of the tailings changes in time from slurry to solid. A layer of water may be maintained over the solids during the life of the mine, and the tailings may be covered with inert material on abandonment. Releases may be both gaseous and particulate. This paper indicates ways in which radon emanation and the suspension of long-lived particulate activity might be quantified, and areas requiring further exploration are identified

  1. Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach.

    Science.gov (United States)

    Mudd, Gavin M

    2008-02-01

    The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting.

  2. Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach

    International Nuclear Information System (INIS)

    Mudd, Gavin M.

    2008-01-01

    The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting

  3. Cancer mortality in a Texas county with prior uranium mining and milling activities, 1950-2001

    International Nuclear Information System (INIS)

    Boice, John D Jr; Mumma, Michael; Schweitzer, Sarah; Blot, William J

    2003-01-01

    Uranium was discovered in Karnes County, Texas, in 1954 and the first uranium mill began operating in 1961 near Falls City. Uranium milling and surface and in situ mining continued in Karnes County until the early 1990s. Remediation of uranium tailings ponds was completed in the 1990s. There were three mills and over 40 mines operating in Karnes County over these years and potential exposure to the population was from possible environmental releases into the air and ground water. From time to time concerns have been raised in Karnes County about potential increased cancer risk from these uranium mining and milling activities. To evaluate the possibility of increased cancer deaths associated with these uranium operations, a mortality survey was conducted. The numbers and rates of cancer deaths were determined for Karnes County and for comparison for four 'control' counties in the same region with similar age, race, urbanisation and socioeconomic distributions reported in the 1990 US Census. Comparisons were also made with US and Texas general population rates. Following similar methods to those used by the National Cancer Institute, standardised mortality ratios (SMRs) were computed as the ratio of observed numbers of cancers in the study and control counties compared to the expected number derived from general population rates for the United States. Relative risks (RRs) were computed as the ratios of the SMRs for the study and the control counties. Overall, 1223 cancer deaths occurred in the population residing in Karnes County from 1950 to 2001 compared with 1392 expected based on general population rates for the US. There were 3857 cancer deaths in the four control counties during the same 52 year period compared with 4389 expected. There was no difference between the total cancer mortality rates in Karnes County and those in the control counties (RR = 1.0; 95% confidence interval 0.9-1.1). There were no significant increases in Karnes County for any cancer when

  4. Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO3)

    DEFF Research Database (Denmark)

    Mørup, Steen; Rasmussen, Helge Kildahl; Brok, Erik

    2012-01-01

    We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO3) after increasing time of high-energy ball-milling in an inert atmosphere. Refinement of X-ray diffraction data show that the hexagonal crystal structure of ilmenite is maintained...

  5. Uranium mining and milling sites in Argentina: environmental radiological monitoring (1980-1994)

    International Nuclear Information System (INIS)

    Bomben, A.M.; Gomez, J.C.; Oliveira, A.A.

    1995-01-01

    Environmental radiological monitoring in the vicinity of uranium mining and milling plants in Argentina is performed on a routine basis, in order to assess the possibility of significant environmental contamination due to uranium mill wastes and mill tailings of plants still operating or those where the exploitation have concluded. Dissolved natural uranium and 226 Ra concentrations in surface waters are measured in samples taken from rivers near the mills, according to a special monitoring plan set up for each facility. In addition, 222 Rn emanation rates from ore tailings are measured at times. In this paper the environmental radiological monitoring program results obtained for the 1980-1994 period are shown. From the data analyses it can be concluded that there are not significant differences for the concentrations of the radionuclides of interest, between the surface water samples taken from river location above and below the plants discharge points. Besides, no significant exposure results for the population living in the surrounding areas due to the uranium mining and milling plants operation or their wastes. (author). 2 refs., 5 figs

  6. 40 CFR 61.142 - Standard for asbestos mills.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Standard for asbestos mills. 61.142... § 61.142 Standard for asbestos mills. (a) Each owner or operator of an asbestos mill shall either discharge no visible emissions to the outside air from that asbestos mill, including fugitive sources, or...

  7. Investigation of planetary milling for nano-silicon carbide reinforced aluminium metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Kollo, Lauri, E-mail: lauri.kollo@staff.ttu.e [Laboratory of Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Department of Materials Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn (Estonia); Leparoux, Marc; Bradbury, Christopher R.; Jaeggi, Christian [Laboratory of Advanced Materials Processing, EMPA, Feuerwerkerstrasse 39, 3602 Thun (Switzerland); Carreno-Morelli, Efrain; Rodriguez-Arbaizar, Mikel [University of Applied Sciences of Western Switzerland, Design and Materials Unit, 1950 Sion (Switzerland)

    2010-01-21

    High-energy planetary milling was used for mixing aluminium powders with 1 vol.% of silicon carbide (SiC) nanoparticles. A number of milling parameters were modified for constituting the relationship between the energy input from the balls and the hardness of the bulk nanocomposite materials. It was shown that mixing characteristics and reaction kinetics with stearic acid as process control agent can be estimated by normalised input energy from the milling bodies. For this, the additional parameter characterising the vial filling was determined experimentally. Depending on the ball size, a local minimum in filling parameter was found, laying at 25 or 42% filling of the vial volume for the balls with diameter of 10 and 20 mm, respectively. These regions should be avoided to achieve the highest milling efficiency.After a hot compaction, fourfold difference of hardness for different milling conditions was detected. Therewith the hardness of the Al-1 vol.% nanoSiC composite could be increased from 47 HV{sub 0.5} of pure aluminium to 163 HV{sub 0.5} when milling at the highest input energy levels.

  8. New approach to recycling and waste-to-energy in paper production, Urban Mill

    Energy Technology Data Exchange (ETDEWEB)

    Ristola, P. [Metso Corporation (Finland)

    2002-10-01

    Greenfield paper mills are commonly perceived as massive investments with a high level of associated impact on the local environment. Parallel to this, increasingly strict targets are being set by modem legislation for reducing waste disposal at landfills. One long-term solution to this dilemma lies in extended materials recycling, combined with effective utilisation of waste as energy. Metso Paper's Urban Mill is a unique pilot concept that promises to become an important part of such a solution. The novelty of Metso Paper's new eco-efficient Urban Mill concept lies in its combination of a small paper mill with using solid waste to generate energy. The roots of the concept go back to the early 1990s, when several mini-mills were built to produce raw materials for corrugated containers in North America. The competitiveness of mini-mills like this is based on several benefits: lowcost, high-quality waste paper raw material, utilisation of adjacent facilities for utilities, and modern machines with lean manning and low inbound and outbound logistics costs.

  9. Time-dependent evolution of olive mill wastewater sludge organic and inorganic components and resident microbiota in multi-pond evaporation system.

    Science.gov (United States)

    Jarboui, Raja; Chtourou, Mohamed; Azri, Chafai; Gharsallah, Néji; Ammar, Emna

    2010-08-01

    The physico-chemical and microbiological characterizations of olive mill wastewater sludge (OMWS) were investigated in five OMW evaporation ponds of the open-pond system in Sfax (Tunisia), during the olive oil production period in 2004. Time-dependent changes in both physico-chemical parameters and the microbiota were investigated. Mathematical models and principal component analysis (PCA) were used to establish the correlations between the studied parameters. During the effluent time-dependent changes in the ponds, the result of OMWS analysis showed an increase of sludge index (SI), ash content, total solids (TS), volatile solids (VS), ethyl acetate extractive (EAE) and total phosphorus (Total P), as well as microbial flora especially the yeasts and moulds. The SI, TS, VS and Total P changes with time fit a simple linear equation, while EAE, phenols and NH(4)(+) fit a second-degree polynomial model. The PCA analysis exhibited three correlated groups. The first group included temperature, ash content, evaporation, SI, TS, VS, Total P, EAE, yeasts and moulds. The second group was made by bacteria and moisture; and the third group by NH(4)(+), oil and phenol. Such modelling might be of help in the prediction of OMW changes in natural evaporation ponds. (c) 2010 Elsevier Ltd. All rights reserved.

  10. A Scandinavian chemical wood pulp mill. Part 1. Energy audit aiming at efficiency measures

    Energy Technology Data Exchange (ETDEWEB)

    Klugman, Sofia [Department of Technology and Building Environment, Gaevle University, SE-801 76 Gaevle (Sweden); Karlsson, Magnus; Moshfegh, Bahram [Department of Mechanical Engineering, Division of Energy Systems, Linkoeping University, SE-581 83 Linkoeping (Sweden)

    2007-03-15

    A Swedish wood-pulp mill is surveyed in terms of energy supply and use in order to determine the energy-saving potential. Conservation measures are of increasing interest to Swedish industry, as energy prices have continued to rise in recent years. The electricity price particularly increased after the deregulation of the Scandinavian electricity market in 1996. The deregulation expanded to all of the EU in July 2004, which may increase the Swedish electricity price further until it reaches the generally higher European price level. Furthermore, oil prices have increased and the emissions trading scheme for CO{sub 2} adds to the incentive to reduce oil consumption. The energy system at the surveyed pulp mill is described in terms of electricity and process heat production and use. The total energy-saving potential is estimated and some saving points are identified. The heat that today is wasted at the mill has been surveyed in order to find potential for heat integration or heat export. The result shows that the mill probably could become self-sufficient in electricity. Particularly important in that endeavour is updating old pumps. (author)

  11. Degradation and biodegradability improvement of the olive mill wastewater by peroxi-electrocoagulation/electrooxidation-electroflotation process with bipolar aluminum electrodes.

    Science.gov (United States)

    Esfandyari, Yahya; Mahdavi, Yousef; Seyedsalehi, Mahdi; Hoseini, Mohammad; Safari, Gholam Hossein; Ghozikali, Mohammad Ghanbari; Kamani, Hossein; Jaafari, Jalil

    2015-04-01

    Olive mill wastewater is considered as one of the most polluting effluents of the food industry and constitutes a source of important environmental problems. In this study, the removal of pollutants (chemical oxygen demand (COD), biochemical oxygen demand (BOD5), polyphenols, turbidity, color, total suspended solids (TSS), and oil and grease) from olive oil mill processing wastewater by peroxi-electrocoagulation/electrooxidation-electroflotation process with bipolar aluminum electrodes was evaluated using a pilot continuous reactor. In the electrochemical unit, aluminum (Al), stainless steel, and RuO2/Ti plates were used. The effects of pH, hydrogen peroxide doses, current density, NaCl concentrations, and reaction times were studied. Under optimal conditions of pH 4, current density of 40 mA/m(2), 1000 mg/L H2O2, 1 g/L NaCl, and 30-min reaction time, the peroxi-electrochemical method yielded very effective removal of organic pollution from the olive mill wastewater diluted four times. The treatment process reduced COD by 96%, BOD5 by 93.6%, total, polyphenols by 94.4%, color by 91.4%, turbidity by 88.7, suspended solids by 97% and oil and grease by 97.1%. The biodegradability index (BOD5/COD) increased from 0.29 to 0.46. Therefore, the peroxi-electrocoagulation/electrooxidation-electroflotation process is considered as an effective and feasible process for pre-treating olive mill wastewater, making possible a post-treatment of the effluent in a biological system.

  12. Counterbalance of cutting force for advanced milling operations

    Science.gov (United States)

    Tsai, Nan-Chyuan; Shih, Li-Wen; Lee, Rong-Mao

    2010-05-01

    The goal of this work is to concurrently counterbalance the dynamic cutting force and regulate the spindle position deviation under various milling conditions by integrating active magnetic bearing (AMB) technique, fuzzy logic algorithm and an adaptive self-tuning feedback loop. Since the dynamics of milling system is highly determined by a few operation conditions, such as speed of spindle, cut depth and feedrate, therefore the dynamic model for cutting process is more appropriate to be constructed by experiments, instead of using theoretical approach. The experimental data, either for idle or cutting, are utilized to establish the database of milling dynamics so that the system parameters can be on-line estimated by employing the proposed fuzzy logic algorithm as the cutting mission is engaged. Based on the estimated milling system model and preset operation conditions, i.e., spindle speed, cut depth and feedrate, the current cutting force can be numerically estimated. Once the current cutting force can be real-time estimated, the corresponding compensation force can be exerted by the equipped AMB to counterbalance the cutting force, in addition to the spindle position regulation by feedback of spindle position. On the other hand, for the magnetic force is nonlinear with respect to the applied electric current and air gap, the characteristics of the employed AMB is investigated also by experiments and a nonlinear mathematic model, in terms of air gap between spindle and electromagnetic pole and coil current, is developed. At the end, the experimental simulations on realistic milling are presented to verify the efficacy of the fuzzy controller for spindle position regulation and the capability of the dynamic cutting force counterbalance.

  13. Understanding Biomass Ignition in Power Plant Mills

    DEFF Research Database (Denmark)

    Schwarzer, Lars; Jensen, Peter Arendt; Glarborg, Peter

    2017-01-01

    Converting existing coal fired power plants to biomass is a readily implemented strategy to increase the share of renewable energy. However, changing from one fuel to another is not straightforward: Experience shows that wood pellets ignite more readily than coal in power plant mills or storages...

  14. Yang-Mills theory in Coulomb gauge; Yang-Mills-theorie in Coulombeichung

    Energy Technology Data Exchange (ETDEWEB)

    Feuchter, C.

    2006-07-01

    In this thesis we study the Yang-Mills vacuum structure by using the functional Schroedinger picture in Coulomb gauge. In particular we discuss the scenario of colour confinement, which was originally formulated by Gribov. After a short introduction, we recall some basic aspects of Yang-Mills theories, its canonical quantization in the Weyl gauge and the functional Schroedinger picture. We then consider the minimal Coulomb gauge and the Gribov problem of the gauge theory. The gauge fixing of the Coulomb gauge is done by using the Faddeev-Popov method, which enables the resolution of the Gauss law - the constraint on physical states. In the third chapter, we variationally solve the stationary Yang-Mills Schroedinger equation in Coulomb gauge for the vacuum state. Therefor we use a vacuum wave functional, which is strongly peaked at the Gribov horizon. The vacuum energy functional is calculated and minimized resulting in a set of coupled Schwinger-Dyson equations for the gluon energy, the ghost and Coulomb form factors and the curvature in gauge orbit space. Using the angular approximation these integral equations have been solved analytically in both the infrared and the ultraviolet regime. The asymptotic analytic solutions in the infrared and ultraviolet regime are reasonably well reproduced by the full numerical solutions of the coupled Schwinger-Dyson equations. In the fourth chapter, we investigate the dependence of the Yang-Mills wave functional in Coulomb gauge on the Faddeev-Popov determinant. (orig.)

  15. Influencing Factors and Workpiece's Microstructure in Laser-Assisted Milling of Titanium

    Science.gov (United States)

    Wiedenmann, R.; Liebl, S.; Zaeh, M. F.

    Today's lightweight components have to withstand increasing mechanical and thermal loads. Therefore, advanced materials substitute conventional materials like steel or aluminum alloys. Using these high-performance materials the associated costs become prohibitively high. This paper presents the newest fundamental investigations on the hybrid process 'laser-assisted milling' which is an innovative technique to process such materials. The focus is on the validation of a numerical database for a CAD/CAM process control unit which is calculated by using simulation. Prior to that, the influencing factors on a laser-assisted milling process are systematically investigated using Design of Experiments (DoE) to identify the main influencing parameters coming from the laser and the milling operation.

  16. Effect of mechanical milling on the electrical and magnetic properties of nanostructured Ni0.5Zn0.5Fe2O4

    International Nuclear Information System (INIS)

    Sivakumar, N; Narayanasamy, A; Ponpandian, N; Greneche, J-M; Shinoda, K; Jeyadevan, B; Tohji, K

    2006-01-01

    Nanocrystalline Ni 0.5 Zn 0.5 Fe 2 O 4 spinel ferrite with a grain size of 50 nm was prepared by using the ceramic method. The grain size was further reduced to 14 nm by milling the as-prepared ferrite particles in a high-energy ball mill. From the impedance spectroscopy studies we have observed that the dc electrical conductivity increases upon milling. Furthermore, the cation distribution data, as obtained from the in-field Moessbauer and extended x-ray absorption fine structure measurements, suggested a decrease in the conductivity for the milled sample. The increase in conductivity of the milled sample is, therefore, attributed to conduction by the oxygen vacancies created by mechanical milling. The higher values obtained for the activation energy for conduction are also evidence for the oxygen vacancy conduction. The increase in Neel temperature from 573 to 611 K on reducing the grain size from 50 to 14 nm has been explained based on the changes in the cation distribution. The observed increase in the coercivity of the milled sample has been attributed to surface anisotropy of increasing number of ions on the surface. The Moessbauer spectra show canted spin structure for the milled samples

  17. Study on Sumbawa gold ore liberation using rod mill: effect of rod-number and rotational speed on particle size distribution

    Science.gov (United States)

    Prasetya, A.; Mawadati, A.; Putri, A. M. R.; Petrus, H. T. B. M.

    2018-01-01

    Comminution is one of crucial steps in gold ore processing used to liberate the valuable minerals from gaunge mineral. This research is done to find the particle size distribution of gold ore after it has been treated through the comminution process in a rod mill with various number of rod and rotational speed that will results in one optimum milling condition. For the initial step, Sumbawa gold ore was crushed and then sieved to pass the 2.5 mesh and retained on the 5 mesh (this condition was taken to mimic real application in artisanal gold mining). Inserting the prepared sample into the rod mill, the observation on effect of rod-number and rotational speed was then conducted by variating the rod number of 7 and 10 while the rotational speed was varied from 60, 85, and 110 rpm. In order to be able to provide estimation on particle distribution of every condition, the comminution kinetic was applied by taking sample at 15, 30, 60, and 120 minutes for size distribution analysis. The change of particle distribution of top and bottom product as time series was then treated using Rosin-Rammler distribution equation. The result shows that the homogenity of particle size and particle size distribution is affected by rod-number and rotational speed. The particle size distribution is more homogeneous by increasing of milling time, regardless of rod-number and rotational speed. Mean size of particles do not change significantly after 60 minutes milling time. Experimental results showed that the optimum condition was achieved at rotational speed of 85 rpm, using rod-number of 7.

  18. Uranium mill tailings management practices in Saskatchewan, Canada

    International Nuclear Information System (INIS)

    Clifton, A.W.; Barsi, R.G.; Melis, L.A.

    1984-01-01

    Uranium was discovered in Saskatchewan in 1934. The first major mill began operating at Beaverlodge in 1953; two other mills began production in the same area in 1955 and 1957. Waste management measures were limited at the early mills. A new generation of mills was brought into production beginning in 1975 utilizing engineered waste management systems. The paper presents a brief description of the geography and physical environment of northern Saskatchewan, Canada; reviews milling operations and waste managements systems; describes the evolution of waste management systems; and, comments on environmental control measures regulating the industry

  19. A Novel Role of Eruca sativa Mill. (Rocket Extract: Antiplatelet (NF-κB Inhibition and Antithrombotic Activities

    Directory of Open Access Journals (Sweden)

    Eduardo Fuentes

    2014-12-01

    Full Text Available Background: Epidemiological studies have shown the prevention of cardiovascular diseases through the regular consumption of vegetables. Eruca sativa Mill., commonly known as rocket, is a leafy vegetable that has anti-inflammatory activity. However, its antiplatelet and antithrombotic activities have not been described. Methods: Eruca sativa Mill. aqueous extract (0.1 to 1 mg/mL, was evaluated on human platelets: (i P-selectin expression by flow cytometry; (ii platelet aggregation induced by ADP, collagen and arachidonic acid; (iii IL-1β, TGF-β1, CCL5 and thromboxane B2 release; and (iv activation of NF-κB and PKA by western blot. Furthermore, (v antithrombotic activity (200 mg/kg and (vi bleeding time in murine models were evaluated. Results: Eruca sativa Mill. aqueous extract (0.1 to 1 mg/mL inhibited P-selectin expression and platelet aggregation induced by ADP. The release of platelet inflammatory mediators (IL-1β, TGF-β1, CCL5 and thromboxane B2 induced by ADP was inhibited by Eruca sativa Mill. aqueous extract. Furthermore, Eruca sativa Mill. aqueous extract inhibited NF-κB activation. Finally, in murine models, Eruca sativa Mill. aqueous extract showed significant antithrombotic activity and a slight effect on bleeding time. Conclusion: Eruca sativa Mill. presents antiplatelet and antithrombotic activity.

  20. Assessment of crystalline disorder in cryo-milled samples of indomethacin using atomic pair-wise distribution functions

    DEFF Research Database (Denmark)

    Bøtker, Johan P; Karmwar, Pranav; Strachan, Clare J

    2011-01-01

    to analyse the cryo-milled samples. The high similarity between the ¿-indomethacin cryogenic ball milled samples and the crude ¿-indomethacin indicated that milled samples retained residual order of the ¿-form. The PDF analysis encompassed the capability of achieving a correlation with the physical......The aim of this study was to investigate the usefulness of the atomic pair-wise distribution function (PDF) to detect the extension of disorder/amorphousness induced into a crystalline drug using a cryo-milling technique, and to determine the optimal milling times to achieve amorphisation. The PDF...... properties determined from DSC, ss-NMR and stability experiments. Multivariate data analysis (MVDA) was used to visualize the differences in the PDF and XRPD data. The MVDA approach revealed that PDF is more efficient in assessing the introduced degree of disorder in ¿-indomethacin after cryo-milling than...

  1. Torrefied Biomass Pellets—Comparing Grindability in Different Laboratory Mills

    Directory of Open Access Journals (Sweden)

    Jan Hari Arti Khalsa

    2016-10-01

    Full Text Available The firing and co-firing of biomass in pulverized coal fired power plants around the world is expected to increase in the coming years. Torrefaction may prove to be a suitable way of upgrading biomass for such an application. For transport and storage purposes, the torrefied biomass will tend to be in pellet form. Whilst standard methods for the assessment of the milling characteristics of coal exist, this is not the case for torrefied materials—whether in pellet form or not. The grindability of the fuel directly impacts the overall efficiency of the combustion process and as such it is an important parameter. In the present study, the grindability of different torrefied biomass pellets was tested in three different laboratory mill types; cutting mill (CM, hammer mill (HM and impact mill (IM. The specific grinding energy (SGE required for a defined mass throughput of pellets in each mill was measured and results were compared to other pellet characterization methods (e.g., durability, and hardness as well as the modified Hardgrove Index. Seven different torrefied biomass pellets including willow, pine, beech, poplar, spruce, forest residue and straw were used as feedstock. On average, the particle-size distribution width (across all feedstock was narrowest for the IM (0.41 mm, followed by the HM (0.51 mm and widest for the CM (0.62 mm. Regarding the SGE, the IM consumed on average 8.23 Wh/kg while CM and HM consumed 5.15 and 5.24 Wh/kg, respectively. From the three mills compared in this study, the IM seems better fit for being used in a standardized method that could be developed in the future, e.g., as an ISO standard.

  2. The potential for energy savings when reducing the water consumption in a kraft pulp mill

    Energy Technology Data Exchange (ETDEWEB)

    Wising, Ulrika; Berntsson, Thore [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Chemical Engineering and Environmental Science; Stuart, Paul [Ecole Polytechnique, Montreal (Canada). Dept. of Chemical Engineering

    2004-05-01

    In this paper an existing pulp and paper mill has been studied in a systematic way regarding the reduction of water consumption, and the resulting increased potential for energy integration. It has been found that when the mill's hot water consumption is decreased, the live steam demand for the mill also decreases. Also when decreasing the hot water consumption, the quantity and temperature of available excess heat increases. This excess heat can be used for evaporation, thereby reducing the live steam demand further by up to 1.5 GJ/t. A pinch analysis was performed at an existing mill and it was found that if pinch violations are removed, the hot water consumption is not an important factor any more. Removing all the pinch violations and using the remaining excess heat for evaporation yields a significantly larger energy savings for the mill (4.0 GJ/t). From an economic optimum perspective it is probably most profitable to do a combination of reducing water consumption, removing pinch violations, and use the remaining excess heat for evaporation.

  3. Blue-shift in photoluminescence of ion-milled HgCdTe films and relaxation of defects induced by the milling

    International Nuclear Information System (INIS)

    Pociask, M.; Izhnin, I.I.; Mynbaev, K.D.; Izhnin, A.I.; Dvoretsky, S.A.; Mikhailov, N.N.; Sidorov, Yu.G.; Varavin, V.S.

    2010-01-01

    Simultaneous measurements of electrical conductivity, the Hall coefficient, and photoluminescence (PL) spectra of ion-milled Hg 1 - x Cd x Te films (x ∼ 0.30 and 0.38) were performed during post-milling ageing of the films at 293 K. In the course of the PL study, a 'relaxation' of the blue-shift of the PL band of ion-milled Hg 0.70 Cd 0.30 Te was observed. The relaxation was caused by the decrease of the electron concentration due to gradual disintegration of defects induced by the milling. It is shown that while ion milling substantially changes the electrical properties of Hg 1 - x Cd x Te, its PL spectrum in the long-term is affected insignificantly.

  4. KSC ADVANCED GROUND BASED FIELD MILL V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Advanced Ground Based Field Mill (AGBFM) network consists of 34 (31 operational) field mills located at Kennedy Space Center (KSC), Florida. The field mills...

  5. Wet milling versus co-precipitation in magnetite ferrofluid preparation

    Directory of Open Access Journals (Sweden)

    Almásy László

    2015-01-01

    Full Text Available Various uses of ferrofluids for technical applications continuously raise the interest in improvement and optimization of preparation methods. This paper deals with preparation of finely granulated magnetite particles coated with oleic acid in hydrocarbon suspensions following either chemical co-precipitation from iron salt precursors or wet milling of micron size magnetite powder with the goal to compare the benefits and disadvantages of each method. Microstructural measurements showed that both methods gave similar magnetite particle size of 10-15 nm. Higher saturation magnetization was achieved for the wet-milled magnetite suspension compared to relatively rapid co-precipitation synthesis. Different efficacies of ferrophase incorporation into kerosene could be related to the different mechanisms of oleic acid bonding to nanoparticle surface. The comparative data show that wet milling represents a practicable alternative to the traditional co-precipitation since despite of longer processing time, chemicals impact on environment can be avoided as well as the remnant water in the final product.

  6. Loop quantum corrected Einstein Yang-Mills black holes

    Science.gov (United States)

    Protter, Mason; DeBenedictis, Andrew

    2018-05-01

    In this paper, we study the homogeneous interiors of black holes possessing SU(2) Yang-Mills fields subject to corrections inspired by loop quantum gravity. The systems studied possess both magnetic and induced electric Yang-Mills fields. We consider the system of equations both with and without Wilson loop corrections to the Yang-Mills potential. The structure of the Yang-Mills Hamiltonian, along with the restriction to homogeneity, allows for an anomaly-free effective quantization. In particular, we study the bounce which replaces the classical singularity and the behavior of the Yang-Mills fields in the quantum corrected interior, which possesses topology R ×S2 . Beyond the bounce, the magnitude of the Yang-Mills electric field asymptotically grows monotonically. This results in an ever-expanding R sector even though the two-sphere volume is asymptotically constant. The results are similar with and without Wilson loop corrections on the Yang-Mills potential.

  7. TECHNOLOGICAL FEATURES OF MILLING AND FRACTIONATION OF FLAXSEEDS

    Directory of Open Access Journals (Sweden)

    A. Feskova

    2015-01-01

    Full Text Available Summary. The optimal parameters of milling and fractionation of flaxseeds were substantiated. It was found that the hull fraction with the highest content of lignan secoisolariciresinol diglucoside SDG was obtained when flaxseeds were grinded using a rotatory impact continuous operation mill at the rotation 1380-1640 rpm. Studies have shown that with the increasing of the rotor speed the number of unbriken seeds decreased. However, due to the fact that the shells are crushed more, they become more difficult to separate from the cotyledons. For identification and quantification of SDG the HPLC-MS method was used. It is found that the optimum separation membranes and cotyledon fraction occurs at sifting milled seeds sequentially through the sieves having meshes of 1 and 0.5 mm. The technology of industrial production of lignans-containing fraction and flour on the basis of flaxseeds processing were proposed. This technology includes milling flaxseeds at the rotation 1380-1640 rpm, with subsequent 2% silicon dioxide addition and stepwise sieving using sieves with the mesh size 2 mm. To use a fraction membranes high in lignans as raw material for biologically active additives to food it needed additional enforcement-ground to a size not more than 0.4 mm (technological features of capsulation. The developed technology allowed getting with maximum yields of lignans-containing fraction (10% yield and flaxseed flour (80% yield.

  8. NMR measurements in milled RE-TM2 compounds (RE=Gd and TM=Co, Fe)

    International Nuclear Information System (INIS)

    Tribuzy, C.V.; Guimaraes, A.P.; Biondo, A.; Larica, C.; Alves, K.M.B.

    1996-09-01

    Milled samples of the Laves phase intermetallic compounds Gd Fe 2 and Gd CO 2 were measured by NMR at 4.2 K. The milling was made from the crystalline intermetallic compounds, inside a cylindrical tool made of hard steel, under argon atmosphere, for several different time intervals. The initial compounds were produced from high purity elements in an arc furnace, under inert atmosphere. Their X-ray diffraction patterns agreed with those of the literature. The milling of Gd Fe 2 and of Gd CO 2 , induces amorphization. Above 1 hour the milling of Gd Fe 2 leads to segregation of α-Fe and formation of a Gd-Fe phase. These results are shown in the X-ray analysis. The spin-echo pulse NMR technique was utilized to study some structural and magnetic as a function of milling time. The measurements were made in a broad band pulse NMR spectrometer. The NMR spectra of the 155 Gd 157 Gd isotopes in Gd Fe 2 show a broadening and displacement of the NMR lines, reflecting the introduction of defects, some kind of disorder and also the formation of a new Gd-rich phase after 1 hour. This result is in agreement with the X-ray spectra. In both systems, the spectra of the amorphous samples show broader lines, and the measured hyperfine fields do not change much with milling. (author). 9 refs., 4 figs

  9. Effects of ball milling on microstructures and thermoelectric properties of higher manganese silicides

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Shi, Li, E-mail: lishi@mail.utexas.edu [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States); Zhou, Jianshi; Goodenough, John B. [Materials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712 (United States); Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712 (United States)

    2015-08-25

    Highlights: • The already low κ{sub L} of HMS can be suppressed further by decreasing the grain size. • The ball milling process can lead to the formation of secondary MnSi and W/C-rich phases. • The formation of the MnSi ad W/C rich phases is found to suppress the thermoelectric power factor. - Abstract: Bulk nanostructured higher manganese silicide (HMS) samples with different grain size are prepared by melting, subsequent ball milling (BM), and followed by spark plasma sintering (SPS). The effects of BM time on the microstructures and thermoelectric properties of these samples are investigated. It is found that BM effectively reduces the grain size to about 90 nm in the sample after SPS, which leads to a decrease in both the thermal conductivity and electrical conductivity. By prolonging the BM time, MnSi and tungsten/carbon-rich impurity phases are formed due to the impact-induced decomposition of HMS and contamination from the tungsten carbide jar and balls during the BM, respectively. These impurities result in a reduced Seebeck coefficient and increased thermal conductivity above room temperature. The measured size-dependent lattice thermal conductivities agree qualitatively with the reported calculation results based on a combined phonon and diffuson model. The size effects are found to be increasingly significant as temperature decreases. Because of the formation of the impurity phases and a relatively large grain size, the ZT values are not improved in the ball-milled HMS samples. These findings suggest the need of alternative approaches for the synthesis of pure HMS with further reduced grain size and controlled impurity doping in order to enhance the thermoelectric figure-of-merit of HMS via nanostructuring.

  10. STUDY ON REDUCING AND MELTING BEHAVIOR OF MILL SCALE/PETROLEUM COKE BLEND

    Directory of Open Access Journals (Sweden)

    Bruno Deves Flores

    2015-07-01

    Full Text Available Self-reducing tests were carried out under isothermal and non-isothermal condition in a muffle furnace, aiming to assess the reduction and melting of a self-reducing blend of mill scale and petroleum coke (85-15% in weight. The products obtained were analyzed by mass loss and wet analysis. Further investigations for the products from the non-isothermal condition were done by X-ray diffraction, nude eye inspection and carbon analyzer. It was observed that mass loss fraction and metallization degree are directly related and both increase with time and temperature. In the non-isothermal maximum mass loss was achieved in 8 minutes, reaching metallization degrees above 90%. It was observed that the reduction of iron oxide occurs mainly in solid state and the smelting of the samples is directly related to the iron carburization process. Thus, the use of self-reducing mixtures shows a possible way to recycle mill scale.

  11. The Semi-Quantitative Study of Magnetization Process on Milling and Reannealing of Barium Hexaferrite (BaO.6Fe2O3

    Directory of Open Access Journals (Sweden)

    Ridwan

    2009-07-01

    Full Text Available Barium hexaferrite (BaO.6Fe2O3 is as a hard magnetic material with good chemical stability which has been intensively used as permanent magnet components. Many works have been done in order to improve their magnetic properties either through chemical process or powders metallurgy technique. In this work, commercial BaO.6Fe2O3 was milled using high-energy milling machine for 10, 20 and 30 hours and followed by reannealing for 3 hours at 1000⁰C in air. X-ray diffraction pattern indicate no phase decomposition occurred caused the mill processing, annealing of milled powders recovered the crystal system and promoted crystallite growth. The magnetic hysteresis curve measured by vibrating sample magnetometer (VSM shows the coercivity of annealed BaO.6Fe2O3 increases to two times higher than the original one. By using Jiles-Atherton model, all the hysteresis parameters Ms, k, α, a and c, have been determined adopted to the Genetic Algorithm (GA. The analyzed hysteretic parameters obtained from this work is congruent to the change of magnetic properties of as-milled and annealed powders of barium hexaferrite.

  12. ALSTOM Schusselmuhle fur die feinvermahlung von anhydrit ALSTOM bowl mill for anhydrite fine grinding

    CERN Document Server

    Angleys, M

    2003-01-01

    After the ALSTOM bowl mill had proved a success during numerous laboratory tests using different industrial minerals, for the first time a mill, type SM 20/12 was commissioned for ATLAS s.c. at Lodz /Poland for anhydrite grinding. Based on corresponding laboratory tests with anhydrite, it was possible to adapt the equipment to the requirements of the material with modified properties. Due to the project preparation together with the customer, the mill could be installed and commissioned according to schedule by a joint team of engineers for erection and commissioning.

  13. Polycrystalline Nd2Fe14B/α-Fe nanocomposite flakes with a sub-micro/nanometre thickness prepared by surfactant-assisted high-energy ball milling

    International Nuclear Information System (INIS)

    Tang, Xin; Chen, Xi; Chen, Renjie; Yan, Aru

    2015-01-01

    Highlights: • Nd 2 Fe 14 B/α-Fe flakes are formed by peeling along preferential planes. • (0 0 l) planes are found to be preferential cleavage planes. • Magnetic properties degrade with increasing ball milling time. • Anisotropic nanocomposite magnets are fabricated. - Abstract: A surfactant-assisted high-energy ball milling technique was employed to synthesize Nd 2 Fe 14 B/α-Fe nanoparticles and nanoflakes from melt-spun nanocrystalline powders. The microstructure evolution in ball milling process was investigated. In the beginning stage (0–4 h) of ball milling, raw powders were crushed into micrometre-sized particles. While flakes were mainly formed by reducing thickness of particles via peeling layer by layer along preferential planes in the late stage (8–16 h). The selected area electron diffraction and high-resolution transmission electron microscopy images show that preferential cleavage planes are basal planes. With ball milling proceeding, more and more defects were induced by ball milling. As a result, the coercivity and remanence decreased to 1.6 kOe and 3.2 kGs, respectively. After 16 h ball milling, the exchange decoupling occurred due to severe amorphorization. A weakly-textured nanocomposite magnet was fabricated after 12 h ball milling and the anisotropy in magnetic properties can be further improved by employing settling down process to select particle size and aligning particles in external field

  14. Effect Of Milling Time On Microstructure Of AA6061 Composites Fabricated Via Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    Tomiczek B.

    2015-06-01

    Full Text Available The aim of this work is to determine the effect of manufacturing conditions, especially milling time, on the microstructure and crystallite size of a newly developed nanostructural composite material with the aluminium alloy matrix reinforced with halloysite nanotubes. Halloysite, being a clayey mineral of volcanic origin, is characterized by high porosity and large specific surface area. Thus it can be used as an alternative reinforcement in metal matrix composite materials. In order to obtain this goal, composite powders with fine microstructures were fabricated using high-energy mechanical alloying, cold compacting and hot extrusion techniques. The obtained composite powders of aluminium alloy reinforced with 5, 10 and 15 wt% of halloysite nanotubes were characterized with SEM, TEM and XRD analysis. It has been proven that the use of mechanical alloying leads to a high degree of deformation, which, coupled with a decreased grain size below 100 nm and the dispersion of the refined reinforcing particles–reinforces the material very well.

  15. Quantum Yang–Mills Dark Energy

    Directory of Open Access Journals (Sweden)

    Roman Pasechnik

    2016-02-01

    Full Text Available In this short review, I discuss basic qualitative characteristics of quantum non-Abelian gauge dynamics in the non-stationary background of the expanding Universe in the framework of the standard Einstein–Yang–Mills formulation. A brief outlook of existing studies of cosmological Yang–Mills fields and their properties will be given. Quantum effects have a profound impact on the gauge field-driven cosmological evolution. In particular, a dynamical formation of the spatially-homogeneous and isotropic gauge field condensate may be responsible for both early and late-time acceleration, as well as for dynamical compensation of non-perturbative quantum vacua contributions to the ground state of the Universe. The main properties of such a condensate in the effective QCD theory at the flat Friedmann–Lemaítre–Robertson–Walker (FLRW background will be discussed within and beyond perturbation theory. Finally, a phenomenologically consistent dark energy can be induced dynamically as a remnant of the QCD vacua compensation arising from leading-order graviton-mediated corrections to the QCD ground state.

  16. Evaluation of the chemical and nutritional characteristics of almonds (Prunus dulcis (Mill). D.A. Webb) as influenced by harvest time and cultivar.

    Science.gov (United States)

    Summo, Carmine; Palasciano, Marino; De Angelis, Davide; Paradiso, Vito M; Caponio, Francesco; Pasqualone, Antonella

    2018-04-30

    Several authors studied the effect of harvest time on chemical and nutritional composition of almonds, but the results are partly conflicting, probably due to differences in the cultivars considered and to different agronomic and climatic conditions in the growing areas. In this paper the influence of harvest time and cultivar on the chemical and nutritional composition of almonds (Prunus dulcis (Mill). D.A. Webb) was evaluated. Ten cultivars were considered, grown in the same orchard and subjected to the same agronomical regime. Almonds were collected at two different harvest times: i) when the fruits were unripe, but already edible, and showed green and moist hull, and ii) when the fruits were ripe, with dry brown hull. The analyses of proximate composition, fatty acid profile, total phenolic compounds and antioxidant activity were carried out. Lipid content increased (palmonds. Genotype strongly influenced fatty acid composition and total phenolic compounds. The changes of bioactive compounds and antioxidant activity suggest that the synthesis of antioxidants occur also in the last stage of ripening. Unripe almonds, a valuable niche product, showed interesting nutritional value. This article is protected by copyright. All rights reserved.

  17. Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

    Science.gov (United States)

    Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

    2015-12-01

    In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder.

  18. Synthesis of the Mg2Ni alloy prepared by mechanical alloying using a high energy ball mill

    International Nuclear Information System (INIS)

    Iturbe G, J. L.; Lopez M, B. E.; Garcia N, M. R.

    2010-01-01

    Mg 2 Ni was synthesized by a solid state reaction from the constituent elemental powder mixtures via mechanical alloying. The mixture was ball milled for 10 h at room temperature in an argon atmosphere. The high energy ball mill used here was fabricated at ININ. A hardened steel vial and three steel balls of 12.7 mm in diameter were used for milling. The ball to powder weight ratio was 10:1. A small amount of powder was removed at regular intervals to monitor the structural changes. All the steps were performed in a little lucite glove box under argon gas, this glove box was also constructed in our Institute. The structural evolution during milling was characterized by X-ray diffraction and scanning electron microscopy techniques. The hydrogen reaction was carried out in a micro-reactor under controlled conditions of pressure and temperature. The hydrogen storage properties of mechanically milled powders were evaluated by using a thermogravimetric analysis system. Although homogeneous refining and alloying take place efficiently by repeated forging, the process time can be reduced to one fiftieth of the time necessary for conventional mechanical milling and attrition. (Author)

  19. ROMI 4.0: Updated Rough Mill Simulator

    Science.gov (United States)

    Timo Grueneberg; R. Edward Thomas; Urs Buehlmann

    2012-01-01

    In the secondary hardwood industry, rough mills convert hardwood lumber into dimension parts for furniture, cabinets, and other wood products. ROMI 4.0, the US Department of Agriculture Forest Service's ROugh-MIll simulator, is a software package designed to simulate the cut-up of hardwood lumber in rough mills in such a way that a maximum possible component yield...

  20. Effect of ball mill treatment on kinetics of amorphous Ni78Si10B12 alloy crystallization

    International Nuclear Information System (INIS)

    Tomilin, I.A.; Mochalova, T.Yu.; Kaloshkin, S.D.; Kostyukovich, T.G.; Lopatina, E.A.

    1993-01-01

    The effect of the parameters of Ni 78 Si 10 B 12 alloy amorphous strip milling in a ball planetary mill on the stability of powder amorphous state, crytallization kinetics and dispersity is studied by the methods of differential scanning microcaloremetry and X-ray diffraction analysis. Energy intensity of milling conditions is assessed. An increase of input energy results in a decrease of activation energy of powder crystallization. Strip milling parameters which enable to avaintain the amorphous state of the material are determined

  1. Ball Milling Treatment of Black Dross for Selective Dissolution of Alumina in Sodium Hydroxide Leaching

    OpenAIRE

    Thi Thuy Nhi Nguyen; Man Seung Lee; Thi Hong Nguyen

    2018-01-01

    A process consisting of ball milling followed by NaOH leaching was developed to selectively dissolve alumina from black dross. From the ball milling treatment, it was found that milling speed greatly affected the leaching behavior of silica and the oxides of Ca, Fe, Mg, and Ti present in dross. The leaching behavior of the mechanically activated dross was investigated by varying NaOH concentration, leaching temperature and time, and pulp density. In most of the leaching conditions, only alumi...

  2. Influence of temperature on hydrogen production from bread mill wastewater by sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Tang, G.L.; Huang, J.; Li, Y.Y.; Sun, Z.J. [China Agricultural Univ., Beijing (China). College of Resources and Environmental Sciences; Tang, Q.Q. [Nanjing Univ., Nanjing (China). Medical School

    2008-07-01

    Hydrogen (H{sub 2}) energy has been touted as a sustainable and clean energy source that can solve environmental problems such as acid rain, greenhouse gases and transboundary pollution. While most hydrogen is currently produced from nonrenewable sources such as oil, natural gas, and coal, these processes are energy-intensive and costly. The biological production of hydrogen using fermentative bacteria is an environmentally friendly and energy-saving process which has recently attracted much attention as an effective way of converting biomass into H{sub 2}. Waste-based H{sub 2} production processes mainly include wastewater from paper mills, municipal solid waste, rice winery wastewater, and food wastewater from cafeterias. This study investigated the use of bread mill wastewater for biological production of hydrogen due to its high production potential. Annual bread production in China is estimated to be over 1.5 million tons, producing 10 m{sup 3} of wastewater per ton of bread. The wastewater has high chemical oxygen demand and carbohydrate concentrations and is therefore suitable for anaerobic treatment processes. This study evaluated the effect of temperature on H{sub 2} production from bread mill wastewater by sewage sludge in lab-scale experiments. H{sub 2} production, the distribution of volatile fatty acids and the lag-phase time were influenced by temperature. H{sub 2} production and H{sub 2} yield increased with increasing temperature. The optimal temperature for H{sub 2} production was 50 degrees C. Butyrate, acetate and alcohol were the main by-products of H{sub 2} fermentation. According to 16S rDNA analysis, the dominant microflora was Clostridium, but the microbial species varied with temperature. The activation energy for H{sub 2} production was estimated to be 92 kJ per mol for bread mill wastewater. It was concluded that bread mill wastewater could potentially serve as a substrate for H{sub 2} production. This research provides a means of

  3. Effect of additional nickel on crystallization degree evolution of expanded graphite during ball-milling and annealing

    International Nuclear Information System (INIS)

    Wang Liqin; Yue Xueqing; Zhang Fucheng; Zhang Ruijun

    2010-01-01

    Expanded graphite (EG) and a mixture of EG and nickel (EG-Ni system) were ball-milled and subsequently annealed, respectively. The products were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscopy (TEM). After 100 h milling, the average crystallite thickness (L c ) of EG and EG-Ni system deceases from 14.5 to 8.0 and 9.6 nm, respectively, while the interlayer spacing (d 002 ) increases from 0.3341 to 0.3371 and 0.3348 nm, respectively. It can be concluded that ball-milling decreases the crystallization degree of EG, while the additional nickel restrains this process. For the samples ball-milled for 80 h, the disorder parameter I D /(I D + I G ) ratio of EG and EG-Ni system is in the range of 20.7-55.8% and 31.7-45.8%, respectively, implying that the presence of nickel is beneficial to more homogeneous ball-milling of EG. When the samples after ball-milling for 80 h were annealed for 4 h, the average crystallite thickness of EG and EG-Ni system increases from 8.5 to 9.0 nm and from 11.8 to 15.5 nm, respectively. It is deduced that annealing improves the crystallization degree of ball-milled EG, and the additional nickel is helpful for this process.

  4. Flaking behavior and microstructure evolution of nickel and copper powder during mechanical milling in liquid environment

    International Nuclear Information System (INIS)

    Xiao Xiao; Zeng Zigao; Zhao Zhongwei; Xiao Songwen

    2008-01-01

    To prepare metal flakes with a high flaking level and investigate the microstructure of metal flakes, nickel and copper powder were mechanically milled in liquid environment and the microstructure of powders was investigated by X-ray diffraction. The milling process can be divided into flaking and broken stages. At the flaking stage, milled metal powders exhibited high flaking level and flaky microshape, and became preferred orientation. While at the broken stage, the milled powders presented a low flaking level and irregular microshape, and was not preferred orientation any longer. The grain size, microstrain and dislocation density along direction varied with milling time differently from that along direction. The flaking level of the milled powders was related to the preferred orientation, and more closely to the deformation mechanism. We can strengthen the formation of preferred orientation to obtain metal powders with a high flaking level

  5. Persistence of malathion residues in stored milled rice: Direct and indirect applications

    International Nuclear Information System (INIS)

    Arshad, J.H.

    1990-01-01

    Two experiments were carried out: (i) to study the persistence of malathion residues in stored milled rice following multiple applications of 14 C-malathion to the bagged rice and (ii) to determine the degradation of malathion in stored milled rice and stored paddy following direct and single application of 14 C-malathion. The storage conditions were similar to those found in the local rice godowns. Three applications of malathion to the bagged milled rice resulted in the accumulation of malathion and its metabolites in and/or on the rice grains over the storage period. After 9 months' storage, ca. 4% of the total applied radioactivity, which amounted to 10 μg/g equivalent of 14 C residues, were found in and/or on the grains. About one fourth of the residue remained as the unchanged parent compound. On the other hand, when 14 C-malathion at the 10 ppm level was mixed directly with the milled rice or paddy prior to storage, the amount of malathion (recovered in the chloroform extracts) decreased from 6.2 μg/g at zero time to 2.9 μg/g after 3 months' storage for the milled rice samples. The major metabolite in the milled rice and paddy samples was malathion monocarboxylic acid with trace amounts of malathion dicarboxylic acid and malaoxon. (author). 5 refs, 3 tabs

  6. Parametric optimization of CNC end milling using entropy ...

    African Journals Online (AJOL)

    user

    Bayoumi,. Kopac and Krajnik (2007) had presented the robust design of flank milling parameters dealing with the ... to manufacture low cost, high quality products in short time. ... CNC machines are considered most suitable in flexible manufacturing system. ... important factor that greatly influences production rate and cost.

  7. Simple grain mill boosts production and eases women's workload ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... grain mill boosts production and eases women's workload. 11 janvier 2013. Image ... It aims to increase the production, improve the processing, develop new ... farmer societies, women's self-help groups, and the food-processing industry.

  8. Real-time particle size analysis using focused beam reflectance measurement as a process analytical technology tool for a continuous granulation-drying-milling process.

    Science.gov (United States)

    Kumar, Vijay; Taylor, Michael K; Mehrotra, Amit; Stagner, William C

    2013-06-01

    Focused beam reflectance measurement (FBRM) was used as a process analytical technology tool to perform inline real-time particle size analysis of a proprietary granulation manufactured using a continuous twin-screw granulation-drying-milling process. A significant relationship between D20, D50, and D80 length-weighted chord length and sieve particle size was observed with a p value of 0.05).

  9. Synthesis of niobium carbide by a high energy milling technique of powder metallurgy

    International Nuclear Information System (INIS)

    Antonello, Rodrigo Tecchio; Gonzalez, Cezar Henrique; Urtiga Filho, Severino Leopoldino; Araujo Filho, Oscar Olimpio de; Ambrozio Filho, Francisco

    2010-01-01

    The aim of this work is to obtain and characterize the Niobium Carbide (NbC) by a suitable high energy milling technique using a SPEX Mill vibratory type and niobium and carbon (graphite) powders. Since this carbide is scarced in the national market and it's necessary to apply this NbC as a reinforcement in two molybdenum high speed steels (AISI M2 and AISI M3:2) object of another work motivated this research. The powders were submitted to a high energy milling procedure for suitable times and conditions and then were characterized by means of Scanning Electronic Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (DRX) techniques. The ball-to-powder weight ratio was 10:1. The analysed samples showed that the high-energy milling is an alternative route of the NbC synthesis. (author)

  10. Synthesis of niobium carbide (NbC) by powder metallurgy high energy milling technique

    International Nuclear Information System (INIS)

    Antonello, Rodrigo Tecchio; Urtiga Filho, Severino Leopoldino; Araujo Filho, Oscar Olimpio de; Ambrozio Filho, Francisco; Gonzalez, Cezar Henrique

    2009-01-01

    The aim of this work is to obtain and characterize the Niobium Carbide (NbC) by a suitable high energy milling technique using a SPEX Mill vibratory type and niobium and carbon (graphite) powders. Since this carbide is scarce in the national market and it's necessary to apply this NbC as a reinforcement in two molybdenum high speed steels (AISI M2 and AISI M3:2) object of another work motivated this research. The powders were submitted to a high energy milling procedure for suitable times and conditions and then were characterized by means of Scanning Electronic Microscopy (SEM) and X-ray diffraction (DRX) techniques. The ball-to-powder weight ratio was 10:1. The analysed samples showed that the high-energy milling is an alternative route of the NbC synthesis. (author)

  11. Hydrogen storage in Mg-Ni-Fe compounds prepared by melt spinning and ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Palade, P. [Settore Materiali, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy); National Institute for Physics of Materials, Atomistilor 105 bis, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania); Sartori, S. [Settore Materiali, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy); Maddalena, A. [Settore Materiali, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy); Principi, G. [Settore Materiali, Dipartimento di Ingegneria Meccanica, Universita di Padova, via Marzolo 9, 35131 Padova (Italy)]. E-mail: giovanni.principi@unipd.it; Lo Russo, S. [Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy); Lazarescu, M. [National Institute for Physics of Materials, Atomistilor 105 bis, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania); Schinteie, G. [National Institute for Physics of Materials, Atomistilor 105 bis, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania); Kuncser, V. [National Institute for Physics of Materials, Atomistilor 105 bis, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania); Filoti, G. [National Institute for Physics of Materials, Atomistilor 105 bis, P.O. Box MG-7, 077125 Bucharest-Magurele (Romania)

    2006-05-18

    Magnesium-rich Mg-Ni-Fe intermetallic compounds have been prepared by two different routes: (a) short time ball milling of ribbons obtained by melt spinning; (b) long time ball milling of a mixture of MgH{sub 2}, Ni and Fe powders. The first type of samples displays an hydrogen desorption kinetics better than the second one. Pressure composition isotherm measurements exhibit for both type of samples two plateaux, the lower and wider corresponding to the MgH{sub 2} phase and the upper and shorter corresponding to the Mg{sub 2}NiH{sub 4} phase. The presence of the two types of hydrides is confirmed by X-ray diffraction analysis. Moessbauer spectroscopy shows that in melt spun and subsequently milled samples iron is mainly in a disordered structure and segregates after hydrogenation, while in directly milled powders remains mainly unalloyed. After multiple hydrogen absorption/desorption cycles the main part of iron is in metallic state in samples of both types, those of first type preserving better hydrogen desorption kinetics.

  12. Pavement maintenance procedures with and without milling materials

    Directory of Open Access Journals (Sweden)

    Rafiqul A. Tarefder

    2016-01-01

    Full Text Available This study evaluates maintenance treatment followed by different Districts of New Mexico Department of Transportation (NMDOT. In addition, two case studies on the use of old pavement materials, called the “millings”, in maintenance projects are reported. Based on this study, it is observed that none of the Districts have a written procedure for maintenance work. Rather Districts rely on the experience of the maintenance crew for conducting maintenance projects. All Districts prefer to use chip seal for maintenance irrespective of distress conditions of the pavements. Patching and crack sealing are usually done before chip sealing to extend the life of the chip seals. Sand seal, scrub seal, and slurry seal projects are not done by District maintenance crews but by outside contractors. It is also observed that all Districts are interested in using millings in maintenance projects and most have already used millings in at least one maintenance project with some success and failure. Most of the Districts have used coarse fraction of millings in chip seal projects successfully. However, they failed to find a proper way to process the fine fractions of millings. Case Study I shows that fine millings can be used to construct thin overlay when mixed with emulsion in pug mill or hot drums. Case Study II concludes that fine millings can be used as fine/sand seal successfully following the same procedure and using the same equipment as chip seal. Keywords: Millings, Maintenance, Emulsion, Rutting, Pug-mill

  13. Uranium Mill Tailings Remedial Action Project Vicinity Property Program

    International Nuclear Information System (INIS)

    Little, L.E.; Potter, R.F.; Arpke, P.W.

    1988-01-01

    The Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Grand Junction Project Vicinity Property Program is a $165 million program for the removal and disposal of uranium mill tailings that were used in the construction of approximately 4,000 residences, commercial buildings, and institutional facilities in the City of Grand Junction and surrounding Mesa County, Colorado. This paper discusses the UMTRA Vicinity Property Program and the economic benefits of this program for the City of Grand Junction and Mesa County, Colorado. The Bureau of Reclamation Economic Assessment Model (BREAM) was used to estimate the increases in employment and increases in personal income in Mesa County that result from the Vicinity Property Program. The effects of program-related changes in income and taxable expenditures on local and state tax revenue are also presented

  14. Optimal Cluster Mill Pass Scheduling With an Accurate and Rapid New Strip Crown Model

    International Nuclear Information System (INIS)

    Malik, Arif S.; Grandhi, Ramana V.; Zipf, Mark E.

    2007-01-01

    Besides the requirement to roll coiled sheet at high levels of productivity, the optimal pass scheduling of cluster-type reversing cold mills presents the added challenge of assigning mill parameters that facilitate the best possible strip flatness. The pressures of intense global competition, and the requirements for increasingly thinner, higher quality specialty sheet products that are more difficult to roll, continue to force metal producers to commission innovative flatness-control technologies. This means that during the on-line computerized set-up of rolling mills, the mathematical model should not only determine the minimum total number of passes and maximum rolling speed, it should simultaneously optimize the pass-schedule so that desired flatness is assured, either by manual or automated means. In many cases today, however, on-line prediction of strip crown and corresponding flatness for the complex cluster-type rolling mills is typically addressed either by trial and error, by approximate deflection models for equivalent vertical roll-stacks, or by non-physical pattern recognition style models. The abundance of the aforementioned methods is largely due to the complexity of cluster-type mill configurations and the lack of deflection models with sufficient accuracy and speed for on-line use. Without adequate assignment of the pass-schedule set-up parameters, it may be difficult or impossible to achieve the required strip flatness. In this paper, we demonstrate optimization of cluster mill pass-schedules using a new accurate and rapid strip crown model. This pass-schedule optimization includes computations of the predicted strip thickness profile to validate mathematical constraints. In contrast to many of the existing methods for on-line prediction of strip crown and flatness on cluster mills, the demonstrated method requires minimal prior tuning and no extensive training with collected mill data. To rapidly and accurately solve the multi-contact problem

  15. Indian Americans at Mille Lacs.

    Science.gov (United States)

    Holbert, Victoria L.; And Others

    The Training Center for Community Programs prepared a report on the Mille Lacs (Chippewa) Reservation in Minnesota. Data for the report were from 2 separate sources: a survey conducted by the Training Center with the assistance of the Mille Lacs community action program (1967) and an attitudinal survey conducted by Victoria Holbert during 1969.…

  16. Dynamic and Stochastic Structures of U.S. Cotton Exports and Mill Demand

    OpenAIRE

    Fadiga, Mohamadou L.

    2006-01-01

    This study employs a structural time-series method to model and estimate U.S. cotton exports and mill use. The results show that the stochastic process governing cotton export fluctuations is transitory, while the process pertaining to mill use has transitory, seasonal, and secular origins. The estimated structural relationships after accounting for the unobserved components indicate U.S. cotton exports respond directly to higher international price relative to domestic price of cotton, while...

  17. Magneto-optical properties of α-Fe2O3@ZnO nanocomposites prepared by the high energy ball-milling technique

    Science.gov (United States)

    Chaudhury, Chandana Roy; Roychowdhury, Anirban; Das, Anusree; Das, Dipankar

    2016-05-01

    Magnetic-fluorescent nanocomposites (NCs) with 10 wt% of α-Fe2O3 in ZnO have been prepared by the high energy ball-milling. The crystallite sizes of α-Fe2O3 and ZnO in the NCs are found to vary from 65 nm to 20 nm and 47 nm to 15 nm respectively as milling time is increased from 2 to 30 h. XRD analysis confirms presence of α-Fe2O3 and ZnO in pure form in all the NCs. UV-vis study of the NCs shows a continuous blue-shift of the absorption peak and a steady increase of band gap of ZnO with increasing milling duration that are assigned to decreasing particle size of ZnO in the NCs. Photoluminescence (PL) spectra of the NCs reveal three weak emission bands in the visible region at 421, 445 and 485 nm along with the strong near band edge emission at 391 nm. These weak emission bands are attributed to different defect - related energy levels e.g. Zn-vacancy, Zn interstitial and oxygen vacancy. Dc and ac magnetization measurements show presence of weakly interacting superparamagnetic (SPM) α-Fe2O3 particles in the NCs. 57Fe-Mössbauer study confirms presence of SPM hematite in the sample milled for 30 h. Positron annihilation lifetime measurements indicate presence of cation vacancies in ZnO nanostructures confirming results of PL studies.

  18. Ground beetle populations near a kraft mill

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, R.; Hastings, L.; Mercer, W.R.; Smith, A.

    1973-02-01

    Twenty species of ground beetles (Family Carabidae) and one species of carrion beetle (Family Silphidae) were collected in six stations east of a kraft paper mill in Thunder Bay, Ontario, from May to August, 1971. The beetle population decreased markedly towards the mill. There was no apparent statistical difference in size variation of specimens near the mill and those further away.

  19. 21 CFR 515.10 - Medicated feed mill license applications.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Medicated feed mill license applications. 515.10... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS MEDICATED FEED MILL LICENSE Applications § 515.10 Medicated feed mill license applications. (a) Medicated feed mill license applications (Forms FDA 3448) may...

  20. Effect of hydraulic retention time on biohydrogen and volatile fatty acids production during acidogenic digestion of dephenolized olive mill wastewaters

    International Nuclear Information System (INIS)

    Scoma, Alberto; Bertin, Lorenzo; Fava, Fabio

    2013-01-01

    The influence of Hydraulic Retention Time (HRT) on the performances of a recently developed biotechnological anaerobic acidogenic process fed with dephenolized Olive Mill Wastewater (OMW) was investigated. The study was carried out under mesophilic conditions in Packed Bed Biofilm Reactors (PBBRs), filled with ceramic cubes and inoculated with a characterized and acclimated acidogenic microbial consortium. The PBBRs were fed with a HRT of 7, 5, 3 or 1 day, which corresponded to Organic Loading Rates (OLRs) of about 5.5, 7.8, 12.9 and 38.8 g L −1 d −1 , respectively. A significant production of a H 2 -rich biogas was observed when shorter HRTs were applied: in particular, H 2 relative amount and productivity increased from 3% to 32% and from 0.20 to 6.10 dm 3 m −3 h −1 , respectively, by decreasing the HRT from 7 to 1 day. On the contrary, shorter HRTs turned into a lower accumulation of Volatile Fatty Acids (VFAs), whose highest amounts were found with HRTs of 7 and 5 days (about 18.4 and 19.7 g L −1 COD equivalents, respectively). The highest conversion yield of COD into VFAs (36%) was obtained with a HRT of 5 days, when VFAs represented about 78% of the effluent COD. HRT also influenced the composition of the VFA mixture: acetic, propionic and butyric acid were the most prominent VFAs, being their relative amounts higher when PBBRs were operated with shorter HRTs (up to 19, 12 and 42% of the whole mixture, respectively, when HRT was 1 day). -- Highlights: ► HRT affects the acidogenic digestion of dephenolized olive mill wastewater. ► A significant production of bioH 2 can be coupled to that of volatile fatty acids. ► Higher H 2 and lower VFA productions were obtained by shortening the HRT

  1. High-energy ball milling of powder B-C mixtures

    International Nuclear Information System (INIS)

    Ramos, Alfeu S.; Taguchi, Simone P.; Ramos, Erika C.T.; Arantes, Vera L.; Ribeiro, Sebastiao

    2006-01-01

    The present work reports on the preparation of B-10 at.% C and B-18 at.% C powders by high-energy ball milling and further heat treatment. The milling process was carried out in a planetary ball mill. Following the milling process, powder samples were heat-treated at 1200 deg. C for 4 h using inert atmosphere. The milled and heat-treated B-10C and B-18C powders were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. A reduction on the intensity of B and C peaks was noticed after milling for 2 h, probably due the fine powder particle sizes because the pronounced fracture mechanism during ball milling of brittle starting components. The XRD patterns of B-10C and B-18C powders milled for 6 h indicated the presence of other peaks, suggesting that a metastable structure could have been formed. After milling for 90 h, these unknown peaks were still present. A large amount of B 4 C was formed after heat treatment at 1200 deg. C for 4 h beside these unknown peaks

  2. The yang mills gravity dual

    International Nuclear Information System (INIS)

    Crooks, David E.; Evans, Nick

    2003-01-01

    We describe a ten dimensional supergravity geometry which is dual to a gauge theory that is non-supersymmetric Yang Mills in the infra-red but reverts to N=4 super Yang Mills in the ultra-violet. A brane probe of the geometry shows that the scalar potential of the gauge theory is stable. We discuss the infra-red behaviour of the solution. The geometry describes a Schroedinger equation potential that determines the glueball spectrum of the theory; there is a mass gap and a discrete spectrum. The glueball mass predictions match previous AdS/CFT Correspondence computations in the non-supersymmetric Yang Mills theory, and lattice data, at the 10% level. (author)

  3. Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing

    International Nuclear Information System (INIS)

    Brocq, M.

    2010-10-01

    In the context of the development of new ODS (Oxide Dispersion Strengthened) steels as core materials in future nuclear reactors, we investigated a new process inspired by reactive ball-milling which consists in using YFe 3 andFe 2 O 3 as starting reactants instead of Y 2 O 3 to produce a dispersion of nano-oxides in a steel matrix and the influence of synthesis conditions on the nano-oxide characteristics were studied. For that aim, ODS steels were prepared by ball-milling and then annealed. Multi-scale characterizations were performed after each synthesis step, using notably atom probe tomography and small angle neutron scattering. The process inspired by reactive ball-milling was shown to be efficient for ODS steel synthesis, but it does not modify the nano-oxide characteristics as compared to those of oxides directly incorporated in the matrix by ball-milling. Broadly speaking, the nature of the starting oxygen bearing reactants has no influence on nano-oxide formation. Moreover, we showed that the nucleation of nano-oxides nucleation can start during milling and continues during annealing with a very fast kinetic. The final characteristics of nano-oxides formed in this way can be monitored through ball-milling parameters (intensity, temperature and atmosphere) and annealing parameters (duration and temperature). (author)

  4. Effect of milling time and CNT concentration on hardness of CNT/Al2024 composites produced by mechanical alloying

    International Nuclear Information System (INIS)

    Pérez-Bustamante, R.; Pérez-Bustamante, F.; Estrada-Guel, I.; Licea-Jiménez, L.; Miki-Yoshida, M.; Martínez-Sánchez, R.

    2013-01-01

    Carbon nanotube/2024 aluminum alloy (CNT/Al 2024 ) composites were fabricated with a combination of mechanical alloying (MA) and powder metallurgy routes. Composites were microstructurally and mechanically evaluated at sintering condition. A homogeneous dispersion of CNTs in the Al matrix was observed by a field emission scanning electron microscopy. High-resolution transmission electron microscopy confirmed not only the presence of well dispersed CNTs but also needle-like shape aluminum carbide (Al 4 C 3 ) crystals in the Al matrix. The formation of Al 4 C 3 was suggested as the interaction between the outer shells of CNTs and the Al matrix during MA process in which crystallization took place after the sintering process. The mechanical behavior of composites was evaluated by Vickers microhardness measurements indicating a significant improvement in hardness as function of the CNT content. This improvement was associated to a homogeneous dispersion of CNTs and the presence of Al 4 C 3 in the aluminum alloy matrix. - Highlights: ► The 2024 aluminum alloy was reinforced by CNTs by mechanical alloying process. ► Composites were microstructural and mechanically evaluated after sintering condition. ► The greater the CNT concentration, the greater the hardness of the composites. ► Higher hardness in composites is achieved at 20 h of milling. ► The formation of Al 4 C 3 does not present a direct relationship with the milling time.

  5. Uranium mill tailings remedial action technology

    International Nuclear Information System (INIS)

    Hartley, J.N.; Gee, G.W.

    1984-01-01

    The uranium milling process involves the hydrometallurgical extraction of uranium from ores and the resultant generation of large quantities of waste referred to as tailings. Uranium mill tailings have been identified as requiring remediation because they contain residual radioactive material that is not removed in the milling process. Potential radiation exposure can result from direct contact with the tailings, from radon gas emitted by the tailings, and from radioactive contamination of groundwater. As a result, the technology developed under the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) and the US Nuclear Regulatory Commission (NRC) Uranium Recovery Program have focused on radon control, groundwater contamination and the long-term protection of the containment system. This paper briefly summarizes the UMTRAP and NRC remedial action technology development. 33 references, 9 figures, 5 tables

  6. Tool wear in terms of vibration effects in milling medium-density fibreboard with an industrial robot

    International Nuclear Information System (INIS)

    Tratar, Janez; Pusavec, Franci; Kopac, Janez

    2014-01-01

    Machining with robots represents a promising, highly flexible and cost effective alternative to standard machining and hand labour applications when machining mid tolerance soft material end products. One of the most challenging issues is to know the vibration characteristics in milling with the robots which greatly affect tool life. In general the technological bases of tool life expectancy while milling with robot arms are not available or studied. That's why the purpose of this paper is to investigate the influence of attained vibrations analysis during the milling process and correlated tool wear. Primarily the study is focused on tool wear according to the distance between the milling position and the robot's base. Results show that increasing distance between the robot's base and the milling position significantly affects tool wear because of the attained vibrations in proportion to the increasing distance respectively. Tool wear has also proved to be greater in comparison to machining with CNC machine and applicable new information for woodworking industry.

  7. Feasibility of vermicomposting dewatered sludge from paper mills using Perionyx excavatus

    Directory of Open Access Journals (Sweden)

    Puspanjali Sonowal

    2013-06-01

    Full Text Available India has a large network of pulp and paper mills of varying capacity. On an industrial scale the sludge from paper and pulp mills is disposed of either as landfill or incinerated. Both methods result in the loss of a valuable resource and have obvious environmental and economic disadvantages. The solid waste from pulp and paper mills is a source of organic matter and its proper disposal and management is the responsibility of the industry. As composting/vermicomposting could be used to transform this waste trials were carried out to determine the feasibility of converting dewatered sludge (DS into a value added end product using an earthworm, Perionyx excavatus. The vermicomposting of the waste resulted in an increase in its electrical conductivity (EC, ash content, total nitrogen (TN, total phosphorous (TP and available phosphorous (AP, respectively, and a decrease in total organic carbon (TOC, biochemical oxygen demand (BOD, chemical oxygen demand (COD, oxygen uptake rate (OUR and evolution of carbon dioxide (CO2. Overall, the best treatment was T5 in which there was a 76.1% increase in TP, 58.7% in TN, 74.5% decrease in TOC , and a reduction of 6.7 fold in the production of CO2 and 10.7 fold in BOD, respectively. Our trials demonstrate that vermicomposting using an epigeic earthworm, Perionyx excavatus, is an alternate and environmentally safe way of recycling paper mill sludge if it is mixed with an appropriate amount of cow dung and food processing waste. Overall T5 was the best combination of paper mill sludge and waste for vermicomposting followed by T3, T2, T4 and T1, respectively.

  8. Uranium mill tailings

    International Nuclear Information System (INIS)

    McLaren, L.H.

    1982-11-01

    This bibliography contains information on uranium mill tailings included in the Department of Energy's Energy Data Base from January 1981 through October 1982. The abstracts are grouped by subject category as shown in the table of contents. Entries in the subject index also facilitate access by subject, e.g., Mill Tailings/Radiation Hazards. Within each category the arrangement is by report number for reports, followed by nonreports in reverse chronological order. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. (335 abstracts)

  9. Geometrical characterization of micro end milling tools

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo; Bissacco, Giuliano

    2005-01-01

    Performance of the milling process is directly affected by the accuracy of tool geometry. Development of methods suitable for dimensional characterization of such tools, with low measurement uncertainties is therefore of relevance. The present article focuses on the geometrical characterization...... of a flat micro end milling tool with a nominal mill diameter of 200 microns. An experimental investigation was carried out involving two different non-contact systems...

  10. An extended topological Yang-Mills theory

    International Nuclear Information System (INIS)

    Deguchi, Shinichi

    1992-01-01

    Introducing infinite number of fields, we construct an extended version of the topological Yang-Mills theory. The properties of the extended topological Yang-Mills theory (ETYMT) are discussed from standpoint of the covariant canonical quantization. It is shown that the ETYMT becomes a cohomological topological field theory or a theory equivalent to a quantum Yang-Mills theory with anti-self-dual constraint according to subsidiary conditions imposed on state-vector space. On the basis of the ETYMT, we may understand a transition from an unbroken phase to a physical phase (broken phase). (author)

  11. Environmental design of a uranium mill

    International Nuclear Information System (INIS)

    Quan, C.H.; Ring, R.J.; McNaughton, S.J.

    2002-01-01

    In the frame work of the Cleaner Technology Project for Uranium Mining and Milling, Australian Nuclear and Technology Organization (ANSTO), Environment Division of ANSTO has carried out a programme of research which seeks to identify, investigate and develop cleaner technologies that have the potential to minimize the environmental impact of uranium mining and milling. This paper describes three design options of a new uranium mill that can meet environmental, technical and economical objectives. The feasibility of such an approach was examined in the laboratory and in a pilot plant study. (author)

  12. Prevalence of respiratory symptoms and disorders among rice mill workers in India.

    Science.gov (United States)

    Ghosh, Tirthankar; Gangopadhyay, Somnath; Das, Banibrata

    2014-05-01

    Lung function tests have become an integral part of assessment of pulmonary disease. Diseases of the respiratory system induced by occupational dusts are influenced by the duration of exposure. The aim of the study is to investigate the impairment of lung function and prevalence of respiratory symptoms among the rice mill workers. A total of 120 rice mill workers from three districts of Karnataka were included in this study. Fifty urban dwellers from the same socio-economic level were selected as controls. The study included clinical examination, assessment of respiratory symptoms, pulmonary function test, measurement of peak expiratory flow rate, absolute eosinophil count, ESR estimation, total IgE estimation and radiographic test. The present study has shown that the rice mill workers complained of several types of respiratory disorders like phlegm (40.8 %), dyspnea (44.2 %), chest tightness (26.7 %), cough (21.7 %), and nose irritation (27.5 %). Rice mill workers exposed to dust presented significantly (p workers are having significantly higher absolute eosinophil counts, total IgE and ESR than control groups. The hematological findings suggest that the harmful effects may be linked to both non-specific irritation and allergic responses to rice husk dust among rice mill workers. Dust exposure in the working environment affects the lung function values and increased the respiratory symptoms among the rice mill workers.

  13. Flaking behavior and microstructure evolution of nickel and copper powder during mechanical milling in liquid environment

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Xiao [College of Metallurgical Science and Engineering, Central South University, Changsha 410083, Hunan (China); Changsha Research Institute of Mining and Metallurgy, Changsha 410012, Hunan (China); Zeng Zigao [Changsha Research Institute of Mining and Metallurgy, Changsha 410012, Hunan (China); Zhao Zhongwei [College of Metallurgical Science and Engineering, Central South University, Changsha 410083, Hunan (China); Xiao Songwen [Changsha Research Institute of Mining and Metallurgy, Changsha 410012, Hunan (China)], E-mail: swinxiao@yahoo.com.cn

    2008-02-25

    To prepare metal flakes with a high flaking level and investigate the microstructure of metal flakes, nickel and copper powder were mechanically milled in liquid environment and the microstructure of powders was investigated by X-ray diffraction. The milling process can be divided into flaking and broken stages. At the flaking stage, milled metal powders exhibited high flaking level and flaky microshape, and <2 0 0> became preferred orientation. While at the broken stage, the milled powders presented a low flaking level and irregular microshape, and <2 0 0> was not preferred orientation any longer. The grain size, microstrain and dislocation density along <2 0 0> direction varied with milling time differently from that along <1 1 1> direction. The flaking level of the milled powders was related to the <2 0 0> preferred orientation, and more closely to the deformation mechanism. We can strengthen the formation of <2 0 0> preferred orientation to obtain metal powders with a high flaking level.

  14. Effect of process variables on synthesis of MgB2 by a high energy ball mill

    Directory of Open Access Journals (Sweden)

    Kurama Haldun

    2016-01-01

    Full Text Available The discovery of superconductivity of MgB2 in 2001, with a critical temperature of 39 K, offered the promise of important large-scale applications at around 20 K. Except than the other featured synthesis methods, mechanical activation performed by high energy ball mills, as bulk form synthesis or as a first step of wire and thin film productions, has considered as an effective alternative production route in recent years. The process of mechanical activation (MA starts with mixing the powders in the right proportion and loading the powder mixture into the mill with the grinding media. The milled powder is then consolidated into a bulk shape and heat-treated to obtain desired microstructure and properties. Thus, the important components of the MA process are the raw materials, mill type and process variables. During the MA process, heavy deformation of particles occure. This is manifested by the presence of a variety of crystal defects such as dislocations, vacancies, stacking faults and increased number of particle boundaries. The presence of this defect structure enhances the diffusivity of solute hence the critical currents and magnetic flux pinning ability of MgB2 are improved. The aim of the present study is to determine the effects of process variables such as ball-to-powder mass ratio, size of balls, milling time, annealing temperature and contribution of process control agent (toluene on the product size, morphology and conversion level of precursor powders to MgB2 after subsequent heat treatment. The morphological analyses of the samples were performed by a high vacuum electron microscope ZEISS SUPRA VP 50. The phase compositions of the samples were performed with an Rigaku-Rint 2200 diffractometer, with nickel filtered Cu Kα radiation and conversion level. The MgB2 phase wt % was calculated by the Rietveld refinement method. The obtained results were discussed according to the process variables to find out their affect on the structure

  15. Artificial intelligence versus statistical modeling and optimization of continuous bead milling process for bacterial cell lysis

    Directory of Open Access Journals (Sweden)

    Shafiul Haque

    2016-11-01

    Full Text Available AbstractFor a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD was studied in a continuous bead milling process. A full factorial Response Surface Model (RSM design was employed and compared to Artificial Neural Networks coupled with Genetic Algorithm (ANN-GA. Significant process variables, cell slurry feed rate (A, bead load (B, cell load (C and run time (D, were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v, cell loading OD600 nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN coupled with GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h: 258.08, bead loading (%, v/v: 80%, cell loading (OD600 nm: 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN in combination with evolutionary optimization (GA for representing undefined biological functions which is the case for common industrial processes involving biological moieties.

  16. The ionic conductivity and dielectric properties of Ba{sub 1−x}Sn{sub x}F{sub 2} solid solutions prepared by mechanochemical milling

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Mohamad M., E-mail: mmohamad@kfu.edu.sa [Department of Physics, College of Science, King Faisal University, Al-Ahsaa 31982 (Saudi Arabia); Department of Science and Mathematics, Faculty of Education in The New Valley, Assiut University, El-Kharga 72511 (Egypt); Yamane, Yohei; Yamada, Koji [Department of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Narashino, Chiba 275-8575 (Japan)

    2013-09-01

    Highlights: • New Ba{sub 1−x}Sn{sub x}F{sub 2} compositions have been synthesized by the mechanochemical milling. • Considerably higher ionic conductivity is obtained when increasing SnF{sub 2} content. • The increased conductivity is due to the enhanced mobility of fluoride ions -- Abstract: Solid solutions of Ba{sub 1−x}Sn{sub x}F{sub 2} fluoride ion conductors, with x = 0.1–0.4, have been synthesized by the mechanochemical milling technique for the first time. All of the prepared materials crystallize in the cubic fluorite-type structure, which indicates that the solid solution can be synthesized in the studied composition range by the mechanochemical milling technique at ambient temperature and pressure. The ionic conduction of the investigated materials has been studied by impedance spectroscopy. The ionic conductivity increased considerably, by up to six orders of magnitude compared to pure un-milled BaF{sub 2}, with increasing SnF{sub 2} content. From the analysis of the conductivity spectra of the investigated materials it is found that the concentration of mobile fluoride ions is independent of temperature with almost the same values for the investigated materials. The present results suggest that the enhanced mobility of mobile ions is the origin of the higher ionic conductivity. The dielectric properties and the associated relaxation phenomena of the current materials are also described.

  17. Health concerns in uranium mining and milling

    International Nuclear Information System (INIS)

    Archer, V.E.

    1981-01-01

    Mortality of uranium miners form both lung cancer and other respiratory diseases is strongly dependent on exposure to radon daughters, cigarette smoking and height. Lung cancer among 15 different mining groups (uranium, iron, led, zinc) was analyzed to determine what factors influence incidence and the induction-latent period. At low exposure or exposure rates, alpha radiation is more efficient in inducing lung cancer, producing an upward convex exposure-response curve. The induction-latent period is shortened by increased age at start of mining, by cigarette smoking and by high exposure rates. For a follow-up period of 20 to 25 years, the incidence increases with age at start of mining, with magnitude of exposure and with amount of cigarette smoking. Instead of extrapolating downward from high exposures to estimate risk at low levels, it is suggested that it might be more appropriate to use cancer rates associated with background radiation as the lowest point on the exposure-response curve. Although health risks are much greater in uranium mines than mills, there is some health risk in the mills from long-lived radioactive materials

  18. Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans

    Directory of Open Access Journals (Sweden)

    Sri Mulato

    2006-12-01

    Full Text Available One of improtant steps in secondary coffee processing that influence on final product quality such as consistency and uniformity is milling process. Usually, Indonesian smallholder used "lumpang" for milling coffee roasted beans to coffee powder product which caused the final product not uniformed and consistent, and low productivity. Milling process of coffee roasted beans can be done by disk mill type mechanical grinder which is used by smallholder for milling several cereals. Indonesian Coffee and Cocoa Research Institute have developed disk mill type grinding machine for milling coffee roasted beans. Objective of this research is to find performance of disk mill type grinding machine for size reducing process of Robusta roasted beans from several size dried beans and roasting level treatments. Robusta dried beans which are taken from dry processing method have 13—14% moisture content (wet basis, 680—685 kg/m3 density, and classified in 3 sizes level. The result showed that the disk mill type of grinding machine could be used for milling Robusta roasted beans. Machine hascapacity 31—54 kg/h on 5,310—5,610 rpm axle rotation and depend on roasting level. Other technical parameters were 91—98% process efficientcy, 19—31 ml/ kg fuel consumption, 0.3—1% slips, 50—55% particles had diameter less than 230 mesh and 38—44% particles had diameter bigger than 100 mesh, 32—38% lightness was increased, 0.6—12.6% density was decreased, and solubility of coffee powder between 28—30%. Cost milling process per kilogram of Robusta roasted beans which light roast on capacity 30 kg/hour was Rp362.9. Key words : Coffee roasted, Robusta, disk mill, mechanical grinder, size reduction.

  19. Management of wastes from uranium mines and mills

    International Nuclear Information System (INIS)

    Thomas, K.T.

    1981-01-01

    Uranium mining and milling operations have not given rise to much concern about their hazards, and with advancing technologies for mill processing and waste management, the situation will continue to improve. However, the disposal of large quantities of waste produced in mining and milling does have an environmental impact, owing to the long half-lives and the ready availability of the toxic radionuclides Ra-226 and Rn-222. This article deals with the management of wastes from uranium mines and mills

  20. Code of practice on radiation protection in the mining and milling of radioactive ores 1987

    International Nuclear Information System (INIS)

    1987-01-01

    This Code was formulated under provisions of the Environment Protection (Nuclear Codes) Act 1978 in close consultation with the Governments of the States and the Northern Territory. It is a major revision of the Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores (1980), incorporating changes flowing from advances in internationally agreed radiation protection philosophy, and experience gained in Australia in uranium mining and milling operations and the extraction of monazite from mineral sands. The Code specifies the standards, practices, procedures, and measures to prevent or limit risk to employees and to the public from uranium mining and milling, mineral sands operations and extraction of radioactive ores. To assist the industry in meeting the requirements and responsibilities imposed by the Code, guidelines to the former Code will be reviewed and, if appropriate, revised. New guidelines to assist compliance with changed requirements will also be prepared. The Act provides for the revision of codes of practice. The Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores (1987) will be reviewed from time to time and revised if necessary to ensure that the highest standards of radiation protection in the mining and milling of radioactive ores are maintained

  1. Code of practice on radiation protection in the mining and milling of radioactive ores 1987

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This Code was formulated under provisions of the Environment Protection (Nuclear Codes) Act 1978 in close consultation with the Governments of the States and the Northern Territory. It is a major revision of the Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores (1980), incorporating changes flowing from advances in internationally agreed radiation protection philosophy, and experience gained in Australia in uranium mining and milling operations and the extraction of monazite from mineral sands. The Code specifies the standards, practices, procedures, and measures to prevent or limit risk to employees and to the public from uranium mining and milling, mineral sands operations and extraction of radioactive ores. To assist the industry in meeting the requirements and responsibilities imposed by the Code, guidelines to the former Code will be reviewed and, if appropriate, revised. New guidelines to assist compliance with changed requirements will also be prepared. The Act provides for the revision of codes of practice. The Code of Practice on Radiation Protection in the Mining and Milling of Radioactive Ores (1987) will be reviewed from time to time and revised if necessary to ensure that the highest standards of radiation protection in the mining and milling of radioactive ores are maintained.

  2. Structural modifications of ultra-high molecular weight polyethylene (UHMWPE) processed in attritor type mill

    International Nuclear Information System (INIS)

    Gabriel, Melina C.; Carvalho, Benjamim de M.; Pinheiro, Luis A.; Cintho, Osvaldo M.; Capocchi, Jose D.T.; Kubaski, Evaldo T.

    2009-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) is a polyethylene that has a high melt viscosity, hence its processing becomes very difficult. High-energy mechanical milling provides physical and chemical changes in polymers that have been studied recently. In order to study these changes in UHMWPE, powder of this polymer was mechanical milled in attritor type mill with a ball-to-powder weight ratio of 40:1 for 8 hours, varying the rotation speed: 200, 300, 400, 500 e 600 rpm. The polymer was characterized by scanning electron microscopy (SEM) and xray diffraction (XRD). From the XRD results it was noted that as the rotation speed increased the monoclinic phase also increased up to 500 rpm. For 600 rpm, the amount of monoclinic phase apparently decreased. At this rotation speed, the deformation rate probably increased the process temperature, allowing the monoclinic phase to return to its initial structural orthorhombic form. (author)

  3. Synthesis of the Mg{sub 2}Ni alloy prepared by mechanical alloying using a high energy ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Iturbe G, J. L.; Lopez M, B. E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Garcia N, M. R., E-mail: joseluis.iturbe@inin.gob.m [UNAM, Facultad de Estudios Superiores Zaragoza, Batalla 5 de Mayo s/n, Esq. Fuerte de Loreto, Col. Ejercito de Oriente, 09230 Mexico D. F. (Mexico)

    2010-07-01

    Mg{sub 2}Ni was synthesized by a solid state reaction from the constituent elemental powder mixtures via mechanical alloying. The mixture was ball milled for 10 h at room temperature in an argon atmosphere. The high energy ball mill used here was fabricated at ININ. A hardened steel vial and three steel balls of 12.7 mm in diameter were used for milling. The ball to powder weight ratio was 10:1. A small amount of powder was removed at regular intervals to monitor the structural changes. All the steps were performed in a little lucite glove box under argon gas, this glove box was also constructed in our Institute. The structural evolution during milling was characterized by X-ray diffraction and scanning electron microscopy techniques. The hydrogen reaction was carried out in a micro-reactor under controlled conditions of pressure and temperature. The hydrogen storage properties of mechanically milled powders were evaluated by using a thermogravimetric analysis system. Although homogeneous refining and alloying take place efficiently by repeated forging, the process time can be reduced to one fiftieth of the time necessary for conventional mechanical milling and attrition. (Author)

  4. A connection between the Einstein and Yang-Mills equations

    International Nuclear Information System (INIS)

    Mason, L.J.; Newman, E.T.

    1989-01-01

    It is our purpose here to show an unusual relationship between the Einstein equations and the Yang-Mills equations. We give a correspondence between solutions of the self-dual Einstein vacuum equations and the self-dual Yang-Mills equations with a special choice of gauge group. The extension of the argument to the full Yang-Mills equations yields Einstein's unified equations. We try to incorporate the full Einstein vacuum equations, but the approach is incomplete. We first consider Yang-Mills theory for an arbitrary Lie-algebra with the condition that the connection 1-form and curvature are constant on Minkowski space. This leads to a set of algebraic equations on the connection components. We then specialize the Lie-algebra to be the (infinite dimensional) Lie algebra of a group of diffeomorphisms of some manifold. The algebraic equations then become differential equations for four vector fields on the manifold on which the diffeomorphisms act. In the self-dual case, if we choose the connection components from the Lie-algebra of the volume preserving 4-dimensional diffeomorphism group, the resulting equations are the same as those obtained by Ashtekar, Jacobsen and Smolin, in their remarkable simplification of the self-dual Einstein vacuum equations. (An alternative derivation of the same equations begins with the self-dual Yang-Mills connection now depending only on the time, then choosing the Lie-algebra as that of the volume preserving 3-dimensional diffeomorphisms). When the reduced full Yang-Mills equations are used in the same context, we get Einstein's equations for his unified theory based on absolute parallelism. To incorporate the full Einstein vacuum equations we use as the Lie group the semi-direct product of the diffeomorphism group of a 4-dimensional manifold with the group of frame rotations of an SO(1, 3) bundle over the 4-manifold. This last approach, however, yields equations more general than the vacuum equations. (orig.)

  5. Oxidant reduction and biodegradability improvement of paper mill effluent by irradiation

    International Nuclear Information System (INIS)

    Tiezheng Wang; Waite, T.D.; Kurucz, C.

    1994-01-01

    Paper mill bleach processing wastewaters represent a large input of hazardous compounds to the environment and these compounds are usually non-biodegradable. A preliminary study using a 5000 Ci 60 Co gamma radiation source as a surrogate for electron beam irradiation, potentially an emerging technology for wastewater treatment, to treat a paper mill bleach effluent showed that for an absorbed dose of 800 krads, chemical oxygen demand (COD) was reduced by 13.5% and 5 day biochemical oxygen demand (BOD 5 ) was increased 58.6%. These changes altered the value of COD/BOD 5 from 14 to 5. For the same dose, the absorbable organic halogen (AOX) was reduced 76.2%. These results suggested the possibility of using the electron beam process to detoxify paper mill effluent thereby generating a more biodegradable wastewater. (author)

  6. 78 FR 31315 - Kraft Pulp Mills NSPS Review

    Science.gov (United States)

    2013-05-23

    ... Kraft Pulp Mills NSPS Review; Proposed Rule #0;#0;Federal Register / Vol. 78 , No. 100 / Thursday, May...-OAR-2012-0640; FRL-9815-9] RIN 2060-AR64 Kraft Pulp Mills NSPS Review AGENCY: Environmental Protection... performance standards for kraft pulp mills. These revised standards include particulate matter emission limits...

  7. Uranium mining and milling

    International Nuclear Information System (INIS)

    Floeter, W.

    1976-01-01

    In this report uranium mining and milling are reviewed. The fuel cycle, different types of uranium geological deposits, blending of ores, open cast and underground mining, the mining cost and radiation protection in mines are treated in the first part of this report. In the second part, the milling of uranium ores is treated, including process technology, acid and alkaline leaching, process design for physical and chemical treatment of the ores, and the cost. Each chapter is clarified by added figures, diagrams, tables, and flowsheets. (HK) [de

  8. Influence of spark plasma sintering conditions on the sintering and functional properties of an ultra-fine grained 316L stainless steel obtained from ball-milled powder

    Energy Technology Data Exchange (ETDEWEB)

    Keller, C., E-mail: clement.keller@insa-rouen.fr [Groupe de Physique des Matériaux, CNRS-UMR 6634, Université de Rouen, INSA de Rouen, Avenue de l' Université, 76800 Saint-Etienne du Rouvray (France); Tabalaiev, K.; Marnier, G. [Groupe de Physique des Matériaux, CNRS-UMR 6634, Université de Rouen, INSA de Rouen, Avenue de l' Université, 76800 Saint-Etienne du Rouvray (France); Noudem, J. [Laboratoire de Cristallographie des Matériaux, CNRS-UMR 6508, Université de Caen, ENSICAEN, 7 bd du Maréchal Juin, 14050 Caen (France); Sauvage, X. [Groupe de Physique des Matériaux, CNRS-UMR 6634, Université de Rouen, INSA de Rouen, Avenue de l' Université, 76800 Saint-Etienne du Rouvray (France); Hug, E. [Laboratoire de Cristallographie des Matériaux, CNRS-UMR 6508, Université de Caen, ENSICAEN, 7 bd du Maréchal Juin, 14050 Caen (France)

    2016-05-17

    In this work, 316L samples with submicrometric grain size were sintered by spark plasma sintering. To this aim, 316L powder was first ball-milled with different conditions to obtain nanostructured powder. The process control agent quantity and milling time were varied to check their influence on the crystallite size of milled powder. Samples were then sintered by spark plasma sintering using different sets of sintering parameters (temperature, dwell time and pressure). For each sample, grain size and density were systematically measured in order to investigate the influence of the sintering process on these two key microstructure parameters. Results show that suitable ball-milling and subsequent sintering can be employed to obtain austenitic stainless steel samples with grain sizes in the nanometer range with porosity lower than 3%. However, ball-milling and subsequent sintering enhance chromium carbides formation at the sample surface in addition to intragranular and intergranular oxides in the sample as revealed by X-ray diffraction and transmission electron microscopy. It has been shown that using Boron nitride together with graphite foils to protect the mold from powder welding prevent such carbide formation. For mechanical properties, results show that the grain size refinement strongly increases the hardness of the samples without deviation from Hall-Petch relationship despite the oxides formation. For corrosion resistance, grain sizes lower than a few micrometers involve a strong decrease in the pitting potential and a strong increase in passivation current. As a consequence, spark plasma sintering can be considered as a promising tool for ultra-fine grained austenitic stainless steel.

  9. Water footprints of products of oil palm plantations and palm oil mills in Thailand.

    Science.gov (United States)

    Suttayakul, Phetrada; H-Kittikun, Aran; Suksaroj, Chaisri; Mungkalasiri, Jitti; Wisansuwannakorn, Ruthairat; Musikavong, Charongpun

    2016-01-15

    The water footprint (WF) of fresh fruit bunches (FFBs) from oil palm plantations and crude palm oil (CPO) from palm oil mills in southern and eastern Thailand were determined over 25 years. Climatic conditions, soil characteristics, and the characteristics of oil palm growth were considered. The WF of FFBs was 1063 m(3)/ton (t) on average. Green, blue, and grey waters comprised of 68, 18, and 14% of total WF, respectively. The oil palm plantations in Thailand required smaller amounts of indirect blue water. The average WF for producing a ton of CPO of seven mills was 5083 m(3). Most of the waters used in the mills originated from indirect green, blue and grey waters from the plantations. The direct blue water used in the mills had less impact on the total WF, lower than 1% of the total WF. Average percentages of green, blue, and grey waters of 69, 16, and 15% of total WF were determined for the mills, respectively. The water deprivation of the FFBs and CPO ranged from 0.73-12.9 and 3.44-58.3 m(3)H2Oeq/t, respectively. In 2013, the CPO production in Thailand including green, blue, and grey waters from plantation and blue water from mills required 11,343 million m(3) water. If the oil palm variety Suratthani 7 is used in the plantation, it would increase the yield from 15.2 to 22.8 t FFBs/ha-year and decrease the WF to 888 m(3)/t FFBs. The average value of the oil extraction rate (OER) of mills was 18.1%. With an increase in the OER of 1%, a reduction of the WF of 250 m(3)/t CPO or 5.1% of total WF could be obtained. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Assessing the value of pulp mill biomass savings in a climate change conscious economy

    International Nuclear Information System (INIS)

    Adahl, Anders; Harvey, Simon; Berntsson, Thore

    2006-01-01

    Pulp mills use significant amounts of biofuels, both internal and purchased. Biofuels could contribute to reach greenhouse gas emission targets at competitive costs. Implementing process integration measures at a pulp mill in order to achieve pulp production with less use of energy (biofuels) has not only on-site consequences but also off-site consequences, such as substitution of fossil fuels elsewhere by the saved pulp mill biofuels, and less on-site electric power generation. In this paper a method, a linking model, is suggested to analyse pulp mill biofuel saving measures when carbon dioxide (CO 2 ) external costs are internalised. The linking model is based on equilibrium economics and links information from CO 2 constrained energy market future scenarios with process integration measures. Pulp mill economics and marginal energy market CO 2 response are identified. In an applied study, four process integration measures at a Swedish pulp mill were analysed using five energy market future scenarios emanating from a Nordic energy model. The investigated investment alternatives for biofuel savings all result in positive net annual savings, irrespectively of the scenario used. However, CO 2 emissions may increase or decrease depending on the future development of the Nordic energy market

  11. Elemental characterization of Tummalapalle uranium mill tailing

    International Nuclear Information System (INIS)

    Patra, A.C.; Sahoo, S.K.; Thakur, V.K.; Dubey, J.S.; Jha, S.K.; Tripathi, R.M.; Sharma, D.B.

    2018-01-01

    Elements are present in environmental matrices at varying concentrations. Their levels may increase due to anthropogenic activities like transportation, industrial activities, agriculture, urbanization and human activities. Trace elements can be classified as potentially toxic (eg. cadmium, arsenic, mercury, lead, nickel), probably essential (eg. cobalt, vanadium) and essential (eg. iron, zinc, copper, selenium, manganese). Due to the expansion of the Indian Nuclear Power Programme, new uranium mining sites are coming up. Mining and milling produce large quantities of low active mill tailings contained in engineered Tailings Ponds. The tailings are amenable for interaction with the geochemical forces and can act as potential sources of contamination. Thus it is necessary to ascertain the concentrations of elements that are present therein. In this paper we aim to characterize the uranium tailings generated from Tummalapalle uranium mining facility in Kadappa district, Andhra Pradesh, India

  12. Milling of Nanoparticles Reinforced Al-Based Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    Alokesh Pramanik

    2018-03-01

    Full Text Available This study investigated the face milling of nanoparticles reinforced Al-based metal matrix composites (nano-MMCs using a single insert milling tool. The effects of feed and speed on machined surfaces in terms of surface roughness, surface profile, surface appearance, chip surface, chip ratio, machining forces, and force signals were analyzed. It was found that surface roughness of machined surfaces increased with the increase of feed up to the speed of 60 mm/min. However, at the higher speed (100–140 mm/min, the variation of surface roughness was minor with the increase of feed. The machined surfaces contained the marks of cutting tools, lobes of material flow in layers, pits and craters. The chip ratio increased with the increase of feed at all speeds. The top chip surfaces were full of wrinkles in all cases, though the bottom surfaces carried the evidence of friction, adhesion, and deformed material layers. The effect of feed on machining forces was evident at all speeds. The machining speed was found not to affect machining forces noticeably at a lower feed, but those decreased with the increase of speed for the high feed scenario.

  13. Structural evolution in nanocrystalline Cu obtained by high-energy mechanical milling: Phases formation of copper oxides

    International Nuclear Information System (INIS)

    Khitouni, Mohamed; Daly, Rakia; Mhadhbi, Mohsen; Kolsi, Abdelwaheb

    2009-01-01

    Nanocrystalline copper with mean crystallite size of 18 nm was synthesized by using high-energy mechanical milling. The structural and morphological changes during mechanical milling especially, the formation of CuO and Cu 2 O phases were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy in transmittance mode (FTIR). Mechanical milling of Cu results in a continuous decrease in the Cu means crystallite size and an increase in microstrain. Moreover, milling of Cu, in air synthetic, results in partial oxidation to Cu 2 O and CuO. Prolonged milling supports the formation of CuO oxide. SEM results show that flattened Cu flakes were laid and welded on each other and tend to form a matrix of randomly welded thin layers of highly deformed particles.

  14. 2D and 3D milled surface roughness of high volume fraction SiCp/Al composites

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2015-06-01

    Full Text Available This paper presents a study on surface roughness generated by high speed milling of high volume fraction (65% silicon carbide particle-reinforced aluminum matrix (SiCp/Al composites. Typical 2D (Ra and Rz and 3D (Sa and Sq surface roughness parameters were selected to evaluate the influence of the milling parameters on the surface quality in comparison with aluminum alloy. The 3D topography of the milled surface was studied as well. The results indicate that 3D parameters (Sa and Sq are more capable to describe the influence of the milling parameters on the surface quality, and among them Sq is preferable due to its good sensitivity. Sq decreases with milling speed and increases with feed rate. The influence of axial depth of cut (ADOC is negligible.

  15. PENGARUH TEKNIK PENYAYATAN PAHAT MILLING PADA CNC MILLING 3 AXIS TERHADAP TINGKAT KEKASARAN PERMUKAAN BENDA BERKONTUR

    Directory of Open Access Journals (Sweden)

    Irawan Irawan

    2016-06-01

    Full Text Available Dalam perindustrian penggunaan mesin CNC Milling sangat di andalkan untuk mendapatkan hasil yang optimum baik secara kualitas maupun kuantitas. Akan tetapi muncul permasalahan,bagaimana pengaruh perbedaan teknik penyayatan terhadap nilai kekasaran permukaan benda kerja berkontur dalam proses milling CNC. Penelitian ini bertujuan untuk mengetahui pengaruh metode penyayatan pahat milling terhadap kekasaran permukaan benda kerja berkontur yang di hasilkan pada proses freis dengan menggunakan mesin milling CNC - 3Axis Makino S33. Peneliitan ini merancang dan membuat molding Cover stop kontak dikarenakan permukaan produk cover stop kontak memiliki permukaan yang berkontur. Molding ini terdiri dari Core dan Cavity. Benda kerja yang akan di ujicoba adalah bagian Core sebanyak 3 buah. Dalam pengerjaanya benda ujicoba diberikan perlakuan yang sama antara lain, kedalaman pemotongan, kecepatan spindle, dan jenis pahat yang di gunakan, kemudian dari ke 3 benda kerja tersebut masing- masing di tentukan 3 titik pengukuran. Dari hasil pengujian yang di peroleh kemudian dilakukan analisis tabel. Nilai kekasaran permukaan terendah (rata-rata kekasaran 0.899µ m dengan waktu permesinan tercepat (waktu proses 1 jam 08 menit pada penggunaan metode penyayatan 3D offset finishing. Penulis menyarankan agar dalam proses freis menggunakan mesin milling CNC 3Axis Makino S33 pada permukaan benda yang berkontur, untuk mendapatkan nilai kekasaran yang terendah disarankan menggunakan metode penyayatan 3D offset finishing.

  16. Structural and magnetic properties of Fe{sub 60}Al{sub 40} alloys prepared by means of a magnetic mill

    Energy Technology Data Exchange (ETDEWEB)

    Bernal-Correa, R. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Rosales-Rivera, A., E-mail: arosalesr@unal.edu.c [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Pineda-Gomez, P. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Universidad de Caldas, Manizales (Colombia); Salazar, N.A. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia)

    2010-04-16

    A study on synthesis, structural and magnetic characterization of Fe{sub 60}Al{sub 40} (at.%) alloys prepared by means of mechanical alloying process is presented. The mechanical alloying was performed using a milling device with magnetically controlled ball movement (Uni-Ball-Mill 5 equipment) at several milling times. The characterization was carried out via X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The effects of milling time on the structural state, morphological evolution and magnetic behaviour of the Fe{sub 60}Al{sub 40} (at.%) alloys are discussed. Besides, in this current study we emphasize the result that indicating a ferro-para-ferromagnetic transition from a correlation between X-ray diffraction and magnetization data.

  17. Implications of an assessment of potential organic contamination of ground water at an inactive uranium mill

    International Nuclear Information System (INIS)

    Price, J.B.

    1986-01-01

    Laws and regulations concerning remedial actions at inactive uranium mills explicitly recognize radiological and nonradiological hazards and may implicitly recognize the potential presence of hazardous wastes at these mill sites. Ground-water studies at the sites have placed an increasing emphasis on screening for priority pollutants. The Grand Junction, Colorado, mill site was deemed to have a high potential for the presence of organic compounds in ground water, and was chosen as a prototype for assessing the presence of organic compounds in ground water at inactive sites. Lessons learned from the assessment of organics at the Grand Junction site were used to develop a screening procedure for other inactive mill sites

  18. Low-energy mechanically milled τ-phase MnAl alloys with high coercivity and magnetization

    International Nuclear Information System (INIS)

    Lu, Wei; Niu, Junchao; Wang, Taolei; Xia, Kada; Xiang, Zhen; Song, Yiming; Zhang, Hong; Yoshimura, Satoru; Saito, Hitoshi

    2016-01-01

    The high cost of rare earth elements makes the use of high-performance permanent magnets commercially very expensive. MnAl magnetic material is one of the most promising Rare-Earth-free permanent magnets due to its obvious characteristics. However, the coercivity of MnAl alloys produced by melt spinning followed by appropriate treatment is relatively low. In this investigation, a high coercivity up to 5.3 kOe and saturation magnetization of ∼62 emu/g (with an applied magnetic field of 19.5 kOe) were obtained in the mechanically milled τ-phase Mn_5_7Al_4_3 alloy. As milling time goes on, the coercivity firstly increases and then decreases, leading to the formation of knee-point coercivity, while the saturation magnetization decreases simultaneously. The structural imperfections such as disordering and defects play the most important role in the changes of magnetic properties of τ-phase MnAl alloys processed by low-energy mechanical milling. The present results will be helpful for the development of processing protocols for the optimization of τ-phase MnAl alloys as high performance Rare-Earth-free permanent magnets. - Highlights: • Successful fabrication of pure τ-phase Mn_5_7Al_4_3 alloy by melt spinning and low-energy ball milling processes. • High coercivity (~5.3 kOe) and magnetization (~62 emu/g) were obtained in τ-phase Mn_5_7Al_4_3 alloy. • Disordering and defects play the most important role in the changes of magnetic properties.

  19. Low-energy mechanically milled τ-phase MnAl alloys with high coercivity and magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei, E-mail: weilu@tongji.edu.cn [School of Materials Science and Engineering, Shanghai Key Lab. of D& A for Metal-Functional Materials, Tongji University, Shanghai 200092 (China); Research Center for Engineering Science, Akita University, Akita 010-8502 Japan (Japan); Niu, Junchao; Wang, Taolei; Xia, Kada; Xiang, Zhen; Song, Yiming [School of Materials Science and Engineering, Shanghai Key Lab. of D& A for Metal-Functional Materials, Tongji University, Shanghai 200092 (China); Zhang, Hong; Yoshimura, Satoru; Saito, Hitoshi [Research Center for Engineering Science, Akita University, Akita 010-8502 Japan (Japan)

    2016-08-05

    The high cost of rare earth elements makes the use of high-performance permanent magnets commercially very expensive. MnAl magnetic material is one of the most promising Rare-Earth-free permanent magnets due to its obvious characteristics. However, the coercivity of MnAl alloys produced by melt spinning followed by appropriate treatment is relatively low. In this investigation, a high coercivity up to 5.3 kOe and saturation magnetization of ∼62 emu/g (with an applied magnetic field of 19.5 kOe) were obtained in the mechanically milled τ-phase Mn{sub 57}Al{sub 43} alloy. As milling time goes on, the coercivity firstly increases and then decreases, leading to the formation of knee-point coercivity, while the saturation magnetization decreases simultaneously. The structural imperfections such as disordering and defects play the most important role in the changes of magnetic properties of τ-phase MnAl alloys processed by low-energy mechanical milling. The present results will be helpful for the development of processing protocols for the optimization of τ-phase MnAl alloys as high performance Rare-Earth-free permanent magnets. - Highlights: • Successful fabrication of pure τ-phase Mn{sub 57}Al{sub 43} alloy by melt spinning and low-energy ball milling processes. • High coercivity (~5.3 kOe) and magnetization (~62 emu/g) were obtained in τ-phase Mn{sub 57}Al{sub 43} alloy. • Disordering and defects play the most important role in the changes of magnetic properties.

  20. Research on the Treatment of Aluminum Alloy Chemical Milling Wastewater with Fenton Process

    Science.gov (United States)

    Zong-liang, Huang; Ru, Li; Peng, Luo; Jun-li, Gu

    2018-03-01

    The aluminum alloy chemical milling wastewater was treated by Fenton method. The effect of pH value, reaction time, rotational speed, H2O2 dosage, Fe2+ dosage and the molar ratio between H2O2 and Fe2+ on the COD removal rate of aluminum alloy chemical milling wastewater were investigated by single factor experiment and orthogonal experiment. The results showed that the optimum operating conditions for Fenton oxidation were as follows: the initial pH value was 3, the rotational speed was 250r/min, the molar ratio of H2O2 and Fe2+ was 8, the reaction time was 90 min. Under the optimum conditions, the removal rate of the wastewater’s COD is about 72.36%. In the reaction kinetics that aluminum alloy chemical milling wastewater was oxidized and degraded by Fenton method under the optimum conditions, the reaction sequence of the initial COD was 0.8204.

  1. Completion of the uranium mill tailings remedial project and cleanup of the former mill site at Grand Junction, Colorado

    International Nuclear Information System (INIS)

    Rael, G.J.; Cox, S.W.; Artiglia, E.W.

    2000-01-01

    The United States Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Surface Project has successfully completed the cleanup of 22 former uranium mill sites, more than 5400 vicinity properties, and has constructed 18 entombment cells. The Project has recently received the United States Nuclear Regulatory Commission's approval and certification for the last two disposal sites, with these sites being placed under the general license for long term custodial care of residual radioactive material. The UMTRA site located at Grand Junction, Colorado is a good example of the technical, political, economic, and public relations challenges that were overcome in achieving success. The UMTRA Team discussed, negotiated, planned, and eventually acted on this uranium mill tailings problem and brought the project to a successful conclusion for the community. From the early 1940s through the 1970s, uranium ore was mined in significant quantities under United States federal contracts for the government's national defence programmes, i.e. the Manhattan Engineering District and Atomic Energy Commission programmes. The problem started as the need for uranium decreased in the late 1960s, resulting in mills shutting down, leaving behind large quantities of process waste tailings and contaminated mill buildings. The former Climax Uranium Company mill site in Grand Junction was one of the largest of these sites. (author)

  2. Prevention, Minimization and Control of Environmental Pollution at Mexico Sugar Mill

    Directory of Open Access Journals (Sweden)

    Dominguez-Manjarrez Candi Ashanti

    2014-10-01

    Full Text Available This research paper aims to recommend control measures directed towards preventing and minimizing pollution, looking forward to the improvement of the environmental management on the sugar industry in Mexico. This issue has been put on hold due to the necessity to address the economic, social and technological issues affecting it over time. In order to better understand the productive process and the actual problem that the industry is facing, while proposing effective and possible actions for improvement, a sugar mill type was selected as a case of study. A comprehensive assessment of the production process for the standard sugar was made, considering the activities in the field and at the mill. The proposed measures in the sugar mill allowed savings in consumption of ground water average 3,620 cubic meters per day, during the period of study, reduction in solid waste generated average 325 kilograms per day by implementing a waste separation program, and reducing atmospheric emissions of particles acting as fuel for a boiler operated with bagasse. The prevention, minimization and pollution control measures proposed can be applied to other mills in the country with the appropriate adaptations.

  3. 7 CFR 868.301 - Definition of milled rice.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Definition of milled rice. 868.301 Section 868.301... FOR CERTAIN AGRICULTURAL COMMODITIES United States Standards for Milled Rice Terms Defined § 868.301 Definition of milled rice. Whole or broken kernels of rice (Oryza sativa L.) from which the hulls and at...

  4. Fault Detection in Coal Mills used in Power Plants

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Mataji, Babak

    2006-01-01

    In order to achieve high performance and efficiency of coal-fired power plants, it is highly important to control the coal flow into the furnace in the power plant. This means suppression of disturbances and force the coal mill to deliver the required coal flow, as well as monitor the coal mill...... in order to detect faults in the coal mill when they emerge. This paper deals with the second objective. Based on a simple dynamic model of the energy balance a residual is formed for the coal mill. An optimal unknown input observer is designed to estimate this residual. The estimated residual is following...... tested on measured data of a fault in a coal mill, it can hereby be concluded that this residual is very useful for detecting faults in the coal mill....

  5. Analytical Prediction of Three Dimensional Chatter Stability in Milling

    Science.gov (United States)

    Altintas, Yusuf

    The chip regeneration mechanism during chatter is influenced by vibrations in three directions when milling cutters with ball end, bull nose, or inclined cutting edges are used. A three dimensional chatter stability is modeled analytically in this article. The dynamic milling system is formulated as a function of cutter geometry, the frequency response of the machine tool structure at the cutting zone in three Cartesian directions, cutter engagement conditions and material property. The dynamic milling system with nonlinearities and periodic delayed differential equations is reduced to a three dimensional linear stability problem by approximations based on the physics of milling. The chatter stability lobes are predicted in the frequency domain using the proposed analytical solution, and verified experimentally in milling a Titanium alloy with a face milling cutter having circular inserts.

  6. A Unified Field Theory of Gravity, Electromagnetism, and the Yang-Mills Gauge Field

    Directory of Open Access Journals (Sweden)

    Suhendro I.

    2008-01-01

    Full Text Available In this work, we attempt at constructing a comprehensive four-dimensional unified field theory of gravity, electromagnetism, and the non-Abelian Yang-Mills gauge field in which the gravitational, electromagnetic, and material spin fields are unified as intrinsic geometric objects of the space-time manifold S4 via the connection, with the general- ized non-Abelian Yang-Mills gauge field appearing in particular as a sub-field of the geometrized electromagnetic interaction.

  7. Consolidation theory and its applicability to the dewatering and covering of uranium-mill tailings

    International Nuclear Information System (INIS)

    Gates, T.E.

    1982-11-01

    This report is a review and evaluation of soil consolidation theories applicable for evaluating settlement during dewatering and subsequent covering of uranium-mill tailings. Such theories may be used to predict both consolidation and water flow related effects in uranium-mill tailings during drainage, following sluicing into burial pits. A consolidation theory to be useful must consider the effect of time-dependent loads, nonhomogeneous soil mass, nonlinear variation of soil properties with the stress-state parameters, large strain, and saturated and unsaturated flow. Constitutive relations linking the stress-deformation-state variables with void ratio should be adopted for predicting both consolidation and fluid-flow interaction in unsaturated uranium-mill tailings

  8. Replacing chemicals in recycle mills with mechanical alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Institute of Paper Science Technology

    2002-07-01

    A high-intensity spark fired underwater decomposes a small amount of the water into hydroxyl radicals, which are strong oxidants. These are able to oxidize contaminants such as glue and wood pitch that enter paper recycling mills as a part of the incoming furnish and cost the industry several hundred million dollars. The sparking technique is safe, inexpensive, and is capable of treating large volumes of water, which makes it attractive for mill applications. Several mill trials were run. Sparking caused a decrease in the tack of the deposits in one case. Lower bleach use occurred in two other mills; sparking reduced the degree of ink reattachment to fiber. The payback for either application is attractive. Sparking induced deposition of contaminants in another mill, which is a positive development--if it can be controlled. The technique is also able to degas water and to oxidize odor-causing sulfur compounds. Although one unit has been purchased by a mill, second-order effects caused by the technology needs to be defined further before the technology can be broadly applied.

  9. Evaluation of chemical stabilizers and windscreens for wind erosion control of uranium mill tailings

    International Nuclear Information System (INIS)

    Elmore, M.R.; Hartley, J.N.

    1984-08-01

    Potential wind erosion of uranium mill tailings is a concern for the surface disposal of tailings at uranium mills. Wind-blown tailings may subsequently be redeposited on areas outside the impoundment. Pacific Northwest Laboratory (PNL) is investigating techniques for fugitive dust control at uranium mill tailings piles. Laboratory tests, including wind tunnel studies, were conducted to evaluate the relative effectiveness of 43 chemical stabilizers. Seventeen of the more promising stabilizers were applied to test plots on a uranium tailings pile at the American Nuclear Corporation-Gas Hills Project mill site in central Wyoming. The durabilities of these materials under actual site conditions were evaluated over time. In addition, field testing of commercially available windscreens was conducted. Test panels were constructed of eight different materials at the Wyoming test site to compare their durability. A second test site was established near PNL to evaluate the effectiveness of windscreens at reducing wind velocity, and thereby reduce the potential for wind erosion of mill tailings. Results of the laboratory land field tests of the chemical stabilizers and windscreens are presented, along with costs versus effectiveness of these techniques for control of wind erosion at mill tailings piles. 12 references, 4 figures, 6 tables

  10. Uranium exploration, mining and milling proposal, Navajo Indian Reservation, New Mexico

    International Nuclear Information System (INIS)

    Babby, W.D.

    1974-01-01

    The Secretary of the Interior has been requested to approve an exploration permit and mining lease which are part of a uranium exploration, mining, and milling Agreement, negotiated between the Navajo Tribe and the Exxon Corporation. The exploration area is a 400,000 acre tract located on the Navajo Reservation in San Juan County, New Mexico. If uranium ore in sufficient quantities to warrant development is discovered, Exxon is authorized to take a total of 51,200 acres to lease for mining, of which only 5,120 surface acres may be used for mining and milling purposes. While all exploration and predevelopment costs prior to mining must be borne by Exxon, the Navajo Tribe has reserved the right to participate in the venture on either a royalty basis or as a partner holding up to a 40 percent working interest. Impacts resulting from exploration will include disturbance of soils and vegetation and air quality degradation resulting from the vehicular movement and the operation of drilling equipment. If mining and milling takes place significant environmental impacts include: sub-surface water depletion, soils and vegetation disturbance, air quality degradation, interruption of the wildlife habitat, population increases, increased demands on community services and facilities, and disruption of established lifestyles and social patterns. Low levels of radioactive emissions will be found at mine and mill sites. Income and employment opportunities from the project to the Navajo Tribe, Navajo people, and the entire San Juan County community will be significant

  11. Practitioner Profile: An Interview With Amanda Mills

    Directory of Open Access Journals (Sweden)

    Amanda Mills

    2012-01-01

    Full Text Available For more than 25 years, Amanda Mills has been working with arts organizations across Canada and with artists of all kinds to assist them in achieving financial sanity. She has taught business management at the University of Victoria and has prepared thousands of tax returns for writers, visual artists, choreographers, actors, filmmakers, broadcasters, and creative entrepreneurs. Ten years ago, bringing together her work on trauma, with twenty years of business management, Mills founded Loose Change Financial Therapy – the place where money and feelings meet. Mills has presented Loose Change workshops for social workers, teachers, psychotherapists, artists, anti-poverty activists, sex trade workers, women’s groups, and the general public.  She has been a guest on major Canadian radio and television broadcasts and profiled in many major Canadian newspapers and periodicals. Mills is also a crisis counselor and co-wrote a bestselling book on recovering from trauma. A tax professional and business manager, she is certified as a financial counselor under the Bankruptcy and Insolvency Act. Mills is also currently completing a certificate in mediation.

  12. GEOMETRICAL CHARACTERIZATION OF MICRO END MILLING TOOLS

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo

    The milling process is one of the most common metal removal operation used in industry. This machining process is well known since the beginning of last century and has experienced, along the years, many improvements of the basic technology, as concerns tools, machine tools, coolants/lubricants, ......The milling process is one of the most common metal removal operation used in industry. This machining process is well known since the beginning of last century and has experienced, along the years, many improvements of the basic technology, as concerns tools, machine tools, coolants....../lubricants, milling strategies and controls. Moreover the accuracy of tool geometry directly affects the performance of the milling process influencing the dimensional tolerances of the machined part, the surface topography, the chip formation, the cutting forces and the tool-life. The dimensions of certain...... geometrical details, as for instance the cutting edge radius, are determined by characteristics of the manufacturing process, tool material, coating etc. While for conventional size end mills the basic tool manufacturing process is well established, the reduction of the size of the tools required...

  13. Disposal of olive mill wastewater with DC arc plasma method.

    Science.gov (United States)

    Ibrahimoglu, Beycan; Yilmazoglu, M Zeki

    2018-07-01

    Olive mill wastewater is an industrial waste, generated as a byproduct of olive oil production process and generally contains components such as organic matter, suspended solids, oil, and grease. Although various methods have been developed to achieve the disposal of this industrial wastewater, due to the low cost, the most common disposal application is the passive storage in the lagoons. The main objective of this study is to reduce pollution parameters in olive mill wastewater and draw water to discharge limits by using plasma technology. Plasma-assisted disposal of olive mill wastewater method could be an alternative disposal technique when considering potential utilization of treated water in agricultural areas and economic value of flammable plasma gas which is the byproduct of disposal process. According to the experimental results, the rates of COD (chemical oxygen demand) and BOD (biological oxygen demand) of olive mill wastewater are decreased by 94.42% and 95.37%, respectively. The dissolved oxygen amount is increased from 0.36 to 6.97 mg/l. In addition, plasma gas with high H 2 content and treated water that can be used in agricultural areas for irrigation are obtained from non-dischargeable wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. A model of unified quantum chromodynamics and Yang-Mills gravity

    International Nuclear Information System (INIS)

    HSU Jongping

    2012-01-01

    Based on a generalized Yang-Mills framework, gravitational and strong interactions can be unified in analogy with the unification in the electroweak theory. By gauging T(4) × [SU(3)] color in flat space-time, we have a unified model of chromo-gravity with a new tensor gauge field, which couples universally to all gluons, quarks and anti-quarks. The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same 'effective Riemann metric tensors’ in the geometric-optics (or classical) limit. The emergence of effective metric tensors in the classical limit is essential for the unified model to agree with experiments. The unified model suggests that all gravitational, strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework. (author)

  15. A model of unified quantum chromodynamics and Yang-Mills gravity

    Institute of Scientific and Technical Information of China (English)

    HSU Jong-Ping

    2012-01-01

    Based on a generalized Yang-Mills framework,gravitational and strong interactions can be unified in analogy with the unification in the clectroweak theory.By gauging T(4) × [SU(3)]color in fiat space-time,we have a unified model of chromo-gravity with a new tensor gauge field,which couples universally to all gluons,quarks and anti-quarks.The space-time translational gauge symmetry assures that all wave equations of quarks and gluons reduce to a Hamilton-Jacobi equation with the same ‘effective Riemann metric tensors' in the geometric-optics (or classical) limit.The emergence of effective metric tensors in the classical limit is essential for the unified model to agree with experiments.The unified model suggests that all gravitational,strong and electroweak interactions appear to be dictated by gauge symmetries in the generalized Yang-Mills framework.

  16. EPA's role in uranium mining and milling

    International Nuclear Information System (INIS)

    Smith, P.B.

    1980-01-01

    EPA's role and actions in regulating uranium mining and milling are reviewed and updated. Special emphasis is given to EPA's current activities under the Uranium Mill Tailings Radiation Control Act of 1978

  17. The influence of the milling environment on the sintered structure of a W-Cu composite

    International Nuclear Information System (INIS)

    Costa, F.A.; Gomes, U.U.; Acchar, W.; Ambrozio Filho, F.; Silva, A.G.P.; Lima, S.J.G.

    2009-01-01

    This work reports an investigation about the influence of the environment of milling on the characteristics of the powders and on the structure and density of sintered samples made of these powders. Mixtures of composition W-30wt%Cu were milled for 51 hours in a high energy planetary mill in dry and wet (cyclohexane) conditions. The milled powders have composite particles. The powders were pressed and sintered at 1050 deg, 1150 deg and 1200 deg C under flowing hydrogen. The isothermal times were 0 minutes for the first two temperatures and 60 minutes for the latter. The samples reached around 95% of relative density. The powders were characterized by means of XRD and SEM. The sintered samples were characterized by means of SEM, optical microscopy and density measurement. (author)

  18. Pengaruh Lama Miling Terhadap Sifat Absorpsi Material Penyimpan Hidrogen MgH2 yang Dikatalisasi Dengan Fe (The Role of Milling Time on the Absorption Behaviour of MgH2 Catalyzed by Fe

    Directory of Open Access Journals (Sweden)

    Mustanir Mustanir

    2009-12-01

    Full Text Available Hidrida logam berbasis MgH2 dengan sisipan 1 wt% katalis Fe telah berhasil disintesis dengan teknik ball milling. Hasil proses miling selama 80 jam menunjukkan bahwa ukuran butir material telah membentuk struktur nanokristal. Hal ini ditunjukkan oleh profil difraksi sinar-X dimana terjadi pelebaran puncakpuncak difraksinya dengan meningkatnya waktu miling. Hasil uji absorpsi secara gravimetrik diketahui bahwa MgH2 berkatalis 1 wt% Fe mampu menyerap hydrogen sebesar 5,5 wt% dalam waktu ~20 menit pada temperatur 300 oC. Hasil ini sekaligus memperlihatkan bahwa sejumlah kecil katalis Fe bekerja secara baik dalam memperbaiki sifat absorpsi material penyimpan hydrogen berbasis Mg.(Metal hydrides are of great interest as hydrogen storage media especially for automotive application. Hydrides of magnesium and magnesium alloys are particularly attractive as they combine potentially high hydrogen storage capacities, 7.6 wt%. But, unfortunately, the sorption properties are poor. For example, conventional hydrogenation of magnesium requires prolonged treatment at temperatures of 300 oC and above. Here, we report the absorption properties of MgH2 catalyzed with a small amount of Fe element (1wt% under argon atmosphere prepared by ball milling in 80 hours. As the results, it showed the influence of milling time on the absortion kinetics of material which could absorp hydrogen in amount 5.5 within 20 minutes at 300 oC. It is obvious that longer milling time and small amount of catalyst could improve the sorption properties of Mg-based hydrides. © 2009 BCREC UNDIP. All rights reserved[Received: 13rd November 2009, Revised: 25th December 2009, Accepted: 31st December 2009][How to Cite: M. Mustanir, Z. Jalil. (2009. Pengaruh Lama Miling Terhadap Sifat Absorpsi Material Penyimpan Hidrogen MgH2 yang Dikatalisasi Dengan Fe (The Role of Milling Time on the Absorption Behaviour of MgH2 Catalyzed by Fe. Bulletin of Chemical Reaction Engineering and Catalysis, 4(2: 69

  19. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    Directory of Open Access Journals (Sweden)

    Kunal Ganguly

    2012-09-01

    Full Text Available This project aims to address the problems that are facing a large aluminum company in a Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills operations were in. Si x Sigma DMAIC methodologies were use d in the project to determine the project's CTQ characteristics, defining the possible causes, Identifying the variation sources, establishing variable relationships and Implementing Control Plans. The project can be useful for any company that needs to fi nd the most cost efficient way to improve and utilize its resources.

  20. XRD and HREM studies from the decomposition of icosahedral AlCuFe single-phase by high-energy ball milling

    International Nuclear Information System (INIS)

    Patino-Carachure, C.; Tellez-Vazquez, O.; Rosas, G.

    2011-01-01

    Highlights: → Point defects induced during milling leading to an order-disorder quasicrystal transition. → Nanoquasicrystalline regions of 12 nm are obtained. → Highly ordered i-phase with high symmetry transforms to a crystalline phase of intermetallic character and lower symmetry. - Abstract: In this investigation the Al 64 Cu 24 Fe 12 alloy was melted in an induction furnace and solidified under normal casting conditions. In order to obtain the icosahedral phase (i-phase) in a single-phase region, the as-cast sample was subject to a heat treatment at 700 deg. C under argon atmosphere. Subsequently, the i-phase was milled for different times in order to evaluate phase stability under heavy deformation. X-ray diffraction (XRD) and high-resolution electron microscopy (HREM) analysis were conducted to the structural characterization of ball-milled powders. XRD results indicated a reduction in quasicrystal size during mechanical ball milling to about 30 h. HREM analysis revealed the presence of aperiodic nano-domains, for example, with apparent fivefold symmetry axis. Therefore, the i-phase remains stable over the first 30 h of ball-milling time. However, among 30-50 h of mechanical milling the i-phase transforms progressively into β-cubic phase.

  1. XRD and HREM studies from the decomposition of icosahedral AlCuFe single-phase by high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Patino-Carachure, C.; Tellez-Vazquez, O. [Instituto de Investigaciones Metalurgicas, UMSNH, Edificio U, Ciudad Universitaria, Morelia, Michoacan 58000 (Mexico); Rosas, G., E-mail: grtrejo@umich.mx [Instituto de Investigaciones Metalurgicas, UMSNH, Edificio U, Ciudad Universitaria, Morelia, Michoacan 58000 (Mexico)

    2011-10-13

    Highlights: > Point defects induced during milling leading to an order-disorder quasicrystal transition. > Nanoquasicrystalline regions of 12 nm are obtained. > Highly ordered i-phase with high symmetry transforms to a crystalline phase of intermetallic character and lower symmetry. - Abstract: In this investigation the Al{sub 64}Cu{sub 24}Fe{sub 12} alloy was melted in an induction furnace and solidified under normal casting conditions. In order to obtain the icosahedral phase (i-phase) in a single-phase region, the as-cast sample was subject to a heat treatment at 700 deg. C under argon atmosphere. Subsequently, the i-phase was milled for different times in order to evaluate phase stability under heavy deformation. X-ray diffraction (XRD) and high-resolution electron microscopy (HREM) analysis were conducted to the structural characterization of ball-milled powders. XRD results indicated a reduction in quasicrystal size during mechanical ball milling to about 30 h. HREM analysis revealed the presence of aperiodic nano-domains, for example, with apparent fivefold symmetry axis. Therefore, the i-phase remains stable over the first 30 h of ball-milling time. However, among 30-50 h of mechanical milling the i-phase transforms progressively into {beta}-cubic phase.

  2. Risk factors for respiratory work disability in a cohort of pulp mill workers exposed to irritant gases

    Directory of Open Access Journals (Sweden)

    Torén Kjell

    2011-09-01

    Full Text Available Abstract Background The association between chronic respiratory diseases and work disability has been demonstrated a number of times over the past 20 years, but still little is known about work disability in occupational cohorts of workers exposed to respiratory irritants. This study investigated job or task changes due to respiratory problems as an indicator of work disability in pulp mill workers occupationally exposed to irritants. Methods Data about respiratory symptoms and disease diagnoses, socio-demographic variables, occupational exposures, gassing episodes, and reported work changes due to respiratory problems were collected using a questionnaire answered by 3226 pulp mill workers. Information about work history and departments was obtained from personnel files. Incidence and hazard ratios for respiratory work disability were calculated with 95% confidence intervals (CI. Results The incidence of respiratory work disability among these pulp mill workers was 1.6/1000 person-years. The hazard ratios for respiratory work disability were increased for workers reporting gassings (HR 5.3, 95% CI 2.7-10.5 and for those reporting physician-diagnosed asthma, chronic bronchitis, and chronic rhinitis, when analyzed in the same model. Conclusions This cohort study of pulp mill workers found that irritant peak exposure during gassing episodes was a strong predictor of changing work due to respiratory problems, even after adjustment for asthma, chronic bronchitis, and chronic rhinitis.

  3. Reclamation of uranium mining and milling disturbances

    International Nuclear Information System (INIS)

    Farmer, E.E.; Schuman, G.E.

    1987-01-01

    Since 1945 the history of uranium mining and milling in the US has been a story of wide fluctuations in market prices and in mining and milling capacity. The late 1960's and the 1970's saw a sizeable reduction in the production of yellowcake because of an earlier over-supply, a leveling off of the military demand, and a failure of the nuclear electric power industry to create the anticipated commercial demand. The decline in the domestic production of yellowcake has continued through the early 1980's to the present. Today, there are five operating uranium mills in the US: one in Wyoming, two in Utah, one in New Mexico, and one in Texas. Of these five mills, three are operating on a reduced schedule, as little as three days a month. A significant portion of the current US production of uranium goes overseas to fulfill Japanese, French, and other European contracts. There is still a sizeable reclamation job to be accomplished on old uranium wastes, both tailings impoundments and overburden embankments. Before the Uranium Mill Tailings Control Act of 1978 (PL 95-604), reclamation was frequently omitted altogether, or else done in a haphazard fashion. We do not know the total area of unreclaimed, radioactive, uranium overburden wastes in the western US, but the area is large, probably several thousand hectares. Fortunately, these overburden wastes are almost entirely located in remote areas. Mill tailings are more difficult to reclaim than overburden, and tailings represent a more serious health hazards. There are approximately 25 million metric tons of unreclaimed uranium mill tailings, with variable health hazards, located in the US

  4. Influence of nepheline syenite and milling time on the rheological properties of a porcelain stoneware tile slip

    Directory of Open Access Journals (Sweden)

    Jazayeri, S. H.

    2003-08-01

    Full Text Available The rheological properties of porcelain stoneware tile slips were investigated using a rotational rheometer. The first step in the study was to evaluate the rheological behaviour of a reference slip at different particle size distributions to determine the optimum conditions at which to carry out the investigation of the influence of nepheline syenite in the mix. In the second step part of the K-feldspar in the reference mix was replaced with nepheline syenite such that the mix composition contained 10 % nepheline syenite. The flow curve, yield stress and thixotropy of the slips were evaluated at different milling times in order to study the effect of particle size on the rheological behaviour. The milling times for the reference mix and for the mix with nepheline syenite which resulted in the best rheological parameters were found.

    Se han investigado las propiedades reológicas de barbotinas de porcelana dura para pavimentos usando un reómetro rotacional. El primer paso del estudio fue evaluar el comportamiento reológico de una barbotina de referencia con diferentes distribuciones de tamaño de partícula con el fin de determinar las condiciones óptimas bajo las cuales estudiar la influencia de nefelina sienita en la mezcla. En la segunda etapa, parte del feldespato potásico de la mezcla de referencia se substituyó por nefelina sienita de forma que la composición de la mezcla tuviera un 10% de neflina sienita. Se evaluaron las curvas de flujo, los puntos de fluidez y la tixotropía de las barbotinas tras diferentes tiempos de molienda con el fin de estudiar el efecto del tamaño de partícula en el comportamiento reológico. Se determinaron los tiempos de molienda en los que se alcanzaban los mejores parámetros reológicos para la mezcla de referencia y la de nefelina sienita.

  5. A survey of present levels of radiocesium in Swedish pulp mill liquors and the implications for wood radiocesium transfer factors

    International Nuclear Information System (INIS)

    Ravila, A.; Holm, E.

    1998-01-01

    Assessments of the impact from radioactive fallout on the pulp industry and the accumulation processes for radionuclides in such industries, using wood and water as primary raw materials, have been conducted in previous studies. Hitherto, there is a general lack of data on present levels of radioactivity in pulp mill liquors apart from the few mills studied by [NILSSON (1992)] [RAVILA AND HOLM (1992)] [MANJON ET AL. (1996) and [KROSSHAVN ET AL. (1997)]. A survey was therefore initiated to describe and compare the present activity levels in pulp mill liquors from various mill locations in Sweden. The 137 Cs activity in pulp mill liquors were compared with the mill location and the deposition pattern of the Chernobyl fallout and nuclear weapons fallout. The large input of wood (approx. 2500 m 3 day -1 ) to an average Nordic Kraft mill and the relatively long-term retention time for radiocesium in the Kraft mill recovery cycle enables representative sampling of substances directly related to the activity concentration in wood

  6. Comparative Study by MS and XRD of Fe50Al50 Alloys Produced by Mechanical Alloying, Using Different Ball Mills

    International Nuclear Information System (INIS)

    Rojas Martinez, Y.; Perez Alcazar, G. A.; Bustos Rodriguez, H.; Oyola Lozano, D.

    2005-01-01

    In this work we report a comparative study of the magnetic and structural properties of Fe 50 Al 50 alloys produced by mechanical alloying using two different planetary ball mills with the same ball mass to powder mass relation. The Fe 50 Al 50 sample milled during 48 h using the Fritsch planetary ball mill pulverisette 5 and balls of 20 mm, presents only a bcc alloy phase with a majority of paramagnetic sites, whereas that sample milled during the same time using the Fritsch planetary ball mill pulverisette 7 with balls of 15 mm, presents a bcc alloy phase with paramagnetic site (doublet) and a majority of ferromagnetic sites which include pure Fe. However for 72 h of milling this sample presents a bcc paramagnetic phase, very similar to that prepared with the first system during 48 h. These results show that the conditions used in the first ball mill equipment make more efficient the milling process.

  7. Nanostructured Al/Al4C3 composites reinforced with graphite or fullerene and manufactured by mechanical milling and spark plasma sintering

    International Nuclear Information System (INIS)

    Robles Hernández, F.C.; Calderon, H.A.

    2012-01-01

    Highlights: ► Fullerene mix (C 60 + C 70 + soot) is effective to manufacture nanostructured Al/Al 4 C 3 . ► Carbon in the fullerene mix is more reactive with Al that that present in graphite. ► A complete transformation of carbon into Al 4 C 3 is observed in the Al/fullerene. ► Milling and sintering conditions preserve the nanostructured nature of the composites. ► Hardness improvement: 375% Al/graphite and 582% for Al/fullerene composites. - Abstract: Nanostructured Al matrix composites with reinforcements of graphite or fullerene (C 60 + C 70 + soot) have been produced by mechanical milling and spark plasma sintering (SPS). X-ray diffraction and transmission electron microscopy show that C 60 + C 70 withstand longer mechanical milling/alloying times than graphite. Fullerene is a good control agent during mechanical alloying resulting in a denser Al/fullerene composite when compared to the Al/graphite one. A refinement mechanism that takes place during mechanical alloying of fullerene and graphite is experimentally found and correspondingly discussed. Such a mechanism plays a major role in the amorphization of graphite. The larger surface area of the fullerene mix after milling promotes a better interaction with Al and hence allows its complete transformation into Al 4 C 3 during the SPS process. The sintered products show an increase in hardness for the Al/fullerene composite of 6 times and only 4 times for the Al/graphite composite. The SPS technique shows to be an excellent method to transform the fullerene into Al 4 C 3 while preserving its nanostructured nature.

  8. Comparison of hydrogen storage properties of pure Mg and milled ...

    Indian Academy of Sciences (India)

    Administrator

    increase the hydriding and dehydriding rates, pure Mg was ground under hydrogen atmosphere (reactive .... Hydrogen storage properties of pure Mg and milled pure Mg. 833. Figure 3. ... elongated and flat shapes via collisions with the steel.

  9. ( Rosa damascena Mill.) by microbial inoculation

    African Journals Online (AJOL)

    This study was carried out to determine the effects of microbial inoculation in breaking seed dormancy and on the germination of Rosa damascena Mill. Seeds of R. damascena Mill. are the most used scented rose species in rose oil production. The most important production centers around the world are Turkey and ...

  10. Comparison of Wet and Dry Grinding in Electromagnetic Mill

    Directory of Open Access Journals (Sweden)

    Szymon Ogonowski

    2018-03-01

    Full Text Available Comparison of dry and wet grinding process in an electromagnetic mill is presented in this paper. The research was conducted in a batch copper ore grinding. Batch mode allows for precise parametrization and constant repetitive conditions of the experiments. The following key aspects were tested: processing time, feed size, size of the grinding media, mass of the material and graining media, and density of the pulp. The particles size distribution of the product samples was analyzed in the laboratory after each experiment. The paper discusses the experimental results as well as the concept of dry and wet grinding and classification circuits for the electromagnetic mill. The main points of the discussion are the size reduction effectiveness and power consumption of the entire system.

  11. Synthesis of Cu(In,Ga)Se{sub 2} crystals using a crank ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Suzuka; Noji, Hideki; Akaki, Yoji [Miyakonojo National College of Technology, 473-1 Yoshio, Miyakonojo Miyazaki 885-8567 (Japan); Okamoto, Tomoichiro [Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2015-06-15

    Cu(In,Ga)Se{sub 2} (CIGS) crystals were synthesized by a mechanochemical (MC) process using a crank ball mill. The molar ratios of starting materials were Cu:In:Ga:Se=1:1-x:x:2 (0≤x≤1) and Cu:In:Ga:Se=1:0.7:0.3:y (2≤y≤3). The reaction time reduced with decreasing Se and Ga molar ratios. The collection rate decreased with longer reaction times. From XRD patterns, we confirmed that the CuInSe{sub 2} and/or CuGaSe{sub 2}crystals were successfully grown when the powders reacted. Although the crystals grown with a selenium molar ration of 2 were Se-poor, those grown at a molar ratio of 3 were Se-rich. When Se increasing molar ratio, Cu, In, and Ga were away from the stoichiometric. With a molar ratio of Cu:In:Ga:Se=1:0.7:0.3:2.5∝2.7, their composition became stoichiometric. Crystal morphology was varied. CIGS crystals were thus successfully synthesized using a crank ball mill. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. A Simple Flight Mill for the Study of Tethered Flight in Insects.

    Science.gov (United States)

    Attisano, Alfredo; Murphy, James T; Vickers, Andrew; Moore, Patricia J

    2015-12-10

    Flight in insects can be long-range migratory flights, intermediate-range dispersal flights, or short-range host-seeking flights. Previous studies have shown that flight mills are valuable tools for the experimental study of insect flight behavior, allowing researchers to examine how factors such as age, host plants, or population source can influence an insects' propensity to disperse. Flight mills allow researchers to measure components of flight such as speed and distance flown. Lack of detailed information about how to build such a device can make their construction appear to be prohibitively complex. We present a simple and relatively inexpensive flight mill for the study of tethered flight in insects. Experimental insects can be tethered with non-toxic adhesives and revolve around an axis by means of a very low friction magnetic bearing. The mill is designed for the study of flight in controlled conditions as it can be used inside an incubator or environmental chamber. The strongest points are the very simple electronic circuitry, the design that allows sixteen insects to fly simultaneously allowing the collection and analysis of a large number of samples in a short time and the potential to use the device in a very limited workspace. This design is extremely flexible, and we have adjusted the mill to accommodate different species of insects of various sizes.

  13. Yang-Mills analogs of general-relativistic solutions

    International Nuclear Information System (INIS)

    Singlton, D.

    1998-01-01

    Some solutions of Yang-Mills equations, which can be found with the use of the general relativistic theory and Yang-Mills theory, are discussed. Some notes concerning possible physical sense of these solutions are made. Arguments showing that some of such solutions in the Yang-Mills theory (similar to the general relativistic ones) may be connected with the confinement phenomenon are given in particular. The motion of probe particles located into the phonon potential similar to the Schwarz-Child one is briefly discussed for this purpose [ru

  14. Rubber lining design for grinding mills: influence on economy and capacity

    Energy Technology Data Exchange (ETDEWEB)

    Nillson, G

    1979-11-01

    There is a difference in design parameters between steel linings and rubber linings for grinding mills. The basic design parameters for rubber are described and a comparison is made between steel and rubber in different applications. If a rubber lining is correctly designed, it will give at least the same capacity as any other type of lining. A rubber lining can often be made thinner than other types of lining and, in such cases, the increased mill diameter will increase the capacity. What has been said above regarding capacity applies equally to grinding efficiency. The grind can sometimes be changed by altering the lifter height and lifter profile. Rubber linings of the correct quality and design will always give improved lining economy, except for large primary ball mills. We trust that new designs and rubber qualities will change the picture in the future. What is said about lining economy is especially true when taking reduced downtime and maintenance into consideration. The lining must be designed to reduce sliding over the shell, which leads to heavy wear. When used for dry grinding, the adverse effects of temperature must be observed.

  15. Polycrystalline Nd{sub 2}Fe{sub 14}B/α-Fe nanocomposite flakes with a sub-micro/nanometre thickness prepared by surfactant-assisted high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xin, E-mail: tangshincn@gmail.com [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Chen, Xi [Mechanical and Electrical Engineering College, Xinxiang University, No. 192, Jinsui Road, Xinxiang, Henan 453003 (China); Chen, Renjie; Yan, Aru [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-09-25

    Highlights: • Nd{sub 2}Fe{sub 14}B/α-Fe flakes are formed by peeling along preferential planes. • (0 0 l) planes are found to be preferential cleavage planes. • Magnetic properties degrade with increasing ball milling time. • Anisotropic nanocomposite magnets are fabricated. - Abstract: A surfactant-assisted high-energy ball milling technique was employed to synthesize Nd{sub 2}Fe{sub 14}B/α-Fe nanoparticles and nanoflakes from melt-spun nanocrystalline powders. The microstructure evolution in ball milling process was investigated. In the beginning stage (0–4 h) of ball milling, raw powders were crushed into micrometre-sized particles. While flakes were mainly formed by reducing thickness of particles via peeling layer by layer along preferential planes in the late stage (8–16 h). The selected area electron diffraction and high-resolution transmission electron microscopy images show that preferential cleavage planes are basal planes. With ball milling proceeding, more and more defects were induced by ball milling. As a result, the coercivity and remanence decreased to 1.6 kOe and 3.2 kGs, respectively. After 16 h ball milling, the exchange decoupling occurred due to severe amorphorization. A weakly-textured nanocomposite magnet was fabricated after 12 h ball milling and the anisotropy in magnetic properties can be further improved by employing settling down process to select particle size and aligning particles in external field.

  16. Milling damage on Carbon Fibre Reinforced Polymer using TiAlN coated End mills

    International Nuclear Information System (INIS)

    Konneh, Mohamed; Kassim, Abdullah Abdul Rahman; Izman, Sudin

    2015-01-01

    This paper reports on the damage caused by milling Carbon Fibre Reinforced Composite (CFRP) with 2-flute 4 mm-diameter solid carbide end mills, coated with titanium aluminium nitride. The machining parameters considered in work are, rotation speed, feed rate and depth of cut. Experiments were designed based on Box-Behnken design and the experiments conducted on a Mikrotool DT-110 CNC micro machine. A laser tachometer was used to ascertain a rotational speed for conducting any machining trial. Optical microscopy examination reveals minimum delamination value of 4.05 mm at the spindle speed of 25,000 rpm, depth of cut of 50μm and feed rate of 3 mm/min and the maximum delamination value of 5.04 mm at the spindle speed of 35000 rpm, depth of cut of 150μm and feed rate of 9 mm/min A mathematical model relating the milling parameters and delamination has been established. (paper)

  17. Milling damage on Carbon Fibre Reinforced Polymer using TiAlN coated End mills

    Science.gov (United States)

    Konneh, Mohamed; Izman, Sudin; Rahman Kassim, Abdullah Abdul

    2015-07-01

    This paper reports on the damage caused by milling Carbon Fibre Reinforced Composite (CFRP) with 2-flute 4 mm-diameter solid carbide end mills, coated with titanium aluminium nitride. The machining parameters considered in work are, rotation speed, feed rate and depth of cut. Experiments were designed based on Box-Behnken design and the experiments conducted on a Mikrotool DT-110 CNC micro machine. A laser tachometer was used to ascertain a rotational speed for conducting any machining trial. Optical microscopy examination reveals minimum delamination value of 4.05 mm at the spindle speed of 25,000 rpm, depth of cut of 50μm and feed rate of 3 mm/min and the maximum delamination value of 5.04 mm at the spindle speed of 35000 rpm, depth of cut of 150μm and feed rate of 9 mm/min A mathematical model relating the milling parameters and delamination has been established.

  18. Modeling of Surface Geometric Structure State After Integratedformed Milling and Finish Burnishing

    Science.gov (United States)

    Berczyński, Stefan; Grochała, Daniel; Grządziel, Zenon

    2017-06-01

    SGS modeling enables substantial acceleration of the computing process. There is a visible reduction of the Ra parameter value for milled and burnished surfaces as the burnishing force rises. The tests determined an optimal burnishing force at a level of 500 N (lowest Ra = 0.24 μm). Further increase in the value of burnishing force turned out not to affect the surface roughness, which is consistent with the results obtained from experimental studies.

  19. Experimental evaluation of tool run-out in micro milling

    Science.gov (United States)

    Attanasio, Aldo; Ceretti, Elisabetta

    2018-05-01

    This paper deals with micro milling cutting process focusing the attention on tool run-out measurement. In fact, among the effects of the scale reduction from macro to micro (i.e., size effects) tool run-out plays an important role. This research is aimed at developing an easy and reliable method to measure tool run-out in micro milling based on experimental tests and an analytical model. From an Industry 4.0 perspective this measuring strategy can be integrated into an adaptive system for controlling cutting forces, with the objective of improving the production quality, the process stability, reducing at the same time the tool wear and the machining costs. The proposed procedure estimates the tool run-out parameters from the tool diameter, the channel width, and the phase angle between the cutting edges. The cutting edge phase measurement is based on the force signal analysis. The developed procedure has been tested on data coming from micro milling experimental tests performed on a Ti6Al4V sample. The results showed that the developed procedure can be successfully used for tool run-out estimation.

  20. 40 CFR 63.1347 - Standards for raw and finish mills.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Standards for raw and finish mills. 63... and Operating Limits § 63.1347 Standards for raw and finish mills. The owner or operator of each new or existing raw mill or finish mill at a facility which is a major source subject to the provisions...

  1. Preparation of natural pyrite nanoparticles by high energy planetary ball milling as a nanocatalyst for heterogeneous Fenton process

    Energy Technology Data Exchange (ETDEWEB)

    Fathinia, Siavash [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Fathinia, Mehrangiz [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Rahmani, Ali Akbar [Department of Mining Engineering, Faculty of Engineering and Technology, Imam Khomeini International University, Qazvin (Iran, Islamic Republic of); Khataee, Alireza, E-mail: a_khataee@tabrizu.ac.ir [Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2015-02-01

    Graphical abstract: - Highlights: • Pyrite nanoparticles were successfully produced by planetary ball milling process. • The physical and chemical properties of pyrite nanoparticles were fully examined. • The degradation of AO7 was notably enhanced by pyrite nanoparticles Fenton system. • The influences of basic operational parameters were investigated using CCD. - Abstract: In the present study pyrite nanoparticles were prepared by high energy mechanical ball milling utilizing a planetary ball mill. Various pyrite samples were produced by changing the milling time from 2 h to 6 h, in the constant milling speed of 320 rpm. X-ray diffraction (XRD), scanning electron microscopy (SEM) linked with energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR) analysis and Brunauer–Emmett–Teller (BET) were performed to explain the characteristics of primary (unmilled) and milled pyrite samples. The average particle size distribution of the produced pyrite during 6 h milling was found to be between 20 nm and 100 nm. The catalytic performance of the different pyrite samples was examined in the heterogeneous Fenton process for degradation of C.I. Acid Orange 7 (AO7) solution. Results showed that the decolorization efficiency of AO7 in the presence of 6 h-milled pyrite sample was the highest. The impact of key parameters on the degradation efficiency of AO7 by pyrite nanoparticles catalyzed Fenton process was modeled using central composite design (CCD). Accordingly, the maximum removal efficiency of 96.30% was achieved at initial AO7 concentration of 16 mg/L, H{sub 2}O{sub 2} concentration of 5 mmol/L, catalyst amount of 0.5 g/L and reaction time of 25 min.

  2. Effect of milling on the damping behavior of nano-structured copper

    Energy Technology Data Exchange (ETDEWEB)

    Srikanth, Narasimalu; Thein, Maung Aye; Gupta, Manoj

    2004-02-05

    In the present study, elemental Cu powder was mechanically milled (MMed) for 10 h to reduce the grain (crystalline) size in the nano-range (<100 nm). The mechanically milled powder (10 h-MMed) and elemental powder without mechanical milling (MM) (0 h-MMed) was consolidated by die-cold compaction and were further hot extruded at different temperatures to maintain a crystallite size within the nano-range. Further, the specimen was tested by a novel free-free type suspended beam arrangement, coupled with circle-fit approach to determine damping characteristics. The characterization results help to understand the effect of the nano-size grains on the overall damping capacity of the bulk samples compared to a normal micro-crystalline sample. Results show that the damping capacity of the nano-grained material increases due to the presence of process induced microstructural changes similar to the damping behavior of a micro-grain sized specimen.

  3. Energy efficiency improvement and cost saving opportunities for the Corn Wet Milling Industry: An ENERGY STAR Guide for Energy and Plant Managers

    Energy Technology Data Exchange (ETDEWEB)

    Galitsky, Christina; Worrell, Ernst; Ruth, Michael

    2003-07-01

    Corn wet milling is the most energy intensive industry within the food and kindred products group (SIC 20), using 15 percent of the energy in the entire food industry. After corn, energy is the second largest operating cost for corn wet millers in the United States. A typical corn wet milling plant in the United States spends approximately $20 to $30 million per year on energy, making energy efficiency improvement an important way to reduce costs and increase predictable earnings, especially in times of high energy-price volatility. This report shows energy efficiency opportunities available for wet corn millers. It begins with descriptions of the trends, structure and production of the corn wet milling industry and the energy used in the milling and refining process. Specific primary energy savings for each energy efficiency measure based on case studies of plants and references to technical literature are provided. If available, typical payback periods are also listed. The report draws upon the experiences of corn, wheat and other starch processing plants worldwide for energy efficiency measures. The findings suggest that given available resources and technology, there are opportunities to reduce energy consumption cost-effectively in the corn wet milling industry while maintaining the quality of the products manufactured. Further research on the economics of the measures, as well as the applicability of these to different wet milling practices, is needed to assess the feasibility of implementation of selected technologies at individual plants.

  4. Heavy metals adsorption on rolling mill scale; Adsorcion de metales pesados sobre cascarill de laminacion

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, F. A.; Martin, M. I.; Perez, C.; Lopez-Delgado, A.; Alguacil, E. J.

    2003-07-01

    A great quantity of industries are responsible for contaminating the environment with the heavy metals which are containing in their wastewaters. The recovery of these metals is both from an environmental and economical points of view of the upmost interest. A study is made of the use of mill scale-originating in the hot rolling of steel-as an adsorbent for the removal of heavy metals from liquid effluents. The adsorption of Zn''2+, Cd''2+ y Pb''2+ on the rolling mill scale was investigated by determination of adsorption isotherms. The effect of time, equilibrium temperature and concentration of metal solution on mill scale adsorption efficiency was evaluated. The adsorption process was analysed using the theories of Langmuir and Freundlich. Desorption process of metals from loaded mill scales was also studied using several doser bent at different experimental conditions. It has been proved that the mill scale is an effective adsorbent for the cations studies in aqueous solutions within the range of the working concentrations. (Author) 32 refs.

  5. Peculiarities of binding composition production in vortex jet mill

    Science.gov (United States)

    Zagorodnyuk, L. Kh; Lesovik, V. S.; Sumskoy, D. A.; Elistratkin, M. Yu; Makhortov, D. S.

    2018-03-01

    The article investigates the disintegration of perlite production waste in a vortex jet mill; the regularities of milling were established. Binding compositions were obtained at different ratios of cement vs. perlite sand production waste in the vortex jet mill in various milling regimes. The peculiarities of milling processes were studied, and technological and physicomechanical properties of the binding compositions were determined as well. The microstructure of the cement stones made of activated Portland cement and binding compositions in the vortex jet mill was elucidated by electron microscopy. The open pores of the cement-binding compositions prepared using perlite fillers were found to be filled by newgrowths at different stages of collective growth. The microstructure of the binding compositions is dense due to rationally proportioned composition, effective mineral filler— perlite waste — that creates additional substrates for internal composite microstructure formation, mechanochemical activation of raw mixture, which allows obtaining composites with required properties.

  6. Evaluation of Surface Roughness and Power Consumption in Machining FCD 450 Cast Iron using Coated and Uncoated Irregular Milling Tools

    International Nuclear Information System (INIS)

    Yusoff, Ahmad Razlan; Arsyad, Fitriyanti

    2016-01-01

    In this project, the effects of different cutting parameters on surface roughness and power consumption when machining FCD450 cast iron were studied using coated and uncoated irregular milling tool geometry of variable helix and pitch. Their responses on roughness and power consumption were evaluated based on the spindle speed, feed rate, and depth of cut, machining length and machining time. Results showed that except spindle speed and machining length, other parameters such as feed rate, axial and radial depth of cut and also machining time proportionate with surface roughness. The power consumption proportionately increase for all cutting parameters except feedrate. It is showed that the average decrement 27.92 percent for surface roughness and average decrement 9.32 percent for power consumption by using coated compared to uncoated tool. Optimum cutting parameters for both minimum surface roughness and power consumption can be determined. The coated tools performed better than uncoated milling tools for responses of surface roughness and power consumption to increase machining productivity and profit. (paper)

  7. Effects of X-ray irradiation to genetic transformation of Eruca sativa Mill mediated by agrobacterium rhizogenes

    International Nuclear Information System (INIS)

    Wu Zhenhua; Zhang Hong; Liu Bin; Li Ning; Niu Bingtao; Wang Genxuan; Li Sha; Sun Peng

    2008-01-01

    To investigate the effects of X-ray irradiation to the hairy root induction of Eruca sativa Mill, and to provide basic experimental data for concerted reaction of irradiation to the Genetic transformation technology. The aseptic cotyledons of Eruca sativa Mill were jointly treated with the X-ray at dose of 5, 10, 15, 20 Gy respectively and the different infected time, then the influence of explant age, pre-culturing time, dose of X-ray and infected time were studied. Furthermore, the hairy roots were testified in molecular level by the polymerase chain reaction(PCR). The irradiation of X-ray at dose of 15 Gy can improve the frequency of Eruca sativa Mill hairy root induction in a dose-dependent manner. Moreover, the transformation frequency in pre-infection plus irradiation group is higher than that in pre-irradiation plus infection group at the same irradiation dose. In addition, the PCR analysis also demonstrated that rolB gene of T-DNA from Ri plasmid had been integrated into the genome of the transformed roots. The irradiation of X-ray has some positive effects on the hairy root induction of Eruca sativa Mill, and the optimal revulsive dose is 15 Gy ora little bit more. (authors)

  8. 77 FR 43369 - Alumax Mill Products, Inc. Doing Business as Alcoa Mill Products Texarkana a Subsidiary of Alcoa...

    Science.gov (United States)

    2012-07-24

    ... Products, Inc., a subsidiary of Alcoa, Inc. The intent of the Department's certification is to properly... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,149] Alumax Mill Products, Inc. Doing Business as Alcoa Mill Products Texarkana a Subsidiary of Alcoa, Inc. Nash, TX; Amended...

  9. An investigation on the compressibility of aluminum/nano-alumina composite powder prepared by blending and mechanical milling

    International Nuclear Information System (INIS)

    Razavi Hesabi, Z.; Hafizpour, H.R.; Simchi, A.

    2007-01-01

    The densification response of aluminum powder reinforced with 5 vol.% nanometric alumina particles (35 nm) during uniaxial compaction in a rigid die was studied. The composite powder was prepared by blending and mechanical milling procedures. To determine the effect of the reinforcement nanoparticles on the compressibility of aluminum powder, monolithic Al powder, i.e. without the addition of alumina, was also examined. It was shown that at the early stage of compaction when the rearrangement of particles is the dominant mechanism of the densification, disintegration of the nanoparticle clusters and agglomerates under the applied load contributes in the densification of the composite powder prepared by blending method. As the compaction pressure increases, however, the load partitioning effect of the nanoparticles decreases the densification rate of the powder mixture, resulting in a lower density compared to the monolithic aluminum. It was also shown that mechanical milling significantly impacts the compressibility of the unreinforced and reinforced aluminum powders. Morphological changes of the particles upon milling increase the contribution of particle rearrangement in densification whilst the plastic deformation mechanism is significantly retarded due to the work-hardening effect of the milling process. Meanwhile, the distribution of alumina nanoparticles is improved by mechanical milling, which in fact, affects the compressibility of the composite powder. This paper addresses the effect of mechanical milling and reinforcement nanoparticles on the compressibility of aluminum powder

  10. High resolution Transmission Electron Microscopy characterization of a milled oxide dispersion strengthened steel powder

    Energy Technology Data Exchange (ETDEWEB)

    Loyer-Prost, M., E-mail: marie.loyer-prost@cea.fr [DEN-Service de Recherches de Métallurgie Physique, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Merot, J.-S. [Laboratoire d’Etudes des Microstructures – UMR 104, CNRS/ONERA, BP72-29, Avenue de la Division Leclerc, 92 322, Châtillon (France); Ribis, J. [DEN-Service de Recherches de Métallurgie Appliquée, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Le Bouar, Y. [Laboratoire d’Etudes des Microstructures – UMR 104, CNRS/ONERA, BP72-29, Avenue de la Division Leclerc, 92 322, Châtillon (France); Chaffron, L. [DEN-Service de Recherches de Métallurgie Appliquée, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Legendre, F. [DEN-Service de la Corrosion et du Comportement des Matériaux dans leur Environnement, CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2016-10-15

    Oxide Dispersion Strengthened (ODS) steels are promising materials for generation IV fuel claddings as their dense nano-oxide dispersion provides good creep and irradiation resistance. Even if they have been studied for years, the formation mechanism of these nano-oxides is still unclear. Here we report for the first time a High Resolution Transmission Electron Microscopy and Energy Filtered Transmission Electron Microscopy characterization of an ODS milled powder. It provides clear evidence of the presence of small crystalline nanoclusters (NCs) enriched in titanium directly after milling. Small NCs (<5 nm) have a crystalline structure and seem partly coherent with the matrix. They have an interplanar spacing close to the (011) {sub bcc} iron structure. They coexist with larger crystalline spherical precipitates of 15–20 nm in size. Their crystalline structure may be metastable as they are not consistent with any Y-Ti-O or Ti-O structure. Such detailed observations in the as-milled grain powder confirm a mechanism of Y, Ti, O dissolution in the ferritic matrix followed by a NC precipitation during the mechanical alloying process of ODS materials. - Highlights: • We observed an ODS ball-milled powder by high resolution transmission microscopy. • The ODS ball-milled powder exhibits a lamellar microstructure. • Small crystalline nanoclusters were detected in the milled ODS powder. • The nanoclusters in the ODS milled powder are enriched in titanium. • Larger NCs of 15–20 nm in size are, at least, partly coherent with the matrix.

  11. Biogeochemical aspects of uranium mineralization, mining, milling, and remediation

    Science.gov (United States)

    Campbell, Kate M.; Gallegos, Tanya J.; Landa, Edward R.

    2015-01-01

    Natural uranium (U) occurs as a mixture of three radioactive isotopes: 238U, 235U, and 234U. Only 235U is fissionable and makes up about 0.7% of natural U, while 238U is overwhelmingly the most abundant at greater than 99% of the total mass of U. Prior to the 1940s, U was predominantly used as a coloring agent, and U-bearing ores were mined mainly for their radium (Ra) and/or vanadium (V) content; the bulk of the U was discarded with the tailings (Finch et al., 1972). Once nuclear fission was discovered, the economic importance of U increased greatly. The mining and milling of U-bearing ores is the first step in the nuclear fuel cycle, and the contact of residual waste with natural water is a potential source of contamination of U and associated elements to the environment. Uranium is mined by three basic methods: surface (open pit), underground, and solution mining (in situ leaching or in situ recovery), depending on the deposit grade, size, location, geology and economic considerations (Abdelouas, 2006). Solid wastes at U mill tailings (UMT) sites can include both standard tailings (i.e., leached ore rock residues) and solids generated on site by waste treatment processes. The latter can include sludge or “mud” from neutralization of acidic mine/mill effluents, containing Fe and a range of coprecipitated constituents, or barium sulfate precipitates that selectively remove Ra (e.g., Carvalho et al., 2007). In this chapter, we review the hydrometallurgical processes by which U is extracted from ore, the biogeochemical processes that can affect the fate and transport of U and associated elements in the environment, and possible remediation strategies for site closure and aquifer restoration.This paper represents the fourth in a series of review papers from the U.S. Geological Survey (USGS) on geochemical aspects of UMT management that span more than three decades. The first paper (Landa, 1980) in this series is a primer on the nature of tailings and radionuclide

  12. Third-order least squares modelling of milling state term for improved computation of stability boundaries

    Directory of Open Access Journals (Sweden)

    C.G. Ozoegwu

    2016-01-01

    Full Text Available The general least squares model for milling process state term is presented. A discrete map for milling stability analysis that is based on the third-order case of the presented general least squares milling state term model is first studied and compared with its third-order counterpart that is based on the interpolation theory. Both numerical rate of convergence and chatter stability results of the two maps are compared using the single degree of freedom (1DOF milling model. The numerical rate of convergence of the presented third-order model is also studied using the two degree of freedom (2DOF milling process model. Comparison gave that stability results from the two maps agree closely but the presented map demonstrated reduction in number of needed calculations leading to about 30% savings in computational time (CT. It is seen in earlier works that accuracy of milling stability analysis using the full-discretization method rises from first-order theory to second-order theory and continues to rise to the third-order theory. The present work confirms this trend. In conclusion, the method presented in this work will enable fast and accurate computation of stability diagrams for use by machinists.

  13. Radiological survey of the inactive uranium-mill tailings at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Haywood, F.F.; Christian, D.J.; Ellis, B.S.; Hubbard, H.M. Jr.; Lorenzo, D.; Shinpaugh, W.H.

    1980-06-01

    The inactive uranium-mill tailings pile at Ambrosia Lake, New Mexico, contains approximately 1520 Ci of 226 Ra in 2.4 million metric tons of tailings covering an area of 43 hectares. All of the former mill buildings were intact and, at the time of this survey, several were in use. The tailings have not been stabilized, but the crusty surface is reported to be resistant to wind erosion. The average gamma-ray exposure rate 1 m above the tailings is 720 μR/h while the average rate in the former mill area is 150 μR/h. The adjacent area, between the mill site, ponds, and tailings pile, has an average exposure rate of 230 μR/h. Gamma radiation measurements outside these areas, as well as the results of analyses of surface or near-surface sediment and soil samples, show fairly wide dispersion of contamination around the site. The subsurface distribution of 226 Ra in 18 holes drilled at the site, calculated from gamma-ray monitoring data, is presented graphically and compared with measured concentrations in two holes

  14. Health concerns in uranium mining and milling

    International Nuclear Information System (INIS)

    Archer, V.E.

    1981-01-01

    Mortality of uranium miners from both lung cancer and other respiratory diseases is strongly dependent on exposure to radon daughters, cigarette smoking and height. Lung cancer among 15 different mining groups (uranium, iron, lead, zinc) was analyzed to determine what factors influence incidence and the induction-latent period. At low exposure or exposure rates, alpha radiation is more efficient in inducing lung cancer, producing an upward convex exposure-response curve. The induction-latent period is shortened by increased age at start of mining, by cigarette smoking and by high exposure rates. Instead of extrapolating downward from high exposures to estimate risk at low levels, it is suggested that it might be more appropriate to use cancer rates associated with background radiation as the lowest point on the exposure-response curve. Although health risks are much greater in uranium mines than mills, there is some health risk in the mills from long-lived radioactive materials

  15. 46 CFR 50.25-3 - Manufacturer or mill certification.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Manufacturer or mill certification. 50.25-3 Section 50... PROVISIONS Acceptance of Material and Piping Components § 50.25-3 Manufacturer or mill certification. (a) A manufacturer or mill producing materials used in certain products for installation on inspected vessels, shall...

  16. FINITE ELEMENT ANALYSIS OF HASTELLOY C-22HS IN END MILLING

    Directory of Open Access Journals (Sweden)

    K. Kadirgama

    2011-12-01

    Full Text Available This paper presents a finite element analysis of the stress distribution in the end milling operation of nickel-based superalloy HASTELLOY C-2000. Commercially available finite element software was used to develop the model and analyze the distribution of stress components in the machined surface of HASTELLOY C-22HS following end milling with coated carbide tools. The friction interaction along the tool-chip interface was modeled using the Coulomb friction law. It was found that the stress had lower values under the cut surface and that it increased gradually near the cutting edge.

  17. Radiation health and safety aspects in uranium milling

    International Nuclear Information System (INIS)

    Smart, B.C.

    1982-01-01

    This presentation deals mainly with radiation levels associated with the uranium milling operations, including yellowcake production. The regulation of uranium mills has not received much attention in the past because radiation levels have been generally low, and uranium milling has been substantially free of occupational illness. More attention is being directed towards minimizing exposures, and the Canadian Atomic Energy Control Board is working on new regulations which will reflect the recommendations of various hearings and the International Commission on Radiological Protection. Emphasis is now being placed on improving monitoring methods. At the beginning of 1982 a gamma dosimetry program will be put into effect for all uranium mine and mill workers. An improved method is also being sought to determine radon daughter exposures more accurately. It is expected that a better knowledge of monitoring and assessing thoron daughter levels in mine and mill facilities will be obtained soon. This radiation contribution will be included when calculating a combined radiation exposure factor for individual workers. Programs are underway to better monitor and assess uranium dust inhalation. Initial studies indicate that the present precautions taken to avoid dust inhalation at the mills are effective. A more complete study will be undertaken in 1982

  18. Saddle point solutions in Yang-Mills-dilaton theory

    International Nuclear Information System (INIS)

    Bizon, P.

    1992-01-01

    The coupling of a dilaton to the SU(2)-Yang-Mills field leads to interesting non-perturbative static spherically symmetric solutions which are studied by mixed analytical and numerical methods. In the abelian sector of the theory there are finite-energy magnetic and electric monopole solutions which saturate the Bogomol'nyi bound. In the nonabelian sector there exist a countable family of globally regular solutions which are purely magnetic but have zero Yang-Mills magnetic charge. Their discrete spectrum of energies is bounded from above by the energy of the abelian magnetic monopole with unit magnetic charge. The stability analysis demonstrates that the solutions are saddle points of the energy functional with increasing number of unstable modes. The existence and instability of these solutions are 'explained' by the Morse-theory argument recently proposed by Sudarsky and Wald. (author)

  19. Radiological health aspects of uranium milling

    International Nuclear Information System (INIS)

    Fisher, D.R.; Stoetzel, G.A.

    1983-05-01

    This report describes the operation of conventional and unconventional uranium milling processes, the potential for occupational exposure to ionizing radiation at the mill, methods for radiological safety, methods of evaluating occupational radiation exposures, and current government regulations for protecting workers and ensuring that standards for radiation protection are adhered to. In addition, a survey of current radiological health practices is summarized

  20. Radiological health aspects of uranium milling

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Stoetzel, G.A.

    1983-05-01

    This report describes the operation of conventional and unconventional uranium milling processes, the potential for occupational exposure to ionizing radiation at the mill, methods for radiological safety, methods of evaluating occupational radiation exposures, and current government regulations for protecting workers and ensuring that standards for radiation protection are adhered to. In addition, a survey of current radiological health practices is summarized.

  1. 7 CFR 58.419 - Curd mill and miscellaneous equipment.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Curd mill and miscellaneous equipment. 58.419 Section... Service 1 Equipment and Utensils § 58.419 Curd mill and miscellaneous equipment. Knives, hand rakes... of the curd mill should be of stainless steel. All pieces of equipment shall be so constructed that...

  2. Assessment of heavy metals introduced into food through milling process: health implications

    International Nuclear Information System (INIS)

    Adeti, P.J.

    2015-07-01

    /kg to 10.09 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. which shows that the Cu, Cr and Ni concentration decreases from the first month (first milling) to the fourth month (fourth milling). The Ghanaian made plate was found to wear faster relative to Nigerian- , Indian and Nigerian made plate with that of showing the least rate of wear. The Ghananaian made plates was found to cause more contamination than the other two but generally, the Indian made plates caused least contamination.The Indian made plates had the least Cd and Pb concentration levels. The elemental concentration and the risk assessment calculations have shown that contamination of milled products are highest within the first month of the use of the grinding plates but can decreases considerably with time. The HRI value for first milled maize with locally made grinding plate showed human health problem for Cr and Ni metals contaminations in the maize flour. (author)

  3. Activity of Plodia interpunctella (Lepidoptera: Pyralidae) in and around flour mills.

    Science.gov (United States)

    Doud, C W; Phillips, T W

    2000-12-01

    Studies were conducted at two flour mills where male Indian meal moths, Plodia interpunctella (Hübner), were captured using pheromone-baited traps. Objectives were to determine the distribution of male P. interpunctella at different locations in and around the mills throughout the season, and to monitor moth activity before and after one of the mills was fumigated with methyl bromide to assess efficacy of treatment. Commercially available sticky traps baited with the P. interpunctella sex pheromone were placed at various locations outside and within the larger of the two mills (mill 1). Moths were captured inside mill 1 after methyl bromide fumigations. The highest numbers of P. interpunctella were caught outside the facility and at ground floor locations near outside openings. Additional traps placed in the rooms above the concrete stored-wheat silos at mill 1 during the second year captured more moths than did traps within the mill's production and warehouse areas. In another study, moths were trapped at various distances from a smaller flour mill (mill 2) to determine the distribution of moths outdoors relative to the mill. There was a negative correlation between moth capture and distance from the facility, which suggested that moth activity was concentrated at or near the flour mill. The effectiveness of the methyl bromide fumigations in suppressing moth populations could not be assessed with certainty because moths captured after fumigation may have immigrated from outside through opened loading bay warehouse doors. This study documents high levels of P. interpunctella outdoors relative to those recorded inside a food processing facility. Potential for immigration of P. interpunctella into flour mills and other stored product facilities from other sources may be greater than previously recognized. Moth entry into a food processing facility after fumigation is a problem that should be addressed by pest managers.

  4. 33 CFR 117.225 - Yellow Mill Channel.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Yellow Mill Channel. 117.225 Section 117.225 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Connecticut § 117.225 Yellow Mill Channel. The...

  5. Remediation of uranium mill tailings wastes in Australia: a critical review

    International Nuclear Information System (INIS)

    Mudd, G.M.

    2000-01-01

    Australia has been an active participant in the global uranium mining industry since its inception in the 1940s. By the late 1950s five major mining and milling projects were operating, several small mines supplied custom ores. All of these projects were closed by the early 1960s, except for Rum Jungle which continued under government subsidy. Most sites have had lasting Environmental impacts. The advances in nuclear power in the 1960s saw increasing demand for uranium and Australia again explored with remarkable success in the Northern Territory, South Australia and Western Australia. After several government inquiries in the 1970s, Ranger, Nabarlek and Olympic Dam were operating by the mid 1980s. The principal risks from uranium mill tailings wastes arise from their radioactive nature and often their chemical toxicities. A critical review of the rehabilitation of abandoned uranium mines and mill tailings as a comparison for current projects is presented. It is concluded that the management of uranium mill tailings wastes is a complex task, requiring a sound multi-disciplinary approach. The problems include groundwater contamination, erosion, radon emanation and gamma radiation. evidence to data from the remediation of old and modern sites does not demonstrate effective long-term closure and safety

  6. Coal Moisture Estimation in Power Plant Mills

    DEFF Research Database (Denmark)

    Andersen, Palle; Bendtsen, Jan Dimon; Pedersen, Tom S.

    2009-01-01

    Knowledge of moisture content in raw coal feed to a power plant coal mill is of importance for efficient operation of the mill. The moisture is commonly measured approximately once a day using offline chemical analysis methods; however, it would be advantageous for the dynamic operation...... of the plant if an on-line estimate were available. In this paper we such propose an on-line estimator (an extended Kalman filter) that uses only existing measurements. The scheme is tested on actual coal mill data collected during a one-month operating period, and it is found that the daily measured moisture...

  7. Influence of the control atmosphere and milling time on the morphology and microstructure of pure copper and copper-2.5 % lithium powders produced by mechanical alloying; Influencia de la atmosfera de control y tiempo de molienda sobre la morfologia y microestructura de polvos de cobre puro y cobre-2,5% litio producidos por aleado mecanio

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, P. A.; Alvarez, M. P.; Penaloza, A.; Zuniga, A.; Ordonez, S.

    2009-07-01

    In the present work was investigated the effect of two milling parameters, atmosphere and milling time, on the morphology and microstructure of pure copper powder and a mixture of copper-2,5 wt. % lithium. The mechanical alloying was performed in a SPEX 8000D mill, using steel containers and balls. The two control atmospheres were argon and nitrogen and the milling time was varied from 3 up to 30 hours. The microstructural changes and the phases after milling were analyzed using scanning microscopy and X ray diffraction, whereas the amount of iron was measured by atomic absorption spectroscopy and the amount of oxygen by infrared spectroscopy. The results show the effect of the milling parameters studied on the microstructure as well as on the chemical composition of the samples. (Author) 22 refs.

  8. Mesophilic and thermophilic activated sludge post-treatment of paper mill process water

    NARCIS (Netherlands)

    Vogelaar, J.C.T.; Bouwhuis, E.; Klapwijk, A.; Spanjers, H.; Lier, van J.B.

    2002-01-01

    Increasing system closure in paper mills and higher process water temperatures make the applicability of thermophilic treatment systems increasingly important. The use of activated sludge as a suitable thermophilic post-treatment system for anaerobically pre-treated paper process water from a paper

  9. Focused ion beam milling of nanocavities in single colloidal particles and self-assembled opals

    International Nuclear Information System (INIS)

    Woldering, Leon A; Otter, A M; Husken, Bart H; Vos, Willem L

    2006-01-01

    We present a new method of realizing single nanocavities in individual colloidal particles on the surface of silicon dioxide artificial opals using a focused ion beam milling technique. We show that both the radius and the position of the nanocavity can be controlled with nanometre precision, to radii as small as 40 nm. The relation between the defect size and the milling time has been established. We confirmed that milling not only occurs on the surface of the spheres, but into and through them as well. We also show that an array of nanocavities can be fashioned. Structurally modified colloids have interesting potential applications in nanolithography, as well as in chemical sensing and solar cells, and as photonic crystal cavities

  10. Analysis of Startup Process and Its Optimization for a Two-Stand Reversible Cold Rolling Mill

    Directory of Open Access Journals (Sweden)

    Guangming Liu

    2017-01-01

    Full Text Available Dynamic characteristic analysis of a two-stand reversible cold rolling mill in the startup process was carried out. The delay algorithm of the interstand thickness was proposed. A new method combined with the accelerated secant and the tangent methods was established to solve the simultaneous equations. The thickness and interstand tension transition processes with different static tension establishing processes were analyzed. Both mills were operated under constant rolling force control mode in the above process. The results show that the strip thickness in the rolling gap reduces in the static mill screwdown process. The entry stand runs inversely to establish the static interstand tension. This area becomes an abnormal thickness reduction area of the incoming strip. It results in several abnormal interstand tension increases in the subsequent startup process. The tension increase leads to an impact force on the strip that is the main reason of the strip breakage in the startup process. So the static tension establishing process was optimized, and the interstand tension fluctuation and the strip breakage accidents both reduced significantly. The results are beneficial to the startup process of the two-stand reversible cold rolling mill.

  11. 46 CFR 50.25-5 - Products requiring manufacturer or mill certification.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Products requiring manufacturer or mill certification... manufacturer or mill certification. (a) Products required to be certified by a manufacturer or by mill... accepted without referring to its manufacturer or mill certification, if: (1) The product is marked in...

  12. Performance Study of Graphite Anode Slurry in Lithium-ion Flow Battery by Ball Milling

    Directory of Open Access Journals (Sweden)

    FENG Cai-mei

    2018-02-01

    Full Text Available Graphite anode slurry of lithium-ion flow battery was prepared by the method of ball milling. The morphology, conductivity, specific capacity and cycle performance of graphite anode slurry were studied. Results show that the addition of conductive carbon material can improve the suspension stability of the electrode slurry; the ball milling process can not only improve the suspension stability but also reduce the resistivity of the mixed powders of graphite and conductive carbon materials, the ball milling effect is satisfactory when the mass ratio of the balls and the solid particles is 5:1, but too high ratio of the milling ball and the solid materials can destroy the layer structure of the graphite and affect the stability of the slurry. Increasing the fraction of the graphite and conductive carbon materials can form stable electrical network structure in the slurry and improve the reversible capacity; at the premise of keeping the flowability of the electrode slurry, the reversible specific capacity can be more than 40mAh/g. The capacity loss of graphite anode slurry mainly occurs in the first charging-discharging process, as the increase of the cycles, the capacity loss rate decreases, the capacity goes stable after 5 cycles.

  13. Hydrophilic functionalized silicon nanoparticles produced by high energy ball milling

    Science.gov (United States)

    Hallmann, Steffen

    The mechanochemical synthesis of functionalized silicon nanoparticles using High Energy Ball Milling (HEBM) is described. This method facilitates the fragmentation of mono crystalline silicon into the nanometer regime and the simultaneous surface functionalization of the formed particles. The surface functionalization is induced by the reaction of an organic liquid, such as alkynes and alkenes with reactive silicon sites. This method can be applied to form water soluble silicon nanoparticles by lipid mediated micelle formation and the milling in organic liquids containing molecules with bi-functional groups, such as allyl alcohol. Furthermore, nanometer sized, chloroalkyl functionalized particles can be synthesized by milling the silicon precursor in the presence of an o-chloroalkyne with either alkenes or alkynes as coreactants. This process allows tuning of the concentration of the exposed, alkyl linked chloro groups, simply by varying the relative amounts of the coreactant. The silicon nanoparticles that are formed serve as the starting point for a wide variety of chemical reactions, which may be used to alter the surface properties of the functionalized nanoparticles. Finally, the use of functionalized silicon particles for the production of superhydrophobic films is described. Here HEBM proves to be an efficient method to produce functionalized silicon particles, which can be deposited to form a stable coating exhibiting superhydrophobic properties. The hydrophobicity of the silicon film can be tuned by the milling time and thus the resulting surface roughness of the films.

  14. Mineralogy and geochemistry of uranium mill tailings

    International Nuclear Information System (INIS)

    Pagel, M.; Somot, S.

    2002-01-01

    We have investigated three main types of uranium mill tailings: (1) acid mill tailings (Mounana, Gabon), (2) neutralized acid mill tailings (Ecarpiere and Jouac, France) and (3) alkaline mill tailings (Lodeve, France). We have focused especially on radium behaviour which is of major environmental concern in these tailings, but other metals were also studied. It is shown that in type 1 , trapping of 226 Ra by anglesite and barite is dominant whereas in types 2 and 3, 226 Ra is mainly or significantly scavenged by Fe- Mn oxyhydroxides. This study points out the importance of keeping conditions in which these oxyhydroxides will be stable for the long-term. Uranium would be also released during acidification of the tailings. This shows the importance to know more about the behavior of Ra during the crystallization of oxyhydroxides and during tailings diagenesis. Therefore, it is very important to study the sorption of Ra by clay minerals or late authigeneous minerals such as barite. (author)

  15. 75 FR 30844 - General Mills, Inc.; Withdrawal of Food Additive Petition

    Science.gov (United States)

    2010-06-02

    ...] (formerly Docket No. 2007F-0454) General Mills, Inc.; Withdrawal of Food Additive Petition AGENCY: Food and... 7M4770) had been filed by General Mills, Inc., One General Mills Blvd., Minneapolis, MN 55426. The... use in food production. General Mills, Inc., has now withdrawn the petition without prejudice to a...

  16. Nano-sized crystalline drug production by milling technology.

    Science.gov (United States)

    Moribe, Kunikazu; Ueda, Keisuke; Limwikrant, Waree; Higashi, Kenjirou; Yamamoto, Keiji

    2013-01-01

    Nano-formulation of poorly water-soluble drugs has been developed to enhance drug dissolution. In this review, we introduce nano-milling technology described in recently published papers. Factors affecting the size of drug crystals are compared based on the preparation methods and drug and excipient types. A top-down approach using the comminution process is a method conventionally used to prepare crystalline drug nanoparticles. Wet milling using media is well studied and several wet-milled drug formulations are now on the market. Several trials on drug nanosuspension preparation using different apparatuses, materials, and conditions have been reported. Wet milling using a high-pressure homogenizer is another alternative to preparing production-scale drug nanosuspensions. Dry milling is a simple method of preparing a solid-state drug nano-formulation. The effect of size on the dissolution of a drug from nanoparticles is an area of fundamental research, but it is sometimes incorrectly evaluated. Here, we discuss evaluation procedures and the associated problems. Lastly, the importance of quality control, process optimization, and physicochemical characterization are briefly discussed.

  17. Analytical Modelling Of Milling For Tool Design And Selection

    International Nuclear Information System (INIS)

    Fontaine, M.; Devillez, A.; Dudzinski, D.

    2007-01-01

    This paper presents an efficient analytical model which allows to simulate a large panel of milling operations. A geometrical description of common end mills and of their engagement in the workpiece material is proposed. The internal radius of the rounded part of the tool envelope is used to define the considered type of mill. The cutting edge position is described for a constant lead helix and for a constant local helix angle. A thermomechanical approach of oblique cutting is applied to predict forces acting on the tool and these results are compared with experimental data obtained from milling tests on a 42CrMo4 steel for three classical types of mills. The influence of some tool's geometrical parameters on predicted cutting forces is presented in order to propose optimisation criteria for design and selection of cutting tools

  18. Higher derivative super Yang-Mills theories

    International Nuclear Information System (INIS)

    Bergshoeff, E.; Rakowski, M.; Sezgin, E.

    1986-11-01

    The most general higher derivative Yang-Mills actions of the type (F 2 +α2F 4 ) which are globally supersymmetric up to order α 2 in six and ten dimensional spacetimes are given. The F 4 -terms turn out to occur in the combination α 2 (tr F 4 - 1/4(tr F 2 ) 2 ), where the trace is over the Lorentz indices. This result agrees with the low energy limit of the open superstring in ten dimensions, where α is the string tension. Surprisingly, the transformation rules of the Yang-Mills multiplet receive order α 2 corrections even in the off-shell formulation. For the case of Abelian Yang-Mills group, the action is expressed in Born-Infeld form with a metric generically given by (1+α 2 F 2 +...). (author)

  19. 33 CFR 117.800 - Mill Neck Creek.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Mill Neck Creek. 117.800 Section 117.800 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.800 Mill Neck Creek. The draw of the...

  20. Matrix Structure Evolution and Nanoreinforcement Distribution in Mechanically Milled and Spark Plasma Sintered Al-SiC Nanocomposites.

    Science.gov (United States)

    Saheb, Nouari; Aliyu, Ismaila Kayode; Hassan, Syed Fida; Al-Aqeeli, Nasser

    2014-09-19

    Development of homogenous metal matrix nanocomposites with uniform distribution of nanoreinforcement, preserved matrix nanostructure features, and improved properties, was possible by means of innovative processing techniques. In this work, Al-SiC nanocomposites were synthesized by mechanical milling and consolidated through spark plasma sintering. Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray Spectroscopy (EDS) facility was used for the characterization of the extent of SiC particles' distribution in the mechanically milled powders and spark plasma sintered samples. The change of the matrix crystallite size and lattice strain during milling and sintering was followed through X-ray diffraction (XRD). The density and hardness of the developed materials were evaluated as function of SiC content at fixed sintering conditions using a densimeter and a digital microhardness tester, respectively. It was found that milling for 24 h led to uniform distribution of SiC nanoreinforcement, reduced particle size and crystallite size of the aluminum matrix, and increased lattice strain. The presence and amount of SiC reinforcement enhanced the milling effect. The uniform distribution of SiC achieved by mechanical milling was maintained in sintered samples. Sintering led to the increase in the crystallite size of the aluminum matrix; however, it remained less than 100 nm in the composite containing 10 wt.% SiC. Density and hardness of sintered nanocomposites were reported and compared with those published in the literature.

  1. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation

    Energy Technology Data Exchange (ETDEWEB)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; Kammer, Frank von der; Hofmann, Thilo, E-mail: thilo.hofmann@univie.ac.at

    2016-09-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a “green” agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. - Highlights: • Rapid aggregation and sedimentation were observed in bare milled ZVI particles. • Agar agar improved the stability of milled ZVI particle suspensions. • Agar agar enhanced the transport of milled ZVI particles in heterogeneous sands. • Agar agar reduced the reactivity of milled ZVI particles towards TCE.

  2. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation

    International Nuclear Information System (INIS)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; Kammer, Frank von der; Hofmann, Thilo

    2016-01-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a “green” agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. - Highlights: • Rapid aggregation and sedimentation were observed in bare milled ZVI particles. • Agar agar improved the stability of milled ZVI particle suspensions. • Agar agar enhanced the transport of milled ZVI particles in heterogeneous sands. • Agar agar reduced the reactivity of milled ZVI particles towards TCE.

  3. Formation of metacinnabar by milling of liquid mercury and elemental sulfur for long term mercury storage

    International Nuclear Information System (INIS)

    Lopez, F.A.; Lopez-Delgado, A.; Padilla, I.; Tayibi, H.; Alguacil, F.J.

    2010-01-01

    In this paper we present the results of the formation of black HgS (metacinnabar) from liquid mercury and elemental sulfur using the mechanical energy provided by a ball mill in different conditions. Metacinnabar formation was observed even after short milling times (15 min) and unreacted liquid mercury was no longer detected after 60 min of milling. The reaction mechanism was monitored with a scanning electron microscope. The impact and friction forces of milling on the Hg and S mixture resulted in the formation of metacinnabar by reducing the size of mercury drops, giving rise to microspheres, and lowering the surface tension to allow sulfur grains to become adhered at the reaction interface. After 60 min of milling, the metacinnabar formation reaction was observed to be more than 99.99% complete, yielding a Toxicity Characteristic Leaching Procedure value of 3.1 μg/L Hg. The reaction product thus complies with the limits of the most stringent Universal Treatment Standard requirements, which allow a maximum TCLP concentration of 25 μg/L.

  4. Cutting Temperature Investigation of AISI H13 in High Speed End Milling

    Directory of Open Access Journals (Sweden)

    Muhammad Riza

    2016-10-01

    Full Text Available Heat produced at the tool-chip interface during high speed milling operations have been known as a significant factor that affect to tool life and workpiece geometry or properties. This paper aims to investigate cutting temperature behaviours of AISI H13 (48 HRC under high speed machining circumstances during pocketing. The experiments were conducted on CNC vertical machining centre by using PVD coated carbide insert. Milling processes were done at cutting speeds 150, 200 and 250 m/min and feed rate were 0.05, 0.1 and 0.15 mm/tooth. Depths of cut applied were 0.1, 0.15 and 0.2 mm. Tool path method applied in this experiment was contour in. Results presented in this paper indicate that by increasing cutting speed the cutting temperature is lower than low cutting speed. However, by decreasing feed rate leads to cutting temperature low. Cutting temperature phenomena at the corner of pocket milling were also investigated. The phenomena showed that cutting temperature tends to decrease a moment when cutter comes to the corner of pocket and turning point of tool path and increase extremely a moment before leaving the corner and turning point.

  5. Comparative Study by MS and XRD of Fe{sub 50}Al{sub 50} Alloys Produced by Mechanical Alloying, Using Different Ball Mills

    Energy Technology Data Exchange (ETDEWEB)

    Rojas Martinez, Y., E-mail: yarojas@ut.edu.co [University of Tolima, Department of Physics (Colombia); Perez Alcazar, G. A. [University of Valle, Department of Physics (Colombia); Bustos Rodriguez, H.; Oyola Lozano, D., E-mail: doyolalozano@yahoo.com.mx [University of Tolima, Department of Physics (Colombia)

    2005-02-15

    In this work we report a comparative study of the magnetic and structural properties of Fe{sub 50}Al{sub 50} alloys produced by mechanical alloying using two different planetary ball mills with the same ball mass to powder mass relation. The Fe{sub 50}Al{sub 50} sample milled during 48 h using the Fritsch planetary ball mill pulverisette 5 and balls of 20 mm, presents only a bcc alloy phase with a majority of paramagnetic sites, whereas that sample milled during the same time using the Fritsch planetary ball mill pulverisette 7 with balls of 15 mm, presents a bcc alloy phase with paramagnetic site (doublet) and a majority of ferromagnetic sites which include pure Fe. However for 72 h of milling this sample presents a bcc paramagnetic phase, very similar to that prepared with the first system during 48 h. These results show that the conditions used in the first ball mill equipment make more efficient the milling process.

  6. Impact of industrial hammer mill rotor speed on extraction efficiency and quality of extra virgin olive oil.

    Science.gov (United States)

    Polari, Juan J; Garcí-Aguirre, David; Olmo-García, Lucía; Carrasco-Pancorbo, Alegría; Wang, Selina C

    2018-03-01

    Crushing is a key step during olive oil extraction. Among commercial crushers, the hammer mill is the most widely used due to its robustness and high throughput. In the present work, the impact of hammer mill rotor speed on extraction yield and overall quality of super-high-density Arbosana olive oils were assessed in an industrial facility. Our results show that increasing the rotor speed from 2400rpm to 3600rpm led to a rise in oil yield of 1.2%, while conserving quality parameters. Sensory analysis showed more pungency with increased rotation speed, while others attributes were unaffected. Volatile compounds showed little variation with the differences in crusher speed; however, total phenols content, two relevant secoiridoids, and triterpenoids levels increased with rotor speed. Hammer mill rotor speed is a processing variable that can be tuned to increase the extraction efficiency and modulate the chemical composition of extra virgin olive oil. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Update of NRC uranium mill licensing activities

    International Nuclear Information System (INIS)

    Martin, J.B.

    1978-01-01

    Increased vigilance must be given to controlling emissions from active milling operations, particularly windblown tailings, to assure that the soon-to-be-effective EPA Fuel Cycle Standard is met. Comprehensive environmental monitoring programs will have to be developed to confirm that, in fact, the limit is met. Just as was the case last year, tailings management and disposal is still the major item of concern relating to uranium milling operations. As stated earlier, the NRC feels that below-grade disposal is the preferred method of tailings disposal in that it provides the greatest assurances of long-term isolation. In any event, tailings must be disposed of in such a way that no active care is required of disposal sites, to avoid committing future generations to a significant, lingering obligation to care for wastes generated to produce benefits which they will only indirectly receive, if at all. While the primary means of providing long-term isolation of tailings must be by physical barriers, as a prudent, supplementary measure of control, we are concluding in the GEIS on Uranium Milling that ownership of disposal sites by a Government agency is desirable. We expect a low level of continued surveillance at disposal sites with small expense involved. We are concluding that requiring operators to contribute on the order of $100,000 per disposal site to cover ongoing expenses would be the most apropriate means of conforming to the principle that the waste generator should pay full costs of waste disposal. We feel such an arrangement would be fair, simple, and efficient, favoring it over complicated schemes involving such things as taxes on product or tailings generated and continued management of ear-marked funds. Legislation is now pending in the Congress which would give NRC direct regulatory control over mill tailings and put into place the authorities needed to implement the long-term control and funding arrangements discussed above

  8. Methane Emission from Digestion of Palm Oil Mill Effluent (POME in a Thermophilic Anaerobic Reactor

    Directory of Open Access Journals (Sweden)

    I Irvan

    2012-04-01

    Full Text Available As the issue of global warming draws increasing concern, many studies to reduce CO2 and CH4 gases (greenhouse gases, GHG have been implemented in several countries, including in Indonesia. Considering that Indonesia has a huge numbers of palm oil mills, no doubt if their waste water treatment as one of the major sources in GHG.  This paper presents the results from a research project between Metawater Co., Ltd.-Japan and University of Sumatera Utara-Indonesia. The objective of the research is to study the methane emission of thermophilic fermentation in the treatment of palm oil mill effluent (POME on a laboratory scale. Anaerobic digestion was performed in two-litre water jacketed biodigester type continuous stirred tank reactor (CSTR and operated at a thermophilic temperature (55 oC. As raw material, a real liquid waste (POME from palm oil mill was used. Fresh POME was obtained from seeding pond of PTPN II waste water treatment facility which has concentration of 39.7 g of VS/L and COD value of 59,000 mg/L. To gain precise results, complete recording and reliable equipment of reactor was employed. As the experimental results, for hydraulic retention time (HRT 8 days, VS decomposition rate of 63.5% and gas generation of 6.05-9.82 L/day were obtained, while for HRT 6 and 4 days, VS decomposition rate of 61.2, 53.3% and gas generation of  6.93-8.94  and  13.95-16.14 L/day were obtained respectively. Keywords—methane (CH4, palm oil mill effluent (POME, anaerobic digestion, thermophilic, green house gases (GHG

  9. Low cost biosorbent "banana peel" for the removal of phenolic compounds from olive mill wastewater: kinetic and equilibrium studies.

    Science.gov (United States)

    Achak, M; Hafidi, A; Ouazzani, N; Sayadi, S; Mandi, L

    2009-07-15

    The aim of this work is to determine the potential of application of banana peel as a biosorbent for removing phenolic compounds from olive mill wastewaters. The effect of adsorbent dosage, pH and contact time were investigated. The results showed that the increase in the banana peel dosage from 10 to 30 g/L significantly increased the phenolic compounds adsorption rates from 60 to 88%. Increase in the pH to above neutrality resulted in the increase in the phenolic compounds adsorption capacity. The adsorption process was fast, and it reached equilibrium in 3-h contact time. The Freundlich and Langmuir adsorption models were used for mathematical description of the adsorption equilibrium and it was found that experimental data fitted very well to both Freundlich and Langmuir models. Batch adsorption models, based on the assumption of the pseudo-first-order, pseudo-second-order and intraparticle diffusion mechanism, showed that kinetic data follow closely the pseudo-second-order than the pseudo-first-order and intraparticle diffusion. Desorption studies showed that low pH value was efficient for desorption of phenolic compounds. These results indicate clearly the efficiency of banana peel as a low-cost solution for olive mill wastewaters treatment and give some preliminary elements for the comprehension of the interactions between banana peel as a bioadsorbent and the very polluting compounds from the olive oil industry.

  10. Health physics program for the Edgemont Uranium Mill decommissioning project

    International Nuclear Information System (INIS)

    Polehn, J.L.; Wallace, R.G.; Reed, R.P.; Wilson, G.T.

    1986-01-01

    The Tennessee Valley Authority (TVA) is actively involved in decommissioning a uranium mill located near the town of Edgemont, South Dakota. The Edgemont Mill Decommissioning Project, which is unique in many respects, will involve dismantlement of the old inactive mill building and excavation and transportation of several million tons of uranium mill tailings to a permanent disposal site. To ensure that workers are adequately protected from radiation exposure during decommissioning operations, a health physics program appropriate for the decommissioning situation was developed. The Edgemont Mill Decommissioning Project Health Physics Manual (HPM) gives the programmatic requirements for worker radiation protection. The requirements of the HPM are implemented by means of detailed onsite operating procedures. The Edgemont project health physics program was developed using currently available regulations and guidance for an operating uranium mill with appropriate modifications for decommissioning. This paper discusses the development, implementation, and documentation of that program

  11. Cutting force response in milling of Inconel: analysis by wavelet and Hilbert-Huang Transforms

    Directory of Open Access Journals (Sweden)

    Grzegorz Litak

    Full Text Available We study the milling process of Inconel. By continuously increasing the cutting depth we follow the system response and appearance of oscillations of larger amplitude. The cutting force amplitude and frequency analysis has been done by means of wavelets and Hilbert-Huang transform. We report that in our system the force oscillations are closely related to the rotational motion of the tool and advocate for a regenerative mechanism of chatter vibrations. To identify vibrations amplitudes occurrence in time scale we apply wavelet and Hilbert-Huang transforms.

  12. Infrared finiteness in Yang--Mills theories

    International Nuclear Information System (INIS)

    Appelquist, T.; Carazzone, J.; Kluberg-Stern, H.; Roth, M.

    1976-01-01

    The infrared divergences of renormalizable theories with coupled massless fields (in particular, the Yang--Mills theory) are shown to cancel for transition probabilities corresponding to finite-energy-resolution detectors, just as in quantum electrodynamics. This result is established through lowest nontrivial order in perturbation theory for the detection of massive muons in a quantum electrodynamic theory containing massless electrons or the detection of massive quarks in a Yang--Mills theory

  13. Preparation of 50Ni-45Ti-5Zr powders by high-energy ball milling and hot pressing

    Energy Technology Data Exchange (ETDEWEB)

    Marinzeck de Alcantara Abdala, Julia, E-mail: juabdala@yahoo.com.b [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi, 2911, 12244-000 Sao Jose dos Campos (Brazil); Bacci Fernandes, Bruno, E-mail: brunobacci@yahoo.com.b [Divisao de Engenharia Mecanica, Instituto Tecnologico de Aeronautica, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Santos, Dalcy Roberto dos, E-mail: dalcy@iae.cta.b [Instituto de Aeronautica e Espaco, Centro Tecnologico Aeroespacial, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Rodrigues Henriques, Vinicius Andre, E-mail: vinicius@iae.cta.b [Instituto de Aeronautica e Espaco, Centro Tecnologico Aeroespacial, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Moura Neto, Carlos de, E-mail: mneto@ita.b [Divisao de Engenharia Mecanica, Instituto Tecnologico de Aeronautica, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Saraiva Ramos, Alfeu, E-mail: alfeu@univap.b [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi, 2911, 12244-000 Sao Jose dos Campos (Brazil)

    2010-04-16

    This study reports on the preparation of the 50Ni-45Ti-5Zr (at.%) alloy by high-energy ball milling and hot pressing. The elemental powder mixture was processed in silicon nitride and hardened steel vials, and samples were collected after different milling times. To recover the previous powders in addition wet milling isopropyl alcohol (for 20 min) was adopted. The mechanically alloyed powders were hot-pressed under vacuum at 900 {sup o}C for 1 h using pressure levels close to 200 MPa. The milled powders were characterized by means of scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry techniques. It was noted that the ductile starting powders were continuously cold-welded during ball milling. This fact was more pronounced during the processing of 50Ni-45Ti-5Zr powders in hardened steel vial. After milling for 5 h, the results suggested that amorphous and nanocrystalline structures were achieved. The complete consolidation was found after hot pressing of mechanically alloyed 50Ni-45Ti-5Zr powders, and a large amount of the B2-NiTi phase was formed mainly after processing in stainless steel balls and vial.

  14. Long-term stabilization of uranium mill tailings

    International Nuclear Information System (INIS)

    Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

    1983-01-01

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

  15. Adjustment of milling plants to changed fuel qualities, Increase of performance of the mills MPS {sup registered} 180 at GK Kiel by means of an exchange of wing separators against lamellae separators; Anpassung von Mahlanlagen an veraenderte Brennstoffqualitaeten. Leistungssteigerung der Muehlen MPS {sup registered} 180 im GK Kiel durch den Austausch der Fluegelsichter gegen Lamellensichter

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, Axel [Gemeinschaftskraftwerk Kiel GmbH, Kiel (Germany); Krause, Thomas [Hitachi Power Europe GmbH, Duisburg (Germany); Hufmann, Theo [E.ON Engineering GmbH, Gelsenkirchen (Germany)

    2008-07-01

    By means of heat and power generation, the municipal power station Kiel at the east bank of the Kieler Foerde has the possibility of uncoupling a thermal performance of up to 295 MW into the district heating grid of public utilities Kiel. The necessary conversion of the fuel required an increase of the performance of the mill in order to be able to grind the larger fuel flow during continuous boiler performance. For this, in the first step the exchange of the wing separators against lamella separators was selected. The authors of the contribution under consideration report on an adjustment of the crushing mills at changing fuel qualities.

  16. Evaluation of dynamic response for monopole and hybrid wind mill tower

    Science.gov (United States)

    Shah, Hemal J.; Desai, Atul K.

    2017-07-01

    The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovat