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Sample records for ball milling pretreatments

  1. Ball milling pretreatment of oil palm biomass for enhancing enzymatic hydrolysis.

    Science.gov (United States)

    Zakaria, Mohd Rafein; Fujimoto, Shinji; Hirata, Satoshi; Hassan, Mohd Ali

    2014-08-01

    Oil palm biomass, namely empty fruit bunch and frond fiber, were pretreated using a planetary ball mill. Particle sizes and crystallinity index values of the oil palm biomass were significantly reduced with extended ball mill processing time. The treatment efficiency was evaluated by the generation of glucose, xylose, and total sugar conversion yields from the pretreatment process compared to the amount of sugars from raw materials. Glucose and xylose contents were determined using high-performance liquid chromatography. An increasing trend in glucose and xylose yield as well as total sugar conversion yield was observed with decreasing particle size and crystallinity index. Oil palm frond fiber exhibited the best material yields using ball milling pretreatment with generated glucose, xylose, and total sugar conversion yields of 87.0, 81.6, and 85.4%, respectively. In contrast, oil palm empty fruit bunch afforded glucose and xylose of 70.0 and 82.3%, respectively. The results obtained in this study showed that ball mill-treated oil palm biomass is a suitable pretreatment method for high conversion of glucose and xylose.

  2. Comparison on structural modification of industrial lignin by wet ball milling and ionic liquid pretreatment

    Directory of Open Access Journals (Sweden)

    Yongshui Qu

    2015-06-01

    Full Text Available As the most abundant aromatic compounds, lignin is still underutilized due to its relatively low quality. In order to improve its quality, two pretreatment technologies, wet ball milling (WBM and ionic liquid pretreatment (ILP were tested on the industrial lignin and evaluated on the average molecular weight and polydispersity, surface morphology, and functional groups changes. The results showed that the lignin pretreated by the WBM with phosphoric acid presented dramatic decrease of polydipersity (23% and increase of phenolic hydroxyl content (9%. While, the ILP treated samples exhibited the significant reduction of the average molecular weight and polydispersity. The decrease on the particle size and the emergence of the porous structure were found when treated with [Emim][OAc]. In addition, the remarkable reduction of the methoxy groups were observed to be 50% and 45% after treated with [Bmim]Cl and [Emim][OAc], respectively.

  3. Combined pretreatment using ozonolysis and ball milling to improve enzymatic saccharification of corn straw.

    Science.gov (United States)

    Shi, Feng; Xiang, Heji; Li, Yongfu

    2015-03-01

    Two clean pretreatments, ozonolysis (OZ) and planetary ball milling (BM) were applied separately and in combination to improve the enzymatic hydrolysis of corn straw. Pretreatment of corn straw by OZ and BM alone improved the enzymatic hydrolysis significantly, primarily through delignification and decrystallization of cellulose, respectively. When combined, OZ-BM and BM-OZ pretreatments made the enzymatic hydrolysis more efficient. The glucose and xylose yield of corn straw treated with OZ for 90 min followed by BM for 8 min (OZ90-BM8) reached to 407.8 and 101.9 mg/g-straw, respectively under cellulase loading of 15 FPU/g-straw, which was fivefold more than that of untreated straw. Under much lower cellulase loading of 1.5 FPU/g-straw, the glucose and xylose yield of treated straw OZ90-BM8 remained at 416.0 and 108.4 mg/g-straw, respectively, while the yield of untreated straw decreased. These findings indicate that the combined OZ-BM can be used as a promising pretreatment for corn straw.

  4. Process engineering with planetary ball mills.

    Science.gov (United States)

    Burmeister, Christine Friederike; Kwade, Arno

    2013-09-21

    Planetary ball mills are well known and used for particle size reduction on laboratory and pilot scales for decades while during the last few years the application of planetary ball mills has extended to mechanochemical approaches. Processes inside planetary ball mills are complex and strongly depend on the processed material and synthesis and, thus, the optimum milling conditions have to be assessed for each individual system. The present review focuses on the insight into several parameters like properties of grinding balls, the filling ratio or revolution speed. It gives examples of the aspects of grinding and illustrates some general guidelines to follow for modelling processes in planetary ball mills in terms of refinement, synthesis' yield and contamination from wear. The amount of energy transferred from the milling tools to the powder is significant and hardly measurable for processes in planetary ball mills. Thus numerical simulations based on a discrete-element-method are used to describe the energy transfer to give an adequate description of the process by correlation with experiments. The simulations illustrate the effect of the geometry of planetary ball mills on the energy entry. In addition the imaging of motion patterns inside a planetary ball mill from simulations and video recordings is shown.

  5. Effects and mechanism of ball milling on torrefaction of pine sawdust.

    Science.gov (United States)

    Gong, Chunxiao; Huang, Jing; Feng, Chen; Wang, Guanghui; Tabil, Lope; Wang, Decheng

    2016-08-01

    The effects and mechanism of ball milling on the torrefaction process were studied. Ball- and hammer-milled (screen size 1mm) pine sawdust samples were torrefied at three temperatures (230, 260, and 290°C) and two durations (30 and 60min) to investigate into their torrefaction behavior and physicochemical properties. The results showed that, under identical torrefaction conditions, torrefied ball-milled pine sawdust had a higher carbon content and fixed carbon, and lower hydrogen and oxygen contents than torrefied hammer-milled pine sawdust. Torrefied ball-milled pine sawdust produced lower mass and energy yields, but higher heating values than torrefied hammer-milled pine sawdust. Ball milling destroyed the crystalline structure of cellulose and thus reduced the thermal stability of hemicellulose, cellulose, and lignin, causing them to degrade at relatively lower temperatures. In conclusion, biomass pretreated with a combination of ball milling and torrefaction has the potential to produce an alternative fuel to coal.

  6. 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.

  7. Structural evolution of ball-milled permalloy

    Energy Technology Data Exchange (ETDEWEB)

    Brzozka, K., E-mail: kbrzozka@poczta.f [Technical University, Department of Physics (Poland); Oleksakova, D.; Kollar, P. [P.J. Safarik University, Department of Condensed Matter Physics, Institute of Physics, Faculty of Science (Slovakia); Szumiata, T.; Gorka, B.; Gawronski, M. [Technical University, Department of Physics (Poland)

    2006-02-15

    Two series of Fe{sub 19.8}Ni{sub 80.2} samples obtained by ball milling and differing in the form of starting material were investigated by Moessbauer spectroscopy. In the case of milled elemental powder, strong structural evolution was stated: both {alpha} and {gamma} phases arise and a small amount of pure iron is present as well. The annealing of as-milled powder at 490{sup o}C causes faster forming of {gamma}-(Ni-Fe) phase. Only slight changes in atomic order were stated in the series of milled polycrystalline ribbon.

  8. CVD carbon powders modified by ball milling

    Directory of Open Access Journals (Sweden)

    Kazmierczak Tomasz

    2015-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Li

    2011-05-04

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

  10. Formation of surface coating on milling balls during milling of Cr powders

    Institute of Scientific and Technical Information of China (English)

    王成国; 齐宝森; 王瑞华

    2002-01-01

    The formation regularity of surface coating on milling balls during milling of Cr powders was investigated, revealing that the plastic deformation of the balls surface plays an important role in the formation of coating and that the stronger affinity between the powders and the balls is a necessary pre-condition for the coating. The size of Cr powders, the coating thickness and the microhardness vary consistently with milling time during milling. At initial milling stage, the powder size decreases, while the coating thickness and the microhardness increase, however, after milling for 24h, they all change slightly with prolonged milling, indicating a dynamic equilibrium between the powders cold welding and crashing, i.e. an almost equal rate for the powders attaching to and breaking off the milling balls.

  11. 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 ca...

  12. Reasonable Ball Size of Ball Mill for Preparing Coal Water Fuel and Forecasting Productive Capacity

    Institute of Scientific and Technical Information of China (English)

    张荣曾; 刘炯天; 徐志强; 郑明

    2002-01-01

    By using the matrix theory, a 5-parameter grinding mathema tical model is established. Based on the properties of feed coal and requirement s for size distribution of final product, the model gives the required grinding probability for various particles and corresponding ball size distribution. By u sing this model, 3 different sizes of ball mill are designed and put into commer cial use for coal water fuel. The forecasted ball mill capacity, the particle si zes and particle size distribution as well as the coal water fuel quality parame ters are all in line with industrial operation results, which have proved the su itability of the model.

  13. Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

    Directory of Open Access Journals (Sweden)

    Zhiliang Chen

    2016-07-01

    Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

  14. 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....

  15. Calculation Method for Media in Ball Mills by Layers

    Institute of Scientific and Technical Information of China (English)

    徐志强; 张荣曾; 曾鸣

    2002-01-01

    Based on analyzing the moving principle of media in ball mill, it is implicated that there is the significant difference of movement situation among each single layer. A new method to calculate each single was put forward. The results from lab experiment and actual data from 26 sets industrial mills state indicate that the new calculation method reaches the high accuracy with excellent practicab ility.

  16. Improvement on ball-milling composite process of metal matrix micro-nanometer powder using nanosuspension as the precursor

    Science.gov (United States)

    Wang, Hongyu; Zhou, Jianzhong; Li, Xiangfeng; Shen, Qing; Cheng, Man

    2014-12-01

    The wet ball-milling preparation of metal matrix micro-nanometer powder using nanosuspension as the precursor can well solve the agglomeration of nanoscale component, but the micro-nanometer powder prepared by the method can hardly meet the requirement of powder feeding in laser cladding process and its composite effect is still not desirable enough. Aiming at the problem, the ball-milling composite process of metal matrix micro-nanometer powder using nanosuspension as the precursor was analyzed. It has been found that the morphological diversity of original micron powder is the main influencing factor of the deliverability and the composite effect of micro-nanometer powder. In addition, the deposition of the compounding powder in the bottom of ball-milling tank also has some negative influences on the composite effect. Accordingly, two improving measures namely the micron powder pretreatment with Ball Mill Reshaping + Screening and the additional stirring during ball-milling process are proposed and experimented. Results show that the micron powder pretreatment could significantly improve the composite effect and the deliverability of micro-nanometer powder, and the additional stirring could further improve the composite effect of micro-nanometer powder.

  17. Formation of ball-milled Fe-Mo nanostructured powders

    Energy Technology Data Exchange (ETDEWEB)

    Moumeni, H. [Laboratoire de Magnetisme et de Spectroscopie des Solides, LM2S, Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba-Algerie (Algeria) and Departement de Physique, Faculte des Sciences et de l' Ingenierie, Universite de Guelma, B.P. 401, 24000 Guelma-Algerie (Algeria)]. E-mail: hmoumeni@yahoo.fr; Alleg, S. [Laboratoire de Magnetisme et de Spectroscopie des Solides, LM2S, Departement de Physique, Faculte des Sciences, Universite de Annaba, B.P. 12, 23000 Annaba-Algerie (Algeria); Greneche, J.M. [Laboratoire de Physique de l' Etat Condense, UMR CNRS 6087, Universite du Maine, Faculte des Sciences, F-72085, Le Mans Cedex 9 (France)

    2006-08-10

    Nanostructured Fe-6 wt.%Mo powders were prepared by mechanical alloying in a high-energy planetary ball-mill. The structural changes and the kinetics of Mo dissolution were studied by using X-ray diffraction. The crystallite size reduction down to about 11 nm is accompanied by the introduction of internal strains up to 1.1% (root-mean square strain, rms). After 24 h of milling, a bcc Fe(Mo) solid solution is formed. The kinetics of Mo dissolution into the Fe matrix during the milling process can be described by two regimes characterized by small values of Avrami parameter which do not exceed unit.

  18. 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.

  19. Ball-milled sulfur-doped graphene materials contain metallic impurities originating from ball-milling apparatus: their influence on the catalytic properties.

    Science.gov (United States)

    Chua, Chun Kiang; Sofer, Zdeněk; Khezri, Bahareh; Webster, Richard D; Pumera, Martin

    2016-07-21

    Graphene materials have found applications in a wide range of devices over the past decade. In order to meet the demand for graphene materials, various synthesis methods are constantly being improved or invented. Ball-milling of graphite to obtain graphene materials is one of the many versatile methods to easily obtain bulk quantities. In this work, we show that the graphene materials produced by ball-milling are spontaneously contaminated with metallic impurities originating from the grinding bowls and balls. Ball-milled sulfur-doped graphene materials obtained from two types of ball-milling apparatus, specifically made up of stainless steel and zirconium dioxide, were investigated. Zirconium dioxide-based ball-milled sulfur-doped graphene materials contain a drastically lower amount of metallic impurities than stainless steel-based ball-milled sulfur-doped graphene materials. The presence of metallic impurities is demonstrated by their catalytic effects toward the electrochemical catalysis of hydrazine and cumene hydroperoxide. The general impression toward ball-milling of graphite as a versatile method for the bulk production of 'metal-free' graphene materials without the need for post-processing and the selection of ball-milling tools should be cautioned. These findings would have wide-reaching implications for graphene research.

  20. Modeling on the Effect of Coal Loads on Kinetic Energy of Balls for Ball Mills

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    Yan Bai

    2015-07-01

    Full Text Available This paper presents a solution for the detection and control of coal loads that is more accurate and convenient than those currently used. To date, no research has addressed the use of a grinding medium as the controlled parameter. To improve the accuracy of the coal load detection based on the kinetic energy of balls in a tubular ball mill, a Discrete Element Method (DEM model for ball kinematics based on coal loads is proposed. The operating process for a ball mill and the ball motion, as influenced by the coal quality and the coal load, was analyzed carefully. The relationship between the operating efficiency of a coal pulverizing system, coal loads, and the balls’ kinetic energy was obtained. Origin and Matlab were utilized to draw the variation of parameters with increasing coal loads in the projectile and cascading motion states. The parameters include the balls’ real-time kinetic energy, the friction energy consumption, and the mill’s total work. Meanwhile, a method of balanced adjacent degree and a physical experiment were proposed to verify the considerable effect of the balls’ kinetic energy on coal loads. The model and experiment results indicate that a coal load control method based on the balls’ kinetic energy is therefore feasible for the optimized operation of a coal pulverizing system.

  1. Micromorphological changes and mechanism associated with wet ball milling of Pinus radiata substrate and consequences for saccharification at low enzyme loading.

    Science.gov (United States)

    Vaidya, Alankar A; Donaldson, Lloyd A; Newman, Roger H; Suckling, Ian D; Campion, Sylke H; Lloyd, John A; Murton, Karl D

    2016-08-01

    In this work, substrates prepared from thermo-mechanical treatment of Pinus radiata chips were vibratory ball milled for different times. In subsequent enzymatic hydrolysis, percent glucan conversion passed through a maximum value at a milling time of around 120min and then declined. Scanning electron microscopy revealed breakage of fibers to porous fragments in which lamellae and fibrils were exposed during ball milling. Over-milling caused compression of the porous fragments to compact globular particles with a granular texture, decreasing accessibility to enzymes. Carbon-13 NMR spectroscopy showed partial loss of interior cellulose in crystallites, leveling off once fiber breakage was complete. A mathematical model based on observed micromorphological changes supports ball milling mechanism. At a low enzyme loading of 2FPU/g of substrate and milling time of 120min gave a total monomeric sugar yield of 306g/kg of pulp which is higher than conventional pretreatment method such as steam exploded wood.

  2. A Method to Determine the Ball Filling, in Miduk Copper Concentrator SAG Mill

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    Ali Kamali Moaveni

    2012-12-01

    Full Text Available The aim of this research work was to investigate on the ball filling estimation of Miduk semi-autogenous (SAG Mill via an utilized method. Miduk copper concentrator is located in Kerman Province, Iran, and its size reduction stage includes one gyratory crusher which feeds one SAG mill (9.75 dia.(m*3.88 length(m following two parallel ball mills (5dia.(m*7lenght(m. After SAG mill, a trommel screen produces two over and under size materials which the oversize part is circulated into SAG mill and undersize reports to hydrocyclone for further process. Ball filling identify was implemented in this work using mill`s load sampling and ball abrasion test.These methods could estimate ball filling variation with easy, undeniable, and useful tests. Also, these tests have shown the digression of operating ball filling amount and its manual designed. To make more homogenous load, mill load samplings were carried out from 6 points after whirling the mill via inching motor. Acquired load sampling results were compared with ball abrasion tests. Ball abrasion tests were calculated for 3 different conditions include maximum, average, and minimum ball abrasion. However, the calculated maximum and minimum conditions never occurred. However, these are just for obtaining to ball filling variation in the mill. The results obtained from this work show, the ball filling percentage variation is between 1.2– 3.7% which is lower than mill ball filling percentage, according to the designed conditions (15%. In addition, acquired load samplings result for mill ball filling was 1.3%.

  3. Effect of High-energy Ball Milling on Synthetic Reaction in Al- TiO2- C System

    Institute of Scientific and Technical Information of China (English)

    KOU Shengzhong; XU Guangji; DING Yutian

    2005-01-01

    High-energy ball milling has a great influence on the temperature characters of synthetic reaction in Al-TiO2- C system by changing the size, distribution state and wet ability of reactants. Reaction temperature characters ( reaction ignition time, ignition temperature tine , the maximum temperature and temperature rising rate ) were changed by different milling time. The longer the milling time, the earlier the reaction, the quicker the temperature rise and the higher the maximum temperature. When the milling time exceeded 10 hours, the reactivity of reactants was so high that the synthetic reaction could take place at 850℃ directly without a long time pretreatment at 670℃ . The microstructure of synthetic composites became uniform and the reinforced particles ( TiC and α-Al2 O3 ) became fine with milling time increasing.

  4. SAXS study of nanocrystalline materials produced by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez van Raap, M.; Socolovky, L.; Mendoza Zelis, L.; Sanchez, F.H. [La Plata Univ. Nacional (Argentina). Dept. de Fisica; Kellermann, Guinther; Torriani, Iris [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil)

    1997-12-31

    Full text. SAXS characterization of nanocrystalline materials produced by ball milling was performed at the Brazilian National Synchrotron Light-SAXS beam line. Two kind of sample were used: pure metals (Fe and Pd) milled in Ar atmosphere in a vibratory horizontal mill Resc MM2 for 12, 25 and 48 h. And Fe y Cu 1-y(05,0.10,0.14,0.18,0.20,0.35 and 0.45) alloys subjected to 75 milling hours in a low energy mill. SAXS data was collected with (formula) corresponding to a photon energy just below Fe absorption edge to avoid fluorescence, and with two camera length to be able to see Guinier and Porod regions. Mechanical work performed on any materials produces simultaneously reduction in particles sizes and in grain sizes up to the nanometer scale, increase in micro strain storage and defects. Broadening of the XRD reflection lines with milling time gives an estimation of grain sizes and volume deformation (micro strain), but no information is obtained on the nature of the defects, which due to the high milling intensity could be clustered as voids. On the other hand, for a mixture of two elements, besides the facts listed above, alloying in different metastable states (amorphous, extended solid solution, granular materials, etc.) can be obtained depending on the system and on composition. For the Fe y Cu 1-y alloys studied here, previous results indicates: the alloys are fcc, a dependence of the magneto resistivity on Fe concentration can be recorded (maximum at 0.20) and from HREM the existence of inclusion of 7.3 nm size was proposed. Our preliminary data analysis of the recorded SAXS patterns shows that for the metals no clear dependence with milling time can be established, a distribution of sizes can be predicted from the Guinier region behavior and a Porod region can be fitted indicating a fairly sharp density contrast. Patterns recorded Fe y Cu 1-y are similar of those recorded for milled metals, the possibility of distinguish from voids or from composition

  5. The Tool Life of Ball Nose end Mill Depending on the Different Types of Ramping

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    Vopát Tomáš

    2014-12-01

    Full Text Available The article deals with the cutting tool wear measurement process and tool life of ball nose end mill depending on upward ramping and downward ramping. The aim was to determine and compare the wear (tool life of ball nose end mill for different types of copy milling operations, as well as to specify particular steps of the measurement process. In addition, we examined and observed cutter contact areas of ball nose end mill with machined material. For tool life test, DMG DMU 85 monoBLOCK 5-axis CNC milling machine was used. In the experiment, cutting speed, feed rate, axial depth of cut and radial depth of cut were not changed. The cutting tool wear was measured on Zoller Genius 3s universal measuring machine. The results show different tool life of ball nose end mills depending on the copy milling strategy.

  6. Homogeneity of ball milled ceramic powders: Effect of jar shape and milling conditions

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    M. Broseghini

    2017-02-01

    Full Text Available This paper contains data and supporting information of and complementary to the research article entitled “Effect of jar shape on high-energy planetary ball milling efficiency: simulations and experiments” (Broseghini et al., [1]. Calcium fluoride (CaF2 was ground using two jars of different shape (cylindrical and half-moon installed on a planetary ball-mill, exploring different operating conditions (jar-to-plate angular velocity ratio and milling time. Scanning Electron Microscopy (SEM images and X-Ray Powder Diffraction data (XRPD were collected to assess the effect of milling conditions on the end-product crystallite size. Due to the inhomogeneity of the end product, the Whole Powder Pattern Model (WPPM, (Scardi, 2008 [2] analysis of XRPD data required the hypothesis of a bimodal distribution of sizes – respectively ground (fine fraction and less-to-not ground (coarse fraction – confirmed by SEM images and suggested by the previous literature (Abdellatief et al., 2013 [3,4]. Predominance of fine fraction clearly indicates optimal milling conditions.

  7. 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...

  8. An analytical model for force prediction in ball nose micro milling of inclined surfaces

    DEFF Research Database (Denmark)

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

    2010-01-01

    Ball nose micro milling is a key process for the generation of free form surfaces and inclined surfaces often present in mould inserts for micro replication. This paper presents a new cutting force model for ball nose micro milling that is capable of taking into account the effect of the edge rad...

  9. Remediation of oil-contaminated sand by coal agglomeration using ball milling.

    Science.gov (United States)

    Shin, Yu-Jen; Shen, Yun-Hwei

    2011-10-01

    The mechanical shear force provided by a less energy intensive device (usually operating at 20-200 rpm), a ball mill, was used toperform coal agglomeration and its effects on remediation of a model fuel oil-contaminated sand were evaluated. Important process parameters such as the amount of coal added, milling time, milling speed and the size of milling elements are discussed. The results suggested that highly hydrophobic oil-coal agglomerates, formed by adding suitable amounts of coal into the oil-contaminated sand, could be mechanically liberated from cleaned sand during ball milling and recovered as a surface coating on the steel balls. Over 90% removal of oil from oil-contaminated sand was achieved with 6 wt% of coal addition and an optimum ball milling time of 20 min and speed of 200 rpm. This novel process has considerable potential for cleaning oil-contaminated sands.

  10. Influence of milling time on fineness of Centella Asiatica particle size produced using planetary ball mill

    Science.gov (United States)

    Borhan, M. Z.; Ahmad, R.; Rusop, M.; Abdullah, S.

    2012-11-01

    Centella Asiatica (C. Asiatica)contains asiaticoside as bioactive constituent which can be potentially used in skin healing process. Unfortunately, the normal powders are difficult to be absorbed by the body effectively. In order to improve the value of use, nano C. Asiatica powder was prepared. The influence of milling time was carried out at 0.5, 2, 4, 6, 8 hours and 10 hours. The effect of ball milling at different times was characterized using particles size analysis and FTIR Spectroscopy. The fineness of ground product was evaluated by recording the z-Average (nm), undersize distribution and polydispersity index (PdI). The results show that the smallest size particles by mean is 233 nm while FTIR spectra shows that there is no changing in the major component in the C. Asiatica powders with milling time.

  11. Surface modification of titanium hydride with epoxy resin via microwave-assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Rong [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Chen, Ding, E-mail: ma97chen@hotmail.com [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Zhang, Qianxia [College of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Bian, Zhibing; Dai, Haixiong; Zhang, Chi [Jiangsu Jinling Special Paint Co., Ltd., Yangzhou 225212 (China)

    2014-10-15

    Highlights: • TiH{sub 2} was modified with epoxy resin by microwave-assisted ball milling. • The epoxy ring was opened under the coupling effect of microwave and ball milling. • Microwave-assisted ball milling improved the compatibility of TiH{sub 2} with epoxy. - Abstract: Surface modification of titanium hydride with epoxy resin was carried out via microwave-assisted ball milling and the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermo-gravimetry (TG) and Fourier transform infrared spectroscopy (FT-IR). A sedimentation test was performed to investigate the compatibility of the modified nano titanium hydride with the epoxy resin. The results show that the epoxy resin molecules were grafted on the surface of nano titanium hydride particles during the microwave-assisted ball milling process, which led to the improvement of compatibility between the nanoparticles and epoxy resin. According to the FT-IR, the grafting site was likely to be located around the epoxy group due to the fact that the epoxy ring was opened. However, compared with microwave-assisted ball milling, the conventional ball milling could not realize the surface modification, indicating that the coupling effect of mechanical force and microwave played a key role during the process.

  12. Properties of high-energy ball-milled Fe-Se based superconductors.

    Science.gov (United States)

    Ahn, Jung-Ho; Sangjun-Oh

    2012-02-01

    We have synthesized FeSe0.5Te0.5 superconductors by high-energy ball-milling and subsequent annealing. High-energy ball-milling of elemental powder mixtures resulted in the formation of metastable and/or nanocrystalline phases. Both XRD and DSC results show that the ball-milled powers were completely transformed to FeSe0.5Te0.5 with the grain size of a few nanometers during sintering at low temperatures. The resulting materials exhibited superconducting transition at 14 K. The enhancement of critical current density was observed for the high-energy ball-milled powder, compared with the un-milled powders.

  13. 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.

  14. Synthesis of Fe3O4 nanoparticles by wet milling iron powder in a planetary ball mill

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fe3O4 nanoparticles with sizes ranging from 30 to 80nm were synthesized by wet milling iron powders in a planetary ball mill. The phase composition and the morphologies of the as-synthesized products were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Nanosized Fe3O4 particles were prepared by wet milling metallic iron powder (-200 mesh, 99%)rotation speed of 300 rpm. The use of the iron balls in this method played a key role in Fe3O4 formation. The present technique is simple and the process is easy to carry out.

  15. Microstructure Evolution of Ti/BN Powder Blend during Ball Milling and Heat Treatment

    Institute of Scientific and Technical Information of China (English)

    Jianlin LI; Keao HU; Yong ZHONG

    2001-01-01

    Ball milled Ti/BN composite powder was prepared by high energy ball milling for 40 h, using Ti and BN (the molar ratio of Ti/BN is 3:2) as starting materials. The as-milled composite powder consists of TiN, Ti and amorphous phase. TiN formed while the milled powder was annealed at 400℃. The heat treatment at 700℃ led to the formation of TiB2 and TiB. The nanocrystalline Ti and amorphous phase converted to TiN and TiB2 when the powder was heated to 1300℃.

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

    Directory of Open Access Journals (Sweden)

    Daqiang Gao

    2011-12-01

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

  17. 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 hi...... 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.......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...

  18. Micronutrient dynamics after thermal pretreatment of olive mill solid waste.

    Science.gov (United States)

    Almansa, Ana R; Rodriguez-Galan, Monica; Borja, Rafael; Fermoso, Fernando G

    2015-09-01

    This study investigated metal dynamics, and their bioavailability, before and after thermal pretreatment of olive mill solid waste (OMSW), using a sequential metal extraction scheme. The 11.5% increase of cobalt in the most available fraction after the pretreatment coupled to the increase of methane production rate have been a good indicator that the OMSW anaerobic digestion might be metal limited due to the lack of cobalt.

  19. Structural and magnetic stability of high energy ball milled Co{sub 2}MnSi

    Energy Technology Data Exchange (ETDEWEB)

    Vinesh, A., E-mail: attatappa85@gmail.com [Department of Physics, Amity School of Applied Sciences, Amity University Haryana, Gurgaon 122413 (India); Sudheesh, V.D. [Department of Physics, MohanlalSukhadia University Udaipur, Rajasthan 313001 (India); Sebastian, Varkey [Department of Physics, Nimalagiri College, Nirmalagiri, Kannur, Kerala 670701 (India); Lakshmi, N.; Venugopalan, K. [Department of Physics, MohanlalSukhadia University Udaipur, Rajasthan 313001 (India)

    2015-07-15

    Structural and magnetic properties of ball milled Co{sub 2}MnSi have been studied and compared with that of ordered bulk sample. The milled sample (with average size determined using the Williamson–Hall method) shows that the chemical ordering for this sample is very stable and is little effected by high energy ball milling. However, the reduction in the saturation magnetic moment of the milled sample shows that there is spin disordering induced on ball milling – attributable to the formation of a magnetically dead layer at the surface of the nano-sized samples. The ordered sample (unmilled) has a saturation moment value of 4.4 µ{sub B} per formula unit at room temperature and is in agreement with the prediction of Slater Pauling curve. On milling it reduces to ~3 µ{sub B} per formula unit at room temperature with an accompanying increase in the coercivity, retentivity and squareness factor. - Highlights: • We studied the magnetic and structural properties of bulk and ball milled Co{sub 2}MnSi. • Structural disordering is minimal even at 36 nm. • Constant value of T{sub C} shows strong ferromagnetic interaction in smaller particles. • Formation of magnetically dead surface layer results reduction in magnetic moment. • Variation of magnetic parameters is systematic with variation in milling time/size.

  20. Titania Prepared by Ball Milling: Its Characterization and Application as Liquefied Petroleum Gas Sensor

    CERN Document Server

    Yadav, B C; Singh, Satyendra; Yadav, T P

    2012-01-01

    Present paper reports the LPG sensing of TiO2 obtained through ball milling. The milled powder was characterized by XRD, TEM and UV-visible spectroscopy. Further the ball milled powder was compressed in to pellet using hydraulic press. This pellet was investigated with the exposure of LPG. Variations in resistance with exposure of LPG to the sensing pellet were recorded. The sensitivity of the sensor was ~ 11 for 5 vol.% of LPG. Response and recovery times of the sensor were ~ 100 and 250 sec. The sensor was quite sensitive to LPG and results were found reproducible within 91%.

  1. PREPARING NANO-CRYSTALLINE La DOPED WC/Co POWDER BY HIGH ENERGY BALL MILLING

    Institute of Scientific and Technical Information of China (English)

    S. Liu; D.Q. Yi; Y.X. Li; D. Zou

    2002-01-01

    The La doped WC/Co powder was prepared by high energy ball milling. The changesof crystal structure, micrograph and defect of the powder were investigated by means ofXRD (X-ray diffraction), SEM (scanning electron microscope) and DTA (differentialthermal analysis). The results show that adding trace La element into carbides iseffective to minish the grain size of WC/Co powder. The La doped carbides powderwith grain size of 30nm can be obtained after 1Oh ball milling. The XRD peak of Cophase disappeared after 20h ball milling, which indicated solid solution (or secondarysolid solution) of Co phase in WC phase. The La doped powder with grain size of1Ohm is obtained after 30h ball milling. A peak of heat release at the temperatureof 470℃ was emerged in DTA curve within the range of heating temperature, whichshowed that the crystal structure relaxation of the powder appeared in the process ofhigh energy ball milling. After consolidated the La doped WC/Co alloy by high energyball milling exhibits ultra-fine grain Sizes and better mechanical properties.

  2. Catalytic Effect of Nb2O5 in MgH2-Nb2O5 Ball-Milled Composites

    Directory of Open Access Journals (Sweden)

    Somei Ohnuki

    2012-09-01

    Full Text Available We report a study on the desorption properties, crystallography and chemical state of MgH2 and 1 mol% Nb2O5 ball-milled composites. Desorption temperatures of the composites decreased with increase of ball-milling time. Size of MgH2 crystallites decreased during ball-milling. Reduction of Nb2O5 after ball-milling was confirmed by tracing the chemical state of Nb and was further supported by TEM observation. The reduced phases may act as more effective catalysts improving the desorption properties.

  3. COMPARISON ON REFINEMENT OF IRON POWDER BY BALL MILLING ASSISTED BY DIFFERENT EXTERNAL FIELDS

    Institute of Scientific and Technical Information of China (English)

    L.Y. Dai; B. Cao; M. Zhu

    2006-01-01

    The cryogenic milling and milling in conjunction with dielectric barrier discharge plasma (DBDP)have been separately set up. The combined effect of low temperature and plasma on ball milling has been investigated by examining the refinement of particle size and grain size of iron powder using scanning electron microscopy, X-ray diffraction, and small angle X-ray scattering. It was found that the mean size of iron particles could reach 104nm only after 10 hours of ball milling in conjunction with DBDP, whereas a minimum average grain size of 8.4nm was obtained by cryomilling at -20℃; however, it is difficult to refine the particle size and grain size under the same milling condition in the absence of DBDP and cryogenic temperature.

  4. Preparation and Characterization of Stainless Steel/TiC Nanocomposite Particles by Ball-milling Method

    Institute of Scientific and Technical Information of China (English)

    CHEN Wenyi; ZHOU Jian

    2009-01-01

    A stainless steel/10wt%TiC nanocomposite particles were prepared by high-energy ball-milling method using stainless steel, carbon and titanium as raw materials. The evolution of phase composition, microstructure and specific surface area of the stainless steel/TiC nanocomposite particles with increasing ball-milling time in the range of 0-100 h were investigated by XRD, SEM, TEM and BET techniques. The results showed that the stainless steel/TiC nano-composite particles were fabricated when the ball-milling time was longer than 20 h. However, the nanocomposite particles were soldered and agglomerated again when the ball-milling time was longer than 60 h. The microstructure of the composite particles transformed from lamellar structure to nanostructure during the repeated process of the cold welding and cracking. TEM image reveals clearly that the in-situ TiC nanoparticles with grain size of 3-8 nm are in the interior of the stainless steel/TiC nanocomposite particles obtained by ball-milling 100 h.

  5. Effect of ball milling process on the microstructure of titanium-nanohydroxyapatite composite powder

    Institute of Scientific and Technical Information of China (English)

    PANG Pengsha; LI Wei; LIU Ying

    2007-01-01

    Titanium-nanohydroxyapatite (Ti-nHA) composite powders, composed of titanium with 10 vol.% and 20 vol.%of nano-hydroxyapatite, were milled in a planetary ball mill using alcohol media to avoid excessive heat. XRD and SEM were performed for characterization of the microstructure, and the homogeneity of Ti/HA nanocomposite powder was evaluated by EPMA with prolonged ball milling time. The results show that under the condition of wet milling, the grain size of Ti-nHA composite powders is decreased with the increase in ball milling time and the amount of the addition of nHA.While for milling of 30 h, the nanocomposite powder with fine structure, which consists of the nano-hydroxyapatite (nHA)particles and titanium (Ti) phase, is obtained. Three stages of milling can be observed from the element mapping of Ti, Ca,and P by EPMA; meanwhile, it is found that the nHA would be more homogenously distributed after milling for 30 h.

  6. Effect of ball milling and heat treatment process on MnBi powders magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wei; Polikarpov, Evgueni; Choi, Jung-Pyung; Bowden, Mark E.; Sun, Kewei; Cui, Jun

    2016-09-01

    The metallic compound MnBi has high intrinsic coercivity with large positive temperature coefficient. The coercivity of MnBi exceeds 12 kOe and 26 kOe at 300 K and 523 K, respectively. Hence MnBi is a good candidate for the hard phase in exchange coupled nanocomposite magnets. In order to maximize the loading of the soft phase, the size of the MnBi particle has to be close to 500 nm, the size of single magnetic domain. Low energy milling is the common method to reduce MnBi particle size. However, only 3-7 mu m size particle can be achieved without significant decomposition. Here, we report our effort on preparing submicron MnBi powders using traditional powder metallurgy methods. Mn55Bi45 magnetic powders were prepared using arc melting method, followed by a series of thermal-mechanical treatment to improve purity, and finished with low energy ball milling at cryogenic temperature to achieve submicron particle size. The Mn55Bi45 powders were decomposed during ball milling process and recovered during 24 h 290 degrees C annealing process. With increasing ball-milling time, the saturation magnetization of MnBi decreases, while the coercivity increases. Annealing after ball milling recovers some of the magnetization, indicating the decomposition occurred during the ball-milling process can be reversed. The coercivity of Mn55Bi45 powders are also improved as a result of the heat treatment at 290 degrees C for 24 h. The world record magnetization 71.2 emu/g measured applying a field of 23 kOe has been achieved via low energy ball mill at room temperature

  7. Effect of annealing on the magnetic properties of ball milled NiO powders

    Energy Technology Data Exchange (ETDEWEB)

    Kisan, Bhagaban [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Saravanan, P. [Defence Metallurgical Research laboratory, Hyderabad 500058 (India); Layek, Samar; Verma, H.C. [Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Hesp, David; Dhanak, Vinod [Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Krishnamurthy, Satheesh [Materials Engineering, The Open University, Milton Keynes MK7 6AA (United Kingdom); Perumal, A., E-mail: perumal@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

    2015-06-15

    We report systematic investigations on structural and magnetic properties of nanosized NiO powders prepared by the ball milling process followed by systematic annealing at different temperatures. Both as-milled and annealed NiO powders exhibit face centered cubic structure, but average crystallite size decreases (increases) with increasing milling time (annealing temperature). Pure NiO exhibits antiferromagnetic nature, which transforms into ferromagnetic one with moderate moment at room temperature with decreasing crystallite size. The on-set of ferromagnetic behavior in the as-milled powders was observed at higher temperatures (>750 K) as compared to bulk Ni (~630 K). On the other hand, annealing of as-milled powders showed a large reduction in magnetic moment and the rate of decrease of moment strongly depends on the milling conditions. The observed properties are discussed on the basis of crystallite size variation, defect density, oxidation/reduction of Ni and interaction between uncompensated surfaces and particle core with lattice expansion. - Highlights: • Preparation of fine NiO powder using top-to-bottom approach using planetary ball mill. • Effect of milling on instituting room temperature ferromagnetism with size reduction. • Stability of ferromagnetic properties at high temperatures in milled NiO powders • Effect of annealing process on the structural properties of milled NiO powders. • Understanding the origin of ferromagnetism at 300 K in NiO powders through annealing.

  8. Use of high energy ball milling on the sintering optimization of alumina ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Simoni, Helio R.; Saito, Eduardo; Santos, Claudinei dos; Santos, Felipe Antunes, E-mail: heliorss@ppgem.eel.usp.br, E-mail: claudinei@demar.eel.usp.br, E-mail: felipeantunes@usp.br [Universidade de Sao Paulo (EEL/USP) Lorena, SP (Brazil). Escola de Engenharia; Ramos, Alfeu Saraiva, E-mail: alfeuramos@uol.com.br [Unersidade Estadual Paulista Julio de Mesquista Filho (UNESP/FEG), Guaratingueta, SP (Brazil). Faculdade de Engenharia; Silva, Oliverio Moreira M., E-mail: silvaoliva@bol.com.br [Instituto de Aeronautica e Espacao (CTA/IAE/AMR), Sao Jose dos Campos, SP (Brazil). Centro Tecnico Aeroespacial

    2009-07-01

    In this work, the effect of the milling time on the densification of the alumina ceramics with or without 5wt.%Y{sub 2}O{sub 3}, is evaluated, using high-energy ball milling. The milling was performed with different times of 0, 2, 5 or 10 hours. All powders, milled at different times, were characterized by X-Ray Diffraction presenting a reduction of the crystalline degree and crystallite size as function of the milling time increasing. The powders were compacted by cold uniaxial pressing and sintered at 1550°C-60min. Green density of the compacts presented an increasing as function of the milling time and sintered samples presented evolution on the densification as function of the reduction of the crystallite size of the milled powders. (author)

  9. Study on the Method for Collecting Vibration Signals from Mill Shell Based on Measuring the Fill Level of Ball Mill

    Directory of Open Access Journals (Sweden)

    Peng Huang

    2014-01-01

    Full Text Available At present the method for measuring the fill level which used the vibration signal of mill shell shows its advantage compared with other methods. However, this method is developed late, and the technique for collecting the vibration signal from mill shell is immature. In this paper, a novel method for collecting the vibration data from mill shell is proposed. Firstly, the layout scheme of vibration sensors on mill shell is given by analyzing the axial and circumferential movement of coal powder in roller. And a special data acquisition system is developed, which can acquire vibration data from different axial and circumferential positions on mill shell. Then the sampling frequency is obtained based on impact model and hierarchical model of steel balls. At the same time, the impact region on mill shell caused by steel balls is considered as the collecting region of vibration signals. Experimental result shows that vibration signals collected by the method proposed in this paper present a high sensitivity to the changes on fill level compared with vibration data of mill bearing, which provides a reliable basis for accurate measurement of the fill level.

  10. Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Morup, Steen; Rasmussen, Helge K. [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Brok, Erik [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Keller, Lukas [Laboratory for Neutron Scattering, Paul Scherrer Institute, CH-5232 Villigen PSI (Switzerland); Frandsen, Cathrine, E-mail: fraca@fysik.dtu.dk [Department of Physics, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark)

    2012-09-14

    We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO{sub 3}) 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 after high-energy ball-milling of up to 128 h, but neutron diffraction studies reveal significant cation redistribution of Fe{sup 2+} and Ti{sup 4+} ions in the ball-milled samples. Moessbauer spectroscopy studies show that the magnetic hyperfine field of Fe{sup 2+}, which is around 5 T before ball-milling, increases, and after milling times longer than 4 h a broad distribution of hyperfine fields with values up to around 40 T for Fe{sup 2+} is seen. This can be explained by the cation disorder induced by the ball-milling which affects the orbital contribution to the magnetic hyperfine field. In contrast to some ball-milled spinel ferrites, the Neel temperature of ilmenite is not significantly affected by the cation disorder. -- Highlights: Black-Right-Pointing-Pointer High-energy ball-milling of FeTiO{sub 3} results in cation disorder. Black-Right-Pointing-Pointer The magnetic hyperfine field of {sup 57}Fe is strongly affected by the ball-milling. Black-Right-Pointing-Pointer The Neel temperature of FeTiO{sub 3} is not significantly affected by cation disorder.

  11. Effect of Milling Time on Al-Fe-Cr-20 Wt. % Al2O3composite Prepared Through Ball Milling

    Directory of Open Access Journals (Sweden)

    Hameedur Rehman Khan

    2014-07-01

    Full Text Available One of the main challenges towards achieving a homogeneous distribution of the ceramic phase in the metal matrix composites is agglomeration of the reinforcement particles. Mechanical alloying is among the most important processing techniques used for manufacturing of metal matrix composites (MMCs.An attempt was made to synthesize Al-Fe-Cr-Al2O3composites synthesized through mechanical alloying. Al2O3 is used as reinforcement. Ethanol (5 wt. % has been used as a process control agent (PCA. Mechanical alloying is carried out in a conventional ball mill using stainless steel grinding media at 115 rpm in the argon environment for 5h, 10h and 15h. The ball to powder weight ratio was maintained at 20:1. The characterization of the ball milled powder was followed by scanning electron microscopy (SEM. Showed the formation of a homogeneous phase for all compositions after milling for 15 h. XRD patterns were recorded for the milled powders, and analyzed using Williamson–Hall method and Scherrer’s equation to determine the lattice strain and grain size.EDX is performed to check the contamination of composites during the mechanical alloying.XRD is used to study structural evolution of synthesized aluminium composite. Effect of milling time is investigated on synthesized Al-Fe-Cr-20 wt. % Al2O3 composites.

  12. Fabrication of Lead Zirconate Titanate Powder Using Ultrasonic Ball Milling Technique

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this research, the ultrasonic ball milling technique has been used to fabricate lead zirconate titanate (PZT) ceramics.PZT with the composition nearly the morphotropic phase boundary (MPB): Pb(Zr0.52 Ti0.48 )O3 was studied. The effect of milling time on phase formation of sample powder was examined by X-ray diffraction technique (XRD). Moreover, the physical, dielectric, piezoelectric properties and microstructure of PZT ceramics were investigated. The present results reveal that the ultrasonic ball milling technique results the homogeneous and small size of PZT powder. Furthermore, there is a significantly change occurs in the size of the particles with the short time of milling process.

  13. The Key Role of Ball Milling Time in the Microstructure and Mechanical Property of Ni-TiCNP Composites

    Science.gov (United States)

    Zhou, Xiaoling; Huang, Hefei; Xie, Ruobing; Yang, Chao; Li, Zhijun; Jiang, Li; Ye, Xiangxi; Xu, Hongjie

    2016-12-01

    Titanium carbide nanoparticle-reinforced nickel-based alloys (Ni-TiCNP composites) with ball milling time ranging from 8 to 72 h were prepared by ball milling and spark plasma sintering. Transmission electron microscopy (TEM) and scanning electron microscopy equipped with electron backscatter diffraction were used to characterize the microstructures. Their hardness and tensile properties were measured using the Vickers pyramid method and tensile tests. TEM results showed that a slight coarsening of TiCNP occurred during the ball milling process. The grain sizes of the Ni-TiCNP composites with various ball milling times were different, but they were all much smaller than those of the pure Ni. In all cases, the Ni-TiCNP composites showed higher strengths and hardness values than the unreinforced pure nickel. Furthermore, the strength of the Ni-TiCNP composites increased initially and then decreased as a function of ball milling time. The maximum strengths occurred in the 24-h ball milling sample, which presented the lowest average grain size. The Hall-Petch strengthening was suggested to be the main reason responsible for such variations in mechanical properties. Additionally, the elongation percentage of the Ni-TiCNP composites decreased gradually with ball milling time. This may be caused by the change of microvoids in the composite as the ball milling time varies, which is also related to their fracture behavior.

  14. 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.

  15. Amorphous solid dispersions of sulfonamide/soluplus® and sulfonamide/PVP prepared by ball milling

    OpenAIRE

    Healy, Anne,

    2013-01-01

    PUBLISHED The aim of this paper is to investigate the physicochemical properties of binary amorphous dispersions of poorly soluble sulfonamide/polymeric excipient prepared by ball milling. The sulfonamides selected were sulfathiazole (STZ), sulfadimidine (SDM), sulfamerazine (SMZ) and sulfadiazine (SDZ). The excipients were polyvinylpyrrolidone (PVP) and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft co-polymer, commercially known as Soluplus®. Co-milled systems were cha...

  16. Electrochemical Properties of CeMg12+x%Ni Composites (x=0~200) Prepared by Ball-Milling

    Institute of Scientific and Technical Information of China (English)

    Wang Li; Wang Xinhua; Chen Changpin; Xiao Xuezhang

    2005-01-01

    The electrochemical properties of the as-cast and ball-milled CeMg12+x%(mass fraction) Ni (vs. CeMg12) (x=0, 50, 100 and 200) composites were investigated. The microstructure and discharge capacity of the ball-milled CeMg12+x%Ni composites differ greatly depending on the amount of Ni introduced during ball-milling. The more nickel powder added, the more advantageous for the formation of the amorphous structure. And the discharge capacities of the ball-milled composites increase with increasing amount of nickel added. After 90 h ball-milling, the CeMg12+200% Ni composite exhibits a high discharge capacity of 1170 mAh·g-1(CeMg12)-1 at 303 K. The improvement of electrochemical capacity is attributed to the formation of a homogeneous amorphous structure as well as the modification of the surface state after Ni addition.

  17. Effect of Initial Aluminum Alloy Particle Size on the Damage of Carbon Nanotubes during Ball Milling

    Directory of Open Access Journals (Sweden)

    Xian Zhu

    2016-03-01

    Full Text Available Damage to carbon nanotubes (CNTs during the fabrication process of CNT reinforced composites has great influence on their mechanical properties. In this study, the 2014 Al with powder sizes of 20, 9 and 5 μm was selected to study the effect of initial particle size on the damage to carbon nanotubes (CNTs during ball milling. The result shows that for CNTs in the ball milled CNT/Al (with powder size of 20 and 9 μm mixtures, the intensity ratio of the D band and the G band (ID/IG first increased and then reached a plateau, mainly because most of the CNTs are embedded, to a certain extent, in the aluminum powder after milling, which could protect the CNTs from damage during further milling. While for CNTs in the ball milled CNT/Al (with powder size of 5 μm mixture, the ID/IG ratio continues to climb from 1.31 to 2.33 with time, indicating continuous damage to the CNTs occurs during the milling. Differential scanning calorimetry (DSC analysis demonstrates that the chemical instability increased with an increase in the damage level of CNTs, resulting in the formation of aluminum carbide (Al4C3 at a lower temperature before the melting of aluminum, which is detrimental to their mechanical properties.

  18. 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.

  19. Design of Ball-Milling Experiments on Bi2Te3 Thermoelectric Material

    Science.gov (United States)

    Kanatzia, A.; Papageorgiou, Ch.; Lioutas, Ch.; Kyratsi, Th.

    2013-07-01

    In this work, factorial ball-milling experiments have been applied to Bi2Te3 material, for the first time, aiming to investigate the effect of the main process parameters on the structural features and thermoelectric properties of the ball-milled materials. The selected main parameters were the duration of milling, the speed, and the ball-to-material ratio. Analysis suggests a strong effect of the speed and duration of processing, whereas the ball-to-material ratio is of minor importance. This approach is advantageous for better understanding of the milling mechanism and the importance of the role of each independent parameter as well as their interaction. All experiments led to nanocrystalline Bi2Te3, whose structural features were studied. The nanocrystalline size was estimated based on x-ray diffraction analysis, while transmission electron microscopy (TEM) studies were also performed to confirm the presence of nanoscale crystals. A mathematical model was developed based on statistical analysis for prediction of the crystalline size and the Seebeck coefficient of the nanopowders. The thermoelectric properties were also investigated on selected, highly dense pellets fabricated via hot-pressing of the nanopowders.

  20. 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...

  1. Effect of ball milling on hydrogen storage of Mg3La alloy

    Institute of Scientific and Technical Information of China (English)

    DONG Hanwu; OUYANG Liuzhang; SUN Tai; ZHU Min

    2008-01-01

    Hydrogen storage and microstructure of ball milled Mg3La alloy were investigated by X-ray diffraction and pressure-composition-isotherm measurement. The ball milled Mg3La alloy could absorb hydrogen up to 4wt.% at 300 °C for the first time, along with a decomposing course. Following tests showed that the average reversible hydrogen storage capacity was 2.7wt.%. The enthalpy and entropy of dehydrogenation reaction of the decomposed ball milled Mg3La and hydrogen were calculated. XRD patterns indicated the existence of MgH2 and LaH3 in the decomposed hydride and the formation of Mg when hydrogen was desorbed. After the first hydrogenation, all the latter hydrogenation/dehydrogenation reactions could be taken place between Mg and MgH2. The ball milled Mg3La alloy exhibited better hydriding kinetics than that of the as-cast Mg3La alloy at room temperature. The kinetic curve could be well fitted by Avrami-Erofeev equation.

  2. Synthesis of FeTi hydrogen storage material via ball milling: effect of milling energy and atmosphere.

    OpenAIRE

    Livramento, Vanessa; Rangel, C. M.; Correia, J. Brito; Shohoji, Nobumitsu; R.A. Silva

    2008-01-01

    Attempts were made earlier to synthesize and activate the FeTi intermetallic during ball milling (BM), for H2 storage using sodium boron tetra-hydride (NaBH4) additive as a process controlling agent. Simple reactive milling starting from Fe and Ti powders resulted in heavy agglomeration of powders, due to the self sustaining nature of the reaction following an incubation period. When NaBH4 was used as the process control agent to avoid agglomeration, this resulted in the production of titaniu...

  3. Synthesis of aluminum nitride powders from a plasma-assisted ball milled precursor through carbothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Zhi-jie [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Dai, Le-yang [Marine Engineering Institute, Jimei University, Xiamen 361021 (China); Yang, De-zheng; Wang, Sen [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Zhang, Bao-jian [Marine Engineering Institute, Jimei University, Xiamen 361021 (China); Wang, Wen-chun, E-mail: wangwenc@dlut.edu.cn [Key Lab of Materials Modification (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Cheng, Tie-han [Pinggao Group Co. Ltd., State Grid Corporation of China, Pingdingshan 467000 (China)

    2015-01-15

    Highlights: • A novel and high efficiency synthesizing AlN powders method combining mechanical ball milling and DBDP has been developed. • The particle size, the crystallite size, the lattice distortion, the morphology of Al{sub 2}O{sub 3} powders, and the AlN conversion rate are investigated and compared under the ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP. • The ball milled Al{sub 2}O{sub 3} powders with DBDP have small spherical structure morphology with very fine particles size and high specific surface area, which result in a higher chemical efficiency and a higher AlN conversion rate at lower thermal temperature. - Abstract: In this paper, aluminum nitride (AlN) powers have been produced with a novel and high efficiency method by thermal annealing at 1100–1600 °C of alumina (Al{sub 2}O{sub 3}) powders which were previously ball milled for various time up to 40 h with and without the assistant of dielectric barrier discharge plasma (DBDP). The ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP and the corresponding synthesized AlN powers are characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. From the characteristics of the ball milled Al{sub 2}O{sub 3} powders with DBDP and without DBDP, it can be seen that the ball milled Al{sub 2}O{sub 3} powders with DBDP have small spherical structure morphology with very fine particles size and high specific surface area, which result in a higher chemical efficiency and a higher AlN conversion rate at lower thermal temperature. Meanwhile, the synthesized AlN powders can be known as hexagonal AlN with fine crystal morphology and irregular lump-like structure, and have uniform distribution with the average particle size of about between 500 nm and 1000 nm. This provides an important method for fabricating ultra fine powders and synthesizing nitrogen compounds.

  4. Effect of ball milling energy on rheological and thermal properties of amaranth flour.

    Science.gov (United States)

    Roa, Diego F; Baeza, Rosa I; Tolaba, Marcela P

    2015-12-01

    Pearled amaranth grains obtained by abrasive milling were processed by planetary ball milling to produce amaranth flours. The influence of milling energy on rheological and thermal behavior of amaranth flour dispersions and stability during 24 h storage at 4 °C were investigated based on a factorial design. The rheological behavior of flour dispersions (4 % and 8 % w/v) was determined using a rotational viscometer, while gelatinization degree was determined by differential scanning calorimetry as a measure of structural changes.The power law model was found to be suitable in expressing the relationship between shear stress and shear rate. Flour dispersions showed a pseudoplastic behavior. However this character decreased with the storage being dependent on flour concentration and milling energy. A decrease of the consistency index and an increase of the flow behavior index were observed as a result of the increasing milling energy. Gelatinization enthalpy decrease showed the loss of crystalline structure due to ball milling. Amaranth flour dispersions presented increasing stability during storage. It was observed, that the stability changed with the concentration of amaranth flours.Thus, more stable dispersions were obtained as the flour concentration increased. The highly milled sample was the most stable sample during the storage.

  5. Structural transition and softening in Al–Fe intermetallic compounds induced by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Basariya, M. Raviathul, E-mail: ravia80@gmail.com [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India); Roy, Rajat K.; Pramanick, A.K.; Srivastava, V.C. [CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Mukhopadhyay, N.K. [Department of Metallurgical Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India)

    2015-06-25

    In the present investigation, powders of as-cast ingots of Al–25 at%Fe and Al–34.5 at%Fe alloys close to Al{sub 3}Fe and Al{sub 2}Fe intermetallic phases are subjected to high energy ball milling to understand the possibility of formation of amorphous and/or nanocrystalline phases or any other metastable phases. The development of microstructure, evolution of various metastable phases and their stability are investigated by x-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. Mechanical milling of the alloys, up to 50 h, was carried out in high energy planetary ball mill. It resulted in phase transformation from monoclinic and triclinic structures of Al{sub 3}Fe and Al{sub 2}Fe, respectively, to orthorhombic structure pertaining to Al{sub 5}Fe{sub 2} phase and structural transformation from crystalline to amorphous phase. Hardness measurements revealed a transition from hardening to softening behavior in these mechanically milled alloys undergoing prolonged milling. The softening effect in the milled powders, having a composite structure involving nanocrystalline and amorphous phases, is attributed to the competing phenomenon of grain size reduction and amorphous phase formation with increasing milling time.

  6. Onset of chaotic dynamics in a ball mill: Attractors merging and crisis induced intermittency

    Science.gov (United States)

    Manai, G.; Delogu, F.; Rustici, M.

    2002-09-01

    In mechanical treatment carried out by ball milling, powder particles are subjected to repeated high-energy mechanical loads which induce heavy plastic deformations together with fracturing and cold-welding events. Owing to the continuous defect accumulation and interface renewal, both structural and chemical transformations occur. The nature and the rate of such transformations have been shown to depend on variables, such as impact velocity and collision frequency that depend, in turn, on the whole dynamics of the system. The characterization of the ball dynamics under different impact conditions is then to be considered a necessary step in order to gain a satisfactory control of the experimental set up. In this paper we investigate the motion of a ball in a milling device. Since the ball motion is governed by impulsive forces acting during each collision, no analytical expression for the complete ball trajectory can be obtained. In addition, mechanical systems exhibiting impacts are strongly nonlinear due to sudden changes of velocities at the instant of impact. Many different types of periodic and chaotic impact motions exist indeed even for simple systems with external periodic excitation forces. We present results of the analysis on the ball trajectory, obtained from a suitable numerical model, under growing degree of impact elasticity. A route to high dimensional chaos is obtained. Crisis and attractors merging are also found.

  7. 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.

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

    Science.gov (United States)

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

    2012-01-01

    We have studied the microstructure and the magnetoresistivity of polycrystalline YBa2Cu3Oy (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 Y2O3, Ba2CO3 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, Tco, 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.

  9. Microwave absorption properties of FeSi flaky particles prepared via a ball-milling process

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chao [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yuan, Yong [Precision Machinery Research Institute of Shanghai Space Flight Academy, Shanghai 201600 (China); Jiang, Jian-tang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Gong, Yuan-xun [Aerospace Research Institute of Special Material and Processing Technology, Beijing 100074 (China); Zhen, Liang, E-mail: lzhen@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); MOE Key Laboratory of Micro-system and Micro-structures Manufacturing, Harbin Institute of Technology, Harbin 150080 (China)

    2015-12-01

    Flaky FeSi alloy particles with different aspect ratio were produced via ball-milling and a subsequent annealing. The microstructure and the morphology of the particles were examined by XRD and SEM. The dc resistivity, the static magnetization properties and electromagnetic properties were measured. Particles with high aspect ratio were found possess high permittivity and permeability. On the other hand, the variation of grain size and defects density was found influence the permittivity and permeability. High specific area was believed contribute to the intense dielectric loss and the high shape magnetic anisotropy lead to high permeability in the target band. Increased electromagnetic parameters compel the absorption peak’s shift to lower frequency. Coating using flaky FeSi particles milled for 12 h as fillers presented a reflection loss of −10 dB at 2 GHz and a matching thickness of 1.88 mm. The flaky FeSi alloy particles prepared through ball-milling and annealing can be promising candidates for EMA application at 1–4 GHz band. - Highlights: • Large quantity of flakey FeSi particles were produced through a simple way. • Coatings with as-milled FeSi particles exhibit excellent EMA performance in L-S band. • Shape and size of particles can be controlled via adjusting the ball-milling time. • Shape/size along with the microstructure influence the electromagnetic properties. • Shape/size contribute more to the excellent EMA performance compared to microstructure.

  10. Modeling High-Energy Ball Milling in the Alumina-Yttria System

    Science.gov (United States)

    Alkebro, J.; Bégin-Colin, S.; Mocellin, A.; Warren, R.

    2002-02-01

    Experimental results from high-energy ball milling of alumina-yttria powder mixtures have been analyzed with models collected from the literature. Depending on the milling conditions, either there is formation of an intermediate phase in the alumina-yttria system (yttrium aluminum perovskite, YAP), or the sample becomes mostly amorphous. Variations due to milling tool material can be accounted for by local models based on the Hertzian theory of elastic bodies, but the effects of changing mills are poorly accounted for by published models. Therefore, the concept of an impact frequency distribution over the energy spectrum is introduced as a tool for studying the characteristics of the mills. The pressure on the powder trapped between two colliding bodies has been found to be the factor deciding the outcome of the process. The threshold behavior of the system yields an amorphous structure for low pressures, and formation of YAP when impact pressures exceed the threshold value.

  11. Phase transformation of nanocrystalline anatase powders during high energy planetary ball milling

    Institute of Scientific and Technical Information of China (English)

    潘晓燕; 陈怡; 马学鸣; 朱丽慧

    2003-01-01

    The microstructure evolution of nanocrystalline anatase during high energy planetary milling was studied by X-ray diffraction and transmission electron microscopy. The results show that mechanical activation induces the transformations from anatase to srilankite and rutile at room temperature and under ambient pressure, which should primarily be attributed to the rise of local temperature and pressure at the collision sites of the powders and the balls. In addition, the additional energy caused by defects, lattice distortion and the refinement of the crystallite is responsible for the transformations. As milling time increases, anatase phase content reduces and the amounts of both srilankite and rutile phase increase. And the transformation from srilankite to rutile phase takes place by further milling. In anatase phase, the crystallite size decreases and lattice strain rises with milling time. There is no indication of the formation of amorphous phase during milling.

  12. Magnesium-based nanocomposites synthesized by high-energy ball milling for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, H.; Nakatomi, S.; Tanaka, K.; Hashimoto, Y.; Sakata, Y. [Yamaguchi Univ., Tokiwadai (Japan)

    2010-07-01

    Nanocrystalline MgH{sub 2} obtained by ball milling with cyclohexane or benzene showed excellent properties for hydrogen storage. 1 at% Al-added nanocrystalline magnesium samples obtained by milling of MgH{sub 2} with solutions of Al(C{sub 2}H{sub 5}){sub 3} in benzene showed the reversible hydrogen absorption/desorption cycles even at 0.1 MPa of hydrogen. Moreover, the hydrogen storage properties of magnesium hydride were markedly improved upon nanocomposite formation by ball milling of MgH{sub 2} with Sn or SiC. For MgH{sub 2}/Sn and MgH{sub 2}/SiC nanocomposites, the dissociation temperature at 0.1 MPa of hydrogen was raised, compared to that for MgH{sub 2}. (orig.)

  13. Electromagnetic properties of Co flaky particles prepared via ball-milling method

    Science.gov (United States)

    Liu, Chao; Jiang, Jian-Tang; Yuan, Yong; Gong, Yuan-Xun; Zhen, Liang

    2016-10-01

    Flaky cobalt particles with different aspect ratio were produced with ball-milling method. The phase structure and morphology of the particles were identified by XRD analysis and SEM observation. The static magnetic and electromagnetic properties of the particles were measured and effects of shape, microstructure and filling fraction were investigated. Phase transition from fcc lattice to hcp lattice occur due to the drive of ball-milling is responsible for the largely increased coercivity. Particles with high aspect ratio are found to possess high permittivity and permeability, compelling the frequency of absorption peak to shift to low frequency. Coatings using cobalt particles milled for 20 h as fillers present a RL peak of -33 dB at 8 GHz at the thickness of 2.5 mm together with a broad effective absorbing (RL below -10 dB) bandwidth covering 6-10 GHz.

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

    Directory of Open Access Journals (Sweden)

    Yong Luo

    2016-10-01

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

  15. Magnetic properties of ball-milled TbFe2 and TbFe2B

    Indian Academy of Sciences (India)

    J Arout Chelvane; S Kasiviswanathan; M V Rao; G Markandeyulu

    2004-04-01

    The magnetic properties of ball-milled TbFe2 and TbFe2B were studied by magnetization measurements. X-ray diffraction studies on TbFe2B showed that boron occupied interstitial position in the crystal structure, just as hydrogen did. The value of the saturation magnetization of TbFe2B was found to be smaller than that of TbFe2. This is explained on the basis of a charge transfer between the boron atoms and the 3d band of Fe. The anisotropy of TbFe2B was found to be large compared to that of TbFe2. X-ray diffractograms for the ball milled samples showed that after 80 h of milling, a predominantly amorphous phase was obtained. TbFe2B was found to undergo easy amorphization compared to TbFe2. Magnetization of TbFe2 was found to decrease rapidly with initial milling hours and was found to be constant with further hours of milling. TbFe2B exhibited an anomalous behaviour with an increase in moment with milling hours and this may be due to the segregation of -Fe.

  16. Ball Mill Synthesis of Bulk Quaternary Cu2ZnSnSe4 and Thermoelectric Studies

    Science.gov (United States)

    Tiwari, Kunal J.; Prem Kumar, D. S.; Mallik, Ramesh Chandra; Malar, P.

    2017-01-01

    In this work, quaternary chalcogenide Cu2ZnSnSe4 (CZTSe) was synthesized using a mechanochemical ball milling process and its thermoelectric properties were studied by electrical resistivity, Seebeck coefficient, and thermal conductivity measurements. The synthesis process comprises three steps viz., wet ball milling of the elemental precursors, vacuum annealing, and densification by hot pressing. The purpose of this is to evaluate the feasibility of introducing wet milling in place of vacuum melting in solid state synthesis for the reaction of starting elements. We report the structural characterization and thermoelectric studies conducted on samples that were milled at 300 rpm and 500 rpm. X-ray diffraction (XRD) analysis showed the existence of multiple phases in the as-milled samples, indicating the requirement for heat treatment. Therefore, the ball milled powders were cold pressed and vacuum annealed to eliminate the secondary phases. Annealed samples were hot pressed and made into dense pellets for further investigations. In addition to XRD, energy dispersive spectroscopy (EDS) studies were performed on hot pressed samples to study the composition. XRD and EDS studies confirm CZTSe phase formation along with ZnSe secondary phase. Electrical resistivity and Seebeck coefficient measurements were done on the hot pressed samples in the temperature range 340-670 K to understand the thermoelectric behaviour. Thermal conductivity was calculated from the specific heat capacity and thermal diffusivity values. The thermoelectric figure of merit zT values for samples milled at 300 rpm and 500 rpm are ˜0.15 and ˜0.16, respectively, at 630 K, which is in good agreement with the values reported for solid state synthesized compounds.

  17. Following mechanical activation of salbutamol sulphate during ball-milling with isothermal calorimetry.

    Science.gov (United States)

    Gaisford, Simon; Dennison, Mansa; Tawfik, Mahmoud; Jones, Matthew D

    2010-06-30

    Formulation of actives for pulmonary delivery with dry powder inhaler devices frequently requires a particle size reduction step. The high-energy forces imparted to a material during milling, as well as reducing particle size, can cause a significant change in physicochemical properties, in particular mechanical activation of the surface (manifested as generation of amorphous regions) which can affect formulated product performance. It is not clear whether particle size reduction occurs prior to, or concomitantly with, generation of amorphous content. In this study the formation of amorphous content with time in crystalline salbutamol sulphate was quantified with isothermal gas perfusion calorimetry as the sample was ball-milled. The data showed that the most particle size reduction occurred initially (d(0.5) dropping from 12.83+/-0.4 to 4.2+/-0.4 within 5 min). During this time period, no detectable amorphous content was observed. Between 5 and 15 min milling time the particle size distribution remained relatively constant but the amorphous content increased non-linearly with time. After 20 min milling time the particle size increased slightly. The data suggest that particle size reduction occurs initially upon application of a force to the crystal. Once maximum particle size reduction has occurred the crystal absorbs the force being applied and the crystal lattice becomes disordered. After extended milling the conditions in the ball mill (heat and/or humidity) may cause crystallisation of some of the amorphous material resulting in particle-particle fusion. It would appear that the ball-milling process could be optimised to achieve the desired particle size distribution but without any loss of crystalline structure.

  18. Effect of ball milling on properties of porous Ti–7.5Mo alloy for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC (China); Chang, Tien-Yu [Department of Mechanical and Automation Engineering, Da-Yeh University, Changhua, Taiwan, ROC (China); Ho, Wen-Fu, E-mail: fujii@mail.dyu.edu.tw [Advanced Materials and BioMaterials Lab, Department of Materials Science and Engineering, Da-Yeh University, Changhua, Taiwan, ROC (China)

    2014-01-05

    Highlights: • Porous Ti–7.5Mo was successfully prepared through a space-holder sintering method. • The mechanical properties of porous Ti–7.5Mo are comparable to those of natural bone. • Porous Ti–7.5Mo exhibited better apatite-forming abilities after surface treatment. • The inner surfaces of porous specimens exhibited better apatite-inducing ability. -- Abstract: Porous titanium has been used to anchor implants through bone growth into the porous structure. This bone ingrowth provides a strong implant/bone bond, and the pores may be interconnected three-dimensionally to provide enough space for the attachment and proliferation of new bone tissues and to facilitate the transport of body fluids. In the present study, porous scaffolds fabricated from three kinds of ball-milled Ti–7.5Mo alloy particles were successfully prepared through a space-holder sintering method, and the compressive strengths and moduli of all the sintered porous Ti–7.5Mo conform to the basic mechanical property requirement of cancellous bones. However, the porous Ti–7.5Mo fabricated from particles ball milled for 15 h (TM15) possesses a relatively higher strength. Moreover, the elastic modulus of TM15 is 1.72 GPa, which is comparable to that reported for cancellous bone. Furthermore, the porous TM15 alloy exhibited better apatite-forming abilities after pretreatment (with NaOH or NaOH + water) and subsequent immersion in simulated body fluid (SBF) at 37 °C. After soaking in a SBF solution for 21 days, a dense apatite layer covered the inner and outer surfaces of the pretreated porous TM15 substrates, thereby providing favorable bioactive conditions for bone bonding and growth.

  19. APPLICATION OF SIMPLIFIED METHOD FOR DETERMINING THE WI TO PREDICT THE PERFORMANCE OF BALLS MILLS IN SOSSEGO PLANT

    Directory of Open Access Journals (Sweden)

    Vladmir Kronemberger Alves

    2013-12-01

    Full Text Available Over the years Vale S.A. has developed a methodology for scaling industrial comminution circuit that is being constantly improved and implemented in developing new routes and process optimization of circuits in operation. This work will be given a focus on the methodology of simplified balls mill Work Index (WI Anaconda in performance prediction of Sossego Plant ball mill. The great advantage of this methodology is to reduce the time and weight to determine the energy consumption in ball mills, whose values can be used in studies of variability, geometallurgy and design and control of industrial grinding circuits.

  20. Atomic scale study of ball milled Ni-Fe2O3 using Mössbauer spectroscopy

    Science.gov (United States)

    Yadav, Ravi Kumar; Govindaraj, R.; Vinod, K.; Kumar, P. A. Manoj; Amarendra, G.

    2016-05-01

    Evolution of hyperfine fields at Fe atoms has been studied in a detailed manner in a mixture of Ni and α-Fe2O3 subjected to high energy ball milling using Mossbauer spectroscopy. Mossbauer results indicate the dispersion of α-Fe2O3 particles in Ni matrix in the as ball milled condition. Evolution of α-Fe2O3 due to ball milling, reduction of the valence of associated Fe and possible interaction between the oxide particles with Ni in the matrix due to annealing treatments has been elucidated in the present study.

  1. Magnetic property and microstructure of single crystalline Nd2Fe14B ultrafine particles ball milled from HDDR powders

    Energy Technology Data Exchange (ETDEWEB)

    Li, WF; Hu, XC; Cui, BZ; Yang, JB; Han, JZ; Hadjipanayis, GC

    2013-08-01

    In this work we report the microstructure and magnetic property of single crystalline Nd2Fe14B ultrafine particles ball milled from HDDR Nd-Fe-B alloys. The average size of the particles is 283 nm, and TEM observation reveals that these particles are single crystalline. The coercivity of these particles is 6.0 kOe, which is much higher than that of the particles ball milled from sintered and hot pressed Nd-Fe-B magnets. Micromagnetic analysis shows that the coercivity degradation is caused by surface damage during ball milling. (C) 2013 Elsevier B.V. All rights reserved.

  2. Effect of ball-milling on the physicochemical properties of maize starch

    Directory of Open Access Journals (Sweden)

    Shenghua He

    2014-09-01

    Full Text Available The effect of ball-milling on physicochemical properties of maize starch was evaluated. Results found that the cold water solubility (CWS of maize starch was positively correlated with the time of milling up to 3 h. There was no significant influence of using a ceramic pot versus a stainless steel pot on CWS. However, following 5 h of ball-milling CWS increased quite dramatically in the ceramic pot (72.6% and in the stainless steel pot (70.7%, as compared to the untreated maize starches (2.9%. In addition, as CWS increased, the regions of amorphism enlarged at the expense of the crystalline regions, resulting in a change from the native starch state (oval with a smooth surface to having more of a rough, abrasive surface. Finally, the transparency of the starch increased as CWS increased and that the syneresis of freeze–thawed ball-milled maize starch also increased with an increase in the number of freeze–thaw cycles.

  3. 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

  4. Microstructure and Physical Properties of Tb2TiO5 Neutron Absorber Synthesized by Ball Milling and Sintering

    Science.gov (United States)

    Huang, Jinghua; Ran, Guang; Liu, Tengjiao; Shen, Qiang; Li, Ning

    2016-10-01

    Tb2TiO5 neutron absorber was synthesized by ball milling and sintering. Microstructure character of ball-milled Tb4O7-17.605%TiO2 (mass fraction, %) powders and sintered bulks was analyzed using XRD, SEM and TEM. The microhardness, coefficient of thermal expansion and thermal conductivity of sintered bulks were measured. The experiment results showed that the nanocrystalline solid solution was obtained during ball milling. After 96 h of ball milling, TiO2 was completely solved in Tb4O7 and the crystal size of Tb4O7 was up to 37 nm. The bulk materials prepared by cold isostatic pressing were sintered at 1300 °C. Tb2TiO5 bulks with an orthorhombic structure were obtained. The microhardness of sintered bulks, as well as the thermal conductivity, increased firstly with increasing ball milling time and then decreased. The coefficient of thermal expansion decreased initially and then increased with increasing ball milling time. For the sintered bulk with powder milled for 48 h, the highest values of both microhardness and thermal conductivity were observed, whereas the lowest coefficient of thermal expansion was exhibited. In addition, with increasing testing temperature, the thermal conductivity of sintered bulks initially fell and then rebounded while an opposite trend was found in the coefficient of thermal expansion.

  5. Hydrogen Sorption Properties of the Intermetallic Mg2Ni Obtained by Using a Simoloyer Ball Milling

    Directory of Open Access Journals (Sweden)

    Bormann R.

    2010-07-01

    Full Text Available Intermetallic Mg2Ni was produced from elemental powder blends by mechanical alloying in a batch scale using a rotary horizontal mill (Simoloyer. Fast hydrogenation kinetics are obtained: 2.2 wt.% of hydrogen is absorbed within 10 minutes at 300 °C. Hydrogen sorption kinetics were further improved by adding Pd (1 mol% powder as a catalyst during ball milling. Crack formation and concomitant particle size reduction was observed by scanning electron microscopy after hydrogen cycling, which is attributed to internal stresses in the particles.

  6. Sintered Fe-Ni-Cu-Sn-C Alloys Made of Ball-Milled Powders

    Directory of Open Access Journals (Sweden)

    Romański A.

    2014-10-01

    Full Text Available The main objective of this paper was to perform sinterability studies of ball-milled Fe-12%Ni-6.4%Cu-1.6%Sn-0.6%C powders. A mixture of precisely weighed amounts of elemental iron, nickel and graphite, and pre-alloyed 80/20 bronze powders was ball-milled for 8, 30 and 120 hours. After cold-pressing at 400 MPa the specimens were sintered at 900oC for 30 minutes in a reducing atmosphere and subsequently tested for density and hardness as well as subjected to structural studies using scanning electron microscopy (SEM and X-ray diffraction (XRD analysis.

  7. 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......(upsilon) almost-equal-to 0.25. The effect is ascribed to the production of single-domain magnetic grains. Mossbauer spectroscopy reveals the presence of iron oxide phases which could not be seen by x-ray and electron diffraction measurements....

  8. Excess lithium storage in LiFePO4-Carbon interface by ball-milling

    Science.gov (United States)

    Guo, Hua; Song, Xiaohe; Zheng, Jiaxin; Pan, Feng

    2016-07-01

    As one of the most popular cathode materials for high power lithium ion batteries (LIBs) of the electrical-vehicle (EV), lithium iron phosphate (LiFePO4 (LFP)) is limited to its relatively lower theoretical specific capacity of 170mAh g-1. To break the limits and further improve the capacity of LFP is promising but challenging. In this study, the ball-milling method is applied to the mixture of LFP and carbon, and the effective capacity larger than the theoretical one by 30mAh g-1 is achieved. It is demonstrated that ball-milling leads to the LFP-Carbon interface to store the excess Li-ions.

  9. Synthesis and characterization of ball milled Fe-doped ZnO diluted magnetic semiconductor

    Institute of Scientific and Technical Information of China (English)

    R. Elilarassi; G. Chandrasekaran

    2012-01-01

    Fe-doped ZnO (Zn0.99Fe0.01O) powders are successfully prepared by ball milling with different milling time,and are investigated using X-ray diffraction (XRD),scanning electron microscope (SEM),ultraviolet-visible (UV-VIS) spectroscopy,vibrating sample magnetometer (VSM) and electron paramagnetic resonance (EPR) spectroscopy.The structural analysis using XRD reveals that the Fe-doped ZnO milled at different milling time can crystallize in a wurtzite structure,and in the XRD patterns,the secondary phase related to Fe cluster with the sensitivity of the XRD instrument can not be found.The SEM image of the sample milled for 24 h shows the presence of spherical nanoparticles.From the optical analysis,the optical band gap is found to decrease with increasing the milling time,which indicates the incorporation of Fe2+ ions into the ZnO lattice.The magnetization measurement using VSM reveals that the nanoparticles exhibit ferromagnetic behavior at room temperature,and the magnetization increases gradually with increasing the milling time.The conclusion is further confirmed by the electron paramagnetic resonance of the nanoparticles examined at room temperature,which shows an intense and broad ferromagnetic resonance signal related to Fe ions.

  10. Fabrication and microstructure of nanostructured Mg-3Ni-2MnO_2 by ball milling in hydrogen atmosphere

    Institute of Scientific and Technical Information of China (English)

    FANG Wen-bin; FANG Wa; SUN Hong-fei; YU Zhen-xing

    2009-01-01

    Nanostructured Mg-3Ni-2MnO_2 was synthesized by ball milling elemental powders of Mg, Ni and MnO_2 in hydrogen atmosphere. The microstructures of the powder prepared at different milling time were analyzed by X-ray diffractometry(XRD), scanning electron microscopy(SEM) and high resolution electron microscopy(HREM). The milling time is the most key parameter impacting on the grain size and the microstructure of material. With prolonging the milling time, particle size becomes smaller and smaller. But after the ball milling time reaches about 20 h, reduction of grain size becomes slowly. When the milling time is more than 50 h, nanocrystailine fully forms. When the milling time is more than 80 h, there are more amorphous phases in materials. The average particle diameter of material is about 1 μm and the grain size is 10-30 nm.

  11. High-performance ball-milled SiOx anodes for lithium ion batteries

    Science.gov (United States)

    Zhang, Junying; Zhang, Chunqian; Liu, Zhi; Zheng, Jun; Zuo, Yuhua; Xue, Chunlai; Li, Chuanbo; Cheng, Buwen

    2017-01-01

    High-performance SiOx was scalable synthesized by means of simple high-energy ball-milling method, and used as anode materials for lithium ion batteries. The electrochemical performance of SiOx electrode after high-energy ball-milling is improved effectively compared to raw SiOx. That is benefit for the reduced size of SiOx powder. By changing the species of conductive agents, improved cyclic performance and excellent rate capability were achieved. Under galvanostatic mode with current density of 0.3 A/g, SiOx electrode after high-energy ball-milling with optimized conductive agents delivers a reversible capacity of 1416.8 mAh/g with coulombic efficiency as high as 99.8% and capacity retention of 83.6% (1184.8 mAh/g) even after 100 cycles. The approach is simple and can be adopted for large scale production of high performance SiOx anode materials.

  12. Preparation of MgTiO3 Ceramics by High Energy Ball Milling

    Institute of Scientific and Technical Information of China (English)

    TAO Zhendong; ZHANG Ying; YANG Zhongxi; WANG Yingzi; MENG Shanshan; TENG Tieli

    2006-01-01

    MgTiO3 precursor was mechanochemically synthesized by high-energy ball milling of MgO and TiO2. The sintering characteristic of the resulted MgTiO3 precursor was investigated. The experimental results indicate that particles of both MgO and TiO2 powders become smaller rapidly, and then the crystalline structures of MgO and TiO2 change significantly. MgTiO3 was observed by XRD after 30 hours of ball milling. Strong diffraction peaks of MgTiO3 were observed after 50 hours of ball milling. HRTEM observation proves that dense MgTiO3 ceramics with a compact crystalline structure can be sintered from mechanochemically activated MgTiO3 precursor, the volume density of the resulting ceramic is as high as 95% of the theoretical density, the porosity and average pore diameter of the ceramic are measured as 4.95% and 50 nm respectively, and the transverse strength exceeded 500 MPa.

  13. Application of mechano-chemical synthesis for protective coating on steel grinding media prior to ball milling of copper

    Indian Academy of Sciences (India)

    Indranil Lahiri; K Balasubramanian

    2007-04-01

    One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for prevention of Fe contamination.

  14. Processing and microstructural characterization of a Ti-Cr-Nb alloy synthesized by high-energy ball-milling

    Directory of Open Access Journals (Sweden)

    José Fernando Ribeiro de Castro

    2012-10-01

    Full Text Available Ti-based body centered cubic (BCC solid solutions are promising materials for hydrogen storage. These alloys are usually synthesized by melting processes and have large amounts of vanadium as alloying element to stabilize the BCC phase at room temperature. In this work high energy ball-milling was evaluated as processing route for a Ti - based BCC solid solution. Moreover, the feasibility of Nb as stabilizer for the BCC phase is also investigated. The results show that the BCC phase is rapidly formed by ball-milling. After 2 hours of milling the alloy is mainly composed by BCC phase. Moreover, the time of milling must be limited in order to minimize the contamination with iron promoted by the wearing of milling balls and vials.

  15. Homogeneous nanoparticle dispersion prepared with impurity-free dispersant by the ball mill technique

    Institute of Scientific and Technical Information of China (English)

    Lingyun Zhou; Hui Zhang; Hui Zhang; Zhong Zhang

    2013-01-01

    The homogeneous dispersion of nanoparticles in solvents or polymer matrices is essential tor prac tical application of nanocomposites.In this study,the planetary ball milling technique was used to de-agglomerate silica nanoparticles in butyl acetate.The size of the nanosilica aggregates was evaluated by TEM and SEM.With the addition of polyacrylate polymer to the organic solvent,the nanoparticle agglomerates were effectively broken up by planetary ball milling at the proper milling time; however,re-agglomeration occurred after a longer milling time.The results of TGA and FTIR indicated that the polyacrylate molecules could be adsorbed in situ onto the nanoparticles.Behaving similar to a dispersant,the adsorbed polyacrylate reduced the blend viscosity significantly and prevented re-agglomeration of the nanoparticles.Utilizing the polyacrylate polymer both as the dispersant and the polymer matrix,the polyacrylate-based nanocoatings were further prepared.The optical transmittance and haze value of the nanocoatings were found to be sensitive to the dispersion level of the nanoparticles,and the elastic modulus and hardness of the nanocoatings were improved in comparison with those of the neat polymer coating.

  16. Ultrasound pretreatment for enhanced biogas production from olive mill wastewater.

    Science.gov (United States)

    Oz, Nilgun Ayman; Uzun, Alev Cagla

    2015-01-01

    This study investigates applicability of low frequency ultrasound technology to olive mill wastewaters (OMWs) as a pretreatment step prior to anaerobic batch reactors to improve biogas production and methane yield. OMWs originating from three phase processes are characterized with high organic content and complex nature. The treatment of the wastewater is problematic and alternative treatment options should be investigated. In the first part of the study, OMW samples were subjected to ultrasound at a frequency of 20kHz with applied powers varying between 50 and 100W under temperature controlled conditions for different time periods in order to determine the most effective sonication conditions. The level of organic matter solubilization at ultrasound experiments was assessed by calculating the ratio of soluble chemical oxygen demand/total chemical oxygen demand (SCOD/TCOD). The results revealed that the optimum ultrasonic condition for diluted OMW is 20kHz, 0.4W/mL for 10min. The application of ultrasound to OMW increased SCOD/TCOD ratio from 0.59 to 0.79. Statistical analysis (Friedman's tests) show that ultrasound was significantly effective on diluted OMW (p0.05). For raw OMW, this increase has been found to be limited due to high concentration of suspended solids (SS). In the second part of the study, biogas and methane production rates of anaerobic batch reactor fed with the ultrasound pretreated OMW samples were compared with the results of control reactor fed with untreated OMW in order to determine the effect of sonication. A nonparametric statistical procedure, Mann-Whitney U test, was used to compare biogas and methane production from anaerobic batch reactors for control and ultrasound pretreated samples. Results showed that application of low frequency ultrasound to OMW significantly improved both biogas and methane production in anaerobic batch reactor fed with the wastewater (preactor fed with ultrasound pretreated diluted OMW produced approximately 20

  17. Structural, microstructural and magnetocaloric investigations in high-energy ball milled NiMnGa powders

    Science.gov (United States)

    de Santanna, Y. V. B.; de Melo, M. A. C.; Santos, I. A.; Coelho, A. A.; Gama, S.; Cótica, L. F.

    2008-11-01

    In this paper, structural, microstrucutural and magnetocaloric properties of Ni 2.18Mn 0.82Ga alloys submitted to high-energy ball milling are reported. A 7-layered orthorhombic martensitic ( Pnnm) phase was detected in post-milling annealed samples, which reached a microstrucuture composed predominantly by nanograins. The magnetocaloric effect is strongly weakened in comparison with as-cast samples of similar composition. This effect can be attributed to the absence of the mesoscale twin-related martensitic variants in the nanostructurated powders. However, post-milled samples annealed at 1123 K for 4 h present relative cooling powers as high as those observed for manganites. Therefore, these materials can be considered as potential candidates for use as regenerators in prototypal magnetic refrigerators.

  18. 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.

  19. HRTEM and Nanoindentation Studies of Bulk WC Nanocrystalline Materials Prepared by Spark Plasma Sintering of Ball-Milled Powders

    Science.gov (United States)

    Sherif El-Eskandarany, M.; Al-Hazza, Abdulsalam; Al-Hajji, L. A.

    2017-01-01

    In the present work, mechanical milling technique using a high-energy ball mill was employed for preparing of nanoscaled WC grains powders with an average grain size of 7 nm in diameters of WC. The present study demonstrates a successful consolidation process achieved at 1250 °C for sintering of ball-milled WC powders into full dense bulk buttons (above 99.6%), using SPS technique. The as-consolidated WC bulk nanocrystalline buttons revealed high hardness value ( 24 GPa) with low elastic modulus ( 332 GPa). Moreover, they possessed a high fracture toughness (15 MPa m1/2) that has never been reported for pure WC.

  20. Formation of a 25 mol% Fe2O3-Al2O3 solid solution prepared by ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Mørup, Steen; Linderoth, Søren

    1996-01-01

    The phase transformation process of a 25 mol% Fe2O3-Al2O3 powder mixture during high-energy ball milling has been studied by x-ray diffraction and Mossbauer spectroscopy. A metastable solid solution of 25 mol % Fe2O3 in Al2O3 with corundum structure has successfully been prepared after a milling...... time of 122 h. This demonstrates that the high-energy ball milling technique is able to prepare metastable solid solutions with an extended range of compositions in ceramic/ceramic systems with a positive hear of mixing....

  1. Strong textured SmCo5 nanoflakes with ultrahigh coercivity prepared by multistep (three steps) surfactant-assisted ball milling

    Science.gov (United States)

    Zuo, Wen-Liang; Zhao, Xin; Xiong, Jie-Fu; Zhang, Ming; Zhao, Tong-Yun; Hu, Feng-Xia; Sun, Ji-Rong; Shen, Bao-Gen

    2015-08-01

    The high coercivity of 26.2 kOe for SmCo5 nanoflakes are obtained by multistep (three steps) surfactant-assisted ball milling. The magnetic properties, phase structure and morphology are studied by VSM, XRD and SEM, respectively. The results demonstrate that the three step ball-milling can keep more complete crystallinity (relatively less defects) during the process of milling compared with one step high energy ball-milling, which enhances the texture degree and coercivity. In addition, the mechanism of coercivity are also studied by the temperature dependence of demagnetization curves for aligned SmCo5 nanoflakes/resin composite, the result indicates that the magnetization reversal could be controlled by co-existed mechanisms of pinning and nucleation.

  2. Magnetic and Magnetocaloric Properties of High-Energy Ball-Milled Nanocrystalline CeMn2Ge2 Compound

    Science.gov (United States)

    Kaya, Melike; Dincer, Ilker; Akturk, Selcuk; Elerman, Yalcin

    2016-10-01

    CeMn2Ge2 nanopowders have been obtained by high-energy ball milling for 5 and 10 hours from bulk compound to investigate the effect of milling time on magnetic and magnetocaloric properties. CeMn2Ge2 nanopowders have been characterized by X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, and magnetization measurements. The average grain size of the nanoparticles from XRD measurements is about 12.2 and 8 nm for 5-hour and 10-hour ball-milled samples, respectively. The investigations reveal that magnetic entropy change (∆ S m) can be altered by changing the particle size of the compound. Maximum ∆ S m is -2.45 and -1.30 J kg-1 K-1 for the 5- and 10-hour ball-milled nanopowders, respectively.

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

    Science.gov (United States)

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

    2012-05-01

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

  4. Microstructural Characterization of Calcite-Based Powder Materials Prepared by Planetary Ball Milling

    Directory of Open Access Journals (Sweden)

    Wen-Tien Tsai

    2013-08-01

    Full Text Available In this work, a planetary ball milling was used to modify the surface properties of calcite-based material from waste oyster shell under the rotational speed of 200–600 rpm, grinding time of 5–180 min and sample mass of 1–10 g. The milling significantly changed the microstructural properties of the calcite-based minerals (i.e., surface area, pore volume, true density, and porosity. The surface characterization of the resulting powder should be macroporous and/or nonporous based on the nitrogen adsorption/desorption isotherms. Under the optimal conditions at the rotational speed of 400 rpm, grinding time of 30 min and sample mass of 5 g, the resulting calcite-based powder had larger specific surface area (i.e., 10.64 m2·g−1 than the starting material (i.e., 4.05 m2·g−1. This finding was also consistent with the measurement of laser-diffraction (i.e., 9.7 vs. 15.0 μm of mean diameter. In addition, the results from the scanning electron microscope (SEM observation indicated that surface roughness can be enhanced as particle size decreases as a result of particle-particle attrition. Thus, grinding the aquacultural bioresource by a high-energy ball milling can create the fine materials, which may be applied in the fields of inorganic minerals like aggregate and construction material.

  5. Synthesis and Characterizations of Nanocrystalline WC-Co Composite Powders by a Unique Ball Milling Process

    Institute of Scientific and Technical Information of China (English)

    Jun SHEN; Jianfei SUN; Faming ZHANG

    2004-01-01

    In order to explore the high efficiency of fabricating nanocrystalline WC-Co composite powders, this paper presented a unique high energy ball milling process with variable rotation rate and repeatious circulation, by which nanocrystalline WC-10Co0.8VC-0.2Cr3C2 (wt pct) composite powders with mean grain size of 25 nm were prepared in 32 min, and the quantity of the powders for a batch was as much as 800 grams. The as-prepared powders were analyzed and characterized by chemical analysis,X-ray diffraction (XRD), transmission electron microscopy (TEM) and differential thermal analysis (DTA). The results show that high energy ball milling with variable rotation rates and repeatious circulation could be used to produce nanocrystalline WC-Co powder composites with high efficiency. The compositions of the powders meet its specifications with low impurity content. The mean grain size decreases, lattice distortion and system energy increase with increasing the milling time. The morphology of nanocrystalline WC-Co particles displays dominantly sphere shape and their particle sizes are all lower than 80nm. The eutectic temperature of the nanocrystalline WC-10Co-0.8VC-0.2Cr3C2 composites is about 1280℃.

  6. Pretreatment of Palm Oil Mill Effluent (POME Using Magnetic Chitosan

    Directory of Open Access Journals (Sweden)

    N. Saifuddin

    2011-01-01

    Full Text Available Chitosan is a natural organic polyelectrolyte of high molecular weight and charge density; obtained from deacetylation of chitin. This study explored the potential and effectiveness of applying chitosan-magnetite nanocomposite particles as a primary coagulant and flocculent, in comparison with chitosan for pre-treatment of palm oil mill effluent (POME. A series of batch coagulation processes with chitosan-magnetite nanocomposite particles and chitosan under different conditions, i.e. dosage and pH were conducted, in order to determine their optimum conditions. The performance was assessed in terms of turbidity, total suspended solids (TSS and chemical oxygen demand (COD reductions. Chitosan-magnetite particles showed better parameter reductions with much lower dosage consumption, compared to chitosan, even at the original pH of POME, i.e. 4.5. At pH 6, the optimum chitosan-magnetite dosage of 250 mg/L was able to reduce turbidity, TSS and COD levels by 98.8%, 97.6% and 62.5% respectively. At this pH, the coagulation of POME by chitosan-magnetite was brought by the combination of charge neutralization and polymer bridging mechanism. On the other hand, chitosan seems to require much higher dosage, i.e. 370 mg/L to achieve the best turbidity, TSS and COD reductions, which were 97.7%, 91.7% and 42.70%, respectively. The synergistic effect of cationic character of both the chitosan amino group and the magnetite ion in the pre-treatment process for POME brings about enhanced performance for effective agglomeration, adsorption and coagulation.

  7. Tuning the length dispersion of multi-walled carbon nanotubes by ball milling

    Directory of Open Access Journals (Sweden)

    László Forró

    2013-09-01

    Full Text Available The statistical analysis of the length distribution of catalytic chemical vapour deposition synthesized multi-walled carbon nanotubes cut by planetary ball milling is reported. The nanotube lengths follow a log-normal distribution in a broad range of grinding time and rotational speed. We show that the scale parameter of the distribution, which equals the mean of the natural logarithm of the tube lengths, decreases linearly with the product of the duration time and the rotational speed. This relation can be used for tailoring nanotube lengths by a suitable choice of process parameters for a wide range of applications.

  8. 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.

  9. Bulk Al/SiC nanocomposite prepared by ball milling and hot pressing method

    Institute of Scientific and Technical Information of China (English)

    GU Wan-li

    2006-01-01

    Nano-sized Al/SiC powders were prepared by mechanical alloying method. Two sorts of SiC particle,i.e.,nano-sized and popular micron-sized SiC were utilized. The particle size and microstructure of the milled powder were characterised. Effects of the particle size and agglomerate state of SiC,as well as the microstructure of Al/SiC nanocomposite were studied by SEM and TEM. The results show that nano-sized SiC particles is dispersed in aluminium uniformly after ball milled for only 2 h,whereas the similar process need about 10 h for popular micron-sized SiC particle. The bulk Al/SiC nanocomposite can be fabricated by hot pressing the nano-sized Al/SiC powders at temperature about 723 K under pressure of 100 MPa.

  10. 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)

  11. Metastable phase transitions in Mo-Si and V-Si systems activated by high energy ball milling

    Institute of Scientific and Technical Information of China (English)

    柳林

    2002-01-01

    Mechanical alloying of Mo-Si (Mo33Si67) and V-Si (V75Si25) powder mixtures was activated by high energy ball milling at ambient temperature. The metastable phase transitions in both systems during milling were investigated by X-ray diffraction, scanning and transmission electron microscopy. It is found that the alloying processes are closely related to the milling conditions. As far as the Mo-Si system is concerned, ball milling leads to the formation of both α-MoSi2 (room temperature phase) and β-MoSi2 (high temperature phase), but lower energy milling favors the formation of β phase, while higher energy milling promotes the formation of α phase. In addition, if the milling energy is high enough, the Mo/Si reaction is governed by a self-propagating high temperature process. On the other hand, two different pathways of phase transition in the V-Si system were also identified depending on the milling intensity, i.e. weak milling leads to amorphous transition, whereas intensive milling causes the formation of V3Si and V5Si3 intermetallic compounds. Finally, the thermodynamics and kinetics related to the different phase transitions in the two systems were discussed.

  12. 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)

  13. 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.

  14. Structural Investigations of Nanocrystalline Cu-Cr-Mo Alloy Prepared by High-Energy Ball Milling

    Science.gov (United States)

    Kumar, Avanish; Pradhan, Sunil Kumar; Jayasankar, Kalidoss; Debata, Mayadhar; Sharma, Rajendra Kumar; Mandal, Animesh

    2017-02-01

    Cu-Cr-Mo alloy could be a suitable candidate material for collector electrodes in high-power microwave tube devices. An attempt has been made to synthesize ternary Cu-Cr-Mo alloys by mechanical alloying of elemental Cu, Cr, and Mo powders, to extend the solid solubility of Cr and Mo in Cu, using a commercial planetary ball mill. For the first ternary alloy, a mixture of 80 wt.% Cu, 10 wt.% Cr, and 10 wt.% Mo was mechanically milled for 50 h. For the second ternary alloy, a mixture of 50 wt.% Cr and 50 wt.% Mo was mechanically milled for 50 h to obtain nanocrystalline Cr(Mo) alloy, which was later added to Cu powder and milled for 40 h to obtain Cu-20 wt.%Cr(Mo) alloy. Both nanocrystalline Cu-Cr-Mo ternary alloys exhibited crystallite size below 20 nm. It was concluded that, with addition of nanocrystalline Cr(Mo) to Cu, it was possible to extend the solid solubility of Cr and Mo in Cu, which otherwise was not possible by mechanical alloying of elemental powders. The resulting microstructure of the Cu-20 wt.%Cr(Mo) alloy comprised a homogeneous distribution of fine and hard (Cr, Mo) particles in a copper matrix. Furthermore, Cu-20 wt.%Cr(Mo) alloy showed better densification compared with Cu-10 wt.%Cr-10 wt.%Mo alloy.

  15. Ultrafine Sm-Fe-N Particles Prepared by Planetary Ball Milling

    Directory of Open Access Journals (Sweden)

    Neil D.

    2013-01-01

    Full Text Available Ultrafine magnetically hard particles are needed for the bottom­up fabrication of anisotropic exchanged­coupled permanent magnets. In this study we have chosen Sm2Fe17Nx because of its high anisotropy field and large saturation magnetization. A multi­stage planetary ball milling process was used. The key is to find the right balance of energy used to mill the precursor particles; it must be high enough to break the particles and reduce their size but, not so high as to destroy the crystal structure of the nanoparticles that would lead to deterioration of the magnetic properties. First the coarse powders were subjected to a wet milling with 2.0 mm diameter media. In each subsequent stage the media size was reduced to maintain the milling balance. Using such a process produced particles in a size range from 100 - 800 nm with a coercivity as high as 10 kOe at room temperature.

  16. Characterization and Magnetic Properties of Nickel Ferrite Nanoparticles Prepared by Ball Milling Technique

    Institute of Scientific and Technical Information of China (English)

    G.Nabiyouni; M.Jafari Fesharaki; M.Mozafari; J.Amighian

    2010-01-01

    @@ Nickel ferrite nanoparicles with various grain sizes are synthesized using annealing treatment followed by ball milling of its bulk component materials.Commercially available nickel and iron oxide powders are first mixed,and then annealed at 1100℃ in an oxygen environment furnace and for 3h.The samples are then milled for different times in an SPEX mill.X-ray diffraction pattern indicates that in this stage the sample is single phase.The average grain size is estimated by scanning electron microscopy(SEM)and x-ray diffraction techniques.Magnetic behavior of the sample at room temperature is studied using a superconducting quantum interference device(SQUID).The Curie temperature of the powders is measured by an LCR meter unit.The x-ray diffraction patterns clearly indicate that increasing the milling time leads to a decrease in the grain size and consequently leads to a decrease in the saturation magnetization as well as the Curie temperatures.This result is attributed to the spin-glass-like surface layer on the nanocrystalline nickel ferrite with a ferrimagnetically aligned core.

  17. TEM and HRTEM studies of ball milled 6061 aluminium alloy powder with Zr addition.

    Science.gov (United States)

    Lityńska-Dobrzyńska, L; Dutkiewicz, J; Maziarz, W; Rogal, Ł

    2010-03-01

    The effect of mechanical alloying on the microstructure of atomized 6061 aluminium alloy powder and 6061 powder with a zirconium addition was studied in the work. The atomized 6061 aluminium alloy powder and 6061 powder with addition of 2 wt.% Zr were milled in a planetary ball mill and investigated using X-ray diffraction measurements, conventional and high-resolution electron microscopy (TEM/HRTEM) and high-angle annular dark field scanning transmission electron microscopy combined with energy dispersive X-ray microanalysis. An increase of stresses was observed in milled powders after the refinement of crystallites beyond 100 nm. In the powder with zirconium addition, some part of the Zr atoms diffused in aluminium forming a solid solution containing up to 0.5 wt.% Zr. The remaining was found to form Zr-rich particles containing up to 88 wt.% Zr and were identified as face centred cubic (fcc) phase with lattice constant a= 0.48 nm. That fcc phase partially transformed into the L1(2) ordered phase. Eighty-hour milling brought an increase of microhardness (measured with Vickers method) from about 50 HV (168 MPa) for the initial 6061 powder to about 170 HV (552 MPa). The addition of zirconium had no influence on the microhardness.

  18. Synthesis of Cu(In,Ga)Se{sub 2} crystals using a crank ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Suzuka; Noji, Hideki; Akaki, Yoji [Miyakonojo National College of Technology, 473-1 Yoshio, Miyakonojo Miyazaki 885-8567 (Japan); Okamoto, Tomoichiro [Nagaoka University of Technology, 1603-1 Kamitomioka, Nagaoka, Niigata 940-2188 (Japan)

    2015-06-15

    Cu(In,Ga)Se{sub 2} (CIGS) crystals were synthesized by a mechanochemical (MC) process using a crank ball mill. The molar ratios of starting materials were Cu:In:Ga:Se=1:1-x:x:2 (0≤x≤1) and Cu:In:Ga:Se=1:0.7:0.3:y (2≤y≤3). The reaction time reduced with decreasing Se and Ga molar ratios. The collection rate decreased with longer reaction times. From XRD patterns, we confirmed that the CuInSe{sub 2} and/or CuGaSe{sub 2}crystals were successfully grown when the powders reacted. Although the crystals grown with a selenium molar ration of 2 were Se-poor, those grown at a molar ratio of 3 were Se-rich. When Se increasing molar ratio, Cu, In, and Ga were away from the stoichiometric. With a molar ratio of Cu:In:Ga:Se=1:0.7:0.3:2.5∝2.7, their composition became stoichiometric. Crystal morphology was varied. CIGS crystals were thus successfully synthesized using a crank ball mill. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Electromagnetic properties of flake-shaped Fe–Si alloy particles prepared by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Lei [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Jiang, Jian-Tang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Wang, Zeng-Quan [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Gong, Yuan-Xun [Department of Physics, Harbin Institute of Technology, Harbin 150001 (China); Aerospace Research Institute of Special Material and Processing Technology, Beijing 100074 (China); Liu, Chao [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhen, Liang, E-mail: lzhen@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); MOE Key Laboratory of Micro-system and Micro-structures Manufacturing, Harbin Institute of Technology, Harbin 150080 (China)

    2014-11-15

    Flake-shaped Fe–Si alloy particles with high aspect ratios were fabricated by ball milling commercially available Fe–Si powder, aiming to fabricate high-performance microwave absorbing fillers for coatings applied in 1–4 GHz range. To compare with spherical particles, higher permittivity and permeability was observed by using flaky particles as fillers. High aspect ratios contributed to an enhanced dielectric relaxation in the 1–4 GHz band, resulting in an increased permittivity. The thin thickness together with the high resistivity of Fe–Si flakes was believed to be helpful for suppressing the effect of eddy current and thus lead to an increase in the permeability. The electromagnetic wave absorbing (EMA) performances were observed to be enhanced. With a thin thickness of 2 mm, a wide absorption band with a minimum reflection loss of −12 dB was achieved in 1–4 GHz range, when using 75 wt% of flaky Fe–Si particles as fillers. The study indicated that flake-shaped Fe–Si particles were a promising candidate for EMA materials in L and S bands. - Highlights: • Flaky Fe–Si alloy particles were prepared in large scale via a simple ball milling method. • Coatings containing flakes Fe–Si particles present excellent EMA performance in L–S band. • The high shape anisotropy and the thin thickness contribute to the excellent EM property.

  20. Experimental Investigation into the Effect of Ball End Milling Parameters on Surface Integrity of Inconel 718

    Science.gov (United States)

    Bhopale, Nandkumar N.; Joshi, Suhas S.; Pawade, Raju S.

    2015-02-01

    In machining of Inconel 718, various difficulties such as increased tool wear and poor machined surface quality are frequently encountered due to its high temperature strength and poor thermal properties. This work considers the effect of number of passes and the machining environment on the machined surface quality in ball end milling of Inconel 718, which hitherto has not been adequately understood. To this effect, extensive experimentation has been carried out to analyze machined surface quality and integrity in terms of surface roughness, surface damage, and microhardness variation in the machined surfaces. The machined surfaces show formation of distinct bands as a function of instantaneous machining parameters along the periphery of cutting tool edge. A distinct variation is also observed in the measured values of surface roughness and microhardness in these regions. The minimum surface roughness is obtained in the stable cutting zone and it increases toward the periphery of the cutter on band #2 and band #3. Microhardness of depth beneath the machined surface shows that the machining affected zone varies from 60 to 100 µm in ball end milling under various machining conditions.

  1. Hydrogen generation by the hydrolysis reaction of ball-milled aluminium-lithium alloys

    Science.gov (United States)

    Chen, Xingyu; Zhao, Zhongwei; Liu, Xuheng; Hao, Mingming; Chen, Ailiang; Tang, Zhongyang

    2014-05-01

    The addition of Li can prevent an inert alumina film from forming on the surface of Al alloy particles, allowing the rapid hydrogen generation of Al alloys to be achieved. However, because the Li content is less than 10%, the hydrogen generation rate and hydrogen yield of Al-Li alloys are significantly decreased. In this work, NaCl is introduced to prepare Al-Li alloys with low Li contents by ball milling. The research results show that by increasing the amount of NaCl added, the ball milling time and Li content can effectively improve the hydrogen generation of the alloys. Under optimal preparation conditions, the ultimate hydrogen yield of Al-Li alloys can reach 100%. The initial water temperature has almost no effect on the generation of hydrogen, even at 0 °C. Ca2+ and Mg2+ can combine with OH- to form the insoluble compounds Ca(OH)2 and Mg(OH)2, which can prevent hydrogen generation. NO3- reacts with Al to form ammonia and reduce the hydrogen yield of the alloys. Therefore, Al-Li alloys should be prevented from reacting with water containing Ca2+, Mg2+ and NO3-. Al-Li alloys must be stored in isolation from air to maintain good hydrogen-generation performances.

  2. Electrochemical properties of LiFePO{sub 4} prepared via ball-milling

    Energy Technology Data Exchange (ETDEWEB)

    Fey, George Ting-Kuo; Chen, Yun Geng [Department of Chemical and Materials Engineering, National Central University, Chung-Li 32054 Taiwan (China); Kao, Hsien-Ming [Department of Chemistry, National Central University, Chung-Li 32054 Taiwan (China)

    2009-04-01

    LiFePO{sub 4} cathode materials with distinct particle sizes were prepared by a planetary ball-milling method. The effects of particle size on the morphology, thermal stability and electrochemical performance of LiFePO{sub 4} cathode materials were investigated. The ball-milling method decreased particle size, thereby reducing the length of diffusion and improving the reversibility of the lithium ion intercalation/deintercalation. It is worth noting that the small particle sample prepared using malonic acid as a carbon source achieved a high capacity of 161 mAh g{sup -1} at a 0.1 C rate and had a very flat capacity curve during the early 50 cycles. However, the big particle samples ({proportional_to}400 nm) decayed more dramatically in capacity than the small particle size samples ({proportional_to}200 nm) at high current densities. The improvement in electrode performance was mainly due to the fine particles, the small size distribution, and the increase in electronic conductivity as a result of carbon coating. The structure and morphology of the ground LiFePO{sub 4} samples were characterized with XRD, FE-SEM, TEM, EDS, and DSC techniques. (author)

  3. Ball mill assisted rapid mechanochemical extraction method for natural products from plants.

    Science.gov (United States)

    Wang, Man; Bi, Wentao; Huang, Xiaohua; Chen, David Da Yong

    2016-06-03

    A ball mill assisted mechanochemical extraction method was developed to extract compounds of natural product (NP) from plant using ionic liquid (IL). A small volume ball mill, also known as PastPrep(®) Homogenizer, which is often used for high-speed lysis of biological samples and for other applications, was used to dramatically increase the speed, completeness and reproducibility of the extraction process at room temperature to preserve the chemical integrity of the extracted compounds. In this study, tanshinones were selected as target compounds to evaluate the performance of this extraction method. Factors affecting the extraction efficiency, such as the duration, IL concentration and solid/liquid ratio were systematically optimized using the response surface methodology. Under the optimized conditions, the described method was more efficient and much faster than the conventional extraction methods such as methanol based ultrasound assisted extraction (UAE) and heat reflux extraction (HRE) that consumes a lot more organic solvent. In addition, the natural products of interest were enriched by anion metathesis of ionic liquids, combining extraction and preconcentration in the same process. The extractant was analyzed by HPLC and LC-MS. The reproducibility (RSD, n=5), correlation coefficient (r(2)) of the calibration curve, and the limit of detection, were determined to be in the range of 4.7-5.2%, 0.9992-0.9995, and 20-51ng/mL, respectively.

  4. Effect of ball to powder ratio on the ZrO{sub 2} phase transformations during milling

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, M.; Razavi, M., E-mail: m-razavi@merc.ac.ir; Rahimipour, M.R.; Jamal Abbasi, B.

    2014-07-01

    Effect of milling time and ball to powder weight ratio (BPR) were investigated on the phase transformation of monoclinic zirconia during high energy ball milling. Degree of phase transformation was studied by X-ray diffraction (XRD) and quantitative phase analysis (Rietveld refinement). Morphology and microstructure were monitored by scanning and transmission electron microscopy, respectively. Higher milling time and BPR led to the more transformation, smaller mean grain size and larger strain. There was approximately 80% tetragonal zirconia in the 80 h milled powder with the BPR 25:1. A nanostructure powder with the mean grain size less than 10 nm was obtained in both BPRs that were in consistence with TEM images. Stress and strain inducing in the lattice of m-ZrO{sub 2} was proposed as the main mechanism of its transformation.

  5. Influence of emulsifiers on the optimization of processing parameters of refining milk chocolate in the ball mill

    OpenAIRE

    Pajin Biljana; Zarić Danica; Dokić Ljubica; Šereš Zita; Šoronja-Simović Dragana; Omorjan Radovan; Lončarević Ivana

    2011-01-01

    Chocolate manufacture is a complex process which includes a large number of technology operations. One of the obligatory phases is milling, called refining, which aims at obtaining the appropriate distribution of particle size, resulting in the chocolate with optimal physical and sensory characteristics. The aim of this work was to define and optimize the process parameters for the production of milk chocolate by a non-conventional procedure, using the ball mill. The quality of chocolat...

  6. Surfactant Removal Study for Nano-Scale SmCo5 Powder Prepared by High Energy Ball Milling (Postprint)

    Science.gov (United States)

    2014-04-01

    DD-MM-YY) 2. REPORT TYPE 3. DATES COVERED (From - To) April 2014 Interim 19 March 2014 – 31 March 2014 4. TITLE AND SUBTITLE SURFACTANT ...thickness of 300 nm were prepared by high energy ball milling using valeric acid as a surfactant . In order to remove the surfactant the as-milled...investigated. Partial (58%) and nearly complete (96%) surfactant removal was observed by DSC after treatments at 200°C and 400°C, respectively, without oxide

  7. Crystal Structure and Hydrogen Storage Behaviors of Mg/MoS2 Composites from Ball Milling

    Institute of Scientific and Technical Information of China (English)

    HAN Zongying; ZHOU Shixue; WANG Naifei; ZHANG Qianqian; ZHANG Tonghuan; RAN Weixian

    2016-01-01

    The Mg/MoS2 composites were prepared by ball milling under argon atmosphere, and the effect of MoS2 on the crystal structure and hydrogen storage properties of Mg was investigated. It is found that 10 wt% of MoS2 is sufifcient to prevent particle aggregation and cold welding during the milling process. The crystallite size of Mg will remain constant at slightly less than 38.8 nm with the milling process due to the size conifnement effect of MoS2. The dehydrogenation temperature of MgH2 is reduced to 390.4-429.4℃ due to the crystallite size reduction. Through iftting by Johnson-Mehl-Avrami model, it is found that Mg crystal grows by three dimension controlled by interface transformation during the process of MgH2 decomposition. MoS2 has a weak catalyst effect on the decomposition of MgH2 and activation energy of 148.9 kJ/mol is needed for the dehydrogenation process calculated by the Arrhenius equation.

  8. 酶解-球磨法制备微细化淀粉的性质研究%Properties of micronized starch prepared by amylase hydrolysis and ball milling

    Institute of Scientific and Technical Information of China (English)

    吴国利; 扶雄; 黄强; 刘莎

    2011-01-01

    Native starch mashing with the traditional ball milling method takes much time and energy consumption,and the product is easily being gelatinized. In this paper, micronized starch was prepared by partially hydrolysis with amylase and then micronized with ball milling. The properties of the micronized starch were compared with native corn starch and ball milling starch. The results showed that the particle size of ball milling starch was slightly larger than that of native corn starch (12. 90 pm) ;While the particle size of amylase hydrolysis and ball milling pretreated starch was reduced significantly,and the crystalline structure was partially destroyed,part of the maltese cross lost, the intensity of birefringence weakened and crystal-linity reduced significantly.%传统微细化小颗粒淀粉的制备采用原淀粉直接球磨的方法,耗时长,能耗高,产物易糊化.采用先酶解再球磨的新工艺制备微细化小颗粒淀粉,并与玉米原淀粉、原淀粉球磨淀粉的性质进行比较.结果表明:玉米原淀粉的表面积平均粒径为12.90 μm,原淀粉球磨淀粉的表面积平均粒径略有增大,而酶解-球磨淀粉的表面积平均粒径显著降低;酶解-球磨淀粉的结晶结构受到一定程度的破坏,部分偏光十字消失,双折射强度减弱,结晶度显著降低.

  9. Comparative Study by MS and XRD of Fe{sub 50}Al{sub 50} Alloys Produced by Mechanical Alloying, Using Different Ball Mills

    Energy Technology Data Exchange (ETDEWEB)

    Rojas Martinez, Y., E-mail: yarojas@ut.edu.co [University of Tolima, Department of Physics (Colombia); Perez Alcazar, G. A. [University of Valle, Department of Physics (Colombia); Bustos Rodriguez, H.; Oyola Lozano, D., E-mail: doyolalozano@yahoo.com.mx [University of Tolima, Department of Physics (Colombia)

    2005-02-15

    In this work we report a comparative study of the magnetic and structural properties of Fe{sub 50}Al{sub 50} alloys produced by mechanical alloying using two different planetary ball mills with the same ball mass to powder mass relation. The Fe{sub 50}Al{sub 50} sample milled during 48 h using the Fritsch planetary ball mill pulverisette 5 and balls of 20 mm, presents only a bcc alloy phase with a majority of paramagnetic sites, whereas that sample milled during the same time using the Fritsch planetary ball mill pulverisette 7 with balls of 15 mm, presents a bcc alloy phase with paramagnetic site (doublet) and a majority of ferromagnetic sites which include pure Fe. However for 72 h of milling this sample presents a bcc paramagnetic phase, very similar to that prepared with the first system during 48 h. These results show that the conditions used in the first ball mill equipment make more efficient the milling process.

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

    Science.gov (United States)

    Scott, Spencer M.; Yao, Tiankai; Lu, Fengyuan; Xin, Guoqing; Zhu, Weiguang; Lian, Jie

    2017-03-01

    High-energy ball milling was used to synthesize Th1-xLaxO2-0.5x (x = 0.09, 0.23) solid solutions, as well as improve the sinterability of ThO2 powders. Dense La-doped ThO2 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 ThO2 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.

  11. Study of effect of planetary ball milling on ZnO nanopowder synthesized by co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, K.P., E-mail: kiranshinde_phy@yahoo.co.in [Superconductivity Research Centre, Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of); Pawar, R.C. [Department of Materials Engineering, Hanyang University, Ansan 426-791 (Korea, Republic of); Sinha, B.B. [Nano Functional Materials Research Group, Department of Powder Materials, Korea Institute of Material Science, Changwon 641-831 (Korea, Republic of); Kim, H.S.; Oh, S.S. [Superconductivity Research Centre, Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of); Chung, K.C. [Nano Functional Materials Research Group, Department of Powder Materials, Korea Institute of Material Science, Changwon 641-831 (Korea, Republic of)

    2014-12-25

    Highlights: • Synthesis of ZnO nanopowder by co-precipitation method. • Particle size reduction using planetary ball milling. • PL spectra shows shifting towards higher wavelength with decrease in intensity. • The bandgap energy (E{sub g}) of ZnO powders varied from 3.13 to 2.85 eV. - Abstract: Nanocrystalline ZnO powders have been synthesized by co-precipitation method and investigated planetary ball milling effects on structural and optical properties. These powders were characterized using X-ray diffraction, field emission scanning electronic microscope, Infrared spectrophotometer, UV–vis spectrophotometer and Photoluminescence. It was found that prepared ZnO powders have hexagonal close packed structure which was annealed at 500 °C for 30 min. The bandgap energy of ZnO powders varied from 3.13 to 2.85 eV. The room temperature PL spectra exhibits low intensity UV emission peak at 383 nm and green emission band around 520 nm shows shifting towards higher wavelength with decrease in intensity of peak with time of planetary ball milling. Hence, it was observed that planetary ball milling can be used to tailor the optoelectronic properties of ZnO nanostructures.

  12. 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 ...

  13. Enhancement of the initial hydrogenation of Mg by ball milling with alkali metal amides MNH2 (M = Li or Na).

    Science.gov (United States)

    Chu, Hailiang; Qiu, Shujun; Sun, Lixian; Huot, Jacques

    2015-10-14

    The introduction of 4 wt% of MNH2 (M = Li, Na) and other additives (Li, MgH2, NaCl, and NaBr) into pure Mg by ball milling greatly enhances the first hydrogenation (activation). Under 2 MPa of H2 at 608 K, the best activation performance is achieved with the NaNH2 additive.

  14. Reaction between LiBH4 and MgH2 induced by high-energy ball milling

    Science.gov (United States)

    Ding, Zhao; Zhao, Xuzhe; Shaw, Leon L.

    2015-10-01

    Previous studies of ab initio density functional theory (DFT) calculations have predicted that reactions between LiBH4 and MgH2 can take place at temperature near 200 °C. However, such predictions have been shown to be inconsistent with many experiments. Herein, we have designed a novel process termed as ball milling with aerosol spraying (BMAS) to prove, for the first time, that the reaction between LiBH4 and MgH2 can indeed occur during ball milling at room temperature. Through this BMAS process we have demonstrated unambiguously the formation of MgB2 and LiH during ball milling of MgH2 while aerosol spraying of the LiBH4/THF solution. In this BMAS process, aerosol spraying of the LiBH4/THF solution leads to the formation of LiBH4 nanoparticles which decompose to form Li2B12H12. The Li2B12H12 formed then reacts with MgH2 in situ during ball milling to form MgB2 and LiH. The discovery made in this study has significant implications in making LiBH4 + MgH2 as a viable system for reversible hydrogen storage applications near ambient temperature in the future.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

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

  16. Particle fracture and plastic deformation in vanadium pentoxide powders induced by high energy vibrational ball-mill

    Indian Academy of Sciences (India)

    Partha Chatterjee; S P Sen Gupta; Suchitra Sen

    2001-04-01

    An X-ray powder profile analysis in vanadium pentoxide powder milled in a high energy vibrational ball-mill for different lengths of time (0–250 h), is presented. The strain and size induced broadening of the Bragg reflection for two different crystallographic directions ([001] and [100]) was determined by Warren–Averbach analysis using a pattern-decomposition method assuming a Pseudo–Voigt function. The deformation process caused a decrease in the crystallite size and a saturation of crystallite size of ∼ 10 nm was reached after severe milling. The initial stages of milling indicated a propensity of size-broadening due to fracture of the powder particles caused by repeated ball-to-powder impact whereas with increasing milling time microstrain broadening was predominant. WA analysis indicated significant plastic strain along with spatial confinement of the internal strain fields in the crystallite interfaces. Significant strain anisotropy was noticed in the different crystallographic directions. A near-isotropy in the crystallite size value was noticed for materials milled for 200 h and beyond. The column-length distribution function obtained from the size Fourier coefficients progressively narrowed down with the milling time.

  17. Microwave Absorption Properties of Iron Nanoparticles Prepared by Ball-Milling

    Science.gov (United States)

    Chu, Xuan T. A.; Ta, Bach N.; Ngo, Le T. H.; Do, Manh H.; Nguyen, Phuc X.; Nam, Dao N. H.

    2016-05-01

    A nanopowder of iron was prepared using a high-energy ball milling method, which is capable of producing nanoparticles at a reasonably larger scale compared to conventional chemical methods. Analyses using x-ray diffraction and magnetic measurements indicate that the iron nanoparticles are a single phase of a body-centered cubic structure and have quite stable magnetic characteristics in the air. The iron nanoparticles were then mixed with paraffin and pressed into flat square plates for free-space microwave transmission and reflection measurements in the 4-8 GHz range. Without an Al backing plate, the Fe nanoparticles seem to only weakly absorb microwave radiation. The reflected signal S 11 drops to zero and a very large negative value of reflection loss ( RL) are observed for Al-backed samples, suggesting the existence of a phase matching resonance near frequency f ˜ 6 GHz.

  18. Solvent-free ball-milling subcomponent synthesis of metallosupramolecular complexes.

    Science.gov (United States)

    Giri, Chandan; Sahoo, Prasit Kumar; Puttreddy, Rakesh; Rissanen, Kari; Mal, Prasenjit

    2015-04-20

    Subcomponent self-assembly from components A, B, C, D, and Fe(2+) under solvent-free conditions by self-sorting leads to the construction of three structurally different metallosupramolecular iron(II) complexes. Under carefully selected ball-milling conditions, tetranuclear [Fe4 (AD2 )6 ](4-) 22-component cage 1, dinuclear [Fe2 (BD2 )3 ](2-) 11-component helicate 2, and 5-component mononuclear [Fe(CD3 )](2+) complex 3 were prepared simultaneously in a one-pot reaction from 38 components. Through subcomponent substitution reaction by adding subcomponent B, the [Fe4 (AD2 )6 ](4-) cage converts quantitatively to the [Fe2 (BD2 )3 ](2-) helicate, which, in turn, upon addition of subcomponent C, transforms to [Fe(CD3 )](2+) , following the hierarchical preference based on the thermodynamic stability of the complexes.

  19. Structural study of ball-milled sodium alanate under high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Selva Vennila, R. [Center for Study of Matter at Extreme Conditions, Florida International University, Miami, FL 33199 (United States)], E-mail: selva.raju@fiu.edu; Drozd, Vadym; George, Lyci; Saxena, Surendra K. [Center for Study of Matter at Extreme Conditions, Florida International University, Miami, FL 33199 (United States); Liermann, Hanns-Peter [High Pressure Collaboration Access Team (HPCAT) and Geophysical Laboratory, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Liu, H.Z. [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Building 434E, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); Stowe, Ashley C.; Berseth, Polly; Anton, Donald; Zidan, Ragaiy [Savannah River National Laboratory, Energy Security Department, Aiken, SC 29808 (United States)

    2009-04-03

    Ball-milled NaAlH{sub 4} was studied up to 15 GPa in a diamond anvil cell (DAC) by X-ray diffraction using a synchrotron radiation source. Lattice parameters were determined from the X-ray diffraction data at various pressures up to 6.5 GPa. Intensity of the powder diffraction patterns decreased with increasing pressure. Amorphisation started at a pressure of {approx}6.5 GPa and completed at 13.5 GPa. Reversible phase transformation from amorphous phase to the tetragonal phase was observed. A fit to the pressure-volume data equation of state was obtained using the Birch-Murnaghan equation of state and the bulk modulus was found to be 52.16 {+-} 0.9 GPa which is twice higher than the unmilled NaAlH{sub 4}.

  20. 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.

  1. ELECTROMAGNETIC MICROWAVE PROPERTIES OF Fe82B17Cu1 BALL MILLED ALLOY

    Science.gov (United States)

    Tian, N.; Fan, X. D.; Wang, J. W.; You, C. Y.; Lu, Z. X.; Ge, L. L.

    2013-07-01

    High saturation magnetization and magnetic anisotropy are helpful for getting a high frequency electromagnetic microwave absorption performance. The α-Fe possesses a high saturation magnetization. Fe-B phases exhibit a relatively higher magnetic anisotropy and higher resistivity than α-Fe simultaneously. In this work, we made nanocrystalline powders of Fe82B17Cu1, mainly consisting of α-Fe and Fe2B phases, by ball milling and post-annealing. Electromagnetic microwave characterization shows that Fe82B17Cu1 powders possess a relative high permeability and considerable permittivity. Due to a good electromagnetic impedance matching, a good electromagnetic microwave absorption property (RL < -35 dB) has been achieved at 3.6 GHz. The experimental frequency and the matching thickness are coincident with the quarter wavelength matching condition.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shengnan, E-mail: snzhang@c-nin.com [Northwest Institute for Non-Ferrous Metal Research, 710016, Xi' an (China); Liu, Jixing [Northwest Institute for Non-Ferrous Metal Research, 710016, Xi' an (China); School of Materials and Metallurgical, Northeast University, Shenyang, 110016 (China); Feng, Jianqing; Wang, Yao; Ma, Xiaobo; Li, Chengshan; Zhang, Pingxiang [Northwest Institute for Non-Ferrous Metal Research, 710016, Xi' an (China)

    2015-08-01

    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{sub 2} and Fe{sub 7}Se{sub 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.

  3. Microstructural evolution during high energy ball milling of Fe2O3-SiO2 powders

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Zhou, Y.X.; Mørup, Steen;

    1996-01-01

    The reaction of a 25 mol% Fe2O3-SiO2 (hematite-amorphous silica) powder mixture during high energy ball milling in both closed and open containers has been studied by x-ray diffraction and Mossbauer spectroscopy. After around 21 h of milling, the alpha-Fe2O3 powders with an average particle size...... of 15 nm have formed and no reaction between alpha-Fe2O3 and SiO2 is found in the two types of milling containers. This demonstrates that the high energy mechanical milling technique is able to prepare a dispersion of ultrafine alpha-Fe2O3 particles. After extended milling in the open container all iron...

  4. 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.

  5. Curie temperature and magnetic properties of aluminum doped barium ferrite particles prepared by ball mill method

    Science.gov (United States)

    Chen, Daming; Harward, Ian; Baptist, Joshua; Goldman, Sara; Celinski, Zbigniew

    2015-12-01

    Barium ferrite has attracted considerable interest in the fields of permanent magnets and perpendicular magnetic recording due to its strong uniaxial anisotropy and high Curie temperature (Tc). We prepared aluminum doped barium ferrite ceramics (BaAlxFe12-xO19, 0≤x≤6) by the ball mill method. The powder was milled for 96 h, and after forming pellets, annealed for 48 h in air at 1000 °C. The X-ray diffraction (XRD) data show that there are only single hexagonal phases in the samples without any impurity phase. The crystal lattice constants, a and c, were calculated by Cohen's method. Both a and c decrease with increasing x, ranging from 0.588 nm and 2.318 nm to 0.573 nm and 2.294 nm, respectively. A Vibrating Sample Magnetometer (VSM) and Superconducting Quantum Interference Device (SQUID) were used to investigate Tc and magnetic properties of BaFe12-xAlxO19. It is found that Tc decreases with increasing x, from 425 °C to 298 °C. It is also found that the saturated magnetization (4πMs) decreases with increasing x, while the coercivity (Hc) increases with the increase in x. The anisotropy field was also determined from the SQUID measurement.

  6. Preparation of lithium ferrite nanoparticles by high energy ball milling and characterizations

    Directory of Open Access Journals (Sweden)

    J. Touthang

    2016-11-01

    Full Text Available Ferrites are ferrimagnetic ceramic materials with inherent useful electromagnetic properties. Of them, spinelstructured ferrites are promising materials for microwave device applications; stress/torsion sensors and energy storage applications like anode materials in lithium batteries, fuel cells, solar cells etc. Nanostructured spinels further have high and wide scope of potential applications. In the present study, two different types of varied sized ferrimagnetic lithium ferrite spinel nanoparticles prepared using chemical sol-gel auto-combustion method were chosen. The prepared spinel particles were heated at 300°C for 1h. After heating the powders were milled using a High Energy Ball Mill for 30 minutes to further grind the particles and then subjected to various characterizations. Structural characterization was done using X-Ray Diffraction Method (XRD. The study revealed the spinel structure of these samples. Structural parameter such as lattice constant was determined using XRD data and found that the lattice parameter agrees with the standard data. DLS study found the agglomerations of the nanoparticles. The synthesized nanospinel particles were also characterized by the UVVis Spectroscopy, the Fourier Transform Infrared Spectroscopy (FTIR. Finally the magnetic hysteresis properties were studied using a Vibrating Sample Magnetometer (VSM.

  7. Hydriding-dehydriding properties of Mg2Ni alloy modified by ball-milling in tetrahydrofuran

    Institute of Scientific and Technical Information of China (English)

    CHEN Changpin; WANG Wei; CHEN Yun; CHEN Lixin; WANG Qidong

    2004-01-01

    A new approach of ball-milled Mg2Ni in tetrahydrofuran (THF) to improve the hydriding kinetics of Mg2Ni alloy is suggested and studied. It is found that the modified alloy displayed the improved activity for hydriding even at relatively low temperature (e.g., 323-373 K). In the case of the sample milled in THF for 20 h, the hydrogen content (mass fraction)reaches 1.6 % at 323 K, 2.1% at 348 K and 3.4% at 448 K, respectively. The use of THF during grinding led to the change of the structure, which is reflected by the broadening and weakening of the diffraction peaks in the XRD spectra. The XPS analysis shows that Mg (2s) binding energy peak of Mg2Ni after modification shifted from a lower binding energy to a higher one, indicating the charge transference between Mg and THF and the formation of catalytically active electron donor-acceptor (EDA) complexes on the surface of modified Mg2Ni alloy.

  8. Effects of Raw Material Content on Efficiency of TiN Synthesized by Reactive Ball Milling Ti and Urea

    Institute of Scientific and Technical Information of China (English)

    SUN Jin-Feng; LI Xiao-Pu; LIANG Bao-Yan; ZHAO Yu-Cheng; WANG Ming-Zhi

    2009-01-01

    Ti and urea mixed according to the molar ratios of 2:1, 3:1 and 4:1 are milled under the same condition. The structures of the as-synthesized powders are analyzed by an x-ray diffractometer (XRD). The decomposed tem-perature of the urea and the products decomposed are characterized by differential scanning calorimetry (DSC)and thermogravimetry analysis-Fourier transform infrared (TG-FTIR) spectrometry. The results show that the reaction progress is a diffusion reaction. The efficiency of TiN synthesized by reactive ball milling can be increased by increasing the content of Ti. The reactive ball milling time decreases from more than 90 h to 40 h correspond-ing to the content ratio between Ti and urea increasing from 2:1 to 4:1. Ammonia gas (NHa) and cyanic acid (HNCO), the decomposed products of urea, react with the refined Ti to form TiN. The grain refinement of Ti has a significant effect on the efficiency of reactive ball milling.

  9. Electrochemical properties of CeMg11 Ni+ x % Ni composites (x=0, 50, 100 and 200) prepared by ball-milling

    Institute of Scientific and Technical Information of China (English)

    WANG Li; WANG Xin-hua; CHEN Li-xin; CHEN Chang-pin

    2005-01-01

    The electrochemical properties of the as-cast CeMg11 Ni and ball-milled CeMg11 Ni+ x% Ni(x = 0, 50,100 and 200, mass fraction) composites were investigated. The results show that homogeneous amorphous phase of CeMg11 Ni+x% Ni composite can be obtained by ball-milling, and discharge capacity of the ball-milled CeMg11 Ni+x% Ni composites differs greatly depending on the amount of Ni introduced during milling. The CeMg11 Ni+200% Ni composite after 90 h ball-milling was found to exhibit a large discharge capacity of about 1 012 mAh/g at 303 K,and it also shows better charge-discharge cycling stability than those with lower Ni content. This remarkable improvement in electrochemical properties of the ball-milled composites seems to be attributed to the formation of an amorphous composite as well as the improvement of the surface state of the ball-milled particles.

  10. Phase transformation in magnesium hydride induced by ball milling; Changement de phase induit par broyage mecanique dans l'hydrure de magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Huot, J. [Universite du Quebec a Trois-Rivieres, Institut de Recherche sur l' Hydrogene, Quebec (Canada); Swainson, I. [Canadian Neutron Beam Centre, National Research Council Canada, Chalk River Lab. (Canada); Schulz, R. [Institut de Recherche d' Hydro-Quebec, Expertise Chimie et Materiaux, Quebec (Canada)

    2006-01-15

    The synthesis of magnesium hydride by reactive ball milling leads to the formation of a metastable orthorhombic {gamma}-MgH{sub 2} phase along with tetragonal {beta}-MgH{sub 2}. The structures of the {beta}-MgD{sub 2} and {gamma}-MgD{sub 2} phases of ball milled nanocrystalline MgD{sub 2} were studied by neutron powder diffraction. The ball-milled {beta}-MgD{sub 2} and {gamma}-MgD{sub 2} structures are distorted compared to the same phases synthesized by high-pressure and high temperature. Two Mg-D bond lengths are significantly distorted in {beta}-MgD{sub 2} while in the {gamma}-MgD{sub 2} phase, only one bond length is largely affected. The micro-stress associated with the strain fields and deformations caused by the ball milling is most likely the driving force of this phase transformation. (authors)

  11. Curie temperature and magnetic properties of aluminum doped barium ferrite particles prepared by ball mill method

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Daming [Center for Magnetism and Magnetic Nanostructures, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, Colorado 80918 (United States); College of Materials and Chemical Engineering, Hainan University, Haikou 570228, Hainan (China); Harward, Ian; Baptist, Joshua; Goldman, Sara; Celinski, Zbigniew [Center for Magnetism and Magnetic Nanostructures, University of Colorado at Colorado Springs, 1420 Austin Bluffs Pkwy, Colorado Springs, Colorado 80918 (United States)

    2015-12-01

    Barium ferrite has attracted considerable interest in the fields of permanent magnets and perpendicular magnetic recording due to its strong uniaxial anisotropy and high Curie temperature (T{sub c}). We prepared aluminum doped barium ferrite ceramics (BaAl{sub x}Fe{sub 12−x}O{sub 19}, 0≤x≤6) by the ball mill method. The powder was milled for 96 h, and after forming pellets, annealed for 48 h in air at 1000 °C. The X-ray diffraction (XRD) data show that there are only single hexagonal phases in the samples without any impurity phase. The crystal lattice constants, a and c, were calculated by Cohen's method. Both a and c decrease with increasing x, ranging from 0.588 nm and 2.318 nm to 0.573 nm and 2.294 nm, respectively. A Vibrating Sample Magnetometer (VSM) and Superconducting Quantum Interference Device (SQUID) were used to investigate T{sub c} and magnetic properties of BaFe{sub 12−x}Al{sub x}O{sub 19}. It is found that T{sub c} decreases with increasing x, from 425 °C to 298 °C. It is also found that the saturated magnetization (4πM{sub s}) decreases with increasing x, while the coercivity (H{sub c}) increases with the increase in x. The anisotropy field was also determined from the SQUID measurement. - Highlights: • The Curie temperature and magnetic properties of aluminum doped barium ferrite particles were studied systemically. • The relation between 4πM{sub s} and composition x at 50 K (both experimental value and theoretical calculation) was revealed. • Occupation number for spin up and spin down as a function of temperature was shown. • The relation between 4πM{sub s} and composition x from 50 K to room temperature was revealed.

  12. Bioconversion of paper mill sludge to bioethanol in the presence of accelerants or hydrogen peroxide pretreatment.

    Science.gov (United States)

    Gurram, Raghu Nandan; Al-Shannag, Mohammad; Lecher, Nicholas Joshua; Duncan, Shona M; Singsaas, Eric Lawrence; Alkasrawi, Malek

    2015-09-01

    In this study we investigated the technical feasibility of convert paper mill sludge into fuel ethanol. This involved the removal of mineral fillers by using either chemical pretreatment or mechanical fractionation to determine their effects on cellulose hydrolysis and fermentation to ethanol. In addition, we studied the effect of cationic polyelectrolyte (as accelerant) addition and hydrogen peroxide pretreatment on enzymatic hydrolysis and fermentation. We present results showing that removing the fillers content (ash and calcium carbonate) from the paper mill sludge increases the enzymatic hydrolysis performance dramatically with higher cellulose conversion at faster rates. The addition of accelerant and hydrogen peroxide pretreatment further improved the hydrolysis yields by 16% and 25% (g glucose / g cellulose), respectively with the de-ashed sludge. The fermentation process of produced sugars achieved up to 95% of the maximum theoretical ethanol yield and higher ethanol productivities within 9h of fermentation.

  13. 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.

  14. Effect of soya milk on nutritive, antioxidative, reological and textural properties of chocolate produced in a ball mill

    OpenAIRE

    Zarić Danica B.; Pajin Biljana S.; Rakin Marica B.; Šereš Zita I.; Dokić Ljubica P.; Tomić Jelena M.

    2011-01-01

    Chocolate is a complex rheological system in which non-fat cocoa particles and sugar particles are enveloped by crystal matrix of cocoa butter. Physical properties of chocolate depend on ingredient composition, method of production and properly performed pre-crystallization phase. In this work, chocolate was produced in an unconventional way, i.e. in a ball mill applying variable refining time (30, 60 and 90 min) and pre-crystallization temperature in chocolate masses (26, 28 and 30⁰C)....

  15. Characterization of cationic starch flocculants synthesized by dry process with ball milling activating method.

    Science.gov (United States)

    Su, Yuting; Du, Hongying; Huo, Yinqiang; Xu, Yongliang; Wang, Jie; Wang, Liying; Zhao, Siming; Xiong, Shanbai

    2016-06-01

    The cationic starch flocculants were synthesized by the reaction of maize starch which was activated by a ball-milling treatment with 2,3-epoxypropyl trimethyl ammonium chlorides (ETMAC) using the dry method. The cationic starches were characterized by several approaches including scanning electron microscope (SEM), degree of substitution (DS), infrared spectrum (IR), X-ray diffraction (XRD), flocculating activity, electron spin resonance (ESR), and solid-state nuclear magnetic resonance (NMR). The effect of mechanical activation on starch etherifying modification was investigated. The mechanical activation cracked starch granules and destructed their crystal structures. This resulted in enhancements to the reaction activity and reaction efficiency, which was approved by ESR and solid state NMR. The starch flocculants, synthesized by the reaction of mechanically activated starches at 90°C for 2.5h with ETMAC at molar ratio of 0.40:1.00, showed good flocculation activity. The substitution degree (0.300) and reaction efficiency (75.06%) of starch flocculants synthesized with mechanically activated starches were significantly greater than those of starch flocculants with native starches (P<0.05).

  16. Catalytic hydrodechlorination of monochloroacetic acid in wastewater using Ni-Fe bimetal prepared by ball milling.

    Science.gov (United States)

    Zhu, Hong; Xu, Fuyuan; Zhao, Jianzhuang; Jia, Linfang; Wu, Kunming

    2015-09-01

    Monochloroacetic acid (MCA) is a chemically stable and biologically toxic pollutant. It is often generated during the production of the pesticide dimethoate. Conventional wastewater treatment processes have difficulty degrading it. In this work, the dechlorination effects of Ni-Fe bimetal prepared using ball milling (BM) technology for the high concentrations of MCA in wastewater were examined. The MCA in aqueous solution was found to be degraded efficiently by the Ni-Fe bimetal. However, S-(methoxycarbonyl) methyl O, O-dimethyl phosphorodithioate (SMOPD) in wastewater, a by-product of the dimethoate production process, significantly inhibited the reductive dechlorination activity of Ni-Fe bimetal. Increasing the reaction temperature in the MCA wastewater enhanced the reduction activity of the Ni-Fe bimetal effectively. Oxygen was found to be unfavorable to dechlorination. Sealing the reaction to prevent oxidation was found to render the degradation process more efficient. The process retained over 88% efficiency after 10 treatment cycles with 50 g/L of Ni-Fe bimetal under field conditions.

  17. Environmentally friendly pretreatment of plant biomass by planetary and attrition milling.

    Science.gov (United States)

    Kim, Hyeon Jeong; Lee, Siseon; Kim, Jungbae; Mitchell, Robert J; Lee, Jin Hyung

    2013-09-01

    This study evaluated the use of planetary and attrition milling as pretreatment processes for lignocellulosic biomass using rice straw. Planetary milling reduced the rice straw crystallinity from 0.48 to 0.11. Since the samples could be milled and enzymatically treated using the same media, loss of the biomass due to washing was effectively eliminated. In contrast, conventional sodium hydroxide and soaking in aqueous ammonia (SAA) processes showed a loss of 34.2% and 14.8%, respectively. Furthermore, milling produced significantly lower concentrations of soluble phenolics than the alkali treatments. Using a bioluminescent bioreporter strain that is sensitive to these phenolics, neither of the milled samples elicited a response while the sodium hydroxide and SAA samples led to a 25.8 and 4.7 -fold induction, respectively. Although planetary milling produced more reducing sugars than attrition milling before saccharification, both had similar monosaccharide yields, i.e., 0.38 and 0.34 g/g-biomass, respectively, when 40 g/l rice straw was treated.

  18. Recycling process for recovery of gallium from GaN an e-waste of LED industry through ball milling, annealing and leaching

    Energy Technology Data Exchange (ETDEWEB)

    Swain, Basudev, E-mail: swain@iae.re.kr; Mishra, Chinmayee; Kang, Leeseung; Park, Kyung-Soo, E-mail: kspark@iae.re.kr; Lee, Chan Gi; Hong, Hyun Seon, E-mail: hshong@iae.re.kr

    2015-04-15

    Waste dust generated during manufacturing of LED contains significant amounts of gallium and indium, needs suitable treatment and can be an important resource for recovery. The LED industry waste dust contains primarily gallium as GaN. Leaching followed by purification technology is the green and clean technology. To develop treatment and recycling technology of these GaN bearing e-waste, leaching is the primary stage. In our current investigation possible process for treatment and quantitative leaching of gallium and indium from the GaN bearing e-waste or waste of LED industry dust has been developed. To recycle the waste and quantitative leaching of gallium, two different process flow sheets have been proposed. In one, process first the GaN of the waste the LED industry dust was leached at the optimum condition. Subsequently, the leach residue was mixed with Na{sub 2}CO{sub 3}, ball milled followed by annealing, again leached to recover gallium. In the second process, the waste LED industry dust was mixed with Na{sub 2}CO{sub 3}, after ball milling and annealing, followed acidic leaching. Without pretreatment, the gallium leaching was only 4.91 w/w % using 4 M HCl, 100 °C and pulp density of 20 g/L. After mechano-chemical processing, both these processes achieved 73.68 w/w % of gallium leaching at their optimum condition. The developed process can treat and recycle any e-waste containing GaN through ball milling, annealing and leaching. - Highlights: • Simplest process for treatment of GaN an LED industry waste developed. • The process developed recovers gallium from waste LED waste dust. • Thermal analysis and phase properties of GaN to Ga{sub 2}O{sub 3} and GaN to NaGaO{sub 2} revealed. • Solid-state chemistry involved in this process reported. • Quantitative leaching of the GaN was achieved.

  19. Grinding Wear Behaviour of Stepped Austempered Ductile Iron as Media Material During Comminution of Iron Ore in Ball Mills

    Science.gov (United States)

    Raghavendra, H.; Bhat, K. L.; Udupa, K. Rajendra; Hegde, M. M. Rajath

    2011-01-01

    An attempt has been made to evaluate the suitability of austempered ductile iron (ADI) as media material for grinding iron ore in a ball mill. Spheroidal graphite (S.G) iron balls are austenitised at 900° C for 60 minutes and given stepped austempering treatment at 280° C for 30 minutes and 60 minutes followed by 380° C for 60 minutes in each case. These materials are characterised by measuring hardness, analysing X-ray diffraction (X-RD), studying microstructure using optical and scanning electron microscope (SEM). Grinding wear behaviour of these materials was assessed for wear loss in wet condition at different pH value of the mineral slurry and found that the wear rate of grinding media material decreases with increase in pH of the slurry. The wear resistance of ADI balls were compared with forged En31 steel balls and found that the stepped austempered ductile iron is superior to forged En31 steel balls.

  20. Investigation of surface integrity in high-speed ball end milling of cantilever shaped thin plate of Inconel 718

    Directory of Open Access Journals (Sweden)

    N.N. Bhopale

    2012-12-01

    Full Text Available The paper addresses the effects of cutting speed and feed on the work piece deflection and surface integrity during milling of cantilever shaped Inconel 718 plate under different cutter orientations. The experiments were conducted on a CNC vertical milling machine using 10 mm diameter TiAlN coated solid carbide ball end milling cutter. Surface integrity is assessed in terms of micro hardness beneath the machined surface. The micro-hardness profile shows different patterns at various cutting parameters. It is observed that at large cutting speed as well as feeds, thicker work piece with larger work piece inclination shows higher micro hardness as compared to the other machining conditions.

  1. The structure and magnetic properties of Sm-Fe-N powders prepared by ball milling at low temperature

    Science.gov (United States)

    Fang, Qiuli; An, Xiaoxin; Wang, Fang; Li, Ying; Du, Juan; Xia, Weixing; Yan, Aru; Liu, J. Ping; Zhang, Jian

    2016-07-01

    Sm-Fe-N powders have great potential to be used for preparing high-performance bonded permanent magnets because of their high anisotropy field and large saturation magnetization. In this work, we report the morphology, structure, oxygen content and magnetic properties of the Sm-Fe-N powders prepared by high energy ball milling at low temperature. Compared with the samples milled at room temperature, the Sm-Fe-N powders prepared at low temperature display more homogeneous morphology, less decomposition, lower oxygen content, and therefore enhanced magnetic performance. Our experimental results indicate that the low temperature milling will be a promising method for fabricating Sm-Fe-N bonded magnets with high-performance.

  2. Effect of starting composition on formation of MoSi2–SiC nanocomposite powder via ball milling

    Indian Academy of Sciences (India)

    M Zakeri; M Ahmadi

    2012-08-01

    MoSi2–SiC nanocomposite powders were successfully synthesized by ball milling Mo, Si and graphite elemental powders. Effects of milling time and annealing temperature were also investigated. The composite formation and phase transformation were monitored by X-ray diffraction. The microstructure of milled powders was studied by SEM, TEM and XRD peak profile analysis. Formation of this composite was completed after 10 and 20 h of milling for 25%SiC and 50%SiC, respectively. High temperature polymorph (HTP) of MoSi2 was obtained at the end of milling (20 h). On the other hand, annealing led to transformation of HTP to low temperature polymorph (LTP) of MoSi2. Mo5Si3 was formed during annealing as a product of a reaction between MoSi2 and excess graphite. Mean grain size <50 nm was obtained for 20 h milled sample on the basis of peak profile analysis and TEM images.

  3. Preparation of an additive-free sample with a MgH2 phase by planetary ball milling of Mg with10 wt% MgH2

    Science.gov (United States)

    Hong, Seong-Hyeon; Song, Myoung Youp

    2016-11-01

    In order to prepare an additive-free sample with a MgH2 phase, 90 wt% Mg+10 wt% MgH2 (named Mg-10MgH2) was milled under hydrogen atmosphere in a planetary ball mill for different durations (2 h, 5 h, and 10 h). The hydrogen absorption and release properties of the prepared samples were investigated and compared with those of purchased pure MgH2 samples. Mg-10MgH2 milled for 5 h had the largest quantity of hydrogen released at 648 K for 100 min of 5.96 wt%. Mg-10MgH2 milled for 5 h released 0.11 wt% H for 10 min, 4.85 wt% H for 30 min, and 5.83 wt% H for 60 min at 648 K at the first cycle. Mg-10MgH2 milled for 5 h absorbed 5.39 wt% H for 5 min and 5.92 wt% H for 60 min at 648 K at the second cycle. Dehydriding curves were also obtained at the first cycle of Mg-10MgH2 samples milled for 5 h using Mg powder with or without sieving (200 mesh). The dehydriding curve at 648 K of a Mg-10MgH2 sample milled for 5 h in the planetary ball mill was compared with that of the sample milled for 24 h in a horizontal ball mill.

  4. 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

  5. The coercivity mechanism of Pr–Fe–B nanoflakes prepared by surfactant-assisted ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Zuo, Wen-Liang, E-mail: wlzuo@iphy.ac.cn; Zhang, Ming; Niu, E.; Shao, Xiao-Ping; Hu, Feng-Xia; Sun, Ji-Rong; Shen, Bao-Gen, E-mail: shenbg@aphy.iphy.ac.cn

    2015-09-15

    The strong (00l) textured Pr{sub 12+x}Fe{sub 82−x}B{sub 6} (x=0, 1, 2, 3, 4) nanoflakes with high coercivity were prepared by surfactant-assisted ball milling (SABM). The thickness and length of the flakes are mainly in the range of 50−200 nm and 0.5−2 μm, respectively. A coercivity of 4.16 kOe for Pr{sub 15}Fe{sub 79}B{sub 6} nanoflakes was obtained, which is the maximum coercivity of R{sub 2}Fe{sub 14}B (R=Pr, Nd) nanoflakes or nanoparticles reported up to now. The results of XRD and SEM for the aligned Pr{sub 15}Fe{sub 79}B{sub 6} nanoflakes indicate that a strong (00l) texture is obtained and the easy magnetization direction is parallel to the surface of the flakes. The angular dependence of coercivity for aligned sample indicates that the coercivity mechanism of the as-milled nanoflakes is mainly dominated by domain wall pinning. Meanwhile, the field dependence of coercivity, isothermal (IRM) and dc demagnetizing (DCD) remanence curves also indicate that the coercivity is mainly determined by domain wall pinning, and nucleation also has an important effect. In addition, the mainly interaction of flakes is dipolar coupling. The research of coercivity mechanism for Pr{sub 15}Fe{sub 79}B{sub 6} nanoflakes is important for guidance the further increase its value, and is useful for the future development of the high performance nanocomposite magnets and soft/hard exchange spring magnets. - Highlights: • A coercivity of 4.16 kOe for Pr{sub 15}Fe{sub 79}B{sub 6} nanoflakes was obtained. • The strong (00l) textured is obtained for Pr{sub 15}Fe{sub 79}B{sub 6} nanoflakes. • The interaction of nanoflakes is mainly dipolar coupling. • Domain wall pinning is the mainly coercivity mechanism.

  6. Enhancing the enzymatic hydrolysis of corn stover by an integrated wet-milling and alkali pretreatment.

    Science.gov (United States)

    He, Xun; Miao, Yelian; Jiang, Xuejian; Xu, Zidong; Ouyang, Pingkai

    2010-04-01

    An integrated wet-milling and alkali pretreatment was applied to corn stover prior to enzymatic hydrolysis. The effects of NaOH concentration in the pretreatment on crystalline structure, chemical composition, and reducing-sugar yield of corn stover were investigated, and the mechanism of increasing reducing-sugar yield by the pretreatment was discussed. The experimental results showed that the crystalline structure of corn stover was disrupted, and lignin was removed, while cellulose and hemicellulose were retained in corn stover by the pretreatment with 1% NaOH in 1 h. The reducing-sugar yield from the pretreated corn stovers increased from 20.2% to 46.7% when the NaOH concentration increased from 0% to 1%. The 1% NaOH pretreated corn stover had a holocellulose conversion of 55.1%. The increase in reducing-sugar yield was related to the crystalline structure disruption and delignification of corn stover. It was clarified that the pretreatment significantly enhanced the conversion of cellulose and hemicellulose in the corn stover to sugars.

  7. Preparation of ultrafine magnetic biochar and activated carbon for pharmaceutical adsorption and subsequent degradation by ball milling.

    Science.gov (United States)

    Shan, Danna; Deng, Shubo; Zhao, Tianning; Wang, Bin; Wang, Yujue; Huang, Jun; Yu, Gang; Winglee, Judy; Wiesner, Mark R

    2016-03-15

    Ball milling was used to prepare two ultrafine magnetic biochar/Fe3O4 and activated carbon (AC)/Fe3O4 hybrid materials targeted for use in pharmaceutical removal by adsorption and mechanochemical degradation of pharmaceutical compounds. Both hybrid adsorbents prepared after 2h milling exhibited high removal of carbamazepine (CBZ), and were easily separated magnetically. These adsorbents exhibited fast adsorption of CBZ and tetracycline (TC) in the initial 1h. The biochar/Fe3O4 had a maximum adsorption capacity of 62.7mg/g for CBZ and 94.2mg/g for TC, while values obtained for AC/Fe3O4 were 135.1mg/g for CBZ and 45.3mg/g for TC respectively when data were fitted using the Langmuir expression. Solution pH values slightly affected the sorption of TC on the adsorbents, while CBZ sorption was almost pH-independent. The spent adsorbents with adsorbed CBZ and TC were milled to degrade the adsorbed pollutants. The adsorbed TC itself was over 97% degraded after 3h of milling, while about half of adsorbed CBZ were remained. The addition of quartz sand was found to improve the mechanochemical degradation of CBZ on biochar/Fe3O4, and its degradation percent was up to 98.4% at the dose of 0.3g quarts sand/g adsorbent. This research provided an easy method to prepare ultrafine magnetic adsorbents for the effective removal of typical pharmaceuticals from water or wastewater and degrade them using ball milling.

  8. Effect of Surfactant Molecular Weight on Particle Morphology of SmCo5 Prepared by High Energy Ball Milling

    Science.gov (United States)

    2014-04-01

    palmitic acid (Aldrich), undecanoic acid (Aldrich), and valeric acid (Aldrich) were used as received at a concen- tration equivalent to 30% by... Acid 296 3 420 16.2 Oleic Acid 246 4 456 15.3 Palmitic Acid 236 3 418 16.6 Myristic Acid 216 3 398 15.7 Undecanoic Acid 246 5 376 16.6 Octanoic Acid ...ball milling (HEBM) is a widely used technique for producing nanostructured magnetic materials with oleic acid (OA) being the most commonly utilized

  9. Analysis and correction of the machining errors of small plastic helical gears by ball-end milling

    Institute of Scientific and Technical Information of China (English)

    Gao Sande; Huang Loulin; and Han Baoling

    2012-01-01

    Many small-size precise plastic helical involutes gears are used in electrical appliances to transmit rotary movements con- tinuously and smoothly. Ball-end milling is an effective method for trial manufacture or small batch production of this type of gear, but the precision of the gear is usually low. In this research, the main sources of the errors of the gear, machining errors of the tooth profile and trace of the gear obtained were analyzed. The correction amounts for these errors are then determined by using a CNC gear tester. They are used to generate a new 3D-CAD model for gear machining with better nrecision.

  10. Effective Route to Graphitic carbon Nitride from Ball-Milled Amorphous carbon in NH3 Atmosphere Under Annealing

    Institute of Scientific and Technical Information of China (English)

    费振义; 刘玉先

    2003-01-01

    Graphitic carbon nitride (g-C3N4) powders were successfully synthesized from ball-milled amorphous carbon under NHs atmosphere at high temperature, for the first time to the best of our knowledge. The combined characteristic data obtained by x-ray diffraction, high-resolution transmission-electron microscopy, electron energy loss spectroscopy, Raman spectroscopy, energy dispersive spectroscopic analysis, and Fourier transformation infrared spectroscopy provide substantial evidence for the graphite-like sp2-bonded structure with C3N4 stoichiometry.

  11. Nanostructured MgH2 Obtained by Cold Rolling Combined with Short-time High-energy Ball Milling

    OpenAIRE

    Ricardo Floriano; Daniel Rodrigo Leiva; Stefano Deledda; Bjørn Christian Hauback; Walter José Botta

    2013-01-01

    MgH2 was processed by short time high-energy ball milling (BM) and cold rolling (CR). A new alternative processing route (CR + BM) using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were evaluated. The CR + BM processing (compared to BM and CR process) resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear depen...

  12. Determining cement ball mill dosage by artificial intelligence tools aimed at reducing energy consumption and environmental impact

    Directory of Open Access Journals (Sweden)

    Julio R. Gómez Sarduy

    2012-10-01

    Full Text Available Energy management systems can be improved by using artificial intelligence techniques such as neural networks and genetic algorithms for modelling and optimising equipment and system energy consumption. This paper proposes modelling ball mill consumption as used in the cement industry from field variables. The regression model was based on artificial neural networks for predicting the electricity consumption of the mill’s main drive and evaluating established consumption rate performance. This research showed the influence of the amount of pozzolanic ash, gypsum and clinker on a mill’s power consumption; the dose determined according to the model ensured minimum energy consumption using a simple genetic algorithm. The estimated savings potential from the proposed dose was 36 600 kWh / year for mill number 1, representing $5,793.78 / year and a 33,708 kg CO2 / year reduction in the environmental impact of gas left to escape.

  13. Influence of emulsifiers on the optimization of processing parameters of refining milk chocolate in the ball mill

    Directory of Open Access Journals (Sweden)

    Pajin Biljana

    2011-01-01

    Full Text Available Chocolate manufacture is a complex process which includes a large number of technology operations. One of the obligatory phases is milling, called refining, which aims at obtaining the appropriate distribution of particle size, resulting in the chocolate with optimal physical and sensory characteristics. The aim of this work was to define and optimize the process parameters for the production of milk chocolate by a non-conventional procedure, using the ball mill. The quality of chocolate mass, produced on this way, is determined by measuring the following parameters: moisture, size of the largest cocoa particle, yield flow, and Casson plastic viscosity. A special consideration of this study is the optimization of the types and amounts of emulsifiers, which are responsible for achieving the appropriate rheological and physical characteristics of the chocolate mass. The obtained parameters are compared with those which are typical for the standard procedure.

  14. Magnetic hardening of high-energy ball-milled nanocrystalline LaMn{sub 2}Si{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Elmali, Ayhan [Department of Physics Engineering, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey)], E-mail: elmali@eng.ankara.edu.tr; Tekerek, Simsek; Dincer, Ilker; Elerman, Yalcin [Department of Physics Engineering, Faculty of Engineering, Ankara University, 06100 Besevler-Ankara (Turkey); Theissmann, Ralf [Institute for Materials Science, Darmstadt Technology University, Petersenstr. 23, 64287 Darmstadt (Germany); Institute for NanoTechnology, Forschungszentrum Karlsruhe (Germany); Ehrenberg, Helmut [Institute for Materials Science, Darmstadt Technology University, Petersenstr. 23, 64287 Darmstadt (Germany); Institute for Solid State and Materials Research, Institute for Complex Materials, Helmholtzstr. 20, D-01069 Dresden (Germany); Fuess, Hartmut [Institute for Materials Science, Darmstadt Technology University, Petersenstr. 23, 64287 Darmstadt (Germany)

    2008-02-15

    Nanocrystalline LaMn{sub 2}Si{sub 2} powders have been obtained by high-energy ball milling for 30 min from bulk alloys. After milling a high coercivity about 6 kOe is observed at 10 K in contrast to neglectable coercivity for the bulk LaMn{sub 2}Si{sub 2} at 5 K. The average grain size of the optimum particles which is obtained from X-ray diffraction pattern and HRTEM picture is about 20 nm. The magnetic hardening is observed for the nanocrystalline LaMn{sub 2}Si{sub 2,} reflected in the coercivity field strength of 6 kOe at 10 K.

  15. Bismuth-ceramic nanocomposites through ball milling and liquid crystal synthetic methods

    Science.gov (United States)

    Dellinger, Timothy Michael

    Three methods were developed for the synthesis of bismuth-ceramic nanocomposites, which are of interest due to possible use as thermoelectric materials. In the first synthetic method, high energy ball milling of bismuth metal with either MgO or SiO2 was found to produce nanostructured bismuth dispersed on a ceramic material. The morphology of the resulting bismuth depended on its wetting behavior with respect to the ceramic: the metal wet the MgO, but did not wet on the SiO2. Differential Scanning Calorimetry measurements on these composites revealed unusual thermal stability, with nanostructure retained after multiple cycles of heating and cooling through the metal's melting point. The second synthesis methodology was based on the use of lyotropic liquid crystals. These mixtures of water and amphiphilic molecules self-assemble to form periodic structures with nanometer-scale hydrophilic and hydrophobic domains. A novel shear mixing methodology was developed for bringing together reactants which were added to the liquid crystals as dissolved salts. The liquid crystals served to mediate synthesis by acting as nanoreactors to confine chemical reactions within the nanoscale domains of the mesophase, and resulted in the production of nanoparticles. By synthesizing lead sulfide (PbS) and bismuth (Bi) particles as proof-of-concept, it was shown that nanoparticle size could be controlled by controlling the dimensionality of the nanoreactors through control of the liquid crystalline phase. Particle size was shown to decrease upon going from three-dimensionally percolating nanoreactors, to two dimensional sheet-like nanoreactors, to one dimensional rod-like nanoreactors. Additionally, particle size could be controlled by varying the precursor salt concentration. Since the nanoparticles did not agglomerate in the liquid crystal immediately after synthesis, bismuth-ceramic nanocomposites could be prepared by synthesizing Bi nanoparticles and mixing in SiO2 particles which

  16. XRD and Moessbauer characterization of iron-doped SnO{sub 2} powders obtained by ball-milling

    Energy Technology Data Exchange (ETDEWEB)

    Brito, A.D.B. de; Alves, H.W.L.; Raposo, M.T. [Universidade Federal de Sao Joao del-Rei (UFSJ), MG (Brazil); Ardisson, J.D. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2012-07-01

    Full text: Rutile SnO{sub 2} (or cassiterite) is a semiconductor oxide, with many industrial applications, mainly as spin source for spintronics because of the relevant electronic and magnetic properties changes when doped with transition elements (TE) like Fe, Co, Ni and Co. Therefore, it is meaningful for the materials science research to study the properties of SnO{sub 2} nanomaterials doped by a TE ion. In this work, mechanical alloying process has been used to produce SnO{sub 2} doped with iron. The samples were characterized by X-Ray and Moessbauer spectroscopy. The crystalline alloy were obtained by milling in a planetary ball mill with a zirconia milling assembly for up to 24 hours in air, at room temperature. The mill rotation speed was 250 rpm and two different powder-to-ball weight ratios, 1:20 and 1:10, were used. X-ray diffraction analyses of SnO{sub 2} powders indicate only the formation of the cassiterite phase. X-Ray diffraction results of SnO{sub 2} doped with 10% of iron show some peaks quite wider when compared with diffraction peaks of the undoped samples, suggesting the absorption of iron probably in a new phase with tin. However, this phase cannot be identified by X-Ray diffraction. Moessbauer spectroscopy analyses (table below) indicate the presence of 85% of {alpha}-Fe and two new phases, both related to Fe-Sn phase magnetically disordered. On the other hand, {sup 119}Sn-Moessbauer spectroscopy measurements show the presence of tetrahedral tin (IV), chemical environment of the tin species. Based on the obtained results, thermal annealing and new measurements with both XRD and Moessbauer spectroscopies will be performed and compared with them. (author)

  17. Nanocrystalline {beta}-sialon by reactive sintering of a SiO{sub 2}-AlN mixture subjected to high-energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Tessier, P. [Groupe Minutia, Boucherville, Que. (Canada)]. E-mail: pascal.tessier@airliquide.com; Alamdari, H.D. [Groupe Minutia, Boucherville, Que. (Canada)]. E-mail: alamdari.houshang@nanoxnps.com; Dubuc, R. [Groupe Minutia, Boucherville, Que. (Canada); Boily, S. [Groupe Minutia, Boucherville, Que. (Canada)

    2005-04-05

    A mixture of powders of silica and aluminum nitride is subjected to high-energy ball milling for different milling times. This material is subsequently compacted by uniaxial pressing and sintered at 1450 deg. C. The resulting pellets are crushed and analysed by X-ray diffraction. For short milling times, the amount of phase transformation is minimal and the resulting material mostly consists of cristobalite and aluminum nitride. For long milling times, nanocrystalline {beta}-SiAl{sub 2}O{sub 2}N{sub 2} is mainly produced.

  18. High-temperature large diamagnetism in ball-milled Sr0.6Ca0.4CuO2

    Science.gov (United States)

    Hernando, A.; Herrero, E.; Vázquez, M.; Alonso, J.; González, A.; Rivero, G.; Rojo, J. M.; Vallet-Regi, M.; González Calbet, J.

    1997-10-01

    The observation of a large effective diamagnetic susceptibility of -3.4×10-6 emu g-1 Oe-1 up to temperatures above 1000 K in highly deformed ball-milled Sr0.6Ca0.4CuO2 is reported. These samples do not exhibit superconductivity at low temperature. This anomalously strong diamagnetism increases with milling time and reaches a maximum value after 500 h of milling. A model is proposed in which excess holes, introduced during milling, have wave functions that are extended over the CuO2 planes of the crystallites, resulting in large values of the diamagnetic susceptibility.

  19. Agile Thermal Management STT-RX. Catalytic Influence of Ni-based Additives on the Dehydrogentation Properties of Ball Milled MgH2 (PREPRINT)

    Science.gov (United States)

    2011-12-01

    milled MgH2 (PREPRINT) Patrick J. Shamberger, Jonathan E. Spowart, and Andrey A. Voevodin Thermal Sciences & Materials Branch Placidus B...the dehydrogentation properties of ball milled MgH2 (PREPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F...LaNi5 on the dehydrogenation properties of milled MgH2 , was investigated. MgH2 milled in the presence of Ni (5wt%) and Zr2Ni5 (5wt%) catalysts for 2 h

  20. Synthesis of Fe–Si–B–Mn-based nanocrystalline magnetic alloys with large coercivity by high energy ball milling

    Indian Academy of Sciences (India)

    P D Reddi; N K Mukhopadhyay; B Majumdar; A K Singh; S S Meena; S M Yusuf; N K Prasad

    2014-06-01

    Alloys of Fe–Si–B with varying compositions of Mn were prepared using high energy planetary ball mill for maximum duration of 120 h. X-ray diffraction (XRD) analysis suggests that Si gets mostly dissolved into Fe after 80 h of milling for all compositions. The residual Si was found to form an intermetallic Fe3Si. The dissolution was further confirmed from the field emission scanning electron microscopy/energy dispersive X-ray analysis (FE-SEM/EDX). With increased milling time, the lattice parameter and lattice strain are found to increase. However, the crystallite size decreases from micrometer (75–95 m) to nanometer (10–20 nm). Mössbauer spectra analysis suggests the presence of essentially ferromagnetic phases with small percentage of super paramagnetic phase in the system. The saturation magnetization (s), remanance (r) and coercivity (c) values for Fe–0Mn sample after 120 h of milling were 96.4 Am2/kg, 11.5 Am2/kg and 12.42 k Am-1, respectively. However, for Fe–10Mn–5Cu sample the s, c and r values were found to be 101.9 Am2/kg, 10.98 kA/m and 12.4 Am2/kg, respectively. The higher value of magnetization could be attributed to the favourable coupling between Mn and Cu.

  1. Catalytic wet oxidation of the pretreated synthetic pulp and paper mill effluent under moderate conditions.

    Science.gov (United States)

    Garg, Anurag; Mishra, I M; Chand, Shri

    2007-01-01

    In the present study, catalytic wet oxidation (CWO) was investigated for the destruction of organic pollutants in the thermally pretreated effluent from a pulp and paper mill under moderate temperature and pressure conditions. The thermal pretreatment studies were conducted at atmospheric pressure and 368K using copper sulfate as a catalyst. The thermal pretreatment reduced COD by about 61%. The filtrate of the thermal pretreatment step was used at pH 8.0 for CWO at 383-443K temperature and a total pressure of 0.85MPa for 4h. Catalysts used for the reaction include copper sulfate, 5% CuO/95% activated carbon, 60% CuO/40% MnO(2), and 60% CuO/40% CeO(2). Maximum COD reduction was found to be 89% during CWO step using 5% CuO/95% activated carbon with a catalyst loading of 8gl(-1) at 443K and 0.85MPa total pressure. Overall COD reduction for the pretreatment and the CWO was found to be 96%. Besides this, 60% CuO/40% CeO(2) catalyst also exhibited the similar activity as that of obtained with 5% CuO/95% activated carbon catalyst at 423K temperature and 0.85MPa total pressure. The pH of the solution during the experimental runs decreases initially due to the formation of carboxylic acid and then increases due to the decomposition of acids.

  2. Facile and Cost-Effective Synthesis and Deposition of a YBCO Superconductor on Copper Substrates by High-Energy Ball Milling

    Science.gov (United States)

    Alami, Abdul Hai; Assad, Mhd Adel; Aokal, Camilia

    2016-12-01

    The article investigates the synthesis and deposition of YBCO on a copper substrate for various functional purposes. The superconductor is first prepared by mechanically alloying elemental components (yttrium, barium, and copper) for 50 hours in a high-energy ball mill with subsequent protocol of heat treatment in an oxygen-rich atmosphere to arrive at stoichiometric ratios of YBa2Cu3O7. The material is then deposited on a thin copper substrate also by ball milling under various parameters of rotational speed and deposition time to select the best and most homogenous substrate coverage. Atomic force microscopy has confirmed the desired results, and other microstructural, thermal, and electrical techniques are used to characterize the obtained material. High-energy ball milling proved to be a versatile means to synthesize and deposit the material in a straightforward manner and controllable parameters for different deposit thicknesses and coverages.

  3. Facile and Cost-Effective Synthesis and Deposition of a YBCO Superconductor on Copper Substrates by High-Energy Ball Milling

    Science.gov (United States)

    Alami, Abdul Hai; Assad, Mhd Adel; Aokal, Camilia

    2016-09-01

    The article investigates the synthesis and deposition of YBCO on a copper substrate for various functional purposes. The superconductor is first prepared by mechanically alloying elemental components (yttrium, barium, and copper) for 50 hours in a high-energy ball mill with subsequent protocol of heat treatment in an oxygen-rich atmosphere to arrive at stoichiometric ratios of YBa2Cu3O7. The material is then deposited on a thin copper substrate also by ball milling under various parameters of rotational speed and deposition time to select the best and most homogenous substrate coverage. Atomic force microscopy has confirmed the desired results, and other microstructural, thermal, and electrical techniques are used to characterize the obtained material. High-energy ball milling proved to be a versatile means to synthesize and deposit the material in a straightforward manner and controllable parameters for different deposit thicknesses and coverages.

  4. Enhancement of dewatering performance of digested paper mill sludge by chemical pretreatment

    Science.gov (United States)

    Lin, Y. Q.; Zeng, C.; Wu, H. H.; Zeng, B. X.

    2016-08-01

    The wide application of anaerobic digestion (AD) for waste sludge results in a huge amount of digested sludge, while the appropriate reuse of digested sludge depends on effective solid-liquid separation. Thus, chemical (acid/alkali) pretreatment effects on dewaterability of digested paper mill sludge (DPMS) for better downstream reuse based on enhanced solid- liquid separation were investigated in this research. The dewatering properties of paper mill sludge (PMS) were also investigated to elucidate the impact of AD on sludge dewaterability. The results indicated that a higher DPMS dewaterability was noted with acid pretreatment (pH5). A 41.37% moisture content and 74.41% dewatering efficiency were determined for DPMS after acid (pH5) pretreatment within 25 min. In addition, a 7.13 mg•g-1 VSS of extracellular polymeric substances (EPS) and 101.50 μm of average particle size were observed. It was also observed that both EPS concentrations and particle sizes were key parameters influencing DPMS dewaterability. Lower EPS concentrations with larger average particle sizes contributed to enhanced sludge dewaterability. Moreover, dewaterability of PMS was higher than that of DPMS, which illustrated that AD would decrease the sludge dewaterability.

  5. Finite size effects and spin transition in ball-milled γ-(FeMn) 30Cu 70 nanostructured alloys

    Science.gov (United States)

    Restrepo, J.; Greneche, J. M.; González, J. M.

    2004-12-01

    Fe 15Mn 15Cu 70 alloys were prepared by high-energy ball milling over a wide range of grinding times from 15 min to 72 h. The corresponding magnetic properties were followed by means of vibrating sample magnetometry, magnetic susceptibility and Mössbauer spectroscopy. By using a Rietveld structural analysis of high-resolution X-ray diffraction data, lattice parameter and grain size correlations with magnetization and coercive force were carried out. Results revealed a strong microstructural dependence of the magnetic properties with the grain size, resembling a finite size-driven magnetic transition at a critical crystallite value of around 8.5 nm. This behavior is endorsed by a partial low- to high-spin transition according to isomer shift results, at a critical unit-cell volume of around 50 Å 3 at 77 K attributed to strong local variations of the interatomic spacing as a consequence of the employed ball-milling procedure. Finally, as concerns to temperature behavior, samples exhibited a freezing temperature at around 61 K and a wide distribution of relaxation times ascribed to the presence of interacting CuMn and FeMnCu clusters.

  6. Synthesis and hydrogen storage properties of mechanically ball-milled SiC/MgH{sub 2} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Imamura, H., E-mail: hi-khm@yamaguchi-u.ac.j [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Nakatomi, S.; Hashimoto, Y.; Kitazawa, I.; Sakata, Y. [Graduate School of Science and Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611 (Japan); Mae, H.; Fujimoto, M. [Yamaguchi Prefectural Industrial Technology Institute, 4-1-1 Asutopia, Ube 755-0195 (Japan)

    2009-11-20

    The hydrogen storage characteristics of SiC/MgH{sub 2} nanocomposites which are prepared by mechanical ball milling of MgH{sub 2} and SiC with cyclohexane have been studied. MgH{sub 2} as a starting material exhibited a desorption peak of hydrogen at 705 K in thermal desorption spectrometry (TDS), while the ball-milled SiC/MgH{sub 2} nanocomposites showed much lower desorption temperatures near 437 K. The hydrogen storage properties of SiC/MgH{sub 2} were significantly improved as a result of nanocomposite formation. In addition, the nanocomposites were characterized by X-ray diffraction (XRD), thermogravimetry (TG), differential scanning calorimeter (DSC) and pressure-composition isotherm (PCT) measurements. For the SiC/MgH{sub 2} nanocomposites, the reversibility of hydrogen absorption/desorption was observed, but heating above 573 K led to the irreversible breakdown of nanocomposites into MgH{sub 2} and SiC.

  7. 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.

  8. Fast environment-friendly ball mill-assisted deep eutectic solvent-based extraction of natural products.

    Science.gov (United States)

    Wang, Man; Wang, Jiaqin; Zhang, Yue; Xia, Qian; Bi, Wentao; Yang, Xiaodi; Chen, David Da Yong

    2016-04-22

    A fast environment-friendly extraction method, ball mill-assisted deep eutectic solvent-based extraction, was used for the extraction of natural products from plants. In this study, tanshinones were selected as target compounds to evaluate the efficiency of the developed extraction method. Under the optimized experimental conditions, cryptotanshinone (0.176 mg/g), tanshinone I (0.181 mg/g), and tanshinone II A (0.421 mg/g) were extracted from Salvia miltiorrhiza Bunge, and the developed method was found to be greener, more efficient, and faster than conventional, environmentally harmful extraction methods such as methanol-based ultrasound-assisted extraction and heat reflux extraction. The analytical performances including recovery, reproducibility (RSD, n=5), correlation of determination (r(2)), and the limit of detection, with the ranges of 96.1-103.9%, 1.6-1.9%, 0.9973-0.9984, and 5-8 ng/mL, were respectively obtained. Application of ball mill-assisted deep eutectic solvent-based extraction may fundamentally shape the future development of extraction methods.

  9. Chemical reactions of metal powders with organic and inorganic liquids during ball milling

    Science.gov (United States)

    Arias, A.

    1975-01-01

    Chromium and/or nickel powders were milled in metal chlorides and in organic liquids representative of various functional groups. The powders always reacted with the liquid and became contaminated with elements from them. The milled powders had specific surface areas ranging from 0.14 to 37 sq m/g, and the total contamination with elements from the milling liquid ranged from 0.01 to 56 weight percent. Compounds resulting from substitution, addition, or elimination reactions formed in or from the milling liquid.

  10. Spin-glass-like behaviour in ball milled Fe{sub 30}Cr{sub 70} alloy studied by ac magnetic susceptibility

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Blanco, D.; Gorria, P. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Fernandez-Martinez, Alejandro [Lawrence Livermore National Laboratory 7000 East Avenue, Livermore, CA 9455 (United States); Perez, M.J. [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Cuello, Gabriel J. [Institut Laue-Langevin, BP 156, 6, rue Jules Horowitz, 38042 Grenoble Cedex 9 (France); Blanco, J.A., E-mail: jabr@uniovi.es [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain)

    2011-06-15

    Research highlights: > Spin-glass-like behaviour o owing an re-entrant spin-glass transition. > No critical divergence observed in the maxima of the real and magnetic susceptibility on ball milled Fe{sub 30}Cr{sub 70}. > High temperature Curie-Weiss behavior of the magnetic susceptibility on ball milled Fe{sub 30}Cr{sub 70}. > Moderate shift of the freezing temperature per frequency in ball milled Fe{sub 30}Cr{sub 70} obtained from the temperature dependence of the real magnetic susceptibility - Abstract: Nominal nanostructured Fe{sub 30}Cr{sub 70} obtained from ball milling during 110 h has been investigated from dc magnetization and ac magnetic susceptibility. The as-milled sample is not monophasic and is formed of two phases, Fe{sub 20{+-}2}Cr{sub 80{+-}2} ({approx}86 {+-} 2%) and iron ({approx}14 {+-} 2%). The ac susceptibility measurements show evidence of a re-entrant spin-glass-like transition for the Fe{sub 20}Cr{sub 80} phase below 30 K. The shift of the freezing temperature per frequency decade is moderate when compared to that found in conventional spin-glass alloys. A Vogel-Fulcher activation process can be used to explain the frequency variation. The results are also analyzed in terms of Cole-Cole formalism for extracting information of relaxation time ({tau} {approx} 10{sup -5} to 10{sup -4} s).

  11. Nanoscale characterisation and clustering mechanism in an Fe-Y{sub 2}O{sub 3} model ODS alloy processed by reactive ball milling and annealing

    Energy Technology Data Exchange (ETDEWEB)

    Brocq, M., E-mail: mathilde.brocq@cea.fr [CEA, DEN, DMN, Service de Recherches de Metallurgie Physique, F-91191 Gif-sur-Yvette (France); Radiguet, B.; Le Breton, J.-M.; Cuvilly, F.; Pareige, P. [Universite et INSA de Rouen, Groupe de Physique des Materiaux - UMR 6634 CNRS, 76801 Saint Etienne du Rouvray (France); Legendre, F. [CEA, DEN, DMN, Service de Recherches de Metallurgie Physique, F-91191 Gif-sur-Yvette (France)

    2010-03-15

    Reactive ball milling and annealing is proposed as a new production method for oxide dispersion strengthened (ODS) steels. A highly concentrated Fe-38 atm.% Y{sub 2}O{sub 3} ODS model alloy was processed by reactive ball milling and annealing of YFe{sub 3} and Fe{sub 2}O{sub 3} powders so as to induce the chemical reaction 2YFe{sub 3} + Fe{sub 2}O{sub 3} {yields} 8Fe + Y{sub 2}O{sub 3}. The model alloy was characterised after milling and annealing by complementary techniques, including atom probe tomography. Ball milling up to the stationary state results in the formation of two metastable nanometric interconnected phases: super-saturated {alpha}-iron and an yttrium and oxygen rich phase. Annealing leads the system towards equilibrium through: (i) a chemical evolution of each phase to nearly pure {alpha}-Fe and Y{sub 2}O{sub 3} oxide slightly sub-stoichiometric in oxygen; and (ii) growth of the phases. A pure iron matrix reinforced by nanometric Y{sub 2}O{sub 3} particles was successfully synthesised by reactive ball milling and annealing.

  12. Characteristics of the Ti1.27Fe + 11 wt.% Ni Composite Obtained by Arc Melting and Ball Milling

    Directory of Open Access Journals (Sweden)

    J. Bonifacio-Martínez

    2013-01-01

    Full Text Available The Ti1.27Fe + 11 wt.% Ni composite synthesized by arc melting and ball milling and its possible use in hydrogen storage were studied. First the intermetallic Ti1.27Fe was obtained from elemental powders of Ti and Fe by using the arc melting in argon atmosphere and was cracked in a reactor, after that nickel powder was added to the Ti1.27Fe alloy before the milling. The mixture was subjected to high-energy ball milling to produce the Ti1.27Fe/Ni composite. Nanocrystalline phases Ti1.27Fe + Ni were observed after 5 h of milling. Hydrogenation results indicated that in the first cycle of hydriding the maximum amount of hydrogen release was 2.10 wt.% for the composite at 100∘C, under hydrogen pressure of 0.8 MPa and without prior activation.

  13. 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.

  14. Fibrillation of Aspen by Alkaline Cold Pre-treatment and Vibration Milling

    Directory of Open Access Journals (Sweden)

    Kärt KÄRNER

    2016-09-01

    Full Text Available In this article an attempt to fibrillate aspen bleached chemi-thermo mechanical pulp (BCTMP fibre in an environmentally friendly way is reported. The effects of various NaOH, KOH, urea and ethanol aqueous solutions at lowered temperature were tested for pre-treatment. The pre-treatment was followed by vibration milling aiming to peel off outer cell wall layers and to fibrillate S2 layer of the aspen wood fibre. The effects of the treatments were evaluated by scanning electron microscopy (SEM. The results show that it is possible to fibrillate BCTMP aspen fibres by using alkaline aqueous solutions at low temperatures followed by a mechanical treatment. A strong dependence on fibrillation of cellulose on temperature, time and alkali concentration was established.DOI: http://dx.doi.org/10.5755/j01.ms.22.3.7412

  15. Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing; Synthese et caracterisation d'un acier ODS prepare par un procede inspiredu broyage reactif: etude de l'influence des conditions de broyage et recuit

    Energy Technology Data Exchange (ETDEWEB)

    Brocq, M.

    2010-10-15

    In the context of the development of new ODS (Oxide Dispersion Strengthened) steels as core materials in future nuclear reactors, we investigated a new process inspired by reactive ball-milling which consists in using YFe{sub 3} andFe{sub 2}O{sub 3} as starting reactants instead of Y{sub 2}O{sub 3} to produce a dispersion of nano-oxides in a steel matrix and the influence of synthesis conditions on the nano-oxide characteristics were studied. For that aim, ODS steels were prepared by ball-milling and then annealed. Multi-scale characterizations were performed after each synthesis step, using notably atom probe tomography and small angle neutron scattering. The process inspired by reactive ball-milling was shown to be efficient for ODS steel synthesis, but it does not modify the nano-oxide characteristics as compared to those of oxides directly incorporated in the matrix by ball-milling. Broadly speaking, the nature of the starting oxygen bearing reactants has no influence on nano-oxide formation. Moreover, we showed that the nucleation of nano-oxides nucleation can start during milling and continues during annealing with a very fast kinetic. The final characteristics of nano-oxides formed in this way can be monitored through ball-milling parameters (intensity, temperature and atmosphere) and annealing parameters (duration and temperature). (author)

  16. 酸解-球磨法制备小颗粒淀粉及形成机理研究%Form Mechanism of Micronized Starch Prepared by Acid Hydrolysis and Ball Milling

    Institute of Scientific and Technical Information of China (English)

    刘莎; 扶雄; 黄强

    2011-01-01

    传统微细化小颗粒淀粉的制备采用原淀粉直接球磨的方法,耗时长,能耗高,产物易糊化.采用先酸解再球磨的新工艺制备了微细化小颗粒淀粉,并与玉米原淀粉、酸处理淀粉的物化性质进行了比较.结果表明,玉米原淀粉的表面积平均粒径为12.9μm,酸处理后淀粉的表面积平均粒径没有明显变化,而微细化淀粉的表面积平均粒径有显著降低;酸处理淀粉的结晶度较原淀粉有所增加,而酸水解后球磨淀粉结晶结构减弱,部分偏光十字消失,双折射强度减弱.%Starch mashing with the traditional ball milling method takes much time and energy consumption, and the product is easily being gelatinized. In this work, micronized starch was prepared by partially hydrolysis with inorganic acid and then micronized with ball milling. The physicochemical properties of the micronized starch were compared with native corn starch and acid modified starch. Results: The particle size of acid modified starch is similar to that of native corn starch( 12.9 μm) ,and is reduced significantly after the micronization. The crystalline structure of the acid pretreated corn starch is destroyed by the ball milling,part of the polarization cross disappear,and the intensity of birefringence is weakened.

  17. Spark plasma sintered Sm(2)Co(17)-FeCo nanocomposite permanent magnets synthesized by high energy ball milling.

    Science.gov (United States)

    Sreenivasulu, G; Gopalan, R; Chandrasekaran, V; Markandeyulu, G; Suresh, K G; Murty, B S

    2008-08-20

    Nanocomposite Sm(2)Co(17)-5 wt% FeCo magnets were synthesized by high energy ball milling followed by consolidation into bulk shape by the spark plasma sintering technique. The evolution of magnetic properties was systematically investigated in milled powders as well as in spark plasma sintered samples. A high energy product of 10.2 MGOe and the other magnetic properties of M(s) = 107 emu g(-1), M(r) = 59 emu g(-1), M(r)/M(s) = 0.55 and H(c) = 6.4 kOe were achieved in a 5 h milled and spark plasma sintered Sm(2)Co(17)-5 wt% FeCo nanocomposite magnet. The spark plasma sintering was carried out at 700 °C for 5 min with a pressure of 70 MPa. The nanocomposite showed a higher Curie temperature of 955 °C for the Sm(2)Co(17) phase in comparison to its bulk Curie temperature for the Sm(2)Co(17) phase (920 °C). This higher Curie temperature can improve the performance of the magnet at higher temperatures.

  18. Effect of Stiffness of Rolling Joints on the Dynamic Characteristic of Ball Screw Feed Systems in a Milling Machine

    Directory of Open Access Journals (Sweden)

    Dazhong Wang

    2015-01-01

    Full Text Available Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC milling machine set ermined as a research object, the stiffness of its fixed joint between the column and the body together with the stiffness parameters of the rolling joints is evaluated according to the Takashi Yoshimura method. Then, a finite element (FE model is established for the machine tool. The correctness of the FE model and the stiffness calculation method of the rolling joints are validated by theoretical and experimental modal analysis results of the machine tool’s workbench. Under the two modeling methods of joints incorporating the stiffness parameters and rigid connection, a theoretical modal analysis is conducted for the CNC milling machine. The natural frequencies and modal shapes reveal that the joints’ dynamic characteristic has an important influence on the dynamic performance of a whole machine tool, especially for the case with natural frequency and higher modes.

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

    Directory of Open Access Journals (Sweden)

    Abhijit Banerjee

    2012-12-01

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

  20. Study of Al composites prepared by high-energy ball milling; Effect of processing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza-Duarte, J.M.; Estrada-Guel, I.; Carreño-Gallardo, C.; Martínez-Sánchez, R.

    2015-09-15

    The present work deals with the synthesis of some Al-based composites prepared by mechanical milling and processing by powder metallurgy followed by the evaluation of process conditions as: type of additive, their concentration and milling intensity studying its effect on the characteristics of the powder composite and mechanical performance of the composite. Powder samples were microstructural characterized by electronic microscopy (SEM–TEM) and the mechanical response was followed by hardness and compressive tests. A pronounced effect on the mechanical response of the specimens was evident after the addition of reinforced particles and milling intensity. Microscopy studies showed a uniform dispersion of the reinforcing particles in the metallic matrix at nanometric scale and an important grain refinement of the Al matrix was confirmed. After processing, a 66% increase on the mechanical response was reached with 1% of additive complemented with short milling intensities.

  1. High performance amorphous-Si@SiOx/C composite anode materials for Li-ion batteries derived from ball-milling and in situ carbonization

    Science.gov (United States)

    Wang, Dingsheng; Gao, Mingxia; Pan, Hongge; Wang, Junhua; Liu, Yongfeng

    2014-06-01

    Amorphous-Si@SiOx/C composites with amorphous Si particles as core and coated with a double layer of SiOx and carbon are prepared by ball-milling crystal micron-sized silicon powders and carbonization of the citric acid intruded in the ball-milled Si. Different ratios of Si to citric acid are used in order to optimize the electrochemical performance. It is found that SiOx exists naturally at the surfaces of raw Si particles and its content increases to ca. 24 wt.% after ball-milling. With an optimized Si to citric acid weight ratio of 1/2.5, corresponding to 8.4 wt.% C in the composite, a thin carbon layer is coated on the surfaces of a-Si@SiOx particles, moreover, floc-like carbon also forms and connects the carbon coated a-Si@SiOx particles. The composite provides a capacity of 1450 mA h g-1 after 100 cycles at a current density of 100 mA g1, and a capacity of 1230 mA h g-1 after 100 cycles at 500 mA g1 as anode material for lithium-ion batteries. Effects of ball-milling and the addition of citric acid on the microstructure and electrochemical properties of the composites are revealed and the mechanism of the improvement in electrochemical properties is discussed.

  2. Orange-red light emitting europium-doped calcium molybdate phosphor prepared by high-energy ball milling

    Science.gov (United States)

    Hong, Woo Tae; Lee, Joo Hyun; Park, Jin Young; Yang, Hyun Kyoung; Jeong, Jung Hyun; Moon, Byung Kee

    2016-09-01

    Europium-doped calcium molybdates (CaMoO4:Eu3+) were successfully synthesized by a high-energy ball milling method. The x-ray diffraction patterns confirmed their powellite structure, and the field emission scanning electron microscope image exhibited the spherical particles with submicron size. The photoluminescence (PL) properties of Eu3+ in these phosphors were also studied by analyzing the excitation and emission spectra for the effect of europium concentration. The CaMoO4:Eu3+ PL excitation and PL spectra show charge transfer band and several transition peaks correlated with host lattice band gap and f-f transitions of Eu3+, respectively. By sintering Ca0.95MoO4:0.05Eu3+ phosphor at 1200°C, PL intensity has a maximum value at 618 nm with Commision Internationale de I'Eclairage 1931 (CIE 1931) chromaticity coordinates (0.609, 0.343).

  3. Influence of Process Control Agent on Characterization and Structure of Micron Chitosan Powders Prepared by Ball Milling Method

    Directory of Open Access Journals (Sweden)

    ZHANG Chuan-jie

    2016-12-01

    Full Text Available With ethyl alcohol or distilled water as process control agent (PCA, micron chitosan powder was prepared by ball milling method. The yield rate, particle size distribution, micro morphology, viscosity average molecular mass, chemical and crystal structures, and thermal properties of these different micron chitosan powders were measured. The results indicate that the yield rate of micron chitosan powders prepared with ethyl alcohol as PCA increases significantly, and improves to 94.7% from 25% while the amount of ethyl alcohol is 0.75mL/g. The particle size distribution of micron chitosan powder prepared with ethyl alcohol as PCA is concentrated, while the D50 and D90 in size are 824nm and 1629nm respectively. Chitosan do not react with ethyl alcohol used as PCA, but the viscosity average molecular mass of prepared micron chitosan powder decreases by 23%, the crystal structures are destroyed slightly, and its thermal stability is slightly weakened.

  4. Superthermostability of nanoscale TIC-reinforced copper alloys manufactured by a two-step ball-milling process

    Science.gov (United States)

    Wang, Fenglin; Li, Yunping; Xu, Xiandong; Koizumi, Yuichiro; Yamanaka, Kenta; Bian, Huakang; Chiba, Akihiko

    2015-12-01

    A Cu-TiC alloy, with nanoscale TiC particles highly dispersed in the submicron-grained Cu matrix, was manufactured by a self-developed two-step ball-milling process on Cu, Ti and C powders. The thermostability of the composite was evaluated by high-temperature isothermal annealing treatments, with temperatures ranging from 727 to 1273 K. The semicoherent nanoscale TiC particles with Cu matrix, mainly located along the grain boundaries, were found to exhibit the promising trait of blocking grain boundary migrations, which leads to a super-stabilized microstructures up to approximately the melting point of copper (1223 K). Furthermore, the Cu-TiC alloys after annealing at 1323 K showed a slight decrease in Vickers hardness as well as the duplex microstructure due to selective grain growth, which were discussed in terms of hardness contributions from various mechanisms.

  5. Comparison of pretreating pyrite cinder by high pressure roller grinding with damp milling to improve pelletization%高压辊磨和润磨预处理强化硫酸渣球团对比研究

    Institute of Scientific and Technical Information of China (English)

    朱德庆; 陈栋; 潘建

    2011-01-01

    The pretreatment of pyrite cinder was studied using high pressure roll grinding (HPRG), which aims to improve the quality of green pellets and reinforce roasting performance of pyrite cinder pellets, and HPRG was compared with damp milling was made. The results show that both HPRG and damp milling can significantly improve green ball quality while bentonite consumption is dramatically reduced, the drop number of green balls increases from 9.0 times without pretreatment to more than 30.0 times from 0.5 m height by pretreating the pyrite cinder using HPRG and 27.4 times from 0.5 m height by using damp milling, the compressive strength increases from 7.2 N per pellet without pretreatment to 10.6 N per pellet by using HPGR to pretreat cinder and 13.7 N per pellet by using damp milling, respectively. Thermal shock temperature of green balls is above 540 ℃ and the moisture of green pellets drops by 6.5%. After the pyrite cider is pretreated by HPRG and damp milling, the preheating and roasting temperatures of the pyrite cinder pellets are decreased by 150 ℃ and 80 ℃, respectively, and the roasting time is shortened by 6 mines. Therefore, the roasting performance of pyrite cinder pellets is reinforced greatly by HPRG and damp milling. The mechanisms of HPRG and damp milling show that specific surface areas and surface energy and activity are improved, and that solid diffusion reactions are enhanced, resulting in strong bonding inside fired pellets. However, productivity of HPRG is much higher than that of damp milling, and unit energy consumption is lower than that of damp milling.%采用高压辊磨技术预处理硫酸渣改善生球质量和强化球团焙烧,并且与传统的润磨技术进行对比.研究结果表明:高压辊磨和润磨预处理硫酸渣均可大幅度提高生球质量,在膨润土用量大幅降低的同时,生球落下强度从9 0次/(0.5 m)分别增加到大于30.0次/(0.5 m)和27.4次/(0.5 m),抗压强度从7.2 N/个分别增加到10

  6. Hydrothermal and wet disk milling pretreatment for high conversion of biosugars from oil palm mesocarp fiber.

    Science.gov (United States)

    Zakaria, Mohd Rafein; Norrrahim, Mohd Nor Faiz; Hirata, Satoshi; Hassan, Mohd Ali

    2015-04-01

    Eco-friendly pretreatment methods for lignocellulosic biomass are being developed as alternatives to chemical based methods. Superheated steam (SHS), hot compressed water (HCW) and wet disk milling (WDM) were used individually and with combination to partially remove hemicellulose and alter the lignin composition of recalcitrant structure of oil palm mesocarp fiber (OPMF). The efficiency of the pretreatment methods was evaluated based on the chemical compositions altered, SEM analysis, power consumption and degree of enzymatic digestibility. Hemicellulose removal (94.8%) was more pronounced under HCW compared to SHS, due to maximal contact of water and production of acetic acid which enhanced further degradation of hemicellulose. Subsequent treatment with WDM resulted in defibrillation of OPMF and expansion of the specific surface area thus increasing the conversion of cellulose to glucose. The highest glucose yield was 98.1% (g/g-substrate) when pretreated with HCW (200 °C, 20 min) and WDM which only consumed 9.6 MJ/kg of OPMF.

  7. Dielectric and photocatalytic properties of sulfur doped TiO{sub 2} nanoparticles prepared by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Jalalah, Mohammed [Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Electrical Engineering Department, College of Engineering, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Faisal, M. [Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Bouzid, Houcine [Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Department of Physics, Faculty of Sciences and Arts, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Ismail, Adel A., E-mail: adelali141@yahoo.com [Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Nanostructured and Nanotechnology Materials Division, Central Metallurgical R and D Institute, CMRDI, P.O. Box 87, Helwan, 11421, Cairo (Egypt); Chemistry Department, Science and Art at Sharurah, Najran University (Saudi Arabia); Al-Sayari, Saleh A. [Promising Centre for Sensors and Electronic Devices (PCSED), Advanced Materials and Nano-Research Centre, Najran University, P.O. Box 1988, Najran, 11001 (Saudi Arabia); Chemistry Department, Science and Art at Sharurah, Najran University (Saudi Arabia)

    2013-09-01

    Graphical abstract: - Highlights: • Designing of visible light responsive photocatalyst utilizing ball milling. • Sulphur used as dopant in commercial TiO{sub 2} P25 at different atomic percentage. • S doping resulted in an intense increase in absorption in the visible light region. • Newly design photocatalyst exhibited excellent photocatalytic performance. • 0.11 at.% S-doped TiO{sub 2} shows 3-times higher activity than that of TiO{sub 2} P25. - Abstract: Sulfur (S) doped commercial TiO{sub 2} P-25 has been achieved by changing the amount of thiourea using ball milling technique. The results of XRD clearly reveal biphasial anatase and rutile mixtures for all prepared samples and doping of S does not change the morphology of the TiO{sub 2}. The optical absorption edge of S-doped TiO{sub 2} was red shifted with indirect bandgap energy of 2.8 eV. The dielectric studies confirm that the dielectric constant of TiO{sub 2} increases after doping, however it becomes more conductive. Newly designed S-doped TiO{sub 2} photocatalysts exhibited excellent photocatalytic performance for the degradation of methylene blue (MB) under visible light. The overall photocatalytic activity of 0.11 at.% S-doped TiO{sub 2} was significantly 3-times higher than that of commercial TiO{sub 2} P-25 and complete degradation of MB has taken place after 90 min of irradiation under visible light while only 35% dye degraded when the reaction has been carried out in the presence of undoped TiO{sub 2}.

  8. Sulfur-graphene nanostructured cathodes via ball-milling for high-performance lithium-sulfur batteries.

    Science.gov (United States)

    Xu, Jiantie; Shui, Jianglan; Wang, Jianli; Wang, Min; Liu, Hua-Kun; Dou, Shi Xue; Jeon, In-Yup; Seo, Jeong-Min; Baek, Jong-Beom; Dai, Liming

    2014-10-28

    Although much progress has been made to develop high-performance lithium-sulfur batteries (LSBs), the reported physical or chemical routes to sulfur cathode materials are often multistep/complex and even involve environmentally hazardous reagents, and hence are infeasible for mass production. Here, we report a simple ball-milling technique to combine both the physical and chemical routes into a one-step process for low-cost, scalable, and eco-friendly production of graphene nanoplatelets (GnPs) edge-functionalized with sulfur (S-GnPs) as highly efficient LSB cathode materials of practical significance. LSBs based on the S-GnP cathode materials, produced by ball-milling 70 wt % sulfur and 30 wt % graphite, delivered a high initial reversible capacity of 1265.3 mAh g(-1) at 0.1 C in the voltage range of 1.5-3.0 V with an excellent rate capability, followed by a high reversible capacity of 966.1 mAh g(-1) at 2 C with a low capacity decay rate of 0.099% per cycle over 500 cycles, outperformed the current state-of-the-art cathode materials for LSBs. The observed excellent electrochemical performance can be attributed to a 3D "sandwich-like" structure of S-GnPs with an enhanced ionic conductivity and lithium insertion/extraction capacity during the discharge-charge process. Furthermore, a low-cost porous carbon paper pyrolyzed from common filter paper was inserted between the 0.7S-0.3GnP electrode and porous polypropylene film separator to reduce/eliminate the dissolution of physically adsorbed polysulfide into the electrolyte and subsequent cross-deposition on the anode, leading to further improved capacity and cycling stability.

  9. 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

  10. Significantly improved dehydrogenation of ball-milled MgH2 doped with CoFe2O4 nanoparticles

    Science.gov (United States)

    Shan, Jiawei; Li, Ping; Wan, Qi; Zhai, Fuqiang; Zhang, Jun; Li, Ziliang; Liu, Zhaojiang; Volinsky, Alex A.; Qu, Xuanhui

    2014-12-01

    CoFe2O4 nanoparticles are added to magnesium hydride (MgH2) by high-energy ball milling in order to improve its hydriding properties. The hydrogen storage properties and catalytic mechanism are investigated by pressure-composition-temperature (PCT), differential thermal analysis (DTA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The nonisothermal desorption results show that the onset desorption temperature of the MgH2 + 7 mol% CoFe2O4 is 160 °C, which is 200 °C lower than of the as-received MgH2. The dehydrogenation process of the MgH2 doped with the CoFe2O4 nanoparticles includes two steps. DTA curves and XRD patterns reveal that a chemical reaction happens between MgH2 and CoFe2O4, forming the final products of the ternary combination, corresponding to Co3Fe7, MgO and Co. The onset desorption temperature of the ball-milled MgH2 doped with Co3Fe7, MgO and Co is about 260 °C, approximately 100 °C lower than the un-doped MgH2, demonstrating that the ternary combination (Co3Fe7, MgO, and Co) also has a great catalytic effect on the MgH2 hydrogen storage properties. It is also confirmed that the various methods of adding the ternary combination have different effects on the MgH2 hydriding-dehydriding process.

  11. Synthesis, characterization and performance of high energy ball milled meso-scale zero valent iron in Fenton reaction.

    Science.gov (United States)

    Ambika, Selvaraj; Devasena, M; Nambi, Indumathi Manivannan

    2016-10-01

    Understanding contaminant degradation by different sized zero valent iron (ZVI) particles is one important aspect in addressing the long-term stability of these particles in field studies. In this study, meso zero valent iron (mZVI) particles were synthesised in a milling time of 10 h using ball milling technique. The efficacy of mZVI particles for removal of phenol was quantitatively evaluated in comparison with coarse zero valent iron (cZVI) and nano zero valent iron (nZVI) particles. Phenol degradation experiments were carried out in sacrificial batch mode at room temperature independently with cZVI, nZVI and mZVI under varied pH conditions of 3, 4, 6, 7, 8 and 10. Batch experiments substantiating the reactivity of mZVI under unbuffered pH system were also carried out and compared with buffered and poorly buffered pH systems. mZVI particles showed consistent phenol degradation at circum-neutral pH with efficiency of 44%, 67%, and 89% in a span of 5, 10 and 20 min respectively. The dissolved iron species and residual iron formation were also measured as a function of pH. Unbuffered systems at circum-neutral pH produced less residual iron when compared to buffered and poorly buffered systems. At this pH, oxidation of Fe(2+) produced a different oxidant Ferryl ion, which was found to effectively participate in phenol degradation.

  12. Preparation of Mg-MgH2 flakes by planetary ball milling with stearic acid and their hydrogen storage properties

    Science.gov (United States)

    Hong, Seong-Hyeon; Song, Myoung Youp

    2016-05-01

    Many studies preparing magnesium hydride using catalyst addition were performed, resulting in the preparation of additive-containing magnesium hydride. Preparation of a sample with a MgH2 phase without additives requires high pressure and high temperature and is time-demanding. In order to prepare an additive-free sample with a MgH2 phase, 90 wt% Mg+10 wt% MgH2 (named 90Mg+10MgH2) was milled under a hydrogen atmosphere with 6 wt% stearic acid as a process-controlling agent, which led to a formation of Mg-MgH2 flakes. The hydrogen storing and releasing properties of the prepared flakes were investigated and compared with those of purchased MgH2. A sample with a majority fraction of MgH2 phase was prepared by planetary ball milling of 90 Mg+10 MgH2 with 6 wt% stearic acid. The resultant particles of 90 Mg+10 MgH2 obtained after hydridingdehydriding cycling were much smaller and had significantly more cracks and defects than those of MgH2 after hydriding-dehydriding cycling. 90 Mg+10 MgH2 released 0.12 wt% hydrogen for 4 min, 3.70 wt% for 20 min, and 5.30 wt% for 60 min at 648 K at the first cycle.

  13. Surface Generation Modeling in Ball Nose End Milling: a review of relevant literature

    DEFF Research Database (Denmark)

    Bissacco, Giuliano

    One of the most common metal removal operation used in industry is the milling process. This machining process is well known since the beginning of last century and has experienced, along the years, many improvements of the basic technology, as concerns tools, machine tools, coolants/lubricants, ...

  14. Pretreatment of palm oil mill effluent (POME) using Moringa oleifera seeds as natural coagulant.

    Science.gov (United States)

    Bhatia, Subhash; Othman, Zalina; Ahmad, Abdul Latif

    2007-06-25

    Moringa oleifera seeds, an environmental friendly and natural coagulant are reported for the pretreatment of palm oil mill effluent (POME). In coagulation-flocculation process, the M. oleifera seeds after oil extraction (MOAE) are an effective coagulant with the removal of 95% suspended solids and 52.2% reduction in the chemical oxygen demand (COD). The combination of MOAE with flocculant (NALCO 7751), the suspended solids removal increased to 99.3% and COD reduction was 52.5%. The coagulation-flocculation process at the temperature of 30 degrees C resulted in better suspended solids removal and COD reduction compared to the temperature of 40, 55 and 70 degrees C. The MOAE combined with flocculant (NALCO 7751) reduced the sludge volume index (SVI) to 210mL/g with higher recovery of dry mass of sludge (87.25%) and water (50.3%).

  15. Production of titanium-tin alloy powder by ball milling: Formation of titanium-tin oxynitride composite powder produced by annealing in air

    Energy Technology Data Exchange (ETDEWEB)

    Bolokang, A.S., E-mail: Sylvester.Bolokang@transnet.net [Department of Physics, University of the Western Cape, Private Bag x 17, Bellville 7535 (South Africa); DST/CSIR National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Transnet Engineering, Product Development, Private Bag X 528, Kilnerpark, Pretoria 0127 (South Africa); Motaung, D.E., E-mail: dmotaung@csir.co.za [DST/CSIR National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, Pretoria 0001 (South Africa); Arendse, C.J.; Muller, T.F.G. [Department of Physics, University of the Western Cape, Private Bag x 17, Bellville 7535 (South Africa)

    2015-02-15

    Highlights: • HCP solid solution of Ti{sub 75}-Sn{sub 25} powder was synthesized by ball milling. • Formation of Ti-Sn to intermetallic Ti{sub 3}Sn was realized after annealing in Ar. • Thermal analysis of milled Ti-Sn in air yielded HCP with a = 4.985 Å; c = 2.962 Å. • Thermal analysis of milled Ti{sub 3}Sn in air yielded HCP with a = 4.582 Å; c = 2.953 Å. • Raman analysis has confirmed structural change upon annealing. - Abstract: Phase transformation was induced by ball milling and annealing of Ti{sub 75}-Sn{sub 25} powder. HCP solid solution was induced by Ball milling and yielded a compressed lattice parameters a = 2.929 Å; c = 4.780 Å and c/a = 1.63. Upon annealing in Ar at 700 °C, Ti{sub 3}Sn intermetallic with lattice parameters a = 5.916 Å; c = 4.764 Å with (c/a = 0.80) was detected. Subsequent TGA analysis of HCP milled Ti-Sn and Ti{sub 3}Sn intermetallic in air have resulted in tetragonal oxynitride powders with lattice parameters a = 4.985 Å; c = 2.962 Å, c/a = 0.594 for the former and a = 4.582 Å; c = 2.953 Å and c/a = 0.644 for the latter, respectively. The powder morphology was monitored by the high-resolution transmission electron microscopy while the roughness of the milled was analysed by the atomic force microscopy. Phase transformation was monitored by the X-ray diffraction and complemented by the Raman spectroscopy.

  16. Pre-treatment and membrane ultrafiltration using treated palm oil mill effluent (POME

    Directory of Open Access Journals (Sweden)

    Wong Pui Wah

    2002-11-01

    Full Text Available Treatment of palm oil mill effluent (POME has always been a topic of research in Malaysia. This effluent that is extremely rich in organic content needs to be properly treated to minimize environmental hazards before it is released into watercourses. The common practice for treating POME in Malaysia involves a combination of aerobic and anaerobic methods. The purpose of tertiary treatment is to allow the treated water to be reused in the mill operations for other purposes such as feed water. The proposed treatment will also ensure the industry to meet a more stringent discharge standard in terms of the BOD, COD and nitrogen values. In this study membrane ultrafiltration is used as the tertiary treatment method. Before the actual membrane operation was conducted, the samples were pre-treated using three separate method namely filtration, centrifugation and coagulation. It was found that the combination of filtrationultrafiltration treatment POME produced the best-treated sample quality in terms of pollutant contents elimination, namely % BOD, % COD and % nitrogen removal.

  17. Experimental and theoretical study of phase transitions under ball milling; Etude experimentale et modelisation des changements de phases sous broyage a haute energie

    Energy Technology Data Exchange (ETDEWEB)

    Pochet, P

    1997-12-31

    The aim of this work was to determine how phase transition s under ball-milling depend on the milling conditions and to find out if one can rationalize such transitions with the theory of driven alloys. We have chosen two phase transitions: the order-disorder transition in Fe Al and the precipitation-dissolution NiGe. In the case of Fe Al we have found that the steady-state long range order parameter achieved under ball milling intensity; moreover the same degree of order is achieved starting from an ordered alloy or a disordered solid solution. On the way to fully disordered state the degree of order either decreases monotonically or goes through a short lived transient state. This behaviour is reminiscent of a first order transition while the equilibrium transition is second order. All the above features are well reproduced by a simple model of driven alloys, which was originally build for alloys under irradiation. The stationary degree of order results of two competitive atomic jump mechanisms: the forced displacements induced by the shearing of the grains, and the thermally activated jumps caused by vacancies migrations. Finally we have performed atomistic simulations with a Monte Carlo kinetic algorithm, which revealed the role of the fluctuations in the intensity of the forcing. Moreover we have shown that specific atomistic mechanisms are active in a dilute NiGe solid solution which might lead to ball milling induced precipitation in under-saturated solid solution. (author). 149 refs.

  18. Thermoelectric properties of polythiophene/MWNT composites prepared by ball-milling

    Science.gov (United States)

    Wang, Dagang; Wang, Lei; Wang, Wenxin; Bai, Xiaojun; Li, Junqin

    2012-04-01

    Polythiophene /multi-wall carbon nanotubes (MWNT) composites were prepared by ball-mailing. The morphology and internal structure of the composites were evaluated by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD). Their thermoelectric properties, i.e., the electrical conductivity, the Seebeck coefficient and the thermal conductivity, were investigated in detail. The remarkably increased electrical conductivity, the slightly increased Seebeck coefficient and the relatively insensitive thermal conductivity with increasing MWNT content led to an obvious enhancement in the thermoelectric figure of merit. The results showed that the MWNT were uniformly dispersed in the polymer matrix, and that increasing the electrical conductivity is the key factor for enhancing the thermoelectric figure of merit. This study suggested a simple way to improve the thermoelectric performances of conducting polymers.

  19. Effect of zirconium on grain growth and mechanical properties of a ball-milled nanocrystalline FeNi alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kotan, Hasan, E-mail: hkotan@ncsu.edu [Department of Materials Science and Engineering, NC State University, 911 Partners Way, Room 3078, Raleigh, NC 27606-7907 (United States); Darling, Kris A. [U.S. Army Research Laboratory, Weapons and Materials Research Directorate, RDRL-WMM-F, Aberdeen Proving Ground, MD 21005-5069 (United States); Saber, Mostafa; Koch, Carl C.; Scattergood, Ronald O. [Department of Materials Science and Engineering, NC State University, 911 Partners Way, Room 3078, Raleigh, NC 27606-7907 (United States)

    2013-02-25

    Highlights: Black-Right-Pointing-Pointer Pure Fe, Fe{sub 92}Ni{sub 8}, and Fe{sub 91}Ni{sub 8}Zr{sub 1} powders were hardened up to 10 GPa by ball milling. Black-Right-Pointing-Pointer Annealing of Fe and Fe{sub 92}Ni{sub 8} leads to reduced hardness and extensive grain growth. Black-Right-Pointing-Pointer The addition of Zr to Fe{sub 92}Ni{sub 8} increases its stability and strength by second phases. Black-Right-Pointing-Pointer The second phases are found to promote the stability of Fe{sub 91}Ni{sub 8}Zr{sub 1} by Zener pinning. Black-Right-Pointing-Pointer The Zr-containing precipitates contribute to the overall strength of the material. - Abstract: Grain growth of ball-milled pure Fe, Fe{sub 92}Ni{sub 8}, and Fe{sub 91}Ni{sub 8}Zr{sub 1} alloys has been studied using X-ray diffractometry (XRD), focused ion beam (FIB) microscopy and transmission electron microscopy (TEM). Mechanical properties with respect to compositional changes and annealing temperatures have been investigated using microhardness and shear punch tests. We found the rate of grain growth of the Fe{sub 91}Ni{sub 8}Zr{sub 1} alloy to be much less than that of pure Fe and the Fe{sub 92}Ni{sub 8} alloy at elevated temperatures. The microstructure of the ternary Fe{sub 91}Ni{sub 8}Zr{sub 1} alloy remains nanoscale up to 700 Degree-Sign C where only a few grains grow abnormally whereas annealing of pure iron and the Fe{sub 92}Ni{sub 8} alloy leads to extensive grain growth. The grain growth of the ternary alloy at high annealing temperatures is coupled with precipitation of Fe{sub 2}Zr. A fine dispersion of precipitated second phase is found to promote the microstructural stability at high annealing temperatures and to increase the hardness and ultimate shear strength of ternary Fe{sub 91}Ni{sub 8}Zr{sub 1} alloy drastically when the grain size is above nanoscale.

  20. 基于LABVIEW的球磨机筒体应力测试系统%Stress measuring system for barrels of ball mills based on LABVIEW

    Institute of Scientific and Technical Information of China (English)

    李斌; 董为民

    2011-01-01

    研究开发了基于LABVIEW平台的球磨机测试系统,结合有限元分析结果,在球磨机筒体关键处进行了应力测量与分析,为提高筒体设计效率和寿命提供了试验依据.%The paper develops a measuring system for ball mills based on LABVIEW, and carries out stress measurement and analysis at key points of the barrel of a ball mill in combination with the finite element analysis results, which offers experimental data for improving the designing efficiency and the lifespan of the barrel.

  1. Comparison of particle sizes between 238PuO2 before aqueous processing, after aqueous processing, and after ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Mulford, Roberta Nancy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    Particle sizes determined for a single lot of incoming Russian fuel and for a lot of fuel after aqueous processing are compared with particle sizes measured on fuel after ball-milling. The single samples of each type are believed to have particle size distributions typical of oxide from similar lots, as the processing of fuel lots is fairly uniform. Variation between lots is, as yet, uncharacterized. Sampling and particle size measurement methods are discussed elsewhere.

  2. 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...... that tin in the hematite phase plays an important role in high gas sensitivity....

  3. 溢流型球磨机物料检测方法的研究%Detection Method of Materials in the Overflow Ball Mill

    Institute of Scientific and Technical Information of China (English)

    高莹

    2014-01-01

    对溢流型球磨机工作过程中出现给料过多的情况进行原因分析,针对这些原因给出可能解决问题的方案,再根据实际情况分析方案的合理性,并在实际设计和现场调试过程中采用相应的方案,使溢流型球磨机与物料输送系统之间建立联锁关系,实现必要的联锁控制,给出联锁控制的流程图和PLC程序梯形图。最后给出了现场实际应用的效果。%As a crushing equipment , ball mill has been widely applied in the mining and chemical industries . Overflow ball mill is one of the equipments w hich have been used earlier and commonly . During the practi-cal application in the mines , due to over feeding , the ball mills are overloaded , broken and even broken dow n . T he thesis has analyzed the reasons of over feeding , and brought up the solutions accordingly . Then , based on the actual situation on site , the most reasonable and effective solution will be selected . During the designing and commissioning , the solution will be applied and established interlocking relation-ships between the overflow ball mill and the material transfer system . Control flow diagram and PLC pro-gram diagram will be provided as well .

  4. On the Design of QM3500X6000P Large Ball Mill%浅谈QM3500X6000P大型球磨机的设计

    Institute of Scientific and Technical Information of China (English)

    崔向东; 赵红美

    2012-01-01

    介绍了QM3500X6000P大型球磨机的工作原理、主要参数的确定、起动特点及其起动力矩校核的新方法。%This thesis introduces the working principle of QM3500X6000P large ball mill, the confirmation of main parameter, starting characteristics and a new method of checking starting torque.

  5. Preparation of fine-grained tungsten heavy alloys by spark plasma sintered W–7Ni–3Fe composite powders with different ball milling time

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, D.P., E-mail: dpxiang@hainu.edu.cn [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Ding, L. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); Li, Y.Y.; Chen, G.B. [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Zhao, Y.W. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China)

    2013-06-15

    Highlights: ► We fabricate fine-grained W–7Ni–3Fe alloys using HEBM assisted SPS method. ► The γ-(Ni, Fe, W) phase is not observed in HEBM raw powders. ► The density of the WHAs gradually decreased with increasing HEBM time. ► The hardness and bending strength of the WHAs show different trends of variation. ► The intergranular fracture was the main bending fracture mode of the WHAs. -- Abstract: The fine-grained tungsten heavy alloys (WHAs) with grain size of about 1–3 μm were successfully prepared by spark plasma sintered W–7Ni–3Fe composite powders with different high-energy ball milling (HEBM) time. This study analyzes the effects of HEBM time not only on the composite powders but on the microstructure and mechanical properties of WHAs. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to investigate the microstructure and phase evolution rules of powders and alloys, respectively. The γ-(Ni, Fe, W) is not observed in XRD patterns of the ball milled powders. With prolonging HEBM time, the W phase diffraction peak becomes increasingly wider, and its intensity continues to decline. However, the completely amorphous structures are not formed even after HEBM 40 h. The relative density of the WHAs prepared by HEBM assisted SPS technique decreases gradually with increasing the ball milling time. For the WHAs sintered in 1150 °C for 8 min, the W grains grow finer and the content of the γ-(Ni, Fe, W) binding phase greatly increases with prolonging the HEBM time. Meanwhile, over 5 h of HEBM time, the bending strength continuously decreases and the hardness slightly increases. The intergranular fracture of the W grains is the main bending fracture mode in all the WHAs. The microporous of different sizes are distributed on the bending fracture and progressively increased with prolonging the ball milling time.

  6. The influence of CNC milling and ball burnishing on shaping complex 3D surfaces

    Science.gov (United States)

    Bachtiak-Radka, Emilia; Dudzińska, Sara; Grochała, Daniel; Berczyński, Stefan; Olszak, Wiesław

    2017-03-01

    Hybrid techniques for surface treatment should ensure compliance with exterior layer state and stress requirements. The more factors which influence final treatment effects, the more difficult it is to conduct a technological process combining different treatment methods. A combination of shaping milling with finishing burnishing can provide very good smoothness and satisfactory stress conditions. However, implementation of predefined geometric surface specifications (GPS) is very difficult. This article presents the results of the effect of technological parameters of both treatments combined into a single operation on surface topography. A new surface geometry evaluation approach, combining both relative and absolute changes of isotropy and surface roughness, enabling an objective efficiency comparison of machining operations combined in a single operation, is presented.

  7. Band gap-engineered ZnO and Ag/ZnO by ball-milling method and their photocatalytic and Fenton-like photocatalytic activities

    Science.gov (United States)

    Choi, Young In; Jung, Hye Jin; Shin, Weon Gyu; Sohn, Youngku

    2015-11-01

    The hybridization of ZnO with Ag has been performed extensively to increase the efficiency of ZnO in various applications, including catalysis. In this study, a wet (w) and dry (d) ball-milling method was used to hybridize Ag with ZnO nanoparticles, and their physicochemical properties were examined. Visible light absorption was enhanced and the band gap was engineered by ball-milling and Ag hybridization. Their photocatalytic activities were tested with rhodamine B (RhB) and a mixed dye (methyl orange + RhB + methylene blue) under visible light irradiation. For pure RhB, the photocatalytic activity was decreased by ball-milling and was observed in the order of ZnO(d) degradation of RhB and methylene blue (MB) in the mixed dye (or the simulated real contaminated water), the photocatalytic activity was observed in the order of Ag/ZnO(d) degradation of RhB and methylene blue (MB). In the mixed dye over all the catalysts, methyl orange (MO) was degraded most rapidly. The relative degradation rates of RhB and MB were found to be dependent on the catalyst and reaction conditions.

  8. Optimization of Process Parameters for in High-Energy Ball Milling of CNTs/Al2024 Composites Through Response Surface Methodology

    Institute of Scientific and Technical Information of China (English)

    Li Guo; Xiaolan Cai; Lei Zhou; Cui Hu; Changjiang Yang; Ziyang Wang; Wenzhong Zhang; Gang Peng

    2016-01-01

    The mathematical models are developed to evaluate the ultimate tensile strength( UTS) and hardness of CNTs/Al2024 composites fabricated by high⁃energy ball milling. The effects of the preparation variables which are milling time, rotational speed, mass fraction of CNTs and ball to powder ratio on UST and hardness of CNTs/Al2024 composites are investigated. Based on the central composite design( CCD) , a quadratic model is developed to correlate the fabrication variables to the UST and hardness. From the analysis of variance ( ANOVA) , the most influential factor on each experimental design response is identified. The optimum conditions for preparing CNTs/Al2024 composites are found as follows: 1. 53 h milling time, 900 r/min rotational speed, mass fraction of CNTs 2. 87% and Ball to powder ratio 25 ∶ 1. The predicted maximum UST and hardness are 273.30 MPa and 261.36 HV, respectively. And the experimental values are 283.25 MPa and 256.8 HV, respectively. It is indicated that the predicted UST and hardness after process optimization are found to agree satisfactory with the experimental values.

  9. Magnetic properties of ball-milled Fe{sub 0.6}Mn{sub 0.1}Al{sub 0.3} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Rebolledo, A.F. [Insituto de Magnetismo Aplicado, P.O. Box 155, 28230 Las Rozas (Madrid) (Spain); Romero, J.J. [Insituto de Magnetismo Aplicado, P.O. Box 155, 28230 Las Rozas (Madrid) (Spain)]. E-mail: juanjromero@adif.es; Cuadrado, R. [Insituto de Magnetismo Aplicado, P.O. Box 155, 28230 Las Rozas (Madrid) (Spain); Gonzalez, J.M. [Insituto de Magnetismo Aplicado, P.O. Box 155, 28230 Las Rozas (Madrid) (Spain); Instittuo de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Ines de la Cruz s/n, 28049 Madrid (Spain); Pigazo, F. [Instittuo de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Ines de la Cruz s/n, 28049 Madrid (Spain); Palomares, F.J. [Instittuo de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Ines de la Cruz s/n, 28049 Madrid (Spain); Medina, M.H. [Departamento de Fisica, Universidad Tecnologica de Pereira, La Julita, A. A. 097, Pereira (Colombia); Perez Alcazar, G.A. [Insituto de Magnetismo Aplicado, P.O. Box 155, 28230 Las Rozas (Madrid) (Spain); Depto. de Fisica, edificio 230, Universidad del Valle, A.A. 25360 Cali (Colombia)

    2007-09-15

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

  10. Removal of fluoride from drinking water using modified ultrafine tea powder processed using a ball-mill

    Science.gov (United States)

    Cai, Huimei; Xu, Lingyun; Chen, Guijie; Peng, Chuanyi; Ke, Fei; Liu, Zhengquan; Li, Daxiang; Zhang, Zhengzhu; Wan, Xiaochun

    2016-07-01

    A low-cost and highly efficient biosorbent was prepared by loading zirconium(IV) onto ball-milled, ultrafine tea powder (UTP-Zr) for removal of fluoride from drinking water. To evaluate the fluoride adsorption capacity of UTP-Zr over a wide range of conditions, the biosorbent dosage, contact time, initial pH, initial fluoride concentration and presence of other ions were varied. UTP-Zr performed well over the considerably wide pH range of 3-10. The residual concentration of Zr in the treated water was below the limit of detection (0.01 mg/L). Fluoride adsorption by the UTP-Zr biosorbent followed the Langmuir model, with a maximum adsorption capacity of 12.43 mgF/g at room temperature. The fluoride adsorption kinetics fit the pseudo-second-order kinetic model. The synthesized biosorbent was characterized by BET, SEM, EDS, XRD and XPS to reveal how UTP-Zr interacts with fluoride. Results from this study demonstrated that UTP-based biosorbents will be useful and safe for the removal of fluoride from drinking water.

  11. A comparison between different X-ray diffraction line broadening analysis methods for nanocrystalline ball-milled FCC powders

    Energy Technology Data Exchange (ETDEWEB)

    Soleimanian, V. [Shahrekord University, Department of Physics, Faculty of Sciences, P.O. Box 115, Shahrekord (Iran, Islamic Republic of); Shahrekord University, Nanotechnology Research Center, Shahrekord (Iran, Islamic Republic of); Mojtahedi, M. [Pooya Gharb Branch of University of Applied Science and Technology, Department of Materials Engineering, Kermanshah (Iran, Islamic Republic of)

    2015-06-15

    The microstructural characteristics of aluminum, copper and nickel powders are investigated using different X-ray diffraction line broadening analysis approaches. Prior to analysis, the powders were ball-milled to produce a nanocrystalline structure with high density of probable types of lattice defects. A variety of methods, including Scherrer, Williamson-Smallman, Williamson-Hall, Warren-Averbach, modified Williamson-Hall, modified Warren-Averbach, Rietveld refinement and whole powder pattern modeling (WPPM) approaches are applied. In this way, microstructural characteristics such as crystallite size, microstrain, dislocation density, effective outer cut-off radius of dislocations and the probability of twining and stacking faults are calculated. On the other hand, the results of conventional and advanced line broadening analysis methods are compared. It is revealed that the density of linear and planar defects in the mechanically deformed aluminum powder is significantly smaller than that of copper and nickel, as well as the level of anisotropic strain broadening. Moreover, the WPPM procedure provided a better profile fitting with more accurate results. (orig.)

  12. DEM modeling of ball mills with experimental validation: influence of contact parameters on charge motion and power draw

    Science.gov (United States)

    Boemer, Dominik; Ponthot, Jean-Philippe

    2017-01-01

    Discrete element method simulations of a 1:5-scale laboratory ball mill are presented in this paper to study the influence of the contact parameters on the charge motion and the power draw. The position density limit is introduced as an efficient mathematical tool to describe and to compare the macroscopic charge motion in different scenarios, i.a. with different values of the contact parameters. While the charge motion and the power draw are relatively insensitive to the stiffness and the damping coefficient of the linear spring-slider-damper contact law, the coefficient of friction has a strong influence since it controls the sliding propensity of the charge. Based on the experimental calibration and validation by charge motion photographs and power draw measurements, the descriptive and predictive capabilities of the position density limit and the discrete element method are demonstrated, i.e. the real position of the charge is precisely delimited by the respective position density limit and the power draw can be predicted with an accuracy of about 5 %.

  13. Nanostructured MgH2 obtained by cold rolling combined with short-time high-energy ball milling

    Directory of Open Access Journals (Sweden)

    Ricardo Floriano

    2012-01-01

    Full Text Available MgH2 was processed by short time high-energy ball milling (BM and cold rolling (CR. A new alternative processing route (CR + BM using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were evaluated. The CR + BM processing (compared to BM and CR process resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear dependence between the size/shape of the particles which compose the starting material and the efficiency of crystallite size reduction during the BM process. On the other hand, we observed that a short BM step improved the kinetic properties of the cold rolled material. It shows that the particle size reduction of MgH2 obtained by CR combined with the increase in specific surface area attained by short BM step could be key factors to allow the use of the CR + BM route.

  14. Nanostructured MgH2 obtained by cold rolling combined with short-time high-energy ball milling

    Directory of Open Access Journals (Sweden)

    Ricardo Floriano

    2013-02-01

    Full Text Available MgH2 was processed by short time high-energy ball milling (BM and cold rolling (CR. A new alternative processing route (CR + BM using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were evaluated. The CR + BM processing (compared to BM and CR process resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear dependence between the size/shape of the particles which compose the starting material and the efficiency of crystallite size reduction during the BM process. On the other hand, we observed that a short BM step improved the kinetic properties of the cold rolled material. It shows that the particle size reduction of MgH2 obtained by CR combined with the increase in specific surface area attained by short BM step could be key factors to allow the use of the CR + BM route.

  15. 泡沫铝层合结构钢球磨煤机隔声罩降噪性能研究%Study on reduction noise properties of foamed aluminum laminated structure acoustical enclosure for ball mill

    Institute of Scientific and Technical Information of China (English)

    于英华; 余国军

    2012-01-01

    In order to explore a new way for reduction noise of ball mill,the view point of using foamed aluminum laminated structure in ball mill acoustical enclosures was put forward based noise properties of ball mill.The laminated structure plate used to ball mills acoustical enclosures was designed,reduction noise properties of it were studied by theoretical analysis and test.The results show that the new ball mill acoustical enclosures can improve the reduction noise and environmental protection capabilities of the ball mill acoustical enclosure.%为探索钢球磨煤机的降噪新途径,针对钢球磨煤机噪声的特点,提出将泡沫铝层合结构应用于钢球磨煤机隔声罩中的观点。设计了泡沫铝钢球磨煤机隔声罩板的层合结构,并运用理论分析和实验分析的方法对其降噪性能进行研究。结果表明,用泡沫铝层合结构制造钢球磨煤机隔声罩,可提高隔声罩的降噪性能,并可提高隔声罩环保性能。

  16. Effect of Microwave and Ultrasonic Pretreatments on Biogas Production from Anaerobic Digestion of Palm Oil Mill Effleunt

    Directory of Open Access Journals (Sweden)

    N. Saifuddin

    2009-01-01

    Full Text Available Problem Statement: Oil palm production is a major agricultural industry in Malaysia. In 2006, palm oil mills in Malaysia produced more than 58 million tonnes of Palm Oil Mill Effluent (POME. Existing treatment in a series of open lagoons at high ambient temperatures, results in the uncontrolled production of methane and carbon dioxide, which are both green house gases (GHGs. With the increased worldwide concern on environmentally friendly production processes particularly the emission of methane, it is important to develop an alternative concept for POME treatment. This study elucidates the effects of pre-treatment of palm oil mill effluent by microwave irradiation and ultrasonic on anaerobic digestion. Approach: Effects of pre-treatment on sludge characterisation parameters were monitored. The Soluble Chemical Oxygen Demand (SCOD/total COD ratio and biodegradability of soluble organic matter increased significantly after both the pre-treatments which indicated an increase in disintegration of the floc structure of the sludge. Three identical bioreactors with working volume of 5 litres were used as anaerobic digesters at 32-35°C. The reactors were separately fed with pre-treated sludge (microwave, ultrasonic and combination of microwave and ultrasonic and control sludge at different Hydraulic Retention Times (HRT to check for the production of methane. Results: The maximum SCOD/TCOD ratio reached almost 29% after 30 min of ultrasonic treatment, while it was 45% after 7 min of microwave irradiation. The BOD5/SCOD ratio also increased after the pre-treatments suggesting the biodegradability of the soluble organic material increased during the treatment. It was observed that TVFA released was increased after both the treatments, with microwave treatment showing a higher yield of TVFA. Greatest enhancement in methane production was shown by the 3 min microwave plus 10 min ultrasonic treatment. Conclusion: The microwave in combination with

  17. Improved critical current density in ex situ processed MgB2 tapes by the size reduction of grains and crystallites by high-energy ball milling

    Science.gov (United States)

    Fujii, Hiroki; Ishitoya, Akira; Itoh, Shinji; Ozawa, Kiyoshi; Kitaguchi, Hitoshi

    2017-03-01

    We have fabricated Fe-sheathed MgB2 tapes through an ex situ process in a powder-in-tube (PIT) technique using powders ball milled under various conditions. Although the ex situ processed wires and tapes using the high-energy ball milled MgB2 powders have been studied and the decrease of grain and crystallite sizes of MgB2 and the critical current density (Jc) improvement of those conductors were reported so far, the use of filling powders milled at a higher rotation speed than previously reported further decreases the crystallite size and improves the Jc properties. The improved Jc values at 4.2 K and 10 T were nearly twice as large as those previously reported. Those milled powders and hence as-rolled tapes easily receive contamination in air. Thus, the transport Jc properties are easily deteriorated and scattered unless the samples are handled with care. The optimized heat treatment temperature (Topt) of those tape samples at which best performance in the Jc property is obtained decreases by more than 100 °C, compared with that of tapes using the as-received MgB2 powder.

  18. The phase analysis of spark plasma sintered MgB2 after ball milling.

    Science.gov (United States)

    Kang, Deuk-Kyun; Kim, Dong-Woong; Kim, Cheol-Jin; Ahn, In-Shup

    2010-01-01

    Mg and amorphous B powders below 10 and 3 micro meter were used as raw materials, and mixed by planetary-mill for 9 hours at argon atmosphere. MgB2 bulk was fabricated at the various temperatures by Spark Plasma Sintering. In the sintering process, mixed powders were sintered in graphite mold, at the pressure of 55 Mpa. The fabricated MgB2 samples were evaluated with XRD, EDS, FE-SEM, PPMS. MgB2, MgO and Fe phases were observed from XRD result. In the results, MgO and Fe were impurity which may affect superconducting properties of MgB2 samples, and it's distribution could be confirmed from EDS mapping result. In order to confirm the formation of MgB2 phase, DTA was used as heating rate of 10 degrees C/min at Ar atmosphere from room temperature to 1200 degrees C. In the PPMS result, the Tc (critical temperature) was about 21 K, and the density of spark plasma sintered samples increased to 1.87 g/cm3 by increasing sintering temperature.

  19. Fabrication, characterization and application of Cu{sub 2}ZnSn(S,Se){sub 4} absorber layer via a hybrid ink containing ball milled powders

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chunran [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); College of Mathematics and Physics, Bohai University, Jinzhou 121013 (China); Yao, Bin, E-mail: binyao@jlu.edu.cn [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Li, Yongfeng, E-mail: liyongfeng@jlu.edu.cn [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Xiao, Zhenyu [State Key Laboratory of Superhard Materials and College of Physics, Jilin University, Changchun 130023 (China); Ding, Zhanhui [Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, Changchun 130012 (China); Zhao, Haifeng; Zhang, Ligong; Zhang, Zhenzhong [State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, No. 3888 Dongnanhu Road, Changchun 130033 (China)

    2015-09-15

    Highlights: • CZTS powders are prepared from binary sulfides by a low cost ball milling process. • Elaborated on phase evolution and formation mechanism of CZTS. • Proposed a hybrid ink approach to resolve difficulty in deposition of CZTS film. • CZTSSe solar cells with highest efficiency of 4.2% are fabricated. • Small-grained CZTS layer hinders the collection of minority carriers. - Abstract: Cu{sub 2}ZnSnS{sub 4} (CZTS) powder with kesterite structure was prepared by ball milling of mixture of Cu{sub 2}S, ZnS and SnS{sub 2} powders for more than 15 h. By dispersing the milled CZTS powder in a Cu-, Zn- and Sn-chalcogenide precursor solution, a hybrid ink was fabricated. With the hybrid ink, a precursor CZTS film was deposited on Mo coated soda-lime glass by spin-coating. In order to obtain Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) absorber film with kesterite structure, the CZTS film was annealed at 560 °C for 15 min in Se ambient. It is demonstrated that the annealed film is dominated by a thick layer of kesterite CZTSSe with larger grain size and Cu{sub 8}Fe{sub 3}Sn{sub 2}(S,Se){sub 12} impurity phase with the exception of a very thin layer of kesterite CZTS with smaller grain size at interface between the CZTSSe and Mo layers. Solar cell device was fabricated by using the annealed CZTSSe film as absorber layer, and its conversion efficiency reached 4.2%. Mechanism of formation of the kesterite CZTS powder and CZTSSe film as well as effect of impurity phases on conversion efficiency are discussed in the present paper. The present results suggest that the hybrid ink approach combining with ball milling is a simple, low cost and promising method for preparation of kesterite CZTSSe absorber film and CZTSSe-based solar cell.

  20. Mechanical ball-milling preparation of fullerene/cobalt core/shell nanocomposites with high electrochemical hydrogen storage ability.

    Science.gov (United States)

    Bao, Di; Gao, Peng; Shen, Xiande; Chang, Cheng; Wang, Longqiang; Wang, Ying; Chen, Yujin; Zhou, Xiaoming; Sun, Shuchao; Li, Guobao; Yang, Piaoping

    2014-02-26

    The design and synthesis of new hydrogen storage nanomaterials with high capacity at low cost is extremely desirable but remains challenging for today's development of hydrogen economy. Because of the special honeycomb structures and excellent physical and chemical characters, fullerenes have been extensively considered as ideal materials for hydrogen storage materials. To take the most advantage of its distinctive symmetrical carbon cage structure, we have uniformly coated C60's surface with metal cobalt in nanoscale to form a core/shell structure through a simple ball-milling process in this work. The X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, high-solution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrometry (EDX) elemental mappings, and X-ray photoelectron spectroscopy (XPS) measurements have been conducted to evaluate the size and the composition of the composites. In addition, the blue shift of C60 pentagonal pinch mode demonstrates the formation of Co-C chemical bond, and which enhances the stability of the as-obtained nanocomposites. And their electrochemical experimental results demonstrate that the as-obtained C60/Co composites have excellent electrochemical hydrogen storage cycle reversibility and considerably high hydrogen storage capacities of 907 mAh/g (3.32 wt % hydrogen) under room temperature and ambient pressure, which is very close to the theoretical hydrogen storage capacities of individual metal Co (3.33 wt % hydrogen). Furthermore, their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible C60/Co↔C60/Co-Hx reaction is the dominant cycle process.

  1. Biological treatment with fungi of olive mill wastewater pre-treated by photocatalytic oxidation with nanomaterials.

    Science.gov (United States)

    Nogueira, V; Lopes, I; Freitas, A C; Rocha-Santos, T A P; Gonçalves, F; Duarte, A C; Pereira, R

    2015-05-01

    Olive mill wastewater (OMW) still is a major environmental problem due to its high chemical oxygen demand (COD) and total phenolic content (TPC), contributing for the high toxicity and recalcitrant nature. Several attempts have been made for developing more efficient treatment processes, but no chemical or biological approaches were found to be totally effective, especially in terms of toxicity reduction. In this context, the main purpose of this study was to investigate the treatability of OMW by the combination of photocatalytic oxidation, using two nanomaterials as catalysts (TiO2 and Fe2O3), with biological degradation by fungi (Pleurotus sajor caju and Phanerochaete chrysosporium). Photocatalytic oxidation was carried out using different systems, nano-TiO2/UV, nano-Fe2O3/UV, nano-TiO2/H2O2/UV and nano-Fe2O3/H2O2/UV. The effectiveness of the treatment was assessed through color (465nm), aromatics (270nm), COD and TPC reductions, as well as by the decrease in toxicity using the bacterium Vibrio fischeri. The chemical treatment with the system nano-TiO2/H2O2/UV promoted 43%, 14%, 38% and 31% reductions in color, aromatics content, COD and TPC, respectively. However no toxicity reduction was observed. The combination with a biological treatment increased the reduction of COD and TPC as well as a reduction in toxicity. The treatment with P. chrysosporium promoted the highest reduction in toxicity, but P. sajor caju was responsible for the best reduction in COD and TPC. However, the biological treatment was more effective when no hydrogen peroxide was used in the pre-treatment.

  2. Facile synthesis and regeneration of Mg(BH4)2 by high energy reactive ball milling of MgB2.

    Science.gov (United States)

    Gupta, Shalabh; Hlova, Ihor Z; Kobayashi, Takeshi; Denys, Roman V; Chen, Fu; Zavaliy, Ihor Y; Pruski, Marek; Pecharsky, Vitalij K

    2013-01-28

    We report direct hydrogenation of MgB(2) in a planetary ball mill. Magnesium borohydride, Mg(BH(4))(2), and various polyhedral borane anion salts have been synthesized at pressures between 50 and 350 bar H(2) without the need for subsequent isothermal hydrogenation at elevated temperature and pressure. The obtained products release ∼4 wt% H(2) below 390 °C, and a major portion of Mg(BH(4))(2) transforms back to MgB(2) at around 300 °C, demonstrating the possibility of reversible hydrogen storage in an Mg(BH(4))(2)-MgB(2) system.

  3. Preparation of Sn-Si-C Composite as Li-ion Battery Anode Material by High Energy Ball Milling and Its Properties

    Institute of Scientific and Technical Information of China (English)

    LI Yan-hong; LIU Yuan; QIUXin-ping

    2011-01-01

    Electrochemically active Sn-Si-C composite was synthesized by high energy ball milling (HEBM) in Ar atmosphere.The so-obtained composite was characterized by X-ray diffraction and field emission scanning electron microscopy. Lithium insertion/extraction characteristics of the composites were examined by constant current charge-discharge and cyclic voltammetry methods.The results show that there is no new alloy generated by HEBM.The composite synthesized by two-step HEBM resulted in initial lithium insertion specific capacity as high as 1224 mA.h/g and higher reversible lithium extraction specific capacity of 855 mA.h/g.

  4. Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al2O3 under inspection

    Directory of Open Access Journals (Sweden)

    Franziska Bernhardt

    2010-01-01

    Full Text Available Although a plethora of synthetic procedures mediated by KF-loaded aluminas is available in the literature, there is almost no data concerning the influence of parameters such as alumina modification or KF-loading on experimental results. Hence, the Pd-catalyzed, solvent-free Suzuki–Miyaura reaction was chosen as model reaction to investigate the effect of the above mentioned parameters on the results of coupling reactions. The results from ball milling experiments led to the conclusion that self-prepared and commercially available KF–Al2O3 differ in water content. The higher the residual water content, the higher are the product yields.

  5. Magnetic properties of ball-milled nanocrystalline alloys Fe sub 7 sub 8 B sub 1 sub 3 Si sub 9

    CERN Document Server

    Pekala, M; Jachimowicz, M

    2002-01-01

    Magnetic properties of nanocrystalline Fe sub 7 sub 8 B sub 1 sub 3 Si sub 9 alloys are studied for three series prepared by ball milling starting from amorphous ribbons, crystallized ribbons, and elemental powders. Temperature variation of static magnetization results in strong ferromagnetic interaction which is weakly dependent on the initial material. Magnetic hysteresis loops show that saturation magnetization, magnetic remanence, and coercive field increase with frequency for both series of ribbon samples, whereas they decrease for alloys prepared from elemental powders. Power losses raise faster for the alloys prepared from elemental powders than for the two other alloys. (author)

  6. Effect of soya milk on nutritive, antioxidative, reological and textural properties of chocolate produced in a ball mill

    Directory of Open Access Journals (Sweden)

    Zarić Danica B.

    2011-01-01

    Full Text Available Chocolate is a complex rheological system in which non-fat cocoa particles and sugar particles are enveloped by crystal matrix of cocoa butter. Physical properties of chocolate depend on ingredient composition, method of production and properly performed pre-crystallization phase. In this work, chocolate was produced in an unconventional way, i.e. in a ball mill applying variable refining time (30, 60 and 90 min and pre-crystallization temperature in chocolate masses (26, 28 and 30⁰C. Two types of chocolate were produced: chocolate with 20% of powdered cow’s milk (R1 and chocolate with 20% of soya milk powder (R2. The quality of chocolate was followed by comparing nutritive composition, 23 polyphenol content, hardness of chocolate, solid triglyceride content (SFC and rheological parameters (Casson yield flow (Pa, Casson viscosity (Pas, the area of the thixotropic loop, elastic modulus and creep curves. The aim of this paper is determining changes caused by replacing cow’s milk with soya milk powder in respect of nutritive, rheological and sensory properties, as well as defining optimal parameters: precrystallization temperature and refining time of soya milk chocolate in order to obtain suitable sensory and physical properties identical to those of milk chocolate mass. The results show that replacing powdered cow’s milk with soya milk powder affects the increase in nutritive value of soya milk chocolate. R2 chocolate mass showed the increase in essential amino acids and fatty acids. This chocolate mass also showed the increase in total polyphenols by 28.1% comparing to R1 chocolate mass. By comparing viscosity, yield stress, shear stress and the area of the thixotropic loop, it can be observed that R1 chocolate mass represents a more organized and simpler system than the mass with soya milk (R2, as it shows lower values for all the above mentioned parameters, regardless of the refining time and pre-crystallization temperature

  7. Contamination Effects on Improving the Hydrogenation/Dehydrogenation Kinetics of Binary Magnesium Hydride/Titanium Carbide Systems Prepared by Reactive Ball Milling

    Directory of Open Access Journals (Sweden)

    M. Sherif El-Eskandarany

    2015-10-01

    Full Text Available Ultrafine MgH2 nanocrystalline powders were prepared by reactive ball milling of elemental Mg powders after 200 h of high-energy ball milling under a hydrogen gas pressure of 50 bar. The as-prepared metal hydride powders were contaminated with 2.2 wt. % of FeCr-stainless steel that was introduced to the powders upon using stainless steel milling tools made of the same alloy. The as-synthesized MgH2 was doped with previously prepared TiC nanopowders, which were contaminated with 2.4 wt. % FeCr (materials of the milling media, and then ball milled under hydrogen gas atmosphere for 50 h. The results related to the morphological examinations of the fabricated nanocomposite powders beyond the micro-and nano-levels showed excellent distributions of 5.2 wt. % TiC/4.6 wt. % FeCr dispersoids embedded into the fine host matrix of MgH2 powders. The as-fabricated nanocomposite MgH2/5.2 wt. % TiC/4.6 wt. % FeCr powders possessed superior hydrogenation/dehydrogenation characteristics, suggested by the low value of the activation energy (97.74 kJ/mol, and the short time required for achieving a complete absorption (6.6 min and desorption (8.4 min of 5.51 wt. % H2 at a moderate temperature of 275 C under a hydrogen gas pressure ranging from 100 mbar to 8 bar. van’t Hoff approach was used to calculate the enthalpy (DH and entropy (DS of hydrogenation for MgH2, which was found to be 72.74 kJ/mol and 112.79 J/mol H2/K, respectively. Moreover, van’t Hoff method was employed to calculate the DH and DS of dehydrogenation, which was found to be 76.76 kJ/mol and 119.15 J/mol H2/K, respectively. This new nanocomposite system possessed excellent absorption/desorption cyclability of 696 complete cycles, achieved in a cyclic-life-time of 682 h.

  8. Improvement of Center -driven Overflow Ball Mill with Double -wall Partition%中心传动双仓溢流型球磨机改进

    Institute of Scientific and Technical Information of China (English)

    李兴

    2015-01-01

    磨机广泛应用于选矿、冶金、水泥厂、化工、电力等工矿企业粉磨各种矿石及其它可磨性物料。中心传动双仓溢流型球磨机应用于拜耳法生产氧化铝,在生产中用于对原矿浆的细磨,对于中心传动双仓溢流型球磨机在全国的使用没有几例。针对目前出现的问题,结合球磨机、管磨机在该行业成熟的使用经验进行了分析处理,找到合理的改进措施,取得了一定的社会和经济效益。%Mill is widely used in mineral processing,metallurgy,cement plant,chemical industry,electric pow-er and other industrial and mining enterprises to smash all kinds of ores and other materials.Center -driven over-flow ball mill with double -wall partition is used in alumina production by Bayer process,but few were applied in the grinding of original pulp.Aiming at these problems,the service experience of ball mill and tube mill in this industry was analyzed and then rational improvement measures were found,thus achieving some social and economic benefits.

  9. Enhanced magnetic properties of NiO powders by the mechanical activation of aluminothermic reduction of NiO prepared by a ball milling process

    Science.gov (United States)

    Padhan, Aneeta Manjari; Ravikumar, P.; Saravanan, P.; Alagarsamy, Perumal

    2016-11-01

    We report the effect of mechanical activation on NiO-Al (x wt%) reduction reaction and resulting structural and magnetic properties by carrying out high-energy planetary ball milling. The pure NiO (un-milled) and milled NiO-Al (x≤2.5) powders exhibit face centered cubic structure, but the antiferromagnetic nature of pure NiO powder shows significant room temperature ferromagnetism with moderate moment and coercivity after milling due to non-stoichiometry in NiO caused by the defects, size reduction and oxidation of Ni. On the other hand, the addition of Al between 2.5 and 10% in NiO forms solid solution of NiO-Al with considerable reduction in the moment due to the atomic disorder. With increasing Al above 10%, NiO reduction reaction progresses gradually and as a result, the average magnetization increases from 0.57 to 4.3 emu/g with increasing Al up to 25%. A maximum of 91% reduction was observed for NiO-Al (40%) powders in 30 h of milling with a large increase in magnetization (~24 emu/g) along with the development of α-Al2O3. Thermomagnetization data reveal the presence of mixed magnetic phases in milled NiO powders and the component of induced ferromagnetic phase fades out with increasing Al due to the formation of Ni from the NiO-Al reduction reaction. The changes in the structural and magnetic properties are discussed on the basis of mechanical activation on the reduction of NiO by Al. The controlled reduction reaction with different Al content in NiO-Al is encouraging for the applications in catalysis and process of ore reduction.

  10. Nitrogen-doped graphene by all-solid-state ball-milling graphite with urea as a high-power lithium ion battery anode

    Science.gov (United States)

    Liu, Chao; Liu, Xingang; Tan, Jiang; Wang, Qingfu; Wen, Hao; Zhang, Chuhong

    2017-02-01

    Nitrogen-doped graphene nanosheets (NGNS) are prepared by a novel mechanochemical method via all-solid-state ball-milling graphite with urea. The ball-milling process does not only successfully exfoliate the graphite into multi-layer (new solid doping and assist-grinding agents, has the advantages of low cost and good water solubility that can simplify the fabrication process. The as-prepared NGNS are investigated in detail by XRD, SEM, HRTEM, TGA, XPS and Raman spectroscopy. The doping nitrogens are around 3.15% and dominated (>94%) by pyrindic-N and pyrrolic-N which facilitates the NGNS with enhanced electronic conductivity and Li-ion storage capability. For the first time, we demonstrate that the all-solid-state prepared NGNS exhibits, especially at high currents, enhanced cycling stability and rate capability as Lithium ion battery (LIB) anode active material when compared to pristine graphite and undoped graphene in half-cell configuration. The method presented in this article may provide a simple, clean, economical and scalable strategy for preparation of NGNS as a feasible and promising anode material for LIBs.

  11. Finite size effects and spin transition in ball-milled {gamma}-(FeMn){sub 30}Cu{sub 70} nanostructured alloys

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, J. [Grupo de Estado Solido, Instituto de Fisica, Universidad de Antioquia, A. A. 1226, Medellin (Colombia)]. E-mail: jrestre@fisica.udea.edu.co; Greneche, J.M. [Laboratoire de Physique de l' Etat Condense, UMR CNRS 6087, Universite du Maine, 72085 Le Mans, Cedex 9 (France); Gonzalez, J.M. [Instituto de Magnetismo Aplicado, P.O. Box 155. 28230 Las Rozas, Madrid (Spain)

    2004-12-31

    Fe{sub 15}Mn{sub 15}Cu{sub 70} alloys were prepared by high-energy ball milling over a wide range of grinding times from 15 min to 72 h. The corresponding magnetic properties were followed by means of vibrating sample magnetometry, magnetic susceptibility and Moessbauer spectroscopy. By using a Rietveld structural analysis of high-resolution X-ray diffraction data, lattice parameter and grain size correlations with magnetization and coercive force were carried out. Results revealed a strong microstructural dependence of the magnetic properties with the grain size, resembling a finite size-driven magnetic transition at a critical crystallite value of around 8.5 nm. This behavior is endorsed by a partial low- to high-spin transition according to isomer shift results, at a critical unit-cell volume of around 50 A{sup 3} at 77 K attributed to strong local variations of the interatomic spacing as a consequence of the employed ball-milling procedure. Finally, as concerns to temperature behavior, samples exhibited a freezing temperature at around 61 K and a wide distribution of relaxation times ascribed to the presence of interacting CuMn and FeMnCu clusters.

  12. Investigation of physical properties and stability of indomethacin-cimetidine and naproxen-cimetidine co-amorphous systems prepared by quench cooling, coprecipitation and ball milling

    DEFF Research Database (Denmark)

    Lim, Ai Wei; Löbmann, Korbinian; Grohganz, Holger;

    2016-01-01

    OBJECTIVES: The objective was to characterize the structural behaviour of indomethacin-cimetidine and naproxen-cimetidine co-amorphous systems (1 : 1 molar ratio) prepared by quench cooling, co-evaporation and ball milling. METHODS: Powder X-ray diffraction (PXRD) and DSC were used to characterise...... the samples. Structural relaxation (i.e. molecular mobility) behaviour was obtained from the Kohlrausch-Williams-Watts (KWW) relationship. KEY FINDINGS: A glass transition temperature (Tg ), on average 20 °C higher than the predicted Tg (calculated from the Fox equation), was observed in all samples...... by quench cooling (ln τ(β) = 2.4) and co-evaporation (ln τ(β) = 2.5). In contrast, molecular mobility of the naproxen-cimetidine samples followed the order co-evaporation (ln τ(β) = 0.8), quench cooling (ln τ(β) = 1.6) and ball milling (ln τ(β) = 1.8). CONCLUSION: The estimated relaxation times by the DSC...

  13. 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.

  14. One Step Ball-Milling Synthesis of LiFePO4 Nanoparticles as the Cathode Material of Li-lon Batteries

    Institute of Scientific and Technical Information of China (English)

    AI Xinping; LI Hai; LI Xiaoyan; LIAO Qinlin; LIU Bingdong; YANG Hanxi

    2006-01-01

    A one-step synthetic method was used to synthesize Olivline LiFePO4 powders by direct ball milling the stoichiometric mixture of Fe, Li3 PO4, and FePO4 powders.XRD and TEM measurements revealed that the as-prepared LiFePO4 powder have a homogeneous Olivine structure and a uniform size distribution of ca. 50 nm. Based on this material,a LiFePO4/C composite was prepared and used for the cathode material of Li-ion batteries. The charge-discharge experiments demonstrated that the LiFePO4/C composite material has a high capacity of 132 mAh/g at 0.1 C and a quite highrate capability of 95 mAh/g at 1 C. This new ball-milling method may provide a completely green synthetic route for preparing the materials of this type cost-effectively and in large volume.

  15. Research on Ball Best Gradation Technology of Coal Mill%磨煤机钢球最佳级配技术应用研究

    Institute of Scientific and Technical Information of China (English)

    宋绍伟

    2012-01-01

    The steady - state abrasion model and a lot of engineering tests are conducted to determine the optimal ball grade and reasonable loading; by changing the high chrome steel balls carbon chrome ration, adding manganese, tungsten and other alloying elements and the use of special oil quenching process, a diverse high - chromium alloy wear - resistant ball is successfully developed, improving the stability of the best grading, effectively reducing the mill current energy efficiency significantly. Practice shows that: using the technology,thermal power plant reduced 37% ball mill load,achieving 23% less power consumption and 61% less steel consumption, which is a substantial energy saving; with the mill load decreases , the failure rate of the gears, bearings and transmissions and other equipment was significantly reduced , extending equipment life, and also saving a lot of maintenance costs, which has broad prospects for promotion.%应用钢球磨损稳态模型计算和工程试验确定钢球最佳级配和合理的钢球装载量;通过改变高铬钢球的铬碳比,增添锰、钨等合金元素以及采用特殊的油淬火热处理工艺,研制成功了多元高铬合金耐磨钢球,提高了最佳级配的稳定性,有效地降低了磨煤机电流,节能效益显著.实践表明:火电厂使用该技术后,磨煤机钢球装载量减少37%、电耗降低23%、钢耗降低61%,实现了火电厂磨煤机的大幅度节能降耗;随着磨煤机负载的减小,大小齿轮、轴瓦和变速箱等设备的故障率明显降低,设备寿命得到延长,同时也节省了大量的维护成本,具有广阔的推广前景.

  16. An X-Ray Absorption Spectroscopy Study of Ball-Milled Lithium Tantalate and Lithium Titanate Nanocrystals

    Science.gov (United States)

    Chadwick, A. V.; Pickup, D. M.; Ramos, S.; Cibin, G.; Tapia-Ruiz, N.; Breuer, S.; Wohlmuth, D.; Wilkening, M.

    2017-02-01

    Previous work has shown that nanocrystalline samples of lithium tantalate and titanate prepared by high-energy milling show unusually high lithium ion conductivity. Here, we report an X-ray absorption spectroscopy (XAS) study at the Ti K-edge and the Ta L3 edge of samples that have been milled for various lengths of time. For both systems the results show that milling creates amorphous material whose quantity increases with the milling time. The more extensive data for the tantalate shows that milling for only 30 minutes generates ∼25% amorphous content in the sample. The content rises to ∼60% after 16 hours. It is suggested that it is the motion of the lithium ions through the amorphous content that provides the mechanism for the high ionic conductivity.

  17. Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol - Comparison of five pretreatment technologies

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Thygesen, Anders; Thomsen, Sune Tjalfe

    2013-01-01

    A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma......-assisted pretreatment (PAP) and ball milling (BM), to determine effects of the pretreatment methods on the conversion of C. linum into ethanol by simultaneous saccharification and fermentation (SSF). WO and BM showed the highest ethanol yield of 44. g ethanol/100. g glucan, which was close to the theoretical ethanol...... yield of 57. g ethanol/100. g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae...

  18. Nanocrystalline Nd{sub 2}Fe{sub 17} synthesized by high-energy ball milling: crystal structure, microstructure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Pablo; Gorria, Pedro; Perez, Maria J; Sanchez Llamazares, Jose L; Blanco, Jesus A [Departamento de Fisica, Universidad de Oviedo, Calvo Sotelo, s/n, 33007 Oviedo (Spain); Franco, Victorino [Departamento Fisica de la Materia Condensada, ICMSE-CSIC, Universidad de Sevilla, PO Box 1065, 41080 Sevilla (Spain); Sanchez Marcos, Jorge [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain); Puente Orench, Ines, E-mail: alvarezpablo.uo@uniovi.e [Institute Laue-Langevin, BP 156, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9 (France)

    2010-06-02

    Nanocrystalline Nd{sub 2}Fe{sub 17} powders have been obtained by means of high-energy ball milling from nearly single-phase bulk alloys produced by arc melting and high temperature homogenization annealing. The rhombohedral Th{sub 2}Zn{sub 17}-type crystal structure of the bulk alloy remains unaltered after the milling process, with almost unchanged values for the cell parameters. However, the severe mechanical processing induces drastic microstructural changes. A decrease of the mean crystalline size down to around 10 nm is observed, giving rise to a considerable augmentation of the disordered inter-grain boundaries. This modification of the microstructure affects the magnetic behaviour of the milled powders, although the magnetic structure remains collinear ferromagnetic. While a unique ferro-to-paramagnetic transition temperature, T{sub C} = 339 {+-} 2 K, is observed in the bulk alloy, the nanocrystalline samples exhibit a more likely distribution of T{sub C} values. The latter seems to be responsible for the significant broadening of the temperature range in which magneto-caloric effect is observed, and the lowering of the maximum value of the magnetic entropy change.

  19. Synthesis of Vanadium-Vanadium Carbide in-situ nanocomposites by high energy ball milling and spark plasma sintering

    Directory of Open Access Journals (Sweden)

    Krishnan Vinoadh Kumar

    2016-01-01

    Full Text Available In the present work, Vanadium-Vanadium Carbide (V-V2C in-situ nanocomposites were synthesized by mechanically milling vanadium powders with 0.5 wt.% stearic acid. Milled powders were consolidated using spark plasma sintering at 1150, 1250 and 1350°C for 10 min. Phase and morphology of the milled powders were studied using X-ray diffraction and scanning electron microscopy. X-ray diffraction analysis of 10 h milled powder shows the evolution of amorphous phase. Energy dispersive X-ray spectroscopy studies on milled powder shows the presence of carbon, which could be due to the decomposition of stearic acid during milling. Degree of crystallinity of milled powder was confirmed using the selective area electron diffraction pattern. X-ray diffraction analysis of sintered samples indicate sharp peaks from vanadium and vanadium carbide (V2C, endorsing amorphous to nanocrystalline transformation. Micro-hardness value of sintered samples increases with increasing sintering temperature.

  20. Preparation of Capsaicin Powders by Balling Milling%球磨法制备天然辣椒素粉体工艺研究

    Institute of Scientific and Technical Information of China (English)

    黄永鹏; 钟辉; 陈博; 焦剑岚

    2012-01-01

    Capsaicin powders were prepared by ball milling with the materials of capsaicin and silica gel. The mass ratio of steel balls to capsaicin and silica gel, the mass ratio of capsaicin to silica gel, the milling time and the velocity of revolution were changed according to orthogonal design of the experiments. The results of the orthogonal experiments show that the optimum parameters in the preparation of capsaicin are as follows: the mass ratio of steel balls to capsaicin and silica gel is 5 M, the mass ratio of capsaicin to silica gel is 4:6, the milling time is 20 min and the velocity of revolution is 300 r/min. 94.98% volume fraction of capsaicin particles small than 10 (xm in size are obtained under the optimum parameters.%以天然辣椒素和硅胶为原料和辅料,采用球磨法制备天然辣椒素粉体,采用正交实验法,对球料质量比、天然辣椒素与硅胶的质量比、球磨时间、球磨机转速等参数进行4因素3水平的正交实验设计,研究这些工艺参数对球磨法制备天然辣椒素粉体的影响.结果表明,制备天然辣椒素粉体的最佳工艺为球料质量比为5∶1,天然辣椒素与硅胶的质量比为4∶6,球磨时间为20 min,转速为300 r/min,在此条件下,制备的天然辣椒素粉体中粒径小于10 μm的颗粒的体积分数为94.98%.

  1. Progress in high-energy ball milling for the preparation of absorbing materials%吸波材料的高能球磨工艺研究进展

    Institute of Scientific and Technical Information of China (English)

    王锰刚; 谌静; 谢国治; 陈文俊; 李艳; 张泽敖; 王嘉波; 沈杨; 孙康; 周倜

    2016-01-01

    High-energy ball milling method has become a important way to prepare various absorbing materials, because of simple control, environmental production, low cost and high efficiency. This paper summarizes the recent research progress of high-energy ball milling process in absorbing materials,indicating that high-energy ball milling process in absorbing materials, especially in flaky absorbing materials with shape anisotropy, which has very broad application prospects. Then we look forward to the development prospects of high-energy ball milling process in absorbing materials.%高能球磨法由于其便于控制、生产环保、成本低、效率高等优点成为制备吸波材料的一种重要方法。总结了近期高能球磨工艺在吸波材料领域的应用研究进展,表明高能球磨工艺在吸波领域,尤其是在制备具有形状各向异性的片状吸波材料领域,具有十分广阔的应用前景,展望了高能球磨工艺在未来吸波材料领域的发展前景。

  2. Ultrathin SmCo5 nanoflakes with high-coercivity prepared by solid particle (NaCl) and surfactant co-assisted ball milling

    Science.gov (United States)

    Zuo, Wen-Liang; Zhao, Xin; Zhao, Tong-Yun; Hu, Feng-Xia; Sun, Ji-Rong; Shen, Bao-Gen

    2016-05-01

    The ultrathin SmCo5 nanoflakes with average thickness smaller than 50 nm are prepared by a novel method of solid particle (NaCl) and surfactant co-assisted ball milling. The as-prepared nanoflakes exhibit a narrower thickness distribution of 10–50 nm and high coercivity of 23 kOe. The possible formation mechanism of nanoflakes are proposed. Temperature dependence of demagnetization curves indicate that the magnetization reversal may be controlled by both nucleation and pinning. The results of X-ray powder diffraction and magnetic measurement for aligned SmCo5 nanoflakes resin composite indicate that the nanoflakes have a high texture degree. The ultrathin thickness and high coercivity are beneficial for preparing the high performance soft/hard coupling magnets and nanocomposite magnets.

  3. Microstructure and Electrical Properties of Er2O3-Doped ZnO-Based Varistor Ceramics Prepared by High-Energy Ball Milling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microstructure, electrical properties and density of ZnO-based varistor ceramics with different Er2O3 content prepared by high-energy ball milling (HEBM) and sintered at 800 ℃ were investigated. With increasing Er2O3 content, the ZnO grain size decreases due to the Er-rich phases inhibiting grain growth;and nonlinear coefficient (α) decreases because of the decrease of barrier height (φB). The breakdown voltage (Eb) and density increase, whereas leakage current (IL) decreases with increasing Er2O3 content. The barrier height (φB), donor concentration (Nd), density of interface states (Ns) decrease and barrier width (ω) increases with increasing Er2O3 content due to acceptor effect of Er2O3 in varistor ceramics.

  4. Effect of ball milling and thermal treatment on exchange bias and magnetocaloric properties of Ni48Mn39.5Sn10.5Al2 ribbons

    Science.gov (United States)

    Czaja, P.; Przewoźnik, J.; Fitta, M.; Bałanda, M.; Chrobak, A.; Kania, B.; Zackiewicz, P.; Wójcik, A.; Szlezynger, M.; Maziarz, W.

    2016-03-01

    The combined effect of ball milling and subsequent heat treatment on microstructure, magnetic, magnetocaloric and exchange bias properties of Ni48Mn39.5Sn10.5Al2 ribbons is reported. The annealing treatment results in the increase of the critical martensitic transformation temperature. The magnetic entropy change ΔSM of the order of 7.9 and -2.3 J kg K-1 for the annealed 50-32 μm powder fraction is determined. This is less than in the as melt spun ribbon but appears at a considerably higher temperature. At the same time EB is decreased due to annealing treatment. This decrease is attributed to the strengthened ferromagnetic exchange coupling due heat induced stress and structural relaxation.

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

    Directory of Open Access Journals (Sweden)

    Ivo Marek

    2016-05-01

    Full Text Available In this study, bulk ultrafine-grained and micro-crystalline cobalt was prepared using a combination of high-energy ball milling and subsequent spark plasma sintering. The average grain sizes of the ultrafine-grained and micro-crystalline materials were 200 nm and 1 μm, respectively. Mechanical properties such as the compressive yield strength, the ultimate compressive strength, the maximum compressive deformation and the Vickers hardness were studied and compared with those of a coarse-grained as-cast cobalt reference sample. The bulk ultrafine-grained sample showed an ultra-high compressive yield strength that was greater than 1 GPa, which is discussed with respect to the preparation technique and a structural investigation.

  6. Study on design of thrust blocks of large-scale ball mills with seismic loadings%地震载荷作用下大型球磨机止推块的抗震设计研究

    Institute of Scientific and Technical Information of China (English)

    刘普林; 郭勤涛; 姬建刚; 陈剑

    2011-01-01

    In order to study the anti-seismic performance of large-scale ball mills, the paper firstly establishes a finite element model of overall system composed of the ball mill barrel and the foundation. Then it finds the most dangerous conditions of earthquake, and respectively uses current national anti-seismic design code and Australian anti-seismic standards as the input stimulus to obtain the acceleration peak response of ball mills with seismic loadings in the finite element analysis software Nastran. In addition, the paper uses the peak response as the input loadings, establishes the finite element sub-model of the most dangerous parts of the ball mill, and further analyzes the contact strength of the dangerous parts. The analysis provides a theoretical basis for the anti-seismic structural design of large-scale ball mills and the overall anti-seismic design.%为了研究大型球磨机的抗震性能,首先建立了球磨机回转体和地基基础的整体系统有限元模型;寻找地震作用最危险工况,分别以我国现行抗震设计规范和澳大利亚抗震标准作为输入激励,在有限元分析软件Nastran中得到球磨机地震加速度峰值响应;然后,以该峰值响应作为输入载荷,建立了球磨机最危险部位的有限元子模型,进一步分析该危险部位的接触强度.该分析为大型球磨机抗震结构设计及整体抗震设计提供了理论依据.

  7. Research on Smooth Connection for Edge Curves of Conical Ball End Mill%锥形球头立铣刀刀刃曲线光滑过渡研究

    Institute of Scientific and Technical Information of China (English)

    乔小峰; 刘志兵; 庞思勤; 王西彬; 何理论

    2013-01-01

    针对锥形球头立铣刀的几何特征,应用广义螺旋运动概念建立了刀刃螺旋线的通用数学模型.利用微分几何的基本原理,研究了锥形球头立铣刀的刀刃曲线建模方法,设计了一种新的锥形球头立铣刀复合型刀刃曲线,解决了复合型刀刃曲线的光滑过渡问题,并应用Matlab软件对所设计的刀刃曲线进行了建模和验证.为锥形球头类刀具的进一步设计提供了理论方法和依据.%According to the geometrical characteristics of conical ball end mills,the general mathematical model of helical edge curves was established by using the concept of generalized helical movement.With the basic principles of differential geometry,the modelling method for edge curves of conical ball end mill was studied and a novel edge curve of conical ball end mill was designed,and the problem on the smooth connection of composite edge curves of conical ball end mill was also studied.Beside,the smooth connection of composite edge curves was modeled and verified by using Matlab.As a result,a theoretical method and basis for the further design of conical ball end mills was provided.

  8. Study on Comminution Process and Micronization Efficiency of Potato Starch by Ball Milling%马铃薯淀粉的球磨破碎方式和微细化效果研究

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    采用机械球磨方法对马铃薯淀粉进行微粉碎,研究了球磨过程中淀粉颗粒的形貌、粒度分布及比表面积的变化特征,探讨了淀粉颗粒的破碎方式和粉碎模型,并考察了马铃薯淀粉微细化的效果。%Potato starch is mechanically ground by ball milling.The granular appearance,granule size distribution and specific surface of the starch are studied before and after milling.The comminution process and micronization effciency of the starch are discussed based on ultra-micronization model.The results show that potato starch can be effectively micronized by ball milling.

  9. Growth and development of tomato plants Lycopersicon Esculentum Mill. under different saline conditions by fertirrigation with pretreated cheese whey wastewater.

    Science.gov (United States)

    Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse

    2013-01-01

    Pretreated cheese whey wastewater (CWW) has been used at different salinity levels: 1.75, 2.22, 3.22, 5.02 and 10.02 dS m(-1) and compared with fresh water (1.44 dS m(-1)). Two cultivars (cv.) of the tomato plant Lycopersicon Esculentum Mill. (Roma and Rio Grande) were exposed to saline conditions for 72 days. Salinity level (treatment) had no significant effects on the fresh weight and dry matter of the leaves, stems and roots. Similar results were found when specific leaf area, leaflet area, ramifications number of 1st order/plant, stem diameter and length, nodes number/stem and primary root length were considered. Conversely, the salinity level significantly influenced the Soil Plant Analysis Development (SPAD) index and the distance between nodes in the plant stem. In the first case, an increase of 21% was obtained in the salinity levels of 5.02 and 10.02 dS m(-1) for cv. Rio Grande, compared with the control run. The results showed that the pretreated CWW can be a source of nutrients for tomato plants, with reduced effects on growth and development.

  10. Thermal pretreatment of olive mill wastewater for efficient methane production: control of aromatic substances degradation by monitoring cyclohexane carboxylic acid.

    Science.gov (United States)

    Pontoni, Ludovico; d'Antonio, Giuseppe; Esposito, Giovanni; Fabbricino, Massimiliano; Frunzo, Luigi; Pirozzi, Francesco

    2015-01-01

    Anaerobic digestion is investigated as a sustainable depurative strategy of olive oil mill wastewater (OOMW). The effect of thermal pretreatment on the anaerobic biodegradation of aromatic compounds present in (OMWW) was investigated. The anaerobic degradation of phenolic compounds, well known to be the main concern related to this kind of effluents, was monitored in batch anaerobic tests at a laboratory scale on samples pretreated at mild (80±1 °C), intermediate (90±1 °C) and high temperature (120±1 °C). The obtained results showed an increase of 34% in specific methane production (SMP) for OMWW treated at the lowest temperature and a decrease of 18% for treatment at the highest temperature. These results were related to the different decomposition pathways of the lignocellulosic compounds obtained in the tested conditions. The decomposition pathway was determined by measuring the concentrations of volatile organic acids, phenols, and chemical oxygen demand (COD) versus time. Cyclohexane carboxylic acid (CHCA) production was identified in all the tests with a maximum concentration of around 200 µmol L(-1) in accordance with the phenols degradation, suggesting that anaerobic digestion of aromatic compounds follows the benzoyl-CoA pathway. Accurate monitoring of this compound was proposed as the key element to control the process evolution. The total phenols (TP) and total COD removals were, with SMP, the highest (TP 62.7%-COD 63.2%) at 80 °C and lowest (TP 44.9%-COD 32.2%) at 120 °C. In all cases, thermal pretreatment was able to enhance the TP removal ability (up to 42% increase).

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

    Energy Technology Data Exchange (ETDEWEB)

    Dudina, Dina V.; Lomovsky, Oleg I. [Institute of Solid State Chemistry and Mechanochemistry SB RAS, Kutateladze str. 18, Novosibirsk 630128 (Russian Federation); Valeev, Konstantin R.; Tikhov, Serguey F.; Boldyreva, Natalya N. [Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Salanov, Aleksey N.; Cherepanova, Svetlana V.; Zaikovskii, Vladimir I. [Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Novosibirsk State University (NSU), Pirogova str. 2, Novosibirsk 630090 (Russian Federation); Andreev, Andrey S. [Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Novosibirsk State University (NSU), Pirogova str. 2, Novosibirsk 630090 (Russian Federation); Soft Matter Sciences and Engineering Laboratory, UMR 7615 CNRS UPMC, ESPCI ParisTech, 10 rue Vauquelin, Paris 75005 (France); Lapina, Olga B.; Sadykov, Vladislav A. [Boreskov Institute of Catalysis SB RAS, pr. Lavrentieva 5, Novosibirsk 630090 (Russian Federation); Novosibirsk State University (NSU), Pirogova str. 2, Novosibirsk 630090 (Russian Federation)

    2015-04-25

    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{sub 2}(+Cu) → Cu{sub 9}Al{sub 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.

  12. Preparation of a sample with a single MgH2 phase by horizontal ball milling and the first hydriding reaction of 90 wt% Mg-10 wt% MgH2

    Science.gov (United States)

    Hong, Seong-Hyeon; Song, Myoung Youp

    2015-03-01

    In order to prepare an additive-free sample with a single MgH2 phase, 90 wt% Mg-10 wt% MgH2 (named 90Mg-10MgH2) was milled under a hydrogen atmosphere in a horizontal ball mill, and then hydrided. The hydrogen absorption and desorption properties of the prepared samples were investigated, and compared with those of milled pure Mg and purchased MgH2. X-ray diffraction analysis, measurement of specific BET surface areas, and observation of the prepared samples by scanning electron microscope were performed. The 90Mg-10MgH2 sample after hydriding-dehydriding cycling had small and large particles with fine particles on their surfaces, and had much finer particles and more defects than the milled pure Mg sample after hydridingdehydriding cycling. The specific BET surface areas of the milled Mg and 90Mg-10MgH2 were measured as 7.81 and 99.81 m2/g, respectively. A sample that had almost a single MgH2 phase could be prepared by horizontal ball milling and the first hydriding reaction of 90Mg-10MgH2. 90Mg-10MgH2 released 5.82 wt% H for about 70 min, while unmilled MgH2 (Aldrich) released 6.04 wt% H for about 100 min, at 648 K.

  13. 黄金矿山大型球磨机综合节能研究及应用%Study on comprehensive energy saving of large-scale ball mills in gold mines and its application

    Institute of Scientific and Technical Information of China (English)

    谢敏雄; 梅治福

    2014-01-01

    球磨机是岩金矿山选矿厂的重要设备,同时也是能耗大户。以三山岛金矿8000 t/d新立选矿厂MQY5.5 m ×8.5 m大型球磨机为工程实例,简要介绍了球磨机磨矿效能的影响因数,着重分析研究了大型球磨机磨矿效能影响因素优化节能、大型球磨机设计及参数优化节能、磨矿自动化及磨矿系统最大临界负荷节能。综合节能研究及生产应用取得了磨矿能耗降低17.24%的显著效果。%Ball mills are important equipment in ore-dressing plant of rock gold mines and they are also quite en-ergy-consuming.The paper,with MQY5.5 m ×8.5 m large-scale ball mills in 8 000 t/d Xinli ore-dressing plant as an example,briefly introduces influence parameters of ball mill efficiency and focuses on energy saving through optimiza-tion of influence parameters,design of large-scale ball mills and energy saving through its parameter optimization,mill-ing automation and energy saving through maximum critical load.A significant reslut of 17.24 %energy saving is a-chieved in the study and production application.

  14. Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol--comparison of five pretreatment technologies.

    Science.gov (United States)

    Schultz-Jensen, Nadja; Thygesen, Anders; Leipold, Frank; Thomsen, Sune Tjalfe; Roslander, Christian; Lilholt, Hans; Bjerre, Anne Belinda

    2013-07-01

    A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma-assisted pretreatment (PAP) and ball milling (BM), to determine effects of the pretreatment methods on the conversion of C. linum into ethanol by simultaneous saccharification and fermentation (SSF). WO and BM showed the highest ethanol yield of 44 g ethanol/100g glucan, which was close to the theoretical ethanol yield of 57 g ethanol/100g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae, containing high amounts of glucan and cleaned from salts, enhanced the ethanol yield significantly.

  15. Effects of Wheel Wear on the Manufacturing Errors of Ball-Nose End Milling Cutter%砂轮磨损对球头立铣刀制造误差的影响研究

    Institute of Scientific and Technical Information of China (English)

    夏文胜; 周兆锋; 成岗; 何林

    2013-01-01

    The ball-nose end milling cutter is an important cutting tool which is used to cut the complicated high-precision curved surface. In the manufacturing process of grinding ball-nose end milling cutter, as the grinding time increased, the wheel will be wear, the edge curve of ball-nose end milling cutter will also change. In the paper, the grinding simulation system and parameters analysis system of rake face of ball-nose end milling cutter was established, the means of Visual Basic, based on SolidWorks software platform. Effects of grinding wheel wear on the edge strip width and edge curve of ball-nose end milling cutter was investigated. The obtained results can provide theoretical guides to the manufacturing process of ball-nose end milling cutter, and provide the guidance for the follow-up to develop the correct error compensation strategy.%球头立铣刀是加工复杂高精度曲面的重要刀具.在磨削加工球头立铣刀的制造过程中,随着磨削时间的增加,砂轮会出现磨损,球头立铣刀的刃形曲线会随之发生变化.文章以SolidWorks为开发平台,基于球头立铣刀前刀面的磨削加工运动关系,利用Visual Basic语言进行二次开发,开发出球头立铣刀前刀面的磨削仿真加工系统和刀具参数分析系统,分析了砂轮磨损对球头立铣刀刃带宽度和刃形曲线的影响.分析结果可为实际加工过程提供理论指导,有助于制定正确的磨削制造工艺,并为后续制定正确误差补偿策略提供重要指导.

  16. Thermal behaviour of Cu-Ti and Cu-Ti-H amorphous powders prepared by ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Baricco, M. (Ist. Elettrotecnico Nazionale Galileo Ferraris and INFM/GNSM, Research Unity, Turin (Italy)); Battezzati, L. (Dipt. di Chimica Inorganica, Chimica Fisica e Chimica dei Materiali, Turin Univ. (Italy)); Soletta, I.; Schiffini, L. (Dipt. di Chimica, Univ. di Sassari (Italy)); Cowlam, N. (Dept. of Physics, Univ. of Sheffield (UK))

    1991-03-25

    Solid state amorphization reactions in Cu-Ti have been studied by means of DSC and structural techniques. The influence of hydrogen from the parent titanium powder on the amorphization and crystallization processes has been investigated. For Cu-Ti a diffusion-controlled process can be inferred for solid state amorphization from the parabolic trend of the heat of crystallization, as a function of the milling time. The presence of hydrogen in the alloys is found to modify the crystallization behaviour of the amorphous phase. A DSC method for the determination of the amount of hydrogen present in the alloys is given. (orig.).

  17. Magnetocaloric effect in high-energy ball-milled Gd{sub 5}Si{sub 2}Ge{sub 2} and Gd{sub 5}Si{sub 2}Ge{sub 2}/Fe nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Rajkumar, D.M.; Manivel Raja, M. [Defence Metallurgical Research Laboratory, Hyderabad-500 058 (India); Gopalan, R. [Defence Metallurgical Research Laboratory, Hyderabad-500 058 (India)], E-mail: rg_gopy@yahoo.com; Chandrasekaran, V. [Defence Metallurgical Research Laboratory, Hyderabad-500 058 (India)

    2008-04-15

    Evolution of structure and magnetocaloric properties in ball-milled Gd{sub 5}Si{sub 2}Ge{sub 2} and Gd{sub 5}Si{sub 2}Ge{sub 2}/0.1 wt% Fe nanostructured powders were investigated. The high-energy ball-milled powders were composed of very fine grains (70-80 nm). Magnetization decreased with milling time due to decrease in the grain size and randomization of the magnetic moments at the surface. The magnetic entropy change ({delta}S{sub M}) was calculated from the isothermal magnetization curves and a maximum value of 0.45 J/kg K was obtained for 32 h milled Gd{sub 5}Si{sub 2}Ge{sub 2} alloy powder for a magnetic field change of 2 T while it was still low in Fe-contained alloy powders. The thermo-magnetic measurements revealed that the milled powders display distribution of magnetic transitions, which is desirable for practical magnetic refrigerant to cover a wide temperature span.

  18. A Mössbauer and magnetic study of ball milled Fe-doped ZnO Powders

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, Ligia E., E-mail: ligia.zamora@correounivalle.edu.co; Paz, J. C.; Piamba, J. F.; Tabares, J. A.; Alcázar, G. A. Pérez [Universidad del Valle, Departamento de física (Colombia)

    2015-06-15

    The structural and magnetic properties of Fe-doped ZnO are reported in this study, as obtained by mechanical alloying from elemental powders of ZnO and Fe. The properties of Zn{sub 0.90}Fe{sub 0.10}O samples alloying while varying the milling time (6, 12, 24 and 36 h) are also reported. The Rietveld refinement of X-ray Diffraction (XRD) patterns revealed that the system presents two structures: the würtzite structure of ZnO and the bcc structure of α-Fe. The Mössbauer spectra show that the samples present three components: a ferromagnetic component, associated with the Fe phase and two paramagnetic components, associated with the Fe atoms, which penetrate inside the ZnO matrix behaving as Fe{sup 3+} and Fe{sup 2+}. The milling time contributes to an increase in the paramagnetic sites, and a solubility limit of the Fe atoms in the ZnO lattice was detected. The VSM measurements at room temperature detected ferromagnetic behavior with a saturation magnetization of 11 emu/g and a coercive field of 330 Oe for the sample alloyed over 24 h. A similar behavior was shown by the other samples.

  19. Flank wear and I-kaz 3D correlation in ball end milling process of Inconel 718

    Directory of Open Access Journals (Sweden)

    M.A.S.M. Tahir

    2015-12-01

    Full Text Available Tool wear may deteriorate the machine product quality due to high surface roughness, dimension exceeding tolerance and also to machine tool itself. Tool wear monitoring system is vital to be used in machining process to achieve high quality of the machined product and at the same time improve the productivity. Nowadays, many monitoring system developed using various sensor and statistical technique to analyze the signals being used. In this paper, I-kaz 3D method is used to analyze cutting force signal in milling process of Inconel 718 for monitoring the status of tool wear in milling process. The results from analyzing cutting force show that I-kaz 3D coefficient has a correlation with cutting tool condition. Tool wear will generate high value of I-kaz 3D coefficient than the sharp cutting tool. Furthermore, the three dimension graphical representation of I-kaz 3D for all cutting condition shown that the degree of scattering data increases with tool wear progression.

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

    Energy Technology Data Exchange (ETDEWEB)

    Carreño-Gallardo, C.; Estrada-Guel, I. [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología-Chihuahua, Miguel de Cervantes No. 120, CP 31109, Chihuahua, México (Mexico); López-Meléndez, C. [Universidad La Salle Chihuahua, Prol. Lomas de Majalca No. 11201, CP 31020, Chihuahua, México (Mexico); Martínez-Sánchez, R., E-mail: roberto.martinez@cimav.edu.mx [Centro de Investigación en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnología-Chihuahua, Miguel de Cervantes No. 120, CP 31109, Chihuahua, México (Mexico)

    2014-02-15

    Highlights: • Synthesis of 2024-SiC{sub 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{sub 2024} alloy was reinforced with silicon carbide nanoparticles (SiC{sub 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{sub NP} were homogeneously dispersed into the Al{sub 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{sub NP} content. In this research several strengthening mechanisms were observed, but the main was the obstruction of dislocations movement by the addition of SiC{sub NP}.

  1. Hydrogen storage properties of MgH2-diatomite composites obtained by high-energy ball milling.

    Science.gov (United States)

    Milovanović, S; Matović, L; Drvendzija, M; Novaković, J G

    2008-12-01

    To investigate the effects of specific porous microstructure of diatomite on the hydrogen storage properties of MgH(2), a two-step preparation was carried out. The first step was decrepitation of MgH(2) particle size during 10 h of milling. The second step was additional 1 h of milling with diatomite. The microstructure and phase composition of materials was characterized by X-ray diffraction, whereas the powder morphology and degree of additive dispersion were analyzed by scanning electron microscopy. The hydrogen desorption behaviour of nanocomposites was investigated by differential scanning calorimetry. The results show that addition of porous diatomite structure leads to decrease in desorption temperature, since there was no other effect that can have an influence on kinetics, such as formation of the metastable gamma-phase, reduction of oxides to the native metal and/or homogeneous dispersion of the catalyst. This indicates that the microstructure of added material plays the main role in the enhancement of desorption properties of composites.

  2. Studies of superspin glass state and AC-losses in La{sub 0.7}Sr{sub 0.3}MnO{sub 3} nanoparticles obtained by high-energy ball-milling

    Energy Technology Data Exchange (ETDEWEB)

    Phong, P.T., E-mail: ptphong.nh@khanhhoa.edu.vn [Department of Advanced Materials Chemistry, Dongguk University-Gyeongju, 707 Suckjang-dong, Gyeongbuk, Gyeongju-Si 780-714 (Korea, Republic of); Nha Trang Pedagogic College, 1 Nguyen Chanh Street, Khanh Hoa Province, Nha Trang City (Viet Nam); Manh, D.H. [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi City (Viet Nam); Nguyen, L.H. [Nha Trang Pedagogic College, 1 Nguyen Chanh Street, Khanh Hoa Province, Nha Trang City (Viet Nam); Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi City (Viet Nam); Tung, D.K. [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay District, Ha Noi City (Viet Nam); Phuc, N.X., E-mail: phucnx1949@gmail.com [Nha Trang Pedagogic College, 1 Nguyen Chanh Street, Khanh Hoa Province, Nha Trang City (Viet Nam); Lee, I.-J., E-mail: lij@dongguk.ac.kr [Department of Advanced Materials Chemistry, Dongguk University-Gyeongju, 707 Suckjang-dong, Gyeongbuk, Gyeongju-Si 780-714 (Korea, Republic of)

    2014-11-15

    Single-phase perovskite compound La{sub 0.7}Sr{sub 0.3}MnO{sub 3} was synthesized by a high-energy ball milling method. Nanoparticle nature of this manganite with the average particle diameter of 11 nm was revealed from structure and morphology characterizations. The results of ac magnetic susceptibility measurements show that the system can be described as an ensemble of interacting magnetic nanoparticles, which indicates that the dipole–dipole interactions are strong enough to create superspin glass state in the sample. Furthermore, the specific loss power which is exhausted on the irradiation of an ensemble of particles with a magnetic field has been calculated and measured experimentally. - Highlights: • LSMO nanopowder was prepared by the high-energy ball-milling method. • The superspin glass state of LSMO nanopowder was studied. • The SLP has been calculated and measured experimentally.

  3. Effects of magnetic field heat treatment on Sm–Co/α-Fe nanocomposite permanent magnetic materials prepared by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Su, Yanfeng [Faculty of Science, Ningbo University, Ningbo 315211 (China); Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Su, Hao [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhu, Yuejin [Faculty of Science, Ningbo University, Ningbo 315211 (China); Wang, Fang [School of Materials Science and Engineering, NingBo University of Technology, Ningbo, Zhe Jiang Province (China); Du, Juan; Xia, Weixing; Yan, Aru; Liu, J. Ping [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Zhang, Jian, E-mail: zhangj@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China)

    2015-10-25

    Effects of magnetic field heat treatment on the structure and magnetic properties of Sm–Co/α-Fe nanocomposite permanent magnetic materials fabricated by high energy ball milling are investigated in the present work. After a magnetic field heat treatment below 700 °C on as-milled amorphous Sm–Co/α-Fe samples, the nanocomposite magnets with strong hard and soft magnetic interaction, showing a hysteresis loop of single phase characteristic, are obtained. The coercivity increases with the increase of annealing temperature. The coercivity, remanence and remanence ratio of the Sm–Co/Fe nanocomposite magnets are all enhanced after a heat treatment at a magnetic field as compared with those of nanocomposite magnets heat treated without a magnetic field. X ray diffraction analysis shows that the diffusion between the Sm–Co hard and α-Fe soft phases is suppressed by the magnetic field applied during the heat treatment process, leading to the inhibition of the grain growth of nanocrystal Sm–Co and α-Fe phases, and a finer nanostructure is obtained. Thus, a higher coercivity, remanence and remanence ratio are realized in Sm–Co/α-Fe nanocomposite magnets after the magnetic field heat treatment. Magnetic field heat treatment also makes the direction of c axis of Sm–Co hard grains along the heat treatment magnetic field direction, leading to an enhancement of magnetic anisotropy of the Sm–Co/Fe nanocomposite magnets. - Highlights: • Effects of magnetic field heat treatment on SmCo{sub 5}/Fe magnets were investigated. • Magnetic properties are improved obviously after magnetic field heat treatment. • The reasons for the improvement of magnetic properties were discussed. • The results are significant for fabrication of anisotropic nanocomposite magnets.

  4. Development of MQY6095 ball mill and FEA of key structures%MQY6095型球磨机开发与关键结构有限元分析

    Institute of Scientific and Technical Information of China (English)

    马振刚; 李建明; 刘楠楠; 唐威; 田磊

    2011-01-01

    To adapt to the large-scale development trend of ball mills, MQY6095 ball mill has been developed.In the paper, based on the structural characteristics of the ball mill, stress and distortion of the rotary body are computed using FEM, and then the stress at the round comer of the end cover and the quill shaft are calculated by applying radial force to the quill shaft. Lastly the pressure distribution and the velocity distribution of the oil film of the bearing are calculated with computing fluid dynamics method. The field application shows that the analysis results is coincident well with the measured data, which indicates that the design ensures the reliability of the ball mill.%为了适应球磨机大型化的发展趋势,开发了MQY6095型球磨机.针对该球磨机的结构特点,用有限元方法计算得到了回转部的整体应力和变形,然后在中空轴处施加支撑力,计算中空轴和端盖圆角处的应力,最后用计算流体动力学方法计算得到了轴承油膜的压力分布和速度分布.现场应用表明,分析结果与实际观测值吻合得很好,说明该设计方法有效地保证了球磨机设计的可靠性.

  5. Effect of ball-milling and Fe-/Al-doping on the structural aspect and visible light photocatalytic activity of TiO2 towards Escherichia coli bacteria abatement.

    Science.gov (United States)

    Schlur, Laurent; Begin-Colin, Sylvie; Gilliot, Pierre; Gallart, Mathieu; Carré, Gaëlle; Zafeiratos, Spiros; Keller, Nicolas; Keller, Valérie; André, Philippe; Greneche, Jean-Marc; Hezard, Bernard; Desmonts, Marie-Hélène; Pourroy, Geneviève

    2014-05-01

    Escherichia coli abatement was studied in liquid phase under visible light in the presence of two commercial titania photocatalysts, and of Fe- and Al-doped titania samples prepared by high energy ball-milling. The two commercial titania photocatalysts, Aeroxide P25 (Evonik industries) exhibiting both rutile and anatase structures and MPT625 (Ishihara Sangyo Kaisha), a Fe-, Al-, P- and S-doped titania exhibiting only the rutile phase, are active suggesting that neither the structure nor the doping is the driving parameter. Although the MPT625 UV-visible spectrum is shifted towards the visible domain with respect to the P25 one, the effect on bacteria is not increased. On the other hand, the ball milled iron-doped P25 samples exhibit low activities in bacteria abatement under visible light due to charge recombinations unfavorable to catalysis as shown by photoluminescence measurements. While doping elements are in interstitial positions within the rutile structure in MPT625 sample, they are located at the surface in ball milled samples and in isolated octahedral units according to (57)Fe Mössbauer spectrometry. The location of doping elements at the surface is suggested to be responsible for the sample cytotoxicity observed in the dark.

  6. 浅谈球磨机在金川选矿厂的应用现状和发展趋势%Current application status and development tendency of ball mills in Jinchuan concentrator

    Institute of Scientific and Technical Information of China (English)

    鲁培兴

    2012-01-01

    简要介绍球磨机的发展状况以及金川选矿厂球磨机的应用现状,根据目前金川选矿厂技术改造或扩建中采用球磨机的性能特点,归纳出金川选矿厂今后将采用大型化、高可靠性的球磨机,并实现球磨机的计算机自动控制。%The paper briefl y introduced the development status of the ball mill as well as its current application in the concentrator of Jinchuan Group Co.,Ltd.(abbreviated as Jinchuan concentrator).According to the performance of the ball mills applied in technical innovation or scale expansion in Jinchuan concentrator,it indicated that the large-scale and high-reliability ball mills should be used,and automatic control by computers should be realized in Jinchuan concentrator.

  7. Electric modulus formalism and electrical transport property of ball mill synthesized nanocrystalline Mn doped ZrO{sub 2} solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S. [Department of Physics, National Institute of Technology, Durgapur, Burdwan 713209, West Bengal (India); Nandy, A. [Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India); Meikap, A.K., E-mail: meikapnitd@yahoo.com [Department of Physics, National Institute of Technology, Durgapur, Burdwan 713209, West Bengal (India); Pradhan, S.K. [Department of Physics, The University of Burdwan, Golapbag, Burdwan 713104, West Bengal (India)

    2015-12-15

    Here we report the formation of Mn doped nanocrystalline ZrO{sub 2} solid solution synthesized by high energy ball-milling method and the transport mechanism in the temperature range 298 K

  8. Binding of carbon coated nano-silicon in graphene sheets by wet ball-milling and pyrolysis as high performance anodes for lithium-ion batteries

    Science.gov (United States)

    Sun, Wei; Hu, Renzong; Zhang, Miao; Liu, Jiangwen; Zhu, Min

    2016-06-01

    A novel approach has been developed to prepare silicon@carbon/graphene sheets (Si@C/G) composite with a unique structure, in which carbon coated Si nanoparticles are uniformly dispersed in a matrix of graphene sheets, to enhance the cycleability and electronic conductivity of Si-based anodes for Li-ion batteries. In this study, Si nanoparticles and expanded graphite (EG) are treated by combining high-energy wet ball-milling in sucrose solution with subsequent pyrolysis treatment to produce this Si@C/G composite. To achieve better overall electrochemical performance, the carbon content of the composites is also studied systematically. The as-designed Si30@C40/G30 (Si:C:G = 30:40:30, by weight) composite exhibits a high Li-storage capacity of 1259 mAh g-1 at a current density of 0.2 A g-1 in the first cycle. Further, a stable cycleability with 99.1/88.2% capacity retention from initial reversible charge capacity can be achieved over 100/300 cycles, showing great promise for batteries applications. This good electrochemical performance can be attributed to the uniform coating and binding effect of pyrolytic carbon as well as the network of graphene sheets, which increase the electronic conductivity and Li+ diffusion in the composite, and effectively accommodated the volume change of Si nanoparticles during the Li+ alloying and dealloying processes.

  9. Preparation of Nylon Ball-stirring Mill Lining Modified by Polyurethane%聚氨酯改性尼龙球磨机内衬的研制

    Institute of Scientific and Technical Information of China (English)

    赵伟; 杨洁; 赵彩荣; 周刚

    2013-01-01

    A polyurethane prepolymer w as synthesized to modify the monomer casting nylon. The result showed that when the prepolymer prepared at the NCO content of 4% with PTMG molecular weight of 2000 and the prepolymer dosage was 15% mass fraction of copolymer,copolymer had maximum impact strength. The modified material used in ball-stirring mill lining had better temperature-resistance property than polyurethane lining.%采用相对分子质量为2000的聚四亚甲基醚二醇(PTMG)合成NCO质量分数为4.0%的聚氨酯预聚体,用于增韧改性铸型(MC)尼龙.结果表明,当预聚体的用量为共聚物质量分数的15%,共聚产品显示出最大的冲击强度,将此改性材料应用于球磨机内衬,显示出比聚氨酯内衬更好的耐温性能.

  10. Fabricating fine-grained tungsten heavy alloy by spark plasma sintering of low-energy ball-milled W–2Mo–7Ni–3Fe powders

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, D.P., E-mail: dpxiang@hainu.edu.cn [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Ding, L. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China); Li, Y.Y. [School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Chen, X.Y.; Zhang, T.M. [Key Laboratory of Advanced Materials of Tropical Island Resources, Ministry of Education, Hainan University, Haikou 570228 (China)

    2013-08-20

    Fine-grained W–2Mo–7Ni–3Fe heavy alloys were fabricated by low-energy ball milling (LEBM)-assisted spark plasma sintering at a temperature range of 1000–1250 °C. The effects of sintering temperature on the phase evolution, microstructural characteristics, and mechanical properties of the alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), hardness testing, and universal testing. The XRD results show that small intermetallic compounds, such as NiW and Ni{sub 2}W{sub 4}C, form in the alloys. The W–2Mo–7Ni–3Fe alloys are characterized by white W grains, a gray W-rich microstructure that contains Mo, and a black γ–(Ni, Fe, W, Mo) binding phase. The X-ray energy dispersive analysis (EDS) shows that the Mo, Ni, and Fe that form a solid solution with W in the gray structure gradually decrease with increasing temperature. The hardness and bending strength of the alloys initially increase and then decrease with rising sintering temperature. Moreover, the alloys sintered at different temperatures exhibit dissimilar bending fracture modes.

  11. 膨润土的有机改性与球磨细小化及其助留性能研究%Organic modification and ball milling of bentonite and its retention properties

    Institute of Scientific and Technical Information of China (English)

    陈威; 李友明; 万小芳

    2011-01-01

    采用十八烷基三甲基溴化铵(STAB)对膨润土进行了有机改性并对改性膨润土球磨细小化。对制得的改性膨润土进行了扫描电镜(SEM)、傅里叶红外光谱(FT-IR)、X射线衍射(XRD)实验分析。结果表明,有机表面活性剂STAB已经进入膨润土的片层间,层间距由1.256nm增大到2.694nm;晶面间距增大的最佳实验条件为:STAB用量为40%,反应时间为4h,反应温度为75℃。通过对球磨后的改性膨润土进行SEM观察发现,球磨时间2h能使其颗粒基本达到亚微米至纳米级,粒度分布范围为100~500nm。对球磨改性膨%Stearyltrimethyl ammonium bromide was used for organic modification of bentonite and then ball milled the modified bentonite.The organically modified bentonite was analyzed by SEM,FT-IR and XRD.The results show that the stearyltrimethyl ammonium bromide has been interalated into the layers of bentonite.The layer distance of the bentonite is increased from 1.256nm to 2.694nm.The appropriate experimental conditions of interplanar spacing increasing were the dosage of STAB 40%,reaction time 4h,temperature 75℃.The ball milled organically modified bentonite was analyzed by SEM.The results show that the particle mainly reach submicron to nanometer when ball mill 2h.The particle size distribution range is from 100 to 500nm.Ball milled organically modified bentonite/CPAM can improve retention rate of OCC pulp obviously than organically modified bentonite/CPAM because of smaller grains and better unigormity of ball milled bentonite.

  12. Influence of Ball Milling on Boron Carbide's Particle Size and Content of Free C%球磨对碳化硼粒度及游离碳的影响

    Institute of Scientific and Technical Information of China (English)

    王慧华; 孙树臣; 王德永; 涂赣峰; 马伟民; 郭卓; 曹大力; 马雷

    2012-01-01

    Boron carbide powders show wide application advantages in the fields of wear-resistant materials and high-hardness ceramics.The ball milling technologies have strong effect on the particle size of boron carbide.The influence of milling factors on particle size distribution of boron carbide and the content of free C with increasing milling time were investigated in this paper.The results show that the particle size distribution curve of boron carbide shifted to small size direction with increasing milling time;the refinement slowed down when after milling for 60 h and the concentration of ultrafine particles could be improved with further milling.The different ball-to-powder mass ratio had slight effect on particle size distribution curve of boron carbide when the milling time reached a certain level.The content of free C increased significantly in the range of 20~40 h and became marginally after further milling.The morphologies of the starting material and milled powder were observed by scanning electronic microscopy.X-ray diffraction showed that some strong diffractions of free C were detected after milling for 60 h.%主要研究球磨因素对碳化硼粒度分布的影响,并考察游离碳含量随球磨时间的变化规律.实验结果表明:随着球磨时间增加,碳化硼粒径分布曲线向粒径小的方向移动,当球磨时间达到60 h,粉体粒径细化程度减缓,继续球磨可进一步提高超细颗粒含量;当球磨时间达到一定程度,不同的球料比对粉体粒径分布曲线影响较小;游离碳含量随着球磨时间增加而提高,在20~40 h碳含量增加显著,之后增加缓慢;SEM电镜显示球磨前后粉体显微形貌发生显著变化;XRD分析显示球磨60 h后粉体中出现很强的游离碳衍射峰.

  13. Synthesis, structural and hydrogenation properties of Mg-rich MgH2-TiH2 nanocomposites prepared by reactive ball milling under hydrogen gas.

    Science.gov (United States)

    Cuevas, Fermin; Korablov, Dmytro; Latroche, Michel

    2012-01-21

    MgH(2)-TiH(2) nanocomposites have been obtained by reactive ball milling of elemental powders under 8 MPa of hydrogen pressure. The composites consist of a mixture of β-rutile MgH(2), γ-orthorhombic high pressure MgH(2) and ε-tetragonal TiH(2) phases with nanosized crystallites ranging from 4 to 12 nm. In situ hydrogen absorption curves on milling reveal that nanocomposite formation occurs in less than 50 min through the consecutive synthesis of the TiH(2) and MgH(2) phases. The abrasive and catalytic properties of TiH(2) speed up the formation of the MgH(2) phase. Thermodynamic, kinetic and cycling hydrogenation properties have been determined for the 0.7MgH(2)-0.3TiH(2) composite and compared to nanometric MgH(2). Only the MgH(2) phase desorbs hydrogen reversibly at moderate temperature (523 to 598 K) and pressure (10(-3) to 1 MPa). The presence of TiH(2) does not modify the thermodynamic properties of the Mg/MgH(2) system. However, the MgH(2)-TiH(2) nanocomposite exhibits outstanding kinetic properties and cycling stability. At 573 K, H-sorption takes place in less than 100 s. This is 20 times faster than for a pure nanometric MgH(2) powder. We demonstrate that the TiH(2) phase inhibits grain coarsening of Mg, which allows extended nucleation of the MgH(2) phase in Mg nanoparticles before a continuous and blocking MgH(2) hydride layer is formed. The low crystallinity of the TiH(2) phase and its hydrogenation properties are also compatible with a gateway mechanism for hydrogen transfer from the gas phase to Mg. Mg-rich MgH(2)-TiH(2) nanocomposites are an excellent media for hydrogen storage at moderate temperatures.

  14. 基于 PFC3D的新型球磨机数值模拟研究%Study on the movement of grinding medium in ball mill based on PFC3D

    Institute of Scientific and Technical Information of China (English)

    李笑同; 朴香兰

    2015-01-01

    In order to explore the ways to improve the fatigue life and the production efficiency of the ball mill,the paper established the discrete element model of the traditional ball mill and also the ball mill with variable structures.And this paper carried out an analysis and simulation of the motion of grinding medium with different rotational speeds and scale board heights to determine the position of the rotational board.Through the simulation experiments we found that the falling speed of the grinding ball in grinding chamber rose from 2 m/s to 5 m/s.This behavior could not only increase the impact force of grinding medium effectively but also avoid the limitation of improving the grinding efficiency of the traditional ball mill by changing the parameters of the quality of grinding grain and the diameter of the cylinder,etc.%为探索能够提高球磨机生产效率和延长球磨机研磨寿命的途径,利用 PFC3D 程序,建立了传统球磨机与变结构球磨机的离散元模型,针对不同转速、不同衬板高度,对磨介运动进行了仿真与分析,确定了辅助结构-旋转档板的位置。通过模拟实验发现,研磨腔内磨球的下落速度由原来的2m/s,增长到了5m/s 左右。有效地提高了磨介的冲击力,避免了传统球磨机需要通过改变研磨介质磨粒的质量和滚筒的直径等参数来提高研磨效率的局限性。

  15. 基于复制测量法的球头立铣刀磨损预测研究%Study on Prediction of Ball End Mill Wear Based on Copy Measurement

    Institute of Scientific and Technical Information of China (English)

    孙博; 陈锦江; 王芳; 孙占伟; 田广伟

    2016-01-01

    论文提出一种测量球头立铣刀磨损量的复制测量方法并分析该方法的误差。以铣刀径向磨损量为研究对象进行刀具磨损试验,找出铣削参数对刀具磨损的影响规律,得出径向磨损量增量与铣削参数的铣刀磨损模型和刀具寿命经验公式,并通过试验验证磨损模型具有较高精度,可用于磨损量预测。%This paper proposes a copy measurement of ball end mill wear and analyzes the error of this meth-od. The radial mill wear quantity as the research object for the tool wear test, find out the influence law of milling parameters on tool wear. It is concluded that the radial wear increment and the milling parameters of milling cutter tool wear model and tool life experience formula can be obtained, and through the test the wear model has higher accuracy and is useful to predict the amount of wear.

  16. Structural characterization and Mössbauer studies of nanocrystalline Fe{sub 60}Ni{sub 20}Cr{sub 10}B{sub 10} alloy prepared by high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Slimi, M., E-mail: msrammeh@yahoo.fr [Laboratoire de Chimie Inorganique, UR-11-ES-73, université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Azabou, M. [Laboratoire de Chimie Inorganique, UR-11-ES-73, université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Suñol, J.J. [Departament de Fisica, Universitat de Girona, Campus Montilivi, Girona 17071 (Spain); Khitouni, M. [Laboratoire de Chimie Inorganique, UR-11-ES-73, université de Sfax, B.P. 1171, 3000 Sfax (Tunisia); Greneche, J.M. [LUNAM, Institut des Molécules et Matériaux du Mans, IMMM UMR CNRS 6283, Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France)

    2015-11-01

    Nanostructured Fe(Ni,Cr) and NiFe solid state powders were elaborated from elemental powders of Fe, Ni, Cr and B using planetary high-energy ball mill. Scanning electron microscopy (SEM) was employed to examine the morphology of the powdered samples as a function of milling time. The transformations occurring in the material during milling were studied at the atomic scale with the use of X-ray diffraction and {sup 57}Fe Mössbauer spectrometry. The thermal behavior of the milled powders was examined by differential scanning calorimetry (DSC). The results, as well as dissimilarity between calorimetric curves of the powders after 10 and 50 h of milling, indicated the formation of a nanostructured Fe(Ni,Cr) and NiFe solid solutions. - Highlights: • It is a complete study about the alloying process of a nanostructured alloy. • We establish the relation between microstructure and structure defects. • Mössbauer analysis confirms the coexistence of the bcc-Fe(Ni,Cr) and fcc-Ni(Fe) solid solutions.

  17. Glueballs amass at RHIC and LHC Colliders! - The early quarkless 1st order phase transition at $T=270$ MeV - from pure Yang-Mills glue plasma to GlueBall-Hagedorn states

    CERN Document Server

    Stoecker, Horst; Schramm, Stefan; Senzel, Florian; Greiner, Carsten; Beitel, Maxim; Gallmeister, Kai; Gorenstein, Mark; Mishustin, Igor; Vasak, David; Steinheimer, Jan; Struckmeier, Juergen; Vovchenko, Volodymyr; Satarov, Leonid; Xu, Zhe; Zhuang, Pengfei; Csernai, Laszlo P; Sinha, Bikash; Raha, Sibaji; Biró, Tamás Sándor; Panero, Marco

    2016-01-01

    The early stage of high multiplicity pp, pA and AA collider is represented by a nearly quarkless, hot, deconfined pure gluon plasma. According to pure Yang-Mills Lattice Gauge Theory, this hot pure glue matter undergoes, at a high temperature, $T_c = 270$ MeV, a first order phase transition into a confined Hagedorn-GlueBall fluid. These new scenario should be characterized by a suppression of high $p_T$ photons and dileptons, baryon suppression and enhanced strange meson production. We propose to observe this newly predicted class of events at LHC and RHIC.

  18. Studies of superspin glass state and AC-losses in La0.7Sr0.3MnO3 nanoparticles obtained by high-energy ball-milling

    Science.gov (United States)

    Phong, P. T.; Manh, D. H.; Nguyen, L. H.; Tung, D. K.; Phuc, N. X.; Lee, I.-J.

    2014-11-01

    Single-phase perovskite compound La0.7Sr0.3MnO3 was synthesized by a high-energy ball milling method. Nanoparticle nature of this manganite with the average particle diameter of 11 nm was revealed from structure and morphology characterizations. The results of ac magnetic susceptibility measurements show that the system can be described as an ensemble of interacting magnetic nanoparticles, which indicates that the dipole-dipole interactions are strong enough to create superspin glass state in the sample. Furthermore, the specific loss power which is exhausted on the irradiation of an ensemble of particles with a magnetic field has been calculated and measured experimentally.

  19. [Formula: see text]-mediated amination/cyclization of ketones with 2-aminopyridines under high-speed ball milling: solvent- and metal-free synthesis of 2,3-substituted imidazo[1,2-a]pyridines and zolimidine.

    Science.gov (United States)

    Wang, Fang-Jian; Xu, Hui; Xin, Ming; Zhang, Ze

    2016-08-01

    Under solvent-free high-speed ball milling, an I[Formula: see text]-promoted condensation/cyclization of easily available methyl ketones or 1,3-dicarbonyl compounds with 2-aminopyridines has been developed, which allows the quick assembly of 2,3-substituted imidazo[1,2-a]pyridines (IPs) with broad molecular diversity, including the antiulcer drug zolimidine. The advantages of high yields, good functional group compatibility, short reaction time (within 90 min), free use of heating, solvent and metal, employment of cheap starting materials, and simple work-up procedure make this protocol a very efficient alternative to traditional synthesis of IPs.

  20. Appropriate conditions for applying NaOH-pretreated two-phase olive milling waste for codigestion with food waste to enhance biogas production.

    Science.gov (United States)

    Al-Mallahi, Jumana; Furuichi, Toru; Ishii, Kazuei

    2016-02-01

    The high methane gas production potential of two phase olive milling waste (2POMW) makes its application to biogas plants in business an economical process to increase the productivity of the plants. The objective of this study was to investigate the appropriate conditions for the codigestion of NaOH-pretreated 2POMW with food waste. NaOH pretreatment can increase the methane production by increasing the soluble chemical oxygen demand (sCOD), but it may cause inhibition because of higher levels of alkalinity, sodium ion, volatile fatty acids and long chain fatty acids (LCFAs). Therefore, the first experimental phase of this study aimed to investigate the effect of different mixing ratios of 2POMW to food waste. A continuous stirred tank reactor experiment with different mixing ratios of 3%, 4.3%, 5.7% and 8.3% (2POMW: food waste) was conducted. NaOH pretreatment in the range of 6-20% was used. A mixing ratio up to 4.3%, when 10% NaOH pretreatment was used, caused no inhibition and increased methane production by 445.9mL/g-VS(2POMW). For this mixing ratio an additional experimental phase was conducted with the 20% NaOH pretreatment as the 20% NaOH pretreatment had the highest sCOD. The methane gas production was increased by 503.6mL/g-VS(2POMW). However, pH adjustment was required for applying this concentration of the high alkalinity 20% NaOH-pretreated 2POMW. Therefore, we consider using 10% NaOH pretreatment in a mixing ratio of 4.3% to be more applicable. The increase in methane gas production was correlated to the oleic acid concentration inside the reactors. The high oleic acid concentration of 61.8mg/L for the 8.3% mixing ratio was responsible for the strong inhibition. This study showed that adjusting the appropriate mixing ratio of the NaOH-pretreated 2POMW could increase the electricity production of a reactor that regularly receives food waste.

  1. 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)

  2. The importance of pretreatment tailoring on the performance of ultrafiltration membranes to treat two-phase olive mill wastewater

    Directory of Open Access Journals (Sweden)

    Ochando Pulido, J. M.

    2015-03-01

    Full Text Available In this work, the performance of an ultrafiltration (UF membrane in the treatment of the effluents by-produced by olive mills is addressed by applying different pretreatments on the raw effluents. By conducting a photo-catalytic process (UV/TiO2 PC after pH-temperature flocculation (pH-T F higher threshold flux values were observed for all feed stocks than by applying solely the pH-T F process, with an 18.8–34.2% increment. In addition, the performance of the UF membrane was also improved in terms of rejection efficiency, such that higher rejection values were yielded by the membrane for the organic pollutants (RCOD by 48.5 vs. 39.9% and 53.4 vs. 42.0%. The UF membrane performance was also improved in terms of the volume feed recovery factor (VFR, achieving up to 88.2 vs. 87.2% and 90.7 vs. 89.3%. Results in the same line were also observed when the highly polluted olives oil washing wastewater raw stream was previously mixed with the effluent stream coming from the washing of the olives. This permits the UF to permeate, achieving the standard limits to reuse the purified effluent for irrigation purposes (COD values below 1000 mg·L−1, which makes the treatment process cost-effective and results in making the olive oil production process environmentally friendly.En este estudio se aborda el rendimiento de una membrana de ultrafiltración (UF para el tratamiento de los efluentes generados por la industria oleícola, mediante la aplicación de distintos pretratamientos. Tras aplicar un proceso fotocatalítico (UV/TiO2 PC después de una floculación pH-temperatura (pH-T F se observaron flujos límite para todos los efluentes mayores que tras la aplicación únicamente del proceso pH-T F, con incrementos del 18.8–34.2 %. Además, el rendimiento de la membrana de UF mejoró en términos de eficiencia de rechazo, con mayores valores de rechazo respecto de los contaminantes orgánicos (RCOD, 48.5 vs. 39.9 % y 53.4 vs. 42.0 %. El rendimiento de

  3. C, N co-doped TiO2/TiC0.7N0.3 composite coatings prepared from TiC0.7N0.3 powder using ball milling followed by oxidation

    Science.gov (United States)

    Hao, Liang; Wang, Zhenwei; Zheng, Yaoqing; Li, Qianqian; Guan, Sujun; Zhao, Qian; Cheng, Lijun; Lu, Yun; Liu, Jizi

    2017-01-01

    Ball milling followed by heat oxidation was used to prepared C, N co-doped TiO2 coatings on the surfaces of Al2O3 balls from TiC0.7N0.3 powder. The as-prepared coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectrophotometer (UV-vis). The results show that continuous TiC0.7N0.3 coatings were formed after ball milling. C, N co-doped TiO2/TiC0.7N0.3 composite coatings were prepared after the direct oxidization of TiC0.7N0.3 coatings in the atmosphere. However, TiO2 was hardly formed in the surface layer of TiC0.7N0.3 coatings within a depth less than 10 nm during the heat oxidation of TiC0.7N0.3 coatings in carbon powder. Meanwhile, the photocatalytic activity evaluation of these coatings was conducted under the irradiation of UV and visible light. All the coatings showed photocatalytic activity in the degradation of MB no matter under the irradiation of UV or visible light. The C, N co-doped TiO2/TiC0.7N0.3 composite coatings showed the most excellent performance. The enhancement under visible light irradiation should attribute to the co-doping of carbon and nitrogen, which enhances the absorption of visible light. The improvement of photocatalytic activity under UV irradiation should attribute to the synergistic effect of C, N co-doping, the formation of rutile-anatase mixed phases and the TiO2/TiC0.7N0.3 composite microstructure.

  4. Effect of Ultrasonic Pretreatment on Biomethane Potential of Two-Phase Olive Mill Solid Waste: Kinetic Approach and Process Performance

    Science.gov (United States)

    Rincón, B.; Bujalance, L.; Fermoso, F. G.; Martín, A.

    2014-01-01

    The effect of ultrasound (US) pretreatment on two-phase olive mil solid waste (OMSW) composition and subsequent anaerobic biodegradation was evaluated by chemical oxygen demand solubilization and biochemical methane potential (BMP) tests. OMSW was ultrasonically pretreated at a power of 200 W and frequency of 24 kHz for time periods of 20, 40, 60, 90, 120, and 180 minutes, corresponding to specific energies of 11367, 21121, 34072, 51284, 68557, and 106003 kJ/kg total solids, respectively. In order to evaluate the US pretreatment, a low, medium, and high exposure time, that is, 20, 90, and 180 min, were selected for BMP tests. Methane yields of 311 ± 15, 393 ± 14, and 370 ± 20 mL CH4/g VSadded (VS: volatile solids) were obtained for 20, 90, and 180 minutes, respectively, while the untreated OMSW gave 373 ± 4 mL CH4/g VSadded. From a kinetic point of view, the BMP tests showed a first exponential stage and a second sigmoidal stage. In the first stage, the kinetic constant obtained for US pretreated OMSW at 20 minutes was 46% higher than those achieved for the pretreated OMSW at 90 and 180 minutes and 48% higher than that for untreated OMSW. The maximum methane production rate achieved was 12% higher than that obtained for untreated OMSW. PMID:25197705

  5. Effect of ultrasonic pretreatment on biomethane potential of two-phase olive mill solid waste: kinetic approach and process performance.

    Science.gov (United States)

    Rincón, B; Bujalance, L; Fermoso, F G; Martín, A; Borja, R

    2014-01-01

    The effect of ultrasound (US) pretreatment on two-phase olive mil solid waste (OMSW) composition and subsequent anaerobic biodegradation was evaluated by chemical oxygen demand solubilization and biochemical methane potential (BMP) tests. OMSW was ultrasonically pretreated at a power of 200 W and frequency of 24 kHz for time periods of 20, 40, 60, 90, 120, and 180 minutes, corresponding to specific energies of 11367, 21121, 34072, 51284, 68557, and 106003 kJ/kg total solids, respectively. In order to evaluate the US pretreatment, a low, medium, and high exposure time, that is, 20, 90, and 180 min, were selected for BMP tests. Methane yields of 311 ± 15, 393 ± 14, and 370 ± 20 mL CH₄/g VSadded (VS: volatile solids) were obtained for 20, 90, and 180 minutes, respectively, while the untreated OMSW gave 373 ± 4 mL CH₄/g VSadded. From a kinetic point of view, the BMP tests showed a first exponential stage and a second sigmoidal stage. In the first stage, the kinetic constant obtained for US pretreated OMSW at 20 minutes was 46% higher than those achieved for the pretreated OMSW at 90 and 180 minutes and 48% higher than that for untreated OMSW. The maximum methane production rate achieved was 12% higher than that obtained for untreated OMSW.

  6. Lime pretreatment of lignocellulosic biomass

    Science.gov (United States)

    Chang, Shushien

    Lignocellulose is a valuable alternative energy source. The susceptibility of lignocellulosic biomass to enzymatic hydrolysis is constrained due to its structural features, so pretreatment is essential to enhance enzymatic digestibility. Of the chemicals used as pretreatment agents, it has been reported that alkalis improve biomass digestibility significantly. In comparison with other alkalis such as NaOH and ammonia, lime (calcium hydroxide) has many advantages; it is very inexpensive, is safe, and can be recovered by carbonating wash water. The effects of lime pretreatment were explored on switchgrass and poplar wood, representing herbaceous and woody biomass, respectively. The effects of pretreatment conditions (time, temperature, lime loading, water loading, particle size, and oxygen pressure) have been systematically studies. Lime alone enhances the digestibility of switchgrass significantly; under the recommended conditions, the 3-d total sugar (glucose + xylose) yields of lime-treated switchgrass were 7 times that of untreated sample. When treating poplar wood, lime must be combined with oxygen to achieve high digestibility; oxidative lime pretreatment increased the 3-d total sugar yield of poplar wood to 12 times that of untreated sample. In a fundamental study, to determine why lime pretreatment is effective, the effects of three structural features on enzymatic digestibility were studied: lignin content, acetyl content, and crystallinity index (CrI). Poplar wood was treated with peracetic acid, potassium hydroxide, and ball milling to produce model lignocelluloses with a broad spectrum of lignin contents, acetyl contents, and CrI, respectively. Enzymatic hydrolysis was performed on the model lignocelluloses to determine the digestibility. Correlations between lignin/carbohydrate ratio, acetyl/carbohydrate ratio, CrI and digestibility were developed. The 95% prediction intervals show that the correlations predict the 1-h and 3-d total sugar conversions of

  7. Preparation of Mn3O4 from manganese sulfate by solid-state ball milling reaction at room temperature%硫酸锰室温固相球磨制备四氧化三锰

    Institute of Scientific and Technical Information of China (English)

    马玉文; 冯雅丽; 李浩然

    2013-01-01

    利用软锰矿吸收硫酸镁热解尾气二氧化硫制得硫酸锰,再与碳酸氢铵室温下固相球磨反应,制备出前躯体碳酸锰,经热分解获得四氧化三锰.分别考察了物料比、球磨时间、球料比等因素对硫酸锰转化率的影响,采用XRD对产物进行了分析.结果表明,在n(碳酸氢铵)∶n(硫酸锰)=3.5∶1、球磨时间为40 min、球料质量比为5∶1时,硫酸锰的转化率可达99.8%,将固相产物在1 000℃热解1h后所制备的四氧化三锰纯度为99.9%.该工艺操作简单,产品纯度高,成本低,为硫酸锰制备四氧化三锰提供了新的途径.%Manganese sulfate was prepared by reaction between pyrolusite and sulfur oxide from the pyrolysis of magnesium sulfate.Mn3O4 can be prepared by pyrolysing the precursor MnCO3.The precursor was synthesized by solid-state ball milling reaction between NH4HCO3 and MnSO4 · H2O at room temperature.Effects of materials mix ratio, milling time, and ball-feed mass ratio on the conversion of manganese sulfate were investigated respectively.The products were analyzed by XRD.Results showed that the conversion rate of MnSO4 · H2O could reach 99.8% under the conditions of mix ratio 3.5:1 (amount-of-substance ratio of NH4HCO3 to MnSO4 · H2O),milling time 40 min, and ball-feed mass ratio 5:1 .The Mn3O4, whose purity was 99.9%, can be prepared by pyrolysing manganese carbonate at 1 000℃ for 1 h.The process has the advantages of simple in operation, high product purity, and low cost, and it can provide a new route for the preparation Mn3O4 from MnSO4 · H2O.

  8. Study on Process of Preparing Fe-Al2O3 Magnetic Abrasive by High Energy Ball Milling%高能球磨法制备Al2O3/Fe磁性磨粒的工艺研究

    Institute of Scientific and Technical Information of China (English)

    王晓峰; 李文辉

    2013-01-01

    Magnetic abrasive finishing machining technology is a new technology to use the magnetic field force produced by permanent magnetic or electromagnetic device asthe driving force of magnetic abrasive finishing machining of parts surface,which can realize the surface polishing,deburring,eliminating the micro crack,and reducing the surface roughness of parts.4 new technology of preparing magnetic abrasives used high energy ball milling was put forward and the working principle was analyzed in the ball milling.Pure iron powder was used as the magnetic phase,corundum powder as the abrasive,and three different times Fe-Al2O3 magnetic abrasives were prepared by high energy ball milling method.X-ray diffraction and SEM were used to analyze the morphology and phase components of the magnetic abrasives.Magnetic flux density of the magnetic abrasives were tested by the instrument.It finds that the process is easy and low cost,so it would have great hope to accomplish large-scale industrialized production.%磁性磨粒光整加工技术是利用永磁或者电磁发生装置产生的磁场力作为磁性磨粒的源动力对零件表面进行光整加工的一种新技术,它可以实现对零件进行表面抛光、去除毛刺、消除微观裂纹、降低表面粗糙度等加工.提出应用高能球磨法制备磁性磨粒的新工艺,分析了球磨过程中的工作原理.用纯铁粉作为磁性体,三氧化二铝粉作为磨料相,采用高能球磨法制备了三种不同时间的Fe-Al2O3磁性磨粒.采用X射线衍射仪和扫描电子显微镜分析了该磁性磨粒的物相组成和外观形貌,用特斯拉仪测试了磁性磨粒的磁感应强度.发现了该工艺简单,成本低,且有望进行大规模工业化生产.

  9. Preparation of Bismuth Subcarbonate by Ball-milling Coversion Method Using Bismuth Oxide%球磨转化法由氧化铋制取次碳酸铋研究

    Institute of Scientific and Technical Information of China (English)

    蒋叶; 唐朝波; 唐谟堂; 杨声海; 何静; 陈永明; 杨建广

    2013-01-01

      针对次碳酸铋传统制备工艺存在试剂消耗大、产生大量氨氮废水等问题,提出了一种用氧化铋和碳酸氢铵机械球磨直接制备次碳酸铋新工艺,考察了碳酸氢铵浓度、液固体积质量比、球料质量比、反应时间对氧化铋转化率的影响。结果表明,在碳酸氢铵浓度为2.5 mol/L、液固体积质量比为7∶1、球料质量比为8∶1、反应时间为2 h、室温条件下,氧化铋转化率达93.23%。该工艺流程简短,成本低,转化母液可循环利用,解决了传统工艺试剂消耗大及产生大量氨氮废水等问题。%A new process for preparation of bismuth subcarbonate by ball-milling coversion method using bismuth oxide has been proposed .T he effects of ammonium bicarbonate concentrate ,liquid/solid ratio ,mass ratio of ball to bismuth oxide and milling time on conversion rate of bismuth oxide were ex-amined .The results showed that the direct conversion rate of bismuth oxide colud reach 93 .23% under the optimum conditions which the ammonium bicarbonate concentration was 2 .5 mol/L ,liquid/solid ratio was 7∶1 ,mass ratio of ball to bismuth oxide was 8∶1 ,and milling 2 hours at room temperature . The process has the advantage of short procedure ,cheap reactant ,low cost ,and mother liquid can be u-tilized circularly .

  10. Preparation of Mo-Re-C samples containing Mo7Re13C with the β-Mn-type structure by solid state reaction of planetary-ball-milled powder mixtures of Mo, Re and C, and their crystal structures and superconductivity

    Science.gov (United States)

    Oh-ishi, Katsuyoshi; Nagumo, Kenta; Tateishi, Kazuya; Takafumi, Ohnishi; Yoshikane, Kenta; Sugiyama, Machiko; Oka, Kengo; Kobayashi, Ryota

    2017-01-01

    Mo-Re-C compounds containing Mo7Re13C with the β-Mn structure were synthesized with high-melting-temperature metals Mo, Re, and C powders using a conventional solid state method with a planetary ball milling machine instead of the arc melting method. Use of the ball milling machine was necessary to obtain Mo7Re13C with the β-Mn structure using the solid state method. Almost single-phase Mo7Re13C with a trace of impurity were obtained using the synthesis method. By XRF and lattice parameter measurements on the samples, Fe element existed in the compound synthesized using the planetary ball milling machine with a pot and balls made of steel, though Fe element was not detected in the compound synthesized using a pot and balls made of tungsten carbide. The former compound containg the Fe atom did not show superconductivity but the latter compound without the Fe atom showed superconductivity at 6.1 K.

  11. Record critical current densities in IG processed bulk YBa{sub 2}Cu{sub 3}O{sub y} fabricated using ball-milled Y{sub 2}Ba{sub 1}Cu{sub 1}O{sub 5} phase

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, Miryala; Kenta, Nakazato; Murakami, Masato [Department of Materials Science and Engineering, Superconducting Materials Laboratory, Shibaura Institute of Technology, Tokyo (Japan); Zeng, XianLin; Koblischka, Michael R. [Institute of Experimental Physics, Saarland University, Saarbruecken (Germany); Diko, Pavel [Institute of Experimental Physics, Material Physics Laboratory, Slovak Academy of Sciences, Kosice (Slovakia)

    2016-02-15

    The infiltration-growth (IG) technique enables the uniform and controllable Y{sub 2}BaCuO{sub 5} (Y211) secondary phase particles formation within the YBa{sub 2}Cu{sub 3}O{sub y} (Y123) matrix. Recent results clarified that the flux pinning performance of the Y123 material was dramatically improved by optimizing the processing conditions during the IG process. In this paper, we adapted the IG technique and produced several samples with addition of nanometer-sized Y211 secondary phase particles, which were produced by a ball milling technique. We found that the performance of the IG processed Y123 material dramatically improved in the low field region for a ball milling time of 12 h as compared to the samples without a ball milling step. Magnetization measurements showed a sharp superconducting transition with an onset T{sub c} at around 92 K. The critical current density (J{sub c}) at 77 K and zero field was determined to be 224 022 Acm{sup -2}, which is higher than the not ball-milled sample. Furthermore, microstructural observations exhibited a uniform microstructure with homogenous distribution of nanosized Y-211 inclusions within the Y-123 matrix. The improved performance of the Y-123 material can be understood in terms of fine distribution of the secondary phases. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Effect of microstructure on abrasion amount of steel balls for mill%显微组织对球磨机钢球磨损量的影响

    Institute of Scientific and Technical Information of China (English)

    张达富; 刘锦燕; 陈义

    2016-01-01

    Effect of microstructure on abrasion of steel balls by two different heat-treatment was studied by the abrasion-test machine,metalloscope and scanning electron microscopy (SEM) .The results show that the abrasion amount of high hardness steel balls with martensite microstructure is larger,and the relatively low hardness of tempered martensite and retained austenite erosion rate is lower.It is found that the abrasion mechanism of steel balls is given priority with peeling method,which indicates that the wear resistance of steel balls is directly related to the microstructure.%分别采用磨损试验机、金相显微镜和扫描电镜(SEM)等研究了两种热处理工艺下的钢球显微组织对磨损量的影响.结果表明,硬度较大的含马氏体组织的钢球磨损量较大,而硬度相对较低的回火马氏体+残留奥氏体磨损量较低.钢球的磨损机理以剥落方式为主,这说明钢球的耐磨性与显微组织有直接关系.

  13. Synthesis and analysis of nanocrystalline β1-Cu3Al and β2-NiAl intermetallic-reinforced aluminum matrix composite by high energy ball milling

    Science.gov (United States)

    Nguyen, Hong-Hai; Nguyen, Minh-Thuyet; Kim, Won Joo; Kim, Jin-Chun

    2017-01-01

    Nanocrystalline β1-Cu3Al and β2-NiAl intermetallic compounds were in-situ reinforced in the aluminum matrix with the atomic composition of Al67Cu20Ni13 by the mechanical alloying of elemental powders. Both β1-Cu3Al, β2-NiAl phases that can be only co-synthesized in Cu base alloys have been obtained after 15h milling in this study. The phase evolution during milling process was investigated by X-ray diffraction. The β1-Cu3Al, β2-NiAl phases were metastable with further milling time up to 40 h. Specially, unreacted Al matrix has been totally transformed to amorphous state in the final powder. A remarkable crystalline size of 6.5 nm was reached after 15 h milling time. Thermal stability of the milled powder was also studied by differential thermal analysis. It is shown that β1-Cu3Al, β2-NiAl phases were stable up to higher than 550 °C. Moreover, the inter-diffusion between Al matrix and Cu3Al within the temperature range of 620-740 °C led to the formation of superstructure ζ1-Al3Cu4 phase.

  14. Production of Stell Ball for E-type Coal Mill by Lost Foam Casting and Its Numerical Simulation%E型磨煤机钢球消失模铸造工艺及数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘瑞丽; 叶升平; 薛国祯; 孙爱民

    2012-01-01

    用消失模工艺铸造E型磨煤机用耐磨空心钢球,设计了侧注、顶注两种工艺方案,并用华铸CAE分析系统对两种方案进行充型和凝固模拟,并对两种方案的模拟结果进行分析和对比.另将试验结果和模拟结果作对比.分析了在铸造大型空心钢球方面,用消失模工艺方法生产的优势和劣势.%A wear-resistant hollow stell ball for E-type coal mill was produced by lost foam casting process. Two pouring schemes including the top pouring and the side pouring were designed. The filling and solidification of the two schemes were simulated by the Huazhu CAE software. The simulated results were analyzed comparatively. And the experiment results were well in agreement with the simulated ones. The advantages and disadvantages of producing large wear-resistant hollow steel ball with lost foam casting process were described.

  15. Ball clay

    Science.gov (United States)

    Virta, R.L.

    2011-01-01

    The article discusses the latest developments in the global ball clay mining industry, particularly in the U.S., as of June 2011. It cites several firms that are involved in ball clay mining in the U.S., including HC Spins Clay Co. Inc., the Imerys Group and Old Hickory Clay Co. Among the products made from ball clay are ceramic tiles, sanitaryware, as well as fillers, extenders and binders.

  16. Integrated analysis of hydrothermal flow through pretreatment

    Directory of Open Access Journals (Sweden)

    Archambault-Leger Veronique

    2012-07-01

    Full Text Available Abstract Background The impact of hydrothermal flowthrough (FT pretreatment severity on pretreatment and solubilization performance metrics was evaluated for three milled feedstocks (corn stover, bagasse, and poplar and two conversion systems (simultaneous saccharification and fermentation using yeast and fungal cellulase, and fermentation by Clostridium thermocellum. Results Compared to batch pretreatment, FT pretreatment consistently resulted in higher XMG recovery, higher removal of non-carbohydrate carbon and higher glucan solubilization by simultaneous saccharification and fermentation (SSF. XMG recovery was above 90% for FT pretreatment below 4.1 severity but decreased at higher severities, particularly for bagasse. Removal of non-carbohydrate carbon during FT pretreatment increased from 65% at low severity to 80% at high severity for corn stover, and from 40% to 70% for bagasse and poplar. Solids obtained by FT pretreatment were amenable to high conversion for all of the feedstocks and conversion systems examined. The optimal time and temperature for FT pretreatment on poplar were found to be 16 min and 210°C. At these conditions, SSF glucan conversion was about 85%, 94% of the XMG was removed, and 62% of the non carbohydrate mass was solubilized. Solubilization of FT-pretreated poplar was compared for C. thermocellum fermentation (10% inoculum, and for yeast-fungal cellulase SSF (5% inoculum, cellulase loading of 5 and 10 FPU/g glucan supplemented with β-glucosidase at 15 and 30 U/g glucan. Under the conditions tested, which featured low solids concentration, C. thermocellum fermentation achieved faster rates and more complete conversion of FT-pretreated poplar than did SSF. Compared to SSF, solubilization by C. thermocellum was 30% higher after 4 days, and was over twice as fast on ball-milled FT-pretreated poplar. Conclusions XMG removal trends were similar between feedstocks whereas glucan conversion trends were significantly

  17. 磷石膏-碳铵-氨水球磨制备硫酸铵和碳酸钙%Ammonium Sulfate and Calcium Carbonate Prepared by Ball-milling from Phosphogypsum-Ammonium Bicarbonate-Ammonia Water

    Institute of Scientific and Technical Information of China (English)

    李娜; 邓跃全; 董发勤; 罗绍东; 李珊珊; 彭宝瑶

    2013-01-01

    Ammonium sulfate and calcium carbonate were prepared using phosphogypsum, ammonium bicarbonate and ammonia water as raw materials by ball-milling technique. The optimum conditions were explored through orthogonal test, the major elements and phase composition of two kinds of products were analyzed by XRF and XRD, and the grain size distribution and poisonous elements of calcium carbonate were determined using laser particle size analyzer and ICP. The analysis results showed that the optimum technological conditions were as follows: the liquid-solid ratio was 0.5, the response time was 45 min, the ball-material ratio was 3:1, rotational speed was 600 r/min, and the average conversion reaction was up to 97.95%; the product quality of ammonium sulfate reached the standard of byproduct ammonium sulfate, poisonous and harmful elements contents of calcium carbonate were far lower than quality criteria of soil environment allows. Preparation of ammonium sulfate and calcium carbonate from phosphogypsum by ball-milling achieved the purpose of effectively using phosphogypsum.%  以磷石膏、碳酸氢铵和氨水为原料,采用球磨工艺制备硫酸铵和碳酸钙.通过正交试验设计,探索磷石膏球磨制备硫酸铵和碳酸钙的最佳工艺条件,采用 XRF 和 XRD 分析了2种产物的化学组成及物相组成,采用激光粒度仪和 ICP 分别测定了碳酸钙的粒度分布及有毒有害元素含量.结果表明,球磨制备硫酸铵和碳酸钙适宜的工艺条件为:液固比0.5,反应时间45 min,球料比3∶1,转速600 r/min,反应的平均转化率达97.95%;硫酸铵产品质量达到了副产硫酸铵标准,碳酸钙中有毒有害元素的含量远低于土壤环境质量标准要求.磷石膏球磨制备硫酸铵和碳酸钙,实现了磷石膏的高效利用.

  18. 高能球磨法制备超细镍粉的研究%Preparation of Ultrafine Nickel Powder by High-energy Ball Milling

    Institute of Scientific and Technical Information of China (English)

    李黎瑛; 张振忠; 赵芳霞; 寿奉良

    2012-01-01

    The influences of milling time and process control agents on the preparation of ultrafine nickel powder were studied systematically by granularity test, SEM and XRD. The results show that: with increasing milling time, the nickel powder particle size decreases rapidly at first and then the particle size changes slightly, the nickel powder can milling effectively by adding process control agent KH-570, the dispersion properties, sheet extent and the surface cleanliness are also improved. Milling 36 h the nickel powder with the process control agent KH-570 can obtain 5. 76 μm high-purity nickel powder.%采用粒度测试、SEM和XRD等分析手段,系统研究了球磨时间和过程控制剂对制备超细镍粉的影响.结果表明:随着球磨时间的延长,镍粉的粒度在初期减小较快,后期的减小趋于平缓;过程控制剂KH-570的加入能有效加快超细镍粉的细化,提高分散性能、片状化程度和表面的洁净度.加入过程控制剂KH-570,球磨36 h,能获得粒度为5.76 μm的高纯镍粉.

  19. Oxidative lime pretreatment of Alamo switchgrass.

    Science.gov (United States)

    Falls, Matthew; Holtzapple, Mark T

    2011-09-01

    Previous studies have shown that oxidative lime pretreatment is an effective delignification method that improves the enzymatic digestibility of many biomass feedstocks. The purpose of this work is to determine the recommended oxidative lime pretreatment conditions (reaction temperature, time, pressure, and lime loading) for Alamo switchgrass (Panicum virgatum). Enzymatic hydrolysis of glucan and xylan was used to determine the performance of the 52 studied pretreatment conditions. The recommended condition (110°C, 6.89 bar O(2), 240 min, 0.248 g Ca(OH)(2)/g biomass) achieved glucan and xylan overall yields (grams of sugar hydrolyzed/100 g sugar in raw biomass, 15 filter paper units (FPU)/g raw glucan) of 85.9 and 52.2, respectively. In addition, some glucan oligomers (2.6 g glucan recovered/100 g glucan in raw biomass) and significant levels of xylan oligomers (26.0 g xylan recovered/100 g xylan in raw biomass) were recovered from the pretreatment liquor. Combining a decrystallization technique (ball milling) with oxidative lime pretreatment further improved the overall glucan yield to 90.0 (7 FPU/g raw glucan).

  20. Market Demand and Application About Mill Ball and Rod%耐磨球段的市场需求及应用

    Institute of Scientific and Technical Information of China (English)

    徐佩芬; 吴海平

    2012-01-01

    The market demand and application status of wear resisting ball and rod, which is widely applied in industrial production of material grinding, for example metallurgical mines, building and cement, thermal power generation, coal processing and magnetic materials, was analyzed, and the market demand and the development trend in the next few years in China were predicted. The results show that the specification of wear resisting ball and rod products is complete in China, their properties have already been caught up with the foreign similar products. The market demand of wear resisting ball and rod products in 2012 is 172.82 million ton and that in 2015 will be up to 208.74 million ton, compared with that in 2010, it is increased by 44.34%. From the point of optimizing resource allocation and establishing the benign market, enterprise merger and integration is a developing trend of wear resisting ball and rod in the future.%对广泛用于冶金矿山、建材水泥、火力发电、煤炭加工、磁性材料等物料研磨生产过程中的耐磨球段的市场需求及应用现状进行了分析,并对未来几年的市场需求进行了预测.结果表明:中国耐磨球段产品规格齐全,产品性能已经赶上国外同类产品.2012年中国耐磨球段产品预计需求量为172.82万t,至2015年将达到208.74万t,较2010年增长44.34%.从优化资源配置,建立良性市场角度分析,产业兼并整合是耐磨球段行业未来发展方向.

  1. The effect of calcination on reactive milling of anthracite as potential precursor for graphite production

    Energy Technology Data Exchange (ETDEWEB)

    Burgess-Clifford, Caroline E.; Van Essendelft, Dirk T. [The EMS Energy Institute, C211 Coal Utilization Laboratory, Penn State University, University Park, PA 16802 (United States); Narayanan, Deepa L. [Puget Sound Energy, 10885 NE 4th PSE-09S, Bellevue, WA 98004 (United States); Jain, Puja; Lueking, Angela D. [Department of Energy and Mineral Engineering, Pennsylvania State University, 120 Hosler, University Park, PA 16802 (United States); Sakti, Apurba [School of Earth Atmospheric and Environmental Sciences, University of Manchester, Manchester (United Kingdom)

    2009-12-15

    The effect of a pretreatment using reactive ball milling and calcination on the graphitizability of an anthracite coal is explored. A thermal anneal of Buck Mountain anthracite at 1400 C in argon increased the L{sub c} crystallite dimension (from 12 to 20 A) and led to an increase in the oxidation temperature of the product. Ball milling of the coal reduced particle size with a nominal effect on carbon order and the degree of graphitization after the 1400 C thermal anneal (L{sub c} from 18 to 29 A). Ball milling in cyclohexene led to a substantial increase in the graphitizability at 1400 C (L{sub c} from 12 to 50 A). The enhanced reactivity was due to both carbon structure and introduced metal. The products of the mechano-chemical pretreatment and thermal anneal consisted of nanographene ribbons and multi-walled nanopolyhedral particles. It oxidized at moderate temperatures and had a high (74.3%) degree of graphitization based on X-ray diffraction analysis; the derived material has potential as filler for production of graphite. (author)

  2. Soft Sensor for Ball Mill Fill Level Based on CART-LSSVM Model%基于CART-LSSVM的球磨机料位软测量方法研究

    Institute of Scientific and Technical Information of China (English)

    张兴; 李伟; 阎高伟; 庞宇松

    2015-01-01

    Ball mill is a high energy consumption equipment used in electricity,grinding and metallurgical indus-tries.Accurate measurement of its fill level(FL)can improve operational efficiency and safety performance. Howev-er,The real-time measurement of FL is difficult to realize,and the components of bearing vibration of ball mill are complex and redundant. Aiming at these problems,a new soft sensor approach of FL based on Classification and Re-gression Tree(CART)and Least Squares Support Vector Machine(LSSVM)is proposed. Firstly,the Power Spectrum density(PSD)of bearing vibration is obtained by welch method,essential features are achieved by partition subse-quently. Secondly,these features are adopted to build CART,and branch nodes of the best model is selected as fea-tures. Finally,the LSSVM are used to implement the non-linear mapping between features and FL. The comparative experiments verifies that this model is feasible and practical with high prediction accuracy.%球磨机是用于电力、磨矿和冶金等行业的高能耗设备,准确测量其滚筒料位能够提高运行效率和安全性能.针对其滚筒内料位难以实时检测,球磨机的轴承振动信号中存在较多的冗余特征,提出了一种基于分类回归树和最小二乘支持向量机的软测量方法,首先用Welch法获得振动信号的功率谱密度,并分割得到基本特征,然后建立分类回归树模型,根据最优树模型的分支节点进行特征选择,最后利用最小二乘支持向量机实现特征变量与料位间的非线性映射.通过实验结果的对比分析,验证了该模型的有效性和实用性,以及良好的预测精度.

  3. M(o)ssbauer study on Fe-doped TiO2 by high-energy ball milling%高能球磨法制备的含铁TiO2的穆斯堡尔谱研究

    Institute of Scientific and Technical Information of China (English)

    蒋冬梅; 潘晓燕; 石旺舟; 马学鸣

    2006-01-01

    The structural evolution of Fe-doped TiO2 by high-energy ball milling was investigated by X-ray diffraction and M(o)ssbauer spectroscopy. The results show that the original anatase-TiO2 transforms to srilankite-type and rutile-type during ball milling. Iron atoms are preferable to dissolve in rutile-TiO2 and there are two relative doublets appearing in M(o)ssbauer spectra. A doublet is found in the condition of Fe atoms dissolved in srilankite TiO2 lattice. M(o)ssbauer spectra show that the composition distribution is nonuniform in TiO2 during the mechanical alloying with Fe atoms rich at the interface or surface of TiO2 crystalline.

  4. 球头铣刀曲面加工的刀具切触区域解析建模%Analytical Modeling of Cutter Engagement Regions in Ball-end Milling of Curved Surface

    Institute of Scientific and Technical Information of China (English)

    王亮; 王敏杰; 魏兆成; 王升福

    2012-01-01

    针对球头铣刀三维曲面加工,提出一种刀具切触区域仿真的通用解析模型.采用微分方法,将曲面加工过程离散为一系列连续的微小斜平面稳态加工.以每一小斜面切削过程为研究对象,建立描述刀具进给方向变化的数学模型,针对不同的进给方向并基于空间坐标系旋转变换,提出一组确定刀具切触边界曲线及各边界交点的解析公式,以精确界定刀具切触区域的封闭几何.通过与Z-Map模型的切触区域仿真对比,验证了本文模型的有效性及其精确高效的特点.%This paper presents a generalized analytical model of cutter engagement region simulations for ball - end milling of 3D curved surface. With differential method, the curved surface machining is treated as a series of sequential small inclined surfaces steady state milling. According to the cutting process of each small inclined surface, the mathematical models which are used to describe the variation of cutter feed direction are established. Through space coordinate system rotation transformation, a set of analytic formula of cutter contact boundaries and the intersection points are proposed, in order to exactly determine the closed geometry of engagement regions for different feed directions. The effectiveness and characteristics of accuracy and high - efficiency of the model presented in this paper are verified by the comparison of engagement region simulations with Z - Map model.

  5. Coagulation-Sedimentation-Extraction Pretreatment Methods for The Removal of Suspended Solids and Residual Oil From Palm Oil Mill Effluent (Pome

    Directory of Open Access Journals (Sweden)

    Abdul Latif Ahmad, Norliza Ibrahim , Suzylawati Ismail and Subhash Bhatia

    2012-08-01

    Full Text Available Suspended solids and residual oil removal in a liquid are relevant to numerous research areas and industry. The suspended solid cannot be removed completely by plain settling. Large and heavy particles can settle out readily, but smaller and lighter particles settle very slowly or in some cases do not settle at all. Because of this, it requires efficient physical-chemical pretreatment methods.   Our current research is to study the pretreatment methods in the removal of suspended solids and residual oil content in POME. Preliminary analysis shows that POME contains 40,000 mg/L suspended solid and 4,000 mg/L oil and grease content that relatively very high compared to the maximum allowable limit by the Malaysian Department of Environment which are only 400 mg/L and 50 mg/L respectively. The methods chosen were coagulation-sedimentation method for suspended solids removal and solvent extraction for residual oil removal.  Jar test apparatus was used as the standard procedure for bench-scale testing and alum was used as the coagulant. Parameters studied were alum dosage, mixing time, mixing speed, sedimentation time and pH. For removal of residual oil, six different organic solvents; n-hexane, n-heptane, benzene, petroleum ether, pentane and petroleum benzene were used. For every solvent the effect of solvent ratio, mixing time, mixing speed and pH were analyzed. The results show that the optimum conditions in removal of suspended solid from POME were at pH 4.11, sedimentation time of 100 minutes and 150 rpm mixing speed with 1.5 hr mixing time. N-hexane give the best performance in extracting residual oil from POME with solvent to POME ratio of 6:10. It was estimated about 0.54 grams of oil and grease can be extracted with optimum variables at pH 4, mixing speed of 200 rpm, and 20 minutes mixing time.  Key Words: palm oil mill effluent, coagulation, suspended solid, residual oil, solvent extraction.

  6. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  7. Discussion on the structure optimization of parts in design liaison of the order(manufacture)of large-scale ball mills%大型球磨机订购(制造)设计联络中零部件结构优化的探讨

    Institute of Scientific and Technical Information of China (English)

    刘永松; 来绩伟

    2015-01-01

    In light of the problems in the use of large-scale ball mills,the flaws in the structure of main parts of ball mills are analyzed and countermeasures are proposed.Through design liaison,structure optimization of main parts is conducted in advance to eliminate the flaws.The structure optimization of main parts in design liaison works double efficiently in improving the operation rate of ball mills.%针对大型球磨机使用中存在的问题,对球磨机主要零部件结构缺陷进行分析并提出解决方案。通过设计联络,提前对球磨机主要零部件结构进行优化,消除设备缺陷。大型球磨机设计联络中对主要零部件结构进行优化,对提高球磨机的运转率有着事半功倍的作用。

  8. Structure, magnetic and magnetoresistance properties of Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} manganite oxide prepared by ball milling method

    Energy Technology Data Exchange (ETDEWEB)

    Cherif, W., E-mail: wajdi_cherif@yahoo.fr [Sfax University, Faculty of Sciences, B.P. 1171, 3000 Sfax (Tunisia); Ellouze, M., E-mail: mohamed.ellouze@fss.rnu.tn [Sfax University, Faculty of Sciences, B.P. 1171, 3000 Sfax (Tunisia); Lehlooh, A.-F., E-mail: foued.elhalouani@enis.rnu.tn [King Faisal University, Hofuf 31982 (Saudi Arabia); Elhalouani, F., E-mail: alehlooh@yahoo.com [Sfax University, National School of Engineers, B.P. W, 3038 (Tunisia); Mahmood, S.H., E-mail: s.mahmood@ju.edu.jo [University of Jordan, Amman (Jordan)

    2012-07-15

    A sample of Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} nanoparticles was synthesized by the ball milling method. X-ray diffraction pattern of the sample showed orthorhombic system with Pnma space group. The average crystallite size of 110 nm was obtained by both Scanning Electron Microscopy and X-ray diffraction. Magnetic measurements showed para-to-ferromagnetic transition with a Curie temperature of T{sub C}=269 K. Electrical investigations showed that all our samples exhibit a semi-conducting behavior above T{sub C} and a metallic-like one at lower temperatures. The sample exhibited a large magnetoresistance of 30% at room temperature in an applied magnetic field of 2 T. The transport and the magnetic properties were interpreted in terms of the existence of magnetic polarons in the sample. - Highlights: Black-Right-Pointing-Pointer Magnetic and structural properties of Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} nanoparticles. Black-Right-Pointing-Pointer Average particle size from 110 nm fabricated by mechanical system. Black-Right-Pointing-Pointer Large magnetoresistance of 30% at room temperature.

  9. Electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 ceramics prepared by high energy ball-milling and conventional sintering

    Science.gov (United States)

    Mahfoz Kotb, H.; Ahmad, Mohamad M.

    2016-12-01

    We report on the measurements of the electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 (NLCTO) ceramics prepared by high energy ball-milling and conventional sintering without any calcination steps. The x-ray powder diffraction analysis shows that pure perovskite-like CCTO phase is obtained after sintering at 1025 °C-1075 °C. Higher sintering temperatures result in multi-phase ceramics due to thermal decomposition. Scanning electron microscope observations reveal that the grain size is in a range of ˜3 μm-5μm for these ceramics. Impedance spectroscopy measurements performed in a wide frequency range (1 Hz-10 MHz) and at various temperatures (120 K-470 K) are used to study the dielectric and electrical properties of NLCTO ceramics. A good compromise between high ɛ‧ (5.7 × 103 and 4.1 × 103 at 1.1 kHz and 96 kHz, respectively) and low tan δ (0.161 and 0.126 at 1.1 kHz and 96 kHz, respectively) is obtained for the ceramic sintered at 1050 °C. The observed high dielectric constant behavior is explained in terms of the internal barrier layer capacitance effect.

  10. Microscopic structure and properties changes of cassava stillage residue pretreated by mechanical activation.

    Science.gov (United States)

    Liao, Zhengda; Huang, Zuqiang; Hu, Huayu; Zhang, Yanjuan; Tan, Yunfang

    2011-09-01

    This study has focused on the pretreatment of cassava stillage residue (CSR) by mechanical activation (MA) using a self-designed stirring ball mill. The changes in surface morphology, functional groups and crystalline structure of pretreated CSR were examined by using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) under reasonable conditions. The results showed that MA could significantly damage the crystal structure of CSR, resulting in the variation of surface morphology, the increase of amorphous region ratio and hydrogen bond energy, and the decrease in crystallinity and crystalline size. But no new functional groups generated during milling, and the crystal type of cellulose in CSR still belonged to cellulose I after MA.

  11. Hydrogen storage properties of a Mg-Ni-Fe mixture prepared via planetary ball milling in a H{sub 2} atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Song, Myoung Youp; Baek, Sung Hwan [Division of Advanced Materials Engineering, Department of Hydrogen and Fuel Cells, Research Center of Advance Materials Development, Engineering Research Institute, Chonbuk National University, 664-14 1ga Deogjindong Deogjingu, Jeonju, Jeonbuk, 561-756 (Korea); Bobet, Jean-Louis [ICMCB, CNRS (UPR 9048), Universite de Bordeaux 1, 33608 Pessac cedex (France); Hong, Seong-Hyeon [Powder Materials Research Center, KIMS, Korea Institute of Machinery and Materials, 66 Sangnamdong, Changwon, Kyungnam, 641-010 (Korea)

    2010-10-15

    A sample composition has been designed based on previously reported data. An 80 wt%Mg-13.33 wt%Ni-6.67 wt%Fe (referred to as Mg-13.33Ni-6.67Fe) sample exhibited higher hydriding and dehydriding rates after activation and a larger hydrogen storage capacity compared to those of other mixtures prepared under similar conditions. After activation (at n = 3), the sample absorbed 4.60 wt%H for 5 min and 5.61 wt%H for 60 min at 593 K under 12 bar H{sub 2}. The sample desorbed 1.57 wt%H for 5 min and 3.92 wt%H for 30 min at 593 K under 1.0 bar H{sub 2}. Rietveld analysis of the XRD pattern using FullProf program showed that the as-milled Mg-13.33Ni-6.67Fe sample contained Mg(OH){sub 2} and MgH{sub 2} in addition to Mg, Ni, and Fe. The Mg(OH){sub 2} phase is believed to be formed through the reaction of Mg or MgH{sub 2} with water vapor in the air. The dehydrided Mg-13.33Ni-6.67Fe sample after hydriding-dehydriding cycling contained Mg, Mg{sub 2}Ni, MgO, and Fe. (author)

  12. TX1600G 数控镗铣加工中心滚珠丝杠热特性分析%Thermal Characteristics Analysis of Ball Screw of TX1600G CNC Boring and Milling Machining Center

    Institute of Scientific and Technical Information of China (English)

    孙军; 秦显军; 钱彬彬; 黄圆

    2015-01-01

    This paper takes TX1600G CNC bor-ing and milling machining center as example and mainly studies the impact of different feed speed and coolant flow on the system heat balance,under the conditions of the moving heat source.To un-derstand the ball screw in actual working condi-tions,ANSYS was first used to establish a simpli-fied three dimensional model of the ball screw, and then the heat source was moved to simulate heat transmission on nut and bearing,so the tem-perature model and thermal error compensation model of lead screw are established.Results show that the increase of feed speed can shorten the time for heat balance of the system,but the thermal e-quilibrium temperature was increased;coolant flu-id can effectively reduce the thermal equilibrium temperature and the thermal equilibrium time. Thermal error modeling and the analysis of tem-perature field also provide necessary theoretical ba-sis to the thermal compensation of the system.%以 TX1600G 数控镗铣加工中心为例,主要研究在移动热源施加条件下,不同的进给速度以及冷却液流量对系统热平衡的影响。为得到滚珠丝杠在实际工作中的状态,利用 ANSYS 建立丝杠的简化三维模型,施加移动热源来模拟螺母和轴承的传动热量,从而得到丝杠的温度模型,建立热误差补偿模型。结果表明,进给速度的增加可以缩短系统的热平衡时间,但热平衡温度有所升高;冷却液可以有效地降低热平衡温度和缩短热平衡时间。热误差模型建立和温度场分析,为系统的热补偿提供必要的理论依据。

  13. Science of Ball Lightning (Fire Ball)

    Science.gov (United States)

    Ohtsuki, Yoshi-Hiko

    1989-08-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Preface * Ball Lightning -- The Continuing Challenge * Hungarian Ball Lightning Observations in 1987 * Nature of Ball Lightning in Japan * Phenomenological and Psychological Analysis of 150 Austrian Ball Lightning Reports * Physical Problems and Physical Properties of Ball Lightning * Statistical Analysis of the Ball Lightning Properties * A Fluid-Dynamical Model for Ball Lightning and Bead Lightning * The Lifetime of Hill's Vortex * Electrical and Radiative Properties of Ball Lightning * The Candle Flame as a Model of Ball Lightning * A Model for Ball Lightning * The High-Temperature Physico-Chemical Processes in the Lightning Storm Atmosphere (A Physico-Chemical Model of Ball Lightning) * New Approach to Ball Lightning * A Calculation of Electric Field of Ball Lightning * The Physical Explanation to the UFO over Xinjiang, Northern West China * Electric Reconnection, Critical Ionization Velocity, Ponderomotive Force, and Their Applications to Triggered and Ball Lightning * The PLASMAK™ Configuration and Ball Lightning * Experimental Research on Ball Lightning * Performance of High-Voltage Test Facility Designed for Investigation of Ball Lightning * List of Participants

  14. 基于S7-300PLC的球磨机配料过程自动控制系统%Automatic Control System of Ball Mill Blending Process Based on S7-300 PLC

    Institute of Scientific and Technical Information of China (English)

    王全铁; 包岩峰

    2011-01-01

    Ball mill blending process is one of the key producing processes in the sintering alumina production.In this blending process,raw materials are ground and blended in the mill to produce raw slurry.The automatic control system was designed and developed by using S7-300 PLC of Siemens Company in consideration of this industry features and technique requested.The structure,functions and control strategy of this system were all discussed,and the control software was developed.Control software includes the logic control program,continuous control program and picture monitoring.The proposed control system can not only improve the quality of raw slurry,but also can lower energy consumption and create more profit for its enterprise.%球磨机配料过程是氧化铝行业对原料进行加工处理的重要工序。在该过程中,碱赤泥浆等多种原料被输送到球磨机中进行混合、研磨后形成生料浆。针对该工业过程的特点及技术要求,利用Siemens公司的S7-300 PLC设计并开发了球磨机配料过程的自动控制系统,包括系统的结构和功能、硬件设计、各种软件程序的开发等。其中软件程序的开发包括逻辑控制程序、连续控制程序和监控画面的开发。所设计和开发的控制系统不仅可以大幅度提高生料浆质量,同时可以节能降耗,为企业创造更多的效益。

  15. Steel balls forming by cross rolling with upsetting

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2013-01-01

    Full Text Available The paper describes a process of forming four balls with a diameter of 22 mm by means of cross rolling with upsetting. The paper also presents the tool used to form semi-finished balls. Owing to the application of the finite element method (FEM, the course of the rolling process as well as temperature and strain distributions in the obtained balls could be presented. The rolling tests conducted in laboratory conditions at the Lublin University of Technology have proved that the balls produced with the developed rolling method meet the demands for grinding media used in ball mills.

  16. Novel spin glasses by mechanical milling

    Institute of Scientific and Technical Information of China (English)

    周国富; H.Bakker

    1996-01-01

    Novel spin-glass alloys were synthesized by milling intermetallic compounds and also by milling mixtures of crystalline elemental powder in a high-energy ball mill.Spin glass behaviour was found in amorphous Co2Ge,which was amorphised by milling in mechanically disordered crystalline GdAl2 in ball-milled crystalline and amorphous CoZr,and in mechanically alloyed Co-Cu,which formed a supersaturated f.c.c.solid solution.All these materials are binary alloys and tlie concentration of the magnetic element is high,which makes them novel types of spin glasses.It is shown that ball milling may not only lead to structural metallic glasses,but can also generate the magnetic pendant of a structural glass,namely the spin glass.

  17. Gray Prediction Model-free Adaptive Control Strategy of Ball Mill%球磨机灰色预测无模型自适应控制策略

    Institute of Scientific and Technical Information of China (English)

    马光; 李栋; 杨晓冬

    2016-01-01

    The ball mill load control system is a complex system featuring large time hysteresis,time-varying,strong nonlinearity,multivariable and strong coupling. In order to further overcome the large time lag and uncertainty and other problems of such load control system,the scheme of gray prediction model - free adaptive control ( MFAC ) is proposed. For this control system, PID, gray prediction PID, MFAC, and gray prediction MFAC are respectively applied in simulation analysis. The applications verify the feasibility and rationality of this strategy,and it is indicated that gray prediction model-free adaptive control has good control performance and practical value.%球磨机负荷控制系统是一个具有大时滞、强时变性、强非线性及多变量与强耦合等特性的复杂系统。为了更好地克服球磨机负荷控制系统中存在的大滞后和不确定性等问题,提出了灰色预测无模型自适应控制( MFAC )策略。在控制系统下,分别采用PID、灰色预测PID、MFAC及灰色预测MFAC进行控制仿真分析。实际应用验证了该策略的可行性与合理性,表明了灰色预测无模型控制策略具有良好的控制性能和实用价值。

  18. Hydrogen Storage Properties and Mechanism of Mg-In-Zn Ternary Solid Solution by Ball Milling%球磨制备Mg-In-Zn三元固溶体的储氢性能及机理

    Institute of Scientific and Technical Information of China (English)

    钟海长; 赖桂文; 朱子文; 郑青榕

    2014-01-01

    Mg0. 92 In0. 05 Zn0. 03 ternary solid solution with reduced lattice constants was prepared by the method of sintering-ball milling. The phases, phase transitions during hydrogenation and dehydrogenation process and microstructure of the alloy were analyzed by powder X-ray diffraction ( XRD) . The morphology and phase distributions were observed by SEM. PCT and kinetic curves were measured by Sievert’ method to determine the apparent activation energy of hydrogenation, enthalpy and entropy change of hydrogenation and dehydrogenation. The results show that Mg0. 92 In0. 05 Zn0. 03 ternary solid solution has good activation performances and kinetic properties, with the enthalpy of hydrogenation reduced to -68. 6 kJ/mol H2 .%采用“烧结-球磨”方法制备Mg0.92 In0.05 Zn0.03三元固溶体合金,减小了Mg的晶格常数.利用粉末X-射线衍射分析合金的相组成、微观结构和吸放氢过程的相转变,通过扫描电镜观察合金的微观形貌及相分布.采用体积法测定合金的等温吸放氢曲线( PCT)和动力学曲线,确定了合金的吸放氢反应焓变、熵变及氢化反应激活能.结果表明: Mg0.92 In0.05 Zn0.03三元固溶体具有良好的活化性能和动力学性能,脱氢反应焓降低至-68.6 kJ/mol H2.

  19. Influence of high-energy ball-milling on properties of CuCo/ZrO2 catalyst for higher alcohols synthesis%高能球磨对CuCo/ZrO2催化剂合成低碳醇性能的影响

    Institute of Scientific and Technical Information of China (English)

    士丽敏; 邓思玉

    2011-01-01

    研究高能球磨技术对浸渍法制备CuCo/ZrO2催化剂结构与合成低碳醇性能的影响,借助N2吸附-脱附等温线、扫描电镜、X射线衍射和程序升温还原等测试技术对催化剂进行表征,并以CO加氢合成低碳醇为模型反应对其催化性能进行评价.研究结果表明,催化剂制备过程中引入高能球磨技术可显著提高CuCo/ZrO2催化剂的CO转化率和C2+OH选择性.%The catalytic properties of high-energy ball-milled CuCa/ZrO2 catalysts for the synthesis of higher alcohols from syngas and the effects of high-energy ball-milling method on the structure and per formance of the catalysts were Investigated. The catalysts were characteriied by means of BET,SEM,XRD and H2-IPB techniques. The results indicated that CO conversion and selectivity to C2+OH were enhanced significantly when the high-energy ball-miffing method was used in the process of the catalyst preparation.

  20. Split-ball resonator

    CERN Document Server

    Kuznetsov, Arseniy I; Fu, Yuan Hsing; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Kivshar, Yuri; Pickard, Daniel S; Lukiyanchuk, Boris

    2014-01-01

    We introduce a new concept of split-ball resonator and demonstrate a strong omnidirectional magnetic dipole response for both gold and silver spherical plasmonic nanoparticles with nanometer-scale cuts. Tunability of the magnetic dipole resonance throughout the visible spectral range is demonstrated by a change of the depth and width of the nanoscale cut. We realize this novel concept experimentally by employing the laser-induced transfer method to produce near-perfect spheres and helium ion beam milling to make cuts with the nanometer resolution. Due to high quality of the spherical particle shape, governed by strong surface tension forces during the laser transfer process, and the clean, straight side walls of the cut made by helium ion milling, magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. Structuring arbitrary features on the surface of ideal spherical resonators with nanoscale dimensions provides new ways of engineering hybrid resonant modes and ultra-high near-f...

  1. 酶磨法处理玉米秸秆的糖化发酵研究%Saccharification and Ethanol Fermentation of Corn Stalk Pretreated by Enzymatic Hydrolysis and Wet-milling

    Institute of Scientific and Technical Information of China (English)

    邵世芳; 吴琴燕

    2011-01-01

    将纤维素酶、木聚糖酶分别与湿磨相结合对玉米秸秆进行了预处理,对不同料液浓度的酶磨玉米秸秆进行了糖化发酵研究.试验结果表明:当经纤维素酶、木聚糖酶酶磨处理的玉米秸秆料液的酶解浓度均为6%时,还原糖收率最高,分别为37.2%和33.5%;对酶解后的料液进行酒精发酵,发现在酶解料液浓度为11%时,酒精浓度最高,分别为3.0%和2.8%.%In this study, the corn stalk was pretreated respectively by cellulase and xylanase hydrolysis combined with wet - milling, and then the saccharification and ethanol fermentation of the pretreated corn stalk at different concentrations were carried out by using commercially - available cellulase and yeast, respectively. The results showed that when the enzymatic hydrolysis concentration of the corn stalk pretreated by cellulase or xylanase combined with wet - milling was all 6%, the maximum recovery rate of reducingsugar was obtained, being 37.2% and 33.5% respectively. In the ethanol fermentation process, it was found that the maximum alcoholicity was 3.0% and 2.8% respectively as the corn stalk solution which had been hydrolyzed by cellulase and xylanase was at the concentration of 11%.

  2. Online SAG Mill Pluse Measurement and Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Raj Rajamani; Jose Delgadillo; Vishal Duriseti

    2007-06-30

    The grinding efficiency of semi autogenous milling or ball milling depends on the tumbling motion of the total charge within the mill. Utilization of this tumbling motion for efficient breakage of particles depends on the conditions inside the mill. However, any kind of monitoring device to measure the conditions inside the mill shell during operation is virtually impossible due to the severe environment presented by the tumbling charge. An instrumented grinding ball, which is capable of surviving a few hours and transmitting the impacts it experiences, is proposed here. The spectrum of impacts collected over 100 revolutions of the mills presents the signature of the grinding environment inside mill. This signature could be effectively used to optimize the milling performance by investigating this signature's relation to mill product size, mill throughput, make-up ball size, mill speed, liner profile and ball addition rates. At the same time, it can also be used to design balls and liner systems that can survive longer in the mill. The technological advances made in electronics and communication makes this leap in instrumentation certainly viable. Hence, the instrumented grinding ball offers the ability to qualitatively observe and optimize the milling environment. An instrumented load cell package that can measure the force of impacts inside the grinding chamber of a mill is developed here. The signal from the instrumented load cell package is interpreted in terms of a histogram termed as an impact spectrum which is a plot of the number of impacts at a specific energy level against the energy. It reflects on the average force regime of the mill. The instrumented load cell package was calibrated against the ultra fast load cell which has been unanimously accepted as a standard to measure single breakage events. The load cell package was successfully used to produce impact spectra in an 8.5 inch lab scale mill. The mill speed and the ball size were varied to

  3. Preparation of bismuth subcarbonate by liquid ball-milling transformation method from bismuth oxide%液相球磨法由氧化铋制备次碳酸铋的动力学

    Institute of Scientific and Technical Information of China (English)

    叶龙刚; 蒋叶; 唐朝波; 陈永明; 唐谟堂

    2014-01-01

    In order to solve the problems of environment pollution and high cost in traditional process of bismuth subcarbonate preparation, a new process using ball-milling transformation method from NH4HCO3 and Bi2O3 was proposed. Additionally, the kinetics of bismuth subcarbonate preparation was studied. Effects of reaction temperature, particle size of bismuth oxide, solid-to-liquid ratio and concentrations of ammonium bicarbonate on the conversion rate of bismuth oxide were studied. The results indicate that the conversion rate of bismuth oxide significantly increased under the conditions of higher temperature, smaller particle size, higher concentration of ammonium bicarbonate and smaller solid-to-liquid ratio. The XRD and ICP-AES analyses show that the purity of product is high. The reaction kinetics with activation energy of 9.783 kJ/mol was analyzed by shrinking core model, and the whole transformation process is controlled by solid product layer diffusion. A semi-empirical kinetics equation was obtained to describe the conversion process.%为解决传统次碳酸铋生产过程中成本高和环境污染问题,提出采用液相球磨法由氧化铋制备次碳酸铋的新工艺,研究用碳酸氢氨和氧化铋制备次碳酸铋反应过程的动力学,考察反应温度、氧化铋粒度、液固比以及碳酸氢氨浓度对氧化铋转化率的影响。结果表明,在9~30°C的范围内,升高反应温度、减小氧化铋粉末的粒度、扩大液固比以及提高碳酸氢氨浓度均有利于氧化铋转化率的提高。对反应产物的表征分析表明,产品的纯度较高、杂质少;SEM结果显示产品次碳酸铋主要呈针棒状形态。反应过程受产物层的扩散控制,可用未反应收缩核模型描述,反应的表观活化能为9.783 kJ/mol,同时获得了描述反应过程的半经验动力学方程。

  4. Pilot scale hybrid processes for olive mill wastewater treatment, energy production and water reuse: comparison between fungal and electro-coagulation pre-treatments

    Energy Technology Data Exchange (ETDEWEB)

    Sayadi, S.

    2009-07-01

    Olive oil mill wastewaters (OMW) cause disposal problems because they contain powerful pollutants such as phenolic compounds. Complete biodegradation or removal of these compounds is hardly achieved by a single treatment method. In this work, we investigated 2 integrated technologies for the treatment of the recalcitrant contaminants of OMW, allowing water recovery and reuse for agricultural purposes. (Author)

  5. The effect of pretreatment on the purification of paper mill circulation waters by UF and NF techniques; Esikaesittelyvaiheiden vaikutus ultra- ja nanosuodatustekniikoilla tapahtuvaan kiertovesien puhdistukseen - EKT 09

    Energy Technology Data Exchange (ETDEWEB)

    Nuortila-Jokinen, J.; Nystroem, M. [Lappeenranta Univ. of Technology (Finland). Dept. of Chemical Technology

    1998-12-31

    In this study pretreatment methods for nanofiltration of paper machine save-all clarified water fractions (clear filtrate) were tested. The clear filtrates resulting from both an acidic and a neutral paper making process were used. Tubular compact modules from Stork-Friesland and a Vibration Shear Enhanced Processing (VSEP) - unit from New Logic Int. equipped with various different membranes were used. It was shown, that pretreatment with porous membranes, such as micro- or ultrafiltration membranes was not economically feasible, because the flux in the nanofiltration stage was not increased. The chemical pretreatment enhanced nanofiltration flux at neutral pH by about 20 % and the amount of irreversible fouling was reduced from 40 % to 20 %. Moreover, the chemical dosage needed was low, 0.5 mg/l. This indicates that chemical pretreatment could turn up to be a feasible way to increase the capacity of a nanofiltration plant. It was also shown, that the VSEP module, which tolerates even some amount of fibre and thus needs only coarse pretreatment, such as bend screens, gave at neutral pH nanofiltration fluxes, which were higher than those obtained earlier with other membrane modules. In general, it was seen, that pH is one of the most important factors affecting the membrane behaviour: at acidic pH lower fluxes and more fouling were obtained. (orig.) 6 refs. CACTUS Research Programme

  6. Effects of mechanical milling on the carbothermal reduction of oxide of WC/Co hardmetal scrap

    Science.gov (United States)

    Lee, Gil-Geun; Ha, Gook-Hyun

    2016-03-01

    The effects of mechanical milling on the carbothermal reduction of oxidized WC/Co hardmetal scrap with solid carbon were examined. Mixed powders were manufactured by milling the WC/Co hard metal scrap oxide and carbon powder in either a tumbler-ball mill or a planetary-ball mill. The milling type affected the carbothermal reduction of the oxide owing to the differing collision energies (mechanical milling energies) in the mills. The hardmetal scrap oxide powder (WO3, CoWO4) milled at high energy was more greatly reduced and at a lower temperature than that milled at lower mechanical energy. The formation of WC by the carburization reaction with solid carbon reached completion at a lower temperature after higher-energy milling than after lower-energy milling. The WC/Co composite particles synthesized by the combined oxidationmechanical milling-carbothermal reduction process were smaller when the initial powder was milled at higher mechanical energy.

  7. Bouncing Balls that Spin

    Science.gov (United States)

    Knipp, Peter

    2008-01-01

    When a ball bounces elastically against a floor, the vertical component (v[subscript y]) of the velocity of the ball's mass-center changes sign. This is a special case of the elastic collision of two balls (i.e., two objects, neither of which is much more massive than the other), in which case the balls' post-collision relative velocity (=…

  8. Dispersion Stability and Mechanism of Nano-WS2 Particulates in Base Lubrication Oil after High Power Ultrasund/Ball-milling/Surface Modification Treatment%超声球磨活化处理后纳米WS2颗粒在基础润滑油中的分散稳定性及机理

    Institute of Scientific and Technical Information of China (English)

    毛大恒; 刘阳; 石琛

    2013-01-01

    Nano-WS2 particulates were dispersed in PAO6 base lubrication oil by using the methods of ballmilling stir,ball-milling stir/surface modification and high power ultrasound/ball-milling stir/surface modification on homemade ultrasonic/ball milling experimental device,the dispersion stability of nano-WS2 particulates in base oil and the effect of surface modifier on diepersion stability of WS2 were studied,and the despersive mechanism was analysed,too.The results show that the dispersion state of the nano-WS2 particulates was best after compound action of high power ultrasonic/ball-milling stir/surface modification.The mechanism show that compound action of high power ultrasonic/ball-milling stir/surface modification could break up the nano-WS2 agglomerations and then strengthen the surfactivity of nano-WS2 particulates,and thus lead to the change of particulates' surface characteristics from hydrophilicity to lipophilicity,After surface modifying,the long carbon chains on WS2 surface could form stereo-hindrance layer,combined with solvation layer formed by lubricant molecule,to prevent nanometer particulates from aggregate,and ultimately made nanometer WS2 particulates dispered in baseoil stably for a long time.%用自制的超声球磨试验装置采用不同的分散方法(球磨搅拌分散,球磨搅拌、表面活性剂分散,强超声、球磨搅拌、表面活性剂分散)将纳米WS2颗粒分散于PAO6基础润滑油中,研究了纳米WS2颗粒在基础油中的分散稳定性以及表面活性剂对纳米WS2颗粒分散稳定性的影响,并对其分散机理进行了分析.结果表明:强超声、球磨搅拌、表面活性剂分散的复合处理对提高纳米WS2颗粒在基础油中分散稳定性的效果最好,其机理是将基础油中的纳米WS2团聚体解聚,并使解聚后的纳米WS2颗粒表面活性增强,表面特性由亲水疏油转变为亲油疏水,经表面修饰后的纳米WS2颗粒被长碳链极性分子和润滑油分子所包围,

  9. Effect of Pretreatment on Mixed Fermentation of Paper Mill Sludge and Food Waste%预处理对造纸污泥和餐厨垃圾混合发酵的影响

    Institute of Scientific and Technical Information of China (English)

    林云琴; 武书彬; 梁嘉晋

    2012-01-01

    为揭示联产氢气和甲烷复合工艺中预处理对物料液化水解率及系统产气性能的影响,利用不同浓度的酸( H2 SO4)、碱(NaOH)预处理造纸污泥和餐厨垃圾混合物,在中温-高温条件下将预处理后的物料进行混合发酵联产氢气和甲烷,研究了不同浓度的酸/碱预处理后,造纸污泥和餐厨垃圾混合发酵联产氢气和甲烷性能.结果表明:酸/碱顸处理对物料产生了明显的水解作用,物料中的大分子物质被降解为小分子颗粒;预处理对混合发酵产氢阶段具有明显的促进作用,其中以添加10% NaOH(以物料总固体计)的碱预处理效果最佳,其氢气产率较未经预处理的对照(CK)提高了50.20%,挥发性固体(VS)去除率达到了16.06%;预处理在产氢后的产甲烷阶段对甲烷产率没有明显的促进作用,各反应器的甲烷产率与CK相近或低于CK,VS总去除率也以CK为最高.%In order to reveal the effed of pretreatment on the organics hydrolysis and biogas production in the hydrogen-methane co-production process, a mesophilic-thermophilic anaerobic co-digestion of paper mill sludge (PS) and food waste (FW) pretreated with H2SO4 or NaOH in batch reactors was carried out, and the mixed fermentation performances of paper mill sludge and food waste pretreated with H2SO4 or NaOH at different concentralions were investigated. The results show that the pretreatment enhances the hydrolysis of organics and makes the macro-molecular organic compounds degrade into micromolecular particles, and thai the pretreatment obviously increases the hydrogen yield, especially the pretreatment with NaOH at the dosage of 10% (calculated on the basis of the mass of total solid) , which results in a hydrogen yield increment of 50.20% (as compared with the check reactor) and a VS (Volatile Solids) removal of 16.06%. However, the pretreatment has no obvious effect on the methane production after the hydrogen fermentation, concretely, both

  10. 基于残留高度球刀铣削粗糙度建模及参数优化∗%Modeling of Surface Roughness with Ball-end Cutters Milling Based on Scallop Height and Optimum of Cutting Parameters

    Institute of Scientific and Technical Information of China (English)

    肖军民

    2015-01-01

    基于P20模具钢数控球刀铣削试验,对表面粗糙度的影响因素进行了研究。在试验数据极差分析的基础上得出了如下结论:加工残留高度是球刀铣削粗糙度最重要的影响因素。基于试验数据,利用最小二乘多元线性回归方法,推导并求解出P20模具钢球刀铣削粗糙度的数学模型。利用最优化设计方法和MATLAB优化工具箱,以加工效率为目标函数和以粗糙度预测模型为约束条件,针对实际的问题优选了铣削工艺参数。优化的工艺参数在保证表面加工质量的基础上可大幅提高加工效率,这为数控加工企业降低生产成本提供了重要的理论依据和案例参考。%The affecting factors on surface roughness are studied based on NC milling tests with ball-end cut-ters for P20 mould steel. Based on the analysis of the test data conclusions are as follows:scallop height is the most important influencing factors of surface roughness for ball-end cutters milling. Based on the experi-mental data, the mathematical model of surface roughness with ball-end cutters milling for P20 mould steel is derived and solved by using of regression analysis method of least square. Aiming at the actual milling problem the cutting parameters are optimized by using of optimum tool-box of MATLAB software and opti-mal design method. The optimized cutting parameters can greatly improve the machining efficiency ensuring quality of the machined surface, it provides the important theory evidence and case reference for NC machi-ning enterprises to reduce production costs.

  11. 葛花粉体高效球磨制备技术及其醒酒活性测定%High efficient ball milling technology and determination alcohol metabolism of Flos puerariae

    Institute of Scientific and Technical Information of China (English)

    许阳; 杜先锋; 王一见

    2013-01-01

    The mechanism for Flos puerariae facilitating alcohol metabolism was studied.The relativity between particle size and the release rate of efficacy was demonstrated.The activity of alcohol dehydrogenase (ADH) in vitro and the dissolution of total material and flavonoids from four kinds of powder of Flos puerariae which used different methods to shatter were compared.The results showed that four kinds of powder could activate ADH,but grade Ⅱ powder had an obvious advantage over grade Ⅰ powder in the total dissolution test.Its instant dissolution can reached 8.6 times of that of plant body.There was the same trend in the amount of flavonoids dissolution and the activation rate of ADH.The amount of flavonoids dissolution in grade Ⅱ powder was 57.98% higher than that in plant body and activation rate was 2 times of that in it.The grade Ⅱ powder which was gained by high efficient ball milling technology had a more beneficial effect on these tests than other powder.It was also indicated that it was useful to select Flos puerariae to facilitate alcohol metabolism,this new efficient technology provided a theoretical basis for the development of new sober up functional foods.%为探究葛花粉体粒径与功效释放速度的相关性及其醒酒机理,通过比较4种不同粉碎方法处理得到的植物本体、常规粉体、Ⅰ级粉体、Ⅱ级粉体在总物质溶出度、黄酮溶出量及乙醇脱氢酶(ADH)体外活性实验方面的差异性,发现4种粉体均可在体外激活乙醇脱氢酶,但在总溶出度上Ⅱ级粉体优于Ⅰ级粉体,其次是常规粉体和植物本体,其瞬时溶出度可达到植物本体的8.6倍.在黄酮溶出量和ADH激活率上也呈现相同趋势,Ⅱ级粉体黄酮溶出含量较植物本体提高57.98%,激活率为本体的2倍.实验表明,采用高效球磨技术制备的葛花Ⅱ级粉体较其他粉体均呈现出最优实验结果,且其醒酒作用机制与其能激活乙醇脱氢酶有关,为开发新

  12. Efficient Fuel Pretreatment: Simultaneous Torrefaction and Grinding of Biomass

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt

    2013-01-01

    Combining torrefaction and grinding of biomass in one reactor may be an attractive fuel pretreatment process. A combined laboratory torrefaction and ball mill reactor has been constructed for studies of the influence of temperature and residence time on the product yields and particle size......, and ash composition, where straw has a higher alkali content. This and other studies indicate that the large difference in the alkali contents of the biomasses is the main cause for the observed difference in torrefaction characteristics. Experiments with separate particle heating and grinding showed...... of straw for 90 min yielded a higher mass loss (27–60 wt %) and relative size reduction (59–95%) compared with spruce (mass loss of 10–56 wt % and size reduction of 20–60%). The two types of biomass investigated differ with respect to hemicellulose type, lignocellulosic composition, particle morphology...

  13. Pretreated cheese whey wastewater management by agricultural reuse: chemical characterization and response of tomato plants Lycopersicon esculentum Mill. under salinity conditions.

    Science.gov (United States)

    Prazeres, Ana R; Carvalho, Fátima; Rivas, Javier; Patanita, Manuel; Dôres, Jóse

    2013-10-01

    The agricultural reuse of pretreated industrial wastewater resulting from cheese manufacture is shown as a suitable option for its disposal and management. This alternative presents attractive advantages from the economic and pollution control viewpoints. Pretreated cheese whey wastewater (CWW) has high contents of biodegradable organic matter, salinity and nutrients, which are essential development factors for plants with moderate to elevated salinity tolerance. Five different pretreated CWW treatments (1.75 to 10.02 dS m(-1)) have been applied in the tomato plant growth. Fresh water was used as a control run (average salinity level=1.44 dS m(-1)). Chemical characterization and indicator ratios of the leaves, stems and roots were monitored. The sodium and potassium leaf concentrations increased linearly with the salinity level in both cultivars, Roma and Rio Grande. Similar results were found in the stem sodium content. However, the toxic sodium accumulations in the cv. Roma exceeded the values obtained in the cv. Rio Grande. In this last situation, K and Ca uptake, absorption, transport and accumulation capacities were presented as tolerance mechanisms for the osmotic potential regulation of the tissues and for the ion neutralization. Consequently, Na/Ca and Na/K ratios presented lower values in the cv. Rio Grande. Na/Ca ratio increased linearly with the salinity level in leaves and stems, regardless of the cultivar. Regarding the Na/K ratio, the values demonstrated competition phenomena between the ions for the cv. Rio Grande. Despite the high chloride content of the CWW, no significant differences were observed for this nutrient in the leaves and stems. Thus, no nitrogen deficiency was demonstrated by the interaction NO3(-)/Cl(-). Nitrogen also contributes to maintain the water potential difference between the tissues and the soil. Na, P, Cl and N radicular concentrations were maximized for high salinity levels (≥2.22 dS m(-1)) of the pretreated CWW.

  14. Pitt Mill Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Oder, R.R.; Borzone, L.A.

    1990-05-01

    Results of a technical and economic evaluation of application of the Pitt Mill to fine coal grinding are presented. The Pitt Mill is a vertically oriented, batch operated, intermediate energy density (0. 025 kW/lb media), stirred ball mill. The mill grinds coal from coarse sizes (typically 3/16 inch or 4 mesh topsize) to the 10 micron to 20 micron mean particle diameter size range in a single step using a shallow grinding bed containing inexpensive, readily available, course grinding media. Size reduction is efficient because of rapid product circulation through the grinding bed caused by action of a novel circulation screw mounted on the agitator shaft. When a dispersant is employed, the grinding can be carried out to 50% to 60% solids concentration. Use of coarse grinding media offers the possibility of enhanced mineral liberation because size reduction is achieved more by impact shattering than by attrition. The batch method offers the possibility of very close control over product particle size distribution without overproduction of fines. A two- phase program was carried out. In the first phase, Grinding Studies, tests were run to determine a suitable configuration of the Pitt Mill. Machine design parameters which were studied included screw configuration, media type, agitator RPM, time, media size, and slurry chamber aspect ratio. During the last part of this phase of the program, tests were carried out to compare the results of grinding Pocahontas seam, Pittsburgh {number sign}8, and East Kentucky Mingo County coals by the Pitt Mill and by a two-stage grinding process employing a Netzsch John mill to feed a high energy density (0.05 kW/Lb media) disc mill. 22 refs., 25 tabs.

  15. Having a Ball with Fitness Balls

    Science.gov (United States)

    McNulty, Betty

    2011-01-01

    Fitness programs can be greatly enhanced with the addition of fitness balls. They are a fun, challenging, economical, and safe way to incorporate a cardiovascular, strength, and stretching program for all fitness levels in a physical education setting. The use of these balls has become more popular during the last decade, and their benefits and…

  16. Vertical mill simulation applied to iron ores

    Directory of Open Access Journals (Sweden)

    Douglas Batista Mazzinghy

    2015-04-01

    Full Text Available The application of vertical mills in regrind circuits is consolidated. This type of mill is now attracting interest in primary grinding applications, due to its higher efficiency when compared to ball mills, which are usually used at this stage. In this study, a coarse sample of iron ore was tested in a pilot scale grinding circuit with a vertical mill. Other three samples of pellet feed had already been tested with the methodology used in this study. The sample of coarse iron ore was characterized in laboratory tests carried out in a small batch ball mill. Selection and breakage function parameters were determined from the laboratory tests. The parameters were then used for simulating the pilot scale tests using Modsim™ software. The model previously implemented in Modsim™ has been successfully applied to represent the vertical mill operated with different ores. The simulations produced particle size distributions that were very close to the actual size distributions, and the predictions were accomplished only by imputing the calibrated parameters from the batch tests, the power draw and the feed size distribution of the pilot tests. The methodology is therefore useful for scale-up and simulation of vertical mills, only requiring laboratory tests that can be carried out in standard laboratory batch ball mills with small amounts of samples.

  17. 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.

  18. Preparation of Carbon Nanotubes(CNT)/TiO2 Composite Powder by High Energy Ball Milling and Sol-Gel and its Properties%高能球磨和溶胶凝胶制备碳纳米管掺杂TiO2复合粉及其性能

    Institute of Scientific and Technical Information of China (English)

    陈守刚; 赵文杨

    2011-01-01

    Carbon nanotubes(CNT)/TiO2 nanocomposite powder has been prepared by high energy ball milling and sol-gel methods. The morphology, microstructure and photocatalytic activity of the products were characterized by scanning electron microscopy , X-ray diffraction, and UV-vis spectroscopy. The results show that the photocatalytic activity of this composite synthesised by 5% carbon nanotubes and TiO2 powders powder is improved effectively. The composite powder prepared by high energy ball milling method is smaller in size and more uniform in distribution with better photocatalytic activity and is more practical than that prepared by sol-gel.%采用高能球磨法和溶胶-凝胶方法制备了碳纳米管掺杂的Ti02纳米复合粉体,通过扫描电子显微镜、X射线衍射、紫外分光光度计等方法对比分析了复合粉体的形貌、微观结构以及光催化活性.实验结果表明,5%碳纳米管掺杂的Ti02复合粉体的光催化活性得到了有效提高,其中高能球磨法制备的复合粉体颗粒细小、分布均匀,具有更好的光催化活性和实际应用意义.

  19. Extraction of metals from spent hydrotreating catalysts: physico-mechanical pre-treatments and leaching stage.

    Science.gov (United States)

    Ferella, Francesco; Ognyanova, Albena; De Michelis, Ida; Taglieri, Giuliana; Vegliò, Francesco

    2011-08-15

    The present paper is focused on physico-mechanical pre-treatments of spent hydrotreating catalysts aimed at concentration of at least one of the valuable metals contained in such secondary raw material. In particular, dry Ni-Mo and Co-Mo as well as wet Ni-Mo catalysts were used. Flotation, grain size separation and attrition processes were tested. After that, a rods vibrating mill and a ball mill were used to ground the catalysts in order to understand the best mechanical pre-treatment before leaching extraction. The results showed that flotation is not able to concentrate any metals due to the presence of coke or other depressant compounds. The particle size separation produces two fractions enriched in Mo and Co when dry Co-Mo catalyst is used, whereas attrition is not suitable as metals are uniformely distributed in rings' volume. Roasting at 550°C and vibrating grinding are the most suitable pre-treatments able to produce fractions easily leached by NaOH and H(2)SO(4) after grain size separation.

  20. Microstructure variation of Al-2.5wt%Pb alloy during high energy ball milling and sintering%Al-2.5%Pb合金在高能球磨和烧结过程中的组织结构变化

    Institute of Scientific and Technical Information of China (English)

    吴志方; 周; 周帆; 吴润

    2015-01-01

    用机械合金化方法制备了Al-2.5wt% Pb合金,采用X射线衍射仪(XRD)和扫描电子显微镜(SEM)分析了Al-2.5wt% Pb合金在高能球磨和烧结过程中的组织结构变化.结果表明,该合金粉末经30 h球磨后,可以获得纳米级Pb颗粒均匀弥散分布在Al基体上的组织.在随后的烧结过程中,纳米相Pb的长大可以用Ostwald熟化的经典-LSW理论来描述.%Al-2.5wt% Pb alloy was prepared by mechanical alloying.The microstructure variation of high energy ball milling and subsequent sintered Al-2.5wt% Pb alloy was investigated by X-ray diffraction and scanning electron microscopy.The result shows that Pb nanoparticles are dispersed homogeneously in Al matrix microstructure by milling for 30 h in Al-2.5wt% Pb alloy powder.In subsequent sintering process,the growth of Pb nanophase can be well formulated by the classical Ostwald ripening theory-LSW.

  1. Scale-up from batch to flow-through wet milling process for injectable depot formulation.

    Science.gov (United States)

    Lehocký, Róbert; Pěček, Daniel; Štěpánek, František

    2016-12-01

    Injectable depot formulations are aimed at providing long-term sustained release of a drug into systemic circulation, thus reducing plasma level fluctuations and improving patient compliance. The particle size distribution of the formulation in the form of suspension is a key parameter that controls the release rate. In this work, the process of wet stirred media milling (ball milling) of a poorly water-soluble substance has been investigated with two main aims: (i) to determine the parametric sensitivity of milling kinetics; and (ii) to develop scale-up methodology for process transfer from batch to flow-through arrangement. Ball milling experiments were performed in two types of ball mills, a batch mill with a 30ml maximum working volume, and a flow-through mill with a 250ml maximum working volume. Milling parameters were investigated in detail by methodologies of QbD to map the parametric space. Specifically, the effects of ball size, ball fill level, and rpm on the particle breakage kinetics were systematically investigated at both mills, with an additional parameter (flow-rate) in the case of the flow-through mill. The breakage rate was found to follow power-law kinetics with respect to dimensionless time, with an asymptotic d50 particle size in the range of 200-300nm. In the case of the flow-through mill, the number of theoretical passes through the mill was found to be an important scale-up parameter.

  2. Physics of ball sports

    Science.gov (United States)

    Cohen, C.; Clanet, C.

    2016-06-01

    Ball sports have been part of human history for thousands of years [1]. Nowadays, 13 of them are part of the Olympic games (badminton, basketball, beach volley, football/soccer, golf, handball, hockey, rugby, table tennis, tennis, volleyball, water polo, ice hockey). All these games differ by launcher (hand, club, racket, bat), ball (size, shape and mass), pitch size and number of players. These differences induce different ball velocities. Apart from the velocities and the way to maximize them, we discuss in this article the ball trajectories and their impact on the size of sports fields.

  3. Characterization of Al{sub 2}O{sub 3}NP-Al{sub 2024} and Ag{sub C}NP-Al{sub 2024} composites prepared by mechanical processing in a high energy ball mill

    Energy Technology Data Exchange (ETDEWEB)

    Carreno-Gallardo, C. [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia-Chihuahua, Miguel de Cervantes No. 120, C.P. 31109, Chihuahua (Mexico); Universidad Autonoma Metropolitana, Departamento de Materiales, Av. San Pablo No. 180, Col Reynosa-Tamaulipas, CP 02200, D.F. (Mexico); Estrada-Guel, I. [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia-Chihuahua, Miguel de Cervantes No. 120, C.P. 31109, Chihuahua (Mexico); Romero-Romo, M. [Universidad Autonoma Metropolitana, Departamento de Materiales, Av. San Pablo No. 180, Col Reynosa-Tamaulipas, CP 02200, D.F. (Mexico); Cruz-Garcia, R. [Universidad Autonoma de Chihuahua (UACH), Facultad de Ingenieria, Circuito No. 1 Nuevo Campus Universitario, C.P. 31125, Chihuahua (Mexico); Lopez-Melendez, C. [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia-Chihuahua, Miguel de Cervantes No. 120, C.P. 31109, Chihuahua (Mexico); Universidad La Salle Chihuahua, Prol. Lomas de Majalca No. 11201, C.P. 31020, Chihuahua (Mexico); Martinez-Sanchez, R., E-mail: roberto.martinez@cimav.edu.mx [Centro de Investigacion en Materiales Avanzados (CIMAV), Laboratorio Nacional de Nanotecnologia-Chihuahua, Miguel de Cervantes No. 120, C.P. 31109, Chihuahua (Mexico)

    2012-09-25

    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{sub 2}O{sub 3} and Ag{sub 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{sub 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{sub 2024}. Highlights: Black-Right-Pointing-Pointer Aluminum-based nanocomposites were synthesized bay milling process. Black-Right-Pointing-Pointer An homogeneous nanoparticles dispersion was reached and mechanical properties were enhanced. Black-Right-Pointing-Pointer 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{sub 2}O{sub 3} and Ag{sub 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{sub 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{sub 2024}.

  4. Happy Balls, Unhappy Balls, and Newton's Cradle

    Science.gov (United States)

    Kagan, David

    2010-01-01

    The intricacies of Newton's Cradle are well covered in the literature going as far back as the time of Newton! These discussions generally center on the highly elastic collisions of metal spheres. Thanks to the invention of happy and unhappy balls, you can build and study the interaction of less elastic systems (see Fig. 1).

  5. Compact Q-balls

    CERN Document Server

    Bazeia, D; Marques, M A; Menezes, R; da Rocha, R

    2016-01-01

    In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

  6. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  7. Relación entre factores micro- estructurales e impacto repetido en aleaciones de alto cromo para bolas de molino. // Relationship among factors micro - structural and impact repeated in alloys of high chromium for mill balls.

    Directory of Open Access Journals (Sweden)

    E. Albertin

    2008-01-01

    Full Text Available Las aleaciones de alto cromo son empleadas para la fabricación de bolas de molino en industrias de procesamiento deminerales. Los usuarios y fabricantes requieren lograr mejores resultados técnicos-económicos en sus aplicaciones, por loque necesitan aumentar los conocimientos relacionados con los aspectos estructurales de estos materiales. En este trabajo serealiza una investigación con vistas a establecer relaciones entre la estructura de las aleaciones y su comportamiento ante elimpacto repetido que es un fenómeno característico en estos procesos.Se funden bolas con varias aleaciones hipo eutécticas, eutécticas, e hipereutécticas; se prueban en un equipo que simula elimpacto repetido. Los resultados permiten comprobar los buenos resultados de aleaciones hipo eutécticas con relaciones deCr/C altas y a su vez altos contenidos de Cr y de aleaciones eutécticas para menores relaciones de Cr/C y menorescontenidos de Cr, en ambos casos los carburos eutécticos son de forma simétrica, regulares y no forman redes continuas decarburos asimétricos bordeando los granos, que presentan peores comportamiento en el impacto repetido y que son el casode las hipoeutécticas con bajas relaciones Cr/C y las hipereutécticas donde aparecen también grandes carburos primariosPalabras claves: Alto-cromo, bolas de molino, impacto repetido, desgaste.____________________________________________________________________________Abstract.High Chromium alloys are used to manufacture grinding balls for the Industry of Construction Materials. Customers andusers need to improve their knowledge about the relationships between microstructure and the parts damage in these alloysto obtain better technical-economics results. In this paper the results of a research to obtain different microstructures ofeutectics, hipoeutectics and hipereutectics alloys are presented, searching for the lesser damage in these alloys. These alloysare tested in a repeated impact testing

  8. The influence of milling on the dissolution performance of simvastatin

    DEFF Research Database (Denmark)

    Zimper, Ulrike; Aaltonen, Jaakko; Krauel-Goellner, Karen

    2012-01-01

    properties such as solubility and dissolution rate and, therefore, process induced solid state modifications need to be monitored. The aim of this study was two-fold: firstly, to investigate the dissolution rates of milled and unmilled simvastatin; and secondly, to screen for the main milling factors...... milling frequency, milling time and ball quantity at a set drug load, out of which milling frequency was found to be the most important factor for particle size as well as process induced disorder. Milling frequency and milling time exhibited an interaction effect on the responses. The optimum milling...... revealed that the process induced disorder was negligible with regard to the dissolution rate. The predicted primary particle size of 1.4 µm could be confirmed experimentally, but due to agglomeration of the primary particles a dissolution rate advantage was not shown, highlighting the importance...

  9. 球磨机锥面分级衬板分级效果的离散单元法仿真研究%Simulation and study of classifying effects of cone classifying finers in ball mills based on discrete element method

    Institute of Scientific and Technical Information of China (English)

    赵选恒; 董为民; 郑广明

    2012-01-01

    The classifying mechanism of cone classifying liners was explained, and the classifying effects of the ball mills with several typical cone classifying liners were simulated by the discrete element simulation soil-ware EDEM2.3. The obtained data was analysed, and the cone classifying liner with the best classifying effects---cone classifying liner with dual slopes was identified, which provided theoretical basis for the selection of liners.%阐述了球磨机锥面分级衬板的分级机理,应用离散元仿真软件EDEM2.3,对几种典型的锥面分级衬板对磨球的分级作用进行仿真,并对结果数据进行分析,选出分级效果最佳的锥面分级衬板——双斜度分级衬板,为衬板的选用提供理论依据。

  10. Theory of ball lightning

    CERN Document Server

    Wu, H -C

    2014-01-01

    We present a comprehensive explanation on ball lightning, a luminous sphere occasionally witnessed after ordinary lightning. In the last decade, it has been well established that natural lightning routinely generates relativistic electrons, which account for observed x rays. So we assume that, in a ball lightning event, a well-defined relativistic electron bunch is produced by the stepped leader of lightning. When this electron bunch strikes various media, a powerful microwave pulse is emitted by the coherent transition radiation mechanism. This intense microwave ionizes air, evacuates plasmas by its radiation pressure to form a globular plasma cavity, and then gets trapped inside the cavity. This theory successfully explains all characteristics of ball lightning, especially the appearance of ball lightning in fully-screened aircraft. Moreover, the proposed radiation mechanism fully explains the strongest radio signals from lightning and nanosecond spikes in the signals are direct evidences on the generation ...

  11. Aerodynamics of sports balls

    Science.gov (United States)

    Mehta, R. D.

    1985-01-01

    Research data on the aerodynamic behavior of baseballs and cricket and golf balls are summarized. Cricket balls and baseballs are roughly the same size and mass but have different stitch patterns. Both are thrown to follow paths that avoid a batter's swing, paths that can curve if aerodynamic forces on the balls' surfaces are asymmetric. Smoke tracer wind tunnel tests and pressure taps have revealed that the unbalanced side forces are induced by tripping the boundary layer on the seam side and producing turbulence. More particularly, the greater pressures are perpendicular to the seam plane and only appear when the balls travel at velocities high enough so that the roughness length matches the seam heigh. The side forces, once tripped, will increase with spin velocity up to a cut-off point. The enhanced lift coefficient is produced by the Magnus effect. The more complex stitching on a baseball permits greater variations in the flight path curve and, in the case of a knuckleball, the unsteady flow effects. For golf balls, the dimples trip the boundary layer and the high spin rate produces a lift coefficient maximum of 0.5, compared to a baseball's maximum of 0.3. Thus, a golf ball travels far enough for gravitational forces to become important.

  12. Effect of wet grinding on structural properties of ball clay

    Science.gov (United States)

    Purohit, A.; Hameed, A.; Chander, S.; Nehra, S. P.; Singh, P.; Dhaka, M. S.

    2015-05-01

    In this paper, the effect of wet grinding on structural properties of ball clay is undertaken. The wet grinding treatment was performed employing ball and vibro mills for different time spells of 2, 4, 8 and 16 hours. The structural properties were carried out using X-ray diffraction (XRD). The structure of ground samples is found to be simple cubic. The crystallographic parameters are calculated and slight change in lattice constant, inter planner spacing and particle size is observed with grinding treatment. The results are in agreement with the available literature.

  13. Preparation and performance research of Ce-TiO2/KL ball photocatalysts

    Institute of Scientific and Technical Information of China (English)

    于晓娟; 熊领领; 马国平; 梁愿; 刘奎仁

    2014-01-01

    The Ce-TiO2/KL (diatomite) ball photocatalyst was prepared and characterized based on the pretreated diatomite. The re-sults showed that comparing with the crude diatomite, proper pretreatment could significantly improve its SiO2 purity and specific surface area. The surface of diatomite was clear with uniform pore structure and big pore size. With diatomite ball as carrier, the sup-ported Ce-TiO2/KL ball photocatalyst was prepared by sol-gel method. The photocatalytic performances of the supported Ce-TiO2/ KL ball and Ce-TiO2/KL powder photocatalysts under various preparation conditions were studied in view of photocatalytic degrada-tion rate of Rhodamine B (Rh B) solution. The degradation rate of the ball photocatalysts for Rh B reached 94.6% and could be re-used for many times, which showed much better photocatalytic performance and stability than powder photocatalysts.

  14. Lime Pretreatment

    Science.gov (United States)

    Sierra, Rocio; Granda, Cesar Benigno; Holtzapple, Mark T.

    Lime pretreatment has proven to be a useful method for selectively reducing the lignin content of lignocellulosic biomass without significant loss in carbohydrates, thus realizing an important increase in biodigestibility. In lime pretreatment, the biomass is pretreated with calcium hydroxide and water under different conditions of temperature and pressure. It can be accomplished in one of three fashions: (1) short-term pretreatment that lasts up to 6 h, requires temperatures of 100-160°C, and can be applied with or without oxygen (pressure ~200 psig); (2) long-term pretreatment taking up to 8 weeks, requiring only 55-65°C, and capable of running with or without air (atmospheric pressure); and (3) simple pretreatment requiring 1 h in boiling water, without air or oxygen. Nonoxidative conditions are effective at low lignin contents (below ~18% lignin), whereas oxidative conditions are required for high lignin contents (above ~18% lignin).

  15. 不锈钢表面振动冲击加速渗铝工艺研究%Study on low-temperature aluminizing on a stainless steel assisted by ball milling

    Institute of Scientific and Technical Information of China (English)

    王德仁; 陈亮; 何业东

    2012-01-01

    In order to accelerate the formation process of aluminide coating on 1Cr18Ni9Ti stainless steel substrate at relatively low temperature,mechanical vibration and impact were applied to 1Cr18Ni9Ti sample during aluminizing by a similar ball peening process.The coating was obtained by aluminizing at 600 ℃ for 4 h,6 h and 8 h,and the aluminizing coating weight gain,coating thickness,alloying element distribution across aluminizing coating were investigated.High temperature oxidation kinetics of coatings and bare sample were measured at 900 ℃ for 100 h.The results show that a dence layer of aluminizing coating can formed on 1Cr18Ni9Ti steel substrate and the coating thickness can reach 35 μm after vibration aluminization at 600 ℃ for 4 h.Oxidation resistance performance measurement reveals that the optimal duration time is 6 h because the weight gain for 6 h is less than 4 h and 8 h.%研究了利用喷丸加速制备涂层技术,对1Cr18Ni9Ti不锈钢分别进行600℃×4、6和8 h渗铝处理,研究了1Cr18Ni9Ti试样的单位面积增重、Al涂层厚度、主要元素沿涂层截面的分布;并将不同温度下获得的铝化物涂层与空白试样一起进行了高温氧化测试实验(900℃×100 h)。结果表明,在较低的温度600℃和较短的时间4 h,可以在1Cr18Ni9Ti钢基体上形成35μm厚的铝化物涂层;但抗氧化性能测试结果却表明,振动渗制处理6 h获得的铝化物涂层性能优于处理4 h和8 h的涂层。

  16. Tunguska Dark Matter Ball

    CERN Document Server

    Froggatt, C D

    2014-01-01

    It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

  17. Interacting Q-balls

    CERN Document Server

    Brihaye, Yves

    2007-01-01

    We construct explicit examples of new axially symmetric, non-spinning Q-ball solutions that have not been studied so far. These solutions can be interpreted as angular excitations of the fundamental Q-balls and are related to the spherical harmonics. Correspondingly, they have higher energy and their energy densities possess two local maxima on the positive z-axis. We also study two Q-balls interacting via a potential term in 3+1 dimensions and construct examples of stationary, solitonic-like objects in (3+1)-dimensional flat space-time that consist of two interacting global scalar fields. We concentrate on configurations composed of one spinning and one non-spinning Q-ball and study the parameter-dependence of the energy and charges of the configuration. In addition, we present numerical evidence that for fixed values of the coupling constants two different types of 2-Q-ball solutions exist: solutions with defined parity, but also solutions which are asymmetric with respect to reflexion through the x-y-axis.

  18. The bowling balls

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    10 November 1972: CERN’s Bent Stumpe places an order for 12 bowling balls for a total cost of 95 US dollars. Although not evident at first sight, he is buying the heart of some of the first tracking devices to be used in the SPS control room. Today, Bent Stumpe’s device would be called a desktop mouse…   The first order for 4 bowling balls later changed to 12 balls. The bowling balls became the heart of Bent Stumpe's mouse. Almost 40 years ago, the web, Wikipedia and Google did not exist and it was much more difficult to know whether other people in other parts of the world or even in the same laboratory were facing the same problems or developing the same tools. At that time, Bent Stumpe was an electronics engineer, newly recruited to work on developments for the SPS Central Control room. One of the things his supervisor asked him to build as soon as possible was a device to control a pointer on a screen, also called a tracker ball. The heart of the device was the...

  19. Kinetic study of ferronickel slag grinding at variation of ball filling and ratio of feed to grinding balls

    Science.gov (United States)

    Sanwani, Edy; Ikhwanto, Muhammad

    2017-01-01

    The objective of this paper is to investigate the effect of ball filling and ratio of feed to grinding balls on the kinetic of grinding of ferronickel slag in a laboratory scale ball mill. The experiments were started by crushing the ferronickel slag samples using a roll crusher to produce -3 mesh (-6.7 mm) product. This product, after sampling and sample dividing processes, was then used as feed for grinding process. The grinding was performed with variations of ball filling and ratio of feed to grinding balls for 150 minutes. At every certain time interval, particle size analysis was carried out on the grinding product. The results of the experiments were also used to develop linear regression model of the effect of grinding variables on the P80 of the product. Based on this study, it was shown that P80 values of the grinding products declined sharply until 70 minutes of grinding time due to the dominant mechanism of impact breakage and then decreased slowly after 70 minutes until 150 minutes of grinding time due to dominant mechanism of attrition breakage. Kinetics study of the grinding process on variations of grinding ball filling showed that the optimum rate of formation of fine particles for 20%, 30%, 40% and 50% mill volume was achieved at a particle size of 400 µm in which the best initial rate of formation occurred at 50% volume of mill. At the variations of ratio of feed to grinding balls it was shown that the optimum rate of grinding for the ratio of 1:10, 1: 8 and 1: 6 was achieved at a particle size of 400 µm and for the ratio of 1: 4 was at 841 µm in which the best initial rate of formation occurred at a 1:10 ratio. In this study, it was also produced two regression models that can predict the P80 value of the grinding product as a function of the variables of grinding time, ball filling and the ratio of the feed to grinding balls.

  20. Split Q-balls

    Science.gov (United States)

    Bazeia, D.; Losano, L.; Marques, M. A.; Menezes, R.

    2017-02-01

    We investigate the presence of non-topological solutions of the Q-ball type in (1 , 1) spacetime dimensions. The model engenders the global U (1) symmetry and is of the k-field type, since it contains a new term, of the fourth-order power in the derivative of the complex scalar field. It supports analytical solution of the Q-ball type which is stable quantum mechanically. The new solution engenders an interesting behavior, with the charge and energy densities unveiling a splitting profile.

  1. On the magnetic properties of pseudo-Laves phases RE{sub 1-y}Y{sub y}Ni{sub 4-x}Al{sub x}Mg with RE = La, Ce and Gd prepared by both melting and ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Couillaud, S.; Chevalier, B. [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33600 Pessac (France); Paul-Boncour, V. [ICMPE-CMTR, CNRS-UPEC, UMR 7182, 2-8 rue Henri Dunant, 94320 Thiais (France); Bobet, J.-L., E-mail: bobet@icmcb-bordeaux.cnrs.fr [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33600 Pessac (France)

    2012-06-05

    Highlights: Black-Right-Pointing-Pointer LaNi{sub 4}Mg did not exhibit any magnetic ordering but a paramagnetic behaviour. Black-Right-Pointing-Pointer All the compounds with Gd order ferromagnetically at a temperature ranging from 77 to 15 K. Black-Right-Pointing-Pointer Dilution of Gd atom by Y leads to a decrease of the Curie temperature below a critical number of Gd atoms. - Abstract: Magnetic properties of RE{sub 1-y}Y{sub y}Ni{sub 4-x}Al{sub x}Mg (RE = La, Ce and Gd) are reported. LaNi{sub 4}Mg displays a weak magnetization indicating that Ni is non magnetic as often observed in RENi{sub 2} compounds. The magnetization of CeNi{sub 4}Mg compounds shows a Curie Weiss behaviour with an effective paramagnetic moment {mu}{sub eff} = 2.2 {mu}{sub B}. The magnetization of Gd compounds is dominated by the contribution of Gd moment with a paramagnetic effective moment close to 7.7 {mu}{sub B}/Gd for all studied compounds. The Curie temperature, which is 75 K for GdNi{sub 2}, decreases almost linearly with the number of Gd neighbours when more than half Gd is replaced by Y. The decrease of crystallinity of GdNi{sub 4}Mg, which is monitored by ball milling and heat treatment, strongly influences the magnetic properties and a relationship between the transition temperature and the crystallites size is reported.

  2. Effect of Synthesized MgNi4Y Catalyst on Hydrogen Desorption Properties of Milled MgH2

    Science.gov (United States)

    ChitsazKhoyi, Leila; Raygan, Shahram; Pourabdoli, Mehdi

    2015-03-01

    It has been reported that ball milling and adding catalyst can improve hydrogen desorption properties of MgH2. In this study, simultaneous effect of adding catalyst and ball milling on hydrogen desorption properties of MgH2 was studied. Mechanical alloying and heat treatment methods were used to synthesize MgNi4Y intermetallic as a catalyst. In this regard, pure Mg, Ni, and Y elemental powders were ball milled in different conditions and then heat treated at 1073 K (800 °C) for 4 hours. XRD and FESEM methods were used to investigate properties of the samples. It was found that, after 10 hours of ball milling and then heat treating at 1073 K (800 °C), MgNi4Y intermetallic was formed almost completely. The results of Sievert tests showed that as-received MgH2 did not release any significant amount of hydrogen at 623 K (350 °C). But, after ball milling for 10 hours, 0.8 wt pct hydrogen was released from MgH2 at 623 K (350 °C) in 40 minutes. Adding 10 wt pct catalyst via ball milling to MgH2 led to releasing 3.5 wt pct hydrogen in the same conditions. In addition, increasing ball milling time from 10 to 65 hours increased the amount of released hydrogen from 51 to 85 pct of theoretical hydrogen desorption value and improved kinetic of desorption process.

  3. The Mathematics of Bouncing Balls.

    Science.gov (United States)

    Martin, Kathleen

    1989-01-01

    Describes an activity which uses the computer to produce an environment that encourages an inductive reasoning approach to ratio and proportion through a billiard ball simulation. Provides examples of graphs and bouncing ball data. (RT)

  4. Have a Ball

    Institute of Scientific and Technical Information of China (English)

    程炜

    2003-01-01

    Before being sent to prison Carl drove big cars and ate in expensive restaurants. No one knew where he got his money but he was certainly having a ball. When the judge sentenced him.to prison he said, “I hope you have a bail, Carl.” To have a bait is to have a wonderful time.

  5. A Spiky Ball

    OpenAIRE

    Naszódi, Márton

    2015-01-01

    The Illumination Problem may be phrased as the problem of covering a convex body in Euclidean $n$-space by a minimum number of translates of its interior. By a probabilistic argument, we show that, arbitrarily close to the Euclidean ball, there is a centrally symmetric convex body of illumination number exponentially large in the dimension.

  6. Effect of immobilized cellulase on evaluating hydrolysis efficiency of pretreated cellulose material%固定化纤维素酶对预处理纤维素原料水解效果的影响

    Institute of Scientific and Technical Information of China (English)

    吕浩; 邢楠楠; 林增祥; 杜健; 张红漫

    2011-01-01

    Cellulase was immobilized by chitosan gel beads using the cross-linking embedding method. The immobilized enzyme was used to hydrolyze cellulic material corn stover pretreated by steam explosion , ball milling, ultrasonic, spray, and high-temperature processes. Results showed that the steam explosion pretreatment could obtain the best enzymatic hydrolysis efficiency, glucose yield reached 95% ; the ball mill was second to it, glucose yield reached 60%. Meanwhile, the cellulose structures before and after pretreatment were characterized by electron microscopy and FT-IR. It indicated that the physical structure and chemical composition of pretreated materials changed significantly. The steam explosion method and the ball milling method could make the natural structure of the material completely destroy thus increasing the surface area. The internal hydrogen bonds and functional groups of cellulose had been changed during the course of steam explosion, it caused the material more easily to be hydrolized.%以壳聚糖为载体用交联法制备固定化纤维素酶,考察固定化纤维素酶对蒸爆、球磨、超声波、喷淋、高温预处理玉米秸秆纤维素原料的酶解效果.结果表明:物料经蒸爆预处理后酶水解效率最高可以达到95%,球磨预处理水解效率次之,达到60%.用电镜和FT-IR对处理前后秸秆结构进行表征分析,证明预处理对物料的物理结构及化学组成有一定的影响.蒸爆法和球磨法可以使物料致密的天然结构彻底破坏,从而增加物料的比表面积;蒸爆预处理可以使纤维素内部氢键和官能团改变,使物料更易于酶解.

  7. Simulation study on model-free adaptive control based on grey prediction in ball mill load control%基于灰色预测的无模型控制在球磨机负荷控制中的仿真研究

    Institute of Scientific and Technical Information of China (English)

    程启明; 程尹曼; 汪明媚; 王映斐

    2011-01-01

    The load object of ball mill in thermal power plant has complex traits of large time-delay, slow time-var-ying, strong nonlinearity and etc. It is difficult to obtain satisfactory control performance using conventional control methods. In this paper, a model-free adaptive control method based on gray prediction is introduced for load control.This control method combines the adaptive, anti-interference features of model-free control with the time-delay prediction, overshoot suppression and rapid stabling of gray prediction model. The measured output value of load object is replaced by the predicted result of gray model, then, model-free adaptive control is used for close-loop control.Simulation results show that the proposed control method has fast response, small overshoot, good robustness and strong anti-interference ability ; it can effectively solve the problems such as large time-delay, nonlinearity and adaptability.%火电厂钢球磨煤机的负荷对象具有大滞后、慢时变、强非线性等复杂特性,采用常规控制方法难以获得满意的控制效果,本文提出了基于灰色预测的无模型自适应负荷控制方法.该方法融合了无模型控制的自适应、抗干扰特性与灰色预测模型的预测时延、抑制超调和快速稳定特性,它将灰色模型的预测结果代替负荷对象输出测量值,再进行无模型自适应闭环控制.仿真结果表明这种控制方法系统响应快、超调小、鲁棒性好、抗干扰能力强,可以有效解决大滞后、非线性及适应性等问题.

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

    Directory of Open Access Journals (Sweden)

    S. Motozuka

    2015-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-15

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

  10. BLEACHING NEPTUNE BALLS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

  11. Mechanically milled aluminium matrix composites reinforced with halloysite nanotubes

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2012-12-01

    Full Text Available Purpose: The present work describes fabrication of aluminium AlMg1SiCu matrix composite materials reinforced with halloysite nanotubes by powder metallurgy techniques and hot extrusion.Design/methodology/approach: Mechanical milling, compacting and hot extrusion successively are considering as a method for manufacturing metal composite powders with a controlled fine microstructure and enhanced mechanical properties. It is possible by the repeated welding and fracturing of powders particles mixture in a highly energetic ball mill.Findings: The milling process has a huge influence on the properties of powder materials, changing the spherical morphology of as-received powder during milling process to flattened one due to particle deformation followed by welding and fracturing particles of deformed and hardened enough which allows to receive equiaxial particles morphology again. The investigation shows that so called brittle mineral particles yields to plastic deformation as good as ductile aluminium alloy particles. That indicates that the halloysite powder can play a role of the accelerator during mechanical milling. High energy ball milling as a method of mechanical milling improves the distribution of the halloysite reinforcing particles throughout the aluminium matrix, simultaneously reducing the size of particles. The apparent density changes versus milling time can be used to control the composite powders production by mechanical milling and the presence of halloysite reinforcements particles accelerates the mechanical milling process.Research limitations/implications: Contributes to knowledge about technology, structure and properties of aluminium alloy matrix composite material reinforced with mineral nanoparticles.Practical implications: Conducted research shows that applied technology allows obtaining very good microstructural characteristics.Originality/value: It has been confirmed that halloysite nanotubes can be applied as an effective

  12. Crystal Ball Functional Model

    Science.gov (United States)

    Plotnick, David

    2016-09-01

    The A2 collaboration of the MAinz MIkrotron is dedicated to studying meson production and nucleon structure and behavior via photon scattering. The photons are made via bremsstrahlung process and energy-tagged using the Glasgow Photon tagger. The photon beam then interacts in a variety of targets: cryogenic, polarized or solid state, and scattered particles deposit their energy within the NaI crystals. Scintillators are able to give results on particles energy and time. Events are reconstructed by combining information from the Tagging spectrometer, the Crystal Ball detector, the TAPS forward wall spectrometer, a Cherenkov detector, and multi-wire proportional chambers. To better understand the detector and experimental events, a live display was built to show energies deposited in crystals in real-time. In order to show a range of energies and particles, addressable LEDs that are individually programmable were used. To best replicate the Crystal Ball, 3D printing technology was employed to build a similar highly segmented icosahedron that can hold each LED, creating a 3D representation of what photons see during experiments. The LEDs were controlled via Arduino microcontroller. Finally, we implemented the Experimental Physics and Industrial Control System to grab live event data, and a simple program converts this data in to color and crystal number data that is able to communicate with the Arduino. Using these simple parts, we can better visualize and understand the tools used in nuclear physics. This material is based upon work supported by the National Science Foundation Grant No. IIA-1358175.

  13. Crystal Ball Replica

    Science.gov (United States)

    Ajamian, John

    2016-09-01

    The A2 collaboration of the Institute for Nuclear Physics of Johannes Gutenberg University performs research on (multiple) meson photoproduction and nucleon structure and dynamics using a high energy polarized photon beam at specific targets. Particles scattered from the target are detected in the Crystal Ball, or CB. The CB is composed of 672 NaI crystals that surround the target and can analyze particle type and energy of ejected particles. Our project was to create a replica of the CB that could display what was happening in real time on a 3 Dimensional scale replica. Our replica was constructed to help explain the physics to the general public, be used as a tool when calibrating each of the 672 NaI crystals, and to better analyze the electron showering of particles coming from the target. This poster will focus on the hardware steps necessary to construct the replica and wire the 672 programmable LEDS in such a way that they can be mapped to correspond to the Crystal Ball elements. George Washington NSF Grant.

  14. Effect of milling time on the formation of carbon nanotube by mechano-thermal method

    Indian Academy of Sciences (India)

    Ertan Evin; Ömer Güler; Mustafa Aksoy; Seval Hale Güler

    2015-08-01

    Mechano-thermal method was used for synthesizing the carbon nanotubes (CNTs) in this study. In this method, graphite powders in the elemental form were firstly exposed to milling process in high-energy ball milling and then the milled powders were annealed at high temperatures. As a result of milling of the graphite, ultra-active disordered carbon structures were obtained. This structure serves as a carbon source for the formation of nanotubes during the annealing process. This study investigated the effect of the milling process. For this purpose, graphite powders were milled at different periods such as 5 and 150 h and then annealed at 1600°C. The transmission electron microscopy and scanning electron microscopy examinations demonstrated that CNTs formed in samples milled both for 5 and 150 h. However, the difference in the milling time influenced the amount of CNTs, their size and the formation of other structures except from nanotubes.

  15. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  16. Structural characterization of mechanically milled ZnO: influence of zirconia milling media

    Energy Technology Data Exchange (ETDEWEB)

    Vojisavljevic, K; Sreckovic, T; Brankovic, Z; Brankovic, G [Institute of Multidisciplinary Research, Kneza Viseslava 1, 11030 Belgrade (Serbia); Scepanovic, M; Grujic-Brojcin, M [Center for Solid State Physics and New Materials, Institute of Physics, Pregrevica 118, 11080 Belgrade (Serbia)], E-mail: katarina@cms.bg.ac.yu

    2008-11-26

    Zinc oxide nanoparticles were obtained by milling in a planetary ball mill with a zirconia milling assembly for up to 5 h in air. The samples were characterized by scanning electron microscopy, x-ray diffraction (XRD) and Raman spectroscopy methods. The deviation of the lattice parameters from single crystal values was related to defect creation and increase of strain inside the hexagonal lattice of milled ZnO nanoparticles. The observed redshift and peak broadening of the major first-order Raman modes were ascribed to the formation of intrinsic defects by mechanical milling combined with the effects of phonon confinement in nanosized powders. To investigate the type of intrinsic defects and impurities introduced during milling, it was necessary to analyze both milled and thermally treated ZnO. After thermal treatment, the intensity of the Raman spectra increased and the peak positions reverted to values similar to those in unmilled ZnO powder, pointing to defect annihilation. XRD patterns of sintered samples confirmed the existence of zirconia impurities and the Rietveld analysis revealed a small amount of zirconium introduced in the ZnO crystal lattice on the Zn sites or interstitial sites. The large influence of those impurities on the micro-Raman spectra of thermally treated samples was observed in this study.

  17. Structural characterization of mechanically milled ZnO: influence of zirconia milling media

    Science.gov (United States)

    Vojisavljević, K.; Šćepanović, M.; Srećković, T.; Grujić-Brojčin, M.; Branković, Z.; Branković, G.

    2008-11-01

    Zinc oxide nanoparticles were obtained by milling in a planetary ball mill with a zirconia milling assembly for up to 5 h in air. The samples were characterized by scanning electron microscopy, x-ray diffraction (XRD) and Raman spectroscopy methods. The deviation of the lattice parameters from single crystal values was related to defect creation and increase of strain inside the hexagonal lattice of milled ZnO nanoparticles. The observed redshift and peak broadening of the major first-order Raman modes were ascribed to the formation of intrinsic defects by mechanical milling combined with the effects of phonon confinement in nanosized powders. To investigate the type of intrinsic defects and impurities introduced during milling, it was necessary to analyze both milled and thermally treated ZnO. After thermal treatment, the intensity of the Raman spectra increased and the peak positions reverted to values similar to those in unmilled ZnO powder, pointing to defect annihilation. XRD patterns of sintered samples confirmed the existence of zirconia impurities and the Rietveld analysis revealed a small amount of zirconium introduced in the ZnO crystal lattice on the Zn sites or interstitial sites. The large influence of those impurities on the micro-Raman spectra of thermally treated samples was observed in this study.

  18. Images in Christmas Balls

    CERN Document Server

    Van Beveren, E; Rupp, G; Beveren, Eef van; Kleefeld, Frieder; Rupp, George

    2006-01-01

    We describe light-reflection properties of spherically curved mirrors, like balls in the Christmas tree. In particular, we study the position of the image which is formed somewhere beyond the surface of a spherical mirror, when an eye observes the image of a pointlike light source. The considered problem, originally posed by Abu Ali Hasan Ibn al-Haitham -- alias Alhazen -- more than a millennium ago, turned out to have the now well known analytic solution of a biquadratic equation, being still of great relevance, e.g. for the aberration-free construction of telescopes. We do not attempt to perform an exhaustive survey of the rich historical and engineering literature on the subject, but develop a simple pedagogical approach to the issue, which we believe to be of continuing interest in view of its maltreating in many high-school textbooks.

  19. Effect of Milling on the Mechanical Properties of Chopped SiC Fiber-Reinforced ZrB2

    Directory of Open Access Journals (Sweden)

    S. Guicciardi

    2013-05-01

    Full Text Available This work aims at studying the effect of the milling conditions on the microstructure and mechanical properties of a ZrB2-5 vol% Si3N4 matrix reinforced with chopped Hi-Nicalon SiC fibers. Several composites were obtained using different milling conditions in terms of time, speed and type of milling media. The composites were prepared from commercial powders, ball milled, dried and shaped, and hot pressed at 1720 °C. Their relative bulk densities achieved values as high as 99%. For each material the fiber length distribution, the extent of reacted fiber area and matrix mean grain size were evaluated in order to ascertain the effects of milling time, milling speed and type of milling media. While the fracture toughness and hardness were statistically the same independently of the milling conditions, the flexural strength changed. From the results obtained, the best milling conditions for optimized mechanical properties were determined.

  20. The dynamics of hurricane balls

    Science.gov (United States)

    Andersen, W. L.; Werner, Steven

    2015-09-01

    We examine the theory of the hurricane balls toy. This toy consists of two steel balls, welded together that are sent spinning on a horizontal surface somewhat like a top. Unlike a top, at high frequency the symmetry axis approaches a limiting inclination that is not perpendicular to the surface. We calculate (and experimentally verify) the limiting inclinations for three toy geometries. We find that at high frequencies, hurricane balls provide an easily realized and testable example of the Poinsot theory of freely rotating symmetrical bodies.

  1. Lignocellulosic biomass-Thermal pretreatment with steam: Pretreatment techniques for biofuels and biorefineries

    DEFF Research Database (Denmark)

    Toor, Saqib; Rosendahl, Lasse; Hoffmann, Jessica

    2013-01-01

    With the ever rising demand for more energy and the limited availability of depleted world resources, many are beginning to look for alternatives to fossil fuels. Liquid biofuel, in particular, is of key interest to decrease our dependency on fuels produced from imported petroleum. Biomass pre......-treatment remains one of the most pressing challenges in terms of cost-effective production of biofuels. The digestibility of lingo-cellulosic biomass is limited by different factors such as the lignin content, the crystallinity of cellulose, and the available cellulose accessibility to hydrolytic enzymes. A number...... of different pretreatment methods are known to enhance the digestibility of lingo-cellulosic biomass by affecting these limiting factors. Some of them are: milling, thermal pretreatment with steam or hot water, acid pre-treatment and alkaline pre-treatment. This chapter will focus on one of the more promising...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    analysis was performed on samples of indomethacin obtained by cryogenic ball milling (cryo-milling) for different periods of time. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), polarised light microscopy (PLM) and solid state nuclear magnetic resonances (ss-NMR) were also used...

  3. EFFECT OF CUP AND BALL TYPES ON MECHANO-CHEMICAL SYNTHES IS OF Al2O3–TiC NANOCOMPOSITE POWDER

    Directory of Open Access Journals (Sweden)

    M. Zakeri

    2012-07-01

    Full Text Available Al2O3–TiC nanocomposite powder was successfully synthesized by ball milling TiO2, Al and graphite powders. Effects of cup and ball type, milling time and annealing were investigated. XRD was used to characterize milled and annealed powders. The morphological and microstructural evolutions were studied by SEM and TEM. Results showed that the formation of this composite begins after 20 h and completes after 35 h of milling with stainless steel cup and balls. In contrast, there is no reaction during milling (up to 80 h with ZrO2 cup and balls. Fe and ZrO2 were the major impurities introduced during milling with stainless steel and ZrO2 cups, respectively. The Fe impurity was removed by leaching in 3HCl·HNO3 solution for 4 days. Mean grain size less than 7 nm was achieved at the end of milling. In spite of grain growth, this composite maintained its nanocrystalline nature after annealing at 1000°C.

  4. Synthesis of Nanocrystalline WC Single-Phase Refractory via Mechanical Milling

    Directory of Open Access Journals (Sweden)

    Mansour Razavi

    2011-01-01

    Full Text Available In this paper the possibility of production of nanocrystalline WC single-phase by mechanical milling has been investigated. The raw materials containing tungsten and carbon with WC as nucleation were milled in a planetary ball mill and sampled in different times. Studies showed that after 75 hours of milling the WC with W2C was produced and remained constant in higher milling time. Adding WC to raw materials at the beginning process leads to the fact that after 50 hours of milling only WC was synthesized without undesirable W2C phase. This material remained stable until higher times of milling too. From broadening of XRD peaks, the crystalline size in synthesized WC was estimated in nanometer scale which lower than the system containing primary WC, and it means that the strain in this system was lower than first system.

  5. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    A technique involving a small ball with a transmitter embedded inside it has been successfully tested in Sector 7-8. The ball is sent through the LHC beam pipes to check the LHC interconnections. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI). During the tests the ball is inserted very carefully into the vacuum chamber.A game of ping-pong at the LHC? On 13 September a rather unusual test was carried out in Sector 7-8 of the accelerator. A ball just a bit smaller than a ping-pong ball was carefully introduced into one of the accelerator’s two vacuum pipes, where it travelled 800 metres in the space of a few mi...

  6. Accounting for nonstoichiometry of niobium carbide NbC y upon milling to a nanocrystalline state

    Science.gov (United States)

    Kurlov, A. S.; Gusev, A. I.

    2013-12-01

    The dependence of the size of particles in the prepared nanocrystalline powders on the composition of nonstoichiometric compounds within their homogeneity intervals has been considered in terms of the high-energy ball milling model. It has been shown that the effect of nonstoichiometry on the milling manifests itself in the concentration dependences of the main characteristics (parameters of the crystal structure, energy of interatomic bonds, elastic properties) of the milled nonstoichiometric compound. The results of model calculations performed for nonstoichiometric cubic niobium carbides NbC y have been compared with the experimental data on milling of the NbC0.93 carbide.

  7. Solid state amorphization in the Al-Fe binary system during high energy milling

    Energy Technology Data Exchange (ETDEWEB)

    Urban, P., E-mail: purban@us.es; Montes, J. M.; Cintas, J. [University of Seville, Department of Mechanical and Materials Engineering, ETSI, Camino de los Descubrimientos s/n, Seville, 41092 (Spain); Cuevas, F. G., E-mail: fgcuevas@dqcm.uhu.es [University of Huelva, Department of Chemistry and Materials Science, ETSI, Campus La Rábida, Carretera Palos s/n, Palos de la Frontera, Huelva, 21819 (Spain)

    2013-12-16

    In the present study, mechanical alloying (MA) of Al75Fe25 elemental powders mixture was carried out in argon atmosphere, using a high energy attritor ball mill. The microstructure of the milled products at different stages of milling was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The results showed that the amorphous phase content increased by increasing the milling time, and after 50 hours the amorphization process became complete. Heating the samples resulted in the crystallization of the synthesized amorphous alloys and the appearance of the equilibrium intermetallic compounds Al{sub 5}Fe{sub 2}.

  8. Fluid mechanics relevant to flow through pretreatment of cellulosic biomass.

    Science.gov (United States)

    Archambault-Léger, Véronique; Lynd, Lee R

    2014-04-01

    The present study investigates fluid mechanical properties of cellulosic feedstocks relevant to flow through (FT) pretreatment for biological conversion of cellulosic biomass. The results inform identifying conditions for which FT pretreatment can be implemented in a practical context. Measurements of pressure drop across packed beds, viscous compaction and water absorption are reported for milled and not milled sugarcane bagasse, switchgrass and poplar, and important factors impacting viscous flow are deduced. Using biomass knife-milled to pass through a 2mm sieve, the observed pressure drop was highest for bagasse, intermediate for switchgrass and lowest for poplar. The highest pressure drop was associated with the presence of more fine particles, greater viscous compaction and the degree of water absorption. Using bagasse without particle size reduction, the instability of the reactor during pretreatment above 140kg/m(3) sets an upper bound on the allowable concentration for continuous stable flow.

  9. Steel mill products analysis using qualities methods

    Directory of Open Access Journals (Sweden)

    B. Gajdzik

    2016-10-01

    Full Text Available The article presents the subject matter of steel mill product analysis using quality tools. The subject of quality control were bolts and a ball bushing. The Pareto chart and fault mode and effect analysis (FMEA were used to assess faultiness of the products. The faultiness analysis in case of the bolt enabled us to detect the following defects: failure to keep the dimensional tolerance, dents and imprints, improper roughness, lack of pre-machining, non-compatibility of the electroplating and faults on the surface. Analysis of the ball bushing has also revealed defects such as: failure to keep the dimensional tolerance, dents and imprints, improper surface roughness, lack of surface premachining as well as sharp edges and splitting of the material.

  10. Effect of chip size on steam explosion pretreatment of softwood.

    Science.gov (United States)

    Ballesteros, I; Oliva, J M; Navarro, A A; González, A; Carrasco, J; Ballesteros, M

    2000-01-01

    Although considerable progress has been made in technology for converting lignocellulosic biomass into ethanol, substantial opportunities still exist to reduce production costs. In biomass pretreatment, reducing milling power is a technological improvement that will substantially lower production costs for ethanol. Improving sugar yield from hemicellulose hydrolysis would also reduce ethanol production costs. Thus, it would be desirable to test innovative pretreatment conditions to improve the economics by reducing electrical power of the milling stage and by optimizing pretreatment recovery of hemicellulose, as well as to enhance cellulose hydrolysis. The objective of this study was to evaluate the effect of chip size (2-5, 5-8, and 8-12 mm) on steam-explosion pretreatment (190 and 210 degrees C, 4 and 8 min) of softwood (Pinus pinaster).

  11. Hydrothermal pretreatment of biomass for pellet production

    Energy Technology Data Exchange (ETDEWEB)

    Tooyserkani, Z. [British Columbia Univ., Vancouver, BC (Canada). Clean Energy Research Centre, Biomass and Bioenergy Research Group

    2010-07-01

    This presentation discussed innovative technologies for the production of wood pellets using the hydrothermal pre-treatment of biomass. Conventional techniques use low-cost mill residues, such as saw dust and shavings, as feedstock to produce durable, low-ash pellets. However, mill residues are becoming less available as a result of fewer saw mills, increased pellet production, and increased competition for saw dust. Advanced techniques use mixed biomass such as logging residue as feedstock, creating pellets that are durable for handling and long-term storage, of a higher energy density for transport and mixing with coal for co-firing, and a choice feedstock for biofuels. Advanced pellet production uses steam explosion/pre-treatment in which biomass receives a short-term high-pressure steam treatment followed by sudden decompression. Mild torrefaction seems to have positive feedback, and steam-treated pellets are durable with superior hydrophobicity. 3 figs., 3 tabs.

  12. 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.

  13. Effect of the milling conditions on the formation of nanostructured Fe-Co powders

    Energy Technology Data Exchange (ETDEWEB)

    Alleg, Safia; Bentayeb, Fatima Z.; Bensalem, Rachid; Djebbari, Chafia [Laboratoire de Magnetisme et de Spectroscopie des Solides, Departement de Physique, Faculte des Sciences, Universite de Annaba (Algeria); Bessais, Lotfi [CNRS-Laboratoire de Chimie Metallurgique des Terres Rares-Groupe des Laboratoires de Thiais (France); Greneche, Jean M. [Laboratoire de Physique de l' Etat Condense, UMR CNRS, Universite du Maine, Le Mans cedex (France)

    2008-07-15

    Nanostructured Fe-12Co (wt%) powders were prepared by mechanical alloying in a planetary ball mill. The milling process was carried out at different milling conditions. The obtained powders were characterized by X-ray diffraction, {sup 57}Fe Moessbauer spectrometry and magnetic measurements. The low and high speed ball-milling conditions lead to the formation of a single and two-bcc Fe(Co) structure, respectively, having different crystallite sizes, microstrains hyperfine parameters and magnetic properties. The average hyperfine magnetic field values: left angle B right angle {sub 1}=34.8 T and left angle B right angle {sub 2} =28.2 T of the two-bcc Fe(Co) structure could be attributed to the nanocrystalline grains and to the grain boundaries, respectively. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. New bulk glassy alloys in Cu-Zr-Ag ternary system prepared by casting and milling

    Science.gov (United States)

    Janovszky, D.; Tomolya, K.; Sveda, M.; Solyom, J.; Roosz, A.

    2009-01-01

    The thermal stability, crystallization behaviour and glass forming ability of Cu-Zr-Ag system have been investigated on the basis of a ternary phase diagram. We altered the concentration of the alloys from the Cu58Zr42 to the concentration of the deep eutectic point of the Cu-Zr-Ag ternary system and we calculated the glass forming ability parameters. This paper summerises the results of the procedure during which Cu-Zr-Ag amorphous alloys with different Ag content (0-25%) were prepared by casting and ball-milling. Wedge-shaped samples were prepared from the ingots by centrifugal casting into copper mold. The supercooled liquid region (ΔTx) exceeded 75K. Following the characterization of the cast alloys, master alloys of identical composition were milled in a Fritsch Pulverisette 2 ball-mill. The powders, milled for various periods of time were analysed by XRD in order to define the amorphous fraction.

  15. Compressive properties of a reaction milled NiAl-AlN composite

    OpenAIRE

    Whittenberger, J. Daniel; Arzt, Eduard; Luton, Michael J.

    1990-01-01

    Cryomilling (high intensity mechanical ball milling in a liquid nitrogen bath) of the B2 crystal structure nickel aluminide leads to a NiAl composite containing about 10 vol. % of AlN particles. This is the result of a reaction milling process, where nitrogen incorporated into the matrix during cryomilling reacts with Al during subsequent thermomechanical processing to form the composite. Compressive testing at 1300 K of such materials densified by 1505 K extrusion or isostatic pressing at 13...

  16. Research on Cutting Force of Turn-Milling Based on Thin-Walled Blade

    Directory of Open Access Journals (Sweden)

    Lida Zhu

    2016-01-01

    Full Text Available Turn-milling is regarded as the milling of a curved surface while rotating the workpiece around its center point, which combines effectively the advantages of both turning and milling, wherein it allows for good metal removal with the difficult-to-cut thin-walled workpieces in aviation. The objective of the present work is to study cutting force by turn-milling in cutting condition. Aiming at the deformation properties of thin-walled blade, the predicted models of rigid cutting force and flexible cutting force with ball cutter are provided, respectively, in turn-milling process. The deformation values of blade and cutter are calculated, respectively, based on the engaged trajectory by using the iterative algorithm. The rigid and flexible cutting forces are compared and the influence degrees of cutting parameters on cutting forces are analyzed. These conclusions provide theoretical foundation and reference for turn-milling mechanism research.

  17. Vertical bounce of two vertically aligned balls

    Science.gov (United States)

    Cross, Rod

    2007-11-01

    When a tennis ball rests on top of a basketball and both drop to the floor together, the tennis ball is projected vertically at high speed. A mass-spring model of the impact, as well as air track data, suggest that the tennis ball should be projected at relatively low speed. Measurements of the forces on each ball and the bounce of vertically aligned superballs are used to resolve the discrepancy.

  18. Silicon Nitride Balls For Cryogenic Bearings

    Science.gov (United States)

    Butner, Myles F.; Ng, Lillian W.

    1990-01-01

    Resistance to wear greater than that of 440C steel. Experiments show lives of ball bearings immersed in liquid nitrogen or liquid oxygen increased significantly when 440C steel balls (running on 440C steel races) replaced by balls of silicon nitride. Developed for use at high temperatures, where lubrication poor or nonexistent. Best wear life of any bearing tested to date and ball material spalls without fracturing. Plans for future tests call for use of liquid oxygen as working fluid.

  19. Processing of Polysulfone to Free Flowing Powder by Mechanical Milling and Spray Drying Techniques for Use in Selective Laser Sintering

    Directory of Open Access Journals (Sweden)

    Nicolas Mys

    2016-04-01

    Full Text Available Polysulfone (PSU has been processed into powder form by ball milling, rotor milling, and spray drying technique in an attempt to produce new materials for Selective Laser Sintering purposes. Both rotor milling and spray drying were adept to make spherical particles that can be used for this aim. Processing PSU pellets by rotor milling in a three-step process resulted in particles of 51.8 μm mean diameter, whereas spray drying could only manage a mean diameter of 26.1 μm. The resulting powders were characterized using Differential Scanning Calorimetry (DSC, Gel Permeation Chromatography (GPC and X-ray Diffraction measurements (XRD. DSC measurements revealed an influence of all processing techniques on the thermal behavior of the material. Glass transitions remained unaffected by spray drying and rotor milling, yet a clear shift was observed for ball milling, along with a large endothermic peak in the high temperature region. This was ascribed to the imparting of an orientation into the polymer chains due to the processing method and was confirmed by XRD measurements. Of all processed powder samples, the ball milled sample was unable to dissolve for GPC measurements, suggesting degradation by chain scission and subsequent crosslinking. Spray drying and rotor milling did not cause significant degradation.

  20. Does Ease to Block a Ball Affect Perceived Ball Speed? Examination of Alternative Hypotheses

    Science.gov (United States)

    Witt, Jessica K.; Sugovic, Mila

    2012-01-01

    According to an action-specific account of perception, the perceived speed of a ball can be a function of the ease to block the ball. Balls that are easier to stop look like they are moving slower than balls that are more difficult to stop. This was recently demonstrated with a modified version of the classic computer game Pong (Witt & Sugovic,…

  1. LHC gets the ball rolling

    CERN Multimedia

    2007-01-01

    1. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI).2. During the tests the ball is inserted very carefully into the vacuum chamber.1. Le groupe pluridisciplinaire qui a mené le projet de balle RF pour vérifier les interconnexions avec, de gauche à droite, Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS) et Marek Gasior (AB/BI).2. Lors des tests, la balle est insérée dans la chambre à vide avec beaucoup de précaution.

  2. The correct "ball bearings" data.

    Science.gov (United States)

    Caroni, C

    2002-12-01

    The famous data on fatigue failure times of ball bearings have been quoted incorrectly from Lieblein and Zelen's original paper. The correct data include censored values, as well as non-fatigue failures that must be handled appropriately. They could be described by a mixture of Weibull distributions, corresponding to different modes of failure.

  3. Idea Bank: Wiffle Ball Physics

    Science.gov (United States)

    Lancor, Rachael

    2009-01-01

    Projectile motion, a cornerstone topic of introductory physics, is usually a student's first exposure to the problem-solving techniques used in this subject. Often, this is an inactive learning experience--students work with pencil and paper to read and solve projectile motion problems (e.g., diagrams and descriptions of balls being hit, kicked,…

  4. 顺铣与逆铣的比较及铣床改进建议%Comparison of Climb-milling to Up-cut-milling and Suggestions on Improving Milling Machine

    Institute of Scientific and Technical Information of China (English)

    王敏之

    2012-01-01

    阐述了顺铣与逆铣的不同特点.指出普通铣床纵向进给机构普遍采用滑动丝杠限制了运用顺铣法的结构性缺陷.提出机床厂可将普通铣床的纵向进给机构改装成滚珠丝杠的建议,使之发挥更好的作用.%The difference between the climb-milling and the up-cut-milling was elaborated. The structural defect was pointed out that the use of the climb-milling method was limited by the level sliding feed mechanism of ordinary milling machine. It is proposed that the level feed mechanism of ordinary milling machine in the machine tool plant can be modified into ball screw pair, so that a greater economic efficiency is played by it.

  5. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  6. Effect of milling atmosphere on structural and magnetic properties of Ni Zn ferrite nanocrystalline

    Institute of Scientific and Technical Information of China (English)

    Abdollah Hajalilou; Mansor Hashim; Reza Ebrahimi-Kahrizsangi; Mohamad Taghi Masoudi

    2015-01-01

    Powder mixtures of Zn, NiO, and Fe2O3 are mechanically alloyed by high energy ball milling to produce Ni–Zn ferrite with a nominal composition of Ni0.36Zn0.64Fe2O4. The effects of milling atmospheres (argon, air, and oxygen), milling time (from 0 to 30 h) and heat treatment are studied. The products are characterized using x-ray diffractometry, field emission scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy, and transmitted electron microscopy. The results indicate that the desired ferrite is not produced during the milling in the samples milled under either air or oxygen atmospheres. In those samples milled under argon, however, Zn/NiO/Fe2O3 reacts with a solid-state diffusion mode to produce Ni–Zn ferrite nanocrystalline in a size of 8 nm after 30-h-milling. The average crystallite sizes decrease to 9 nm and 10 nm in 30-h-milling samples under air and oxygen atmospheres, respectively. Annealing the 30-h-milling samples at 600 ◦C for 2 h leads to the formation of a single phase of Ni–Zn ferrite, an increase of crystallite size, and a reduction of internal lattice strain. Finally, the effects of the milling atmosphere and heating temperature on the magnetic properties of the 30-h-milling samples are investigated.

  7. Research on the thermal load of CNC milling machine

    Science.gov (United States)

    Nie, Xue-Jun; Wu, Ping-Dong

    2011-05-01

    Machine tool accuracy is the assurance of top-quality products in machining processes. In the all kinds of errors related to machine tools, thermal errors of machine tools' parts play an important role in machining accuracy and directly influence both the surface finish and the geometric shape of the finished workpiece. Therefore the objective of this work was to analyze the temperature field and thermal deformation in some parts of CNC machine tools. In this paper, the thermal boundary condition of main spindle and driving ball screw in CNC milling machine are discussed, some parameters in heat transfer process are calculated. Based on steady heat transfer process, the thermal analysis about spindle and ball screw is carried out under ANSYS environment, and their temperature fields are obtained when milling machine is working. Then the deformations of main spindle and ball screw are acquired by applying the thermal structure coupling element. Furthermore, in order to decrease main parts' deformations and improve the accuracy of CNC milling machine, some suggests are proposed.

  8. Mechanically Milled Irregular Zinc Nanoparticles for Printable Bioresorbable Electronics.

    Science.gov (United States)

    Mahajan, Bikram K; Yu, Xiaowei; Shou, Wan; Pan, Heng; Huang, Xian

    2017-02-20

    Bioresorbable electronics is predominantly realized by complex and time-consuming anhydrous fabrication processes. New technology explores printable methods using inks containing micro- or nano-bioresorbable particles (e.g., Zn and Mg). However, these particles have seldom been obtained in the context of bioresorbable electronics using cheap, reliable, and effective approaches with limited study on properties essential to printable electronics. Here, irregular nanocrystalline Zn with controllable sizes and optimized electrical performance is obtained through ball milling approach using polyvinylpyrrolidone (PVP) as a process control agent to stabilize Zn particles and prevent cold welding. Time and PVP dependence of the ball milled particles are studied with systematic characterizations of morphology and composition of the nanoparticles. The results reveal crystallized Zn nanoparticles with a size of ≈34.834 ± 1.76 nm and low surface oxidation. The resulting Zn nanoparticles can be readily printed onto bioresorbable substrates and sintered at room temperature using a photonic sintering approach, leading to a high conductivity of 44 643 S m(-1) for printable zinc nanoparticles. The techniques to obtain Zn nanoparticles through ball milling and processing them through photonic sintering may potentially lead to a mass fabrication method for bioresorbable electronics and promote its applications in healthcare, environmental protection, and consumer electronics.

  9. Wear Studies of MIL-L-23699 Aircraft Turbine Engine. Synthetic Base Lubricating Oils - I. The Development of a Procedure and Initial Findings

    Science.gov (United States)

    and contaminants in MIL-L-23699 aircraft turbine engine synthetic base lubricating oils . The procedure employs a linear ball-on-flat principle and is...wear of water in gas-turbine lubricating oils . The MIL-L-23699 oils exhibit a linear relationship between the removal of bearing surface material (wear

  10. 75 FR 71463 - Woodland Mills Corporation Mill Spring, NC; Notice of Revised Determination on Reconsideration

    Science.gov (United States)

    2010-11-23

    ... Employment and Training Administration Woodland Mills Corporation Mill Spring, NC; Notice of Revised... of Woodland Mills Corporation, Mill Spring, North Carolina, to apply for Trade Adjustment Assistance... yarn produced by Woodland Mills Corporation, Mill Spring, North Carolina Woodland Mills...

  11. Influence of mechanical milling on structural and magnetic properties of Cu2+ substituted MnFe2O4

    Science.gov (United States)

    Tanna, A. R.; Joshi, H. H.

    2016-09-01

    Polycrystalline ceramic powders of copper doped manganese ferrite (Mn1-xCuxFe2O4, x = 0.25, 0.50 and 0.75) synthesized by ceramic technique have been subjected to high-energy ball-milling to study the influence of mechanical milling on structural and magnetic properties through X-ray diffraction, scanning electron microscopy, fourier transform infrared spectroscopy and magnetization measurements. The compositional stoichiometry has been ascertained by energy dispersive analysis of X-rays mapping before commencement of high-energy ball milling of the powders. The X-ray diffraction patterns of all as prepared specimens show cubic (fcc) spinel structure with no traces of any impurity of ingredients or unexpected structural phase. The Jahn-Teller (JT) structural distortion evolves after 30 h of prolonged ball milling in all the samples, in fact the tetragonal distortion of the unit cell appears in the sample with x = 0.75 just after 18 h of milling duration. The saturation magnetization at 77 K temperature in the peak field of 5 kOe has been measured for each specimen and the Curie temperatures have been determined through thermal variation of low field (0.5 Oe) AC susceptibility. Infrared spectra also reflect the JT distortion of the unit cell due to ball milling.

  12. 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)

  13. Pretreatment techniques for biofuels and biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhen (ed.) [Chinese Academy of Sciences, Kunming, YN (China). Xishuangbanna Tropical Botonical Garden

    2013-02-01

    The first book focused on pretreatment techniques for biofuels contributed by the world's leading experts. Extensively covers the different types of biomass, various pretreatment approaches and methods that show the subsequent production of biofuels and chemicals. In addition to traditional pretreatment methods, novel techniques are also introduced and discussed. An accessible reference work for students, researchers, academicians and industrialists in biorefineries. This book includes 19 chapters contributed by the world's leading experts on pretreatment methods for biomass. It extensively covers the different types of biomass (e.g. molasses, sugar beet pulp, cheese whey, sugarcane residues, palm waste, vegetable oil, straws, stalks and wood), various pretreatment approaches (e.g. physical, thermal, chemical, physicochemical and biological) and methods that show the subsequent production of biofuels and chemicals such as sugars, ethanol, extracellular polysaccharides, biodiesel, gas and oil. In addition to traditional methods such as steam, hot-water, hydrothermal, diluted-acid, organosolv, ozonolysis, sulfite, milling, fungal and bacterial, microwave, ultrasonic, plasma, torrefaction, pelletization, gasification (including biogas) and liquefaction pretreatments, it also introduces and discusses novel techniques such as nano and solid catalysts, organic electrolyte solutions and ionic liquids. This book offers a review of state-of-the-art research and provides guidance for the future paths of developing pretreatment techniques of biomass for biofuels, especially in the fields of biotechnology, microbiology, chemistry, materials science and engineering. It intends to provide a systematic introduction of pretreatment techniques. It is an accessible reference work for students, researchers, academicians and industrialists in biorefineries.

  14. Studies On Falling Ball Viscometry

    CERN Document Server

    Singh, Amit Vikram; Gupta-Bhaya, Pinaki

    2012-01-01

    A new method of accurate calculation of the coefficient of viscosity of a test liquid from experimentally measured terminal velocity of a ball falling in the test liquid contained in a narrow tube is described. The calculation requires the value of a multiplicative correction factor to the apparent coefficient of viscosity calculated by substitution of terminal velocity of the falling ball in Stokes formula. This correction factor, the so-called viscosity ratio, a measure of deviation from Stokes limit, arises from non-vanishing values of the Reynolds number and the ball/tube radius ratio. The method, valid over a very wide range of Reynolds number, is based on the recognition of a relationship between two measures of wall effect, the more widely investigated velocity ratio, defined as the ratio of terminal velocity in a confined medium to that in a boundless medium and viscosity ratio. The calculation uses two recently published correlation formulae based on extensive experimental results on terminal velocit...

  15. Ball Screw Actuator Including a Stop with an Integral Guide

    Science.gov (United States)

    Wingett, Paul T. (Inventor); Perek, John (Inventor); Geck, Kellan (Inventor)

    2015-01-01

    An actuator includes a housing assembly, a ball nut, a ball screw, and a ball screw stop. The ball nut is rotationally mounted in the housing assembly, is adapted to receive an input torque, and is configured, upon receipt thereof, to rotate and supply a drive force. The ball screw is mounted within the housing assembly and extends through the ball nut. The ball screw has a first end and a second end, and is coupled to receive the drive force from the ball nut. The ball screw is configured, upon receipt of the drive force, to selectively translate between a stow position and a deploy position. The ball screw stop is mounted on the ball screw to translate therewith and is configured to at selectively engage the housing assembly while the ball screw is translating, and engage the ball nut when the ball screw is in the deploy position.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-05

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

  17. Revitalizing America's Mills: A Report on Brownfields Mill Projects

    Science.gov (United States)

    This report focuses on mills -- former textile, wood, paper, iron, and steel mills. The report describes the challenges and opportunities of mill sites with case studies highlighting some of the most creative solutions from across the country.

  18. Characterization of mechanically milled and spark plasma sintered Al2124-CNT nanocomposites

    Directory of Open Access Journals (Sweden)

    Saheb N.

    2015-01-01

    Full Text Available In the present work, ball milling and spark plasma sintering were used to develop Al2124-CNT nanocomposites. The effect of milling time on the grain size and lattice strain of the ball milled Al2124 alloy powder and the effect of sintering time and temperature on the grain size of the matrix in spark plasma sintered Al2124 alloy and CNT-reinforced Al2124 nanocomposites were investigated. The density and hardness of the developed materials were evaluated as functions of the sintering parameters. It was found that ball milling not only reduced the particle size of the Al2124 powder but also decreased the grain size of the α-aluminum phase to 50 nm and increased its lattice strain. A milling time of 6 hours was found to be the optimum time to reach a nanostructured α-aluminum matrix. The grain size of the α-aluminum phase in the sintered samples increased with increasing sintering temperature and time to reach maximum values at a sintering temperature of 500°C and a sintering time of 20 minutes. Although sintering led to grain growth, the grain size of the α-aluminium matrix remained in the nanometer range and did not exceed 150 nm. The relative density and hardness of the sintered samples increased with increasing sintering temperature and time to reach maximum values at a sintering temperature of 500°C and a sintering time of 20 minutes.

  19. Fluid Mechanics of Cricket and Tennis Balls

    Science.gov (United States)

    Mehta, Rabindra D.

    2009-11-01

    Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports. The main interest is in the fact that the ball can often deviate from its initial straight path, resulting in a curved, or sometimes an unpredictable, flight path. It is particularly fascinating that that not all the parameters that affect the flight of a ball are always under human influence. Lateral deflection in flight, commonly known as swing, swerve or curve, is well recognized in cricket and tennis. In tennis, the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight, which gives rise to what is commonly known as the Magnus effect. It is now well recognized that the aerodynamics of sports balls are strongly dependent on the detailed development and behavior of the boundary layer on the ball's surface. A side force, which makes a ball curve through the air, can also be generated in the absence of the Magnus effect. In one of the cricket deliveries, the ball is released with the seam angled, which trips the laminar boundary layer into a turbulent state on that side. The turbulent boundary layer separates relatively late compared to the laminar layer on the other side, thereby creating a pressure difference and hence side force. The fluid mechanics of a cricket ball become very interesting at the higher Reynolds numbers and this will be discussed in detail. Of all the round sports balls, a tennis ball has the highest drag coefficient. This will be explained in terms of the contribution of the ``fuzz" drag and how that changes with Reynolds number and ball surface wear. It is particularly fascinating that, purely through historical accidents, small disturbances on the ball surface, such as the stitching on cricket balls and the felt cover on tennis balls are all about the right size to affect boundary layer transition and development in the Reynolds numbers of interest. The fluid

  20. Effects of milling and active surfactants on rheological behavior of powder injection molding feedstock

    Institute of Scientific and Technical Information of China (English)

    范景莲; 黄伯云; 曲选辉

    2001-01-01

    The effects of milling and active surfactants on the rheological behavior of powder injection molding feedstock were discussed. The feedstock consists of traditional compositional 90W-7Ni-3Fe powder mixture and a wax based polymer binder. Before mixing feedstock, the powder mixture was milled for different times in a QM-1 high-energy ball mill. The viscosity of the feedstock was examined in a capillary rheometer. The rheological behavior was evaluated from viscosity data. The results show that the feedstock belongs to a pseudoplastic fluid, milling decreases viscosity of the feedstock and the sensitivity of viscosity to shear strain rate. The flowability, rheology and powder loading of this feedstock are improved by milling. Active surfactants such as stearic acid (SA) and di-n-octyl-o-phthalate (DOP) have great influences on the rheological properties of the feedstock. DOP improves the flowability and rheological stability of the feedstock further.

  1. Plasma-Assisted Pretreatment of Wheat Straw

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Leipold, Frank; Bindslev, Henrik;

    2011-01-01

    O3 generated in a plasma at atmospheric pressure and room temperature, fed with dried air (or oxygen-enriched dried air), has been used for the degradation of lignin in wheat straw to optimize the enzymatic hydrolysis and to get more fermentable sugars. A fixed bed reactor was used combined...... straw with desired lignin content because of the online analysis. The O3 consumption of wheat straw and its polymeric components, i.e., cellulose, hemicellulose, and lignin, as well as a mixture of these, dry as well as with 50% water, were studied. Furthermore, the process parameters dry matter content...... and milled particle size (the extent to which the wheat straw was milled) were investigated and optimized. The developed methodology offered the advantage of a simple and relatively fast (0.5–2 h) pretreatment allowing a dry matter concentration of 45–60%. FTIR measurements did not suggest any structural...

  2. CuZrAl amorphous alloys prepared by casting and milling

    Science.gov (United States)

    Tomolya, K.; Janovszky, D.; Sveda, M.; Hegman, N.; Solyom, J.; Roosz, A.

    2009-01-01

    Several preparation methods are available for the production of amorphous alloys. During the experiment described in this paper (Cu58Zr42)100-xAlx (x = 0-14,8; in at%) amorphous alloys were prepared by casting and ball-milling. The ingots were produced by arc melting. Wedge-shaped samples were prepared from the ingots by centrifugal casting into copper mould. The microstructures of these samples were defined by SEM. The amorphous samples were analysed by DSC and the activation energy of the crystallization processes was calculated from the measured temperatures. The master alloys of identical composition were milled by ball-mill for different periods of time. The powders were analysed by XRD in order to define the amorphous fractions.

  3. From Schwinger Balls to Curved Space

    CERN Document Server

    Allahbakhshi, Davood

    2016-01-01

    It is shown that the Reissner-Nordstrom black hole is also a gravitational Schwinger ball. It is also shown that both massless and massive-particle gravitational Schwinger balls are thermodynamic systems by deriving the first law of thermodynamics for them. Inconsistency between classical geometrical and microscopic definitions of the horizon is discussed. We propose a new metric, more consistent with microscopic picture of black hole, as gravitational Schwinger ball, by speculations. It has some interesting features.

  4. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg–Cu–Y metallic glass powder through dealloying pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xuekun; Li, Ran, E-mail: liran@buaa.edu.cn; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao, E-mail: zhangtao@buaa.edu.cn

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg{sub 65}Cu{sub 25}Y{sub 10} metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core–shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  5. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg-Cu-Y metallic glass powder through dealloying pretreatment

    Science.gov (United States)

    Luo, Xuekun; Li, Ran; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg65Cu25Y10 metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core-shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  6. Left atrial ball valve thrombus

    Directory of Open Access Journals (Sweden)

    R. Balaji

    2013-10-01

    Full Text Available "Ball valve thrombus" which is a spherical free floating clot in left atrium is an often quoted, but uncommonly encountered complication in patients with severe mitral stenosis of rheumatic origin, who are in atrial fibrillation. We describe the case of a 31-year-old lady with rheumatic heart disease, severe mitral stenosis and moderately severe aortic stenosis who had undergone closed mitral valvotomy 13 years ago. The patient presented with an episode of non-exertional syncope and breathlessness on exertion of 6 months duration and was in normal sinus rhythm. Echocardiography facilitated ante-mortem diagnosis and prompt institution of surgery was life saving.

  7. The Soccer-Ball Problem

    Science.gov (United States)

    Hossenfelder, Sabine

    2014-07-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

  8. The Soccer-ball Problem

    CERN Document Server

    Hossenfelder, S

    2014-01-01

    The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. Motivated by Loop Quantum Gravity, this modified Lorentz-symmetry is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the "soccer-ball problem." This article briefly reviews the problem and the status of existing solution attempts.

  9. Ball Bearing Stacking Automation System

    Directory of Open Access Journals (Sweden)

    Shafeequerrahman S . Ahmed

    2013-01-01

    Full Text Available This document is an effort to introduce the concept of automation in small scale industries and or small workshops that are involved in the manufacturing of small objects such as nuts, bolts and ball bearing in this case. This an electromechanical system which includes certain mechanical parts that involves one base stand on which one vertical metallic frame is mounted and hinged to this vertical stand is an in humanized effort seems inadequate in this era making necessary the use of Electronics, Computer in the manufacturing processes leading to the concept of Automated Manufacturing System (AMS.The ball bearing stack automation is an effort in this regard. In our project we go for stack automation for any object for example a ball bearing, be that is still a manual system there. It will be microcontroller based project control system equipped with microcontroller 89C51 from any manufacturer like Atmel or Philips. This could have been easily implemented if a PLC could be used for manufacturing the staking unit but I adopted the microcontroller based system so that some more modification in the system can be effected at will as to use the same hardware .Although a very small object i.e. ball bearig or small nut and fixture will be tried to be stacked, the system with more precision and more power handling capacity could be built for various requirements of the industry. For increasing more control capacity, we can use another module of this series. When the bearing is ready, it will be sent for packing. This is sensed by an inductive sensor. The output will be proceeds by PLC and microcontroller card which will be driving the assembly in order to put it into pads or flaps. This project will also count the total number of bearings to be packed and will display it on a LCD for real time reference and a provision is made using a higher level language using hyper terminal of the computer

  10. Investigation of milling energy input on structural variations of processed olivine powders for CO{sub 2} sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Atashin, Sanam; Wen, John Z.; Varin, Robert A., E-mail: ravarin@uwaterloo.ca

    2015-01-05

    Highlights: • Milling energy input in kJ/g determines the microstructure of olivine powders. • The optimum energy input for a minimum olivine particle size is about 14 kJ/g. • The crystallite size of olivine decreases up to 55 kJ/g energy input and then saturates. • The effect of structural strain on material’s disorder is negligible above 55 kJ/g energy input. • The overall energy input for producing desirable olivine microstructure absorbing CO{sub 2} is about 55 kJ/g. - Abstract: This study aims to identify the correlation between microstructure of mechanically processed olivine powders and the milling energy input, for an ultimate purpose of optimizing the ball milling approach for achieving the best CO{sub 2} sequestration characteristics. Powders were processed in a high energy magneto ball mill. A variety of instrumental techniques such as scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) and X-ray diffraction (XRD) were utilized to characterize the particle size, specific surface area, pore volume, crystallinity and crystallite size of processes powders obtained with different levels of milling energy input. In each case, the variation of microstructural parameters with milling energy is compared for different milling devices extracted from the literature. Structural parameters of activated powders are correlated as a function of milling energy input, regardless of the ball mill type. The optimal range of milling energy input, expected to achieve the most desirable microstructure for CO{sub 2} sequestration is found to be about 55 kJ/g.

  11. Biomechanical properties of wheat grains: the implications on milling

    Science.gov (United States)

    Reith, Martin

    2017-01-01

    Millennia of continuous innovation have driven ever increasing efficiency in the milling process. Mechanically characterizing wheat grains and discerning the structure and function of the wheat bran layers can contribute to continuing innovation. We present novel shear force and puncture force testing regimes to characterize different wheat grain cultivars. The forces endured by wheat grains during the milling process can be quantified, enabling us to measure the impact of commonly applied grain pretreatments, such as microwave heating, extended tempering, enzyme and hormone treatments on grains of different ‘hardness’. Using these methods, we demonstrate the importance of short tempering phases prior to milling and identify ways in which our methods can detect differences in the maximum force, energy and breaking behaviours of hard and soft grain types. We also demonstrate for the first time, endosperm weakening in wheat, through hormone stratification on single bran layers. The modern milling process is highly refined, meaning that small, cultivar specific, adjustments can result in large increases in downstream profits. We believe that methods such as these, which enable rapid testing of milling pretreatments and material properties can help to drive an innovation process that has been core to our industrial efforts since prehistory. PMID:28100826

  12. Effect of moisture on pretreatment efficiency for anaerobic digestion of lignocellulosic substrates.

    Science.gov (United States)

    Peces, M; Astals, S; Mata-Alvarez, J

    2015-12-01

    The present study evaluates the effect of moisture in low-temperature and ultrasound pretreatment on lignocellulosic substrates anaerobic biodegradability, where brewer's spent grain was used as model substrate. Besides moisture content, low-temperature pretreatment was also evaluated in terms of temperature (60-80°C) and exposure time (12-72 h). Likewise, ultrasonication was also evaluated in terms of specific energy (1000-50,000 kJ kg TS(-1)). In addition, the effect of substrate particle size reduction by milling pretreatment was also considered. The results clearly demonstrated that substrate moisture (total solid concentration) is a significant parameter for pretreatment performance, although it has been rarely considered in pretreatment optimisation. Specifically, moisture optimisation increased the methane yield of brewer's spent grain by 6% for low-temperature pretreatment (60°C), and by 14% for ultrasound pretreatment (1000 kJ kg TS(-1)) towards the control (without pretreatment). In both pretreatments, the experimental optimum total solid concentration was 100 gTS kg(-1). Thus, lowering substrate moisture, a strategy suggested attaining energetic pretreatment feasibility, needs to be analysed as another pretreatment variable since it might have limited correlation. Finally, a preliminary energetic balance of the pretreatments under study showed that the extra methane production could not cover the energetic pretreatment expenses.

  13. Effect of milling time on the synthesis of magnetite nanoparticles by wet milling

    Energy Technology Data Exchange (ETDEWEB)

    Can, Musa Mutlu [SNTG Laboratory, Physics Engineering Department, Hacettepe University, Beytepe, 06800, Ankara (Turkey); Ozcan, Sadan, E-mail: sadan@hacettepe.edu.tr [SNTG Laboratory, Physics Engineering Department, Hacettepe University, Beytepe, 06800, Ankara (Turkey); Ceylan, Abdullah; Firat, Tezer [SNTG Laboratory, Physics Engineering Department, Hacettepe University, Beytepe, 06800, Ankara (Turkey)

    2010-08-15

    In this study, nanosize magnetite (Fe{sub 3}O{sub 4}) particles have been prepared directly from metallic iron (Fe) powder within distilled water (H{sub 2}O) by using a planetary ball mill, and the effect of milling time has been investigated. According to Rietveld refinement result obtained from X-ray diffraction (XRD) analyses, the amount of Fe decreases from 98.2% to 0.0%, and it is transformed into Fe{sub 3}O{sub 4}, from 1.8% to 100.0%, with the increasing milling time from 1 to 48 h. Due to similar crystal structure of the magnetite and maghemite ({gamma}-Fe{sub 2}O{sub 3}), FTIR and Raman spectroscopies as well as a chemical analysis method was used to verify the magnetite structure. FTIR spectra have clearly revealed absorption peaks around 628, 581 and 443 cm{sup -1}, which are in good agreement with the characteristic absorption peaks of Fe{sub 3}O{sub 4}. In addition Raman analysis verified the formation of magnetite phase with a clear main band peak at 671 cm{sup -1}. Chemical analyses have shown that the total amount of Fe in the milled sample for 48 h is 73.04%, which contains 24.10% Fe{sup 2+} and 49.34% Fe{sup 3+}. These results are consistent with the theoretically estimated values of the magnetite. It has been observed that the saturation magnetization decreased from 146.02 to 63.68 emu/g with increasing milling time due to the formation of the ferrimagnetic magnetite phase.

  14. Impact of thermal pretreatment on the fast pyrolysis conversion of Southern Pine

    Energy Technology Data Exchange (ETDEWEB)

    Tyler L. Westover; Manunya Phanphanich; Micael L. Clark; Sharna R. Rowe; Steven E. Egan; Christopher T Wright; Richard D. Boardman; Alan H. Zacher

    2013-01-01

    Background: Thermal pretreatment of biomass ranges from simple (nondestructive) drying to more severe treatments that cause devolatization, depolymerization and carbonization. These pretreatments have demonstrated promise for transforming raw biomass into feedstock material that has improved milling, handling, storage and conversion properties. In this work, southern pine material was pretreated at 120, 180, 230 and 270 degrees C, and then subjected to pyrolysis tests in a continuous-feed bubbling-fluid bed pyrolysis system. Results: High pretreatment temperatures were associated with lower specific grinding energies, higher grinding rates and lower hydrogen and oxygen contents. Higher pretreatment temperatures were also correlated with increased char production, decreased total acid number and slight decrease in the oxygen content of the pyrolysis liquid fraction. Conclusion: Thermal pretreatment has both beneficial and detrimental impacts on fast pyrolysis conversion of pine material to bio-oil, and the effect of thermal pretreatment on upgrading of pyrolysis bio-oil requires further attention.

  15. Photoregulation of Anthocyanin Synthesis : VIII. Effect of Light Pretreatments.

    Science.gov (United States)

    Mancinelli, A L

    1984-06-01

    A comparative study of the spectral sensitivity of anthocyanin production in dark-grown and light-pretreated systems was carried out in Brassica oleracea L., Lycopersicon esculentum Mill., Secale cereale L. and Spirodela polyrrhiza L. Light pretreatments bring about an enhancement of the inductive, red-far red reversible response in all systems, a decrease of the continuous irradiation response in cabbage, rye, and tomato seedlings, and an enhancement of the continuous irradiation response in cabbage leaf disks. Light pretreatments also bring about a marked change in the spectral sensitivity of the continuous irradiation response. The different effect of light pretreatments on the photosensitivity of the response to short and long wavelength irradiations suggests that two photoreceptors, phytochrome and cryptochrome, may be involved in the photoregulation of anthocyanin production.

  16. Effects of milling media on the fabrication of melt-derived bioactive glass powder for biomaterial application

    Science.gov (United States)

    Ibrahim, Nurul Farhana; Mohamad, Hasmaliza; Noor, Siti Noor Fazliah Mohd

    2016-12-01

    The present work aims to study the effects of using different milling media on bioactive glass produced through melt-derived method for biomaterial application. The bioactive glass powder based on SiO2-CaO-Na2O-P2O5 system was fabricated using two different types of milling media which are tungsten carbide (WC) and zirconia (ZrO2) balls. However, in this work, no P2O5 was added in the new composition. XRF analysis indicated that tungsten trioxide (WO3) was observed in glass powder milled using WC balls whereas ZrO2 was observed in glass powder milled using ZrO2 balls. Amorphous structure was detected with no crystalline peak observed through XRD analysis for both glass powders. FTIR analysis confirmed the formation of silica network with the existence of functional groups Si-O-Si (bend), Si-O-Si (tetrahedral) and Si-O-Si (stretch) for both glass powders. The results revealed that there was no significant effect of milling media on amorphous silica network glass structure which shows that WC and zirconia can be used as milling media for bioactive glass fabrication without any contamination. Therefore, the fabricated BG can be tested safely for bioactivity assessment in biological fluids environment.

  17. Anaerobic digestion of pulp and paper mill wastewater and sludge.

    Science.gov (United States)

    Meyer, Torsten; Edwards, Elizabeth A

    2014-11-15

    sludge) and primary sludge is still in its infancy. Current research is mainly focused on developing efficient pretreatment methods that enable fast hydrolysis of complex organic matter, shorter sludge residence times and as a consequence, smaller sludge digesters. Previous experimental studies indicate that the anaerobic digestibility of non-pretreated biosludge from pulp and paper mills varies widely, with volatile solids (VS) removal rates of 21-55% and specific methane yields ranging between 40 and 200 mL g(-1) VS fed. Pretreatment can increase the digestibility to some extent, however in almost all reported cases, the specific methane yield of pretreated biosludge did not exceed 200 mL g(-1) VS fed. Increases in specific methane yield mostly range between 0 and 90% compared to non-pretreated biosludge, whereas larger improvements were usually achieved with more difficult-to-digest biosludge. Thermal treatment and microwave treatment are two of the more effective methods. The heat required for the elevated temperatures applied in both methods may be provided from surplus heat that is often available at pulp and paper mills. Given the large variability in specific methane yield of non-pretreated biosludge, future research should focus on the links between anaerobic digestibility and sludge properties. Research should also involve mill-derived primary sludge. Although biosludge has been the main target in previous studies, primary sludge often constitutes the bulk of mill-generated sludge, and co-digestion of a mixture between both types of sludge may become practical. The few laboratory studies that have included mill primary sludge indicate that, similar to biosludge, the digestibility can range widely. Long-term studies should be conducted to explore the potential of microbial adaptation to lignocellulosic material which can constitute more than half of the organic matter in pulp and paper mill sludge.

  18. Understanding of alkaline pretreatment parameters for corn stover enzymatic saccharification

    Directory of Open Access Journals (Sweden)

    Chen Ye

    2013-01-01

    pretreatment technology indicates that the main challenge for commercialization is chemical recovery. However, repurposing or co-locating a biorefinery with a paper mill would be advantageous from an economic point of view.

  19. Delayed Equation for Charged Rigid Nonrelativistic Ball

    CERN Document Server

    Vlasov, A A

    2002-01-01

    Simple expression for self-force acting on radiating rigid charged ball is derived (Sommerfeld ball). It is shown that appropriate delayed equation of motion has solutions in general differ from that for Sommerfeld sphere - there are no "radiationless" solutions, but there are oscillating without damping solutions though self-force has nonzero value.

  20. Soccer Ball Lift Coefficients via Trajectory Analysis

    Science.gov (United States)

    Goff, John Eric; Carre, Matt J.

    2010-01-01

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

  1. NCI and Leidos Play Ball | Poster

    Science.gov (United States)

    By Carolynne Keenan, Contributing Writer The ping of an aluminum bat off a ball or the thump of a pop-up fly ball caught in a glove are two sounds familiar to baseball fans. Slow-pitch softball sounds—like those in the August game between mixed teams of NCI and Leidos Biomedical Research (formerly SAIC-Frederick) players—are similar.

  2. Coefficient of Restitution of a Tennis Ball

    Directory of Open Access Journals (Sweden)

    Andre Roux

    2007-06-01

    Full Text Available The coefficient of restitution (COR of a tennis ball was investigated over a range of impact velocities. It was found that the COR of the ball was lower than ATP regulations specify, and that the COR decreased with increasing impact velocity.

  3. HA/Ti composite for biomedical application by mechanical milling

    Institute of Scientific and Technical Information of China (English)

    刘咏; 刘芳; 周科朝; 黄伯云

    2003-01-01

    In order to overcome the poor mechanical properties of HA and the low bioactivity of Ti, HA/Ti com-posites with various compositions were prepared by mechanical milling. The effects of milling condition and the com-position on the microstructure, the density and the hardness of the composites were studied. The results show thatduring the ball milling process, Ti particles are refined and the homogeneity of the HA/Ti mixtures is improved;HA will partially decompose due to the existence of Ti and high sintering temperature. The microstructure of HA/Ti composites is highly dependent on the milling condition and the composition. In the microstructure, Ti phase con-nects to be a continuous network, and HA/Ti mixtures disperse in the network. The longer the milling time, the fi-ner the network will be. The density of HA/Ti composites decreases with the content of HA increasing and themilling time prolonging, because HA deteriorates the sinterability of Ti. The hardness of HA/Ti composites increa-ses firstly with the content of HA increasing, and then drops when the content of HA exceeds 30%. Addition ofHA will strengthen the HA/Ti composite but will decrease the density of the composite, which accounts for theeffect of HA on the hardness of the composites.

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

    Science.gov (United States)

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

    2010-03-01

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

  5. La balle et la plume

    Directory of Open Access Journals (Sweden)

    Peter Marquis

    2012-06-01

    Full Text Available Fin octobre 2008, la nouvelle fit l’effet d’une bombe : Barack Obama, alors candidat à la présidence américaine, demanda à la chaîne câblée Fox News de retarder le début du sixième match de la World Series de base-ball afin de diffuser un spot de campagne. Son adversaire, John McCain, soutenu par le camp républicain et une partie de la population, monta aussitôt au créneau pour dénoncer l’hérésie : s’arroger le droit de perturber cette grande finale du championnat au déroulement immuable reve...

  6. Enzymatic corn wet milling: engineering process and cost model

    Directory of Open Access Journals (Sweden)

    McAloon Andrew J

    2009-01-01

    Full Text Available Abstract Background Enzymatic corn wet milling (E-milling is a process derived from conventional wet milling for the recovery and purification of starch and co-products using proteases to eliminate the need for sulfites and decrease the steeping time. In 2006, the total starch production in USA by conventional wet milling equaled 23 billion kilograms, including modified starches and starches used for sweeteners and ethanol production 1. Process engineering and cost models for an E-milling process have been developed for a processing plant with a capacity of 2.54 million kg of corn per day (100,000 bu/day. These models are based on the previously published models for a traditional wet milling plant with the same capacity. The E-milling process includes grain cleaning, pretreatment, enzymatic treatment, germ separation and recovery, fiber separation and recovery, gluten separation and recovery and starch separation. Information for the development of the conventional models was obtained from a variety of technical sources including commercial wet milling companies, industry experts and equipment suppliers. Additional information for the present models was obtained from our own experience with the development of the E-milling process and trials in the laboratory and at the pilot plant scale. The models were developed using process and cost simulation software (SuperPro Designer® and include processing information such as composition and flow rates of the various process streams, descriptions of the various unit operations and detailed breakdowns of the operating and capital cost of the facility. Results Based on the information from the model, we can estimate the cost of production per kilogram of starch using the input prices for corn, enzyme and other wet milling co-products. The work presented here describes the E-milling process and compares the process, the operation and costs with the conventional process. Conclusion The E-milling process

  7. GREET Pretreatment Module

    Energy Technology Data Exchange (ETDEWEB)

    Adom, Felix K.; Dunn, Jennifer B.; Han, Jeongwoo

    2014-09-01

    A wide range of biofuels and biochemicals can be produced from biomass via different pretreatment technologies that yield sugars. This report documents the material and energy flows that occur when fermentable sugars from four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar) are produced via dilute acid pretreatment and ammonia fiber expansion. These flows are documented for inclusion in the pretreatment module of the Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Process simulations of each pretreatment technology were developed in Aspen Plus. Material and energy consumption data from Aspen Plus were then compiled in the GREET pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  8. BALL - biochemical algorithms library 1.3

    Directory of Open Access Journals (Sweden)

    Stöckel Daniel

    2010-10-01

    Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

  9. Cricket Ball Aerodynamics: Myth Versus Science

    Science.gov (United States)

    Mehta, Rabindra D.; Koga, Demmis J. (Technical Monitor)

    2000-01-01

    Aerodynamics plays a prominent role in the flight of a cricket ball released by a bowler. The main interest is in the fact that the ball can follow a curved flight path that is not always under the control of the bowler. ne basic aerodynamic principles responsible for the nonlinear flight or "swing" of a cricket ball were identified several years ago and many papers have been published on the subject. In the last 20 years or so, several experimental investigations have been conducted on cricket ball swing, which revealed the amount of attainable swing, and the parameters that affect it. A general overview of these findings is presented with emphasis on the concept of late swing and the effects of meteorological conditions on swing. In addition, the relatively new concept of "reverse" swing, how it can be achieved in practice and the role in it of ball "tampering", are discussed in detail. A discussion of the "white" cricket ball used in last year's World Cup, which supposedly possesses different swing properties compared to a conventional red ball, is also presented.

  10. Gravitational Waves from Q-ball Formation

    CERN Document Server

    Chiba, Takeshi; Yamaguchi, Masahide

    2009-01-01

    We study the detectability of the gravitational waves (GWs) from the Q-ball formation associated with the Affleck-Dine (AD) mechanism, taking into account both of the dilution effect due to Q-ball domination and of finite temperature effects. The AD mechanism predicts the formation of non-topological solitons, Q-balls, from which GWs are generated. Q-balls with large conserved charge $Q$ can produce a large amount of GWs. On the other hand, the decay rate of such Q-balls is so small that they may dominate the energy density of the universe, which implies that GWs are significantly diluted and that their frequencies are redshifted during Q-ball dominated era. Thus, the detectability of the GWs associated with the formation of Q-balls is determined by these two competing effects. We find that there is a finite but small parameter region where such GWs may be detected by future detectors such as DECIGO or BBO, only in the case when the thermal logarithmic potential dominates the potential of the AD field. Otherw...

  11. Shock-Absorbent Ball-Screw Mechanism

    Science.gov (United States)

    Hirr, Otto A., Jr.; Meneely, R. W.

    1986-01-01

    Actuator containing two ball screws in series employs Belleville springs to reduce impact loads, thereby increasing life expectancy. New application of springs increases reliability of equipment in which ball screws commonly used. Set of three springs within lower screw of ball-screw mechanism absorbs impacts that result when parts reach their upper and lower limits of movement. Mechanism designed with Belleville springs as shock-absorbing elements because springs have good energy-to-volume ratio and easily stacked to attain any stiffness and travel.

  12. Horizontal stability of a bouncing ball

    Science.gov (United States)

    McBennett, Brendan G.; Harris, Daniel M.

    2016-09-01

    We present an investigation of a partially elastic ball bouncing on a vertically vibrated concave parabolic surface in two dimensions. In particular, we demonstrate that simple vertical motion, wherein the ball bounces periodically at the parabola's vertex, is unstable to horizontal perturbations when the parabolic coefficient defining the surface shape exceeds a critical value. The result is a new periodic solution where the ball bounces laterally over the vertex. As the parabola is further steepened, this new solution also becomes unstable which gives rise to other complex periodic and chaotic bouncing states, all characterized by persistent lateral motion.

  13. Release Control of Dye from Agar Ball

    OpenAIRE

    板屋, 智之; 山村, 俊貴; 唐澤, 有太朗

    2013-01-01

    Agar is a special product of Nagano prefecture. To utilize agar gel as adsorbing or releasing material of dyes or drugs, spherical agar gel “agar ball” was prepared by dropping aqueous agar solution into salad oil. And releasing behavior of a dye (rhodamine B) from agar ball was studied. The dye is released easily from agar ball, but the release can be controlled by hybiridazation of agar and galatin. In addition, it was found that agar ball could extract the dye from oil phase containing the...

  14. Titanium carbide coatings for aerospace ball bearings

    Science.gov (United States)

    Boving, Hans J.; Haenni, Werner; Hintermann, HANS-E.

    1988-01-01

    In conventional ball bearings, steel to steel contacts between the balls and the raceways are at the origin of microwelds which lead to material transfer, surface roughening, lubricant breakdown, and finally to a loss in the bearing performances. To minimize the microwelding tendencies of the contacting partners it is necessary to modify their surface materials; the solid to solid collisions themselves are difficult to avoid. The use of titanium carbide coated steel balls can bring spectacular improvements in the performances and lifetimes of both oil-grease lubricated and oil-grease free bearings in a series of severe applications.

  15. Designing hollow nano gold golf balls.

    Science.gov (United States)

    Landon, Preston B; Mo, Alexander H; Zhang, Chen; Emerson, Chris D; Printz, Adam D; Gomez, Alan F; DeLaTorre, Christopher J; Colburn, David A M; Anzenberg, Paula; Eliceiri, Matthew; O'Connell, Connor; Lal, Ratnesh

    2014-07-09

    Hollow/porous nanoparticles, including nanocarriers, nanoshells, and mesoporous materials have applications in catalysis, photonics, biosensing, and delivery of theranostic agents. Using a hierarchical template synthesis scheme, we have synthesized a nanocarrier mimicking a golf ball, consisting of (i) solid silica core with a pitted gold surface and (ii) a hollow/porous gold shell without silica. The template consisted of 100 nm polystyrene beads attached to a larger silica core. Selective gold plating of the core followed by removal of the polystyrene beads produced a golf ball-like nanostructure with 100 nm pits. Dissolution of the silica core produced a hollow/porous golf ball-like nanostructure.

  16. Impact of milling, enzyme addition, and steam explosion on the solid waste biomethanation of an olive oil production plant.

    Science.gov (United States)

    Donoso-Bravo, Andres; Ortega-Martinez, E; Ruiz-Filippi, G

    2016-02-01

    Anaerobic digestion is a consolidated bioprocess which can be further enhanced by incorporating an upstream pretreatment unit. The olive oil production produces a large amount of solid waste which needs to be properly managed and disposed. Three different pretreatment techniques were evaluated in regard to their impact on the anaerobic biodegradability: manual milling of olive pomace (OP), enzyme maceration, direct enzyme addition, and thermal hydrolysis of two-phase olive mill waste. The Gompertz equation was used to obtain parameters for comparison purposes. A substrate/inoculum ratio 0.5 was found to be the best to be used in anaerobic batch test with olive pomace as substrate. Mechanical pretreatment of OP by milling increases the methane production rate while keeping the maximum methane yield. The enzymatic pretreatment showed different results depending on the chosen pretreatment strategies. After the enzymatic maceration pretreatment, a methane production of 274 ml CH4 g VS added (-1) was achieved, which represents an improvement of 32 and 71 % compared to the blank and control, respectively. The direct enzyme addition pretreatment showed no improvement in both the rate and the maximum methane production. Steam explosion showed no improvement on the anaerobic degradability of two-phase olive mill waste; however, thermal hydrolysis with no rapid depressurization enhanced notoriously both the maximum rate (50 %) and methane yield (70 %).

  17. Synthesis of niobium carbide (NbC) by powder metallurgy high energy milling technique

    Energy Technology Data Exchange (ETDEWEB)

    Antonello, Rodrigo Tecchio; Urtiga Filho, Severino Leopoldino, E-mail: rodrigoantonello@yahoo.com.br, E-mail: urtiga@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Engenharia Mecanica; Araujo Filho, Oscar Olimpio de; Ambrozio Filho, Francisco; Gonzalez, Cezar Henrique, E-mail: oscaroaf98@hotmail.com, E-mail: gonzalez@ufpe.br, E-mail: ambrozio@fei.edu.br [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais

    2009-07-01

    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)

  18. A study of high-energy milling for the production of sintered PrFeB magnets

    Directory of Open Access Journals (Sweden)

    Elio Alberto Périgo

    2007-09-01

    Full Text Available Sintered Pr16Fe76B8 magnets have been produced using the hydrogen decrepitation (HD process and high-energy planetary ball milling. Investigations have been carried out to evaluate the influence of the milling speed and time. The best magnetic properties obtained were Br = (1020 ± 20 mT, µ0iHc = (1420 ± 30 mT and (BHmax/= (200 ± 4 kJm-3, for a magnet prepared with the alloy milled at 200 rpm for 4.5 ks. Magnets prepared from this powder exhibited a superior intrinsic coercivity compared to that of magnets produced using low-energy ball milling. However, the remanence and energy product of the latter were somewhat lower. An important feature was the dramatic reduction in the processing time (about 90%. Microstructural observation have shown that increasing the milling time and keeping constant the rotational mill speed caused an exponential grain size reduction in the sintered magnet. Increasing the milling speed also reduced the grain size and influenced both remanence and intrinsic coercivity.

  19. MgH2-K2Ti6O13-Ni球磨复合体系的微观结构与解氢性能%Microstructures and Dehydrogenation Properties of Ball-milled MgH2-K2 Ti6 O13-Ni Composite Systems

    Institute of Scientific and Technical Information of China (English)

    张健; 汤旺; 邵磊; 余小峰; 龙春光; 陈荐

    2016-01-01

    The K2 Ti6 O13 whisker separate‐doped and K2 Ti6 O13 whisker and Ni powder multi‐doped MgH2 hydrogen storage composite systems were prepared by mechanical milling method .The micro‐structures and dehydrogenation properties of the prepared samples were characterized by some testing methods such as X‐ray diffraction (XRD) ,scanning electron microscope (SEM ) and differential scan‐ning calorimeter (DSC) .The results show that the K2 Ti6O13 whisker not only plays the roles in refi‐ning the MgH2 crystalline grain ,but also inhibit the agglomeration of MgH2 particles in K2 Ti6 O13 whisker separate‐doped system ,which results in the decreased dehydrogenation temperature of MgH2 matrix .When the mass ratio of K2 Ti6 O13 to MgH2 is 3∶7 ,the improvement effect on dehydrogena‐tion properties of MgH2 is the most remarkable .As compared with pure ball‐milled MgH2 ,the dehy‐drogenation temperature of MgH2 in K2 Ti6 O13 whisker separate‐doped system is decreased by nearly 75℃ .For K2Ti6O13 whisker and Ni powder multi‐dopedsystem ,the dehydrogenation temperature of MgH2 matrix is further decreased compared to K2 Ti6O13 whisker separate‐doped one due to the dual effects of refined MgH2 crystalline grain by K2 Ti6 O13 whisker and destabilized MgH2 lattice by Ni so‐lution .As compared with pure ball‐milled MgH2 , the dehydrogenation temperature of MgH2 in K2 Ti6 O13 whisker and Ni powder multi‐doped system is decreased by nearly 87℃ .%采用机械球磨法制备了K2 Ti6 O13晶须单独掺杂、以及K2 Ti6 O13晶须与Ni粉复合掺杂的MgH2储氢复合体系,并通过XRD ,SEM ,DSC等检测手段对其微观结构与解氢性能进行表征。结果表明:当K2 Ti6 O13晶须单独掺杂于MgH2时,K2Ti6O13晶须起到助磨细化MgH2晶粒的作用,同时还抑制了MgH2颗粒的团聚,有效降低了MgH2基体的解氢温度,且当K2Ti6O13与MgH2质量配比为3∶7时,MgH2解氢性能的改善效果尤为明显

  20. DEVELOPMENT OF TECHNOLOGY FOR ANODE BALL PRODUCTION

    Directory of Open Access Journals (Sweden)

    G. V. Kozhevnikova

    2015-01-01

    Full Text Available Technology of copper anode balls manufacturing by means of cross-wedge rolling method is developed. The technology satisfies the requirements towards anode balls’ crystalline structure, form and geometrical dimensions accuracy.

  1. Static Load Distribution in Ball Bearings

    Science.gov (United States)

    Ricci, Mario

    2010-01-01

    A numerical procedure for computing the internal loading distribution in statically loaded, single-row, angular-contact ball bearings when subjected to a known combined radial and thrust load is presented. The combined radial and thrust load must be applied in order to avoid tilting between inner and outer rings. The numerical procedure requires the iterative solution of Z + 2 simultaneous nonlinear equations - where Z is the number of the balls - to yield an exact solution for axial and radial deflections, and contact angles. Numerical results for a 218 angular-contact ball bearing have been compared with those from the literature and show significant differences in the magnitudes of the ball loads, contact angles, and the extent of the loading zone.

  2. Hyperbolic monotonicity in the Hilbert ball

    Directory of Open Access Journals (Sweden)

    Reich Simeon

    2006-01-01

    Full Text Available We first characterize -monotone mappings on the Hilbert ball by using their resolvents and then study the asymptotic behavior of compositions and convex combinations of these resolvents.

  3. Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

    Science.gov (United States)

    Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

    2013-09-01

    We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025).

  4. Investigation on the Surface Coating of Grinding Balls

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The surface coating of grinding balls was investigated experimentally. The results show that a coating may form on the surface of grinding balls when Cr or Al powders are subjected to ball grinding. The plastic deformation of the ball surface plays an important role during the coating formation, and the strong binding force between the powders and the balls is a necessary pre-condition. The thickness of coating increases with the plasticity of the powders and the balls. Annealing the balls with coating will result in an obvious diffusion of the elements in the bonding zone of inter-face.

  5. Aerodynamic drag of modern soccer balls

    OpenAIRE

    Asai, Takeshi; SEO, KAZUYA

    2013-01-01

    Soccer balls such as the Adidas Roteiro that have been used in soccer tournaments thus far had 32 pentagonal and hexagonal panels. Recently, the Adidas Teamgeist II and Adidas Jabulani, respectively having 14 and 8 panels, have been used at tournaments; the aerodynamic characteristics of these balls have not yet been verified. Now, the Adidas Tango 12, having 32 panels, has been developed for use at tournaments; therefore, it is necessary to understand its aerodynamic characteristics. Through...

  6. Q-balls with scalar charges

    CERN Document Server

    Rubakov, V

    2010-01-01

    We consider Friedberg-Lee-Sirlin Q-balls in a (3+1)-dimensional model with vanishing scalar potential of one of the fields. The Q-ball is stabilized by the gradient energy of this field and carries scalar charge, over and beyond the global charge. The latter property is inherent also in a model with the scalar potential that does not vanish in some finite field region near the origin.

  7. Process parameter dependent growth phenomena of naproxen nanosuspension manufactured by wet media milling.

    Science.gov (United States)

    Bitterlich, A; Laabs, C; Krautstrunk, I; Dengler, M; Juhnke, M; Grandeury, A; Bunjes, H; Kwade, A

    2015-05-01

    The production of nanosuspensions has proved to be an effective method for overcoming bioavailability challenges of poorly water soluble drugs. Wet milling in stirred media mills and planetary ball mills has become an established top-down-method for producing such drug nanosuspensions. The quality of the resulting nanosuspension is determined by the stability against agglomeration on the one hand, and the process parameters of the mill on the other hand. In order to understand the occurring dependencies, a detailed screening study, not only on adequate stabilizers, but also on their optimum concentration was carried out for the active pharmaceutical ingredient (API) naproxen in a planetary ball mill. The type and concentration of the stabilizer had a pronounced influence on the minimum particle size obtained. With the best formulation the influence of the relevant process parameters on product quality was investigated to determine the grinding limit of naproxen. Besides the well known phenomenon of particle agglomeration, actual naproxen crystal growth and morphology alterations occurred during the process which has not been observed before. It was shown that, by adjusting the process parameters, those effects could be reduced or eliminated. Thus, besides real grinding and agglomeration a process parameter dependent ripening of the naproxen particles was identified to be a concurrent effect during the naproxen fine grinding process.

  8. 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.

  9. The MillSOT-A Spiral Orbit Tribometer on a Milling Machine

    Science.gov (United States)

    Pepper, Stephen V.

    2014-01-01

    A spiral orbit tribometer (SOT) intended to characterize friction and wear phenomena has been constructed on a milling machine. The instrument, essentially a retainerless thrust bearing with one ball and flat races, is exceedingly simple and inexpensive to construct. The capabilities of the tribometer to measure both the coefficient of friction and contact electrical resistance are demonstrated with clean specimens as well as with well known lubricants such as molybdenum disulphide and Krytox oil. Operation in a purged environment of inert gas is also demonstrated. The results with these lubricants are quite close to what is obtained by other methods. Suggestions for extending the capabilities of the tribometer are given. This arrangement may find use in university mechanical engineering laboratories to introduce and study rolling contact motion as well as for research in contact mechanics and tribology.

  10. 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...

  11. Structural and magnetic properties of Fe{sub 60}Al{sub 40} alloys prepared by means of a magnetic mill

    Energy Technology Data Exchange (ETDEWEB)

    Bernal-Correa, R. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Rosales-Rivera, A., E-mail: arosalesr@unal.edu.c [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Pineda-Gomez, P. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Universidad de Caldas, Manizales (Colombia); Salazar, N.A. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia)

    2010-04-16

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

  12. IMPROVING ENERGY EFFICIENCY VIA OPTIMIZED CHARGE MOTION AND SLURRY FLOW IN PLANT SCALE SAG MILLS

    Energy Technology Data Exchange (ETDEWEB)

    Raj K. Rajamani; Sanjeeva Latchireddi; Sravan K. Prathy; Trilokyanath Patra

    2005-12-01

    The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. 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, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling

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

    Science.gov (United States)

    Ribas, D.; Cernik, M.; Martí, V.; Benito, J. A.

    2016-07-01

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

  14. Preparation and investigation of Al–4 wt% B4C nanocomposite powders using mechanical milling

    Indian Academy of Sciences (India)

    A Alizadeh; E Taheri-Nassaj; H R Baharvandi

    2011-08-01

    Boron carbide nanoparticles were produced using commercially available boron carbide powder (0.8 m).Mechanical milling was used to synthesize Al nanostructured powder in a planetary ball-mill under argon atmosphere up to 20 h. The same process was applied for Al–4 wt% B4C nanocomposite powders to explore the role of nanosize reinforcements on mechanical milling stages. Scanning electron microscopy (SEM) analysis as well as apparent density measurements were used to optimize the milling time needed for completion of the mechanical milling process. The results show that the addition of boron carbide particles accelerate the milling process, leading to a faster work hardening rate and fracture of aluminum matrix. FE-SEM images show that distribution of boron carbide particles in aluminum matrix reaches a full homogeneity when steady state takes place. The better distribution of reinforcement throughout the matrix would increase hardness of the powder. To study the compressibility of milled powder, modified heckel equation was used to consider the pressure effect on yield strength as well as reinforcing role of B4C particles. For better distribution of reinforcement throughout the matrix, , modified heckel equation was used to consider the pressure effect on yield strength as well as reinforcing role of B4C particles.

  15. Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

    NARCIS (Netherlands)

    Postma, Dees B. W.; den Otter, A. Rob; Zaal, Frank T. J. M.

    2014-01-01

    When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its init

  16. Effect of a ball skill intervention on children's ball skills and cognitive functions

    NARCIS (Netherlands)

    Westendorp-Haverdings, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

    2014-01-01

    Purpose: This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning

  17. Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-05-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers' movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key pointsPlayers have shorter initial move time when they are facing the ball machine.Using the ball machine results in different swing timing and movement coordination.The use of the ball machine should be limited.

  18. Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

    Science.gov (United States)

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-01-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key points Players have shorter initial move time when they are facing the ball machine. Using the ball machine results in different swing timing and movement coordination. The use of the ball machine should be limited. PMID:24790483

  19. Catalytic effect of nanoparticle 3d-transition metals on hydrogen storage properties in magnesium hydride MgH2 prepared by mechanical milling.

    Science.gov (United States)

    Hanada, Nobuko; Ichikawa, Takayuki; Fujii, Hironobu

    2005-04-21

    We examined the catalytic effect of nanoparticle 3d-transition metals on hydrogen desorption (HD) properties of MgH(2) prepared by mechanical ball milling method. All the MgH(2) composites prepared by adding a small amount of nanoparticle Fe(nano), Co(nano), Ni(nano), and Cu(nano) metals and by ball milling for 2 h showed much better HD properties than the pure ball-milled MgH(2) itself. In particular, the 2 mol % Ni(nano)-doped MgH(2) composite prepared by soft milling for a short milling time of 15 min under a slow milling revolution speed of 200 rpm shows the most superior hydrogen storage properties: A large amount of hydrogen ( approximately 6.5 wt %) is desorbed in the temperature range from 150 to 250 degrees C at a heating rate of 5 degrees C/min under He gas flow with no partial pressure of hydrogen. The EDX micrographs corresponding to Mg and Ni elemental profiles indicated that nanoparticle Ni metals as catalyst homogeneously dispersed on the surface of MgH(2). In addition, it was confirmed that the product revealed good reversible hydriding/dehydriding cycles even at 150 degrees C. The hydrogen desorption kinetics of catalyzed and noncatalyzed MgH(2) could be understood by a modified first-order reaction model, in which the surface condition was taken into account.

  20. Silicon ball grid array chip carrier

    Science.gov (United States)

    Palmer, David W.; Gassman, Richard A.; Chu, Dahwey

    2000-01-01

    A ball-grid-array integrated circuit (IC) chip carrier formed from a silicon substrate is disclosed. The silicon ball-grid-array chip carrier is of particular use with ICs having peripheral bond pads which can be reconfigured to a ball-grid-array. The use of a semiconductor substrate such as silicon for forming the ball-grid-array chip carrier allows the chip carrier to be fabricated on an IC process line with, at least in part, standard IC processes. Additionally, the silicon chip carrier can include components such as transistors, resistors, capacitors, inductors and sensors to form a "smart" chip carrier which can provide added functionality and testability to one or more ICs mounted on the chip carrier. Types of functionality that can be provided on the "smart" chip carrier include boundary-scan cells, built-in test structures, signal conditioning circuitry, power conditioning circuitry, and a reconfiguration capability. The "smart" chip carrier can also be used to form specialized or application-specific ICs (ASICs) from conventional ICs. Types of sensors that can be included on the silicon ball-grid-array chip carrier include temperature sensors, pressure sensors, stress sensors, inertia or acceleration sensors, and/or chemical sensors. These sensors can be fabricated by IC processes and can include microelectromechanical (MEM) devices.