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

NASA Astrophysics Data System (ADS)

El-Eskandarany, M. Sherif

2017-05-01

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

A new approach for remediation of As-contaminated soil: ball mill-based technique.

PubMed

Shin, Yeon-Jun; Park, Sang-Min; Yoo, Jong-Chan; Jeon, Chil-Sung; Lee, Seung-Woo; Baek, Kitae

2016-02-01

In this study, a physical ball mill process instead of chemical extraction using toxic chemical agents was applied to remove arsenic (As) from contaminated soil. A statistical analysis was carried out to establish the optimal conditions for ball mill processing. As a result of the statistical analysis, approximately 70% of As was removed from the soil at the following conditions: 5 min, 1.0 cm, 10 rpm, and 5% of operating time, media size, rotational velocity, and soil loading conditions, respectively. A significant amount of As remained in the grinded fine soil after ball mill processing while more than 90% of soil has the original properties to be reused or recycled. As a result, the ball mill process could remove the metals bound strongly to the surface of soil by the surface grinding, which could be applied as a pretreatment before application of chemical extraction to reduce the load.

Microstructural Evolution of Dy2O3-TiO2 Powder Mixtures during Ball Milling and Post-Milled Annealing

PubMed Central

Huang, Jinhua; Ran, Guang; Lin, Jianxin; Shen, Qiang; Lei, Penghui; Wang, Xina; Li, Ning

2016-01-01

The microstructural evolution of Dy2O3-TiO2 powder mixtures during ball milling and post-milled annealing was investigated using XRD, SEM, TEM, and DSC. At high ball-milling rotation speeds, the mixtures were fined, homogenized, nanocrystallized, and later completely amorphized, and the transformation of Dy2O3 from the cubic to the monoclinic crystal structure was observed. The amorphous transformation resulted from monoclinic Dy2O3, not from cubic Dy2O3. However, at low ball-milling rotation speeds, the mixtures were only fined and homogenized. An intermediate phase with a similar crystal structure to that of cubic Dy2TiO5 was detected in the amorphous mixtures annealed from 800 to 1000 °C, which was a metastable phase that transformed to orthorhombic Dy2TiO5 when the annealing temperature was above 1050 °C. However, at the same annealing temperatures, pyrochlore Dy2Ti2O7 initially formed and subsequently reacted with the remaining Dy2O3 to form orthorhombic Dy2TiO5 in the homogenous mixtures. The evolutionary mechanism of powder mixtures during ball milling and subsequent annealing was analyzed. PMID:28772375

The study on dynamic properties of monolithic ball end mills with various slenderness

NASA Astrophysics Data System (ADS)

Wojciechowski, Szymon; Tabaszewski, Maciej; Krolczyk, Grzegorz M.; Maruda, Radosław W.

2017-10-01

The reliable determination of modal mass, damping and stiffness coefficient (modal parameters) for the particular machine-toolholder-tool system is essential for the accurate estimation of vibrations, stability and thus the machined surface finish formed during the milling process. Therefore, this paper focuses on the analysis of ball end mill's dynamical properties. The tools investigated during this study are monolithic ball end mills with different slenderness values, made of coated cemented carbide. These kinds of tools are very often applied during the precise milling of curvilinear surfaces. The research program included the impulse test carried out for the investigated tools clamped in the hydraulic toolholder. The obtained modal parameters were further applied in the developed tool's instantaneous deflection model, in order to estimate the tool's working part vibrations during precise milling. The application of the proposed dynamics model involved also the determination of instantaneous cutting forces on the basis of the mechanistic approach. The research revealed that ball end mill's slenderness can be considered as an important milling dynamics and machined surface quality indicator.

Matrix model of the grinding process of cement clinker in the ball mill

NASA Astrophysics Data System (ADS)

Sharapov, Rashid R.

2018-02-01

In the article attention is paid to improving the efficiency of production of fine powders, in particular Portland cement clinker. The questions of Portland cement clinker grinding in closed circuit ball mills. Noted that the main task of modeling the grinding process is predicting the granulometric composition of the finished product taking into account constructive and technological parameters used ball mill and separator. It is shown that the most complete and informative characterization of the grinding process in a ball mill is a grinding matrix taking into account the transformation of grain composition inside the mill drum. Shows how the relative mass fraction of the particles of crushed material, get to corresponding fraction. Noted, that the actual task of reconstruction of the matrix of grinding on the experimental data obtained in the real operating installations. On the basis of experimental data obtained on industrial installations, using matrix method to determine the kinetics of the grinding process in closed circuit ball mills. The calculation method of the conversion of the grain composition of the crushed material along the mill drum developed. Taking into account the proposed approach can be optimized processing methods to improve the manufacturing process of Portland cement clinker.

Effect of heat treatment and ball milling on MnBi magnetic materials

NASA Astrophysics Data System (ADS)

Li, Chunhong; Guo, Donglin; Shao, Bin; Li, Kejian; Li, Bingbing; Chen, Dengming

2018-01-01

MnBi alloy was prepared using arc melting, and was then heated at various temperatures and times. The alloy was ball milled for various lengths of time, following a heat treatment at 573 K for 20 h. The effects of the heat treatment and the ball milling on the magnetic performances of the material were investigated by analyzing the phases, the particle sizes, and the grain sizes. Results showed that the mass percentage of the LTP MnBi phase increased as the heat treatment time increased. The mass percentage initially increased and then decreased as the heat treatment temperature increased. The saturation magnetization increased quickly as the mass percentage of the LTP MnBi increased following the heat treatment. The value rose as high as 71.39 emu g-1 at 573 K for 30 h. The magnetization decreased, due to the decomposition of MnBi phases after ball milling. The coercivity increased simultaneously, due to the grain refinement, the presence of stresses, defects, and an amorphous phase. This value was improved from 0.09 to 14.65 KOe after ball milling for 24 h.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Wei; Polikarpov, Evgueni; Choi, Jung-Pyung

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,more » 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« less

Preparation of Si nano-crystals with controlled oxidation state from SiO disproportionated by ZrO2 ball-milling

NASA Astrophysics Data System (ADS)

Okamoto, Yuji; Harada, Yoshitomo; Ohta, Narumi; Takada, Kazunori; Sumiya, Masatomo

2016-09-01

We demonstrate that a SiO disproportionation reaction can be achieved simply by high energy mechanochemical milling. The planetary ball-milling of ZrO2 for a few minutes generated Si nano-crystals. Milling conditions including rotation speed, ball number, milling time, and type of ball material were able to control the oxidation states of Si. The ball-milled SiO powder was tested as an anode of a lithium battery. ZrO2 contamination from the vial and balls was eliminated by dipping the ball-milled SiO powder in (NH4)HSO4 molten salt and heating for 5 min. The disproportionated SiO powder showed characteristics comparable to those of a powder prepared by a conventional heating process taking several hours.

Ball milling: An experimental support to the energy transfer evaluated by the collision model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Magini, M.; Iasonna, A.; Padella, F.

1996-01-01

In recent years several attempts have been made in order to understand the fundamentals of the ball milling process. The aim of these approaches is to establish predictive capabilities for this process, i.e. the possibility of obtaining a given product by suitable choosing the proper milling conditions. Maurice and Courtney have modeled ball milling in a planetary and in a vibratory mill including parameters like impact times, areas of the colliding surfaces (derived from hertzian collision theory), powder strain rates and pressure peak during collision. Burgio et al derived the kinematic equations of a ball moving on a planetary millmore » and the consequent ball-to-powder energy transfer occurring in a single collision event. The fraction of input energy transferred to the powder was subsequently estimated by an analysis of the collision event. Finally an energy map was constructed which was the basis for a model with predictive capabilities. The aim of the present article is to show that the arguments used to construct the model of the milling process has substantial experimental support.« less

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

PubMed

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

2013-10-14

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

Effect of ball-milling to the surface morphology of CaCO3

NASA Astrophysics Data System (ADS)

Sulimai, N. H.; Rani, Rozina Abdul; Khusaimi, Z.; Abdullah, S.; Salifairus, M. J.; Alrokayan, Salman; Khan, Haseeb; Rusop, M.

2018-05-01

Calcium Carbonate can be synthesized in many approaches. This work studied on the physical changes to Calcium Carbonate (CaCO3) by ball-milling activity in different parameters; number of ball; collision duration; revolution per minute (RPM). Zirconia balls were used in the work because it has the best durability to withstand ball-milling conditions set. Industrial grade CaCO3 particles that were run in aforementioned parameters were characterized by Field Emission Scanning Electron Microscope (FE-SEM) to study the physical changes on the size and surface of the CaCO3. They were also characterized with Fourier Transform Infra-red Spectroscopy (FTIR) were fingerprint of CaCO3 regions were identified and any changes in the band position and intensity were discussed. Number of Zirconia balls and collision duration is directly proportional to the absorbance intensity whereas it is inversely proportional for the rpm. The best number of parameters producing the highest Absorbance is 100 Zirconia balls in duration of 1 hour and 100rpm.

Ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling

NASA Astrophysics Data System (ADS)

Bangi, Uzma K. H.; Park, Hyung-Ho; Han, Wooje; Prakshale, Vipul M.; Deshmukh, Lalasaheb P.

2017-05-01

The experimental results on the ultrasonically assisted synthesis of lead oxide nanoflowers using ball milling have been reported in the present work. Lead oxide nanoflowers were prepared employing mixed ligands by subjecting the formed precipitate to ultrasonication and grinding/ball milling. The effect of ball milling as well as fine grinding in agate mortar on the microstructure and surface morphology of the lead oxide was studied. The characteristics of synthesized PbO were studied using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and field emission scanning electron microscopy techniques. XRD results demonstrated the tetragonal phase of PbO with crystallite size of around 25 nm and strain of 3.6 × 10-3 calculated from Williamson-Hall plot. FESEM images manifested the formation of nanodiscs and nanoflowers with a diameter of around 300 nm and thickness of 50 nm. XPS spectra revealed the formation of PbO with photoelectron peak of Pb 4f and O 1 s lied at 137.68 and 529.96 eV. Moreover, FTIR spectrum exhibited Pb-O bond peak in the range of 400-530 cm-1.

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

NASA Astrophysics Data System (ADS)

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

2018-04-01

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

A co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals from ball-milled woods

Treesearch

Lanxing Du; Jinwu Wang; Yang Zhang; Chusheng Qi; Michael P. Wolcott; Zhiming Yu

2017-01-01

This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80 min or 120 min (BMW80, BMW120) and then enzymatically hydrolyzed. 78.3% cellulose conversion of...

Comparison of characteristics of hydroxyapatite powders synthesized from cuttlefish bone via precipitation and ball milling techniques

NASA Astrophysics Data System (ADS)

Faksawat, K.; Kaewwiset, W.; Limsuwan, P.; Naemchanthara, K.

2017-09-01

The aim of this work was to compare characteristics of hydroxyapatite synthesized by precipitation and ball milling techniques. The cuttlefish bone powder was a precursor in calcium source and the di ammonium hydrogen orthophosphate powders was a precursor in phosphate source. The hydroxyapatite was synthesized by the both techniques such as precipitation and ball milling techniques. The phase formation, chemical structure and morphology of the both hydroxyapatite powders have been examined by X-ray diffractometer (XRD), Fourier transform infrared spectroscope (FTIR) and field emission scanning electron microscope (FESEM), respectively. The results show that the hydroxyapatite synthesized by precipitation technique formed hydroxyapatite phase slower than the hydroxyapatite synthesized by ball milling technique. The FTIR results show the chemical structures of sample in both techniques are similar. The morphology of the hydroxyapatite from the both techniques were sphere like shapes and particle size was about in nano scale. The average particle size of the hydroxyapatite by ball milling technique was less than those synthesized by precipitation technique. This experiment indicated that the ball milling technique take time less than the precipitation technique in hydroxyapatite synthesis.

Magnetic properties of ball-milled SrFe12O19 particles consolidated by Spark-Plasma Sintering

PubMed Central

Stingaciu, Marian; Topole, Martin; McGuiness, Paul; Christensen, Mogens

2015-01-01

The room-temperature magnetic properties of ball-milled strontium hexaferrite particles consolidated by spark-plasma sintering are strongly influenced by the milling time. Scanning electron microscopy revealed the ball-milled SrFe12O19 particles to have sizes varying over several hundred nanometers. X-Ray powder-diffraction studies performed on the ball-milled particles before sintering clearly demonstrate the occurrence of a pronounced amorphization process. During sintering at 950 oC, re-crystallization takes place, even for short sintering times of only 2 minutes and transformation of the amorphous phase into a secondary phase is unavoidable. The concentration of this secondary phase increases with increasing ball-milling time. The remanence and maximum magnetization values at 1T are weakly influenced, while the coercivity drops dramatically from 2340 Oe to 1100 Oe for the consolidated sample containing the largest amount of secondary phase. PMID:26369360

Parametric evaluation of ball milling of SiC in water

NASA Technical Reports Server (NTRS)

Kiser, J. D.; Herbell, T. P.; Freedman, M. R.

1985-01-01

A statistically designed experiment was conducted to determine optimum conditions for ball milling alpha-SiC in water. The influence of pH adjustment, volume percent solids loading, and mill rotational speed on grinding effectiveness was examined. An equation defining the effect of those milling variables on specific surface area was obtained. The volume percent solids loading of the slurry had the greatest influence on the grinding effectiveness in terms of increase in specific surface area. As grinding effectiveness improved, mill and media wear also increased. Contamination was minimized by use of sintered alpha-SiC milling hardware.

Analyses of factors affecting nickel ferrite nanoparticles synthesis in ultrasound-assisted aqueous solution ball milling.

PubMed

Yuan, Zhuang; Chen, Zhen-hua; Chen, Ding; Kang, Zhi-tao

2015-01-01

Ball milling experiments were conducted with and without ultrasound wave assistance in deionized water using NiCO3·2Ni(OH)2·4H2O as raw materials. In the reaction process of NiFe2O4 prepared by ultrasound-assisted aqueous solution ball milling, some influencing factors including raw materials, ultrasonic frequency, ball to powder ratio and liquid level were changed. Samples were characterized by X-ray diffraction, fluorescence measurements and electroconductivity detections. The results indicate that more hydroxyl radicals and ions can be generated under the coupling effect of ultrasonic and ball milling. The fluorescence measurements and electroconductivity detections also reflect the reaction speed, allowing for optimal parameters to be determined. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed

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

2018-01-23

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

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

PubMed

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.

Effects of ball milling on the physicochemical and sorptive properties of biochar: Experimental observations and governing mechanisms.

PubMed

Lyu, Honghong; Gao, Bin; He, Feng; Zimmerman, Andrew R; Ding, Cheng; Huang, Hua; Tang, Jingchun

2018-02-01

With the goal of combining the advantages of ball-milling and biochar technologies, a variety of ball-milled biochars (BM-biochars) were synthesized, characterized, and tested for nickel (Ni(II)) removal from aqueous solution. Ball milling increased only the external surface area of low temperature biochars, but still dramatically enhanced their ability to sorb aqueous Ni(II). For higher temperature biochars with relatively low surface area, ball milling increased both external and internal surface area. Measurements of pH, zeta potential, stability, and Boehm titration demonstrated that ball milling also added oxygen-containing functional groups (e.g., carboxyl, lactonic, and hydroxyl) to biochar's surface. With these changed, all the BM-biochars showed much better Ni(II) removal efficiency than unmilled biochars. Ball-milled 600 °C bagasse biochar (BMBG600) showed the greatest Ni(II) adsorption capacity (230-650 compared to 26-110 mmol/kg for unmilled biochar) and the adsorption was dosage and pH dependent. Compared with the unmilled biochar, BMBG600 also displayed faster adsorption kinetics, likely due to an increase in rates of intra-particle diffusion in the latter. Experimental and modeling results suggest that the increase in BM-biochar's external and internal surface areas exposed its graphitic structure, thus enhancing Ni(II) adsorption via strong cation-π interaction. In addition, the increase in acidic surface functional groups enhanced Ni(II) adsorption by BM-biochar via electrostatic interaction and surface complexation. Ball milling thus has great potential to increase the efficiency of environmentally friendly biochar for various environmental applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Ball Mill Treatment on the Physicochemical Properties and Digestibility of Protein Extracts Generated from Scallops (Chlamys farreri)

PubMed Central

Wu, Di; Wu, Chao; Chen, Hui; Wang, Zhenyu; Yu, Cuiping; Du, Ming

2018-01-01

The effects of ball mill treatment (0, 2, 4, 6, 8, and 10 min) on the physicochemical and digestible properties of scallops (Chlamys farreri) protein (CFP) were investigated. The CFP particle size decreased with increasing ball-milling time. The content of free sulfhydryl (SH) of CFP increased from 13.08 ± 0.25 μmol/g protein to 18.85 ± 0.24 μmol/g protein when the ball-milling time increased from 0 min to 10 min. A sharp increase of the surface hydrophobicity index (H0) from 48.53 ± 0.27 to 239.59 ± 0.37 was found when the ball-milling time increased from 0 min to 4 min. Furthermore, the foaming capacity increased from 46.08 ± 6.12% to 65.11 ± 1.05% with increasing ball-milling time from 0 min to 6 min, after which it reached a plateau. SDS-PAGE results showed that ball mill treatment did not change the primary structure of CFP. Digestible properties of BMCFP simulated gastrointestinal digestion as a function of ball mill treatment were analyzed by Tricine-SDS-PAGE and nitrogen recovery index. After 60 min of simulated human gastro digestion, nitrogen recovery index of CFP had a significant rise from 42.01 ± 0.31% to 58.78 ± 3.37% as the ball-milling time increased from 0 min to 6 min. Peptides from hydrolysates of Chlamys farreri protein (CFP) were identified by ultraperformance liquidchromatographysystem coupled to a Synapt Mass Quadrupole Time-of-Flight Mass Spectrometer (UPLC-Q-TOF-MS). After 2 h and 4 h of simulated human duodenal digestion, the number of peptides with 7–10 amino acids length increased apparently with the ball-milling time increased. This study presents an approach to investigating the effect of the ball-milling process on the physicochemical and digestible properties of CFP, which may provide valuable information on the application of CFP as an ingredient in food products. PMID:29425186

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

PubMed

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

2017-10-26

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

Characterization of ball-milled carbon nanotube dispersed aluminum mixed powders

NASA Astrophysics Data System (ADS)

Maleque, M. A.; Abdullah, U.; Yaacob, I.; Ali, Y.

2016-04-01

Currently, carbon nanotube (CNT) is attracting much interest as fibrous materials for reinforcing aluminum matrix composites due to unique properties, such as high strength, elastic modulus, flexibility and high aspect ratios. However, the quality of the dispersion is the major concerning factor which determines the homogeneity of the enhanced mechanical and tribological properties of the composite. This work study and characterized carbon nanotube dispersion in ballmilled CNT-aluminum mixed powders with four different formulations such as 1, 1.5, 2 and 2.5 wt% CNT under high energy planetary ball milling operations. The ball milling was performed for two hours at constant milling speed of 250 rpm under controlled atmosphere. The characterization is performed using FESEM and EDX analyzer for mapping, elemental and line analysis. The experimental results showed homogeneous dispersion of CNTs in aluminum matrix. The composite mixture showed similar pattern from mapping, elemental and line analysis. Identification of only two peaks proved that controlled atmosphere during milling prevented the formation of inter metallic compounds such as aluminum carbide in the composite mixture. Therefore, this CNT-A1 composite powder mixture can be used for new nano-composite development without any agglomeration problem.

Synthesis and characterization of magnetite-maghemite nanoparticles obtained by the high-energy ball milling method

NASA Astrophysics Data System (ADS)

Velásquez, A. A.; Marín, C. C.; Urquijo, J. P.

2018-03-01

We present the process of synthesis and characterization of magnetite-maghemite nanoparticles by the ball milling method. The particles were synthesized in a planetary ball mill equipped with vials and balls of tempered steel, employing dry and wet conditions. For dry milling, we employed microstructured analytical-grade hematite (α-Fe2O3), while for wet milling, we mixed hematite and deionized water. Milling products were characterized by X-ray diffraction, transmission electron microscopy, room temperature Mössbauer spectroscopy, vibrating sample magnetometry, and atomic absorption spectroscopy. The Mössbauer spectrum of the dry milling product was well fitted with two sextets of hematite, while the spectrum of the wet milling product was well fitted with three sextets of spinel phase. X-ray measurements confirmed the phases identified by Mössbauer spectroscopy in both milling conditions and a reduction in the crystallinity of the dry milling product. TEM measurements showed that the products of dry milling for 100 h and wet milling for 24 h consist of aggregates of nanoparticles distributed in size, with mean particle size of 10 and 15 nm, respectively. Magnetization measurements of the wet milling product showed little coercivity and a saturation magnetization around 69 emu g-1, characteristic of a nano-spinel system. Atomic absorption measurements showed that the chromium contamination in the wet milling product is approximately two orders of magnitude greater than that found in the dry milling product for 24 h, indicating that the material of the milling bodies, liberated more widely in wet conditions, plays an important role in the conversion hematite-spinel phase.

Laboratory-produced ball lightning

NASA Astrophysics Data System (ADS)

Golka, Robert K., Jr.

1994-05-01

For 25 years I have actively been searching for the true nature of ball lightning and attempting to reproduce it at will in the laboratory. As one might expect, many unidentified lights in the atmosphere have been called ball lightning, including Texas Maffa lights (automobile headlights), flying saucers (UFOs), swamp gas in Ann Arbor, Michigan, etc. For 15 years I thought ball lightning was strictly a high-voltage phenomenon. It was not until 1984 when I was short-circuiting the electrical output of a diesel electric railroad locomotive that I realized that the phenomenon was related more to a high current. Although I am hoping for some other types of ball lightning to emerge such as strictly electrostatic-electromagnetic manifestations, I have been unlucky in finding laboratory provable evidence. Cavity-formed plasmodes can be made by putting a 2-inch burning candle in a home kitchen microwave oven. The plasmodes float around for as long as the microwave energy is present.

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

NASA Astrophysics Data System (ADS)

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.

Synthesis of nanostructured vanadium powder by high-energy ball milling: X-ray diffraction and high-resolution electron microscopy characterization

NASA Astrophysics Data System (ADS)

Krishnan, Vinoadh Kumar; Sinnaeruvadi, Kumaran

2016-10-01

Vanadium metal powders, ball milled with different surfactants viz., stearic acid, KCl and NaCl, have been studied by X-ray diffraction and transmission electron microscopy. The surfactants alter the microstructural and morphological characteristics of the powders. Ball milling with stearic acid results in solid-state amorphization, while powders milled with KCl yield vanadium-tungsten carbide nanocomposite mixtures. NaCl proved to be an excellent surfactant for obtaining nanostructured fusion-grade vanadium powders. In order to understand the reaction mechanism behind any interstitial addition in the ball-milled powders, CHNOS analysis was performed.

Atomic scale study of ball milled Ni-Fe{sub 2}O{sub 3} using Mössbauer spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Ravi Kumar; Govindaraj, R., E-mail: govind@igcar.gov.in; Vinod, K.

Evolution of hyperfine fields at Fe atoms has been studied in a detailed manner in a mixture of Ni and α-Fe{sub 2}O{sub 3} subjected to high energy ball milling using Mossbauer spectroscopy. Mossbauer results indicate the dispersion of α-Fe{sub 2}O{sub 3} particles in Ni matrix in the as ball milled condition. Evolution of α-Fe{sub 2}O{sub 3} 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.

Synthesis of Cu-W nanocomposite by high-energy ball milling.

PubMed

Venugopal, T; Rao, K Prasad; Murty, B S

2007-07-01

The Cu-W bulk nanocomposites of different compositions were successfully synthesized by high-energy ball milling of elemental powders. The nanocrystalline nature of the Cu-W composite powder is confirmed by X-ray diffraction analysis, transmission electron microscopy, and atomic force microscopy. The Cu-W nanocomposite powder could be sintered at 300-400 degrees C below the sintering temperature of the un-milled Cu-W powders. The Cu-W nanocomposites showed superior densification and hardness than that of un-milled Cu-W composites. The nanocomposites also have three times higher hardness to resistivity ratio in comparison to Oxygen free high conductivity copper.

Structural and Kinetic Hydrogen Sorption Properties of Zr0.8Ti0.2Co Alloy Prepared by Ball Milling

PubMed Central

He, Hui; Tang, Tao; Huang, Zhiyong; Sang, Ge; Zhang, Guanghui; Ba, Jingwen; Liu, Meng

2018-01-01

The effects of ball milling on the hydrogen sorption kinetics and microstructure of Zr0.8Ti0.2Co have been systematically studied. Kinetic measurements show that the hydrogenation rate and amount of Zr0.8Ti0.2Co decrease with increasing the ball milling time. However, the dehydrogenation rate accelerates as the ball milling time increases. Meanwhile, the disproportionation of Zr0.8Ti0.2Co speeds up after ball milling and the disproportionation kinetics is clearly inclined to be linear with time at 500°C. It is found from X-ray powder diffraction (XRD) results that the lattice parameter of Zr0.8Ti0.2Co gradually decreases from 3.164 Å to 3.153 Å when the ball milling time extends from 0 h to 8 h, which is mainly responsible for the hydrogen absorption/desorption behaviors. In addition, scanning electron microscope (SEM) images demonstrate that the morphology of Zr0.8Ti0.2Co has obviously changed after ball milling, which is closely related to the hydrogen absorption kinetics. Besides, high-resolution transmission electron microscopy (HRTEM) images show that a large number of disordered microstructures including amorphous regions and defects exist after ball milling, which also play an important role in hydrogen sorption performances. This work will provide some insights into the principles of how to further improve the hydrogen sorption kinetics and disproportionation property of Zr0.8Ti0.2Co. PMID:29721128

Effect of ball milling on structures and properties of dispersed-type dental amalgam.

PubMed

Chern Lin, Jiin-Huey; Chen, Fred Ying-Yi; Chiang, Hui-Ju; Ju, Chien-Ping

2011-04-01

The purpose of the present study was to investigate the effect of ball milling on the initial mercury vapor release rate and mechanical properties such as compressive strength, diametral tensile strength and creep value, of the dispersed-type dental amalgam, and comparison was made with respect to two commercial amalgam alloys. Ball milling was employed to modify the configuration of the originally spherical-shaped Ag-Cu-Pd dispersant alloy particles. Improvement in mechanical properties while maintaining a low early-stage mercury vapor release rate of the amalgam is attempted. The experimental results show that the amalgam (AmB10) which was made from Ag-Cu-Pd dispersant alloy particles that were ball-milled for 10 min and heat-treated at 300 °C for 2 days exhibited a low initial mercury vapor release rate of 69 pg/mm(2)/s, which was comparable with that of commercial amalgam alloy Tytin (68 pg/mm(2)/s), and was lower than that of Dispersalloy (73 pg/mm(2)/s). As for mechanical properties, amalgam AmB10 exhibited the highest 1h compressive strength (228 MPa), which was higher than that of commercial amalgam alloy Dispersalloy by 72%; while its 24h diametral tensile strength was also the highest (177 MPa), and was higher than that of Dispersalloy by 55%. Furthermore, the creep value of the amalgams made from Ag-Cu-Pd alloy particles with 10 min ball-milling and heat treatment at 300 °C for 2 days was measured to be 0.12%, which was about 20% that of Dispersalloy. It is found that ball milling of the dispersant Ag-Cu-Pd alloy particles for 10 min was able to modify the configuration of the alloy particles into irregular-shapes. Subsequently, heat treatment at 300 °C significantly lowered the initial mercury vapor release rate, increased its 1h compressive strength and 1h diametral tensile strength, and lowered its creep value. Copyright © 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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.

Magnetoresistivity and microstructure of YBa2Cu3Oy prepared using planetary ball milling

NASA Astrophysics Data System (ADS)

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.

The Effect of High Energy Ball Milling on the Dynamic Response of Aluminum Powders

NASA Astrophysics Data System (ADS)

Beason, Matthew T.; Justice, Andrew W.; Gunduz, Ibrahim E.; Son, Steven F.

2017-06-01

Ball milling is an effective method to enhance the reactivity of intermetallic reactives by reducing characteristic diffusions distances. During this process, ductile reactants are mixed into a lamellar material with nanoscale features, resulting in significant strain hardening. Plate impact experiments using a single stage light gas gun have been performed to evaluate the effect of high energy ball milling (HEBM) on the mechanical properties and dynamic response of cold pressed aluminum compacts. The average grain size of the milled material is evaluate and suggested as a method of correlating the measured response to the properties of milled composites. This material is based upon work supported by the Department of Energy, National Nuclear Security Administration, under Award Number(s) DE-NA0002377, as well as individual funding (Beason) by the Department of Defense through the NDSEG.

Effect of ball-milling surfactants on the interface chemistry in hot-compacted SmCo5 magnets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, WF; Sepehri-Amin, H; Zheng, LY

2012-11-01

Anisotropic SmCo5 nanoflakes prepared by high-energy ball-milling with surfactants have great potential in applications for high-performance nanocomposite magnets. For such "nanocomposite" applications, the surface structure and chemistry of nanoflakes are crucial for achieving high coercivity. In this study, hot-pressed samples from anisotropic SmCo5 nanoflakes, ball-milled with different surfactants, oleic acid (OA) and oleylamine (OY), were investigated. Interface layers between the SmCo5 nanoflakes were found to consist of samarium oxides and a soft magnetic Co phase. These surface layers contribute to the degradation of hard magnetic performance, which is confirmed by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy analysis of themore » cross-section of a single flake ball-milled with OA. Samples milled with OY show a much thinner interface layer in compacted samples, which means that the surface degradation during ball-milling with OY is much less than that with OA. The results show clearly that the choice of proper surfactant and the control of processing parameters are the key factors for improving the surface condition of the nanoflakes and the resulting hard magnetic properties. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.« less

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

NASA Astrophysics Data System (ADS)

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

2018-04-01

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

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

PubMed Central

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

2017-01-01

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

Study of Initial Stages of Ball-Milling of Cu Powder Using X-ray Diffraction

NASA Astrophysics Data System (ADS)

Gayathri, N.; Mukherjee, Paramita

2018-04-01

The initial stage of size refinement of Cu powder is studied using detailed X-ray diffraction (XRD) analysis to understand the mechanism of formation of nanomaterials during the ball-milling process. The study was restricted to samples obtained for milling time up to 240 min to understand the deformation mechanism at the early stages of ball milling. Various model based approaches for the analysis of the XRD were used to study the evolution of the microstructural parameters such as domain size and microstrain along the different crystallographic planes. It was seen that the domain size saturates at a low value along the (311) plane whereas the size along the (220) and (200) plane is still higher. The r.m.s microstrain showed a non-monotonic change along the different crystallographic directions up to the milling time of 240 min.

6. FF coal pulverizer (ball mill inside). GG building in ...

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

6. FF coal pulverizer (ball mill inside). GG building in background did preliminary crushing; pulverizer to left, coal conveyor and air cleaning towers to right; conveyor on left brought crushed coal to FF. Looking north/northeast - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

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

NASA Astrophysics Data System (ADS)

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.

Effect of ball milling on the physicochemical properties of atorvastatin calcium sesquihydrate: the dissolution kinetic behaviours of milled amorphous solids.

PubMed

Kobayashi, Makiko; Hattori, Yusuke; Sasaki, Tetsuo; Otsuka, Makoto

2017-01-01

The purposes of this study were to clarify the amorphization by ball milling of atorvastatin calcium sesquihydrate (AT) and to analyse the change in dissolution kinetics. The amorphous AT was prepared from crystal AT by ball milling and analysed in terms of the changes of its physicochemical properties by powder X-ray diffraction analysis (XRD), thermal analysis and infrared spectroscopy (IR). Moreover, to evaluate the usefulness of the amorphous form for pharmaceutical development, intrinsic solubility of the ground product was evaluated using a dissolution kinetic method. The XRD results indicated that crystalline AT was transformed into amorphous solids by more than 30-min milling. The thermal analysis result suggested that chemical potential of the ground AT are changed significantly by milling. The IR spectra of the AT showed the band shift from the amide group at 3406 cm -1 with an intermolecular hydrogen bond to a free amide group at 3365 cm -1 by milling. The dissolution of amorphous AT follows a dissolution kinetic model involving phase transformation. The initial dissolution rate of the ground product increased with the increase in milling time to reflect the increase in the intrinsic solubility based on the amorphous state. © 2016 Royal Pharmaceutical Society.

Influence of ball milling on the particle size and antimicrobial properties of Tridax procumbens leaf nanoparticles.

PubMed

Karthik, Subramani; Suriyaprabha, Rangaraj; Balu, Kolathupalayam Shanmugam; Manivasakan, Palanisamy; Rajendran, Venkatachalam

2017-02-01

The herbal nanoparticles were prepared from shade dried Tridax procumbens plant leaves employing ball milling technique using different process parameters, like ball ratio/size and milling time. The obtained nanoparticles were comprehensively characterised using X-ray diffraction, Fourier transform infrared spectroscopy, UV-visible spectroscopy, dynamic light scattering, scanning electron microscopy and antimicrobial analysis techniques. The crystallinity of the nanoparticles was retained without altering even though the particle size changes due to milling periods. The antibacterial activities of the prepared herbal nanoparticles against Staphylococcus aureus and Escherichia coli were explored to understand the influence of particle size on antimicrobial activities and their functional properties. The increase in ball ratio and milling time periods leads to a decrease in nanoparticle size from 114 to 45 nm which in turn increases the antimicrobial activities. The above study confirms that antimicrobial activity relies on nanoparticle size. The observed knowledge on influence of particle size on antimicrobial activities will help to optimise the production of potential herbal nanoparticles for different biomedical applications.

ZnO nanoparticles obtained by ball milling technique: Structural, micro-structure, optical and photo-catalytic properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balamurugan, S., E-mail: scandium.chemistry@gmail.com; Joy, Josny; Godwin, M. Anto

The ZnO nanoparticles were obtained by ball milling of commercial grade ZnO powder at 250 rpm for 20 h and studied their structural, micro-structure, optical and photo-catalytic properties. Due to ball milling significant decrease in lattice parameters and average crystalline size is noticed for the as-milled ZnO nano powder. The HRSEM images of the as-milled powder consist of agglomerated fine spherical nanoparticles in the range of ~10-20 nm. The room temperature PL spectrum of as-milled ZnO nano powder excited under 320 nm reveals two emission bands at ~406 nm (violet emission) and ~639 nm (green emission). Interestingly about 98 % of photo degradation of methylene (MB)more » by the ZnO catalyst is achieved at 100 minutes of solar light irradiation.« less

The Effect of Powder Ball Milling on the Microstructure and Mechanical Properties of Sintered Fe-Cr-Mo-Mn-(Cu) Steel

NASA Astrophysics Data System (ADS)

Kulecki, P.; Lichańska, E.

2017-12-01

The effect of ball milling powder mixtures of Höganäs pre-alloyed iron Astaloy CrM, low-carbon ferromanganese Elkem, elemental electrolytic Cu and C-UF graphite on the sintered structure and mechanical properties was evaluated. The mixing was conducted using Turbula mixer for 30 minutes and CDI-EM60 frequency inverter for 1 and 2 hours. Milling was performed on 150 g mixtures with (in weight %) CrM + 1% Mn, CrM + 2% Mn, CrM + 1% Mn + 1% Cu and CrM + 2% Mn + 1% Cu, all with 0.6%C. The green compacts were single pressed at 660 MPa according to PN-EN ISO 2740. Sintering was carried out in a laboratory horizontal furnace Carbolite STF 15/450 at 1250°C for 60 minutes in 5%H2 - 95%N2 atmosphere with a heating rate of 75°C/min, followed by sintering hardening at 60°C/min cooling rate. All the steels were characterized by martensitic structures. Mechanical testing revealed that steels based on milled powders have slightly higher mechanical properties compared to those only mixed and sintered. The best combination of mechanical properties, for ball milled CrM + 1% Mn + 1% Cu was UTS 1046 MPa, TRS 1336 MPa and A 1.94%.

Synthesis of Nano-Size AlN Powders by Carbothermal Reduction from Plasma-Assisted Ball Milling Precursor

NASA Astrophysics Data System (ADS)

Liu, Zhijie; Wang, Wenchun; Yang, Dezheng; Wang, Sen; Dai, Leyang

2016-07-01

Nano-size aluminum nitride (AlN) powders have been successfully synthesized with a high efficiency method through annealing from milling assisted by discharge plasma (p-milling) alumina (Al2O3) precursors. The characterization of the p-milling Al2O3 powders and the synthesized AlN are investigated. Compared to conventional ball milling (c-milling), it can be found that the precursors by p-milling have a finer grain size with a higher specific surface area, which lead to a faster reaction efficiency and higher conversion to AlN at lower temperatures. The activation energy of p-milling Al2O3 is found to be 371.5 kJ/mol, a value that is much less than the reported value of the unmilled and the conventional milled Al2O3. Meanwhile, the synthesized AlN powders have unique features, such as an irregular lamp-like morphology with uniform particle distribution and fine average particle size. The results are attributed to the unique synergistic effect of p-milling, which is the effect of deformation, fracture, and cold welding of Al2O3 powders resulting from ball milling, that will be enhanced due to the introduction of discharge plasma. supported by National Natural Science Foundation of China (No. 51177008)

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

NASA Astrophysics Data System (ADS)

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.

Study of the preparation of Cu-TiC composites by reaction of soluble Ti and ball-milled carbon coating TiC

NASA Astrophysics Data System (ADS)

Xu, Xuexia; Li, Wenbin; Wang, Yong; Dong, Guozhen; Jing, Shangqian; Wang, Qing; Feng, Yanting; Fan, Xiaoliang; Ding, Haimin

2018-06-01

In this work, Cu-TiC composites have been successfully prepared by reaction of soluble Ti and carbon coating TiC. Firstly, the ball milling of graphite and TiC mixtures is used to obtain the carbon coating TiC which has fine size and improved reaction activity. After adding the ball milled carbon coating TiC into Cu-Ti melts, the soluble Ti will easily react with the carbon coating to form TiC. This process will also improve the wettability between Cu melts and TiC core. As a result, besides the TiC prepared by reaction of soluble Ti and carbon coating, the ball milled TiC will also be brought into the melts. Some of these ball-milled TiC particles will go on being coated by the formed TiC from the reaction of Ti and the coating carbon and left behind in the composites. However, most of TiC core will be further reacted with the excessive Ti and be transformed into the newly formed TiC with different stoichiometry. The results indicate that it is a feasible method to synthesize TiC in Cu melts by reaction of soluble Ti and ball-milled carbon coating TiC.

An environmentally friendly ball milling process for recovery of valuable metals from e-waste scraps.

PubMed

Zhang, Zhi-Yuan; Zhang, Fu-Shen; Yao, TianQi

2017-10-01

The present study reports a mechanochemical (MC) process for effective recovery of copper (Cu) and precious metals (i.e. Pd and Ag) from e-waste scraps. Results indicated that the mixture of K 2 S 2 O 8 and NaCl (abbreviated as K 2 S 2 O 8 /NaCl hereafter) was the most effective co-milling reagents in terms of high recovery rate. After co-milling with K 2 S 2 O 8 /NaCl, soluble metallic compounds were produced and consequently benefit the subsequent leaching process. 99.9% of Cu and 95.5% of Pd in the e-waste particles could be recovered in 0.5mol/L diluted HCl in 15min. Ag was concentrated in the leaching residue as AgCl and then recovered in 1mol/L NH 3 solution. XRD and XPS analysis indicated that elemental metals in the raw materials were transformed into their corresponding oxidation state during ball milling process at low temperature, implying that solid-solid phase reactions is the reaction mechanism. Based on the results and thermodynamic parameters of the probable reactions, possible reaction pathways during ball milling were proposed. Suggestion on category of e-waste for ball milling process was put forward according to the experiment results. The designed metal recovery process of this study has the advantages of highly recovery rate and quick leaching speed. Thus, this study offers a promising and environmentally friendly method for recovering valuable metals from e-waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of ball milling on atomic structure and magnetic properties of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} glassy alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taghvaei, Amir Hossein, E-mail: Amirtaghvaei@gmail.com; Department of Materials Science and Engineering, Shiraz University of Technology, Shiraz; Stoica, Mihai

2014-06-01

The influence of ball milling on the atomic structure and magnetic properties of the Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} metallic glass with a high thermal stability and excellent soft magnetic properties has been investigated. After 14 h of milling, the obtained powders were found to consist mainly of an amorphous phase and a small fraction of the (Co,Fe){sub 21}Ta{sub 2}B{sub 6} nanocrystals. The changes in the reduced pair correlation functions suggest noticeable changes in the atomic structure of the amorphous upon ball milling. Furthermore, it has been shown that milling is accompanied by introduction of compressive and dilatational sites inmore » the glassy phase and increasing the fluctuation of the atomic-level hydrostatic stress without affecting the coordination number of the nearest neighbors. Ball milling has decreased the thermal stability and significantly affected the magnetic properties through increasing the saturation magnetization, Curie temperature of the amorphous phase and coercivity. - Highlights: • Ball milling affected the atomic structure of Co{sub 40}Fe{sub 22}Ta{sub 8}B{sub 30} metallic glass. • Mechanically-induced crystallization started after 4 h milling. • Milling increased the fluctuation of the atomic-level hydrostatic stress in glass. • Ball milling influenced the thermal stability and magnetic properties.« less

Ball mill tool for crushing coffee and cocoa beans base on fraction size sieving results

NASA Astrophysics Data System (ADS)

Haryanto, B.; Sirait, M.; Azalea, M.; Alvin; Cahyani, S. E.

2018-02-01

Crushing is one of the operation units that aimed to convert the size of solid material to be smoother particle’s size. The operation unit that can be used in this crushing is ball mill. The purpose of this study is to foresee the effect of raw material mass, grinding time, and the number of balls that are used in the ball mill tool related to the amount of raw material of coffee and cocoa beans. Solid material that has become smooth is then sieved with sieve mesh with size number: 50, 70, 100, and 140. It is in order to obtain the mass fraction that escaped from each sieve mesh. From the experiment, it can be concluded that mass percentage fraction of coffee powder is bigger than cocoa powder that escaped from the mesh. Hardness and humidity of coffee beans and cocoa beans have been the important factors that made coffee beans is easier to be crushed than cocoa beans.

Study of morphology and magnetic properties of the HoNi{sub 3} crystalline and ball-milled compound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bajorek, Anna, E-mail: anna.bajorek@us.edu.pl; Silesian Center for Education and Interdisciplinary Research, University of Silesia, 75 Pułku Piechoty 1A, 41-500 Chorzów; Skornia, Paweł

2015-03-15

The morphology and magnetic properties of the HoNi{sub 3} crystalline and ball-milled intermetallic compounds are presented. The polycrystalline HoNi{sub 3} bulk compound crystallizes in the rhombohedral PuNi{sub 3} — type of crystal structure and indicates ferrimagnetic arrangement with the Curie temperature of T{sub C} = 57 ± 2 K, the helimagnetic temperature T{sub h} = 23 ± 2 K with the total saturation magnetic moment of 6.84 μ{sub B}/f.u. at 2 K. The use of the ball-milling method leads to the formation of HoNi{sub 3} nanoflakes with typical thickness of less than 100 nm prone to agglomeration upon milling. Themore » increase of grinding duration leads to the reduction in crystallite size, which was confirmed by various complementary microscopical and diffraction studies. Moreover, the increase in milling duration results in the emergence of the relatively small coercivity (H{sub C}), remanence (M{sub r}) and a variation of the saturation magnetization (M{sub S}). - Graphical abstract: Display Omitted - Highlights: • The ball-milling method exhibits significant potential for producing RT{sub 3} nanopowders. • The AFM method was used for the first time in analysis of R–T nanoflakes morphology. • HoNi{sub 3} compound forms polycrystalline and textured nanoflakes evolving upon milling. • The decrease in crystallite size via grinding is confirmed by XRD, TEM and AFM. • The magnetic parameters were sensitive to the extension of pulverization b.« less

High-resolution neutron diffraction study of microstructural changes in nanocrystalline ball-milled niobium carbide NbC{sub 0.93}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balagurov, Anatoly M.; Bobrikov, Ivan A.; Bokuchava, Gizo D.

2015-11-15

High resolution neutron diffraction was applied for elucidating of the microstructural evolution of nanocrystalline niobium carbide NbC{sub 0.93} powders subjected to high-energy ball milling. The diffraction patterns were collected with the high resolution Fourier diffractometer HRFD by using the reverse time-of-flight (RTOF) mode of data acquisition. The traditional single diffraction line analysis, the Rietveld method and more advanced Whole Powder Pattern Modeling technique were applied for the data analysis. The comparison of these techniques was performed. It is established that short-time milling produces a non-uniform powder, in which two distinct fractions with differing microstructure can be identified. Part of themore » material is in fact milled efficiently, with a reduction in grain size, an increase in the quantity of defects, and a corresponding tendency to decarburize reaching a composition NbC{sub 0.80} after 15 h of milling. The rest of the powder is less efficiently processed and preserves its composition and lower defect content. Larger milling times should have homogenized the system by increasing the efficiently milled fraction, but the material is unable to reach a uniform and homogeneous state. It is definitely shown that RTOF neutron diffraction patterns can provide the very accurate data for microstructure analysis of nanocrystalline powders. - Highlights: • The NbC{sub 0.93} powder was processed by high-energy ball milling. • The microstrain and dislocation density increase with milling time increase. • The corresponding decrease in crystallite size with milling time was observed. • The material exhibits the presence of two fractions after ball milling. • The RTOF neutron diffraction data are suitable for accurate microstructure analysis.« less

Amorphization of the prototypical zeolitic imidazolate framework ZIF-8 by ball-milling.

PubMed

Cao, Shuai; Bennett, Thomas D; Keen, David A; Goodwin, Andrew L; Cheetham, Anthony K

2012-08-14

We report the rapid amorphization of the prototypical substituted zeolitic imidazolate framework, ZIF-8, by ball-milling. The resultant amorphous ZIF-8 (a(m)ZIF-8) possesses a continuous random network (CRN) topology with a higher density and a lower porosity than its crystalline counterpart. A decrease in thermal stability upon amorphization is also evident.

Impact of planetary ball milling parameters on the microstructure and pinning properties of polycrystalline superconductor Y3Ba5Cu8Oy

NASA Astrophysics Data System (ADS)

Slimani, Y.; Hannachi, E.; Azzouz, F. Ben; Salem, M. Ben

2018-06-01

We have reported the influence of planetary high energy ball milling parameters on morphology, microstructure and flux pinning capability of polycrystalline Y3Ba5Cu8Oy. Samples were prepared through the standard solid-state reaction by using two different milling methods, ball milling in a planetary crusher and hand grinding in a mortar. Phase analysis by X-ray diffraction (XRD) method, microstructural examination by scanning electron microscope (SEM), electrical resistivity, the global and intra-granular critical current densities measurements are done to characterize the samples. The processing parameters of the planetary milling have a considerable impact on the final product properties. SEM observations show the presence of nanoscale entities submerged within the Y3Ba5Cu8Oy crystallites. The results show that the fine grain microstructure of the Y3Ba5Cu8Oy bulk induced by ball milling process contributes to critical currents density enhancement in the magnetic field and promotes an optimized flux pinning ability.

On the amorphization behavior and hydrogenation performance of high-energy ball-milled Mg{sub 2}Ni alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2013-06-15

Amorphous Mg{sub 2}Ni alloy was prepared by high energy ball-milling starting with polycrystalline Mg{sub 2}Ni which was prepared with the help of a metallurgy method by using a SPEX 8000D mill. The microstructural and phase structure characterization of the prepared materials was performed via scanning electron microscopy, transition electron microscope and X-ray diffraction. The thermal stabilities were investigated by differential scanning calorimetry. The apparent activation energies were determined by means of the Kissinger method. The first and second crystallization reactions take place at ∼ 255 °C and ∼ 410 °C, and the corresponding activation energy of crystallization is E{sub a1}more » = 276.9 and E{sub a2} = 382.4 kJ/mol, respectively. At 3 MPa hydrogen pressure and 250 °C, the hydrogen absorption capacities of crystalline, partially and fully amorphous Mg{sub 2}Ni alloy are 2.0 wt.%, 3.2 wt.% and 3.5 wt.% within 30 min, respectively. - Graphical Abstract: We mainly focus on the amorphization behavior of crystalline Mg{sub 2}Ni alloy in the high energy ball-milling process and the crystallization behavior of the amorphous Mg{sub 2}Ni alloy in a follow-up heating process. The relationship of milling, microstructure and hydrogenation properties is established and explained by models. - Highlights: • Amorphous Mg{sub 2}Ni has been obtained by high energy ball milling the as-cast alloy. • The amorphization behavior of polycrystalline Mg{sub 2}Ni is presented. • The crystallization behavior of the amorphous Mg{sub 2}Ni alloy is illustrated. • Establish the relationship of milling, microstructure and hydrogenation properties.« less

Long-Term Effects on Graphene Supercapacitors of Using a Zirconia Bowl and Zirconia Balls for Ball-Mill mixing of Active Materials

NASA Astrophysics Data System (ADS)

Song, Dae-Hoon; Kim, Jin-Young; Kahng, Yung Ho; Cho, Hoonsung; Kim, Eung-Sam

2018-04-01

Improving the energy storage performance of supercapacitor electrodes based on reduced graphene oxide (RGO) is one of the main subjects in this research field. However, when a zirconia bowl and zirconia balls were used for ball-mill mixing of the active materials for RGO supercapacitors, the energy storage performance deteriorated over time. Our study revealed that the source of the problem was the inclusion of zirconia bits from abrasion of the bowl and the balls during the ballmill mixing, which increased during a period of 1 year. We probed two solutions to this problem: 1) hydrofluoric (HF) acid treatment of the RGO supercapacitors and 2) use of a tempered steel bowl and tempered steel balls for the mixing. For both cases, the energy storage performance was restored to near the initial level, showing a specific capacitance ( C sp ) of 200 F/g. Our results should lead to progress in research on RGO supercapacitors.

Effects of Processing Parameters on the Synthesis of (K0.5Na0.5)NbO3 Nanopowders by Reactive High-Energy Ball Milling Method

PubMed Central

Duc Van, Nguyen

2014-01-01

The effects of ball milling parameters, namely, the ball-to-powder mass ratio and milling speed, on the synthesis of (K0.5Na0.5)NbO3 nanopowders by high-energy ball milling method from a stoichiometric mixture containing Na2CO3, K2CO3, and Nb2O5 were investigated in this paper. The results indicated that the single crystalline phase of (K0.5Na0.5)NbO3 was received in as-milled samples synthesized using optimized ball-to-powder mass ratio of 35 : 1 and at a milling speed of 600 rpm for 5 h. In the optimized as-milled samples, no remaining alkali carbonates that can provide the volatilizable potassium-containing species were found and (K0.5Na0.5)NbO3 nanopowders were readily obtained via the formation of an intermediate carbonato complex. This complex was mostly transformed into (K0.5Na0.5)NbO3 at temperature as low as 350°C and its existence was no longer detected at spectroscopic level when calcination temperature crossed over 700°C. PMID:24592146

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

PubMed

Nguyen, Duc Van

2014-01-01

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

High-energy ball milling technique for ZnO nanoparticles as antibacterial material

PubMed Central

Salah, Numan; Habib, Sami S; Khan, Zishan H; Memic, Adnan; Azam, Ameer; Alarfaj, Esam; Zahed, Nabeel; Al-Hamedi, Salim

2011-01-01

Nanoparticles of zinc oxide (ZnO) are increasingly recognized for their utility in biological applications. In this study, the high-energy ball milling (HEBM) technique was used to produce nanoparticles of ZnO from its microcrystalline powder. Four samples were ball milled for 2, 10, 20, and 50 hours, respectively. The structural and optical modifications induced in the ‘as synthesized’ nanomaterials were determined by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM), and photoluminescence emission spectra (PL). SEM and TEM results show a gradual decrease in particle size from around 600 to ∼30 nm, with increased milling time. The initial microstructures had random shapes, while the final shape became quite spherical. XRD analysis showed ZnO in a hexagonal structure, broadening in the diffracted peaks and going from larger to smaller particles along with a relaxation in the lattice constant c. The value of c was found to increase from 5.204 to 5.217 Å with a decrease in particle size (600 to ∼30 nm). PL result showed a new band at around 365 nm, whose intensity is found to increase as the particles size decreases. These remarkable structural and optical modifications induced in ZnO nanoparticles might prove useful for various applications. The increase in c value is an important factor for increasing the antibacterial effects of ZnO, suggesting that the HEBM technique is quite suitable for producing these nanoparticles for this purpose. PMID:21720499

Analysis of NO-suppressing activity of Strawberry Wine supplemented with ball-milled achenes.

PubMed

Lee, Pao-Ju; Tsai, Tsung-Yu; Chen, Shaun

2018-04-01

Inflammation is generally thought to be involved in the development of several chronical diseases, therefore, phytochemicals to modulate immune responses has attracted great interests. The objective of the present study was to evaluate the potential anti-inflammatory effects of wine supplemented using ball-milled achene on modulating NO production and inducible nitric oxide synthase (iNOS) expression. Ball-milled achenes were added in strawberry must prior to fermentation, and the wine samples were then concentrated and extracted with water and/or ethanol prior to analysis. Bioactivities of wine extracts were evaluated using the cell viability assay, cell cycle measurements, NO production and iNOS expression in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Treatments of achenes supplemented strawberry wine extract up to 100 μg/mL inhibited the proliferation of LPS-stimulated RAW264.7 cell via affecting the progression of cell cycle. Moreover, no detectable cytotoxicity in RAW264.7 cells was observed. The supplemented wine extract suppressed the action of LPS and led to a decreased NO production in stimulated cells. The inhibitory effect of the wine extract on NO production was determined to be a 25-40% decrease in the level of 25-100 μg/mL, in contrast to a 10% decrease for conventional wine samples. Additionally, an alcoholic wine extract (100 μg/mL) led to a 40.31% decrease in iNOS expression in LPS-stimulated cells, which was more effective than the same dose of tocopherol. The results show that strawberry wine supplemented with ball-milled achenes causes a substantial inhibition of NO production, and this biofunction is exerted via the down-regulation of iNOS expression.

Grinding arrangement for ball nose milling cutters

NASA Technical Reports Server (NTRS)

Burch, C. F. (Inventor)

1974-01-01

A grinding arrangement for spiral fluted ball nose end mills and like tools includes a tool holder for positioning the tool relative to a grinding wheel. The tool is mounted in a spindle within the tool holder for rotation about its centerline and the tool holder is pivotably mounted for angular movement about an axis which intersects that centerline. A follower arm of a cam follower secured to the spindle cooperates with a specially shaped cam to provide rotation of the tool during the angular movement of the tool holder during the grinding cycle, by an amount determined by the cam profile. In this way the surface of the cutting edge in contact with the grinding wheel is maintained at the same height on the grinding wheel throughout the angular movement of the tool holder during the grinding cycle.

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

NASA Astrophysics Data System (ADS)

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

Effect of combination ultrasonic and ball milling techniques of commercial fillers dispersion on mechanical properties of natural rubber (NR) latex films

NASA Astrophysics Data System (ADS)

Hamran, Noramirah; Rashid, Azura A.

2017-07-01

Commercial fillers such as silica and carbon black generally impart the reinforcing effects in dry rubber compound, but have an adverse effect on Natural rubber (NR) latex compounds. The addition of commercial fillers in NR latex has reduced the mechanical properties of NR latex films due to the destabilization effect in the NR latex compounds which govern by the dispersion quality, particle size and also the pH of the dispersion itself. The ball milling process is the conventional meth od of preparation of dispersions and ultrasonic has successfully used in preparation of nano fillers such as carbon nanotube (CNT). In this study the combination between the conventional methods; ball milling together the ultrasonic method were used to prepare the silica and carbon black dispersions. The different duration of ball milling (24, 48 and 72 hours) was compared with the ultrasonic method (30, 60, 90 and 120 minutes). The combination of ball milling and ultrasonic from the optimum individual technique was used to investigate the reduction of particle size of the fillers. The particle size analyzer, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) test were carried out to investigate the obtained particle size and the tensile and tear test were carried out to investigate the mechanical properties of the NR latex films. The reduction of filler particle size is expected to impart the properties of NR latex films.

Synthesis of graphene nanoflakes by grinding natural graphite together with NaCl in a planetary ball mill

NASA Astrophysics Data System (ADS)

Alinejad, Babak; Mahmoodi, Korosh

Natural graphite is a soft material that conventional milling methods fail to grind into nanoparticles. We found that adding NaCl into graphite during milling allows obtaining graphene nanoflakes of about 50×200nm2 as evidenced by Transmission Electron Microscope (TEM). NaCl particles are substantially brittle and harder than graphite, serving as milling agents by both helping to chop graphite into smaller pieces and preventing graphite particles from agglomeration. After milling, NaCl can be easily washed away by water. Probable mechanism for exfoliation of graphene during the modified ball milling may be explained by NaCl and graphene slipping or sliding against and over each other, exfoliating the graphene particles into thin layers.

Kinetic study of ferronickel slag grinding at variation of ball filling and ratio of feed to grinding balls

NASA Astrophysics Data System (ADS)

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.

Mechanochemical destruction of mirex co-ground with iron and quartz in a planetary ball mill.

PubMed

Yu, Yunfei; Huang, Jun; Zhang, Wang; Zhang, Kunlun; Deng, Shubo; Yu, Gang

2013-02-01

Mechanochemical destruction (MCD) has been recognized as a promising non-combustion technology for the disposal of obsolete pesticides belonging to the persistent organic pollutants (POPs). Mirex, a termiticide ever used for many years in China, was ball milled in the presence of various reagent(s) in a planetary ball mill at room temperature to investigate the destruction efficiency. The ground samples were characterized and analyzed by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, gas chromatography (GC), and ion chromatography (Martins, Bicego et al.). Under the same conditions of mill rotary rate and charge ratio, the mixture of iron powder and quartz sand (Fe/SiO(2)) was found best in promoting the mirex destruction. Mirex was completed destroyed after 2 h grinding at a charge ratio of 36:1 (reagent/mirex, m/m) and a mill rotation speed of 550 rpm. No organic compound was detected by GC/μECD screening. The yield of water-soluble chlorine determined by ion chromatography (Martins, Bicego et al.) in the final residue accounted for 90.7% of chlorine in the original mirex, which indicated a nearly complete dechlorination. Signals of both graphite and amorphous carbon were found in the Raman spectra of the co-ground powder samples. With the main final degradation products of water soluble Cl and carbon, the mechanism of the mechanochemical destruction approach should be dechlorination followed by the carbonization. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hydroamination reactions of alkynes with ortho-substituted anilines in ball mills: synthesis of benzannulated N-heterocycles by a cascade reaction.

PubMed

Weiße, Maik; Zille, Markus; Jacob, Katharina; Schmidt, Robert; Stolle, Achim

2015-04-20

It was demonstrated that ortho-substituted anilines are prone to undergo hydroamination reactions with diethyl acetylenedicarboxylate in a planetary ball mill. A sequential coupling of the intermolecular hydroamination reaction with intramolecular ring closure was utilized for the syntheses of benzooxazines, quinoxalines, and benzothiazines from readily available building blocks, that is, electrophilic alkynes and anilines with OH, NH, or SH groups in the ortho position. For the heterocycle formation, it was shown that several stress conditions were able to initiate the reaction in the solid state. Processing in a ball mill seemed to be advantageous over comminution with mortar and pestle with respect to process control. In the latter case, significant postreaction modification occurred during solid-state analysis. Cryogenic milling proved to have an adverse effect on the molecular transformation of the reagents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

Surface hardening of Al alloys through controlled ball-milling and sintering.

PubMed

Kim, Seek Hyeoun; Kim, Yong Jin; Ahn, Jung-Ho

2012-07-01

One of the drawbacks of aluminum and its alloys is the lack of proper heat-treatment for surface-hardening. In the present work, a new and simple method of hardening the surface of aluminum and its alloys was developed. Low-energy ball-milling using specific process control agents (PCAs) was employed, using subsequent sintering in a controlled atmosphere. The PCAs in the present work were very effective both for milling and the formation of hard nanocrystalline dispersoids during sintering. The residual oxygen in a sintering atmosphere also played an important role in the formation of AIN or Al-O-N dispersoids. Through the proper control of the processing atmosphere and PCAs, the hardness and thickness of the hardened layers could be adjusted. The results of the wear test showed that the present aluminum alloys can be effectively utilized as light-weight components with a good wear resistance. Furthermore, the present method involves a simple forming process of die-compaction and sintering.

Generation of drugs coated iron nanoparticles through high energy ball milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radhika Devi, A.; Murty, B. S.; Chelvane, J. A.

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.

High-Energy Ball Milling as Green Process To Vitrify Tadalafil and Improve Bioavailability.

PubMed

Krupa, Anna; Descamps, Marc; Willart, Jean-François; Strach, Beata; Wyska, Elżbieta; Jachowicz, Renata; Danède, Florence

2016-11-07

In this study, the suitability of high-energy ball milling was investigated with the aim to vitrify tadalafil (TD) and improve its bioavailability. To achieve this goal, pure TD as well as binary mixtures composed of the drug and Soluplus (SL) were coprocessed by high-energy ball milling. Modulated differential scanning calorimetry (MDSC) and X-ray powder diffraction (XRD) demonstrated that after such coprocessing, the crystalline form of TD was transformed into an amorphous form. The presence of a single glass transition (T g ) for all the comilled formulations indicated that TD was dispersed into SL at the molecular level, forming amorphous molecular alloys, regardless of the drug concentration. The high values of T g determined for amorphous formulations, ranging from 70 to 147 °C, foreshow their high stability during storage at room temperature, which was verified by XRD and MDSC studies. The stabilizing effect of SL on the amorphous form of TD in comilled formulations was confirmed. Dissolution tests showed immediate drug release with sustained supersaturation in either simulated gastric fluid of pH 1.2 or in phosphate buffer of pH 7.2. The beneficial effect of both amorphization and coamorphization on the bioavailability of TD was found. In comparison to aqueous suspension, the relative bioavailability of TD was only 11% for its crystalline form and 53% for the crystalline physical mixture, whereas the bioavailability of milled amorphous TD and the comilled solid dispersion was 128% and 289%, respectively. Thus, the results provide evidence that not only the presence of polymeric surfactant but also the vitrification of TD is necessary to improve bioavailability.

The effects of ball size distribution on attritor efficiency

NASA Astrophysics Data System (ADS)

Cook, T. M.; Courtney, T. H.

1995-09-01

A study was undertaken to determine how media dynamics are altered when differently sized grinding balls are used in an attritor. Cinematographic techniques identify the extent of segregation/mixing of the differently sized balls within the attritor as a function of impeller rotational velocity and small ball number fraction. This permits determination of rotational velocities needed to most efficiently use the tactic of milling with differently sized media. Cinematographic observations show that the close-packed media array, assumed when balls of the same size are used for milling, is disrupted when differently sized balls are used. Monitoring powder particle numbers as a function of milling time for the situations when the same and differently sized balls are used can be used to assess relative milling efficiencies. Results indicate powder deformation, fracture, and welding are enhanced through employment of differently sized balls. This conclusion is reinforced by observations of microstructural characteristics of powder processed with the different type of media.

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

PubMed

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. Copyright © 2015 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2017-01-01

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 2 hours 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 1 hour. The biochar/Fe3O4 had a maximum adsorption capacity of 62.7 mg/g for CBZ and 94.2 mg/g for TC, while values obtained for AC/Fe3O4 were 135.1 mg/g for CBZ and 45.3 mg/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 3 hours 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 0.3 g 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. PMID:26685062

Structural and Mössbauer characterization of the ball-milled Fex(Al2O3)100-x system

NASA Astrophysics Data System (ADS)

Paesano, A.; Matsuda, C. K.; Cótica, L. F.; de Medeiros, S. N.; da Cunha, J. B. M.; Hallouche, B.; Silva, S. L.

2004-09-01

Metal-oxide composites were synthesized by high-energy ball milling of metallic iron (α-Fe) and alumina (α-Al2O3) powders, varying the starting relative concentration and the milling time. The samples were characterized by scanning electron microscopy, x-ray diffraction, and Mössbauer spectroscopy. The results revealed the formation of a FeAl2O3+W spinel phase (hercynite) and of iron (super)paramagnetic nanoprecipitates, in addition to residual magnetic iron and alumina. We also observed that the relative amounts of nanoprecipitates and hercynite for isochronally milled samples were correlated with the sample nominal concentration x, with the precursor iron being relatively more converted in those phases for low x values. Particularly for x =10 milled sample, the relative amounts of the (super)paramagnetic and spinel phases were observed to increase linearly with the milling time. An x =20/24h milled sample was annealed in H2 atmosphere and revealed the reduction of hercynite, with iron phase separation.

High energy ball milling study of Fe{sub 2}MnSn Heusler alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jain, Vivek Kumar, E-mail: vivek.jain129@gmail.com; Lakshmi, N.; Jain, Vishal

The structural and magnetic properties of as-melted and high energy ball milled alloy samples have been studied by X-ray diffraction, DC magnetization and electronic structure calculations by means of density functional theory. The observed properties are compared to that of the bulk sample. There is a very good enhancement of saturation magnetization and coercivity in the nano-sized samples as compared to bulk which is explained in terms of structural disordering and size effect.

Solvent-free cross-dehydrogenative coupling reactions under high speed ball-milling conditions applied to the synthesis of functionalized tetrahydroisoquinolines.

PubMed

Su, Weike; Yu, Jingbo; Li, Zhenhua; Jiang, Zhijiang

2011-11-04

Solvent-free reaction using a high-speed ball milling technique has been first applied to cross-dehydrogenative coupling (CDC) reactions between tetrahydroisoquinolines and three types of pronucleophiles such as nitroalkanes, alkynes, and indoles. All coupling products were obtained in good yields at short reaction times (no more than 40 min). When alkynes and indoles were used as pronucleophile, the reactions can be catalyzed efficiently by recoverable copper balls without any additional metal catalyst.

Si@SiOx/Graphene nanosheet anode materials for lithium-ion batteries synthesized by ball milling process

NASA Astrophysics Data System (ADS)

Tie, Xiaoyong; Han, Qianyan; Liang, Chunyan; Li, Bo; Zai, Jiantao; Qian, Xuefeng

2017-12-01

Si@SiOx/Graphene nanosheet (GNS) nanocomposites as high performance anode materials for lithium-ion batteries are synthesized by mechanically blending the mixture of expanded graphite with Si nanoparticles, and characterized by X-ray diffraction, Raman spectrum, field emission scanning electron microscopy and transmission electron microscopy. During the ball milling process, the size of Si nanoparticles will decrease, and the layer of expanded graphite can be peeled off to thin multilayers. Electrochemical performances reveal that the obtained Si@SiOx/GNS nanocomposites exhibit improved cycling stability, high reversible lithium storage capacity and superior rate capability, e.g. the discharge capacity is kept as high as 1055 mAh g-1 within 50 cycles at a current density of 200 mA g-1, retaining 63.6% of the initial value. The high performance of the obtained nanocomposites can be ascribed to GNS prepared through heat-treat and ball-milling methods, the decrease in the size of Si nanoparticles and SiOx layer on Si surface, which enhance the interactions between Si and GNS.

Highly active and stable Ni-Fe bimetal prepared by ball milling for catalytic hydrodechlorination of 4-chlorophenol.

PubMed

Xu, Fuyuan; Deng, Shubo; Xu, Jie; Zhang, Wang; Wu, Min; Wang, Bin; Huang, Jun; Yu, Gang

2012-04-17

A novel Ni-Fe bimetal with high dechlorination activity for 4-chlorophenol (4-CP) was prepared by ball milling (BM) in this study. Increasing Ni content and milling time greatly enhanced the dechlorination activity, which was mainly attributed to the homogeneous distribution of Ni nanoparticles (50-100 nm) in bulk Fe visualized by scanning electron microscopy/energy dispersive X-ray spectrometry (SEM/EDS) with image mapping. In comparison with the Ni-Fe bimetal prepared by a chemical solution deposition (CSD) process, the ball milled Ni-Fe bimetal possessed high dechlorination activity and stability before being used up. Dechlorination kinetics indicated that the dechlorination rates of 4-CP increased with increasing Ni-Fe dose but decreased with increasing solution pH. Solution pH had a significant effect on the dechlorination of 4-CP and the passivation of the Ni-Fe bimetal. The enhanced pH during the dechlorination process significantly accelerated the formation of passivating film on the bimetallic surface. The Ni-Fe bimetal at the dose of 60 g/L was reused 10 times without losing dechlorination activity for 4-CP at initial pH less than 6.0, but the gradual passivation was observed at initial pH above 7.0.

13. TROJAN MILL, INTERIOR SHOWING PRIMARY MILL No. 1 (ALLIS ...

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

13. TROJAN MILL, INTERIOR SHOWING PRIMARY MILL No. 1 (ALLIS CHALMERS BALL MILL) FROM EAST, c. 1919. ELECTRIC MOTOR AND DRIVE SHAFT CLEARLY VISIBLE. CREDIT WR. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

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

NASA Astrophysics Data System (ADS)

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.

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

NASA Astrophysics Data System (ADS)

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

2017-06-01

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

High energy ball milling and supercritical carbon dioxide impregnation as co-processing methods to improve dissolution of tadalafil.

PubMed

Krupa, Anna; Descamps, Marc; Willart, Jean-François; Jachowicz, Renata; Danède, Florence

2016-12-01

Tadalafil (TD) is a crystalline drug of a high melting point (T m =299°C) and limited solubility in water (<5μg/mL). These properties may result in reduced and variable bioavailability after oral administration. Since the melting of TD is followed by its decomposition, the drug processing at high temperatures is limited. The aim of the research is, therefore, to improve the dissolution of TD by its co-processing with the hydrophilic polymer Soluplus® (SL) at temperatures below 40°C. In this study, two methods, i.e. high energy ball-milling and supercritical carbon dioxide impregnation (scCO 2 ) are compared, with the aim to predict their suitability for the vitrification of TD. The influence of the amount of SL and the kind of co-processing method on TD thermal properties is analyzed. The results show that only the high energy ball milling process makes it possible to obtain a completely amorphous form of TD, with the characteristic X-ray 'halo' pattern. The intensity of the Bragg peaks diminishes for all the formulations treated with scCO 2 , but these samples remain crystalline. The MDSC results show that high energy ball milling is capable of forcing the mixing of TD and SL at a molecular level, providing a homogeneous amorphous solid solution. The glass transition temperatures (T g ), determined for the co-milled formulations, range from 79°C to 139°C and they are higher than T g of pure SL (ca. 70°C) and lower than T g of pure TD (ca. 149°C). In contrast to the co-milled formulations which are in the form of powder, all the formulations after scCO 2 impregnation form a hard residue, sticking to the reaction vessel, which needs to be ground before analysis or further processing. Finally, the dissolution studies show that not only has SL a beneficial effect on the amount of TD dissolved, but also both co-processing methods make the dissolution enhancement of TD possible. After co-processing by scCO 2 , the amount of TD dissolved increases with the

Microstructure characterization and phase transformation kinetic study of ball-milled m-ZrO 2-30 mol% a-TiO 2 mixture by Rietveld method

NASA Astrophysics Data System (ADS)

Pradhan, S. K.; Dutta, H.

2005-05-01

High-energy ball milling of monoclinic ZrO 2-30 mol% anatase TiO 2 mixture at different durations results in the formation of m-ZrO 2-a-TiO 2 solid solution from which the nucleation of nanocrystalline cubic (c) ZrO 2 polymorphic phase sets in. Post-annealing of 12 h ball-milled sample at different elevated temperatures for 1 h results in almost complete formation of c-ZrO 2 phase. Microstructure of the unmilled, all the ball milled and annealed samples has been characterized by Rietveld's X-ray powder structure refinement method. Particle size, rms lattice strain, change in lattice parameters and phase content of individual phases have been estimated from Rietveld analysis, and are utilized to interpret the results. In course of milling, (1 1 1) of cubic lattice became parallel to ( 1bar 1 1) plane of monoclinic lattice due to the orientation effect and cubic phase may have been formed on the (0 0 1) of the m-ZrO 2-a-TiO 2 solid solution lattice. A comparative study of microstructure and phase transformation kinetics of ZrO 2-10, 20 and 30 mol% a-TiO 2 ball-milled and post-annealed samples reveals that rate of phase transformation m→c-ZrO 2 increases with increasing a-TiO 2 concentration and ∼30 mol% of nanocrystalline c-ZrO 2 phase can be obtained within 4 h of milling time in the presence of 30 mol% of a-TiO 2. The post-annealing treatment at 773, 873 and 973 K for 1 h duration each reveals that rate of c-ZrO 2 formation with increasing temperature is retarded with increasing a-TiO 2 concentration but the amount of c-ZrO 2 becomes almost equal (∼95 mol%) at 973 K. It suggests that almost fully stabilized nanocrystalline c-ZrO 2 can be formed by adding a tetravalent solute to m-ZrO 2.

Influence of Iron Oxide Particles on the Strength of Ball-Milled Iron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lesuer, D R; Syn, C K; Sherby, O D

2005-12-07

Detailed microstructural and mechanical property studies of ball-milled iron, in the powder and consolidated states, are reviewed and assessed. The analyses cover three and one-half orders of magnitude of grain size (from 6 nm to 20 mm) and focus on the influence of oxide particles on the strength. The study includes the early work of Koch and Yang, Kimura and Takaki and continues with the more recent work of Umemoto et al and Belyakov, Sakai et al. It is shown that the major contributors to strength are the nanooxide particles. These particles are created by adiabatic shear banding during ball-millingmore » leading to a bimodal distribution of particles. The predicted strength from particles, {sigma}{sub p}, is given by {sigma}{sub p} = B {center_dot} (D*{sub S}){sup -1/2} where D*{sub S} is the surface-to-surface interparticle spacing, and B = 395 MPa {center_dot} {micro}m{sup -1/2}. A model is proposed that accounts for the influence of the bimodal particle size distribution on strength.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raghavendra, H.; Bhat, K. L.; Udupa, K. Rajendra

2011-01-17

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 deg. C for 60 minutes and given stepped austempering treatment at 280 deg. C for 30 minutes and 60 minutes followed by 380 deg. 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 atmore » 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.« less

Dehydriding properties of Ti or/and Zr-doped sodium aluminum hydride prepared by ball-milling

NASA Astrophysics Data System (ADS)

Xiao, Xue-Zhang; Chen, Li-Xin; Wang, Xin-Hua; Li, Shou-Quan; Hang, Zhou-Ming; Chen, Chang-Pin; Wang, Qi-Dong

2007-12-01

The NaAlH4 complex is attracting great attention for its potential applications in hydrogen-powered fuel-cell vehicles due to its high hydrogen storage capacity and suitable thermodynamic properties. However, its practicable hydrogen storage capacity presently obtained is less than the theoretical capacity (5.6 wt.%). To improve the hydrogen capacity, we chose metallic Ti or/and Zr powder as catalyst dopants, and prepared the sodium aluminum hydride by hydrogenation of ball-milled NaH/Al mixture containing 10 mol% dopants with different proportions of Ti and Zr, and then investigated the effects on their hydrogen storage (dehydriding) properties. The results showed that different catalyst dopants affected the dehydriding properties greatly. The catalysis of metal Ti as a catalyst dopant alone on dehydriding kinetics for the entire dehydrogenation process of ball-milled (NaH/Al) composite was higher than that of adopting Zr alone. The synergistic catalytic effect of Ti and Zr together as co-dopants on the dehydrogenation process of (NaH/Al) composite was higher than that using only Ti or Zr as dopant individually. The composite doped with proper proportion of Ti and Zr together (8 mol% Ti+ 2 mol% Zr) as co-dopants exhibited the highest dehydriding kinetic property and desorption capacity.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

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

PubMed

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

2014-04-25

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

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

PubMed Central

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

2014-01-01

The mass production of highly dense oxides with high-temperature and high-pressure phases allows us to discover functional properties that have never been developed. To date, the quenching of highly dense materials at the gramme-level at ambient atmosphere has never been achieved. Here, we provide evidence of the formation of orthorhombic Fe2TiO4 from trigonal FeTiO3 as a result of the high-temperature (>1250 K) and high-pressure (>23 GPa) condition induced by the high collision energy of 150 gravity generated between steel balls. Ilmenite was steeply quenched by the surrounding atmosphere, when iron-rich ilmenite (Fe2TiO4) with a high-temperature and high-pressure phase was formed by planetary collisions and was released from the collision points between the balls. Our finding allows us to infer that such intense planetary collisions induced by high-energy ball milling contribute to the mass production of a high-temperature and high-pressure phase. PMID:24763088

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

PubMed Central

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

2017-01-01

The impact behavior between the charge and lifter has significant effect to address the mill processing, and is affected by various factors including mill speed, mill filling, lifter height and media shape. To investigate the multi-body impact load behavior, a series of experiments and Discrete Element Method (DEM) simulations were performed on a laboratory-scale mill, in order to improve the grinding efficiency and prolong the life of the lifter. DEM simulation hitherto has been extensively applied as a leading tool to describe diverse issues in granular processes. The research results shown as follows: The semi-empirical power draw of Bond model in this paper does not apply very satisfactorily for the ball mills, while the power draw determined by DEM simulation show a good approximation for the measured power draw. Besides, the impact force on the lifter was affected by mill speed, grinding media filling, lifter height and iron ore particle. The maximum percent of the impact force between 600 and 1400 N is at 70–80% of critical speed. The impact force can be only above 1400 N at the grinding media filling of 20%, and the maximum percent of impact force between 200 and 1400 N is obtained at the grinding media filling of 20%. The percent of impact force ranging from 0 to 200 N decreases with the increase of lifter height. However, this perfect will increase above 200 N. The impact force will decrease when the iron ore particles are added. Additionally, for the 80% of critical speed, the measured power draw has a maximum value. Increasing the grinding media filling increases the power draw and increasing the lifter height does not lead to any variation in power draw. PMID:28773243

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

PubMed

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

2017-07-31

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

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

PubMed Central

El-Eskandarany, M. Sherif; Shaban, Ehab

2015-01-01

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 (∆H) and entropy (∆S) 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 ΔH and ΔS 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. PMID:28793606

Microwave Absorption Properties of Iron Nanoparticles Prepared by Ball-Milling

NASA Astrophysics Data System (ADS)

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.

Dioxins reformation and destruction in secondary copper smelting fly ash under ball milling

PubMed Central

Cagnetta, Giovanni; Hassan, Mohammed Mansour; Huang, Jun; Yu, Gang; Weber, Roland

2016-01-01

Secondary copper recovery is attracting increasing interest because of the growth of copper containing waste including e-waste. The pyrometallurgical treatment in smelters is widely utilized, but it is known to produce waste fluxes containing a number of toxic pollutants due to the large amount of copper involved, which catalyses the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (“dioxins”). Dioxins are generated in secondary copper smelters on fly ash as their major source, resulting in highly contaminated residues. In order to assess the toxicity of this waste, an analysis of dioxin-like compounds was carried out. High levels were detected (79,090 ng TEQ kg−1) in the ash, above the Basel Convention low POPs content (15,000 ng TEQ kg−1) highlighting the hazardousness of this waste. Experimental tests of high energy ball milling with calcium oxide and silica were executed to assess its effectiveness to detoxify such fly ash. Mechanochemical treatment obtained 76% dioxins reduction in 4 h, but longer milling time induced a partial de novo formation of dioxins catalysed by copper. Nevertheless, after 12 h treatment the dioxin content was substantially decreased (85% reduction) and the copper, thanks to the phenomena of incorporation and amorphization that occur during milling, was almost inactivated. PMID:26975802

Dioxins reformation and destruction in secondary copper smelting fly ash under ball milling

NASA Astrophysics Data System (ADS)

Cagnetta, Giovanni; Hassan, Mohammed Mansour; Huang, Jun; Yu, Gang; Weber, Roland

2016-03-01

Secondary copper recovery is attracting increasing interest because of the growth of copper containing waste including e-waste. The pyrometallurgical treatment in smelters is widely utilized, but it is known to produce waste fluxes containing a number of toxic pollutants due to the large amount of copper involved, which catalyses the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (“dioxins”). Dioxins are generated in secondary copper smelters on fly ash as their major source, resulting in highly contaminated residues. In order to assess the toxicity of this waste, an analysis of dioxin-like compounds was carried out. High levels were detected (79,090 ng TEQ kg-1) in the ash, above the Basel Convention low POPs content (15,000 ng TEQ kg-1) highlighting the hazardousness of this waste. Experimental tests of high energy ball milling with calcium oxide and silica were executed to assess its effectiveness to detoxify such fly ash. Mechanochemical treatment obtained 76% dioxins reduction in 4 h, but longer milling time induced a partial de novo formation of dioxins catalysed by copper. Nevertheless, after 12 h treatment the dioxin content was substantially decreased (85% reduction) and the copper, thanks to the phenomena of incorporation and amorphization that occur during milling, was almost inactivated.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Nitrogen-doped graphene catalysts: High energy wet ball milling synthesis and characterizations of functional groups and particle size variation with time and speed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhuang, Shiqiang; Nunna, Bharath Babu; Boscoboinik, Jorge Anibal

Nitrogen-doped graphene (N-G) catalyst emerges as one of the promising non-platinum group metal (non-PGM) catalysts with the advantages of low cost, high oxygen reduction reaction (ORR) activity, stability, and selectivity to replace expensive PGM catalysts in electrochemical systems. This research investigated nanoscale high energy wet (NHEW) ball milling for the synthesis of N-G catalysts to make conventional problems such as sintering or localized overheating issues negligible. The successful synthesis of N-G catalysts with comparable catalytic performance to 10 wt% Pt/C by using this method has been published. This paper focuses on understanding the effect of grinding speed and grinding timemore » on the particle size and chemical state of N-G catalysts through the physical and chemical characterization. The research result shows that (1) the final particle size, nitrogen doping percentage, and nitrogen bonding composition of synthesized N-G catalysts are predictable and controllable by adjusting the grinding time, the grinding speed, and other relative experimental parameters; (2) the final particle size of N-G catalysts could be estimated from the derived relation between the cracking energy density and the particle size of ground material in the NHEW ball milling process with specified experimental parameters; and (3) the chemical composition of N-G catalysts synthesized by NHEW ball milling is controllable by adjusting the grinding time and grinding speed.« less

Nitrogen-doped graphene catalysts: High energy wet ball milling synthesis and characterizations of functional groups and particle size variation with time and speed

DOE PAGES

Zhuang, Shiqiang; Nunna, Bharath Babu; Boscoboinik, Jorge Anibal; ...

2017-07-26

Nitrogen-doped graphene (N-G) catalyst emerges as one of the promising non-platinum group metal (non-PGM) catalysts with the advantages of low cost, high oxygen reduction reaction (ORR) activity, stability, and selectivity to replace expensive PGM catalysts in electrochemical systems. This research investigated nanoscale high energy wet (NHEW) ball milling for the synthesis of N-G catalysts to make conventional problems such as sintering or localized overheating issues negligible. The successful synthesis of N-G catalysts with comparable catalytic performance to 10 wt% Pt/C by using this method has been published. This paper focuses on understanding the effect of grinding speed and grinding timemore » on the particle size and chemical state of N-G catalysts through the physical and chemical characterization. The research result shows that (1) the final particle size, nitrogen doping percentage, and nitrogen bonding composition of synthesized N-G catalysts are predictable and controllable by adjusting the grinding time, the grinding speed, and other relative experimental parameters; (2) the final particle size of N-G catalysts could be estimated from the derived relation between the cracking energy density and the particle size of ground material in the NHEW ball milling process with specified experimental parameters; and (3) the chemical composition of N-G catalysts synthesized by NHEW ball milling is controllable by adjusting the grinding time and grinding speed.« less

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

PubMed

Swain, Basudev; Mishra, Chinmayee; Kang, Leeseung; Park, Kyung-Soo; Lee, Chan Gi; Hong, Hyun Seon

2015-04-01

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 Na2CO3, ball milled followed by annealing, again leached to recover gallium. In the second process, the waste LED industry dust was mixed with Na2CO3, after ball milling and annealing, followed acidic leaching. Without pretreatment, the gallium leaching was only 4.91 w/w % using 4M HCl, 100°C and pulp density of 20g/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. Copyright © 2015 Elsevier Inc. All rights reserved.

Morphological and XPS study of ball milled Fe1-xAlx (0.3≤x≤0.6) alloys

NASA Astrophysics Data System (ADS)

Rajan, Sandeep; Kumar, Anil; Vyas, Anupam; Brajpuriya, Ranjeet

2018-05-01

The paper presents mechanical and XPS study of ball milled Fe1-xAlx (0.3≤x≤0.6) alloys. The author prepared the solid solution of Fe(Al) with different composition of Al by using mechanical alloying (MA) technique. The MA process induces a progressive dissolution of Al into Fe, resulted in the formation of an extended Fe(Al) solid solution with the bcc structure after 5 hr of milling. The SEM Images shows that the initial shape of particles disappeared completely, and their structure became a mixture of small and large angular-shaped crystallites with different sizes. The TEM micrograph also confirms the reduction in crystallite size and alloy formation. XPS study shows the shift in the binding energy position of both Fe and Al Peaks provide strong evidence of Fe(Al) phase formation after milling.

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

PubMed

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.

Structural and phase transformations during ball milling of titanium in medium of liquid hydrocarbons

NASA Astrophysics Data System (ADS)

Dorofeev, G. A.; Lubnin, A. N.; Lad'yanov, V. I.; Mukhgalin, V. V.; Puskkarev, B. E.

2014-02-01

It has been shown using X-ray diffraction, scanning electron microscopy, and chemical analysis that, upon ball milling of α-titanium in liquid organic media (toluene and n-heptane), a nanocrystalline fcc phase is formed that is a metastable carbohydride Ti(C,H) deficient in hydrogen and carbon compared to stable carbohydrides. The dimensions of powder particles after milling in toluene and n-heptane differ substantially (are 5-10 and 20-30 μm, respectively. It has been shown that the kinetics of the formation of Ti(C,H) is independent of the milling medium. The atomic ratios H/C in the products of mechanosynthesis agree well with those corresponding to the employed organic media, i.e., H/C = 1.1 for toluene and 2.3 for n-heptane. A solid-liquid mechanism of mechanosynthesis is suggested, which includes repeated processes of particle fracturing with the formation of fresh surfaces, adsorption of liquid hydrocarbons on these surfaces, and subsequent cold welding of the newly formed particles. It is assumed that the formation of the fcc phase in the process of milling is connected with the generation of stacking faults in α-Ti. Upon annealing at 550°C, the fcc phase decomposes with the formation of stable titanium carbide TiC (annealing in a vacuum) or stable titanium carbohydride and a β-Ti(H) solid solution (annealing in argon) with a partial reverse transformation Ti(C,H) → α-Ti in both cases.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santos, Desireé M. de los, E-mail: desire.delossantos@uca.es; Navas, Javier, E-mail: javier.navas@uca.es; Sánchez-Coronilla, Antonio

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.more » 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.« less

Structural and Mössbauer characterization of the ball milled Fe x(Cr 2O 3) 1- x system

NASA Astrophysics Data System (ADS)

Biondo, Valdecir; de Medeiros, Suzana Nóbrega; Paesano, Andrea, Jr.; Ghivelder, Luis; Hallouche, Bachir; da Cunha, João Batista Marimon

2009-08-01

The Fe x(Cr 2O 3) 1- x system, with 0.10 ≤ X ≤ 0.80, was mechanically processed for 24 h in a high-energy ball-mill. In order to examine the possible formation of iron-chromium oxides and alloys, the milled samples were, later, thermally annealed in inert (argon) and reducing (hydrogen) atmospheres. The as-milled and annealed products were characterized by X-ray diffraction, Mössbauer spectroscopy, transmission electron microscopy and magnetization. The as-milled samples showed the formation of an Fe 1+ YCr 2- YO 4- δ nanostructured and disordered spinel phase, the α 1-Fe(Cr) and α 2-Cr(Fe) solid solutions and the presence of non-exhausted precursors. For the samples annealed in inert atmosphere, the chromite (FeCr 2O 4) formation and the recrystallization of the precursors were verified. The hydrogen treated samples revealed the reduction of the spinel phase, with the phase separation of the chromia phase and retention of the Fe-Cr solid solutions. All the samples, either as-milled or annealed, presented the magnetization versus applied field curves typical for superparamagnetic systems.

Aerodynamic Resistance of a Ball-Tube Mill During Transport of a Polydisperse Coal Gas Suspension

NASA Astrophysics Data System (ADS)

Ivanov, S. D.; Kudryashov, A. N.; Oshchepkov, V. V.

2018-03-01

Analysis of experimental data on aerodynamic resistance of a ball-tube mill is given. It is shown that this resistance has two components brought about by the pressure losses resulting from the injection of dust particles into the main flow after coal grinding and from the transport of homogeneous gas suspension flow. A dimensionless equation has been obtained for the dependence of the pressure loss in flow of a homogeneous dust-air mixture on Reynolds number. Functional dependences of the mean-square velocity of the floating of coal particles and of their average diameter on the polydispersity parameters of coal dust have been found. An empirical dependence of pressure loss due to the injection of a polydisperse coal gas suspension into the main flow on the average velocity of floating of coal particles, their average size, and on the size of the mill has been obtained.

Aerodynamic Resistance of a Ball-Tube Mill During Transport of a Polydisperse Coal Gas Suspension

NASA Astrophysics Data System (ADS)

Ivanov, S. D.; Kudryashov, A. N.; Oshchepkov, V. V.

2018-05-01

Analysis of experimental data on aerodynamic resistance of a ball-tube mill is given. It is shown that this resistance has two components brought about by the pressure losses resulting from the injection of dust particles into the main flow after coal grinding and from the transport of homogeneous gas suspension flow. A dimensionless equation has been obtained for the dependence of the pressure loss in flow of a homogeneous dust-air mixture on Reynolds number. Functional dependences of the mean-square velocity of the floating of coal particles and of their average diameter on the polydispersity parameters of coal dust have been found. An empirical dependence of pressure loss due to the injection of a polydisperse coal gas suspension into the main flow on the average velocity of floating of coal particles, their average size, and on the size of the mill has been obtained.

Synthesis of fcc Mg-Ti-H alloys by high energy ball milling: Structure and electrochemical hydrogen storage properties

NASA Astrophysics Data System (ADS)

Rousselot, Steeve; Guay, Daniel; Roué, Lionel

Mg-Ti-H alloys were synthesized by high energy ball milling from equimolar mixtures of MgH 2 + TiH 2, MgH 2 + Ti and Mg + TiH 2 in the presence of 10 wt.% Pd. X-ray diffraction analyses combined with Rietveld refinement revealed that after 60 h of milling, all as-milled Mg-Ti-H alloys are made of two face-centered-cubic (fcc) phases, with lattice parameters ∼4.47 and ∼4.25 Å, in different proportions depending on the composition of the initial mixture. The Mg-Ti-H alloys displayed a similar electrochemical behavior, i.e. their hydrogen discharge capacity was highest during the first cycle and then decreased rapidly with cycling. The maximum discharge capacities of the 60 h-milled MgH 2 + TiH 2, MgH 2 + Ti and Mg + TiH 2 materials were 300, 443 and 454 mAh g -1, respectively. No apparent correlation could be established between the maximum discharge capacity of the Mg-Ti-H materials and the two fcc phase proportion.

Processing and Characterization of Fe-Mn-Cu-Sn-C Alloys Prepared by Ball Milling and Spark Plasma Sintering

NASA Astrophysics Data System (ADS)

Bączek, Elżbieta; Konstanty, Janusz; Romański, Andrzej; Podsiadło, Marcin; Cyboroń, Jolanta

2018-03-01

In this work, Fe-Mn-Cu-Sn-C alloys were prepared by means of powder metallurgy (PM). Powder mixtures were ball-milled for 8, 30 and 120 h and densified to < 1% porosity using spark plasma sintering (SPS) at 900 °C and 35 MPa. After consolidation, all samples of the Fe alloys were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), hardness and flexural strength tests. Resistance to abrasive wear was evaluated in both three-body abrasion and two-body abrasion tests. The SEM observations revealed an evident dependence of grain size and microstructural homogeneity on milling time. The XRD analysis showed a marked increase in austenite content in the as-sintered specimens with milling time. Although the proportion of deformation-induced martensite was small, the strengthening effect of abrasion on the subsurface layer of the investigated alloys was clearly indicated by Knoop hardness measurements.

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

PubMed

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

2017-01-01

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

Unraveling the synthesis of homoleptic [Ag(N,N-diaryl-NHC)2]Y (Y = BF4, PF6) complexes by ball-milling.

PubMed

Beillard, Audrey; Bantreil, Xavier; Métro, Thomas-Xavier; Martinez, Jean; Lamaty, Frédéric

2016-11-28

A user-friendly and general mechanochemical method was developed to access rarely described NHC (N-heterocyclic carbene) silver(i) complexes featuring N,N-diarylimidazol(idin)ene ligands and non-coordinating tetrafluoroborate or hexafluorophosphate counter anions. Comparison with syntheses in solution clearly demonstrated the superiority of the ball-milling conditions.

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

PubMed

Khataee, Alireza; Fathinia, Siavash; Fathinia, Mehrangiz

2017-01-01

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

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

NASA Astrophysics Data System (ADS)

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.

Sharpening ball-nose mill cutters

NASA Technical Reports Server (NTRS)

Burch, C. F.

1977-01-01

Economical attachment allows faster, more precise grinding. Vibrationless and rigid relation between grinding wheel and cutter allows for extremely high finish and accurate grinding. Leveling device levels flutes with respect to toolholder rotation that generates ball-nose radius. Constant relief around entire profile of cutting edge produces longer tool life.

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

NASA Astrophysics Data System (ADS)

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 %.

Easily recycled Bi2O3 photocatalyst coatings prepared via ball milling followed by calcination

NASA Astrophysics Data System (ADS)

Cheng, Lijun; Hu, Xumin; Hao, Liang

2017-06-01

Bi2O3 photocatalyst coatings derived from Bi coatings were first prepared by a two-step method, namely ball milling followed by the calcination process. The as-prepared samples were characterized by XRD, SEM, XPS and UV-Vis spectra, respectively. The results showed that monoclinic Bi2O3 coatings were obtained after sintering Bi coatings at 673 or 773 K, while monoclinic and triclinic mixed phase Bi2O3 coatings were obtained at 873 or 973 K. The topographies of the samples were observably different, which varied from flower-like, irregular, polygonal to nanosized particles with the increase in calcination temperature. Photodegradation of malachite green under simulated solar irradiation for 180 min showed that the largest degradation efficiency of 86.2% was achieved over Bi2O3 photocatalyst coatings sintered at 873 K. The Bi2O3 photocatalyst coatings, encapsulated with Al2O3 ball with an average diameter around 1 mm, are quite easily recycled, which provides an alternative visible light-driven photocatalyst suitable for practical water treatment application.

Carbon Nanotube-Reinforced Aluminum Matrix Composites Produced by High-Energy Ball Milling

NASA Astrophysics Data System (ADS)

Travessa, Dilermando N.; da Rocha, Geovana V. B.; Cardoso, Kátia R.; Lieblich, Marcela

2017-05-01

Although multiwall carbon nanotubes (MWCNT) are promising materials to strengthen lightweight aluminum matrix composites, their dispersion into the metallic matrix is challenge. In the present work, MWCNT were dispersed into age-hardenable AA6061 aluminum alloy by high-energy ball milling and the blend was subsequently hot-extruded. The composite bars obtained were heat-treated by solution heat treatment at 520 °C and artificially aged at 177 °C for 8 h, in order to reach the T6 temper. Special attention was given to the integrity of the MWCNT along the entire composite production. The microstructure of the obtained bars was evaluated by optical and scanning electron microscopy, and the mechanical properties were evaluated by Vickers microhardness tests. Raman spectroscopy, x-ray diffraction and transmission electron microscopy were employed to evaluate the structural integrity of MWCNT. It was found that milling time is critical to reach a proper dispersion of the reinforcing phase. The composite hardness increased up to 67% with the dispersion of 2% in weight of MWCNT, when comparing with un-reinforced bars produced by similar route. However, age hardening was not observed in composite bars after heat treatment. It was also found that MWCNT continuously degraded along the process, being partially converted into Al4C3 in the final composite.

Contamination risk of stable isotope samples during milling.

PubMed

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

2016-07-15

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

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

NASA Astrophysics Data System (ADS)

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 (<10 layers) graphene nanosheets, but at the same time, enables the N element to be doped onto the graphene. Urea, acting as a 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.

Reactive Ball Milling to Fabricate Nanocrystalline Titanium Nitride Powders and Their Subsequent Consolidation Using SPS

NASA Astrophysics Data System (ADS)

El-Eskandarany, M. Sherif

2017-05-01

The room-temperature reactive ball milling (RBM) approach was employed to synthesize nanostructured fcc-titanium nitride (TiN) powders, starting from milling hcp-titanium (Ti) powders under 10 bar of a nitrogen gas atmosphere, using a roller mill. During the first and intermediate stage of milling, the agglomerated Ti powders were continuously disintegrated into smaller particles with fresh surfaces. Increasing the RBM time led to an increase in the active-fresh surfaces of Ti, resulting increasing of the mole fraction of TiN against unreacted hcp-Ti. Toward the end of the RBM time (20 h), ultrafine spherical powder (with particles 0.5 μm in diameter) of the fcc-TiN phase was obtained, composed of nanocrystalline grains with an average diameter of 8 nm. The samples obtained after different stages of RBM time were consolidated under vacuum at 1600 °C into cylindrical bulk compacts of 20 mm diameter, using spark plasma sintering technique. These compacts that maintained their nanocrystalline characteristics with an average grain size of 56 nm in diameter, possessed high relative density (above 99% of the theoretical density). The Vickers hardness of the as-consolidated TiN was measured and found to be 22.9 GPa. The modulus of elasticity and shear modulus of bulk TiN were measured by a nondestructive test and found to be 384 and 189 GPa, respectively. In addition, the coefficient of friction of the end-product TiN bulk sample was measured and found to be 0.35.

A Reaction-ball-milling-driven Surface Coating Strategy to Suppress Pulverization of Microparticle Si Anodes.

PubMed

Yang, Yaxiong; Qu, Xiaolei; Zhang, Lingchao; Gao, Mingxia; Liu, Yongfeng; Pan, Hongge

2018-06-01

In this work, we report on a novel reaction-ball-milling surface coating strategy to suppress the pulverization of microparticle Si anodes upon lithiation/delithiation. By energetic milling the partially prelithiated microparticle Si in a CO2 atmosphere, a multicomponent amorphous layer composed of SiOx, C, SiC and Li2SiO3 is successfully coated on the surface of Si microparticles. The coating level strongly depends on the milling reaction duration, and the 12-h milled prelithiated Si microparticles (BM12h) under a pressure of 3 bar of CO2 exhibits a good conformal coating with 1.006 g cm3 of tap density. The presence of SiC remarkably enhances the mechanical properties of the SiOx/C coating matrix with an approximately 4-fold increase in the elastic modulus and the hardness values, which effectively alleviates the global volume expansion of the Si microparticles upon lithiation. Simultaneously, the existence of Li2SiO3 insures the Li-ion conductivity of the coating layer. Moreover, the SEI film formed on the electrode surface maintains relatively stable upon cycling due to the remarkably suppressed crack and pulverization of particles. These processes work together to allow the BM12h sample to offer much better cycling stability, as its reversible capacity remains at 1439 mAh g-1 at 100 mA g-1 after 100 cycles, which is nearly 4 times that of the pristine Si microparticles (381 mAh g-1). This work opens up new opportunities for the practical applications of micrometre-scaled Si anode.

Comparison of particle sizes between 238PuO 2 before aqueous processing, after aqueous processing, and after ball milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulford, Roberta Nancy

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.

NORTH ELEVATION OF GOLD HILL MILL, LOOKING SOUTH. AT LEFT ...

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

NORTH ELEVATION OF GOLD HILL MILL, LOOKING SOUTH. AT LEFT EDGE IS THE SINGLE CYLINDER “HOT SHOT” ENGINE THAT PROVIDED POWER FOR THE MILL. JUST IN FRONT OF IT IS AN ARRASTRA. AT CENTER IS THE BALL MILL AND SECONDARY ORE BIN. JUST TO THE RIGHT OF THE BALL MILL IS A RAKE CLASSIFIER, AND TO THE RIGHT ARE THE CONCENTRATION TABLES. WARM SPRINGS CAMP IS IN THE DISTANCE. SEE CA-292-4 FOR IDENTICAL B&W NEGATIVE. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

NORTH ELEVATION OF GOLD HILL MILL, LOOKING SOUTH. AT LEFT ...

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

NORTH ELEVATION OF GOLD HILL MILL, LOOKING SOUTH. AT LEFT EDGE IS THE SINGLE CYLINDER “HOT SHOT” ENGINE THAT PROVIDED POWER FOR THE MILL. JUST IN FRONT OF IT IS AN ARRASTRA. AT CENTER IS THE BALL MILL AND SECONDARY ORE BIN. JUST TO THE RIGHT OF THE BALL MILL IS A RAKE CLASSIFIER, AND TO THE RIGHT ARE THE CONCENTRATION TABLES. WARM SPRINGS CAMP IS IN THE DISTANCE. SEE CA-292-17 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

Characterisation of an Al-BN nanocomposite prepared by ball milling and hot extrusion

NASA Astrophysics Data System (ADS)

Arlic, U.; Drozd, Z.; Trojanová, Z.; Molnárová, O.; Kasakewitsch, A.

2017-07-01

Aluminium-matrix-nanocomposites were manufactured by ball milling of microscale aluminium powder with BN nanoparticles in air, followed by subsequent consolidation by hot extrusion. The microstructure of the samples was studied using scanning electron microscopy. Vickers microhardness measurements were used to probe the mechanical properties of the samples. The amplitude dependent damping of the nanocomposites was measured at room temperature after thermal treatment of samples, and the linear thermal expansion was measured over a wide temperature range from room temperature up to 670K in the as-extruded state. The experimental results give a comprehensive picture of the behaviour of this nanocomposite system over the range of thermomechanical treatment conditions examined in this study. Based on these experimental data some possible influences of BN nanoparticles on the anelastic, plastic and thermal properties of microcrystalline aluminium are discussed.

Microstructure transformation of Cr-Al coating on carbon steel prepared by ball milling method as a function of tungsten doping

NASA Astrophysics Data System (ADS)

Wismogroho, A. S.; Sudiro, T.; Didik, A.; Ciswandi

2018-03-01

In present work, Cr-Al coatings containing 0, 1, 2, 3, and 5% W have been prepared on the surface of low carbon steel by mechanical alloying technique. The composition of each powder was milled for 2 hour in a stainless steel crucible with a ball to powder ratio of 10:1. Afterward, the Cr-Al-W powder and substrate were mechanically alloyed in air for 1 hour. The heat treatment of coated samples was carried out at 800 °C in a vacuum furnace for 2 hour. In order to characterize the phase composition and microstructure of the coating before and after heat treatment, XRD and SEM-EDX were used. The analysis results reveal that the ball milling process induces the formation of homogeneous Cr-Al-W coating structure with a thickness of about 80 μm. The phase observation shows individual peaks of each starting elements, along with the occurrence of powder refinement and solid solution formation. After heat treatment, AlCr2 and Al8Cr5 phases were formed. The addition of W accelerates the formation of AlCr2, but inhibits the formation of Al8Cr5. The detail of the results was presented in this paper.

Purification of Tronoh Silica Sand via preliminary process of mechanical milling

NASA Astrophysics Data System (ADS)

H, Nazratulhuda; M, Othman

2016-02-01

The purification of Tronoh silica sand is an important step in expanding technical applications of this silica sand. However no research on purifying of Tronoh silica sand has been reported. This study is focused on ball milling technique as a preliminary technique for Tronoh silica sand purification. The objectives are to study the effect of ball milling to the purification of the silica sand and to analyze its characteristics after the ball milling process. The samples before and after milling process were analyzed by using XRF, XRD, SEM and TEM. Results showed that the purity of SiO2 was increased, the size of the particles has been reduced and the surface area has increased. The crystalline phases for the silica before and after 4 hour milling time were remained constant.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swain, Basudev, E-mail: swain@iae.re.kr; Mishra, Chinmayee; Kang, Leeseung

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,more » 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.« less

Voss with Bonner Ball Neutron Detector Control Unit in Destiny laboratory

NASA Image and Video Library

2001-03-23

ISS002-E-5714 (23 March 2001) --- Astronaut James S. Voss, Expedition Two flight engineer, sets up the Bonner Ball Neutron Detector (BBND) in the Destiny laboratory. The BBND is connected to the Human Research Facility (HRF). This image was recorded with a digital still camera.

9. VIEW TO SOUTHSOUTHWEST, MINE WAREHOUSE, LABORATORY AND GRINDING/ROD MILL ...

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

9. VIEW TO SOUTH-SOUTHWEST, MINE WAREHOUSE, LABORATORY AND GRINDING/ROD MILL (FOREGROUND), AND SAMPLING BUILDING AND WATER TOWER (BACKGROUND). - Vanadium Corporation of America (VCA) Naturita Mill, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

Phase transformation and magnetic properties of MnAl powders prepared by elemental-doping and salt-assisted ball milling

NASA Astrophysics Data System (ADS)

Qian, Hui-Dong; Si, Ping-Zhan; Choi, Chul-Jin; Park, Jihoon; Cho, Kyung Mox

2018-05-01

The effects of elemental doping of Si and Fe on the ɛ→τ phase transformation and the magnetic properties of MnAl were studied. The magnetic powders of Si- and Fe-doped MnAl were prepared by using induction melting followed by water-quenching, annealing, and salt-assisted ball-milling. The Fe-doped MnAl powders are mainly composed of the L10-structured τ-phase, while the Si-doped MnAl are composed of τ-phase and a small fraction of γ2- and β-phases. A unique thin leaves-like morphology with thickness of several tens of nanometers and diameter size up to 500 nm were observed in the Si-doped MnAl powders. The Fe-doped MnAl powders show irregular shape with much larger dimensions in the range from several to 10 μm. The morphology difference of the samples was ascribed to the variation of the mechanical properties affected by different doping elements. The phase transformation temperatures of the ɛ-phase of the samples were measured. The doping of Fe decreases the onset temperature of the massive phase transformation in MnAl, while the Si-doping increases the massive phase transformation temperature. Both Fe and Si increase the Curie temperature of MnAl. A substantially enhanced coercivity up to 0.45 T and 0.42 T were observed in the ball-milled MnAl powders doped with Si and Fe, respectively.

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

NASA Astrophysics Data System (ADS)

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

2012-10-01

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

Structural, Morphological, Differential Scanning Calorimetric and Thermogravimetric Studies of Ball Milled Fe Doped Nanoscale La0.67Sr0.33MnO3 Manganite

NASA Astrophysics Data System (ADS)

Astik, Nidhi; Jha, Prafulla K.; Pratap, Arun

2018-03-01

The ball milling route has been used to produce the La0.67Sr0.33Mn0.85Fe0.15O3 (LSMFO) nanocrystalline sample from oxide precursors. The sample was characterized using x-ray diffraction (XRD), a scanning electron microscope (SEM), energy dispersive x-ray spectroscopy (EDAX), differential scanning calorimetry (DSC) and thermogravimetric (TGA) measurements. The x-ray diffraction confirms the phase purity of sample and shows that the sample crystallizes in the rhombohedral perovskite structure with a R-3c space group. The scanning electron micrograph shows the presence of well-faceted crystallites of LSMFO. The EDAX spectrum demonstrates the molar ratio of different elements of nanocrystalline LSMFO. Furthermore, the crystallite size using the Debye-Scherrer formula and William-Hall analysis has been found as 24 nm and 29 nm, respectively. Our results support the idea that a good quality nanocrystalline LSMFO sample can be obtained using the ball milling route. We also discuss the DSC and TGA curves and analyse the results in terms of phase transition, calcination temperature and activation barrier energies.

Drawing Sensors with Ball-Milled Blends of Metal-Organic Frameworks and Graphite

PubMed Central

Ko, Michael; Aykanat, Aylin; Smith, Merry K.

2017-01-01

The synthetically tunable properties and intrinsic porosity of conductive metal-organic frameworks (MOFs) make them promising materials for transducing selective interactions with gaseous analytes in an electrically addressable platform. Consequently, conductive MOFs are valuable functional materials with high potential utility in chemical detection. The implementation of these materials, however, is limited by the available methods for device incorporation due to their poor solubility and moderate electrical conductivity. This manuscript describes a straightforward method for the integration of moderately conductive MOFs into chemiresistive sensors by mechanical abrasion. To improve electrical contacts, blends of MOFs with graphite were generated using a solvent-free ball-milling procedure. While most bulk powders of pure conductive MOFs were difficult to integrate into devices directly via mechanical abrasion, the compressed solid-state MOF/graphite blends were easily abraded onto the surface of paper substrates equipped with gold electrodes to generate functional sensors. This method was used to prepare an array of chemiresistors, from four conductive MOFs, capable of detecting and differentiating NH3, H2S and NO at parts-per-million concentrations. PMID:28946624

Effect of ball milling and dynamic compaction on magnetic properties of Al2O3/Co(P) composite particles

NASA Astrophysics Data System (ADS)

Denisova, E. A.; Kuzovnikova, L. A.; Iskhakov, R. S.; Bukaemskiy, A. A.; Eremin, E. V.; Nemtsev, I. V.

2014-05-01

The evolution of the magnetic properties of composite Al2O3/Co(P) particles during ball milling and dynamic compaction is investigated. To prepare starting composite particles, the Al2O3 granules were coated with a Co95P5 shell by electroless plating. The magnetic and structural properties of the composite particles are characterized by scanning electron microscopy, X-ray diffraction, and the use of the Physical Property Measurement System. The use of composite core-shell particles as starting powder for mechanoactivation allows to decrease treatment duration to 1 h and to produce a more homogeneous bulk sample than in the case of the mixture of Co and Al2O3 powders. The magnetic properties of the milled composite particles are correlated with changes in the microstructure. Reduction in grain size of Co during milling leads to an increase of the volume fraction of superparamagnetic particles and to a decrease of the saturation magnetization. The local magnetic anisotropy field depends on the amount of hcp-Co phase in sample. The anisotropy field value decreases from 8.4 kOe to 3.8 kOe with an increase in milling duration up to 75 min. The regimes of dynamic compaction were selected so that the magnetic characteristics—saturation magnetization and coercive field—remained unchanged.

Ball Lightning in Zero Gravity in the Laboratory

NASA Astrophysics Data System (ADS)

Alexeff, Igor; Parameswaran, Sriram; Grace, Michael

2004-11-01

We have created balls of orange plasma in atmospheric - pressure air that survive for over 1/2 second without power input. The technique used was to create a pulsed horizontal electric arc in a zero - gravity environment using 6 neon - sign transformers in parallel, each producing 16,000 V at 60 mA. The zero - gravity environment reduces heat losses by reducing thermal convection, creating a larger ball. Previous work (1) suggests that the ball lifetime scales as the square of the ball radius. The balls were photographed after power turnoff with a high - speed 16 mm movie camera. Movies of the balls being formed and decaying will be shown. We suggest that there are several other forms of ball lightning (2). 1.Igor Alexeff et. al. International Conference On Plasma Science, Jeju, Korea, June 2-5, 2003, Conference Record, p 254. 2. Igor Alexeff and Mark Rader, IEEE Transactions on Plasma Science, Vol. 20, No. 6, Dec. 1992, pp.669-671. Igor Alexeff and Mark Rader, Fusion Technology, Vol. 27, May 1995, p. 271.

Lignocellulose fermentation and residual solids characterization for senescent switchgrass fermentation by Clostridium thermocellum in the presence and absence of continuous in situ ball-milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balch, Michael L.; Holwerda, Evert K.; Davis, Mark F.

Milling during lignocellulosic fermentation, henceforth referred to as cotreatment, is investigated as an alternative to thermochemical pretreatment as a means of enhancing biological solubilization of lignocellulose. We investigate the impact of milling on soluble substrate fermentation by Clostridium thermocellum with comparison to yeast, document solubilization for fermentation of senescent switchgrass with and without ball milling, and characterize residual solids. Soluble substrate fermentation by C. thermocellum proceeded readily in the presence of continuous ball milling but was completely arrested for yeast. Total fractional carbohydrate solubilization achieved after fermentation of senescent switchgrass by C. thermocellum for 5 days was 0.45 without cotreatmentmore » or pretreatment, 0.81 with hydrothermal pretreatment (200 degrees C, 15 minutes, severity 4.2), and 0.88 with cotreatment. Acetate and ethanol were the main fermentation products, and were produced at similar ratios with and without cotreatment. Analysis of solid residues was undertaken using molecular beam mass spectrometry (PyMBMS) and solid-state nuclear magnetic resonance spectroscopy (NMR) in order to provide insight into changes in plant cell walls during processing via various modes. The structure of lignin present in residual solids remaining after fermentation with cotreatment appeared to change little, with substantially greater changes observed for hydrothermal pretreatment - particularly with respect to formation of C-C bonds. The observation of high solubilization with little apparent modification of the residue is consistent with cotreatment enhancing solubilization primarily by increasing the access of saccharolytic enzymes to the feedstock, and C. thermocellum being able to attack all the major linkages in cellulosic biomass provided that these linkages are accessible.« less

Implementing a Remote Laboratory Experience into a Joint Engineering Degree Program: Aerodynamic Levitation of a Beach Ball

ERIC Educational Resources Information Center

Jernigan, S. R.; Fahmy, Y.; Buckner, G. D.

2009-01-01

This paper details a successful and inexpensive implementation of a remote laboratory into a distance control systems course using readily available hardware and software. The physical experiment consists of a beach ball and a dc blower; the control objective is to make the height of the aerodynamically levitated beach ball track a reference…

The milling of pristine and brominated P-100 graphite fibers

NASA Technical Reports Server (NTRS)

Dillehay, M. E.; Gaier, J. R.

1986-01-01

Techniques were developed for the ball milling of pristine and brominated P-100 graphite fibers. Because of the lubrication properties of graphite, large ball loads (50 percent by volume) were required. Use of 2-propanol as a milling medium enhanced the efficiency of the process. Milled brominated P-100 fibers had resistivities which were indistinguishable from milled pristine P-100 fibers. Apparent loss of bromine from the brominated fibers suggests that bromine would not be the intercalate of choice in applications where milled fibers of this type are required. Other intercalates which do not degas may be more appropriate for a milled fiber application. These same results, however, do provide evidence that bromine molecules leave the fiber surface when removed from overpressure of bromine. While exploring possible solvent media for milling purposes, it was found that brominated fibers are stable in a wide variety of organic solvents.

Preparation of Mo-Re-C samples containing Mo{sub 7}Re{sub 13}C 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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh-ishi, Katsuyoshi, E-mail: oh-ishi@kc.chuo-u.ac.jp; Nagumo, Kenta; Tateishi, Kazuya

Mo-Re-C compounds containing Mo{sub 7}Re{sub 13}C 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 Mo{sub 7}Re{sub 13}C with the β-Mn structure using the solid state method. Almost single-phase Mo{sub 7}Re{sub 13}C 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 amore » 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. - Graphical abstract: Temperature dependence of the magnetic susceptibility measured under 10 Oe for the superconducting PBM-T samples without Fe element and non-superconducting PBM-S with Fe element. The inset is the enlarged view of the data for the PBM-S sample.« less

Preparation of TiO2-Decorated Boron Particles by Wet Ball Milling and their Photoelectrochemical Hydrogen and Oxygen Evolution Reactions

PubMed Central

Jung, Hye Jin; Nam, Kyusuk; Sung, Hong-Gye; Hyun, Hyung Soo; Sohn, Youngku; Shin, Weon Gyu

2016-01-01

TiO2-coated boron particles were prepared by a wet ball milling method, with the particle size distribution and average particle size being easily controlled by varying the milling operation time. Based on the results from X-ray photoelectron spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis, and Fourier transform infrared spectroscopy, it was confirmed that the initial oxide layer on the boron particles surface was removed by the wet milling process, and that a new B–O–Ti bond was formed on the boron surface. The uniform TiO2 layer on the 150 nm boron particles was estimated to be 10 nm thick. Based on linear sweep voltammetry, cyclic voltammetry, current-time amperometry, and electrochemical impedance analyses, the potential for the application of TiO2-coated boron particles as a photoelectrochemical catalyst was demonstrated. A current of 250 μA was obtained at a potential of 0.5 V for hydrogen evolution, with an onset potential near to 0.0 V. Finally, a current of 220 μA was obtained at a potential of 1.0 V for oxygen evolution. PMID:28774132

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

NASA Astrophysics Data System (ADS)

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.

Modeling of Surface Geometric Structure State After Integratedformed Milling and Finish Burnishing

NASA Astrophysics Data System (ADS)

Berczyński, Stefan; Grochała, Daniel; Grządziel, Zenon

2017-06-01

The article deals with computer-based modeling of burnishing a surface previously milled with a spherical cutter. This method of milling leaves traces, mainly asperities caused by the cutting crossfeed and cutter diameter. The burnishing process - surface plastic treatment - is accompanied by phenomena that take place right in the burnishing ball-milled surface contact zone. The authors present the method for preparing a finite element model and the methodology of tests for the assessment of height parameters of a surface geometrical structure (SGS). In the physical model the workpieces had a cuboidal shape and these dimensions: (width × height × length) 2×1×4.5 mm. As in the process of burnishing a cuboidal workpiece is affected by plastic deformations, the nonlinearities of the milled item were taken into account. The physical model of the process assumed that the burnishing ball would be rolled perpendicularly to milling cutter linear traces. The model tests included the application of three different burnishing forces: 250 N, 500 N and 1000 N. The process modeling featured the contact and pressing of a ball into the workpiece surface till the desired force was attained, then the burnishing ball was rolled along the surface section of 2 mm, and the burnishing force was gradually reduced till the ball left the contact zone. While rolling, the burnishing ball turned by a 23° angle. The cumulative diagrams depict plastic deformations of the modeled surfaces after milling and burnishing with defined force values. The roughness of idealized milled surface was calculated for the physical model under consideration, i.e. in an elementary section between profile peaks spaced at intervals of crossfeed passes, where the milling feed fwm = 0.5 mm. Also, asperities after burnishing were calculated for the same section. The differences of the obtained values fall below 20% of mean values recorded during empirical experiments. The adopted simplification in after-milling

Insertion compounds and composites made by ball milling for advanced sodium-ion batteries

PubMed Central

Zhang, Biao; Dugas, Romain; Rousse, Gwenaelle; Rozier, Patrick; Abakumov, Artem M.; Tarascon, Jean-Marie

2016-01-01

Sodium-ion batteries have been considered as potential candidates for stationary energy storage because of the low cost and wide availability of Na sources. However, their future commercialization depends critically on control over the solid electrolyte interface formation, as well as the degree of sodiation at the positive electrode. Here we report an easily scalable ball milling approach, which relies on the use of metallic sodium, to prepare a variety of sodium-based alloys, insertion layered oxides and polyanionic compounds having sodium in excess such as the Na4V2(PO4)2F3 phase. The practical benefits of preparing sodium-enriched positive electrodes as reservoirs to compensate for sodium loss during solid electrolyte interphase formation are demonstrated by assembling full C/P′2-Na1[Fe0.5Mn0.5]O2 and C/‘Na3+xV2(PO4)2F3' sodium-ion cells that show substantial increases (>10%) in energy storage density. Our findings may offer electrode design principles for accelerating the development of the sodium-ion technology. PMID:26777573

Magnetic properties of FeCuNbSiB nanocrystalline alloy powder cores using ball-milled powder

NASA Astrophysics Data System (ADS)

Kim, G. H.; Noh, T. H.; Choi, G. B.; Kim, K. Y.

2003-05-01

Cold-pressed nanocrystalline powder cores were fabricated using powders of nanocrystalline ribbons which were ball milled for short time. Their magnetic properties at high frequency were measured. The powder size ranges from 20 to 850 μm and the contents of the glass binder are between 1 and 8 wt %. For cores composed of large particles of 300-850 μm with 5 wt % glass binder, we obtained a stable permeability of 100 up to 800 kHz, a maximum level 31 of quality factor at frequency of 50 kHz, and 320 mW/cm3 core loss at f=50 kHz and Bm=0.1 T. This is mainly due to the good soft magnetic properties of the powders and the higher insulation of powder cores which cause low eddy current losses.

Properties of dispersion-strengthened chromium - 4-volume-percent-thoria alloys produced by ball milling in hydrogen iodide

NASA Technical Reports Server (NTRS)

Arias, A.

1974-01-01

The effects of processing variables on the tensile properties and ductile-to-brittle transition temperature (DBTT) of Cr + 4 vol. %ThO2 alloys and of pure Cr produced by ball milling in hydrogen iodide were investigated. Hot rolled Cr + ThO2 was stronger than either hot pressed Cr + ThO2 or pure Cr at temperatures up to 1537 C. Hot pressed Cr + ThO2 had a DBTT of 501 C as compared with minus 8 to 24 C for the hot rolled Cr + ThO2 and with 139 C for pure Cr. It is postulated that the dispersoid in the hot rolled alloys lowers the DBTT by inhibiting recovery and recrystallization of the strained structure.

Bioethanol production from ball milled bagasse using an on-site produced fungal enzyme cocktail and xylose-fermenting Pichia stipitis.

PubMed

Buaban, Benchaporn; Inoue, Hiroyuki; Yano, Shinichi; Tanapongpipat, Sutipa; Ruanglek, Vasimon; Champreda, Verawat; Pichyangkura, Rath; Rengpipat, Sirirat; Eurwilaichitr, Lily

2010-07-01

Sugarcane bagasse is one of the most promising agricultural by-products for conversion to biofuels. Here, ethanol fermentation from bagasse has been achieved using an integrated process combining mechanical pretreatment by ball milling, with enzymatic hydrolysis and fermentation. Ball milling for 2 h was sufficient for nearly complete cellulose structural transformation to an accessible amorphous form. The pretreated cellulosic residues were hydrolyzed by a crude enzyme preparation from Penicillium chrysogenum BCC4504 containing cellulase activity combined with Aspergillus flavus BCC7179 preparation containing complementary beta-glucosidase activity. Saccharification yields of 84.0% and 70.4% for glucose and xylose, respectively, were obtained after hydrolysis at 45 degrees C, pH 5 for 72 h, which were slightly higher than those obtained with a commercial enzyme mixture containing Acremonium cellulase and Optimash BG. A high conversion yield of undetoxified pretreated bagasse (5%, w/v) hydrolysate to ethanol was attained by separate hydrolysis and fermentation processes using Pichia stipitis BCC15191, at pH 5.5, 30 degrees C for 24 h resulting in an ethanol concentration of 8.4 g/l, corresponding to a conversion yield of 0.29 g ethanol/g available fermentable sugars. Comparable ethanol conversion efficiency was obtained by a simultaneous saccharification and fermentation process which led to production of 8.0 g/l ethanol after 72 h fermentation under the same conditions. This study thus demonstrated the potential use of a simple integrated process with minimal environmental impact with the use of promising alternative on-site enzymes and yeast for the production of ethanol from this potent lignocellulosic biomass. 2009. Published by Elsevier B.V.

Particle size reduction of Si3N4 with Si3N4 milling hardware

NASA Technical Reports Server (NTRS)

Herbell, T. P.; Freedman, M. R.; Kiser, J. D.

1986-01-01

The grinding of Si3N4 powder using reaction bonded Si3N4 attrition, vibratory, and ball mills with Si3N4 media was examined. The rate of particle size reduction and the change in the chemical composition of the powder were determined in order to compare the grinding efficiency and the increase in impurity content resulting from mill and media wear for each technique. Attrition and vibratory milling exhibited rates of specific surface area increase that were approximately eight times that observed in ball milling. Vibratory milling introduced the greatest impurity pickup.

Magneto-optical properties of α-Fe2O3@ZnO nanocomposites prepared by the high energy ball-milling technique

NASA Astrophysics Data System (ADS)

Chaudhury, Chandana Roy; Roychowdhury, Anirban; Das, Anusree; Das, Dipankar

2016-05-01

Magnetic-fluorescent nanocomposites (NCs) with 10 wt% of α-Fe2O3 in ZnO have been prepared by the high energy ball-milling. The crystallite sizes of α-Fe2O3 and ZnO in the NCs are found to vary from 65 nm to 20 nm and 47 nm to 15 nm respectively as milling time is increased from 2 to 30 h. XRD analysis confirms presence of α-Fe2O3 and ZnO in pure form in all the NCs. UV-vis study of the NCs shows a continuous blue-shift of the absorption peak and a steady increase of band gap of ZnO with increasing milling duration that are assigned to decreasing particle size of ZnO in the NCs. Photoluminescence (PL) spectra of the NCs reveal three weak emission bands in the visible region at 421, 445 and 485 nm along with the strong near band edge emission at 391 nm. These weak emission bands are attributed to different defect - related energy levels e.g. Zn-vacancy, Zn interstitial and oxygen vacancy. Dc and ac magnetization measurements show presence of weakly interacting superparamagnetic (SPM) α-Fe2O3 particles in the NCs. 57Fe-Mössbauer study confirms presence of SPM hematite in the sample milled for 30 h. Positron annihilation lifetime measurements indicate presence of cation vacancies in ZnO nanostructures confirming results of PL studies.

Particle-size reduction of Si3N4 powder with Si3N4 milling hardware

NASA Technical Reports Server (NTRS)

Herbell, T. P.; Freedman, M. R.; Kiser, J. D.

1986-01-01

The grinding of Si3N4 powder using reaction bonded Si3N4 attrition, vibratory, and ball mills with Si3N4 media was examined. The rate of particle size reduction and the change in the chemical composition of the powder were determined in order to compare the grinding efficiency and the increase in impurity content resulting from mill and media wear for each technique. Attrition and vibratory milling exhibited rates of specific surface area increase that were approximately eight times that observed in ball milling. Vibratory milling introduced the greatest impurity pickup.

The MillSOT-A Spiral Orbit Tribometer on a Milling Machine

NASA Technical Reports Server (NTRS)

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.

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

PubMed

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Bhattacharyya, Anirban

The following research fundamentally deals with the cause and implications of nonlinearities in breakage rates of materials in wet grinding systems. The innate dependence of such nonlinearities on fines content and the milling environment during wet grinding operations is also tested and observed. Preferential breakage of coarser size fractions as compared to the finer size fractions in a particle population were observed and discussed. The classification action of the pulp was deemed to be the probable cause for such a peculiarity. Ores with varying degrees of hardness and brittleness were used for wet grinding experiments, primarily to test the variations in specific breakage rates as a function of varying hardness. For this research, limestone, quartzite, and gold ore were used. The degree of hardness is of the order of: limestone, quartzite, gold ore. Selection and breakage function parameters were determined in the course of this research. Functional forms of these expressions were used to compare experimentally derived parameter estimates. Force-fitting of parameters was not done in order to examine the realtime behavior of particle populations in wet grinding systems. Breakage functions were established as being invariant with respect to such operating variables like ball load, mill speed, particle load, and particle size distribution of the mill. It was also determined that specific selection functions were inherently dependent on the particle size distribution in wet grinding systems. Also, they were consistent with inputs of specific energy, according to grind time. Nonlinearity trends were observed for 1st order specific selection functions which illustrated variations in breakage rates with incremental inputs of grind time and specific energy. A mean particle size called the fulcrum was noted below which the nonlinearities in the breakage trends were observed. This magnitude of the fulcrum value varied with percent solids and slurry filling, indicating

Influence of ball milling and annealing conditions on the properties of L10 FePt nanoparticles fabricated by a new green chemical synthesis method

NASA Astrophysics Data System (ADS)

Hu, X. C.; Capobianchi, A.; Gallagher, R.; Hadjipanayis, G. C.

2014-05-01

In this work, a new green chemical strategy for the synthesis of L10 FePt alloy nanoparticles is reported. The precursor is a polycrystalline molecular complex (Fe(H2O)6PtCl6), in which Fe and Pt atoms are arranged on alternating planes and milled with NaCl to form nanocrystals. Then the mixture was annealed under reducing atmosphere (5% H2 and 95% Ar) at temperatures varying from 350 °C to 500 °C for 2 h with a heating rate of 5 °C/min. After the reduction, the mixture was washed with water to remove the NaCl and L10 FePt nanoparticles were obtained. The X-Ray Diffraction pattern showed the presence of the characteristic peaks of the fct phase of FePt nanoparticles. Influence of precursor/NaCl ratio and ball milling time on particle size was investigated. Transmission electron microscopy images revealed that smaller precursor/NaCl ratio (10 mg/20 g) and longer milling time (15 h) lead to smaller particle size and narrower size distribution. Milling time does not influence the coercivity much but the decrease of the amount of precursor leads to a decrease of coercivity from 10.8 kOe to 4.8 kOe.

Hydrogen storage properties of Mg xFe (x: 2, 3 and 15) compounds produced by reactive ball milling

NASA Astrophysics Data System (ADS)

Puszkiel, J. A.; Arneodo Larochette, P.; Gennari, F. C.

This work deals with the assessment of the thermo-kinetic properties of Mg-Fe based materials for hydrogen storage. Samples are prepared from Mg xFe (x: 2, 3 and 15) elemental powder mixtures via low energy ball milling under hydrogen atmosphere at room temperature. The highest yield is obtained with Mg 15Fe after 150 h of milling (90 wt% of MgH 2). The thermodynamic characterization carried out between 523 and 673 K shows that the obtained Mg-Fe-H hydride systems have similar thermodynamic parameters, i.e. enthalpy and entropy. However, in equilibrium conditions, Mg 15Fe has higher hydrogen capacity and small hysteresis. In dynamic conditions, Mg 15Fe also shows better hydrogen capacity (4.85 wt% at 623 K absorbed in less than 10 min and after 100 absorption/desorption cycles), reasonably good absorption/desorption times and cycling stability in comparison to the other studied compositions. From hydrogen uptake rate measurements performed at 573 and 623 K, the rate-limiting step of the hydrogen uptake reaction is determined by fitting particle kinetic models. According to our results, the hydrogen uptake is diffusion controlled, and this mechanism does not change with the Mg-Fe proportion and temperature.

Interfacial Reaction During High Energy Ball Milling Dispersion of Carbon Nanotubes into Ti6Al4V

NASA Astrophysics Data System (ADS)

Adegbenjo, A. O.; Olubambi, P. A.; Potgieter, J. H.; Nsiah-Baafi, E.; Shongwe, M. B.

2017-12-01

The unique thermal and mechanical properties of carbon nanotubes (CNTs) have made them choice reinforcements for metal matrix composites (MMCs). However, there still remains a critical challenge in achieving homogeneous dispersion of CNTs in metallic matrices. Although high energy ball milling (HEBM) has been reported as an effective method of dispersing CNTs into metal matrices, a careful selection of the milling parameters is important not to compromise the structural integrity of CNTs which may cause interfacial reactions with the matrix. In this study, multi-walled carbon nanotubes (MWCNTs) were purified by annealing in argon and vacuum atmospheres at 1000 and 1800 °C, respectively, for 5 h to remove possible metallic catalyst impurities. Subsequently, 1, 2 and 3 wt.% MWCNTs were dispersed by adapted HEBM into Ti6Al4V alloy metal matrix. Raman spectroscopy (RS), x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectrometry and transmission electron microscopy techniques were used to characterize the as-received and annealed MWCNTs, as well as the admixed MWCNT/Ti6Al4V nanocomposite powders. The experimental results showed that vacuum annealing successfully eliminated retained nickel (Ni) catalysts from MWCNTs, while the adapted HEBM method achieved a relative homogeneous dispersion of MWCNTs into the Ti6Al4V matrix and helped to control interfacial reactions between defective MWCNTs and the metal matrix.

Phase analysis of ZrO2-SiO2 systems synthesized through Ball milling mechanical activations

NASA Astrophysics Data System (ADS)

Nurlaila, Rizka; Musyarofah, Muwwaqor, Nibras Fuadi; Triwikantoro, Kuswoyo, Anton; Pratapa, Suminar

2017-01-01

Zircon powders have been produced from raw materials of amorphous zirconia and amorphous silica powders obtained from natural zircon sand of Kalimantan Tengah, Indonesia. Synthesis process was started with the extraction of zircon powder to produce sodium silicate solution and pure zircon powder. The amorphous zirconia and silica powders were prepared by alkali fusion and co-precipitation techniques. The powders were mixed using a planetary ball mill, followed by a calcination of various holding time of 3, 10, and 15 h. Phase characterization was done using X-Ray Diffraction (XRD) technique and analysis of the diffraction data was carried out using Rietica and MAUD software. The identified phases after the calcination were zircon, tetragonal zirconia, and cristobalite. The highest zircon content was obtained in the sample calcinated for15 hours - reaching 99.66 %wt. Crystallite size analysis revealed that the samples calcinated for 3, 10, and 15 h exhibited zircon crystal size of 176 (1) nm, 191 (1) nm and 233 (1) nm respectively.

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Synthesis of ZnO Nanocrystal-Graphene Composite by Mechanical Milling and Sonication-Assisted Exfoliation

NASA Astrophysics Data System (ADS)

Arora, Sweety; Srivastava, Chandan

2017-02-01

A ZnO nanocrystal-graphene composite was synthesized by a two-step method involving mechanical milling and sonication-assisted exfoliation. Zn metal powder was first ball-milled with graphite powder for 30 h in water medium. This ball-milled mixture was then subjected to exfoliation by sonication in the presence of sodium lauryl sulfate surfactant to produce graphene decorated with spherical agglomerates of ultrafine nanocrystalline ZnO. The presence of a few layers of graphene was confirmed by Raman spectroscopy and atomic force microscopy measurements. The size, phase identity and composition of the ZnO nanocrystals was determined by transmission electron microscopy measurements.

Milling assisted synthesis of calcium zirconate СаZrО3

NASA Astrophysics Data System (ADS)

Kalinkin, A. M.; Nevedomskii, V. N.; Kalinkina, E. V.; Balyakin, K. V.

2014-08-01

Monophase calcium zirconate (CaZrO3) has been prepared from the equimolar ZrO2 + CaCO3 mixture by two-step synthesis process. In the first step, mechanical treatment of the mixture is performed in an AGO-2 planetary ball mill. In the second step, the milled mixture is annealed to form calcium zirconate. High-energy ball milling of the (ZrO2+CaCO3) mixture results in decrease in the temperature of CaZrO3 formation during annealing at 950 °C. The enhancement of CaZrO3 synthesis is due to accumulation of excess energy by the reagents, decreasing the particle size and notable increase in the interphase area because of “smearing” of CaCO3 on ZrO2 particles during milling. Nanocrystalline calcium zirconate has been produced by controlling the annealing temperature and time.

Textured Pr{sub 2}Fe{sub 14}B flakes with submicron or nanosize thickness prepared by surfactant-assisted ball milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zuo, Wen-Liang, E-mail: wlzuo@iphy.ac.cn, E-mail: shenbg@aphy.iphy.ac.cn; Liu, Rong-Ming; Zheng, Xin-Qi

2014-05-07

The textured Pr{sub 2}Fe{sub 14}B nanoflakes were produced by surfactant-assisted ball milling (SABM). Single phase tetragonal structure was characterized for the samples before and after SABM by X-ray diffraction (XRD). The thickness and length of the as-milled flakes are mainly in the range of 50–150 nm and 0.5–2 μm, respectively. For the field-aligned Pr{sub 2}Fe{sub 14}B nanoflakes, the out-of-plane texture (the easy magnetization direction (EMD) along the c-axis) is indicated from the increasing (00l) peaks in the XRD patterns. SEM image demonstrates that the EMD is parallel to flaky surface, which is different from the RCo{sub 5} (R = rare earth) system with EMDmore » perpendicular to the surface. We propose a hypothesis that the easy glide planes are related with the area of crystal planes. In addition, a large coercivity H{sub c} = 3.9 kOe is observed in the Pr{sub 2}Fe{sub 14}B flakes with strong texture.« less

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

PubMed

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

Combining hot-compressed water and ball milling pretreatments to improve the efficiency of the enzymatic hydrolysis of eucalyptus

PubMed Central

Inoue, Hiroyuki; Yano, Shinichi; Endo, Takashi; Sakaki, Tsuyoshi; Sawayama, Shigeki

2008-01-01

Background Lignocellulosic biomass such as wood is an attractive material for fuel ethanol production. Pretreatment technologies that increase the digestibility of cellulose and hemicellulose in the lignocellulosic biomass have a major influence on the cost of the subsequent enzymatic hydrolysis and ethanol fermentation processes. Pretreatments without chemicals such as acids, bases or organic solvents are less effective for an enzymatic hydrolysis process than those with chemicals, but they have a less negative effect on the environment. Results The enzymatic digestibility of eucalyptus was examined following a combined pretreatment without chemicals comprising a ball milling (BM) and hot-compressed water (HCW) treatment. The BM treatment simultaneously improved the digestibility of both glucan and xylan, and was effective in lowering the enzyme loading compared with the HCW treatment. The combination of HCW and BM treatment reduced the BM time. The eucalyptus treated with HCW (160°C, 30 minutes) followed by BM (20 minutes) had an approximately 70% yield of total sugar with a cellulase loading of 4 FPU/g substrate. This yield was comparable to the yields from samples treated with HCW (200°C, 30 minutes) or BM (40 minutes) hydrolyzed with 40 FPU/g substrate. Conclusion The HCW treatment is useful in improving the milling efficiency. The combined HCW-BM treatment can save energy and enzyme loading. PMID:18471309

8. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

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

8. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. It received steam from the locomotive type, fire-tube portable boiler in the background. The engine's water pump which pumped water from the feed-water clarifying cistern, in between the boiler and engine, through a pre-heat system and on to the boiler, is seen in front of the fluted cylinder. The fly-ball governor, missing its balls, the steam port, and manual throttle valve are above and behind the cylinder. The flywheel, drive shaft, and pulley are on the left side of the engine bed. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Effect of mechanical milling on barium titanate (BaTiO3) perovskite

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

Effects of milling media on the fabrication of melt-derived bioactive glass powder for biomaterial application

NASA Astrophysics Data System (ADS)

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.

Preparation of folic acid conjugated hematite nanoparticles using high energy ball milling for biomedical applications

NASA Astrophysics Data System (ADS)

Sahu, Dwipak Prasad; Jammalamadaka, S. Narayana

2018-04-01

The controlled release and targeted delivery of drug to tumour sites using magnetic nanoparticles (MNPs) for the treatment of cancer & other ailments is current focus of research. Here we describe our efforts in functionalization of hematite nanoparticles α-Fe2O3 with polyethylene glycol (PEG) and activation with Folic Acid (FA) (ligand) using a high energy ball milling process. An extra peak at 48.3° in XRD hints an encapsulation of polyethylene glycol on α-Fe2O3 nanoparticles (NPs). The decrease in the intensity of absorption spectra peaks in UV - Vis NIR spectrum pertinent to activated α-Fe2O3 NPs indicate indeed there is a conjugation of folic acid on top of PEG. Thermo-gravimetric analysis shows 5% weight loss for the activated α-Fe2O3 NPs due to desorption of chemi-adsorbed PEG from NPs and its further decomposition. Magnetization measurements indicates indeed the coercivity persists even after activating the NPs with FA. We believe presence of coercivity in MNPs can be exploited in magnetic hyperthermia treatment of cancer cell by applying suitable amount of field at the targeted site.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

Synthesis and Self-Assembly of the "Tennis Ball" Dimer and Subsequent Encapsulation of Methane. An Advanced Organic Chemistry Laboratory Experiment

NASA Astrophysics Data System (ADS)

Hof, Fraser; Palmer, Liam C.; Rebek, Julius, Jr.

2001-11-01

While important to the biological and materials sciences, noncovalent interactions, self-folding, and self-assembly often receive little discussion in the undergraduate chemistry curriculum. The synthesis and NMR characterization of a molecular "tennis ball" in an advanced undergraduate organic chemistry laboratory is a simple and effective way to introduce the relevance of these concepts. In appropriate solvents, the monomer dimerizes through a seam of eight hydrogen bonds with encapsulation of a guest molecule and symmetry reminiscent of a tennis ball. The entire experiment can be completed in three lab periods, however large-scale synthetic preparation of the starting monomer by a teaching assistant would reduce the laboratory to a single lab period for NMR studies.

Effect of wet grinding on structural properties of ball clay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purohit, A., E-mail: anuradha.purohit34@gmail.com; Chander, S.; Dhaka, M. S.

2015-05-15

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.

An investigation of the generation and properties of laboratory-produced ball lightning

NASA Astrophysics Data System (ADS)

Oreshko, A. G.

2015-06-01

The experiments revealed that ball lightning is a self-confining quasi-neutral in a whole plasma system that rotates around its axis. Ball lightning has a structure of a spherical electric domain, consisting of a kernel with excess negative charge and an external spherical layer with excess positive charge. The excess of charges of one sort and the lack of charges of the other sort in the kernel or in the external spherical layer significantly reduces the possibility of electron capture by means of an electric field, created by the nearest ions and leads to a drastic slowdown of recombination process. Direct proof has been obtained that inside of ball lightning - in an external spherical layer that rotates around the axis - there is a circular current of sub-relativistic particles. This current creates and maintains its own poloidal magnetic field of ball lightning, i.e. it carries out the function of magnetic dynamo. The kernel of ball lightning is situated in a region with minimum values of induction of the magnetic field. The inequality of positive and negative charges in elements of ball lightning also significantly reduces losses of the charged plasma on bremsstrahlung. Ball lightning generation occurs in a plasmic vortex. The ball lightning energy in the region of its generation significantly differs from the ball lightning energy, which is drifting in space. The axial component of kinetic energy of particles slightly exceeds 100 keV and the rotational component of the ions energy is a bit greater than 1 MeV. Ball lightning is `embedded' in atmosphere autonomous accelerator of charged particles of a cyclotron type due to self-generation of strong crossed electric and magnetic fields. A discussion of the conditions of stability and long-term existence of ball lightning is given.

Mechanically Milled Irregular Zinc Nanoparticles for Printable Bioresorbable Electronics.

PubMed

Mahajan, Bikram K; Yu, Xiaowei; Shou, Wan; Pan, Heng; Huang, Xian

2017-05-01

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. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

NASA Technical Reports Server (NTRS)

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.

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

NASA Astrophysics Data System (ADS)

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

2013-11-01

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

Science of Ball Lightning (Fire Ball)

NASA Astrophysics Data System (ADS)

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

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

PubMed Central

Marek, Ivo; Vojtěch, Dalibor; Michalcová, Alena; Kubatík, Tomáš František

2016-01-01

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. PMID:28773514

Demonstration of a silicon nitride attrition mill for production of fine pure Si and Si3N4 powders

NASA Technical Reports Server (NTRS)

Herbell, T. P.; Glasgow, T. K.; Orth, N. W.

1984-01-01

To avoid metallic impurities normally introduced by milling ceramic powders in conventional steel hardware, an attrition mill (high-energy stirred ball mill) was constructed with the wearing parts (mill body, stirring arms, and media) made from silicon nitride. Commercial silicon and Si3N4 powders were milled to fine uniform particles with only minimal contamination - primarily from wear of the sintered Si3N4 media.

Improved oral bioavailability of probucol by dry media-milling.

PubMed

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

2017-09-01

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

Effect of milling methods on performance of Ni-Y 2O 3-stabilized ZrO 2 anode for solid oxide fuel cell

NASA Astrophysics Data System (ADS)

Cho, Hyoup Je; Choi, Gyeong Man

A Ni-YSZ (Y 2O 3-stabilized ZrO 2) composite is commonly used as a solid oxide fuel cell anode. The composite powders are usually synthesized by mixing NiO and YSZ powders. The particle size and distribution of the two phases generally determine the performance of the anode. Two different milling methods are used to prepare the composite anode powders, namely, high-energy milling and ball-milling that reduce the particle size. The particle size and the Ni distribution of the two composite powders are examined. The effects of milling on the performance are evaluated by using both an electrolyte-supported, symmetric Ni-YSZ/YSZ/Ni-YSZ cell and an anode-supported, asymmetric cell. The performance is examined at 800 °C by impedance analysis and current-voltage measurements. Pellets made by using high-energy milled NiO-YSZ powders have much smaller particle sizes and a more uniform distribution of Ni particles than pellets made from ball-milled powder, and thus the polarization resistance of the electrode is also smaller. The maximum power density of the anode-supported cell prepared by using the high-energy milled powder is ∼850 mW cm -2 at 800 °C compared with ∼500 mW cm -2 for the cell with ball-milled powder. Thus, high-energy milling is found to be more effective in reducing particle size and obtaining a uniform distribution of Ni particles.

Effect of milling on particle shape and surface energy heterogeneity of needle-shaped crystals.

PubMed

Ho, Raimundo; Naderi, Majid; Heng, Jerry Y Y; Williams, Daryl R; Thielmann, Frank; Bouza, Peter; Keith, Adam R; Thiele, Greg; Burnett, Daniel J

2012-10-01

Milling and micronization of particles are routinely employed in the pharmaceutical industry to obtain small particles with desired particle size characteristics. The aim of this study is to demonstrate that particle shape is an important factor affecting the fracture mechanism in milling. Needle-shaped crystals of the β polymorph of D-mannitol were prepared from recrystallization in water. A portion of the recrystallized materials was ball-milled. Unmilled and milled sieved fractions of recrystallized D-mannitol were analyzed by dynamic image analysis (DIA) and inverse gas chromatography (IGC) at finite concentration to explain the breakage/fracture behavior. In the process of ball-milling, D-mannitol preferentially fractured along their shortest axis, exposing (011) plane with increased hydrophilicity and increased bounding rectangular aspect ratio. This is in contrary to attachment energy modeling which predicts a fracture mechanism across the (010) plane with increased hydrophobicity, and small change in particle shape. Crystal size, and more importantly, crystal shape and facet-specific mechanical properties, can dictate the fracture/cleavage behavior of organic crystalline materials. Thorough understanding of the crystal slip systems, combining attachment energy prediction with particle shape and surface characterization using DIA and IGC, are important in understanding fracture behavior of organic crystalline solids in milling and micronization.

Solvent-free MALDI-MS for the analysis of a membrane protein via the mini ball mill approach: case study of bacteriorhodopsin.

PubMed

Trimpin, Sarah; Deinzer, Max L

2007-01-01

A mini ball mill (MBM) solvent-free matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) method allows for the analysis of bacteriorhodopsin (BR), an integral membrane protein that previously presented special analytical problems. For well-defined signals in the molecular ion region of the analytes, a desalting procedure of the MBM sample directly on the MALDI target plate was used to reduce adduction by sodium and other cations that are normally attendant with hydrophobic peptides and proteins as a result of the sample preparation procedure. Mass analysis of the intact hydrophobic protein and the few hydrophobic and hydrophilic tryptic peptides available in the digest is demonstrated with this robust new approach. MS and MS/MS spectra of BR tryptic peptides and intact protein were generally superior to the traditional solvent-based method using the desalted "dry" MALDI preparation procedure. The solvent-free method expands the range of peptides that can be effectively analyzed by MALDI-MS to those that are hydrophobic and solubility-limited.

Fe-FeS2 adsorbent prepared with iron powder and pyrite by facile ball milling and its application for arsenic removal.

PubMed

Min, Xiaobo; Li, Yangwenjun; Ke, Yong; Shi, Meiqing; Chai, Liyuan; Xue, Ke

2017-07-01

Arsenic is one of the major pollutants and a worldwide concern because of its toxicity and chronic effects on human health. An adsorbent of Fe-FeS 2 mixture for effective arsenic removal was successfully prepared by mechanical ball milling. The products before and after arsenic adsorption were characterized with scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The adsorbent shows high arsenic removal efficiency when molar ratio of iron to pyrite is 5:5. The experimental data of As(III) adsorption are fitted well with the Langmuir isotherm model with a maximal adsorption capacity of 101.123 mg/g. And As(V) data were described perfectly by the Freundlich model with a maximal adsorption capacity of 58.341 L/mg. As(III) is partial oxidized to As(V) during the adsorption process. High arsenic uptake capability and cost-effectiveness of waste make it potentially attractive for arsenic removal.

Cryo-Milling and the Hydrogen Storage Properties of NaAlH4

NASA Astrophysics Data System (ADS)

Feller, Kevin; Dobbins, Tabbetha

2013-03-01

High energy ball milling of metal hydrides is a common way to both introduce catalysts (e.g. TiCl3) and to simultaneously increase the surface area. Both catalysis and increased surface area improve hydrogen storage capacity of the material. Nanostructuring of hydrides by depositing them into mesoporous templates (such as anodized alumina, MOFs, and SBA-15) has become a common way to increase surface area. However, the mesoporous template does not add hydrogen storage capacity--and thus, tends to decreased overall storage weight percent for the nanostructured hydride material. As with most materials, hydrides become brittle at low temperatures and will tend to fracture more readily. We will process Sodium Aluminum Hydride (NaAlH4) using cryogenic high energy ball milling using an in-house modified chamber SPEX Certiprep M8000 mixer/mill in order to gain a nanostructured hydride without mesoporous template material. Details of the modified mixer mill design will be presented. Ultimately, our planned future work is to study the resultant material using x-ray diffraction (Scherrer method for crystallite size), absorption/desorption temperature programmed desorption (TPD), and ultrasmall-angle x-ray scattering (USAXS) microstructural quantification to understand the role of cryomilling on enhancing the material's ability to store (and release) hydrogen.

Microstructure-Property Correlation in Magnesium-based Hydrogen Storage Systems: The Case for Ball-milled Magnesium Hydride Powder and Magnesium-based Multilayered Composites

NASA Astrophysics Data System (ADS)

Danaie, Mohsen

The main focus of this thesis is the characterization of defects and microstructure in high-energy ball milled magnesium hydride powder and magnesium-based multilayered composites. Enhancement in kinetics of hydrogen cycling in magnesium can be achieved by applying severe plastic deformation. A literature survey reveals that, due to extreme instability of alpha-MgH 2 in transmission electron microscope (TEM), the physical parameters that researchers have studied are limited to particle size and grain size. By utilizing a cryogenic TEM sample holder, we extended the stability time of the hydride phase during TEM characterization. Milling for only 30 minutes resulted in a significant enhancement in desorption kinetics. A subsequent annealing cycle under pressurized hydrogen reverted the kinetics to its initial sluggish state. Cryo-TEM analysis of the milled hydride revealed that mechanical milling induces deformation twinning in the hydride microstructure. Milling did not alter the thermodynamics of desorption. Twins can enhance the kinetics by acting as preferential locations for the heterogeneous nucleation of metallic magnesium. We also looked at the phase transformation characteristics of desorption in MgH2. By using energy-filtered TEM, we investigated the morphology of the phases in a partially desorbed state. Our observations prove that desorption phase transformation in MgH2 is of "nucleation and growth" type, with a substantial energy barrier for nucleation. This is contrary to the generally assumed "core-shell" structure in most of the simulation models for this system. We also tested the hydrogen storage cycling behavior of bulk centimeter-scale Mg-Ti and Mg-SS multilayer composites synthesized by accumulative roll-bonding. Addition of either phase (Ti or SS) allows the reversible hydrogen sorption at 350°C, whereas identically roll-bonded pure magnesium cannot be absorbed. In the composites the first cycle of absorption (also called "activation

Process parameter dependent growth phenomena of naproxen nanosuspension manufactured by wet media milling.

PubMed

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Ball Screw Actuator Including a Compliant Ball Screw Stop

NASA Technical Reports Server (NTRS)

Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

2015-01-01

An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

Ball Screw Actuator Including a Compliant Ball Screw Stop

NASA Technical Reports Server (NTRS)

Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

2017-01-01

An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

Solid state amorphization in the Al-Fe binary system during high energy milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urban, P., E-mail: purban@us.es; Montes, J. M.; Cintas, J.

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{submore » 2}.« less

Bowling Ball Spotting

NASA Technical Reports Server (NTRS)

1985-01-01

Exactatron, an accurate weighing and spotting system in bowling ball manufacture, was developed by Ebonite International engineers with the assistance of a NASA computer search which identified Jet Propulsion Laboratory (JPL) technology. The JPL research concerned a means of determining the center of an object's mass, and an apparatus for measuring liquid viscosity, enabling Ebonite to identify the exact spotting of the drilling point for top weighting.

A comparison of the amorphization of zeolitic imidazolate frameworks (ZIFs) and aluminosilicate zeolites by ball-milling.

PubMed

Baxter, Emma F; Bennett, Thomas D; Cairns, Andrew B; Brownbill, Nick J; Goodwin, Andrew L; Keen, David A; Chater, Philip A; Blanc, Frédéric; Cheetham, Anthony K

2016-03-14

X-ray diffraction has been used to investigate the kinetics of amorphization through ball-milling at 20 Hz, for five zeolitic imidazolate frameworks (ZIFs) - ZIF-8, ZIF-4, ZIF-zni, BIF-1-Li and CdIF-1. We find that the rates of amorphization for the zinc-containing ZIFs increase with increasing solvent accessible volume (SAV) in the sequence ZIF-8 > ZIF-4 > ZIF-zni. The Li-B analogue of the dense ZIF-zni amorphizes more slowly than the corresponding zinc phase, with the behaviour showing a correlation with their relative bulk moduli and SAVs. The cadmium analogue of ZIF-8 (CdIF-1) amorphizes more rapidly than the zinc counterpart, which we ascribe primarily to its relatively weak M-N bonds as well as the higher SAV. The results for the ZIFs are compared to three classical zeolites - Na-X, Na-Y and ZSM-5 - with these taking up to four times longer to amorphize. The presence of adsorbed solvent in the pores is found to render both ZIF and zeolite frameworks more resistant to amorphization. X-ray total scattering measurements show that amorphous ZIF-zni is structurally indistinguishable from amorphous ZIF-4 with both structures retaining the same short-range order that is present in their crystalline precursors. By contrast, both X-ray total scattering measurements and (113)Cd NMR measurements point to changes in the local environment of amorphous CdIF-1 compared with its crystalline CdIF-1 precursor.

Economical drive for large tube mills by means of planetary gears

NASA Technical Reports Server (NTRS)

Ackle, W.

1980-01-01

The performance of heavy-duty planetary gear drives for ball mills used in the cement industry since 1967 is described. These gear drives transmit up to 8500 HP per installation. A reliable method for establishing gear drive efficiency is described and possible savings due to higher efficiency are indicated.

Effect of Milling Time on the Blocking Temperature of Nanoparticles of Magnetocaloric Gd5Si4

NASA Astrophysics Data System (ADS)

Hadimani, Ravi; Gupta, Shalbh; Harstad, Shane; Pecharsky, Vitalij; Jiles, David; David C Jiles Team; Vitalij Pecharsky Collaboration

Extensive research has been done on giant magnetocaloric material Gd5(SixGe1-x)4 to improve adiabatic temperature/isothermal entropy change. However, there have been only a few reports on fabrication of nanostructure/nanoparticles that can be used to tune various properties by changing the length scale. Recently we have reported fabrication of room temperature ferromagnetic nanoparticles of Gd5Si4 using high energy ball milling. These nanoparticles have potential applications in biomedical engineering such as better T2 MRI contrast agents and in hypothermia. Here we report the effect of milling time on the blocking temperature, micro-structure, crystal structure, and magnetic properties of these nanoparticles. Magnetization vs. temperature at an applied field of 100 Oe is measured for all the ball milled samples. Bulk Gd5Si4 has a transition temperature of ~340 K. There are two phase transitions observed in the nanoparticles, one near 300 K corresponding to the Gd5Si4 phase and another between 75-150 K corresponding to Gd5Si3. Zero Field Cooling (ZFC) and Field Cooling (FC) were measured. The blocking temperatures for the nanoparticles increase with decrease in milling time.

Laser Sintering Technology and Balling Phenomenon.

PubMed

Oyar, Perihan

2018-02-01

The aim of this review was to evaluate the balling phenomenon which occurs typically in Selective Laser Sintering (SLS). The balling phenomenon is a typical SLS defect, and observed in laser sintered powder, significantly reduces the quality of SLS, and hinders the further development of SLS Technology. Electronic database searches were performed using Google Scholar. The keywords "laser sintering, selective laser sintering, direct metal laser melting, and balling phenomenon" were searched in title/abstract of publications, limited to December 31, 2016. The inclusion criteria were SLS, balling phenomenon, some alloys (such as Cr-Co, iron, stainless steel, and Cu-based alloys) mechanical properties, microstructure and bond strength between metal-ceramic crown, laboratory studies, full text, and in English language. A total of 100 articles were found the initial search and yielded a total of 50 studies, 30 of which did not fulfill the inclusion criteria and were therefore excluded. In addition, 20 studies were found by screening the reference list of all included publications. Finally, 40 studies were selected for this review. The method in question is regulated by powder material characteristics and the conditions of laser processing. The procedure of formation, affecting factors, and the mechanism of the balling effect are very complex.

Great (Flame) Balls of Fire! Structure of Flame Balls at Low Lewis-number-2 (SOFBALL-2)

NASA Technical Reports Server (NTRS)

Ronney, Paul; Weiland, Karen J.; Over, Ann (Technical Monitor)

2002-01-01

Everyone knows that an automobile engine wastes fuel and energy when it runs with a fuel-rich mixture. 'Lean' burning, mixing in more air and less fuel, is better for the environment. But lean mixtures also lead to engine misfiring and rough operation. No one knows the ultimate limits for lean operation, for 'weak' combustion that is friendly to the environment while still moving us around. This is where the accidental verification of a decades-old prediction may have strong implications for designing and running low-emissions engines in the 21st century. In 1944, Soviet physicist Yakov Zeldovich predicted that stationary, spherical flames are possible under limited conditions in lean fuel-air mixtures. Dr. Paul Ronney of the University of Southern California accidentally discovered such 'flame balls' in experiments with lean hydrogen-air mixtures in 1984 during drop-tower experiments that provided just 2.2 seconds of near weightlessness. Experiments aboard NASA's low-g aircraft confirmed the results, but a thorough investigation was hampered by the aircraft's bumpy ride. And stable flame balls can only exist in microgravity. The potential for investigating combustion at the limits of flammability, and the implications for spacecraft fire safety, led to the Structure of Flame Balls at Low Lewis-number (SOFBALL) experiment flown twice aboard the Space Shuttle on the Microgravity Sciences Laboratory-1 (MSL-1) in 1997. Success there led to the planned reflight on STS-107. Flame balls are the weakest fires yet produced in space or on Earth. Typically each flame ball produced only 1 watt of thermal power. By comparison, a birthday candle produces 50 watts. The Lewis-number measures the rate of diffusion of fuel into the flame ball relative to the rate of diffusion of heat away from the flame ball. Lewis-number mixtures conduct heat poorly. Hydrogen and methane are the only fuels that provide low enough Lewis-numbers to produce stable flame balls, and even then only for

21. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

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

21. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model no. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. Steam-feed pipe at top left of engine. Steam exhaust pipe leaves base of engine on right end and projects upwards. The boiler feed and supply pipe running water through the engine's pre-heat system are seen running to the lower left end of the engine. Pulley in the foreground was not used. The centrifugals were powered by a belt running from the flywheel in the background. Ball-type governor and pulley are on left end of the engine. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

OVERVIEW OF STAMP MILL SITE,LOOKING SOUTHWEST. THE LOWER TRAM TERMINAL ...

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

OVERVIEW OF STAMP MILL SITE,LOOKING SOUTHWEST. THE LOWER TRAM TERMINAL IS OUT OF FRAME, JUST TO THE RIGHT. WATER TANK, LOADING PLATFORM, AND TRAM TRESTLE LEADING UP TO THE TRAM TERMINAL ARE AT RIGHT. THE STRUCTURE AT EXTREME RIGHT BELOW THE TRESTLE, ARE REMAINS OF A SECONDARY ORE BIN, WITH BALL MILL FOUNDATIONS AND WOOD DEBRIS JUST BELOW ON THE SECOND LEVEL. AT CENTER IS A BOILER AND THE FRAME WORK OF A FILTER PRESS. THE SMALL STRUCTURE AT CENTER LEFT IS AN INTERPRETIVE SIGN PLACED BY THE PARK SERVICE. AT LOWER LEFT, THIRD LEVEL OF THE MILL, ARE THE REMAINS OF A BLACKSMITH'S FORGE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

Synthesis and magnetization studies of nanopowder Fe₇₀Ni₂₀Cr₁₀ alloys prepared by high energy milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chater, R., E-mail: chatersamy@yahoo.fr; Bououdina, M., E-mail: mboudina@gmail.com; Department of Physics, College of Science, University of Bahrain, PO Box 32038, Kingdom of Bahrain

2013-05-01

Nanocrystalline Fe{sub 1–x–y}Ni xCr y (x=20, y=10% in Wt)) alloy samples were prepared by mechanical alloying process. Fe, Ni and Cr elemental powders have been ball milled in a planetary mill for various periods of time, up to 27 h. XRD analysis allowed the determination of the structure of the mixture, the average crystallite size and the lattice parameter as a function of milling time. The complete formation of FeNiCr is observed after 27 h milling. With increasing milling time from 0 to 27 h, it is observed that the lattice parameter increases from 0.3515 to 0.3593 nm as wellmore » as an increase of microstrain from 0.15 to 0.40%, whereas the grain size decreases from 48 to 13 nm. Grain morphology of the powders at different formation stages was examined using SEM. Saturation magnetization and coercive fields derived from the hysteresis curves are discussed as a function of milling time. - Graphical abstract: Fe₇₀Ni₂₀Cr₁₀ nanopowders were prepared using a planetary ball mill. The structure and microstructure vary with milling time; thereby important modifications of the magnetic properties were observed and discussed. Highlights: • Nanocrystalline Fe₇₀Ni₂₀Cr₁₀ alloy were prepared by the mechanical alloying process. • The complete formation of Fe₇₀Ni₂₀Cr₁₀ is observed after 24 h milling. • With increasing milling time, the grain size decreases, while the strain increases. • The SEM images allowed following the morphology of the materials at different stages. • M s and H C derived from the hysteresis are discussed as a function of milling time.« less

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

PubMed

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.

RadBall Technology Testing and MCNP Modeling of the Tungsten Collimator.

PubMed

Farfán, Eduardo B; Foley, Trevor Q; Coleman, J Rusty; Jannik, G Timothy; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J

2010-01-01

The United Kingdom's National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall(™), which can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. RadBall(™) consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly more opaque, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner, which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation matrix provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. RadBall(™) has no power requirements and can be positioned in tight or hard-to reach locations. The RadBall(™) technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This study focuses on the RadBall(™) testing and modeling accomplished at SRNL.

Pretreatment of eucalyptus wood chips for enzymatic saccharification using combined sulfuric acid-free ethanol cooking and ball milling.

PubMed

Teramoto, Yoshikuni; Tanaka, Noriko; Lee, Seung-Hwan; Endo, Takashi

2008-01-01

A combined sulfuric acid-free ethanol cooking and pulverization process was developed in order to achieve the complete saccharification of the cellulosic component of woody biomass, thereby avoiding the problems associated with the use of strong acid catalysts. Eucalyptus wood chips were used as a raw material and exposed to an ethanol/water/acetic acid mixed solvent in an autoclave. This process can cause the fibrillation of wood chips. During the process, the production of furfural due to an excessive degradation of polysaccharide components was extremely low and delignification was insignificant. Therefore, the cooking process is regarded not as a delignification but as an activation of the original wood. Subsequently, the activated solid products were pulverized by ball-milling in order to improve their enzymatic digestibility. Enzymatic hydrolysis experiments demonstrated that the conversion of the cellulosic components into glucose attained 100% under optimal conditions. Wide-angle X-ray diffractometry and particle size distribution analysis revealed that the scale affecting the improvement of enzymatic digestibility ranged from 10 nm to 1 microm. Field emission scanning electron microscopy depicted that the sulfuric acid-free ethanol cooking induced a pore formation by the removal of part of the lignin and hemicellulose fractions in the size range from a few of tens nanometers to several hundred nanometers. (c) 2007 Wiley Periodicals, Inc.

James L. Tuck Los Alamos ball lightning pioneer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, D.A.

1999-07-01

James Tuck was well known for starting the Project Sherwood group at Los Alamos Scientific Laboratory in 1952. This group was formed to study and develop concepts for controlled fusion energy. In his later years after retiring from Controlled Fusion Division, he continued research at Los Alamos on the topic of ball lightning. He traveled widely giving lectures on both observations of others and his own experimental efforts. He collected anecdotal observations obtained from those in his lecture audiences during his travels and from responses from newspaper articles where he asked for specific information from ball lightning observers. He finallymore » cut off this collection of data when the number of responses became overwhelming. The author's primary publication on ball lightning was a short laboratory report. He planned on publishing a book on the subject but this was never completed before his death. Tuck focused his experimental effort on attempting to duplicate the production of plasma balls claimed to be observed in US Navy submarines when a switch was opened under overload conditions with battery power. During lunch breaks he made use of a Los Alamos N-division battery bank facility to mock up a submarine power pack and switch gear. This non-funded effort was abruptly terminated when an explosion occurred in the facility. An overview of Tuck's research and views will be given. The flavor Jim's personality as well as a ball produced with his experimental apparatus will be shown using video chips.« less

Synthesis of Multimetal-Graphene Composite by Mechanical Milling

NASA Astrophysics Data System (ADS)

Saiphaneendra, Bachu; Srivastava, Avi Krishna; Srivastava, Chandan

2016-10-01

Multimetal-graphene composites were synthesized using the ball milling technique. To prepare the composite, graphite powder was mixed with Fe, Cr, Co, Cu and Mg powders. This mixture was then mechanically milled for 35 h in toluene medium. After milling, the multimetal-graphite mixture was mixed with sodium lauryl sulfate and sonicated for 2 h. Sonication led to the exfoliation of graphene sheets. Formation of graphene was confirmed from x-ray diffraction and Raman spectroscopy. Transmission electron microscopy-based analysis revealed the formation of multimetal deposits over the graphene surface. Compositional analysis of the multimetal deposits revealed fairly uniform distribution of all the five component metal atoms over the graphene sheet. The average composition of the multimetal deposit was determined to be 11.4 ± 4 at.% Mg, 33.8 ± 19 at.% Cr, 21.8 ± 16 at.% Fe, 9.4 ± 5.7 at.% Co and 23.6 ± 12 at.% Cu.

Structure and electrochemical behaviour of metastable Mg 50Ti 50 alloy prepared by ball milling

NASA Astrophysics Data System (ADS)

Rousselot, S.; Bichat, M.-P.; Guay, D.; Roué, L.

A 50-50 mixture of Mg and Ti was milled for different times, and the cycling discharge capacities of the resulting compounds were evaluated in KOH media. From Rietveld refinement analysis of the X-ray diffraction patterns, it is shown that a metastable hcp Mg 50Ti 50 compound is formed after 20 h of milling. This material has a very low-electrochemical hydriding activity. However, in the presence of 10 wt.% Pd (added before milling), it displays a maximum discharge capacity of ca. 400 mAh g -1 after three charge/discharge cycles. The irreversible structural evolution of the Mg 50Ti 50 alloy from a hcp phase to a fcc phase upon cycling is demonstrated.

10. RW Meyer Sugar Mill: 18761889. Simple, singlecylinder, horizontal, reciprocating ...

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

10. RW Meyer Sugar Mill: 1876-1889. Simple, single-cylinder, horizontal, reciprocating steam engine, model No. 1, 5' x 10', 6 hp, 175 rpm. Manufactured by Ames Iron Works, Oswego, New York, 1879. View: Steam engine powered the mill's centrifugals. To the left of the horizontal (fluted) cylinder is the water pump which moved the boiler feed water through the engine's pre-heat system (the exhaust steam heated the boiler feedwater before it was pumped on to the boiler). The steam-feed port, manual throttle valve, and fly-ball governor and pulley and to the right of the cylinder. The drive shaft with flywheel to the left and pulley to the right are seen behind the piston rod, cross-head, wrist pen, connecting rod and the slide valve and eccentric. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy

PubMed Central

Julien, Patrick A; Malvestiti, Ivani

2017-01-01

We provide the first in situ and real-time study of the effect of milling frequency on the course of a mechanochemical organic reaction conducted using a vibratory shaker (mixer) ball mill. The use of in situ Raman spectroscopy for real-time monitoring of the mechanochemical synthesis of a 2,3-diphenylquinoxaline derivative revealed a pronounced dependence of chemical reactivity on small variations in milling frequency. In particular, in situ measurements revealed the establishment of two different regimes of reaction kinetics at different frequencies, providing tentative insight into processes of mechanical activation in organic mechanochemical synthesis. PMID:29114323

The effect of milling time on the synthesis of Cu{sub 54}Mg{sub 22}Ti{sub 18}Ni{sub 6} alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kursun, C., E-mail: celalkursun@ksu.edu.tr; Gogebakan, M., E-mail: gogebakan@ksu.edu.tr

In the present work, nanocrystalline Cu{sub 54}Mg{sub 22}Ti{sub 18}Ni{sub 6} alloy was produced by mechanical alloying from mixtures of pure crystalline Cu, Mg, Ti and Ni powders using a Fritsch planetary ball mill with a ball to powder ratio of 10:1. Morphological changes, microstructural evolution and thermal behaviour of the Cu-Mg-Ti-Ni powders at different stages of milling were characterised by X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray detection (SEM/EDX) and differential thermal analysis (DTA). This alloy resulted in formation of single phase solid solution with FCC structure α-Cu (Mg, Ti, Ni) after 80 h of milling. In the initialmore » stage of milling different sized and shaped elemental powders became uniform during mechanical alloying. The homogeneity of the Cu{sub 54}Mg{sub 22}Ti{sub 18}Ni{sub 6} alloy increased with increasing milling time. The EDX result also confirmed the compositional homogeneity of the powder alloy. The crystallite size of alloy was calculated below 10 nm from XRD data.« less

Ball clay

USGS Publications Warehouse

Virta, R.L.

2001-01-01

Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

Degradation of trichloroethene with a noval ball milled Fe-C nanocomposite

DOE PAGES

Gao, Jie; Wang, Wei; Rondinone, Adam Justin; ...

2015-07-18

Nanoscale zero-valent iron (NZVI) is effective in reductively degrading dense non-aqueous phase liquids (DNAPLs), such as trichloroethene (TCE), in groundwater (i.e., dechlorination) although the NZVI technology itself still suffers from high material costs and inability to target hydrophobic contaminants in source zones. To address these problems, we developed a novel, inexpensive iron-carbon (Fe-C) nanocomposite material by simultaneously milling micron-size iron and activated carbon powder. Microscopic and X-ray diffraction (XRD) characterization of the composite material revealed that nanoparticles of Fe were dispersed in activated carbon and a new iron carbide phase was formed. Bench-scale studies showed that this material instantaneously sorbedmore » >90% of TCE from aqueous solutions and subsequently decomposed TCE into non-chlorinated products. Compared to milled Fe, Fe-C nanocomposite dechlorinated TCE at a slightly slower rate and favored the production of ethene over other TCE degradation products such as C 3-C 6 compounds. When placed in hexane-water mixture, the Fe-C nanocomposite materials are preferentially partitioned into the organic phase, indicating the ability of the composite materials to target DNAPL during remediation.« less

Relativistic-microwave theory of ball lightning.

PubMed

Wu, H-C

2016-06-22

Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

Relativistic-microwave theory of ball lightning

NASA Astrophysics Data System (ADS)

Wu, H.-C.

2016-06-01

Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics.

Relativistic-microwave theory of ball lightning

PubMed Central

Wu, H.-C.

2016-01-01

Ball lightning, a fireball sometimes observed during lightnings, has remained unexplained. Here we present a comprehensive theory for the phenomenon: At the tip of a lightning stroke reaching the ground, a relativistic electron bunch can be produced, which in turn excites intense microwave radiation. The latter ionizes the local air and the radiation pressure evacuates the resulting plasma, forming a spherical plasma bubble that stably traps the radiation. This mechanism is verified by particle simulations. The many known properties of ball lightning, such as the occurrence site, relation to the lightning channels, appearance in aircraft, its shape, size, sound, spark, spectrum, motion, as well as the resulting injuries and damages, are also explained. Our theory suggests that ball lighting can be created in the laboratory or triggered during thunderstorms. Our results should be useful for lightning protection and aviation safety, as well as stimulate research interest in the relativistic regime of microwave physics. PMID:27328835

The synthesis of Cu/Fe/Fe3O4 catalyst through the aqueous solution ball milling method assisted by high-frequency electromagnetic field

NASA Astrophysics Data System (ADS)

Yingzhe, Zhang; Yuxing, He; Qingdong, Qin; Fuchun, Wang; Wankun, Wang; Yongmei, Luo

2018-06-01

In this paper, nano-magnetic Cu/Fe/Fe3O4 catalyst was prepared by a new aqueous solution ball milling method assisted by high-frequency electromagnetic field at room temperature. The products were characterized by means of X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED), and vibrating sample magnetometer (VSM). Microwave induced catalytic degradation of methylene blue (MB) was carried out in the presence of Cu/Fe/Fe3O4. The concentration of methylene blue was determined by UV-Vis spectrophotometry. The solid catalyst showed high catalytic activity of degrade MB and considerable saturation magnetization, lower remanence and coercivity. It indicate that the catalyst can be effectively separated for reuse by simply applying an external magnetic field and it can greatly promote their potential industrial application to eliminate organic pollutants from waste-water. Finally, we found that it is the non-thermal effect of microwave that activated the catalytic activity of Cu/Fe/Fe3O4 to degrade MB.

Reexamination of Ball-Race Conformity Effects on Ball Bearing Life

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Poplawski, Joseph V.; Root, Lawrence E.

2007-01-01

The analysis in this report considers the life of the ball set as well as the respective lives of the races to reassess the effect of ball-race conformity on ball bearing life. The related changes in ball bearing life are incorporated in life factors that can be used to modify the bearing predicted life using the Lundberg-Palmgren equations and the ANSI/ABMA and ISO Standards. Two simple algebraic relationships were established to calculate life factors LF(sub c) to determine the effect of inner- and outer-race conformity combinations on bearing L(sub 10) life for deepgroove and angular-contact ball bearings, respectively. Depending on the bearing type and series as well as conformity combinations, the calculated life for deep-groove ball bearings can be over 40 percent less than that calculated by the Lundberg-Palmgren equations. For angular-contact ball bearings, the life can vary between +16 and -39 percent from that calculated by the Lundberg-Palmgren equations. Comparing the two ball bearing types, the life factors LF(sub c) for the deep-groove bearings can be as much as 40 percent lower than that for angular-contact ball bearings.

Effect of milling time on microstructure and mechanical properties of Cu-Ni-graphite composites

NASA Astrophysics Data System (ADS)

Wang, Yiran; Gao, Yimin; Li, Yefei; Zhang, Chao; Huang, Xiaoyu; Zhai, Wenyan

2017-09-01

Cu-Ni-graphite composites are intended for application in switch slide baseplate materials. The microstructure of the composites depends strongly on the ball milling time, and a suitable time can significantly improve the properties of the Cu-Ni-graphite composites. In this study, a two-step milling method was employed. The morphology evolution and microstructural features of the powder was characterized at different milling times. Afterwards, the Cu-Ni-graphite composites were prepared in the process of cold pressing, sintering, re-pressing and re-sintering as a function of the different milling times. Finally, both the microstructure and mechanical properties of the Cu-Ni-graphite composites are discussed. The results show that no new phase was generated during the milling process. The morphology evolution of the mixture of Cu/Ni powder changed from spherical-like to cubic-like, plate-like and flake-like with an increasing milling time. The microstructure of the composites consisted of α-phase and graphite. The boundary area and quantity of pores changed as the milling time increased. The relative density, hardness and flexural strength reached maximum values at 15 h of milling time.

A general theory for ball lightning structure and light output

NASA Astrophysics Data System (ADS)

Morrow, R.

2018-03-01

A general theory for free-floating ball lightning is presented which unifies the phantom plasma ball theory involving the production of very little light, with theories for ball lightning involving light output produced by burning particles from the soil. The mechanism for the formation of plasma balls is shown to be quite general, producing very similar plasma balls independent of initial ion densities over four orders of magnitude. All that is required is an excess of positive ions in the initial ball of ions. The central plasma density after 1 s is shown to be the reciprocal of the ion neutralization coefficient for all cases, both analytically and computationally. Further, the plasma region has zero electric field in all cases. Surrounding the plasma ball is a sphere of positive ions moving away from the centre via their own space-charge field; this space-charge field, which is the same in all cases near the plasma ball, drives negative ions and negative particles towards the plasma centre. The connection with burning particle theories is the proposition that the burning particles are highly-charged which is very likely after a lightning strike. Burning negatively charged particles would be driven into the plasma ball region and trapped while any positively charged particles would be driven away. The plasma ball structure is shown to last more than 10 s and the ‘burnout time’ for a typical coal particle (as an example) has been measured at 5-10 s this is comparable with the lifetimes observed for ball lightning. The light output from a few hundred particles is estimated to be ~1 W, a typical output for ball lightning. Finally, suggestions are made for the generation of ball lightning in the laboratory.

Colorimetric protein determination in microalgae (Chlorophyta): association of milling and SDS treatment for total protein extraction.

PubMed

Mota, Maria Fernanda S; Souza, Marcella F; Bon, Elba P S; Rodrigues, Marcoaurelio A; Freitas, Suely Pereira

2018-05-24

The use of colorimetric methods for protein quantification in microalgae is hindered by their elevated amounts of membrane-embedded intracellular proteins. In this work, the protein content of three species of microalgae was determined by the Lowry method after the cells were dried, ball-milled, and treated with the detergent sodium dodecyl sulfate (SDS). Results demonstrated that the association of milling and SDS treatment resulted in a 3- to 7-fold increase in protein quantification. Milling promoted microalgal disaggregation and cell wall disruption enabling access of the SDS detergent to the microalgal intracellular membrane proteins and their efficient solubilization and quantification. © 2018 Phycological Society of America.

Ball clay

USGS Publications Warehouse

Virta, R.L.

2013-01-01

Four companies — H.C. Spinks Clay Co., Inc., Imerys, Old Hickory Clay Co. and Unimin Corp. — mined ball clay in five U.S. states in 2012. Production, on the basis of preliminary data, was 900 kt (992,000 st), with an estimated value of $42.3 million. This was a slight increase in tonnage from 886 kt (977,000 st), with a value of $40.9 million in 2011. Tennessee was the leading ball clay producing state, with 63 percent of domestic production, followed by Texas, Mississippi, Kentucky and Indiana. Reported ball clay production from Indiana probably was fire clay rather than ball clay. About 69 percent of total ball clay production was airfloat, 20 percent was crude and 11 percent was water-slurried.

Ball valve extractor

DOEpatents

Herndon, Charles; Brown, Roger A.

2002-01-01

An apparatus and process for removing a ball valve is provided. The ball valve removal tool provides a handle sliding along the length of a shaft. One end of the shaft is secured within an interior cavity of a ball valve while the opposite end of the shaft defines a stop member. By providing a manual sliding force to the handle, the handle impacts the stop member and transmits the force to the ball valve. The direction of the force is along the shaft of the removal tool and disengages the ball valve from the ball valve housing.

Biomechanical Analysis of Weighted-Ball Exercises for Baseball Pitchers.

PubMed

Fleisig, Glenn S; Diffendaffer, Alek Z; Aune, Kyle T; Ivey, Brett; Laughlin, Walter A

Weighted-ball throwing programs are commonly used in training baseball pitchers to increase ball velocity. The purpose of this study was to compare kinematics and kinetics among weighted-ball exercises with values from standard pitching (ie, pitching standard 5-oz baseballs from a mound). Ball and arm velocities would be greater with lighter balls and joint kinetics would be greater with heavier balls. Controlled laboratory study. Twenty-five high school and collegiate baseball pitchers experienced with weighted-ball throwing were tested with an automated motion capture system. Each participant performed 3 trials of 10 different exercises: pitching 4-, 5-, 6-, and 7-oz baseballs from a mound; flat-ground crow hop throws with 4-, 5-, 6-, and 7-oz baseballs; and flat-ground hold exercises with 14- and 32-oz balls. Twenty-six biomechanical parameters were computed for each trial. Data among the 10 exercises were compared with repeated measures analysis of variance and post hoc paired t tests against the standard pitching data. Ball velocity increased as ball mass decreased. There were no differences in arm and trunk velocities between throwing a standard baseball and an underweight baseball (4 oz), while arm and trunk velocities steadily decreased as ball weight increased from 5 to 32 oz. Compared with values pitching from a mound, velocities of the pelvis, shoulder, and ball were increased for flat-ground throws. In general, as ball mass increased arm torques and forces decreased; the exception was elbow flexion torque, which was significantly greater for the flat-ground holds. There were significant differences in body positions when pitching on the mound, flat-ground throws, and holds. While ball velocity was greatest throwing underweight baseballs, results from the study did not support the rest of the hypothesis. Kinematics and kinetics were similar between underweight and standard baseballs, while overweight balls correlated with decreased arm forces, torques

Synthesis and characterization of NaCo(1-x)MnxO2 solid electrolyte using sol-gel method: the effect of milling speed variations

NASA Astrophysics Data System (ADS)

Suyati, L.; Widyayanti, O. A.; Qushoyyi, M.; Darmawan, A.; Nuryanto, R.

2018-04-01

Battery is a device that converts chemical energy into electrical energy through electrochemical process. Further research on the synthesis of cathode of Na-ion battery that has good conductivity to maximize the battery performance needs to be conducted. One of the production steps of the NaCo(1-x)NaCo cathode synthesis in the Na-Ion battery was a ball-milling process, in which by the ball-milling process, the crystal size of NaCo(1-x)MnxO2 cathode can be minimized. The purpose of this study was to determine the effect of variation of ball-milling speed to the characteristics of resulting product including the oxide types composing NaCo(1-x)MnxO2 cathode, surface morphology, and conductivity. The main ingredients used were sodium acetate, manganese acetate, cobalt acetate with molar ratio of 0.7: 0.66: 0.22, respectively and citric acid as chelating agent with the M/CA ratio of 1: 1. The variations of milling speed were 0, 300, 400, 500, 600 and 700 rpm. Characterization of the product was conducted using XRD, SEM-EDS, and conductivity meter (LCR-meter). The result showed that a solid electrolyte of NaCo(1-x)MnxO2 consisting of NaMnO2, NaO2, CoO, Co2O3, MnO2 components was successfully synthesized. The observation on the milling speed at 400 rpm showed that the solid electrolyte produced had the highest conductivity i.e. 4.08 x 10-6 Scm-1 with a homogeneous surface morphology and had a spinel formula NaCo0,65Mn0,35O2.

Ball clay

USGS Publications Warehouse

Virta, R.L.

2000-01-01

Part of the 1999 Industrial Minerals Review. The state of the ball clay industry in 1999 is presented. Record highs in the sales and use of ball clay were attained in 1999 due to the continued strength of the U.S. economy. U.S. production was estimated at 1.25 million st for the year, with more than half of that amount mined in Tennessee. Details of the consumption, price, imports, and exports of ball clay in 1999 and the outlook for ball clay over the next few years are provided.

Moment of Inertia of a Ping-Pong Ball

ERIC Educational Resources Information Center

Cao, Xian-Sheng

2012-01-01

This note describes how to theoretically calculate and experimentally measure the moment of inertia of a Ping-Pong[R] ball. The theoretical calculation results are in good agreement with the experimental measurements that can be reproduced in an introductory physics laboratory.

Development of an electromechanical principle for wet and dry milling

NASA Astrophysics Data System (ADS)

Halbedel, Bernd; Kazak, Oleg

2018-05-01

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

Ball clay

USGS Publications Warehouse

Virta, Robert L.

2010-01-01

The article reports on the global market performance of ball clay in 2009 and presents an outlook for its 2010 performance. Several companies mined ball call in the country including Old Hickey Clay Co., Kentucky-Tennessee Clay Co., and H.C. Spinks Clay Co. Information on the decline in ball clay imports and exports is also presented.

Analysis of Particle Distribution in Milled Al-Based Composites Reinforced by B4C Nanoparticles

NASA Astrophysics Data System (ADS)

Alihosseini, Hamid; Dehghani, Kamran

2017-04-01

In the present work, high-energy ball milling was employed to synthesize Al-(5-10 wt.%)B4C nanocomposite. To do this, two sizes of particles of 50 nm as nanoparticles (NPs) and 50 μm as coarse particles (CPs) were used. The morphology and microstructure of the milled powders were characterized using particle size analyzer, SEM, TEM and EDX techniques. It was found that milling time, B4C particles size and their content strongly affect the characteristics of powders during milling process. The breaking and cold welding of powders was recognized as two main competitive actions during the milling process that influence the microstructural evolutions. It was found that the presence of CPs led to the formation of microcracks which promote the fracture process of Al powders. The dominated mechanisms during the fabrication of composites and nanocomposites were discussed. Also, the theoretical issues regarding the changes in morphology and distribution of B4C particles in CPs and NPs are clarified.

Having a Ball with Fitness Balls

ERIC Educational Resources Information Center

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…

Filtration effects on ball bearing life and condition in a contaminated lubricant

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Moyer, D. W.

1978-01-01

Ball bearings were fatigue tested with a noncontaminated MIL-L-23699 lubricant and with a contaminated MIL-L-23699 lubricant under four levels of filtration. The test filters had absolute particle removal ratings of 3, 30, 49, and 105 microns. Aircraft turbine engine contaminants were injected into the filter's supply line at a constant rate of 125 milligrams per bearing hour. Bearing life and running track condition generally improved with finer filtration. The experimental lives of 3- and 30-micron filter bearings were statistically equivalent, approaching those obtained with the noncontaminated lubricant bearings. Compared to these bearings, the lives of the 49-micron bearings were statistically lower. The 105-micron bearings experienced gross wear. The degree of surface distress, weight loss, and probable failure mode were dependent on filtration level, with finer filtration being clearly beneficial.

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

NASA Astrophysics Data System (ADS)

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

1998-04-01

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

Ball lightning from atmospheric discharges via metal nanosphere oxidation: from soils, wood or metals.

PubMed

Abrahamson, John

2002-01-15

The slow (diffusion-limited) oxidation of metal nanoparticles has previously been proposed as the mechanism for ball lightning energy release, and argued to be the result of a normal lightning strike on soil. Here this basic model of networked nanoparticles is detailed further, and extended to lightning strikes on metal structures, and also to the action of other storm-related discharges or man-made discharges. The basic model predicted the important properties of "average" observed ball lightning, and the extension in this paper also covers high-energy examples of ball lightning. Laboratory checks of the theory are described, and predictions given of what conditions are necessary for observing ball lightning in the laboratory. Key requirements of the model are a sheltered region near the strike foot and starting materials which can generate a metal vapour under intensive heating, including soil, wood or a metal structure. The evolution of hydrocarbons (often plastics) along with metal vapour can ensure the local survival of the metal vapour even in an oxidizing atmosphere. Subsequent condensation of this vapour to metallic nanoparticles in networks provides the coherence of a ball structure, which also releases light over an extended time. Also discussed is the passage of ball lightning through a sheet of building material, including glass, and its occasional charring of flesh on close contact.

Effect of milling atmosphere on structural and magnetic properties of Ni-Zn ferrite nanocrystalline

NASA Astrophysics Data System (ADS)

Hajalilou, Abdollah; Hashim, Mansor; Ebrahimi-Kahrizsangi, Reza; Masoudi Mohamad, Taghi

2015-04-01

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. Project supported by the University Putra Malaysia Graduate Research Fellowship Section.

Ball clay

USGS Publications Warehouse

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.

Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

PubMed Central

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

Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

PubMed

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.

Nano-Crystalline Thermally Evaporated Bi2Se3 Thin Films Synthesized from Mechanically Milled Powder

NASA Astrophysics Data System (ADS)

Amara, A.; Abdennouri, N.; Drici, A.; Abdelkader, D.; Bououdina, M.; Chaffar Akkari, F.; Khemiri, N.; Kanzari, M.; Bernède, J. C.

2017-08-01

Bi2Se3 powder has been successfully synthesized via mechanical ball milling of bismuth and selenium as starting materials. X-ray diffraction characterization revealed the formation of the rhombohedral and orthorhombic phases of Bi2Se3 material belonging to systems with space groups R\\bar{3}m and Pbnm, respectively. The advantageous last finding is confirmed by the Rietveld refinement of the x-ray diffraction data. Furthermore, the analysis of the x-ray data of thermally deposited thin films revealed that both orthorhombic and rhombohedral phases are coexisting in the layer. The morphology of the ball milled powder was studied by scanning electron microscopy. The phase formation of the material is confirmed by Raman spectroscopy. M-H (Magnetization versus Magnetic field) curve indicates that Bi2Se3 powder has a ferromagnetic behavior. Additionally, absorbance and transmittance measurements were carried out on the obtained thermally evaporated thin films and yielded a band gap of 1.33 eV supporting the potential application of the heterogeneous rhombohedral/orthorhombic Bi2Se3 material in photovoltaics.

Stemless ball valve

NASA Technical Reports Server (NTRS)

Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

2012-01-01

A stemless ball valve comprising: a right flange; left flange; ball with an axis pin and two travel pins; ball seal on either side of the ball; guide sleeve with inner walls comprising two channels; cartridge guide holder; inner magnetic cartridge; and outer magnetic cartridge. The ball is situated inside of the guide sleeve, and a travel pin is located in each of the two channels. The guide sleeve is situated inside of the cartridge guide holder, which is located adjacent to and outside of the inner magnetic cartridge and secured to the inner magnetic cartridge such that when the inner magnetic cartridge rotates, the cartridge guide holder also rotates. The cartridge guide holder is secured to the guide sleeve such that when the cartridge guide holder rotates, the travel pins move within the channels in the inner walls of the guide sleeve, thereby causing the ball to rotate.

The use of inverse phase gas chromatography to measure the surface energy of crystalline, amorphous, and recently milled lactose.

PubMed

Newell, H E; Buckton, G; Butler, D A; Thielmann, F; Williams, D R

2001-05-01

To assess differences in surface energy due to processing induced disorder and to understand whether the disorder dominated the surfaces of particles. Inverse gas chromatography was used to compare the surface energies of crystalline, amorphous, and ball milled lactose. The milling process made ca 1% of the lactose amorphous, however the dispersive contribution to surface energy was 31.2, 37.1, and 41.6 mJ m(-2) for crystalline, spray dried and milled lactose, respectively. A physical mixture of crystalline (99%) and amorphous (1%) material had a dispersive surface energy of 31.5 mJ m(-2). Milling had made the surface energy similar to that of the amorphous material in a manner that was very different to a physical mixture of the same amorphous content. The milled material will have similar interfacial interactions to the 100% amorphous material.

Novel device for male infertility screening with single-ball lens microscope and smartphone.

PubMed

Kobori, Yoshitomo; Pfanner, Peter; Prins, Gail S; Niederberger, Craig

2016-09-01

To investigate the usefulness of a novel semen analysis device consisting of a single-ball lens microscope paired with a state-of-the-art smartphone equipped with a camera. Laboratory investigation. University research laboratory. A total of 50 semen samples obtained from volunteers were analyzed for count, concentration, and motility with an 0.8-mm ball lens and three types of smartphone. Comparisons were made with results obtained with a laboratory-based computer-assisted sperm analysis (CASA) system. None. Sperm concentration; sperm motility. Sperm concentration counted with a ball lens and each smartphone showed a very strong correlation with the CASA results. Likewise, sperm motility calculated with our device showed significant correlations to CASA. If eight spermatozoa or fewer were found on the field of view of an iPhone 6s, the semen specimens were considered to be below the lower reference limit for sperm concentration of World Health Organization 2010 guidelines (15 × 10(6) spermatozoa/mL). The sensitivity was 87.5%, and specificity was 90.9%. Smartphones have great potential to analyze semen because they are portable, contain excellent digital cameras, and can be easily attached to a microscope. A single-ball lens microscope is inexpensive and easy to use for acquiring digital microscopic movies. Given its small size and weight, the device can support testing for male fertility at home or in the field, making it much more convenient and economical than current practice. This single-ball lens microscope provides an easy solution for global users to rapidly screen for male infertility. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Effect of milling on DSC thermogram of excipient adipic acid.

PubMed

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.

17. DETAIL, FOURTEENINCH LIQUID OXYGEN BALL VALVE. Looking south southeast. ...

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

17. DETAIL, FOURTEEN-INCH LIQUID OXYGEN BALL VALVE. Looking south southeast. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

Fatigue life of high-speed ball bearings with silicon nitride balls

NASA Technical Reports Server (NTRS)

Parker, R. J.; Zaretsky, E. V.

1974-01-01

Hot-pressed silicon nitride was evaluated as a rolling-element bearing material. The five-ball fatigue tester was used to test 12.7-mm- diameter silicon nitride balls at maximum Hertz stresses ranging from 4.27 x 10 to the 9th power n/sq m to 6.21 x 10 to the 9th power n/sq m at a race temperature of 328K. The fatigue life of NC-132 hot-pressed silicon nitride was found to be equal to typical bearing steels and much greater than other ceramic or cermet materials at the same stress levels. A digital computer program was used to predict the fatigue life of 120-mm- bore angular-contact ball bearings containing either steel or silicon nitride balls. The analysis indicates that there is no improvement in the lives of bearings of the same geometry operating at DN values from 2 to 4 million where silicon nitride balls are used in place of steel balls.

16. DETAIL SHOWING LIQUID OXYGEN TANK FOURTEENINCH BALL VALVE. Looking ...

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

16. DETAIL SHOWING LIQUID OXYGEN TANK FOURTEEN-INCH BALL VALVE. Looking southwest. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

Golf Ball

NASA Technical Reports Server (NTRS)

1998-01-01

The Ultra 500 Series golf balls, introduced in 1995 by Wilson Sporting Goods Company, has 500 dimples arranged in a pattern of 60 spherical triangles. The design employs NASA's aerodynamics technology analysis of air loads of the tank and Shuttle orbiter that was performed under the Space Shuttle External Tank program. According to Wilson, this technology provides 'the most symmetrical ball surface available, sustaining initial velocity longer and producing the most stable ball flight for unmatched accuracy and distance.' The dimples are in three sizes, shapes and depths mathematically positioned for the best effect. The selection of dimples and their placement optimizes the interaction of opposing forces of lift and drag. Large dimples reduce air drag, enhance lift, and maintain spin for distance. Small dimples prevent excessive lift that destabilizes the ball flight and the medium size dimples blend the other two.

Effect of ball geometry on endurance limit in bending of drilled balls

NASA Technical Reports Server (NTRS)

Munson, H. E.

1975-01-01

Four designs of drilled (cylindrically hollow) balls were tested for resistance to bending fatigue. Bending fatigue has been demonstrated to be a limiting factor in previous evaluations of the drilled ball concept. A web reinforced drilled ball was most successful in resisting bending fatigue. Another design of through drilled design, involving a heavier wall than the standard reference ball, also showed significant improvement in resistance to bending fatigue.

Fizz-Ball Fizzics

ERIC Educational Resources Information Center

Moinester, Murray; Gerland, Lars; Liger-Belair, Gerard; Ocherashvili, Aharon

2012-01-01

We describe the fluid dynamics principles governing the up-down oscillatory cycling of a bubble-covered, low-density, low-mass ball of material (referred to henceforth as a "fizz-ball") immersed inside a glass of bubbling (super-saturated) carbonated liquid. The bubbles serve to desaturate the liquid of excess CO[subscript 2]. The fizz-ball acts…

Ball Bearing Mechanics

NASA Technical Reports Server (NTRS)

Hamrock, Bernard J.; Dowson, Duncan

1981-01-01

Load-deflection relationships for different types of elliptical contacts such as those found in a ball bearing are developed. Simplified expressions that allow quick calculations of deformation to be made simply from a knowledge of the applied load, the material properties, and the geometry of the contacting elements are presented. Ball bearings subjected to radial, thrust and combined ball loads are analyzed. A design criterion for fatigue life of ball bearings is developed. The section of a satisfactory lubricant, as well as describing systems that provide a constant flow of lubricant to the contact, is considered.

A Comparative Study of Two Types of Ball-on-Ball Collision

ERIC Educational Resources Information Center

White, Colin

2017-01-01

This paper describes three methods of measuring the coefficient of restitution (CoR) for two different types of ball-on-ball collision. The first collision type (for which two different CoR measurement procedures are described) is a static, hanging steel ball forming part of a Newton's cradle arrangement, which is then hit by its adjacent…

The grinding behavior of ground copper powder for Cu/CNT nanocomposite fabrication by using the dry grinding process with a high-speed planetary ball mill

NASA Astrophysics Data System (ADS)

Choi, Heekyu; Bor, Amgalan; Sakuragi, Shiori; Lee, Jehyun; Lim, Hyung-Tae

2016-01-01

The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

Stemless ball valve

NASA Technical Reports Server (NTRS)

Burgess, Kevin (Inventor); Yakos, David (Inventor); Walthall, Bryan (Inventor)

2011-01-01

A stemless ball valve comprising two flanges and a ball with a channel, two axis pins and two travel pins. One end of each axis and travel pin is fixedly attached to the ball, and the other end of each axis pin is lodged into a notch in the first or second flange such that the axis pin is allowed to rotate in the notch. The guide sleeve comprises two channels, and one end of each travel pin is situated within one of the two channels in the guide sleeve. An outer magnetic cartridge causes the inner magnetic cartridge and guide sleeve to rotate, and when the guide sleeve rotates, the travel pins move up and down within the channels in the guide sleeve. The movement of the travel pins within the channels in the guide sleeve causes the ball to rotate, thereby opening and closing the ball valve.

Brown carbon in tar balls from smoldering biomass combustion

Treesearch

R. K. Chakrabarty; H. Moosmuller; L.-W. A. Chen; K. Lewis; W. P. Arnott; C. Mazzoleni; M. K. Dubey; C. E. Wold; W. M. Hao; S. M. Kreidenweis

2010-01-01

We report the direct observation of laboratory production of spherical, carbonaceous particles - "tar balls" - from smoldering combustion of two commonly occurring dry mid-latitude fuels. Real-time measurements of spectrally varying absorption Angstrom coefficients (AAC) indicate that a class of light absorbing organic carbon (OC) with wavelength dependent...

Quartz ball valve

NASA Technical Reports Server (NTRS)

Goetz, C.; Ingle, W. M. (Inventor)

1980-01-01

A ball valve particularly suited for use in the handling of highly corrosive fluids is described. It is characterized by a valve housing formed of communicating segments of quartz tubing, a pair of communicating sockets disposed in coaxial alignment with selected segments of tubing for establishing a pair of inlet ports communicating with a common outlet port, a ball formed of quartz material supported for displacement between the sockets and configured to be received alternately thereby, and a valve actuator including a rod attached to the ball for selectively displacing the ball relative to each of the sockets for controlling fluid flow through the inlet ports.

Wear-resistant ball bearings for space applications

NASA Technical Reports Server (NTRS)

Boving, H.; Hintermann, H. E.; Hanni, W.; Bondivenne, E.; Boeto, M.; Conde, E.

1977-01-01

Ball bearings consisting of steel parts of which the rings are coated with hard, wear resistant, chemical vapor deposited TiC are described. Experiments conducted in ultrahigh vacuum, using cages of various materials with self-lubricating properties, show that such bearings are suitable for space applications. The results of laboratory tests on the ESA Meteosat Radiometer Focalizing mechanism, which contains six coated bearings, are summarized.

Individual ball possession in soccer

PubMed Central

Hoernig, Martin

2017-01-01

This paper describes models for detecting individual and team ball possession in soccer based on position data. The types of ball possession are classified as Individual Ball Possession (IBC), Individual Ball Action (IBA), Individual Ball Control (IBC), Team Ball Possession (TBP), Team Ball Control (TBC) und Team Playmaking (TPM) according to different starting points and endpoints and the type of ball control involved. The machine learning approach used is able to determine how long the ball spends in the sphere of influence of a player based on the distance between the players and the ball together with their direction of motion, speed and the acceleration of the ball. The degree of ball control exhibited during this phase is classified based on the spatio-temporal configuration of the player controlling the ball, the ball itself and opposing players using a Bayesian network. The evaluation and application of this approach uses data from 60 matches in the German Bundesliga season of 2013/14, including 69,667 IBA intervals. The identification rate was F = .88 for IBA and F = .83 for IBP, and the classification rate for IBC was κ = .67. Match analysis showed the following mean values per match: TBP 56:04 ± 5:12 min, TPM 50:01 ± 7:05 min and TBC 17:49 ± 8:13 min. There were 836 ± 424 IBC intervals per match and their number was significantly reduced by -5.1% from the 1st to 2nd half. The analysis of ball possession at the player level indicates shortest accumulated IBC times for the central forwards (0:49 ± 0:43 min) and the longest for goalkeepers (1:38 ± 0:58 min), central defenders (1:38 ± 1:09 min) and central midfielders (1:27 ± 1:08 min). The results could improve performance analysis in soccer, help to detect match events automatically, and allow discernment of higher value tactical structures, which is based on individual ball possession. PMID:28692649

Ban Deodorant Ball Mortar.

ERIC Educational Resources Information Center

Carpenter, D. Rae, Jr.; And Others

1988-01-01

Discusses a demonstration of vertical collision of two balls. Shows the theoretical height ratio using mathematical expression and diagrams. Compares it with researchers' experimental results. Expands the two-ball collision to multi-ball system. (YP)

Effects of milling on functional properties of rice flour.

PubMed

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

2008-05-01

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

Characterization and Infrared Emission Spectroscopy of Ball Plasmoid Discharges

NASA Astrophysics Data System (ADS)

Dubowsky, Scott E.; McCall, Benjamin J.

2015-06-01

Plasmas at atmospheric pressure serve many purposes, from ionization sources for ambient mass spectrometry (AMS) to plasma-assisted wound healing. Of the many naturally occurring ambient plasmas, ball lightning is one of the least understood; there is currently no solid explanation in the literature for the formation and lifetime of natural ball lightning. With the first measurements of naturally occurring ball lightning being reported last year, we have worked to replicate the natural phenomenon in order to elucidate the physical and chemical processes by which the plasma is sustained at ambient conditions. We are able to generate ball-shaped plasmoids (self-sustaining plasmas) that are analogous to natural ball lightning using a high-voltage, high-current, pulsed DC system. Improvements to the discharge electronics used in our laboratory and characterization of the plasmoids that are generated from this system will be described. Infrared emission spectroscopy of these plasmoids reveals emission from water and hydroxyl radical -- fitting methods for these molecular species in the complex experimental spectra will be presented. Rotational temperatures for the stretching and bending modes of H2O along with that of OH will be presented, and the non-equilibrium nature of the plasmoid will be discussed in this context. Cen, J.; Yuan, P,; Xue, S. Phys. Rev. Lett. 2014, 112, 035001. Dubowsky, S.E.; Friday, D.M.; Peters, K.C.; Zhao, Z.; Perry, R.H.; McCall, B.J. Int. J. Mass Spectrom. 2015, 376, 39-45.

Ceramic Rail-Race Ball Bearings

NASA Technical Reports Server (NTRS)

Balzer, Mark A.; Mungas, Greg S.; Peters, Gregory H.

2010-01-01

Non-lubricated ball bearings featuring rail races have been proposed for use in mechanisms that are required to function in the presence of mineral dust particles in very low-pressure, dry environments with extended life. Like a conventional ball bearing, the proposed bearing would include an inner and an outer ring separated by balls in rolling contact with the races. However, unlike a conventional ball bearing, the balls would not roll in semi-circular or gothic arch race grooves in the rings: instead, the races would be shaped to form two or more rails (see figure). During operation, the motion of the balls would push dust particles into the spaces between the rails where the particles could not generate rolling resistance for the balls

Exfoliation of graphene sheets via high energy wet milling of graphite in 2-ethylhexanol and kerosene.

PubMed

Al-Sherbini, Al-Sayed; Bakr, Mona; Ghoneim, Iman; Saad, Mohamed

2017-05-01

Graphene sheets have been exfoliated from bulk graphite using high energy wet milling in two different solvents that were 2-ethylhexanol and kerosene. The milling process was performed for 60 h using a planetary ball mill. Morphological characteristics were investigated using scanning electron microscope (SEM) and transmission electron microscope (TEM). On the other hand, the structural characterization was performed using X-ray diffraction technique (XRD) and Raman spectrometry. The exfoliated graphene sheets have represented good morphological and structural characteristics with a valuable amount of defects and a good graphitic structure. The graphene sheets exfoliated in the presence of 2-ethylhexanol have represented many layers, large crystal size and low level of defects, while the graphene sheets exfoliated in the presence of kerosene have represented fewer number of layers, smaller crystal size and higher level of defects.

Detonator-activated ball shutter

DOEpatents

McWilliams, Roy A.; von Holle, William G.

1983-01-01

A detonator-activated ball shutter for closing an aperture in about 300.mu. seconds. The ball shutter containing an aperture through which light, etc., passes, is closed by firing a detonator which propels a projectile for rotating the ball shutter, thereby blocking passage through the aperture.

Detonator-activated ball shutter

DOEpatents

McWilliams, R.A.; Holle, W.G. von.

1983-08-16

A detonator-activated ball shutter for closing an aperture in about 300[mu] seconds. The ball shutter containing an aperture through which light, etc., passes, is closed by firing a detonator which propels a projectile for rotating the ball shutter, thereby blocking passage through the aperture. 3 figs.

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

NASA Astrophysics Data System (ADS)

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.

Impact of initial catalyst form on the 3D structure and performance of ball-milled Ni-catalyzed MgH 2 for hydrogen storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

House, Stephen D.; Vajo, John J.; Ren, Chai

Although it has been shown that the hydrogen storage kinetics of metal hydrides can be significantly improved by the addition of transition metal-based catalysts, relatively little attention has been paid to the impact that the form in which these catalysts are introduced during synthesis has on the resulting structure and how this alters performance. Two mixtures of MgH 2 doped with Ni were prepared via high-energy ball-milling under identical conditions, one using a pure Ni nanopowder catalyst and the other using anhydrous NiCl 2. The resulting Ni catalyst particles of the NiCl 2-doped material were 10-100 times smaller, as wellmore » as more uniform in size and shape. Electron tomography revealed that the additive form also altered its incorporation and 3D spatial distribution, with Ni particles limited to the outer surface in the NiCl 2-doped case. The significantly lower desorption performance measured in the NiCl 2-doped material is attributed to regions of MgCl 2 acting as barriers between the MgH 2 and Ni, hindering the ability of the latter to effectively catalyze the reactions. Finally, this work demonstrates the hazards in assuming different catalyst forms produce similar final structures and highlights the potential of catalyst form as a synthesis tool for optimizing the material structure and performance.« less

Impact of initial catalyst form on the 3D structure and performance of ball-milled Ni-catalyzed MgH 2 for hydrogen storage

DOE PAGES

House, Stephen D.; Vajo, John J.; Ren, Chai; ...

2017-02-24

Although it has been shown that the hydrogen storage kinetics of metal hydrides can be significantly improved by the addition of transition metal-based catalysts, relatively little attention has been paid to the impact that the form in which these catalysts are introduced during synthesis has on the resulting structure and how this alters performance. Two mixtures of MgH 2 doped with Ni were prepared via high-energy ball-milling under identical conditions, one using a pure Ni nanopowder catalyst and the other using anhydrous NiCl 2. The resulting Ni catalyst particles of the NiCl 2-doped material were 10-100 times smaller, as wellmore » as more uniform in size and shape. Electron tomography revealed that the additive form also altered its incorporation and 3D spatial distribution, with Ni particles limited to the outer surface in the NiCl 2-doped case. The significantly lower desorption performance measured in the NiCl 2-doped material is attributed to regions of MgCl 2 acting as barriers between the MgH 2 and Ni, hindering the ability of the latter to effectively catalyze the reactions. Finally, this work demonstrates the hazards in assuming different catalyst forms produce similar final structures and highlights the potential of catalyst form as a synthesis tool for optimizing the material structure and performance.« less

Inserts Automatically Lubricate Ball Bearings

NASA Technical Reports Server (NTRS)

Hager, J. A.

1983-01-01

Inserts on ball-separator ring of ball bearings provide continuous film of lubricant on ball surfaces. Inserts are machined or molded. Small inserts in ball pockets provide steady supply of lubricant. Technique is utilized on equipment for which maintenance is often poor and lubrication interval is uncertain, such as household appliances, automobiles, and marine engines.

A controlled study on batted ball speed and available pitcher reaction time in slowpitch softball

PubMed Central

McDowell, M; Ciocco, M

2005-01-01

Objectives: To investigate safety risks in slowpitch softball by conducting laboratory and experimental studies on the performance of high tech softball bats with polyurethane softballs. To compare the results with the recommended safety standards. Methods: ASTM standard compression testing of seven softball models was conducted. Using these seven softball models, bat/ball impact testing was performed using seven adult male softball players and six high tech softball bat models to determine mean batted ball speeds. Over 500 bat/ball impact measurements were recorded and analysed. Available pitcher reaction time was calculated from the mean batted ball speed measurements. Results: According to the United States Specialty Sports Association and the Amateur Softball Association, the maximum initial batted ball speed should be 137.2 km/h, which corresponds to a minimum pitcher reaction time of 0.420 second. These experiments produced mean batted ball speeds of 134.0–159.7 km/h, which correspond to available pitcher reaction times of 0.409–0.361 second. Conclusion: The use of high tech softball bats with polyurethane softballs can result in batted ball speeds that exceed the recommended safety limits, which correspond to decreased available pitcher reaction times. PMID:15793092

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

DTIC Science & Technology

2014-04-01

nanostructured materials to the high temperatures required for surfactant removal is known to result in grain growth and oxidation . In other studies...and oxidation . In other studies, select surfactant systems, such as octanoic acid or oleylamine, have been used, however, a systematic study examining...argon atmosphere to prevent oxidation . The vial was loaded into a SPEX 8000 D mill for 1 h. After milling, each powder sample was washed with ace- tone

Study of the dynamic properties and effects of temperature using a spring model for the bouncing ball

NASA Astrophysics Data System (ADS)

Wadhwa, Ajay

2013-05-01

We studied the motion of a bouncing ball by representing it through an equivalent mass-spring system executing damped harmonic oscillations. We represented the elasticity of the system through the spring constant ‘k’ and the viscous damping effect, causing loss of energy, through damping constant ‘c’. By including these two factors we formed a differential equation for the equivalent mass-spring system of the bouncing ball. This equation was then solved to study the elastic and dynamic properties of its motion by expressing them in terms of experimentally measurable physical quantities such as contact time, coefficient of restitution, etc. We used our analysis for different types of ball material: rubber (lawn-tennis ball, super ball, soccer ball and squash ball) and plastic (table-tennis ball) at room temperature. Since the effect of temperature on the bounce of a squash ball is significant, we studied the temperature dependence of its elastic properties. The experiments were performed using audio and surface-temperature sensors interfaced with a computer through a USB port. The work presented here is suitable for undergraduate laboratories. It particularly emphasizes the use of computer interfacing for conducting conventional physics experiments.

Factors Influencing Ball-Player Impact Probability in Youth Baseball

PubMed Central

Matta, Philip A.; Myers, Joseph B.; Sawicki, Gregory S.

2015-01-01

Background: Altering the weight of baseballs for youth play has been studied out of concern for player safety. Research has shown that decreasing the weight of baseballs may limit the severity of both chronic arm and collision injuries. Unfortunately, reducing the weight of the ball also increases its exit velocity, leaving pitchers and nonpitchers with less time to defend themselves. The purpose of this study was to examine impact probability for pitchers and nonpitchers. Hypothesis: Reducing the available time to respond by 10% (expected from reducing ball weight from 142 g to 113 g) would increase impact probability for pitchers and nonpitchers, and players’ mean simple response time would be a primary predictor of impact probability for all participants. Study Design: Nineteen subjects between the ages of 9 and 13 years performed 3 experiments in a controlled laboratory setting: a simple response time test, an avoidance response time test, and a pitching response time test. Methods: Each subject performed these tests in order. The simple reaction time test tested the subjects’ mean simple response time, the avoidance reaction time test tested the subjects’ ability to avoid a simulated batted ball as a fielder, and the pitching reaction time test tested the subjects’ ability to avoid a simulated batted ball as a pitcher. Results: Reducing the weight of a standard baseball from 142 g to 113 g led to a less than 5% increase in impact probability for nonpitchers. However, the results indicate that the impact probability for pitchers could increase by more than 25%. Conclusion: Pitching may greatly increase the amount of time needed to react and defend oneself from a batted ball. Clinical Relevance: Impact injuries to youth baseball players may increase if a 113-g ball is used. PMID:25984261

Fabrication of micro-lens array on convex surface by meaning of micro-milling

NASA Astrophysics Data System (ADS)

Zhang, Peng; Du, Yunlong; Wang, Bo; Shan, Debin

2014-08-01

In order to develop the application of the micro-milling technology, and to fabricate ultra-precision optical surface with complex microstructure, in this paper, the primary experimental research on micro-milling complex microstructure array is carried out. A complex microstructure array surface with vary parameters is designed, and the mathematic model of the surface is set up and simulated. For the fabrication of the designed microstructure array surface, a micro three-axis ultra-precision milling machine tool is developed, aerostatic guideway drove directly by linear motor is adopted in order to guarantee the enough stiffness of the machine, and novel numerical control strategy with linear encoders of 5nm resolution used as the feedback of the control system is employed to ensure the extremely high motion control accuracy. With the help of CAD/CAM technology, convex micro lens array on convex spherical surface with different scales on material of polyvinyl chloride (PVC) and pure copper is fabricated using micro tungsten carbide ball end milling tool based on the ultra-precision micro-milling machine. Excellent nanometer-level micro-movement performance of the axis is proved by motion control experiment. The fabrication is nearly as the same as the design, the characteristic scale of the microstructure is less than 200μm and the accuracy is better than 1μm. It prove that ultra-precision micro-milling technology based on micro ultra-precision machine tool is a suitable and optional method for micro manufacture of microstructure array surface on different kinds of materials, and with the development of micro milling cutter, ultraprecision micro-milling complex microstructure surface will be achieved in future.

Optical and Acoustic Sensor-Based 3D Ball Motion Estimation for Ball Sport Simulators †.

PubMed

Seo, Sang-Woo; Kim, Myunggyu; Kim, Yejin

2018-04-25

Estimation of the motion of ball-shaped objects is essential for the operation of ball sport simulators. In this paper, we propose an estimation system for 3D ball motion, including speed and angle of projection, by using acoustic vector and infrared (IR) scanning sensors. Our system is comprised of three steps to estimate a ball motion: sound-based ball firing detection, sound source localization, and IR scanning for motion analysis. First, an impulsive sound classification based on the mel-frequency cepstrum and feed-forward neural network is introduced to detect the ball launch sound. An impulsive sound source localization using a 2D microelectromechanical system (MEMS) microphones and delay-and-sum beamforming is presented to estimate the firing position. The time and position of a ball in 3D space is determined from a high-speed infrared scanning method. Our experimental results demonstrate that the estimation of ball motion based on sound allows a wider activity area than similar camera-based methods. Thus, it can be practically applied to various simulations in sports such as soccer and baseball.

Synthesis of Nanostructured Carbides of Titanium and Vanadium from Metal Oxides and Ferroalloys Through High-energy Mechanical Milling and Heat Treatment

NASA Astrophysics Data System (ADS)

Basu, P.; Jian, P. F.; Seong, K. Y.; Seng, G. S.; Masrom, A. K.; Hussain, Z.; Aziz, A.

2010-03-01

Carbides of Ti and V have been synthesized directly from their oxides and ferroalloys through mechanical milling and heat treatment. The powder mixtures are milled in a planetary ball mill from 15-80 hours and subsequently heat treated at 1000-1300° C for TiO2-C mixtures, at 500-550° C for V2O5-C mixtures and at 600-1000° C for (Fe-V)-C mixtures. The milled and heat treated powders are characterized by SEM, EDAX, XRD, and BET techniques. Nanostructured TiC has been successfully synthesized under suitable processing conditions. However, carbides of vanadium is unidentified even though possibilities of V2O5-C reaction are indicated with an extent of induced amorphism in the powder mixture. Density, specific surface area and particle size of the milled and heat treated mixtures are correlated with heat treatment temperatures. Similar attempts are also made to synthesize vanadium carbides from industrial grade Fe-V.

Enhancing the Bounce of a Ball

NASA Astrophysics Data System (ADS)

Cross, Rod

2010-10-01

In sports such as baseball, softball, golf, and tennis, a common objective is to hit the ball as fast or as far as possible. Another common objective is to hit the ball so that it spins as fast as possible, since the trajectory of the ball through the air is strongly affected by ball spin. In an attempt to enhance both the coefficient of restitution (COR) and the spin of a golf ball, I conducted several experiments to see what would happen when a 45-g, 42.8-mm diameter golf ball bounced on: (a) a 58-mm diameter, 103-g Super Ball®; (b) an 8-mm thick, 56-mm diameter circular disk of Super Ball material cut from a large Super Ball and glued to a 3.4-kg lead brick; and (c) a 3-mm thick sheet of rubber glued to a 3.4-kg lead brick. (See Fig. 1.)

Influence of excipients in comilling on mitigating milling-induced amorphization or structural disorder of crystalline pharmaceutical actives.

PubMed

Balani, Prashant N; Ng, Wai Kiong; Tan, Reginald B H; Chan, Sui Yung

2010-05-01

The feasibility of using excipients to suppress the amorphization or structural disorder of crystalline salbutamol sulphate (SS) during milling was investigated. SS was subjected to ball-milling in the presence of alpha-lactose monohydrate (LAC), adipic acid (AA), magnesium stearate (MgSt), or polyvinyl pyrrolidone (PVP). X-ray powder diffraction, dynamic vapor sorption (DVS), high sensitivity differential scanning calorimetry (HSDSC) were used to analyze the crystallinity of the milled mixtures. Comilling with crystalline excipients, LAC, AA, and MgSt proved effective in reducing the amorphization of SS. LAC, AA, or MgSt acting as seed crystals to induce recrystallization of amorphous SS formed by milling. During comilling, both SS and LAC turned predominantly amorphous after 45 min but transformed back to a highly crystalline state after 60 min. Amorphous content was below the detection limits of DVS (0.5%) and HSDSC (5%). Comilled and physical mixtures of SS and ALM were stored under normal and elevated humidity conditions. This was found to prevent subsequent changes in crystallinity and morphology of comilled SS:LAC as compared to significant changes in milled SS and physical mixture. These results demonstrate a promising application of comilling with crystalline excipients in mitigating milling induced amorphization of pharmaceutical actives.

Ball Collision Experiments

ERIC Educational Resources Information Center

Cross, R.

2015-01-01

Experiments are described on collisions between two billiard balls and between a bat and a ball. The experiments are designed to extend a student's understanding of collision events and could be used either as a classroom demonstration or for a student project.

Detection of internally infested popcorn using electrically conductive roller mills

USDA-ARS?s Scientific Manuscript database

To detect popcorn kernels infested by the internal feeding stored-product insect pest Sitophilus zeamais, maize weevil, a laboratory roller mill was modified so that the electrical conductivity of the grain is measured while the kernels are milled between the rolls. When a kernel with a S. zeamais l...

Flue gas desulfurization chemistry studies: limestone grindability. Volume 2. Grindability testing. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmann, D.L.; Luke, K.W.; Terry, J.C.

1984-07-01

The results of a study to determine the relative grindability of US limestones and to relate grindability to petrographic properties are presented in this report. A laboratory ball mill test was developed to provide a quick and simple measure of grindability. These values were then used to explore possible correlations between grindability and the chemical and physical properties of the limestones. Chemical analyses and thin section petrographic analyses were used to characterize the limestone samples. The results of the laboratory ball mill test were compared to the results of an industrial grinding test, the Bond Work Index, for six samplesmore » which covered the grindability range. The two tests compared well with a correlation coefficient greater than 0.9. While the laboratory test is not sufficient to provide ball mill design specifications, it can be used as a screening and quality control test. The grinding results, expressed as a grindability index, ranged in values from 2 to 15. This represents a seven-fold range in the relative difficulties to grind for the limestones tested. From the petrographic analysis results, a strong correlation was found between the grindability and the fraction of macrocrystalline (> 5 ..mu..m) carbonate minerals present in the limestone. However, based on the high degree of variability characteristic of most limestone deposits, petrographic information should, in general, only be used to qualitatively predict the grindability of a specific limestone. An actual grinding test is recommended for a quantitative evaluation.« less

Aerodynamics of sports balls

NASA Astrophysics Data System (ADS)

Mehta, R. D.

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.

Aerodynamics of sports balls

NASA Technical Reports Server (NTRS)

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.

Effect of Practicing Soccer Juggling With Different Sized Balls Upon Performance, Retention, and Transfer to Ball Reception.

PubMed

Raastad, Olav; Aune, Tore Kristian; van den Tillaar, Roland

2016-10-01

The aim of this study was to investigate if making the skill acquisition phase more difficult or easier would enhance performance in soccer juggling, and if this practice has a positive intertask transfer effect to ball reception performance. Twenty-two adolescent soccer players were tested in juggling a soccer ball and in the control of an approaching ball at a pre, post and retention test. The participants were randomly divided in a small ball size and bigger ball size training group that both trained four times per week for 6 weeks. At the post and retention test both groups enhanced performance in soccer juggling test with no difference between groups and no increase in ball reception performance at these tests. It was concluded that about intra task transfer and retention of soccer juggling skills, it does not matter if you increase (small balls) or decrease the difficulty (larger balls) when using the same amount of practice time within the skill acquisition phase in soccer juggling. In addition that for ball juggling and ball reception (inter task) these two tasks differ too much in afferent information and movement characteristics that no positive transfer between these two skills no positive intertask transfer can be expected.

Experimental evaluation of 150-millimeter bore ball bearing to 3 million DN using either solid or drilled balls

NASA Technical Reports Server (NTRS)

Scibbe, H. W.; Munson, H. E.

1973-01-01

Seven 150-mm bore ball bearings were run under 8900 Newton (2000 lb) thrust load at speeds from 6670 to 20,000 rpm (1 to 3 million DN). Four of the bearings had conventional solid balls and three bearing had drilled (cylindrically hollow) balls with 50 percent mass reduction. The bearings were under-race cooled and slot-lubricated with Type 2 ester oil at flow rates from 4.35 to 5.80 liters per minute (1.15 to 1.57 gal min). Friction torque and temperatures were measured on all bearings. No significant difference in torque was noted, between the solid and drilled ball bearings. One bearing of each type was rerun at 17,800 Newtons (4000 lb) thrust load. The solid ball bearings performed satisfactorily at 3 million DN. However, at about 2 million DN the drilled ball bearing experienced a broken ball and cracks appeared in two other balls as the result of flexure fatigue. Metallurgical examination of the cracked balls indicated a brittle structure in the bore of the drilled balls.

Ball clay

USGS Publications Warehouse

Virta, R.L.

2007-01-01

The article offers information on ball clay. Among the companies that mine ball clay in the U.S. are H.C. Spinks Clay, Kentucky-Tennessee Clay and Old Hickory Clay. In 2006, an estimated 1.2 million tons of the mineral was sold or used domestically and exported. Forty-percent of the total sales is accounted for ceramic floor and wall tile followed by sanitaryware and miscellaneous ceramics. Its average value was $ 45 per ton in 2006.

High temperature ferromagnetism in Ni doped ZnO nanoparticles: Milling time dependence

NASA Astrophysics Data System (ADS)

Pal, Bappaditya; Giri, P. K.; Sarkar, D.

2014-04-01

We report on the room temperature ferromagnetism (RT FM) in the Zn1-xNixO (x = 0, 0.03, and 0.05) nanoparticles (NPs) synthesized by a ball milling technique. X-ray diffraction analysis confirms the single crystalline ZnO wurtzite structure with presence of small intensity secondary phase related peak which disappear with increasing milling time for Ni doped samples. HRTEM lattice images show that the doped NPs are single crystalline with a dspacing of 2.44 Å. Energy-dispersive X-ray spectroscopy analysis confirms the presence of Ni ions in the ZnO matrix. Magnetic measurement (RT) exhibits the hysteresis loop with saturation magnetization (Ms) of 1.6-2.56 (emu/g) and coercive field (Hc) of 296-322 Oe. M-T measurement shows a Curie temperature of the order of 325°C for 3% Ni doped sample. Micro -Raman studies show doping/disorder induced additional modes at ˜510, 547, 572 cm-1 in addition to 437 cm-1 peak of pure ZnO. UV-Vis absorption spectra illustrate band gap shift due to doping. Alteration of Ms value with the variation of doping concentration and milling time has been studied and discussed.

Mechanical and Microstructure Study of Nickel-Based ODS Alloys Processed by Mechano-Chemical Bonding and Ball Milling

NASA Astrophysics Data System (ADS)

Amare, Belachew N.

Due to the need to increase the efficiency of modern power plants, land-based gas turbines are designed to operate at high temperature creating harsh environments for structural materials. The elevated turbine inlet temperature directly affects the materials at the hottest sections, which includes combustion chamber, blades, and vanes. Therefore, the hottest sections should satisfy a number of material requirements such as high creep strength, ductility at low temperature, high temperature oxidation and corrosion resistance. Such requirements are nowadays satisfied by implementing superalloys coated by high temperature thermal barrier coating (TBC) systems to protect from high operating temperature required to obtain an increased efficiency. Oxide dispersive strengthened (ODS) alloys are being considered due to their high temperature creep strength, good oxidation and corrosion resistance for high temperature applications in advanced power plants. These alloys operating at high temperature are subjected to different loading systems such as thermal, mechanical, and thermo-mechanical combined loads at operation. Thus, it is critical to study the high temperature mechanical and microstructure properties of such alloys for their structural integrity. The primary objective of this research work is to investigate the mechanical and microstructure properties of nickel-based ODS alloys produced by combined mechano-chemical bonding (MCB) and ball milling subjected to high temperature oxidation, which are expected to be applied for high temperature turbine coating with micro-channel cooling system. Stiffness response and microstructure evaluation of such alloy systems was studied along with their oxidation mechanism and structural integrity through thermal cyclic exposure. Another objective is to analyze the heat transfer of ODS alloy coatings with micro-channel cooling system using finite element analysis (FEA) to determine their feasibility as a stand-alone structural

Ball motion and sliding friction in an arched outer-race ball bearing

NASA Technical Reports Server (NTRS)

Hamrock, B. J.

1974-01-01

The motion of the ball and sliding friction in an arched outer-race ball bearing under thrust load is analyzed. Fatigue life evaluations were made. The analysis is applied to a 150-millimeter-bore ball bearing. The results indicated that for high-speed light-load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be optimal. Also, for an arched bearing a considerable amount of spinning occurs at the outer-race contacts.

Training Level Does Not Affect Auditory Perception of The Magnitude of Ball Spin in Table Tennis.

PubMed

Santos, Daniel P R; Barbosa, Roberto N; Vieira, Luiz H P; Santiago, Paulo R P; Zagatto, Alessandro M; Gomes, Matheus M

2017-01-01

Identifying the trajectory and spin of the ball with speed and accuracy is critical for good performance in table tennis. The aim of this study was to analyze the ability of table tennis players presenting different levels of training/experience to identify the magnitude of the ball spin from the sound produced when the racket hit the ball. Four types of "forehand" contact sounds were collected in the laboratory, defined as: Fast Spin (spinning ball forward at 140 r/s); Medium Spin (105 r/s); Slow Spin (84 r/s); and Flat Hit (less than 60 r/s). Thirty-four table tennis players of both sexes (24 men and 10 women) aged 18-40 years listened to the sounds and tried to identify the magnitude of the ball spin. The results revealed that in 50.9% of the cases the table tennis players were able to identify the ball spin and the observed number of correct answers (10.2) was significantly higher (χ 2 = 270.4, p <0.05) than the number of correct answers that could occur by chance. On the other hand, the results did not show any relationship between the level of training/experience and auditory perception of the ball spin. This indicates that auditory information contributes to identification of the magnitude of the ball spin, however, it also reveals that, in table tennis, the level of training does not interfere with the auditory perception of the ball spin.

Telescoping magnetic ball bar test gage

DOEpatents

Bryan, J.B.

1984-03-13

A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out is disclosed. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine. 3 figs.

Telescoping magnetic ball bar test gage

DOEpatents

Bryan, J.B.

1982-03-15

A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengagable servo drives which cannot be clutched out. Two gage balls are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit and a rigid member. One gage ball is secured by a magnetic socket knuckle assembly which fixes its center with respect to the machine being tested. The other gage ball is secured by another magnetic socket knuckle assembly which is engaged or held by the machine in such manner that the center of that ball is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball. As the moving ball executes its trajectory, changes in the radial distance between the centers of the two balls caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly actuated by the parallel reed flexure unit. Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball locations, thereby determining the accuracy of the machine.

Ball feeder for replenishing evaporator feed

DOEpatents

Felde, David K.; McKoon, Robert H.

1993-01-01

Vapor source material such as uranium, which is to be dropped into a melt in an evaporator, is made into many balls of identical diameters and placed inside a container. An elongated sloping pipe is connected to the container and leads to the evaporator such that these balls can travel sequentially therealong by gravity. A metering valve in this pipe for passing these balls one at a time is opened in response to a signal when it is ascertained by a detector that there is a ball ready to be passed. A gate in the pipe near the evaporator momentarily stops the motion of the traveling ball and is then opened to allow the ball drop into the melt at a reduced speed.

Ball feeder for replenishing evaporator feed

DOEpatents

Felde, D.K.; McKoon, R.H.

1993-03-23

Vapor source material such as uranium, which is to be dropped into a melt in an evaporator, is made into many balls of identical diameters and placed inside a container. An elongated sloping pipe is connected to the container and leads to the evaporator such that these balls can travel sequentially therealong by gravity. A metering valve in this pipe for passing these balls one at a time is opened in response to a signal when it is ascertained by a detector that there is a ball ready to be passed. A gate in the pipe near the evaporator momentarily stops the motion of the traveling ball and is then opened to allow the ball drop into the melt at a reduced speed.

The Goldenrod Ball Gall

ERIC Educational Resources Information Center

Fischer, Richard B.

1974-01-01

The paper presents a generalized life history of the goldenrod ball gall, a ball-shaped swelling found almost exclusively on the Canada goldenrod, Solidago canadensis, and caused by a peacock fly know as Eurosta soldiaginis. (KM)

Ball motion and sliding friction in an arched outer race ball bearing

NASA Technical Reports Server (NTRS)

Hamrock, B. J.

1973-01-01

The motion of the ball and sliding friction in an arched outer race ball bearing under thrust loads is determined. Fatigue life evaluations were made. The analysis is applied to a 150 millimeter bore ball bearing. The results indicated that for high speed-light load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be an optimal. For an arched bearing it was also found that a considerable amount of spinning occurs at the outer race contacts.

Ball motion and sliding friction in an arched outer race ball bearing

NASA Technical Reports Server (NTRS)

Hamrock, B. J.

1974-01-01

The motion of the ball and sliding friction in an arched outer-race ball bearing under thrust load is determined. Fatigue life evaluations were made. The analysis is applied to a 150 millimeter bore ball bearing. The results indicated that for high speed-light load applications the arched bearing has significant improvement in fatigue life over that of a conventional bearing. An arching of 0.254 mm (0.01 in.) was found to be an optimal. For an arched bearing it was also found that a considerable amount of spinning occurs at the outer race contacts.

Fluid Mechanics of Cricket and Tennis Balls

NASA Astrophysics Data System (ADS)

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

Enhancing the Bounce of a Ball

ERIC Educational Resources Information Center

Cross, Rod

2010-01-01

In sports such as baseball, softball, golf, and tennis, a common objective is to hit the ball as fast or as far as possible. Another common objective is to hit the ball so that it spins as fast as possible, since the trajectory of the ball through the air is strongly affected by ball spin. In an attempt to enhance both the coefficient of…

Titanium clip ball joint: a partial ossicular reconstruction prosthesis.

PubMed

Beutner, Dirk; Luers, Jan Christoffer; Bornitz, Matthias; Zahnert, Thomas; Huttenbrink, Karl-Bernd

2011-06-01

To describe a new titanium clip prosthesis for partial ossicular reconstruction with a micro ball joint in the headplate for compensation of tympanic membrane displacements. Laboratory experiments followed by 18 consecutive patients. A micro ball joint was implemented into a headplate of titanium middle ear prosthesis. First, the new prosthesis was tested in the laboratory in temporal bone experiments. Second, the new prosthesis was clinically installed in 18 patients. Results of laser Doppler vibrometry and force measurements in the laboratory experiments, analysis of a questionnaire, and preoperative and postoperative pure tone audiometry. The frictional resistance in the joint was measured to be 12 mN that should allow for adequate mobility under physiologic conditions. The effective sound transmission of the prosthesis was demonstrated by laser Doppler vibrometry. Intraoperatively, the installation of the prosthesis was always straightforward with headplate prosthesis shaft angles between 60 and 90 degrees. Postoperatively, pure tone audiometry revealed satisfying hearing results with a remaining average air-bone gap of 18.2 dB over the frequencies 500, 1,000, 2,000, and 3,000 Hz. No signs of prosthesis dislocation were discovered within the follow-up period of approximately 6 months. The experimental data show that the new modified prosthesis headplate fulfills the requirements necessary for sound transmission. The joint allows the plate to follow movements of the tympanic membrane. This characteristic in conjunction with the proven clip design ensure for optimal prosthesis placement and effectiveness.

Evaluation of hard red spring wheat quality using four different roller mills

USDA-ARS?s Scientific Manuscript database

Domestic and overseas buyers pay premium price for hard red spring (HRS) wheat due to high protein content and excellent milling and baking performances. For efficient quality identification of wheat samples, a wheat quality laboratory needs an objective and simple experimental milling procedure and...

Ceramic ball grid array package stress analysis

NASA Astrophysics Data System (ADS)

Badri, S. H. B. S.; Aziz, M. H. A.; Ong, N. R.; Sauli, Z.; Alcain, J. B.; Retnasamy, V.

2017-09-01

The ball grid array (BGA), a form of chip scale package (CSP), was developed as one of the most advanced surface mount devices, which may be assembled by an ordinary surface ball bumps are used instead of plated nickel and gold (Ni/Au) bumps. Assembly and reliability of the BGA's printed circuit board (PCB), which is soldered by conventional surface mount technology is considered in this study. The Ceramic Ball Grid Array (CBGA) is a rectangular ceramic package or square-shaped that will use the solder ball for external electrical connections instead of leads or wire for connections. The solder balls will be arranged in an array or grid at the bottom of the ceramic package body. In this study, ANSYS software is used to investigate the stress on the package for 2 balls and 4 balls of the CBGA package with the various force range of 1-3 Newton applied to the top of the die, top of the substrate and side of the substrate. The highest maximum stress was analyzed and the maximum equivalent stress was observed on the solder ball and the die. From the simulation result, the CBGA package with less solder balls experience higher stress compared to the package with many solder balls. Therefore, less number of solder ball on the CBGA package results higher stress and critically affect the reliability of the solder balls itself, substrate and die which can lead to the solder crack and also die crack.

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

NASA Astrophysics Data System (ADS)

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.

Phase study of SiO2-ZrO2 composites prepared from polymorphic combination of starting powders via a ball-milling followed by calcination

NASA Astrophysics Data System (ADS)

Musyarofah; Nurlaila, R.; Muwwaqor, N. F.; Saukani, M.; Kuswoyo, A.; Triwikantoro; Pratapa, S.

2017-04-01

The effects of SiO2-ZrO2 polymorphic combinations as starting powders and calcination temperature on phase composition of the SiO2-ZrO2 composites were studied. Stoichiometric (1:1 mol%) mixtures of the SiO2-ZrO2 composites were mechanically activated using a ball-milling for 5 h followed by calcinations at 1000, 1100 and 1200 °C for 3 h. The composites used in the present study were a-SiO2+ a-ZrO2, a-SiO2+ t-ZrO2, c-SiO2+ a-ZrO2 and c-SiO2+ t-ZrO2 which were symbolized by AA, AT, CA and CT, respectively. Prefixes a, t and c denote amorphous, tetragonal and cristobalite, respectively. The phase composition was determined by Rietveld analysis of X-ray diffraction (XRD) data using Rietica software. The identified phases for all calcined samples were a combination among t-ZrO2, c-SiO2, m-ZrO2 and zircon (ZrSiO4). Amorphous zirconia formed a transient tetragonal zirconia phase during heating, which reacted with silica to form zircon. The zircon phase was not found to form even at 1200 °C in the AT and CT mixtures and at 1100 °C in the CA mixture. The AA mixture in particular crystallized to form zircon at a lower temperature with more composition fraction than the others, ca 82.9 (14) mol%.

Fabrication of an r-Al2Ti intermetallic matrix composite reinforced with α-Al2O3 ceramic by discontinuous mechanical milling for thermite reaction

NASA Astrophysics Data System (ADS)

Mosleh, A.; Ehteshamzadeh, M.; Taherzadeh Mousavian, R.

2014-10-01

In this study, a powder mixture with an Al/TiO2 molar ratio of 10/3 was used to form an r-Al2Ti intermetallic matrix composite (IMC) reinforced with α-Al2O3 ceramic by a novel milling technique, called discontinuous mechanical milling (DMM) instead of milling and ignition of the produced thermite. The results of energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) of samples with varying milling time indicate that this fabrication process requires considerable mechanical energy. It is shown that Al2Ti-Al2O3 IMC with small grain size was produced by DMM after 15 h of ball milling. Peaks for γ-TiAl as well as Al2Ti and Al2O3 are observed in XRD patterns after DMM followed by heat treatment. The microhardness of the DMM-treated composite produced after heat treatment was higher than Hv 700.

Intense alpha-particle emitting crystallites in uranium mill wastes

USGS Publications Warehouse

Landa, E.R.; Stieff, L.R.; Germani, M.S.; Tanner, A.B.; Evans, J.R.

1994-01-01

Nuclear emulsion microscopy has demonstrated the presence of small, intense ??-particle emitting crystallites in laboratory-produced tailings derived from the sulfuric acid milling of uranium ores. The ??-particle activity is associated with the isotope pair 210Pb 210Po, and the host mineral appears to be PbSO4 occurring as inclusions in gypsum laths. These particles represent potential inhalation hazards at uranium mill tailings disposal areas. ?? 1994.

Telescoping magnetic ball bar test gage

DOEpatents

Bryan, James B.

1984-01-01

A telescoping magnetic ball bar test gage for determining the accuracy of machine tools, including robots, and those measuring machines having non-disengageable servo drives which cannot be clutched out. Two gage balls (10, 12) are held and separated from one another by a telescoping fixture which allows them relative radial motional freedom but not relative lateral motional freedom. The telescoping fixture comprises a parallel reed flexure unit (14) and a rigid member (16, 18, 20, 22, 24). One gage ball (10) is secured by a magnetic socket knuckle assembly (34) which fixes its center with respect to the machine being tested. The other gage ball (12) is secured by another magnetic socket knuckle assembly (38) which is engaged or held by the machine in such manner that the center of that ball (12) is directed to execute a prescribed trajectory, all points of which are equidistant from the center of the fixed gage ball (10). As the moving ball (12) executes its trajectory, changes in the radial distance between the centers of the two balls (10, 12) caused by inaccuracies in the machine are determined or measured by a linear variable differential transformer (LVDT) assembly (50, 52, 54, 56, 58, 60) actuated by the parallel reed flexure unit (14). Measurements can be quickly and easily taken for multiple trajectories about several different fixed ball (10) locations, thereby determining the accuracy of the machine.

Correlation of Shoulder and Elbow Kinetics With Ball Velocity in Collegiate Baseball Pitchers.

PubMed

Post, Eric G; Laudner, Kevin G; McLoda, Todd A; Wong, Regan; Meister, Keith

2015-06-01

Throwing a baseball is a dynamic and violent act that places large magnitudes of stress on the shoulder and elbow. Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables throughout the throwing motion. However, very little research has directly examined the relationship between these kinetic variables and ball velocity. To examine the correlation of peak ball velocity with elbow-valgus torque, shoulder external-rotation torque, and shoulder-distraction force in a group of collegiate baseball pitchers. Cross-sectional study. Motion-analysis laboratory. Sixty-seven asymptomatic National Collegiate Athletic Association Division I baseball pitchers (age = 19.5 ± 1.2 years, height = 186.2 ± 5.7 cm, mass = 86.7 ± 7.0 kg; 48 right handed, 19 left handed). We measured peak ball velocity using a radar gun and shoulder and elbow kinetics of the throwing arm using 8 electronically synchronized, high-speed digital cameras. We placed 26 reflective markers on anatomical landmarks of each participant to track 3-dimensional coordinate data. The average data from the 3 highest-velocity fastballs thrown for strikes were used for data analysis. We calculated a Pearson correlation coefficient to determine the associations between ball velocity and peak elbow-valgus torque, shoulder-distraction force, and shoulder external-rotation torque (P < .05). A weak positive correlation was found between ball velocity and shoulder-distraction force (r = 0.257; 95% confidence interval [CI] = 0.02, 0.47; r(2) = 0.066; P = .018). However, no significant correlations were noted between ball velocity and elbow-valgus torque (r = 0.199; 95% CI = -0.043, 0.419; r(2) = 0.040; P = .053) or shoulder external-rotation torque (r = 0.097; 95% CI = -0.147, 0.329; r(2) = 0.009; P = .217). Although a weak positive correlation was present between ball velocity and shoulder-distraction force, no significant association was seen between ball velocity and elbow

Emission Spectroscopy of Atmospheric-Pressure Ball Plasmoids: Higher Energy Reveals a Rich Chemistry

NASA Astrophysics Data System (ADS)

Dubowsky, Scott E.; Rose, Amber Nicole; Glumac, Nick; McCall, Benjamin J.

2017-06-01

Ball plasmoids (self-sustaining spherical plasmas) are a particularly unique example of a non-equilibrium air plasma. These plasmoids have lifetimes on the order of hundreds of milliseconds without an external power source, however, current models dictate that a ball plasmoid should recombine in a millisecond or less. Ball plasmoids are considered to be a laboratory analogue of natural ball lightning, a phenomenon that has eluded scientific explanation for centuries. We are searching for the underlying physicochemical mechanism(s) by which ball plasmoids and (by extension) ball lightning are stabilized using a variety of diagnostic techniques. This presentation will focus on optical emission spectroscopy (OES) of ball plasmoid discharges between 190-850 nm. The previous generation of OES measurements of this system showed emission from only a few atomic and molecular species, however, the energy available for the discharges in these experiments was limited by the size of the capacitor banks and voltages to which the capacitor banks were charged. We are capable of generating plasmoids at much higher energies, and as a result we are the first to report a very rich chemistry previously not observed in ball plasmoids. We have identified signals from species including NO A^{2}Σ^{+}→X^{2}Π, OH A^{2}Σ^{+}→X^{2}Π, NH A^{3}Π→X^{3}Σ^{-}, AlO A^{2}Π→X^{2}Σ^{+}, NH^{+} B^{2}Δ→X^{2}Π, W I, Al I, Cu I, and H_{α}, all of which have not yet been reported for this system. Analysis of the emission spectra and fitting procedures will be discussed, rotational temperatures of constituent species will be reported, and theories of ball plasmoid stabilization based upon these new results will be presented. Versteegh, A.; Behringer, K.; Fantz, U.; Fussman, G.; Jüttner, B.; Noack, S. Plas. Sour. Sci. Technol. 2008, 17(2), 024014 Stephan, K. D.; Dumas, S.; Komala-Noor, L.; McMinn, J. Plas. Sour. Sci. Technol. 2013, 22(2), 025018

Cricket Ball Aerodynamics: Myth Versus Science

NASA Technical Reports Server (NTRS)

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.

2012 Problem 15: Frustrating Golf Ball

NASA Astrophysics Data System (ADS)

Huang, Shan; Zhu, Zheyuan; Gao, Wenli; Wang, Sihui

2015-10-01

This paper studies the condition for a golf ball to escape from a hole. The two determining factors are the ball's initial velocity v0 and its deviation from the center of the hole d. There is a critical escaping velocity vc for every deviation d. The ball's motion is analyzed by calculating the change of velocity whenever the ball collides with the hole. The critical conditions predicted by our theory are verified through experiment.

Corrosion-Resistant Ball Bearings

NASA Technical Reports Server (NTRS)

Zdankiewicz, E. M.; Linaburg, E. L.; Lytle, L. J.

1990-01-01

Self-lubricating bearing system withstands highly corrosive environment of wastewater-recycling unit. New bearings contain cobalt-based-alloy balls and races, graphite/polyimide polymer ball cages, and single integral polytetrafluoroethylene seals on wet sides. Materials and design prevent corrosion by acids and provide lubrication.

Device Rotates Bearing Balls For Inspection

NASA Technical Reports Server (NTRS)

Burley, R. K.

1988-01-01

Entire surface of ball inspected automatically and quickly. Device holds and rotates bearing ball for inspection by optical or mechanical surface-quality probe, eddy-current probe for detection of surface or subsurface defects, or circumference-measuring tool. Ensures entire surface of ball moves past inspection head quickly. New device saves time and increases reliability of inspections of spherical surfaces. Simple to operate and provides quick and easy access for loading and unloading of balls during inspection.

Physics in a Glitter Ball

ERIC Educational Resources Information Center

Trikosko, Walter

2011-01-01

Maui Toys' Water Bouncer (Fig. 1) is a water-filled ball containing glitter. Buy one and put it on your desk and students can't keep their hands off of it. Pitch the ball in the air giving it a quick spin. When you catch it you will see a sparkling vortex. Twist the ball around different ways and the angular momentum of the fluid keeps the axis of…

Playing Ball in a Space Station

ERIC Educational Resources Information Center

Simoson, Andrew J.

2006-01-01

How does artificial gravity affect the path of a thrown ball? This paper contrasts ball trajectories on the Little Prince's asteroid planet B-612 and Arthur C. Clarke's rotating-drum spacecraft of 2001, and demonstrates curve balls with multiple loops in the latter environment.

PEPC LRU: Ball Support Assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alger, T

1999-05-14

The PEPC LRU upper ball support assembly consists of a ball and a pneumatic air cylinder/conical seat latching mechanism to be attached to the optics support frame,and a ball attached to the PEPC LRU. Both components are designed to allow manual positioning in three axes. Upon insertion of the PEPC LRU into the structure, the upper pneumatic cylinder is actuated to latch the two assemblies together through the conical seat device to grab the lower ball to support the LRU weight. To be conservative, the design load for the assembly is 1500 pounds (the prototype PEPC LRU weight was measuredmore » to be near 1380 pounds).« less

Introduction to ball bearings

NASA Technical Reports Server (NTRS)

Hamrock, B. J.; Dowson, D.

1981-01-01

The purpose of a ball bearing is to provide a relative positioning and rotational freedom while transmitting a load between two structures, usually a shaft and a housing. For high rotational speeds (e.g., in gyroscope ball bearings) the purpose can be expanded to include rotational freedom with practically no wear in the bearing. This condition can be achieved by separating the bearing parts with a coherent film of fluid known as an elastohydrodynamic film. This film can be maintained not only when the bearing carries the load on a shaft, but also when the bearing is preloaded to position the shaft to within micro- or nano-inch accuracy and stability. Background information on ball bearings is provided, different types of ball bearings and their geometry and kinematics are defined, bearing materials, manufacturing processes, and separators are discussed. It is assumed, for the purposes of analysis, that the bearing carries no load.

Flare angles measured with ball gage

NASA Technical Reports Server (NTRS)

Cleghorn, D.; Wall, W. A.

1968-01-01

Precision tungsten carbide balls measure the internal angle of flared joints. Measurements from small and large balls in the flare throat to an external reference point are made. The difference in distances and diameters determine the average slope of the flare between the points of ball contact.

Mechanical intermixing of components in (CoMoNi)-based systems and the formation of (CoMoNi)/WC nanocomposite layers on Ti sheets under ball collisions

NASA Astrophysics Data System (ADS)

Romankov, S.; Park, Y. C.; Shchetinin, I. V.

2017-11-01

Cobalt (Co), molybdenum (Mo), and nickel (Ni) components were simultaneously introduced onto titanium (Ti) surfaces from a composed target using ball collisions. Tungsten carbide (WC) balls were selected for processing as the source of a cemented carbide reinforcement phase. During processing, ball collisions continuously introduced components from the target and the grinding media onto the Ti surface and induced mechanical intermixing of the elements, resulting in formation of a complex nanocomposite structure onto the Ti surface. The as-fabricated microstructure consisted of uniformly dispersed WC particles embedded within an integrated metallic matrix composed of an amorphous phase with nanocrystalline grains. The phase composition of the alloyed layers, atomic reactions, and the matrix grain sizes depended on the combination of components introduced onto the Ti surface during milling. The as-fabricated layer exhibited a very high hardness compared to industrial metallic alloys and tool steel materials. This approach could be used for the manufacture of both cemented carbides and amorphous matrix composite layers.

Ball mounting fixture for a roundness gage

DOEpatents

Gauler, Allen L.; Pasieka, Donald F.

1983-01-01

A ball mounting fixture for a roundness gage is disclosed. The fixture includes a pair of chuck assemblies oriented substantially transversely with respect to one another and mounted on a common base. Each chuck assembly preferably includes a rotary stage and a wobble plate affixed thereto. A ball chuck affixed to each wobble plate is operable to selectively support a ball to be measured for roundness, with the wobble plate permitting the ball chuck to be tilted to center the ball on the axis of rotation of the rotary stage. In a preferred embodiment, each chuck assembly includes a vacuum chuck operable to selectively support the ball to be measured for roundness. The mounting fixture enables a series of roundness measurements to be taken with a conventional rotating gagehead roundness instrument, which measurements can be utilized to determine the sphericity of the ball.

Linear momentum, angular momentum and energy in the linear collision between two balls

NASA Astrophysics Data System (ADS)

Hanisch, C.; Hofmann, F.; Ziese, M.

2018-01-01

In an experiment of the basic physics laboratory, kinematical motion processes were analysed. The motion was recorded with a standard video camera having frame rates from 30 to 240 fps the videos were processed using video analysis software. Video detection was used to analyse the symmetric one-dimensional collision between two balls. Conservation of linear and angular momentum lead to a crossover from rolling to sliding directly after the collision. By variation of the rolling radius the system could be tuned from a regime in which the balls move away from each other after the collision to a situation in which they re-collide.

A Study on the Effects of Ball Defects on the Fatigue Life in Hybrid Bearings

NASA Technical Reports Server (NTRS)

Tang, Ching-Yao; Foerster, Chad E.; O'Brien, Michael J.; Hardy, Brian S.; Goyal, Vinay K.; Nelson, Benjamin A.; Robinson, Ernest Y.; Ward, Peter C.; Hilton, Michael R.

2014-01-01

Hybrid ball bearings using silicon nitride ceramic balls with steel rings are increasingly being used in space mechanism applications due to their high wear resistance and long rolling contact fatigue life. However, qualitative and quantitative reports of the effects of ball defects that cause early fatigue failure are rare. We report on our approach to study these effects. Our strategy includes characterization of defects encountered in use, generation of similar defects in a laboratory setting, execution of full-scale bearing tests to obtain lifetimes, post-test characterization, and related finite-element modeling to understand the stress concentration of these defects. We have confirmed that at least one type of defect of appropriate size can significantly reduce fatigue life. Our method can be used to evaluate other defects as they occur or are encountered.

Polyurethane retainers for ball bearings

NASA Technical Reports Server (NTRS)

Christy, R. I.

1973-01-01

Evaluation of a new ball bearing retainer material is reported. A special composite polyurethane foam ball retainer has been developed that has virtually zero wear, is chemically inert to hydrocarbon lubricants, and stores up to 60 times as much lubricant per unit volume as the most commonly used retainer material, cotton phenolic. This new retainer concept shows promise of years of ball bearing operation without reoiling, based on life testing in high vacuum.

Borner Ball Neutron Detector

NASA Technical Reports Server (NTRS)

2002-01-01

The Bonner Ball Neutron Detector measures neutron radiation. Neutrons are uncharged atomic particles that have the ability to penetrate living tissues, harming human beings in space. The Bonner Ball Neutron Detector is one of three radiation experiments during Expedition Two. The others are the Phantom Torso and Dosimetric Mapping.

Respiratory disease in ball pythons (Python regius) experimentally infected with ball python nidovirus.

PubMed

Hoon-Hanks, Laura L; Layton, Marylee L; Ossiboff, Robert J; Parker, John S L; Dubovi, Edward J; Stenglein, Mark D

2018-04-01

Circumstantial evidence has linked a new group of nidoviruses with respiratory disease in pythons, lizards, and cattle. We conducted experimental infections in ball pythons (Python regius) to test the hypothesis that ball python nidovirus (BPNV) infection results in respiratory disease. Three ball pythons were inoculated orally and intratracheally with cell culture isolated BPNV and two were sham inoculated. Antemortem choanal, oroesophageal, and cloacal swabs and postmortem tissues of infected snakes were positive for viral RNA, protein, and infectious virus by qRT-PCR, immunohistochemistry, western blot and virus isolation. Clinical signs included oral mucosal reddening, abundant mucus secretions, open-mouthed breathing, and anorexia. Histologic lesions included chronic-active mucinous rhinitis, stomatitis, tracheitis, esophagitis and proliferative interstitial pneumonia. Control snakes remained negative and free of clinical signs throughout the experiment. Our findings establish a causal relationship between nidovirus infection and respiratory disease in ball pythons and shed light on disease progression and transmission. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

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

PubMed

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

2016-01-01

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

Casing window milling with abrasive fluid jet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vestavik, O.M.; Fidtje, T.H.; Faure, A.M.

1995-12-31

Methods for through tubing re-entry drilling of multilateral wells has a large potential for increasing hydrocarbon production and total recovery. One of the bottle-necks of this technology is initiation of the side-track by milling a window in the casing downhole. A new approach to this problem has been investigated in a joint industry project. An experimental set-up has been built for milling a 4 inch window in a 7 inch steel casing at surface in the laboratory. A specially designed bit developed at RIF using abrasive jet cutting technology has been used for the window milling. The bit has anmore » abrasive jet beam which is always directed in the desired side-track direction, even if the bit is rotating uniformly. The bit performs the milling with a combined mechanical and hydraulic jet action. The method has been successfully demonstrated. The experiments has shown that the window milling can be performed with very low WOB and torque, and that only small side forces are required to perform the operation. Casing milling has been performed without a whipstock, a cement plug has been the only support for the tool. The tests indicate that milling operations can be performed more efficiently with less time and costs than what is required with conventional techniques. However, the method still needs some development of the downhole motor for coiled tubing applications. The method can be used both for milling and drilling giving the advantage of improved rate of penetration, improved bit life and increased horizontal reach. The method is planned to be demonstrated downhole in the near future.« less

Ball mounting fixture for a roundness gage

DOEpatents

Gauler, A.L.; Pasieka, D.F.

1983-11-15

A ball mounting fixture for a roundness gage is disclosed. The fixture includes a pair of chuck assemblies oriented substantially transversely with respect to one another and mounted on a common base. Each chuck assembly preferably includes a rotary stage and a wobble plate affixed thereto. A ball chuck affixed to each wobble plate is operable to selectively support a ball to be measured for roundness, with the wobble plate permitting the ball chuck to be tilted to center the ball on the axis of rotation of the rotary stage. In a preferred embodiment, each chuck assembly includes a vacuum chuck operable to selectively support the ball to be measured for roundness. The mounting fixture enables a series of roundness measurements to be taken with a conventional rotating gagehead roundness instrument, which measurements can be utilized to determine the sphericity of the ball. 6 figs.

Automatic ball bar for a coordinate measuring machine

DOEpatents

Jostlein, H.

1997-07-15

An automatic ball bar for a coordinate measuring machine determines the accuracy of a coordinate measuring machine having at least one servo drive. The apparatus comprises a first and second gauge ball connected by a telescoping rigid member. The rigid member includes a switch such that inward radial movement of the second gauge ball relative to the first gauge ball causes activation of the switch. The first gauge ball is secured in a first magnetic socket assembly in order to maintain the first gauge ball at a fixed location with respect to the coordinate measuring machine. A second magnetic socket assembly secures the second gauge ball to the arm or probe holder of the coordinate measuring machine. The second gauge ball is then directed by the coordinate measuring machine to move radially inward from a point just beyond the length of the ball bar until the switch is activated. Upon switch activation, the position of the coordinate measuring machine is determined and compared to known ball bar length such that the accuracy of the coordinate measuring machine can be determined. 5 figs.

Automatic ball bar for a coordinate measuring machine

DOEpatents

Jostlein, Hans

1997-01-01

An automatic ball bar for a coordinate measuring machine determines the accuracy of a coordinate measuring machine having at least one servo drive. The apparatus comprises a first and second gauge ball connected by a telescoping rigid member. The rigid member includes a switch such that inward radial movement of the second gauge ball relative to the first gauge ball causes activation of the switch. The first gauge ball is secured in a first magnetic socket assembly in order to maintain the first gauge ball at a fixed location with respect to the coordinate measuring machine. A second magnetic socket assembly secures the second gauge ball to the arm or probe holder of the coordinate measuring machine. The second gauge ball is then directed by the coordinate measuring machine to move radially inward from a point just beyond the length of the ball bar until the switch is activated. Upon switch activation, the position of the coordinate measuring machine is determined and compared to known ball bar length such that the accuracy of the coordinate measuring machine can be determined.

31. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill: oneton ...

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

31. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill: one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: View down at the mill from top of the mill's circular masonry enclosure. Mill animals circling above the mill, on top of the enclosure, dragged booms radiating from the drive shaft to power the mill. The drive-shaft is no longer in its upright positon but is lying next to the mill in the foreground. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Nanoelectric Materials Laboratory Development

NASA Technical Reports Server (NTRS)

Allen, Lee; Hill, Curtis

2015-01-01

The Ultracapacitor Research and Development project is a collaborative effort between the NASA Marshall Space Flight Center's (MSFC's) ES43 Parts, Packaging, and Fabrication Branch and the EM41 Nonmetallic Materials Branch. NASA's Ultracapacitor Research is an effort to develop solid-state energy storage devices through processing of ceramic materials into printable dielectric inks, which can be formed and treated to produce solid state ultracapacitor cells capable of exceeding lithium-ion battery energy density at a fraction of the weight. Research and development efforts into solid state ultracapacitors have highlighted a series of technical challenges such as understanding as-received nature of ceramic powders, treatment and optimization of ceramic powders, dielectric and conductor ink formulation, and firing of printed (green) ultracapacitor cells. Two facilities have been continually developed since project inception: the Additive Electronics Lab in Bldg. 4487 and the Nanoelectric Materials Lab in Bldg. 4602. The Nanoelectric Materials Lab has become a unique facility at MSFC, capable of custom processing a wide range of media for additive electronics. As research has progressed, it was discovered that additional in-house processing was necessary to achieve smaller, more uniform particle diameters. A vibratory mill was obtained that can agitate powder and media in three directions, which has shown to be much more effective than ball milling. However, in order to understand the effects of milling, a particle size analysis system has been installed to characterize as-received and milled materials Continued research into the ultracapacitor technology included advanced milling and optimization of ceramic nanoparticles, fluidized bed treatment of atomic-layer deposition- (ALD-) coated ceramic particles, custom development of dielectric and conductor inks, as well as custom ink precursors such as polyvinylidene diflouride- (PVDF-) loaded vehicles. Experiments with

The relationships between impact location and post-impact ball speed, bat torsion, and ball direction in cricket batting.

PubMed

Peploe, C; McErlain-Naylor, S A; Harland, A R; King, M A

2018-06-01

Three-dimensional kinematic data of bat and ball were recorded for 239 individual shots performed by twenty batsmen ranging from club to international standard. The impact location of the ball on the bat face was determined and assessed against the resultant instantaneous post-impact ball speed and measures of post-impact bat torsion and ball direction. Significant negative linear relationships were found between post-impact ball speed and the absolute distance of impact from the midline medio-laterally and sweetspot longitudinally. Significant cubic relationships were found between the distance of impact from the midline of the bat medio-laterally and both a measure of bat torsion and the post-impact ball direction. A "sweet region" on the bat face was identified whereby impacts within 2 cm of the sweetspot in the medio-lateral direction, and 4.5 cm in the longitudinal direction, caused reductions in ball speed of less than 6% from the optimal value, and deviations in ball direction of less than 10° from the intended target. This study provides a greater understanding of the margin for error afforded to batsmen, allowing researchers to assess shot success in more detail, and highlights the importance of players generating consistently central impact locations when hitting for optimal performance.

Stemless Ball Valve

NASA Technical Reports Server (NTRS)

Burgess, Robert K.; Yakos, David; Walthall, Bryan

2012-01-01

This invention utilizes a new method of opening and closing a ball valve. Instead of rotating the ball with a perpendicular stem (as is the case with standard ball valves), the ball is rotated around a fixed axis by two guide pins. This innovation eliminates the leak point that is present in all standard ball valves due to the penetration of an actuation stem through the valve body. The VOST (Venturi Off-Set-Technology) valve has been developed for commercial applications. The standard version of the valve consists of an off-set venturi flow path through the valve. This path is split at the narrowest portion of the venturi, allowing the section upstream from the venturi to be rotated. As this rotation takes place, the venturi becomes restricted as one face rotates with respect to the other, eventually closing off the flow path. A spring-loaded seal made of resilient material is embedded in the upstream face of the valve, making a leak-proof seal between the faces; thus a valve is formed. The spring-loaded lip seal is the only seal that can provide a class six, or bubble-tight, seal against the opposite face of the valve. Tearing action of the seal by high-velocity gas on this early design required relocation of the seal to the downstream face of the valve. In the stemless embodiment of this valve, inner and outer magnetic cartridges are employed to transfer mechanical torque from the outside of the valve to the inside without the use of a stem. This eliminates the leak path caused by the valve stems in standard valves because the stems penetrate through the bodies of these valves.

Eddy-Current Inspection of Ball Bearings

NASA Technical Reports Server (NTRS)

Bankston, B.

1985-01-01

Custom eddy-current probe locates surface anomalies. Low friction air cushion within cone allows ball to roll easily. Eddy current probe reliably detects surface and near-surface cracks, voids, and material anomalies in bearing balls or other spherical objects. Defects in ball surface detected by probe displayed on CRT and recorded on strip-chart recorder.

Relation Between Hertz Stress-Life Exponent, Ball-Race Conformity, and Ball Bearing Life

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Poplawski, Joseph V.; Root, Lawrence E.

2008-01-01

ANSI/ABMA and ISO standards based on Lundberg-Palmgren bearing life theory are normalized for ball bearings having inner- and outerrace conformities of 52 percent (0.52) and made from pre-1940 bearing steel. The Lundberg-Palmgren theory incorporates an inverse 9th power relation between Hertz stress and fatigue life for ball bearings. The effect of race conformity on ball set life independent of race life is not incorporated into the Lundberg-Palmgren theory. In addition, post-1960 vacuum-processed bearing steel exhibits a 12th power relation between Hertz stress and life. The work reported extends the previous work of Zaretsky, Poplawski, and Root to calculate changes in bearing life--that includes the life of the ball set--caused by race conformity, Hertz stress-life exponent, ball bearing type and bearing series. The bearing fatigue life in actual application will usually be equal to or greater than that calculated using the ANSI/ABMA and ISO standards that incorporate the Lundberg-Palmgren theory. The relative fatigue life of an individual race is more sensitive to changes in race conformity for Hertz stress-life exponent n of 12 than where n = 9. However, when the effects are combined to predict actual bearing life for a specified set of conditions and bearing geometry, the predicted life of the bearing will be greater for a value of n = 12 than n = 9.

Relation between Hertz Stress-Life Exponent, Ball-Race Conformity, and Ball Bearing Life

NASA Technical Reports Server (NTRS)

Zaretsky, Erwin V.; Poplawski, Joseph V.; Root, Lawrence E.

2006-01-01

ANSI/ABMA and ISO standards based on Lundberg-Palmgren bearing life theory are normalized for ball bearings having inner- and outer-race conformities of 52 percent (0.52) and made from pre-1940 bearing steel. The Lundberg-Palmgren theory incorporates an inverse 9th power relation between Hertz stress and fatigue life for ball bearings. The effect of race conformity on ball set life independent of race life is not incorporated into the Lundberg-Palmgren theory. In addition, post-1960 vacuum-processed bearing steel exhibits a 12th power relation between Hertz stress and life. The work reported extends the previous work of Zaretsky, Poplawski, and Root to calculate changes in bearing life, that includes the life of the ball set, caused by race conformity, Hertz stress-life exponent, ball bearing type and bearing series. The bearing fatigue life in actual application will usually be equal to or greater than that calculated using the ANSI/ABMA and ISO standards that incorporate the Lundberg-Palmgren theory. The relative fatigue life of an individual race is more sensitive to changes in race conformity for Hertz stress-life exponent n of 12 than where n = 9. However, when the effects are combined to predict actual bearing life for a specified set of conditions and bearing geometry, the predicted life of the bearing will be greater for a value of n = 12 than n = 9.

Shock-Absorbent Ball-Screw Mechanism

NASA Technical Reports Server (NTRS)

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.

Projectile Activity for the Laboratory: A Safe and Inexpensive Approach to Several Concepts

ERIC Educational Resources Information Center

Farkas, N.; Ramsier, R. D.

2006-01-01

We present a simple laboratory activity for introductory-level physics students which involves rolling balls down pipes and analysing their subsequent flight trajectories. Using balls of equal size but different mass allows students to confront their misconceptions of a mass dependence of the exit speed of the balls from the pipes. The concepts of…

Minimisation of costs by using disintegration at a full-scale anaerobic digestion plant.

PubMed

Winter, A

2002-01-01

Various half-scale and lab-scale investigations have already shown that the disintegration of excess sludge is a possible pre-treatment to optimise anaerobic digestion. To control these results different methods of disintegration were investigated at a full-scale plant. Two stirred ball mills and a plant for oxidation with ozone were applied. A positive influence of disintegration on the anaerobic biodegradability can be established with application of a stirred ball mill. Biogas production as well as the degree of degradation were increased by about 20%. Laboratory investigations also validate that disintegration increases the polymer demand and leads to a lower solid content after dewatering. A higher pollution level of process water after dewatering even with ammonia and COD corroborates the results of the anaerobic degradation. Capital costs for the stirred ball mill, costs for energy, manpower and maintenance can be covered if the specific costs for disposal are high. If the development of costs in future and the current discussion about sludge disposal are taken into account sewage sludge disintegration can be a suitable technique to minimise costs at waste water treatment plants.

Latching Solenoid-Operated Ball Valve

NASA Technical Reports Server (NTRS)

Brudnicki, Myron

1994-01-01

Proposed solenoid-operated ball valve latches in open or closed position until energized to change position. Electrical energy consumed only during opening or closing motion. Valve ball contains central channel through which fluid could flow. Made of highly magnetically permeable steel. When appropriate coil(s) energized by brief pulse (or pulses) of electrical current at appropriate polarity, ball rotates clockwise until permanent magnets come to rest against hard stops in housing, and inlet and outlet ports aligned with central channel so fluid flows through valve. Magnets adhere to stops by magnetic attraction, latching valve in open position. To close valve, appropriate coil(s) energized by pulse (or pulses) of appropriate polarity to generate magnetic forces rotating ball counterclockwise until magnets make contact with hard stops, and inlet and outlet ports sealed.

Line profile analysis of ODS steels Fe20Cr5AlTiY milled powders at different Y2O3 concentrations

NASA Astrophysics Data System (ADS)

Afandi, A.; Nisa, R.; Thosin, K. A. Z.

2017-04-01

Mechanical properties of material are largely dictated by constituent microstructure parameters such as dislocation density, lattice microstrain, crystallite size and its distribution. To develop ultra-fine grain alloys such as Oxide Dispersion Strengthened (ODS) alloys, mechanical alloying is crucial step to introduce crystal defects, and refining the crystallite size. In this research the ODS sample powders were mechanically alloyed with different Y2O3 concentration respectively of 0.5, 1, 3, and 5 wt%. MA process was conducted with High Energy Milling (HEM) with the ball to powder ratio of 15:1. The vial and the ball were made of alumina, and the milling condition is set 200 r.p.m constant. The ODS powders were investigated by X-Ray Diffractions (XRD), Bragg-Brentano setup of SmartLab Rigaku with 40 KV, and 30 mA, step size using 0.02°, with scanning speed of 4°min-1. Line Profile Analysis (LPA) of classical Williamson-Hall was carried out, with the aim to investigate the different crystallite size, and microstrain due to the selection of the full wide at half maximum (FWHM) and integral breadth.

Dual load path ball screw with rod end swivel

NASA Technical Reports Server (NTRS)

Wngett, Paul (Inventor)

2002-01-01

A dual drive ball has a ball screw shaft coupled at one end to a gear train and coupled at the other end to a ball screw nut. The ball screw shaft and ball screw nut are connected through complementary helical grooves filled with ball bearing balls. The outer surface of the ball screw nut is plined and can be driven by a second gear train. An output tube is coupled at one end to the ball screw nut and at its opposite end has a connector portion with a groove on its inner surface. A rod end has a coupling member for coupling to a surface to be actuated and a shaft portion with a groobe on its outer surface. This shaft portion is received with in the outputtube portion and the corresponding grooves are coupled through the use of a plurality of ball bearing balls.

Correlation of Shoulder and Elbow Kinetics With Ball Velocity in Collegiate Baseball Pitchers

PubMed Central

Post, Eric G.; Laudner, Kevin G.; McLoda, Todd A.; Wong, Regan; Meister, Keith

2015-01-01

Context Throwing a baseball is a dynamic and violent act that places large magnitudes of stress on the shoulder and elbow. Specific injuries at the elbow and glenohumeral joints have been linked to several kinetic variables throughout the throwing motion. However, very little research has directly examined the relationship between these kinetic variables and ball velocity. Objective To examine the correlation of peak ball velocity with elbow-valgus torque, shoulder external-rotation torque, and shoulder-distraction force in a group of collegiate baseball pitchers. Design Cross-sectional study. Setting Motion-analysis laboratory. Patients or Other Participants Sixty-seven asymptomatic National Collegiate Athletic Association Division I baseball pitchers (age = 19.5 ± 1.2 years, height = 186.2 ± 5.7 cm, mass = 86.7 ± 7.0 kg; 48 right handed, 19 left handed). Main Outcome Measure(s) We measured peak ball velocity using a radar gun and shoulder and elbow kinetics of the throwing arm using 8 electronically synchronized, high-speed digital cameras. We placed 26 reflective markers on anatomical landmarks of each participant to track 3-dimensional coordinate data. The average data from the 3 highest-velocity fastballs thrown for strikes were used for data analysis. We calculated a Pearson correlation coefficient to determine the associations between ball velocity and peak elbow-valgus torque, shoulder-distraction force, and shoulder external-rotation torque (P < .05). Results A weak positive correlation was found between ball velocity and shoulder-distraction force (r = 0.257; 95% confidence interval [CI] = 0.02, 0.47; r2 = 0.066; P = .018). However, no significant correlations were noted between ball velocity and elbow-valgus torque (r = 0.199; 95% CI = −0.043, 0.419; r2 = 0.040; P = .053) or shoulder external-rotation torque (r = 0.097; 95% CI = −0.147, 0.329; r2 = 0.009; P = .217). Conclusions Although a weak positive correlation was present between ball velocity

Solution-state 2D NMR of ball-milled plant cell wall gels in DMSO-d6/pyridine-d5†

PubMed Central

Ralph, John

2014-01-01

NMR fingerprinting of the components of finely divided plant cell walls swelled in DMSO has been recently described. Cell wall gels, produced directly in the NMR tube with perdeutero-dimethylsulfoxide, allowed the acquisition of well resolved/dispersed 2D 13C–1H correlated solution-state NMR spectra of the entire array of wall polymers, without the need for component fractionation. That is, without actual solubilization, and without apparent structural modification beyond that inflicted by the ball milling and ultrasonication steps, satisfactorily interpretable spectra can be acquired that reveal compositional and structural details regarding the polysaccharide and lignin components in the wall. Here, the profiling method has been improved by using a mixture of perdeuterated DMSO and pyridine (4:1, v/v). Adding pyridine provided not only easier sample handling because of the better mobility compared to the DMSO-d6-only system but also considerably elevated intensities and improved resolution of the NMR spectra due to the enhanced swelling of the cell walls. This modification therefore provides a more rapid method for comparative structural evaluation of plant cell walls than is currently available. We examined loblolly pine (Pinus taeda, a gymnosperm), aspen (Populus tremuloides, an angiosperm), kenaf (Hibiscus cannabinus, an herbaceous plant), and corn (Zea mays L., a grass, i.e., from the Poaceae family). In principle, lignin composition (notably, the syringyl : guaiacyl : p-hydroxyphenyl ratio) can be quantified without the need for lignin isolation. Correlations for p-coumarate units in the corn sample are readily seen, and a variety of the ferulate correlations are also well resolved; ferulates are important components responsible for cell wall cross-linking in grasses. Polysaccharide anomeric correlations were tentatively assigned for each plant sample based on standard samples and various literature data. With the new potential for chemometric analysis

The principal time balls of New Zealand

NASA Astrophysics Data System (ADS)

Kinns, Roger

2017-04-01

Accurate time signals in New Zealand were important for navigation in the Pacific. Time balls at Wellington and Lyttelton were noted in the 1880 Admiralty list of time signals, with later addition of Otago. The time ball service at Wellington started in March 1864 using the first official observatory in New Zealand, but there was no Wellington time ball service during a long period of waterfront redevelopment during the 1880s. The time ball service restarted in November 1888 at a different harbour location. The original mechanical apparatus was used with a new ball, but the system was destroyed by fire in March 1909 and was never replaced. Instead, a time light service was inaugurated in 1912. The service at Lyttelton, near Christchurch, began in December 1876 after construction of the signal station there. It used telegraph signals from Wellington to regulate the time ball. By the end of 1909, it was the only official time ball in New Zealand, providing a service that lasted until 1934. The Lyttelton time ball tower was an iconic landmark in New Zealand that had been carefully restored. Tragically, the tower collapsed in the 2011 earthquakes and aftershocks that devastated Christchurch. A daily time ball service at Port Chalmers, near Dunedin, started in June 1867, initially using local observatory facilities. The service appears to have been discontinued in October 1877, but was re-established in April 1882 as a weekly service, with control by telegraph from Wellington. The service had been withdrawn altogether by the end of 1909. Auckland never established a reliable time ball service, despite provision of a weekly service for mariners by a public-spirited citizen between August 1864 and June 1866. A time ball was finally installed on the Harbour Board building in 1901, but the signal was unreliable and it ceased in 1902. Complaints from ships' masters led to various proposals to re-establish a service. These concluded with erection of a time ball on the new

The dynamics of hurricane balls

NASA Astrophysics Data System (ADS)

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.

Water ball collision

NASA Technical Reports Server (NTRS)

Fujimoto, K.

1986-01-01

What happens if a stainless steel ball hits a water ball in the weightless space ot the Universe? In other words, it was the objective of our experiments in the Space to observe the surface tension of liquid by means of making a solid collide with a liquid. Place a small volume of water between 2 glass sheets to make a thin water membrane: the 2 glass sheets cannot be separated unless an enormous force is applied. It is obvious from this phenomenom that the surface tension of water is far greater than presumed. On Earth, however, it is impossible in most cases to observe only the surface tension of liquid, because gravity always acts on the surface tension. Water and stainless steel balls were chosen the liquid and solids for the experiments. Because water is the liquid most familiar to us, its properties are well known. And it is also of great interest to compare its properties on the Earth with those in the weightless space.

Ball Screw Actuator Including a Stop with an Integral Guide

NASA Technical Reports Server (NTRS)

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.

Promoting ball skills in preschool-age girls.

PubMed

Veldman, Sanne L C; Palmer, Kara K; Okely, Anthony D; Robinson, Leah E

2017-01-01

Evidence supports that girls are less proficient than boys at performing ball skills. This study examined the immediate and long-term effects of a ball skill intervention on preschool-age girls' ball skill performance. Randomized controlled trial. Girls (M age =47.24±7.38 months) were randomly assigned to a high autonomy, mastery-based 9-week motor skill intervention (the Children's Health Activity Motor Program; CHAMP, 540min; n=38) or a control group (free-play; n=16). Ball skill proficiency was assessed at pretest, posttest, and retention test (after 9 weeks) using the object control subscale of the Test of Gross Motor Development - 2nd Edition. Treatment efficacy was examined using linear mixed models. Two models were fit: one for short-term changes (pretest to posttest) and one for long-term changes (pretest to retention). Linear mixed models revealed a significantly time*treatment interaction for both models. Post hoc analysis confirmed that girls in CHAMP experienced significant gains in ball skills from pretest to posttest (p<.001) and pretest to retention (p<.001). Moreover, girls in CHAMP were no different from the control group at pretest (p>.05) but had significantly higher ball skills scores at both posttest (p<.001) and retention (p<.001). This study demonstrates the positive effects of a ball skill intervention (i.e., CHAMP) on improving girls' ball skills both short- and long-term. Findings suggest that early childhood interventions that focus on the development of ball skills in young girls might be an avenue to improve girls' ball skill performance. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

A formula for comparison of selected sport ball compressibility.

PubMed Central

Dowell, L J; Krebs, G

1991-01-01

The purpose of this study was to develop a formula to determine and compare the compressibility of selected sport balls. Six balls (basketball, volleyball, soccer ball, baseball, handball, golf ball) were dropped ten times from each of four different heights onto a smooth solid surface overlaid with a white sheet of typing paper, overlaid with a sheet of carbon paper. The diameter of the area of contact of each ball imprinted onto the typing paper was measured in millimetres with calipers. From the data, the distance (d) that each ball compressed for each velocity (v) was calculated. It was found that a linear relationship existed between velocity at impact and the distance for each ball studied. The compressibility coefficient (c) for each ball was calculated and a formula was developed to determine the distance each ball would compress at a given velocity. When velocity is measured in metres per second and the distance a ball compresses is measured in millimetres, the formula to determine d for selected balls, in order of compressibility is: basketball d = 3.07v, volleyball d = 2.90v, soccer ball d = 2.80v, baseball d = 0.77v, handball d = 0.53v, and golf ball d = 0.17v. PMID:1913029

N-type nano-silicon powders with ultra-low electrical resistivity as anode materials in lithium ion batteries

NASA Astrophysics Data System (ADS)

Yue, Zhihao; Zhou, Lang; Jin, Chenxin; Xu, Guojun; Liu, Liekai; Tang, Hao; Li, Xiaomin; Sun, Fugen; Huang, Haibin; Yuan, Jiren

2017-06-01

N-type silicon wafers with electrical resistivity of 0.001 Ω cm were ball-milled to powders and part of them was further mechanically crushed by sand-milling to smaller particles of nano-size. Both the sand-milled and ball-milled silicon powders were, respectively, mixed with graphite powder (silicon:graphite = 5:95, weight ratio) as anode materials for lithium ion batteries. Electrochemical measurements, including cycle and rate tests, present that anode using sand-milled silicon powder performed much better. The first discharge capacity of sand-milled silicon anode is 549.7 mAh/g and it is still up to 420.4 mAh/g after 100 cycles. Besides, the D50 of sand-milled silicon powder shows ten times smaller in particle size than that of ball-milled silicon powder, and they are 276 nm and 2.6 μm, respectively. In addition, there exist some amorphous silicon components in the sand-milled silicon powder excepting the multi-crystalline silicon, which is very different from the ball-milled silicon powder made up of multi-crystalline silicon only.

Determination of ethyl glucuronide in hair: a rapid sample pretreatment involving simultaneous milling and extraction.

PubMed

Mönch, Bettina; Becker, Roland; Nehls, Irene

2014-01-01

A combination of simultaneous milling and extraction known as micropulverized extraction was developed for the quantification of the alcohol marker ethyl glucuronide (EtG) in hair samples using a homogeneous reference material and a mixer mill. Best extraction results from 50 mg of hair were obtained with 2-mL plastic tubes containing two steel balls (∅ = 5 mm), 0.5 mL of water and with an oscillating frequency of 30 s(-1) over a period of 30 min. EtG was quantified employing a validated GC-MS procedure involving derivatization with pentafluoropropionic acid anhydride. This micropulverization procedure was compared with dry milling followed by separate aqueous extraction and with aqueous extraction after manual cutting to millimeter-size snippets. Micropulverization yielded 28.0 ± 1.70 pg/mg and was seen to be superior to manually cutting (23.0 ± 0.83 pg/mg) and equivalent to dry grinding (27.7 ± 1.71 pg/mg) with regard to completeness of EtG extraction. The option to process up to 20 samples simultaneously makes micropulverization especially valuable for the high throughput of urgent samples.

Heated-Pressure-Ball Monopropellant Rocket Engine

NASA Technical Reports Server (NTRS)

Greene, William D.

2005-01-01

A recent technology disclosure presents a concept for a monopropellant thermal spacecraft thruster that would feature both the simplicity of a typical prior pressure-fed propellant supply system and the smaller mass and relative compactness of a typical prior pump-fed system. The source of heat for this thruster would likely be a nuclear- fission reactor. The propellant would be a cryogenic fluid (a liquefied low-molecular-weight gas) stored in a tank at a low pressure. The propellant would flow from the tank, through a feedline, into three thick-walled spherical tanks, denoted pressure balls, that would be thermally connected to the reactor. Valves upstream and downstream of the pressure balls would be operated in a three-phase cycle in which propellant would flow into one pressure ball while the fluid underwent pressurization through heating in another ball and pressurized propellant was discharged from the remaining ball into the reactor. After flowing through the reactor, wherein it would be further heated, the propellant would be discharged through an exhaust nozzle to generate thrust. A fraction of the pressurized gas from the pressure balls would be diverted to maintain the desired pressure in the tank.

Ball bearing heat analysis program (BABHAP)

NASA Technical Reports Server (NTRS)

1978-01-01

The Ball Bearing Heat Analysis Program (BABHAP) is an attempt to assemble a series of equations, some of which are non-linear algebraic systems, in a logical order, which when solved, provide a complex analysis of load distribution among the balls, ball velocities, heat generation resulting from friction, applied load, and ball spinning, minimum lubricant film thickness, and many additional characteristics of ball bearing systems. Although initial design requirements for BABHAP were dictated by the core limitations of the PDP 11/45 computer, (approximately 8K of real words with limited number of instructions) the program dimensions can easily be expanded for large core computers such as the UNIVAC 1108. The PDP version of BABHAP is also operational on the UNIVAC system with the exception that the PDP uses 029 punch and the UNIVAC uses 026. A conversion program was written to allow transfer between machines.

Rapid Aluminum Nanoparticle Production by Milling in NH₃ and CH₃NH₂ Atmospheres: An Experimental and Theoretical Study.

PubMed

McMahon, Brandon W; Yu, Jiang; Boatz, Jerry A; Anderson, Scott L

2015-07-29

Ball milling of aluminum in gaseous atmospheres of ammonia and monomethylamine (MMA) was found to produce particles in the 100 nm size range with high efficiency. A combination of mass spectrometry, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis with mass spectrometric product analysis (TGA-MS), scanning electron microscopy (SEM), infrared spectroscopy, and dynamic light scattering (DLS) was used to study the particles and the chemical interactions responsible for particle production. To help understand the nature of the surface chemistry, high level quantum chemical calculations were performed to predict the structures and energetics for binding and reactions of NH3 and MMA on aluminum surfaces. Both NH3 and MMA react with aluminum under milling conditions, producing H2 and other gaseous products, and leaving the surfaces functionalized. The surface functionalization enhances size reduction by reducing the surface free energy and the tendency toward mechanochemical welding. For both NH3 and MMA, the particle cores are metallic aluminum, but the surface chemical properties are quite different. The ammonia-milled particles are capped by an AlNxOyHz layer ∼10 nm thick, which passivates the particles. The MMA-milled particles are capped with a thinner passivating layer, such that they are pyrophoric in air and react with N2 at elevated temperatures.

Flight trajectory of a rotating golf ball with grooves

NASA Astrophysics Data System (ADS)

Baek, Moonheum; Kim, Jooha; Choi, Haecheon

2014-11-01

Dimples are known to reduce drag on a sphere by the amount of 50% as compared to a smooth surface. Despite the advantage of reducing drag, dimples deteriorate the putting accuracy owing to their sharp edges. To minimize this putting error but maintain the same flight distance, we have devised a grooved golf ball (called G ball hereafter) for several years. In this study, we modify the shape and pattern of grooves, and investigate the flow characteristics of the G ball by performing wind-tunnel experiments at the Reynolds numbers of 0 . 5 ×105 - 2 . 5 ×105 and the spin ratios (ratio of surface velocity to the free-stream velocity) of 0 - 0.6 that include the real golf-ball velocity and rotational speed. We measure the drag and lift forces on the rotating G ball and compare them with those of a smooth ball and two well-known dimpled balls. The lift-to-drag ratio of the G ball is much higher than that of a smooth ball and is in between those of the two dimpled balls. The trajectories of flying golf balls are computed. The flight distance of G ball is almost the same as that of one dimpled ball but slightly shorter than that of the other dimpled ball. The fluid-dynamic aspects of these differences will be discussed at the talk. Supported by 2011-0028032, 2014M3C1B1033980.

Acting Administrator Lightfoot Visits Ball Aerospace

NASA Image and Video Library

2017-04-06

Acting NASA Deputy Administrator Lesa Roe, second from left, and acting NASA Administrator Robert Lightfoot, second from left, are seen with Mike Gazarik, vice president of Engineering at Ball Aerospace, left and Shawn Conley, test operations manager at Ball Aerospace, left, in front of the large semi-anechoic chamber, Thursday, April 6, 2017 during a visit to Ball Aerospace in Boulder, Colo. Photo Credit: (NASA/Joel Kowsky)

Effect of Synthesis Procedure on Thermoelectric Property of SiGe Alloy

NASA Astrophysics Data System (ADS)

Li, Jing; Han, Jun; Jiang, Tao; Luo, Lili; Xiang, Yongchun

2018-05-01

SiGe thermoelectric material has been synthesized by ball milling combined with hot pressing (HP) or spark plasma sintering (SPS). Effects of ball milling time, powder to ball weight ratio and sintering method on microstructure and thermoelectric properties of SiGe are studied. The results show that longer ball milling time leads to decreased density and worse electrical properties. In the sintering process, SPS results in much larger density and better electrical properties than HP. The Si0.795Ge0.2B0.005 sample prepared by 2 h ball milling combined with SPS obtains a maximum power factor of 3.0 mW m-1 K-2 at 860 K and ZT of 0.95 at 1000 K.

Milling the Mistletoe: Nanotechnological Conversion of African Mistletoe (Loranthus micranthus) Intoantimicrobial Materials.

PubMed

Sarfraz, Muhammad; Griffin, Sharoon; Gabour Sad, Tamara; Alhasan, Rama; Nasim, Muhammad Jawad; Irfan Masood, Muhammad; Schäfer, Karl Herbert; Ejike, Chukwunonso E C C; Keck, Cornelia M; Jacob, Claus; Ebokaiwe, Azubuike P

2018-04-20

Nanosizing represents a straight forward technique to unlock the biological activity of complex plant materials. The aim of this study was to develop herbal nanoparticles with medicinal value from dried leaves and stems of Loranthus micranthus with the aid of ball-milling, high speed stirring, and high-pressure homogenization techniques. The milled nanoparticles were characterized using laser diffraction analysis, photon correlation spectroscopy analysis, and light microscopy. The average size of leaf nanoparticles was around 245 nm and that of stem nanoparticles was around 180 nm. The nanoparticles were tested for their antimicrobial and nematicidal properties against a Gram-negative bacterium Escherichia coli , a Gram-positive bacterium Staphylococcus carnosus , fungi Candida albicans and Saccharomyces cerevisiae , and a nematode Steinernemafeltiae . The results show significant activities for both leaf and (particularly) stem nanoparticles of Loranthus micranthus on all organisms tested, even at a particle concentration as low as 0.01% ( w / w ). The results observed indicate that nanoparticles (especially of the stem) of Loranthus micranthus could serve as novel antimicrobial agents with wide-ranging biomedical applications.

Ball-morph: definition, implementation, and comparative evaluation.

PubMed

Whited, Brian; Rossignac, Jaroslaw Jarek

2011-06-01

We define b-compatibility for planar curves and propose three ball morphing techniques between pairs of b-compatible curves. Ball-morphs use the automatic ball-map correspondence, proposed by Chazal et al., from which we derive different vertex trajectories (linear, circular, and parabolic). All three morphs are symmetric, meeting both curves with the same angle, which is a right angle for the circular and parabolic. We provide simple constructions for these ball-morphs and compare them to each other and other simple morphs (linear-interpolation, closest-projection, curvature-interpolation, Laplace-blending, and heat-propagation) using six cost measures (travel-distance, distortion, stretch, local acceleration, average squared mean curvature, and maximum squared mean curvature). The results depend heavily on the input curves. Nevertheless, we found that the linear ball-morph has consistently the shortest travel-distance and the circular ball-morph has the least amount of distortion.

Rolling-element fatigue life of AMS 5900 balls

NASA Technical Reports Server (NTRS)

Parker, R. J.

1983-01-01

The rolling-element fatigue life of AMS 5900 12.7-mm (1/2-in.) dia was determined in five-ball fatigue testers. The 10% life with the warm headed AMS 5900 balls was equivalent to that of AMS 5749 and over eight times that of AISI M-50. The AMS balls fabricated by cold heading had small surface cracks which initiated fatigue spalls where these cracks were crossed by running tracks. The cold-headed AMS 5900 balls had a 10% fatigue life an order of magnitude less than that of the warm headed balls even when failures on the cold headed balls at visible surface cracks were omitted.

30. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill: oneton ...

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

30. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill: one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1885-1870. View: Masonry-lined passage-way leading to the mill at the center of its circular masonry enclosure. The passageway permitted cane to be carried to the mill and cane trash (bagasse) to be carried away. Bridges over the passageways, no longer in place, permitted the mill animals to circle and power the mill from above. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Measurements of drag and lift on smooth balls in flight

NASA Astrophysics Data System (ADS)

Cross, Rod; Lindsey, Crawford

2017-07-01

Measurements are presented on the drag and lift coefficients for three relatively smooth balls launched in air and tracked with two cameras separated horizontally by 6.4 m. The ball spin was varied in order to investigate whether the Magnus force would increase or decrease when the ball spin was increased. For one ball, the Magnus force increased. For another ball, the Magnus force decreased almost to zero after reaching a maximum. For the third ball, the Magnus force was negative at low ball spins and positive at high ball spins. For one of the balls, the ball spin increased with time as it travelled through the air.

Ball-joint grounding ring

NASA Technical Reports Server (NTRS)

Aperlo, P. J. A.; Buck, P. A.; Weldon, V. A.

1981-01-01

In ball and socket joint where electrical insulator such as polytetrafluoroethylene is used as line to minimize friction, good electrical contact across joint may be needed for lightning protection or to prevent static-charge build-up. Electrical contact is maintained by ring of spring-loaded fingers mounted in socket. It may be useful in industry for cranes, trailers, and other applications requiring ball and socket joint.

12. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill: oneton ...

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

12. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill: one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: Historical view, 1934, T.T. Waterman Collection, Hawaiian Sugar Planters' Association, Oahu, Hawaii. Masonry-lined passageway leading to the mill at the center of its circular masonry enclosure. The passageway permitted cane to be carried to the mill and cane trash (bagasse) to be carried away after milling. Bridges over the passageways, not in place, permitted the mill animals to circle and power the mill from above. View shows area prior to substantial overgrowth existing in 1978 views of the area. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Measuring the rebound resilience of a bouncing ball

NASA Astrophysics Data System (ADS)

Wadhwa, Ajay

2012-09-01

Some balls which are made of high-quality rubber (an elastomeric) material, such as tennis or squash balls, could be used for the determination of an important property of such materials called resilience. Since a bouncing ball involves a single impact we call this property 'rebound resilience' and express it as the ratio of the rebound height to the initial drop height of the ball. We determine the rebound resilience for three different types of ball by calculating the coefficient of restitution of the ball-surface combination from the experimentally measurable physical quantities, such as initial drop height and time interval between successive bounces. Using these we also determine the contact time of balls with the surface of impact. For measurements we have used audio, motion and surface-temperature sensors that were interfaced through a USB port with a computer.

Carbon nanotube balls and their application in supercapacitors.

PubMed

Kang, Da-Young; Moon, Jun Hyuk

2014-01-08

We have provided a design of the macroscopic morphology of carbon nanotubes (CNTs) using emulsion droplet confinement. The evaporation of CNT-dispersed aqueous emulsion droplets in oil produces spherical CNT assemblies, i.e., CNT balls. In this emulsion-assisted method, compact packing of CNT was obtained by the presence of capillary pressure during droplet evaporation. The size of the CNT balls could be controlled by changing the concentration of the CNT dispersion solution; typically, CNT balls with an average size in the range of 8-12 μm were obtained with a Brunauer-Emmett-Teller (BET) specific area of 200 m(2)/g. Heat treatment of the CNT balls, which was required to remove residual solvent, and cement CNTs was followed, and their effect has been characterized; the heat treatment at high temperature desorbed surface oxygenated groups of CNTs and created defective carbon structures, but did not change pore structure. The dispersion of CNT balls was applied to form CNT ball-assembled film for a supercapacitor electrode. The specific capacitance of 80 F/g was obtained at 500 °C heat treatment, but the CNT balls prepared at a higher temperature actually decreased the capacitance, because of the removal of surface oxygenated groups, thereby decreasing the pseudo-capacitance. The capacitive properties of CNT ball-assembled electrodes were compared to CNT films; the CNT ball electrodes showed 40% higher specific electrochemical capacitance and higher rate performance, which is attributed to the compact packing of CNTs in the CNT ball and the hierarchical porous structures in the ball assemblies.

Q-balls in flat potentials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Copeland, Edmund J.; Tsumagari, Mitsuo I.

2009-07-15

We study the classical and absolute stability of Q-balls in scalar field theories with flat potentials arising in both gravity-mediated and gauge-mediated models. We show that the associated Q-matter formed in gravity-mediated potentials can be stable against decay into their own free particles as long as the coupling constant of the nonrenormalizable term is small, and that all of the possible three-dimensional Q-ball configurations are classically stable against linear fluctuations. Three-dimensional gauge-mediated Q-balls can be absolutely stable in the thin-wall limit, but are completely unstable in the thick-wall limit.

Novel concept of recycling sludge and dust to BOF converter through dispersed in-situ phase induced by composite ball explosive reaction

NASA Astrophysics Data System (ADS)

Tang, Fu-ping; Yu, Shu-juan; Fei, Peng; Hou, Hou-yu; Qian, Feng; Wang, Xiao-feng

2017-08-01

Recycling of iron and steelmaking dusts is a key issue in environmental protection efforts and to ensure efficient utilization. In this investigation, we developed a novel recovery process that uses a dispersed in-situ phase induced by an explosive reaction of composite balls of iron and steelmaking dusts. We designed and prepared composite balls for this function using a laboratory model batch-type balling disc (at 12 r/min) and optimized the feeding modes in 180-t and 260-t basic oxygen furnace (BOF) converters. The results indicate that feeding composite balls into BOF converters is an effective novel technology for recovering iron and steelmaking dusts. The period after hot metal charging and prior to the oxygen-blowing process is the most reasonable time to feed composite balls. Composite ball treatment is not appropriate for steel production with sulfur requirements lower than 80 ppm. The maximum composite ball feeding amount is 40 kg/t and the iron yield rate is better than 95%. Compared with the conventional recycling process of sludge and dust, this novel technology is more convenient and efficient, saving up to 309 RMB per ton of steel. Further investigation of this novel recycling technology is merited.

Hex ball torque test

NASA Technical Reports Server (NTRS)

Robinson, B. A.; Foster, C. L.

1986-01-01

A series of torque tests were performed on four flight-type hex ball universal joints in order to characterize and determine the actual load-carrying capability of this device. The universal joint is a part of manual actuation rods for scientific instruments within the Hubble Space Telescope. It was found that the hex ball will bind slightly during the initial load application. This binding did not affect the function of the universal joint, and the units would wear-in after a few additional loading cycles. The torsional yield load was approximately 50 ft-lb, and was consistent among the four test specimens. Also, the torque required to cause complete failure exceeded 80 ft-lb. It is concluded that the hex ball universal joint is suitable for its intended applications.

Novel mathematical model to estimate ball impact force in soccer.

PubMed

Iga, Takahito; Nunome, Hiroyuki; Sano, Shinya; Sato, Nahoko; Ikegami, Yasuo

2017-11-22

To assess ball impact force during soccer kicking is important to quantify from both performance and chronic injury prevention perspectives. We aimed to verify the appropriateness of previous models used to estimate ball impact force and to propose an improved model to better capture the time history of ball impact force. A soccer ball was fired directly onto a force platform (10 kHz) at five realistic kicking ball velocities and ball behaviour was captured by a high-speed camera (5,000 Hz). The time history of ball impact force was estimated using three existing models and two new models. A new mathematical model that took into account a rapid change in ball surface area and heterogeneous ball deformation showed a distinctive advantage to estimate the peak forces and its occurrence times and to reproduce time history of ball impact forces more precisely, thereby reinforcing the possible mechanics of 'footballer's ankle'. Ball impact time was also systematically shortened when ball velocity increases in contrast to practical understanding for producing faster ball velocity, however, the aspect of ball contact time must be considered carefully from practical point of view.

Associations between timing in the baseball pitch and shoulder kinetics, elbow kinetics, and ball speed.

PubMed

Urbin, M A; Fleisig, Glenn S; Abebe, Asheber; Andrews, James R

2013-02-01

A baseball pitcher's ability to maximize ball speed while avoiding shoulder and elbow injuries is an important determinant of a successful career. Pitching injuries are attributed to microtrauma brought about by the repetitive stress of high-magnitude shoulder and elbow kinetics. Over a number of pitches, variations in timing peak angular velocities of trunk segment rotations will be significantly associated with ball speed and upper extremity kinetic parameters. Descriptive laboratory study. Kinematic and kinetic data were derived from 9 to 15 fastball pitches performed by 16 active, healthy collegiate (n = 8) and professional (n = 8) pitchers via 3-dimensional motion capture (240 Hz). Each pitch was decomposed into 4 phases corresponding to the time between peak angular velocities of sequential body segment rotations. Four mixed models were used to evaluate which phases varied significantly in relation to ball speed, peak shoulder proximal force, peak shoulder internal rotation torque, and peak elbow varus torque. Mixed-model parameter coefficient estimates were used to quantify the influence of these variations in timing on ball speed and upper extremity kinetics. All 4 mixed models were significant (P < .05). The time from stride-foot contact to peak pelvis angular velocity varied significantly in relation to all upper extremity kinetic parameters and ball speed. Increased time in this phase correlated with decreases in all parameters. Decreased ball speed also correlated with increased time between peak upper torso and elbow extension angular velocities. Decreased shoulder proximal force also correlated with increased time between peak pelvis and upper torso angular velocities. There are specific phases that vary in relation to ball speed and upper extremity kinetic parameters, reinforcing the importance of effectively and consistently timing segmental interactions. For the specific interactions that varied significantly, increased phase times were associated

33. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill, oneton ...

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

33. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill, one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: From above the mill showing the three 15' x 22' horizontal rolls, mill frame or cheeks, portland cement foundation, and lower part of vertical drive shaft lying next mill in foreground. The loose metal piece resting on top of the mill frame matched the indented portion of the upper frame to form a bracket and bearing for the drive shaft when it was in its proper upright position. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Mills' ratio

NASA Astrophysics Data System (ADS)

Baricz, Árpád

2008-04-01

In this paper we study the monotonicity properties of some functions involving the Mills' ratio of the standard normal law. From these we deduce some new functional inequalities involving the Mills' ratio, and we show that the Mills' ratio is strictly completely monotonic. At the end of this paper we present some Turán-type inequalities for Mills' ratio.

Extreme ball lightning event of August 6, 1868 in County Donegal, Ireland.

DOE Office of Scientific and Technical Information (OSTI.GOV)

VanDevender, J. Pace; McGinley, Niall; van Doorn, Peter

2008-04-01

Although laboratory experiments have produced glowing balls of light that fade in <1 s after external power is removed and theories have been proposed to explain low-energy events, energetic ball lightning is not understood. A seminal event that illuminates the fundamental nature of ball lightning is needed to advance our understanding of the phenomenon. We report such a seminal event: the energetic ball lightning event of August 6, 1868, in County Donegal, Ireland, extensively reported to the Royal Society by M. Fitzgerald. It lasted for 20 minutes, left a 6 m square hole and a 100 m long by 1.2more » m deep trench, tore away a 25 m long and 1.5 m deep stream bank that diverted the course of the stream, and terminated by producing a shallow cave in the opposite bank of the stream. We found and characterized the site and show that the geomorphology and carbon dating support the account by M. Fitzgerald. We find that the excavation is not consistent with chemical, nuclear, or electrostatic forces but is consistent with Analysis of the event and the local conditions in 2006 is consistent with magnetic induction at {approx} 1 MHz frequency expelling the moderately conductive, water saturated peat down to the underlying clay/rock layer. The 60-cm diameter--which diminished to 10 cm diameter without reducing the impact of the ball lightning on the environment--and the size of the depressions, the yield strength of the peat, and the lack of any mention of smoke or steam in Fitzgerald's report would be consistent with the core of the ball lightning being a magnetically levitated mini black hole weighing more than 20,000 kg. The results suggest that such energetic ball lightning should be detectable at great distances by its electromagnetic emissions, which might provide a characteristic signature to reveal the source of the energy and the equilibrium configuration of the contained currents. Unexplained intermittent emissions in the MHz range are necessary but not

How does gravity save or kill Q-balls?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamaki, Takashi; Sakai, Nobuyuki; Department of Education, Yamagata University, Yamagata 990-8560

2011-02-15

We explore stability of gravitating Q-balls with potential V{sub 4}({phi})=(m{sup 2}/2){phi}{sup 2}-{lambda}{phi}{sup 4}+({phi}{sup 6}/M{sup 2}) via catastrophe theory, as an extension of our previous work on Q-balls with potential V{sub 3}({phi})=(m{sup 2}/2){phi}{sup 2}-{mu}{phi}{sup 3}+{lambda}{phi}{sup 4}. In flat spacetime Q-balls with V{sub 4} in the thick-wall limit are unstable and there is a minimum charge Q{sub min}, where Q-balls with Qballs with arbitrarily small charge, no matter how weak gravity is. That is, gravity saves Q-balls with small charge. We also show how stabilitymore » of Q-balls changes as gravity becomes strong.« less

Structural and Magnetic Properties Evolution of Co-Nd Substituted M-type Hexagonal Strontium Ferrites Synthesized by Ball-Milling-Assisted Ceramic Process

NASA Astrophysics Data System (ADS)

Chen, Wen; Wu, Wenwei; Zhou, Chong; Zhou, Shifang; Li, Miaoyu; Ning, Yu

2018-03-01

M-type hexagonal Sr1- x Co x Nd x Fe12- x O19 ( x = 0, 0.08, 0.16, and 0.24) has been synthesized by ball milling, followed by calcination in air. The calcined products have been characterized by x-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectra, and vibrating sample magnetometry. XRD and SEM analyses confirm the formation of M-type Sr hexaferrite with platelet-like morphology when Sr1- x Co x Nd x Fe12- x O19 ( x = 0, 0.08, 0.16, and 0.24) precursors are calcined at 950°C in air for 2.5 h. Lattice parameters " a" and " c" values of Sr1- x Co x Nd x Fe12- x O19 reflect a very small variation after doping of Nd3+ and Co2+ ions. Average crystallite size of Sr1- x Co x Nd x Fe12- x O19 sample, calcined at 1150°C, decreased obviously after doping of Co2+ and Nd3+ ions. This is because the bond energy of Nd3+-O2- is much larger than that of Sr2+-O2-. Magnetic characterization indicates that all the samples exhibit good magnetic properties. Substitution of Sr2+ and Fe3+ ions by Nd3+ and Co2+ ions can improve the specific saturation magnetizations and remanence of Sr1- x Co x Nd x Fe12- x O19. Sr0.84Co0.16Nd0.16Fe11.84O19, calcined at 1050°C, has the highest specific saturation magnetization value (74.75 ± 0.60 emu/g), remanence (45.15 ± 0.32 emu/g), and magnetic moment (14.34 ± 0.11 μ B); SrFe12O19, calcined at 1150°C, has the highest coercivity value (4037.01 ± 42.39 Oe). These magnetic parameters make this material a promising candidate for applications such as high-density magnetic recording and microwave absorbing materials.

Simulation of General Physics laboratory exercise

NASA Astrophysics Data System (ADS)

Aceituno, P.; Hernández-Aceituno, J.; Hernández-Cabrera, A.

2015-01-01

Laboratory exercises are an important part of general Physics teaching, both during the last years of high school and the first year of college education. Due to the need to acquire enough laboratory equipment for all the students, and the widespread access to computers rooms in teaching, we propose the development of computer simulated laboratory exercises. A representative exercise in general Physics is the calculation of the gravity acceleration value, through the free fall motion of a metal ball. Using a model of the real exercise, we have developed an interactive system which allows students to alter the starting height of the ball to obtain different fall times. The simulation was programmed in ActionScript 3, so that it can be freely executed in any operative system; to ensure the accuracy of the calculations, all the input parameters of the simulations were modelled using digital measurement units, and to allow a statistical management of the resulting data, measurement errors are simulated through limited randomization.

Effect of PDC bit design and confining pressure on bit-balling tendencies while drilling shale using water base mud

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hariharan, P.R.; Azar, J.J.

1996-09-01

A good majority of all oilwell drilling occurs in shale and other clay-bearing rocks. In the light of relatively fewer studies conducted, the problem of bit-balling in PDC bits while drilling shale has been addressed with the primary intention of attempting to quantify the degree of balling, as well as to investigate the influence of bit design and confining pressures. A series of full-scale laboratory drilling tests under simulated down hole conditions were conducted utilizing seven different PDC bits in Catoosa shale. Test results have indicated that the non-dimensional parameter R{sub d} [(bit torque).(weight-on-bit)/(bit diameter)] is a good indicator ofmore » the degree of bit-balling and that it correlated well with Specific-Energy. Furthermore, test results have shown bit-profile and bit-hydraulic design to be key parameters of bit design that dictate the tendency of balling in shales under a given set of operating conditions. A bladed bit was noticed to ball less compared to a ribbed or open-faced bit. Likewise, related to bit profile, test results have indicated that the parabolic profile has a lesser tendency to ball compared to round and flat profiles. The tendency of PDC bits to ball was noticed to increase with increasing confining pressures for the set of drilling conditions used.« less

12. TROJAN MILL, INTERIOR SHOWING PRIMARY MILL No. 1 (MONADNOCK ...

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

12. TROJAN MILL, INTERIOR SHOWING PRIMARY MILL No. 1 (MONADNOCK CHILEAN) FROM EAST, c. 1912. ELEVATOR No. 1 ADJACENT TO MILL. CREDIT WR. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

Nd2Fe14C-based magnet with better permanent magnetic properties prepared by a simple mechanochemical method

NASA Astrophysics Data System (ADS)

Geng, Hongmin; Ji, Yuan; Zhang, Jingjing; Gao, Yuchao; Yan, Yu; Wang, Wenquan; Su, Feng; Du, Xiaobo

2017-11-01

Nd2Fe14C-based magnet is prepared by a mechanochemical method, namely high-energy ball-milling Nd2Fe11Bx (x = 0-0.15) alloy in heptane (C7H16), followed by annealing to 850 °C in vacuum. Under the action of high-energy ball-milling, Nd2Fe11Bx react with heptane to form NdH2+δ, Fe-(CB), C, etc. H2 is released and Nd2Fe17, Nd2Fe17Cx (x = 0-3), Nd2Fe14C, Nd carbides and α-Fe are formed in the subsequent annealing. C amount depends on ball-milling time t. Long time ball milling or high C content suppresses the formation of 2:17 phase and favors the formation of 2:14:1 phase in the final products. Excessive ball-milling results in the quick increase of α-Fe. The maximum of magnetically hard Nd2Fe14C is obtained at t = 4 h. For Nd2Fe11 samples, there exists considerable quantity of Nd carbides and α-Fe phase appears earlier and increases rapidly with extending the ball-milling time t. The addition of B element shortens the ball-milling time of the formation of maximum Nd2Fe14C and prominently suppresses the formation of Nd carbide and α-Fe. The optimum magnetic properties, coercivity iHc of 1193.7 kA/m, remanence Mr of 580.9 kA/m, maximum magnetic energy product (BH)max of 91.7 kJ/m3 is approaching to its theoretic value of 99.2 kJ/m3 for isotropic Nd2Fe14C magnet, are obtained in Nd2Fe11B0.06 alloy ball milled for 3.5 h.

Acting Administrator Lightfoot Visits Ball Aerospace

NASA Image and Video Library

2017-04-06

Acting NASA Deputy Administrator Lesa Roe, right, speaks with Rob Strain, president of Ball Aerospace, Thursday, April 6, 2017 during a visit to Ball Aerospace in Boulder, Colo. Photo Credit: (NASA/Joel Kowsky)

Golf Ball Roll Distance: A Field Exercise to Explore Management Factors Affecting Putting Green Speed

ERIC Educational Resources Information Center

Bigelow, Cale A.; Walker, Kristina S.

2007-01-01

Putting greens are the most important golf course use area and regularly draw comments regarding their appearance and playing condition. This field laboratory exercise taught students how to properly measure putting green speed, an important functional characteristic, using a Stimpmeter device that measures golf ball roll distance (BRD).…

Application of coordinate transform on ball plate calibration

NASA Astrophysics Data System (ADS)

Wei, Hengzheng; Wang, Weinong; Ren, Guoying; Pei, Limei

2015-02-01

For the ball plate calibration method with coordinate measurement machine (CMM) equipped with laser interferometer, it is essential to adjust the ball plate parallel to the direction of laser beam. It is very time-consuming. To solve this problem, a method based on coordinate transformation between machine system and object system is presented. With the fixed points' coordinates of the ball plate measured in the object system and machine system, the transformation matrix between the coordinate systems is calculated. The laser interferometer measurement data error due to the placement of ball plate can be corrected with this transformation matrix. Experimental results indicate that this method is consistent with the handy adjustment method. It avoids the complexity of ball plate adjustment. It also can be applied to the ball beam calibration.

Aerodynamic drag of modern soccer balls.

PubMed

Asai, Takeshi; Seo, Kazuya

2013-12-01

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 a wind tunnel test and ball trajectory simulations, this study shows that the aerodynamic resistance of the new 32-panel soccer ball is larger in the high-speed region and lower in the middle-speed region than that of the previous 14- and 8-panel balls. The critical Reynolds number of the Roteiro, Teamgeist II, Jabulani, and Tango 12 was ~2.2 × 10(5) (drag coefficient, C d  ≈ 0.12), ~2.8 × 10(5) (C d  ≈ 0.13), ~3.3 × 10(5) (C d  ≈ 0.13), and ~2.4 × 10(5) (C d  ≈ 0.15), respectively. The flight trajectory simulation suggested that the Tango 12, one of the newest soccer balls, has less air resistance in the medium-speed region than the Jabulani and can thus easily acquire large initial velocity in this region. It is considered that the critical Reynolds number of a soccer ball, as considered within the scope of this experiment, depends on the extended total distance of the panel bonds rather than the small designs on the panel surfaces.

Magnetic properties and coercivity mechanism of Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes prepared by surfactant-assisted ball milling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, M. L.; Yue, M., E-mail: yueming@bjut.edu.cn; Wu, Q.

2016-05-15

Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes with CaCu{sub 5} structure were successfully prepared by surfactant-assisted high-energy ball milling (SAHEBM). The crystal structure and magnetic properties of Sm{sub 1-x}Pr{sub x}Co{sub 5} (x=0-0.6) nanoflakes were studied by X-ray diffraction and vibrating sample magnetometer. Effects of Pr addition on the structure, magnetic properties and coercivity mechanism of Sm{sub 1-x}Pr{sub x}Co{sub 5} nanoflakes were systematically investigated. XRD results show that all the nanoflakes have a hexagonal CaCu{sub 5}-type (Sm, Pr){sub 1}Co{sub 5} main phase and the (Sm, Pr){sub 2}Co{sub 7} impurity phase, and all of the samples exhibit a strong (00l) texture after magneticmore » alignment. As the Pr content increases, remanence firstly increases, then slightly reduced, while anisotropy field (H{sub A}) and H{sub ci} of decrease monotonically. Maximum energy product [(BH){sub max}] of the flakes increases first, peaks at 24.4 MGOe with Pr content of x = 0.4, then drops again. Magnetization behavior analysis indicate that the coercivity mechanism is mainly controlled by inhomogeneous domain wall pinning, and the pinning strength weakens with the increased Pr content, suggesting the great influence of H{sub A} on the coercivity of flakes.« less

Bending stresses in spherically hollow ball bearing and fatigue experiments

NASA Technical Reports Server (NTRS)

Nypan, L. J.; Coe, H. H.; Parker, R. J.

1975-01-01

Spherically hollow balls of 21.7, 50.0, and 56.5 percent mass reduction were operated in ball bearings and in a five-ball fatigue tester with differing outcomes. Available theoretical and experimental treatments of stresses in spherically hollow balls are reviewed and compared. Bending stresses are estimated for these spherically hollow balls to better understand the differences in ball bearing and fatigue test experience.

Bending stresses in spherically hollow ball bearing and fatigue experiments

NASA Technical Reports Server (NTRS)

Nypan, L. J.; Coe, H. H.; Parker, R. J.

1975-01-01

Spherically hollow balls of 21.7, 50.0 and 56.5 per cent mass reduction have been operated in ball bearings and in a 5-ball fatigue tester with differing outcomes. Available theoretical and experimental treatments of stresses in spherically hollow balls are reviewed and compared. Bending stresses are estimated for these spherically hollow balls to better understand the differences in ball bearing and fatigue test experience.

1. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill: oneton ...

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

1. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill: one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: Historical view, 1934, from T.T. Waterman collection, Hawaiian Sugar Planters' Association. Large rectangular piece lying in front of the mill is the top of the mill frame appearing in its proper place in 1928 views. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Ball to separator contact forces in angular contact ball bearings under thrust and radial loads

NASA Technical Reports Server (NTRS)

Nypan, L. J.

1978-01-01

Experimental data are reported on ball to cage contact forces in a 110 mm bore ball bearing operating at speeds to 12,000 rpm under radial and thrust loads. Information is also reported on cage to inner race land contact force, cage to inner race land clearance, and cage to shaft speed ratios.

Ball to separator contact forces in angular contact ball bearings under thrust and radial loads

NASA Technical Reports Server (NTRS)

Nypan, L. J.

1977-01-01

Experimental data is reported on ball to cage contact forces in a 110 mm bore ball bearing operating at speeds to 12000 rpm under radial and thrust loads. Information is also reported on cage to inner race land contact force, cage to inner race land clearance, and cage to shaft speed ratios.

Apparatus and method for inspecting a bearing ball

NASA Technical Reports Server (NTRS)

Bankston, B. F. (Inventor)

1985-01-01

A method and apparatus for inspecting the surface of a ball bearing is disclosed which includes a base having a high friction non-abrasive base scanning surface. A holding device includes a cone-shaped cup recess in which a ball element is received. Air is introduced through a passage to relieve friction between the wall of the recess and the ball element and facilitate rolling of the ball over the high friction base surface. The holding device is moved over the base scanning surface in a predetermined pattern such that the entire surface of the ball element is inspected byan eddy current probe which detects any surface defects.

Experimental evaluation of stresses in spherically hollow balls

NASA Technical Reports Server (NTRS)

Nypan, L. J.

1974-01-01

An analysis was undertaken to evaluate stresses within spherically hollow ball bearings proportioned for 40, 50, and 60% mass reductions. Strain gage rosettes were used to determine principal strains and stresses in the steel ball models statically loaded in various orientations. Dimensionless results are reported for the balls under flate plate contact loads. Similitude considerations permit these results to be applied to calculate stresses in hollow ball bearings proportioned to these mass reductions.

2. RW Meyer Sugar Mill: 18761899. Threeroll sugar mill, oneton ...

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

2. RW Meyer Sugar Mill: 1876-1899. Three-roll sugar mill, one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: Top roll and one bottom roll, mill housing or cheeks, and spur pinion gears. The broken projection on the mill beside the bottom roll indicates the location of the cane tray. The cane juice crushed from the cane flowed into the juice tray below the bottom rolls. It then flowed into a wooden gutter and through a short tunnel in the mill's masonry enclosure and on to the boiling house for further processing. The opening at the base of the masency wall (In the photograph) is where the gutter ran from the mill to the boiling house. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Enzymatic corn wet milling: engineering process and cost model

PubMed Central

Ramírez, Edna C; Johnston, David B; McAloon, Andrew J; Singh, Vijay

2009-01-01

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 was found to be cost

Behaviour of a Bouncing Ball

ERIC Educational Resources Information Center

Cross, Rod

2015-01-01

The bounce of a ball is a seemingly innocuous event that can be used to illustrate many aspects of elementary and even advanced mechanics. Both normal and oblique bounces on a rigid surface are considered in this article, emphasizing qualitative features of the bounce process. If the ball bounces at an oblique angle then it can slide throughout…

Reflections on a Bouncing Ball

ERIC Educational Resources Information Center

Rohr, Jim; Lopez, Veronica; Rohr, Tyler

2014-01-01

While observing the bounce heights of various kinds of sports balls dropped from different heights onto a variety of surfaces, we thought of the following question: Could measurements of drop and bounce heights of balls of different diameters, but of the same material, falling from different heights, but on the same surface, be expressed by a…

Accuracy and Reliability of a New Tennis Ball Machine

PubMed Central

Brechbuhl, Cyril; Millet, Grégoire; Schmitt, Laurent

2016-01-01

The aim was to evaluate the reliability of a newly-developed ball machine named 'Hightof', on the field and to assess its accuracy. The experiment was conducted in the collaboration of the 'Hawk-Eye' technology. The accuracy and reliability of this ball machine were assessed during an incremental test, with 1 min of exercise and 30 sec of recovery, where the frequency of the balls increased from 10 to 30 balls·min-1. The initial frequency was 10 and increased by 2 until 22, then by 1 until 30 balls·min-1. The reference points for the impact were 8.39m from the net and 2.70m from lateral line for the right side and 2.83m for the left side. The precision of the machine was similar on the right and left sides (0.63 ± 0.39 vs 0.63 ± 0.34 m). The distances to the reference point were 0.52 ± 0.42, 0.26 ± 0.19, 0.52 ± 0.37, 0.28 ± 0.19 m for the Y-right, X-right, Y-left and X-left impacts. The precision was constant and did not increase with the intensity. (e.g ball frequency). The ball velocity was 86.3 ± 1.5 and 86.5 ± 1.3 km·h-1 for the right and the left side, respectively. The coefficient of variation for the velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min-1). Conclusion: both the accuracy and the reliability of this new ball machine appear satisfying enough for field testing and training. Key points The reliability and accuracy of a new ball machine named 'Hightof' were assessed. The impact point was reproducible and similar on the right and left sides (±0.63 m). The precision was constant and did not increase with the intensity (e.g ball frequency). The coefficient of variation of the ball velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min-1). PMID:27274663

Accuracy and Reliability of a New Tennis Ball Machine.

PubMed

Brechbuhl, Cyril; Millet, Grégoire; Schmitt, Laurent

2016-06-01

The aim was to evaluate the reliability of a newly-developed ball machine named 'Hightof', on the field and to assess its accuracy. The experiment was conducted in the collaboration of the 'Hawk-Eye' technology. The accuracy and reliability of this ball machine were assessed during an incremental test, with 1 min of exercise and 30 sec of recovery, where the frequency of the balls increased from 10 to 30 balls·min(-1). The initial frequency was 10 and increased by 2 until 22, then by 1 until 30 balls·min(-1). The reference points for the impact were 8.39m from the net and 2.70m from lateral line for the right side and 2.83m for the left side. The precision of the machine was similar on the right and left sides (0.63 ± 0.39 vs 0.63 ± 0.34 m). The distances to the reference point were 0.52 ± 0.42, 0.26 ± 0.19, 0.52 ± 0.37, 0.28 ± 0.19 m for the Y-right, X-right, Y-left and X-left impacts. The precision was constant and did not increase with the intensity. (e.g ball frequency). The ball velocity was 86.3 ± 1.5 and 86.5 ± 1.3 km·h(-1) for the right and the left side, respectively. The coefficient of variation for the velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min(-1)). both the accuracy and the reliability of this new ball machine appear satisfying enough for field testing and training. Key pointsThe reliability and accuracy of a new ball machine named 'Hightof' were assessed.The impact point was reproducible and similar on the right and left sides (±0.63 m).The precision was constant and did not increase with the intensity (e.g ball frequency).The coefficient of variation of the ball velocity ranged between 1 and 2% in all stages (ball velocity ranging from 10 to 30 balls·min(-1)).

34. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill, oneton ...

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

34. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill, one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: Side view of mill. Vertical drive shaft lying on ground in foreground. When drive-shaft was in upright position its bevel gear was meshed with the bevel gear of the top roll, transmitting the animals'circular motion around the drive shaft to the horizontal rolls. The foundation is of portland cement. The heavy timber mill bed, between the mill and the portland cement foundation has rolled away. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Revitalizing America's Mills: A Report on Brownfields Mill Projects

EPA Pesticide Factsheets

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.

32. RW Meyer Sugar Mill: 18761889. Threeroll sugar mill, oneton ...

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

32. RW Meyer Sugar Mill: 1876-1889. Three-roll sugar mill, one-ton daily processing capacity. Manufactured by Edwin Maw, Liverpool, England, ca. 1855-1870. View: End of mill into which cane was fed between top and bottom roll. - R. W. Meyer Sugar Mill, State Route 47, Kualapuu, Maui County, HI

Experimental comparison and validation of hot-ball method with guarded hot plate method on polyurethane foams

NASA Astrophysics Data System (ADS)

Hudec, Ján; Glorieux, Christ; Dieška, Peter; Kubičár, Ľudovít

2016-07-01

The Hot-ball method is an innovative transient method for measuring thermophysical properties. The principle is based on heating of a small ball, incorporated in measured medium, by constant heating power and simultaneous measuring of the ball's temperature response since the heating was initiated. The shape of the temperature response depends on thermophysical properties of the medium, where the sensor is placed. This method is patented by Institute of Physics, SAS, where the method and sensors based on this method are being developed. At the beginning of the development of sensors for this method we were oriented on monitoring applications, where relative precision is much more important than accuracy. Meanwhile, the quality of sensors was improved good enough to be used for a new application - absolute measuring of thermophysical parameters of low thermally conductive materials. This paper describes experimental verification and validation of measurement by hot-ball method. Thanks to cooperation with Laboratory of Soft Matter and Biophysics of Catholic University of Leuven in Belgium, established Guarded Hot Plate method was used as a reference. Details about measuring setups, description of the experiments and results of the comparison are presented.

A new milling machine for computer-aided, in-office restorations.

PubMed

Kurbad, Andreas

Chairside computer-aided design/computer-aided manufacturing (CAD/CAM) technology requires an effective technical basis to obtain dental restorations with optimal marginal accuracy, esthetics, and longevity in as short a timeframe as possible. This article describes a compact, 5-axis milling machine based on an innovative milling technology (5XT - five-axis turn-milling technique), which is capable of achieving high-precision milling results within a very short processing time. Furthermore, the device's compact dimensioning and state-of-the-art mode of operation facilitate its use in the dental office. This model is also an option to be considered for use in smaller dental laboratories, especially as the open input format enables it to be quickly and simply integrated into digital processing systems already in use. The possibility of using ceramic and polymer materials with varying properties enables the manufacture of restorations covering all conceivable indications in the field of fixed dental prosthetics.

Effects of BOSU ball(s) during sit-ups with body weight and added resistance on core muscle activation.

PubMed

Saeterbakken, Atle H; Andersen, Vidar; Jansson, June; Kvellestad, Ann C; Fimland, Marius S

2014-12-01

The objective of this study was to assess the electromyographic activity of the rectus abdominis (upper and lower part) and external oblique during sit-ups performed on BOSU ball(s). Twenty-four men participated in a familiarization session, and in the next session, they performed the experimental tests in randomized order. The sit-ups were performed with 10 repetitions with body weight and with 10 repetition maximum (10RM) using elastic bands as external resistance under 4 different conditions: (a) on a stable surface, (b) with the BOSU ball under their feet (dome side down, lower-body instability), (c) BOSU ball under the low back (dome side up, upper-body instability), and (d) with BOSU balls under both feet and the low back (dual instability). The feet were not attached to the surface. We observed that with body weight, external oblique activation was decreased by upper-body instability and dual instability by 22-24% (p = 0.002-0.006), whereas the rectus abdominis was not affected by the surface. Using 10RM loads, the upper and lower rectus abdominis activities were increased by upper body and dual instability by 21-24% compared with that for a stable surface (P ≤ 0.001-0.036). Further, lower-body instability did not affect muscle activities significantly with either load for any condition. Hence, BOSU balls under the low back can increase and decrease abdominal muscle activation depending on the load, whereas placing a BOSU ball under the feet with the dome side down had little impact.

Solid state amorphization kinetic of alpha lactose upon mechanical milling.

PubMed

Caron, Vincent; Willart, Jean-François; Lefort, Ronan; Derollez, Patrick; Danède, Florence; Descamps, Marc

2011-11-29

It has been previously reported that α-lactose could be totally amorphized by ball milling. In this paper we report a detailed investigation of the structural and microstructural changes by which this solid state amorphization takes place. The investigations have been performed by Powder X-ray Diffraction, Solid State Nuclear Magnetic Resonance ((13)C CP-MAS) and Differential Scanning Calorimetry. The results reveal the structural complexity of the material in the course of its amorphization so that it cannot be considered as a simple mixture made of a decreasing crystalline fraction and an increasing amorphous fraction. Heating this complexity can give rise to a fully nano-crystalline material. The results also show that chemical degradations upon heating are strongly connected to the melting process. Copyright © 2011 Elsevier Ltd. All rights reserved.

Zn(1-x)Cu(x)O (0.02 ≤ x ≤ 0.1) Nanomaterials Prepared by Ball Milling, Citrate Sol Gel, and Molten Salt Flux Methods.

PubMed

Balamurugan, S; Melba, K

2015-06-01

The Cu doped ZnO, (Zn(1-x)Cu(x))O (x = 0.02, 0.04, 0.06, 0.08, and 0.1) nanomaterials were prepared by ball milling technique (BMT), citrate sol gel (CSG), and molten salt flux (MSF) methods. The various as-prepared (Zn(1-x)Cu(x))O materials were analyzed by powder X-ray diffraction (pXRD), FT-IR, and SEM-EDX measurements in order to check the phase formation, purity, surface morphology and elements present in the annealed materials. Due to the preparation methods as well as doping of 'x' slight variations in cell parameters are seen. The average crystalline size of CSG method shows smaller size (25-35 nm) than BMT and MSF approaches. The materials obtained by MSF technique reveal the average crystalline size in the range of 32-72 nm whereas the BMT materials exhibit 36-50 nm for the composition, 0.02 ≤ x ≤ 0.1. The presence of functional groups and the chemical bonding in (Zn(1-x)Cu(x))O system is confirmed through FT-IR measurements. It is evident from the FT-IR data that bands seen at 400-500 cm(-1) are characteristics of M-O (M = metal ion) bonding in the studied materials. The micro images observed by SEM exhibiting polycrystalline character as compared with the crystallite size obtained from XRD. Among the three approaches employed in the present investigations, in terms of average particle size the CSG method may be concluded as an efficient method for the preparation of Zn(1-x)Cu(x)O nanomaterials.

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

NASA Astrophysics Data System (ADS)

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

2015-11-01

In this work, we prepared nanocrystalline Fe2Mn1-xCuxAl (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 Fe2Mn1-xCuxAl 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.

Ball Screw Actuator Including an Axial Soft Stop

NASA Technical Reports Server (NTRS)

Forrest, Steven Talbert (Inventor); Woessner, George (Inventor); Abel, Steve (Inventor); Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

2016-01-01

An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

Split-ball resonator as a three-dimensional analogue of planar split-rings

NASA Astrophysics Data System (ADS)

Kuznetsov, Arseniy I.; Miroshnichenko, Andrey E.; Hsing Fu, Yuan; Viswanathan, Vignesh; Rahmani, Mohsen; Valuckas, Vytautas; Ying Pan, Zhen; Kivshar, Yuri; Pickard, Daniel S.; Luk'Yanchuk, Boris

2014-01-01

Split-ring resonators are basic elements of metamaterials, which can induce a magnetic response in metallic nanosctructures. Tunability of such response up to the visible frequency range is still a challenge. Here we introduce the concept of the split-ball resonator and demonstrate the strong magnetic response in the visible for both gold and silver spherical plasmonic nanoparticles with nanometre scale cuts. We realize this concept experimentally by employing the laser-induced transfer method to produce near-perfect metallic spheres and helium ion beam milling to make cuts with the clean straight sidewalls and nanometre resolution. The magnetic resonance is observed at 600 nm in gold and at 565 nm in silver nanoparticles. This method can be applied to the structuring of arbitrary three-dimensional features on the surface of nanoscale resonators. It provides new ways for engineering hybrid resonant modes and ultra-high near-field enhancement.

Optimization of Parameters for Manufacture Nanopowder Bioceramics at Machine Pulverisette 6 by Taguchi and ANOVA Method

NASA Astrophysics Data System (ADS)

Van Hoten, Hendri; Gunawarman; Mulyadi, Ismet Hari; Kurniawan Mainil, Afdhal; Putra, Bismantoloa dan

2018-02-01

This research is about manufacture nanopowder Bioceramics from local materials used Ball Milling for biomedical applications. Source materials for the manufacture of medicines are plants, animal tissues, microbial structures and engineering biomaterial. The form of raw material medicines is a powder before mixed. In the case of medicines, research is to find sources of biomedical materials that will be in the nanoscale powders can be used as raw material for medicine. One of the biomedical materials that can be used as raw material for medicine is of the type of bioceramics is chicken eggshells. This research will develop methods for manufacture nanopowder material from chicken eggshells with Ball Milling using the Taguchi method and ANOVA. Eggshell milled using a variation of Milling rate on 150, 200 and 250 rpm, the time variation of 1, 2 and 3 hours and variations the grinding balls to eggshell powder weight ratio (BPR) 1: 6, 1: 8, 1: 10. Before milled with Ball Milling crushed eggshells in advance and calcinate to a temperature of 900°C. After the milled material characterization of the fine powder of eggshell using SEM to see its size. The result of this research is optimum parameter of Taguchi Design analysis that is 250 rpm milling rate, 3 hours milling time and BPR is 1: 6 with the average eggshell powder size is 1.305 μm. Milling speed, milling time and ball to powder weight of ratio have contribution successively equal to 60.82%, 30.76% and 6.64% by error equal to 1.78%.

The differences in analysing strategy of viscosity experiment between freshmen and laboratory assistant

NASA Astrophysics Data System (ADS)

Anggrayni, S.; Mubarok, H.; Putri, N. P.; Suprapto, N.; Kholiq, A.

2018-03-01

The viscosity is defined by dimension of a fluid that resists the force tending to motive the fluid to flow. The aim of viscosity experiment is to determine the fluid viscosity coefficient value. By using graphical analysis, the result of oil viscosity coefficient value which performed by laboratory assistant showed: (1) 0.20 Pa.s using solid ball with accuracy 99.64% and (2) 0.21 Pa.s using smaller solid ball with accuracy 99.17%. Meanwhile, the result of oil viscosity coefficient value which performed by freshmen showed: (1) 0.44 Pa.s using solid ball with accuracy 87.85% and (2) 0.32 Pa.s using smaller solid ball with accuracy 89.84%. The differences result of the freshmen and assistant laboratory viscosity experiment are caused by the freshmen calculated the coefficient viscosity value without velocity correction factor and they used small range fluid so the times are not identified well.

Acting Administrator Lightfoot Visits Ball Aerospace

NASA Image and Video Library

2017-04-06

Acting NASA Administrator Robert Lightfoot, left, views a clean room with Tim Schoenweis, senior project engineer for the Ozone Mapping Profiler Suite (OMPS) at Ball Aerospace, right, Thursday, April 6, 2017 at Ball Aerospace in Boulder, Colo. Photo Credit: (NASA/Joel Kowsky)

Acting Administrator Lightfoot Visits Ball Aerospace

NASA Image and Video Library

2017-04-06

Acting NASA Deputy Administrator Lesa Roe, center, views a clean room with Tim Schoenweis, senior project engineer for the Ozone Mapping Profiler Suite (OMPS) at Ball Aerospace, left, Thursday, April 6, 2017 at Ball Aerospace in Boulder, Colo. Photo Credit: (NASA/Joel Kowsky)

How Magnus Bends the Flying Ball--Experimenting and Modeling

ERIC Educational Resources Information Center

Timková, V.; Ješková, Z.

2017-01-01

Students are well aware of the effect of the deflection of sports balls when they have been given a spin. A volleyball, tennis, or table tennis ball served with topspin results in an additional downward force that makes the ball difficult to catch and return. In soccer, the effect of sidespin causes the ball to curve unexpectedly sideways,…

Mucormycosis (Mucor fungus ball) of the maxillary sinus.

PubMed

Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

2014-01-01

A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp.

The strange flight behaviour of slowly spinning soccer balls

NASA Astrophysics Data System (ADS)

Mizota, Taketo; Kurogi, Kouhei; Ohya, Yuji; Okajima, Atsushi; Naruo, Takeshi; Kawamura, Yoshiyuki

2013-05-01

The strange three-dimensional flight behaviour of slowly spinning soccer balls is one of the most interesting and unknown phenomenon associated with the trajectories of sports balls. Many spectators have experienced numerous exciting and emotional instances while observing the curious flight behaviour of these balls. We examine the aerodynamic mechanisms of erratic ball behaviours through real flight observations, unsteady force measurements and flow pattern visualisations. The strange behaviour is elucidated by the relationship between the unsteady forces on the ball and the wake flow. The irregular changes in position for twin longitudinal vortices have already been discovered in the supercritical Reynolds number region of a sphere with a smooth surface. This finding is applicable to the strange behaviour of the flight of soccer balls with this supercritical flow. The players, spectators, and television viewers will gain greater insight into the effects of soccer ball flights.

Rivastigmine hydrogen tartrate polymorphs: Solid-state characterisation of transition and polymorphic conversion via milling

NASA Astrophysics Data System (ADS)

Amaro, Maria Inês; Simon, Alice; Cabral, Lúcio Mendes; de Sousa, Valéria Pereira; Healy, Anne Marie

2015-11-01

Rivastigmine (RHT) is an active pharmaceutical ingredient that is used for the treatment of mild to moderately severe dementia in Alzheimer's disease, and is known to present two polymorphic forms and to amorphise upon granulation. To date there is no information in the scientific or patent literature on polymorphic transition and stability. Hence, the aim of the current study was to gain a fundamental understanding of the polymorphic forms by (1) evaluating RHT thermodynamic stability (monotropy or enantiotropy) and (2) investigating the potential for polymorphic transformation upon milling. The two polymorphic and amorphous forms were characterised using X-ray powder diffractometry, thermal analyses, infra-red spectroscopy and water sorption analysis. The polymorphic transition was found to be spontaneous (ΔG0 < 0) and exothermic (ΔH0 < 0), indicative of a monotropic polymorph pair. The kinetic studies showed a fast initial polymorphic transition characterised by a heterogeneous nucleation, followed by a slow crystal growth. Ball milling can be used to promote the polymorphic transition and for the production of RHT amorphous form.

Aerodynamics in the classroom and at the ball park