WorldWideScience

Sample records for high energy milling

  1. High-Energy Ball-Milling of Alloys and Compounds

    International Nuclear Information System (INIS)

    Le Caer, G.; Delcroix, P.; Begin-Colin, S.; Ziller, T.

    2002-01-01

    After outlining some characteristics of high-energy ball-milling, we discuss selected examples of phase transformation and of alloy synthesis which focus on deviations from archetypal behaviours and throw light on the milling mechanisms. Some contributions of Moessbauer spectrometry to the characterization of ground materials are described.

  2. 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%.

  3. 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....

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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

  9. 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)

  10. 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.

  11. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: uu_gg_oo@yahoo.com.mx [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico) and Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN, Legaria 694, Col. Irrigacion, Del. Miguel Hidalgo (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM, Circuito de la Investigacion Cientifica s/n, C.U. Del. Coyoacan (Mexico); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN, Cerrada de CECATI s/n, Col. Santa Catarina, Del. Azcapotzalco (Mexico)

    2011-10-15

    Highlights: {yields} PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. {yields} During high-energy milling oxygen has to be chemically reduced from the lead oxide. {yields} Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  12. Solid-state reactions to synthesize nanostructured lead selenide semiconductor powders by high-energy milling

    International Nuclear Information System (INIS)

    Rojas-Chavez, H.; Reyes-Carmona, F.; Jaramillo-Vigueras, D.

    2011-01-01

    Highlights: → PbSe synthesized from PbO instead of Pb powder do not require an inert atmosphere. → During high-energy milling oxygen has to be chemically reduced from the lead oxide. → Solid-state and solid-gas chemical reactions promote both solid and gaseous products. -- Abstract: Both solid-solid and gas-solid reactions have been traced during high-energy milling of Se and PbO powders under vial (P, T) conditions in order to synthesize the PbSe phase. Chemical and thermodynamic arguments are postulated to discern the high-energy milling mechanism to transform PbO-Se micropowders onto PbSe-nanocrystals. A set of reactions were evaluated at around room temperature. Therefore an experimental campaign was designed to test the nature of reactions in the PbO-Se system during high-energy milling.

  13. Analysis of crystallite size and microdeformation crystal lattice the tungsten carbide milling in mill high energy

    International Nuclear Information System (INIS)

    Silva, F.T. da; Nunes, M.A.M.; Souza, C.P. de; Gomes, U.U.

    2010-01-01

    The tungsten carbide (WC) has wide application due to its properties like high melting point, high hardness, wear resistance, oxidation resistance and good electrical conductivity. The microstructural characteristics of the starting powders influences the final properties of the carbide. In this context, the use of nanoparticle powders is an efficient way to improve the final properties of the WC. The high energy milling stands out from other processes to obtain nanometric powders due to constant microstructural changes caused by this process. Therefore, the objective is to undertake an analysis of microstructural characteristics on the crystallite size and microdeformations of the crystal lattice using the technique of X-ray diffraction (XRD) using the Rietveld refinement. The results show an efficiency of the milling process to reduce the crystallite size, leading to a significant deformation in the crystal lattice of WC from 5h milling. (author)

  14. 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

  15. 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.)

  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. Ammonia synthesis over multi-promoted iron catalysts obtained by high-energy ball-milling

    DEFF Research Database (Denmark)

    Jacobsen, C.J.H.; Jiang, Jianzhong; Mørup, Steen

    1999-01-01

    The feasibility of producing ammonia synthesis catalysts from high-energy ball-milling of a simple mixture of the constituent oxides has been investigated. The effect of ball-milling the fused oxidic precursor of the industrial KM1 ammonia synthesis catalyst has also been studied. The results show...

  18. Fe-Al2O3 nanocomposites prepared by high-energy ball milling

    DEFF Research Database (Denmark)

    Linderoth, Søren; Pedersen, M.S.

    1994-01-01

    Nanocomposites of alpha-Fe and alpha-Al2O3, prepared by high-energy ball milling, exhibit coercivities which are enhanced by about two orders of magnitude with respect to the bulk value. The degree of enhancement depends on the volume fraction (x(upsilon)) of Fe, with a maximum for x(upsilon) alm......Nanocomposites of alpha-Fe and alpha-Al2O3, prepared by high-energy ball milling, exhibit coercivities which are enhanced by about two orders of magnitude with respect to the bulk value. The degree of enhancement depends on the volume fraction (x(upsilon)) of Fe, with a maximum for x...

  19. Study of magnetic properties of nano-powders prepared by pyrite -> troilite transformation via high energy milling

    DEFF Research Database (Denmark)

    Balaz, P.; Alacova, A.; Godocikova, E.

    2004-01-01

    The preparation of nanocrystalline troilite by high-energy milling of FeS2 sulphide with elemental Fe acting as reducing element is reported. X-ray difractometry was used in order to determine the presence of different phases in investigated samples. This technique allowed us to identify the form......-->troilite transformation is almost finished already after 25 minutes of high-energy milling.......The preparation of nanocrystalline troilite by high-energy milling of FeS2 sulphide with elemental Fe acting as reducing element is reported. X-ray difractometry was used in order to determine the presence of different phases in investigated samples. This technique allowed us to identify...

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Refining the microstructure of an AISI M2 tool steel by high-energy milling

    International Nuclear Information System (INIS)

    Postiglioni, R.V.; Alamino, A.E; Vurobi Junior, S.

    2009-01-01

    Samples of AISI M2 steel were produced by high-energy milling from chips of machining in Spex high energy mill, compaction and sintering of the powder obtained. The powder was analyzed by X-ray diffraction, and then compressed in discs of 8mm in diameter. The specimens have sintering at 1200 deg C for 1 hour under vacuum atmosphere, followed by annealing, quenching and tempering for 1 hour at 315 deg C and 540°C. Along with each disc, a sample of as-received steel was subjected to the same heat treatments to compare the final microstructure. After standard metallographic preparation, samples were etched with Beraha's reagent, characterized by optical microscopy, quantitative metallography, scanning electron microscopy with micro analysis and mapping by EDS, besides Vickers hardness. The steel produced by high-energy milling presented more refined carbide and better distribution in the microstructure. There was also reduction in the size of prior austenitic grains. (author)

  5. 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

  6. 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

  7. 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.

  8. PbSe nanocubes obtained by high-energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: hrojasc@ipn.mx [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - IPN (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM (Mexico); Achimovicova, M. [Slovak Academy of Sciences, Institute of Geotechnics (Slovakia); Daneu, N. [Jozef Stefan Institute, Department for Nanostructured Materials (Slovenia); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN (Mexico)

    2012-06-15

    In this study, PbSe nanocubes were obtained by high-energy milling, and their optical properties were investigated by measuring the UV-VIS-IR spectra in the range of 200-2,000 nm. The optical absorption of all samples showed a strong UV emission band at 1.45 eV. Previously, to obtain only PbSe nanocubes, an intermediate phase was identified, PbSeO{sub 3}. Although both PbSeO{sub 3} and PbSe were traced through this study, a major effort is devoted to characterize the latter. To trace how chemical transitions evolve from precursors to PbSe, X-ray diffraction and Rietveld refinement were carried out. Therefore, the following parameters were evaluated as a function of milling time: phase percentages, area-to-volume ratio, average crystallite dimensions, specific surface area, and morphology changes. To corroborate previous findings, nitrogen adsorption and transmission electron microscopy techniques were used. All the set experimental results unambiguously confirm that crystallites show a cubic morphology, with its average crystallite size distribution being around 24 nm.

  9. Mechanically Induced Graphite-Nanodiamonds-Phase Transformations During High-Energy Ball Milling

    Science.gov (United States)

    El-Eskandarany, M. Sherif

    2017-05-01

    Due to their unusual mechanical, chemical, physical, optical, and biological properties, nearly spherical-like nanodiamonds have received much attention as desirable advanced nanomaterials for use in a wide spectrum of applications. Although, nanodiamonds can be successfully synthesized by several approaches, applications of high temperature and/or high pressure may restrict the real applications of such strategic nanomaterials. Distinct from the current preparation approaches used for nanodiamonds preparation, here we show a new process for preparing ultrafine nanodiamonds (3-5 nm) embedded in a homogeneous amorphous-carbon matrix. Our process started from high-energy ball milling of commercial graphite powders at ambient temperature under normal atmospheric helium gas pressure. The results have demonstrated graphite-single wall carbon nanotubes-amorphous-carbon-nanodiamonds phase transformations carried out through three subsequent stages of ball milling. Based on XRD and RAMAN analyses, the percentage of nanodiamond phase + C60 (crystalline phase) produced by ball milling was approximately 81%, while the amorphous phase amount was 19%. The pressure generated on the powder together the with temperature increase upon the ball-powder-ball collision is responsible for the phase transformations occurring in graphite powders.

  10. Processing of an AISI D2 tool steel by high-energy milling

    International Nuclear Information System (INIS)

    Spagnol, N.J.R.; Araujo, G.F.; Vurobi Junior, S.; Cintho, O.M.

    2009-01-01

    Full text: Chips of machining of AISI D2 steel were processed in Spex high-energy mill. The powder obtained was analyzed by x-ray diffraction, and then compressed in the form of discs of 8mm in diameter. The samples were treated at 1200 deg C for 1 hour under vacuum atmosphere for sintering. Then specimens were subjected to annealing, quenching and tempering at 400°C and 525 deg C. Along with each disc, a sample of as-received steel was subjected to the same heat treatment to evaluate the final microstructures. After metallographic preparation, samples were etched with Berah's reagent, characterized by optical microscopy, Vickers hardness, quantitative metallography and scanning electron microscopy with micro analysis and mapping by EDS. Specimens from high energy milling had reduction in prior austenitic grain size and more refined carbides and better distributed in the microstructure of steel. (author)

  11. Multiple direct exchange in a Yang-Mills theory at high energy

    International Nuclear Information System (INIS)

    McCoy, B.M.; Wu, T.T.

    1976-01-01

    For eighth and higher orders, we obtain the leading high-energy behavior of the sum of all one-layer Feynman diagrams in Yang-Mills theory. These are the contributions from Feynman diagrams where the two incident fast particles exchange directly Yang-Mills bosons that are much less energetic. The incident particles may be either bosons or fermions of arbitrary isospin, and the result is also generalized to include the case of the Higgs scalar. The scattering amplitudes in all these cases are closely related, and all behave as s ln/sub n/ -1 s in the 2n + 2 order. Furthermore, in this leading order for n > or = 2, the exchanged isospins are always 0 and 2, no matter how high the isospins of the incident particles are

  12. Characterization of Al2O3-Co ceramic composite obtained by high energy mill

    International Nuclear Information System (INIS)

    Souza, J.L.; Assis, R.B. de; Carlos, E.M.; Oliveira, T.P.; Costa, F.A. da

    2014-01-01

    This work aims to characterize the ceramic composite Al 2 O3-Co obtained by high energy grinding. The composites were obtained by milling Al 2 O 3 and Co in a high energy mill at a speed of 400 rpm, in proportions of 5 to 20% Cobalt (Co). Ceramic composites with 5 and 20% cobalt were sintered at 1200 and 1300 ° C, with a 60-minute plateau and a heating rate of 10 ° C / min. The samples were characterized by X-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG / DSC) and scanning electron microscopy (SEM). The results show the significant effect of cobalt percentage and high energy grinding on the final properties of the Al 2 O 3 - Co ceramic composite, presenting satisfactory values for the composite with a 20% cobalt percentage, showing to be a promising material for application in cutting tools

  13. Reverse martensitic transformation in alumina-15 vol% zirconia nanostructured powder synthesized by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Maneshian, M.H. [Department of Materials Science and Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9466, Tehran (Iran, Islamic Republic of)], E-mail: mh_maneshian@yahoo.com; Banerjee, M.K. [National Institute of Foundry and Forge Technology, Hatia, Ranchi 834003 (India)

    2008-07-14

    In the present work, three alumina-15 vol% zirconia composites with Y{sub 2}O{sub 3}, MgO as dopants and without oxide as dopant have been investigated. High energy ball milling (HEBM) provides the positive thermodynamic driving force for monoclinic to tetragonal transformation and it reduces starting temperature for the reverse martensitic transformation, meanwhile mobility of zirconium cations and oxygen anions are enhanced in zirconia by HEBM. The general, albeit heuristic, reasoning is corroborated by nanocrystallity, particle size and also the retained monoclinic seem to play an important role. After 10 h HEBM, approximately 28% zirconia tetragonal phase is achieved. Non-stoichiometric tetragonal zirconia phase; Zr{sub 0.95}O{sub 2} is seen to have been achieved by high energy ball milling (HEBM). The structural and compositional evolutions during HEBM have been investigated using X-ray diffraction method (XRD) and scanning electron microscopy (SEM). High resolution transmission electron microscope (TEM) is also used for further understanding about the phenomenological changes taking place during high energy ball milling.

  14. 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.

  15. Synthesis and characterization of high volume fraction Al-Al2O3 nanocomposite powders by high-energy milling

    International Nuclear Information System (INIS)

    Prabhu, B.; Suryanarayana, C.; An, L.; Vaidyanathan, R.

    2006-01-01

    Al-Al 2 O 3 metal matrix composite (MMC) powders with volume fractions of 20, 30, and 50% Al 2 O 3 were synthesized by high-energy milling of the blended component powders. The particle sizes of Al 2 O 3 studied were 50 nm, 150 nm, and 5 μm. A uniform distribution of the Al 2 O 3 reinforcement in the Al matrix was successfully obtained after milling the powders for a period of 20 h at a ball-to-powder ratio of 10:1 in a SPEX mill. The uniform distribution of Al 2 O 3 in the Al matrix was confirmed by characterizing these nanocomposite powders by scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), X-ray mapping, and X-ray diffraction (XRD) techniques

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Magnetic properties of nanocrystalline pyrrhotite prepared by high-energy milling

    DEFF Research Database (Denmark)

    Balaz, P.; Godocikova, E.; Alacova, A.

    2004-01-01

    The nanocrystalline pyrrhotite was prepared by high-energy milling of lead sulphide with elemental Fe acting as reducing element. X-ray diffractometry, Mossbauer spectroscopy and VSM magnetometry were used to determine the properties of nanocrystalline iron sulphide prepared by the corresponding...... mechanochemical reaction. Pyrrhotite Fe1-xS together with the residual Fe metal were identified by the X-ray diffractometry. The kinetic studies performed by Mossbauer spectroscopy and VSM magnetometry allowed us to follow in more details the progress of the nanocrystalline magnetic phase formation during...

  1. Study of the aluminothermic reduction of niobium pentoxide through thermal analysis experiments and high energy milling processing

    Directory of Open Access Journals (Sweden)

    Claudio Parra De Lazzari

    2007-06-01

    Full Text Available Aluminothermic reduction of niobium pentoxide was studied through thermal analysis techniques such as differential thermal analysis (DTA and thermogravimetry (TG as well as through high energy milling processing. Reactants mixtures were composed by powders of Nb2O5 and Al. In the case of DTA-TG experiments, different molar ratios Nb2O5:Al were heated in a dynamic atmosphere of synthetic air under controlled conditions. The high energy milling runs were carried out via SPEX vibratory mill under argon atmosphere and with milling power equal to 7:1 (ratio of mass of balls to mass of mixture with 10 pct excess of Al over the stoichiometric mass of aluminum necessary. In both kinds of experiments, X ray diffraction was used in order to identify the products of reaction. From DTA-TG experiments, it was possible to determine the experimental value of the enthalpy change (-595.9 kJ.mol-1, which is near to the theoretical one. From the milling experiments, it was possible to verify the possibility of the occurance of aluminothermic reducion of niobium pentoxide via this kind of processing.

  2. Effect of expansion temperature of expandable graphite on microstructure evolution of expanded graphite during high-energy ball-milling

    International Nuclear Information System (INIS)

    Yue Xueqing; Li Liang; Zhang Ruijun; Zhang Fucheng

    2009-01-01

    Two expanded graphites (EG), marked as EG-1 and EG-2, were prepared by rapid heating of expandable graphite to 600 and 1000 deg. C, respectively, and ball milled in a high-energy mill (planetary-type) under air atmosphere. The microstructure evolution of the ball-milled samples was characterized by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). XRD analysis shows that the evolution degree of the average crystallite thickness along the c-axis (L c ) of EG-2 is lower than that of EG-1 during the milling process. From the HRTEM images of the samples after 100 h ball-milling, slightly curved graphene planes can be frequently observed both in the two EGs, however, EG-1 and EG-2 exhibit sharply curved graphene planes and smoothly curved graphene planes with high bending angles, respectively.

  3. Quenching ilmenite with a high-temperature and high-pressure phase using super-high-energy ball milling.

    Science.gov (United States)

    Hashishin, Takeshi; Tan, Zhenquan; Yamamoto, Kazuhiro; Qiu, Nan; Kim, Jungeum; Numako, Chiya; Naka, Takashi; Valmalette, Jean Christophe; Ohara, Satoshi

    2014-04-25

    The mass production of highly dense oxides with high-temperature and high-pressure phases allows us to discover functional properties that have never been developed. To date, the quenching of highly dense materials at the gramme-level at ambient atmosphere has never been achieved. Here, we provide evidence of the formation of orthorhombic Fe2TiO4 from trigonal FeTiO3 as a result of the high-temperature (>1250 K) and high-pressure (>23 GPa) condition induced by the high collision energy of 150 gravity generated between steel balls. Ilmenite was steeply quenched by the surrounding atmosphere, when iron-rich ilmenite (Fe2TiO4) with a high-temperature and high-pressure phase was formed by planetary collisions and was released from the collision points between the balls. Our finding allows us to infer that such intense planetary collisions induced by high-energy ball milling contribute to the mass production of a high-temperature and high-pressure phase.

  4. 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.

  5. Niobium Carbide-Reinforced Al Matrix Composites Produced by High-Energy Ball Milling

    Science.gov (United States)

    Travessa, Dilermando Nagle; Silva, Marina Judice; Cardoso, Kátia Regina

    2017-06-01

    Aluminum and its alloys are key materials for the transportation industry as they contribute to the development of lightweight structures. The dispersion of hard ceramic particles in the Al soft matrix can lead to a substantial strengthening effect, resulting in composite materials exhibiting interesting mechanical properties and inspiring their technological use in sectors like the automotive and aerospace industries. Powder metallurgy techniques are attractive to design metal matrix composites, achieving a homogeneous distribution of the reinforcement into the metal matrix. In this work, pure aluminum has been reinforced with particles of niobium carbide (NbC), an extremely hard and stable refractory ceramic. Its use as a reinforcing phase in metal matrix composites has not been deeply explored. Composite powders produced after different milling times, with 10 and 20 vol pct of NbC were produced by high-energy ball milling and characterized by scanning electron microscopy and by X-ray diffraction to establish a relationship between the milling time and size, morphology, and distribution of the particles in the composite powder. Subsequently, an Al/10 pct NbC composite powder was hot extruded into cylindrical bars. The strength of the obtained composite bars is comparable to the commercial high-strength, aeronautical-grade aluminum alloys.

  6. Solid-solid and gas-solid interactions induced during high-energy milling to produce PbTe nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Chavez, H., E-mail: rojas_hugo@ittlahuac2.edu.mx [Instituto Tecnologico de Tlahuac - II (Mexico); Reyes-Carmona, F. [Facultad de Quimica - UNAM (Mexico); Garibay-Febles, V. [Instituto Mexicano del Petroleo, Laboratorio de Microscopia Electronica de Ultra Alta Resolucion (Mexico); Jaramillo-Vigueras, D. [Centro de Investigacion e Innovacion Tecnologica - IPN (Mexico)

    2013-05-15

    Transformations from precursors to nanoparticles by high-energy milling are promoted by two major driving forces, namely physical and/or chemical. While the former has been difficult to trace since stress, strain and recovery may occur almost simultaneously during milling, the latter has been sequentially followed as an evolution from precursors to intermediate phases and thereof to high purity nanocrystals. The specific objective of this work is to discern how solid-solid and partially solid-gas reactions manifest themselves correspondingly as a short-range diffusion through an interface or how vapor species, as a subliming phenomenon, grows as a different phase on an active local surface. These series of changes were traced by sub-cooling the as-milled powders extracted during a milling cycle. Through this experimental technique, samples were electron microscopically analyzed and where it was required, selected area electron diffraction images were obtained. High-resolution transmission electron microscopy results, unambiguously, confirm that nanocrystals in the last stage show a cubic morphology which average size distributions are around 17 nm.

  7. High energy behavior of a six-point R-current correlator in N=4 supersymmetric Yang-Mills theory

    International Nuclear Information System (INIS)

    Bartels, Jochen; Hentschinski, Martin; Mischler, Anna-Maria

    2009-12-01

    We study the high energy limit of a six-point R-current correlator in N=4 supersymmetric Yang-Mills theory for finite N c . We make use of the framework of perturbative resummation of large logarithms of the energy. More specifically, we apply the (extended) generalized leading logarithmic approximation. We find that the same conformally invariant two-to-four gluon vertex occurs as in non-supersymmetric Yang-Mills theory. As a new feature we find a direct coupling of the four-gluon t-channel state to the R-current impact factor. (orig.)

  8. Trends and Effective Use of Energy Input in the Palm Kernel Oil Mills

    Directory of Open Access Journals (Sweden)

    Bamgboye, AI.

    2007-01-01

    Full Text Available This work aims at studying the importance and the efficiency of energy use in a few palm kernel oil mills selected for their representativity. Pattern of energy use, the cost of energy per unit product, energy intensity and normalized performance indicator (NPI were determined. Results show that the medium and the large mills depend largely on fossil fuel; while the small mill depends on electricity. It was found out that the large mill has the most effective use of energy with high energy intensity. The annual cost of energy per unit product of N8,360,000 ($64,307.69; N12,262,250 ($94,325 and N13,353,870 ($102, 722.08 were obtained for small, medium and large mills respectively. The NPI results show that there was no wastage of energy through space heating in energy supplied for production within the factory site.

  9. PULPA CUBA MILL ENERGY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Juan Pedro Hernández Touset

    2015-10-01

    Full Text Available An energy study was performed at Pulpa Cuba Paper Mill, located in Sancti Spiritus, where an energy management system was applied according to NC: ISO 50001, in order to assess the energy system by applying energy management systems for energy and water reduction in the paper mill, in which the current steam generation, distribution and consumption system is diagnosed. The proposal of a modified energy scheme with 1 MW Backpressure Steam Turbine Generator and rehabilitation of the original boiler or installing a lower capacity boiler contributes to save financial resources by the concept of water, fuel and electricity. The implementation of four projects will save 3,095,574 CUC / y and an average payback period of about 1 year is expected.

  10. Plasma sintering of ferritic steel reinforced with niobium carbide prepared by high energy milling

    International Nuclear Information System (INIS)

    Silva Junior, J.F. da; Almeida, E.O.; Gomes, U.U.; Alves Junior, C.; Messias, A.P.; Universidade Federal do Rio Grande do Norte

    2010-01-01

    Plasma is an ionized gas where ions are accelerated from anode to cathode surface, where the sample is placed. There are a lot of collisions on cathode surface by ions heating and sintering the sample. High energy milling (HEM) is often used to produce composite particles to be used on powder metallurgy. These particles can exhibit fine particles and high phase dispersion. This present work aim to study ferritic steels reinforced with 3%NbC prepared by HEM and sintered on plasma furnace. Ferritic steel and NbC powders were milled during 5 hours and characterized by SEM, XRD and laser scattering. Then, these composite powders were compacted in a cylindrical steel die and then sintered in a plasma furnace. Vickers microhardness tests and SEM and XRD analysis were performed on sintered samples. (author)

  11. Obtaining beta phase in Ti through processing in high energy mill powders of Ti and Nb

    International Nuclear Information System (INIS)

    Milanez, Mateus; Ferretto, Aline; Rocha, Marcio Roberto da; Arnt, Angela Coelho; Milanez, Alexandre; Schaeffer, Lirio

    2014-01-01

    An orthopedic implant, ideal, must meet the requirements of biocompatibility, have good mechanical properties among others. Titanium and Niobium exhibit biocompatibility and the β-Ti phase relationships have the highest strength / weight among all titanium alloys, presenting lower values of elastic modulus. The alloy has mechanically produced specific microstructural characteristics and improved mechanical properties compared with conventional powder metallurgy. In this study, a titanium alloy with different additions of niobium was used. The metal powders were mixed via mechanical alloy in high energy mill (attritor). The powder samples were analyzed by X-ray diffraction (X-RD) and property held by adhesive wear testing with a Pin-on-Disk. The present study revealed that through the high-energy milling is possible the atomic interaction between Ti and Nb particles and the mechanical properties are affected by the concentration of Nb. (author)

  12. Synthesis and characterization of FePt nanoparticles by high energy ball milling with and without surfactant

    International Nuclear Information System (INIS)

    Velasco, V.; Martinez, A.; Recio, J.; Hernando, A.; Crespo, P.

    2012-01-01

    Highlights: ► Fe and Pt powders in the presence of surfactants don’t alloyed by HEBM technique. ► FePt alloys obtained by dry milling exhibit particle sizes of around 10 μm. ► FePt alloys obtained by dry milling exhibit soft magnetic behavior. ► A thermal treatment induces a phase transformation from FCC to FCT. - Abstract: FePt nanoparticles were prepared by high energy ball milling (HEBM) in two different ways. In the first one, elemental powders were mixed and milled whereas in the second one the milling was performed in the presence of oleyl amine and oleic acid as surfactants and hexane as a solvent. X-ray diffraction shows that when the milling is performed in dry conditions, Fe and Pt are alloyed after 5 h, whereas in the wet milling procedure alloying does not take place. In the first case, the diffraction pattern corresponds to the disordered FCC phase. This behavior is also corroborated by the evolution of the magnetic characteristics. In the case of the alloy obtained in dry conditions, the powder was heat treated in order to induce the transformation to the ordered phase. Coercivities of 2.5 kOe are obtained after 650 °C for 2 h.

  13. Generation of drugs coated iron nanoparticles through high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Radhika Devi, A.; Murty, B. S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Chelvane, J. A. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Prabhakar, P. K.; Padma Priya, P. V.; Doble, Mukesh [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)

    2014-03-28

    The iron nanoparticles coated with oleic acid and drugs such as folic acid/Amoxicillin were synthesized by high energy ball milling and characterized by X-ray diffraction, Transmission electron microscope, zeta potential, dynamic light scattering, Fourier Transform Infra red (FT-IR) measurements, and thermo gravimetric analysis (TGA). FT-IR and TGA measurements show good adsorption of drugs on oleic acid coated nanoparticles. Magnetic measurements indicate that saturation magnetization is larger for amoxicillin coated particles compared to folic acid coated particles. The biocompatibility of the magnetic nanoparticles prepared was evaluated by in vitro cytotoxicity assay using L929 cells as model cells.

  14. Comparative analysis of niobium and vanadium carbide efficiency in the high energy mechanical milling of aluminum bronze alloy

    Directory of Open Access Journals (Sweden)

    Alexandre Nogueira Ottoboni Dias

    Full Text Available Abstract This study aims to analyze the efficiency of niobium and vanadium carbides in the high energy mechanical milling of aluminum bronze alloy. Two series of experiments were made following the same steps for both niobium carbide (NbC and vanadium carbide (VC additions: 30 g of chips were weighed and placed in a stainless steel jar with 3 % of carbide and 1 % of stearic acid for a mass/sphere relationship of 1:10. The milling was realized using a planetary ball mill for 10, 30 and 50 hours in an inert argon atmosphere at 300 rpm. Results shown in laser diffraction indicate a great reduction in the particle sizes of powders when VC is used. For 30 hours milling, D50 values ranged from 1580 µm with NbC to 182.3 µm with VC addition. The D50 values ranged from 251.5 µm with NbC to 52.26 µm with VC addition, for 50 hours milling. The scanning electron microscopy showed that in 10 hours of milling, the energy was not sufficient to achieve the shear of chips in both cases. For 30 hours, it's possible to observe particles with sizes between 100 µm and 800 µm with NbC addition while for the same milling time, with VC it's possible to see particles with different sizes, but with many shapes of fine particulates. For 50 hours milling, particles achieved the smaller sizes between 50 and 200 µm with NbC and ranging from 5 until 50 µm with VC addition.

  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. Synthesis and characterization of FePt nanoparticles by high energy ball milling with and without surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Velasco, V., E-mail: vvjimeno@fis.ucm.es [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, 28230 Las Rozas (Spain); Martinez, A.; Recio, J. [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, 28230 Las Rozas (Spain); Hernando, A.; Crespo, P. [Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, 28230 Las Rozas (Spain); Dpto. de Fisica de Materiales, UCM, 28040 Madrid (Spain)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer Fe and Pt powders in the presence of surfactants don't alloyed by HEBM technique. Black-Right-Pointing-Pointer FePt alloys obtained by dry milling exhibit particle sizes of around 10 {mu}m. Black-Right-Pointing-Pointer FePt alloys obtained by dry milling exhibit soft magnetic behavior. Black-Right-Pointing-Pointer A thermal treatment induces a phase transformation from FCC to FCT. - Abstract: FePt nanoparticles were prepared by high energy ball milling (HEBM) in two different ways. In the first one, elemental powders were mixed and milled whereas in the second one the milling was performed in the presence of oleyl amine and oleic acid as surfactants and hexane as a solvent. X-ray diffraction shows that when the milling is performed in dry conditions, Fe and Pt are alloyed after 5 h, whereas in the wet milling procedure alloying does not take place. In the first case, the diffraction pattern corresponds to the disordered FCC phase. This behavior is also corroborated by the evolution of the magnetic characteristics. In the case of the alloy obtained in dry conditions, the powder was heat treated in order to induce the transformation to the ordered phase. Coercivities of 2.5 kOe are obtained after 650 Degree-Sign C for 2 h.

  17. 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.)

  18. 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)

  19. Energy conservation achievements by New Shorrock Mills, Ahmedabad

    International Nuclear Information System (INIS)

    Rawal, N.L.; Trivedi, R.M.

    1994-01-01

    The New Shorrock Mills, Ahmedabad is a textile mill manufacturing cloth. Managerial practices like energy auditing and energy conservation monitoring introduced to conserve energy are described. Various measures implemented to conserve energy in machines power; carding, winding, warping and sizing operations; auto looms and lighting power are described. Cost reduction in terms of rupees is given. (N.B.)

  20. 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)

  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. Fabrication and characterization of Cu/YSZ cermet high temperature electrolysis cathode material prepared by high-energy ball-milling method

    International Nuclear Information System (INIS)

    Lee, Sungkyu; Kim, Jong-Min; Hong, Hyun Seon; Woo, Sang-Kook

    2009-01-01

    Cu/YSZ cermet (40 and 60 vol.% Cu powder with balance YSZ) is a more economical cathode material than the conventional Ni/YSZ cermet for high temperature electrolysis (HTE) of water vapor and it was successfully fabricated by high-energy ball-milling of Cu and YSZ powders, pressing into pellets (o 13 mm x 2 mm) and subsequent sintering process at 700 deg. C under flowing 5%-H 2 /Ar gas. The Cu/YSZ composite material thus fabricated was characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured by using 4-probe technique for comparison with that of conventional Ni/YSZ cermets. The effect of composite composition on the electrical conductivity was investigated and a marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold. Also, Cu/YSZ cermet was selected as a candidate for HTE cathode of self-supporting planar unit cell and its electrochemical performance was investigated, paving the way for preliminary correlation of high-energy ball-milling parameters with observed physical and electrochemical performance of Cu/YSZ cermets

  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. Characteristics of Cu–Al2O3 composites of various starting particle size obtained by high-energy milling

    Directory of Open Access Journals (Sweden)

    VIŠESLAVA RAJKOVIĆ

    2009-05-01

    Full Text Available The powder Cu– Al2O3 composites were produced by high-energy milling. Various combinations of particle size and mixtures and approximately constant amount of Al2O3 were used as the starting materials. These powders were separately milled in air for up to 20 h in a planetary ball mill. The copper matrix was reinforced by internal oxidation and mechanical alloying. During the milling, internal oxidation of pre-alloyed Cu-2 mass %-Al powder generated 3.7 mass % Al2O3 nano-sized particles finely dispersed in the copper matrix. The effect of different size of the starting copper and Al2O3 powder particles on the lattice parameter, lattice distortion and grain size, as well as on the size, morphology and microstructure of the Cu– Al2O3 composite powder particles was studied.

  5. Preparation of zinc ferrite nano powders by high energy wet-milling method and investigation of Crystallites size variation during this process

    International Nuclear Information System (INIS)

    Masoudi, H.; Aftabi, A.; Mozafari, M.; Amighian, J.

    2007-01-01

    In this research work ZnFe 2 O 4 nano powders were prepared by high-energy wet-milling process, using metallic Fe and Zn powders. The process was investigated by XRD technique. 10% of the zinc ferrite was formed after 10 h milling. The as-milled sample was annealed at 500, 550 and 600 d egree C . Ultimately a single sample was obtained at 600 d egree C . Using sherrer's formula, the mean crystallite size of the as-milled and annealed powders were calculated. These were in the range of 17.9 to 20.4 nm.

  6. 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.

  7. Minimization of energy and surface roughness of the products machined by milling

    Science.gov (United States)

    Belloufi, A.; Abdelkrim, M.; Bouakba, M.; Rezgui, I.

    2017-08-01

    Metal cutting represents a large portion in the manufacturing industries, which makes this process the largest consumer of energy. Energy consumption is an indirect source of carbon footprint, we know that CO2 emissions come from the production of energy. Therefore high energy consumption requires a large production, which leads to high cost and a large amount of CO2 emissions. At this day, a lot of researches done on the Metal cutting, but the environmental problems of the processes are rarely discussed. The right selection of cutting parameters is an effective method to reduce energy consumption because of the direct relationship between energy consumption and cutting parameters in machining processes. Therefore, one of the objectives of this research is to propose an optimization strategy suitable for machining processes (milling) to achieve the optimum cutting conditions based on the criterion of the energy consumed during the milling. In this paper the problem of energy consumed in milling is solved by an optimization method chosen. The optimization is done according to the different requirements in the process of roughing and finishing under various technological constraints.

  8. Magnetic and frequency properties for nanocrystalline Fe-Ni alloys prepared by high-energy milling method

    International Nuclear Information System (INIS)

    Liu Yongsheng; Zhang Jincang; Yu, Liming; Jia Guangqiang; Jing Chao; Cao Shixun

    2005-01-01

    Fe-based nano-crystalline soft magnetic alloy with Ni-doping was fabricated successfully by high-energy milling. It was proved that a Fe-Ni solid solution is formed and the evaluated average grain size is about 20 nm. The effect of doping Ni on the frequency properties was systematically investigated. From the magnetic measurement results, it can be concluded that, the nickel doped decreases the resonance frequency of Fe-Ni alloy, but Ni doping enhances the frequency stability. The corresponding value of initial permeability as a function of Ni doping concentration was given at 10 kHz and the result indicates that the peak value of initial permeability shifts to the region of low Ni concentration for the samples milled for 72 h

  9. Utilization of aluminum to obtaining a duplex type stainless steel using high energy ball milling

    International Nuclear Information System (INIS)

    Pavlak, I.E.; Cintho, O.M.; Capocchi, J.D.T.

    2010-01-01

    The obtaining of stainless steel using aluminum in its composition - FeMnAl system, has been researches subject since the sixties, by good mechanical properties and resistance to oxidation presented, when compared with conventional FeNiCr stainless steel system. In another point, the aluminum and manganese are low cost then traditional elements. This work, metallic powders of iron, manganese and pure aluminum, were processed in a Spex type high-energy ball mill in nitrogen atmosphere. The milling products were compressed into pastille form and sintered under inert atmosphere. The final products were characterized by optical and electronic microscopy and microhardness test. The metallographic analysis shows a typical austenite and ferrite duplex type microstructure. The presence of these phases was confirmed according X ray diffraction analysis. (author)

  10. 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)

  11. Morphology and magnetic properties of CeCo5 submicron flakes prepared by surfactant-assisted high-energy ball milling

    International Nuclear Information System (INIS)

    Zhang, J.J.; Gao, H.M.; Yan, Y.; Bai, X.; Su, F.; Wang, W.Q.; Du, X.B.

    2012-01-01

    CeCo 5 permanent magnetic alloy has been processed by surfactant assisted high energy ball milling. Heptane and oleic acid were used as the solvent and surfactant, respectively. The amount of surfactant used was 50% by weight of the starting powder. The produced particles were deposited on a piece of copper (4 mm in length and width) under a magnetic field of 27 kOe applied along the copper surface and immobilized by ethyl α-cyanoacrylate. Scanning electron microscope pictures show that the particles are flakes, several μm in length and width and tens of nm in thickness. X-ray diffraction patterns and magnetic measurements prove that the flakes are crystalline with c-axes magnetic anisotropy. The easy magnetization axis is oriented perpendicular to the surface of the flake. A maximum coercivity of 3.3 kOe was obtained for the sample milled for 40 min. - Highlights: ► CeCo 5 permanent magnetic alloy has been processed by surfactant assisted high energy ball milling (HEBM). ► The particles show a flake-like morphology with several μm in length and width and tens nm in thickness. ► The flakes are crystallographic and magnetic anisotropic and the c-axes, also the easy magnetization directions are oriented perpendicular to the surface of the flake. ► Maximum coercivity of 3.3 kOe has been obtained for the sample milled for 40 min.

  12. 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.

  13. Synthesis of Ni3Ta, Ni2Ta and NiTa by high-energy ball milling and subsequent heat treatment

    International Nuclear Information System (INIS)

    Benites, H.S.N.; Silva, B.P da; Ramos, A.S.; Silva, A.A.A.P.; Coelho, G.C.; Lima, B.B. de

    2014-01-01

    The tantalum has relevance for the development of multicomponent Ni-based superalloys which are hardened by solid solution and precipitation mechanisms. Master alloys are normally used in the production step in order to produce refractory metals and alloys. The present work reports on the synthesis of Ni_3Ta, Ni_2Ta and NiTa by high-energy ball milling and subsequent heat treatment. The elemental Ni-25Ta, Ni-33Ta and Ni-50Ta (at.-%) powder mixtures were ball milled under Ar atmosphere using stainless steel balls and vials, 300 rpm and a ball-to-powder weight ratio of 10:1. Following, the as-milled samples were uniaxially compacted and heat-treated at 1100 deg C for 4h under Ar atmosphere. The characterization of as-milled and heat-treated samples was conducted by means of X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. A large amount of Ni_3Ta, Ni_2Ta and NiTa was formed in the mechanically alloyed heat-treated Ni-25Ta, Ni-33Ta and Ni-50Ta alloys. (author)

  14. Morphology and magnetic properties of CeCo{sub 5} submicron flakes prepared by surfactant-assisted high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.J.; Gao, H.M.; Yan, Y.; Bai, X.; Su, F.; Wang, W.Q. [State key Laboratory for Superhard Materials and Department of Physics, Jilin University, Changchun 130012 (China); Du, X.B., E-mail: duxb@jlu.edu.cn [State key Laboratory for Superhard Materials and Department of Physics, Jilin University, Changchun 130012 (China)

    2012-10-15

    CeCo{sub 5} permanent magnetic alloy has been processed by surfactant assisted high energy ball milling. Heptane and oleic acid were used as the solvent and surfactant, respectively. The amount of surfactant used was 50% by weight of the starting powder. The produced particles were deposited on a piece of copper (4 mm in length and width) under a magnetic field of 27 kOe applied along the copper surface and immobilized by ethyl {alpha}-cyanoacrylate. Scanning electron microscope pictures show that the particles are flakes, several {mu}m in length and width and tens of nm in thickness. X-ray diffraction patterns and magnetic measurements prove that the flakes are crystalline with c-axes magnetic anisotropy. The easy magnetization axis is oriented perpendicular to the surface of the flake. A maximum coercivity of 3.3 kOe was obtained for the sample milled for 40 min. - Highlights: Black-Right-Pointing-Pointer CeCo{sub 5} permanent magnetic alloy has been processed by surfactant assisted high energy ball milling (HEBM). Black-Right-Pointing-Pointer The particles show a flake-like morphology with several {mu}m in length and width and tens nm in thickness. Black-Right-Pointing-Pointer The flakes are crystallographic and magnetic anisotropic and the c-axes, also the easy magnetization directions are oriented perpendicular to the surface of the flake. Black-Right-Pointing-Pointer Maximum coercivity of 3.3 kOe has been obtained for the sample milled for 40 min.

  15. Boson-fermion and boson-boson scattering in a Yang-Mills theory at high energy: Sixth-order perturbation theory

    International Nuclear Information System (INIS)

    McCoy, B.M.; Wu, T.T.

    1976-01-01

    Our previous study of Yang-Mills fields is extended by calculating the high-energy behavior of the boson-fermion and of the boson-boson amplitude in sixth-order perturbation theory. In the isovector and isoscalar channels of both these processes the behavior of the amplitude is the same as that found in fermion-fermion scattering

  16. Fabrication mechanism of FeSe superconductors with high-energy ball milling aided sintering process

    International Nuclear Information System (INIS)

    Zhang, Shengnan; Liu, Jixing; Feng, Jianqing; Wang, Yao; Ma, Xiaobo; Li, Chengshan; Zhang, Pingxiang

    2015-01-01

    FeSe Superconducting bulks with high content of superconducting PbO-type β-FeSe phase were prepared with high-energy ball milling (HEBM) aided sintering process. During this process, precursor powders with certain Fe/Se ratio were ball milled first then sintered. The influences of HEBM process as well as initial Fe/Se ratio on the phase evolution process were systematically discussed. With HEBM process and proper initial Fe/Se ratio, the formation of non-superconducting hexagonal δ-FeSe phase were effectively avoided. FeSe bulk with the critical temperature of 9.0 K was obtained through a simple one-step sintering process with lower sintering temperature. Meanwhile, the phase evolution mechanism of the HEBM precursor powders during sintering was deduced based on both the thermodynamic analysis and step-by-step sintering results. The key function of the HEBM process was to provide a high uniformity of chemical composition distribution, thus to successfully avoide the formation of intermediate product during sintering, including FeSe 2 and Fe 7 Se 8 . Therefore, the fundamental principal for the synthesis of FeSe superconductors were concluded as: HEBM aided sintering process, with the sintering temperature of >635 °C and a slow cooling process. - Highlights: • A novel synthesis technique was developed for FeSe based superconductors. • FeSe bulks with high Tc and high β-FeSe phase content has been obtained. • Phase evolution process for the HEBM aided sintering process was proposed

  17. 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

  18. N=4 supersymmetric Yang Mills scattering amplitudes at high energies. The Regge cut contribution

    International Nuclear Information System (INIS)

    Bartels, J.; Sabio Vera, A.

    2008-07-01

    We further investigate, in N=4 supersymmetric Yang Mills theories, the high energy Regge behavior of six-point scattering amplitudes. In particular, for the new Regge cut contribution found in our previous paper, we compute in the leading logarithmic approximation (LLA) the energy spectrum of the BFKL equation in the color octet channel, and we calculate explicitly the two loop corrections to the discontinuities of the amplitudes for the transitions 2→4 and 3→3. We find an explicit solution of the BFKL equation for the octet channel for arbitrary momentum transfers and investigate the intercepts of the Regge singularities in this channel. As an important result we find that the universal collinear and infrared singularities of the BDS formula are not affected by this Regge-cut contribution. (orig.)

  19. A morphological evaluation of a duplex stainless steel processed by high energy Ball Mill

    International Nuclear Information System (INIS)

    Yonekubo, Ariane Emi; Cintho, Osvaldo Mitsuyuki; Aguiar, Denilson Jose Marcolino de; Capocchi, Jose Deodoro Trani

    2009-01-01

    The duplex stainless steels are formed by a ferrite and austenite mixture, giving them a combination of properties. Commercially, these steels are hot rolled, developing an anisotropic, alternated ferrite and austenite elongated lamellae microstructure. In this work, a duplex stainless steel was produced by the mixture of elementary powders with the composition Fe-19.5Cr-5Ni processed in an ATTRITOR ball mill during periods up to 15 hours. The powders obtained were compressed in specimens and were heat treated in the temperatures of 900, 1050 and 1200 °C during 1 hour and analysed by x ray diffraction, optic microscopy, scanning electron microscopy and energy dispersion spectroscopy. An optimized microstructure with ultrafine, equiaxial and regular duplex microstructure was obtained in the 15 hour milling and 1200 °C heat treatment. Afterwards, a commercially super duplex stainless steel UNS S32520 was aged at 800 °C aiming the precipitation of σ phase in order to reduce its toughness and then, milled in SPEX mill. The resulting microstructure was a very fine duplex type with irregular grain boundary morphology duo to the grain growth barrier promoted by the renascent σ phase particles during sintering process. (author)

  20. Synthesis of stoichiometric Ca{sub 2}Fe{sub 2}O{sub 5} nanoparticles by high-energy ball milling and thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, B.F.; Morales, M.A.; Bohn, F.; Carriço, A.S. [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Medeiros, S.N. de, E-mail: sndemedeiros@gmail.com [Departamento de Física Teórica e Experimental, Universidade Federal do Rio Grande do Norte, 59078-900 Natal, RN (Brazil); Dantas, A.L. [Departamento de Física, Universidade do Estado do Rio Grande do Norte, 59610-210 Mossoró, RN (Brazil)

    2016-05-01

    We report the synthesis of Ca{sub 2}Fe{sub 2}O{sub 5} nanoparticles by high-energy ball milling and thermal annealing from α-Fe{sub 2}O{sub 3} and CaCO{sub 3}. Magnetization measurements, Mössbauer and X-ray spectra reveal that annealing at high temperatures leads to better quality samples. Our results indicate nanoparticles produced by 10 h high-energy ball milling and thermal annealing for 2 h at 1100 °C achieve improved stoichiometry and the full weak ferromagnetic signal of Ca{sub 2}Fe{sub 2}O{sub 5}. Samples annealed at lower temperatures show departure from stoichiometry, with a higher occupancy of Fe{sup 3+} in octahedral sites, and a reduced magnetization. Thermal relaxation for temperatures in the 700–1100 °C range is well represented by a Néel model, assuming a random orientation of the weak ferromagnetic moment of the Ca{sub 2}Fe{sub 2}O{sub 5} nanoparticles.

  1. Nitrogen-doped graphene by ball-milling graphite with melamine for energy conversion and storage

    International Nuclear Information System (INIS)

    Xue, Yuhua; Chen, Hao; Qu, Jia; Dai, Liming

    2015-01-01

    N-doped graphene was prepared by ball milling of graphite with melamine. It was found that ball-milling reduced the size of graphite particles from 30 to 1 μm and facilitated the exfoliation of the resultant small particles into few-layer N-doped graphene nanosheets under ultrasonication. The as-prepared N-doped graphene nanoplatelets (NGnPs) exhibited a nitrogen content as high as 11.4 at.%, making them attractive as efficient electrode materials in supercapacitors for energy storage and as highly-active metal-free catalysts for oxygen reduction in fuel cells for energy conversion. (paper)

  2. 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

  3. Eden Mills Community Hall energy audit prepared for Eden Mills going carbon neutral

    Energy Technology Data Exchange (ETDEWEB)

    Lay, R.; Aussant, C. [Enermodal Engineering Ltd., Kitchener, ON (Canada)

    2009-04-22

    This paper described an energy audit conducted as part of the Eden Mills going carbon neutral project during the spring and summer of 2008. The audit included an inspection of the Eden Mills community hall with a special focus on the building's mechanical system and building envelope. A blower door test was performed to depressurize the building and to measure the airtightness of the building envelope. An energy simulation model was then used to estimate energy use according to the buildings functions and components. Recommendations included the addition of wall insulation, the replacement of some windows, and improved return air ducting and warm air distribution systems. Various new thermostat control systems were also recommended, as well as the use of wood pellets in one of the hall's 2 furnaces. 20 tabs., 28 figs.

  4. SnSe/carbon nanocomposite synthesized by high energy ball milling as an anode material for sodium-ion and lithium-ion batteries

    International Nuclear Information System (INIS)

    Zhang, Zhian; Zhao, Xingxing; Li, Jie

    2015-01-01

    Graphical abstract: A homogeneous nanocomposite of SnSe and carbon black was synthesised by high energy ball milling and empolyed as an anode material for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). The nanocomposite anode exhibits excellent electrochemical performances in both SIBs and LIBs. - Highlights: • A homogeneous nanocomposite of SnSe and carbon black was fabricated by high energy ball milling. • SnSe and carbon black are homogeneously mixed at the nanoscale level. • The SnSe/C anode exhibits excellent electrochemical performances in both SIBs and LIBs. - Abstract: A homogeneous nanocomposite of SnSe and carbon black, denoted as SnSe/C nanocomposite, was fabricated by high energy ball milling and empolyed as a high performance anode material for both sodium-ion batteries and lithium-ion batteries. The X-ray diffraction patterns, scanning electron microscopy and transmission electron microscopy observations confirmed that SnSe in SnSe/C nanocomposite was homogeneously distributed within carbon black. The nanocomposite anode exhibited enhanced electrochemical performances including a high capacity, long cycling behavior and good rate performance in both sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs). In SIBs, an initial capacitiy of 748.5 mAh g −1 was obtained and was maintained well on cycling (324.9 mAh g −1 at a high current density of 500 mA g −1 in the 200 th cycle) with 72.5% retention of second cycle capacity (447.7 mAh g −1 ). In LIBs, high initial capacities of approximately 1097.6 mAh g −1 was obtained, and this reduced to 633.1 mAh g −1 after 100 cycles at 500 mA g −1

  5. 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

  6. Simulation of ball motion and energy transfer in a planetary ball mill

    International Nuclear Information System (INIS)

    Lu Sheng-Yong; Mao Qiong-Jing; Li Xiao-Dong; Yan Jian-Hua; Peng Zheng

    2012-01-01

    A kinetic model is proposed for simulating the trajectory of a single milling ball in a planetary ball mill, and a model is also proposed for simulating the local energy transfer during the ball milling process under no-slip conditions. Based on the kinematics of ball motion, the collision frequency and power are described, and the normal impact forces and effective power are derived from analyses of collision geometry. The Hertzian impact theory is applied to formulate these models after having established some relationships among the geometric, dynamic, and thermophysical parameters. Simulation is carried out based on two models, and the effects of the rotation velocity of the planetary disk Ω and the vial-to-disk speed ratio ω/Ω on other kinetic parameters is investigated. As a result, the optimal ratio ω/Ω to obtain high impact energy in the standard operating condition at Ω = 800 rpm is estimated, and is equal to 1.15. (interdisciplinary physics and related areas of science and technology)

  7. Energy Efficiency Feasibility Study and Resulting Plan for the Bay Mills Indian Community

    Energy Technology Data Exchange (ETDEWEB)

    Kushman, Chris [Inter-Tribal Council of Michigan, Inc., Sault Ste. Marie, MI (United States). Environmental Services Division

    2014-03-01

    In 2011 the Inter-Tribal Council of Michigan, Inc. was awarded an Energy Efficiency Development and Deployment in Indian Country grant from the U.S. Department of Energy’s Tribal Energy Program. This grant aimed to study select Bay Mills Indian Community community/government buildings to determine what is required to reduce each building’s energy consumption by 30%. The Bay Mills Indian Community (BMIC) buildings with the largest expected energy use were selected for this study and included the Bay Mills Ellen Marshall Health Center building, Bay Mills Indian Community Administration Building, Bay Mills Community College main campus, Bay Mills Charter School and the Waishkey Community Center buildings. These five sites are the largest energy consuming Community buildings and comprised the study area of this project titled “Energy Efficiency Feasibility Study and Resulting Plan for the Bay Mills Indian Community”. The end objective of this study, plan and the Tribe is to reduce the energy consumption at the Community’s most energy intensive buildings that will, in turn, reduce emissions at the source of energy production, reduce energy expenditures, create long lasting energy conscious practices and positively affect the quality of the natural environment. This project’s feasibility study and resulting plan is intended to act as a guide to the Community’s first step towards planned energy management within its buildings/facilities. It aims to reduce energy consumption by 30% or greater within the subject facilities with an emphasis on energy conservation and efficiency. The energy audits and related power consumption analyses conducted for this study revealed numerous significant energy conservation and efficiency opportunities for all of the subject sites/buildings. In addition, many of the energy conservation measures require no cost and serve to help balance other measures requiring capital investment. Reoccurring deficiencies relating to heating

  8. Study of the viability to obtain quasicrystal in the composition AlCuFe using high-energy milling, followed by pressing and sintering

    International Nuclear Information System (INIS)

    Coelho, Rodrigo Estevam; Cruz, Ramon Mateus Santos; Esteves, Paulo Jesus Costa; Viana, Silvana Garcia; Lima, Severino Jackson Guedes de

    2009-01-01

    This work was observed the phase formations of the mixture Al-Cu-Fe processed vial mechanical alloying, powders pressing at room temperature and subsequent heat treatment. The mixture of powders was made on the nominal composition Al 65 Cu 2 0Fe 15 . A mill of high energy of the horizontal atrittor type was used to process the powders mixtures, in fixed time of two hours of milling. After milling, the powders were pressing in a die closed, with a diameter of about 28mm. The samples were observed by optical microscopy and analyzed X-ray diffractometry. The results obtained in this study provide a basis for setting parameters may be used as a basis for future research and possible applications. (author)

  9. 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.

  10. The effect of surfactant addition on high-energy milling upon the magnetic properties and microstructure of the Pr-Fe-B HDDR magnetic powders

    International Nuclear Information System (INIS)

    Santos, P.B.; Silva, S.C.; Faria, R.N.; Takiishia, H.

    2010-01-01

    Nanomagnetic powders based on the composition Pr 12 Fe 65.9 Co 16 B 6 Nb 0.1 have been obtained from using (a) the hydrogenation, disproportionation, desorption and recombination (HDDR) process; (b) by varying of milling time and (c) with the addition of an oleic acid as a surfactant. The latter has been used to enhance milling condition by preventing the agglomeration of particles and hence to improve the intrinsic coercivity of the material. High-energy mechanical milling has been used to yield magnetic nanoparticles. Powders were characterized magnetically using vibrating sample magnetometer (VSM) and microstructurally by Scanning Electron Microscopy (SEM), Field Emission Gun SEM (FEG-SEM) and X-ray diffraction. (author)

  11. Dehydriding and re-hydriding properties of high-energy ball milled LiBH{sub 4}+MgH{sub 2} mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, Kyle; Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136, Storrs, CT 06269 (United States)

    2010-07-15

    Here we report the first investigation of the dehydriding and re-hydriding properties of 2LiBH{sub 4} + MgH{sub 2} mixtures in the solid state. Such a study is made possible by high-energy ball milling of 2LiBH{sub 4}+MgH{sub 2} mixtures at liquid nitrogen temperature with the addition of graphite. The 2LiBH{sub 4}+MgH{sub 2} mixture ball milled under this condition exhibits a 5-fold increase in the released hydrogen at 265 C when compared with ineffectively ball milled counterparts. Furthermore, both LiBH{sub 4} and MgH{sub 2} contribute to hydrogen release in the solid state. The isothermal dehydriding/re-hydriding cycles at 265 C reveal that re-hydriding is dominated by re-hydriding of Mg. These unusual phenomena are explained based on the formation of nanocrystalline and amorphous phases, the increased defect concentration in crystalline compounds, and possible catalytic effects of Mg,MgH{sub 2} and LiBH{sub 4} on their dehydriding and re-hydriding properties. (author)

  12. 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.

  13. Production of pyrite nanoparticles using high energy planetary ball milling for sonocatalytic degradation of sulfasalazine.

    Science.gov (United States)

    Khataee, Alireza; Fathinia, Siavash; Fathinia, Mehrangiz

    2017-01-01

    Sonocatalytic performance of pyrite nanoparticles was evaluated by the degradation of sulfasalazine (SSZ). Pyrite nanoparticles were produced via a high energy mechanical ball milling (MBM) in different processing time from 2h to 6h, in the constant milling speed of 320rpm. X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR) analysis and Brunauer-Emmett-Teller (BET) confirmed the production of pyrite nanoparticles during 6h of ball milling with the average size distribution of 20-80nm. The effects of various operational parameters including pH value, catalyst amount (mg/L), SSZ concentration (mg/L), ultrasonic frequency (kHz) and reaction time on the SSZ removal efficiency were examined. The obtained results showed that the maximum removal efficiency of 97.00% was obtained at pH value of 4, catalyst dosage of 0.5g/L, SSZ concentration of 10mg/L and reaction time of 30min. Experimental results demonstrated that the kinetic of the degradation process can be demonstrated using Langmuir-Hinshelwood (L-H) kinetic model. The effect of different inorganic ions such as Cl - , CO 3 2- and SO 4 2- was investigated on the L-H reaction rate (k r ) and adsorption (K s ) constants. Results showed that the presence of the mentioned ions significantly influenced the L-H constants. The impact of ethanol as a OH radical scavenger and some enhancers including H 2 O 2 and K 2 S 2 O 8 was investigated on the SSZ removal efficiency. Accordingly, the presence of ethanol suppressed SSZ degradation due to the quenching of OH radicals and the addition of K 2 S 2 O 8 and H 2 O 2 increased the SSZ removal efficiency, due to the formation of SO 4 - and additional OH radicals, respectively. Under the identical conditions of operating parameters, pyrite nanoparticles maintained their catalytic activity during four consecutive runs. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Synthesizing Zno Nanoparticles by High-Energy Milling and Investigating Their Antimicrobial Effect

    Directory of Open Access Journals (Sweden)

    N Mohammadi

    2015-07-01

    Results: The study results demonstrated that size of the synthesized nanoparticles was within the range of 20 -90 nm and their morphology was reported as nanorod and nanoparticles with multifaceted cross-section. An increase in the density of nanoparticles resulted in a rise in the antimicrobial effect. Moreover, Staphylococcus aureus bacteria inhibition zone was 3±0.5 and 7±0.5 mm respectively at the density of 6 and 10 mM. The MIC and MBC of ZnO nanoparticles provided for Staphylococcus aureus were observed 3±3 and 2.5±0 mg/ml, whereas they were reported 7.5±0 and 8±0 mg/ml for Escherichia coli bacteria. Conclusion: The findings of the present study revealed that ZnO nanomaterials could be synthesized by applying high-energy milling on micron-scaled ZnO particles. In addition, they can be utilized in food packaging and preservation process.

  15. 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

  16. Analysis of crystallite size and microdeformation crystal lattice the tungsten carbide milling in mill high energy; Analise do tamanho do cristalito e microdeformacao da rede cristalina do carbeto de tugstenio moidos em moinho de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva, F.T. da; Nunes, M.A.M. [Universidade Federal do Rio Grande do Norte (PPGCEM/UFRN), Natal (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Oliveira, R.M.V. de; Silva, G.G. da [Instituto Federal do Rio Grande do Norte (IFRN), Natal (Brazil); Souza, C.P. de; Gomes, U.U. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil)

    2010-07-01

    The tungsten carbide (WC) has wide application due to its properties like high melting point, high hardness, wear resistance, oxidation resistance and good electrical conductivity. The microstructural characteristics of the starting powders influences the final properties of the carbide. In this context, the use of nanoparticle powders is an efficient way to improve the final properties of the WC. The high energy milling stands out from other processes to obtain nanometric powders due to constant microstructural changes caused by this process. Therefore, the objective is to undertake an analysis of microstructural characteristics on the crystallite size and microdeformations of the crystal lattice using the technique of X-ray diffraction (XRD) using the Rietveld refinement. The results show an efficiency of the milling process to reduce the crystallite size, leading to a significant deformation in the crystal lattice of WC from 5h milling. (author)

  17. A novel fabrication technology of in situ TiB2/6063Al composites: High energy ball milling and melt in situ reaction

    International Nuclear Information System (INIS)

    Zhang, S.-L.; Yang, J.; Zhang, B.-R.; Zhao, Y.-T.; Chen, G.; Shi, X.-X.; Liang, Z.-P.

    2015-01-01

    Highlights: • This paper presents a novel technology to fabricate the TiB 2 /6063Al composites. • The novel technology decreases in situ reaction temperature and shortens the time. • The reaction mechanism of in situ reaction at the low temperature is discussed. • Effect of ball milling time and in situ reaction time on the composites is studied. - Abstract: TiB 2 /6063Al matrix composites are fabricated from Al–TiO 2 –B 2 O 3 system by the technology combining high energy ball milling with melt in situ reaction. The microstructure and tensile properties of the composites are investigated by XRD, SEM, EDS, TEM and electronic tensile testing. The results indicate that high energy ball milling technology decreases the in situ reaction temperature and shortens the reaction time for Al–TiO 2 –B 2 O 3 system in contrast with the conventional melt in situ synthesis. The morphology of in situ TiB 2 particles is exhibited in irregular shape or nearly circular shape, and the average size of the particles is less than 700 nm, thereinto the minimum size is approximately 200 nm. In addition, the morphology and size of the reinforced particles are affected by the time of ball milling and in situ reaction. TEM images indicate that the interface between 6063Al matrix and TiB 2 particles is clear and no interfacial outgrowth is observed. Tensile testing results show that the as-cast TiB 2 /6063Al composites exhibit a much higher strength, reaching 191 MPa, which is 1.23 times as high as the as-cast 6063Al matrix. Besides, the tensile fracture surface of the composites displays the dimple-fracture character

  18. Morphology and magnetic properties of CeCo5 submicron flakes prepared by surfactant-assisted high-energy ball milling

    Science.gov (United States)

    Zhang, J. J.; Gao, H. M.; Yan, Y.; Bai, X.; Su, F.; Wang, W. Q.; Du, X. B.

    2012-10-01

    CeCo5 permanent magnetic alloy has been processed by surfactant assisted high energy ball milling. Heptane and oleic acid were used as the solvent and surfactant, respectively. The amount of surfactant used was 50% by weight of the starting powder. The produced particles were deposited on a piece of copper (4 mm in length and width) under a magnetic field of 27 kOe applied along the copper surface and immobilized by ethyl α-cyanoacrylate. Scanning electron microscope pictures show that the particles are flakes, several μm in length and width and tens of nm in thickness. X-ray diffraction patterns and magnetic measurements prove that the flakes are crystalline with c-axes magnetic anisotropy. The easy magnetization axis is oriented perpendicular to the surface of the flake. A maximum coercivity of 3.3 kOe was obtained for the sample milled for 40 min.

  19. 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.

  20. Study of the sintering behavior of fine, ultrafine and nanocrystalline WC-CO mixtures obtained by high energy milling

    International Nuclear Information System (INIS)

    Salvador, M. D.; Bonache, V.; Amigo, V.; Busquets, D.

    2008-01-01

    In this work the sintering behaviour of fine, ultrafine and nanocrystalline WC-12Co mixtures obtained by high energy milling, as well commercial nano powders, have been studied, in order to evaluate the effect of the particle size and the powder processing, in the densification, microstructural development and mechanical properties of the final product. The consolidation of the mixtures has been made by uniaxial pressing and sintering in vacuum, and by hot isostatic pressing. The sintered materials have been evaluated by measures of density, hardness and indentation fracture toughness, and micro structurally characterized by optical microscopy and scanning and transmission electronic microscopy (SEM and TEM). The results show the improvements in resistant behaviour of the materials obtained from nanocrystalline powders, in spite of the grain growth experienced during the sintering. The best results were obtained for the milling nanocrystalline material, which presents values of hardness higher than 180 HV. (Author) 46 refs

  1. 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.

  2. Improving mine-mill water network design by reducing water and energy requirements

    Energy Technology Data Exchange (ETDEWEB)

    Gunson, A.J.; Klein, B.; Veiga, M. [British Columbia Univ., Vancouver, BC (Canada). Norman B. Keevil Inst. of Mining Engineering

    2010-07-01

    Mining is an energy-intensive industry, and most processing mills use wet processes to separate minerals from ore. This paper discussed water reduction, reuse and recycling options for a mining and mill operation network. A mine water network design was then proposed in order to identify and reduce water and system energy requirements. This included (1) a description of site water balance, (2) a description of potential water sources, (3) a description of water consumers, (4) the construction of energy requirement matrices, and (5) the use of linear programming to reduce energy requirements. The design was used to determine a site water balance as well as to specify major water consumers during mining and mill processes. Potential water supply combinations, water metering technologies, and recycling options were evaluated in order to identify the most efficient energy and water use combinations. The method was used to highlight potential energy savings from the integration of heating and cooling systems with plant water systems. 43 refs., 4 tabs., 3 figs.

  3. 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.

  4. 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.

  5. Correlation of gas sensitivite properties with microstructure of Fe2O3-SnO2 ceramics prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lu, S.W.; Zhou, Y.X.

    1997-01-01

    A remarkable gas sensitivity to ethnaol gas has been observed in nanostructured Fe2O3-SnO2 materials with a composition of 6.4 mol% SnO2 prepared by high energy ball milling. The microstructure of the materials has been examined by x-ray diffraction (XRD) and Mossbauer spectroscopy. It was found...

  6. A novel fabrication technology of in situ TiB{sub 2}/6063Al composites: High energy ball milling and melt in situ reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.-L.; Yang, J. [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Zhang, B.-R. [School of Mechanical Engineering, Qilu University of Technology, Jinan, Shandong 250022 (China); Zhao, Y.-T., E-mail: 278075525@qq.com [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China); Chen, G.; Shi, X.-X.; Liang, Z.-P. [School of Materials Science and Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013 (China)

    2015-08-05

    Highlights: • This paper presents a novel technology to fabricate the TiB{sub 2}/6063Al composites. • The novel technology decreases in situ reaction temperature and shortens the time. • The reaction mechanism of in situ reaction at the low temperature is discussed. • Effect of ball milling time and in situ reaction time on the composites is studied. - Abstract: TiB{sub 2}/6063Al matrix composites are fabricated from Al–TiO{sub 2}–B{sub 2}O{sub 3} system by the technology combining high energy ball milling with melt in situ reaction. The microstructure and tensile properties of the composites are investigated by XRD, SEM, EDS, TEM and electronic tensile testing. The results indicate that high energy ball milling technology decreases the in situ reaction temperature and shortens the reaction time for Al–TiO{sub 2}–B{sub 2}O{sub 3} system in contrast with the conventional melt in situ synthesis. The morphology of in situ TiB{sub 2} particles is exhibited in irregular shape or nearly circular shape, and the average size of the particles is less than 700 nm, thereinto the minimum size is approximately 200 nm. In addition, the morphology and size of the reinforced particles are affected by the time of ball milling and in situ reaction. TEM images indicate that the interface between 6063Al matrix and TiB{sub 2} particles is clear and no interfacial outgrowth is observed. Tensile testing results show that the as-cast TiB{sub 2}/6063Al composites exhibit a much higher strength, reaching 191 MPa, which is 1.23 times as high as the as-cast 6063Al matrix. Besides, the tensile fracture surface of the composites displays the dimple-fracture character.

  7. Influence of B4C-doping and high-energy ball milling on phase formation and critical current density of (Bi,Pb)-2223 HTS

    Science.gov (United States)

    Margiani, N. G.; Mumladze, G. A.; Adamia, Z. A.; Kuzanyan, A. S.; Zhghamadze, V. V.

    2018-05-01

    In this paper, the combined effects of B4C-doping and planetary ball milling on the phase evolution, microstructure and transport properties of Bi1.7Pb0.3Sr2Ca2Cu3Oy(B4C)x HTS with x = 0 ÷ 0.125 were studied through X-ray diffraction (XRD), scanning electron microscopy (SEM), resistivity and critical current density measurements. Obtained results have shown that B4C additive leads to the strong acceleration of high-Tc phase formation and substantial enhancement in Jc. High-energy ball milling seems to produce a more homogeneous distribution of refined doped particles in the (Bi,Pb)-2223 HTS which results in an improved intergranular flux pinning and better self-field Jc performance.

  8. Effects of processing parameters on the synthesis of (K0.5Na0.5)NbO3 nanopowders by reactive high-energy ball milling method.

    Science.gov (United States)

    Nguyen, Duc Van

    2014-01-01

    The effects of ball milling parameters, namely, the ball-to-powder mass ratio and milling speed, on the synthesis of (K0.5Na0.5)NbO3 nanopowders by high-energy ball milling method from a stoichiometric mixture containing Na2CO3, K2CO3, and Nb2O5 were investigated in this paper. The results indicated that the single crystalline phase of (K0.5Na0.5)NbO3 was received in as-milled samples synthesized using optimized ball-to-powder mass ratio of 35 : 1 and at a milling speed of 600 rpm for 5 h. In the optimized as-milled samples, no remaining alkali carbonates that can provide the volatilizable potassium-containing species were found and (K0.5Na0.5)NbO3 nanopowders were readily obtained via the formation of an intermediate carbonato complex. This complex was mostly transformed into (K0.5Na0.5)NbO3 at temperature as low as 350°C and its existence was no longer detected at spectroscopic level when calcination temperature crossed over 700°C.

  9. 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.

  10. 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

  11. 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.

  12. Dispersion of silicon carbide nanoparticles in a AA2024 aluminum alloy by a high-energy ball mill

    International Nuclear Information System (INIS)

    Carreño-Gallardo, C.; Estrada-Guel, I.; López-Meléndez, C.; Martínez-Sánchez, R.

    2014-01-01

    Highlights: • Synthesis of 2024-SiC NP nanocomposite by mechanical milling process. • SiC nanoparticles improved mechanical properties of aluminum alloy 2024 matrix. • A homogeneous distribution of SiC nanoparticles were observed in the matrix • Compressive and hardness properties of the composite are improved significantly. -- Abstract: Al 2024 alloy was reinforced with silicon carbide nanoparticles (SiC NP ), whose concentration was varied in the range from 0 to 5 wt.%; some composites were synthesized with the mechanical milling (MM) process. Structure and microstructure of the consolidated samples were studied by X-ray diffraction and transmission electron microscopy, while mechanical properties were investigated by compressive tests and hardness measurements. The microstructural evidence shows that SiC NP were homogeneously dispersed into the Al 2024 alloy using high-energy MM after 2 h of processing. On the other hand, an increase of the mechanical properties (yield stress, maximum strength and hardness) was observed in the synthesized composites as a direct function of the SiC NP content. In this research several strengthening mechanisms were observed, but the main was the obstruction of dislocations movement by the addition of SiC NP

  13. New alternative energy pathway for chemical pulp mills: From traditional fibers to methane production.

    Science.gov (United States)

    Rodriguez-Chiang, Lourdes; Vanhatalo, Kari; Llorca, Jordi; Dahl, Olli

    2017-07-01

    Chemical pulp mills have a need to diversify their end-product portfolio due to the current changing bio-economy. In this study, the methane potential of brown, oxygen delignified and bleached pulp were evaluated in order to assess the potential of converting traditional fibers; as well as microcrystalline cellulose and filtrates; to energy. Results showed that high yields (380mL CH 4 /gVS) were achieved with bleached fibers which correlates with the lower presence of lignin. Filtrates from the hydrolysis process on the other hand, had the lowest yields (253mL CH 4 /gVS) due to the high amount of acid and lignin compounds that cause inhibition. Overall, substrates had a biodegradability above 50% which demonstrates that they can be subjected to efficient anaerobic digestion. An energy and cost estimation showed that the energy produced can be translated into a significant profit and that methane production can be a promising new alternative option for chemical pulp mills. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Potential for reducing paper mill energy use and carbon dioxide emissions through plant-wide energy audits: A case study in China

    International Nuclear Information System (INIS)

    Kong, Lingbo; Price, Lynn; Hasanbeigi, Ali; Liu, Huanbin; Li, Jigeng

    2013-01-01

    Highlights: ► We audited a paper mill in China to reduce its energy use and CO 2 emissions. ► The energy use and CO 2 emissions of the mill and each paper machine are presented. ► The energy saving potential for the paper machine is estimated at 8–37%. ► The energy saving potential is 967.8 TJ, equal to 14.4% of the mill’s energy use. ► The CO 2 reduction potential is 93,453 tonnes CO 2 for the studied paper mill. -- Abstract: The pulp and paper industry is one of the most energy-intensive industries worldwide. In 2007, it accounted for 5% of total global industrial energy consumption and 2% of direct industrial carbon dioxide (CO 2 ) emissions. An energy audit is a primary step toward improving energy efficiency at the facility level. This paper describes a plant-wide energy audit aimed at identifying energy conservation and CO 2 mitigation opportunities at a paper mill in Guangdong province, China. We describe the energy audit methods, relevant Chinese standards, methods of calculating energy and carbon indicators, baseline energy consumption and CO 2 emissions of the audited paper mill, and nine energy-efficiency improvement opportunities identified by the audit. For each of the nine options, we evaluate the energy conservation and associated CO 2 mitigation potential. The total technical energy conservation potential for these nine opportunities is 967.8 terajoules (TJ), and the total CO 2 mitigation potential is equal to 93,453 tonnes CO 2 annually, representing 14.4% and 14.7%, respectively, of the mill’s total energy consumption and CO 2 emissions during the audit period.

  15. Fabrication and characterization of Cu/YSZ cermet high-temperature electrolysis cathode material prepared by high-energy ball-milling method

    International Nuclear Information System (INIS)

    Lee, Sungkyu; Kang, Kyoung-Hoon; Kim, Jong-Min; Hong, Hyun Seon; Yun, Yongseung; Woo, Sang-Kook

    2008-01-01

    Cu/YSZ composites (40 and 60 vol.% Cu powder with balance YSZ) was successfully fabricated by high-energy ball-milling of Cu and YSZ powders at 400 rpm for 24 h, pressing into pellets (O 13 mm x 2 mm) and subsequent sintering process at 900 deg. C under flowing 5%-H 2 /Ar gas for use as cermet cathode material of high-temperature electrolysis (HTE) of water vapor in a more economical way compared with conventional Ni/YSZ cermet cathode material. The Cu/YSZ composite powders thus synthesized and sintered were characterized using various analytical tools such as XRD, SEM, and laser diffraction and scattering method. Electrical conductivity of sintered Cu/YSZ cermet pellets thus fabricated was measured using 4-probe technique and compared with that of Ni/YSZ cermets. The effect of composites composition on the electrical conductivity was investigated and marked increase in electrical conductivity for copper contents greater than 40 vol.% in the composite was explained by percolation threshold

  16. 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)

  17. 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.

  18. Characterization of high-energy milled alumina powders Caracterização de pós de alumina submetidos a moagem de alta energia

    Directory of Open Access Journals (Sweden)

    Roberto Tomasi

    1998-10-01

    Full Text Available The utilization of reactive high-energy milling has been reported for the synthesis of ceramic powders namely, metal oxides, carbides, borides, nitrides or mixtures of ceramics or ceramic and metal compounds. In this work, high-energy milling was used for reduction of alumina powders to nanometric particle size. The ceramic characteristics of the powders were analyzed in terms of the behavior during deagglomeration, compaction curves, sintering and microstructure characterization. It was observed that the high energy milling has strong effect in producing agglomeration of the nanosized powders. This effect is explained by the high-energy impact of the balls, which may fracture particles or just cause the particles compacting. In this case, strong agglomerates are produced. As the powder surface area increases, stronger agglomerates are produced.Tem sido amplamente divulgada a utilização da moagem reativa de alta energia para a síntese de pós cerâmicos de óxidos de metais, carbetos, boretos, nitretos ou misturas de compostos cerâmicos ou compostos cerâmicos e metálicos. Neste trabalho, a moagem de alta energia (não reativa foi utilizada para a redução de pós de alumina para partículas de dimensões nanométricas. As características cerâmicas dos pós obtidos foram analisadas a partir de resultados de comportamento durante a desaglomeração, curvas de densificação, sinterização e caracterização de microestrutura. Observou-se que a moagem de alta energia tem forte efeito de aglomeração dos pós com partículas em dimensões nanométricas. Esse efeito é explicado pelo impacto de alta energia das bolas, os quais podem fraturar as partículas ou apenas causar a compactação das mesmas. Nesse último caso, que sempre ocorre, são formados aglomerados de alta resistência. O aumento da área superficial do pó produz aglomerados mais resistentes.

  19. 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)

  20. 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

  1. Heterogeneous sono-Fenton-like process using martite nanocatalyst prepared by high energy planetary ball milling for treatment of a textile dye.

    Science.gov (United States)

    Dindarsafa, Mahsa; Khataee, Alireza; Kaymak, Baris; Vahid, Behrouz; Karimi, Atefeh; Rahmani, Amir

    2017-01-01

    High energy planetary ball milling was applied to prepare sono-Fenton nanocatalyst from natural martite (NM). The NM samples were milled for 2-6h at the speed of 320rpm for production of various ball milled martite (BMM) samples. The catalytic performance of the BMMs was greater than the NM for treatment of Acid Blue 92 (AB92) in heterogeneous sono-Fenton-like process. The NM and the BMM samples were characterized by XRD, FT-IR, SEM, EDX and BET analyses. The particle size distribution of the 6h-milled martite (BMM 3 ) was in the range of 10-90nm, which had the highest surface area compared to the other samples. Then, the impact of main operational parameters was investigated on the process. Complete removal of the dye was obtained at the desired conditions including initial pH 7, 2.5g/L BMM 3 dosage, 10mg/L AB92 concentration, and 150W ultrasonic power after 30min of treatment. The treatment process followed pseudo-first order kinetic. Environmentally-friendly modification of the NM, low leached iron amount and repeated application at milder pH were the significant benefits of the BMM 3 . The GC-MS was successfully used to identify the generated intermediates. Eventually, an artificial neural network (ANN) was applied to predict the AB92 removal efficiency based upon the experimental data with a proper correlation coefficient (R 2 =0.9836). Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Case Study: Fort Mill High School--A Culture of Continuous Improvement

    Science.gov (United States)

    Southern Regional Education Board (SREB), 2014

    2014-01-01

    This is the latest in a series of case studies highlighting best practices High Schools That Work (HSTW) network schools and districts are implementing to prepare students better for further studies and careers. Fort Mill High School is in Fort Mill, South Carolina, an outlying suburb of Charlotte, North Carolina. Fort Mill links high quality…

  3. Effect of Annealing to the Formation of The 123 Phase YBa2Cu3O7-x Superconductor Produced by High Energy Milling

    International Nuclear Information System (INIS)

    Didin S Winatapura; Yustinus P, Wisnu A.A; Sukirman, E.

    2008-01-01

    Effect of annealing to the formation of 123 phase YBa 2 Cu 3 O 7-x superconductor produced by high energy milling (HEM) has been investigated. The milling process by using HEM method was performed for 30 hours, and followed by annealing at 500 o C, 600 o C, and 700 o C for 10 hours. The phase quality and quantity inside the specimen was measured by X-rays diffraction technique (XRD), and analyzed using Rietveld method. The microstructure of the specimen was observed with Scanning Electron Microscope (SEM), and electric property of the specimen was measured with four point probe. The result showed that the milling for 30 hours caused the deformation and partial decomposition of 123 phase resulting in another phase. The anneal effect caused the recrystallization process of decomposed 123 phase in such away that reformed 123 phase having finer crystallite size. According to the calculation using the Hall-Williamson's equation, the diameter of the crystallite size, D was obtained of about 496 Armstrong for milled specimen, and D ∼ 1,714 Armstrong for sintered specimen. By decreasing the 123 phase grain size, the intergrain contact surface became larger. It means that the intergrain link of 123 phase became stronger. The critical current (density) of milled specimen was obtained as J c ∼23.74 A.cm -2 , and J c ∼ 3.18 A.cm -2 for sintered specimen. Thus, the transport current that flowed intergrain inside 123 phase increased.(author)

  4. Phase evolution during early stages of mechanical alloying of Cu–13 wt.% Al powder mixtures in a high-energy ball mill

    International Nuclear Information System (INIS)

    Dudina, Dina V.; Lomovsky, Oleg I.; Valeev, Konstantin R.; Tikhov, Serguey F.; Boldyreva, Natalya N.; Salanov, Aleksey N.; Cherepanova, Svetlana V.; Zaikovskii, Vladimir I.; Andreev, Andrey S.; Lapina, Olga B.; Sadykov, Vladislav A.

    2015-01-01

    Highlights: • Phase formation during early stages of Cu–Al mechanical alloying was studied. • The products of mechanical alloying are of highly non-equilibrium character. • X-ray amorphous phases are present in the products of mechanical alloying. • An Al-rich X-ray amorphous phase is distributed between the crystallites. - Abstract: We report the phase and microstructure evolution of the Cu–13 wt.% Al mixture during treatment in a high-energy planetary ball mill with a particular focus on the early stages of mechanical alloying. Several characterization techniques, including X-ray diffraction phase analysis, nuclear magnetic resonance spectroscopy, differential dissolution, thermal analysis, and electron microscopy/elemental analysis, have been combined to study the evolution of the phase composition of the mechanically alloyed powders and describe the microstructure of the multi-phase products of mechanical alloying at different length scales. The following reaction sequence has been confirmed: Cu + Al → CuAl 2 (+Cu) → Cu 9 Al 4 + (Cu) → Cu(Al). The phase evolution was accompanied by the microstructure changes, the layered structure of the powder agglomerates disappearing with milling time. This scheme is further complicated by the processes of copper oxidation, reduction of copper oxides by metallic aluminum, and by variation of the stoichiometry of Cu(Al) solid solutions with milling time. Substantial amounts of X-ray amorphous phases were detected as well. Differential dissolution technique has revealed that a high content of aluminum in the Cu(Al) solid solution-based powders is due to the presence of Al-rich phases distributed between the Cu(Al) crystallites

  5. 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.

  6. Microstructural analysis of sinterized aluminum powder obtained by the high energy milling of beverage cans; Analise microestrutural de po de aluminio sinterizado obtido pela moagem de alta energia de latas de bebidas

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Jose Raelson Pereira de; Peres, Mauricio Mhirdaui, E-mail: mauricioperes@ct.ufrn.br [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2016-07-01

    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.

  7. Si-FeSi2/C nanocomposite anode materials produced by two-stage high-energy mechanical milling

    Science.gov (United States)

    Yang, Yun Mo; Loka, Chadrasekhar; Kim, Dong Phil; Joo, Sin Yong; Moon, Sung Whan; Choi, Yi Sik; Park, Jung Han; Lee, Kee-Sun

    2017-05-01

    High capacity retention Silicon-based nanocomposite anode materials have been extensively explored for use in lithium-ion rechargeable batteries. Here we report the preparation of Si-FeSi2/C nanocomposite through scalable a two-stage high-energy mechanical milling process, in which nano-scale Si-FeSi2 powders are besieged by the carbon (graphite/amorphous phase) layer; and investigation of their structure, morphology and electrochemical performance. Raman analysis revealed that the carbon layer structure comprised of graphitic and amorphous phase rather than a single amorphous phase. Anodes fabricated with the Si-FeSi2/C showed excellent electrochemical behavior such as a first discharge capacity of 1082 mAh g-1 and a high capacity retention until the 30th cycle. A remarkable coulombic efficiency of 99.5% was achieved within a few cycles. Differential capacity plots of the Si-FeSi2/C anodes revealed a stable lithium reaction with Si for lithiation/delithiation. The enhanced electrochemical properties of the Si-FeSi2/C nanocomposite are mainly attributed to the nano-size Si and stable solid electrolyte interface formation and highly conductive path driven by the carbon layer.

  8. 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.

  9. 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

  10. Vertically and Horizontally Mounted Wind Mills : Wind Energy Production in Tampere University of Applied Sciences

    OpenAIRE

    Evdokimova, Ekaterina

    2013-01-01

    The purpose of this thesis was to gather information about vertical and horizontal wind mills and to complete a research on wind power production by wind mills which were installed in Tampere University of Applied Sciences. The horizontally mounted wind mill Windspot 3.5 and vertically mounted wind mill Cypress were installed in summer 2011 but they started functioning and supplying energy only during 2012. In the theoretical part of this thesis wind speed and wind power production is dis...

  11. A top-down assessment of energy, water and land use in uranium mining, milling, and refining

    International Nuclear Information System (INIS)

    Schneider, E.; Carlsen, B.; Tavrides, E.; Hoeven, C. van der; Phathanapirom, U.

    2013-01-01

    Land, water and energy use are key measures of the sustainability of uranium production into the future. As the most attractive, accessible deposits are mined out, future discoveries may prove to be significantly, perhaps unsustainably, more intensive consumers of environmental resources. A number of previous attempts have been made to provide empirical relationships connecting these environmental impact metrics to process variables such as stripping ratio and ore grade. These earlier attempts were often constrained by a lack of real world data and perform poorly when compared against data from modern operations. This paper conditions new empirical models of energy, water and land use in uranium mining, milling, and refining on contemporary data reported by operating mines. It shows that, at present, direct energy use from uranium production represents less than 1% of the electrical energy produced by the once-through fuel cycle. Projections of future energy intensity from uranium production are also possible by coupling the empirical models with estimates of uranium crustal abundance, characteristics of new discoveries, and demand. The projections show that even for the most pessimistic of scenarios considered, by 2100, the direct energy use from uranium production represents less than 3% of the electrical energy produced by the contemporary once-through fuel cycle. - Highlights: • We present environmental impacts of conventional uranium (U) mining and milling technologies. • Impacts include direct energy consumption, land use and water use. • Contemporary mine and mill data is used, updating published estimates that relied on 1970s-era data. • The direct energy used to mine and mill uranium is below 1% of the electrical energy ultimately produced by the uranium. • Even if U demand growth is strong, the direct energy return on investment of U mining and milling will remain well above 1

  12. Automatic in-process chatter avoidance in the high-speed milling process

    NARCIS (Netherlands)

    Dijk, van N.J.M.; Doppenberg, E.J.J.; Faassen, R.P.H.; Wouw, van de N.; Oosterling, J.A.J.; Nijmeijer, H.

    2010-01-01

    High-speed milling is often used in industry to maximize productivity of the manufacturing of high-technology components, such as aeronautical components, mold, and dies. The occurrence of chatter highly limits the efficiency and accuracy of high-speed milling operations. In this paper, two control

  13. Improving Energy Efficiency Via Optimized Charge Motion and Slurry Flow in Plant Scale Sag Mills

    Energy Technology Data Exchange (ETDEWEB)

    Raj K. Rajamani

    2006-07-21

    A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Outokumpu Technology, Kennecott Utah Copper Corporation, and Process Engineering Resources Inc. At Cortez Gold Operations the shell and pulp lifters of the semiautogenous grinding mill was redesigned. The redesigned shell lifter has been in operation for over three years and the redesigned pulp lifter has been in operation for over nine months now. This report summarizes the dramatic reductions in energy consumption. Even though the energy reductions are very large, it is safe to say that a 20% minimum reduction would be achieved in any future installations of this technology.

  14. Optimal energy management in pulp and paper mills

    International Nuclear Information System (INIS)

    Sarimveis, H.K.; Angelou, A.S.; Retsina, T.R.; Rutherford, S.R.; Bafas, G.V.

    2003-01-01

    In this paper, we examine the utilization of mathematical programming tools for optimum energy management of the power plant in pulp and paper mills. The objective is the fulfillment of the total plant requirements in energy and steam with the minimum possible cost. The proposed methodology is based on the development of a detailed model of the power plant using mass and energy balances and a mathematical formulation of the electrical purchase contract, which can be translated into a rigorous mixed integer linear programming optimization problem. The results show that the method can be a very useful tool for the reduction of production cost due to minimization of the fuel and electricity costs

  15. 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.

  16. Underground Milling of High-Grade Uranium Ore

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, C., E-mail: chuck.edwards@amec.com [AMEC Americas Limited, Saskatoon, Saskatchewan (Canada)

    2014-05-15

    There are many safety and technical issues involved in the mining and progressing of high grade uranium ores such as those exploited in Northern Canada at present. With more of this type of mine due to commence production in the near future, operators have been looking at ways to better manage the situation. The paper describes underground milling of high-grade uranium ore as a means of optimising production costs and managing safety issues. In addition the paper presents some examples of possible process flowsheets and plant layouts that could be applicable to such operations. Finally an assessment of potential benefits from underground milling from a variety of viewpoints is provided. (author)

  17. High energy mechano-chemical milling: Convenient approach to synthesis of LiMn1.5Ni0.5O4 high voltage cathode for lithium ion batteries

    International Nuclear Information System (INIS)

    Datta, Moni Kanchan; Ramanathan, Madhumati; Jampani, Prashanth; Saha, Partha; Epur, Rigved; Kadakia, Karan; Chung, Sung Jae; Patel, Prasad; Gattu, Bharat; Manivannan, Ayyakkannu; Kumta, Prashant N.

    2014-01-01

    Graphical abstract: Nanostructured high voltage spinel phase of LiMn 1.5 Ni 0.5 O 4 (LMNO) of particle size ∼10–40 nm has been synthesized by a cost effective high energy mechanical milling (HEMM) approach followed by low temperature thermal treatments. High energy mechanical milling of lithium and manganese oxide precursors followed by moderate heat treatment results in the formation of single phase of LMNO, the high voltage spinel phase. The nanostructured LMNO has been studied as a high voltage cathode for lithium ion rechargeable batteries. Cyclic voltammetry as well as the differential capacity plots of nanostructured LMNO show the occurrence of two major reversible reactions occurring in the potential window of ∼2–3.6 V and ∼3.6–5.1 V with an associated specific capacity ∼105 mAh/g and ∼128 mAh/g, respectively. The nanostructured LMNO synthesized by the HEMM process followed by thermal treatments at ∼773 K, ∼873 K and ∼973 K shows a reversible capacity ∼120–110 mAh/g when cycled at a rate of ∼20 mA/g (∼C/6) in the potential window ∼3.6–5.1 V. Furthermore, the nanostructured HEMM derived LMNO shows a moderate rate capability with a capacity retention ∼87 mAh/g when cycled at ∼80 mA/g (∼C) rate. - Highlights: • Generation of LiMn 1.5 Ni 0.5 O 4 (LMNO) spinel by a cost effective HEMM process. • HEMM derived LMNO spinel phase shows a capacity of ∼128 mAh/g. • HEMM derived spinel exhibits a capacity retention of ∼87 mAh/g at ∼1C rate. • SEM analysis shows good structural integrity of the cycled electrode. • Charge transfer resistance increase during cycling causes capacity fade. - Abstract: The high voltage spinel form of LiMn 1.5 Ni 0.5 O 4 (LMNO) with a particle size ∼10–40 nm has been synthesized for the first time using high energy mechanical milling (HEMM) followed by low temperature thermal treatments using Li 2 O, MnO 2 and NiO as the starting precursors. The nanostructured LMNO cathode

  18. 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.

  19. Surface modification of calcined kaolin with toluene diisocyanate based on high energy ball milling

    International Nuclear Information System (INIS)

    Yuan, Yongbing; Chen, Hongling; Lin, Jinbin; Ji, Yan

    2013-01-01

    The surface of calcined kaolin particle was modified with toluene diisocyanate (TDI) by using high energy ball milling. The prepared hybrids were characterized by FT-IR, MAS NMR, thermal analysis (TGA-DSC), static water contact angle (CA), apparent viscosity and transmission electron microscopy (TEM). FT-IR and MAS NMR spectra demonstrated that TDI molecules were chemically anchored to kaolin surface after modification. The results of thermal analysis showed that the maximum grafting ratio reached up to 446.61% when the mass ratio of TDI/kaolin was 0.5:1.0, and CA measurements revealed that the resultant hybrids exhibited strong hydrophobicity (148.82°). Apparent viscosity and TEM were employed to examine the dispersion properties of blank and modified kaolin particles in poly (dimenthylsiloxane) matrix. The results illustrated that the dispersion stability depended strongly on the grafting ratio of TDI, neither too low nor too high achieved uniform and stable dispersion, and the favorable grafting ratio was obtained when the mass ratio of TDI/kaolin was 0.2:1.0. Further modification of TDI/kaolin (mass ration of TDI/kaolin, 1.0:1.0) particles with bis(aminopropyl)-terminated-poly(dimethylsiloxane) (APS) was also investigated. TEM evidenced that the dispersion properties of the obtained TDI/APS/kaolin particles were remarkably improved in octamethyl cyclotetrasiloxane compared with the original TDI/kaolin particles.

  20. Surface modification of calcined kaolin with toluene diisocyanate based on high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yongbing; Chen, Hongling, E-mail: hlchen@njut.edu.cn; Lin, Jinbin; Ji, Yan

    2013-11-01

    The surface of calcined kaolin particle was modified with toluene diisocyanate (TDI) by using high energy ball milling. The prepared hybrids were characterized by FT-IR, MAS NMR, thermal analysis (TGA-DSC), static water contact angle (CA), apparent viscosity and transmission electron microscopy (TEM). FT-IR and MAS NMR spectra demonstrated that TDI molecules were chemically anchored to kaolin surface after modification. The results of thermal analysis showed that the maximum grafting ratio reached up to 446.61% when the mass ratio of TDI/kaolin was 0.5:1.0, and CA measurements revealed that the resultant hybrids exhibited strong hydrophobicity (148.82°). Apparent viscosity and TEM were employed to examine the dispersion properties of blank and modified kaolin particles in poly (dimenthylsiloxane) matrix. The results illustrated that the dispersion stability depended strongly on the grafting ratio of TDI, neither too low nor too high achieved uniform and stable dispersion, and the favorable grafting ratio was obtained when the mass ratio of TDI/kaolin was 0.2:1.0. Further modification of TDI/kaolin (mass ration of TDI/kaolin, 1.0:1.0) particles with bis(aminopropyl)-terminated-poly(dimethylsiloxane) (APS) was also investigated. TEM evidenced that the dispersion properties of the obtained TDI/APS/kaolin particles were remarkably improved in octamethyl cyclotetrasiloxane compared with the original TDI/kaolin particles.

  1. The effect of the addition of the elements Ni, Zn and Co in a composite AlTiO2 obtained by high-energy milling and sintering process

    International Nuclear Information System (INIS)

    Carvalho, C.O. de; Coelho, R.E.; Conrado, L.C.; Nascimento, C.S.; Teixeira, C.A.; Mendonca, E.S.

    2016-01-01

    The present work use aluminum scrap with addition of TiO 2 , Ni, Zn or Co to preparation and characterization of nanocomposites. The aluminum were cut and subjected to high energy milling for 2 hours at 1200rpm. The obtained powder was added to TiO 2 , Ni, Zn or Co in a nominal composition 97Al-2TiO 2 -1X (X = Ni, Zn or Co) (weight %) and again, the mixture was subjected to milling for 1 hour at 1000rpm. Grinding powders were hot pressed in the closed die and then removed; the compressed were sintered at 950°C in a tubular furnace N 2 passing atmosphere. The samples obtained were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD). The results of SEM images showed a very refined microstructure and an aluminum matrix without porosity. (author)

  2. 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...

  3. 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

  4. Preventing performance drops of coal mills due to high moisture content

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.

    2007-01-01

    Coal mills pulverize and dry the coal dust before it is blown into the furnace in coal-fired power plants. The coal mills can only deliver the requested coal flow if certain conditions are fulfilled. These are normally considered as constraints on individual variables. However, combinations of more...... than one variable might cause problems even though these individually variables are in an acceptable region. This paper deals with such a problem. The combination of a high load of the power plant, a large load change and high moisture content in the coal, can force the coal mill into a state where...... coal is accumulated instead of being blown into the furnace. This paper suggests a simple method for preventing the accumulation of the coal in the mill, by limiting the requested coal flow considering the coal moisture content and the temperature outside the mill.  ...

  5. 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)

  6. Effect of grain size on structural and dielectric properties of barium titanate piezoceramics synthesized by high energy ball milling

    Science.gov (United States)

    Verma, Narendra Kumar; Patel, Sandeep Kumar Singh; Kumar, Dinesh; Singh, Chandra Bhal; Singh, Akhilesh Kumar

    2018-05-01

    We have investigated the effect of sintering temperature on the densification behaviour, grain size, structural and dielectric properties of BaTiO3 ceramics, prepared by high energy ball milling method. The Powder x-ray diffraction reveals the tetragonal structure with space group P4mm for all the samples. The samples were sintered at four different temperatures, (T = 900°C, 1000°C, 1100°C, 1200°C and 1300°C). Density increased with increasing sintering temperature, reaching up to 97% at 1300°C. A grain growth was observed with increasing sintering temperature. Impedance analyses of the sintered samples at various temperatures were performed. Increase in dielectric constant and Curie temperature is observed with increasing sintering temperature.

  7. Characterization of Al{sub 2}O{sub 3}-Co ceramic composite obtained by high energy mill; Caracterizacao de composito ceramico Al{sub 2}O{sub 3}-CO obtido por moagem de alta energia (MAE)

    Energy Technology Data Exchange (ETDEWEB)

    Souza, J.L.; Assis, R.B. de; Carlos, E.M.; Oliveira, T.P.; Costa, F.A. da, E-mail: leonaldojs@hotmail.com [Universidade Federal do Rio Grande do Norte (PPGCEM/UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica

    2014-07-01

    This work aims to characterize the ceramic composite Al{sub 2}O3-Co obtained by high energy grinding. The composites were obtained by milling Al{sub 2}O{sub 3} and Co in a high energy mill at a speed of 400 rpm, in proportions of 5 to 20% Cobalt (Co). Ceramic composites with 5 and 20% cobalt were sintered at 1200 and 1300 ° C, with a 60-minute plateau and a heating rate of 10 ° C / min. The samples were characterized by X-ray diffraction (XRD), thermogravimetry and differential scanning calorimetry (TG / DSC) and scanning electron microscopy (SEM). The results show the significant effect of cobalt percentage and high energy grinding on the final properties of the Al{sub 2}O{sub 3} - Co ceramic composite, presenting satisfactory values for the composite with a 20% cobalt percentage, showing to be a promising material for application in cutting tools.

  8. 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....

  9. Comparison of various milling modes combined to the enzymatic hydrolysis of lignocellulosic biomass for bioenergy production: Glucose yield and energy efficiency

    International Nuclear Information System (INIS)

    Licari, A.; Monlau, F.; Solhy, A.; Buche, P.; Barakat, A.

    2016-01-01

    Bagasse is an abundant by-product from sugarcane production that can be used for conversion into biofuels. Nonetheless, the recalcitrant structures of lignocellulosic fibers required a pretreatment prior conversion into biofuels. In this study, four mechanical deconstruction methods were compared in terms of energy demand and energy efficiency at lab scale: BM (ball mill), VBM (vibratory ball mill), CM (centrifugal mill) and JM (jet mill). Results indicate that VBM was more effective compared to BM, JM and CM in enzymatic accessibility and sugars solubilization: VBM-3h > BM-72 h > JM-5000 rpm > CM-0.12 mm. However, preliminary energetic assessment showed that at lab scale, the CM (centrifugal mill) as mechanical fractionation process appears to be the most efficient in terms of energy-efficiency (kg glucose/kWh) compared to BM, VBM and JM. A comparison with literature pretreatments data highlighted that fine and/or ultrafine milling process (BM, VBM, CM) are simpler saccharification technologies, which not required any chemical or water inputs, thus minimizing waste generation and treatment. - Highlights: • VBM (vibro ball milling) was the most effective in decreasing of cellulose crystallinity. • BM (ball milling) was the most effective in increasing surface area. • The highest energy efficiency was obtained with CM (centrifugal milling).

  10. Abridged acid-base wet-milling synthesis of high purity hydroyapatite

    Directory of Open Access Journals (Sweden)

    Sandi Carolina Ruiz-Mendoza

    2008-06-01

    Full Text Available There is a plethora of routes to produce hydroxyapatite(HA and in general calcium phosphates(CP but production usually leads to a mixture of several phases. Besides ionic contamination, most of these methods are cumbersome, restricted to small volumes of product and require a lot of thermal energy. The acid-base route eliminates foreign ions or additives and its only byproduct is water. Heterogeneous reaction drawback is that solid reactants do not easily come in contact with each other and therefore addition and stirring times become very lengthy and still the product is a mixture. The synthesis started from calcium hydroxide and phosphoric acid (PA. Ball milling was used to favor kinetics and stoichiometry. Six sets of PA addition, paddle stirring and ball milling times were used. Products were evaluated by X ray diffraction (XRD, Fourier Transform Infrared (FTIR, scanning electron microscopy (SEM, X ray fluorescence (XRF and Ca/P ratio. Chemical analysis for calcium proceeded through oxalate precipitate and phosphorus by the phosphomolibdate technique. A set of conditions yielding high purity HA was established.

  11. Chatter detection in milling process based on VMD and energy entropy

    Science.gov (United States)

    Liu, Changfu; Zhu, Lida; Ni, Chenbing

    2018-05-01

    This paper presents a novel approach to detect the milling chatter based on Variational Mode Decomposition (VMD) and energy entropy. VMD has already been employed in feature extraction from non-stationary signals. The parameters like number of modes (K) and the quadratic penalty (α) need to be selected empirically when raw signal is decomposed by VMD. Aimed at solving the problem how to select K and α, the automatic selection method of VMD's based on kurtosis is proposed in this paper. When chatter occurs in the milling process, energy will be absorbed to chatter frequency bands. To detect the chatter frequency bands automatically, the chatter detection method based on energy entropy is presented. The vibration signal containing chatter frequency is simulated and three groups of experiments which represent three cutting conditions are conducted. To verify the effectiveness of method presented by this paper, chatter feather extraction has been successfully employed on simulation signals and experimental signals. The simulation and experimental results show that the proposed method can effectively detect the chatter.

  12. 75 FR 16449 - Dodge Mill Reality LLC; Notice of Declaration of Intention and Soliciting Comments, Protests, and...

    Science.gov (United States)

    2010-04-01

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. DI10-10-000] Dodge Mill...-10-000. c. Date Filed: March 8, 2010. d. Applicant: Dodge Mill Reality LLC. e. Name of Project... of: (1) An existing 275-acre-foot mill pond; (2) an existing 20-foot-high, 400-foot-long earthen mill...

  13. Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling

    DEFF Research Database (Denmark)

    Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth

    2013-01-01

    Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility...

  14. Phase transition of Ni-Mn-Ga alloy powders prepared by vibration ball milling

    International Nuclear Information System (INIS)

    Tian, B.; Chen, F.; Tong, Y.X.; Li, L.; Zheng, Y.F.; Liu, Y.; Li, Q.Z.

    2011-01-01

    Research highlights: → The vibration ball milling with a high milling energy introduces the atomic disorder and large lattice distortion in the alloy during milling and makes the formation of disordered fcc structure phase in the alloy. → The transition temperature and activation energy for disordered fcc → disordered bcc are ∼320 o C and 209 ± 8 kJ/mol, respectively. → The alloy powders annealed at 800 o C for 1 h show a one-stage martensitic transformation with quite lower latent heat compared to the bulk alloy. - Abstract: This study investigated the phase transformation of the flaky shaped Ni-Mn-Ga powder particles with thickness around 1 μm prepared by vibration ball milling and post-annealing. The SEM, XRD, DSC and ac magnetic susceptibility measurement techniques were used to characterize the Ni-Mn-Ga powders. The structural transition of Heusler → disordered fcc occurred in the powders prepared by vibration ball milling (high milling energy) for 4 h, which was different from the structural transition of Heusler → disordered fct of the powders fabricated by planetary ball milling (low milling energy) for 4 h. The two different structures after ball milling should be due to the larger lattice distortion occurred in the vibration ball milling process than in the planetary ball milling process. The structural transition of disordered fcc → disordered bcc took place at ∼320 o C during heating the as-milled Ni-Mn-Ga powders, which was attributed to the elimination of lattice distortion caused by ball milling. The activation energy for this transition was 209 ± 8 kJ/mol. The Ni-Mn-Ga powder annealed at 800 o C mainly contained Heusler austenite phase at room temperature and showed a low volume of martensitic transformation upon cooling. The inhibition of martensitic transformation might be attributed to the reduction of grain size in the annealed Ni-Mn-Ga particles.

  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. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  17. Magnetic interactions in high-energy ball-milled NiZnFe2O4/SiO2 composites

    International Nuclear Information System (INIS)

    Pozo Lopez, G.; Silvetti, S.P.; Urreta, S.E.; Cabanillas, E.D.

    2007-01-01

    Composites Ni 0.5 Zn 0.5 Fe 2 O 4 /SiO 2 are obtained after high-energy ball milling precursor oxides, in stoichiometric proportions, for 200 h at room temperature and further isothermal annealing for 1 h at 1273 K, under air and argon atmosphere, respectively. After 200 h grinding, a complex microstructure develops with small hematite crystals mixed with SiO 2 and remanent NiO and ZnO particles, and very small NiZn ferrite clusters, reaching a mean size of ∼9 nm. The high temperature treatments remove the hematite grains from the powder and promote the growth of NiZn ferrite grains to reach mean sizes nearly ∼20 nm. For treatments in oxidizing atmospheres, the major phases are SiO 2 and NiZn ferrite, while for annealing in Ar a new phase appears, fayalite, which is paramagnetic at room temperature. The M-H loops are all well described by the sum of a ferromagnetic and a superparamagnetic-like contribution. The observed properties are interpreted considering the different magnetic phases obtained, their crystal sizes and their mutual interactions

  18. Obtention of the TiFe compound by high-energy milling of Ti+Fe and TiH{sub 2}+Fe powder mixtures; Obtencao do composto TiFe a partir da moagem de alta energia de misturas Ti+Fe e TiH{sub 2}+Fe

    Energy Technology Data Exchange (ETDEWEB)

    Falcao, R.B.; Dammann, E.D.C.C.; Rocha, C.J.; Leal Neto, R.M., E-mail: railson.falcao@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais. Lab. de Intermetalicos

    2010-07-01

    In this work TiFe compound was obtained by two process routes involving high-energy ball milling: mechanical alloying from Ti and Fe powders (route 1) and mechanical milling from TiH{sub 2} and Fe powders, both followed by an annealing heat treatment. Shaker and planetary ball mills were utilized for times varying from 1-25 hours. Milled and annealed powders were characterized by SEM and X-ray diffraction analyses. TiFe compound was formed in both routes. A strong powder adherence in the milling vial and balls occurred with route 1 in both mills. Powder adherence was significantly reduced by using TiH{sub 2} (route 2) mainly in the planetary mill, in spite of TiFe formation has only occurred after the annealing treatment. (author)

  19. High energy mechano-chemical milling: Convenient approach to synthesis of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} high voltage cathode for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Moni Kanchan, E-mail: mkd16@pitt.edu [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, PA 15261 (United States); Ramanathan, Madhumati [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Jampani, Prashanth [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Saha, Partha [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Epur, Rigved [Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Kadakia, Karan [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Chung, Sung Jae [Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Patel, Prasad; Gattu, Bharat [Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Manivannan, Ayyakkannu [US Department of Energy, National Energy Technology Laboratory, Morgantown, WV 26507 (United States); Kumta, Prashant N., E-mail: pkumta@pitt.edu [Bioengineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Center for Complex Engineered Multifunctional Materials, University of Pittsburgh, PA 15261 (United States); Chemical and Petroleum Engineering, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); Mechanical Engineering and Materials Science, Swanson School of Engineering, University of Pittsburgh, PA 15261 (United States); School of Dental Medicine, University of Pittsburgh, PA 15261 (United States)

    2014-12-15

    Graphical abstract: Nanostructured high voltage spinel phase of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (LMNO) of particle size ∼10–40 nm has been synthesized by a cost effective high energy mechanical milling (HEMM) approach followed by low temperature thermal treatments. High energy mechanical milling of lithium and manganese oxide precursors followed by moderate heat treatment results in the formation of single phase of LMNO, the high voltage spinel phase. The nanostructured LMNO has been studied as a high voltage cathode for lithium ion rechargeable batteries. Cyclic voltammetry as well as the differential capacity plots of nanostructured LMNO show the occurrence of two major reversible reactions occurring in the potential window of ∼2–3.6 V and ∼3.6–5.1 V with an associated specific capacity ∼105 mAh/g and ∼128 mAh/g, respectively. The nanostructured LMNO synthesized by the HEMM process followed by thermal treatments at ∼773 K, ∼873 K and ∼973 K shows a reversible capacity ∼120–110 mAh/g when cycled at a rate of ∼20 mA/g (∼C/6) in the potential window ∼3.6–5.1 V. Furthermore, the nanostructured HEMM derived LMNO shows a moderate rate capability with a capacity retention ∼87 mAh/g when cycled at ∼80 mA/g (∼C) rate. - Highlights: • Generation of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (LMNO) spinel by a cost effective HEMM process. • HEMM derived LMNO spinel phase shows a capacity of ∼128 mAh/g. • HEMM derived spinel exhibits a capacity retention of ∼87 mAh/g at ∼1C rate. • SEM analysis shows good structural integrity of the cycled electrode. • Charge transfer resistance increase during cycling causes capacity fade. - Abstract: The high voltage spinel form of LiMn{sub 1.5}Ni{sub 0.5}O{sub 4} (LMNO) with a particle size ∼10–40 nm has been synthesized for the first time using high energy mechanical milling (HEMM) followed by low temperature thermal treatments using Li{sub 2}O, MnO{sub 2} and NiO as the starting

  20. Fabrication of Fe1.1Se0.5Te0.5 bulk by a high energy ball milling technique

    Science.gov (United States)

    Liu, Jixing; Li, Chengshan; Zhang, Shengnan; Feng, Jianqing; Zhang, Pingxiang; Zhou, Lian

    2017-11-01

    Fe1.1Se0.5Te0.5 superconducting bulks were successfully synthesized by a high energy ball milling (HEBM) aided sintering technique. Two advantages of this new technique have been revealed compared with traditional solid state sintering method. One is greatly increased the density of sintered bulks. It is because the precursor powders with β-Fe(Se, Te) and δ-Fe(Se, Te) were obtained directly by the HEBM process and without formation of liquid Se (and Te), which could avoid the huge volume expansion. The other is the obvious decrease of sintering temperature and dwell time due to the effective shortened length of diffusion paths. The superconducting critical temperature Tc of 14.2 K in our sample is comparable with those in previous reports, and further optimization of chemical composition is on the way.

  1. Preliminary study on the potential of improving pulp quality and energy efficiency in a South African TMP mills

    CSIR Research Space (South Africa)

    Johakimu, Jonas K

    2010-03-01

    Full Text Available The main focus of this work was to evaluate an opportunity for product quality and refining energy efficiency improvement through assessing the current mill practices in South African TMP mills. The fractionation trials were conducted at a CSIR...

  2. 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.

  3. Reversible a-Fe2O3 to Fe3O4 transformation during ball milling

    DEFF Research Database (Denmark)

    Linderoth, Søren; Jiang, Jianzhong; Mørup, Steen

    1997-01-01

    The transformation of hematite to magnetite by high-energy ball milling in a sealed container has been studied by Mossbauer spectroscopy and x-ray diffraction. Mechanisms for this transformation are critically discussed. The dominant mechanism is concluded to be due to bond breaking during the high...... energy ball milling followed by release of the oxygen from the vial. The reverse transformation, magnetite to hematite, is demonstrated to occur by ball milling in air. Mechanisms for this reverse transformation are also put forward....

  4. Plasma sintering of ferritic steel reinforced with niobium carbide prepared by high energy milling; Sinterizacao a plasma de aco ferritico reforcado com carbeto de niobio preparado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Silva Junior, J.F. da; Almeida, E.O.; Gomes, U.U.; Alves Junior, C.; Messias, A.P. [Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Materiais Ceramicos e Metais Especiais; Universidade Federal do Rio Grande do Norte (UFRN), Natal (Brazil). Lab. de Processamento de Materiais por Plasma

    2010-07-01

    Plasma is an ionized gas where ions are accelerated from anode to cathode surface, where the sample is placed. There are a lot of collisions on cathode surface by ions heating and sintering the sample. High energy milling (HEM) is often used to produce composite particles to be used on powder metallurgy. These particles can exhibit fine particles and high phase dispersion. This present work aim to study ferritic steels reinforced with 3%NbC prepared by HEM and sintered on plasma furnace. Ferritic steel and NbC powders were milled during 5 hours and characterized by SEM, XRD and laser scattering. Then, these composite powders were compacted in a cylindrical steel die and then sintered in a plasma furnace. Vickers microhardness tests and SEM and XRD analysis were performed on sintered samples. (author)

  5. 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.

  6. 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...

  7. Obtaining beta phase in Ti through processing in high energy mill powders of Ti and Nb; Obtencao de fase beta no Ti atraves de processamento em moinho de alta energia de pos de Ti e Nb

    Energy Technology Data Exchange (ETDEWEB)

    Milanez, Mateus; Ferretto, Aline; Rocha, Marcio Roberto da; Arnt, Angela Coelho [Universidade do Extremo Sul Catarinense (UNESC), Criciuma, SC (Brazil). Departamento de Engenharia de Materiais; Milanez, Alexandre [Faculdade SATC (FASATC), Criciuma, SC (Brazil). Departamento de Engenharia Mecanica; Schaeffer, Lirio [Universidade Federal do Rio Grande do Sul (LdTM/UFRGS), RS (Brazil). Lab. de Transformacao Mecanica

    2014-07-01

    An orthopedic implant, ideal, must meet the requirements of biocompatibility, have good mechanical properties among others. Titanium and Niobium exhibit biocompatibility and the β-Ti phase relationships have the highest strength / weight among all titanium alloys, presenting lower values of elastic modulus. The alloy has mechanically produced specific microstructural characteristics and improved mechanical properties compared with conventional powder metallurgy. In this study, a titanium alloy with different additions of niobium was used. The metal powders were mixed via mechanical alloy in high energy mill (attritor). The powder samples were analyzed by X-ray diffraction (X-RD) and property held by adhesive wear testing with a Pin-on-Disk. The present study revealed that through the high-energy milling is possible the atomic interaction between Ti and Nb particles and the mechanical properties are affected by the concentration of Nb. (author)

  8. Ultra-high aspect ratio replaceable AFM tips using deformation-suppressed focused ion beam milling

    International Nuclear Information System (INIS)

    Savenko, Alexey; Yildiz, Izzet; Petersen, Dirch Hjorth; Bøggild, Peter; Bartenwerfer, Malte; Krohs, Florian; Oliva, Maria; Harzendorf, Torsten

    2013-01-01

    Fabrication of ultra-high aspect ratio exchangeable and customizable tips for atomic force microscopy (AFM) using lateral focused ion beam (FIB) milling is presented. While on-axis FIB milling does allow high aspect ratio (HAR) AFM tips to be defined, lateral milling gives far better flexibility in terms of defining the shape and size of the tip. Due to beam-induced deformation, it has so far not been possible to define HAR structures using lateral FIB milling. In this work we obtain aspect ratios of up to 45, with tip diameters down to 9 nm, by a deformation-suppressing writing strategy. Several FIB milling strategies for obtaining sharper tips are discussed. Finally, assembly of the HAR tips on a custom-designed probe as well as the first AFM scanning is shown. (paper)

  9. 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.

  10. Saving electrical energy in a saw-mill; Einsparung von elektrischer Energie in einem Saegereibetrieb. Stromeinsparungen in den Bereichen Holzbearbeitung, Foerdertechnik, Holztrocknung, Absauganlagen, Druckluft, Beleuchtung

    Energy Technology Data Exchange (ETDEWEB)

    Wyrsch, I. [Wyrsch Technologies, Kuessnacht am Rigi (Switzerland); Dolder, M. [Ingenieurbuero Dolder, Luzern (Switzerland)

    2005-01-15

    This comprehensive, illustrated report for the Swiss Federal Office of Energy (SFOE) presents the findings of a project that examined the electricity consumption of saw-mills and ways in which the amount of electrical power used in such facilities could be reduced. The Schilliger Holz AG company was taken as an example of a saw-mill in Switzerland. Its power consumption in 2001 was almost 6 gigawatt-hours. The work done in the two phases of the project is described and commented on. The first phase involved the measurement and analysis of power consumption; in the second phase measures to be taken to help save energy were developed. The various machinery and installations in this saw mill are described. These include various systems for the processing of the raw timber through to finished products that include wood for building, decoration and laminates. Measurement data is presented and commented on. Potentials for saving electricity and measures to be taken are described in detail for the various processing plants in the saw-mill.

  11. Production of ferroelectric ceramic SrBi_2Nb_2O_9 (SBN) by high energy milling and their characterization

    International Nuclear Information System (INIS)

    Sancho, E.O.; Pires Junior, G.F.M.; Rodrigues, H.O.; Sombra, A.S.B.; Sales, J.C.

    2011-01-01

    Bismuth compounds, such as SrBi_2Nb_2O_9 (SBN), lead-free, is an alternative to the use of PZT because of its excellent ferroelectric properties, especially regarding the change of polarization. SBN is synthesized by the method of the solid state by high energy ball milling in reactive polymer with zirconia beads, which were subsequently doped with Bi_2O_3 and La_2O_3 aiming to promote intentional changes in the chemical structure of the ceramic, resulting in changes in properties electrical, magnetic and optical materials. The quantitative analysis obtained by Rietveld refinement confirmed the orthorhombic crystal structure with lattice parameters (a = 5.5158 Å, b = 5.5133 Å and c = 25.0765 Å, α = β = γ = 90 °) for indices convergence S = 1.72 (goodness of fit), where S is given by the ratio RWP / Rexp. And, the Raman shifts at 174, 204, 570 and 834 cm-1 indicated the formation of SBN perovskita type. (author)

  12. 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.

  13. Experimental High Speed Milling of the Selected Thin-Walled Component

    Directory of Open Access Journals (Sweden)

    Jozef Zajac

    2017-11-01

    Full Text Available In a technical practice, it is possible to meet thin-walled parts more and more often. These parts are most commonly used in the automotive industry or aircraft industry to reduce the weight of different design part of cars or aircraft. Presented article is focused on experimental high speed milling of selected thin-walled component. The introduction of this article presents description of high speed machining and specification of thin – walled parts. The experiments were carried out using a CNC machine Pinnacle VMC 650S and C45 material - plain carbon steel for automotive components and mechanical engineering. In the last part of the article, described are the arrangements to reduction of deformation of thin-walled component during the experimental high speed milling.

  14. 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.

  15. Non-isothermal synergetic catalytic effect of TiF{sub 3} and Nb{sub 2}O{sub 5} on dehydrogenation high-energy ball milled MgH{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Tiebang, E-mail: tiebangzhang@nwpu.edu.cn; Hou, Xiaojiang; Hu, Rui; Kou, Hongchao; Li, Jinshan

    2016-11-01

    MgH{sub 2}-M (M = TiF{sub 3} or Nb{sub 2}O{sub 5} or both of them) composites prepared by high-energy ball milling are used in this work to illustrate the dehydrogenation behavior of MgH{sub 2} with the addition of catalysts. The phase compositions, microstructures, particle morphologies and distributions of MgH{sub 2} with catalysts have been evaluated. The non-isothermal synergetic catalytic-dehydrogenation effect of TiF{sub 3} and Nb{sub 2}O{sub 5} evaluated by differential scanning calorimetry gives the evidences that the addition of catalysts is an effective strategy to destabilize MgH{sub 2} and reduce hydrogen desorption temperatures and activation energies. Depending on additives, the desorption peak temperatures of catalyzed MgH{sub 2} reduce from 417 °C to 341 °C for TiF{sub 3} and from 417 °C to 336 °C for Nb{sub 2}O{sub 5}, respectively. The desorption peak temperature reaches as low as 310 °C for MgH{sub 2} catalyzed by TiF{sub 3} coupling with Nb{sub 2}O{sub 5}. The non-isothermal synergetic catalytic effect of TiF{sub 3} and Nb{sub 2}O{sub 5} is mainly attributed to electronic exchange reactions with hydrogen molecules, which improve the recombination of hydrogen atoms during dehydrogenation process of MgH{sub 2}. - Highlights: • Catalytic surface for MgH{sub 2} is achieved by high-energy ball milling. • Non-isothermal dehydrogenation behavior of MgH{sub 2} with TiF{sub 3} and/or Nb{sub 2}O{sub 5} is illustrated. • Dehydrogenation activation energies of synergetic catalyzed MgH{sub 2} are obtained. • Synergetic catalytic-dehydrogenation mechanism of TiF{sub 3} and Nb{sub 2}O{sub 5} is proposed.

  16. 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.

  17. Characterization of Printed Circuit Boards for Metal and Energy Recovery after Milling and Mechanical Separation

    Directory of Open Access Journals (Sweden)

    Waldir A. Bizzo

    2014-06-01

    Full Text Available The proper disposal of electrical and electronic waste is currently a concern of researchers and environmental managers not only because of the large volume of such waste generated, but also because of the heavy metals and toxic substances it contains. This study analyzed printed circuit boards (PCBs from discarded computers to determine their metal content and characterized them as solid waste and fuel. The analysis showed that PCBs consist of approximately 26% metal, made up mainly of copper, lead, aluminum, iron and tin, as well as other heavy metals such as cadmium and nickel. Comparison with the results of other studies indicated that the concentration of precious metals (gold and silver has declined over time. Analysis of the leachate revealed high concentrations of cadmium and lead, giving the residue the characteristics of hazardous waste. After milling the PCBs, we found that larger amounts of metal were concentrated in smaller fractions, while the lightest fraction, obtained by density separation, had a gross calorific value of approximately 11 MJ/kg, although with a high ash content. Milling followed by density separation proved potentially useful for recovery of metals and energy-rich fractions.

  18. Global flow of glasma in high energy nuclear collisions

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guangyao; Fries, Rainer J., E-mail: rjfries@comp.tamu.edu

    2013-06-25

    We discuss the energy flow of the classical gluon fields created in collisions of heavy nuclei at collider energies. We show how the Yang–Mills analog of Faraday's Law and Gauss' Law predicts the initial gluon flux tubes to expand or bend. The resulting transverse and longitudinal structure of the Poynting vector field has a rich phenomenology. Besides the well-known radial and elliptic flow in transverse direction, classical quantum chromodynamics predicts a rapidity-odd transverse flow that tilts the fireball for non-central collisions, and it implies a characteristic flow pattern for collisions of non-symmetric systems A+B. The rapidity-odd transverse flow translates into a directed particle flow v{sub 1} which has been observed at RHIC and LHC. The global flow fields in heavy ion collisions could be a powerful check for the validity of classical Yang–Mills dynamics in high energy collisions.

  19. Modelling Of Residual Stresses Induced By High Speed Milling Process

    International Nuclear Information System (INIS)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-01-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction.Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge registered software, is based on data taken from Outeiro and al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature.Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R and D to those given by numerical simulations is achieved.

  20. Effects of high energy ball milling on synthesis and characteristics of Ti-Mg alloys

    CSIR Research Space (South Africa)

    Chikwanda, HK

    2008-01-01

    Full Text Available The synthesis of Ti-Mg alloys using mechanical alloying method has been investigated. Effects of the mechanical alloying parameters on the resultant microstructural features have been studied. This work presents the effects of milling speed...

  1. Whole tree chips for fuel and pulp can cut mill energy costs

    Energy Technology Data Exchange (ETDEWEB)

    Morey, J

    1979-01-01

    Wood that is decaying and going to waste amounts to over 5 billion tons, enough to replace the present oil consumption of the United States. Environmental thinning--removal of dead, dying, and less desirable trees--leaves room for other trees to grow. Environmental thinning should be acceptable to private landowners, making almost every stand of timber available for energy harvest. Environmental thinning uses a small feller buncher shear, a small to medium grapple skidder, and a whole tree chipper. Five or six men, two or three feller bunchers, two grapple skidders, and a whole tree chipper can produce 250 to 300 green tons of whole tree chips per day and deliver it to an energy plant for $10 to $12 per ton. Demand for wood for energy will raise pulpwood prices unless industry adopts whole tree utilization and environmental thinning. Wood energy provides a market for low grade wood. The whole tree chipper can separate stem chips for pulping and top chips, with bark and foliage, for energy uses. A dirt separator available on the Morbark total Chiparvestor helps remove sand, about 40% of the bark, and about 50% of twigs and foliage. Because the fiber has a value as energy, it will be economical to build better screening systems, providing cleaner pulp chips. After screening, bark will remain, but some mills are converting to 100% bark chips. A study indicates that converting from oil to wood and from roundwood to whole tree chips can result in a savings of $4 to $8 million per year for a 1,000 tpd pulp and paper mill.

  2. 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)

  3. Impact Analysis of Roller System Stability for Four-High Mill Horizontal Vibration

    Directory of Open Access Journals (Sweden)

    Xiao-bin Fan

    2016-01-01

    Full Text Available In order to study the hot Compact Strip Production (CSP, four-high mill vibration characteristics, and vibration suppression method, the roller system structure stability was analyzed and calculated at first in the paper. And then, the mill stand gap was measured at field and its influence on roll transverse vibration was analyzed. The drum gear coupling effect on the roller system stability and the automatic balance conditions of the coupling transmission torque were studied; the influence of axial force caused by the roller cross on the system stability was analyzed. Finally, the roller transverse friction chatter vibration mechanics model was established; the simulation analysis was carried out with eliminating mill house-bearing clearance and adding floating support for coupling, respectively. And the characteristics of the roller “jump vibration” were studied. We applied copper gaskets to eliminate or reduce mill house-bearing clearance for suppressing the rolling mill vibration on the spot; the test results show that the roller transverse vibration was suppressed after eliminating clearance.

  4. The state equation of Yang-Mills field dark energy models

    International Nuclear Information System (INIS)

    Zhao Wen; Zhang Yang

    2006-01-01

    In this paper, we study the possibility of building Yang-Mills (YM) field dark energy models with equation of state (EoS) crossing -1, and find that it cannot be realized by the single YM field models, no matter what kind of Lagrangian or initial condition. But the states of -1 -1 to <-1, and it will go to the critical state of ω = -1 with the expansion of the universe, which character is the same as the single YM field models, and the big rip is naturally avoided

  5. 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

  6. 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.

  7. 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.

  8. Molten salts activated by high-energy milling: A useful, low-temperature route for the synthesis of multiferroic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hernández-Ramírez, Anayantzin; Martínez-Luévanos, Antonia [Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, V. Carranza s/n, Saltillo, Coahuila 25280 (Mexico); Fuentes, Antonio F. [CINVESTAV Unidad Saltillo, Apdo. Postal 663, Saltillo, Coahuila 25000 (Mexico); Earth and Environmental Science, University of Michigan, 3514 C.C. Little Building, 1100 N. University Avenue, Ann Arbor, MI 48109-1005 (United States); Nelson, Anna-Gay D.; Ewing, Rodney C. [Earth and Environmental Science, University of Michigan, 3514 C.C. Little Building, 1100 N. University Avenue, Ann Arbor, MI 48109-1005 (United States); Montemayor, Sagrario M., E-mail: smmontemayor@gmail.com [Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, V. Carranza s/n, Saltillo, Coahuila 25280 (Mexico); Earth and Environmental Science, University of Michigan, 3514 C.C. Little Building, 1100 N. University Avenue, Ann Arbor, MI 48109-1005 (United States)

    2014-01-25

    Highlights: • The synthesis route purposed demonstrates the formation of BiFeO{sub 3} at only 500 °C. • The magnetic and ferroelectric properties are comparable to those of bulk BiFeO{sub 3}. • By this route, several phases in Bi{sub 1−x}La{sub x}FeO{sub 3} system are obtained at only 500 °C. • The route developed here could be useful to synthesize other perovskite-type oxides. -- Abstract: There are only a few multiferroic compounds, among which BiFeO{sub 3} is the most important. Research the synthesis of bismuth ferrite, with novel and improved magnetic and electrical properties, has been mainly based on the use of hydrothermal or sol gel methods. However, these methods require either rather extreme conditions or several steps for synthesis. We demonstrate that the use of molten salts, activated by high energy milling, results in pure nanometric BiFeO{sub 3}, LaFeO{sub 3} and intermediate phases in the Bi{sub 1−x}La{sub x}FeO{sub 3} system. The chemical reagents used are Bi(NO{sub 3}){sub 3}⋅5H{sub 2}O, La(NO{sub 3}){sub 3}⋅6H{sub 2}O, Fe(NO{sub 3}){sub 3}⋅9H{sub 2}O and NaOH. A brief milling process of the reagents creates an amorphous precursor and crystalline NaNO{sub 3}. The thermal treatment of the precursors, at 500 °C for two hours, produces a crystalline mixture of Bi{sub 1−x}La{sub x}FeO{sub 3} and NaNO{sub 3}. Simple washing eliminates the NaNO{sub 3}. The characterization of intermediates and final products, through thermal analysis, X-ray diffraction and scanning electronic microscopy, allows the inference of possible mechanism. In addition, vibrating sample magnetometry (VSM) and ferroelectric tests show the typical magnetic and electric polarization loops characteristic of these materials even when formed at the nano-scale.

  9. Energy efficient bead milling of microalgae: Effect of bead size on disintegration and release of proteins and carbohydrates.

    Science.gov (United States)

    Postma, P R; Suarez-Garcia, E; Safi, C; Yonathan, K; Olivieri, G; Barbosa, M J; Wijffels, R H; Eppink, M H M

    2017-01-01

    The disintegration of three industry relevant algae (Chlorella vulgaris, Neochloris oleoabundans and Tetraselmis suecica) was studied in a lab scale bead mill at different bead sizes (0.3-1mm). Cell disintegration, proteins and carbohydrates released into the water phase followed a first order kinetics. The process is selective towards proteins over carbohydrates during early stages of milling. In general, smaller beads led to higher kinetic rates, with a minimum specific energy consumption of ⩽0.47kWhkg DW -1 for 0.3mm beads. After analysis of the stress parameters (stress number and stress intensity), it appears that optimal disintegration and energy usage for all strains occurs in the 0.3-0.4mm range. During the course of bead milling, the native structure of the marker protein Rubisco was retained, confirming the mildness of the disruption process. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. HIGHLY ENERGY EFFICIENT D-GLU (DIRECTED-GREEN LIQ-UOR UTILIZATION) PULPING

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, Lucian A

    2013-04-19

    Purpose: The purpose of the project was to retrofit the front end (pulp house) of a commercial kraft pulping mill to accommodate a mill green liquor (GL) impregna-tion/soak/exposure and accrue downstream physical and chemical benefits while prin-cipally reducing the energy footprint of the mill. A major player in the mill contrib-uting to excessive energy costs is the lime kiln. The project was intended to offload the energy (oil or natural gas) demands of the kiln by by-passing the causticization/slaking site in the recovery area and directly using green liquor as a pulping medium for wood. Scope: The project was run in two distinct, yet mutually compatible, phases: Phase 1 was the pre-commercial or laboratory phase in which NC State University and the Insti-tute of Paper Science and Technology (at the Georgia Institute of Technology) ran the pulping and associated experiments, while Phase 2 was the mill scale trial. The first tri-al was run at the now defunct Evergreen Pulp Mill in Samoa, CA and lead to a partial retrofit of the mill that was not completed because it went bankrupt and the work was no longer the low-hanging fruit on the tree for the new management. The second trial was run at the MeadWestvaco Pulp Mill in Evedale, TX which for all intents and pur-poses was a success. They were able to fully retrofit the mill, ran the trial, studied the pulp properties, and gave us conclusions.

  11. Axial Force Analysis and Roll Contour Configuration of Four-High CVC Mill

    Directory of Open Access Journals (Sweden)

    Guang-ming Liu

    2018-01-01

    Full Text Available In order to analyze the influence of technical parameters on work roll axial force of four-high continuous variable crown (CVC mill, the deformation analyzing model with top roll system and strip was established based on influence function method. Then a CVC work roll curve designing scheme was proposed and it was carried out on some cold rolling mill considering the requirement of comprehensive work roll axial force minimization. The status of comprehensive work roll axial force is improved considering the rolling schedule that is beneficial to the roller bearing. Corresponding to the newly designed work roll contour, the backup roll end chamfer was designed considering comprehensive performance of interroll stress concentration, comprehensive work roll axial force, and strip shape control ability. The distribution of roll wear with newly designed backup roll contour is more even according to the field application data. The newly established roll configuration scheme is beneficial to four-high CVC mill.

  12. 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...

  13. 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.

  14. 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)

  15. Hydrogen desorption from mechanically milled carbon micro coils hydrogenated at high temperature

    International Nuclear Information System (INIS)

    Yoshio Furuya; Shuichi Izumi; Seiji Motojima; Yukio Hishikawa

    2005-01-01

    Carbon micro coils (CMC) have been prepared by the catalytic pyrolysis of acetylene at 750-800 C. The as grown coils have an almost amorphous structure and contain about 1 mass% hydrogen. They have 0.1 - 10 mm coil length, 1-5 μm coil diameter, 0.1-0.5 μm coil pitch and about 100 m 2 /g specific surface area. They were graphitized, as maintaining the morphology of the coils, by heat-treating at a higher temperature than 2500 C in Ar atmosphere. The layer space (d) of graphitized CMC was determined to be 0.341 nm, forming a 'herringbone' structure with an inclination of 10-40 degree versus the coiled fiber axis, having a specific surface area of about 8 m 2 /g. The hydrogen absorption behaviors of CMC were investigated from RT to 1200 C by a thermal desorption spectrometry (TDS) using a quadrupole mass analyzer. In TDS measurements, pre-existing hydrogen, which was due to the residual acetylene incorporated into CMC on its growing, desorbed from 700 C and peaked at about 900 C. The increment in the main peak of desorbed hydrogen in the as-grown CMC heat-treated at 500 C for 1 h under high pressure of hydrogen gas (1.9 or 8.9 MPa) was not remarkable as is shown in Fig.1. While, in the CMC samples milled mechanically for 1 h at RT using a planetary ball mill, the increase of desorbed hydrogen became to be great with the hydrogen pressure (up to 8.9 MPa) on heat-treating at 500 C, as is shown in Fig.2. In these CMC samples, the building up temperature of the hydrogen desorption was shifted to a lower one and the temperature range of desorption became to be wider than those in the as-grown CMC because of the appearance of another desorption peak at about 600 C in addition to the peak ranging from 850 C to 900 C. The same kind of peak was also slightly observed in as-grown CMC (Fig.1). It is clear that this desorption at about 600 C has contributed to the remarkable increase of desorbed hydrogen in the milled CMC. In this work, values of more than 2 mass% were obtained

  16. Utilization of aluminum to obtaining a duplex type stainless steel using high energy ball milling; Obtencao de um aco inoxidavel de estrutura duplex do sistema FeMnAl processado por moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Pavlak, I.E.; Cintho, O.M., E-mail: eng.igorpavlak@yahoo.com.b [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Capocchi, J.D.T. [Universidade de Sao Paulo (USP), SP (Brazil)

    2010-07-01

    The obtaining of stainless steel using aluminum in its composition - FeMnAl system, has been researches subject since the sixties, by good mechanical properties and resistance to oxidation presented, when compared with conventional FeNiCr stainless steel system. In another point, the aluminum and manganese are low cost then traditional elements. This work, metallic powders of iron, manganese and pure aluminum, were processed in a Spex type high-energy ball mill in nitrogen atmosphere. The milling products were compressed into pastille form and sintered under inert atmosphere. The final products were characterized by optical and electronic microscopy and microhardness test. The metallographic analysis shows a typical austenite and ferrite duplex type microstructure. The presence of these phases was confirmed according X ray diffraction analysis. (author)

  17. High-efficient production of boron nitride nanosheets via an optimized ball milling process for lubrication in oil.

    Science.gov (United States)

    Deepika; Li, Lu Hua; Glushenkov, Alexey M; Hait, Samik K; Hodgson, Peter; Chen, Ying

    2014-12-03

    Although tailored wet ball milling can be an efficient method to produce a large quantity of two-dimensional nanomaterials, such as boron nitride (BN) nanosheets, milling parameters including milling speed, ball-to-powder ratio, milling ball size and milling agent, are important for optimization of exfoliation efficiency and production yield. In this report, we systematically investigate the effects of different milling parameters on the production of BN nanosheets with benzyl benzoate being used as the milling agent. It is found that small balls of 0.1-0.2 mm in diameter are much more effective in exfoliating BN particles to BN nanosheets. Under the optimum condition, the production yield can be as high as 13.8% and the BN nanosheets are 0.5-1.5 μm in diameter and a few nanometers thick and of relative high crystallinity and chemical purity. The lubrication properties of the BN nanosheets in base oil have also been studied. The tribological tests show that the BN nanosheets can greatly reduce the friction coefficient and wear scar diameter of the base oil.

  18. NdFeB nanoparticles prepared by wet-milling

    Energy Technology Data Exchange (ETDEWEB)

    Thielsch, Juliane; Lyubina, Julia; Woodcock, Thomas; Schultz, Ludwig; Gutfleisch, Oliver [IFW Dresden (Germany)

    2010-07-01

    Since the prediction of a giant energy product of textured nanocomposite magnets those materials where believed to be the next generation of permanent magnets. For effective exchange-coupling in such two-phase magnets grain sizes need to be in the range of the domain wall width of the hard magnetic phase. That makes a homogenous phase distribution and a microstructure with nanograins necessary. One option of preparing such materials is the synthesis of magnetic nanoparticles which further could be aligned and compacted to a bulk magnet. For this we performed wet-milling experiments of a NdFeGaNbB alloy. XRD studies revealed that by using a surfactant and a solvent during the high energy ball milling process amorphization sets in later than compared to dry milling experiments under the same conditions. Dynamic Light Scattering investigations showed a Gauss distribution of the particle size with a mean diameter of about 12nm which was also proven by TEM. Magnetic properties were measured with SQUID and showed so far rather poor coercivity values.

  19. The determination of radium-226 in uranium ores and mill products by alpha energy spectrometry

    International Nuclear Information System (INIS)

    Zimmerman, J.B.; Armstrong, V.C.

    1975-12-01

    A reliable routine procedure for determining 226 Ra by alpha energy spectrometry is described. Radium is isolated as sulphate from the sample matrix by co-precipitation with a small mass of barium and analysed using a ruggedized silicon surface barrier detector. The method is capable of providing high accuracy over a large 226 Ra concentration range and is applicable to materials such as uranium ores, uranium mill products and effluent streams. Samples resulting from nitric acid leach experiments with Elliot Lake ores were examined using the procedure. The distribution of 223 Ra, 224 Ra and 226 Ra between the leach products, (residue and leach liquor), is discussed. (author)

  20. 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)

  1. Excess heat from kraft pulp mills: Trade-offs between internal and external use in the case of Sweden-Part 2: Results for future energy market scenarios

    International Nuclear Information System (INIS)

    Joensson, Johanna; Svensson, Inger-Lise; Berntsson, Thore; Moshfegh, Bahram

    2008-01-01

    In this paper the trade-off between internal and external use of excess heat from a kraft pulp mill is investigated for four different future energy market scenarios. The work follows the methodology described in Svensson et al. [2008. Excess heat from kraft pulp mills: trade-offs between internal and external use in the case of Sweden-Part 1: methodology. Energy Policy, submitted for publication], where a systematic approach is proposed for investigating the potential for profitable excess heat cooperation. The trade-off is analyzed by economic optimization of an energy system model consisting of a pulp mill and an energy company (ECO). In the model, investments can be made, which increase the system's energy efficiency by utilization of the mill's excess heat, as well as investments that increase the electricity production. The results show that the trade-off depends on energy market prices, the district heating demand and the type of existing heat production. From an economic point of view, external use of the excess heat is preferred for all investigated energy market scenarios if the mill is studied together with an ECO with a small heat load. For the cases with medium or large district heating loads, the optimal use of excess heat varies with the energy market price scenarios. However, from a CO 2 emissions perspective, external use is preferred, giving the largest reduction of global emissions in most cases

  2. Highly anisotropic SmCo5 nanoflakes by surfactant-assisted ball milling at low temperature

    International Nuclear Information System (INIS)

    Liu, Lidong; Zhang, Songlin; Zhang, Jian; Ping Liu, J.; Xia, Weixing; Du, Juan; Yan, Aru; Yi, Jianhong; Li, Wei; Guo, Zhaohui

    2015-01-01

    Surfactant-assisted ball milling (SABM) has been shown to be a promising method for preparing rare earth-transition metal (RE-TM) nanoflakes and nanoparticles. In this work, we prepared SmCo 5 nanoflakes by SABM at low temperature, and 2-methyl pentane and trioctylamine were specially selected as solvent and surfactant, respectively, due to their low melting points. The effects of milling temperature on the morphology, microstructure and magnetic performance of SmCo 5 nanoflakes were investigated systematically. Comparing with the samples milled at room temperature, the SmCo 5 nanoflakes prepared at low temperature displayed more homogeneous morphology and lower oxygen content. Remarkably, better crystallinity, better grain alignment and larger remanence ratio were shown in the samples milled at low temperature, which resulted from the distinct microstructure caused by low milling temperature. The differences in structural evolution between the SmCo 5 nanoflakes milled at room temperature and low temperature, including the formation of nanocrystalline, grain boundary sliding, grain rotation, et al., were discussed. It was found that lowering the temperature of SABM was a powerful method for the fabrication of RE-TM nanoflakes, which showed better hard magnetic properties and lower oxygen content. This was important for the preparation of high-performance sintered magnets, bonded magnets and nanocomposite magnets. - Highlights: • We prepare SmCo 5 nanoflakes by surfactant-assisted ball milling at low temperature. • Better grain alignment and higher remanence ratio are achieved. • The oxygen content is reduced by lowering the milling temperature. • A distinct microstructural evolution caused by low milling temperature is clarified

  3. 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.

  4. 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

  5. Structural evolution and formation mechanisms of TiC/Ti nanocomposites prepared by high-energy mechanical alloying

    International Nuclear Information System (INIS)

    Gu Dongdong; Meiners, Wilhelm; Hagedorn, Yves-christian; Wissenbach, Konrad; Poprawe, Reinhart

    2010-01-01

    In this work, high-energy ball milling of a micrometre-scaled Ti and TiC powder mixture was performed to prepare TiC/Ti nanocomposites. The constituent phases and microstructural characteristics of the milled powders were studied by an x-ray diffractometer, a scanning electron microscope, an energy dispersive x-ray spectroscope and a transmission electron microscope. Formation mechanisms and theoretical basis of the microstructural development were elucidated. It showed that on increasing the applied milling time, the structures of the Ti constituent experienced a successive change from hcp (5 h) to fcc (10 h) and finally to an amorphous state (≥15 h). The hydrostatic stresses caused by the excess free volume at grain boundaries were calculated to be 3.96 and 5.59 GPa for the Ti constituent in 5 and 10 h milled powders, which was responsible for the hcp to fcc polymorphic change. The amorphization of Ti constituent was due to the large defect concentration induced by severe plastic deformation during milling. The milled powder particles underwent two stages of significant refinement at 10 and 20 h during milling. For a higher milling time above 25 h, powder characteristics and chemical compositions became stable. The competitive action and the final equilibrium between the mechanisms of fracturing and cold welding accounted for the microstructural evolution. The ball milled products were typically nanocomposite powders featured by a nanocrystalline/amorphous Ti matrix reinforced with uniformly dispersed TiC nanoparticles. The finest crystalline sizes of the Ti and TiC constituents were 17.2 nm (after 10 h milling) and 13.5 nm (after 20 h milling), respectively.

  6. Energy efficiency and policy in Swedish pulp and paper mills: A data envelopment analysis approach

    International Nuclear Information System (INIS)

    Blomberg, Jerry; Henriksson, Eva; Lundmark, Robert

    2012-01-01

    The paper provides an empirical assessment of the electricity efficiency improvement potential in the Swedish pulp and paper industry by employing data envelopment analysis (DEA) and mill-specific input and output data for the years 1995, 2000 and 2005. The empirical results are discussed in relation to the reported outcomes of the Swedish voluntary energy efficiency programme PFE. The estimated electricity efficiency gap is relatively stable over the time period; it equals roughly 1 TWh per year for the sample mills and this is three times higher than the corresponding self-reported electricity savings in PFE. This result is largely a reflection of the fact that in the pulp and paper industry electricity efficiency improvements are typically embodied in the diffusion of new capital equipment, and there is a risk that some of the reported measures in PFE simply constitute an inefficient speed-up of capital turnover. The above does not preclude, though, that many other measures in PFE may have addressed some relevant market failures and barriers in the energy efficiency market. Overall the analysis suggests that future energy efficiency programs could plausibly be better targeted at explicitly promoting technological progress as well as at addressing the most important information and behaviour-related failures. - Highlights: ► We provide an empirical assessment of the electricity efficiency improvement potential in the Swedish pulp and paper industry. ► The empirical results are discussed in relation to the reported outcomes of the Swedish voluntary energy efficiency programme PFE. ► The estimated electricity efficiency gap is relatively stable over the time period and equals roughly 1 TWh for the sample mills (three times higher than the corresponding self-reported electricity savings in PFE). ► The results suggest that future energy efficiency programs could be better targeted at explicitly promoting technological progress as well as at addressing the

  7. Low energy dynamics of monopoles in supersymmetric Yang-Mills theories with hypermultiplets

    International Nuclear Information System (INIS)

    Kim, Chanju

    2006-01-01

    We derive the low energy dynamics of monopoles and dyons in N = 2 supersymmetric Yang-Mills theories with hypermultiplets in arbitrary representations by utilizing a collective coordinate expansion. We consider the most general case that Higgs fields both in the vector multiplet and in the hypermultiplets have nonzero vacuum expectation values. The resulting theory is a supersymmetric quantum mechanics which has been obtained by a nontrivial dimensional reduction of two-dimensional (4,0) supersymmetric sigma models with potentials

  8. 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.)

  9. 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

  10. Use of high energy ball milling to study the role of graphene nanoplatelets and carbon nanotubes reinforced magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Rashad, Muhammad, E-mail: rashadphy87@gmail.com [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Pan, Fusheng, E-mail: fspan@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing, Chongqing 401123 (China); Zhang, Jianyue [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Asif, Muhammad [School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2015-10-15

    Graphene nanoplatelets (few layer graphene) and carbon nanotubes were used as reinforcement fillers to enhance the mechanical properties of AZ31 magnesium alloy through high energy ball milling, sintering, and hot extrusion techniques. Experimental results revealed that tensile fracture strain of AZ31 magnesium alloy was enhanced by +49.6% with 0.3 wt.% graphene nanoplatelets compared to −8.3% regression for 0.3 wt.% carbon nanotubes. The tensile strength of AZ31 magnesium alloy was decreased (−11.2%) with graphene nanoplatelets addition, while increased (+7.7%) with carbon nanotubes addition. Unlike tensile test, compression tests showed different trend. The compression strength of carbon nanotubes-AZ31 composite was +51.2% greater than AZ31 magnesium alloy as compared to +0.6% increase for graphene nanoplatelets. The compressive fracture strain of carbon nanotubes-AZ31 composite was decreased (−14.1%) while no significant change in fracture strain of graphene nanoplatelets-AZ31 composite was observed. The X-ray diffraction results revealed that addition of reinforcement particles weaken the basal textures which affect the composite's yield asymmetry. Microstructure evaluation revealed the absence of intermetallic phase formation between reinforcements and matrix. The carbon reinforcements in AZ31 magnesium alloy dissolve and isolate β phases throughout the matrix. The increased fracture strain and mechanical strength of graphene nanoplatelets and carbon nanotubes-AZ31 composites are attributed to large specific surface area of graphene nanoplatelets and stiffer nature of carbon nanotubes respectively. - Highlights: • Powder metallurgy method was used to fabricate magnesium composites. • The AZ31-carbon materials composite were blended using ball milling. • The reinforcement particles weaken the basal texture which affects yield asymmetry of composites. • AZ31-graphene nanoplatelets composite exhibited impressive increase in tensile elongation

  11. Use of high energy ball milling to study the role of graphene nanoplatelets and carbon nanotubes reinforced magnesium alloy

    International Nuclear Information System (INIS)

    Rashad, Muhammad; Pan, Fusheng; Zhang, Jianyue; Asif, Muhammad

    2015-01-01

    Graphene nanoplatelets (few layer graphene) and carbon nanotubes were used as reinforcement fillers to enhance the mechanical properties of AZ31 magnesium alloy through high energy ball milling, sintering, and hot extrusion techniques. Experimental results revealed that tensile fracture strain of AZ31 magnesium alloy was enhanced by +49.6% with 0.3 wt.% graphene nanoplatelets compared to −8.3% regression for 0.3 wt.% carbon nanotubes. The tensile strength of AZ31 magnesium alloy was decreased (−11.2%) with graphene nanoplatelets addition, while increased (+7.7%) with carbon nanotubes addition. Unlike tensile test, compression tests showed different trend. The compression strength of carbon nanotubes-AZ31 composite was +51.2% greater than AZ31 magnesium alloy as compared to +0.6% increase for graphene nanoplatelets. The compressive fracture strain of carbon nanotubes-AZ31 composite was decreased (−14.1%) while no significant change in fracture strain of graphene nanoplatelets-AZ31 composite was observed. The X-ray diffraction results revealed that addition of reinforcement particles weaken the basal textures which affect the composite's yield asymmetry. Microstructure evaluation revealed the absence of intermetallic phase formation between reinforcements and matrix. The carbon reinforcements in AZ31 magnesium alloy dissolve and isolate β phases throughout the matrix. The increased fracture strain and mechanical strength of graphene nanoplatelets and carbon nanotubes-AZ31 composites are attributed to large specific surface area of graphene nanoplatelets and stiffer nature of carbon nanotubes respectively. - Highlights: • Powder metallurgy method was used to fabricate magnesium composites. • The AZ31-carbon materials composite were blended using ball milling. • The reinforcement particles weaken the basal texture which affects yield asymmetry of composites. • AZ31-graphene nanoplatelets composite exhibited impressive increase in tensile elongation

  12. Biomass by-product from crystal sugar production: A comparative study between Ngadirejo and Mauritius sugar mill

    Science.gov (United States)

    Gunawan; Bantacut, T.; Romli, M.; Noor, E.

    2018-03-01

    Sugarcane has been used as raw material in crystal sugar industry. Sugar cane that contains high sugar will be utilized into crystals sugar. In addition, the productivity of sugarcane is large enough in 2016 approximately 360 713 tons/year. Crystal sugar itself is a daily necessity for its use in the food and beverage industry. Problem that occurs in Indonesia is the energy consumption. The sugar mills supposed to be an independent energy source which means it can produce its own energy by utilization the material that is available in the sugar mills such as by-product (bagasse, molasses, filter cake, etc.), the by product in every production stage are quite a lot in sugar industry especially in Indonesia. In this paper, a comparison between two sugar mills was examined between Ngedirejo sugar mill and Mauritius sugar mill which has the same geological state as Indonesia. The results of comparison between the two sugar factories demonstrated the difference in terms of productivity of the sugar that has been produced and the effectiveness of the production process in a sugar mill seen from the amount of waste and the by product.

  13. Impact of high-pressure coolant supply on chip formation in milling

    Science.gov (United States)

    Klocke, F.; Döbbeler, B.; Lakner, T.

    2017-10-01

    Machining of titanium alloys is considered as difficult, because of their high temperature strength, low thermal conductivity and low E-modulus, which contributes to high mechanical loads and high temperatures in the contact zone between tool and workpiece. The generated heat in the cutting zone can be dissipated only in a low extent. When cutting steel materials, up to 75% of the process heat is transported away by the chips, contrary to only 25% when machining titanium alloys. As a result, the cutting tool heats up, which leads to high tool wear. Therefore, machining of titanium alloys is only possible with relatively low cutting speeds. This leads to low levels of productivity for milling processes with titanium alloys. One way to increase productivity is to use more cutting edges in tools with the same diameter. However, the limiting factor of adding more cutting edges to a milling tool is the minimum size of the chip spaces, which are sufficient for a stable chip evacuation. This paper presents experimental results on the chip formation and chip size influenced by high-pressure coolant supply, which can lead to smaller chips and to smaller sizes of the chip spaces, respectively. Both influences, the pressure of the supplied coolant and the volumetric flow rate were individually examined. Alpha-beta annealed titanium TiAl6V4 was examined in relation to the reference material quenched and tempered steel 42CrMo4+QT (AISI 4140+QT). The work shows that with proper chip control due to high-pressure coolant supply in milling, the number of cutting edges on the same diameter tool can be increased, which leads to improved productivity.

  14. 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.

  15. 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

  16. 77 FR 58120 - Inman Mills; Notice of Authorization for Continued Project Operation

    Science.gov (United States)

    2012-09-19

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 4362-000] Inman Mills... for a subsequent license was August 31, 2010. Inman Mills, the licensee for Project No. 4362, did not... the license from Inman Mills to Riverdale Development Venture, LLC. 115 FERC ] 62,076 (2006). However...

  17. 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.

  18. 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)

  19. 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)

  20. Moessbauer spectroscopy study of the synthesis of SnFe2O4 by high energy ball milling (HEBM) of SnO and α-Fe2O3

    International Nuclear Information System (INIS)

    Uwakweh, Oswald N C; Perez Moyet, Richard; Mas, Rita; Morales, Carolyn; Vargas, Pedro; Silva, Josue; Rossa, Angel; Lopez, Neshma

    2010-01-01

    The formation of single phase nanoparticles of spinel structured ferrite, SnFe 2 O 4 , by mechanochemical syntheses using HEBM of stoichiometric amounts of solid SnO and α-Fe 2 O 3 with acetone as surfactant was achieved progressively as function of ball milling time. Single phase SnFe 2 O 4 formation commenced from five hours of continuous ball milling, and reached completion after 22 hours, thereby yielding a material with a lattice parameter of 8.543 A, and particle size of 10.91 nm. The coercivity was 4.44 mT, magnetic saturation value of 17.75 Am 2 /kg, and remanent magnetizations of 1.50 Am 2 /kg, correspondingly. The nanosized particles exhibited superparamagnetic behavior phenomenon based on Moessbauer spectroscopy measurements. The kinetic analyses based on the modified Kissinger method yielded four characteristic stages during the thermal evolution of the 22 hours milled state with activation energies of 0.23 kJ/mol, 2.52 kJ/mol, 0.024 kJ/mol, and 1.57 kJ/mol respectively.

  1. 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.

  2. 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.

  3. Comparison of high pressure homogenization and stirred bead milling for the production of nano-crystalline suspensions.

    Science.gov (United States)

    Nakach, Mostafa; Authelin, Jean-René; Perrin, Marc-Antoine; Lakkireddy, Harivardhan Reddy

    2018-05-19

    Currently, the two technologies primarily used for the manufacturing of nano-crystalline suspensions using top down process (i.e. wet milling) are high pressure homogenization (HPH) and stirred bead milling (SBM). These two technologies are based upon different mechanisms, i.e., cavitation forces for HPH and shear forces for stirred bead milling. In this article, the HPH and SBM technologies are compared in terms of the impact of the suspension composition the process parameters and the technological configuration on milling performances and physical quality of the suspensions produced. The data suggested that both HPH and SBM are suitable for producing nano-crystalline suspensions, although SBM appeared more efficient than HPH, since the limit of milling (d 50 ) for SBM was found to be lower than that obtained with HPH (100 nm vs 200 nm). For both these technologies, regardless of the process parameters used for milling and the scale of manufacturing, the relationship of d 90 versus d 50 could be described by a unique master curve (technology signature of milling pathway) outlining that the HPH leads to more uniform particle size distribution as compared to SBM. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Highly anisotropic SmCo{sub 5} nanoflakes by surfactant-assisted ball milling at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lidong; Zhang, Songlin [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Zhang, Jian, E-mail: zhangj@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Ping Liu, J. [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States); Xia, Weixing; Du, Juan; Yan, Aru [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Science, Ningbo 315201 (China); Yi, Jianhong [Institute of Material Science and Engineering, Kunming University of Science and Technology, Kunming 650500 (China); Li, Wei; Guo, Zhaohui [Division of Functional Materials, Central Iron and Steel Research Institute, Beijing 100081 (China)

    2015-01-15

    Surfactant-assisted ball milling (SABM) has been shown to be a promising method for preparing rare earth-transition metal (RE-TM) nanoflakes and nanoparticles. In this work, we prepared SmCo{sub 5} nanoflakes by SABM at low temperature, and 2-methyl pentane and trioctylamine were specially selected as solvent and surfactant, respectively, due to their low melting points. The effects of milling temperature on the morphology, microstructure and magnetic performance of SmCo{sub 5} nanoflakes were investigated systematically. Comparing with the samples milled at room temperature, the SmCo{sub 5} nanoflakes prepared at low temperature displayed more homogeneous morphology and lower oxygen content. Remarkably, better crystallinity, better grain alignment and larger remanence ratio were shown in the samples milled at low temperature, which resulted from the distinct microstructure caused by low milling temperature. The differences in structural evolution between the SmCo{sub 5} nanoflakes milled at room temperature and low temperature, including the formation of nanocrystalline, grain boundary sliding, grain rotation, et al., were discussed. It was found that lowering the temperature of SABM was a powerful method for the fabrication of RE-TM nanoflakes, which showed better hard magnetic properties and lower oxygen content. This was important for the preparation of high-performance sintered magnets, bonded magnets and nanocomposite magnets. - Highlights: • We prepare SmCo{sub 5} nanoflakes by surfactant-assisted ball milling at low temperature. • Better grain alignment and higher remanence ratio are achieved. • The oxygen content is reduced by lowering the milling temperature. • A distinct microstructural evolution caused by low milling temperature is clarified.

  5. Flank wear analysing of high speed end milling for hardened steel D2 using Taguchi Method

    Science.gov (United States)

    Hazza Faizi Al-Hazza, Muataz; Ibrahim, Nur Asmawiyah bt; Adesta, Erry T. Y.; Khan, Ahsan Ali; Abdullah Sidek, Atiah Bt.

    2017-03-01

    One of the main challenges for any manufacturer is how to decrease the machining cost without affecting the final quality of the product. One of the new advanced machining processes in industry is the high speed hard end milling process that merges three advanced machining processes: high speed milling, hard milling and dry milling. However, one of the most important challenges in this process is to control the flank wear rate. Therefore a analyzing the flank wear rate during machining should be investigated in order to determine the best cutting levels that will not affect the final quality of the product. In this research Taguchi method has been used to investigate the effect of cutting speed, feed rate and depth of cut and determine the best level s to minimize the flank wear rate up to total length of 0.3mm based on the ISO standard to maintain the finishing requirements.

  6. 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...

  7. High energy behaviour of nonabelian gauge theories

    International Nuclear Information System (INIS)

    Bartels, J.

    1979-10-01

    The high energy behavior (in the Regge limit) of nonabelian gauge theories is reviewed. After a general remark concerning the question to what extent the Regge limit can be approached within perturbation theory, we first review the reggeization of elementary particles within nonabelian gauge theories. Then the derivation of a unitary high energy description of a massive (= spontaneously broken) nonabelian gauge model is described, which results in a complete reggeon calculus. There is strong evidence that the zero mass limit of this reggeon calculus exists, thus giving rise to the hope that the Regge behavior in pure Yang-Mills theories (QCD) can be reached in this way. In the final part of these lectures two possible strategies for solving this reggeon calculus (both for the massive and the massless case) are outlined. One of them leads to a geometrical picture in which the distribution of the wee partons obeys a diffusion law. The other one makes contact with reggeon field theory and predicts that QCD in the high energy limit is described by critical reggeon field theory. (orig.)

  8. Gathering straw energy balance for co-generation in sugarcane mills; Balanco energetico do recolhimento da palha para cogeracao de energia em usinas de cana-de-acucar

    Energy Technology Data Exchange (ETDEWEB)

    Veiga, Joao Paulo Soto; Bizzo, Waldir Antonio; Carvalho, Danilo Jose; Berton, Rafael Piatto [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica; Linero, Francisco Antonio Barba [Centro de Tecnologia Canavieira (CTC), Piracicaba, SP (Brazil)], E-mails: jpsveiga@fem.unicamp.br, bizzo@fem.unicamp.br, linero@ctc.com.br, liar@fem.unicamp.br, rpberton@fem.unicamp.br

    2012-11-01

    With the requirement and expansion of sugarcane harvest without burning the straw in the field of began to be seen as a potential fuel for co-generation sugarcane mills together bagasse. This study examined the productivity and three ways of gathering and transportation of straw in order to determine the potential energy available in biomass residues and their respective energy consumption on gathering and transport operations. To this were determined parameters for the production of waste per hectare, minimum quantity to be left in the field for maintenance of soil organic carbon and erosion reducing, the amount of straw recovered and milled at the mill, material humidity and diesel and electricity consumption of each step to obtain the final balance of energy recovered. (author)

  9. Electroweak precision tests in high-energy diboson processes

    Science.gov (United States)

    Franceschini, Roberto; Panico, Giuliano; Pomarol, Alex; Riva, Francesco; Wulzer, Andrea

    2018-02-01

    A promising avenue to perform precision tests of the SM at the LHC is to measure differential cross-sections at high invariant mass, exploiting in this way the growth with the energy of the corrections induced by heavy new physics. We classify the leading growing-with-energy effects in longitudinal diboson and in associated Higgs production processes, showing that they can be encapsulated in four real "high-energy primary" parameters. We assess the reach on these parameters at the LHC and at future hadronic colliders, focusing in particular on the fully leptonic W Z channel that appears particularly promising. The reach is found to be superior to existing constraints by one order of magnitude, providing a test of the SM electroweak sector at the per-mille level, in competition with LEP bounds. Unlike LHC run-1 bounds, which only apply to new physics effects that are much larger than the SM in the high-energy tail of the distributions, the probe we study applies to a wider class of new physics scenarios where such large departures are not expected.

  10. The Influence of Milling and Spark Plasma Sintering on the Microstructure and Properties of the Al7075 Alloy

    Science.gov (United States)

    Málek, Přemysl; Minárik, Peter; Novák, Pavel; Průša, Filip

    2018-01-01

    The compact samples of an Al7075 alloy were prepared by a combination of gas atomization, high energy milling, and spark plasma sintering. The predominantly cellular morphology observed in gas atomized powder particles was completely changed by mechanical milling. The continuous-like intermetallic phases present along intercellular boundaries were destroyed; nevertheless, a small amount of Mg(Zn,Cu,Al)2 phase was observed also in the milled powder. Milling resulted in a severe plastic deformation of the material and led to a reduction of grain size from several µm into the nanocrystalline region. The combination of these microstructural characteristics resulted in abnormally high microhardness values exceeding 300 HV. Consolidation through spark plasma sintering (SPS) resulted in bulk samples with negligible porosity. The heat exposition during SPS led to precipitation of intermetallic phases from the non-equilibrium microstructure of both gas atomized and milled powders. SPS of the milled powder resulted in a recrystallization of the severely deformed structure. An ultra-fine grained structure (grain size close to 500 nm) with grains divided primarily by high-angle boundaries was formed. A simultaneous release of stored deformation energy and an increase in the grain size caused a drop of microhardness to values close to 150 HV. This value was retained even after annealing at 425 °C. PMID:29614046

  11. The Influence of Milling and Spark Plasma Sintering on the Microstructure and Properties of the Al7075 Alloy

    Directory of Open Access Journals (Sweden)

    Orsolya Molnárová

    2018-04-01

    Full Text Available The compact samples of an Al7075 alloy were prepared by a combination of gas atomization, high energy milling, and spark plasma sintering. The predominantly cellular morphology observed in gas atomized powder particles was completely changed by mechanical milling. The continuous-like intermetallic phases present along intercellular boundaries were destroyed; nevertheless, a small amount of Mg(Zn,Cu,Al2 phase was observed also in the milled powder. Milling resulted in a severe plastic deformation of the material and led to a reduction of grain size from several µm into the nanocrystalline region. The combination of these microstructural characteristics resulted in abnormally high microhardness values exceeding 300 HV. Consolidation through spark plasma sintering (SPS resulted in bulk samples with negligible porosity. The heat exposition during SPS led to precipitation of intermetallic phases from the non-equilibrium microstructure of both gas atomized and milled powders. SPS of the milled powder resulted in a recrystallization of the severely deformed structure. An ultra-fine grained structure (grain size close to 500 nm with grains divided primarily by high-angle boundaries was formed. A simultaneous release of stored deformation energy and an increase in the grain size caused a drop of microhardness to values close to 150 HV. This value was retained even after annealing at 425 °C.

  12. Environmental impact of uranium mining and milling

    International Nuclear Information System (INIS)

    Dory, A.B.

    1981-08-01

    The Atomic Energy Control Board is now involved from the early planning stages in the development of uranium mine/mill facilities. As a result, new facilities (including tailings management areas) are designed and developed to meet a high standard. The impact of the mines and tailings areas in the Elliot Lake area on ground and surface waters and air quality is discussed in detail

  13. Micro structrual characterization and analysis of ball milled silicon carbide

    Science.gov (United States)

    Madhusudan, B. M.; Raju, H. P.; Ghanaraja., S.

    2018-04-01

    Mechanical alloying has been one of the prominent methods of powder synthesis technique in solid state involving cyclic deformation, cold welding and fracturing of powder particles. Powder particles in this method are subjected to greater mechanical deformation due to the impact of ball-powder-ball and ball-powder-container collisions that occurs during mechanical alloying. Strain hardening and fracture of particles decreases the size of the particles and creates new surfaces. The objective of this Present work is to use ball milling of SiC powder for different duration of 5, 10, 15 and 20 hours by High energy planetary ball milling machine and to evaluate the effect of ball milling on SiC powder. Micro structural Studies using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and EDAX has been investigated.

  14. Modeling and simulation of high-speed milling centers dynamics

    OpenAIRE

    Msaddek , El Bechir; Bouaziz , Zoubeir; Baili , Maher; Dessein , Gilles

    2011-01-01

    International audience; High-speed machining is a milling operation in industrial production of aeronautic parts, molds, and dies. The parts production is being reduced because of the slowing down of the machining resulting from the tool path discontinuity machining strategy. In this article, we propose a simulation tool of the machine dynamic behavior, in complex parts machining. For doing this, analytic models have been developed expressing the cutting tool feed rate. Afterwards, a simulati...

  15. Clean Fuel, Clean Energy Conversion Technology: Experimental and Numerical Investigation of Palm Oil Mill Effluent Biogas Flameless Combustion

    Directory of Open Access Journals (Sweden)

    Seyed Ehsan Hosseini

    2015-08-01

    Full Text Available The combustion of effluent biogas from a palm oil mill is not feasible on a large scale because of its low calorific value (LCV. Therefore, the captured biogas is usually flared because of a lack of appropriate combustion technology. However, such biogas could be an excellent source of energy for combined heat and power (CHP generation in palm oil mills. In this paper, the feasibility of using biogas from palm oil mills in flameless combustion systems is investigated. In computational fluid dynamic (CFD modeling, a two-step reaction scheme is employed to simulate the eddy dissipation method (EDM. In such biogas flameless combustion, the temperature inside the chamber is uniform and hot spots are eliminated. The peak of the non-luminous flame volume and the maximum temperature uniformity occur under stoichiometric conditions when the concentration of oxygen in the oxidizer is 7%. In these conditions, as the concentration of oxygen in the oxidizer increases, the efficiency of palm oil mill effluent biogas flameless combustion increases. The maximum efficiency (around 61% in the experiment is achieved when the percentage of oxygen in the oxidizer is 7%.

  16. The effect of surfactant addition on high-energy milling upon the magnetic properties and microstructure of the Pr-Fe-B HDDR magnetic powders; Efeito da adicao de surfactantes nas propriedades e microestrutura de pos magneticos a base de Pr-Fe-B obtidos via HDDR e moagem de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, P.B.; Silva, S.C.; Faria, R.N.; Takiishia, H., E-mail: pbsantos@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    Nanomagnetic powders based on the composition Pr{sub 12}Fe{sub 65.9}Co{sub 16}B{sub 6}Nb{sub 0.1} have been obtained from using (a) the hydrogenation, disproportionation, desorption and recombination (HDDR) process; (b) by varying of milling time and (c) with the addition of an oleic acid as a surfactant. The latter has been used to enhance milling condition by preventing the agglomeration of particles and hence to improve the intrinsic coercivity of the material. High-energy mechanical milling has been used to yield magnetic nanoparticles. Powders were characterized magnetically using vibrating sample magnetometer (VSM) and microstructurally by Scanning Electron Microscopy (SEM), Field Emission Gun SEM (FEG-SEM) and X-ray diffraction. (author)

  17. Direct heat transfer considerations for improving energy efficiency in pulp and paper Kraft mills

    International Nuclear Information System (INIS)

    Savulescu, Luciana Elena; Alva-Argaez, Alberto

    2008-01-01

    The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks

  18. 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

  19. Potential Co-Generation of Electrical Energy from Mill Waste: A Case Study of the Malaysian Furniture Manufacturing Industry

    Directory of Open Access Journals (Sweden)

    Jegatheswaran Ratnasingam

    2016-04-01

    Full Text Available Furniture manufacturing in Malaysia is an established industry driven primarily by the availability of raw materials and labor. However, the industry suffers from the low-recovery rate of its materials, as it produces a substantial amount of waste during the manufacturing process. Although smaller waste fragments, or off-cuts, are recovered for other purposes, the splinters, shavings, and coarse dust have little economic value and are often discarded. Because wood is a well-established source of bioenergy, this study investigated the potential use of mill waste from the furniture-manufacturing industry for electrical energy generation. Waste from the rubberwood, bamboo, and rattan furniture industries was evaluated for its potential electrical energy generation, and the amount was compared with the electrical energy that was consumed by the furniture industry. The study also compared the emission of greenhouse gases from the combustion of these waste materials against fossil fuels used to generate electricity to assess its potential in terms of the environmental benefits. In conclusion, such mill waste could be utilized as substitute for fossil fuel to generate energy in the furniture industry.

  20. Process optimization and particle engineering of micronized drug powders via milling.

    Science.gov (United States)

    Brunaugh, A; Smyth, H D C

    2017-11-13

    Process control and optimization is a critical aspect of process analytical technology (PAT), quality by design (QbD), and the implementation of continuous manufacturing procedures. While process control and optimization techniques have been utilized in other manufacturing industries for decades, the pharmaceutical industry has only recently begun to adopt these procedures. Micronization, particularly milling, is a generally low-yield, high-energy consumption process that is well suited for a process optimization mindset. This review discusses optimization of the pharmaceutical milling process through design space development, theoretical and empirical modeling, and monitoring of critical quality attributes.

  1. 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

  2. Symmetric energy-momentum tensor in Maxwell, Yang-Mills, and Proca theories obtained using only Noether's theorem

    International Nuclear Information System (INIS)

    Montesinos, M.; Flores, E.

    2006-01-01

    The symmetric and gauge-invariant energy-momentum tensors for source-free Maxwell and Yang-Mills theories are obtained by means of translations in spacetime via a systematic implementation of Noether's theorem. For the source-free neutral Proca field, the same procedure yields also the symmetric energy-momentum tensor. In all cases, the key point to get the right expressions for the energy-momentum tensors is the appropriate handling of their equations of motion and the Bianchi identities. It must be stressed that these results are obtained without using Belinfante's symmetrization techniques which are usually employed to this end. (Author)

  3. Control of Natural Zeolite Properties by Mechanical Activation in Stirred Media Mill

    Directory of Open Access Journals (Sweden)

    Bohács K.

    2017-06-01

    Full Text Available Due to the special characteristics of zeolites, they can be applied in a very wide range of industries, i.e. agricultural, environmental or water treatment purposes. Generally, high added value zeolite products are manufactured by micro- or nanogrinding. However, these processes require high energy input and cause significant wearing of the mill parts. Therefore, the optimization of zeolite grinding, as well as the control of its properties are of a great importance. In the present paper a Hungarian natural zeolite was mechanically activated in stirred media mill for various residence times in distilled water, meanwhile the particle size distribution and the grinding energy were measured. Additionally, on-line tube rheometer was used to study the rheology of the suspension during the grinding process. The particle interaction and the suspension aggregation stability were detected by zeta-potential measurements. Structural changes due to the mechanical activation process were monitored by FTIR. It was found that the material structure of the zeolite, as well as the rheological behaviour of the zeolite suspension and its aggregation stability had been altered due to the mechanical activation in the stirred media mill. It can be concluded that the zeolite product properties can be modified by mechanical activation in order to produce a high added value tailored material.

  4. 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.

  5. 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

  6. High productivity mould robotic milling in Al-5083

    Science.gov (United States)

    Urresti, Iker; Arrazola, Pedro Jose; Ørskov, Klaus Bonde; Pelegay, Jose Angel

    2018-05-01

    Industrial serial robots were usually limited to welding, handling or spray painting operations until very recent years. However, some industries have already realized about their important capabilities in terms of flexibility, working space, adaptability and cost. Hence, currently they are seriously being considered to carry out certain metal machining tasks. Therefore, robot based machining is presented as a cost-saving and flexible manufacturing alternative compared to conventional CNC machines especially for roughing or even pre-roughing of large parts. Nevertheless, there are still some drawbacks usually referred as low rigidity, accuracy and repeatability. Thus, the process productivity is usually sacrificed getting low Material Removal Rates (MRR), and consequently not being competitive. Nevertheless, in this paper different techniques to obtain increased productivity are presented, though an appropriate selection of cutting strategies and parameters that are essential for it. During this research some rough milling tests in Al-5083 are presented where High Feed Milling (HFM) is implemented as productive cutting strategy and the experimental modal analysis named Tap-testing is used for the suitable choice of cutting conditions. Competitive productivity rates are experienced while process stability is checked through the cutting forces measurements in order to prove the effectiveness of the experimental modal analysis for robotic machining.

  7. Distinctive features of high-ash bituminuos coals combution with low milling fineness in furnace chambers with bottom blowing

    Science.gov (United States)

    Zroychikov, N. A.; Kaverin, A. A.; Biryukov, Ya A.

    2017-11-01

    Nowadays the problem of improvement of pulverized coal combustion schemes is an actual one for national power engineering, especially for combustion of coals with low milling fineness with significant portion of moisture or mineral impurities. In this case a big portion of inert material in the fuel may cause impairment of its ignition and combustion. In addition there are a lot of boiler installations on which nitrogen oxides emission exceeds standard values significantly. Decreasing of milling fineness is not without interest as a way of lowering an electric energy consumption for pulverization, which can reach 30% of power plant’s auxiliary consumption of electricity. Development of a combustion scheme meeting the requirements both for effective coal burning and environmental measures (related to NOx emission) is a complex task and demands compromising between these two factors, because implementation of NOx control by combustion very often leads to rising of carbon-in-ash loss. However widespread occurrence of such modern research technique as computer modeling allows to conduct big amount of variants calculations of combustion schemes with low cost and find an optimum. This paper presents results of numerical research of combined schemes of coal combustion with high portion of inert material based on straight-flow burners and nozzles. Several distinctive features of furnace aerodynamics, heat transfer and combustion has been found. The combined scheme of high-ash bituminouos coals combustion with low milling fineness, which allows effective combustion of pointed type of fuels with nitrogen oxides emission reduction has been proposed.

  8. 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

  9. Rock Characteristics and Ball Mill Energy Requirements at ...

    African Journals Online (AJOL)

    These changes can have great impact on milling operations. ... Goldfields Ghana Limited, Tarkwa Gold Mine (TGM), processes ores which occur in ... The parameters examined had deviated from the design; Work Index (WI) for example was ...

  10. 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

  11. 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.

  12. 75 FR 11149 - Bowersock Mills and Power Company; Notice of Application Tendered for Filing With the Commission...

    Science.gov (United States)

    2010-03-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13526-001] Bowersock Mills...: Bowersock Mills Power Company (Bowersock). e. Name of Project: Bowersock Mills and Power Company Expanded....S.C. 791(a)-825(r). h. Applicant Contact: Sarah Hill-Nelson, The Bowersock Mills and Power Company...

  13. 77 FR 35431 - Final Alternative Soils Standards for the Uravan, CO, Uranium Mill

    Science.gov (United States)

    2012-06-13

    ..., Uranium Mill AGENCY: Nuclear Regulatory Commission. ACTION: Notice of Uranium milling alternative... amend their agreements to regulate uranium mill tailings (11e.(2) byproduct material). Six Agreement... transferring the Uravan uranium mill site to the U.S. Department of Energy. The NRC staff found no deficiencies...

  14. 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.

  15. On the closed form mechanistic modeling of milling: Specific cutting energy, torque, and power

    Science.gov (United States)

    Bayoumi, A. E.; Yücesan, G.; Hutton, D. V.

    1994-02-01

    Specific energy in metal cutting, defined as the energy expended in removing a unit volume of workpiece material, is formulated and determined using a previously developed closed form mechanistic force model for milling operations. Cutting power is computed from the cutting torque, cutting force, kinematics of the cutter, and the volumetric material removal rate. Closed form expressions for specific cutting energy were formulated and found to be functions of the process parameters: pressure and friction for both rake and flank surfaces and chip flow angle at the rake face of the tool. Friction is found to play a very important role in cutting torque and power. Experiments were carried out to determine the effects of feedrate, cutting speed, workpiece material, and flank wear land width on specific cutting energy. It was found that the specific cutting energy increases with a decrease in the chip thickness and with an increase in flank wear land.

  16. Wood pellet milling tests in a suspension-fired power plant

    DEFF Research Database (Denmark)

    Masche, Marvin; Puig-Arnavat, Maria; Wadenbäck, Johan

    2018-01-01

    classification (i.e., the classifier cut size) are affected by the internal pellet particle size distribution obtained after pellet disintegration in hot water. Furthermore, optimal conditions for comminuting pellets were identified. The milling behavior was assessed by determining the specific grinding energy...... consumption and the differential mill pressure. The size and shape of comminuted pellets sampled from burner pipes were analyzed by dynamic image analysis and sieve analysis, respectively. The results showed that the internal pellet particle size distribution affected both the milling behavior...... similar. Mill operating changes had a negligible effect on the original elongated wood particle shape. To achieve the desired comminuted product fineness (i.e., the classifier cut size) with lower specific grinding energy consumption, power plant operators need to choose pellets with a finer internal...

  17. 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

  18. 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)

  19. Direct heat transfer considerations for improving energy efficiency in pulp and paper Kraft mills

    Energy Technology Data Exchange (ETDEWEB)

    Savulescu, Luciana Elena; Alva-Argaez, Alberto [Natural Resources (Canada)

    2008-10-15

    The success of any process improvement study depends on the quality of the available data and the way in which the plant-specific characteristics are incorporated in the applied conceptual models; in the context of process integration studies these issues are directly related to the rules followed during the data extraction stage. Improving energy efficiency in a pulp and paper Kraft mill requires the identification of the most promising heat recovery network retrofit projects. In a retrofit analysis using pinch technology/process integration methods, only the process streams associated to the existing heat exchangers and some outlet streams (such as wastewater/effluent streams and vents) with high potential for heat recovery are usually included, while the energy exchanged through non-isothermal stream mixing (NIM) or direct heat transfer (DHT) is often assumed fixed and is not considered in the analysis. Relaxing this assumption requires extracting more data to represent the DHT design configuration that exists in the plant. However, different data extraction options can be considered to represent the DHT configuration depending on the associated process/operation constraints. This work describes a systematic procedure to extract and analyse the impacts of DHT on the overall energy efficiency of a Kraft process with a specific focus on mixing along the pulp line and in water tanks. (author)

  20. 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.

  1. 75 FR 11153 - Main Mill Street Investments, LLC; Notice of Preliminary Permit Application Accepted for Filing...

    Science.gov (United States)

    2010-03-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13631-000] Main Mill Street..., Motions To Intervene, and Competing Applications March 1, 2010. On November 16, Main Mill Street Investments, LLC (Main Mill Street Investments) filed an application for a preliminary permit, pursuant to...

  2. 75 FR 21286 - Bowersock Mills and Power Company; Notice of Application Accepted for Filing, Soliciting Motions...

    Science.gov (United States)

    2010-04-23

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13526-002] Bowersock Mills... License. b. Project No.: 13526-002. c. Date Filed: February 8, 2010. d. Applicant: Bowersock Mills Power Company (Bowersock). e. Name of Project: Bowersock Mills and Power Company Expanded Kansas River...

  3. 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.

  4. High-energy scattering in strongly coupled N=4 super Yang-Mills theory

    International Nuclear Information System (INIS)

    Sprenger, Martin

    2014-11-01

    This thesis concerns itself with the analytic structure of scattering amplitudes in strongly coupled N=4 super Yang-Mills theory (abbreviated N = 4 SYM) in the multi-Regge limit. Through the AdS/CFT-correspondence observables in strongly coupled N = 4 SYM are accessible via dual calculations in a weakly coupled string theory on an AdS 5 x S 5 -geometry, in which observables can be calculated using standard perturbation theory. In particular, the calculation of the leading order of the n-gluon amplitude in N = 4 SYM at strong coupling corresponds to the calculation of a minimal surface embedded into AdS 5 . This surface ends on the concatenation of the gluon momenta, which is a light-like curve. The calculation of the minimal surface area can be reduced to finding the solution of a set of non-linear, coupled integral equations, which have no analytic solution in arbitrary kinematics. In this thesis, we therefore specialise to the multi-Regge limit, the n-particle generalisation of the Regge limit. This limit is especially interesting as even in the description of scattering amplitudes in weakly coupled N = 4 SYM in this limit a certain set of Feynman diagrams has to be resummed. This description organises itself into orders of logarithms of the energy involved in the scattering process. In this expansion each order in logarithms includes terms from every order in the coupling constant and therefore contains information about the strong coupling sector of the theory, albeit in a very specific way. This raises the central question of this thesis, which is how much of the analytic structure of the scattering amplitudes in the multi-Regge limit is preserved as we go to the strong coupling regime. We show that the equations governing the area of the minimal surface simplify drastically in the multi-Regge limit, which allows us to obtain analytic results for the scattering amplitudes. We develop an algorithm for the calculation of scattering amplitudes in the multi

  5. Attritor milling of WC + 6% Co: Effects on powder characteristics and compaction behavior

    International Nuclear Information System (INIS)

    Mashl, S.J.; Smith, D.W.; Becking, G.H.; Hale, T.E.

    1987-01-01

    This study examines the effects of attritor milling on the characteristics and bulk behavior of fine tungsten carbide powders (initial median particle size ≅ 1.5 μm) blended with 6 wt. % cobalt (mps ≅ 1.5 μm). Experiments are performed in order to: Develop a process model relating the specific energy input to the milled median particle size. Examine the effect that changes in milling variables have on the specific energy - median particle size relationship. Observe the effects of variation in the initial particle size distribution on the as-milled particle size distribution, the compaction characteristics of the powder, and the shrinkage which will occur during sintering. The process model is based on Charles' equation, E-bar = A (d/sup -α/ - d/sub o//sup -α/) in which E-bar = the specific energy consumed in milling, d and d = the initial and milled median particle sizes respectively, and A and α are constants. Computer curve fitting techniques are employed to determine the values of the coefficient and exponent in the above equation. The resulting model predicts the experimental data within about +- over 10% over a significant range of d/sub o/ and E-Bar values. The apparent density and compactibility of the attritor milled powders are observed to be very sensitive to the milled particle size distribution

  6. An automated medium scale prototype for anaerobic co-digestion of olive mill wastewater

    Directory of Open Access Journals (Sweden)

    B. Bernardi

    2017-12-01

    Full Text Available Olive oil production constitutes one of the most important agro-industrial business for Mediterranean countries, where 97% of the international production is focused. Such an activity, mainly carried out through three phase olive oil mill plants, generates huge amounts of solid and liquid by-products further than olive oil. Physico-chemical features of these by-products depend on various factors such as soil and climatic conditions, agricultural practices and processing. As currently carried out, the disposal of these by-products may lead to numerous problems taking into account management, economic and particularly environmental aspects. Indeed, olive mill wastewater is not easily biodegradable due to its high chemical and biochemical oxygen demand, its high content in phenolic compounds, high ratio C/N and low pH, leading consequently to soil and water source pollution. Considering, the above-mentioned statements, olive mill waste disposal constitutes nowadays a challenge for oil industry stakeholders. It becomes necessary to look for alternative solutions in order to overcome environmental problems and ensure the sustainability of oil industry. Anaerobic co-digestion of olive mill wastewater with other agro-industrial matrices could be one of these solutions; since it offers the possibility to produce green energy and break down toxicological compounds contained in these wastewater for a better disposal of the digested matrices as soil conditioner. In this contest, this note reports the functioning principle of an automated medium scale plant for anaerobic co-digestion of olive mill wastewater. Keywords: Medium scale prototype, Olive mill wastewater (OMWW, Anaerobic co-digestion (AcoD, Automatic process

  7. 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.

  8. High Speed Milling : By using STL-Technology

    NARCIS (Netherlands)

    Gunnink, J.W.

    1998-01-01

    Despite the wide application of Layered Manufacturing Technologies like Fused Deposition Modelling, Layered Object Manufacturing etc. in the product development processes, milling is stili necessary. This is a result of the fact that Layered Manufacturing processes have some limitations in for

  9. Development of hemicelluloses biorefineries for integration into kraft pulp mills

    Science.gov (United States)

    Ajao, Olumoye Abiodun

    The development and wide spread acceptance of production facilities for biofuels, biochemicals and biomaterials is an important condition for reducing reliance on limited fossil resources and transitioning towards a global biobased economy. Pulp and paper mills in North America are confronted with high energy prices, high production costs and intense competition from emerging economies and low demand for traditional products. Integrated forest biorefineries (IFBR) have been proposed as a mean to diversify their product streams, increase their revenue and become more sustainable. This is feasible because they have access to forest biomass, an established feedstock supply chain and wood processing experience. In addition, the integration of a biorefinery process that can share existing infrastructure and utilities on the site of pulp mill would significantly lower investment cost and associated risks. Kraft pulping mills are promising receptor processes for a biorefinery because they either possess a prehydrolysis step for extracting hemicelluloses sugars prior to wood pulping or it can be added by retrofit. The extracted hemicelluloses could be subsequently transformed into a wide range of value added products for the receptor mill. To successfully implement hemicelluloses biorefinery, novel processes that are technically and economically feasible are required. It is necessary to identify products that would be profitable, develop processes that are energy efficient and the receptor mill should be able to supply the energy, chemicals and material demands of the biorefinery unit. The objective of this thesis is to develop energy efficient and economically viable hemicelluloses biorefineries for integration into a Kraft pulping process. A dissolving pulp mill was the reference case study. The transformation of hemicellulosic sugars via a chemical and biochemical conversion pathway, with furfural and ethanol as representative products for each pathway was studied. In

  10. 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

  11. 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...

  12. 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)

  13. 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

  14. Magnetic structure evolution in mechanically milled nanostructured ZnFe2O4 particles

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Wynn, P.; Mørup, Steen

    1999-01-01

    Nanostructured partially-inverted ZnFe2O4 particles have been prepared from bulk ZnFe2O4 by high-energy ball milling in an open container. The grain size reduction, cation site distributions, and the evolution of magnetic structures have been studied by x-ray diffraction with Rietveld structure...... refinements, transmission electron microscopy, and Mossbauer spectroscopy. It is found that a change of magnetic structure from an antiferromagnetic to a ferrimagnetic (or ferromagnetic) structure occurs in the milled samples. This change is correlated with the redistribution of the cations, Zn and Fe...

  15. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    International Nuclear Information System (INIS)

    Prosviryakov, A.S.; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-01

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al 3 Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al 3 Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al 3 Zr crystals were completely dissolved in Al after 20 h. •Cubic Al 3 Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  16. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Prosviryakov, A.S., E-mail: pro.alex@mail.ru; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-15

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al{sub 3}Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al{sub 3}Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al{sub 3}Zr crystals were completely dissolved in Al after 20 h. •Cubic Al{sub 3}Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  17. 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

  18. 75 FR 61460 - Avondale Mills Inc.; Augusta Canal Authority; Notice of Application for Transfer of License, and...

    Science.gov (United States)

    2010-10-05

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 5044-015] Avondale Mills... and Motions To Intervene September 24, 2010. On September 13, 2010, Avondale Mills Inc. (transferor... Mill Project No. 5044, located on the Augusta Canal in the City of Augusta, Richmond County, Georgia...

  19. 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...

  20. 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.

  1. Crystallite sizes of LiH before and after ball milling and thermal exposure

    International Nuclear Information System (INIS)

    Ortiz, Angel L.; Osborn, William; Markmaitree, Tippawan; Shaw, Leon L.

    2008-01-01

    The powder characteristics of lithium hydride (LiH) as a function of high-energy ball milling condition are systematically investigated via quantitative X-ray diffraction (XRD) analysis. The results obtained from the XRD analysis are compared with those attained from scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area (SSA) analyses. The thermal stability of the ball-milled LiH is also investigated in order to provide physical insights into its cyclic stability in hydrogen sorption and desorption cycles. The results indicate that ball milling is effective in obtaining nano-crystalline LiH powder which is relatively stable with retention of nano-crystals after thermal exposure at 285 deg. C (equivalent to 0.58T m ) for 1 h. The good thermal stability observed is attributed to the presence of many pores in the agglomerates at the ball-milled condition. These pores effectively prevent crystal growth during the thermal exposure

  2. Crystallite sizes of LiH before and after ball milling and thermal exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Angel L. [Departamento de Electronica e Ingenieria Electromecanica, Universidad de Extremadura, Badajoz (Spain); Osborn, William; Markmaitree, Tippawan [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136 Storrs, CT 06269-3136 (United States); Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136 Storrs, CT 06269-3136 (United States)], E-mail: leon.shaw@uconn.edu

    2008-04-24

    The powder characteristics of lithium hydride (LiH) as a function of high-energy ball milling condition are systematically investigated via quantitative X-ray diffraction (XRD) analysis. The results obtained from the XRD analysis are compared with those attained from scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area (SSA) analyses. The thermal stability of the ball-milled LiH is also investigated in order to provide physical insights into its cyclic stability in hydrogen sorption and desorption cycles. The results indicate that ball milling is effective in obtaining nano-crystalline LiH powder which is relatively stable with retention of nano-crystals after thermal exposure at 285 deg. C (equivalent to 0.58T{sub m}) for 1 h. The good thermal stability observed is attributed to the presence of many pores in the agglomerates at the ball-milled condition. These pores effectively prevent crystal growth during the thermal exposure.

  3. Monte Carlo simulations of secondary electron emission due to ion beam milling

    Energy Technology Data Exchange (ETDEWEB)

    Mahady, Kyle [Univ. of Tennessee, Knoxville, TN (United States); Tan, Shida [Intel Corp., Santa Clara, CA (United States); Greenzweig, Yuval [Intel Israel Ltd., Haifa (Israel); Livengood, Richard [Intel Corp., Santa Clara, CA (United States); Raveh, Amir [Intel Israel Ltd., Haifa (Israel); Fowlkes, Jason D. [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rack, Philip [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-07-01

    We present a Monte Carlo simulation study of secondary electron emission resulting from focused ion beam milling of a copper target. The basis of this study is a simulation code which simulates ion induced excitation and emission of secondary electrons, in addition to simulating focused ion beam sputtering and milling. This combination of features permits the simulation of the interaction between secondary electron emission, and the evolving target geometry as the ion beam sputters material. Previous ion induced SE Monte Carlo simulation methods have been restricted to predefined target geometries, while the dynamic target in the presented simulations makes this study relevant to image formation in ion microscopy, and chemically assisted ion beam etching, where the relationship between sputtering, and its effects on secondary electron emission, is important. We focus on a copper target, and validate our simulation against experimental data for a range of: noble gas ions, ion energies, ion/substrate angles and the energy distribution of the secondary electrons. We then provide a detailed account of the emission of secondary electrons resulting from ion beam milling; we quantify both the evolution of the yield as high aspect ratio valleys are milled, as well as the emission of electrons within these valleys that do not escape the target, but which are important to the secondary electron contribution to chemically assisted ion induced etching.

  4. 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)

  5. Microstructure, composition and performance of PVD coatings designed for successful dry high speed milling

    International Nuclear Information System (INIS)

    Muenz, W.-D.; Lembke, M.I.; Lewis, D.B.; Smith, I.J.

    2001-01-01

    Dry high speed machining (HSM), particularly dry high speed milling, demands hard coatings, which exhibit high toughness, high oxidation resistance, a limited amount of residual stress and excellent adhesion to the cemented carbide (CC) substrate. These requirements are met by TiAICrYN coatings grown by the combined cathodic arc/unbalanced magnetron deposition method. Fully sufficient adhesion is achieved by ion implantation of Cr into the CC prior deposition. Residual stress is controlled by an Y - free base layer; high oxidation resistance is provided by an Y - containing 3 μm thick hard coating with 29 GPa hardness and a residual stress well below -7 GPa. Under the influence of temperatures above 800 o C, Y segregates along the columns of TiAIN and plugs the in/out diffusion of elements. A top layer of Y - containing oxynitride reduces the friction against the work piece material (0.9 to 0.65). Cutting tools coated as such may be used for dry milling up to 25 k rpm in steels HRC > 60. (author)

  6. Symmetric energy-momentum tensor in Maxwell, Yang-Mills, and Proca theories obtained using only Noether's theorem

    Energy Technology Data Exchange (ETDEWEB)

    Montesinos, M. [CINVESTAV-IPN, 07360 Mexico D.F. (Mexico); Flores, E. [Facultad de Fisica e Inteligencia Artificial, Universidad Veracruzana, 91000 Xalapa, Veracruz (Mexico)]. E-mail: merced@fis.cinvestav.mx

    2006-07-01

    The symmetric and gauge-invariant energy-momentum tensors for source-free Maxwell and Yang-Mills theories are obtained by means of translations in spacetime via a systematic implementation of Noether's theorem. For the source-free neutral Proca field, the same procedure yields also the symmetric energy-momentum tensor. In all cases, the key point to get the right expressions for the energy-momentum tensors is the appropriate handling of their equations of motion and the Bianchi identities. It must be stressed that these results are obtained without using Belinfante's symmetrization techniques which are usually employed to this end. (Author)

  7. Magnetoresistivity and microstructure of YBa2Cu3Oy prepared using planetary ball milling

    International Nuclear Information System (INIS)

    Hamrita, A.; Ben Azzouz, F.; Madani, A.; Ben Salem, M.

    2012-01-01

    Superconducting properties of YBa 2 Cu 3 O y prepared using planetary ball milling were studied. Y-deficient YBa 2 Cu 3 O y nanoparticles are embedded in the superconducting matrix. Ball milled sample exhibits a large magnetoresistivity in weak magnetic fields at 77 K. We have studied the microstructure and the magnetoresistivity of polycrystalline YBa 2 Cu 3 O y (YBCO or Y-123 for brevity) embedded with nanoparticles of Y-deficient YBCO, generated by the planetary ball milling technique. Bulk samples were synthesized from a precursor YBCO powder, which was prepared from commercial high purity Y 2 O 3 , Ba 2 CO 3 and CuO via a one-step annealing process in air at 950 °C. After planetary ball milling of the precursor, the powder was uniaxially pressed and subsequently annealed at 950 °C in air. Phase analysis by X-ray diffraction (XRD), granular structure examination by scanning electron microscopy (SEM), microstructure investigation by transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDXS) were carried out. TEM analyses show that nanoparticles of Y-deficient YBCO, generated by ball milling, are embedded in the superconducting matrix. Electrical resistance as a function of temperature, ρ(T), revealed that the zero resistance temperature, T co , is 84.5 and 90 K for the milled and unmilled samples respectively. The milled ceramics exhibit a large magnetoresistance in weak magnetic fields at liquid nitrogen temperature. This attractive effect is of high significance as it makes these materials promising candidates for practical application in magnetic field sensor devices.

  8. 75 FR 52523 - Bowersock Mills and Power Company; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2010-08-26

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13526-002-KS] Bowersock Mills and Power Company; Notice of Availability of Environmental Assessment August 19, 2010. In... reviewed the application for an original license for the Bowersock Mills and Power Company's Expanded...

  9. Coexistence of short- and long-range ferromagnetic order in nanocrystalline Fe2Mn1−xCuxAl (x=0.0, 0.1 and 0.3) synthesized by high-energy ball milling

    International Nuclear Information System (INIS)

    Thanh, Tran Dang; Nanto, Dwi; Tuyen, Ngo Thi Uyen; Nan, Wen-Zhe; Yu, YiKyung; Tartakovsky, Daniel M.; Yu, S.C.

    2015-01-01

    In this work, we prepared nanocrystalline Fe 2 Mn 1−x Cu x Al (x=0.0, 0.1 and 0.3) powders by the high energy ball milling technique, and then studied their critical properties. Our analysis reveals that the increase of Cu-doping concentration (up to x=0.3) in these powders leads to a gradual increase of the ferromagnetic–paramagnetic transition temperature from 406 to 452 K. The Banerjee criterion suggests that all the samples considered undergo a second-order phase transition. A modified Arrott plot and scaling analysis indicate that the critical exponents (β=0.419 and 0.442, γ=1.082 and 1.116 for x=0.0 and 0.1, respectively) are located in between those expected for the 3D-Heisenberg and the mean-field models; the values of β=0.495 and γ=1.046 for x=0.3 sample are very close to those of the mean-field model. These features reveal the coexistence of the short- and long-range ferromagnetic order in the nanocrystalline Fe 2 Mn 1−x Cu x Al powders. Particularly, as the concentration of Cu increases, values of the critical exponent shift towards those of the mean-field model. Such results prove the Cu doping favors establishing a long-range ferromagnetic order. - Highlights: • Fe 2 Mn 1−x Cu x Al nanocrystals were prepared by a high energy ball milling method. • A coexistence of the short- and long-range FM order in the nanocrystals. • Cu doping favors establishing a long-range FM order in the nanocrystals. • All the ΔS m (T, H) data are followed a universal master curve

  10. Pulp and Paper Industry Energy Bandwidth Study

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2006-08-01

    The study provides energy estimates for the following four cases: current average mill energy consumption, state-of-the-art art mill energy consumption, mill energy consumption if advanced technologies requiring further R&D were employed, and theoretical minimum mill energy consumption.

  11. Hierarchical SnO2-Graphite Nanocomposite Anode for Lithium-Ion Batteries through High Energy Mechanical Activation

    International Nuclear Information System (INIS)

    Ng, Vincent Ming Hong; Wu, Shuying; Liu, Peijiang; Zhu, Beibei; Yu, Linghui; Wang, Chuanhu; Huang, Hui; Xu, Zhichuan J.; Yao, Zhengjun; Zhou, Jintang; Que, Wenxiu; Kong, Ling Bing

    2017-01-01

    Highlights: •A simple and scalable process to concomitant downsizing to nanoscale, carbon coating, inclusion of voids and conductive network of graphite. •Using tungsten carbide milling media and 80:1 ball to powder ratio, micron SnO 2 particles are comminuted to nanosized SnO 2 crystallites. •Hierarchical structure of carbon-coated SnO2 nanoclusters anchored on thin graphite sheets are prepared. •Impressive reversible capacity of 725 mAh g −1 is achieved by ball milling a mixture of SnO 2 with 20 wt. % graphite for 20 h. •Synthesis parameters such as graphite content and milling time are systematically examined. -- Abstract: Development of novel electrode materials with unique architectural designs is necessary to attain high power and energy density lithium-ion batteries (LIBs). SnO 2 , with high theoretical capacity of 1494 mAh g −1 , is a promising candidate anode material, which has been explored with various strategies, such as dimensional reduction, morphological modifications and composite formation. Unfortunately, most of the SnO 2 -based electrodes are prepared by using complex chemical synthesis methods, which are not feasible to scale up for practical applications. In addition, concomitant irrecoverable initial capacity loss and consequently poor initial Coulombic efficiency still persistently plagued these SnO 2 -based anodes. To overcome hitherto conceived irreversible formation of Li 2 O by conversion reaction, to fully harness its theoretical capacity, this work demonstrates that a hierarchical structured SnO 2 -C nanocomposite with 68.5% initial Coulombic efficiency and reversible capacity of 725 mAh g −1 can be derived from the mixtures of SnO 2 and graphite, by using low cost industrial compatible high energy ball milling activation.

  12. 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)

  13. Surface morphology study in high speed milling of soda lime glass

    Science.gov (United States)

    Konneh, Mohamed; Bagum, Mst. Nasima; Ali, Mohammad Yeakub; Amin, A. K. M. Nurul

    2018-05-01

    Soda lime glass has a wide range of applications in optical, bio-medical and semi-conductor industries. It is undeniably a challenging task to produce micro finish surface on an amorphous brittle solid like soda lime glass due to its low fracture toughness. In order to obtain such a finish surface, ductile machining has been exploited, as this usually cause's plastic flow which control crack propagation. At sub-micro scale cutting parameters, researchers achieved nano finish surface in micro milling operation using coated tool. However it is possible to enhance the rate of material removal (RMR) of soda lime glass at flexible cutting condition. High speed cutting at micro meter level, extend of thermal softening might be prominent than the strain gradient strengthening. The purpose of this study was to explore the effects of high cutting speed end milling parameters on the surface texture of soda lime glass using uncoated carbide tool. The spindle speed, depth of cut and feed rate were varied from 20,000 to 40,000 rpm, 10 to 30 mm/min and 30 to 50 µm respectively. Mathematical model of roughness has been developed using Response Surface Methodology (RSM). Experimental verification confirmed that surface roughness (Ra) 0.38 µm is possible to achieve at increased RMR, 4.71 mm3/min.

  14. 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

  15. 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.)

  16. Study of the sintering behavior of fine, ultrafine and nanocrystalline WC-CO mixtures obtained by high energy milling; Estudio del comportamiento durante la sinterizacion de mezclas WC-Co finas, ultrafinas y nanocristalinas obtenidas por molienda de alta energia

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, M. D.; Bonache, V.; Amigo, V.; Busquets, D.

    2008-07-01

    In this work the sintering behaviour of fine, ultrafine and nanocrystalline WC-12Co mixtures obtained by high energy milling, as well commercial nano powders, have been studied, in order to evaluate the effect of the particle size and the powder processing, in the densification, microstructural development and mechanical properties of the final product. The consolidation of the mixtures has been made by uniaxial pressing and sintering in vacuum, and by hot isostatic pressing. The sintered materials have been evaluated by measures of density, hardness and indentation fracture toughness, and micro structurally characterized by optical microscopy and scanning and transmission electronic microscopy (SEM and TEM). The results show the improvements in resistant behaviour of the materials obtained from nanocrystalline powders, in spite of the grain growth experienced during the sintering. The best results were obtained for the milling nanocrystalline material, which presents values of hardness higher than 180 HV. (Author) 46 refs.

  17. 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)

  18. 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.

  19. High-energy evolution to three loops

    Science.gov (United States)

    Caron-Huot, Simon; Herranen, Matti

    2018-02-01

    The Balitsky-Kovchegov equation describes the high-energy growth of gauge theory scattering amplitudes as well as nonlinear saturation effects which stop it. We obtain the three-loop corrections to the equation in planar N = 4 super Yang-Mills theory. Our method exploits a recently established equivalence with the physics of soft wide-angle radiation, so-called non-global logarithms, and thus yields at the same time the threeloop evolution equation for non-global logarithms. As a by-product of our analysis, we develop a Lorentz-covariant method to subtract infrared and collinear divergences in crosssection calculations in the planar limit. We compare our result in the linear regime with a recent prediction for the so-called Pomeron trajectory, and compare its collinear limit with predictions from the spectrum of twist-two operators.

  20. Effect of raw wood supply system on the wood paying capability of a kraft pulp mill using Scots pine

    Energy Technology Data Exchange (ETDEWEB)

    Dahl, O. (Helsinki Univ. of Technology, Espoo (Finland), Dept. of Forest Products Technology), Email: olli.dahl@tkk.fi; Jylhae, P. (Finnish Forest Research Inst., Kannus (Finland)), Email: paula.jylha@metla.fi; Laitila, J. (Finnish Forest Research Inst., Joensuu (Finland)), Email: juha.laitila@metla.fi; Kaerhae, K. (Metsaeteho Oy, Helsinki (Finland)), Email: kalle.karha@metsateho.fi

    2009-07-01

    Integration of energy wood procurement into that of pulpwood is seen as a means for reducing the high procurement costs of small-diameter wood harvested from first thinnings. In the deepest mode of integration, pulp and energy fractions are separated from each other in the debarking drum of the pulp mill. In the present paper, the competitiveness of the conventional supply chain based on cut-to-length harvesting was compared to the supply systems based on the harvesting of loose whole trees and whole-tree bundling, in the cases of three Scots pine-dominated first-thinning stands using wood paying capability (WPC) of a kraft pulp mill as a decisive criterion. Furthermore, the competitiveness of first thinnings as raw material sources for a pulp mill was evaluated by using intermediate thinnings as s reference. (orig.)

  1. Ball-milling synthesis of ZnO@sulphur/carbon nanotubes and Ni(OH)_2@sulphur/carbon nanotubes composites for high-performance lithium-sulphur batteries

    International Nuclear Information System (INIS)

    Gu, Xingxing; Tong, Chuan-jia; Wen, Bo; Liu, Li-min; Lai, Chao; Zhang, Shanqing

    2016-01-01

    Highlights: • Metal oxides or hydroxides coating sulfur-based composite are successfully prepared. • Large-scale synthesis can be realized via the facile wet ball-milling strategy. • Density functional theory (DFT) calculation is applied to calculate adsorption energy. • ZnO exhibits a higher adsorption energy for Li_2S_8 than that Ni(OH)_2. • ZnO@sulphur/carbon nanotubes composite show excellent cycle and discharge performance. - Abstract: Zinc oxide wrapped sulphur/carbon nanotubes (ZnO@S/CNT) and nickel hydroxide wrapped sulphur/carbon nanotubes (Ni(OH)_2@S/CNT) nanocomposites are prepared using a simple, low cost and scalable ball-milling method. As the cathodes in Li-S batteries, the as-prepared ZnO@S/CNT composite illustrates a superior high initial capacity of 1663 mAh g"−"1 at a charge/discharge rate of 160 mA g"−"1, and maintains a reversible capacity at approximately 942 mAh g"−"1 after 70 cycles. While for Ni(OH)_2@S/CNT composites, its initial capacity is also as high as 1331 mAh g"−"1, but a poorer cycling stability is presented. When the charge/discharge current is increased to 1600 mA g"−"1, a high reversible capacity of 698 mAh g"−"1 after 200 cycles still can be obtained for the ZnO@S/CNT composite, far better than that of Ni(OH)_2@S/CNT composites. The better cycling performance and high discharge capacity can be attributed to the strong interactions between ZnO and S_x"2"− species, which is verified by the density functional theory (DFT) calculation result that the ZnO exhibits a higher adsorption energy for Li_2S_8 than the Ni(OH)_2.

  2. 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.

  3. Regular behaviors in SU(2) Yang-Mills classical mechanics

    International Nuclear Information System (INIS)

    Xu Xiaoming

    1997-01-01

    In order to study regular behaviors in high-energy nucleon-nucleon collisions, a representation of the vector potential A i a is defined with respect to the (a,i)-dependence in the SU(2) Yang-Mills classical mechanics. Equations of the classical infrared field as well as effective potentials are derived for the elastic or inelastic collision of two plane wave in a three-mode model and the decay of an excited spherically-symmetric field

  4. Uranium Mill Tailings Remedial Action Project: technical approach document

    International Nuclear Information System (INIS)

    1986-05-01

    The Uranium Mill Tailings Radiation Control Act of 1978, PL95-604, grants the Secretary of Energy authority and responsibility to perform such actions as are necessary to minimize radiation health hazards and other environmental hazards from inactive uranium mill sites. These cleanup actions are to be performed in compliance with the EPA standards (40 CFR Part 192) which became final on March 7, 1983. This document describes the general technical approaches and design criteria that are adopted by the US Department of Energy (DOE) in order to implement Remedial Action Plans (RAPs) and final designs that comply with EPA standards

  5. A study of the mechanism of microwave-assisted ball milling preparing ZnFe{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingzhe; Wu, Yujiao [College of materials and metallurgical engineering, Guizhou Institute of Technology, Guiyang 550003 (China); 2011 Collaborative Innovation Center of Guizhou Province, Guiyang 550003 (China); Qin, Qingdong [College of materials and metallurgical engineering, Guizhou Institute of Technology, Guiyang 550003 (China); Wang, Fuchun [College of materials and metallurgical engineering, Guizhou Institute of Technology, Guiyang 550003 (China); 2011 Collaborative Innovation Center of Guizhou Province, Guiyang 550003 (China); Chen, Ding [College of Materials Science and Engineering, Hunan University, Changsha, Hunan 410082 (China)

    2016-07-01

    In this paper, well dispersed ZnFe{sub 2}O{sub 4} nano-particles with high magnetization saturation of 82.23 emu/g were first synthesized by microwave assisted ball milling and then the influences of pre-treatments and microwave powers to the progress were studied. It was found that under the both function of crack effect induced by ball milling and rotary motion induced by microwave the synthesized ferrtie nano-particles were well dispersed that is much different from the powders synthesized by normal high energy ball milling. The pre-treatment of ball milling can only enhance the reaction rate in the first several hours but the pre-irradiation of microwave can enhance the hole reaction rate. Further more, it was also been found that with increasing the microwave power, the more raw materials will converted into zinc ferrite in the first 5 h. 5 h latter the microwave power of 720 W is high enough for the coupling effect of microwave and ball milling with stirrer rotation speed of 256 rpm. - Highlights: • ZnFe{sub 2}O{sub 4} with 82.23 emu/g were synthesized without heat treatment. • The produced powder dispersed very well without any dispersant. • The pre-treatment of microwave enhanced the reaction rate much. • The pre-treatment of ball milling enhance chemical rate at beginning.

  6. Rolling of molybdenum and niobium tubes on cold-rolling mill with high stiff stand

    Energy Technology Data Exchange (ETDEWEB)

    Potapov, I N; Shejkh-Ali, A D; Filimonov, G V; Lunev, A G

    1984-03-01

    To develop the technique of tube production the process of rolling is studied and comparative evaluation of the structure formed is carried out. It is shown that billets of rods deformed by screw rolling have the improved plastic properties and are deformed on cold-rolling mill (CRM) with a high degree of reduction without defect formation. High stiff stand of the CRM permits to produce high-quality molybdenum tubes.

  7. Cogeneration of electric energy: The case of pulp and paper mills

    International Nuclear Information System (INIS)

    Harberger, A.C.

    1993-01-01

    Applied welfare economics are utilized to analyze the phenomenon of cogeneration of electricity in the pulp and paper sector. Optimum levels of energy use (and of cogeneration) are defined, and the efficiency costs of various possible deviations from the optimum are shown. An economic analysis is presented of the effects of cost of electricity for the pulp and paper industry, and the impact that cogeneration can have on these costs. The social welfare impacts of cogeneration and electricity subsidies are discussed, together with the issue of crosshauling. It is shown that in Canada a policy focusing on cogeneration without crosshauling leads to optimal results. An added argument against crosshauling involves the implicit transfers involved. These transfers generate benefits for the pulp and paper mills at the expense of the electricity utility and its paying customers or taxpaying public. A strong argument is proposed against allowing of crosshauling

  8. Analysis of the influence of two different milling processes in the properties of precursor powder and [Beta]-TCP cement

    International Nuclear Information System (INIS)

    Cardoso, H.A.I.; Pereira, C.H.R.; Zavaglia, C.A.C.; Motisuke, M.

    2011-01-01

    There are several characteristics that put calcium phosphate cements in evidence, like its bioactivity and in vivo resorption. The influence of two milling processes in the morphological properties of the [beta]-tricalcium phosphate powder, [beta]-TCP, and in the mechanical properties of the cement were analyzed. The powder was obtained by solid state reaction of CaCO_3 and CaHPO_4 at 1050 ° C. It showed high phase purity and absence of toxic elements. The powder was processed in ball mill (A) and high-energy vibratory mill (B), with posterior analyze by SEM and particle size distribution. The powders showed different average and distribution of grain size. Finally, the cement obtained by the process (B) showed values of axial tensile strength significantly greater than that obtained by the process (A). The milling process (B) is much more efficient than the process (A). (author)

  9. Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

    Directory of Open Access Journals (Sweden)

    N. V. Dhandapani

    2015-01-01

    Full Text Available This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

  10. Investigation on Effect of Material Hardness in High Speed CNC End Milling Process.

    Science.gov (United States)

    Dhandapani, N V; Thangarasu, V S; Sureshkannan, G

    2015-01-01

    This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the operator on floor is based on suggested values of the tool manufacturer or by trial and error method. This paper describes effect of various parameters on the surface roughness characteristics of the precision machining part. The prediction method suggested is based on various experimental analysis of parameters in different compositions of input conditions which would benefit the industry on standardization of high speed CNC end milling processes. The results show a basis for selection of parameters to get better results of surface roughness values as predicted by the case study results.

  11. 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

  12. Masslessness of ghosts in equivariantly gauge-fixed Yang-Mills theories

    International Nuclear Information System (INIS)

    Golterman, Maarten; Zimmerman, Leah

    2005-01-01

    We show that the one-loop ghost self-energy in an equivariantly gauge-fixed Yang-Mills theory vanishes at zero momentum. A ghost mass is forbidden by equivariant BRST symmetry, and our calculation confirms this explicitly. The four-ghost self interaction which appears in the equivariantly gauge-fixed Yang-Mills theory is needed in order to obtain this result

  13. Influence of milling process in the surface energy of glass tile frits; Influencia de la molienda en la energia superficial de fritas para esmaltes

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-01

    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{sub 2} by 5% of B{sub 2}O{sub 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{sup 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{sup -}2) and the less acidic constant (0.13 kJ.mol{sup -}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) 30 refs.

  14. Influence of milling process in the surface energy of glass tile frits; Influencia de la molienda en la energia superficial de fritas para esmaltes

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-01

    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{sub 2} by 5% of B{sub 2}O{sub 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{sup 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{sup -}2) and the less acidic constant (0.13 kJ.mol{sup -}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. MnBi particles with high energy density made by spark erosion

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Phi-Khanh, E-mail: phi@ucsd.edu; Jin, Sungho [Materials Science and Engineering, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States); Berkowitz, Ami E. [Physics Department, University of California, San Diego, La Jolla, California 92093 (United States); Center for Magnetic Recording Research, University of California, San Diego, La Jolla, California 92093 (United States)

    2014-05-07

    We report on the properties of low-temperature phase (LTP)-MnBi particles produced by the rapid-quenching technique of spark-erosion. The as-prepared powder consists of amorphous, crystalline, and superparamagnetic particles, mostly as porous aggregates. The major fraction of the powder consists of 20–30 nm particles. A short anneal crystallizes the amorphous particles producing a high moment, >90% of theoretical M{sub S}, albeit with H{sub C} of a few kOe. If lightly milled, the agglomerates are broken up to yield H{sub C} of 1 T. These findings are supported by the x-ray diffraction pattern showing broadened peaks of the predominant LTP-MnBi phase. The combination of spark erosion, milling, and annealing has produced randomly oriented particles with (BH){sub MAX} ∼ 3.0 MGOe. The particles are expected to show record energy product when aligned along their crystallographic easy axes.

  16. 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.

  17. Paper sludge (PS) to bioethanol: Evaluation of virgin and recycle mill sludge for low enzyme, high-solids fermentation.

    Science.gov (United States)

    Boshoff, Sonja; Gottumukkala, Lalitha Devi; van Rensburg, Eugéne; Görgens, Johann

    2016-03-01

    Paper sludge (PS) from the paper and pulp industry consists primarily of cellulose and ash and has significant potential for ethanol production. Thirty-seven PS samples from 11 South African paper and pulp mills exhibited large variation in chemical composition and resulting ethanol production. Simultaneous saccharification and fermentation (SSF) of PS in fed-batch culture was investigated at high solid loadings and low enzyme dosages. Water holding capacity and viscosity of the PS influenced ethanol production at elevated solid loadings of PS. High viscosity of PS from virgin pulp mills restricted the solid loading to 18% (w/w) at an enzyme dosage of 20 FPU/gram dry PS (gdPS), whereas an optimal solid loading of 27% (w/w) was achieved with corrugated recycle mill PS at 11 FPU/gdPS. Ethanol concentration and yield of virgin pulp and corrugated recycle PS were 34.2g/L at 66.9% and 45.5 g/L at 78.2%, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Fatty acid composition of maize germ oil from high-oil hybrids wet-milling processing

    Directory of Open Access Journals (Sweden)

    Jovanović Petar Lj.

    2005-01-01

    Full Text Available Maize germ was obtained by wet-milling laboratory processing of domestic high-oil maize hybrids. After separation, the germ was subjected to extraction of maize oil. Fatty acid composition of maize germ oil was determined by gas chromatography. The results showed very high levels of unsaturated fatty acids and a constant sum of oleic and linoleic acids in oils of different maize hybrids.

  19. Pyrolysis of fibre residues with plastic contamination from a paper recycling mill: Energy recoveries

    International Nuclear Information System (INIS)

    Brown, Logan Jeremy; Collard, François-Xavier; Görgens, Johann

    2017-01-01

    Highlights: • Pyrolysis of fibre-plastics residues from paper recycling mill into fuel products. • Product with remarkable energy content up to 42.8 MJ/kg. • Influence of temperature on the product yields and fuel properties. • Effect of plastic composition on product properties. - Abstract: Pyrolysis is a promising technology for the production of marketable energy products from waste mixtures, as it decomposes heterogeneous material into homogenous fuel products. This research assessed the ability of slow pyrolysis to convert three waste streams, composed of fibre residues contaminated with different plastic mixtures, into char and tarry phase products at three different temperatures (300, 425 and 550 °C). The products were characterised in terms of mass yield, higher heating value (HHV) and gross energy conversion (EC). Significant amounts of hydrocarbon plastics in the feed materials increased the calorific values of the char (up to 32.9 MJ/kg) and tarry phase (up to 42.8 MJ/kg) products, comparable to high volatile bituminous A coal and diesel respectively. For all three waste streams converted at 300 °C, the majority of the energy in the feedstock was recovered in the char product (>80%), while deoxygenation of fibre component resulted in char with increased calorific value (up to 31.6 MJ/kg) being produced. Pyrolysis at 425 °C for two of the waste streams containing significant amounts of plastic produced both a valuable char and tarry phase, which resulted in an EC greater than 74%. Full conversion of plastic at 550 °C increased the tarry phase yield but dramatically decreased the char HHV. The influence of temperature on product yield and HHV was discussed based on the pyrolysis mechanisms and in relation to the plastic composition of the waste streams.

  20. 75 FR 78235 - Dodge Mill Realty, LLC; Notice of Preliminary Permit Application Accepted for Filing and...

    Science.gov (United States)

    2010-12-15

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13890-000] Dodge Mill Realty, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications December 8, 2010. On December 3, 2010, Dodge Mill Realty...

  1. Future CO2 removal from pulp mills - Process integration consequences

    International Nuclear Information System (INIS)

    Hektor, Erik; Berntsson, Thore

    2007-01-01

    Earlier work has shown that capturing the CO 2 from flue gases in the recovery boiler at a pulp mill can be a cost-effective way of reducing mill CO 2 emissions. However, the CO 2 capture cost is very dependent on the fuel price. In this paper, the potential for reducing the need for external fuel and thereby the possibility to reduce the cost for capturing the CO 2 are investigated. The reduction is achieved by using thermal process integration. In alternative 1, the mill processes are integrated and a steam surplus made available for CO 2 capture, but still there is a need for external fuel. In alternative 2, the integration is taken one step further, the reboiler is fed with MP steam, and the heat of absorption from the absorption unit is used for generation of LP steam needed at the mill. The avoidance costs are in both cases lower than before the process integration. The avoidance cost in alternative 1 varies between 25.4 and 30.7 EUR/tonne CO 2 depending on the energy market parameters. For alternative 2, the cost varies between 22.5 and 27.2 EUR/tonne CO 2 . With tough CO 2 reduction targets and correspondingly high CO 2 emission costs, the annual earnings can be substantial, 18.6 MEUR with alternative 1 and 21.2 MEUR with alternative 2

  2. Comminution of B4C powders with a high-energy mill operated in air in dry or wet conditions and its effect on their spark-plasma sinterability

    DEFF Research Database (Denmark)

    Ortiz, Angel L.; Sánchez-Bajo, Florentino; Leal, Victor Manuel Candelario

    2017-01-01

    to the nanoscale. While this is accompanied by oxidation and aggregation, these are not serious drawbacks. Wet shaker milling in methanol (i.e., conventional ball-milling) resulted only in a moderate B4C particle refinement with greater contamination by the milling tools, which limits its usefulness. It was also......-plasma sintering confirmed this recommendation, and also showed the usefulness of dry shaker milling to obtain refined B4C microstructures for structural applications....

  3. High anisotropic NdFeB submicro/nanoflakes prepared by surfactant-assisted ball milling at low temperature

    Science.gov (United States)

    An, Xiaoxin; Jin, Kunpeng; Abbas, Nadeem; Fang, Qiuli; Wang, Fang; Du, Juan; Xia, Weixing; Yan, Aru; Liu, J. Ping; Zhang, Jian

    2017-11-01

    Hard magnetic NdFeB submicro/nanoflakes were successfully prepared by surfactant-assisted ball milling at low temperature (SABMLT) by specially using 2-methyl pentane and trioctylamine (TOA) as solvent and surfactant, respectively. Influences of the amount of TOA and milling temperature on the crystal structure, morphology and magnetic performances of the as-prepared NdFeB powders were investigated systematically. There is significant difference on morphology between the NdFeB powders milled at room and low temperature. The NdFeB powders with flaky morphology could be obtained even with a small amount of TOA by SABMLT, which could not be achieved by surfactant-assisted ball milling at room temperature (SABMRT). The better crystallinity, better grain alignment, higher coercivity, larger saturation magnetization and remanence ratio were achieved in the samples prepared by SABMLT. Furthermore, the final NdFeB powders prepared by SABMLT possessed a lower amount of residual TOA than those prepared by SABMRT. It was demonstrated that SABMLT is a promising way to fabricate rare-earth-transition metal nanoflakes with high anisotropy for permanent magnetic materials. The effective method of preparing NdFeB flakes by lowering temperature will be also useful to fabricate flakes of other functional materials.

  4. N=1 supersymmetric Yang-Mills theory on the lattice

    Energy Technology Data Exchange (ETDEWEB)

    Piemonte, Stefano

    2015-04-08

    Supersymmetry (SUSY) relates two classes of particles of our universe, bosons and fermions. SUSY is considered nowadays a fundamental development to explain many open questions about high energy physics. The N=1 super Yang-Mills (SYM) theory is a SUSY model that describes the interaction between gluons and their fermion superpartners called ''gluinos''. Monte Carlo simulations on the lattice are a powerful tool to explore the non-perturbative dynamics of this theory and to understand how supersymmetry emerges at low energy. This thesis presents new results and new simulations about the properties of N=1 SYM, in particular about the phase diagram at finite temperature.

  5. Synthesis of Randomly Substituted Anionic Cyclodextrins in Ball Milling

    Directory of Open Access Journals (Sweden)

    László Jicsinszky

    2017-03-01

    Full Text Available A number of influencing factors mean that the random substitution of cyclodextrins (CD in solution is difficult to reproduce. Reaction assembly in mechanochemistry reduces the number of these factors. However, lack of water can improve the reaction outcomes by minimizing the reagent’s hydrolysis. High-energy ball milling is an efficient, green and simple method for one-step reactions and usually reduces degradation and byproduct formation. Anionic CD derivatives have successfully been synthesized in the solid state, using a planetary ball mill. Comparison with solution reactions, the solvent-free conditions strongly reduced the reagent hydrolysis and resulted in products of higher degree of substitution (DS with more homogeneous DS distribution. The synthesis of anionic CD derivatives can be effectively performed under mechanochemical activation without significant changes to the substitution pattern but the DS distributions were considerably different from the products of solution syntheses.

  6. 76 FR 9340 - Mill Town Power Project; Notice of Preliminary Permit Application Accepted for Filing and...

    Science.gov (United States)

    2011-02-17

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 13995-000] Mill Town Power Project; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On January 4, 2011, Mill Town Power Project filed an application for a...

  7. Asymptotic properties of spherically symmetric, regular and static solutions to Yang-Mills equations

    International Nuclear Information System (INIS)

    Cronstrom, C.

    1987-01-01

    In this paper the author discusses the asymptotic properties of solutions to Yang-Mills equations with the gauge group SU(2), for spherically symmetric, regular and static potentials. It is known, that the pure Yang-Mills equations cannot have nontrivial regular solutions which vanish rapidly at space infinity (socalled finite energy solutions). So, if regular solutions exist, they must have non-trivial asymptotic properties. However, if the asymptotic behaviour of the solutions is non-trivial, then the fact must be explicitly taken into account in constructing the proper action (and energy) for the theory. The elucidation of the appropriate surface correction to the Yang-Mills action (and hence the energy-momentum tensor density) is one of the main motivations behind the present study. In this paper the author restricts to the asymptotic behaviour of the static solutions. It is shown that this asymptotic behaviour is such that surface corrections (at space-infinity) are needed in order to obtain a well-defined (classical) theory. This is of relevance in formulating a quantum Yang-Mills theory

  8. Techno-Economic Performance Evaluation for Olive Mills Powered by Grid-Connected Photovoltaic Systems

    Directory of Open Access Journals (Sweden)

    Ovidio Rabaza

    2015-10-01

    Full Text Available In recent years, due to the rise in petroleum prices and greenhouse gas emissions, renewable energy has been recommended as a power source for different types of facilities. For the period 2010 to 2020 the European Commission has established three key objectives related to climatic change and energy sustainability, such as reductions of CO2 emissions, increases in the use of renewable energy, and improvements in energy efficiency. A key industry is olive oil production in olive mills, where there is a great opportunity to reduce electricity consumption, increase additional profits related to the reduction of technologies that are harmful to the environment, and to cut back maintenance costs. For this reason, a feasibility study of grid-connected photovoltaics (PV systems has been carried out for different types of olive mills in Andalusia (southern Spain. This region is highly energy dependent, but has an abundance of “green” resources to be exploited. The results of this study contemplate a reduction in spending on electrical power of between 2% and 37%, and an increase in the use of renewable energy of between 2% and 26%. These results are according to the self-consumption or net metering policy and the production capacity of olive oil.

  9. 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

  10. 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

  11. 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

  12. The Structure and Mechanical Properties of High-Strength Bulk Ultrafine-Grained Cobalt Prepared Using High-Energy Ball Milling in Combination with Spark Plasma Sintering

    Czech Academy of Sciences Publication Activity Database

    Marek, I.; Vojtěch, D.; Michalcová, A.; Kubatík, Tomáš František

    2016-01-01

    Roč. 9, č. 5 (2016), č. článku 391. ISSN 1996-1944 Institutional support: RVO:61389021 Keywords : ultrafine-grained material * cobalt * ball milling * spark plasma sintering * mechanical properties Subject RIV: JG - Metallurgy Impact factor: 2.654, year: 2016 www.mdpi.com/1996-1944/9/5/391/pdf

  13. 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

  14. Comparison of wind mill cluster performance: A multicriteria approach

    Energy Technology Data Exchange (ETDEWEB)

    Rajakumar, D.G.; Nagesha, N. [Visvesvaraya Technological Univ., Karnataka (India)

    2012-07-01

    Energy is a crucial input for the economic and social development of any nation. Both renewable and non-renewable energy contribute in meeting the total requirement of the economy. As an affordable and clean energy source, wind energy is amongst the world's fastest growing renewable energy forms. Though there are several wind-mill clusters producing energy in different geographical locations, evaluating their performance is a complex task and not much of literature is available in this area. In this backdrop, an attempt is made in the current paper to estimate the performance of a wind-mill cluster through an index called Cluster Performance Index (CPI) adopting a multi-criteria approach. The proposed CPI comprises four criteria viz., Technical Performance Indicators (TePI), Economic Performance Indicators (EcPI), Environmental Performance Indicators (EnPI), and Sociological Performance Indicators (SoPI). Under each performance criterion a total of ten parameters are considered with five subjective and five objective oriented responses. The methodology is implemented by collecting empirical data from three wind-mill clusters located at Chitradurga, Davangere, and Gadag in the southern Indian State of Karnataka. Totally fifteen different stake holders are consulted through a set of structured researcher administered questionnaire to collect the relevant data in each wind farm. Stake holders involved engineers working in wind farms, wind farm developers, Government officials from energy department and a few selected residential people near the wind farms. The results of the study revealed that Chitradurga wind farm performed much better with a CPI of 45.267 as compared to Gadag (CPI of 28.362) and Davangere (CPI of 19.040) wind farms. (Author)

  15. On the exponentiation of leading infrared divergences in massless Yang-Mills theories

    International Nuclear Information System (INIS)

    Frenkel, J.; Garcia, R.L.

    1977-01-01

    We derive, in the axial gauge, the effective U-matrix which governs the behaviour of leading infrared singularities in the self-energy functions of Yang-Mills particles. We then show in a very simple manner, that these divergences, which determine the leading singularities in massless Yang-Mills theories, exponentiate [pt

  16. Early time evolution of high-energy heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [Cyclotron Institute and Department of Physics, Texas A and M University, College Station, TX 77843 (United States); RIKEN/BNL Research Center, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2007-08-15

    We solve the Yang-Mills equations in the framework of the McLerran-Venugopalan model for small times {tau} after a collision of two nuclei. An analytic expansion around {tau} = 0 leads to explicit results for the field strength and the energy-momentum tensor of the gluon field at early times. We then discuss constraints for the energy density, pressure and flow of the plasma phase that emerges after thermalization of the gluon field.

  17. 78 FR 34091 - Wausau Paper Mills, LLC; Specialty Papers Acquisition, LLC; Notice of Application for Transfer of...

    Science.gov (United States)

    2013-06-06

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project Nos. 2161-034; 2207-045] Wausau Paper Mills, LLC; Specialty Papers Acquisition, LLC; Notice of Application for Transfer of Licenses, and Soliciting Comments and Motions To Intervene On April 22, 2013, Wausau Paper Mills, LLC (transferor) and...

  18. Composition of sugar cane, energy cane, and sweet sorghum suitable for ethanol production at Louisiana sugar mills.

    Science.gov (United States)

    Kim, Misook; Day, Donal F

    2011-07-01

    A challenge facing the biofuel industry is to develop an economically viable and sustainable biorefinery. The existing potential biorefineries in Louisiana, raw sugar mills, operate only 3 months of the year. For year-round operation, they must adopt other feedstocks, besides sugar cane, as supplemental feedstocks. Energy cane and sweet sorghum have different harvest times, but can be processed for bio-ethanol using the same equipment. Juice of energy cane contains 9.8% fermentable sugars and that of sweet sorghum, 11.8%. Chemical composition of sugar cane bagasse was determined to be 42% cellulose, 25% hemicellulose, and 20% lignin, and that of energy cane was 43% cellulose, 24% hemicellulose, and 22% lignin. Sweet sorghum was 45% cellulose, 27% hemicellulose, and 21% lignin. Theoretical ethanol yields would be 3,609 kg per ha from sugar cane, 12,938 kg per ha from energy cane, and 5,804 kg per ha from sweet sorghum.

  19. The effect of the addition of the elements Ni, Zn and Co in a composite AlTiO{sub 2} obtained by high-energy milling and sintering process; Efeito da adicao dos elementos Ni, Zn ou Co no composito AlTiO{sub 2} obtido por moagem de alta energia e sinterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, C.O. de; Coelho, R.E.; Conrado, L.C.; Nascimento, C.S.; Teixeira, C.A.; Mendonca, E.S., E-mail: cristiane.olv.carvalho@hotmail.com [Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia (IFBA), BA (Brazil)

    2016-07-01

    The present work use aluminum scrap with addition of TiO{sub 2}, Ni, Zn or Co to preparation and characterization of nanocomposites. The aluminum were cut and subjected to high energy milling for 2 hours at 1200rpm. The obtained powder was added to TiO{sub 2}, Ni, Zn or Co in a nominal composition 97Al-2TiO{sub 2}-1X (X = Ni, Zn or Co) (weight %) and again, the mixture was subjected to milling for 1 hour at 1000rpm. Grinding powders were hot pressed in the closed die and then removed; the compressed were sintered at 950°C in a tubular furnace N{sub 2} passing atmosphere. The samples obtained were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-ray Diffraction (XRD). The results of SEM images showed a very refined microstructure and an aluminum matrix without porosity. (author)

  20. 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.

  1. Optimization of bead milling parameters for the cell disruption of microalgae: process modeling and application to Porphyridium cruentum and Nannochloropsis oculata.

    Science.gov (United States)

    Montalescot, V; Rinaldi, T; Touchard, R; Jubeau, S; Frappart, M; Jaouen, P; Bourseau, P; Marchal, L

    2015-11-01

    A study of cell disruption by bead milling for two microalgae, Nannochloropsis oculata and Porphyridium cruentum, was performed. Strains robustness was quantified by high-pressure disruption assays. The hydrodynamics in the bead mill grinding chamber was studied by Residence Time Distribution modeling. Operating parameters effects were analyzed and modeled in terms of stress intensities and stress number. RTD corresponded to a 2 CSTR in series model. First order kinetics cell disruption was modeled in consequence. Continuous bead milling was efficient for both strains disruption. SI-SN modeling was successfully adapted to microalgae. As predicted by high pressure assays, N. oculata was more resistant than P. cruentum. The critical stress intensity was twice more important for N. oculata than for P. cruentum. SI-SN modeling allows the determination of operating parameters minimizing energy consumption and gives a scalable approach to develop and optimize microalgal disruption by bead milling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. 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....

  3. Improved critical current densities in bulk FeSe superconductor using ball milled powders and high temperature sintering

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, M.; Furutani, K.; Murakami, M. [Graduate School of Science and Engineering, Superconducting Materials Laboratory, Shibaura Institute of Technology, Tokyo (Japan); Kumar, Dinesh; Rao, M.S. Ramachandra [Department of Physics, Nano Functional Materials Technology Centre and Materials Science Research Centre, Indian Institute of Technology Madras, Chennai (India); Koblischka, M.R. [Institute of Experimental Physics, Saarland University, Saarbruecken (Germany)

    2016-12-15

    The present study is investigating the effect of high temperature sintering combined with ball milled powders for the preparation of FeSe material via solid state sintering technique. The commercial powders of Fe (99.9% purity) and Se (99.9% purity) were mixed in a nominal ratio Fe:Se = 1:1 and thoroughly ground and ball-milled in a glove box during 6 h. Then, the powder mixture was pressed into pellets of 5 mm in diameter and 2 mm thickness using an uniaxial pressure of 100 MPa. The samples were sealed in quartz tubes and sintered at 600 C for 24 h. Then, the pellets were again thoroughly ground and ball-milled in the glove box and pressed into pellets, and the final sintering was performed at two different temperatures, namely at 900 C for 24 h and at 950 C for 24 h. X-ray diffraction results confirmed that both samples showed mainly of the β-FeSe with tetragonal structure. The temperature dependence of magnetization (M-T) curves revealed a sharp superconducting transition T{sub c,} {sub onset} = 8.16 K for the sample sintered at 900 C. Further, scanning electron microscopy observations proved that samples sintered at 900 C show a platelike grain structure with high density. As a result, improved irreversibility fields around 5 T and the critical current density (J{sub c}) values of 6252 A cm{sup -2} at 5 K and self-field are obtained. Furthermore, the normalized volume pinning force versus the reduced field plots indicated a peak position at 0.4 for the sample sintered at 900 C. Improved flux pinning and the high J{sub c} values are attributed to the textured microstructure of the material, produced by a combination of high temperature sintering and ball milling. (copyright 2016 The Authors. Phys. Status Solidi A published by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  4. Coexistence of short- and long-range ferromagnetic order in nanocrystalline Fe{sub 2}Mn{sub 1−x}Cu{sub x}Al (x=0.0, 0.1 and 0.3) synthesized by high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Thanh, Tran Dang, E-mail: thanhxraylab@yahoo.com [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi (Viet Nam); Nanto, Dwi [Physics Education, Syarif Hidayatullah States Islamic University, Jakarta 15412 (Indonesia); Tuyen, Ngo Thi Uyen [Department of Natural Science, Nha Trang Pedagogic College, Nguyen Chanh, Nha Trang, Khanh Hoa (Viet Nam); Nan, Wen-Zhe [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Yu, YiKyung [Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093-0411 (United States); Tartakovsky, Daniel M., E-mail: dmt@ucsd.edu [Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093-0411 (United States); Yu, S.C., E-mail: scyu@cbnu.ac.kr [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi (Viet Nam)

    2015-11-15

    In this work, we prepared nanocrystalline Fe{sub 2}Mn{sub 1−x}Cu{sub x}Al (x=0.0, 0.1 and 0.3) powders by the high energy ball milling technique, and then studied their critical properties. Our analysis reveals that the increase of Cu-doping concentration (up to x=0.3) in these powders leads to a gradual increase of the ferromagnetic–paramagnetic transition temperature from 406 to 452 K. The Banerjee criterion suggests that all the samples considered undergo a second-order phase transition. A modified Arrott plot and scaling analysis indicate that the critical exponents (β=0.419 and 0.442, γ=1.082 and 1.116 for x=0.0 and 0.1, respectively) are located in between those expected for the 3D-Heisenberg and the mean-field models; the values of β=0.495 and γ=1.046 for x=0.3 sample are very close to those of the mean-field model. These features reveal the coexistence of the short- and long-range ferromagnetic order in the nanocrystalline Fe{sub 2}Mn{sub 1−x}Cu{sub x}Al powders. Particularly, as the concentration of Cu increases, values of the critical exponent shift towards those of the mean-field model. Such results prove the Cu doping favors establishing a long-range ferromagnetic order. - Highlights: • Fe{sub 2}Mn{sub 1−x}Cu{sub x}Al nanocrystals were prepared by a high energy ball milling method. • A coexistence of the short- and long-range FM order in the nanocrystals. • Cu doping favors establishing a long-range FM order in the nanocrystals. • All the ΔS{sub m}(T, H) data are followed a universal master curve.

  5. 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)

  6. 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)

  7. INFLUENCE OF CONFIGURATION OF EQUIPMENT OF A HIGH-SPEED ROD MILL ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available The quality of output production has increased in the result of new arrangement of finishing train of block construction of rod mill of RUP «BMZ». Additional using in rolled line of reducing-sizing block at production of high- carbon rolled wire enabled to reduce the dispersion of mechanical characteristics, to decrease the depth of decarburized layer.

  8. Loop groups and Yang-Mills theory in dimension two

    DEFF Research Database (Denmark)

    Gravesen, Jens

    1990-01-01

    Given a connection ω in a G-bundle over S2, then a process called radial trivialization from the poles gives a unique clutching function, i.e., an element γ of the loop group ΩG. Up to gauge equivalence, ω is completely determined by γ and a map f:S2 →g into the Lie algebra. Moreover, the Yang......-Mills function of ω is the sum of the energy of γ and the square of a certain norm of f. In particular, the Yang-Mills functional has the same Morse theory as the energy functional on ΩG. There is a similar description of connections in a G-bundle over an arbitrary Riemann surface, but so far not of the Yang...

  9. Qualitative study the effect of conditions milling of 95.5Sn/4.0Ag/0.5Cu, (wt%) nanopowder

    International Nuclear Information System (INIS)

    Manzato, L.; Anglada-Rivera, J.; Oliveira, M.F. de

    2010-01-01

    The SAC-405, Sn-4.0Ag-0.5Cu (wt%) nanopowders, which has potential applications in microelectronics, such as lead-free solder, were obtained by high energy milling. The purpose of this study was to investigate the structural changes of the SAC-405 produced by high energy milling with times of 12, 24 and 48, under an atmosphere of hydrogen and power grinding 40:1. The crystallite size and micro-deformations of the nanopowders was measured by X-ray diffraction (XRD) using Rietveld method. Preliminary results show that it is possible to obtain nanopowders by mechanical alloying for the SAC-405 alloy with average particle size of 10 ∼ 18 nm. There are also strong indications of a reduction of ∼ 7 deg C melting temperature of the dust that is characteristic of nano-sized particles. (author)

  10. Advanced power generation using biomass wastes from palm oil mills

    International Nuclear Information System (INIS)

    Aziz, Muhammad; Kurniawan, Tedi; Oda, Takuya; Kashiwagi, Takao

    2017-01-01

    This study focuses on the energy-efficient utilization of both solid and liquid wastes from palm oil mills, particularly their use for power generation. It includes the integration of a power generation system using empty fruit bunch (EFB) and palm oil mill effluent (POME). The proposed system mainly consists of three modules: EFB gasification, POME digestion, and additional organic Rankine cycle (ORC). EFBs are dried and converted into a syngas fuel with high calorific value through integrated drying and gasification processes. In addition, POME is converted into a biogas fuel for power generation. Biogas engine-based cogenerators are used for generating both electricity and heat. The remaining unused heat is recovered by ORC module to generate electricity. The influences of three EFB gasification temperatures (800, 900 and 1000 °C) in EFB gasification module; and working fluids and pressure in ORC module are evaluated. Higher EFB gasification leads to higher generated electricity and remaining heat for ORC module. Power generation efficiency increases from 11.2 to 24.6% in case of gasification temperature is increased from 800 to 1000 °C. In addition, cyclohexane shows highest energy efficiency compared to toluene and n-heptane in ORC module. Higher pressure in ORC module also leads to higher energy efficiency. Finally, the highest total generated power and power generation efficiency obtained by the system are 8.3 MW and 30.4%, respectively.

  11. 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.

  12. 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...

  13. Perturbations of the Yang-Mills field in the universe

    International Nuclear Information System (INIS)

    Zhao Wen

    2009-01-01

    It has been suggested that the Yang-Mills (YM) field can be a kind of candidate for the inflationary field at high energy scales or dark energy at very low energy scales, which can naturally give the equation of state -1 -2 , from which it follows that the equation of state of the YM field always goes to -1, independent of the initial conditions. By solving the first order Einstein equations and the YM field equations, we find that in the YM field inflationary models, the scale-invariant primordial perturbation power spectrum cannot be generated. Therefore, only using this kind of YM field is not enough to account for inflationary sources. However, as a kind of candidate for dark energy, the YM field has the 'sound speed' cs 2 S = -1/3 < 0, which makes the perturbation oe have a damping behavior at large scales. This provides a way to distinguish the YM field dark energy models from other kinds of models. (research papers)

  14. 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.

  15. 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

  16. Hydrogen storage materials discovery via high throughput ball milling and gas sorption.

    Science.gov (United States)

    Li, Bin; Kaye, Steven S; Riley, Conor; Greenberg, Doron; Galang, Daniel; Bailey, Mark S

    2012-06-11

    The lack of a high capacity hydrogen storage material is a major barrier to the implementation of the hydrogen economy. To accelerate discovery of such materials, we have developed a high-throughput workflow for screening of hydrogen storage materials in which candidate materials are synthesized and characterized via highly parallel ball mills and volumetric gas sorption instruments, respectively. The workflow was used to identify mixed imides with significantly enhanced absorption rates relative to Li2Mg(NH)2. The most promising material, 2LiNH2:MgH2 + 5 atom % LiBH4 + 0.5 atom % La, exhibits the best balance of absorption rate, capacity, and cycle-life, absorbing >4 wt % H2 in 1 h at 120 °C after 11 absorption-desorption cycles.

  17. Modification of medium-range order in silica glass by ball-milling: real- and reciprocal-space structural correlations for the first sharp diffraction peak

    International Nuclear Information System (INIS)

    Mukai, Akira; Kohara, Shinji; Uchino, Takashi

    2007-01-01

    We have carried out high-energy x-ray diffraction measurements on mechanically milled silica glass. It has been found that the first sharp diffraction peak (FSDP) in the structure factor S(Q) of silica glass appreciably decreases in intensity as a result of mechanical milling, whereas the observed features of the other peaks in S(Q) almost remain unchanged. The corresponding real-space correlation function of the milled samples shows a marked decrease in intensity at r∼5 A. This gives an experimental manifestation that the dominant real-space structural correlation pertaining to the FSDP occurs at r∼5 A

  18. Modification of medium-range order in silica glass by ball-milling: real- and reciprocal-space structural correlations for the first sharp diffraction peak

    Energy Technology Data Exchange (ETDEWEB)

    Mukai, Akira [Department of Chemistry, Kobe University, Kobe 657-8501 (Japan); Kohara, Shinji [SPring-8, Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); Uchino, Takashi [Department of Chemistry, Kobe University, Kobe 657-8501 (Japan)

    2007-11-14

    We have carried out high-energy x-ray diffraction measurements on mechanically milled silica glass. It has been found that the first sharp diffraction peak (FSDP) in the structure factor S(Q) of silica glass appreciably decreases in intensity as a result of mechanical milling, whereas the observed features of the other peaks in S(Q) almost remain unchanged. The corresponding real-space correlation function of the milled samples shows a marked decrease in intensity at r{approx}5 A. This gives an experimental manifestation that the dominant real-space structural correlation pertaining to the FSDP occurs at r{approx}5 A.

  19. Estimation of Moisture Content in Coal in Coal Mills

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Mataji, B.

    the moisture content of the coal is proposed based on a simple dynamic energy model of a coal mill, which pulverizes and dries the coal before it is burned in the boiler. An optimal unknown input observer is designed to estimate the moisture content based on an energy balance model. The designed moisture...

  20. Estimation of Moisture Content in Coal in Coal Mills

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Mataji, Babak

    2006-01-01

    the moisture content of the coal is proposed based on a simple dynamic energy model of a coal mill, which pulverizes and dries the coal before it is burned in the boiler. An optimal unknown input observer is designed to estimate the moisture content based on an energy balance model. The designed moisture...

  1. 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.

  2. The Yang-Mills vacuum wave functional in Coulomb gauge

    International Nuclear Information System (INIS)

    Campagnari, Davide R.

    2011-01-01

    Yang-Mills theories are the building blocks of today's Standard Model of elementary particle physics. Besides methods based on a discretization of space-time (lattice gauge theory), also analytic methods are feasible, either in the Lagrangian or in the Hamiltonian formulation of the theory. This thesis focuses on the Hamiltonian approach to Yang-Mills theories in Coulomb gauge. The thesis is presented in cumulative form. After an introduction into the general formulation of Yang-Mills theories, the Hamilton operator in Coulomb gauge is derived. Chap. 1 deals with the heat-kernel expansion of the Faddeev-Popov determinant. In Chapters 2 and 3, the high-energy behaviour of the theory is investigated. To this purpose, perturbative methods are applied, and the results are compared with the ones stemming from functional methods in Coulomb and Landau gauge. Chap. 4 is devoted to the variational approach. Variational ansatzes going beyond the Gaussian form for the vacuum wave functional are considered and treated using Dyson-Schwinger techniques. Equations for the higher-order variational kernels are derived and their effects are estimated. Chap. 5 presents an application of the previously obtained propagators, namely the evaluation of the topological susceptibility, which is related to the mass of the η meson. Finally, a short overview of the perturbative treatment of dynamical fermion fields is presented.

  3. Influence of Temperature on the Performance of LiNi1/3Co1/3Mn1/3O2 Prepared by High-Temperature Ball-Milling Method

    Directory of Open Access Journals (Sweden)

    Ming Tian

    2018-01-01

    Full Text Available Aiming at the preparation of high electrochemical performance LiNi1/3Co1/3Mn1/3O2 cathode material for lithium-ion battery, LiNi1/3Co1/3Mn1/3O2 was prepared with lithium carbonate, nickel (II oxide, cobalt (II, III oxide, and manganese dioxide as raw materials by high-temperature ball-milling method. Influence of ball-milling temperature was investigated in this work. It was shown that the fine LiNi1/3Co1/3Mn1/3O2 powder with high electrochemical performance can be produced by the high-temperature ball-milling process, and the optimal ball-milling temperature obtained in the current study was 750°C. Its initial discharge capacity was 146.0 mAhg−1 at the rate of 0.1 C, and over 50 cycles its capacity retention rate was 90.2%.

  4. Microstructural characterization of low and high carbon CoCrMo alloy nanoparticles produced by mechanical milling

    Science.gov (United States)

    Simoes, T. A.; Goode, A. E.; Porter, A. E.; Ryan, M. P.; Milne, S. J.; Brown, A. P.; Brydson, R. M. D.

    2014-06-01

    CoCrMo alloys are utilised as the main material in hip prostheses. The link between this type of hip prosthesis and chronic pain remains unclear. Studies suggest that wear debris generated in-vivo may be related to post-operative complications such as inflammation. These alloys can contain different amounts of carbon, which improves the mechanical properties of the alloy. However, the formation of carbides could become sites that initiate corrosion, releasing ions and/or particles into the human body. This study analysed the mechanical milling of alloys containing both high and low carbon levels in relevant biological media, as an alternative route to generate wear debris. The results show that low carbon alloys produce significantly more nanoparticles than high carbon alloys. During the milling process, strain induces an fcc to hcp phase transformation. Evidence for cobalt and molybdenum dissolution in the presence of serum was confirmed by ICP-MS and TEM EDX techniques.

  5. Predicting radon flux from uranium mill tailings

    International Nuclear Information System (INIS)

    Freeman, H.D.; Hartley, J.N.

    1983-11-01

    Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, is developing technology for the design of radon barriers for uranium mill tailings piles. To properly design a radon cover for a particular tailings pile, the radon flux emanating from the bare tailings must be known. The tailings characteristics required to calculate the radon flux include radium-226 content, emanating power, bulk density, and radon diffusivity. This paper presents theoretical and practical aspects of estimating the radon flux from an uranium tailings pile. Results of field measurements to verify the calculation methodology are also discussed. 24 references, 4 figures, 4 tables

  6. 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.

  7. 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.

  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. Ferromagnetic resonance parameters of ball-milled Ni-Zn ferrite nanoparticles

    International Nuclear Information System (INIS)

    Rao, B. Parvatheeswara; Caltun, Ovidiu; Dumitru, Ioan; Spinu, Leonard

    2006-01-01

    Ferrite nanoparticles of the size about 6 nm have been made by using high-energy ball mill on the sintered pellets of the system Ni 0.65 Zn 0.375 In x Ti 0.025 Fe 1.95- x O 4 . XRD, VSM and FMR techniques were used for structural and magnetic characterizations of the samples. The magnetic characteristics of indium-doped samples are compared with those for bulk samples. The differences are discussed in terms of the particle size and small-particle magnetism

  10. Corporate Governance of Sugar Mills in East Java: A Transaction Cost Economics Perspective

    Directory of Open Access Journals (Sweden)

    Ahmad Erani Yustika

    2007-01-01

    Full Text Available Despite Indonesia’s overall achievements during the past two decades%2C the economy is encountering a series of problems. One of the biggest challenges is the unsatisfactory performance of the state-owned enterprises (SOEs. Subsidisies and uncovered loans to the SOEs have drained the government’s fiscal resources%2C and the signing off of employees creates many social problems. Compared with the SOEs in other sectors%2C state-owned sugar mills face more serious crises which not only jeopardise the social fabric%2C but also endanger the production. Research results strengthen the statement that the basic problem in sugar mills is management inefficiency resulting in high transaction costs. This research compares the transaction costs between state-owned (Ngadiredjo and privately-owned (Kebon Agung sugar mills. The study shows that in Kebon Agung Sugar Mill transaction costs are higher than production costs%2C while in Ngadiredjo Sugar Mill the reverse is true. However%2C the high transaction costs in Kebon Agung Sugar Mill cannot be attributed directly to inefficient institutions%2C because Ngadiredjo Sugar Mill incurred high costs for plants%2C land preparation%2C and fertilizer%2C which decreased the proportion of transaction costs. If analyzed in detail%2C the following facts are revealed: (i market transaction costs in Kebon Agung Sugar Mill are higher than in Ngadiredjo Sugar Mill. This is because Kebon Agung Sugar Mill has established cooperation with sugarcane farmers in the form of extensions and transport subsidies; and (ii the political transaction costs proportion in Ngadiredjo Sugar Mill is higher than in Kebon Agung Sugar Mill because of the imposition of many ‘illegal’ fees. Abstract in Bahasa Indonesia : transaction cost economics%2C corporate governance%2C sugar mill%2C East Java.

  11. 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...

  12. Scattering of massless vector, tensor, and other particles in string theory at high energy

    International Nuclear Information System (INIS)

    Antonov, E.N.

    1990-01-01

    The 2 → 2 and 2 → 3 processes are studied in the multi-Regge kinematics for gluons and gravitons, the first excited states of the open and closed strings. The factorization of the corresponding amplitudes is demonstrated. Explicit relations generalizing the Low-Gribov expressions are obtained in the kinematics where one of the external particles is produced with small transverse momentum. The expressions in the limit α' → 0 coincide with the results of Yang-Mills theory and gravitation at high energies

  13. Investigation on Effect of Material Hardness in High Speed CNC End Milling Process

    OpenAIRE

    Dhandapani, N. V.; Thangarasu, V. S.; Sureshkannan, G.

    2015-01-01

    This research paper analyzes the effects of material properties on surface roughness, material removal rate, and tool wear on high speed CNC end milling process with various ferrous and nonferrous materials. The challenge of material specific decision on the process parameters of spindle speed, feed rate, depth of cut, coolant flow rate, cutting tool material, and type of coating for the cutting tool for required quality and quantity of production is addressed. Generally, decision made by the...

  14. 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...

  15. Accelerated aging tests of liners for uranium mill tailings disposal

    International Nuclear Information System (INIS)

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  16. Improvement of the tool life of a micro-end mill using nano-sized SiC/Ni electroplating method.

    Science.gov (United States)

    Park, Shinyoung; Kim, Kwang-Su; Roh, Ji Young; Jang, Gyu-Beom; Ahn, Sung-Hoon; Lee, Caroline Sunyong

    2012-04-01

    High mechanical properties of a tungsten carbide micro-end-mill tool was achieved by extending its tool life by electroplating nano-sized SiC particles (electroplating method on the surface of the micro-end-mill tool was applied using SiC particles and Ni particles. Organic additives (saccharin and ammonium chloride) were added in a Watts bath to improve the nickel matrix density in the electroplating bath and to smooth the surface of the co-electroplating. The morphology of the coated nano-sized SiC particles and the composition were measured using Scanning Electron Microscope and Energy Dispersive Spectrometer. As the Ni/SiC co-electroplating layer was applied, the hardness and friction coefficient improved by 50%. Nano-sized SiC particles with 7 wt% were deposited on the surface of the micro-end mill while the Ni matrix was smoothed by adding organic additives. The tool life of the Ni/SiC co-electroplating coating on the micro-end mill was at least 25% longer than that of the existing micro-end mills without Ni/SiC co-electroplating. Thus, nano-sized SiC/Ni coating by electroplating significantly improves the mechanical properties of tungsten carbide micro-end mills.

  17. Center-symmetric effective theory for high-temperature SU(2) Yang-Mills theory

    International Nuclear Information System (INIS)

    Forcrand, Ph. de; Kurkela, A.; Vuorinen, A.

    2008-01-01

    We construct and study a dimensionally reduced effective theory for high-temperature SU(2) Yang-Mills theory that respects all the symmetries of the underlying theory. Our main motivation is to study whether the correct treatment of the center symmetry can help extend the applicability of the dimensional reduction procedure towards the confinement transition. After performing perturbative matching to the full theory at asymptotically high temperatures, we map the phase diagram of the effective theory using nonperturbative lattice simulations. We find that at lower temperature the theory undergoes a second-order confining phase transition, in complete analogy with the full theory, which is a direct consequence of having incorporated the center symmetry

  18. Domestic uranium mining and milling industry 1991

    International Nuclear Information System (INIS)

    1992-12-01

    This report was prepared by the Energy Information Administration to provide the Secretary of Energy with basic data and analyses for ninth annual determination of the viability of the domestic uranium mining and milling industry. A viability determination is required annually, for the years 1983 through 1992, by Section 170B of the Nuclear Regulatory Commission (NRC) Authorization Act of 1983, Public Law 97-415, which amend the Atomic Energy Act of 1954. Topics include: evolution of the U.S. uranium industry; nuclear power requirements and uranium industry projections; and attributes of industry viability

  19. 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.

  20. 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...

  1. Critical management issues for the Uranium Mill Tailings Remedial Action (UMTRA) Project

    International Nuclear Information System (INIS)

    Themelis, J.G.; Krishnan, K.R.

    1985-01-01

    The Uranium Mill Tailings Radiation Control Act of 1978 (PL95-604) authorized the Secretary of Energy to enter into cooperative agreements with certain states and Indian Tribes to clean up 24 inactive uranium mill tailing sites and associated vicinity properties. The Uranium Mill Tailings Remedial Action (UMTRA) Project includes the three Federal agencies (EPA, DOE, and NRC), eleven state, Indian Tribes, and at least four major contractors. The UMTRA Project extends over a period of ten years. The standards for the Project require a design life of 1000 years with a minimum performance period of 200 years. This paper discusses the critical management issues in dealing with the UMTRA Project and identifies the development of solutions for many of those issues. The highlights to date are promulgation of EPA standards, continued support from Congress and participating states and Indian Tribes, significant leadership shown at all levels, establishment of credibility with the public, and continued motivation of the team. The challenge for tomorrow is making certain NRC will license the sites and maintaining the high level of coordination exhibited to date to assure Project completion on schedule

  2. 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

  3. 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.

  4. A Note on Supergravity Duals of Noncommutative Yang-Mills Theory

    International Nuclear Information System (INIS)

    Das, Sumit R.; Ghosh, Banhiman

    2000-01-01

    A class of supergravity backgrounds have been proposed as dual descriptions of strong coupling large-N noncommutative Yang-Mills (NCYM) theories in 3+1 dimensions. However calculations of correlation functions in supergravity from an evaluation of relevant classical actions appear ambiguous. We propose a resolution of this ambiguity. Assuming that holographic description exists - regardless of whether it is the NCYM theory - we argue that there should be operators in the holographic boundary theory which create normalized states of definite energy and momenta. An operator version of the dual correspondence then provides a calculation of correlators of these operators in terms of bulk Green's functions. We show that in the low energy limit the correlators reproduce expected answers of the ordinary Yang-Mills theory. (author)

  5. Accuracy of depth of cut in micro milling operations

    DEFF Research Database (Denmark)

    Bissacco, Giuliano

    since the magnitude of the cutting forces involved is reduced), which make mechanical micromachining by use of miniaturized tools troublesome or even impossible. This study deals with the use of a conventional 3 axis vertical milling machine equipped with a high speed attached spindle for micro milling...

  6. High heat generation ability in AC magnetic field for nano-sized magnetic Y3Fe5O12 powder prepared by bead milling

    International Nuclear Information System (INIS)

    Aono, Hiromichi; Ebara, Hiroki; Senba, Ryota; Naohara, Takashi; Maehara, Tsunehiro; Hirazawa, Hideyuki; Watanabe, Yuji

    2012-01-01

    Nano-sized magnetic Y 3 Fe 5 O 12 ferrite having a high heat generation ability in an AC magnetic field was prepared by bead milling. A commercial powder sample (non-milled sample) of ca. 2.9 μm in particle size did not show any temperature enhancement in the AC magnetic field. The heat generation ability in the AC magnetic field improved with a decrease in the average crystallite size for the bead-milled Y 3 Fe 5 O 12 ferrites. The highest heat ability in the AC magnetic field was for the fine Y 3 Fe 5 O 12 powder with a 15-nm crystallite size (the samples were milled for 4 h using 0.1 mmφ beads). The heat generation ability of the excessively milled Y 3 Fe 5 O 12 samples decreased. The main reason for the high heat generation property of the milled samples was ascribed to an increase in the Néel relaxation of the superparamagnetic material. The heat generation ability was not influenced by the concentration of the ferrite powder. For the samples milled for 4 h using 0.1 mmφ beads, the heat generation ability (W g −1 ) was estimated using a 3.58×10 −4 fH 2 frequency (f/kHz) and the magnetic field (H/kA m −1 ), which is the highest reported value of superparamagnetic materials. - Highlights: ► The nano-sized Y 3 Fe 5 O 12 powder prepared by bead-milling has the highest heat generation ability in an AC magnetic field. ► The heat generation properties are ascribed to an increase in the Néel relaxation of the superparamagnetic material. ► The heat ability (W g −1 ) can be estimated using 3.58×10 −4 fH 2 (f=kHz, H=kA m −1 ). ► This is an expectable material for use in a drug delivery system for the thermal coagulation therapy of cancer tumors.

  7. Evaluation of cutting force and surface roughness in high-speed milling of compacted graphite iron

    Directory of Open Access Journals (Sweden)

    Azlan Suhaimi Mohd

    2017-01-01

    Full Text Available Compacted Graphite Iron, (CGI is known to have outstanding mechanical strength and weight-to-strength ratio as compared to conventional grey cast iron, (CI. The outstanding characteristics of CGI is due to its graphite particle shape, which is presented as compacted vermicular particle. The graphite is interconnected with random orientation and round edges, which results in higher mechanical strength. Whereas, graphite in the CI consists of a smooth-surfaced flakes that easily propagates cracks which results in weaker and brittle properties as compared to CGI. Owing to its improved properties, CGI is considered as the best candidate material in substituting grey cast iron that has been used in engine block applications for years. However, the smooth implementation of replacing CI with CGI has been hindered due to the poor machinability of CGI especially at high cutting speed. The tool life is decreased by 20 times when comparing CGI with CI under the same cutting condition. This study investigates the effect of using cryogenic cooling and minimum quantity lubrication (MQL during high-speed milling of CGI (grade 450. Results showed that, the combination of internal cryogenic cooling and enhanced MQL improved the tool life, cutting force and surface quality as compared to the conventional flood coolant strategy during high-speed milling of CGI.

  8. Preliminary evaluation of uranium mill tailings conditioning as an alternative remedial action technology

    International Nuclear Information System (INIS)

    Dreesen, D.R.; Cokal, E.J.; Thode, E.F.; Wangen, L.E.; Williams, J.M.

    1981-01-01

    Conditioning of uranium mill tailings is being investigated as an alternative remedial action for inactive tailings piles to be stabilized by the US Department of Energy. Tailings from high priority sites have been characterized for elemental composition, mineralogy, aqueous leachable contaminants, and radon emanation power to provide a baseline to determine the environmental hazard control produced by conditioning. Thermal stabilization of tailings at high temperatures and removal of contaminants by sulfuric acid leaching are being investigated for technical merit as well as economic and engineering feasibility

  9. Magnetic heating characteristics of La0.7SrxCa0.3-xMnO3 nanoparticles fabricated by a high energy mechanical milling method

    Science.gov (United States)

    Do, Hung Manh; Pham, Hong Nam; Chien Nguyen, Van; Bich Hoa Phan, Thi; Tran, Dai Lam; Nguyen, Anh Tuan; Thong Phan, Quoc; Le, Van Hong; Phuc Nguyen, Xuan

    2011-09-01

    Magnetic inductive heating (MIH) of nanoparticles (NPs) attracts considerable research attention, first because of its application to hyperthermia in biological tissues. Most reports so far have dealt with magnetite NPs with a Curie temperature, TC, of as high as above 500 °C. In this paper, we present results of a MIH study in an ac field of frequency 219 and 236 kHz and strength of 40-100 Oe for several samples of La0.7SrxCa0.3-x MnO3 NPs of TC in the region of hyperthermia, that is some tens of degrees above human body temperature. The particle materials were fabricated by a high energy mechanical milling method combined with calcining at various temperatures in the range of 600-900 °C. The heating temperatures of the samples were observed to saturate at a field irradiating time of less than 10 min and at temperatures ranging from 40 to 75 °C depending on the strontium content, the NP concentration, c, and the field parameters. A sudden change in heating rate was clearly revealed in several heating curves for the case of low applied field and low c, which was considered to be related to the onset of a strong decrease in zero-field cooling (ZFC) magnetization of NPs. The initial temperature increase slope, dT/dt, and the saturation temperature, Ts will be analyzed as dependent on the NP concentration. Field dependences of the specific loss power will be analyzed and discussed for various concentrations, c. Evidence of fluid viscosity influence will also be noted.

  10. Magnetic heating characteristics of La0.7SrxCa0.3-xMnO3 nanoparticles fabricated by a high energy mechanical milling method

    International Nuclear Information System (INIS)

    Manh Do, Hung; Nam Pham, Hong; Chien Nguyen, Van; Bich Hoa Phan, Thi; Lam Tran, Dai; Tuan Nguyen, Anh; Hong Le, Van; Phuc Nguyen, Xuan; Thong Phan, Quoc

    2011-01-01

    Magnetic inductive heating (MIH) of nanoparticles (NPs) attracts considerable research attention, first because of its application to hyperthermia in biological tissues. Most reports so far have dealt with magnetite NPs with a Curie temperature, T C , of as high as above 500 °C. In this paper, we present results of a MIH study in an ac field of frequency 219 and 236 kHz and strength of 40–100 Oe for several samples of La 0.7 Sr x Ca 0.3−x MnO 3 NPs of T C in the region of hyperthermia, that is some tens of degrees above human body temperature. The particle materials were fabricated by a high energy mechanical milling method combined with calcining at various temperatures in the range of 600–900 °C. The heating temperatures of the samples were observed to saturate at a field irradiating time of less than 10 min and at temperatures ranging from 40 to 75 °C depending on the strontium content, the NP concentration, c, and the field parameters. A sudden change in heating rate was clearly revealed in several heating curves for the case of low applied field and low c, which was considered to be related to the onset of a strong decrease in zero-field cooling (ZFC) magnetization of NPs. The initial temperature increase slope, dT/dt, and the saturation temperature, T s will be analyzed as dependent on the NP concentration. Field dependences of the specific loss power will be analyzed and discussed for various concentrations, c. Evidence of fluid viscosity influence will also be noted

  11. Highly Al-doped TiO2 nanoparticles produced by Ball Mill Method: structural and electronic characterization

    International Nuclear Information System (INIS)

    Santos, Desireé M. de los; Navas, Javier; Sánchez-Coronilla, Antonio; Alcántara, Rodrigo; Fernández-Lorenzo, Concha; Martín-Calleja, Joaquín

    2015-01-01

    Highlights: • Highly Al-doped TiO 2 nanoparticles were synthesized using a Ball Mill Method. • Al doping delayed anatase to rutile phase transformation. • Al doping allow controlling the structural and electronic properties of nanoparticles. - Abstract: This study presents an easy method for synthesizing highly doped TiO 2 nanoparticles. The Ball Mill method was used to synthesize pure and Al-doped titanium dioxide, with an atomic percentage up to 15.7 at.% Al/(Al + Ti). The samples were annealed at 773 K, 973 K and 1173 K, and characterized using ICP-AES, XRD, Raman spectroscopy, FT-IR, TG, STEM, XPS, and UV–vis spectroscopy. The effect of doping and the calcination temperature on the structure and properties of the nanoparticles were studied. The results show high levels of internal doping due to the substitution of Ti 4+ ions by Al 3+ in the TiO 2 lattice. Furthermore, anatase to rutile transformation occurs at higher temperatures when the percentage of doping increases. Therefore, Al doping allows us to control the structural and electronic properties of the nanoparticle synthesized. So, it is possible to obtain nanoparticles with anatase as predominant phase in a higher range of temperature

  12. Non self-dual Yang-Mills fields

    International Nuclear Information System (INIS)

    Bor, G.

    1991-01-01

    The purpose of the thesis is to prove the existence of a new family of non self-dual finite-energy solutions to the Yang-Mills equations on Euclidean four-space, with SU(2) as a gauge group. The approach is that of equivalent geometry: attention is restricted to a special class of fields, those that satisfy a certain kind of rotational symmetry which it is proved that (1) a solution to the Yang-Mills equations exists for among them, and (2) no solution to the self-duality equations exists among them. The first assertion is proved by an application of the direct method of the calculus of variations (existence and regularity of minimizers), and the second assertion by showing that the self-duality equations, linearized at a symmetric self-dual solution, cannot possess the required symmetry

  13. Gravity flow operated small electricity generator retrofit kit to flour mill industry.

    Science.gov (United States)

    Shekara, Prithivi; Kumar V, Pavan; Hosamane, Gangadharappa Gundabhakthara

    2013-10-01

    Flour milling is a grinding process to produce flour from wheat through comprehensive stages of grinding and separation. The primary energy is required to provide power used in grinding of wheat. In wheat milling, tempering is the process of adding water to wheat before milling to toughen the bran and mellow the endosperm. Gravity flow of the wheat is utilized to rotate the dampener wheel with cups to add water. Low cost gravity flow operated small electricity generator retrofit kit for dampener was designed and developed to justify low cost energy production without expensive solutions. Results of statistical analysis indicated that there was significant difference in mean values for voltage, rpm and flow rate at the 95% probability level. The resulted maximum mechanical power and measured electrical power were 5.1 W and 4.9 W respectively at wheat flow rate of 1.6 Kg/s and dampener wheel rotational velocity of 4.4 rad/s.

  14. Study of de-aggregation of mechanochemically synthesized ZnSe nanoparticles by re-milling in the presence of ZnCl2 solution

    Directory of Open Access Journals (Sweden)

    Marcela Achimovičová

    2013-12-01

    Full Text Available Conventional mechanochemical synthesis of zinc selenide, ZnSe nanoparticles was performed in a planetary ball mill by high-energy milling of zinc (Zn and selenium (Se powders. Mechanochemically synthesized ZnSe was subsequently re-milled in circulation mill in ZnCl2 solution in order to study de-aggregation, physical-chemical and optical properties of ZnSe nanoparticles. The mechanochemically synthesized and re-milled samples were characterized by X-ray diffraction analysis (XRD that confirmed the presence of cubic and hexagonal ZnSe phases. Size of crystallites calculated from XRD patterns has decreased from 50 to 19 nm for cubic ZnSe phase and from 145 to 2.5 nm for hexagonal ZnSe phase after re-milling for 110 min in ZnCl2 solution. Size, phase composition, morphology, and crystallinity of ZnSe nanoparticles were studied by transmission electron microscopy (TEM and selected area electron diffraction (SAED. UV-Vis optical spectroscopy has provided an evidence of blue shift of the re-milled nanocrystalline ZnSe particles from the direct band gap of 2.67 eV characteristic of bulk ZnSe crystals. Colloidal stability of ZnSe nanoparticles dispersions was studied by ? �potential measurements.

  15. The paradox of uranium development: A Polanyian analysis of social movements surrounding the Pinon Ridge Uranium Mill

    Science.gov (United States)

    Malin, Stephanie A.

    Renewal of nuclear energy development has been proposed as one viable solution for reducing greenhouse gas emissions and impacts of climate change. This discussion became concrete as the first uranium mill proposed since the end of the Cold War, the Pinon Ridge Uranium Mill, received state permits in January 2011 to process uranium in southwest Colorado's Paradox Valley. Though environmental contamination from previous uranium activity caused one local community to be bulldozed to the ground, local support for renewed uranium activity emerges among local residents in communities like Nucla, Naturita, and Bedrock, Colorado. Regionally, however, a coalition of organized, oppositionbased grassroots groups fights the decision to permit the mill. Combined, these events allow social scientists a natural laboratory through which to view social repercussions of nuclear energy development. In this dissertation, I use a Polanyian theoretical framework to analyze social, political-economic, and environmental contexts of social movements surrounding PR Mill. My overarching research problem is: How might Polanyian double movement theory be applied to and made empirically testable within the social and environmental context of uranium development? I intended this analysis to inform energy policy debates regarding renewable energy. In Chapter 1, I found various forms of social dislocation lead to two divergent social movement outcomes. Economic social dislocation led to strong mill support among most local residents, according to archival, in-depth interview, and survey data. On the other hand, residents in regional communities experienced two other types of social dislocation -- another kind of economic dislocation, related to concern over boom-bust economies, and environmental health dislocations related to uranium exposure, creating conditions for a regional movement in opposition to PR Mill. In Chapter 2, I focus on regulations and find that two divergent social movements

  16. Uranium Mill Tailings Remedial Action Project, Surface Project Management Plan. Revision 1

    International Nuclear Information System (INIS)

    1994-12-01

    Title I of the Uranium Mill Tailings Radiation Control Act (UMTRCA) authorizes the US Department of Energy (DOE) to undertake remedial action at 24 designated inactive uranium processing sites and associated vicinity properties (VP) containing uranium mill tailings and related residual radioactive materials. The purpose of the Uranium Mill Tailings Remedial Action (UMTRA) Surface Project is to minimize or eliminate radiation health hazards to the public and the environment at the 24 sites and related VPs. This document describes the management organization, system, and methods used to manage the design, construction, and other activities required to clean up the designated sites and associated VPs, in accordance with the UMTRCA

  17. Uranium Mill Tailings Remedial Action Project, Surface Project Management Plan. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-12-01

    Title I of the Uranium Mill Tailings Radiation Control Act (UMTRCA) authorizes the US Department of Energy (DOE) to undertake remedial action at 24 designated inactive uranium processing sites and associated vicinity properties (VP) containing uranium mill tailings and related residual radioactive materials. The purpose of the Uranium Mill Tailings Remedial Action (UMTRA) Surface Project is to minimize or eliminate radiation health hazards to the public and the environment at the 24 sites and related VPs. This document describes the management organization, system, and methods used to manage the design, construction, and other activities required to clean up the designated sites and associated VPs, in accordance with the UMTRCA.

  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. 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.

  20. Environmental control technology for mining, milling, and refining thorium

    International Nuclear Information System (INIS)

    Weakley, S.A.; Blahnik, D.E.; Young, J.K.; Bloomster, C.H.

    1980-02-01

    The purpose of this report is to evaluate, in terms of cost and effectiveness, the various environmental control technologies that would be used to control the radioactive wastes generated in the mining, milling, and refining of thorium from domestic resources. The technologies, in order to be considered for study, had to reduce the radioactivity in the waste streams to meet Atomic Energy Commission (10 CFR 20) standards for natural thorium's maximum permissible concentration (MPC) in air and water. Further regulatory standards or licensing requirements, either federal, state, or local, were not examined. The availability and cost of producing thorium from domestic resources is addressed in a companion volume. The objectives of this study were: (1) to identify the major waste streams generated during the mining, milling, and refining of reactor-grade thorium oxide from domestic resources; and (2) to determine the cost and levels of control of existing and advanced environmental control technologies for these waste streams. Six potential domestic deposits of thorium oxide, in addition to stockpiled thorium sludges, are discussed in this report. A summary of the location and characteristics of the potential domestic thorium resources and the mining, milling, and refining processes that will be needed to produce reactor-grade thorium oxide is presented in Section 2. The wastes from existing and potential domestic thorium oxide mines, mills, and refineries are identified in Section 3. Section 3 also presents the state-of-the-art technology and the costs associated with controlling the wastes from the mines, mills, and refineries. In Section 4, the available environmental control technologies for mines, mills, and refineries are assessed. Section 5 presents the cost and effectiveness estimates for the various environmental control technologies applicable to the mine, mill, and refinery for each domestic resource

  1. 78 FR 44107 - Monadnock Paper Mills, Inc.; Notice of Availability of Environmental Assessment

    Science.gov (United States)

    2013-07-23

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [ Project No. 6597-013-NH] Monadnock Paper Mills, Inc.; Notice of Availability of Environmental Assessment In accordance with the National Environmental Policy Act of 1969 and the Federal Energy Regulatory Commission's (Commission) regulations, 18 CFR...

  2. Research on the characterization and conditioning of uranium mill tailings. III. Summary of uranium mill tailings conditioning research and implications regarding remedial actions

    International Nuclear Information System (INIS)

    Dreesen, D.R.; Cokal, E.J.; Thode, E.F.; Williams, J.M.

    1983-06-01

    This report summarizes the findings of research on uranium mill tailings conditioning technology development performed for the Department of Energy's (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP). Hazards and risks posed by tailings piles are discussed in relation to the goal of conditioning the tailings to reduce these hazards. The results of our efforts regarding characterization of tailings, removal of radionuclides, mineral recovery, thermal stabilization, and engineering/economic analysis of conditioning are presented. The implications of these results for remedial action plans are discussed and conclusions regarding the applicability of these technologies are also presented

  3. TEM sample preparation by femtosecond laser machining and ion milling for high-rate TEM straining experiments

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Thomas; Grapes, Michael D. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Zhang, Yong [Dept. of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Lorenzo, Nicholas; Ligda, Jonathan; Schuster, Brian [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD 21005 (United States); Weihs, Timothy P. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2017-04-15

    To model mechanical properties of metals at high strain rates, it is important to visualize and understand their deformation at the nanoscale. Unlike post mortem Transmission Electron Microscopy (TEM), which allows one to analyze defects within samples before or after deformation, in situ TEM is a powerful tool that enables imaging and recording of deformation and the associated defect motion during mechanical loading. Unfortunately, all current in situ TEM mechanical testing techniques are limited to quasi-static strain rates. In this context, we are developing a new test technique that utilizes a rapid straining stage and the Dynamic TEM (DTEM) at the Lawrence Livermore National Laboratory (LLNL). The new straining stage can load samples in tension at strain rates as high as 4×10{sup 3}/s using two piezoelectric actuators operating in bending while the DTEM at LLNL can image in movie mode with a time resolution as short as 70 ns. Given the piezoelectric actuators are limited in force, speed, and displacement, we have developed a method for fabricating TEM samples with small cross-sectional areas to increase the applied stresses and short gage lengths to raise the applied strain rates and to limit the areas of deformation. In this paper, we present our effort to fabricate such samples from bulk materials. The new sample preparation procedure combines femtosecond laser machining and ion milling to obtain 300 µm wide samples with control of both the size and location of the electron transparent area, as well as the gage cross-section and length. - Highlights: • Tensile straining TEM specimens made by femtosecond laser machining and ion milling. • Accurate positioning of the electron transparent area within a controlled gauge region. • Optimization of femtosecond laser and ion milling parameters. • Fast production of numerous samples with a highly repeatable geometry.

  4. 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.

  5. Determination of rational parameters for process of grinding materials pre-crushed by pressure in ball mill

    Science.gov (United States)

    Romanovich, A. A.; Romanovich, L. G.; Chekhovskoy, E. I.

    2018-03-01

    The article presents the results of experimental studies on the grinding process of a clinker preliminarily ground in press roller mills in a ball mill equipped with energy exchange devices. The authors studied the influence of the coefficients of loading for grinding bodies of the first and second mill chambers, their lengths, angles of inclination, and the mutual location of energy exchange devices (the ellipse segment and the double-acting blade) on the output parameters of the grinding process (productivity, drive power consumption and specific energy consumption). It is clarified that the best results of the disaggregation and grinding process, judging by the minimum specific energy consumption in the grinding of clinker with an anisotropic texture after force deformation between the rolls of a press roller shredder, are achieved at a certain angle of ellipse segment inclination; the length of the first chamber and the coefficients of loading the chambers with grinding bodies.

  6. 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.

  7. 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

  8. Fabrication of an infrared Shack-Hartmann sensor by combining high-speed single-point diamond milling and precision compression molding processes.

    Science.gov (United States)

    Zhang, Lin; Zhou, Wenchen; Naples, Neil J; Yi, Allen Y

    2018-05-01

    A novel fabrication method by combining high-speed single-point diamond milling and precision compression molding processes for fabrication of discontinuous freeform microlens arrays was proposed. Compared with slow tool servo diamond broaching, high-speed single-point diamond milling was selected for its flexibility in the fabrication of true 3D optical surfaces with discontinuous features. The advantage of single-point diamond milling is that the surface features can be constructed sequentially by spacing the axes of a virtual spindle at arbitrary positions based on the combination of rotational and translational motions of both the high-speed spindle and linear slides. By employing this method, each micro-lenslet was regarded as a microstructure cell by passing the axis of the virtual spindle through the vertex of each cell. An optimization arithmetic based on minimum-area fabrication was introduced to the machining process to further increase the machining efficiency. After the mold insert was machined, it was employed to replicate the microlens array onto chalcogenide glass. In the ensuing optical measurement, the self-built Shack-Hartmann wavefront sensor was proven to be accurate in detecting an infrared wavefront by both experiments and numerical simulation. The combined results showed that precision compression molding of chalcogenide glasses could be an economic and precision optical fabrication technology for high-volume production of infrared optics.

  9. 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.

  10. Energy conservation in pulp and paper industry: some thoughts

    Energy Technology Data Exchange (ETDEWEB)

    Sadawarte, N. S.; Prasad, A. K.; Khanolkar, V. D.; Shenoy, S. C.

    1980-03-15

    The pulp and paper industry is highly energy intensive. In view of the spiralling fuel prices and rising power costs, there is an urgent need to conserve energy through better management of various operations in the industry, from the optimal utilization of the forest residues to the shipment of the final product. The total energy concept, e.g., energy generation, distribution and utilization in Indian paper industry is discussed. The need for an energy audit is emphasized and the formats of energy reporting forms are included. Short and long term measures to be enforced to achieve energy savings in the pulp and paper mills are outlined. Some important energy conservation approaches are also discussed. Factors affecting energy efficiency in a pulp and paper mill are reviewed. Some areas where sustained R and D efforts should be focused to make the paper industry nearly self-sufficient in energy generation and utilization are also given. It is essential to have a National Energy Policy clearly defining achievable targets of energy conservation for industry. The Indian paper industry could advantageously form its own committee to review the operation of the various mills in the country and come out with concrete solutions for higher energy efficiency and more effective conservation of energy.

  11. 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.

  12. New Nanoparticles Dispersing Beads Mill with Ultra Small Beads and its Application

    International Nuclear Information System (INIS)

    Inkyo, M; Tahara, T; Imajyo, Y

    2011-01-01

    Two of the major problems related to nanoparticle dispersion with a conventional beads mill are re-agglomeration and damage to the crystalline structure of the particles. The Ultra Apex Mill was developed to solve these problems by enabling the use of ultra-small beads with a diameter of less than 0.1mm. The core of this breakthrough development is centrifugation technology which allows the use of beads as small as 0.015mm. When dispersing agglomerated nanoparticles the impulse of the small beads is very low which means there is little influence on the particles. The surface energy of the nanoparticles remains low so the properties are not likely to change. As a result, stable nanoparticle dispersions can be achieved without re-cohesion. The Ultra Apex Mill is superior to conventional beads mills that are limited to much larger bead sizes. The technology of the Ultra Apex Mill has pioneered practical applications for nanoparticles in various fields: composition materials for LCD screens, ink-jet printing, ceramic condensers and cosmetics.

  13. 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...

  14. 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.

  15. Process for Transition of Uranium Mill Tailings Radiation Control Act Title II Disposal Sites to the U.S. Department of Energy Office of Legacy Management for Long-Term Surveillance and Maintenance

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-03-01

    This document presents guidance for implementing the process that the U.S. Department of Energy (DOE) Office of Legacy Management (LM) will use for assuming perpetual responsibility for a closed uranium mill tailings site. The transition process specifically addresses sites regulated under Title II of the Uranium Mill Tailings Radiation Control Act (UMTRCA) but is applicable in principle to the transition of sites under other regulatory structures, such as the Formerly Utilized Sites Remedial Action Program.

  16. Synthesis, thermal properties and recrystallization of ball-milled high Tc superconductors. (Topological stabilization of metastable phases)

    International Nuclear Information System (INIS)

    Schulz, R.; Lanteigne, J.; Simoneau, M.; Tessier, P.; Neste, A. van; Strom Olsen, J.O.

    1995-01-01

    Amorphous and nanocrystalline phases have been formed by ball-milling Y-Ba-Cu-O and Bi-Ca-Sr-Cu-O. The strong mechanical deformations induce disorder on the oxygen sublattice and on the cation sites. These order-disorder transformations often produce simple cubic perovskite structures. During recrystallization, the chemical order is restored. Small ordered regions nucleate, grow and produce particular metastable configurations which minimize the total elastic strain energy. The sequence of events giving rise to the various metastable phases has been followed by x-ray diffraction and differential scanning calorimetry and is explained in terms of free energy diagrams. The stress and strain fields associated with the Y-Ba disorder are calculated using the elastic properties of the Y-Ba-Cu-O superconductor. A simple model is proposed to explain the stability of the structures observed after thermal treatments. (orig.)

  17. Conductometry and Size Characterization of Polypyrrole Nanoparticles Produced by Ball Milling

    OpenAIRE

    Abbasi, Abdul Malik Rehan; Marsalkova, Miroslava; Militky, Jiri

    2013-01-01

    Polypyrrole (PPy), one of the most extensively investigated conducting polymers, has attracted a great deal of interest because of its good electrical conductivity, environmental stability, and easy synthesis. PPy films were produced by polymerization of pyrrole and tosylate (TsO−) as dopants in the presence of oxidant FeCl3 and polyethylene glycol (Mw 8000) at −5°C for 48 h. High energy milling was carried out at 850 rpm in the dry media with the balls of 10 mm. Particles were then character...

  18. Overview of milling techniques for improving the solubility of poorly water-soluble drugs

    Directory of Open Access Journals (Sweden)

    Zhi Hui Loh

    2015-07-01

    Full Text Available Milling involves the application of mechanical energy to physically break down coarse particles to finer ones and is regarded as a “top–down” approach in the production of fine particles. Fine drug particulates are especially desired in formulations designed for parenteral, respiratory and transdermal use. Most drugs after crystallization may have to be comminuted and this physical transformation is required to various extents, often to enhance processability or solubility especially for drugs with limited aqueous solubility. The mechanisms by which milling enhances drug dissolution and solubility include alterations in the size, specific surface area and shape of the drug particles as well as milling-induced amorphization and/or structural disordering of the drug crystal (mechanochemical activation. Technology advancements in milling now enable the production of drug micro- and nano-particles on a commercial scale with relative ease. This review will provide a background on milling followed by the introduction of common milling techniques employed for the micronization and nanonization of drugs. Salient information contained in the cited examples are further extracted and summarized for ease of reference by researchers keen on employing these techniques for drug solubility and bioavailability enhancement.

  19. Influence of milling parameters on the sorption properties of the LiH–MgB{sub 2} system doped with TiCl{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Nina; Jepsen, Julian; Pistidda, Claudio [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Puszkiel, Julián A. [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Combatientes de Malvinas 3150, 1427 Buenos Aires (Argentina); Karimi, Fahim [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Milanese, Chiara [Pavia H_2 Lab, Department of Chemistry, Physical Chemistry Division, University of Pavia, Viale Taramelli 16, I-27100 Pavia (Italy); Tolkiehn, Martin [SRXPD Beamline HASYLAB, Deutsches-Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Chaudhary, Anna-Lisa, E-mail: anna-lisa.chaudhary@hzg.de [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany); Klassen, Thomas; Dornheim, Martin [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht (Germany)

    2015-10-05

    Highlights: • The LiH–MgB{sub 2} system was doped with TiCl{sub 3} and milling conditions varied. • A heuristic model was used to estimate energy transfer from milling conditions. • Milling parameters were correlated with the energy transfer calculation. • 20 kJ g{sup −1} of energy transfer correlates to the optimum conditions for the system. - Abstract: Hydrogen sorption properties of the LiH–MgB{sub 2} system doped with TiCl{sub 3} were investigated with respect to milling conditions (milling times, ball to powder (BTP) ratios, rotation velocities and degrees of filling) to form the reactive hydride composite (RHC) LiBH{sub 4}–MgH{sub 2}. A heuristic model was applied to approximate the energy transfer from the mill to the powders. These results were linked to experimentally obtained quantities such as crystallite size, specific surface area (SSA) and homogeneity of the samples, using X-ray diffraction (XRD), the Brunauer–Emmett–Teller (BET) method and scanning electron microscopy (SEM), respectively. The results show that at approximately 20 kJ g{sup −1} there are no further benefits to the system with an increase in energy transfer. This optimum energy transfer value indicates that a plateau was reached for MgB{sub 2} crystallite size therefore the there was also no improvement of reaction kinetics due to no change in crystallite size. Therefore, this study shows that an optimum energy transfer value was reached for the LiH–MgB{sub 2} system doped with TiCl{sub 3}.

  20. Local saw mills save Velky Krtis

    International Nuclear Information System (INIS)

    Haluza, I.

    2006-01-01

    After the Bana Dolina coal mine has received its last state subsidy, the only major employer in the region will be the PRP saw mill. The unemployment rate is very high in the Velky Krtis region over 25%. Several agricultural and food processing companies have gone bankrupt and the Bana Dolina mine today only employs around 200 people. Few new jobs have been created. So far only furniture manufacturers from the Swedish company, Furni Finish, have promised the town they will open a new plant, where they may employ around 150. Another potential investment to be made by a Spanish producer of light components is still under negotiation, stated the mayor of Velky Krtis, Jozef Sauver. Should the Spanish company decide to come to the region, about 100 people could find a job at the former Liaz production halls. Currently, PRP is the largest employer in the region. Over the last 7 years, its owners have invested over 60 mil. Sk (1.58 mil. EUR) in the saw mill. Now they are preparing an 80 mil. Sk (2.10 mil. EUR) investment. The new business would process timber waste that is currently sold to the chipboard producer, Bucina DDD. In the future, the material could be used to produce energy. The town council are considering the construction of a new wood-fired heat plant that would use timber waste bought from PRP. (author)

  1. 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.

  2. 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

  3. 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 ...

  4. TEM characterization of Al-C-Cu-Al2O3 composites produced by mechanical milling

    International Nuclear Information System (INIS)

    Santos-Beltran, A.; Gallegos-Orozco, V.; Estrada-Guel, I.; Bejar-Gomez, L.; Espinosa-Magana, F.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2007-01-01

    Novel Al-based composites (Al-C-Cu-Al 2 O 3 ) obtained by mechanical milling (MM), were characterized by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). Analyses of composites were carried out in both, the as-milled and the as-sintered conditions. C nanoparticles were found in the as-milled condition and Al 2 O 3 nanofibers were found in as-sintered products, as determined by EELS. C and Cu react with Al to crystallize in Al 3 C 4 and Al 2 Cu structures, respectively

  5. Wear of carbide inserts with complex surface treatment when milling nickel alloy

    Science.gov (United States)

    Fedorov, Sergey; Swe, Min Htet; Kapitanov, Alexey; Egorov, Sergey

    2018-03-01

    One of the effective ways of strengthening hard alloys is the creating structure layers on their surface with the gradient distribution of physical and mechanical properties between the wear-resistant coating and the base material. The article discusses the influence of the near-surface layer which is modified by low-energy high-current electron-beam alloying and the upper anti-friction layer in a multi-component coating on the wear mechanism of the replaceable multifaceted plates in the dry milling of the difficult to machine nickel alloys.

  6. 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.

  7. Geothermal Mill Redevelopment Project in Massachusetts

    Energy Technology Data Exchange (ETDEWEB)

    Vale, A.Q.

    2009-03-17

    Anwelt Heritage Apartments, LLC redeveloped a 120-year old mill complex into a mixed-use development in a lower-income neighborhood in Fitchburg, Massachusetts. Construction included 84 residential apartments rented as affordable housing to persons aged 62 and older. The Department of Energy (“DOE”) award was used as an essential component of financing the project to include the design and installation of a 200 ton geothermal system for space heating and cooling.

  8. 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-...

  9. 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.

  10. 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

  11. Kinetic parameters of grinding media in ball mills with various liner design and mill speed based on DEM modeling

    Science.gov (United States)

    Khakhalev, P. A.; Bogdanov, VS; Kovshechenko, V. M.

    2018-03-01

    The article presents analysis of the experiments in the ball mill of 0.5x0.3 m with four different liner types based on DEM modeling. The numerical experiment always complements laboratory research and allow obtaining high accuracy output data. An important property of the numerical experiment is the possibility of visualization of the results. The EDEM software allows calculating trajectory of the grinding bodies and kinetic parameters of each ball for the relative mill speed and the different types of mill’s liners.

  12. Stress and accidental defect detection on rolling mill rolls

    International Nuclear Information System (INIS)

    Auzas, J.-D.

    1999-01-01

    During the rolling mill process, rolls are submitted to high pressures that can lead to local decohesion or metallurgical changes. Both these cracks or softened areas must be detected as soon as they appear because of the risk of spalling, marks on the product, and mill wreck. These defects can be detected using the eddy current method, and particularly sensors specially developed for micro-defects detection. These sensors must be adapted to the environment of a roll grinding machine on which they must be installed. Users' schedule of conditions also require them to be attached to a wide range of eddy current generator and automatic computerized interpretation. Mill requirements for new high tech roll grades and quality lead to continuous development and improvement of the tools that will provide immediate 'go - no go' information. This paper is an update of these developments. (author)

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    Energy Technology Data Exchange (ETDEWEB)

    Koljonen, T.; Solantausta, Y. [VTT Energy, Espoo (Finland). New Energy Technologies; Salo, K.; Horvath, A. [Carbona Inc. (Finland)

    1999-11-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  18. IGCC power plant integrated to a Finnish pulp and paper mill. IEA Bioenergy. Techno-economic analysis activity

    International Nuclear Information System (INIS)

    Koljonen, T.; Solantausta, Y.

    1999-01-01

    In Finland, the pulp and paper industry is the largest consumer of energy among the industries and its power demand will increase due to economical and strict environ- mental requirements. The ageing of oil and biomass boilers in Finland also represents a window of opportunity for the introduction of new environmentally sound technology with a high efficiency in power production, e.g., in biomass gasification. This site-specific study describes the technical and economic feasibility of a biomass gasification combined cycle producing heat and power for a typical Finnish pulp and paper mill. The mill produces SC (super calantered) paper 500 000 ADt/a. The paper mill employs sulphate pulp and GW (ground wood) pulp. The capacity of the pulp mill is 400 000 ADt/a (air dry ton/year) of which 120 000 ADt/a is used at the site. The heat demand of the integrate is covered by a recovery boiler and a bark boiler. A condensing steam turbine with two extractions generates electricity for the mill. The aim is to replace an old bark boiler by an IGCC (Integrated Gasification Combined Cycle) to enhance the economy and environmental performance of the power plant. The IGCC feasibility study is conducted for an pulp and paper integrate because of its suitable infrastructure for IGCC and a large amount of wood waste available at the site. For comparison, the feasibility of an IGCC integrated to a pulp mill is also assessed. The IGCC concept described is based on research and development work performed by Carbona, Inc., who acquired the rights for know-how of Enviropower, Inc. The operation and design of the IGCC concept is based on a 20 MWe gas turbine (MW151). The heat of gas turbine exhaust gas is utilised in a HRSG (Heat Recovery Steam Generator) of two pressure levels to generate steam for the pulp and paper mill and the steam turbine. The MCC power plant operates in condensing mode. The total investment cost of the IGCC plant is estimated at FIM 417 million (USD 83.4 million

  19. 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.

  20. 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)

  1. Prototyping of Dental Structures Using Laser Milling

    Science.gov (United States)

    Andreev, A. O.; Kosenko, M. S.; Petrovskiy, V. N.; Mironov, V. D.

    2016-02-01

    The results of experimental studies of the effect of an ytterbium fiber laser radiation parameters on processing efficiency and quality of ZrO2 ceramics widely used in stomatology are presented. Laser operating conditions with optimum characteristics for obtaining high quality final surfaces and rapid material removal of dental structures are determined. The ability of forming thin-walled ceramic structures by laser milling technology (a minimum wall thickness of 50 μm) is demonstrated. The examples of three-dimensional dental structures created in computer 3D-models of human teeth using laser milling are shown.

  2. Eco-design of low energy mechanical milling through implementation of quality function deployment and design for sustainability

    Science.gov (United States)

    Rashid, Muhammad Hanif Abd; Nor, Nik Hisyamudin Muhd; Selamat, Siti Norhana; Hassan, Mohd Fahrul; Rahim, Abd Khalil Abd; Ahmad, Mohd Fauzi; Ismail, Al Emran; Omar, Badrul; Mokhtar, Mohd Faiz; Turan, Faiz Mohd; Yokoyama, Seiji

    2017-04-01

    Malaysia as a developing country favor energy demand by years which created mainly from fossil fuel. Unfortunately, the action leads to significant increment in carbon dioxide (CO2) emission that causing the global warming. The most promising mitigation strategy is by deploying Carbon Capture and Storage (CCS) technology where mineral carbonation was identified as the safest method for permanent storage and does not require continuous monitoring. Accordingly, National Green Technology was launched in 2009 to support the growth of green technology development in Malaysia as a carbon mitigation strategy. Thus, this paper aims to propose the development of a conceptual eco-design for Low Energy Mechanical Milling (LEMM). The concept was proposed by using the Quality Function Deployment (QFD) tool with combination of sustainability determinants (DFS) namely economic, environmental and social which evaluated using Solidworks 2015 sustainability assessment. The results show the new product targets for LEMM in prior on energy consumption (MJ), selling price (MYR), material cost (MYR), carbon footprint (kg CO2) with weightage of 5.2, 4.2, 3.6 and 3.6 respectively. The implementation of DFS criteria into the QFD promote to reduce material used by 16%, 35% reduction of carbon footprint, 28% less energy consumption, 28% lower air acidification, 77% of water eutrophication declined and increased recyclability by 15%.

  3. 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

  4. Preparation, characterization and optoelectronic properties of nanodiamonds doped zinc oxide nanomaterials by a ball milling technique

    Science.gov (United States)

    Ullah, Hameed; Sohail, Muhammad; Malik, Uzma; Ali, Naveed; Bangash, Masroor Ahmad; Nawaz, Mohsan

    2016-07-01

    Zinc oxide (ZnO) is one of the very important metal oxides (MOs) for applications in optoelectronic devices which work in the blue and UV regions. However, to meet the challenges of obtaining ZnO nanomaterials suitable for practical applications, various modifications in physico-chemical properties are highly desirable. One of the ways adopted for altering the properties is to synthesize composite(s) of ZnO with various reinforcements. Here we report on the tuning of optoelectronic properties of ZnO upon doping by nanodiamonds (NDs) using the ball milling technique. A varying weight percent (wt.%) of NDs were ball milled for 2 h with ZnO nanoparticles prepared by a simple precipitation method. The effects of different parameters, the calcination temperature of ZnO, wt.% of NDs and mechanical milling upon the optoelectronic properties of the resulting ZnO-NDs nanocomposites have been investigated. The ZnO-NDs nanocomposites were characterized by IR spectroscopy, powder x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX). The UV-vis spectroscopy revealed the alteration in the bandgap energy (Eg ) of ZnO as a function of the calcination temperature of ZnO, changing the concentration of NDs, and mechanical milling of the resulting nanocomposites. The photoluminescence (PL) spectroscopy showed a decrease in the deep level emission (DLE) peaks and an increase in near-band-edge transition peaks as a result of the increasing concentration of NDs. The decrease in DLE and increase in band to band transition peaks were due to the strong interaction between the NDs and the Zn+; consequently, the Zn+ concentration decreased on the interstitial sites.

  5. Uranium Mill Tailings Remedial Action Amendments Act of 1988. Introduced in the Senate, One Hundredth Congress, Second Session, Report 100-543, September 23, 1988

    International Nuclear Information System (INIS)

    Anon.

    1988-01-01

    The Committee on Energy and Natural Resources reported favorably on the Uranium Mill Tailings Remedial Action Amendments Act of 1987 (S.1991) with some amendments, the principal one being to change the 1987 date to 1988. The purpose of this bill is to authorize the Secretary of the Interior to transfer lands under the jurisdiction of the Bureau of Land Management to the Department of Energy for permanent surveillance and maintenance of remediated mill tailings as required by the Uranium Mill Tailings Radiation Control Act of 1978. The bill also extends the authority of the Secretary of Energy to perform remedial action at designated uranium mill tailings sites and vicinity properties until 30 September 1994. The authority to perform groundwater restoration activities is extended without limitation

  6. Reducibility mill scale industrial waste via coke breeze at 850-950ºC

    Directory of Open Access Journals (Sweden)

    Gaballah N.M.

    2015-01-01

    Full Text Available Mill scale is a very attractive industrial waste due to its elevated iron content (about = 69.33% Fe besides being suiTab. for direct recycling to the blast furnace via sintering plant. In this paper the characteristics of raw materials and the briquettes produced from this mill scale were studied by different methods of analyses. The produced briquettes were reduced with different amounts of coke breeze at varying temperatures, and the reduction kinetics was determined. The activation energy of this reaction ≈ 61.5 kJ/mole for reduction of mill scale with coke breeze in the form of briquettes with 2% molasses where the chemical reaction interface model is applicable.

  7. THE METHODS OF CALCULATIONS OF THE TEMPERATURE BREAKDOWN FIELD IN THE LINE OF THE MODEM HIGH-SPEED WIRE MILL

    Directory of Open Access Journals (Sweden)

    S. M. Zhuchkov

    2007-01-01

    Full Text Available The calculation methods of the temperature field of the breakdown, being rolled in lines of the modern high-speed wire mill, is developed on the basis of solving of problem of the contact exchange of hot metal with cold rollers.

  8. Development of a high specific stiffness mechanically milled FeAl intermetallic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Baccino, R; San Filippo, D; Martel, P; Moret, F

    1996-12-31

    Powder metallurgy techniques such as gas atomization and mechanical milling have been used to develop a FeAl alloy with enhanced ductility and strength at both low and high temperature. The improvement method combines ductility increase by grain boundary strengthening, grain size reduction and oxide dispersion strengthening. The material has been characterized and tested in the form of extruded bars. Microstructure, order and texture of as-extruded and heat treated samples have been studied by TEM, X-ray diffraction and Moessbauer spectroscopy. Physical and mechanical properties of the material are compared to some conventional engineering alloys in order to discuss the conceivable applications in aeronautical and automotive industries. (authors). 22 refs., 4 figs., 2 tabs.

  9. Size effect of primary Y{sub 2}O{sub 3} additions on the characteristics of the nanostructured ferritic ODS alloys: Comparing as-milled and as-milled/annealed alloys using S/TEM

    Energy Technology Data Exchange (ETDEWEB)

    Saber, Mostafa, E-mail: msaber@ncsu.edu; Xu, Weizong; Li, Lulu; Zhu, Yuntian; Koch, Carl C.; Scattergood, Ronald O.

    2014-09-15

    The need for providing S/TEM evidence to clarify the mechanisms of nano-scale precipitate formation was the motivation of this investigation. In this study, an Fe–14Cr–0.4Ti alloy was ball-milled with different amounts of Y{sub 2}O{sub 3} content up to 10 wt.%, and then annealed at temperatures up to 1100 °C. Micron-size Y{sub 2}O{sub 3} particles were substituted for the nano-size counterpart to elucidate the mechanism of oxide precipitate formation. The S/TEM studies revealed that the microstructure of the alloy with 10 wt.% yttria contained amorphous undissolved Y{sub 2}O{sub 3} after ball milling, while a small part of the initial oxide particles were dissolved into the solid solution. Consequently, when the amount of yttria was reduced to 1 wt.%, the amorphous phase of the yttria vanished and the whole content of Y{sub 2}O{sub 3} was dissolved into the BCC solid solution. Defect analysis of precipitates on the annealed samples via S/TEM and micro-hardness studies revealed that the use of micron-size primary oxide particles can produce nano-size precipitates, stable up to temperatures as high as 1100 °C, and uniformly distributed throughout the microstructure. This study indicates that the use of high energy ball milling along with micron-size primary oxide particles can lead to nanostructured ferritic ODS alloys without the use of nano-size primary oxide additions.

  10. Integrated assessmet of the impacts associated with uranium mining and milling

    Energy Technology Data Exchange (ETDEWEB)

    Parzyck, D.C.; Baes, C.F. III; Berry, L.G.

    1979-07-01

    The occupational health and safety impacts are assessed for domestic underground mining, open pit mining, and milling. Public health impacts are calculated for a population of 53,000 located within 88 km (55 miles) of a typical southwestern uranium mill. The collective annual dose would be 6.5 man-lung rem/year, 89% of which is from /sup 222/Rn emitted from mill tailings. The dose to the United States population is estimated to be 6 x 10/sup 4/ man-lung rem from combined mining and milling operations. This may be comparedd with 5.7 x 10/sup 5/ man-lung rem from domestic use of natural gas and 4.4 x 10/sup 7/ man-lung rem from building interiors. Unavoidable adverse environmental impacts appear to be severe in a 250 ha area surrounding a mill site but negligible in the entire potentially impacted area (500,000 ha). The contemporary uranium resource and supply industry and its institutional settings are described in relation to the socio-economic impacts likely to emerge from high levels of uranium mining and milling. Radon and radon daughter monitoring techniques associated with uranium mining and milling are discussed.

  11. Integrated assessmet of the impacts associated with uranium mining and milling

    International Nuclear Information System (INIS)

    Parzyck, D.C.; Baes, C.F. III; Berry, L.G.

    1979-07-01

    The occupational health and safety impacts are assessed for domestic underground mining, open pit mining, and milling. Public health impacts are calculated for a population of 53,000 located within 88 km (55 miles) of a typical southwestern uranium mill. The collective annual dose would be 6.5 man-lung rem/year, 89% of which is from 222 Rn emitted from mill tailings. The dose to the United States population is estimated to be 6 x 10 4 man-lung rem from combined mining and milling operations. This may be comparedd with 5.7 x 10 5 man-lung rem from domestic use of natural gas and 4.4 x 10 7 man-lung rem from building interiors. Unavoidable adverse environmental impacts appear to be severe in a 250 ha area surrounding a mill site but negligible in the entire potentially impacted area (500,000 ha). The contemporary uranium resource and supply industry and its institutional settings are described in relation to the socio-economic impacts likely to emerge from high levels of uranium mining and milling. Radon and radon daughter monitoring techniques associated with uranium mining and milling are discussed

  12. Multifractal properties of ball milling dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

    2014-06-15

    This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

  13. A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge.

    Directory of Open Access Journals (Sweden)

    Martijn Eikelboom

    Full Text Available The Multi-Criteria Decision Analysis (MCDA procedure was used to compare waste management options for kraft pulp mill sludge following its anaerobic digestion. Anaerobic digestion of sludge is advantageous because it produces biogas that may be used to generate electricity, heat and biofuels. However, adequate management of the digested sludge is essential. Landfill disposal is a non-sustainable waste management alternative. Kraft pulp mill digested sludge applied to land may pose risks to the environment and public health if the sludge has not been properly treated. This study is aimed to compare several recycling alternatives for anaerobically digested sludge from kraft pulp mills: land application, landfill disposal, composting, incineration, pyrolysis/gasification, and biofuel production by algae. The MCDA procedure considered nine criteria into three domains to compare digested sludge recycling alternatives in a kraft pulp mill: environmental (CO2 emission, exposure to pathogens, risk of pollution, material and energy recovery, economic (overall costs, value of products and technical (maintenance and operation, feasibility of implementation. The most suitable management options for digested sludge from kraft pulp mills were found to be composting and incineration (when the latter was coupled with recycling ash to the cement industry. Landfill disposal was the worst option, presenting low performance in feasibility of implementation, risk of pollution, material and energy recovery.

  14. A multi-criteria decision analysis of management alternatives for anaerobically digested kraft pulp mill sludge

    Science.gov (United States)

    Eikelboom, Martijn; Lopes, Alice do Carmo Precci; Silva, Claudio Mudadu; Rodrigues, Fábio de Ávila; Zanuncio, José Cola

    2018-01-01

    The Multi-Criteria Decision Analysis (MCDA) procedure was used to compare waste management options for kraft pulp mill sludge following its anaerobic digestion. Anaerobic digestion of sludge is advantageous because it produces biogas that may be used to generate electricity, heat and biofuels. However, adequate management of the digested sludge is essential. Landfill disposal is a non-sustainable waste management alternative. Kraft pulp mill digested sludge applied to land may pose risks to the environment and public health if the sludge has not been properly treated. This study is aimed to compare several recycling alternatives for anaerobically digested sludge from kraft pulp mills: land application, landfill disposal, composting, incineration, pyrolysis/gasification, and biofuel production by algae. The MCDA procedure considered nine criteria into three domains to compare digested sludge recycling alternatives in a kraft pulp mill: environmental (CO2 emission, exposure to pathogens, risk of pollution, material and energy recovery), economic (overall costs, value of products) and technical (maintenance and operation, feasibility of implementation). The most suitable management options for digested sludge from kraft pulp mills were found to be composting and incineration (when the latter was coupled with recycling ash to the cement industry). Landfill disposal was the worst option, presenting low performance in feasibility of implementation, risk of pollution, material and energy recovery. PMID:29298296

  15. Environmental issues and waste management in energy and minerals production

    International Nuclear Information System (INIS)

    Yegulalp, T.M.; Kim, K.

    1992-01-01

    This book includes the following topics: water management in the minerals industry; management of radioactive wastes in the energy industry; the US high-level radioactive waste program; acid mine drainage; health risks from uranium mill tailings; alternate energy sources, such as hydrogen; superconductive magnetic energy storage; nuclear waste

  16. 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.

  17. 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.

  18. Initial angular momentum and flow in high energy nuclear collisions

    Science.gov (United States)

    Fries, Rainer J.; Chen, Guangyao; Somanathan, Sidharth

    2018-03-01

    We study the transfer of angular momentum in high energy nuclear collisions from the colliding nuclei to the region around midrapidity, using the classical approximation of the color glass condensate (CGC) picture. We find that the angular momentum shortly after the collision (up to times ˜1 /Qs , where Qs is the saturation scale) is carried by the "β -type" flow of the initial classical gluon field, introduced by some of us earlier. βi˜μ1∇iμ2-μ2∇iμ1 (i =1 ,2 ) describes the rapidity-odd transverse energy flow and emerges from Gauss's law for gluon fields. Here μ1 and μ2 are the averaged color charge fluctuation densities in the two nuclei, respectively. Interestingly, strong coupling calculations using anti-de Sitter/conformal field theory (AdS/CFT) techniques also find an energy flow term featuring this particular combination of nuclear densities. In classical CGC the order of magnitude of the initial angular momentum per rapidity in the reaction plane, at a time 1 /Qs , is |d L2/d η |≈ RAQs-3ɛ¯0/2 at midrapidity, where RA is the nuclear radius, and ɛ¯0 is the average initial energy density. This result emerges as a cancellation between a vortex of energy flow in the reaction plane aligned with the total angular momentum, and energy shear flow opposed to it. We discuss in detail the process of matching classical Yang-Mills results to fluid dynamics. We will argue that dissipative corrections should not be discarded to ensure that macroscopic conservation laws, e.g., for angular momentum, hold. Viscous fluid dynamics tends to dissipate the shear flow contribution that carries angular momentum in boost-invariant fluid systems. This leads to small residual angular momentum around midrapidity at late times for collisions at high energies.

  19. 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.

  20. Thermogravimetric analysis of the co-combustion of paper mill sludge and municipal solid waste

    International Nuclear Information System (INIS)

    Hu, Shanchao; Ma, Xiaoqian; Lin, Yousheng; Yu, Zhaosheng; Fang, Shiwen

    2015-01-01

    Highlights: • Thermogravimetric analysis of paper mill sludge and municipal solid waste were studied. • The combustion of paper mill sludge could be improved by blending municipal solid waste. • There existed significant interaction during co-combustion of the blends. • The OFW and Starink methods were used to obtain the activation energy. • The average activation energy was the lowest by blending 20% municipal solid waste. - Abstract: The thermal characteristics and kinetics of paper mill sludge (PMS), municipal solid waste (MSW) and their blends in the combustion process were investigated in this study. The mass percentages of PMS in the blends were 10%, 30%, 50%, 70% and 90%, respectively. The experiments were carried out at different heating rates (10 °C/min, 20 °C/min and 30 °C/min) and the temperature ranged from room temperature to 1000 °C in a thermogravimetric simultaneous thermal analyzer. The results suggested that the ignition temperature and burnout temperature of MSW were lower than that of PMS, and the mass loss rate of MSW was larger especially at low temperatures. There were only two mass loss peaks in the differential thermogravimetry (DTG) curve, while three mass loss peaks were observed when the blending ratios of PMS were 30%, 50%, 70%. The value of the comprehensive combustion characteristic index of the blends indicated a good combustibility when the percentage of PMS (PPMS) in the blends was less than 30%. There existed certain interaction between the combustion process of PMS and MSW, especially at high temperature stage. Activation energy (E) value obtained by the Ozawa–Flynn–Wall (OFW) method and the Starink method were very consistent. When the mass percentage of PMS in the blends was 80%, the E average value attained the minimum

  1. Sustainability of uranium mining and milling: toward quantifying resources and eco-efficiency.

    Science.gov (United States)

    Mudd, Gavin M; Diesendorf, Mark

    2008-04-01

    The mining of uranium has long been a controversial public issue, and a renewed debate has emerged on the potential for nuclear power to help mitigate against climate change. The central thesis of pro-nuclear advocates is the lower carbon intensity of nuclear energy compared to fossil fuels, although there remains very little detailed analysis of the true carbon costs of nuclear energy. In this paper, we compile and analyze a range of data on uranium mining and milling, including uranium resources as well as sustainability metrics such as energy and water consumption and carbon emissions with respect to uranium production-arguably the first time for modern projects. The extent of economically recoverable uranium resources is clearly linked to exploration, technology, and economics but also inextricably to environmental costs such as energy/water/chemicals consumption, greenhouse gas emissions, and social issues. Overall, the data clearly show the sensitivity of sustainability assessments to the ore grade of the uranium deposit being mined and that significant gaps remain in complete sustainability reporting and accounting. This paper is a case study of the energy, water, and carbon costs of uranium mining and milling within the context of the nuclear energy chain.

  2. 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

  3. Preliminary study on the potential of improving pulp quality and energy efficiency in a South African TMP mill

    CSIR Research Space (South Africa)

    Johakimu, Jonas K

    2010-09-01

    Full Text Available ). The mill’s screen fractionation process has limited efficiency. Substantial amounts of thick-walled fibres are present in the mill accept pulp samples (i.e. 66% by mass of the mill accept has a freeness of 256 ml CSF (Table 2)). The benefits of adding a...

  4. Highly Al-doped TiO{sub 2} nanoparticles produced by Ball Mill Method: structural and electronic characterization

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Desireé M. de los, E-mail: desire.delossantos@uca.es; Navas, Javier, E-mail: javier.navas@uca.es; Sánchez-Coronilla, Antonio; Alcántara, Rodrigo; Fernández-Lorenzo, Concha; Martín-Calleja, Joaquín

    2015-10-15

    Highlights: • Highly Al-doped TiO{sub 2} nanoparticles were synthesized using a Ball Mill Method. • Al doping delayed anatase to rutile phase transformation. • Al doping allow controlling the structural and electronic properties of nanoparticles. - Abstract: This study presents an easy method for synthesizing highly doped TiO{sub 2} nanoparticles. The Ball Mill method was used to synthesize pure and Al-doped titanium dioxide, with an atomic percentage up to 15.7 at.% Al/(Al + Ti). The samples were annealed at 773 K, 973 K and 1173 K, and characterized using ICP-AES, XRD, Raman spectroscopy, FT-IR, TG, STEM, XPS, and UV–vis spectroscopy. The effect of doping and the calcination temperature on the structure and properties of the nanoparticles were studied. The results show high levels of internal doping due to the substitution of Ti{sup 4+} ions by Al{sup 3+} in the TiO{sub 2} lattice. Furthermore, anatase to rutile transformation occurs at higher temperatures when the percentage of doping increases. Therefore, Al doping allows us to control the structural and electronic properties of the nanoparticle synthesized. So, it is possible to obtain nanoparticles with anatase as predominant phase in a higher range of temperature.

  5. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    International Nuclear Information System (INIS)

    Lopez B, I.; Trapaga M, L. G.; Martinez F, E.; Zoz, H.

    2011-01-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  6. Structural evolution of Ni-20Cr alloy during ball milling of elemental powders

    Energy Technology Data Exchange (ETDEWEB)

    Lopez B, I.; Trapaga M, L. G. [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Juriquilla, 76230 Queretaro (Mexico); Martinez F, E. [Centro de Investigacion e Innovacion Tecnologica, Cerrada de Cecati s/n, Col. Santa Catarina Azcapotzalco, 02250 Mexico D. F. (Mexico); Zoz, H., E-mail: israelbaez@gmail.co [Zoz GmbH, D-57482, Wenden (Germany)

    2011-07-01

    The ball milling (B M) of blended Ni and Cr elemental powders was carried out in a Simoloyer performing on high-energy scale mode at maximum production to obtain a nano structured Ni-20Cr alloy. The phase transformations and structural changes occurring during mechanical alloying were investigated by X-ray diffraction (XRD) and optical microscopy (Om). A gradual solid solubility of Cr and the subsequent formation of crystalline metastable solid solutions described in terms of the Avrami-Ero fe ev kinetics model were calculated. The XRD analysis of the structure indicates that cumulative lattice strain contributes to the driving force for solid solution between Ni and Cr during B M. Microstructure evolution has shown, additionally to the lamellar length refinement commonly observed, the folding of lamellae in the final processing stage. Om observations revealed that the lamellar spacing of Ni rich zones reaches a steady value near 500 nm and almost disappears after 30 h of milling. (Author)

  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. Nanoparticles from Cu-Zn-Al shape memory alloys physically synthesized by ion milling deposition

    Energy Technology Data Exchange (ETDEWEB)

    Pavon, Luis Alberto Lopez [Universidad Autonoma de Nuevo Leon (UANL), Nuevo Leon (Mexico); Cuellara, Enrique Lopez; Castro, Alejandro Torres; Cruza, Azael Martinez de la [Universidad Autonoma de Nuevo Leon (CIIDIT/UANL), Nuevo Leon (Mexico). Centro de Innovacion, Investigacion y Desarrollo en Ingenieria y Tecnologia; Ballesteros, Carmen [Universidad Carlos III de Madrid, Madrid (Spain). Departamento de Fisica; Araujo, Carlos Jose de [Universidade Federal de Campina Grande (UFCG), Campina Grande, PB (Brazil). Departamento de Engenharia Mecanica

    2012-05-15

    In this research, an ion milling equipment was used to elaborate nanoparticles from Cu-Zn-Al alloys with shape memory effect. Two different compositions were used, target A: 75.22Cu-17.12Zn-7.66Al at % with an Ms of -9 deg C and target B: 76.18Cu-15.84Zn-7.98Al with an Ms of 20 degree C. Nanoparticles were characterized by High Resolution Transmission Electron Microscopy, Electron Diffraction and Energy Dispersive X-ray Spectroscopy. The obtained nanoparticles showed a small dispersion, with a size range of 3.2-3.5 nm. Their crystal structure is in good agreement with the bulk martensitic structure of the targets. In this sense, results on morphology, composition and crystal structure have indicated that it is possible to produce nanoparticles of CuZnAl shape memory alloys with martensitic structure in a single process using Ion Milling. (author)

  9. Nanoparticles from Cu-Zn-Al shape memory alloys physically synthesized by ion milling deposition

    International Nuclear Information System (INIS)

    Pavon, Luis Alberto Lopez; Cuellara, Enrique Lopez; Castro, Alejandro Torres; Cruza, Azael Martinez de la; Ballesteros, Carmen; Araujo, Carlos Jose de

    2012-01-01

    In this research, an ion milling equipment was used to elaborate nanoparticles from Cu-Zn-Al alloys with shape memory effect. Two different compositions were used, target A: 75.22Cu-17.12Zn-7.66Al at % with an Ms of -9 deg C and target B: 76.18Cu-15.84Zn-7.98Al with an Ms of 20 degree C. Nanoparticles were characterized by High Resolution Transmission Electron Microscopy, Electron Diffraction and Energy Dispersive X-ray Spectroscopy. The obtained nanoparticles showed a small dispersion, with a size range of 3.2-3.5 nm. Their crystal structure is in good agreement with the bulk martensitic structure of the targets. In this sense, results on morphology, composition and crystal structure have indicated that it is possible to produce nanoparticles of CuZnAl shape memory alloys with martensitic structure in a single process using Ion Milling. (author)

  10. Occupational hearing loss of market mill workers in the city of Accra, Ghana.

    Science.gov (United States)

    Kitcher, Emmanuel D; Ocansey, Grace; Abaidoo, Benjamin; Atule, Alidu

    2014-01-01

    Noise induced hearing loss (NIHL) is an irreversible sensorineural hearing loss associated with exposure to high levels of excessive noise. Prevention measures are not well established in developing countries. This comparative cross sectional study aims to determine the prevalence of hearing loss in both a group of high risk workers and a control group and to assess their knowledge of the effects of noise on hearing health. A total of 101 market mill workers and 103 controls employed within markets in the city of Accra, Ghana, were evaluated using a structured questionnaire and pure tone audiometry. The questionnaire assessed factors including self-reported hearing loss, tinnitus, knowledge on the effects of noise on hearing health and the use of hearing protective devices. Pure tone audiometric testing was conducted for both mill workers and controls. Noise levels at the work premises of the mill workers and controls were measured. Symptoms of hearing loss were reported by 24 (23.76%) and 8 (7.7%) mill workers and controls respectively. Fifty-five (54.5%) and fifty-four (52.37%) mill workers and controls exhibited knowledge of the effects of noise on hearing health. Five (5.0%) mill workers used hearing protective devices. There was significant sensorineural hearing loss and the presence of a 4 kHz audiometric notch among mill workers when compared with controls for the mean thresholds of 2 kHz, 3 kHz and 4 kHz (P = 0. 001). The prevalence of hearing loss in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively (P hearing loss, which may be characteristic of NIHL in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively. The majority of mill workers did not use hearing protection.

  11. Occupational hearing loss of market mill workers in the city of Accra, Ghana

    Directory of Open Access Journals (Sweden)

    Emmanuel D Kitcher

    2014-01-01

    Full Text Available Noise induced hearing loss (NIHL is an irreversible sensorineural hearing loss associated with exposure to high levels of excessive noise. Prevention measures are not well established in developing countries. This comparative cross sectional study aims to determine the prevalence of hearing loss in both a group of high risk workers and a control group and to assess their knowledge of the effects of noise on hearing health. A total of 101 market mill workers and 103 controls employed within markets in the city of Accra, Ghana, were evaluated using a structured questionnaire and pure tone audiometry. The questionnaire assessed factors including self-reported hearing loss, tinnitus, knowledge on the effects of noise on hearing health and the use of hearing protective devices. Pure tone audiometric testing was conducted for both mill workers and controls. Noise levels at the work premises of the mill workers and controls were measured. Symptoms of hearing loss were reported by 24 (23.76% and 8 (7.7% mill workers and controls respectively. Fifty-five (54.5% and fifty-four (52.37% mill workers and controls exhibited knowledge of the effects of noise on hearing health. Five (5.0% mill workers used hearing protective devices. There was significant sensorineural hearing loss and the presence of a 4 kHz audiometric notch among mill workers when compared with controls for the mean thresholds of 2 kHz, 3 kHz and 4 kHz (P = 0. 001. The prevalence of hearing loss in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively (P < 0.5. The prevalence of hearing loss, which may be characteristic of NIHL in the better hearing ears of the mill workers and controls was 24.8% and 4.8% respectively. The majority of mill workers did not use hearing protection.

  12. 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.

  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. Establishing Relationship between Process Parameters and Temperature during High Speed End Milling of Soda Lime Glass

    Science.gov (United States)

    Nasima Bagum, Mst.; Konneh, Mohamed; Yeakub Ali, Mohammad

    2018-01-01

    In glass machining crack free surface is required in biomedical and optical industry. Ductile mode machining allows materials removal from brittle materials in a ductile manner rather than by brittle fracture. Although end milling is a versatile process, it has not been applied frequently for machining soda lime glass. Soda lime glass is a strain rate and temperature sensitive material; especially around glass transition temperature Tg, ductility increased and strength decreased. Hence, it is envisaged that the generated temperature by high-speed end milling (HSEM) could be brought close to the glass transition temperature, which promote ductile machining. In this research, the objective is to investigate the effect of high speed machining parameters on generated temperature. The cutting parameters were optimized to generate temperature around glass transition temperature of soda lime using response surface methodology (RSM). Result showed that the most influencing process parameter is feed rate followed by spindle speed and depth of cut to generate temperature. Confirmation test showed that combination of spindle speed 30,173 rpm, feed rate 13.2 mm/min and depth of cut 37.68 µm generate 635°C, hence ductile chip removal with machined surface Ra 0.358 µm was possible to achieve.

  15. Evaluation of full-strength paper mill effluent for electricity generation ...

    African Journals Online (AJOL)

    In the search for renewable, sustainable and affordable energy sources, microbial fuel cells (MFCs) offer the advantage of a biological oxidation of pollutants to the direct generation of electricity by microorganisms. We thus examined the biodegradability and suitability of unamended paper mill effluent for power production ...

  16. Design and development of PCD micro straight edge end mills for micro/nano machining of hard and brittle materials

    International Nuclear Information System (INIS)

    Cheng, Xiang; Wang, Zhigang; Yamazaki, Kazuo; Nakamoto, Kazuo

    2010-01-01

    One of the biggest challenges for mechanical micro/nano milling is the design and fabrication of high precision and high efficiency micro milling tools. Commercially available micro milling tools are either too expensive (around several hundred US dollars) or simply made from downsizing of macro milling tools, which is sometimes not appropriate for the specific micro/nano milling requirements. So the design and fabrication of custom micro milling tools are necessary. In this paper, a micro straight edge endmill (SEE) is designed. Static and dynamic FEM analyses have been done for the SEEs with different rake angles trying to identify their stiffness and natural frequencies. By wire electrical discharge machining (WEDM), the SEEs made of polycrystalline diamond (PCD) with three different rake angles have been fabricated. The evaluation milling on tungsten carbide (WC) and silicon wafer have processed on a nano milling center. Experimental results show the SEEs have a good ability to simultaneously micro/nano milling of both the side and bottom surfaces with submicron surface roughness, and the SEE has high accuracy for large aspect ratio thin wall machining. The milling experiments on silicon wafer have successfully demonstrated that ductile mode machining was achieved and the coolant played an important role in silicon wafer milling

  17. Singular Minkowski and Euclidean solutions for SU(2) Yang-Mills theory

    International Nuclear Information System (INIS)

    Singleton, D.

    1996-01-01

    In this paper it is examined a solution to the SU(2) Yang-Mills-Higgs system, which is a trivial mathematical extension of recently discovered Schwarzschild- like solutions (Singleton D., Phys. Rev. D, 51 (1955) 5911). Physically, however, this new solution has drastically different properties from the Schwarzschild-like solutions. It is also studied a new classical solution for Euclidean SU(2) Yang-Mills theory. Again this new solution is a mathematically trivial extension of the Belavin-Polyakov-Schwartz-Tyupkin (BPST) (Belavin A. A. et al., Phys. Lett. B, 59 (1975) 85) instanton, but is physically very different. Unlike the usual instanton solution, the present solution is singular on a sphere of arbitrary radius in Euclidean space. Both of these solutions are infinite-energy solutions, so their practical value is somewhat unclear. However, they may be useful in exploring some of the mathematical aspects of classical Yang-Mills theory

  18. Variables affecting energy efficiency and CO2 emissions in the steel industry

    International Nuclear Information System (INIS)

    Siitonen, Sari; Tuomaala, Mari; Ahtila, Pekka

    2010-01-01

    Specific energy consumption (SEC) is an energy efficiency indicator widely used in industry for measuring the energy efficiency of different processes. In this paper, the development of energy efficiency and CO 2 emissions of steelmaking is studied by analysing the energy data from a case mill. First, the specific energy consumption figures were calculated using different system boundaries, such as the process level, mill level and mill site level. Then, an energy efficiency index was developed to evaluate the development of the energy efficiency at the mill site. The effects of different production conditions on specific energy consumption and specific CO 2 emissions were studied by PLS analysis. As theory expects, the production rate of crude steel and the utilisation of recycled steel were shown to affect the development of energy efficiency at the mill site. This study shows that clearly defined system boundaries help to clarify the role of on-site energy conversion and make a difference between the final energy consumption and primary energy consumption of an industrial plant with its own energy production.

  19. Groundwater leaching of neutralized and untreated acid-leached uranium-mill tailings

    International Nuclear Information System (INIS)

    Gee, G.W.; Begej, C.W.; Campbell, A.C.; Sauter, N.N.; Opitz, B.E.; Sherwood, D.R.

    1981-01-01

    Tailings neutralization was examined to determine the effect of neutralization on contaminant release. Column leaching of acid extracted uranium mill tailings from Exxon Highland Mill, Wyoming, Pathfinder Gas Hills Mill, Wyoming, and the Dawn Midnite Mill, Washington, resulted in the flushing of high concentrations of salts in the first four pore volumes of leachate, followed by a steady decrease to the original groundwater salt concentrations. Neutralization decreased the concentration of salts and radionuclides leaching from the tailings and decreased the volume of solution required to return the solution to the groundwater pH and EC. Radium-226 and uranium-238 leached quickly from the tailings in the initial pore volumes of both neutralized and unneutralized tailings, and then decreased significantly. 6 figures, 5 tables

  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. Investigation of wear and tool life of coated carbide and cubic boron nitride cutting tools in high speed milling

    Czech Academy of Sciences Publication Activity Database

    Twardowski, P.; Legutko, S.; Krolczyk, G.; Hloch, Sergej

    2015-01-01

    Roč. 7, č. 6 (2015), s. 1-9 ISSN 1687-8132 Institutional support: RVO:68145535 Keywords : hardened steels * milling tools * high speed machining * tool life * wear Subject RIV: JQ - Machines ; Tools Impact factor: 0.640, year: 2015 http://ade.sagepub.com/content/7/6/1687814015590216.full.pdf+html

  2. The Effect of the Wear of Rotor Pins on Grinding Efficiency in a High-speed Disintegrator

    OpenAIRE

    Karel DVOŘÁK; Dušan DOLÁK; David PALOUŠEK; Ladislav ČELKO; David JECH

    2018-01-01

    One of the directions intensively investigated in the field of milling is high-energy milling (HEM). One type of HEM is high-speed grinding in high-speed disintegrators. This type of mill is particularly suitable for the grinding and activation of fine powder materials. It has several advantages, such as a very intensive and continual refining process. One disadvantage is that its grinding pins are prone to abrasion, which may result in a decrease of the efficiency of grinding. This effect wa...

  3. 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

  4. SO(4)-symmetric solutions of Minkowskian Yang-Mills field equations

    International Nuclear Information System (INIS)

    Luescher, M.

    1977-06-01

    We construct all solutions to the SU(2) Yang-Mills field equations in Minkowski space that are invariant under an SO(4) subgroup of the conformal group. They are real, regular and have finite energy and action. A connection with the instanton solution is pointed out. (orig.) [de

  5. The crystallization of amorphous Fe2MnGe powder prepared by ball milling

    International Nuclear Information System (INIS)

    Zhang, L.; Brueck, E.; Tegus, O.; Buschow, K.H.J.; Boer, F.R. de

    2003-01-01

    We synthesized for the first time the intermetallic compound Fe 2 MnGe. To avoid preferential evaporation of volatile components we exploited mechanical alloying. Amorphous Fe 2 MnGe alloy powder was prepared by planetary ball milling elemental starting materials. The amorphous-to-crystalline transition was studied by means of differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A cubic D0 3 phase is formed at low temperature and transforms to a high-temperature hexagonal D0 19 phase. The apparent activation energy was determined by means of the Kissinger method

  6. 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.

  7. The Theory of High Energy Collision Processes - Final Report DOE/ER/40158-1

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tai, T.

    2011-09-15

    In 1984, DOE awarded Harvard University a new Grant DE-FG02-84ER40158 to continue their support of Tai Tsun Wu as Principal Investigator of research on the theory of high energy collision processes. This Grant was renewed and remained active continuously from June 1, 1984 through November 30, 2007. Topics of interest during the 23-year duration of this Grant include: the theory and phenomenology of collision and production processes at ever higher energies; helicity methods of QED and QCD; neutrino oscillations and masses; Yang-Mills gauge theory; Beamstrahlung; Fermi pseudopotentials; magnetic monopoles and dyons; cosmology; classical confinement; mass relations; Bose-Einstein condensation; and large-momentum-transfer scattering processes. This Final Report describes the research carried out on Grant DE-FG02-84ER40158 for the period June 1, 1984 through November 30, 2007. Two books resulted from this project and a total of 125 publications.

  8. Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

    International Nuclear Information System (INIS)

    Guillaume, B.; Charron, S.

    2000-01-01

    Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)

  9. 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

  10. Potential reduction of carbon emissions from Crude Palm Oil production based on energy and carbon balances

    International Nuclear Information System (INIS)

    Patthanaissaranukool, Withida; Polprasert, Chongchin; Englande, Andrew J.

    2013-01-01

    Highlights: ► We evaluate energy and carbon equivalence from CPO production based on a CBM. ► Energy spent and produced via carbon movement from palm oil mill was determined. ► Scenarios were formulated to evaluate the potential reduction of carbon emission. ► Utilization of biomass from palm oil mill shows the high potential of C-reduction. -- Abstract: This study aimed to evaluate energy and carbon equivalences (CE) associated with palm oil milling and to evaluate sustainability alternatives for energy consumption. Appropriate ways to reduce carbon emissions were also evaluated. A field survey was carried out to quantify the input and output of energy and materials following the conceptual framework of a carbon-balanced model (CBM), which exclude other non-CO 2 greenhouse gases. Survey results indicate that the electrical energy consumption for daily mill start-up averaged 18.7 ± 5.4 kWh/ton Fresh Fruit Bunches (FFBs). This energy is equivalent to 114.4 ± 33.2 kWh/ton Crude Palm Oil (CPO) which was found to be offset by that generated in the mills using palm fiber as a solid fuel. Currently, organic residues contained in the wastewater are anaerobically converted to methane. The methane is used as fuel to generate electricity and sold to an outside grid network at a generation rate of 8.1 ± 2.1 kWh/ton FFB. Based on the CBM approach, carbon emissions observed from the use of fossil energy in palm oil milling were very small; however, total carbon emission from oil palm plantation and palm oil milling were found to be 12.3 kg CE/ton FFB, resulting in the net carbon reduction in CPO production of 2.8 kg CE/ton FFB or 53.7 kg CE/ha-y. Overall, the sum of C-reduction was found 1.2 times greater than that of C-emission. This figure can be increased up to 5.5, if all biomass by-products are used as fuel to generate electricity only. The full potential for carbon reduction from palm oil milling is estimated at 0.94 kW of electric power for every hectare of

  11. 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.

  12. 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

  13. 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

  14. Characterization of Al2O3NP–Al2024 and AgCNP–Al2024 composites prepared by mechanical processing in a high energy ball mill

    International Nuclear Information System (INIS)

    Carreño-Gallardo, C.; Estrada-Guel, I.; Romero-Romo, M.; Cruz-García, R.; López-Meléndez, C.; Martínez-Sánchez, R.

    2012-01-01

    Graphical abstract: Mechanical alloying was used to produce two kinds of metal matrix composites based on 2024 aluminum alloy, the nanocomposites were reinforced with different percentages of Al 2 O 3 and Ag C nanoparticles. The content of nanoparticles has a role important on the mechanical properties of the nanocomposite. 10 h of milling time are enough to former the Al 2024 nanocomposites. The results obtained by differential scanning calorimeter show the temperatures of intermetallic precipitation, which were identified by X-ray diffraction. The results revealed that mechanical alloying is an excellent route to incorporate and distribute NP into Al 2024 . Highlights: ► Aluminum-based nanocomposites were synthesized bay milling process. ► An homogeneous nanoparticles dispersion was reached and mechanical properties were enhanced. ► Phase transformation during heating was characterized by XRD. - Abstract: Mechanical alloying was used to produce two kinds of metal matrix composites based on 2024 aluminum alloy. The nanocomposites were reinforced with different percentages of Al 2 O 3 and Ag C nanoparticles. The content of nanoparticles has an important role on the mechanical properties of the nanocomposites. A milling time of 10 h is enough to form the Al 2024 nanocomposites. The thermograms obtained by differential scanning calorimeter show the temperatures of phase precipitation, which were identified by X-ray diffraction. The results revealed that mechanical alloying is an excellent route for the incorporation and distribution of nanoparticles into Al 2024 .

  15. Annual status report on the Uranium Mill Tailings Remedial Action Program

    International Nuclear Information System (INIS)

    1992-12-01

    This fourteenth annual status report for the Uranium Mill Tailings Remedial Action (UMTRA) Project Office summarizes activities of the Uranium Mill Tailings Remedial Action Surface (UMTRA-Surface) and Uranium Mill Tailings Remedial Action Groundwater (UMTRA-Groundwater) Projects undertaken during fiscal year (FY) 1992 by the US Department of Energy (DOE) and other agencies. Project goals for FY 1993 are also presented. An annual report of this type was a statutory requirement through January 1, 1986, pursuant to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95-604. The DOE will continue to submit annual reports to DOE-Headquarters, the states, tribes, and local representatives through Project completion in order to inform the public of the yearly Project status. The purpose of the remedial action is to stabilize and control the tailings and other residual radioactive material (RRM) located on the inactive uranium processing sites in a safe and environmentally sound manner, and to minimize or eliminate potential health hazards. Commercial and residential properties near designated processing sites that are contaminated with material from the sites, herein referred to as ''vicinity properties (VP),'' are also eligible for remedial action. Included in the UMTRA Project are 24 inactive uranium processing sites and associated VPs located in 10 states, and the VPs associated with the Edgemont, South Dakota, uranium mill currently owned by the Tennessee Valley Authority (TVA) (Figure A.1, Appendix A)

  16. 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.

  17. 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

  18. The magnetic properties of mill scale-derived permanent magnet

    International Nuclear Information System (INIS)

    Woon, H.S.; Hashim, M.M.; Yahya, N.; Zakaria, A.; Lim, K.P.

    2005-01-01

    In the permanent magnet SrO-FeO-Fe 2 O 3 system, there exist several magnetically ordered compounds with a stable phase at room temperature. The most important are the M(SrFe 12 O 19 ), X(SrFe 15 O 23 ) and W(SrFe 18 O 27 ) phases with hexagonal close packed structure. In this project, M(SrFe 12 O 19 ) was prepared using mill scale, a steel-maker byproduct, as raw material. The Malaysia steel industry generates approximately 30,000 metric tons of waste products such as mill scale every year. Transportation and disposal of the byproducts are costly and the environmental regulations are becoming stricter. Hence, local steel mills are to find new ways to recycle the waste as a feedstock for the steel-making process or as a saleable product. The M(SrFe 12 O 19 ) was synthesized using the conventional ceramic process. The formation of the SrFe 12 O 19 was confirmed by X-ray diffraction. The magnetic properties such as the energy product (BH)max, coercive force (iHc) and remanence (Br) were also reported in this paper. (Author)

  19. Architecture and environmental restoration: Remediating uranium mill tailings from buildings

    International Nuclear Information System (INIS)

    Teply, J.D.

    1991-01-01

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) manages the Uranium Mill Tailings Remedial Action (UMTRA) Program in Grand Junction, Colorado. This program is a congressionally mandated clean up of by-product waste that resulted from the extraction of yellow cake from uranium ore. The by-product waste, a fine sand commonly called open-quotes mill tailingclose quotes is contaminated with low-level radioactivity. These mill tailings were available to the community for use as construction material from approximately 1952 to 1966; their use as bedding material for concrete slabs, utilities, backfill materials, concrete sand, and mortar created unique remediation problems that required innovative solutions. This paper describes how design personnel approach the remediation of structures, the evaluation of the buildings, and the factors that must be considered in completing the remediation design. This paper will not address the health risks of the tailings in an inhabited space, the remediation of exterior areas, or the process of determining where the tailings exist in the building

  20. 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