Study On Beneficiation Technology Of Dong Pao Rare-Earth-Barite-Fluorite With Two Product Plans About Content And Recovery Of Rare-Earth Fine Ores

International Nuclear Information System (INIS)

Duong Van Su; Truong Thi Ai; Bui Ba Duy; Bui Thi Bay; Nguyen Hong Ha; Le Thi Hong Ha; Doan Thi Mo; Doan Dac Ban; Nguyen Hoang Son

2014-01-01

The ore sample used in the research was taken from the F3 ore bodies and the sample of the F7, F9 and F16 ore bodies which contain the average of 5.98% TR 2 O 3 ; they are multi-metals ore which is difficult to enrich, highly weather with very complex ingredients. The process of the experiment is the ore is crushed, ground, screened and classified reasonably to -0.1 mm and divided into 3 particle size with the following technique: (1) -0.020 mm is primary sludge and the rare-earth fine ore; (2) 0.075-1 mm is gotten through the sludge concentrating table with the output is the 2 parts: the heavy part which is dried magnetic separator with high magnetism to get the rare-earth fine ore and the light one; (3) Light minerals, non-magnetic and ferromagnetic minerals group are ground together to 85% of them get size within -0.075 mm then mix it with 0.020-0.075 mm group. Using flotation separator, get barite-rare earth mixture and fluorite. After that, we separate this mixture by secondary flotation and get refined rare earth, barite and fluorite mineral. The result of the theme: (1) product plan A-rare-earth fine ore has TR 2 O 3 content archive 42.07% with recovery is 69.70%; (2) product plan B-rare-earth fine ore has TR 2 O 3 content archive 29.64% with recovery is 80.01%. (author)

Rare earth metal alloy magnets

International Nuclear Information System (INIS)

Harris, I.R.; Evans, J.M.; Nyholm, P.S.

1979-01-01

This invention relates to rare earth metal alloy magnets and to methods for their production. The technique is based on the fact that rare earth metal alloys (for e.g. cerium or yttrium) which have been crumbled to form a powder by hydride formation and decomposition can be used for the fabrication of magnets without the disadvantages inherent in alloy particle size reduction by mechanical milling. (UK)

Life cycle inventory of the production of rare earths and the subsequent production of NdFeB rare earth permanent magnets.

Science.gov (United States)

Sprecher, Benjamin; Xiao, Yanping; Walton, Allan; Speight, John; Harris, Rex; Kleijn, Rene; Visser, Geert; Kramer, Gert Jan

2014-04-01

Neodymium is one of the more critical rare earth elements with respect to current availability and is most often used in high performance magnets. In this paper, we compare the virgin production route of these magnets with two hypothetical recycling processes in terms of environmental impact. The first recycling process looks at manual dismantling of computer hard disk drives (HDDs) combined with a novel hydrogen based recycling process. The second process assumes HDDs are shredded. Our life cycle assessment is based both on up to date literature and on our own experimental data. Because the production process of neodymium oxide is generic to all rare earths, we also report the life cycle inventory data for the production of rare earth oxides separately. We conclude that recycling of neodymium, especially via manual dismantling, is preferable to primary production, with some environmental indicators showing an order of magnitude improvement. The choice of recycling technology is also important with respect to resource recovery. While manual disassembly allows in principle for all magnetic material to be recovered, shredding leads to very low recovery rates (<10%).

Rapid separation of individual rare-earth elements from fission products

International Nuclear Information System (INIS)

Baker, J.D.; Gehrke, R.J.; Greenwood, R.C.; Meikrantz, D.H.

1980-01-01

A microprocessor-controlled radiochemical separation system has been developed to rapidly separate rare-earth elements from gross fission products. The system is composed of two high performance liquid chromatography columns coupled in series by a stream-splitting injection valve. The first column separates the rare-earth group by extraction chromatography using dihexyldiethylcarbamylmethylenephosphonate (DHDECMP) adsorbed on Vydac C 8 resin. The second column isolates the individual rare-earth elements by cation exchange using Aminex A-9 resin with α-hydroxyisobutyric acid (α-HIBA) as the eluent. With this system, fission-product rare-earth isotopes with half-lives as short as three minutes have been studied

Enzymes for the biocatalytic production of rare sugars.

Science.gov (United States)

Beerens, Koen; Desmet, Tom; Soetaert, Wim

2012-06-01

Carbohydrates are much more than just a source of energy as they also mediate a variety of recognition processes that are central to human health. As such, saccharides can be applied in the food and pharmaceutical industries to stimulate our immune system (e.g., prebiotics), to control diabetes (e.g., low-calorie sweeteners), or as building blocks for anticancer and antiviral drugs (e.g., L: -nucleosides). Unfortunately, only a small number of all possible monosaccharides are found in nature in sufficient amounts to allow their commercial exploitation. Consequently, so-called rare sugars have to be produced by (bio)chemical processes starting from cheap and widely available substrates. Three enzyme classes that can be used for rare sugar production are keto-aldol isomerases, epimerases, and oxidoreductases. In this review, the recent developments in rare sugar production with these biocatalysts are discussed.

Studies on inclusive meson resonance and particle production

International Nuclear Information System (INIS)

Saarikko, Heimo

1978-01-01

Production and decay of meson resonances are studied in medium energy meson-proton collisions. Strong evidence is found that hadronic collisions are dominated by resonance production. Especially the vector mesons have often large inclusive cross sections, typically of the order of few millibarns at the present energies. In all, a majority of pions and kaons appear to be decay products of resonances or other unstable particles. The detailed kinematics of the parent resonance's decays is found to play an important role in determining inclusive pion spectra. The squared transverse momentum distributions of hadrons heavier than the pion appear to have in common an exponential behaviour, with a universal slope for the esponential fall-off. The observed vector meson yields suggest that only a small fraction of the direct lepton production observed at large transverse momentum in nucleon-nucleon interactions is accounted for by the ''old'' vector mesons. An attempt has been made to separate out the central production and fragmentation components of the meson production. Both the central production and the fragmentation of the incoming meson are found to be important mechanisms in the non-strange meson production whereas the central production of strange meson resonances is rare at our energies. The ratios of the observed meson yields are found to be generally in good agreement with a simple quark-counting model. (author)

Radioactive rare earths from fallout for study of particle movement in the sea

International Nuclear Information System (INIS)

Sugihara, Thomas T.; Bowen, Vaughan T.

1962-01-01

As part of an extensive study of the distribution of long-lived radionuclides from fallout in the Atlantic Ocean, a large number of measurements of cerium-144 and promethium-147 concentration have been made. Comparison of these concentrations as they vary both horizontally and vertically, with simultaneously measured concentrations of strontium-90, indicates that the rare earths are generally depleted in surface water, by comparison with the nuclides known to be soluble. This observation, coupled with frequent observation of rare-earth enrichment at depth, leads us to postulate rapid vertical transport of rare earths by attachment to particles undergoing sedimentation. This is completely plausible in terms of the 'radiocolloid' behaviour generally observed for rare earths at sea-water pH. An attempt is made to interpret this study in the overall picture of the marine geochemistry of the trivalent cations, as well as to emphasize the unique and generally useful aspects of the fallout tracer experiment. (author) [fr

Simultaneous projection of particle-number and angular momentum BCS wave-functions in the rare-earth nuclei

International Nuclear Information System (INIS)

Oudih, M.R.; Benhamouda, N.; Fellah, M.; Allal, N.H.

2000-01-01

A method of simultaneous particle-number and angular-momentum projection of the BCS wave-function is presented. The particle number projection method is of FBCS type. In the frame work of the adiabatic approximation, the rotational energies of the axially symmetric even-even nuclei are established and numerically calculated for the rare-earth region. (author)

Particle production by neutrinos

International Nuclear Information System (INIS)

Schreiner, P.

1979-01-01

A review is given of particle production by neutrinos in charged-current inclusive and exclusive channels. The production rates for various particles in neutrino-nucleon interactions at a beam energy of 25 GeV are compared. The mesons are, of course, dominated by pion production. The p 0 (760) rate is an order of magnitude smaller. Strange and charm pseudoscalar mesons are a further factor of two down in rate. The strange vector mesons are suppressed by more than an order of magnitude relative to K 0 production; however, the charmed D* + (2010) is only a factor of two smaller in rate than the D 0 (1860). With regards to the baryons, most of them are, of course, nucleons. The Λ 0 and Y*(1385) rates are down by one and two orders of magnitudes, respectively. The lower limit on the charmed Σ/sub c/ ++ baryon rate is similar to the Y*(1385) rate. Finally, the quasielastic and one-pion production exclusive channels have about the same cross section as that of the D* + ; associated production of strange particles in the νn → μ - K + Λ channel and the ΔS = +ΔΩ process νp → μ - pK + are down by factors of five and twenty, respectively, compared to the quasielastic cross section

Radiological aspects in a monazite based rare earth production facility

International Nuclear Information System (INIS)

Harikumar, M.; Sujata, R.; Chinnaesakki, S.; Tripathi, R.M.; Puranik, V.D.; Nair, N.N.G.

2011-01-01

One of the largest reserves of monazite in the world is present in the Indian subcontinent. Monazite ore has around 8-9% thorium oxide and nearly 60% Rare earth oxides. Selective acid extraction is used to separate the composite rare earths. The main radiological hazard arises from the presence of thorium and its daughter products. Monitoring of the radiation field and air activity in the rare earths plant is done routinely to reduce the radiation exposure to plant personnel. The separation of uranium and rare earths from Thorium concentrate separated from Monazite is being done as a part of the THRUST (Thorium Retrieval, Recovery of Uranium and Re-storage of Thorium) project from 2004 at Indian Rare Earths Limited, Udyogamandal. The radiological aspect for this extraction of uranium and rare earths was studied. The general radiation field in the rare earth production plant was 0.3-5.0 μGyh -1 and the average short lived air activity was 46 ± 7 mWL. The long lived air activity arising from 232 Th is very insignificant radiologically. The occupational radiation exposure for the rare earths separation plant is only 6 % of the total dose and the estimated average individual dose is 1.6 mSv per year. Studies were also done to estimate the residual radioactivity in the separated rare earth compounds using gamma spectrometry and the results showed significant presence of 227 Ac arising due to the protactinium fraction in the thorium concentrate. This activity is not detectable in a freshly separated rare earth compound but can buildup with time. (author)

Advanced system for separation of rare-earth fission products

International Nuclear Information System (INIS)

Baker, J.D.; Gehrke, R.J.; Greenwood, R.C.; Meikrantz, D.H.

1982-01-01

A microprocessor-controlled radiochemical separation system has been further advanced to separate individual rare-earth elements from mixed fission products in times of a few minutes. The system was composed of an automated chemistry system fed by two approximately 300 μg 252 Cf sources coupled directly by a He-jet to transport the fission products. Chemical separations were performed using two high performance liquid chromatography columns coupled in series. The first column separated the rare-earth group by extraction chromatography using dihexyldiethylcarbamoylmethylphosphonate (DHDECMP) adsorbed on Vydac C 8 resin. The second column isolated the individual rare-earth elements by cation exchange chromatography using Aminex A-9 resin with α-hydroxyisobutyric acid (α-HIBA) as the eluent. Significant results, which have been obtained to date with this advanced system, are the identification of several new neutron-rich rare-earth isotopes including 155 Pm (T=48+-4 s) and 163 Gd (T=68+-3 s). In addition, a half-life of 41+-4 s is reported for 160 Eu. (author)

Calculated apparent yields of rare gas fission products

International Nuclear Information System (INIS)

Delucchi, A.A.

1975-01-01

The apparent fission yield of the rare gas fission products from four mass chains is calculated as a function of separation time for six different fissioning systems. A plot of the calculated fission yield along with a one standard deviation error band is given for each rare gas fission product and for each fissioning system. Those parameters in the calculation that were major contributors to the calculated standard deviation at each separation time were identified and the results presented on a separate plot. To extend the usefulness of these calculations as new and better values for the input parameters become available, a third plot was generated for each system which shows how sensitive the derived fission yield is to a change in any given parameter used in the calculation. (U.S.)

Heavy particle production at the SSC

International Nuclear Information System (INIS)

Brodsky, S.J.; Haber, H.E.; Gunion, J.F.

1984-03-01

Predictions for the production of heavy quarks, supersymmetric particles, and other colored systems at high energy due to intrinsic twist-six components in the proton wavefunction are given. We also suggest the possibility of using asymmetric collision energies (e.g., via intersecting rings at the SSC) in order to facilitate the study of forward and diffractive particle production processes. 9 references

Rare B decays at LHCb

CERN Document Server

Puig Navarro, Albert

2017-01-01

Rare decays are flavour changing neutral current processes that allow sensitive searches for phenomena beyond the Standard Model (SM). In the SM, rare decays are loop-suppressed and new particles in SM extensions can give significant contributions. The very rare decay $B^0_s\\to\\mu^+\\mu^-$ in addition helicity suppressed and constitutes a powerful probe for new (pseudo) scalar particles. Of particular interest are furthermore tests of lepton universality in rare $b\\to s\\ell^+\\ell^-$ decays. The LHCb experiment is designed for the study of b-hadron decays and ideally suited for the analysis of rare decays due to its high trigger efficiency, as well as excellent tracking and particle identification performance. Recent results from the LHCb experiment in the area of rare decays are presented, including tests of lepton universality and searches for lepton flavour violation.

Rare event computation in deterministic chaotic systems using genealogical particle analysis

International Nuclear Information System (INIS)

Wouters, J; Bouchet, F

2016-01-01

In this paper we address the use of rare event computation techniques to estimate small over-threshold probabilities of observables in deterministic dynamical systems. We demonstrate that genealogical particle analysis algorithms can be successfully applied to a toy model of atmospheric dynamics, the Lorenz ’96 model. We furthermore use the Ornstein–Uhlenbeck system to illustrate a number of implementation issues. We also show how a time-dependent objective function based on the fluctuation path to a high threshold can greatly improve the performance of the estimator compared to a fixed-in-time objective function. (paper)

Distributed drift chamber design for rare particle detection in relativistic heavy ion collisions

CERN Document Server

Bellwied, R; Bernardo, V; Caines, H; Christie, W; Costa, S; Crawford, H J; Cronqvist, M; Debbe, R; Dinnwiddie, R; Engelage, J; Flores, I; Fuzesy, R Z; Greiner, L; Hallman, T; Hoffmann, G; Huang, H Z; Jensen, P; Judd, E G; Kainz, K; Kaplan, M; Kelly, S; Lindstrom, P J; Llope, W J; Lo Curto, G; Longacre, R; Milosevich, Z; Mitchell, J T; Mitchell, J W; Mogavero, E; Mutchler, G S; Paganis, S; Platner, E; Potenza, R; Rotondo, F; Russ, D; Sakrejda, I; Saulys, A; Schambach, J; Sheen, J; Smirnoff, N; Stokely, C L; Tang, J; Trattner, A L; Trentalange, S; Visser, G; Whitfield, J P; Witharm, F; Witharm, R; Wright, M

2002-01-01

This report describes a multi plane drift chamber that was designed and constructed to function as a topological detector for the BNL AGS E896 rare particle experiment. The chamber was optimized for good spatial resolution, two track separation, and a high uniform efficiency while operating in a 1.6 T magnetic field and subjected to long term exposure from a 11.6 GeV/nucleon beam of 10 sup 6 Au ions per second.

Laser cladding in-situ carbide particle reinforced Fe-based composite coatings with rare earth oxide addition

Institute of Scientific and Technical Information of China (English)

吴朝锋; 马明星; 刘文今; 钟敏霖; 张红军; 张伟明

2009-01-01

Particulate reinforced metal matrix composite(PR-MMC) has excellent properties such as good wear resistance,corrosion resistance and high temperature properties.Laser cladding is usually used to form PR-MMC on metal surface with various volume fractions of ceramic particles.Recent literatures showed that laser melting of powder mixture containing carbon and carbide-forming elements,was favorable for the formation of in-situ synthesized carbide particles.In this paper,rare earth oxide(RE2O3) was added into t...

A rare sugar xylitol. Part II: biotechnological production and future applications of xylitol.

Science.gov (United States)

Granström, Tom Birger; Izumori, Ken; Leisola, Matti

2007-02-01

Xylitol is the first rare sugar that has global markets. It has beneficial health properties and represents an alternative to current conventional sweeteners. Industrially, xylitol is produced by chemical hydrogenation of D-xylose into xylitol. The biotechnological method of producing xylitol by metabolically engineered yeasts, Saccharomyces cerevisiae or Candida, has been studied as an alternative to the chemical method. Due to the industrial scale of production, xylitol serves as an inexpensive starting material for the production of other rare sugars. The second part of this mini-review on xylitol will look more closely at the biotechnological production and future applications of the rare sugar, xylitol.

Biocatalytic production of D-tagatose: A potential rare sugar with versatile applications.

Science.gov (United States)

Jayamuthunagai, J; Gautam, P; Srisowmeya, G; Chakravarthy, M

2017-11-02

D-tagatose is a naturally existing rare monosaccharide having prebiotic properties. Minimal absorption, low metabolizing energy, and unique clinical properties are the characteristics of D-tagatose. D-tagatose gained international attention by matching the purpose of alternate sweeteners that is much needed for the control of diabetes among world population. Recent efforts in understanding tagatose bioconversion have generated essential information regarding its production and application. This article reviews the evolution of D-tagatose as an important rare sugar by appreciable improvements in production results and its significant applications resulted of its unique physical, chemical, biological, and clinical properties thus considering it an appropriate product for requisite improvements in technical viability. Based on current knowledge and technology projections, the commercialization of D-tagatose rare sugar as food additive is close to reality.

Particle production at collider energies

International Nuclear Information System (INIS)

Geich-Gimbel, C.

1987-11-01

Key features of the SPS panti p Collider and the detectors of the UA-experiments involved are dealt with in chapter 2, which includes and accord to the ramping mode of the Collider, which allowed to raise the c.m. energy to 900 GeV in the UA5/2 experiment. The following chapters concentrate on physics results. Starting with a discussion of cross sections and diffraction dissociation in chapter 3 we then continue with a presentation of basic features of particle production such as rapidity and multiplicity distributions in chapter 4. There one of the unexpected findings at Collider energies, the breakdown of the so-called KNO-scaling, and new regularities potentially governing multiplicity distributions, are discussed. The findings about correlations among the final state particles, which may tell about the underlying dynamics of multi-particle production and be relevant to models thereof, are described in due detail in chapter 5. Transverse spectra and their trends with energy are shown in chapter 6. Results on identified particles are collected in a separate chapter in order to stress that this piece of information was an important outcome of the UA5 experiment. (orig./HSI)

Weak strange particle production: advantages and difficulties

International Nuclear Information System (INIS)

Angelescu, Tatiana; Baker, O.K.

2002-01-01

Electromagnetic strange particle production developed at Jefferson Laboratory was an important source of information on strange particle electromagnetic formfactors and induced and transferred polarization. The high quality of the beam and the detection techniques involved could be an argument for detecting strange particles in weak interactions and answer questions about cross sections, weak formfactors, neutrino properties, which have not been investigated yet. The paper analyses some aspects related to the weak lambda production and detection with the Hall C facilities at Jefferson Laboratory and the limitations in measuring the weak interaction quantities. (authors)

Production of strange particles in hadronization processes

International Nuclear Information System (INIS)

Hofmann, W.

1987-08-01

Strange particles provide an important tool for the study of the color confinement mechanisms involved in hadronization processes. We review data on inclusive strange-particle production and on correlations between strange particles in high-energy reactions, and discuss phenomenological models for parton fragmentation. 58 refs., 24 figs

Thermal and nonthermal particle production without event horizons

International Nuclear Information System (INIS)

Sanchez, N.

1979-01-01

Usually, particle production in accelerated frames is discussed in connection with the presence of event horizons and with a planckian spectrum. Accelerated frames without event horizons, where particle production takes place with thermal as well as nonthermal distributions, are constructed. (Auth.)

Cumulative particle production in the quark recombination model

International Nuclear Information System (INIS)

Gavrilov, V.B.; Leksin, G.A.

1987-01-01

Production of cumulative particles in hadron-nuclear inteactions at high energies is considered within the framework of recombination quark model. Predictions for inclusive cross sections of production of cumulative particles and different resonances containing quarks in s state are made

The fine particle emissions of energy production in Finland

International Nuclear Information System (INIS)

Ohlstroem, M.

1998-01-01

The main purpose of this master's thesis was to define the fine particle (PM2.5, diameter under 2,5 μm) emissions of the energy production and to compare the calculated emission factors between different energy production concepts. The purpose was also to define what is known about fine particle emissions and what should still be studied/measured. The purpose was also to compare briefly the fine particle emissions of energy production and vehicle traffic, and their correlations to the fine particle concentrations of urban air. In the theory part of this work a literature survey was made about fine particles in energy production, especially how they form and how they are separated from the flue gas. In addition, the health effects caused by fine particles, and different measuring instruments were presented briefly. In the experimental part of this work, the aim was to find out the fine particle emissions of different energy production processes by calculating specific emission factors (mg/MJ fuel ) from powerplants' annual total particulate matter emissions (t/a), which were obtained from VAHTI-database system maintained by the Finnish Environmental Institute, and by evaluating the share of fine particles from total emissions with the help of existing measurement results. Only those energy production processes which produce significantly direct emissions of solid particles have been treated (pulverised combustion and oil burners from burner combustion, fluidized bed combustion processes, grate boilers, recovery boilers and diesel engines). The processes have been classified according to boiler type, size category, main fuel and also according to dust separation devices. To be able to compare different energy production processes, shared specific emission factor have been calculated for the similar subprocesses. The fine particle emissions depend strongest on the boiler size category and dust separation devices used. Spent fuel or combustion technique does not have

Perturbative Universality in Soft Particle Production

CERN Document Server

Khoze, V A; Ochs, Wolfgang; Khoze, Valery A.; Lupia, Sergio; Ochs, Wolfgang

1998-01-01

The spectrum of partons in a QCD jet becomes independent of the primary energy in the low momentum limit. This follows within the perturbative QCD from the colour coherence in soft gluon branching. Remarkably, the hadrons follow such behaviour closely, suggesting the parton hadron duality picture to be appropriate also for the low momentum particles. More generally, this scaling property holds for particles of low transverse and arbitrary longitudinal momentum, which explains an old experimental observation (``fan invariance''). Further tests of the perturbatively based picture for soft particle production are proposed for three-jet events in e+e- annihilation and di-jet production events in gamma p, gamma-gamma and p\\bar p collisions. They are based upon the difference in the intensity of the soft radiation from primary q\\bar q and gg antennae.

Gravitational particle production in braneworld cosmology.

Science.gov (United States)

Bambi, C; Urban, F R

2007-11-09

Gravitational particle production in a time variable metric of an expanding universe is efficient only when the Hubble parameter H is not too small in comparison with the particle mass. In standard cosmology, the huge value of the Planck mass M{Pl} makes the mechanism phenomenologically irrelevant. On the other hand, in braneworld cosmology, the expansion rate of the early Universe can be much faster, and many weakly interacting particles can be abundantly created. Cosmological implications are discussed.

A cascade mechanism of three-particle resonance production

International Nuclear Information System (INIS)

Badalyan, A.M.; Polikarpov, M.I.; Simonov, Yu.A.

1976-01-01

We study the mechanism of the three-particle resonance production in a system consisting of a two-particle resonance and of one particle, the resonance and the particle permanently exchanging the decay product particle. The N/D method is used to show that the solution of the unitarity for the resonance-particle amplitude reduces to solving a one-dimensional nonsingular integral equation for the denominator of the amplitude D(y). The contribution from the right-hand cut of the exchange decay diagram is considered explicitly and the final equation contains only the integral over an arbitrary left-hand cut as in the case of the interaction amplitude of stable particles. It is as well shown that if only the right-hand cut is present, than the denominator D(y) for L=0 has no singularities, whereas the amplitude may have virtual or real poles at L=1

Particle and radiation simulations for the proposed rare isotope accelerator facility

Science.gov (United States)

Remec, Igor; Gabriel, Tony A.; Wendel, Mark W.; Conner, David L.; Burgess, Thomas W.; Ronningen, Reginald M.; Blideanu, Valentin; Bollen, Georg; Boles, Jason L.; Reyes, Susana; Ahle, Larry E.; Stein, Werner

2006-06-01

The Rare Isotope Accelerator (RIA) facility, planned to be built in the USA, will be capable of delivering diverse beams, from protons to uranium ions, with energies from 1 GeV to at least 400 MeV per nucleon to rare isotope-producing targets. High beam power—400 kW—will allow RIA to become the most powerful rare isotope beam facility in the world; however, it also creates challenges for the design of the isotope-production targets. This paper focuses on the isotope-separator-on-line (ISOL) target work, particularly the radiation transport aspects of the two-step fission target design. Simulations were performed with the PHITS, MCNPX, and MARS15 computer codes. A two-step ISOL target considered here consists of a mercury or tungsten primary target in which primary beam interactions release neutrons, which in turn induce fissions—and produce rare isotopes—in the secondary target filled with fissionable material. Three primary beams were considered: 1-GeV protons, 622-MeV/u deuterons, and 777-MeV/u 3He ions. The proton and deuterium beams were found to be about equivalent in terms of induced fission rates and heating rates in the target, while the 3He beam, without optimizing the target geometry, was less favorable, producing about 15% fewer fissions and about 50% higher heating rates than the proton beam at the same beam power.

Rare earth permanent magnets in China: production and raw materials

International Nuclear Information System (INIS)

Luo, Y.

1998-01-01

With the development of computer, electronics, communication and modern information industries, NdFeB magnet industry is growing rapidly as a booming business worldwide. Based on the abundance of rare earth and manpower, supporting by the technical teams and the huge domestic market, China NdFeB magnet industry made big jump during the last decade. Its growth rate is the highest one among all other countries. Now China occupies number one place in the world not only due to its richest rare earth reserves, but also due to its output of rare earth, especially, its sales to the international market. China is the only country, who is able to meet the market needs of rare earth worldwide. The current situation of NdFeB magnet industry can be concluded as ''five highs'', i.e. ''high volume growth'', ''high grade development'', ''high expansion of capacity'', ''high value added product'' and ''high variation speed''. The connotations of these ''five highs'' and a brief review on Chinese rare earth industry will be given in this paper. (orig.)

Production of a tracer packet of heavier rare earth elements

International Nuclear Information System (INIS)

Lahiri, S.; Nayak, D.; Maji, S.

2004-01-01

Production of a tracer packet of heavier rare earth elements containing carrier-free radionuclides of 153,155 Tb, 153,155,157 Dy, 159 Ho, 159,161 Er, 161 Tm produced by medium energy 7 Li and 12 C irradiation on an europium oxide target and the subsequent separation of bulk europium from the carrier-free products is described. (author)

Plasma analog of particle-pair production

International Nuclear Information System (INIS)

Tsidulko, Yu.A.; Berk, H.L.

1996-09-01

It is shown that the plasma axial shear flow instability satisfies the Klein-Gordon equation. The plasma instability is then shown to be analogous to spontaneous particle-pair production when a potential energy is present that is greater than twice the particle rest mass energy. Stability criteria can be inferred based on field theoretical conservation laws

Processes for the production of rare earths from monazite (Paper No. 36)

International Nuclear Information System (INIS)

Murthy, T.K.S.

1979-01-01

A few typical cases are briefly described to illustrate different methods available for rare earth concentration and separation from mixed rare earths chloride obtained for monazite. In the case of cerium, rare earths chloride mixture is treated with sodium sulphate to precipitate rare earths as double sulphates from which hydroxide cake is prepared. The cake is dried to oxidise cerium. Trivalent rare earths are selectively leached and the product is treated with HNO 3 . The resulting ceric nitrate solution is purified by liquid-liquid extraction using TBP. The scrubbed extract is reduced with H 2 O 2 and cerous nitrate is recovered by evaporation. Lanthanum is first concentrated by selective precipitation of hydroxides from rare earths chloride using air-ammonia mixture. The hydroxyde cake is dissolved in HNO 3 and NH 4 NO 3 to get the double nitrate which is subjected to counter current crystallisation for purification. Europium is present at a concentration of 0.01% in the rare earths chloride. It is concentrated in several steps by liquid-liquid extraction using di-2-ethyl hexyl phosphoric acid. The product is purified by selective reduction and europium is obtained as europium sulphate. In the same solvent extraction process samarium and gadolinium are also concentrated to about 25%. They are further upgraded to above 90% purity by repetion of liquid-liquid extraction technique. Cerium, lanthanum and europium obtained by the above processes analyse > 99% as oxides. (M.G.B.)

China's Rare Earth Supply Chain: Illegal Production, and Response to new Cerium Demand

Science.gov (United States)

Nguyen, Ruby Thuy; Imholte, D. Devin

2016-07-01

As the demand for personal electronic devices, wind turbines, and electric vehicles increases, the world becomes more dependent on rare earth elements. Given the volatile, Chinese-concentrated supply chain, global attempts have been made to diversify supply of these materials. However, the overall effect of supply diversification on the entire supply chain, including increasing low-value rare earth demand, is not fully understood. This paper is the first attempt to shed some light on China's supply chain from both demand and supply perspectives, taking into account different Chinese policies such as mining quotas, separation quotas, export quotas, and resource taxes. We constructed a simulation model using Powersim Studio that analyzes production (both legal and illegal), production costs, Chinese and rest-of-world demand, and market dynamics. We also simulated new demand of an automotive aluminum-cerium alloy in the US market starting from 2018. Results showed that market share of the illegal sector has grown since 2007-2015, ranging between 22% and 25% of China's rare earth supply, translating into 59-65% illegal heavy rare earths and 14-16% illegal light rare earths. There will be a shortage in certain light and heavy rare earths given three production quota scenarios and constant demand growth rate from 2015 to 2030. The new simulated Ce demand would require supply beyond that produced in China. Finally, we illustrate revenue streams for different ore compositions in China in 2015.

Pair production of arbitrary spin particles by electromagnetic fields

International Nuclear Information System (INIS)

Kruglov, S.I.

2006-01-01

The exact solutions of the wave equation for arbitrary spin particles in the field of the soliton-like electric impulse were obtained. The differential probability of pair production of particles by electromagnetic fields has been evaluated on the basis of the exact solutions. As a particular case, the particle pair production in the constant and uniform electric field were studied

Particle and radiation simulations for the proposed rare isotope accelerator facility

Energy Technology Data Exchange (ETDEWEB)

Remec, Igor [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States)]. E-mail: remeci@ornl.gov; Gabriel, Tony A. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Wendel, Mark W. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Conner, David L. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Burgess, Thomas W. [Oak Ridge National Laboratory, Oak Ridge, P. O. Box 2008, TN 37831-6172 (United States); Ronningen, Reginald M. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Blideanu, Valentin [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Bollen, Georg [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Boles, Jason L. [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Reyes, Susana [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Ahle, Larry E. [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States); Stein, Werner [Lawrence Livermore National Laboratory, P. O. Box 808, L-446, Livermore, CA 94550 (United States)

2006-06-23

The Rare Isotope Accelerator (RIA) facility, planned to be built in the USA, will be capable of delivering diverse beams, from protons to uranium ions, with energies from 1 GeV to at least 400 MeV per nucleon to rare isotope-producing targets. High beam power-400 kW-will allow RIA to become the most powerful rare isotope beam facility in the world; however, it also creates challenges for the design of the isotope-production targets. This paper focuses on the isotope-separator-on-line (ISOL) target work, particularly the radiation transport aspects of the two-step fission target design. Simulations were performed with the PHITS, MCNPX, and MARS15 computer codes. A two-step ISOL target considered here consists of a mercury or tungsten primary target in which primary beam interactions release neutrons, which in turn induce fissions-and produce rare isotopes-in the secondary target filled with fissionable material. Three primary beams were considered: 1-GeV protons, 622-MeV/u deuterons, and 777-MeV/u {sup 3}He ions. The proton and deuterium beams were found to be about equivalent in terms of induced fission rates and heating rates in the target, while the {sup 3}He beam, without optimizing the target geometry, was less favorable, producing about 15% fewer fissions and about 50% higher heating rates than the proton beam at the same beam power.

Recent progress of in-flight separators and rare isotope beam production

Energy Technology Data Exchange (ETDEWEB)

Kubo, Toshiyuki, E-mail: kubo@ribf.riken.jp

2016-06-01

New-generation in-flight separators are being developed worldwide, including the Super-FRS separator at the GSI Facility for Antiproton and Ion Research (FAIR), the ARIS separator at the Michigan State University (MSU) Facility for Rare Isotopes Beams (FRIB), and the BigRIPS separator at the RIKEN RI Beam Factory (RIBF), each of which is aimed at expanding the frontiers of rare isotope (RI) production and advancing experimental studies on exotic nuclei far from stability. Here, the recent progress of in-flight separators is reviewed, focusing on the advanced features of these three representative separators. The RI beam production that we have conducted using the BigRIPS separator at RIKEN RIBF is also outlined.

Gravitational Particle Production and the Moduli Problem

CERN Document Server

Felder, G; Linde, Andrei D; Felder, Gary; Kofman, Lev; Linde, Andrei

2000-01-01

A theory of gravitational production of light scalar particles during and after inflation is investigated. We show that in the most interesting cases where long-wavelength fluctuations of light scalar fields can be generated during inflation, these fluctuations rather than quantum fluctuations produced after inflation give the dominant contribution to particle production. In such cases a simple analytical theory of particle production can be developed. Application of our results to the theory of quantum creation of moduli fields demonstrates that if the moduli mass is smaller than the Hubble constant then these fields are copiously produced during inflation. This gives rise to the cosmological moduli problem even if there is no homogeneous component of the classical moduli field in the universe. To avoid this version of the moduli problem it is necessary for the Hubble constant H during the last stages of inflation and/or the reheating temperature T_R after inflation to be extremely small.

Particle Production under External Fields and Its Applications

Energy Technology Data Exchange (ETDEWEB)

Yoo, Hojin [Univ. of Wisconsin, Madison, WI (United States)

2014-01-01

The thesis presents studies of vacuum pair productions and its applications in early universe cosmology and high energy astrophysics. Vacuum often becomes unstable and spontaneously decays into pairs of particles in rapidly expanding universes or under strong external electromagnetic fields. Theoretically, spontaneous pair productions due to such non-trivial backgrounds of spacetimes or electromagnetic fields are well-understood. However, the effect of particle productions has not been observed so far because of experiemtal difficulties in obtaining large curvatures of space-times or strong electric fields. Although it may be impossible to observe the pair productions directly via laboratory experiments, there are still powerful sources of space-time curvatures or electric fields in cosmology and astrophysics, which result in observations. In Part I, we explore the inflationary models in early universe utilizing pair productions through gravity. We study observable signatures on the cosmic microwave background, such as isocurvature perturbations and non-Gaussianities, generated from the particle production of WIMPzillas and axions during or after inflation. In Part II, we investigate the electron-positron pair production in the magnetosphere of pulsars whose electromagnetic fields are expected to close to or even greater than the pair production threshold. In particular, we demonstrate that the pair production may be responsible for giant pulses from the Crab pulsar.

Experimental particle physics at the University of Pittsburgh

International Nuclear Information System (INIS)

Engels, E. Jr.; Perera, U.; Shepard, P.; Thompson, J.A.

1991-06-01

This report discusses research on the following topics: helios; K-decay and CP violation at INP; rare K-decays at BNL; direct photon production at the Tevatron; CDF; and fractional charge particles in semiconductors

The influence of final state interaction on two-particle correlations in multiple production of particles and resonances

International Nuclear Information System (INIS)

Lednicky, R.; Lyuboshitz, V.L.

1996-01-01

The structure of pair correlations of interacting particles moving with nearby velocities is analysed. A general formalism of the two-particle space-time density matrix, taking into account the space-time coherence of the production process, is developed. The influence of strong final state interaction on two-particle correlations in the case of the production of a system resonance + particle is investigated in detail. It is shown that in the limit of small distances between the resonance and particle production points the effect of final state interaction is enhanced due to logarithmic singularity of the triangle diagram. Numerical estimates indicate that, in this limit, the effect of strong final state interaction becomes important even for two-pion correlations. (author)

Production of neutrinos and neutrino-like particles in proton-nucleus interactions

International Nuclear Information System (INIS)

Dishaw, J.P.

1979-03-01

An experimental search was performed to look for the direct production of neutrinos or neutrino-like particles, i.e., neutral particles which interact weakly with hadrons, in proton-nucleus interactions at 400 GeV incident proton energy. Possible sources of such particles include the semi-leptonic decay of new heavy particles such as charm, and the direct production of a light neutral Higgs particle such as the axion. The production of these particles has been inferred in this experiment by energy nonconservation in the collision of a proton with an iron nucleus. The total visible energy of the interaction was measured using a sampling ionization calorimeter. After correcting for beam intensity effects and cutting the data to eliminate systematic effects in the measurement, the final resolution of the calorimeter was 3.51% and increased with decreasing incident beam energy with a square root dependence on the beam energy. Energy nonconservation in the data is manifest as a non-Gaussian distribution on the low side of the calorimeter measured energy. Model calculations yield the fraction of events expected in this non-Gaussian behavior for the various sources of neutrinos or neutrino-like particles. A maximum likelihood fit to the data with the theoretical fraction of events expected yields the 95% confidence level production cross section upper limit values. The upper limits for general production of neutrino-like particles for various parameterizations of the production cross section are presented. The following specific upper limits have been established: charm particle production -3 times the π 0 production cross section. 144 references

Hadron and photon production of J particles and the origin of J particles

International Nuclear Information System (INIS)

Ting, S.C.C.

1975-01-01

Discovery of the J particles (psi-3105 and psi-3695) is detailed. A few experiments on the production of J particles are described, emphasizing photoproduction of J's by photons and hadrons. Finally, current theoretical attempts at explaining their origin are outlined. (29 figures) (U.S.)

Relaxation from particle production

Energy Technology Data Exchange (ETDEWEB)

Hook, Anson; Marques-Tavares, Gustavo [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States)

2016-12-20

We consider using particle production as a friction force by which to implement a “Relaxion” solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.

The impact of particle production on gravitational baryogenesis

Energy Technology Data Exchange (ETDEWEB)

Lima, J.A.S., E-mail: jas.lima@iag.usp.br [Departamento de Astronomia, Universidade de São Paulo, Rua do Matão 1226, 05508-900, São Paulo (Brazil); Singleton, D., E-mail: dougs@csufresno.edu [Department of Physics, California State University Fresno, Fresno, CA 93740-8031 (United States); ICTP South American Institute for Fundamental Research, UNESP – Univ. Estadual Paulista, Rua Dr. Bento T. Ferraz 271, 01140-070, São Paulo, SP (Brazil); Institute of Experimental and Theoretical Physics Al-Farabi KazNU, Almaty, 050040 (Kazakhstan)

2016-11-10

Baryogenesis driven by curvature effects is investigated by taking into account gravitationally induced particle production in the very early Universe. In our scenario, the baryon asymmetry is generated dynamically during an inflationary epoch powered by ultra-relativistic particles. The adiabatic particle production rate provides both the needed negative pressure to accelerate the radiation dominated Universe and a non-zero chemical potential which distinguishes baryons and anti-baryons thereby producing a baryon asymmetry in agreement with the observed value. Reciprocally, the present day asymmetry may be used to determine the inflationary scale at early times. Successful gravitational baryogenesis is dynamically generated for many different choices of the relevant model parameters.

L-Rhamnose isomerase and its use for biotechnological production of rare sugars.

Science.gov (United States)

Xu, Wei; Zhang, Wenli; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

2016-04-01

L-Rhamnose isomerase (L-RI, EC 5.3.1.14), catalyzing the isomerization between L-rhamnose and L-rhamnulose, plays an important role in microbial L-rhamnose metabolism and thus occurs in a wide range of microorganisms. It attracts more and more attention because of its broad substrate specificity and its great potential in enzymatic production of various rare sugars. In this article, the enzymatic properties of various reported L-RIs were compared in detail, and their applications in the production of L-rhamnulose and various rare sugars including D-allose, D-gulose, L-lyxose, L-mannose, L-talose, and L-galactose were also reviewed.

Particle production in the new inflationary cosmology

International Nuclear Information System (INIS)

Abbott, L.F.; Farhi, E.; Massachusetts Inst. of Tech., Cambridge; Massachusetts Inst. of Tech., Cambridge; Wise, M.B.

1982-01-01

Techniques are developed for computing particle production due to the time dependence of a scalar field expectation value during a phase transition. We review the new version of the inflationary universe and discuss baryon production in this model. (orig.)

Fission product released experiment of coated fuel particles

Energy Technology Data Exchange (ETDEWEB)

Shijiang, Xu; Bing, Yang; Chunhe, Tang; Junguo, Zhu; Jintao, Huang; Binzhong, Zhang [Inst. of Nucl. Energy Technology, Tsinghua Univ., Beijing (China); Jinghan, Luo [Inst. of Atomic Energy, Beijing (China)

1992-01-15

Four samples of coated fuel particles were irradiated in the Heavy-Water Research Reactor of the Institute of Atomic Energy. Each of them was divided into two groups and irradiated to the burn up of 0.394% fima and 0.788% fima in two static capsules, respectively. After irradiation and cooling, post irradiation annealing experiment was carried out, the release ratios of the fission product {sup 133}Xe and {sup 131}I were measured, they are in the order of 10{sup -6}{approx}10{sup -7}. The fission product release ratio of naked kernel was also measured under the same conditions as for the coated fuel particles, the ratio of the fission product release of the coated fuel particles and of the naked kernel was in the order of 10{sup -5}{approx}10{sup -4}.

International conference on production of particles with new quantum numbers: Proceedings

International Nuclear Information System (INIS)

1976-01-01

This report contains papers on the following topics: mechanisms of new particle production; the total cross section for e + e/sup /minus// → hadrons and its associated spectroscopy; recent results on the new particle states below 3.7 GeV produced in e + e/sup /minus// annihilations; new results on J//psi/ and /psi/' decays from DASP; excess muons and new results in /psi/ photoproduction; probing the new particles with hadron beams; properties of prompt leptons; muon production in hadron-hadron collisions; large transverse momentum photons from high energy proton proton collisions; dimuon and trimuon production in deep inelastic muon interactions; streamer chamber search for narrow hadrons with a muon-enriched trigger; threshold effects of new particle production by high energy neutrinos and antineutrinos; the observation of neutrino induced μ/sup /minus//e + events in the Fermilab bubble chamber; search for antineutrino induced μ + e/sup /minus// events; observation of muon-neutrino reactions producing a positron and a strange particle; observation of the reaction ν/sub μ/ + p → ν/sub μ/ + p; search for muonic pairs; strange particle production in neutrino interactions; neutral currents---the structure of the coupling; evidence for parity non-conservation in the weak neutral current; observation of elastic neutrino-proton scattering; threshold and other properties of U particle production in e + e/sup /minus// annihilation; anomalous muon production in e + e/sup /minus// collisions; electron production; strongly interacting heavy lepton; and /psi/'s without charm

Charm and particle production in neutrino interactions

International Nuclear Information System (INIS)

Cazzoli, E.G.; Cnops, A.M.; Connolly, P.L.; Louttit, R.I.; Murtagh, M.J.; Palmer, R.B.; Samios, N.P.; Tso, T.T.; Williams, H.H.

1976-01-01

Ten strange particles were observed in a total of 1086 charged current neutrino interactions obtained in the analysis of 482,000 pictures taken in the Brookhaven Cryogenic 7' Bubble Chamber filled with hydrogen and deuterium. Details of these events are presented together with rates for associated strange particle and ΔS = +-ΔQ production in neutrino interactions

77 FR 51046 - Certain Sintered Rare Earth Magnets, Methods of Making Same and Products Containing Same; Notice...

Science.gov (United States)

2012-08-23

... INTERNATIONAL TRADE COMMISSION [Docket No. 2908] Certain Sintered Rare Earth Magnets, Methods of... Certain Sintered Rare Earth Magnets, Methods of Making Same and Products Containing Same, DN 2908; the..., methods of making same and products [[Page 51047

Nongaussian Features from Inflationary Particle Production

International Nuclear Information System (INIS)

Barnaby, Neil

2010-01-01

The inflaton field can be expected to couple to a number of additional fields whose energy density does not play any significant role in driving inflation. Such couplings may lead to isolated bursts of particle production during inflation, for example via parametric resonance or a phase transition, and leave observable imprints in the cosmological fluctuations. I illustrate this effect for a simple prototype interaction g 2 (φ - φ 0 ) 2 χ between the inflaton, φ, and iso-inflaton, χ. Using both classical lattice simulations and analytical quantum field theory computations, I show that this mechanism generates localized bump-like features in the power spectrum and also a completely new type of nongaussianity. Observations are consistent with relatively large features of this type and the nongaussianity from particle production may be observable in future missions.

Particle production in higher derivative theory

Indian Academy of Sciences (India)

Lemaitre–Robertson–Walker cosmological model during the early stages of the universe is analysed in the framework of higher derivative theory. The universe has been considered as an open thermodynamic system where particle production ...

Measurement of charmed particle production in hadronic reactions

CERN Multimedia

2002-01-01

The aim of the experiment is to measure the production cross-section for charmed particles in hadronic reactions, study their production mechanism, and search for excited charmed hadrons.\\\\ \\\\ Charmed Mesons and Baryons will be measured in $\\pi$ and $p$ interactions on Beryllium between 100 and 200 GeV/c. The trigger will be on an electron from the leptonic decay of one charmed particle by signals from the Cerenkov counter (Ce), the electron trigger calorimeter (eCal), scintillation counters, and proportional wire chambers. The accompanying charmed particle will be measured via its hadronic decay in a two-stage magnetic spectrometer with drift chambers (arms 2, 3a, 3b, 3c), two large-area multicell Cerenkov counters (C2, C3) and a large-area shower counter ($\\gamma$-CAL). The particles which can be measured and identified include $\\gamma, e, \\pi^{\\pm}, \\pi^{0}, K^{\\pm}, p, \\bar{p}$ so that a large number of hadronic decay modes of charmed particles can be studied. \\\\ \\\\ A silicon counter telescope with 5 $\\m...

Subthreshold particle production in heavy-ion collisions

International Nuclear Information System (INIS)

Mosel, U.

1991-01-01

Subthreshold production processes are discussed in the theoretical framework, checking data obtained from hard-photon production in the energy range from 20 to 100 MeV/u. The reactions at higher energies are described and the predictions for particle production cross sections are discussed. A particular attention to properties of hadrons (nucleons and mesons) in the nuclear medium is given. (M.C.K.)

Calcination of kaolinite clay particles for cement production

DEFF Research Database (Denmark)

Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

2014-01-01

Kaolinite rich clay particles calcined under certain conditions can attain favorable pozzolanic properties and can be used to substitute part of the CO2 intensive clinker in cement production. To better guide calcination of a clay material, a transient one-dimensional single particle model...

Preparation and structure of carbonated calcium hydroxyapatite substituted with heavy rare earth ions

Energy Technology Data Exchange (ETDEWEB)

Yasukawa, Akemi, E-mail: yasukawa@cc.hirosaki-u.ac.jp [School of Home Economics, Faculty of Education, Hirosaki University, 1-bunkyo, Hirosaki, Aomori 036-8560 (Japan); Kandori, Kazuhiko [School of Chemistry, Osaka University of Education, 4-698-1 Asahigaoka, Kashiwara, Osaka 582-8582 (Japan); Tanaka, Hidekazu [Department of Material Science, Faculty of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue, Shimane 690-8504 (Japan); Gotoh, Keiko [Faculty of Human Life and Environment, Nara Women' s University, Kita-uoya-nishi, Nara 630-8506 (Japan)

2012-05-15

Highlights: Black-Right-Pointing-Pointer LnCaHap solid solution particles were prepared using five types of heavy rare earth ions by a precipitation method. Black-Right-Pointing-Pointer The length and the crystallinity of the LnCaHap particles first increased and then decreased with increasing Ln{sup 3+} contents. Black-Right-Pointing-Pointer A series of YCaHap solid solution particles formed with Y/(Y + Ca) = 0-0.10 were investigated using various methods in detail. -- Abstract: Calcium hydroxyapatite (CaHap) particles substituted five types of heavy rare earth ions (Ln: Y{sup 3+}, Gd{sup 3+}, Dy{sup 3+}, Er{sup 3+} and Yb{sup 3+}) were synthesized using a precipitation method and characterized using various means. These Ln ions strongly affected the crystal phases and the structures of the products. With increasing Ln/(Ln + Ca) in the starting solution ([X{sub Ln}]), the length and the crystallinity of the particles first increased and then decreased. The rare earth metal-calcium hydroxyapatite (LnCaHap) solid solution particles were obtained at [X{sub Y}] {<=} 0.10 for substituting Y system and at [X{sub Ln}] {<=} 0.01-0.03 for substituting the other Ln systems. LnPO{sub 4} was mixed with LnCaHap at higher [X{sub Ln}] for all Ln systems. A series of yttrium-calcium hydroxyapatite (YCaHap) solid solutions with [X{sub Y}] = 0-0.10 were investigated using XRD, TEM, ICP-AES, IR and TG-DTA in detail.

Preparation and structure of carbonated calcium hydroxyapatite substituted with heavy rare earth ions

International Nuclear Information System (INIS)

Yasukawa, Akemi; Kandori, Kazuhiko; Tanaka, Hidekazu; Gotoh, Keiko

2012-01-01

Highlights: ► LnCaHap solid solution particles were prepared using five types of heavy rare earth ions by a precipitation method. ► The length and the crystallinity of the LnCaHap particles first increased and then decreased with increasing Ln 3+ contents. ► A series of YCaHap solid solution particles formed with Y/(Y + Ca) = 0–0.10 were investigated using various methods in detail. -- Abstract: Calcium hydroxyapatite (CaHap) particles substituted five types of heavy rare earth ions (Ln: Y 3+ , Gd 3+ , Dy 3+ , Er 3+ and Yb 3+ ) were synthesized using a precipitation method and characterized using various means. These Ln ions strongly affected the crystal phases and the structures of the products. With increasing Ln/(Ln + Ca) in the starting solution ([X Ln ]), the length and the crystallinity of the particles first increased and then decreased. The rare earth metal-calcium hydroxyapatite (LnCaHap) solid solution particles were obtained at [X Y ] ≤ 0.10 for substituting Y system and at [X Ln ] ≤ 0.01–0.03 for substituting the other Ln systems. LnPO 4 was mixed with LnCaHap at higher [X Ln ] for all Ln systems. A series of yttrium-calcium hydroxyapatite (YCaHap) solid solutions with [X Y ] = 0–0.10 were investigated using XRD, TEM, ICP-AES, IR and TG–DTA in detail.

A rare sight

CERN Multimedia

Antonella Del Rosso and The LHCb Collaboration

2012-01-01

Today, at the Hadron Collider Physics Symposium in Kyoto, the LHCb collaboration has presented the evidence of a very rare B decay, the rarest ever seen. The result further shrinks the region in which scientists can still look for supersymmetry.   The graph showing evidence of the Bs0 → μ+ μ- decay. The result was presented Monday 12 November at the HCP Conference in Kyoto (photo courtesy of the LHCb Collaboration). Particle decays tell us about the inner properties and functioning of Nature’s physics processes. By studying them and their occurrence, physicists infer the rules that control them. Often, it turns out that some rare decays, which are very difficult to observe, are those in which Nature could reveal the presence of new physics. This is the case of some decays of the Bs0 particle (a particle made of a bottom anti-quark bound to a strange quark), and in particular Bs0 → μ+ μ- whose...

On slow particle production in hadron-nucleus interactions

International Nuclear Information System (INIS)

Stenlund, E.; Otterlund, I.

1982-01-01

A model for slow particle production in hadron-nucleus interactions is presented. The model succesfully predicts correlations between the number of knock-on particles and the number of particles associated with the evaporation process as well as correlations with the number of collisions, ν, between the incident hadron and the nucleons inside the target nucleus. The model provides two independent possibilities to determine the number of primary intranuclear collisions, ν, i.e. by its correlation to the number of knock-on particles or to the number of evaporated particles. The good agreement indicates that the model gives an impact-parameter sensitive description of hardron nucleus reactions. (orig.)

High-energy particle production in solar flares (SEP, gamma-ray and neutron emissions). [solar energetic particles

Science.gov (United States)

Chupp, E. L.

1987-01-01

Electrons and ions, over a wide range of energies, are produced in association with solar flares. Solar energetic particles (SEPs), observed in space and near earth, consist of electrons and ions that range in energy from 10 keV to about 100 MeV and from 1 MeV to 20 GeV, respectively. SEPs are directly recorded by charged particle detectors, while X-ray, gamma-ray, and neutron detectors indicate the properties of the accelerated particles (electrons and ions) which have interacted in the solar atmosphere. A major problem of solar physics is to understand the relationship between these two groups of charged particles; in particular whether they are accelerated by the same mechanism. The paper reviews the physics of gamma-rays and neutron production in the solar atmosphere and the method by which properties of the primary charged particles produced in the solar flare can be deduced. Recent observations of energetic photons and neutrons in space and at the earth are used to present a current picture of the properties of impulsively flare accelerated electrons and ions. Some important properties discussed are time scale of production, composition, energy spectra, accelerator geometry. Particular attention is given to energetic particle production in the large flare on June 3, 1982.

Production of rare sugars from common sugars in subcritical aqueous ethanol.

Science.gov (United States)

Gao, Da-Ming; Kobayashi, Takashi; Adachi, Shuji

2015-05-15

A new isomerization reaction was developed to synthesize rare ketoses. D-tagatose, D-xylulose, and D-ribulose were obtained in the maximum yields of 24%, 38%, and 40%, respectively, from the corresponding aldoses, D-galactose, D-xylose, and D-ribose, by treating the aldoses with 80% (v/v) subcritical aqueous ethanol at 180°C. The maximum productivity of D-tagatose was ca. 80 g/(Lh). Increasing the concentration of ethanol significantly increased the isomerization of D-galactose. Variation in the reaction temperature did not significantly affect the production of D-tagatose from D-galactose. Subcritical aqueous ethanol converted both 2,3-threo and 2,3-erythro aldoses to the corresponding C-2 ketoses in high yields. Thus, the treatment of common aldoses in subcritical aqueous ethanol can be regarded as a new method to synthesize the corresponding rare sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Investigation of the production of cobalt-60 via particle accelerator

Directory of Open Access Journals (Sweden)

Artun Ozan

2017-01-01

Full Text Available The production process of cobalt-60 was simulated by a particle accelerator in the energy range of 5 to 100 MeV, particle beam current of 1 mA, and irradiation time of 1 hour to perform yield, activity of reaction, and integral yield for charged particle-induced reactions. Based on nuclear reaction processes, the obtained results in the production process of cobalt-60 were also discussed in detail to determine appropriate target material, optimum energy ranges, and suitable reactions.

Effect of limestone particle size on egg production and eggshell ...

African Journals Online (AJOL)

Different limestone particle sizes had no effect on any of the tested egg production and eggshell quality parameters. These results suggested that larger particles limestone are not necessarily essential to provide sufficient Ca2+ to laying hens for egg production and eggshell quality at end-of-lay, provided that the dietary Ca ...

Main Injector Particle Production Experiment Status

International Nuclear Information System (INIS)

Lebedev, Andre

2007-01-01

MIPP (FNAL-E907) is a large acceptance spectrometer to measure hadronic particle production - TPC and wire chambers to measure track parameters - TPC dE/dx, ToF, differential Cherenkov and ring imaging Cherenkov give π/K/p separation up to 100 GeV/c

Particle size distribution of selected electronic nicotine delivery system products.

Science.gov (United States)

Oldham, Michael J; Zhang, Jingjie; Rusyniak, Mark J; Kane, David B; Gardner, William P

2018-03-01

Dosimetry models can be used to predict the dose of inhaled material, but they require several parameters including particle size distribution. The reported particle size distributions for aerosols from electronic nicotine delivery system (ENDS) products vary widely and don't always identify a specific product. A low-flow cascade impactor was used to determine the particle size distribution [mass median aerodynamic diameter (MMAD); geometric standard deviation (GSD)] from 20 different cartridge based ENDS products. To assess losses and vapor phase amount, collection efficiency of the system was measured by comparing the collected mass in the impactor to the difference in ENDS product mass. The levels of nicotine, glycerin, propylene glycol, water, and menthol in the formulations of each product were also measured. Regardless of the ENDS product formulation, the MMAD of all tested products was similar and ranged from 0.9 to 1.2 μm with a GSD ranging from 1.7 to 2.2. There was no consistent pattern of change in the MMAD and GSD as a function of number of puffs (cartridge life). The collection efficiency indicated that 9%-26% of the generated mass was deposited in the collection system or was in the vapor phase. The particle size distribution data are suitable for use in aerosol dosimetry programs. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications.

Science.gov (United States)

Roca, Christophe; Alves, Vitor D; Freitas, Filomena; Reis, Maria A M

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed.

Determination Of Rare Earth And Other Elements In YEN-PHU Rare Earth Ore And Other Intermediate Products From The Floatation And Hydrometallurgical Process On Portable XRF Si-PIN Detector

International Nuclear Information System (INIS)

Doan Thanh Son; Phung Vu Phong; Nguyen Hanh Phuc

2014-01-01

The concentration of rare earths elements such as La, Ce, Pr, Nd, Gd and other elements as Ca, Fe, U, Th in Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical process was determined by using Si-PIN detector fluorescence spectrometry. The precision and accuracy of quantitative analysis was tested by standard reference materials and comparative analysis with different analytical methods. The analytical procedures were set-up and applied for the determination of rare earth and other elements in Yen Phu rare earth ore and other intermediate products from the flotation and hydrometallurgical process with high precision and accuracy. (author)

Insight into particle production mechanisms from angular correlations of identified particles in pp collisions measured by ALICE

CERN Multimedia

CERN. Geneva

2017-01-01

Two-particle angular correlations are a robust tool which provide access to the underlying physics phenomena of particle production in collisions of both protons and heavy ions by studying distributions of particles in pseudorapidity and azimuthal angle difference. The correlation measurement is sensitive to several phenomena, including mini-jets, elliptic flow, Bose-Einstein correlations, resonance decays, conservation laws, which can be separated by selections of momentum, particle type and by analysing the shapes of the correlation structures. In this talk, we report measurements of the correlations of identified particles and their antiparticles (for pions, kaons, protons, and lambdas) at low transverse momenta in pp collisions at sqrt(s) = 7 TeV, recently submitted for publication by the ALICE Collaboration [arXiv:1612.08975]. The analysis reveals differences in particle production between baryons and mesons. The correlation functions for mesons exhibit the expected peak dominated by effects of mini-jet...

Study of Rare Events at the Split Field Magnet

CERN Multimedia

2002-01-01

The aim of the experiment is the study of full events associated with special, rare triggers using the almost 4 @p geometry of the improved Split Field Magnet (SFM) detector. Two triggers are used: a) a trigger on an electron produced around 90|0 with a transverse momentum p^t @$>$ 0.5 GeV/c; b) a trigger on very high p^t hadrons (p^t $>$ 5 GeV/c) at @Q @C 45|0, using the SFM chambers to define roads pointing to the interaction region. In the first case, the associated event will be studied to determine the origin of direct electron production in charmed particle production. In the second case, the production of jets or jet-like objects when a high p^t particle is produced in pp collisions will be investigated. To carry out this program, the detection system consists of : \\item a) An improved SFM detector chamber system and layout to detect more of the produced particles and to simplify the pattern recognition problem in multiparticle events. \\item b) An improved program chain for the analysis of SFM events, ...

Production of particles by a variable scalar field

International Nuclear Information System (INIS)

Dolgov, A.D.; Kirilova, D.P.

1990-01-01

The probability of particle production by a spatially homogeneous scalar field χ(t) is calculated. Explicit analytic expressions are obtained in two opposite limiting cases: in perturbation theory and in the quasiclassical approximation. It is shown that if the mass of the produced particles is determined by the field χ(t) is accordance with the expression gχ(t) anti ψψ, then for an oscillatory field χ(t) = χ 0 cos(ωt) the production probability in the limit of small ω is suppressed not exponentially, but only as ω 1/2 . Cosmological applications of these results are discussed

Hadronic J/psi and charmed particle production and correlating quark rearrangement model

International Nuclear Information System (INIS)

Nishitani, Tadashi

1979-01-01

On the basis of the correlating quark rearrangement model, the exclusive and inclusive production cross sections of J/psi and charmed particles in hadron collisions are calculated. It is shown that the inclusive production cross section of charmed particles is several tens of μb at p sub( l) -- 100 GeV/c in hadron collisions. The OZI rule is discussed in connection with the production mechanism of J/psi particles. (author)

Production and propagation of secondary particles near the earth

International Nuclear Information System (INIS)

Derome, L.

2008-01-01

A few years ago the AMS01 embarked experiment showed a particular high component of the cosmic particle flux detected below the geo-magnetic cut which was surprising because this cut represents the minimal energy that is required for cosmic radiation to reach the earth and any cosmic ray below the cut is pushed away by the earth's magnetic field. This work is based on Monte-Carlo simulations involving the generation of primary cosmic particles, their propagation in the earth magnetic field, their interaction with earth's atmosphere and the production of secondary particles. These simulations have shown that the particles below the cut are in fact particles generated in the upper part of the atmosphere, escaping from it and being trapped by the earth's magnetic field. These Monte-Carlo simulations have also been used to assess the composition of below-the-cut flux in terms of protons, electrons, positrons and light nuclei, to check the production of anti-matter in the atmosphere, and to estimate the flux of atmospheric neutrinos. (A.C.)

75 FR 25293 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Rare Earth...

Science.gov (United States)

2010-05-07

... Production Act of 1993--Rare Earth Industry and Technology Association Notice is hereby given that, on March..., 15 U.S.C. 4301 et seq. (``the Act''), the Rare Earth Technology Consortium (``RETC'') has filed..., the identities of the parties to the venture are: Rare Earth Industry and Tecimology Association...

Production of heavy particles by protons on protons

International Nuclear Information System (INIS)

Afek, Y.; Margolis, B.; Polvani, L.

1982-01-01

We calculate the production of heavy particles in the multi-GeV energy range using parton-model and statistical considerations. We discuss both central production and fragmentation. Our picture has implications for the question of the existence of a limiting temperature in hardron interaction

Design of focussing and guide structures for charged particle beams using rare earth cobalt permanent magnets

International Nuclear Information System (INIS)

Halbach, K.

1981-06-01

A number of different methods can be used to describe the magnetic properties of oriented Rare Earth Cobalt (REC) material. It will be shown how these different methods of description lead to different ways to think about, and to execute, the design of magnets that are useful for focusing and guiding charged particle beams. It will also be domonstrated that in some of these magnets, the REC material is used in a somewhat unusual way, requiring magnetics properties of the material that are usually not considered to be of great practical importance

Particle production in e+e- annihilation at 29 GeV

International Nuclear Information System (INIS)

Derrick, M.

1986-01-01

Recent results on particle production in e + e - annihilation at 29 GeV are reviewed. The data were obtained using the High Resolution Spectrometer at PEP and correspond to an integrated luminosity of 300 pb -1 . The mean charged particle multiplicity in gluon jets from the three-jet events is found not to differ from that measured for quark jets. The production of the scalar meson S(975) and the tensor mesons f 0 (1270) and K*(1430) are observed and the rates are compared to the previously observed vector mesons, rho and K*(890). Finally, some of the global properties of charged particle production are presented and compared with similar results from soft hadronic collisions. 16 refs., 7 figs

Polysaccharides enriched in rare sugars: bacterial sources, production and applications

Directory of Open Access Journals (Sweden)

Christophe eRoca

2015-04-01

Full Text Available Microbial extracellular polysaccharides (EPS, produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers.This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals and biomedical applications, are discussed.

Recovery of cobalt-rare earth alloy particles by hydration-disintegration in a magnetic field

International Nuclear Information System (INIS)

McFarland, C.M.; Lerman, T.B.; Rockwood, A.C.

1975-01-01

A process for recovering magnetic alloy particles from a reaction product cake. The cake is placed in a reactor where it is contacted with a flowing water vapor-carrying gas which reacts with its calcium content to disintegrate the cake and produce a hydrated powder comprised substantially of calcium hydroxide and the alloy particles. A magnetic zone is generated into a cross-section of the reactor substantially encircling the inside wall thereof. The zone is generated by at least two poles of opposite polarity running the length of the zone. The hydrated powder is fluidized to dissociate and pass the calcium hydroxide out of the reactor. Finer-sized alloy particles carried by the fluidizing gas into the magnetic zone are subjected to the magnetic field where the poles are rotated or reversed at a rate which reverses the positions of the particles sufficiently to release adherent calcium hydroxide leaving the finer-sized alloy particles substantially within the magnetic zone. (auth)

Particle production in higher derivative theory

Indian Academy of Sciences (India)

Cosmological models; particle production; higher derivative theory of gravitation. PACS No. 98.80. 1. ... is of singular models where the cosmic expansion is driven by the big-bang impulse; all ... According to Gibbs integrability condition, one cannot independently specify an equa- .... [3] B Hartle and S W Hawking Phys. Rev.

L-Arabinose isomerase and its use for biotechnological production of rare sugars.

Science.gov (United States)

Xu, Zheng; Li, Sha; Feng, Xiaohai; Liang, Jinfeng; Xu, Hong

2014-11-01

L-Arabinose isomerase (AI), a key enzyme in the microbial pentose phosphate pathway, has been regarded as an important biological catalyst in rare sugar production. This enzyme could isomerize L-arabinose into L-ribulose, as well as D-galactose into D-tagatose. Both the two monosaccharides show excellent commercial values in food and pharmaceutical industries. With the identification of novel AI family members, some of them have exhibited remarkable potential in industrial applications. The biological production processes for D-tagatose and L-ribose (or L-ribulose) using AI have been developed and improved in recent years. Meanwhile, protein engineering techniques involving rational design has effectively enhanced the catalytic properties of various AIs. Moreover, the crystal structure of AI has been disclosed, which sheds light on the understanding of AI structure and catalytic mechanism at molecular levels. This article reports recent developments in (i) novel AI screening, (ii) AI-mediated rare sugar production processes, (iii) molecular modification of AI, and (iv) structural biology study of AI. Based on previous reports, an analysis of the future development has also been initiated.

Neutral strange particle production in antineutrino-neon charged current interactions

Science.gov (United States)

Willocq, S.; Marage, P.; Aderholz, M.; Allport, P.; Baton, J. P.; Berggren, M.; Clayton, E. F.; Cooper-Sarkar, A. M.; Erriquez, O.; Faulkner, P. J. W.; Guy, J.; Hulth, P. O.; Jones, G. T.; Mobayyen, M. M.; Morrison, D. R. O.; Neveu, M.; O'Neale, S.; Sacton, J.; Sansum, R. A.; Varvell, K.; Venus, W.; Wells, J.; Wittek, W.

1992-06-01

Neutral strange particle production inbar v Ne charged current interactions is studied using the bubble chamber BEBC, exposed to the CERN SPS antineutrino wide band beam. From a sample of 1191 neutral strange particles, the inclusive production rates are determined to be (15.7±0.8)% for K 0 mesons, (8.2±0.5)% for Λ, (0.4±0.2)% forbar Λ and (0.6±0.3)% for Σ0 hyperons. The inclusive production properties of K 0 mesons and Λ hyperons are investigated. The Λ hyperons are found to be polarized in the production plane.

SYMPOSIUM: Rare decays

Energy Technology Data Exchange (ETDEWEB)

Anon.

1989-04-15

Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions.

Multifield stochastic particle production: beyond a maximum entropy ansatz

Energy Technology Data Exchange (ETDEWEB)

Amin, Mustafa A.; Garcia, Marcos A.G.; Xie, Hong-Yi; Wen, Osmond, E-mail: mustafa.a.amin@gmail.com, E-mail: marcos.garcia@rice.edu, E-mail: hxie39@wisc.edu, E-mail: ow4@rice.edu [Physics and Astronomy Department, Rice University, 6100 Main Street, Houston, TX 77005 (United States)

2017-09-01

We explore non-adiabatic particle production for N {sub f} coupled scalar fields in a time-dependent background with stochastically varying effective masses, cross-couplings and intervals between interactions. Under the assumption of weak scattering per interaction, we provide a framework for calculating the typical particle production rates after a large number of interactions. After setting up the framework, for analytic tractability, we consider interactions (effective masses and cross couplings) characterized by series of Dirac-delta functions in time with amplitudes and locations drawn from different distributions. Without assuming that the fields are statistically equivalent, we present closed form results (up to quadratures) for the asymptotic particle production rates for the N {sub f}=1 and N {sub f}=2 cases. We also present results for the general N {sub f} >2 case, but with more restrictive assumptions. We find agreement between our analytic results and direct numerical calculations of the total occupation number of the produced particles, with departures that can be explained in terms of violation of our assumptions. We elucidate the precise connection between the maximum entropy ansatz (MEA) used in Amin and Baumann (2015) and the underlying statistical distribution of the self and cross couplings. We provide and justify a simple to use (MEA-inspired) expression for the particle production rate, which agrees with our more detailed treatment when the parameters characterizing the effective mass and cross-couplings between fields are all comparable to each other. However, deviations are seen when some parameters differ significantly from others. We show that such deviations become negligible for a broad range of parameters when N {sub f}>> 1.

Simultaneous projection of particle-number and angular momentum BCS wave-functions in the rare-earth nuclei

International Nuclear Information System (INIS)

Oudih, M.R.; Fellah, M.; Allal, N.H.; Benhamouda, N.

1999-01-01

It is well established that the BCS wave-functions are neither eigen-functions of the particle-number operator nor of the angular momentum operator. In a previous paper, we have developed a particle-number projection before variation method (of FBCS type). This discrete projection method is based on the SBCS wave-function. The aim of the present contribution is to perform a subsequent angular momentum projection by means of the Peierls-Yoccoz method. The general expression of the system energy, after the double projection, is established in the case of axial symmetry. For practical calculations, an approximation method is introduced. It leads to a semi-classical form of the rotational energy. The rotational spectra have been evaluated numerically for some even-even rare-earth nuclei. The single-particle energies and eigen-states are those of a deformed Woods-Saxon mean field. The obtained results are compared on one hand, to the experimental data, and on the other hand, to the theoretical spectra evaluated by a particle-number projection after variation method (of PBCS type). For all studied nuclei, the spectra determined by the FBCS method reproduce the experimental data better than those of the PBCS method. However, even if the present method is satisfying for low angular momenta, the agreement with the experimental data is lesser for I ≥ 8, particularly for the lighter studied nuclei. (authors)

Practical limitations of single particle ICP-MS in the determination of nanoparticle size distributions and dissolution: case of rare earth oxides.

Science.gov (United States)

Fréchette-Viens, Laurie; Hadioui, Madjid; Wilkinson, Kevin J

2017-01-15

The applicability of single particle ICP-MS (SP-ICP-MS) for the analysis of nanoparticle size distributions and the determination of particle numbers was evaluated using the rare earth oxide, La 2 O 3 , as a model particle. The composition of the storage containers, as well as the ICP-MS sample introduction system were found to significantly impact SP-ICP-MS analysis. While La 2 O 3 nanoparticles (La 2 O 3 NP) did not appear to interact strongly with sample containers, adsorptive losses of La 3+ (over 24h) were substantial (>72%) for fluorinated ethylene propylene bottles as opposed to polypropylene (size distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

Search for additional muons in hadronic production of J/psi particles

International Nuclear Information System (INIS)

Anderson, K.J.; Coleman, R.N.; Karhi, K.P.; Newman, C.B.; Pilcher, J.E.; Rosenberg, E.I.; Thaler, J.J.; Hogan, G.E.; McDonald, K.T.; Sanders, G.H.; Smith, A.J.S.

1980-01-01

A sample of J/psi → μ + μ - decays produced by a 225-GeV/c π - beam on nuclear targets has been analyzed for extra muons. Muons observed in coincidence with J/psi production could indicate either the production of charmed particles or the production of pairs of J/psi particles. We find 90% confidence limits of sigma/sub J/DD-bar/sigma/sub J/<0.016 for associated charm production and sigma/sub J/J/sigma/sub J/<0.005 for the production of J/psi pairs

Particle production in heavy ion collisions

International Nuclear Information System (INIS)

Braun-Munzinger, P.; Redlich, K.; Wroclaw Univ.; Stachel, J.

2003-04-01

The status of thermal model descriptions of particle production in heavy ion collisions is presented. We discuss the formulation of statistical models with different implementation of the conservation laws and indicate their applicability in heavy ion and elementary particle collisions. We analyze experimental data on hadronic abundances obtained in ultra-relativistic heavy ion collisions, in a very broad energy range starting from RHIC/BNL (√(s) = 200 A GeV), SPS/CERN (√(s) ≅ 20 A GeV) up to AGS/BNL (√(s) ≅ 5 A GeV) and SIS/GSI (√(s) ≅ 2 A GeV) to test equilibration of the fireball created in the collision. We argue that the statistical approach provides a very satisfactory description of experimental data covering this wide energy range. Any deviations of the model predictions from the data are indicated. We discuss the unified description of particle chemical freeze-out and the excitation functions of different particle species. At SPS and RHIC energy the relation of freeze-out parameters with the QCD phase boundary is analyzed. Furthermore, the application of the extended statistical model to quantitative understanding of open and hidden charm hadron yields is considered. (orig.)

Particle production at AGS energies

International Nuclear Information System (INIS)

Steadman, S.G.; Rothschild, P.J.; Sung, T.W.; Zachary, D.

1995-01-01

The authors discuss particle production from 14.6 A·GeV/c Si and 11.6 A·GeV/c Au projectiles on Al and Au targets. The second-level trigger utilized by E859 allows high precision measurements of K - , bar p, Λ and bar Λ. The bar Λ yield is larger than expected, and a surprisingly large fraction of the bar p's are observed to arise from the decay of bar Λ

Anomalous couplings in single top and searches for rare top quark couplings with the ATLAS detector

CERN Document Server

Cabrera Urban, Susana; The ATLAS collaboration

2017-01-01

The top quark is the heaviest known fundamental particle and probing its couplings with the other fundamental particle may open a window to physics beyond the Standard Model. Single top-quark production provides a unique window to study the coupling between the top quark, the W boson and the b quark, since it involves the $Wtb$ vertex in both production and decay. Measurements of angular correlations in single top quark events in the t-channel exchange of a W boson are presented based on the 8 TeV ATLAS dataset. Differential cross-sections are measured as a function of angular variables that are sensitive to anomalous contributions to the Wtb vertex and the top quark polarization. Searches for flavour-changing neutral current top-quark interactions are also discussed based on the 8 TeV and 13 TeV ATLAS dataset. Searches for rare top quark decays to Higgs and Z bosons are presented in top quark production, and searches for rare top quark interactions with gluons and Z bosons are presented in single top quark p...

Rare earths

Energy Technology Data Exchange (ETDEWEB)

Cranstone, D A

1979-01-01

Rare earth elements are commonly extracted from the minerals monazite, bastnaesite, and xenotine. New uses for these elements are constantly developing; they have found applications in glass polishing, television tube phosphors, high-strength low-alloy steels, magnets, catalysts, refractory ceramics, and hydrogen sponge alloys. In Canada, rare earths have been produced as byproducts of the uranium mining industry, but there was no production of rare earths in 1978 or 1979. The world sources of and markets for the rare earth elements are discussed.

Strange particles from dense hadronic matter

International Nuclear Information System (INIS)

Rafelski, J.; Letessier, J.; Tounsi, A.

1996-01-01

After a brief survey of the remarkable accomplishments of the current heavy ion collision experiments up to 200A GeV, we address in depth the role of strange particle production in the search for new phases of matter in these collisions. In particular, we show that the observed enhancement pattern of otherwise rarely produced multistrange antibaryons can be consistently explained assuming color deconfinement in a localized, rapidly disintegrating hadronic source. We develop the theoretical description of this source, and in particular study QCD based processes of strangeness production in the deconfined, thermal quark-gluon plasma phase, allowing for approach to chemical equilibrium and dynamical evolution. We also address thermal charm production. Using a rapid hadronization model we obtain final state particle yields, providing detailed theoretical predictions about strange particle spectra and yields as functions of heavy ion energy. Our presentation is comprehensive and self contained: we introduce the procedures used in data interpretation in considerable detail, discuss the particular importance of selected experimental results, and show how they impact the theoretical developments. (author)

SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

Energy Technology Data Exchange (ETDEWEB)

James K. Neathery; Gary Jacobs; Burtron H. Davis

2004-03-31

In this reporting period, a fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of production since the reaction is highly exothermic. Consequently, heavy wax products must be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase FTS. The separation problem is further compounded by catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. Existing pilot-scale equipment was modified to include a filtration test apparatus. After undergoing an extensive plant shakedown period, filtration tests with cross-flow filter modules using simulant FTS wax slurry were conducted. The focus of these early tests was to find adequate mixtures of polyethylene wax to simulate FTS wax. Catalyst particle size analysis techniques were also developed. Initial analyses of the slurry and filter permeate particles will be used by the research team to design improved filter media and cleaning strategies.

Radiological Impacts and Regulation of Rare Earth Elements in Non-Nuclear Energy Production

Directory of Open Access Journals (Sweden)

Timothy Ault

2015-03-01

Full Text Available Energy industries account for a significant portion of total rare earth usage, both in the US and worldwide. Rare earth minerals are frequently collocated with naturally occurring radioactive material, imparting an occupational radiological dose during recovery. This paper explores the extent to which rare earths are used by various non-nuclear energy industries and estimates the radiological dose which can be attributed to these industries on absolute and normalized scales. It was determined that typical rare earth mining results in an occupational collective dose of approximately 0.0061 person-mSv/t rare earth elements, amounting to a total of 330 person-mSv/year across all non-nuclear energy industries (about 60% of the annual collective dose from one pressurized water reactor operated in the US, although for rare earth mining the impact is spread out over many more workers. About half of the collective dose from non-nuclear energy production results from use of fuel cracking catalysts for oil refining, although given the extent of the oil industry, it is a small dose when normalized to the energy equivalent of the oil that is used annually. Another factor in energy industries’ reliance on rare earths is the complicated state of the regulation of naturally occurring radiological materials; correspondingly, this paper also explores regulatory and management implications.

Neutral strange particle production in neutrino interactions at Tevatron energies

International Nuclear Information System (INIS)

De, K.

1988-05-01

This thesis reports on a study of neutral strange particle production by high energy muon-neutrinos. The neutrinos were obtained from a 800 GeV proton beam-dump at Fermilab. Neutrino events were observed using a hybrid bubble chamber detector system. The data contained deep inelastic neutrino-nucleon interactions with an average momentum transfer 2 > = 23 (GeV/c) 2 . Rates for K 0 and Λ production in neutrino and anti-neutrino charged current events are presented. The distributions of these particles in Feynman x and rapidity are also studied. Significant differences were observed in the production mechanism for the K 0 meson and the Λ baryon. The production rates of K 0 's were observed to increase with energy, whereas the rates for Λ production remained essentially constant. In Feynman x, the K 0 's were produced in the central region and the Λ's were produced backwards. The data are compared with the LUND monte carlo for string fragmentation. In the monte carlo, K 0 's are mostly produced from s/bar s/ pair production during fragmentation. The Λ's are generally produced through recombination with the diquark from the target nucleon. The data agree with this model for strange particle production. 39 refs., 24 figs., 10 tabs

Semiclassical description of soliton-antisoliton pair production in particle collisions

Energy Technology Data Exchange (ETDEWEB)

Demidov, S.V.; Levkov, D.G. [Institute for Nuclear Research of the Russian Academy of Sciences,60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation)

2015-11-10

We develop a consistent semiclassical method to calculate the probability of topological soliton-antisoliton pair production in collisions of elementary particles. In our method one adds an auxiliary external field pulling the soliton and antisoliton in the opposite directions. This transforms the original scattering process into a Schwinger pair creation of the solitons induced by the particle collision. One describes the Schwinger process semiclassically and recovers the original scattering probability in the limit of vanishing external field. We illustrate the method in (1+1)-dimensional scalar field model where the suppression exponents of soliton-antisoliton production in the multiparticle and two-particle collisions are computed numerically.

[Research in elementary particles and interactions

International Nuclear Information System (INIS)

Adair, R.; Sandweiss, J.; Schmidt, M.

1992-05-01

Research of the Yale University groups in the areas of elementary particles and their interactions are outlined. Work on the following topics is reported: development of CDF trigger system; SSC detector development; study of heavy flavors at TPL; search for composite objects produced in relativistic heavy-ion collisions; high-energy polarized lepton-nucleon scattering; rare K + decays; unpolarized high-energy muon scattering; muon anomalous magnetic moment; theoretical high-energy physics including gauge theories, symmetry breaking, string theory, and gravitation theory; study of e + e - interactions with the SLD detector at SLAC; and the production and decay of particles containing charm and beauty quarks

Rare earths 1998 market update

International Nuclear Information System (INIS)

Tourre, J.M.

1998-01-01

The rare earth industry has always been a world of rapid change with the emergence of new markets, new ores and new players, as well as the disappearance of old applications. Rare earth based products are used in a great diversity of applications such as hard disk drives, CD drives, batteries, capacitors, pigments, ceramics, polishing powders, fuel cells, flints, catalyst converter, fluid cracking catalysts, etc. South East Asia holds the largest share of the known reserve of rare earth ores and is one of the major markets for rare earth compounds; in the last ten years, China has become the largest producer of rare earth intermediates as well as an important exporter of separated rare earth elements. Today, China has approximately 150 factories producing rare earth compounds, most of which are experiencing financial difficulties due to the lack of knowledge of true market needs, lack of control of their distribution channels and production over-capacity. Recently the Chinese rare earth producers have recognized the situation and efforts are underway to rationalize rare earth production. Japan has dominated many of the major application markets, and is by far the largest market for metal and alloy products. This will remain the case for the next five years; however, new countries are emerging as significant users of rare earth products such as Korea, Taiwan and Malaysia. During the last ten years rare earth producers adjusted to several radical changes that affected the raw materials, the application mix and the price structure. New producers have emerged, especially from China; some have subsequently stopped their activities while others have focused their efforts in a specific market segment

Nuclear fuel particle and method of production

International Nuclear Information System (INIS)

Wagner-Loffler, M.

1975-01-01

The core consisting of fuel oxide (UO 2 or Th or Pu oxide) of a fuel particle coated with carbon-contained material is enriched with a small addition (max 6 wt.%) of a Ba or Sr compound (atomic ratio for nuclear fuel oxide Ba being 5 - 10 : 1) which is to prevent fission products breaking the protective carbon and/or silicon carbide coating; the Ba or Sr molybdate generated is to reduce the pressure of the carbon dioxide produced. Methods to manufacture such nuclear fuel particles are proposed where 1) an agglomerisation and shaping of the spheres in a fast cycling bowle and 2) a formation of drops from a colloidal solution which are made to congeal in a liquid paraffin column, take place followed by the pyrolytic coating of the particles. (UWI/LH) [de

SYMPOSIUM: Rare decays

International Nuclear Information System (INIS)

Anon.

1989-01-01

Late last year, a symposium entitled 'Rare Decays' attracted 115 participants to a hotel in Vancouver, Canada. These participants were particle physicists interested in checking conventional selection rules to look for clues of possible new behaviour outside today's accepted 'Standard Model'. For physicists, 'rare decays' include processes that have so far not been seen, explicitly forbidden by the rules of the Standard Model, or processes highly suppressed because the decay is dominated by an easier route, or includes processes resulting from multiple transitions

Morphology and pore structure of rare earth oxides

International Nuclear Information System (INIS)

Bruce, L.A.; Hoang, M.; Hardin, S.; Turney, T.W.

1991-01-01

The morphology observed by transmission electron microscopy of rare earth oxides, prepared by two different routes, has been related to adsorption, characteristics for nitrogen at 77 K. The most common morphology was that of thin sheets, then small equiaxed particles, and, more rarely, rod-like particles. The presence of small equiaxed particles was found to be a prerequisite for adsorption hysteresis. Evaluation of linear 't' plots indicated freedom from micropores in all samples, but positive deviations in the presence of sheet morphology at high relative pressures left open the possibility of wedge-like pores in these samples. 14 refs., 3 tabs., 5 figs

Primordial black holes formation from particle production during inflation

International Nuclear Information System (INIS)

Erfani, Encieh

2016-01-01

We study the possibility that particle production during inflation can source the required power spectrum for dark matter (DM) primordial black holes (PBH) formation. We consider the scalar and the gauge quanta production in inflation models, where in the latter case, we focus in two sectors: inflaton coupled i) directly and ii) gravitationally to a U(1) gauge field. We do not assume any specific potential for the inflaton field. Hence, in the gauge production case, in a model independent way we show that the non-production of DM PBHs puts stronger upper bound on the particle production parameter. Our analysis show that this bound is more stringent than the bounds from the bispectrum and the tensor-to-scalar ratio derived by gauge production in these models. In the scenario where the inflaton field coupled to a scalar field, we put an upper bound on the amplitude of the generated scalar power spectrum by non-production of PBHs. As a by-product we also show that the required scalar power spectrum for PBHs formation is lower when the density perturbations are non-Gaussian in comparison to the Gaussian density perturbations

Combinative Particle Size Reduction Technologies for the Production of Drug Nanocrystals

Directory of Open Access Journals (Sweden)

Jaime Salazar

2014-01-01

Full Text Available Nanosizing is a suitable method to enhance the dissolution rate and therefore the bioavailability of poorly soluble drugs. The success of the particle size reduction processes depends on critical factors such as the employed technology, equipment, and drug physicochemical properties. High pressure homogenization and wet bead milling are standard comminution techniques that have been already employed to successfully formulate poorly soluble drugs and bring them to market. However, these techniques have limitations in their particle size reduction performance, such as long production times and the necessity of employing a micronized drug as the starting material. This review article discusses the development of combinative methods, such as the NANOEDGE, H 96, H 69, H 42, and CT technologies. These processes were developed to improve the particle size reduction effectiveness of the standard techniques. These novel technologies can combine bottom-up and/or top-down techniques in a two-step process. The combinative processes lead in general to improved particle size reduction effectiveness. Faster production of drug nanocrystals and smaller final mean particle sizes are among the main advantages. The combinative particle size reduction technologies are very useful formulation tools, and they will continue acquiring importance for the production of drug nanocrystals.

Constituent quarks and charge particle production in heavy-ion collisions

International Nuclear Information System (INIS)

Mishra, Aditya Nath; Mazumder, Rakesh; Sahoo, Raghunath; Nandi, Basanta Kumar

2012-01-01

Relativistic heavy-ion collisions aims at producing a state of matter which is governed by partonic degree of freedom. The pseudorapidity density of particle multiplicity and transverse energy are the key observables which provide the properties of matter produced in heavy-ion collisions. Study of their dependence on centrality and collision energy is of paramount importance to understand the particle production mechanism. This may provide insight into the partonic phase that might be created in nuclear collisions. Here, in a constituent quarks framework, charged particle and transverse energy production in heavy-ion collisions are studied both as a function of centrality and collision energy, and hence the study gives a prediction for Pb + Pb collisions

Design of the Advanced Rare Isotope Separator ARIS at FRIB

Energy Technology Data Exchange (ETDEWEB)

Hausmann, M., E-mail: hausmann@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Aaron, A.M. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Amthor, A.M. [Dept. of Physics and Astronomy, Bucknell University, Lewisburg, PA 17837 (United States); Avilov, M.; Bandura, L.; Bennett, R.; Bollen, G.; Borden, T. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Burgess, T.W. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Chouhan, S.S. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Graves, V.B. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Mittig, W. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Morrissey, D.J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Pellemoine, F.; Portillo, M.; Ronningen, R.M.; Schein, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Sherrill, B.M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824 (United States); Zeller, A. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States)

2013-12-15

The Facility for Rare Isotopes Beams (FRIB) at Michigan State University will use projectile fragmentation and induced in-flight fission of heavy-ion primary beams at energies of 200 MeV/u and higher and at a beam power of 400 kW to generate rare isotope beams for experiments in nuclear physics, nuclear astrophysics, and fundamental symmetries, as well as for societal needs. The Advanced Rare Isotope Separator (ARIS) has been designed as a three-stage fragment separator for the efficient collection and purification of the rare isotope beams of interest. A vertically bending preseparator (first stage) with production target and beam dump is fully integrated into a production target facility hot cell with remote handling. The new separator compresses the accepted momentum width of up to ±5% of the beam by a factor of three in the standard operational mode. Provisions for alternate operational modes for specific cases are included in the design. This preseparator is followed by two, horizontally-bending separator stages (second and third stages) utilizing the magnets from the existing A1900 fragment separator at the National Superconducting Cyclotron Laboratory (NSCL). These stages can alternatively be coupled to a single high-resolution separator stage, resulting in the flexibility to optimize the operation for different experiments, including momentum tagging and in-flight particle identification of rare isotope beams. The design of ARIS will be presented with an emphasis on beam physics characteristics, and anticipated operational modes will be described.

EWKino Production and Long-Lived particles at LHC

CERN Document Server

Verducci, M; The ATLAS collaboration

2013-01-01

The Large Hadron Collider has extended the reach of particle-physics experiments with a potential for discovery of new physics at the TeV scale and many searches have been carried out by both ATLAS and CMS. Searches for long-lived particles and electroweak “ino” production using 2012 LHV data have been carried by both ATLAS and CMS. The methodology of the searches (reconstruction techniques, background suppression, etc.) and the sensitivity of these searches are reviewed. Many models of physics beyond the Standard Model predict new particles with long lifetimes. Examples include Supersymmetry with R-parity violation, suppressed decays of the next-to-lightest Supersymmetric particle, or models with hidden sectors. The decay vertices of particles with lifetimes of order 10 ps to 10 ns can be efficiently identified by the ATLAS and CMS detectors. In addition, in quark and gluons collisions it is easy to produce coloured objects like gluinos and squarks, which decay typically to jets and MET, while the cross ...

The crystallization processes in the aluminum particles production technology

Directory of Open Access Journals (Sweden)

Arkhipov Vladimir

2015-01-01

Full Text Available The physical and mathematical model of the crystallization process of liquid aluminum particles in the spray-jet of the ejection-type atomizer was proposed. The results of mathematical modeling of two-phase flow in the spray-jet and the crystallization process of fluid particles are given. The influence of the particle size, of the flow rate and the stagnation temperature gas in the ranges of industrial technology implemented for the production of powders aluminum of brands ASD, on the crystallization characteristics were investigated. The approximations of the characteristics of the crystallization process depending on the size of the aluminum particles on the basis of two approaches to the mathematical description of the process of crystallization of aluminum particles were obtained. The results allow to optimize the process parameters of ejection-type atomizer to produce aluminum particles with given morphology.

STIMULATION OF OXIDANT PRODUCTION IN ALVEOLAR MACROPHAGES BY POLLUTANT AND LATEX PARTICLES

Science.gov (United States)

Air pollutant dusts as well as chemically defined particles were examined for their activating effect on oxidant production (O2- and H2O2) in guinea pig alveolar macrophages (AM). Oxidant production was measured as chemiluminescence of albumin-bound luminol. All particles examine...

Experimental evidence of the impact of rare-earth elements on particle growth and mechanical behaviour of silicon nitride

International Nuclear Information System (INIS)

Satet, Raphaelle L.; Hoffmann, Michael J.; Cannon, Rowland M.

2006-01-01

The impact of various rare-earth and related doping elements (R = Lu, Sc, Yb, Y, Sm, La) on the grain growth anisotropy and the mechanical properties of polycrystalline β-silicon nitride ceramics has been studied. Model experiments, in which Si 3 N 4 particles can grow freely in an R-Si-Mg-oxynitride glass matrix, show that, with increasing ionic radius of the additive, grain anisotropy increases due to non-linear growth kinetics. Toughness and strength are affected by the rare-earth element. Samples of equivalent grain sizes and morphologies yield an increasing toughness with increasing ion size of the R 3+ , reflecting an increasingly intergranular crack path. These samples are also strong and flaw tolerant, but the trends of strength and toughness do not exactly match. The choice of the rare-earth is essential to tailor microstructure, interfacial strength and mechanical properties. However, somewhat different trends for properties from IIIb and lanthanide additives indicate that more than the R 3+ size (i.e., purely ionic bond strength between R 3+ and its neighbours) is important. The electronic structure of the R-element is responsible for the type of dopant adsorption and the properties of the interface

A mechanism for the production of ultrafine particles from concrete fracture.

Science.gov (United States)

Jabbour, Nassib; Rohan Jayaratne, E; Johnson, Graham R; Alroe, Joel; Uhde, Erik; Salthammer, Tunga; Cravigan, Luke; Faghihi, Ehsan Majd; Kumar, Prashant; Morawska, Lidia

2017-03-01

While the crushing of concrete gives rise to large quantities of coarse dust, it is not widely recognized that this process also emits significant quantities of ultrafine particles. These particles impact not just the environments within construction activities but those in entire urban areas. The origin of these ultrafine particles is uncertain, as existing theories do not support their production by mechanical processes. We propose a hypothesis for this observation based on the volatilisation of materials at the concrete fracture interface. The results from this study confirm that mechanical methods can produce ultrafine particles (UFP) from concrete, and that the particles are volatile. The ultrafine mode was only observed during concrete fracture, producing particle size distributions with average count median diameters of 27, 39 and 49 nm for the three tested concrete samples. Further volatility measurements found that the particles were highly volatile, showing between 60 and 95% reduction in the volume fraction remaining by 125 °C. An analysis of the volatile fraction remaining found that different volatile material is responsible for the production of particles between the samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Resummation for supersymmetric particle production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Brensing, Silja Christine

2011-05-10

The search for supersymmetry is among the most important tasks at current and future colliders. Especially the production of coloured supersymmetric particles would occur copiously in hadronic collisions. Since these production processes are of high relevance for experimental searches accurate theoretical predictions are needed. Higher-order corrections in quantum chromodynamics (QCD) to these processes are dominated by large logarithmic terms due to the emission of soft gluons from initial-state and final-state particles. A systematic treatment of these logarithms to all orders in perturbation theory is provided by resummation methods. We perform the resummation of soft gluons at next-to-leading-logarithmic (NLL) accuracy for all possible production processes in the framework of the Minimal Supersymmetric Standard Model. In particular we consider pair production processes of mass-degenerate light-flavour squarks and gluinos as well as the pair production of top squarks and non-mass-degenerate bottom squarks. We present analytical results for all considered processes including the soft anomalous dimensions. Moreover numerical predictions for total cross sections and transverse-momentum distributions for both the Large Hadron Collider (LHC) and the Tevatron are presented. We provide an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions. The inclusion of NLL corrections leads to a considerable reduction of the theoretical uncertainty due to scale variation and to an enhancement of the next-to-leading order (NLO) cross section predictions. The size of the soft-gluon corrections and the reduction in the scale uncertainty are most significant for processes involving gluino production. At the LHC, where the sensitivity to squark and gluino masses ranges up to 3 TeV, the corrections due to NLL resummation over and above the NLO predictions can be as high as 35 % in the case of gluino-pair production, whereas at the

Universal behavior of charged particle production in heavy ion collisions

Science.gov (United States)

Phobos Collaboration; Steinberg, Peter A.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2003-03-01

The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV. Two kinds of universal behavior are observed in charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/pbar-p and e+e- data. N_tot/(N_part/2) in nuclear collisions at high energy scales with sqrt(s) in a similar way as N_tot in e+e- collisions and has a very weak centrality dependence. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

Recovery of fluorine, uranium, and rare earth metal values from phosphoric acid by-product brine raffinate

International Nuclear Information System (INIS)

Wamser, C.A.; Bruen, C.P.

1976-01-01

A method for recovering substantially all of the fluorine and uranium values and at least 90 percent of the rare earth metal values from brine raffinate obtained as by-product in the production of phosphoric acid by the hydrochloric acid decomposition of tricalcium phosphate minerals is described. A basically reacting compound is added to the brine raffinate to effect a pH 9 or greater, whereby fluorine, uranium and rare earth metal values are simultaneously precipitated. These values may then be separately recovered from the precipitate by known processes

A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation

International Nuclear Information System (INIS)

Koch, L.

1959-12-01

In the first part is studied the properties of atoms excited by the passage of α particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10 -9 s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an α particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [fr

Microfluidic Production of Alginate Hydrogel Particles for Antibody Encapsulation and Release.

Science.gov (United States)

Mazutis, Linas; Vasiliauskas, Remigijus; Weitz, David A

2015-12-01

Owing to their biocompatibility and reduced side effects, natural polymers represent an attractive choice for producing drug delivery systems. Despite few successful examples, however, the production of monodisperse biopolymer-based particles is often hindered by high viscosity of polymer fluids. In this work, we present a microfluidic approach for production of alginate-based particles carrying encapsulated antibodies. We use a triple-flow micro-device to induce hydrogel formation inside droplets before their collection off-chip. The fast mixing and gelation process produced alginate particles with a unique biconcave shape and dimensions of the mammalian cells. We show slow and fast dissolution of particles in different buffers and evaluate antibody release over time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Resonant particle production during inflation: a full analytical study

Energy Technology Data Exchange (ETDEWEB)

Pearce, Lauren; Peloso, Marco [School of Physics and Astronomy, University of Minnesota, 116 Church Street S.E., Minneapolis, MN 55455 (United States); Sorbo, Lorenzo, E-mail: lpearce@physics.umn.edu, E-mail: peloso@physics.umn.edu, E-mail: sorbo@physics.umass.edu [Amherst Center for Fundamental Interactions, Department of Physics, University of Massachusetts, 1126 Lederle Graduate Research Tower (LGRT), Amherst, MA 01003 (United States)

2017-05-01

We revisit the study of the phenomenology associated to a burst of particle production of a field whose mass is controlled by the inflaton field and vanishes at one given instance during inflation. This generates a bump in the correlators of the primordial scalar curvature. We provide a unified formalism to compute various effects that have been obtained in the literature and confirm that the dominant effects are due to the rescattering of the produced particles on the inflaton condensate. We improve over existing results (based on numerical fits) by providing exact analytic expressions for the shape and height of the bump, both in the power spectrum and the equilateral bispectrum. We then study the regime of validity of the perturbative computations of this signature. Finally, we extend these computations to the case of a burst of particle production in a sector coupled only gravitationally to the inflaton.

Context dependency and saturating effects of loss of rare soil microbes on plant productivity

Directory of Open Access Journals (Sweden)

Gera eHol

2015-06-01

Full Text Available Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing towards a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

Context dependency and saturating effects of loss of rare soil microbes on plant productivity.

Science.gov (United States)

Hol, W H Gera; de Boer, Wietse; de Hollander, Mattias; Kuramae, Eiko E; Meisner, Annelein; van der Putten, Wim H

2015-01-01

Land use intensification is associated with loss of biodiversity and altered ecosystem functioning. Until now most studies on the relationship between biodiversity and ecosystem functioning focused on random loss of species, while loss of rare species that usually are the first to disappear received less attention. Here we test if the effect of rare microbial species loss on plant productivity depends on the origin of the microbial soil community. Soils were sampled from three land use types at two farms. Microbial communities with increasing loss of rare species were created by inoculating sterilized soils with serially diluted soil suspensions. After 8 months of incubation, the effects of the different soil communities on abiotic soil properties, soil processes, microbial community composition, and plant productivity was measured. Dilution treatments resulted in increasing species loss, which was in relation to abundance of bacteria in the original field soil, without affecting most of the other soil parameters and processes. Microbial species loss affected plant biomass positively, negatively or not at all, depending on soil origin, but not on land use history. Even within fields the effects of dilution on plant biomass varied between replicates, suggesting heterogeneity in microbial community composition. The effects of medium and severe species loss on plant biomass were similar, pointing toward a saturating effect of species loss. We conclude that changes in the composition of the soil microbial community, including rare species loss, can affect plant productivity, depending on the composition of the initial microbial community. Future work on the relation between function and species loss effects should address this variation by including multiple sampling origins.

Validity of the negative binomial distribution in particle production

International Nuclear Information System (INIS)

Cugnon, J.; Harouna, O.

1987-01-01

Some aspects of the clan picture for particle production in nuclear and in high-energy processes are examined. In particular, it is shown that the requirement of having logarithmic distribution for the number of particles within a clan in order to generate a negative binomial should not be taken strictly. Large departures are allowed without distorting too much the negative binomial. The question of the undetected particles is also studied. It is shown that, under reasonable circumstances, the latter do not affect the negative binomial character of the multiplicity distribution

Rutile nanopowders for pigment production: Formation mechanism and particle size prediction

Science.gov (United States)

Zhang, Wu; Tang, Hongxin

2018-01-01

Formation mechanism and particle size prediction of rutile nanoparticles for pigment production were investigated. Anatase nanoparticles were observed by oriented attachment with parallel lattice fringe spaces of 0.2419 nm. Upon increasing the calcination temperature, the (1 1 0) plane of rutile was gradually observed, suggesting that the anatase (1 0 3) planes undergo internal structural rearrangement of oxygen and titanium ions into rutile phase due to ionic diffusion. Backpropagation neural network was used to predict particle size of rutile nanopowders, the prediction errors were all smaller than 2%, providing an efficient method to control particle size in pigment production.

Phenomenology of supersymmetric particle production process at the LHC

International Nuclear Information System (INIS)

Trenkel, Maike Kristina

2009-01-01

We study the hadronic production of strongly interacting SUSY particles in the framework of the MSSM. In particular, we consider top-squark pair, gluino. squark pair, and same sign squark-squark pair production processes. Aiming at precise theoretical predictions, we calculate the cross section contributions of electroweak origin up to the one-loop level. We find sizable effects both from tree-level electroweak subprocesses and next-to-leading order electroweak corrections, reaching the 20% level in kinematical distributions. In a second part of this thesis, we investigate the phenomenology of R-parity violating B 3 SUSY models with the lightest stau (τ 1 ) being the LSP. We analyze the possible τ 1 decay modes, taking into account the dynamical generation of non-zero R-parity violating couplings at lower scales. As an application of our studies which is interesting for experiments at particle accelators, we discuss single slepton production at the LHC and give numerical results for single smuon production. (orig.)

Phenomenology of supersymmetric particle production process at the LHC

Energy Technology Data Exchange (ETDEWEB)

Trenkel, Maike Christina

2009-07-20

We study the hadronic production of strongly interacting SUSY particles in the framework of the MSSM. In particular, we consider top-squark pair, gluino. squark pair, and same sign squark-squark pair production processes. Aiming at precise theoretical predictions, we calculate the cross section contributions of electroweak origin up to the one-loop level. We find sizable effects both from tree-level electroweak subprocesses and next-to-leading order electroweak corrections, reaching the 20% level in kinematical distributions. In a second part of this thesis, we investigate the phenomenology of R-parity violating B{sub 3} SUSY models with the lightest stau ({tau}{sub 1}) being the LSP. We analyze the possible {tau}{sub 1} decay modes, taking into account the dynamical generation of non-zero R-parity violating couplings at lower scales. As an application of our studies which is interesting for experiments at particle accelators, we discuss single slepton production at the LHC and give numerical results for single smuon production. (orig.)

Rapidity correlations in inclusive two-particle production at storage ring energies

CERN Document Server

Dibon, Heinz; Gottfried, Christian; Nefkens, B M K; Neuhofer, G; Niebergall, F; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, K R; Schumacher, P E; Winter, Klaus

1973-01-01

Inclusive two-particle production in the reaction pp to gamma +ch+ (anything) has been measured at the CERN ISR for four energies ( square root s=23, 30.5, 45, and 53 GeV) at two production angles of the charged particles (ch) and at eight production angles of the gamma -rays. The rapidity correlation of the two particles is weak and of short range. The peak correlation is sigma /sub inel/(d/sup 2/ sigma /sub gamma ch//d sigma /sub gamma /d sigma /sub ch/)-1=0.62+or-0.08, the correlation range (y/sub gamma /-y/sub ch/)=1.17+or-0.05, independently of s. The phi correlation extends over a wide gap in rapidity; its strength is increasing with increasing transverse momentum. (7 refs).

Enhanced Laser Cooling of Rare-Earth-Ion-Doped Composite Material

International Nuclear Information System (INIS)

You-Hua, Jia; Biao, Zhong; Xian-Ming, Ji; Jian-Ping, Yin

2008-01-01

We predict enhanced laser cooling performance of rare-earth-ions-doped glasses containing nanometre-sized ul-traBne particles, which can be achieved by the enhancement of local Geld around rare earth ions, owing to the surface plasma resonance of small metallic particles. The influence of energy transfer between ions and the particle is theoretically discussed. Depending on the particle size and the ion emission quantum efficiency, the enhancement of the absorption is predicted. It is concluded that the absorption are greatly enhanced in these composite materials, the cooling power is increased as compared to the bulk material

Characterization of complete particles (VSV-G/SIN-GFP) and empty particles (VSV-G/EMPTY) in human immunodeficiency virus type 1-based lentiviral products for gene therapy: potential applications for improvement of product quality and safety.

Science.gov (United States)

Zhao, Yuan; Keating, Kenneth; Dolman, Carl; Thorpe, Robin

2008-05-01

Lentiviral vectors persist in the host and are therefore ideally suited for long-term gene therapy. To advance the use of lentiviral vectors in humans, improvement of their production, purification, and characterization has become increasingly important and challenging. In addition to cellular contaminants derived from packaging cells, empty particles without therapeutic function are the major impurities that compromise product safety and efficacy. Removal of empty particles is difficult because of their innate similarity in particle size and protein composition to the complete particles. We propose that comparison of the properties of lentiviral products with those of purposely expressed empty particles may reveal potential differences between empty and complete particles. For this, three forms of recombinant lentiviral samples, that is, recombinant vesicular stomatitis virus glycoprotein (VSV-G) proteins, empty particles (VSV-G/Empty), and complete particles (VSV-G/SIN-GFP) carrying viral RNA, were purified by size-exclusion chromatography (SEC). The SEC-purified samples were further analyzed by immunoblotting with six antibodies to examine viral and cellular proteins associated with the particles. This study has demonstrated, for the first time, important differences between VSV-G/Empty particles and complete VSV-G/SIN-GFP particles. Differences include the processing of Gag protein and the inclusion of cellular proteins in the particles. Our findings support the development of improved production, purification, and characterization methods for lentiviral products.

Particle shedding from peristaltic pump tubing in biopharmaceutical drug product manufacturing.

Science.gov (United States)

Saller, Verena; Matilainen, Julia; Grauschopf, Ulla; Bechtold-Peters, Karoline; Mahler, Hanns-Christian; Friess, Wolfgang

2015-04-01

In a typical manufacturing setup for biopharmaceutical drug products, the fill and dosing pump is placed after the final sterile filtration unit in order to ensure adequate dispensing accuracy and avoid backpressure peaks. Given the sensitivity of protein molecules, peristaltic pumps are often preferred over piston pumps. However, particles may be shed from the silicone tubing employed. In this study, particle shedding and a potential turbidity increase during peristaltic pumping of water and buffer were investigated using three types of commercially available silicone tubing. In the recirculates, mainly particles of around 200 nm next to a very small fraction of particles in the lower micrometer range were found. Using 3D laser scanning microscopy, surface roughness of the inner tubing surface was found to be a determining factor for particle shedding from silicone tubing. As the propensity toward particle shedding varied between tubing types and also cannot be concluded from manufacturer's specifications, individual testing with the presented methods is recommended during tubing qualification. Choosing low abrasive tubing can help to further minimize the very low particle counts to be expected in pharmaceutical drug products. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Rare earth elements materials production from apatite ores

International Nuclear Information System (INIS)

Anufrieva, A V; Buynovskiy, A S; Makaseev, Y N; Mazov, I N; Nefedov, R A; Sachkov, V I; Valkov, A V; Andrienko, O S; Stepanova, O B

2016-01-01

The paper deals with the study of processing apatite ores with nitric acid and extraction of the rare earth elements. The rare earth elements can be successfully separated and recovered by extraction from the nitrate- phosphate solution, being an tributyl phosphate as extraction agent. The developed scheme of the processing apatite concentrate provides obtaining rare earth concentrates with high qualitative characteristics. (paper)

Preliminary estimates of the quantities of rare-earth elements contained in selected products and in imports of semimanufactured products to the United States, 2010

Science.gov (United States)

Bleiwas, Donald I.; Gambogi, Joseph

2013-01-01

Rare-earth elements (REEs) are contained in a wide range of products of economic and strategic importance to the Nation. The REEs may or may not represent a significant component of that product by mass, value, or volume; however, in many cases, the embedded REEs are critical for the device’s function. Domestic sources of primary supply and the manufacturing facilities to produce products are inadequate to meet U.S. requirements; therefore, a significant percentage of the supply of REEs and the products that contain them are imported to the United States. In 2011, mines in China produced roughly 97 percent of the world’s supply of REEs, and the country’s production of these elements will likely dominate global supply until at least 2020. Preliminary estimates of the types and amount of rare-earth elements, reported as oxides, in semimanufactured form and the amounts used for electric vehicle batteries, catalytic converters, computers, and other applications were developed to provide a perspective on the Nation’s use of these elements. The amount of rare-earth metals recovered from recycling, remanufacturing, and reuse is negligible when the tonnage of products that contain REEs deposited in landfills and retained in storage is considered. Under favorable market conditions, the recovery of REEs from obsolete products could potentially displace a portion of the supply from primary sources.

Fission product behavior in HTGR fuel particles made from weak-acid resins

International Nuclear Information System (INIS)

Tiegs, T.N.; Henson, T.J.

1979-04-01

Fission product retention and behavior are of utmost importance in HTGR fuel particles. The present study concentrates on particles made from weak-acid resins, which can vary in composition from 100% UO 2 plus excess carbon to 100% UC 2 plus excess carbon. Five compositions were tested: UC 4 58 O 2 04 , UC 3 68 O 0 01 , UC 4 39 O 1 72 , UC 4 63 O 0 97 , and UC 4 14 O 1 53 . Metallographically sectioned particles were examined with a shielded electron microprobe. The distributions of the fission products were determined by monitoring characteristic x-ray lines while scanning the electron beam over the particle surface

Study of heavy particle production

International Nuclear Information System (INIS)

1990-01-01

The collaboration of Columbia University, Fermilab, University of Massachusetts, Mexico and Texas A ampersand M is working on installation of E690 at Fermilab and on analysis of data from the Brookhaven E766 experiment. All the major components of the E690 experiment are in place and final cabling and electronics check outs are being done. In addition to the Brookhaven set-up, the Fermilab set-up has a downstream spectrometer made up of five main ring magnets for detection of a fast 800 GeV proton. This allows us on-line to identify diffraction dissociation of the target proton and to select on the mass produced. We expect copious charm production and some bottom particles. This work should produce papers on charm production at Brookhaven, high mass diffraction dissociation, Lambda-Lambda correlations and polarization of Lamdas

Indoor fine particles: the role of terpene emissions from consumer products.

Science.gov (United States)

Sarwar, Golam; Olson, David A; Corsi, Richard L; Weschler, Charles J

2004-03-01

Consumer products can emit significant quantities of terpenes, which can react with ozone (O3). Resulting byproducts include compounds with low vapor pressures that contribute to the growth of secondary organic aerosols (SOAs). The focus of this study was to evaluate the potential for SOA growth, in the presence of O3, following the use of a lime-scented liquid air freshener, a pine-scented solid air freshener, a lemon-scented general-purpose cleaner, a wood floor cleaner, and a perfume. Two chamber experiments were performed for each of these five terpene-containing agents, one at an elevated O3 concentration and-the other at a lower O3 concentration. Particle number and mass concentrations increased and O3 concentrations decreased during each experiment. Experiments with terpene-based air fresheners produced the highest increases in particle number and mass concentrations. The results of this study clearly demonstrate that homogeneous reactions between O3 and terpenes from various consumer products can lead to increases in fine particle mass concentrations when these products are used indoors. Particle increases can occur during periods of elevated outdoor O3 concentrations or indoor O3 generation, coupled with elevated terpene releases. Human exposure to fine particles can be reduced by minimizing indoor terpene concentrations or O3 concentrations.

China's rare-earth industry

Science.gov (United States)

Tse, Pui-Kwan

2011-01-01

Introduction China's dominant position as the producer of over 95 percent of the world output of rare-earth minerals and rapid increases in the consumption of rare earths owing to the emergence of new clean-energy and defense-related technologies, combined with China's decisions to restrict exports of rare earths, have resulted in heightened concerns about the future availability of rare earths. As a result, industrial countries such as Japan, the United States, and countries of the European Union face tighter supplies and higher prices for rare earths. This paper briefly reviews China's rare-earth production, consumption, and reserves and the important policies and regulations regarding the production and trade of rare earths, including recently announced export quotas. The 15 lanthanide elements-lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium (atomic numbers 57-71)-were originally known as the rare earths from their occurrence in oxides mixtures. Recently, some researchers have included two other elements-scandium and yttrium-in their discussion of rare earths. Yttrium (atomic number 39), which lies above lanthanum in transition group III of the periodic table and has a similar 3+ ion with a noble gas core, has both atomic and ionic radii similar in size to those of terbium and dysprosium and is generally found in nature with lanthanides. Scandium (atomic number 21) has a smaller ionic radius than yttrium and the lanthanides, and its chemical behavior is intermediate between that of aluminum and the lanthanides. It is found in nature with the lanthanides and yttrium. Rare earths are used widely in high-technology and clean-energy products because they impart special properties of magnetism, luminescence, and strength. Rare earths are also used in weapon systems to obtain the same properties.

LEP measurements on production, mass, lifetime of beauty particles

International Nuclear Information System (INIS)

Wormser, G.

1993-10-01

Present knowledge about the individual properties of the different beauty particles is discussed using the results of the LEP experiments. Individual lifetimes for B d 0 and B + are found to be equal within 10% whilst a 15% precision is reached for B s 0 and Λ b . The Λ b lifetime is found to be smaller than τ B + with a 2.7 σ significance. The production rate of each of these particles is measured at the 20% level. Preliminary evidence for Ξ b production has been reported. Finally, the B s 0 meson mass has been measured to be 5373 ± 4 MeV/c 2 . (author) 24 refs., 9 figs., 5 tabs

Softness of Nuclear Matter and the Production of Strange Particles in Neutron Stars

Institute of Scientific and Technical Information of China (English)

陈伟; 文德华; 刘良钢

2003-01-01

In the various models, we study the influences of the softness of nuclear matter, the vacuum fluctuation ofnucleons and σ mesons on the production of strange particles in neutron stars. Wefind that the stiffer the nuclear matter is, the more easily the strange particles is produced in neutron stars. The vacuum fluctuation of nucleons has large effect on strange particle production while that of σ meson has little effect on it.

Neutral-particle-beam production and injection

International Nuclear Information System (INIS)

Post, D.; Pyle, R.

1982-07-01

This paper is divided into two sections: the first is a discussion of the interactions of neutral beams with confined plasmas, the second is concerned with the production and diagnosis of the neutral beams. In general we are dealing with atoms, molecules, and ions of the isotopes of hydrogen, but some heavier elements (for example, oxygen) will be mentioned. The emphasis will be on single-particle collisions; selected atomic processes on surfaces will be included

Particle production in high energy nucleus-nucleus collisions

International Nuclear Information System (INIS)

Stock, R.

1985-05-01

Recent data on the production of pions and strange particles at the Bevalac and Synchrophasotron accelerators are reviewed, covering pion spectra and multiplicity distributions, Λ, K + and K - yields and spectra, and Λ polarization. Emphasis is placed on recent progress in determining the equation of state of compressed fireball nuclear matter from the observed pion yield in central collisions. Further, the information derived from apparent spectral temperatures is critically examined, along with a discussion of thermal and chemical equilibrium attainment in the reactions, as revealed by particle spectra and yields. (orig.)

Review of intermediate and final product characterization on coated particles preparation

International Nuclear Information System (INIS)

Sukarsono; Kristanti Nurwidyaningrum

2015-01-01

Review of the intermediate and final product characterization on preparation of coated particles was done. Product characterization included a tool to measure the character of raw materials, intermediate product and the final product of the process, which affects the success of getting the high temperature reactor fuel are eligible. Equipment's for the characterization of such materials were pH meter, viscometer, microbalance, turbidity meter, tab density measurement, true density measurement and auto pycnometer. Being for the measurement of particles there are two types destructive testing and non destructive. Destructive testing was done by polished the particles then cross sectional imaging of particle observed using an optical microscope. In this way contains errors due to polishing treatment that could not be right on the equator section so it needs correction. Destructive testing also create waste that must be processed from the remnants of the polishing process. By using non-destructive testing, waste was not formed but the imaging results are often unclear due to lack of contrast. Development of non-destructive test equipment has been made using radiographic method and automated microscopy. The overall activity is still much needed additional tools for measurement and for processing, so that the results obtained will not rejected as the specification of nuclear fuel. Similarly, in the case of a sampling test method and limits to a product accepted or rejected, it should be determined based on statistical methods. (author)

Production of neutrinos and neutrino-like particles in proton-nucleus interactions. [400 GeV, cross sections

Energy Technology Data Exchange (ETDEWEB)

Dishaw, J.P.

1979-03-01

An experimental search was performed to look for the direct production of neutrinos or neutrino-like particles, i.e., neutral particles which interact weakly with hadrons, in proton-nucleus interactions at 400 GeV incident proton energy. Possible sources of such particles include the semi-leptonic decay of new heavy particles such as charm, and the direct production of a light neutral Higgs particle such as the axion. The production of these particles has been inferred in this experiment by energy nonconservation in the collision of a proton with an iron nucleus. The total visible energy of the interaction was measured using a sampling ionization calorimeter. After correcting for beam intensity effects and cutting the data to eliminate systematic effects in the measurement, the final resolution of the calorimeter was 3.51% and increased with decreasing incident beam energy with a square root dependence on the beam energy. Energy nonconservation in the data is manifest as a non-Gaussian distribution on the low side of the calorimeter measured energy. Model calculations yield the fraction of events expected in this non-Gaussian behavior for the various sources of neutrinos or neutrino-like particles. A maximum likelihood fit to the data with the theoretical fraction of events expected yields the 95% confidence level production cross section upper limit values. The upper limits for general production of neutrino-like particles for various parameterizations of the production cross section are presented. The following specific upper limits have been established: charm particle production < 670 ..mu..barns, supersymmetric particle production carrying an additional quantum number R < 33 ..mu..barns (mass of 1 GeV), 8 ..mu..barns (mass of 3 GeV); axion production < 10/sup -3/ times the ..pi../sup 0/ production cross section. 144 references.

Evaluation of co-immobilized lactobacillus delbrueckii with porous particles for lactic acid production

Energy Technology Data Exchange (ETDEWEB)

Wang, H.; Seki, M.; Furusaki, S. [The University of Tokyo, Tokyo (Japan)

1996-02-01

Lactic acid production using co-immobilized L.defbrveckii with porous particles has been studied. The effect of co-immobilization with porous particles was verified by measuring the variations of both overall production rate of lactic acid and effective diffusion coefficient in the co-immobilized gel. The effective diffusion coefficient decreased with increasing cell concentration in the co-immobilized gel. However, in the high cell density regimes, the effective diffusion coefficient in co-immobilized gel was higher than that without co-immobilized porous particles. The optimal volume fraction of porous particles in the co-immobilizing gel beads leas estimated experimentally at about 10%(v/v). An approximately 30% increase of the overall production rate was obtained compared to the control culture. Mathematical analysis showed that by co-immobilizing cells with porous particles, the steady-state concentration profiles of proton and undissociated lactic acid changed favorably inside the gel beads. The result indicates that co-immobilization with porous particles is a useful method to improve fermentation efficiency in processes using immobilized cells. 19 refs., 8 figs.

Fission product Pd-SiC interaction in irradiated coated particle fuels

International Nuclear Information System (INIS)

Tiegs, T.N.

1980-04-01

Silicon carbide is the main barrier to fission product release from coated particle fuels. Consequently, degradation of the SiC must be minimized. Electron microprobe analysis has identified that palladium causes corrosion of the SiC in irradiated coated particles. Further ceramographic and electron microprobe examinations on irradiated particles with kernels ranging in composition from UO 2 to UC 2 , including PuO/sub 2 -x/ and mixed (Th, Pu) oxides, and in enrichment from 0.7 to 93.0% 235 U revealed that temperature is the major factor affecting the penetration rate of SiC by Pd. The effects of kernel composition, Pd concentration, other fission products, and SiC properties are secondary

Finite-width effects in unstable-particle production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Falgari, P. [Utrecht Univ. (Netherlands). Inst. for Theoretical Physics; Utrecht Univ. (Netherlands). Spinoza Inst.; Papanastasiou, A.S. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Signer, A. [Paul Scherrer Institut, Villigen (Switzerland); Zuerich Univ. (Switzerland). Inst. for Theoretical Physics

2013-03-15

We present a general formalism for the calculation of finite-width contributions to the differential production cross sections of unstable particles at hadron colliders. In this formalism, which employs an effective-theory description of unstable-particle production and decay, the matrix element computation is organized as a gauge-invariant expansion in powers of {Gamma}{sub X}/m{sub X}, with {Gamma}{sub X} and m{sub X} the width and mass of the unstable particle. This framework allows for a systematic inclusion of off-shell and non-factorizable effects whilst at the same time keeping the computational effort minimal compared to a full calculation in the complex-mass scheme. As a proof-of-concept example, we give results for an NLO calculation of top-antitop production in the q anti q partonic channel. As already found in a similar calculation of single-top production, the finite-width effects are small for the total cross section, as expected from the naive counting {proportional_to}{Gamma}{sub t}/m{sub t}{proportional_to}1%. However, they can be sizeable, in excess of 10%, close to edges of certain kinematical distributions. The dependence of the results on the mass renormalization scheme, and its implication for a precise extraction of the top-quark mass, is also discussed.

Finite-width effects in unstable-particle production at hadron colliders

International Nuclear Information System (INIS)

Falgari, P.; Signer, A.; Zuerich Univ.

2013-03-01

We present a general formalism for the calculation of finite-width contributions to the differential production cross sections of unstable particles at hadron colliders. In this formalism, which employs an effective-theory description of unstable-particle production and decay, the matrix element computation is organized as a gauge-invariant expansion in powers of Γ X /m X , with Γ X and m X the width and mass of the unstable particle. This framework allows for a systematic inclusion of off-shell and non-factorizable effects whilst at the same time keeping the computational effort minimal compared to a full calculation in the complex-mass scheme. As a proof-of-concept example, we give results for an NLO calculation of top-antitop production in the q anti q partonic channel. As already found in a similar calculation of single-top production, the finite-width effects are small for the total cross section, as expected from the naive counting ∝Γ t /m t ∝1%. However, they can be sizeable, in excess of 10%, close to edges of certain kinematical distributions. The dependence of the results on the mass renormalization scheme, and its implication for a precise extraction of the top-quark mass, is also discussed.

Production of new particles in electron-positron annihilation

International Nuclear Information System (INIS)

Gilman, F.J.

1977-02-01

A number of areas are reviewed where there is important progress in the production of new particles in electron--positron annihilation, but of a more detailed quantitative nature. Charmonium states, charmed mesons, and evidence for a charged heavy lepton are covered. 50 references

8th European Conference on Rare Diseases & Orphan Products (ECRD 2016

Directory of Open Access Journals (Sweden)

Michael Schlander

2016-11-01

Daniel Lewi, Patricia Durão P10 The role of a patient organisation in driving the research agenda in a rare disease Heather Band, Andrea West P13 Expertise for rare diseases mapped Marinda J.A. Hammann, Marije C. Effing-Boele, Hanka K. Dekker P14 The hidden costs of rare diseases: a feasibility study Amy Hunter, Amy Simpson P15 FDA’s new natural history grant program: support to build a solid foundation for development of products for rare diseases Gumei Liu, Katherine Needleman, Debra Lewis, Gayatri Rao P17 Understanding the wider impact of adrenal insufficiency: patient organisation involvement in the TAIN project Amy Simpson, Amy Hunter, Martin J Whitaker P20 Bridging the gaps between medical and social care for people living with a rare disease Raquel Castro

Rare earth element recycling from waste nickel-metal hydride batteries.

Science.gov (United States)

Yang, Xiuli; Zhang, Junwei; Fang, Xihui

2014-08-30

With an increase in number of waste nickel-metal hydride batteries, and because of the importance of rare earth elements, the recycling of rare earth elements is becoming increasingly important. In this paper, we investigate the effects of temperature, hydrochloric acid concentration, and leaching time to optimize leaching conditions and determine leach kinetics. The results indicate that an increase in temperature, hydrochloric acid concentration, and leaching time enhance the leaching rate of rare earth elements. A maximum rare earth elements recovery of 95.16% was achieved at optimal leaching conditions of 70°C, solid/liquid ratio of 1:10, 20% hydrochloric acid concentration, -74μm particle size, and 100min leaching time. The experimental data were best fitted by a chemical reaction-controlled model. The activation energy was 43.98kJ/mol and the reaction order for hydrochloric acid concentration was 0.64. The kinetic equation for the leaching process was found to be: 1-(1-x)(1/3)=A/ρr0[HCl](0.64)exp-439,8008.314Tt. After leaching and filtration, by adding saturated oxalic solution to the filtrate, rare earth element oxalates were obtained. After removing impurities by adding ammonia, filtering, washing with dilute hydrochloric acid, and calcining at 810°C, a final product of 99% pure rare earth oxides was obtained. Copyright © 2014 Elsevier B.V. All rights reserved.

Particle-production mechanism in relativistic heavy-ion collisions

International Nuclear Information System (INIS)

Bush, B.W.; Nix, J.R.

1994-01-01

We discuss the production of particles in relativistic heavy-ion collisions through the mechanism of massive bremsstrahlung, in which massive mesons are emitted during rapid nucleon acceleration. This mechanism is described within the framework of classical hadrodynamics for extended nucleons, corresponding to nucleons of finite size interacting with massive meson fields. This new theory provides a natural covariant microscopic approach to relativistic heavy-ion collisions that includes automatically spacetime nonlocality and retardation, nonequilibrium phenomena, interactions among all nucleons, and particle production. Inclusion of the finite nucleon size cures the difficulties with preacceleration and runaway solutions that have plagued the classical theory of self-interacting point particles. For the soft reactions that dominate nucleon-nucleon collisions, a significant fraction of the incident center-of-mass energy is radiated through massive bremsstrahlung. In the present version of the theory, this radiated energy is in the form of neutral scalar (σ) and neutral vector (ω) mesons, which subsequently decay primarily into pions with some photons also. Additional meson fields that are known to be important from nucleon-nucleon scattering experiments should be incorporated in the future, in which case the radiated energy would also contain isovector pseudoscalar (π + , π - , π 0 ), isovector scalar (δ + , δ - , δ 0 ), isovector vector (ρ + , ρ - , ρ 0 ), and neutral pseudoscalar (η) mesons

On thermal gravitational contribution to particle production and dark matter

Directory of Open Access Journals (Sweden)

Yong Tang

2017-11-01

Full Text Available We investigate the particle production from thermal gravitational annihilation in the very early universe, which is an important contribution for particles that might not be in thermal equilibrium or/and might only have gravitational interaction, such as dark matter (DM. For particles with spin 0,1/2 and 1 we calculate the relevant cross sections through gravitational annihilation and give the analytic formulas with full mass-dependent terms. We find that DM with mass between TeV and 1016 GeV could have the relic abundance that fits the observation, with small dependence on its spin. We also discuss the effects of gravitational annihilation from inflatons. Interestingly, contributions from inflatons could be dominant and have the same power dependence on Hubble parameter of inflation as that from vacuum fluctuation. Also, fermion production from inflaton, in comparison to boson, is suppressed by its mass due to helicity selection.

Multiparticle production in particle and nuclear collisions, 2

International Nuclear Information System (INIS)

Kanki, Takeshi; Kinoshita, Kisei; Sumiyoshi, Hiroyuki; Takagi, Fujio.

1990-01-01

Multiparticle dynamics is related to many branches of particle and nuclear physics. This book provides a comprehensive review which covers the whole domain of multiparticle dynamics. The review consists of five chapters. Chapter D, which is the first chapter of this volume, is titled 'Mechanism of Fragmentation' and contains six sections dealing with 'parton densities inside hadrons', 'hadron fragmentation and quark picture', 'recombination type models', 'quark fragmentation models in soft interaction', 'diquark and its fragmentation' and 'fragmentation in string models'. Chapter E 'Diffractive Production of Hadrons' discusses 'diffractive inelastic processes of composite particles', 'diffractive processes and triple-pomeron coupling', 'properties of diffractive inelastic final states', and 'nature of pomeron'. Chapter F 'Unified Descriptions' focuses on 'general chain picture', 'dual parton model', 'Monte Carlo simulations' and 'unification of hard and soft interactions'. Chapter G, titled 'Multiparticle Production in Hadron-Nucleus Collisions and Other Nuclear Processes' and contains 11 sections. Chapter H presents conclusions. (N.K.)

Enhancement of single particle rare earth doped NaYF4: Yb, Er emission with a gold shell

International Nuclear Information System (INIS)

Li, Ling; Green, Kory; Hallen, Hans; Lim, Shuang Fang

2015-01-01

Upconversion of infrared light to visible light has important implications for bioimaging. However, the small absorption cross-section of rare earth dopants has limited the efficiency of these anti-Stokes nanomaterials. We present enhanced excitation absorption and single particle fluorescent emission of sodium yttrium fluoride, NaYF 4 : Yb, Er based upconverting nanoparticles coated with a gold nanoshell through surface plasmon resonance. The single gold-shell coated nanoparticles show enhanced absorption in the near infrared, enhanced total emission intensity, and increased green relative to red emission. We also show differences in enhancement between single and aggregated gold shell nanoparticles. The surface plasmon resonance of the gold-shell coated nanoparticle is shown to be dependent on the shell thickness. In contrast to other reported results, our single particle experimental observations are corroborated by finite element calculations that show where the green/red emission enhancement occurs, and what portion of the enhancement is due to electromagnetic effects. We find that the excitation enhancement and green/red emission ratio enhancement occurs at the corners and edges of the doped emissive core. (paper)

Phenomenology of the minimal inflation scenario: inflationary trajectories and particle production

CERN Document Server

Alvarez-Gaume, Luis; Jimenez, Raul

2012-01-01

We discuss the phenomenology of the minimal inflation scenario. We concentrate on two aspects: inflationary trajectories and particle production. Our findings can be summarized in two main results: first, that inflationary trayectories that are very flat and provide enough number of e-foldings are very natural in the scenario without fine tunning. We present a general formalism to identify attractors in multi-field inflation regardless of trajectories fulfilling the slow-roll conditions. We then explore particle production in the model and show how the inflaton naturally transmutes into the current dark matter particle, thus providing a mechanism to identify the inflaton today: it is the dark matter. One interesting feature of our model is that it provides a novel mechanism to generate particles and entropy in the universe: the filling of the Fermi sphere up to a given momentum pF due to the sea of goldstinos that are an important part of the matter generated after inflation. With this mechanism in hand we pr...

Correcting for particle size effects on plasma actuator particle image velocimetry measurements

Science.gov (United States)

Masati, A.; Sedwick, R. J.

2018-01-01

Particle image velocimetry (PIV) is often used to characterize plasma actuator flow, but particle charging effects are rarely taken into account. A parametric study was conducted to determine the effects of particle size on the velocity results of plasma actuator PIV experiments. Results showed that smaller particles more closely match air flow velocities than larger particles. The measurement uncertainty was quantified by deconvolving the particle image diameter from the correlation diameter. The true air velocity was calculated by linearly extrapolating to the zero-size particle diameter.

Role of hydrotreating products in deposition of fine particles in reactors

Energy Technology Data Exchange (ETDEWEB)

Wang, S.; Chung, K.; Gray, M.R. [University of Alberta, Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

2001-06-11

Hydrotreating reactions may affect the deposition of fine particles, which can eventually lead to reactor plugging. The deposition of fine particles from gas oil was measured in an internally recirculating reactor at 375{degree}C under hydrogen. H{sub 2}S from hydrodesulfurization would convert corrosion products to metal sulfides. Iron sulfide deposited rapidly in the packed bed because the mineral surface did not retain a stabilizing layer of asphaltenic material. Addition of water, to test the role of hydrodeoxygenation, doubled the deposition of clay particles by reducing the surface coating of organic material. Neither ammonia or quinoline had any effect on particle deposition, therefore, hydrodenitrogenation did not affect particle behavior. 16 refs., 4 figs., 3 tabs.

Production mechanism of negative pionlike particles in H2 gas discharge plasma

International Nuclear Information System (INIS)

Uramoto, Joshin.

1996-04-01

Negative pionlike and muonlike particles are produced by an electron bunch and a positive ion bunch which are generated controllably from an electron beam and a gas. Physical characteristics of the negative pionlike particles are the same with those of negative pionlike particles extracted from the H 2 gas discharge. Thus, the production mechanism in the H 2 gas discharge is deduced. (author)

Particle production in hot and dense nuclear matter

International Nuclear Information System (INIS)

Eklund, A.

1992-08-01

The charged particle production in heavy ion reactions at 200 A GeV has been studied for projectiles of 16 O and 32 S on targets of Al, Cu, Ag and Au. Up to 700 charged particles are measured in the pseudorapidity region -1.7 32 S+Au. The measured particle density is used to estimate the energy density attained in central collisions and gives a values of ≅2 GeV/fm 3 . This is close to the energy density predicted for the phase transition from hadronic matter to a quark-gluon plasma. To measure the large number of charged particle produced, finely granulated detector systems are employed. Streamer tube detectors with pad readout and large area, multi-step avalanche chambers with optical readout have been developed for the measurements. The widths of the pseudorapidity distributions of charged particles increase with decreasing centrality of the collision as well as with increasing mass of the target nucleus. This behaviour is assumed to be due to the target fragmentation. The Monte-Carlo model for nucleus-nucleus collisions, VENUS 3.11, which includes rescattering, is in reasonable agreement with the data. The yield of charged particles for central collisions of the heavy targets with 33 S is found to be proportional to the target mass, A, at target rapidity. At midrapidity it is approximately proportional to A 0.3 . At midrapidity the charged particle measurements are supplemented by measurements of the transverse energy. The dimensionless, normalized variances of the multiplicity and transverse energy distributions are, to a large extent, governed by the collision geometry. The change in the normalized variance when studying the charged particle distribution in a narrow angular region is explained as being of statistical nature. (au)

Cerium concentrate and mixed rare earth chloride by the oxidative decomposition of bastnaesite in molten sodium hydroxide

International Nuclear Information System (INIS)

Iijima, Toshio; Kato, Kazuhiro; Kuno, Toyohiko; Okuwaki, Akitsugu; Umetsu, Yoshiaki; Okabe, Taijiro

1993-01-01

Bastnaesite was treated in molten NaOH at 623-777 K for 10-60 min under atmosphere. Cerium-(III) in the ore was easily oxidized 95% or more within 30 min to give an oxidation product composed of solid solutions of CeO 2 -rich and CeO 2 -lean phases and Ce-free rare earth oxide phase. Simultaneously fluoride ion was removed 97% or more. Cerium concentrate was prepared from the oxidation product by leaching with 0.1-3 M HCl solution. The yield of cerium concentrate and the CeO 2 content reached 55-57% and 70-72%, respectively. Mixed rare earth chloride is composed of about 90% rare earth chloride and 10% alkaline earth chloride, and the contents of CeCl 3 , LaCl 3 , NdCl 3 , and PrCl 3 are 11.5, 58.5, 14.4, and 5.4%, respectively. The particle size of resulting cerium concentrate was fairly uniform and about 0.1 μm

Inclusive neutral particle production in anti pp interactions at 22.4 GeV/c

International Nuclear Information System (INIS)

Boos, E.G.; Samojlov, V.V.; Takibaev, Zh.S.

1978-01-01

The results of an analysis of inclusive production of γ(πsup(0)), Ksub(s)ysup(0), Λ, anti Λ particles in anti pp interaction at 22.4 GeV/c are presented. The total and topological inclusive cross sections of neutral particles were obtained. The charged multiplicity dependences of the mean number of πsup(0), Ksup(0)/ anti Ksup(0), Λ/ anti Λ productions were studied. The mean number of Λ/ anti Λ particles decreases with increasing charged multiplicity. The KNO scaling hypothesis for πsup(0), Ksub(s)sup(0), Λ particles was confirmed

Particle production after inflation with non-minimal derivative coupling to gravity

International Nuclear Information System (INIS)

Ema, Yohei; Jinno, Ryusuke; Nakayama, Kazunori; Mukaida, Kyohei

2015-01-01

We study cosmological evolution after inflation in models with non-minimal derivative coupling to gravity. The background dynamics is solved and particle production associated with rapidly oscillating Hubble parameter is studied in detail. In addition, production of gravitons through the non-minimal derivative coupling with the inflaton is studied. We also find that the sound speed squared of the scalar perturbation oscillates between positive and negative values when the non-minimal derivative coupling dominates over the minimal kinetic term. This may lead to an instability of this model. We point out that the particle production rates are the same as those in the Einstein gravity with the minimal kinetic term, if we require the sound speed squared is positive definite

Characterization of Spatial Impact of Particles Emitted from a Cement Material Production Facility on Outdoor Particle Deposition in the Surrounding Community.

Science.gov (United States)

Yu, Chang Ho; Fan, Zhihua Tina; McCandlish, Elizabeth; Stern, Alan H; Lioy, Paul J

2011-10-01

The objective of this study was to estimate the contribution of a facility that processes steel production slag into raw material for cement production to local outdoor particle deposition in Camden, NJ. A dry deposition sampler that can house four 37-mm quartz fiber filters was developed and used for the collection of atmospheric particle deposits. Two rounds of particle collection (3-4 weeks each) were conducted in 8-11 locations 200-800 m downwind of the facility. Background samples were concurrently collected in a remote area located ∼2 km upwind from the facility. In addition, duplicate surface wipe samples were collected side-by-side from each of the 13 locations within the same sampling area during the first deposition sampling period. One composite source material sample was also collected from a pile stored in the facility. Both the bulk of the source material and the particle deposition flux in the study area was higher (24-83 mg/m 2 ·day) than at the background sites (13-17 mg/m 2 ·day). The concentration of Ca, a major element in the cement source production material, was found to exponentially decrease with increasing downwind distance from the facility (P particle deposition. The contribution of the facility to outdoor deposited particle mass was further estimated by three independent models using the measurements obtained from this study. The estimated contributions to particle deposition in the study area were 1.8-7.4% from the regression analysis of the Ca concentration in particle deposition samples against the distance from the facility, 0-11% from the U.S. Environmental Protection Agency (EPA) Chemical Mass Balance (CMB) source-receptor model, and 7.6-13% from the EPA Industrial Source Complex Short Term (ISCST3) dispersion model using the particle-size-adjusted permit-based emissions estimates. [Box: see text].

Collision dynamics and particle production in relativistic nucleus- nucleus collisions at CERN

International Nuclear Information System (INIS)

Harris, J.W.

1990-03-01

The possibility of forming a quark-gluon plasma is the primary motivation for studying nucleus-nucleus collisions at very high energies. Various ''signatures'' for the existence of a quark-gluon plasma in these collisions have been proposed. These include an enhancement in the production of strange particles, suppression of J/Ψ production, observation of direct photons from the plasma, event-by-event fluctuations in the rapidity distributions of produced particles, and various other observables. However, the system will evolve dynamically from a pure plasma or mixed phase through expansion, cooling, hadronization and freezeout into the final state particles. Therefore, to be able to determine that a new, transient state of matter has been formed it will be necessary to understand the space-time evolution of the collision process and the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high temperatures and densities. In this talk I will review briefly the present state of our understanding of the dynamics of these collisions and, in addition, present a few recent results on particle production from the NA35 experiment at CERN. 21 refs., 5 figs

Production cross-sections for high mass particles and transverse momentum spectra

International Nuclear Information System (INIS)

Arnold, R.C.; Halzen, F.

1977-06-01

The concept of transverse-mass (msub(T)) scaling is examined. It is suggested that: (1) experimental data on pion transverse momentum (psub(T)) spectra provide a reliable guide to expectations for high mass particle production; (2) dimensional scaling, e.g. implied by quark-gluon dynamics, yields an estimate of msub(T) -4 spectra at ultra-high energies; however, stronger damping is expected at currently accessible energies; (3) values increase linearly with the produced particle mass. The results of msub(T) scaling are compared with estimates for high mass production in the context of the Drell-Yan model. (author)

Measurement of the particle production properties in ATLAS

CERN Document Server

Bruni, Alessia; The ATLAS collaboration

2017-01-01

Measurements of the particle production properties with the ATLAS detector A correct modelling of the underlying event in proton-proton collisions is important for the proper simulation of kinematic distributions of high-energy collisions. The ATLAS collaboration extended previous studies at 7 TeV with a leading track or jet or Z boson by a new study at 13 TeV, measuring the number and transverse-momentum sum of charged particles as a function of pseudorapidity and azimuthal angle in dependence of the reconstructed leading track. These measurements are sensitive to the underlying-event as well as the onset of hard emissions. The results are compared to predictions of several MC generators. A similar comparison between measurements and MC generator predictions will be shown for the strange meson content in topquark pair events. Studies of particle correlations in high-energy collisions can provide valuable insights into the detailed understanding of the space-time geometry of the hadronization region. The ATLA...

Production and global transport of Titan's sand particles

Science.gov (United States)

Barnes, Jason W.; Lorenz, Ralph D.; Radebaugh, Jani; Hayes, Alexander G.; Arnold, Karl; Chandler, Clayton

2015-06-01

Previous authors have suggested that Titan's individual sand particles form by either sintering or by lithification and erosion. We suggest two new mechanisms for the production of Titan's organic sand particles that would occur within bodies of liquid: flocculation and evaporitic precipitation. Such production mechanisms would suggest discrete sand sources in dry lakebeds. We search for such sources, but find no convincing candidates with the present Cassini Visual and Infrared Mapping Spectrometer coverage. As a result we propose that Titan's equatorial dunes may represent a single, global sand sea with west-to-east transport providing sources and sinks for sand in each interconnected basin. The sand might then be transported around Xanadu by fast-moving Barchan dune chains and/or fluvial transport in transient riverbeds. A river at the Xanadu/Shangri-La border could explain the sharp edge of the sand sea there, much like the Kuiseb River stops the Namib Sand Sea in southwest Africa on Earth. Future missions could use the composition of Titan's sands to constrain the global hydrocarbon cycle.

Fission Product Release Behavior of Individual Coated Fuel Particles for High-Temperature Gas-Cooled Reactors

International Nuclear Information System (INIS)

Minato, Kazuo; Sawa, Kazuhiro; Koya, Toshio; Tomita, Takeshi; Ishikawa, Akiyoshi; Baldwin, Charles A.; Gabbard, William Alexander; Malone, Charlie M.

2000-01-01

Postirradiation heating tests of TRISO-coated UO 2 particles at 1700 and 1800degC were performed to understand fission product release behavior at accident temperatures. The inventory measurements of the individual particles were carried out before and after the heating tests with gamma-ray spectrometry to study the behavior of the individual particles. The time-dependent release behavior of 85 Kr, 110m Ag, 134 Cs, 137 Cs, and 154 Eu were obtained with on-line measurements of fission gas release and intermittent measurements of metallic fission product release during the heating tests. The inventory measurements of the individual particles revealed that fission product release behavior of the individual particles was not uniform, and large particle-to-particle variations in the release behavior of 110m Ag, 134 Cs, 137 Cs, and 154 Eu were found. X-ray microradiography and ceramography showed that the variations could not be explained by only the presence or absence of cracks in the SiC coating layer. The SiC degradation may have been related to the variations

Azimuthal asymmetry of particle production in Au + Au collisions at 11.6 A·GeV/c

International Nuclear Information System (INIS)

Kurita, Kazuyoshi

1996-01-01

Particle production was measured by the E866 forward spectrometer. It was reported earlier in our publication that a correlation between particle ratios and the asymmetry of energy deposition in zero degree calorimeter(ZCAL) was found. To further investigate the azimuthal asymmetry analysis, the forward hodoscope (HODO) was incorporated and the correlation between the particle production and the ''reaction plane'' will be discussed. Preliminary analysis shows enhanced in- plain proton production

Advances in Automated QA/QC for TRISO Fuel Particle Production

International Nuclear Information System (INIS)

Hockey, Ronald L.; Bond, Leonard J.; Batishko, Charles R.; Gray, Joseph N.; Saurwein, John J.; Lowden, Richard A.

2004-01-01

Fuel in most Generation IV reactor designs typically encompasses billions of the TRISO particles. Present day QA/QC methods, done manually and in many cases destructively, cannot economically test a statistically significant fraction of the large number of the individual fuel particles required. Fully automated inspection technologies are essential to economical TRISO fuel particle production. A combination of in-line nondestructive (NDE) measurements employing electromagnetic induction and digital optical imaging analysis is currently under investigation and preliminary data indicate the potential for meeting the demands of this application. To calibrate high-speed NDE methods, surrogate fuel particle samples are being coated with layers containing a wide array of defect types found to degrade fuel performance and these are being characterized via high-resolution CT and digital radiographic images

Rare Decays Probing Physics Beyond the Standard Theory

CERN Document Server

Teubert, Frederic

2016-01-01

In the last 50 years we have seen how an initially ad-hoc and not widely accepted theory of the strong and electroweak interactions (Standard Theory: ST) has correctly predicted the entire accelerator based experimental observations with incredible accuracy (with the important exception of neutrino oscillation experiments). Decays of the ST particles (quarks and leptons), which are rare due to some symmetry of the theory, have played an important role in the formalism of the ST. These rare decays have been powerful tools to search for new particle interactions with the ST particles, which may not necessarily have the same symmetries. In this article, I will describe the indirect search for evidence of new physics (NP) using quark and lepton flavour changing neutral decays, which are highly suppressed within the ST, and constitute strong probes of potential new flavour structures.

An experiment on particle and jet production at midrapidity

International Nuclear Information System (INIS)

Kadija, K.; Paic, G.; Vranic, D.; Brady, F.P.; Draper, J.E.; Romero, J.L.; Carroll, J.; Ghazikhanian, V.; Gulmez, E.; Igo, G.J.; Trentalange, S.; Whitten, C. Jr.; Cherney, M.; Heck, W.; Renfordt, R.E.; Roehrich, D.; Stock, R.; Stroebele, H.; Wenig, S.; Hallman, T.; Madansky, L.; Anderson, B.; Keane, D.; Madey, R.; Watson, J.; Bieser, F.; Bloomer, M.A.; Cebra, D.; Christie, W.; Friedlander, E.; Greiner, D.; Gruhn, C.; Harris, J.W.; Huang, H.; Jacobs, P.; Lindstrom, P.; Matis, H.; McParland, C.; Naudet, C.; Odyniec, G.; Olson, D.; Poskanzer, A.M.; Rai, G.; Rasmussen, J.; Ritter, H.G.; Schambach, J.; Schroeder, L.S.; Seidl, P.A.; Symons, T.J.M.; Tonse, S.; Wieman, H.; Carmony, D.D.; Choi, Y.; Hirsch, A.; Hjort, E.; Porile, N.; Scharenberg, R.P.; Srivastava, B.; Tincknell, M.L.; Chacon, A.D.; Wolf, K.L.; Dominik, W.; Gazdzicki, M.; Braithwaite, W.J.; Cramer, J.G.; Prindle, D.; Trainor, T.A.; Breskin, A.; Chechik, R.; Fraenkel, Z.; Shor, A.; Tserruya, I.

1990-09-01

The aim of this experiment is to search for signatures of Quark-Gluon Plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. Since there is no single accepted signature for the QGP, it is essential to use a flexible detection system at RHIC that can simultaneously measure many experimental observables. The experiment will utilize two aspects of hadron production that are fundamentally new at RHIC: correlations between global observables on an event-by-event basis and the use of hard scattering of partons as a probe of the properties of high density nuclear matter. The event-by-event measurement of global observables--such as temperature, flavor composition, collision geometry, reaction dynamics, and energy or entropy density fluctuations--is possible because of the very high charged particle densities. Event-by-event fluctuations are expected in the vicinity of a phase change, so experiments must be sensitive to threshold-like features in experimental observables as a function of energy density. Full azimuthal coverage with good particle identification and continuous tracking is required to perform these measurements at momenta where the particle yields are maximal. Measurable jet yields at RHIC will allow investigations of hard QCD processes via both highly segmented calorimetry and high p t single particle measurements in a tracking system. A systematic study of particle and jet production will be carried out over a range of colliding nuclei from p + p through Au + Au, over a range of impact parameters from peripheral to central, and over the range of energies available at RHIC. Correlations between observables will be made on an event-by-event basis to isolate potentially interesting event types. In particular, correlations of jet properties with full event reconstruction may lead to some surprising new physics

Feasibility Study for Installing Machine in Production Line to Avoid Particle Contamination Based on CFD Simulation

Science.gov (United States)

Khaokom, Adisorn; Thongsri, Jatuporn

2017-10-01

Ventilation system inside production line for electronic component production needs to meet the factory standard. Because it can eliminate small particles which may cause of human or machine in production as well as it can distribute the circulating air temperature uniformly. CFD is used in this research in order to study the feasibility and plan for machine layout in production line before actual installation. The simulation shows the airflow in every area inside production line. From simulation with releasing the particles from human and machine is found that this ventilation system generates airflow that makes most particles float out of the machines and no particle downs to the conveyor, it results to contamination. In addition, the simulation also shows the range of 19-26 °C air temperature that meets the factory standard. The results of this research are the parts of the data to renovate the production line to get more efficiency and proper on the production.

Research on in-pile release of fission products from coated particle fuels

International Nuclear Information System (INIS)

Fukuda, K.; Iwamoto, K.

1985-01-01

Coated particle fuels fabricated in accordance with VHTR (Very High Temperature gas-cooled Reactor) fuel design have been irradiated by both capsules and an in-pile gas loop (OGL-1), and data on the fission products release under irradiation were obtained for loose coated particles, fuel compacts and fuel rods in the temperature range between 800 deg. C and 1600 deg. C. For the fission gases, temperature- and time dependences of the fractional release(R/B) were measured. Relation between release and failure fraction of the coated particles was elucidated on the VHTR reference fuels. Also measured was tritium concentration in the helium coolant of OGL-1. In-pile release behavior of the metallic fission products was studied by measuring the activities of the fission products adsorbed in the graphite sleeves of the OGL-1 fuel rods and the graphite fuel container of the sweep gas capsules in the PIE. Investigation on palladium interaction with SiC coating layer was included. (author)

Afganistan and rare earths

Directory of Open Access Journals (Sweden)

Emilian M. Dobrescu

2013-05-01

Full Text Available On our planet, over a quarter of new technologies for the economic production of industrial goods, are using rare earths, which are also called critical minerals and industries that rely on these precious items being worth of an estimated nearly five trillion dollars, or 5 percent of world gross domestic product. In the near future, competition will increase for the control of rare earth minerals embedded in high-tech products. Rare minerals are in the twenty-first century what oil accounted for in the twentieth century and coal in the nineteenth century: the engine of a new industrial revolution. Future energy will be produced increasingly by more sophisticated technological equipment based not just on steel and concrete, but incorporating significant quantities of metals and rare earths. Widespread application of these technologies will result in an exponential increase in demand for such minerals, and what is worrying is that minerals of this type are almost nowhere to be found in Europe and in other industrialized countries in the world, such as U.S. and Japan, but only in some Asian countries, like China and Afghanistan.

Entropy production by Q-ball decay for diluting long-lived charged particles

International Nuclear Information System (INIS)

Kasuya, S.

2007-09-01

The cosmic abundance of a long-lived charged particle such as a stau is tightly constrained by the catalyzed big bang nucleosynthesis. One of the ways to evade the constraints is to dilute those particles by a huge entropy production. We evaluate the dilution factor in a case that non-relativistic matter dominates the energy density of the universe and decays with large entropy production. We find that large Q balls can do the job, which is naturally produced in the gauge-mediated supersymmetry breaking scenario. (orig.)

Pollen source and resource limitation to fruit production in the rare species Eremosparton songoricum (Fabaceae)

Science.gov (United States)

Eremosparton songoricum (Litv.) Vass. is a rare, central Asian desert species which shows lower fruit set and seed set (<16%) than most hermaphroditic species. We hypothesized that fruit production was limited by pollen and resources. To evaluate potential fruit abortion due to pollen limitation, su...

Products and kinetics of the heterogeneous reaction of suspended vinclozolin particles with ozone.

Science.gov (United States)

Gan, Jie; Yang, Bo; Zhang, Yang; Shu, Xi; Liu, Changgeng; Shu, Jinian

2010-11-25

Vinclozolin is a widely used fungicide that can be released into the atmosphere via application and volatilization. This paper reports an experimental investigation on the heterogeneous ozonation of vinclozolin particles. The ozonation of vinclozolin adsorbed on azelaic acid particles under pseudo-first-order conditions is investigated online with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The ozonation products are analyzed with a combination of VUV-ATOFMS and GC/MS. Two main ozonation products are observed. The formation of the ozonation products results from addition of O(3) on the C-C double bond of the vinyl group. The heterogeneous reactive rate constant of vinclozolin particles under room temperature is (2.4 ± 0.4) × 10(-17) cm(3) molecules(-1) s(-1), with a corresponding lifetime at 100 ppbv O(3) of 4.3 ± 0.7 h, which is almost comparable with the estimated lifetime due to the reaction with atmospheric OH radicals (∼1.7 h). The reactive uptake coefficient for O(3) on vinclozolin particles is (6.1 ± 1.0) × 10(-4).

Comprehensive Analysis of the Gas- and Particle-Phase Products of VOC Oxidation

Science.gov (United States)

Bakker-Arkema, J.; Ziemann, P. J.

2017-12-01

Controlled environmental chamber studies are important for determining atmospheric reaction mechanisms and gas and aerosol products formed in the oxidation of volatile organic compounds (VOCs). Such information is necessary for developing detailed chemical models for use in predicting the atmospheric fate of VOCs and also secondary organic aerosol (SOA) formation. However, complete characterization of atmospheric oxidation reactions, including gas- and particle-phase product yields, and reaction branching ratios, are difficult to achieve. In this work, we investigated the reactions of terminal and internal alkenes with OH radicals in the presence of NOx in an attempt to fully characterize the chemistry of these systems while minimizing and accounting for the inherent uncertainties associated with environmental chamber experiments. Gas-phase products (aldehydes formed by alkoxy radical decomposition) and particle-phase products (alkyl nitrates, β-hydroxynitrates, dihydroxynitrates, 1,4-hydroxynitrates, 1,4-hydroxycarbonyls, and dihydroxycarbonyls) formed through pathways involving addition of OH to the C=C double bond as well as H-atom abstraction were identified and quantified using a suite of analytical techniques. Particle-phase products were analyzed in real time with a thermal desorption particle beam mass spectrometer; and off-line by collection onto filters, extraction, and subsequent analysis of functional groups by derivatization-spectrophotometric methods developed in our lab. Derivatized products were also separated by liquid chromatography for molecular quantitation by UV absorbance and identification using chemical ionization-ion trap mass spectrometry. Gas phase aldehydes were analyzed off-line by collection onto Tenax and a 5-channel denuder with subsequent analysis by gas chromatography, or by collection onto DNPH-coated cartridges and subsequent analysis by liquid chromatography. The full product identification and quantitation, with careful

Leading Particle Production in Light Flavour Jets

CERN Document Server

Abbiendi, G; Åkesson, P F; Alexander, Gideon; Allison, J; Anderson, K J; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Bailey, I; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Davis, R; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Rembser, C; Rick, Hartmut; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

2000-01-01

The energy distribution and type of the particle with the highest momentum in quark jets are determined for each of the five quark flavours making only minimal model assumptions. The analysis is based on a large statistics sample of hadronic Z0 decays collected with the OPAL detector at the LEP e+e- collider. These results provide a basis for future studies of light flavour production at other centre-of-mass energies. We use our results to study the hadronisation mechanism in light flavour jets and compare the data to the QCD models JETSET and HERWIG. Within the JETSET model we also directly determine the suppression of strange quarks to be gamma_s=0.422+-0.049 (stat.)+-0.059 (syst.) by comparing the production of charged and neutral kaons in strange and non-strange light quark events. Finally we study the features of baryon production.

Study of particle production in hadron-nucleus interactions for neutrino experiments

CERN Document Server

Palczewski, Tomasz Jan

The dissertation presents a study of hadron product ion in the NA61/SHINE large acceptance spectrometer at CERN SPS. The differential cross se ctions were obtained for the production of negatively charged pions, neutral Kaons, and Lam bdas from the proton-Carbon interactions at 31 GeV/c. Methods of particle yields extraction from proton Carbon interactions were developed. An analysis chain of global correction m ethod (h- method) was established for the thin carbon target and as well for T2K replica targ et and compared to the results obtained with full particle identification. The h- method permits to cover larger phase space region not otherwise accessible. In addition, a full chain of V 0 analysis was prepared to obtain neutral Kaon and Lambda results in polar angle and momentum variables (p, θ ). Results on the differential production cross sections and mean mul tiplicities in production processes for negatively charge...

Intrinsic charm and charmed particle production at Serpukhov energies

International Nuclear Information System (INIS)

Zmushko, V.V.

1995-01-01

This paper presents a study of the charmed particle production by protons on nuclei in the framework of two-component model at the Serpukhov energies. This model combines the leading-twist QCD and intrinsic charm contributions. It is shown that both contributions are comparable at 70 GeV energy of a proton, which makes possible the testing of the intrinsic charm predictions: the asymmetry between the leading and non-leading charm production and the A dependence of charm production. The asymmetry for D-bar/D mesons and Λ c + /Λ c - baryons and the cross section ratios for different nuclei are estimated [ru

Kinetic analysis of rare gas metastable production and optically pumped Xe lasers

Science.gov (United States)

Demyanov, A. V.; Kochetov, I. V.; Mikheyev, P. A.; Azyazov, V. N.; Heaven, M. C.

2018-01-01

Optically pumped all-rare-gas lasers use metastable rare gas atoms as the lasing species in mixtures with He or Ar buffer gas. The metastables are generated in a glow discharge, and we report model calculations for the optimal production of Ne*, Ar*, Kr* and Xe*. Discharge efficiency was estimated by solving the Boltzmann equation. Laser efficiency, gain and output power of the CW optically pumped Xe laser were assessed as functions of heavier rare gas content, pressure, optical pump intensity and the optical path length. It was found that, for efficient operation the heavier rare gas content has to be of the order of one percent or less, and the total pressure—in the range 0.3-1.5 atm. Output power and specific discharge power increase approximately linearly with pump intensity over the output range from 300-500 W cm-2. Ternary mixtures Xe:Ar:He were found to be the most promising. Total laser efficiency was found to be nearly the same for pumping the 2p8 or 2p9 state, reaching 61%-70% for a pump intensity of ~720 W cm-2 when the Xe fraction was in the range 0.001 ÷ 0.01 and Ar fraction—0.1 ÷ 0.5. However, when the 2p8 state was pumped, the maximum total efficiency occurred at larger pressures than for pumping of the 2p9 state. The discharge power density required to sustain a sufficient Xe* number density was in the range of tens of watts per cubic centimeter for 50% Ar in the mixture.

Fission Product Release Behavior of Individual Coated Fuel Particles for High-Temperature Gas-Cooled Reactors

Energy Technology Data Exchange (ETDEWEB)

Minato, Kazuo [Japan Atomic Energy Research Institute (Japan); Sawa, Kazuhiro [Japan Atomic Energy Research Institute (Japan); Koya, Toshio [Japan Atomic Energy Research Institute (Japan); Tomita, Takeshi [Japan Atomic Energy Research Institute (Japan); Ishikawa, Akiyoshi [Japan Atomic Energy Research Institute (Japan); Baldwin, Charles A; Gabbard, William Alexander [Oak Ridge National Laboratory (United States); Malone, Charlie M [Oak Ridge National Laboratory (United States)

2000-07-15

Postirradiation heating tests of TRISO-coated UO{sub 2} particles at 1700 and 1800degC were performed to understand fission product release behavior at accident temperatures. The inventory measurements of the individual particles were carried out before and after the heating tests with gamma-ray spectrometry to study the behavior of the individual particles. The time-dependent release behavior of {sup 85}Kr, {sup 110m}Ag, {sup 134}Cs, {sup 137}Cs, and {sup 154}Eu were obtained with on-line measurements of fission gas release and intermittent measurements of metallic fission product release during the heating tests. The inventory measurements of the individual particles revealed that fission product release behavior of the individual particles was not uniform, and large particle-to-particle variations in the release behavior of {sup 110m}Ag, {sup 134}Cs, {sup 137}Cs, and {sup 154}Eu were found. X-ray microradiography and ceramography showed that the variations could not be explained by only the presence or absence of cracks in the SiC coating layer. The SiC degradation may have been related to the variations.

Structure functions and particle production in the cumulative region: two different exponentials

International Nuclear Information System (INIS)

Braun, M.; Vechernin, V.

1997-01-01

In the framework of the recently proposed (QCD-based parton model for the cumulative phenomena in the interactions with nuclei two mechanisms for particle production, direct and spectator ones, are analyzed. It is shown that due to final-state interactions the leading terms of the direct mechanism contribution are cancelled and the spectator mechanism is the dominant one. It leads to a smaller slope of the cumulative particle production rates compared to the slope of the nuclear structure function in the cumulative region x ≥ 1, in agreement with the recent experimental data

Study of strange particle production by neutral currents induced by 1 and 12 GeV neutrinos and antineutrinos

International Nuclear Information System (INIS)

Francois, T.L.B.

1977-01-01

Strange particles production by weak neutral currents was experimentally studied. The first result is a direct confirmation that neutral currents conserve strangeness (by an upper limit on ΔS=-1 production). The two other results, production rate of strange neutral particles and ratio of strange particles production for antineutrinos and neutrinos, prove that these particles are mainly produced in the final hadronic state rather than on strange sea-quarks and give an upper limit on the rate of this type of quark in the nucleon [fr

Pair production of Dirac particles in a d + 1-dimensional noncommutative space-time

Energy Technology Data Exchange (ETDEWEB)

Ousmane Samary, Dine [Perimeter Institute for Theoretical Physics, Waterloo, ON (Canada); University of Abomey-Calavi, International Chair in Mathematical Physics and Applications (ICMPA-UNESCO Chair), Cotonou (Benin); N' Dolo, Emanonfi Elias; Hounkonnou, Mahouton Norbert [University of Abomey-Calavi, International Chair in Mathematical Physics and Applications (ICMPA-UNESCO Chair), Cotonou (Benin)

2014-11-15

This work addresses the computation of the probability of fermionic particle pair production in d + 1-dimensional noncommutative Moyal space. Using Seiberg-Witten maps, which establish relations between noncommutative and commutative field variables, up to the first order in the noncommutative parameter θ, we derive the probability density of vacuum-vacuum pair production of Dirac particles. The cases of constant electromagnetic, alternating time-dependent, and space-dependent electric fields are considered and discussed. (orig.)

Lectures on rare B decays

International Nuclear Information System (INIS)

Masiero, A.

1989-01-01

This paper provides a pedagogical presentation of the class of the rare charmless B decays with strange particles in the final state. These processes involve the flavour changing neutral current transition b → s and, thus, they are GIM suppresses. They constitute a specially promising ground to test the Standard Model and the possible presence of new physics beyond it. In particular I show that the radiative decays b → s + π and b → s + g are priviledged places to look for large supersymmetric enhancements. The author reviews both the present experimental and theoretical situations in this field and point out the challenges that we have to meet in the 90's to have rare B physics play a role comparable to that of rare K physics

Magnetic nanosized rare earth iron garnets R_3Fe_5O_1_2: Sol–gel fabrication, characterization and reinspection

International Nuclear Information System (INIS)

Opuchovic, Olga; Kareiva, Aivaras; Mazeika, Kestutis; Baltrunas, Dalis

2017-01-01

The magnetic nanosized rare earth iron garnets (R_3Fe_5O_1_2, where R=Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were prepared by an aqueous sol–gel method. Herein we present, that all these garnets can be obtained by this effective synthesis method simply by changing the temperature of the final annealing. It was also demonstrated, that a different annealing temperature leads to a different particle size distribution of the final product. The SEM analysis results revealed that the smallest particles were formed in the range of 75–130 nm. The phase purity and structure of the rare earth iron garnets were estimated using XRD analysis and Mössbauer spectroscopy. Magnetic properties were determined by magnetization measurements. The relation between the particle size, composition and magnetic properties of the sol-gel derived garnets were also discussed in this study. - Highlights: • First time series of R_3Fe_5O_1_2 (R=from Sm to Lu) are prepared by sol–gel process. • Different sintering temperature leads to the different particle size distribution. • Correlation between microstructure, composition and magnetic properties is shown.

Universal behavior of charged particle production in heavy ion collisions at RHIC energies

Science.gov (United States)

Steinberg, Peter A.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Ballintijn, M.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.; Phobos Collaboration

2003-04-01

The PHOBOS experiment at RHIC has measured the multiplicity of primary charged particles as a function of centrality and pseudorapidity in Au+Au collisions at √ SNN = 19.6, 130 and 200 GeV. Two kinds of universal behavior are observed in charged particle production in heavy ion collisions. The first is that forward particle production, over a range of energies, follows a universal limiting curve with a non-trivial centrality dependence. The second arises from comparisons with pp/ overlinepp and e +e - data. / in nuclear collisions at high energy scales with √ s in a similar way as Nch in e +e - collisions and has a very weak centrality dependence. This feature may be related to a reduction in the leading particle effect due to the multiple collisions suffered per participant in heavy ion collisions.

Direct search for pair production of heavy stable charged particles in Z decays

International Nuclear Information System (INIS)

Soderstrom, E.; McKenna, J.A.; Abrams, G.S.; Adolphsen, C.E.; Averill, D.; Ballam, J.; Barish, B.C.; Barklow, T.; Barnett, B.A.; Bartelt, J.; Bethke, S.; Blockus, D.; Bonvicini, G.; Boyarski, A.; Brabson, B.; Breakstone, A.; Bulos, F.; Burchat, P.R.; Burke, D.L.; Cence, R.J.; Chapman, J.; Chmeissani, M.; Cords, D.; Coupal, D.P.; Dauncey, P.; DeStaebler, H.C.; Dorfan, D.E.; Dorfan, J.M.; Drewer, D.C.; Elia, R.; Feldman, G.J.; Fernandes, D.; Field, R.C.; Ford, W.T.; Fordham, C.; Frey, R.; Fujino, D.; Gan, K.K.; Gero, E.; Gidal, G.; Glanzman, T.; Goldhaber, G.; Gomez Cadenas, J.J.; Gratta, G.; Grindhammer, G.; Grosse-Wiesmann, P.; Hanson, G.; Harr, R.; Harral, B.; Harris, F.A.; Hawkes, C.M.; Hayes, K.; Hearty, C.; Heusch, C.A.; Hildreth, M.D.; Himel, T.; Hinshaw, D.A.; Hong, S.J.; Hutchinson, D.; Hylen, J.; Innes, W.R.; Jacobsen, R.G.; Jaros, J.A.; Jung, C.K.; Kadyk, J.A.; Kent, J.; King, M.; Koetke, D.S.; Komamiya, S.; Koska, W.; Kowalski, L.A.; Kozanecki, W.; Kral, J.F.; Kuhlen, M.; Labarga, L.; Lankford, A.J.; Larsen, R.R.; Le Diberder, F.; Levi, M.E.; Litke, A.M.; Lou, X.C.; Lueth, V.; Matthews, J.A.J.; Mattison, T.; Milliken, B.D.; Moffeit, K.C.; Munger, C.T.; Murray, W.N.; Nash, J.; Ogren, H.; O'Shaughnessy, K.F.; Parker, S.I.; Peck, C.; Perl, M.L.; Petradza, M.; Pitthan, R.; Porter, F.C.; Rankin, P.; Riles, K.; Rouse, F.R.; Rust, D.R.; Sadrozinski, H.F.W.; Schaad, M.W.; Schumm, B.A.; Seiden, A.; Smith, J.G.; Snyder, A.; Stoker, D.P.; Stroynowski, R.; Swartz, M.; Thun, R.; Trilling, G.H.; Van Kooten, R.; Voruganti, P.; Wagner, S.R.; Watson, S.; Weber, P.; Weinstein, A.J.; Weir, A.J.; Wicklund, E.; Woods, M.; Wu, D.Y.; Yurko, M.; Zaccardelli, C.; von Zanthie, C.

1990-01-01

A search for pair production of stable charged particles from Z decay has been performed with the Mark II detector at the SLAC Linear Collider. Particle masses are determined from momentum, ionization energy loss, and time-of-flight measurements. A limit excluding pair production of stable fourth-generation charged leptons and stable mirror fermions with masses between the muon mass and 36.3 GeV/c 2 is set at the 95% confidence level. Pair production of stable supersymmetric scalar leptons with masses between the muon mass and 32.6 GeV/c 2 is also excluded

Impact-parameter dependence of the electromagnetic particle production in ultrarelativistic heavy-ion collisions

International Nuclear Information System (INIS)

Vidovic, M.; Greiner, M.; Best, C.; Soff, G.

1992-08-01

The cross section for the electromagentic production of different particles in heavy-ion collision is derived within the external field approach. The underlying assumption leading to the equivalent photon method is that the transverse components of the virtual photon momenta are small compared to their longitudinal components. Introducing polarized photon-fusion cross sections, it is possible to generalize the equivalent photon method to describe the impact- parameter dependence of the particle production. The impact- parameter dependent production of scalar and pseudoscalar (spin 0) bosons, charged (spin 0) boson pairs and fermion pairs is discussed in general. (orig.)

Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers

International Nuclear Information System (INIS)

Fowler, W.B.

1989-01-01

Proton beams, from the 1GeV Cosmotron accelerator at Brookhaven, were used in the 1950s to produce strange particles. One big leap forward technologically was the development of the diffusion cloud chamber which made detecting particle tracks more accurate and sensitive. A large co-operative team worked on its development. By the mid 1950s enough tracks had been observed to show the associated production of strange particles. It was the same Brookhaven workers who developed the eighty-inch hydrogen bubble chamber which took the first photograph of the long predicted omega minus particle at the end of the decade. (UK)

The Production of FRW Universe and Decay to Particles in Multiverse

Science.gov (United States)

Ghaffary, Tooraj

2017-09-01

In this study, first, it will be shown that as the Hubble parameter, " H", increases the production cross section for closed and flat Universes increases rapidly at smaller values of " H" and becomes constant for higher values of " H". However in the case of open Universe, the production cross section has been encountered a singularity. Before this singularity, as the H parameter increases, the cross section increases, for smaller H, ( H < 2.5), exhibits a turn-over at moderate values of H, (2.5 < H < 3.5), decreases for larger amount of H After that and for a special value of H, the cross section has been encountered with a singularity. Although the cross section cannot be defined at this singularity but before and after this point, it is certainly equal to zero. After this singularity, the cross section increases rapidly, when H increases. It is shown that if the production cross section of Universe happens before this singularity, it can't achieve to higher values of Hubble parameter after singularity. More over if the production cross section of Universe situates after the singularity, it won't get access to values of Hubble parameter less than the singularity. After that the thermal distribution for particles inside the FRW Universes are obtained. It is found that a large amount of particles are produced near apparent horizon due to their variety in their energy and their probabilities. Finally, comparing the particle production cross sections for flat, closed and open Universes, it is concluded that as the value of k increases, the cross section decreases.

Rare Z boson decays to a hidden sector

Science.gov (United States)

Blinov, Nikita; Izaguirre, Eder; Shuve, Brian

2018-01-01

We demonstrate that rare decays of the Standard Model Z boson can be used to discover and characterize the nature of new hidden-sector particles. We propose new searches for these particles in soft, high-multiplicity leptonic final states at the Large Hadron Collider. The proposed searches are sensitive to low-mass particles produced in Z decays, and we argue that these striking signatures can shed light on the hidden-sector couplings and mechanism for mass generation.

Rare earth element recycling from waste nickel-metal hydride batteries

International Nuclear Information System (INIS)

Yang, Xiuli; Zhang, Junwei; Fang, Xihui

2014-01-01

Highlights: • Leaching kinetics of REEs has rarely been reported. • A new method, including hydrochloric acid leaching and oxalic acid precipitation, was proposed. • REEs recovery rate of 95.16% and pure rare earth oxides of 99% were obtained. • Leaching process was controlled by chemical reaction. • The kinetic equation was determined. - Abstract: With an increase in number of waste nickel-metal hydride batteries, and because of the importance of rare earth elements, the recycling of rare earth elements is becoming increasingly important. In this paper, we investigate the effects of temperature, hydrochloric acid concentration, and leaching time to optimize leaching conditions and determine leach kinetics. The results indicate that an increase in temperature, hydrochloric acid concentration, and leaching time enhance the leaching rate of rare earth elements. A maximum rare earth elements recovery of 95.16% was achieved at optimal leaching conditions of 70 °C, solid/liquid ratio of 1:10, 20% hydrochloric acid concentration, −74 μm particle size, and 100 min leaching time. The experimental data were best fitted by a chemical reaction-controlled model. The activation energy was 43.98 kJ/mol and the reaction order for hydrochloric acid concentration was 0.64. The kinetic equation for the leaching process was found to be: 1−(1−x) 1/3 =A/ρr 0 [HCl] 0.64 exp((−439,800)/(8.314T) )t. After leaching and filtration, by adding saturated oxalic solution to the filtrate, rare earth element oxalates were obtained. After removing impurities by adding ammonia, filtering, washing with dilute hydrochloric acid, and calcining at 810 °C, a final product of 99% pure rare earth oxides was obtained

Simultaneous Polymerization and Polypeptide Particle Production via Reactive Spray-Drying.

Science.gov (United States)

Glavas, Lidija; Odelius, Karin; Albertsson, Ann-Christine

2016-09-12

A method for producing polypeptide particles via in situ polymerization of N-carboxyanhydrides during spray-drying has been developed. This method was enabled by the development of a fast and robust synthetic pathway to polypeptides using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an initiator for the ring-opening polymerization of N-carboxyanhydrides. The polymerizations finished within 5 s and proved to be very tolerant toward impurities such as amino acid salts and water. The formed particles were prepared by mixing the monomer, N-carboxyanhydride of l-glutamic acid benzyl ester (NCAGlu) and the initiator (DBU) during the atomization process in the spray-dryer and were spherical with a size of ∼1 μm. This method combines two steps; making it a straightforward process that facilitates the production of polypeptide particles. Hence, it furthers the use of spray-drying and polypeptide particles in the pharmaceutical industry.

Study of diffusion processes in pumpkin particles during candied fruits production

Directory of Open Access Journals (Sweden)

V. Atamanyuk

2017-12-01

Full Text Available The production of candied fruits is a priority development area of the food industry. The basic process in candied fruits production is diffusion of sugar syrup into vegetable raw material. Kinetics of the diffusion processes depends on sucrose concentration, medium temperature, particles size and internal structure of the fruits.The experiments to determine the factors influencing the diffusion processes were carried out using the installation designed by the authors; the experimental dependences of sucrose concentration change in pumpkin candied fruits on time have been determined at temperatures of 20, 40, 60 and 80°C. Cell sizes and diameter of pores between the cells in raw and blanched pumpkin have been determined. This makes it possible to determine the internal porosity of the pumpkin particle, the value of which determines the coefficient of mass transfer.On the basis of the experiments we derived the dependence, allowing to determine the mass transfer coefficients for sucrose molecules in blanched pumpkin fruits within the temperatures corresponding to the quality of the finished product. The experimental studies and the chosen mathematical model allow us to calculate the change in sucrose concentration in the pumpkin fruits in time at different temperatures and to determine the time required for the candied fruits to reach the equilibrium concentration. Also, the coefficients not depending on temperature, but depending only on the shape of the particles being saturated with sugar syrup, have been determined using the kinetic model of diffusion processes. The obtained theoretical dependences are in good agreement with the experimental data and substantiate the expediency of the chosen temperature and concentration ranges. The designed installation, the obtained experimental and theoretical dependences, and the calculated coefficients allow to create an intensive sucrose diffusion process in pumpkin particles during pumpkin candied

V0 particle production studies at LHCb

CERN Multimedia

Knecht, M

2009-01-01

Although QCD is firmly established as the fundamental theory of strong interactions, the fragmentation process from partons into hadrons is still poorly understood. Phenomenological models tuned to Tevatron data show significant differences when extrapolated to LHC energies. The hadronization process can be probed at the LHC by studying V0 production, i.e. the production of KS mesons and Lambda hyperons. The LHCb experiment, with a rapidity range complementary to that of the other LHC detectors, offers a particularly interesting environment, covering the forward region where the existing models are very tunable but lack predictive power. The first 100 millions minimum bias events at LHCb will already provide a high-statistics and high-purity V0 sample. Measurements will include differential cross sections and production ratios for different strange particles as a function of rapidity and transverse momentum. The analysis can naturally be extended to cover heavier hyperons as well, and eventually lead, w...

New physics from rare beauty

CERN Document Server

AUTHOR|(CDS)2077817; Hulsbergen, W

2010-01-01

The Standard Model (SM) of particle physics offers a framework to describe sub-nuclear physics processes. Despite its success in describing a large variety of sub-nuclear phenomena, the SM leaves open a number of questions and is regarded by particle physicists as an effective quantum field theory, rather than a credible candidate to be the ultimate theory of fundamental interactions. Particle physicists postulates the existence of New Physics (NP) beyond the SM. This would result into the creation of new particles that could then be observed at higher energy regimes than hitherto explored. These particles could be observed directly or indirectly, through their contributions to quantum loops. A promising ground to look for NP are the Flavor Changing Neutral Currents (FCNCs). Due to its precise theoretical prediction, one of the most promising rare decay channel is the $B_s$ meson decaying into two muons. In this dissertation the strategy for an early measurement of the $B_{s} \\rightarrow \\mu \\mu$ branching ra...

Isospin conservation in many-particle production

International Nuclear Information System (INIS)

Reinders, L.J.

1976-01-01

Exact isospin conservation is incorporated into independent pion emission models at high energies. A multipion wave function is constructed which is an eigen state of the isospin operators I 2 and I 3 , with the only restriction being that the wave function is completely symmetric in all momentum variables. In this way isospin conservation can account for the observed broadening of the changed particle distribution, but not the positive changed-neutral correlation for pp and π + p inelastic scattering. The author shows that these difficulties can be overcome by the introduction of clusters. Using the generating function technique a general formalism is given for the production of isospin-zero and isospin-one clusters. In the simplest case of the uncorrelated production of clusters and their subsequent isotropic decay, the topological cross-sections for proton-proton scattering could be fitted fairly well resulting also in a possitive changed-neutral correlation. The number of clusters is approximately constant in an energy range between 110 and 400 GeV

Study of conditions of production and characterization of noble metal micro-particles suspensions

International Nuclear Information System (INIS)

Malabre, Catherine

1983-01-01

As the production and identification of metal micro-particle suspensions are some aspects of issues related to nuclear fuel reprocessing, this research thesis reports the use of ruthenium, molybdenum, niobium, palladium and rhodium (fission metals) to generate such micro-particles. They are produced by erosion of two electrodes between which occurs an electric arc discharge in aqueous media. Different analytic methods are developed to determine the characteristics of so-produced colloidal solutions. A granulometry study is performed by transmission electronic microscopy, light quasi-elastic scattering, and turbidimetry associated to centrifugation. This has lead to the production of steady micro-particle suspensions which have been used in a first set of industrial trials [fr

Neutral strange particle production in neutrino and antineutrino charged-current interactions on neon

Science.gov (United States)

Deprospo, D.; Kalelkar, M.; Aderholz, M.; Akbari, H.; Allport, P. P.; Ammosov, V. V.; Andryakov, A.; Asratyan, A.; Badyal, S. K.; Ballagh, H. C.; Baton, J.-P.; Barth, M.; Bingham, H. H.; Brucker, E. B.; Burnstein, R. A.; Cence, R. J.; Chatterjee, T. K.; Clayton, E. F.; Corrigan, G.; Coutures, C.; Devanand; de Wolf, E.; Ermolov, P.; Erofeeva, I.; Faulkner, P. J.; Foeth, H.; Fretter, W. B.; Gapienko, G.; Gupta, V. K.; Hanlon, J.; Harigel, G.; Harris, F. A.; Ivanilov, A.; Jabiol, M.; Jacques, P.; Jain, V.; Jones, G. T.; Jones, M. D.; Kafka, T.; Kaftanov, V.; Kasper, P.; Kobrin, V.; Kohli, J. M.; Koller, E. L.; Korablev, V.; Kubantsev, M.; Lauko, M.; Lukina, O.; Lys, J. E.; Lyutov, S.; Marage, P.; Milburn, R. H.; Mittra, I. S.; Mobayyen, M. M.; Moreels, J.; Morrison, D. R.; Moskalev, V.; Murzin, V.; Myatt, G.; Nailor, P.; Naon, R.; Napier, A.; Neveu, M.; Passmore, D.; Peters, M. W.; Peterson, V. Z.; Plano, R.; Rao, N. K.; Rubin, H. A.; Ryasakov, S.; Sacton, J.; Sambyal, S. S.; Schmitz, N.; Schneps, J.; Singh, J. B.; Singh, S.; Sivoklokov, S.; Smart, W.; Smirnova, L.; Stamer, P.; Varvell, K. E.; Verluyten, L.; Wachsmuth, H.; Wainstein, S.; Willocq, S.; Yost, G. P.

1994-12-01

A study has been made of neutral strange particle production in νμNe and ν¯μNe charged-current interactions at a higher energy than any previous study. The experiment was done at the Fermilab Tevatron using the 15-ft. bubble chamber, and the data sample consists of 814(154) observed neutral strange particles from 6263(1115) ν(ν¯) charged-current events. For the ν beam (average event energy =150 GeV), the average multiplicities per charged-current event have been measured to be 0.408+/-0.048 for K0, 0.127+/-0.014 for Λ, and 0.015+/-0.005 for Λ¯, which are significantly greater than for lower-energy experiments. The dependence of rates on kinematical variables has been measured, and shows that both K0 and Λ production increase strongly with Eν, W2, Q2, and yB. Compared to lower-energy experiments, single-particle distributions indicate that there is much more K0 production for xF>-0.2, and the enhanced Λ production spans most of the kinematic region. Λ¯ production is mostly in the region ||xF||-0.2 there is a significant excess of Λ production over the model's prediction. The Λ hyperons are found to be polarized in the production plane.

Numerical and analytical simulation of the production process of ZrO2 hollow particles

Science.gov (United States)

Safaei, Hadi; Emami, Mohsen Davazdah

2017-12-01

In this paper, the production process of hollow particles from the agglomerated particles is addressed analytically and numerically. The important parameters affecting this process, in particular, the initial porosity level of particles and the plasma gun types are investigated. The analytical model adopts a combination of quasi-steady thermal equilibrium and mechanical balance. In the analytical model, the possibility of a solid core existing in agglomerated particles is examined. In this model, a range of particle diameters (50μm ≤ D_{p0} ≤ 160 μ m) and various initial porosities ( 0.2 ≤ p ≤ 0.7) are considered. The numerical model employs the VOF technique for two-phase compressible flows. The production process of hollow particles from the agglomerated particles is simulated, considering an initial diameter of D_{p0} = 60 μm and initial porosity of p = 0.3, p = 0.5, and p = 0.7. Simulation results of the analytical model indicate that the solid core diameter is independent of the initial porosity, whereas the thickness of the particle shell strongly depends on the initial porosity. In both models, a hollow particle may hardly develop at small initial porosity values ( p disintegrates at high initial porosity values ( p > 0.6.

Aerosol characteristics and particle production in the upper troposphere over the Amazon Basin

Science.gov (United States)

Andreae, Meinrat O.; Afchine, Armin; Albrecht, Rachel; Amorim Holanda, Bruna; Artaxo, Paulo; Barbosa, Henrique M. J.; Borrmann, Stephan; Cecchini, Micael A.; Costa, Anja; Dollner, Maximilian; Fütterer, Daniel; Järvinen, Emma; Jurkat, Tina; Klimach, Thomas; Konemann, Tobias; Knote, Christoph; Krämer, Martina; Krisna, Trismono; Machado, Luiz A. T.; Mertes, Stephan; Minikin, Andreas; Pöhlker, Christopher; Pöhlker, Mira L.; Pöschl, Ulrich; Rosenfeld, Daniel; Sauer, Daniel; Schlager, Hans; Schnaiter, Martin; Schneider, Johannes; Schulz, Christiane; Spanu, Antonio; Sperling, Vinicius B.; Voigt, Christiane; Walser, Adrian; Wang, Jian; Weinzierl, Bernadett; Wendisch, Manfred; Ziereis, Helmut

2018-01-01

Airborne observations over the Amazon Basin showed high aerosol particle concentrations in the upper troposphere (UT) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (PBL) by 1 or 2 orders of magnitude. The measurements were made during the German-Brazilian cooperative aircraft campaign ACRIDICON-CHUVA, where ACRIDICON stands for Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems and CHUVA is the acronym for Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (global precipitation measurement), on the German High Altitude and Long Range Research Aircraft (HALO). The campaign took place in September-October 2014, with the objective of studying tropical deep convective clouds over the Amazon rainforest and their interactions with atmospheric trace gases, aerosol particles, and atmospheric radiation. Aerosol enhancements were observed consistently on all flights during which the UT was probed, using several aerosol metrics, including condensation nuclei (CN) and cloud condensation nuclei (CCN) number concentrations and chemical species mass concentrations. The UT particles differed sharply in their chemical composition and size distribution from those in the PBL, ruling out convective transport of combustion-derived particles from the boundary layer (BL) as a source. The air in the immediate outflow of deep convective clouds was depleted of aerosol particles, whereas strongly enhanced number concentrations of small particles ( 90 nm) particles in the UT, which consisted mostly of organic matter and nitrate and were very effective CCN. Our findings suggest a conceptual model, where production of new aerosol particles takes place in the continental UT from biogenic volatile organic material brought up by deep convection and converted to condensable

Renormalization and operator product expansion in theories with massless particles

International Nuclear Information System (INIS)

Anikin, S.A.; Smirnov, V.A.

1985-01-01

Renormalization procedure in theories including massless particles is presented. With the help of counterterm formalism the operator product expansion for arbitrary composite fields is derived. The coefficient functions are explicitly expressed in terms of certain Green's functions. (author)

Patchy particles made by colloidal fusion

Science.gov (United States)

Gong, Zhe; Hueckel, Theodore; Yi, Gi-Ra; Sacanna, Stefano

2017-10-01

Patches on the surfaces of colloidal particles provide directional information that enables the self-assembly of the particles into higher-order structures. Although computational tools can make quantitative predictions and can generate design rules that link the patch motif of a particle to its internal microstructure and to the emergent properties of the self-assembled materials, the experimental realization of model systems of particles with surface patches (or `patchy' particles) remains a challenge. Synthetic patchy colloidal particles are often poor geometric approximations of the digital building blocks used in simulations and can only rarely be manufactured in sufficiently high yields to be routinely used as experimental model systems. Here we introduce a method, which we refer to as colloidal fusion, for fabricating functional patchy particles in a tunable and scalable manner. Using coordination dynamics and wetting forces, we engineer hybrid liquid-solid clusters that evolve into particles with a range of patchy surface morphologies on addition of a plasticizer. We are able to predict and control the evolutionary pathway by considering surface-energy minimization, leading to two main branches of product: first, spherical particles with liquid surface patches, capable of forming curable bonds with neighbouring particles to assemble robust supracolloidal structures; and second, particles with a faceted liquid compartment, which can be cured and purified to yield colloidal polyhedra. These findings outline a scalable strategy for the synthesis of patchy particles, first by designing their surface patterns by computer simulation, and then by recreating them in the laboratory with high fidelity.

Inclusive charged particle production at large angles at the CERN ISR

CERN Document Server

Alper, B; Booth, P; Bulos, F; Carroll, L J; Damgaard, G; Duff, Brian G; Heymann, Franz F; Jackson, J N; Jarlskog, G; Jönsson, L B; Klovning, A; Leistam, L; Lillethun, E; Lynch, G; Manning, Geoffrey; Prentice, M; Quarrie, D; von Dardel, Guy F; Weiss, J M

1973-01-01

Three different sets of results are presented: 1. Data on the inclusive production of pi /sup +or-/, K/sup +or-/, p, and p, at low transverse momenta over an angular range of 29 degrees to 90 degrees in the centre-of-mass system and for centre-of-mass energies square root s=31 and 53 GeV. 2. Results from a search for massive particles at 62.5 degrees in the laboratory, square root s=53 GeV-in particular, cross-sections for the production of deuterons and antideuterons are given. 3. Data on inclusive charged particle production of high transverse momentum P/sub T/ between 1.5 and 4.4 GeV/c, at centre-of- mass angles 59.4 degrees and 90 degrees , square root s=44 and 53 GeV. In addition, preliminary measurements have been made at square root s =31 and 44 GeV of pi /sup +or-/, K/sup +or-/, p, and p production ratios at 90 degrees for p/sub T/ between 2.0 and 3.5 GeV.c. (14 refs) .

Processing of monazite at the rare earth division,Udyogamandal

International Nuclear Information System (INIS)

Narayanan, N.S.; Thulasidoss, S.; Ramachandran, T.V.; Swaminathan, T.V.; Prasad, K.R.

1988-01-01

The processing techniques adopted at the Rare Earth Division of the Indian Rare Earths Limited at Udyogamandal, for the production of rare earth compounds of various compositions and purity grades are reviewed. Over 100 different compounds are produced and marketed, and these include mixed rare earths chloride, crude thorium concentrate, cerium oxide, cerium hydrate, rare earths carbonate, didymium salts and individual rare earth oxides and salts. Also, the trisodium phosphate obtained as byproduct in the processing of monazite, is recovered and marketed. The process scheme for monazite essentially involves alkaline digestion of ground monazite, removal of the by-product trisodium phosphate, separation of thorium through preferential dissolution of rare earths hydroxide in hydrochloric acid under controlled pH and temperature conditions followed by purification, and evaporation of the chloride solution to yield pure rare earths chloride. Part of the chloride is utilised for the production of individual rare earth compounds after separation by solvent extraction and ion exchange processes. Individual rare earth compounds of 99.99 %+ purity are regularly produced to cater to the demand within the country. (author) 8 figs., 1 tab

Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

International Nuclear Information System (INIS)

Reedy, R.C.

1984-01-01

A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm -2 . Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures

Determination of end-of-life-failure fractions of HTGR-fuel particles by postirradiation annealing and beta autoradiography

International Nuclear Information System (INIS)

Thiele, B.A.; Herren, M.

1978-11-01

Fission-product contamination of the helium coolant of High-Temperature Gas-Cooled Reactors (HTGR) is strongly influenced by the end-of-life (EOL) failed-particle fraction. Knowledge of the EOL-failure fraction is the basis for model calculations to predict the total fission product release from the reactor core. After disintegration of irradiation fuel rods, fuel particles are placed in individual holes of a graphite tray. During a 5-h heat treatment at 1000 0 C in a helium atmosphere failed particles leak fission products, especially the volatile cesium, into the graphite. After unloading a β-autoradiograph of the tray is made. Holes that housed defective particles are identified from black spots on the β-sensitive film. The EOL-failure fraction is the ratio of defective particles to the total number of particles tested. The technique is called PIAA, PostIrradiation Annealing and Autoradiography. The PIAA technique was applied to particles of a Trisocoated highly-enriched UO 2 fissile batch irradiated to a burnup of 35% FIMA at an irradiation temperature of 1250 0 C. Visual examination showed all particles to be intact. From 11 to 47% of the particles had failed, as determined by PIAA. Further, postirradiation examination showed that localized corrosion of the silicon carbide coating by fission-product rare-earth chlorides had occurred

Precise predictions for supersymmetric particle production at the LHC

Energy Technology Data Exchange (ETDEWEB)

Rothering, Marcel

2016-07-01

One of the main objectives of the Large Hadron Collider (LHC) is the search for physics beyond the Standard Model. Among the most promising candidates is the Minimal Supersymmetric Standard Model (MSSM) which postulates the existence of further particles. Since none of these supersymmetric particles have been found yet, their mass limits have been shifted to high values. Hence, with the available energy of the LHC they would always be produced close to their production threshold. This leads to predictions for cross sections which are characterized by the presence of dominant logarithmic terms stemming from multiple soft gluon emission. These contributions spoil the convergence of the perturbative series and require a resummation to predict reliable results in these critical kinematical phase space regions. As the attention of experimental searches has been shifted towards electroweak supersymmetric particle production at the LHC, we update in this thesis our predictions for direct slepton pair production at proton-proton collision to next-to-leading order (NLO) matched to resummation at the next-to-leading logarithmic (NLL) accuracy. As a benchmark scenario we choose simplified models which have the advantage of only containing a few relevant physical parameters. They are now commonly adopted by the experimental collaborations for slepton and electroweak gaugino searches. We find that the scale dependence is drastically reduced by including NLL corrections, especially for large slepton masses. For increasing mass limits we hint towards the significance of next-to-next-to-leading logarithmic contributions to the cross section. By using modern Monte Carlo techniques we reanalyze ATLAS and CMS results for slepton searches for different assumptions about the compositions of the sleptons and their neutralino decay products. We observe similar mass limits for selectrons and smuons as both collaborations and find that masses for left-handed (right-handed) selectrons and

Inflaton decay and heavy particle production with negative coupling

International Nuclear Information System (INIS)

Greene, B.R.; Prokopec, T.; Roos, T.G.

1997-01-01

We study the decay of the inflaton in a general Z 2 xZ 2 symmetric two scalar theory. Since the dynamics of the system is dominated by states with large occupation numbers which admit a semiclassical description, the decay can be studied by solving the classical equations of motion on the lattice. Of particular interest is the case when the cross coupling between the inflaton and the second scalar field is negative, which is naturally allowed in many realistic models. While the inflaton decays via parametric resonance in the positive coupling case we find that for negative coupling there is a new mechanism of particle production which we call negative coupling instability. Because of this new mechanism the variances of the fields grow significantly larger before the production is shut off by the back reaction of the created particles, which could have important consequences for symmetry restoration by nonthermal phase transitions. We also find that heavy particles are produced much more efficiently with negative coupling, which is of prime importance for GUT baryogenesis. Using a simple toy model for baryogenesis and the results of our lattice simulations we show that for natural values of the cross coupling enough 10 14 GeV bosons are created to produce a baryon to entropy ratio consistent with observation. This is to be contrasted with the situation for positive coupling, where the value of the cross coupling required to produce such massive particles is technically unnatural. In addition to our numerical results we obtain analytical estimates for the maximum variances of the fields in an expanding universe for all cases of interest: massive and massless inflaton, positive and negative cross coupling, with and without significant self-interactions for the second field. copyright 1997 The American Physical Society

Rare-earth-free high energy product manganese-based magnetic materials.

Science.gov (United States)

Patel, Ketan; Zhang, Jingming; Ren, Shenqiang

2018-06-14

The constant drive to replace rare-earth metal magnets has initiated great interest in an alternative. Manganese (Mn) has emerged to be a potential candidate as a key element in rare-earth-free magnets. Its five unpaired valence electrons give it a large magnetocrystalline energy and the ability to form several intermetallic compounds. These factors have led Mn-based magnets to be a potential replacement for rare-earth permanent magnets for several applications, such as efficient power electronics, energy generators, magnetic recording and tunneling applications, and spintronics. For past few decades, Mn-based magnets have been explored in many different forms, such as bulk magnets, thin films, and nanoparticles. Here, we review the recent progress in the synthesis and structure-magnetic property relationships of Mn-based rare-earth-free magnets (MnBi, MnAl and MnGa). Furthermore, we discuss their potential to replace rare-earth magnetic materials through the control of their structure and composition to achieve the theoretically predicted magnetic properties.

Production ampersand marketing of radioisotopes: A vital market for rare earths ampersand specialty metals

International Nuclear Information System (INIS)

Fox, C.J.

1996-01-01

Isotopes that spontaneously emit alpha (α) or beta (β) particles, or gamma rays (γ), are said to be radioactive. The emission process, called open-quotes decay,close quotes is precisely what makes radioactive isotopes, known as open-quotes radioisotopes,close quotes useful in a variety of applications, including nuclear medicine, commercial sterilization, manufacturing, geophysics, agriculture, and research programs in these and various other fields. Until 1960, radioisotope production was limited to government-owned nuclear reactors and particle accelerators in universities and government laboratories, primarily because the enormous cost of building these facilities could only be supported by government budgets. During this time, a few private companies managed to secure commercial rights to exploit the production capabilities of these facilities. Today, these companies and a few government agencies still provide the basis of global commercial radioisotope supply

Production and propagation of secondary particles near the earth; Production et propagation de particules secondaires au voisinage de la Terre

Energy Technology Data Exchange (ETDEWEB)

Derome, L

2008-01-15

A few years ago the AMS01 embarked experiment showed a particular high component of the cosmic particle flux detected below the geo-magnetic cut which was surprising because this cut represents the minimal energy that is required for cosmic radiation to reach the earth and any cosmic ray below the cut is pushed away by the earth's magnetic field. This work is based on Monte-Carlo simulations involving the generation of primary cosmic particles, their propagation in the earth magnetic field, their interaction with earth's atmosphere and the production of secondary particles. These simulations have shown that the particles below the cut are in fact particles generated in the upper part of the atmosphere, escaping from it and being trapped by the earth's magnetic field. These Monte-Carlo simulations have also been used to assess the composition of below-the-cut flux in terms of protons, electrons, positrons and light nuclei, to check the production of anti-matter in the atmosphere, and to estimate the flux of atmospheric neutrinos. (A.C.)

Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at √(s) = 7 TeV

International Nuclear Information System (INIS)

Adam, J.; Adamova, D.; Aggarwal, M.M.

2017-01-01

Two-particle angular correlations were measured in pp collisions at √(s) = 7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon-baryon and anti-baryon-anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an open question. (orig.)

Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at √(s) = 7 TeV

Energy Technology Data Exchange (ETDEWEB)

Adam, J. [Czech Technical Univ., Prague (Czech Republic). Faculty of Nuclear Sciences and Physical Engineering; Adamova, D. [Academy of Sciences of the Czech Republic, Rez u Prahy (Czech Republic). Nuclear Physics Inst.; Aggarwal, M.M. [Panjab Univ., Chandigarh (India). Physics Dept.; Collaboration: ALICE Collaboration; and others

2017-08-15

Two-particle angular correlations were measured in pp collisions at √(s) = 7 TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon-baryon and anti-baryon-anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an open question. (orig.)

Study of charm and bottom particle production using a holographic bubble chamber

CERN Multimedia

2002-01-01

The experimental arrangement consists mainly of a small, rapid cycling, heavy liquid bubble chamber, HOBC, equipped for holography and a muon detector. The high spatial resolution which can be obtained in a small holographic bubble chamber (5-10 $\\mu$m) allows a good efficiency for the detection of shortlived particles like charm and bottom particles. With the one muon trigger the proportion of these particles is greatly enhanced. \\\\\\\\For the first phase of the experiment the emphasis is on the determination of charm cross-sections. The aim is to determine the production cross-sections at 100, 200 and 300 GeV/c for different incident particles, and consequently determine the energy dependence of the charm cross-sections.

Allowed unhindered beta connected states in rare earth nuclei

International Nuclear Information System (INIS)

Sood, P.C.; Ray, R.S.

1986-03-01

The beta-connected states in odd-mass as well as even mass rare earth nuclei, where the transition is of allowed unhindered nature, are listed. The tabulation includes 54 cases of such transitions. Validity of Alaga selection rules is examined and the results are used to assign configurations to the involved single particle and two-particle states. (author)

Rare earths as a future resource

International Nuclear Information System (INIS)

Cornell, D.H.

1988-01-01

The fourteen rare earth or lanthanide elements have recently emerged as an important natural resource because of the rapidly growing demand in the electronic, chemical and metallurgical industries. The Symposium on rare earth elements as a future resource presented a multidisciplinary review of rare earth chemistry, geology, beneficiation, industrial applications and marketing. Papers by experts in many fields were presented on the following topics: chemical properties of the rare earth elements; the analysis of rare earth elements and minerals; beneficiation and extraction of rare earth elements; economic geochemistry and mineralogy of rare earths; present industrial uses of rare earth elements; the role of rare earth elements in high-temperature superconductors; the technical application of high-temperature superconductors; supply and demand for rare earth products - now and in the future, and the geology of rare earth deposits

Rare event simulation using Monte Carlo methods

CERN Document Server

Rubino, Gerardo

2009-01-01

In a probabilistic model, a rare event is an event with a very small probability of occurrence. The forecasting of rare events is a formidable task but is important in many areas. For instance a catastrophic failure in a transport system or in a nuclear power plant, the failure of an information processing system in a bank, or in the communication network of a group of banks, leading to financial losses. Being able to evaluate the probability of rare events is therefore a critical issue. Monte Carlo Methods, the simulation of corresponding models, are used to analyze rare events. This book sets out to present the mathematical tools available for the efficient simulation of rare events. Importance sampling and splitting are presented along with an exposition of how to apply these tools to a variety of fields ranging from performance and dependability evaluation of complex systems, typically in computer science or in telecommunications, to chemical reaction analysis in biology or particle transport in physics. ...

Simulation of high-energy particle production through sausage and kink instabilities in pinched plasma discharges

International Nuclear Information System (INIS)

Haruki, Takayuki; Yousefi, Hamid Reza; Masugata, Katsumi; Sakai, Jun-Ichi; Mizuguchi, Yusuke; Makino, Nao; Ito, Hiroaki

2006-01-01

In an experimental plasma, high-energy particles were observed by using a plasma focus device, to obtain energies of a few hundred keV for electrons, up to MeV for ions. In order to study the mechanism of high-energy particle production in pinched plasma discharges, a numerical simulation was introduced. By use of a three-dimensional relativistic and fully electromagnetic particle-in-cell code, the dynamics of a Z-pinch plasma, thought to be unstable against sausage and kink instabilities, are investigated. In this work, the development of sausage and kink instabilities and subsequent high-energy particle production are shown. In the model used here, cylindrically distributed electrons and ions are driven by an external electric field. The driven particles spontaneously produce a current, which begins to pinch by the Lorentz force. Initially the pinched current is unstable against a sausage instability, and then becomes unstable against a kink instability. As a result high-energy particles are observed

Recovery of rare earths from red mud

International Nuclear Information System (INIS)

Bautista, R.G.

1992-01-01

The prospect for the recovery of rare earths from red mud, the bauxite tailings from the production of alumina is examined. The Jamaican red mud by far has the higher trace concentrations of lanthanum, cerium, neodymium, and yttrium. Scandium is also present. The dissolution of the rare earth is a major extraction problem because of the large volume of other materials. The recovery processes that have been proposed include the production of co-products such as iron, alumina, and titanium concentrates, with the rare earths going with the titanium. In this paper a critical examination of the possible processes are presented with the recommended research projects to be carried out

Proceedings of the meeting on multi-particle production

International Nuclear Information System (INIS)

Ochiai, Fumio; Suzuki, Atsuto; Noda, Hujio; Miyamura, Osamu

1980-02-01

This study meeting was held on September 6 and 7, 1979, at the National Laboratory for High Energy Physics for the purposes of discussing multiple production phenomena including the experiments in KEK, FNAL and CERN and those in cosmic ray domain and obtaining the clues to solve their mechanism. Altogether, 31 papers were presented on the hardware and software aspects of the multiple production phenomena at high energy. The production of particles in high energy p-p reaction and its mechanism, the inclusive production of high meson resonance in p-p collision, the inclusive hadron production in low momentum region at high energy, the cluster analysis using minimal spanning tree, the hadron beam jet in small transverse momentum region, quark-diquark cascade model and the hadron production in proton beam jet, quark recoupling model, the local number fluctuation in pp 405 GeV/c scattering and its analysis, the mode of change of the formula of Kopylov-Podgoretsky-Cocconi when incoherent and coherent emission sources coexist, the motion of fire balls in the mechanism of multiple production, inelastic diffraction and the geometrical structure of protons, cylinder amplitude, nuclear targets as the probes for hadrons and the constituents, the experimental study of pion-nucleus interaction and so on were discussed. (Kako, I.)

Production and characterization of phosphorescent nanopowders doped with rare earth ions

International Nuclear Information System (INIS)

Montes, Paulo Jorge Ribeiro

2009-01-01

In this work the feasibility of employing the synthesis process using a methodology developed by Macedo and Sasaki (Macedo, M. A. e Sasaki, J. M. Fabrication process nano particulate powders. INPI 0203876-5 1998) to produce pore and rare earths doped ceramic nano powders of SrAl 2 O 4 and Ca 12 Al 14 O 33 was investigated. In this new methodology, coconut water is used as a start solvent for the production of the samples. Thermal analysis techniques were employed in order to obtain the best calcination conditions. The structural and microstructural characterizations of the samples were made using powder X-ray diffraction and Atomic Force Microscopy techniques. The analysis by X-ray diffraction showed the formation of the SrAl 2 O 4 and Ca 12 Al 14 O 33 phases in the calcined powders. The emission/excitation spectra exhibited the typical transitions of the rare earth elements indicating the incorporation of the dopant in the nano crystals. Emission characteristics of divalent europium show that the reduction of Eu ions is induced during the synthesis stage. The doped samples show an intense bright emission when exposed to X-rays. That emission is associated with divalent europium transitions, indicating that irradiation also induces the reduction of the valence state of Eu ions from Eu 3+ to Eu 2+ . Radioluminescence spectra (RL) versus time show a decay of the RL intensity to 40% of the initial intensity after 20 minutes of exposure to X-rays. Irradiation also causes a change in color of the samples indicating the production of radiation damage. Analysis of the results of X-ray spectroscopy (XAS- X-ray Absorption Spectroscopy) and the luminescent emission of samples excited by X-rays (XEOL - X-ray Excited Optical Luminescence) enabled the creation of a model that explains that behavior. DXAS technique (Dispersive X-ray Absorption Spectroscopy) was used to monitor the kinetics of the reduction process of Eu ions during irradiation, in order to verify the

Production of slow particle in 1.7 AGeV 84Kr induced emulsion interaction

International Nuclear Information System (INIS)

Li Huiling; Zhang Donghai; Li Xueqin; Jia Huiming

2008-01-01

The production of slow particle in 1.7 AGeV 84 Kr induced emulsion interaction was studied. The experimental results show that the average multiplicity of black, grey and heavily ionized track particle increases with the increase of impact centrality and target size. The average multiplicity of grey track particle and heavily ionized track particle increases with the increase of the number of black track particle. The average multiplicity of heavily ionized track particle increases with the increase of the number of grey track particle, but average multiplicity of black track particle increases with the increase of the number of grey track particle and then saturated. The average multiplicity of grey track particle increases with the increase of the number of heavily ionized track particle, but average multiplicity of black track particle increases with the increase of the number of heavily ionized track particle and then saturated. Those experimental results can be well explained by using the nuclear impact geometry model. (authors)

Measurement of strange particle production in the NICA fixed-target programme

Energy Technology Data Exchange (ETDEWEB)

Friese, Volker [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

2016-08-15

Strange particles provide a sensitive tool to study the dense and hot matter created in relativistic nuclear collisions. Although strangeness production in such collisions has been a topic of experimental and theoretical research for many years, its understanding is far from being complete. This holds in particular for multi-strange hyperons and for lower collision energies as relevant for NICA and FAIR. Multi-strange particles, being sensitive to both the mechanism of strangeness production and the net-baryon density, are expected to shed light on the state of the created matter and to indicate possible transitions to new phases of strongly interacting matter. We thus advocate the measurement of hyperons and φ mesons in a fixed-target experiment at NICA (BM rate at N), which can be achieved by a relatively compact detector system. (orig.)

Microstructure and emission ability of rare earth oxides doped molybdenum cathodes

International Nuclear Information System (INIS)

Yang Jiancan; Nie Zuoren; Wang Yiman

2003-01-01

We adopted high-resolution transmission electron microscopy (TEM) and scanning electron microscopy (SAM) to observe and analyze the microstructure of rare earth oxide (La 2 O 3 , Sc 2 O 3 ) doped molybdenum cathodes. The results show that there are many nanometer particles in the molybdenum matrix besides some sub-micrometer particles in the crystal interfaces. All these particles are rare earth oxides as determined through calculating the electron diffraction pattern. Then we determined the electron work function and the zero-field emission current of molybdenum cathodes by the electron emission measurement. To correlate the emission data with surface composition, we use Auger electron spectroscopy (AES) to analyze the elements on the activated cathode surface and their depth profiles. We found that there were about 20 nm thick layers on an activated cathode surface, which have a high content of rare earth elements. We also use AES to analyze the elements diffusion to the cathode surface from cathode body during heating up to its operating temperature to find out which element positively affects the electron emission

Rare Earth Metals: Resourcefulness and Recovery

Science.gov (United States)

Wang, Shijie

2013-10-01

When we appreciate the digital revolution carried over from the twentieth century with mobile communication and the Internet, and when we enjoy our high-tech lifestyle filled with iDevices, hybrid cars, wind turbines, and solar cells in this new century, we should also appreciate that all of these advanced products depend on rare earth metals to function. Although there are only 136,000 tons of annual worldwide demand, (Cho, Rare Earth Metals, Will We Have Enough?)1 rare earth metals are becoming such hot commodities on international markets, due to not only to their increasing uses, including in most critical military hardware, but also to Chinese growth, which accounts for 95% of global rare earth metal production. Hence, the 2013 technical calendar topic, planned by the TMS/Hydrometallurgy and Electrometallurgy Committee, is particularly relevant, with four articles (including this commentary) contributed to the JOM October Issue discussing rare earth metals' resourcefulness and recovery.

LHCf: physics results on forward particle production at LHC

CERN Document Server

Adriani, O

2013-01-01

The LHCf experiment is dedicated to the measurement of very forward particle production in the high energy hadron-hadron collisions at LHC, with the aim of improving the cosmic-ray air shower developments models. The detector has taken data in p-p collisions at $\\sqrt s$ = 900 GeV, 2.76 TeV and 7 TeV, and in p/Pb collisions at $\\sqrt s$ = 5 TeV. The results of forward production spectra of photons, neutral pions and neutrons, compared with the models most widely used in the High Energy Cosmic Ray physics, are presented in this paper.

Nonlinear interaction of colliding beams in particle storage rings

International Nuclear Information System (INIS)

Herrera, J.C.; Month, M.

1979-01-01

When two beams of high energy particles moving in opposite directions are brought into collision, a large amount of energy is available for the production of new particles. However to obtain a sufficiently high event rate for rare processes, such as the production of the intermediate vector boson (Z 0 and W +- ), large beam currents are also required. Under this circumstance, the high charge density of one beam results in a classical electromagnetic interaction on the particles in the other beam. This very nonlinear space charge force, caled the beam-beam force, limits the total circulating charge and, thereby, the ultimate performance of the colliding ring system. The basic nature of the beam-beam force is discussed, indicating how it is quite different in the case of continuous beams, which cross each other at an angle as compared to the case of bunched beams which collide head-on. Some experimental observations on the beam-beam interaction in proton-proton and electron-positron beams are then reviewed and interpreted. An important aspect of the beam-beam problem in storage rings is to determine at what point in the analysis of the particle dynamics is it relevant to bring in the concepts of stochasticity, slow diffusion, and resonance overlap. These ideas are briefly discussed

Fatty acid biosynthesis is involved in the production of hepatitis B virus particles

International Nuclear Information System (INIS)

Okamura, Hitomi; Nio, Yasunori; Akahori, Yuichi; Kim, Sulyi; Watashi, Koichi; Wakita, Takaji; Hijikata, Makoto

2016-01-01

Hepatitis B virus (HBV) proliferates in hepatocytes after infection, but the host factors that contribute to the HBV lifecycle are poorly understood at the molecular level. We investigated whether fatty acid biosynthesis (FABS), which was recently reported to contribute to the genomic replication of hepatitis C virus, plays a role in HBV proliferation. We examined the effects of inhibitors of the enzymes in the FABS pathway on the HBV lifecycle by using recombinant HBV-producing cultured cells and found that the extracellular HBV DNA level, reflecting HBV particle production, was decreased by treatment with inhibitors suppressed the synthesis of long-chain saturated fatty acids with little cytotoxicity. The reduced HBV DNA level was reversed when palmitic acid, which is the product of fatty acid synthase (FAS) during FABS, was used simultaneously with the inhibitor. We also observed that the amount of intracellular HBV DNA in the cells was increased by FAS inhibitor treatment, suggesting that FABS is associated with HBV particle production but not its genome replication. This suggests that FABS might be a potent target for anti-HBV drug with a mode of action different from current HBV therapy. -- Highlights: •Inhibitors of ACC1 and FAS but not SCD1 decreased production of extracellular HBV DNA. •Products of FABS, long chain fatty acids, increased production of extracellular HBV DNA. •FAS inhibitor increased intracellular levels of HBV DNA and HBcAg. •FABS was suggested to contribute to HBV particle production without significant relation with secretory pathway of the cells.

Fatty acid biosynthesis is involved in the production of hepatitis B virus particles

Energy Technology Data Exchange (ETDEWEB)

Okamura, Hitomi [Laboratory of Human Tumor Viruses, Institute for Virus Research, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyoku, Kyoto 606-8501 (Japan); Nio, Yasunori, E-mail: yasunori.nio@takeda.com [Takeda Pharmaceutical Company Limited, Pharmaceutical Research Division, 26-1, Muraoka-Higashi 2-Chome, Fujisawa, Kanagawa 251-8555 (Japan); Akahori, Yuichi [Laboratory of Human Tumor Viruses, Institute for Virus Research, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyoku, Kyoto 606-8501 (Japan); Kim, Sulyi [Laboratory of Human Tumor Viruses, Institute for Virus Research, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Watashi, Koichi [Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640 (Japan); Department of Applied Biological Science, Tokyo University of Sciences, Noda 278-8510 (Japan); CREST, Japan Science and Technology Agency (JST), Saitama 332-0012 (Japan); Wakita, Takaji [Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640 (Japan); Hijikata, Makoto, E-mail: mhijikat@virus.kyoto-u.ac.jp [Laboratory of Human Tumor Viruses, Institute for Virus Research, Kyoto University, 53 Kawaharacho, Shogoin, Sakyoku, Kyoto 606-8507 (Japan); Graduate School of Biostudies, Kyoto University, Yoshida-Konoecho, Sakyoku, Kyoto 606-8501 (Japan)

2016-06-17

Hepatitis B virus (HBV) proliferates in hepatocytes after infection, but the host factors that contribute to the HBV lifecycle are poorly understood at the molecular level. We investigated whether fatty acid biosynthesis (FABS), which was recently reported to contribute to the genomic replication of hepatitis C virus, plays a role in HBV proliferation. We examined the effects of inhibitors of the enzymes in the FABS pathway on the HBV lifecycle by using recombinant HBV-producing cultured cells and found that the extracellular HBV DNA level, reflecting HBV particle production, was decreased by treatment with inhibitors suppressed the synthesis of long-chain saturated fatty acids with little cytotoxicity. The reduced HBV DNA level was reversed when palmitic acid, which is the product of fatty acid synthase (FAS) during FABS, was used simultaneously with the inhibitor. We also observed that the amount of intracellular HBV DNA in the cells was increased by FAS inhibitor treatment, suggesting that FABS is associated with HBV particle production but not its genome replication. This suggests that FABS might be a potent target for anti-HBV drug with a mode of action different from current HBV therapy. -- Highlights: •Inhibitors of ACC1 and FAS but not SCD1 decreased production of extracellular HBV DNA. •Products of FABS, long chain fatty acids, increased production of extracellular HBV DNA. •FAS inhibitor increased intracellular levels of HBV DNA and HBcAg. •FABS was suggested to contribute to HBV particle production without significant relation with secretory pathway of the cells.

Emanation of 232U and its radioactive daughter products from respirable size particles

International Nuclear Information System (INIS)

Cuddihy, R.G.; Griffith, W.C.; Hoover, M.D.; Kanapilly, G.M.; Stalnaker, N.D.

1978-01-01

This study is to develop a model for the emanation of 232 U and its radioactive daughter products from particles of Th-U fuel material. The radiation doses to internal organs following inhalation of these particles can only be calculated by knowing the rate of emanation of the daughters from particles in the lung and the subsequent excretion or translocation of the daughters to other organs. The emanation mechanisms are recoil of the daughter nuclei from the particle during alpha decay of the parent, diffusion of inert gas daughters from the particle and dissolution of the particle itself in biological fluids. Experiments to evaluate these mechanisms will involve ThO 2 and UO 2 particles in the size range 0.1 to 1.0 μm MMAD uniformly labeled with 232 U. The influence of the material temperature history on emanation will be investigated by heat treating particles at 600 and 1400 0 C

Hard scattering contribution to particle production in high energy heavy-ion collisions

International Nuclear Information System (INIS)

Pareek, Pooja; Mishra, Aditya Nath; Sahoo, Pragati; Sahoo, Raghunath

2014-01-01

Global observables like the multiplicity of produced charged particles and transverse energy, are the key observables used to characterize the properties of the matter created in heavy-ion collisions. In order to study the dependence of the charged particle density on colliding system, center of mass energy and collision centrality, there have been measurements starting few GeV to TeV energies at LHC. There is a need to understand the particle production contribution coming from the QCD hard processes, which scale with number of binary nucleon-nucleon collisions, N coll and soft processes scaling with number of participant nucleons, N part

Molecular and process design for rotavirus-like particle production in Saccharomyces cerevisiae

Directory of Open Access Journals (Sweden)

Palomares Laura A

2011-05-01

Full Text Available Abstract Background Virus-like particles (VLP have an increasing range of applications including vaccination, drug delivery, diagnostics, gene therapy and nanotechnology. These developments require large quantities of particles that need to be obtained in efficient and economic processes. Production of VLP in yeast is attractive, as it is a low-cost protein producer able to assemble viral structural proteins into VLP. However, to date only single-layered VLP with simple architecture have been produced in this system. In this work, the first steps required for the production of rotavirus-like particles (RLP in S. cerevisiae were implemented and improved, in order to obtain the recombinant protein concentrations required for VLP assembly. Results The genes of the rotavirus structural proteins VP2, VP6 and VP7 were cloned in four Saccharomyces cerevisiae strains using different plasmid and promoter combinations to express one or three proteins in the same cell. Performance of the best constructs was evaluated in batch and fed-batch cultures using a complete synthetic media supplemented with leucine, glutamate and succinate. The strain used had an important effect on recombinant protein concentration, while the type of plasmid, centromeric (YCp or episomal (YEp, did not affect protein yields. Fed-batch culture of the PD.U-267 strain resulted in the highest concentration of rotavirus proteins. Volumetric and specific productivities increased 28.5- and 11-fold, respectively, in comparison with batch cultures. Expression of the three rotavirus proteins was confirmed by immunoblotting and RLP were detected using transmission electron microscopy. Conclusions We present for the first time the use of yeast as a platform to express multilayered rotavirus-like particles. The present study shows that the combined use of molecular and bioprocess tools allowed the production of triple-layered rotavirus RLP. Production of VLP with complex architecture in yeasts

Transverse energy and charged particle production in heavy-ion collisions: from RHIC to LHC

International Nuclear Information System (INIS)

Sahoo, Raghunath; Mishra, Aditya Nath

2014-01-01

We study the charged particle and transverse energy production mechanism from AGS, SPS, Relativistic Heavy-Ion Collider (RHIC) to Large Hadron Collider (LHC) energies in the framework of nucleon and quark participants. At RHIC and LHC energies, the number of nucleons-normalized charged particle and transverse energy density in pseudorapidity, which shows a monotonic rise with centrality, turns out to be an almost centrality independent scaling behavior when normalized to the number of participant quarks. A universal function which is a combination of logarithmic and power-law, describes well the charged particle and transverse energy production both at nucleon and quark participant level for the whole range of collision energies. Energy dependent production mechanisms are discussed both for nucleonic and partonic level. Predictions are made for the pseudorapidity densities of transverse energy, charged particle multiplicity and their ratio (the barometric observable, [dE T /dη]/[dN ch /dη] ≡ E T /N ch ) at mid-rapidity for Pb + Pb collisions at √s NN = 5.5 TeV. A comparison with models based on gluon saturation and statistical hadron gas is made for the energy dependence of E T /N ch . (author)

Particle production in high energy nucleus--nucleus experiments at Berkeley

International Nuclear Information System (INIS)

Schroeder, L.S.

1976-09-01

A review of high energy nucleus-nucleus experiments performed at the Berkeley Bevalac is presented. Earlier results on projectile and target fragmentation and pion production are briefly summarized. More recent results on Coulomb effects in projectile fragmentation, heavy ion total cross-sections, γ-ray production, and charged particle multiplicities are presented. Also, recent experiments which may shed light on phenomena arising from the central collision of two energetic nuclei, including recent evidence for and against the observation of nuclear shock waves, are reviewed

Production and characterization of monodisperse uranium particles for nuclear safeguards applications

International Nuclear Information System (INIS)

Knott, Alexander

2016-01-01

Environmental sampling is a very effective measure to detect undeclared nuclear activities. Generally, samples are taken as swipe samples on cotton. These swipes contain minute quantities of particulates which have an inherent signature of their production and release scenario. These inspection samples are assessed for their morphology, elemental composition and their isotopic vectors. Mass spectrometry plays a crucial role in determining the isotopic ratios of uranium. Method validation and instrument calibration with well-characterized quality control (QC)-materials, reference materials (RMs) and certified reference materials (CRMs) ensures reliable data output. Currently, the availability of suitable well defined microparticles containing uranium and plutonium reference materials is very limited. Primarily, metals, oxides and various uranium and plutonium containing solutions are commercially available. Therefore, the IAEA's Safeguards Analytical Services (SGAS) cooperates with the Institute of Nuclear Waste Management and Reactor Safety (IEK-6) at the Forschungszentrum Juelich GmbH in a joint task entitled ''Production of Particle Reference Materials''. The work presented in this thesis has been partially funded by the IAEA, Forschungszentrum Juelich GmbH and the Federal Ministry of Economic Affairs and Energy (BMWi) through the ''Joint Program on the Technical Development and Further Improvement of IAEA Safeguards between the Government of the Federal Republic of Germany and the IAEA''. The first step towards monodisperse microparticles was the development of pure uranium oxide particles made from certified reference materials. The focus of the dissertation is (1) the implementation of a working setup to produce monodisperse uranium oxide particles and (2) the characterization of these particles towards the application as QC-material. Monodisperse uranium oxide particles were produced by spray pyrolysis. It was demonstrated that the particle size can be

Production and characterization of monodisperse uranium particles for nuclear safeguards applications

Energy Technology Data Exchange (ETDEWEB)

Knott, Alexander

2016-07-01

Environmental sampling is a very effective measure to detect undeclared nuclear activities. Generally, samples are taken as swipe samples on cotton. These swipes contain minute quantities of particulates which have an inherent signature of their production and release scenario. These inspection samples are assessed for their morphology, elemental composition and their isotopic vectors. Mass spectrometry plays a crucial role in determining the isotopic ratios of uranium. Method validation and instrument calibration with well-characterized quality control (QC)-materials, reference materials (RMs) and certified reference materials (CRMs) ensures reliable data output. Currently, the availability of suitable well defined microparticles containing uranium and plutonium reference materials is very limited. Primarily, metals, oxides and various uranium and plutonium containing solutions are commercially available. Therefore, the IAEA's Safeguards Analytical Services (SGAS) cooperates with the Institute of Nuclear Waste Management and Reactor Safety (IEK-6) at the Forschungszentrum Juelich GmbH in a joint task entitled ''Production of Particle Reference Materials''. The work presented in this thesis has been partially funded by the IAEA, Forschungszentrum Juelich GmbH and the Federal Ministry of Economic Affairs and Energy (BMWi) through the ''Joint Program on the Technical Development and Further Improvement of IAEA Safeguards between the Government of the Federal Republic of Germany and the IAEA''. The first step towards monodisperse microparticles was the development of pure uranium oxide particles made from certified reference materials. The focus of the dissertation is (1) the implementation of a working setup to produce monodisperse uranium oxide particles and (2) the characterization of these particles towards the application as QC-material. Monodisperse uranium oxide particles were produced by spray pyrolysis. It was

Morphologically and size uniform monodisperse particles and their shape-directed self-assembly

Energy Technology Data Exchange (ETDEWEB)

Collins, Joshua E.; Bell, Howard Y.; Ye, Xingchen; Murray, Christopher Bruce

2017-09-12

Monodisperse particles having: a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology are disclosed. Due to their uniform size and shape, the monodisperse particles self assemble into superlattices. The particles may be luminescent particles such as down-converting phosphor particles and up-converting phosphors. The monodisperse particles of the invention have a rare earth-containing lattice which in one embodiment may be an yttrium-containing lattice or in another may be a lanthanide-containing lattice. The monodisperse particles may have different optical properties based on their composition, their size, and/or their morphology (or shape). Also disclosed is a combination of at least two types of monodisperse particles, where each type is a plurality of monodisperse particles having a single pure crystalline phase of a rare earth-containing lattice, a uniform three-dimensional size, and a uniform polyhedral morphology; and where the types of monodisperse particles differ from one another by composition, by size, or by morphology. In a preferred embodiment, the types of monodisperse particles have the same composition but different morphologies. Methods of making and methods of using the monodisperse particles are disclosed.

Searches for rare top processes and decay and third generation SUSY

CERN Document Server

Zambito, Stefano; The ATLAS collaboration

2018-01-01

Many models of new physics, including natural models of Supersymmetry and vector-like quarks, predict processes that would be visible at the LHC in events with third generation quarks. These include searches for stop and sbottom particles in a variety of decay modes, as well as for flavour-changing neutral current top-quark decays. The modeling of the Standard Model backgrounds to these processes is difficult and vital to the success of the searches. This talk presents recent results from ATLAS and CMS on searches for rare top processes and stop and sbottom pair production, using the data collected during the LHC Run 2.

Mini-jet production in proton-antiproton interactions and particle production in heavy-ion collisions

International Nuclear Information System (INIS)

Wang Haiqiao.

1997-04-01

The thesis is based on the data analysis and detector development of the EMU01/CERN, E863/BNL and UA1/CERN experiments. Particle fluctuations are studied with the scaled factorial moments in the fragmentation region of oxygen induced emulsion interactions from 3.7 to 200 A GeV. The intermittency indices show an energy independent behaviour in the target and projectile regions of pseudorapidity. In order to study the origin of the fluctuations, jet-like and ring-like substructures of particles produced in the azimuthal plane are investigated for the S - Au, S - Em and O - Em interactions at 200 A GeV. The study shows that the two particle azimuthal correlations can be well understood if Bose-Einstein correlations and γ-conversion are included. A nuclear rescattering model, which incorporates the FRITIOF model, has been developed. The model can well describe multiplicity distributions of slow recoiling protons, evaporation particles and their correlations with particles produced in high energy heavy ion collisions. In order to improve the measurements of Pb induced collisions, an automatic system based on the CCD technique and image processing was developed. This system has been used to measure densities of the particles produced. Mini-jet production is studied using the UA1 1987 minimum bias data sample for p (anti) interaction at s 1/2 0 630 GeV. The study shows that the transverse energy distribution of mini-jets is in good agreement with the QCD prediction. The angular distributions of two leading jets show the behaviour of elastic scattering of partons with gluon exchange. 86 refs

A Study of Particle Production in Proton Induced Collisions Using the MIPP Detector at Fermilab

Energy Technology Data Exchange (ETDEWEB)

Mahajan, Sonam [Panjab Univ., Chandigarh (India)

2015-01-01

The Main Injector Particle Production (MIPP) experiment is a fixed target hadron production experiment at Fermilab. MIPP is a high acceptance spectrometer which provides excellent charged particle identification using Time Projection Chamber (TPC), Time of Flight (ToF), multicell Cherenkov (Ckov), ring imaging Cherenkov (RICH) detectors, and Calorimeter for neutrons. The MIPP experiment is designed to measure particle production in interactions of 120 GeV/c primary protons from the Main Injector and secondary beams of $\\pi^{\\pm}, \\rm{K}^{\\pm}$, p and $\\bar{\\rm{p}}$ from 5 to 90 GeV/c on nuclear targets which include H, Be, C, Bi and U, and a dedicated run with the NuMI target. The goal of the experiment is to measure hadron production cross sections or yields using these beams and targets. These hadronic interaction data can have a direct impact on the detailed understanding of the neutrino fluxes of several accelerator-based neutrino experiments like MINOS, MINER$\

Radiolytic gas production in the alpha particle degradation of plastics

International Nuclear Information System (INIS)

Reed, D.T.; Hoh, J.; Emery, J.; Hobbs, D.

1992-01-01

Net gas generation due to alpha particle irradiation of polyethylene and polyvinyl chloride was investigated. Experiments were performed in an air environment at 30, 60, and 100 degree C. The predominant radiolytic degradation products of polyethylene were hydrogen and carbon dioxide with a wide variety of trace organic species noted. Irradiation of polyvinyl chloride resulted in the formation of HCl in addition to the products observed for polyethylene. For both plastic materials, a strong enhancement of net yields was noted at 100 degree C

Production of neutrons in particle accelerators: a PNRI safety concern

International Nuclear Information System (INIS)

Garcia, Corazon M.; Cayabo, Lynette B.; Artificio, Thelma P.; Melendez, Johnylen V.; Piquero, Myrna E.; Parami, Vangeline K.

2002-09-01

In the safety assessment made for the first cyclotron facility in the Philippines, that is the cyclotron in the P.E.T. (Positron Emission Tomography) center of the St. Luke's Medical Center, the concern on the production of neutrons associated with the operation of particle accelerators has been identified. This takes into consideration the principles in the operation of particle accelerators and the associated production of neutrons resulting from their operation, the hazards and risks in their operation. The Bureau of Health Devices and Technology (BHDT) of the Department of Health in the Philippines regulates and controls the presently existing six (6) linear accelerators distributed in different hospitals in the country, being classified as x-ray producing devices. From the results of this study, it is evident that the production of neutrons from the operation of accelerators, produces neutrons and that activation due to neutrons can form radioactive materials. The PNRI (Philippine Nuclear Research Institute) being mandated by law to regulate and control any equipment or devices producing or utilizing radioactive materials should take the proper steps to subject all accelerator facilities and devices in the Philippines such as linear accelerators under its regulatory control in the same manner as it did with the first cyclotron in the country. (Author)

Study of strange particle production in jets with the ALICE experiment at the LHC

CERN Document Server

AUTHOR|(CDS)2082140; Kuhn, Christian

Quark–gluon plasma is a state of matter existing under extreme energy densities and temperatures where quarks and gluons are deconfined. Complex phenomena occurring in the plasma emerge from the strong interaction of its constituents. This hot and dense strongly interacting matter can be created in ultra-relativistic heavy-ion collisions and its properties can be studied by measuring particles produced in the collisions. Partons produced in hard scatterings interact with the medium which modifies the production of particles in jets. Measurements of spectra of identified particles produced in jets represent an important tool for understanding the interplay of various hadronization mechanisms which contribute to the particle production in the medium created in heavy-ion collisions. In this thesis, we present the measurement of the $p_\\text{T}$ spectra of Λ baryons and $\\text{K}^{\\text{0}}_{\\text{S}}$ mesons produced in charged jets in central Pb–Pb collisions at the energy $\\sqrt{s_{\\text{NN}}} = 2.76\\ \\te...

Neutron secondary-particle production cross sections and their incorporation into Monte-Carlo transport codes

International Nuclear Information System (INIS)

Brenner, D.J.; Prael, R.E.; Little, R.C.

1987-01-01

Realistic simulations of the passage of fast neutrons through tissue require a large quantity of cross-sectional data. What are needed are differential (in particle type, energy and angle) cross sections. A computer code is described which produces such spectra for neutrons above ∼14 MeV incident on light nuclei such as carbon and oxygen. Comparisons have been made with experimental measurements of double-differential secondary charged-particle production on carbon and oxygen at energies from 27 to 60 MeV; they indicate that the model is adequate in this energy range. In order to utilize fully the results of these calculations, they should be incorporated into a neutron transport code. This requires defining a generalized format for describing charged-particle production, putting the calculated results in this format, interfacing the neutron transport code with these data, and charged-particle transport. The design and development of such a program is described. 13 refs., 3 figs

Improvement in retention of solid fission products in HTGR fuel particles by ceramic kernel additives

International Nuclear Information System (INIS)

Foerthmann, R.; Groos, E.; Gruebmeier, H.

1975-08-01

Increased requirements concerning the retention of long-lived solid fission products in fuel elements for use in advanced High Temperature Gas-cooled Reactors led to the development of coated particles with improved fission product retention of the kernel, which represent an alternative to silicon carbide-coated fuel particles. Two irradiation experiments have shown that the release of strontium, barium, and caesium from pyrocarbon-coated particles can be reduced by orders of magnitude if the oxide kernel contains alumina-silica additives. It was detected by electron microprobe analysis that the improved retention of the mentioned fission products in the fuel kernel is caused by formation of the stable aluminosilicates SrAl 2 Si 2 O 8 , BaAl 2 Si 2 O 8 and CsAlSi 2 O 6 in the additional aluminasilica phase of the kernel. (orig.) [de

Long-range dispersion interactions. II. Alkali-metal and rare-gas atoms

International Nuclear Information System (INIS)

Mitroy, J.; Zhang, J.-Y.

2007-01-01

The dispersion coefficients for the van der Waals interactions between the rare gases Ne, Ar, Kr, and Xe and the low-lying states of Li, Na, K, and Rb are estimated using a combination of ab initio and semiempirical methods. The rare-gas oscillator strength distributions for the quadrupole and octupole transitions were derived by using high-quality calculations of rare-gas polarizabilities and dispersion coefficients to tune Hartree-Fock single-particle energies and expectation values

Radon decay products and 10-1100 nm aerosol particles in Postojna Cave

Science.gov (United States)

Bezek, M.; Gregorič, A.; Vaupotič, J.

2013-03-01

At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn) decay products and the number concentration and size distribution of aerosol particles in the size range of 10-1100 nm were monitored, with the focus on the unattached fraction (fun) of radon decay products (RnDPs), a key parameter in radon dosimetry. The total number concentration of aerosols during visits in summer was lower (700 cm-3) than in winter (2800 cm-3), and was dominated by 50 nm particles (related to the attached RnDPs) in winter. This explains the higher fun values in summer (0.75) and the lower winter measurement (0.04) and, consequently, DCFD values of 43.6 and 13.1 mSv WLM-1 respectively for the calculated dose conversion factors. The difference is caused by an enhanced inflow of fresh outside air, driven in winter by the higher air temperature in the cave compared to outside, resulting in the introduction of outside aerosol particles into the cave.

Production of identified particles in p–Pb collisions at √sNN = 5.02 TeV measured with ALICE

CERN Multimedia

CERN. Geneva

2014-01-01

Transverse momentum distributions of identified particles have been measured in several multiplicity classes in p-Pb collisions at sqrt(s_NN) = 5.02 TeV. This measurement can shed light on the understanding of possible collective effects in high multiplicity events. Furthermore p-Pb collisions bridge the charged multiplicity gap between pp and low multiplicity Pb–Pb collisions. Studying the particle production in this region can improve the understanding of the underlying production mechanisms. Particles are reconstructed with the central barrel detectors over a wide transverse momentum range (from 0 up to 15 GeV/c), exploiting different identification techniques.   Primary charged particles (pions, kaons, protons, antiprotons, deuterons and anti-deuterons) are identified by their specific energy loss (dE/dx) and time-of-flight. Weakly decaying particles are identified by their characteristic decay topology. Particle-production yields, spectral shapes and particle ratios have been m...

Strange-particle production via the weak interaction

International Nuclear Information System (INIS)

Adera, G. B.; Van Der Ventel, B. I. S.; Niekerk, D. D. van; Mart, T.

2010-01-01

The differential cross sections for the neutrino-induced weak charged current production of strange particles in the threshold energy region are presented. The general representation of the weak hadronic current is newly developed in terms of eighteen unknown invariant amplitudes to parametrize the hadron vertex. The Born-term approximation is used for the numerical calculations in the framework of the Cabibbo theory and SU(3) symmetry. For unpolarized octet baryons four processes are investigated, whereas in the case of polarized baryons only one process is chosen to study the sensitivity of the differential cross section to the various polarizations of the initial-state nucleon and the final-state hyperon.

Production and decay of supersymmetric particles at future colliders

International Nuclear Information System (INIS)

Bartl, A.; Majerotto, W.; Moesslacher, B.

1991-01-01

We describe how supersymmetric particles could be detected at the new colliders HERA, LEP 200, LHC, SSC, and at the possible future linear e + e - collider. We shall present theoretical predictions for production cross sections and decay probabilities, as well as for the important signatures. Our calculations will be based on the Minimal Supersymmetric Standard Model (MSSM) which is the simplest supersymmetric extension of the Standard Model. (authors)

Pion production and particle correlations

International Nuclear Information System (INIS)

Kristiansson, P.

1985-10-01

Intermediate energy heavy ion collisions have been studied using the carbon-beam produced at the CERN SC-accelerator. Cross-sections for π + and π - have been measured over a wide range of large angles at 60, 75 and 86 MeV/nucleon. The yields and shapes are compared to a nucleon-nucleon scattering approach, which underestimates the yields by orders of magnitude. The π - /π + -ratio observed is close to unity for 12 C + 12 C, but the enhancement for 12 C + 208 Pb is much larger than expected from the neutron excess in 208 Pb. Large-angle light-particle correlations for 86 MeV/nucleon carbon induced reactions on different targets (C, Al, Cu, Au) have been studied. An excess of correlations is observed in the particle-particle scattering plane. The strength of this effect increases with observed particle mass and decreases with target mass. (author)

Irradiation performance of coated fuel particles with fission product retaining kernel additives

International Nuclear Information System (INIS)

Foerthmann, R.

1979-10-01

The four irradiation experiments FRJ2-P17, FRJ2-P18, FRJ2-P19, and FRJ2-P20 for testing the efficiency of fission product-retaining kernel additives in coated fuel particles are described. The evaluation of the obtained experimental data led to the following results: - zirconia and alumina kernel additives are not suitable for an effective fission product retention in oxide fuel kernels, - alumina-silica kernel additives reduce the in-pile release of Sr 90 and Ba 140 from BISO-coated particles at temperatures of about 1200 0 C by two orders of magnitude, and the Cs release from kernels by one order of magnitude, - effective transport coefficients including all parameters which contribute to kernel release are given for (Th,U)O 2 mixed oxide kernels and low enriched UO 2 kernels containing 5 wt.% alumina-silica additives: 10g sub(K)/cm 2 s -1 = - 36 028/T + 6,261 (Sr 90), 10g Dsub(K)/cm 2 c -2 = - 29 646/T + 5,826 (Cs 134/137), alumina-silica kernel additives are ineffective for retaining Ag 110 m in coated particles. However, also an intact SiC-interlayer was found not to be effective at temperatures above 1200 0 C, - the penetration of the buffer layer by fission product containing eutectic additive melt during irradiation can be avoided by using additives which consist of alumina and mullite without an excess of silica, - annealing of LASER-failed irradiated particles and the irradiation test FRJ12-P20 indicate that the efficiency of alumina-silica kernel additives is not altered if the coating becomes defect. (orig.) [de

Mass production of polymer nano-wires filled with metal nano-particles.

Science.gov (United States)

Lomadze, Nino; Kopyshev, Alexey; Bargheer, Matias; Wollgarten, Markus; Santer, Svetlana

2017-08-17

Despite the ongoing progress in nanotechnology and its applications, the development of strategies for connecting nano-scale systems to micro- or macroscale elements is hampered by the lack of structural components that have both, nano- and macroscale dimensions. The production of nano-scale wires with macroscale length is one of the most interesting challenges here. There are a lot of strategies to fabricate long nanoscopic stripes made of metals, polymers or ceramics but none is suitable for mass production of ordered and dense arrangements of wires at large numbers. In this paper, we report on a technique for producing arrays of ordered, flexible and free-standing polymer nano-wires filled with different types of nano-particles. The process utilizes the strong response of photosensitive polymer brushes to irradiation with UV-interference patterns, resulting in a substantial mass redistribution of the polymer material along with local rupturing of polymer chains. The chains can wind up in wires of nano-scale thickness and a length of up to several centimeters. When dispersing nano-particles within the film, the final arrangement is similar to a core-shell geometry with mainly nano-particles found in the core region and the polymer forming a dielectric jacket.

Agglomerates, smoke oxide particles, and carbon inclusions in condensed combustion products of an aluminized GAP-based propellant

Science.gov (United States)

Ao, Wen; Liu, Peijin; Yang, Wenjing

2016-12-01

In solid propellants, aluminum is widely used to improve the performance, however the condensed combustion products especially the large agglomerates generated from aluminum combustion significantly affect the combustion and internal flow inside the solid rocket motor. To clarify the properties of the condensed combustion products of aluminized propellants, a constant-pressure quench vessel was adopted to collect the combustion products. The morphology and chemical compositions of the collected products, were then studied by using scanning electron microscopy coupled with energy dispersive (SEM-EDS) method. Various structures have been observed in the condensed combustion products. Apart from the typical agglomerates or smoke oxide particles observed before, new structures including the smoke oxide clusters, irregular agglomerates and carbon-inclusions are discovered and investigated. Smoke oxide particles have the highest amount in the products. The highly dispersed oxide particle is spherical with very smooth surface and is on the order of 1-2 μm, but due to the high temperature and long residence time, these small particles will aggregate into smoke oxide clusters which are much larger than the initial particles. Three types of spherical agglomerates have been found. As the ambient gas temperature is much higher than the boiling point of Al2O3, the condensation layer inside which the aluminum drop is burning would evaporate quickly, which result in the fact that few "hollow agglomerates" has been found compared to "cap agglomerates" and "solid agglomerates". Irregular agglomerates usually larger than spherical agglomerates. The formation of irregular agglomerates likely happens by three stages: deformation of spherical aluminum drops; combination of particles with various shape; finally production of irregular agglomerates. EDS results show the ratio of O to Al on the surface of agglomerates is lower in comparison to smoke oxide particles. C and O account for

Multiple particle production processes in the ''light'' of quantum optics

International Nuclear Information System (INIS)

Friedlander, E.M.

1990-09-01

Ever since the observation that high-energy ''nuclear active'' cosmic-ray particles create bunches of penetrating particles upon hitting targets, a controversy has raged about whether these secondaries are created in a ''single act'' or whether many hadrons are just the result of an intra-nuclear cascade, yielding one meson in every step. I cannot escape the impression that: the latter kind of model appeals naturally as a consequence of an innate bio-morphism in our way of thinking and that in one guise or another it has tenaciously survived to this day, also for hadron-hadron collisions, via multi-peripheral models to the modern parton shower approach. Indeed, from the very beginning of theoretical consideration of multiparticle production, the possibility of many particles arising from a single ''hot'' system has been explored, with many fruitful results, not the least of which are the s 1/4 dependence of the mean produced particle multiplicity and the ''thermal'' shape of the P T spectra. An important consequence of the thermodynamical-hydrodynamical models is that particle emission is treated in analogy to black-body radiation, implying for the secondaries a set of specific Quantum-Statistical properties, very similar to those observed in quantum optics. From here on I shall try to review a number of implications and applications of this QS analogy in the study of multiplicity distributions of the produced secondaries. I will touch only in passing another very important topic of this class, the Bose-Einstein two-particle correlations

Preparing rare earth-silicon-iron-aluminum alloys

International Nuclear Information System (INIS)

Marchant, J.D.; Morrice, E.; Herve, B.P.; Wong, M.M.

1980-01-01

As part of its mission to assure the maximum recovery and use of the Nation's mineral resources, the Bureau of Mines, investigated an improved procedure for producing rare earth-silicon alloys. For example, a charge consisting of 681 grams of mixed rare-earth oxides, 309 grams of ferrosilicon (75 wt-pct Si), and 182 grams of aluminum metal along with a flux consisting of 681 grams of CaO and 45 grams of MgO was reacted at 1500 0 C in an induction furnace. Good slag-metal separation was achieved. The alloy product contained, in weight-percent, 53 RE, 28 Si, 11 Fe, and 4 Al with a rare earth recovery of 80 pct. In current industrial practice rare earth recoveries are usually about 60 pct in alloy products that contain approximately 30 wt-pct each of rare earths and silicon. Metallurgical evaluations showed the alloys prepared in this investigation to be as effective in controlling the detrimental effect of sulfur in steel and cast iron as the commercial rare earth-silicon-iron alloys presently used in the steel industry

Fission product retention in TRISO coated UO2 particle fuels subjected to HTR simulated core heating tests

International Nuclear Information System (INIS)

Baldwin, C.A.; Kania, M.J.

1991-01-01

Results of the examination and analysis of 25,730 individual microspheres from spherical fuel elements HFR-K3/1 and HFR-K3/3 are reported. The parent spheres were irradiated in excess of end-of-life exposure and subsequently subjected to simulated core heating tests in a special high-temperature furnace at Forschungszentrum, Juelich, GmbH (KFA). Following the heating tests, the spheres were electrolytically deconsolidated to obtain unbounded fuel particles for Irradiated Microsphere Gamma Analyzer (IMGA) analysis. For sphere HFR-K3/1, which was heated for 500 h at 1600 deg. C, only four particles were identified as having released fission products. The remaining particles from the sphere showed no statistical evidence of fission product release. Scanning Electron Microscopy (SEM) examination showed that three of the defect particles had large sections of the TRISO coating missing, while the fourth appeared normal. For sphere HFR-K3/3, which was heated for 100 h at 1800 deg. C, the IMGA data revealed that fission product release (cesium) from individual particles was significant and that there was large particle-to-particle variation in retention capabilities. Individual particle release (cesium) averaged ten times the KFA-measured integral spherical fuel element release value. In addition, the bimodal distribution of the individual particle data indicated that two distinct modes of failure at fuel temperatures of 1800 deg. C and above may exist. (author). 6 refs, 6 figs, 4 tabs

Fission product retention in TRISCO coated UO2 particle fuels subjected to HTR simulated core heating tests

International Nuclear Information System (INIS)

Baldwin, C.A.; Kania, M.J.

1990-11-01

Results of the examination and analysis of 25,730 individual microspheres from spherical fuel elements HFR-K3/1 and HFR-K3/3 are reported. The parent spheres were irradiated in excess of end-of-life exposure and subsequently subjected to simulated core heating tests in a special high-temperature furnace at Forschungszentrum, Juelich, GmbH (KFA). Following the heating tests, the spheres were electrolytically deconsolidated to obtain unbonded fuel particles for Irradiated Microsphere Gamma Analyzer (IMGA) analysis. For sphere HFR-K3/1, which was heated for 500 h at 1600 degree C, only four particles were identified as having released fission products. The remaining particles from the sphere showed no statistical evidence of fission product release. Scanning Electron Microscopy (SEM) examination showed that three of the defect particles had large sections of the TRISO coating missing, while the fourth appeared normal. For sphere HFR-K3/3, which was heated for 100 h at 1800 degree C, the IMGA data revealed that fission product release (cesium) from individual particles was significant and that there was large particle-to-particle variation in retention capabilities. Individual particle release (cesium) averaged ten times the KFA-measured integral spherical fuel element release value. In addition, the bimodal distribution of the individual particle data indicated that two distinct modes of failure at fuel temperatures of 1800 degree C and above may exist. 6 refs., 6 figs., 4 tabs

Applied metrology in the production of superconducting model magnets for particle accelerators

Energy Technology Data Exchange (ETDEWEB)

Ferradas Troitino, Jose [CERN; Bestmann, Patrick [CERN; Bourcey, Nicolas [CERN; Carlon Zurita, Alejandro [CERN; Cavanna, Eugenio [ASG Supercond., Genova; Ferracin, Paolo [CERN; Ferradas Troitino, Salvador [CERN; Holik, Eddie Frank [Fermilab; Izquierdo Bermudez, Susana [CERN; Lackner, Friedrich [CERN; Löffler, Christian [CERN; Maury, Gregory [CERN; Perez, Juan Carlos [CERN; Savary, Frederic [CERN; Semeraro, Michela [CERN; Vallone, Giorgio [CERN

2017-12-22

The production of superconducting magnets for particle accelerators involves high precision assemblies and tight tolerances, in order to achieve the requirements for their appropriate performance. It is therefore essential to have a strict control and traceability over the geometry of each component of the system, and also to be able to compensate possible inherent deviations coming from the production process.

Energy dissipation and charged particle production in heavy ion collisions

International Nuclear Information System (INIS)

Mishra, Aditya Nath; Sahoo, Raghunath; Sarkisyan Edward, K.G.; )

2013-01-01

In this paper, we use a model combining the constituent quark picture with Landau relativistic hydrodynamics. Within this model, the secondary particle production in nucleus-nucleus or nucleon-nucleon (p-barp/pp) collisions is basically driven by the amount of the initial effective energy deposited by participants (quarks or nucleons) into the Lorentz contracted overlap region

The production of charmed particles in high-energy 16O-emulsion central interactions

International Nuclear Information System (INIS)

Aoki, S.; Hoshino, K.; Kitamura, H.; Kobayashi, M.; Kodama, K.; Miyanishi, M.; Nakamura, K.; Nakamura, M.; Nakanishi, S.; Niu, K.; Niwa, K.; Nomura, M.; Tajima, H.; Tsukagoshi, K.; Mazzoni, M.A.; Poulard, G.; Meddi, F.; Rosa, G.; Muciaccia, M.T.; Simone, S.; Nakazawa, K.; Tasaka, S.; Sato, Y.

1989-01-01

The production of charmed particles has been detected in 200 GeV per nucleon 16 O-emulsion central interactions. Their production cross section in elementary nucleon-nucleon processes has been estimated to be σ charm =[14.1±9.3(stat.) -8.4 +5.6 (syst.)]μb. (orig.)

Improvement in retention of solid fission products in HTGR fuel particles by ceramic kernel additives

Energy Technology Data Exchange (ETDEWEB)

Foerthmann, R.; Groos, E.; Gruebmeier, H.

1975-08-15

Increased requirements concerning the retention of long-lived solid fission products in fuel elements for use in advanced High Temperature Gas-cooled Reactors led to the development of coated particles with improved fission product retention which represent an alternative to silicon carbide-coated fuel particles. Two irradiation experiments have shown that the release of strontium, barium, and caesium from pyrocarbon-coated particles can be reduced by orders of magnitude if the oxide kernel contains alumina-silica additives. It was detected by electron microprobe analysis that the improved retention of the mentioned fission products in the fuel kernel is caused by formation of the stable aluminosilicates SrAl₂Si₂O₈, BaAl₂Si₂O₈and CsAlSi₂O₆ in the additional alumina-silica phase of the kernel.

Microstructure and mechanical properties of multi-components rare earth oxide-doped molybdenum alloys

International Nuclear Information System (INIS)

Zhang Guojun; Sun Yuanjun; Zuo Chao; Wei Jianfeng; Sun Jun

2008-01-01

Pure molybdenum and molybdenum alloys doped with two- or three-components rare earth oxide particles were prepared by powder metallurgy. Both the tensile property and fracture toughness of the pure molybdenum and multi-components rare earth oxide-doped molybdenum alloys were determined at room temperature. The multi-components rare earth oxide-doped molybdenum alloys are fine grained and contain a homogeneous distribution of fine particles in the submicron and nanometer size ranges, which is why the molybdenum alloys have higher strength and fracture toughness than pure molybdenum. Quantitative analysis is used to explain the increase in yield strength with respect to grain size and second phase strengthening. Furthermore, the relationship between the tensile properties and microstructural parameters is quantitatively established

Gravitationally induced adiabatic particle production: from big bang to de Sitter

Science.gov (United States)

de Haro, Jaume; Pan, Supriya

2016-08-01

In the background of a flat homogeneous and isotropic space-time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology.

Gravitationally induced adiabatic particle production: from big bang to de Sitter

International Nuclear Information System (INIS)

Haro, Jaume de; Pan, Supriya

2016-01-01

In the background of a flat homogeneous and isotropic space–time, we consider a scenario of the Universe driven by the gravitationally induced ‘adiabatic’ particle production with constant creation rate. We have shown that this Universe attains a big bang singularity in the past and at late-time it asymptotically becomes de Sitter. To clarify this model Universe, we performed a dynamical analysis and found that the Universe attains a thermodynamic equilibrium in this late de Sitter phase. Finally, for the first time, we have discussed the possible effects of ‘adiabatic’ particle creations in the context of loop quantum cosmology. (paper)

The rare fluorinated natural products and biotechnological prospects for fluorine enzymology.

Science.gov (United States)

Chan, K K Jason; O'Hagan, David

2012-01-01

Nature has hardly evolved a biochemistry of fluorine although there is a low-level occurrence of fluoroacetate found in selected tropical and subtropical plants. This compound, which is generally produced in low concentrations, has been identified in the plants due to its high toxicity, although to date the biosynthesis of fluoroacetate in plants remains unknown. After that, fluorinated entities in nature are extremely rare, and despite increasingly sophisticated screening and analytical methods applied to natural product extraction, it has been 25 years since the last bona fide fluorinated natural product was identified from an organism. This was the reported isolation of the antibiotic 4-fluorothreonine and the toxin fluoroacetate in 1986 from Streptomyces cattleya. This bacterium has proven amenable to biochemical investigation, the fluorination enzyme (fluorinase) has been isolated and characterized, and the biosynthetic pathway to these bacterial metabolites has been elucidated. Also the fluorinase gene has been cloned into a host bacterium (Salinispora tropica), and this has enabled the de novo production of a bioactive fluorinated metabolite from fluoride ion, by genetic engineering. Biotechnological manipulation of the fluorinase offers the prospects for the assembly of novel fluorinated metabolites by fermentation technology. This is particularly attractive, given the backdrop that about 15-20% of pharmaceuticals licensed each year (new chemical entities) contain a fluorine atom. Copyright © 2012 Elsevier Inc. All rights reserved.

Studies on the separation of rare earth elements and the nuclear decay properties of short lived rare-earth nuclides in U-235 fission products

International Nuclear Information System (INIS)

Ohyoshi, Akira; Ohyoshi, Emiko.

1980-01-01

The effect of a complex-forming agent, with which rare earths consecutively form the complexes, on the separation of a pair of adjacent rare earths by electromigration has been investigated. The relation between the separation factor for two complexes and the ligand-ion concentration was examined in the separation of La-Ce and Ce-Pr pairs with nitrilotriacetic acid. Rare earths were able to be isolated rapidly at the optimum ligand-ion concentration in lower one, and this method was applied to study the nuclear decay properties of the short lived isotopes of La, Ce, Pr, Nd and Yt formed in the fission of U-235. This method permits the direct measurement of the decay of La-144 without the interference from the radiation of other fission products. The gamma-ray spectrum of La-144 was measured with a high resolution Ge(Li) detector, and the gamma-transition was observed. From the decay plots of two strong photopeaks, the half-life of La-144 was determined. In the case of Ce fraction, the photopeaks assigned to respective isotopes were observed. In the studies on the decay properties of Pr-148 and Pr-149, the decay plot of the strong photopeak showed good linearity, and the accurate half-life of Pr-148 was determined. Similarly, the half-life of Pr-149 was longer than the previously reported value. (Kako, I.)

A large acceptance, high-resolution detector for rare K+-decay experiments

International Nuclear Information System (INIS)

Appel, R.; Atoyan, G.S.; Bassalleck, B.; Battiste, E.; Bergman, D.R.; Boesiger, K.; Brown, D.N.; Castillo, V.; Cheung, N.; Dhawan, S.; Do, H.; Egger, J.; Eilerts, S.W.; Felder, C.; Fischer, H.; Gach, H.M.; Giles, R.; Gninenko, S.N.; Herold, W.D.; Hotmer, J.E.; Issakov, V.V.; Karavichev, O.V.; Kaspar, H.; Kraus, D.E.; Lazarus, D.M.; Lebedev, V.A.; Leipuner, L.; Lichard, P.; Lowe, J.; Lozano, J.; Lu, T.; Ma, H.; Magurno, B.; Majid, W.; Menzel, W.; Miller, C.S.; Nickelson, M.; Ober, I.; Pile, P.H.; Pislak, S.; Poblaguev, A.A.; Pomianowski, P.; Postoev, V.E.; Proskurjakov, A.L.; Rehak, P.; Robmann, P.; Schmid, B.; Sher, A.; Sher, Aleksey; Shunko, E.; Steiner, S.; Stever, T.L.; Stotzer, R.W.; Suhov, V.V.; Thompson, J.A.; Truoel, P.; Valine, C.; Weyer, H.; Wolfe, D.M.; Zeller, M.E.

2002-01-01

The detector of the E865-collaboration at the Brookhaven-AGS described here combines a magnetic spectrometer for the charged decay products of 6 GeV/c K + with excellent electromagnetic calorimetry and efficient particle identification for electrons and muons. Its high-resolution, large acceptance and high rate capability made it well suited for the study of extremely rare or forbidden decays with multi-leptonic final states such as K + →π + μ + e - , K + →π + l + l - , K + →l + ν l e - e + and K + →π + π - e + ν e down to branching ratios below 10 -11 in an intense K + beam (∼10 8 per AGS spill)

Rare earth industries: Strategies for Malaysia

International Nuclear Information System (INIS)

2011-01-01

Evidently, many reports cite Malaysia as having reasonably substantial amounts of rare earths elements. In fact, based on the rare earths found in the residual tin deposits alone, Malaysia has about 30,000 tonnes. This does not take into account unmapped deposits which experts believe may offer more tonnages of rare earths. Brazil which is reported to have about 48,000 tonnes has announced plans to invest aggressively in the rare earths business. China has on record the largest reserves with about 36 million tonnes. This explains why China has invested heavily in the entire value chain of the rare earths business. Chinas committed investment in rare earths started many years ago when the country's foremost leaders proclaimed the strategic position of rare earths in the world economy. That forecast is now a reality where the rise in the green high-tech economy is seen driving global demand for rare earths in a big way. Malaysia needs to discover and venture into new economic growth areas. This will help fuel the country's drive to achieve a high income status by 2020 as articulated in the New Economic Model (NEM) and the many supporting Economic Transformation Plans that the Government has recently launched. Rare earths may be the new growth area for Malaysia. However, the business opportunities should not just be confined to the mining, extraction and production of rare earths elements alone if Malaysia is to maximise benefits from this industry. The industry's gold mine is in the downstream products. This is also the sector that China wants to expand. Japan which now controls about 50 % of the global market for downstream rare earths-based high-tech components is desperately looking for partners to grow their stake in the business. Malaysia needs to embark on the right strategies in order to build the rare earths industry in the country. What are the strategies? (author)

Acclimation of a marine microbial consortium for efficient Mn(II) oxidation and manganese containing particle production

International Nuclear Information System (INIS)

Zhou, Hao; Pan, Haixia; Xu, Jianqiang; Xu, Weiping; Liu, Lifen

2016-01-01

Highlights: • An efficient Mn(II) oxidation marine sediments microbial community was obtained. • High-throughput sequencing indicated new Mn(II) oxidation associated genus. • Na_3MnPO_4CO_3 and MnCO_3 were synthesized by the consortium. • Consortium exhibited Mn(II) oxidation performance over a range of harsh conditions. - Abstract: Sediment contamination with metals is a widespread concern in the marine environment. Manganese oxidizing bacteria (MOB) are extensively distributed in various environments, but a marine microbial community containing MOB is rarely reported. In this study, a consortium of marine metal-contaminated sediments was acclimated using Mn(II). The shift in community structure was determined through high-throughput sequencing. In addition, the consortium resisted several harsh conditions, such as toxic metals (1 mM Cu(II) and Fe(III)), and exhibited high Mn(II) oxidation capacities even the Mn(II) concentration was up to 5 mM. Meanwhile, biogenic Mn containing particles were characterized by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and N_2 adsorption/desorption. Dye removal performance of the Mn containing particles was assayed using methylene blue, and 20.8 mg g"−"1 adsorption capacity was obtained. Overall, this study revealed several new genera associated with Mn(II) oxidation and rare biogenic Na_3MnPO_4CO_3_. Results suggested the complexity of natural microbe-mediated Mn transformation.

Mobility of rare earth element in hydrothermal process and weathering product: a review

Science.gov (United States)

Lintjewas, L.; Setiawan, I.

2018-02-01

The Rare Earth Element (REE), consists of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Lu, Ho, Er, Tm, Yb, are important elements to be used as raw materials of advanced technology such as semiconductors, magnets, and lasers. The research of REE in Indonesia has not been done. Several researches were conducted on granitic rocks and weathering product such as Bangka, Sibolga, West Kalimantan, West Sulawesi and Papua. REE can be formed by hydrothermal processes such as Bayan Obo, South China. The REE study on active hydrothermal system (geothermal) in this case also has the potential to produce mineral deposits. The purpose of this review paper is to know the mobility of REE on hydrothermal process and weathering products. Mobility of REE in the hydrothermal process can change the distribution patterns and REE content such as Ce, Eu, La, Lu, Nd, Sm, and Y. Another process besides the hydrothermal is weathering process. REE mobility is influenced by weathering products, where the REE will experience residual and secondary enrichment processes in heavier minerals.

Plateau on temperature dependence of magnetization of nanostructured rare earth titanates

Science.gov (United States)

Rinkevich, A. B.; Korolev, A. V.; Samoylovich, M. I.; Demokritov, S. O.; Perov, D. V.

2018-05-01

Magnetic properties of nanocomposite materials containing particles of rare earth titanates of R2Ti2O7 type, where R is a rare earth ion, including "spin ice" materials are investigated. The descending branches of hysteresis loop have been studied in detail in temperature range from 2 to 50 K. It has been shown that nanocomposites with Yb2Ti2O7, Dy2Ti2O7 and Er2Ti2O7 particles have one intersection point of the descending branches in some temperature range unlike many other nanocomposites. It is shown that magnetization has only weak temperature dependence near this point. It has been obtained that nanocomposites with Pr2Ti2O7 and Nd2Ti2O7 particles have no hysteresis loop. All above findings point out to unusual magnetic structures of the studied samples.

Effects of Rare Earth Elements on Properties of Ni-Base Superalloy Powders and Coatings

Directory of Open Access Journals (Sweden)

Chunlian Hu

2017-02-01

Full Text Available NiCrMoY alloy powders were prepared using inert gas atomization by incorporation of rare earth elements, such as Mo, Nb, and Y into Ni60A powders, the coatings were sprayed by oxy-acetylene flame spray and then remelted with high-frequency induction. The morphologies, hollow particle ratio, particle-size distribution, apparent density, flowability, and the oxygen content of the NiCrMoY alloy powders were investigated, and the microstructure and hardness of the coatings were evaluated by optical microscopy (OM. Due to incorporation of the rare earth elements of Mo, Nb, or Y, the majority of the NiCrMoY alloy particles are near-spherical, the minority of which have small satellites, the surface of the particles is smoother and hollow particles are fewer, the particles exhibit larger apparent density and lower flowability than those of particles without incorporation, i.e., Ni60A powders, and particle-size distribution exhibits a single peak and fits normal distribution. The microstructure of the NiCrMoY alloy coatings exhibits finer structure and Rockwell hardness HRC of 60–63 in which the bulk- and needle-like hard phases are formed.

Hot beta particles in the lung: Results from dogs exposed to fission product radionuclides

Energy Technology Data Exchange (ETDEWEB)

Hahn, F.F.; Griffith, W.C.; Hobbs, C.H. [and others

1995-12-01

The Chernobyl nuclear reactor accident resulted in the release of uranium dioxide fuel and fission product radionuclides into the environment with the fallout of respirable, highly radioactive particles that have been termed {open_quotes}hot beta particles.{close_quotes} There is concern that these hot beta particles (containing an average of 150-20,000 Bq/particle), when inhaled and deposited in the lung, may present an extraordinary hazard for the induction of lung cancer. We reviewed data from a group of studies in dogs exposed to different quantities of beta-emitting radionuclides with varied physical half-lives to determine if those that inhaled hot beta particles were at unusual risk for lung cancer. This analysis indicates that the average dose to the lung is adequate to predict biologic effects of lung cancer for inhaled beta-emitting radionuclides in the range of 5-50 Gy to the lung and with particle activities in the range of 0.10-50 Bq/particle.

Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

International Nuclear Information System (INIS)

Davis, V.T.; Covington, A.M.; Duvvuri, S.S.; Kraus, R.G.; Emmons, E.D.; Kvale, T.J.; Thompson, J.S.

2007-01-01

The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps

Quantum production of particles (the Hawking effect) in nonstationary black holes

International Nuclear Information System (INIS)

Volovich, I.V.; Zagrebnov, V.A.; Frolov, V.P.; AN SSSR, Moscow. Fizicheskij Inst.)

1976-01-01

Particle production in a gravitational field of a black hole with changing mass is considered. It is shown that in the case when parameters are changed adiabatically taking into account the nonstationarity is reduced effectively to the taking into account the dependence of the Hawking radiation temperature on the retarded time

Quantum production of particles (the Hawking effect) in nonstationary black holes

Energy Technology Data Exchange (ETDEWEB)

Volovich, I V; Zagrebnov, V A; Frolov, V P [Joint Inst. for Nuclear Research, Dubna (USSR); AN SSSR, Moscow. Fizicheskij Inst.)

1976-11-01

Particle production in a gravitational field of a black hole with changing mass is considered. It is shown that in the case when parameters are changed adiabatically taking into account the nonstationarity is reduced effectively to the taking into account the dependence of the Hawking radiation temperature on the retarded time.

Cost Minimization for Joint Energy Management and Production Scheduling Using Particle Swarm Optimization

Science.gov (United States)

Shah, Rahul H.

production planning framework are discussed. A modified Particle Swarm Optimization solution technique is adopted to solve the proposed scheduling problem. The algorithm is described in detail and compared to Genetic Algorithm. Case studies are presented to illustrate the benefits of using the proposed model and the effectiveness of the Particle Swarm Optimization approach. Numerical Experiments are implemented and analyzed to test the effectiveness of the proposed model. The proposed scheduling strategy can achieve savings of around 19 to 27 % in cost per part when compared to the baseline scheduling scenarios. By optimizing key production system parameters from the cost per part model, the baseline scenarios can obtain around 20 to 35 % in savings for the cost per part. These savings further increase by 42 to 55 % when system parameter optimization is integrated with the proposed scheduling problem. Using this method, the most influential parameters on the cost per part are the rated power from production, the production rate, and the initial machine reliabilities. The modified Particle Swarm Optimization algorithm adopted allows greater diversity and exploration compared to Genetic Algorithm for the proposed joint model which results in it being more computationally efficient in determining the optimal scheduling. While Genetic Algorithm could achieve a solution quality of 2,279.63 at an expense of 2,300 seconds in computational effort. In comparison, the proposed Particle Swarm Optimization algorithm achieved a solution quality of 2,167.26 in less than half the computation effort which is required by Genetic Algorithm.

Pair production of exotic particles at pp(p-barp) colliding beams

International Nuclear Information System (INIS)

Borisov, G.V.; Pirogov, Yu.F.; Rudakov, K.R.

1986-01-01

A complete set of differential cross sections has been obtained in Born approximation for pair production of exotic particles with various spins J=0, 1/2, 1 and quantum numbers (colored and colorless) both in qq-bar and gg-collisions. The connection of the unitarity of vector boson processes with gauge invariance, factorization properties of non-Abelian gauge amplitudes and the presence of kinematic zeros is used. Besides, the problem of admissibility of massless limit for these processes is being discussed. The yield of exotic particle pairs at pp(p-barp) colliding beams in TeV energy range have been calculated and limits for the accessible mass range have been found

Gravitationally induced particle production and its impact on the WIMP abundance

Directory of Open Access Journals (Sweden)

I. Baranov

2015-12-01

Full Text Available A large set of independent astronomical observations have provided a strong evidence for nonbaryonic dark matter in the Universe. One of the most investigated candidates is an unknown long-lived Weakly Interacting Massive Particle (WIMP which was in thermal equilibrium with the primeval plasma. Here we investigate the WIMP abundance based on the relativistic kinetic treatment for gravitationally induced particle production recently proposed in the literature (Lima and Baranov, 2014 [16]. The new evolution equation is deduced and solved both numerically and through a semi-analytical approach. The predictions of the WIMP observables are discussed and compared with the ones obtained in the standard approach.

Dark matter from gravitational particle production at reheating

Energy Technology Data Exchange (ETDEWEB)

Markkanen, Tommi [Department of Physics, King' s College London, Strand, London WC2R 2LS (United Kingdom); Nurmi, Sami, E-mail: tommi.markkanen@kcl.ac.uk, E-mail: sami.t.nurmi@jyu.fi [Department of Physics, University of Jyväskylä, P.O. Box 35, FI-40014 University of Jyväskylä (Finland)

2017-02-01

We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

Dark matter from gravitational particle production at reheating

International Nuclear Information System (INIS)

Markkanen, Tommi; Nurmi, Sami

2017-01-01

We show that curvature induced particle production at reheating generates adiabatic dark matter if there are non-minimally coupled spectator scalars weakly coupled to visible matter. The observed dark matter abundance implies an upper bound on spectator masses m and non-minimal coupling values ξ. For example, assuming quadratic inflation, instant reheating and a single spectator scalar with only gravitational couplings, the observed dark matter abundance is obtained for m ∼ 0.1 GeV and ξ ∼ 1. Larger mass and coupling values of the spectator are excluded as they would lead to overproduction of dark matter.

Production of charmed particles in nuN collisions due to neutral weak currents

International Nuclear Information System (INIS)

Rekalo, M.P.

1980-01-01

A study is made of associated production of charmed particles in neutrino-nucleon interactions due to neutral weak currents. The angular distribution of the jets of charmed hadrons in nN interactions is determined in the lowest approximation in the quark-gluon coupling constant, according to which a charmed quark and antiquark are produced in an annihilation of a vector gluon and a virtual Z boson. It is shown that only a P-even dependence on the azimuthal angle v occurs in the studied approximation, the P-odd dependence which is possible in the general case being equal to zero. The total cross section for charmed-particle production in neutrino-nucleon interactions is calculated, and the origin of the violation of scale invariance is demonstrated

Neutron-induced particle production in the cumulative and noncumulative regions at intermediate energies

International Nuclear Information System (INIS)

Mashnik, S.G.

1992-01-01

The first systematic measurements of neutron-induced inclusive production of protons, deuterons, tritons and charged pions on carbon, copper, and bismuth in the bombarding energy range of 300-580 MeV and in the angular interval from 51 deg to 165 deg have been analyzed in the framework of the cascade-exciton model. The role of single-particle scattering, the effects of rescattering, the pre-equilibrium emission and 'coalescence' mechanism in particle production in the cumulative (i.e., kinematically - forbidden for quasi-free intranuclear projectile-nucleon collisions) and noncumulative regions are discussed. A week sensitivity of the inclusive distributions to the specific reaction mechanisms and a need of correlation and polarization measurements are noted. 27 refs.; 12 figs.; 1 tab

Radon decay products and 10–1100 nm aerosol particles in Postojna Cave

Directory of Open Access Journals (Sweden)

M. Bezek

2013-03-01

Full Text Available At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn decay products and the number concentration and size distribution of aerosol particles in the size range of 10–1100 nm were monitored, with the focus on the unattached fraction (fun of radon decay products (RnDPs, a key parameter in radon dosimetry. The total number concentration of aerosols during visits in summer was lower (700 cm−3 than in winter (2800 cm−3, and was dominated by 50 nm particles (related to the attached RnDPs in winter. This explains the higher fun values in summer (0.75 and the lower winter measurement (0.04 and, consequently, DCFD values of 43.6 and 13.1 mSv WLM−1 respectively for the calculated dose conversion factors. The difference is caused by an enhanced inflow of fresh outside air, driven in winter by the higher air temperature in the cave compared to outside, resulting in the introduction of outside aerosol particles into the cave.

Data Products From Particle Detectors On-Board NOAA's Newest Space Weather Monitor

Science.gov (United States)

Kress, B. T.; Rodriguez, J. V.; Onsager, T. G.

2017-12-01

NOAA's newest Geostationary Operational Environmental Satellite, GOES-16, was launched on 19 November 2016. Instrumentation on-board GOES-16 includes the new Space Environment In-Situ Suite (SEISS), which has been collecting data since 8 January 2017. SEISS is composed of five magnetospheric particle sensor units: an electrostatic analyzer for measuring 30 eV - 30 keV ions and electrons (MPS-LO), a high energy particle sensor (MPS-HI) that measures keV to MeV electrons and protons, east and west facing Solar and Galactic Proton Sensor (SGPS) units with 13 differential channels between 1-500 MeV, and an Energetic Heavy Ion Sensor (EHIS) that measures 30 species of heavy ions (He-Ni) in five energy bands in the 10-200 MeV/nuc range. Measurement of low energy magnetospheric particles by MPS-LO and heavy ions by EHIS are new capabilities not previously flown on the GOES system. Real-time data from GOES-16 will support space weather monitoring and first-principles space weather modeling by NOAA's Space Weather Prediction Center (SWPC). Space weather level 2+ data products under development at NOAA's National Centers for Environmental Information (NCEI) include the Solar Energetic Particle (SEP) Event Detection algorithm. Legacy components of the SEP event detection algorithm (currently produced by SWPC) include the Solar Radiation Storm Scales. New components will include, e.g., event fluences. New level 2+ data products also include the SEP event Linear Energy Transfer (LET) Algorithm, for transforming energy spectra from EHIS into LET spectra, and the Density and Temperature Moments and Spacecraft Charging algorithm. The moments and charging algorithm identifies electron and ion signatures of spacecraft surface (frame) charging in the MPS-LO fluxes. Densities and temperatures from MPS-LO will also be used to support a magnetopause crossing detection algorithm. The new data products will provide real-time indicators of potential radiation hazards for the satellite

Overview of rare B-decays

CERN Document Server

Prisciandaro, Jessica

2017-01-01

Being extremely suppressed in the Standard Model, rare decays of heavy-flavoured particles are a powerful probe of New Physics, and allow to reach energies beyond those accessible through direct searches. Several new results have been obtained by the LHC experiments. In particular, $b \\to sl^+l^-$ transitions give access to a large spectrum of observables, which provide complementary information on possible New Physics contributions. In this sector, tensions with Standard Model predictions have been observed.

Application of response surface methodology for optimization of parameters for microwave heating of rare earth carbonates

Science.gov (United States)

Yin, Shaohua; Lin, Guo; Li, Shiwei; Peng, Jinhui; Zhang, Libo

2016-09-01

Microwave heating has been applied in the field of drying rare earth carbonates to improve drying efficiency and reduce energy consumption. The effects of power density, material thickness and drying time on the weight reduction (WR) are studied using response surface methodology (RSM). The results show that RSM is feasible to describe the relationship between the independent variables and weight reduction. Based on the analysis of variance (ANOVA), the model is in accordance with the experimental data. The optimum experiment conditions are power density 6 w/g, material thickness 15 mm and drying time 15 min, resulting in an experimental weight reduction of 73%. Comparative experiments show that microwave drying has the advantages of rapid dehydration and energy conservation. Particle analysis shows that the size distribution of rare earth carbonates after microwave drying is more even than those in an oven. Based on these findings, microwave heating technology has an important meaning to energy-saving and improvement of production efficiency for rare earth smelting enterprises and is a green heating process.

Equilibration of particles with abelian charges

International Nuclear Information System (INIS)

Redlich, K.; Tounsi, A.

2002-01-01

We formulate the kinetic equation for time evolution and chemical equilibration of particles that carries an abelian charge. We show that dependently on the thermal conditions inside a fireball the system approaches to different chemical equilibrium limits. The role of exact conservation of quantum numbers in the kinetic description of rarely produced particles is explained. (orig.)

An Overview of Rare Earth Science and Technology

Science.gov (United States)

Gschneidner, Karl, Jr.

2012-02-01

Currently rare earth science and technology is robust: this includes all the major branches of science -- biochemistry, chemistry, materials and physics. There are, however, currently some anomalies and distortions especially in the technology and applications sector of the rare earth field, which is caused by the dominance of China on the sales of rare earths and rare earth containing products. For the past 5 to 10 years ˜95% of rare earths utilized in commerce came from China. Although Chinese actions have lead to sudden and large price spikes and export embargoes, the rare earths are still available but at a higher cost. The start up of production in 2011 at mines in the USA and Australia will alleviate this situation in about two years. Basic and applied research on the condensed matter physics/materials science has hardly been impacted by these events, but new research opportunities are opening up especially with regard to the USA's military and energy security. Magnets seems to be the hottest topic, but research on battery materials, phosphors and catalysts are also (or should be) strongly considered.

Fractional Hoppinglike Motion in Columnar Mesophases of Semiflexible Rodlike Particles

NARCIS (Netherlands)

Naderi, S.; Pouget, E.; Ballesta, P.; van der Schoot, P. P. A. M.; Lettinga, M.P.; Grelet, E

2013-01-01

We report on single-particle dynamics of strongly interacting filamentous fd virus particles in the liquid-crystalline columnar state in aqueous solution. From fluorescence microscopy, we find that rare, discrete events take place, in which individual particles engage in sudden, jumplike motion

A laboratory flow reactor with gas particle separation and on-line MS/MS for product identification in atmospherically important reactions

Directory of Open Access Journals (Sweden)

J. F. Bennett

2009-12-01

Full Text Available A system to study the gas and particle phase products from gas phase hydrocarbon oxidation is described. It consists of a gas phase photochemical flow reactor followed by a diffusion membrane denuder to remove gases from the reacted products, or a filter to remove the particles. Chemical analysis is performed by an atmospheric pressure chemical ionization (APCI triple quadrupole mass spectrometer. A diffusion membrane denuder is shown to remove trace gases to below detectable limits so the particle phase can be studied. The system was tested by examining the products of the oxidation of m-xylene initiated by HO radicals. Dimethylphenol was observed in both the gas and particle phases although individual isomers could not be identified. Two furanone isomers, 5-methyl-2(3Hfuranone and 3-methyl-2(5Hfuranone were identified in the particulate phase, but the isobaric product 2,5 furandione was not observed. One isomer of dimethyl-nitrophenol was identified in the particle phase but not in the gas phase.

Subvisible (2-100 μm) Particle Analysis During Biotherapeutic Drug Product Development: Part 1, Considerations and Strategy.

Science.gov (United States)

Narhi, Linda O; Corvari, Vincent; Ripple, Dean C; Afonina, Nataliya; Cecchini, Irene; Defelippis, Michael R; Garidel, Patrick; Herre, Andrea; Koulov, Atanas V; Lubiniecki, Tony; Mahler, Hanns-Christian; Mangiagalli, Paolo; Nesta, Douglas; Perez-Ramirez, Bernardo; Polozova, Alla; Rossi, Mara; Schmidt, Roland; Simler, Robert; Singh, Satish; Spitznagel, Thomas M; Weiskopf, Andrew; Wuchner, Klaus

2015-06-01

Measurement and characterization of subvisible particles (defined here as those ranging in size from 2 to 100 μm), including proteinaceous and nonproteinaceous particles, is an important part of every stage of protein therapeutic development. The tools used and the ways in which the information generated is applied depends on the particular product development stage, the amount of material, and the time available for the analysis. In order to compare results across laboratories and products, it is important to harmonize nomenclature, experimental protocols, data analysis, and interpretation. In this manuscript on perspectives on subvisible particles in protein therapeutic drug products, we focus on the tools available for detection, characterization, and quantification of these species and the strategy around their application. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Economic Modeling Considerations for Rare Diseases.

Science.gov (United States)

Pearson, Isobel; Rothwell, Ben; Olaye, Andrew; Knight, Christopher

2018-05-01

To identify challenges that affect the feasibility and rigor of economic models in rare diseases and strategies that manufacturers have employed in health technology assessment submissions to demonstrate the value of new orphan products that have limited study data. Targeted reviews of PubMed, the National Institute for Health and Care Excellence's (NICE's) Highly Specialised Technologies (HST), and the Scottish Medicines Consortium's (SMC's) ultra-orphan submissions were performed. A total of 19 PubMed studies, 3 published NICE HSTs, and 11 ultra-orphan SMC submissions were eligible for inclusion. In rare diseases, a number of different factors may affect the model's ability to comply with good practice recommendations. Many products for the treatment of rare diseases have an incomplete efficacy and safety profile at product launch. In addition, there is often limited available natural history and epidemiology data. Information on the direct and indirect cost burden of an orphan disease also may be limited, making it difficult to estimate the potential economic benefit of treatment. These challenges can prevent accurate estimation of a new product's benefits in relation to costs. Approaches that can address such challenges include using patient and/or clinician feedback to inform model assumptions; data from disease analogues; epidemiological techniques, such as matching-adjusted indirect comparison; and long-term data collection. Modeling in rare diseases is often challenging; however, a number of approaches are available to support the development of model structures and the collation of input parameters and to manage uncertainty. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Determination of rare earth elements in products of Chadormalu iron ore concentrator plant (Iran) from beneficiation point of view

International Nuclear Information System (INIS)

Jorjani, E.; Bagherieh, A. H.; Rezai, B.

2007-01-01

:Different samples have been prepared from different products in Chadormalu iron ore concentrator plant: Low intensity magnetite separators concentrate (magnetite concentrate), reverse flotation tail (final hematite concentrate), flotation concentrate (apatite concentrate), final tail (L.I. M.S. tail + reverse flotation concentrate + apatite flotation tail). The samples were used for rare earth elements (REEs) distribution and origin studies. The assay of REEs was determined by ICP-MS spectrometry. The amount of total (light and heavy) REEs were 9631, 291, 199, 2236 ppm and the distributions were 19.3, 3.6, 10.1, 67% in flotation concentrate (apatite concentrate), reverse flotation tail (hematite concentrate), magnetite concentrate and total tail respectively. About 19.3% of total REEs were distributed in apatite concentrate with an assay of 9631 ppm. Therefore, further studies have been conducted on this product. According to the Xray studies the minerals of fluoroapatite, ankerite and calcite are the main mineral phases in apatite concentrate which the apatite is dominant among them. The scanning electron microscopy studies were shown that the high amount of REEs distributed on fluoroapatite mineral. The results have clearly shown that the apatite concentrate that is a by product of iron dressing in Chadormalu plant, with a low economical value and left without any further treatment, can be used as a significant source of REEs. According to this characterization studies, the recovery of a mixed rare earth oxide from fluoroapatite is possible either with the treatment of liquors from the total dissolution of the ore in nitric acid or with the proposed treatment of the phosphogypsum by-product from the conventional sulphuric acid route and the recovery of rare earth oxides from phosphoric acid sludges that the detailed flowsheet needs further extraction work

Acclimation of a marine microbial consortium for efficient Mn(II) oxidation and manganese containing particle production

Energy Technology Data Exchange (ETDEWEB)

Zhou, Hao, E-mail: zhouhao@dlut.edu.cn [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China); Pan, Haixia [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China); Xu, Jianqiang [School of Life Science and Medicine, Dalian University of Technology, Panjin 124221 (China); Xu, Weiping; Liu, Lifen [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Food and Environment, Dalian University of Technology, Panjin 124221 (China)

2016-03-05

Highlights: • An efficient Mn(II) oxidation marine sediments microbial community was obtained. • High-throughput sequencing indicated new Mn(II) oxidation associated genus. • Na{sub 3}MnPO{sub 4}CO{sub 3} and MnCO{sub 3} were synthesized by the consortium. • Consortium exhibited Mn(II) oxidation performance over a range of harsh conditions. - Abstract: Sediment contamination with metals is a widespread concern in the marine environment. Manganese oxidizing bacteria (MOB) are extensively distributed in various environments, but a marine microbial community containing MOB is rarely reported. In this study, a consortium of marine metal-contaminated sediments was acclimated using Mn(II). The shift in community structure was determined through high-throughput sequencing. In addition, the consortium resisted several harsh conditions, such as toxic metals (1 mM Cu(II) and Fe(III)), and exhibited high Mn(II) oxidation capacities even the Mn(II) concentration was up to 5 mM. Meanwhile, biogenic Mn containing particles were characterized by scanning electron microscope (SEM), X-ray powder diffraction (XRD), and N{sub 2} adsorption/desorption. Dye removal performance of the Mn containing particles was assayed using methylene blue, and 20.8 mg g{sup −1} adsorption capacity was obtained. Overall, this study revealed several new genera associated with Mn(II) oxidation and rare biogenic Na{sub 3}MnPO{sub 4}CO{sub 3.} Results suggested the complexity of natural microbe-mediated Mn transformation.

Particle production and Boltzmann integral form of relativistic quantum transport theory

International Nuclear Information System (INIS)

Rafelski, J.; Davis, E.D.; Bialynicki-Birula, I.

1993-01-01

The 3+3+1 dimensional relativistic quantum transport equation for the fermion matter field, combines the particle pair production with flow phenomena, which occur at very different time scale. A direct numerical treatment of dynamical situations is therefore practically impossible. The authors attempt a seperation of these two sectors by the method of prediagonalization of the integral equations. They exploit the structure of the resolvent of the transport equations: it contains two poles corresponding to the flow sector and two to the pair production sector. Their hope for practical applications is to treat matter flow as a classical phenomenon and to be able to obtain an integral term describing the pair production accurately

Abundance and production of particle-associated bacteria and their role in a mangrove-dominated estuary

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, M.J.B.D.; Nair, S.; LokaBharathi, P.A.; Chandramohan, D.

, Azam F (1982) Thymidine incorporation as a measure of heterotrophic bacterioplankton production in marine surface waters: evaluation and field results. Mar Biol 66:109-120 Fukuda R, Ogawa H, Nagata T, Koike I (1998) Direct determination of carbon... in the total and particle-associated bacterial abundance in the Mandovi estuary. TC - total counts, PAB - particle-associated bacteria. Gonsalves et al.: Particle-associated bacterial dynamics 21 0 200 400 600 800 1000 ONDJFMAMJJAS P r o duc t i o n...

A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation; Etude de la fluorescence des gaz rares excites par des particules nucleaires. Utilisation pour la detection des rayonnements nucleaires par scintillation

Energy Technology Data Exchange (ETDEWEB)

Koch, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-12-15

In the first part is studied the properties of atoms excited by the passage of {alpha} particles through the various rare gases at atmospheric pressure. A spectral analysis of the emitted light showed that certain impurities play an important part in producing the fluorescence, and it has led to the conclusion that the light emission contains at least two components - one very short - lived due to the direct deexcitation of the rare gas, the other relatively slower due to the energy transfers to the impurity. The measurement of the life-time of the excited states has confirmed this foregoing hypothesis, the rapid part of the impulse is extremely short: less than 2,25.10{sup -9} s in the case of xenon; the slower part has a life-time depending directly on the nitrogen concentration, nitrogen being the impurity giving the largest effect in all cases. The study of rare gases under the influence of an electric field has made it possible to show that the amount of light produced by an {alpha} particle can be multiplied (by 60, for example, in a field of 600 V:cm) so that the luminescent efficiency is greater than in the case of INaTI. In the second part the characteristics of the rare gases acting as scintillators is examined, the most important property being the absence of fluorescence saturation when the intensity of the excitation incident on the gas is very large. This, together with the very short time of scintillation has made it possible to study a certain number of nuclear physical applications (heavy particle energy-measurements, kinetic studies on nuclear reactors, neutron spectroscopy). (author) [French] On etudie dans la premiere partie les proprietes des atomes excites par le passage de particules {alpha} dans les differents gaz rares a la pression atmospherique. L'etude spectrale de la lumiere emise a montre que certaines impuretes jouent un role considerable dans la fluorescence et on a ete amene a penser que l'emission de lumiere comporte au moins deux

Particle production in field theories coupled to strong external sources, I: Formalism and main results

International Nuclear Information System (INIS)

Gelis, Francois; Venugopalan, Raju

2006-01-01

We develop a formalism for particle production in a field theory coupled to a strong time-dependent external source. An example of such a theory is the color glass condensate. We derive a formula, in terms of cut vacuum-vacuum Feynman graphs, for the probability of producing a given number of particles. This formula is valid to all orders in the coupling constant. The distribution of multiplicities is non-Poissonian, even in the classical approximation. We investigate an alternative method of calculating the mean multiplicity. At leading order, the average multiplicity can be expressed in terms of retarded solutions of classical equations of motion. We demonstrate that the average multiplicity at next-to-leading order can be formulated as an initial value problem by solving equations of motion for small fluctuation fields with retarded boundary conditions. The variance of the distribution can be calculated in a similar fashion. Our formalism therefore provides a framework to compute from first principles particle production in proton-nucleus and nucleus-nucleus collisions beyond leading order in the coupling constant and to all orders in the source density. We also provide a transparent interpretation (in conventional field theory language) of the well-known Abramovsky-Gribov-Kancheli (AGK) cancellations. Explicit connections are made between the framework for multi-particle production developed here and the framework of reggeon field theory

Continuous production of nanostructured particles using spatial atomic layer deposition

International Nuclear Information System (INIS)

Ommen, J. Ruud van; Kooijman, Dirkjan; Niet, Mark de; Talebi, Mojgan; Goulas, Aristeidis

2015-01-01

In this paper, the authors demonstrate a novel spatial atomic layer deposition (ALD) process based on pneumatic transport of nanoparticle agglomerates. Nanoclusters of platinum (Pt) of ∼1 nm diameter are deposited onto titania (TiO 2 ) P25 nanoparticles resulting to a continuous production of an active photocatalyst (0.12–0.31 wt. % of Pt) at a rate of about 1 g min −1 . Tuning the precursor injection velocity (10–40 m s −1 ) enhances the contact between the precursor and the pneumatically transported support flows. Decreasing the chemisorption temperature (from 250 to 100 °C) results in more uniform distribution of the Pt nanoclusters as it decreases the reaction rate as compared to the rate of diffusion into the nanoparticle agglomerates. Utilizing this photocatalyst in the oxidation reaction of Acid Blue 9 showed a factor of five increase of the photocatalytic activity compared to the native P25 nanoparticles. The use of spatial particle ALD can be further expanded to deposition of nanoclusters on porous, micron-sized particles and to the production of core–shell nanoparticles enabling the robust and scalable manufacturing of nanostructured powders for catalysis and other applications

Higher-order QCD corrections to inclusive particle production in panti p collisions

International Nuclear Information System (INIS)

Borzumati, F.M.; Kniehl, B.A.; Kramer, G.

1992-10-01

Inclusive single-particle production cross sections have been calculated including higher-order QCD corrections. Transverse-momentum and rapidity distributions are presented and the scale dependence is studied. The results are compared with experimental data from the CERN Spanti pS Collider and the Fermilab Tevatron. (orig.)

Rare decays and search for new physics

CERN Document Server

Koppenburg, Patrick

2014-01-01

In absence of direct signs of new physics at the LHC, rare decays of heavy flavoured particles provide an ideal laboratory to look for deviations from the Standard Model and explore an energy regime beyond the LHC reach. Here, new results from the LHC and the $B$ factories are presented, with a particular focus on electroweak penguin-mediated $b\\rightarrow s$ transitions

Liquid-borne nano particles impact on the random yield during critical processes in IC’s production

NARCIS (Netherlands)

Wali, F.; Knotter, D. Martin; Kuper, F.G.

2008-01-01

Semiconductor industry faces a continuous challenge to decrease the transistor size as well as to increase the yield by eliminating defect sources. One of the sources of particle defects is ultra pure water used in different production tools at different stages of processing. In this paper, particle

Separation of heavier rare earths from neutron irradiated uranium targets

International Nuclear Information System (INIS)

Bhargava, V.K.; Rao, V.K.; Marathe, S.G.; Sahakundu, S.M.; Iyer, R.H.

1978-01-01

A radiochemical method is described for the separation of heavier rare earths from the fission of uranium. The method is particularly suitable for the separation of low yield (10sup(-5)%-10sup(-7)%), highly asymmetric rare earth fission products viz. sup(179,177)Lu, sup(175)Yb, sup(173)Tm, sup(172,171)Er, sup(167)Ho and sup(161,160)Tb in the neutron induced fission of natural and depleted uranium targets. Additional separation steps have been incorporated for decontamination from sup(239)Np (an activation product) and sup(93-90)Y (a high fission-yield product) which show similar chemical behaviour to rare earths. Separation of individual rare earths is achieved by a cation exchange method performed at 80 deg C by elution with α-hydroxyisobutyric acid (α-HIBA). (author)

K-shell X-ray production cross sections of Ni induced by protons, alpha-particles, and He{sup +}

Energy Technology Data Exchange (ETDEWEB)

Bertol, A.P.L. [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Hinrichs, R. [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Instituto de Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Vasconcellos, M.A.Z., E-mail: marcos@if.ufrgs.br [Programa de Pós-graduação em Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

2015-11-15

The proton, alpha-particle, and He{sup +} induced X-ray emissions of Ni were measured on mono-elemental thin films in order to obtain the K-shell X-ray production cross section in the energy range of 0.7–2.0 MeV for protons, 4.0–6.5 MeV for alpha-particles, and 3.0–4.0 MeV for He{sup +}. The proton-induced X-ray production cross section for Ni agreed well with the theoretical values, endorsing the quality of the measurements. The X-ray production cross section induced with alpha-particles is in good agreement with ECPSSR theory in the complete range of energies, while for He{sup +} that quantity is systematically below. K{sub β}/K{sub α} ratios were evaluated and compared with experimental and theoretical values.

J/psi particle production by 70 GeV/c protons

International Nuclear Information System (INIS)

Antipov, Yu.M.; Bessubov, V.A.; Bubanov, N.P.; Bushmin, Yu.B.; Denisov, S.P.; Gorin, Yu.P.; Lebedev, A.A.; Lednev, A.A.; Mikhailov, Yu.V.; Petrukhin, A.I.

1975-01-01

Invariant mass spectrum of μ + μ - pairs produced by 70 GeV/c protons in Be target are presented. Distinct enhancements in the mass region of rho, ω mesons, PHI meson and J/psi particle are observed. For J/psi production, x, ysup(*) and p 2 distributions are given. The total cross section for the reaction p + Be → (J/psi → μ + μ - ) + ... is equal to 9.5 +- 2.5 nb/nucleus

NLO predictions for the production of a (750 GeV) spin-two particle at the LHC

CERN Document Server

Das, Goutam; Hirschi, Valentin; Maltoni, Fabio; Shao, Hua-Sheng

2017-07-10

We obtain predictions accurate at the next-to-leading order in QCD for the production of a generic spin-two particle in the most relevant channels at the LHC: production in association with colored particles (inclusive, one jet, two jets and $t\\bar t$), with vector bosons ($Z,W^\\pm,\\gamma$) and with the Higgs boson. We present total and differential cross sections as well as branching ratios corresponding to a spin-2 particle of 750 GeV of mass, possibly with non-universal couplings to standard model particles, at 13 TeV of center-of-mass energy. We find that the next-to-leading order corrections give rise to sizeable $K$ factors for many channels, in some cases exposing the unitarity-violating behaviour of non-universal couplings scenarios, and in general greatly reduce the theoretical uncertainties. Our predictions are publicly available in the \\amc\\ framework and can, therefore, be directly used in experimental simulations for any value of the mass and couplings.

Hard jet production in cosmic ray particle interactions at the energy of about 1000 TeV

International Nuclear Information System (INIS)

Buja, Z.; Gladysz, E.; Mikocki, S.; Szarska, M.; Zawiejski, L.

1987-01-01

Eight photon-hadron families with the energy of primary particles of about 1000 TeV detected in a X-ray emulsion chamber of Pamir Experiment have features which indicate the production of hard jets. Lateral distribution and the distribution of transverse momentum flow indicate the existence of two groups of particles. The average transverse momentum for particles in one group is more than 6 times larger then that for the other group. Azimuthal asymmetry is visible in the particle number and transverse momentum flow. Transverse energy E T for individual families oscillates between 26 and 120 GeV with an average value of 57 GeV. The experimental results were compared with Monte Carlo simulation in which QCD parton hard scattering mechanism in interactions of primary hadrons was assumed. An agreement can be reached if the fraction of jet production exceeded 60% and the transverse momenta of jets are not smaller than 40 GeV/c. 37 refs., 11 figs. (author)

Rare earth industries; Moving Malaysia's Green Economy Forward

International Nuclear Information System (INIS)

2011-08-01

There is a famous saying, Where there is risk, there is opportunity. Rare earths present both health and environmental risks as well as potential economic opportunities. However, the risks are manageable thanks to improved technologies and a better understanding of the implications on health and the environment. This explains why there is a rush by many countries to reopen old mines and increase investment in the production of rare earths concentrate and their high value downstream products. Why is there such a scramble to risk money on rare earths? What have ignited global demand? Where are the opportunities? How are the risks associated with rare earths managed? Can Malaysia benefit from this new growth industry? What should be our strategies? This report, produced by the joint Working Group of the Academy of Sciences Malaysia (ASM) and the Majlis Professor Negara (MPN), discusses the science of rare earths and their business prospects; and proposes some strategic directions for Malaysia. The analysis is based on information culled from various secondary sources as well as the groups engagement with experts from the Rare Earths Society of China. (author)

Chemical synthesis and characterization of nano-sized rare-earth ...

Indian Academy of Sciences (India)

2017-12-06

Dec 6, 2017 ... exhibited the average particle size in the range of 36.4–73.8nm. The data on the ... For example, some of the rare-earth ruthenates Ln2Ru2O7 ..... From qualitative band-model consideration of the type discussed by ...

Determination of nanoscale particles in the air of working zone at the metallurgical production

Directory of Open Access Journals (Sweden)

Т.S. Ulanova

2015-03-01

Full Text Available The results of studies of the air of working zone at the metallurgical production on the example of Avisma OJSC (Berezniki, the Perm Territory for the content of nanoscale particles are specified. The maximum nanoparticles concentration in the range of 13523–28609 mln./m3 is determined at the working place of the titanium production smelter with the maximum size of particles of 10–15 nm. At the working place in the administrative building (reference working place the maximum concentration is determined within the range of 524–1000 mln./m3; the maximum size of nanoparticles is 20 nm. It was established that the number concentration of nanoparticles at the reference working places (administration of Avisma OJSC is significantly lower than at the working places of main production processes. The presented studies can be used as the additional factors in the assessment of labor conditions and occupational risk during the manufacture and use of materials containing nanoparticles as well as the production processes with the nanoparticles formation.

Charmed particles production in pA -interactions at √s = 11.8 GeV

Energy Technology Data Exchange (ETDEWEB)

Aleev, A.; Balandin, V.; Boguslavsky, M.; Dunun, V.; Gavrishchuk, O.; Furmanec, N.; Kireev, V.; Konstantinov, V.; Kosarev, I.; Kokoulina, E.; Kuzmin, N.; Lanshikov, G.; Nikitin, V.; Petukhov, Yu.; Rufanov, I.; Topuria, T.; Yukaev, A. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Ardashev, E.; Afonin, A.; Bogolyubsky, M.; Golovnia, S.; Gorokhov, S.; Golovkin, V.; Kholodenko, A.; Kiriyakov, A.; Kurchaninov, L.; Mitrofanov, G.; Moiseev, A.; Petrov, V.; Pleskach, A.; Riadovikov, V.; Ronjin, V.; Senko, V.; Shalanda, N.; Soldatov, M.; Tsyupa, Yu.; Vasiliev, M.; Vorobiev, A.; Yakimchuk, V.; Zapolsky, V.; Zmushko, V. [Institute for High Energy Physics, Protvino, Moscow region (Russian Federation); Basiladze, S.; Bogdanova, G.; Grishin, N.; Grishkevich, Ya.; Ermolov, P.; Karmanov, D.; Kozlov, V.; Kramarenko, V.; Kubarovsky, A.; Larichev, A.; Leflat, A.; Lyutov, S.; Merkin, M.; Orfanitsky, S.; Popov, V.; Tikhonova, L.; Vischnevskaya, A.; Volkov, V.; Voronin, A.; Zotkin, S.; Zotkin, D.; Zverev, E. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (SINP MSU), Federal State Budget Educational Institution of Higher Education M.V. Lomonosov, Moscow (Russian Federation); Collaboration: SVD-2 Collaboration

2017-03-15

The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP, Protvino) are presented. Interactions of the 70GeV proton beam with carbon, silicon and lead targets were studied to detect decays of charmed D{sup 0}, anti D{sup 0}, D{sup +}, D{sup -} mesons and Λ{sub c}{sup +} baryon near their production threshold. Measurements of lifetimes and masses have shown a good agreement with PDG data. The inclusive cross-sections of charm production and their A-dependences have been obtained. The yields of these particles are compared with the theoretical predictions and the data of other experiments. The measured cross-section of the total open charm production (σ{sub tot}(c anti c) = 7.1 ± 2.3(stat) ± 1.4(syst) μb/nucleon) at the collision c.m. energy √s = 11.8 GeV is well above the QCD model predictions. The contributions of different kinds of charmed particles to the total cross-section of the open charm production in proton-nucleus interactions vary with energy. (orig.)

Associated multiplicity of γ-particles in processes of lepton pair production on nuclei

International Nuclear Information System (INIS)

Gevorkyan, S.R.; Gulkanyan, H.R.; Vartanyan, V.A.

1986-01-01

An expression has been obtained for mean multiplicity of g-particles accompanying the process of deep-inelastic lepton pair production on nuclei. The expression allows one to get information on structure peculiarities of leading hadron in this process

Systematics of Charged Particle Production in Heavy-Ion Collisions with the PHOBOS Detector at Rhic

Science.gov (United States)

Steinberg, Peter A.; Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Corbo, J.; Decowski, M. P.; Garcia, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Henderson, C.; Hicks, D.; Hofman, D.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Michałowski, J.; Mignerey, A.; Mülmenstädt, J.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Rafelski, M.; Rbeiz, M.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S. F.; Stodulski, M.; Sukhanov, A.; Tang, J.-L.; Teng, R.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wadsworth, B.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2002-03-01

The multiplicity of charged particles produced in Au+Au collisions as a function of energy, centrality, rapidity and azimuthal angle has been measured with the PHOBOS detector at RHIC. These results contribute to our understanding of the initial state of heavy ion collisions and provide a means to compare basic features of particle production in nuclear collisions with more elementary systems.

In silico assessment of biomedical products: The conundrum of rare but not so rare events in two case studies.

Science.gov (United States)

Viceconti, Marco; Cobelli, Claudio; Haddad, Tarek; Himes, Adam; Kovatchev, Boris; Palmer, Mark

2017-05-01

In silico clinical trials, defined as "The use of individualized computer simulation in the development or regulatory evaluation of a medicinal product, medical device, or medical intervention," have been proposed as a possible strategy to reduce the regulatory costs of innovation and the time to market for biomedical products. We review some of the the literature on this topic, focusing in particular on those applications where the current practice is recognized as inadequate, as for example, the detection of unexpected severe adverse events too rare to be detected in a clinical trial, but still likely enough to be of concern. We then describe with more details two case studies, two successful applications of in silico clinical trial approaches, one relative to the University of Virginia/Padova simulator that the Food and Drug Administration has accepted as possible replacement for animal testing in the preclinical assessment of artificial pancreas technologies, and the second, an investigation of the probability of cardiac lead fracture, where a Bayesian network was used to combine in vivo and in silico observations, suggesting a whole new strategy of in silico-augmented clinical trials, to be used to increase the numerosity where recruitment is impossible, or to explore patients' phenotypes that are unlikely to appear in the trial cohort, but are still frequent enough to be of concern.

Exotic particles at the LHC. Production via the Higgs portal and WIMP dark matter searches

Energy Technology Data Exchange (ETDEWEB)

Hessler, Andre Georg

2016-09-05

This thesis addresses two different aspects of the search for Physics Beyond the Standard Model at the Large Hadron Collider (LHC). First, and motivated by the recent discovery of a new interaction mediated by the Higgs boson, we systematically analyze the impact of the Higgs interaction on the production of new particles at the LHC. Second, we investigate the collider signatures of long-lived particles decaying into leptons and invisible energy, and which are predicted to exist in a class of neutrino mass models with a weakly interacting dark matter particle.

Preparation and characterization of PT-rare earth/C electrocatalysts for PEM fuel cells

International Nuclear Information System (INIS)

Santoro, Thais Aranha de Barros

2009-01-01

Pt-rare earth/C electrocatalysts (rare earth = La, Ce, Pr, Nd, Sm, Tb, Dy, Ho, Er, Tm, and Lu) were prepared (20 wt.% and Pt-to-RE atomic ratio of 50:50) by an alcohol reduction process using H 2 PtCl 6 .6H 2 O (Aldrich) and rare earth (III) chlorides (Aldrich) as metal sources, ethylene glycol as solvent and reducing agent, and Vulcan XC72 as support. The electrocatalysts were characterized by Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Diffractometry (XRD) and Transmission Electron Microscopy (TEM). The energy dispersive x-ray spectroscopy analysis showed that the Pt-Rare Earth atomic ratios obtained for all electrocatalysts were similar to those used in the preparations. In all diffractograms, it was observed a broad peak at about 25 degree which was associated to the Vulcan XC72 support material and four peaks at approximately 28=40 degree, 47 degree, 67 degree and 82 degree, which were associated to the (111), (200), (220), (311), and (222) planes, respectively, of the face-centered cubic (fcc) structure characteristic of platinum and platinum alloys. For the Pt-Rare Earth/C electrocatalysts, it was also observed peaks related to the rare earth oxides on the X ray diffractograms. PtLa/C electrocatalysts were prepared at different atomic ratio. Transmission electronic microscopy micrographs of electrocatalysts showed a reasonable distribution of the Pt particles on the carbon support with some agglomerations, which is in agreement with x-ray diffractometry result. The performance for CO, methanol and ethanol oxidation was investigated by cyclic voltammetry, chronoamperometry and Fourier transform infrared spectroscopy spectroscopy. The electrocatalytic activity of the Pt-Rare Earth/C electro catalyst, specially PtLa/C, were higher than that of the Pt/C electrocatalyst. Fourier transform infrared spectroscopy studies for ethanol oxidation on Pt-Rare Earth/C electrocatalyst showed that acetaldehyde and acetic acid were the main products. The PtLa/C (30

Alpha particles emitted from the surface of granite, clay, and its fired products, 1

International Nuclear Information System (INIS)

Aratani, Michi; Otsuka, Hideko

1975-01-01

As a part of an investigation on ''the effect of long-time irradiation from a trace amount of radioisotopes'', the emitting rate of alpha particles per unit surface area (apparent) coming from natural alpha-particle emitters has been measured. The samples measured were granite and its weathered product; clay, especially potter's clay, and its fired product; pottery ware. The values obtained were 39.1 +-0.9--0.73+-0.08 cpm/100 cm 2 in granite, 16.8+-0.4--6.4+-0.2 cpm/100cm 2 in potter's clay, and 1.36+-0.04--0.82+-0.04 cpm/100cm 2 in pottery ware on substrate, and 1.33+-0.05--0.32+-0.02 cpm/100cm 2 on glazer. (auth.)

Large revealing similarity in multihadron production in nuclear and particle collisions

International Nuclear Information System (INIS)

Mishra, Aditya Nath; Sahoo, Raghunath; Sarkisyan, Edward K.G.; Sakharov, Alexander S.; )

2016-01-01

The dependencies of charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity as well as of charged particle total multiplicity on the collision energy and on the number of nucleon participants, or centrality, measured in nucleus-nucleus collisions are studied in the energy range spanning a few GeV to a few TeV per nucleon. The model in which the multiparticle production is driven by the dissipating effective energy of participants is considered. The model extends the earlier proposed approach, combining the constituent quark picture together with Landau relativistic hydrodynamics shown to interrelate the measurements from different types of collisions. Within this model, the dependence of the charged particle pseudorapidity density and transverse energy pseudorapidity density at midrapidity on the number of participants in heavy-ion collisions are found to be well described in terms of the effective energy defined as a centrality-dependent fraction of the collision energy. For both variables the effective energy approach reveals a similarity in the energy dependence obtained for the most central collisions and centrality data in the entire available energy range

Measurements of very forward particles production spectra at LHC: the LHCf experiment

CERN Document Server

Berti, Eugenio; Bonechi, Lorenzo; Bongi, Massimo; Castellini, Guido; D'Alessandro, Raffaello; Haguenauer, Maurice; Itow, Yoshitaka; Iwata, Taiki; Kasahara, Katsuaki; Makino, Yuya; Masuda, Kimiaki; Matsubayashi, Eri; Menjo, Hiroaki; Muraki, Yasushi; Papini, Paolo; Ricciarini, Sergio; Sako, Takashi; Suzuki, Takuya; Tamura, Tadahisa; Tiberio, Alessio; Torii, Shoji; Tricomi, Alessia; Turner, W C; Ueno, Mana; Zhou, Qi Dong

2017-01-01

Thanks to two small sampling calorimeters installed in the LHC tunnel at ±140 m from IP1, the LHC forward (LHCf) experiment is able to detect neutral particles produced by high energy proton-ion collisions in the very forward region (pseudo-rapidity η > 8.4). The main aim of LHCf is to provide precise measurements of the production spectra relative to these particles, in order to tune hadronic interaction models used by ground-based cosmic rays experiments. In this paper we will present the current status of the LHCf experiment, regarding in particular collected data and analysis results, as well as future prospects

Detecting hidden particles with MATHUSLA

Science.gov (United States)

Evans, Jared A.

2018-03-01

A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.

Strange and Multi-strange Particle Production in pPb and PbPb with CMS

CERN Document Server

Ni, Hong

2017-01-01

Identified particle spectra provide an important tool for understanding the particle production mechanism and the dynamical evolution of the medium created in relativistic heavy ion collisions. Studies involving strange and multi-strange hadrons, such as $K^0_S$, $\\Lambda$, and $\\Xi^-$, carry additional information since there is no net strangeness content in the initial colliding system. Strangeness enhancement in AA collisions with respect to pp and pA collisions has long been considered as one of the signatures for quark-gluon plasma (QGP) formation. Recent observations of collective effects in high-multiplicity pp and pA collisions raise the question of whether QGP can also be formed in the smaller systems. Systematic studies of strange particle abundance, particle ratios, and nuclear modification factors can shed light on this issue. The CMS experiment has excellent strange-particle reconstruction capabilities over a broad kinematic range, and dedicated high-multiplicity triggers in pp and pPb collision...

Effect of Rare Earth Element on Microstructure and Properties of in situ Synthesized TiB2/Al Composites

Directory of Open Access Journals (Sweden)

QU Min

2018-03-01

Full Text Available The effect of rare earth element Ce, Sc and Er on TiB2 particles and matrix alloy micros-tructure of TiB2/Al composites was studied with in situ synthesis method. It shows that the addition of rare earth element improves the microstructure and properties of TiB2/Al composites notably. The particles of TiB2 are relatively homogenously distributed as adding 0.3% (mass fraction rare earth element Sc and Er, moreover, it is Er that refines the microstructure of matrix alloy most significantly, then is Sc. Similarly, it is demonstrated that the addition of Sc and Er results in better tensile strength, which is enhanced by 32% and 31%, respectively; the addition of Er also leads to the best ductility by 85% with optimal tensile property. Meanwhile, fracture morphology analysis reveals that the fracture of the composites is microporous gathered ductile fracture when adding Sc and Er. Finally, it is verified that the mechanism of rare earth element on composites lies in two aspects:one is that the addition of rare earth element improves the wettability of the composites and suppresses the agglomeration of TiB2 particles; the other is that the addition of rare earth element refines the microstructure of matrix alloy and then improves the tensile strength of the composites.

Membrane assisted solvent extraction for rare earth element recovery

Science.gov (United States)

Bhave, Ramesh R.; Kim, Daejin; Peterson, Eric S.

2018-05-15

Systems and methods for the recovery of rare earth elements are provided. The systems and methods generally include membrane assisted solvent extraction using permeable hollow fibers having an immobilized organic phase within the pores of the hollow fibers. The permeable hollow fibers are generally in contact with an acidic aqueous feed on one side thereof and a strip solution on another side thereof. The systems and methods generally include the simultaneous extraction and stripping of rare earth elements as a continuous recovery process that is well suited for post-consumer products, end-of-life products, and other recovery sources of rare earth elements.

Production of Rare Earth Elements from Malaysian Monazite by Selective Precipitation

International Nuclear Information System (INIS)

Che Nor Aniza Che Zainul Bahri; Al- Areqi, W.M.; Amran Abdul Majid; Mohd Izzat Fahmi Mohd Ruf

2016-01-01

Rare earth elements (REEs) are very valuable and have high demands for advanced technology nowadays. REEs can be classified to light rare earth elements (LREEs) and heavy rare earth elements (HREEs). Malaysian rare earth ore especially monazite, is rich with LREEs compared to HREEs. Therefore a study was carried out to extract the REE from Malaysian monazite. The objectives of this study are to determine the content of REEs in Malaysian monazite leach solution, as well as to produce high grade of REEs. Concentrated sulphuric acid was used in digestion process and the filtrate containing the REEs was determined using Inductively Coupled Plasma- Mass Spectrometry (ICP-MS). Ammonia solution was used for REEs precipitation from monazite leach solution. The result indicated that REEs was successfully separated from monazite leach solution through selective precipitation using ammonia at pH 2.34 and the percentage of REEs that successfully separated was 70.03 - 81.85 %. The percentage of REEs which successfully separated from final solution was 96.05 - 99.10 %. Therefore, to have high purification of individual REEs, solvent extraction process should be carried out. (author)

Strange particle production from quark matter droplets

International Nuclear Information System (INIS)

Werner, K.; Hladik, M.

1995-01-01

We recently introduced new methods to study ultrarelativistic nuclear scattering by providing a link between the string model approach and a thermal description. The string model is used to provide information about fluctuations in energy density. Regions of high energy density are considered to be quark matter droplets and treated macroscopically. At SPS energies, we find mainly medium size droplets---with energies up to few tens of Gev. A key issue is the microcanonical treatment of individual quark matter droplets. Each droplet hadronizes instantaneously according to the available n-body phase space. Due to the huge number of possible hadron configurations, special Monte Carlo techniques have been developed to calculate this disintegration. We present results concerning the production of strange particles from such a hadronization as compared to string decay. copyright 1995 American Institute of Physics

Highly efficient production of rare sugars D-psicose and L-tagatose by two engineered D-tagatose epimerases.

Science.gov (United States)

Bosshart, Andreas; Wagner, Nina; Lei, Lei; Panke, Sven; Bechtold, Matthias

2016-02-01

Rare sugars are monosaccharides that do not occur in nature in large amounts. However, many of them demonstrate high potential as low-calorie sweetener, chiral building blocks or active pharmaceutical ingredients. Their production by enzymatic means from broadly abundant epimers is an attractive alternative to synthesis by traditional organic chemical means, but often suffers from low space-time yields and high enzyme costs due to rapid enzyme degradation. Here we describe the detailed characterization of two variants of d-tagatose epimerase under operational conditions that were engineered for high stability and high catalytic activity towards the epimerization of d-fructose to d-psicose and l-sorbose to l-tagatose, respectively. A variant optimized for the production of d-psicose showed a very high total turnover number (TTN) of up to 10(8) catalytic events over a catalyst's lifetime, determined under operational conditions at high temperatures in an enzyme-membrane reactor (EMR). Maximum space-time yields as high as 10.6 kg L(-1) d(-1) were obtained with a small laboratory-scale EMR, indicating excellent performance. A variant optimized for the production of l-tagatose performed less stable in the same setting, but still showed a very good TTN of 5.8 × 10(5) and space-time yields of up to 478 g L(-1) d(-1) . Together, these results confirm that large-scale enzymatic access to rare sugars is feasible. © 2015 Wiley Periodicals, Inc.

Development of electrolytic process in molten salt media for light rare-earth metals production. The metallic cerium electrodeposition

International Nuclear Information System (INIS)

Restivo, T.A.G.

1994-01-01

The development of molten salt process and the respective equipment aiming rare-earth metals recovery was described. In the present case, the liquid cerium metal electrodeposition in a molten electrolytes of cerium chloride and an equimolar mixture of sodium and potassium chlorides in temperatures near 800 C was studied. Due the high chemical reactivity of the rare-earth metals in the liquid state and their molten halides, an electrolytic cell was constructed with controlled atmosphere, graphite crucibles and anodes and a tungsten cathode. The electrolytic process variables and characteristics were evaluated upon the current efficiency and metallic product purity. Based on this evaluations, were suggested some alterations on the electrolytic reactor design and upon the process parameters. (author). 90 refs, 37 figs, 20 tabs

Hadron production in high energy muon scattering. [Quark-parton model, 225 GeV, structure functions, particle ratios

Energy Technology Data Exchange (ETDEWEB)

Hicks, R.G.

1978-01-01

An experiment was performed to study muon-proton scattering at an incident energy of 225 GeV and a total effective flux of 4.3 x 10/sup 10/ muons. This experiment is able to detect charged particles in coincidence with the scattered muon in the forward hemisphere, and results are reported for the neutral strange particles K/sub s//sup 0/ and ..lambda../sup 0/ decaying into two charged particles. Within experimental limits the masses and lifetimes of these particles are consistent with previous measurements. The distribution of hadrons produced in muon scattering is determined, measuring momentum components parallel and transverse to the virtual photon direction, and these distributions are compared to other high energy experiments involving the scattering of pions, protons, and neutrinos from protons. Structure functions for hadron production and particle ratios are calculated. No azimuthal dependence is observed, and lambda production does not appear to be polarized. The physical significance of the results is discussed within the framework of the quark-parton model. 29 references.

Effect of Rare Earth Y on Properties of Nanosized 90W-7Ni-3Fe Composite Powder Fabricated by Spray Drying-Hydrogen Reduction

Directory of Open Access Journals (Sweden)

Y.-Z. Ma

2008-01-01

Full Text Available (W,Ni,Fe composite oxide powder synthesized by spray drying was reduced at 700∘C for 90 minutes in H2 atmosphere. The effect of rare earth Y on H2 reduction of (W,Ni,Fe composite oxide powder was studied. Phase composition, crystalline size, and particle morphology of the reduced powder have been measured by X-ray diffraction and scanning electron microscope (SEM. Fsss particle size and special surface area of the reduced powder were also measured and analyzed. The result showed that new phase Y(Ni0.75W0.25O3 appeared in the reduced powder and particle morphology was nearly spherical or polyhedron by Y additions. The higher the rare earth element content was, the bigger the influencing on particle morphology was. When the rare earth Y content was under 0.8%, with the increase of the rare earth element content, dBET, Fsss, and crystal sizes of the reduced powder decreased greatly.

Production of massless particles in collisions of strings at high energy

International Nuclear Information System (INIS)

Lipatov, L.N.

1988-01-01

The authors obtain explicit formulas (generalizing the Low-Gribov expressions) for the production amplitude of massless particles (gluons and gravitons) with low transverse momenta in the scattering of lower-mass excitations of open and closed strings. In the limit α' → 0 they reproduce the results of calculation of effective vertices for inelastic scattering amplitudes in multi-Regge kinematics in the Yang-Mills theory and in gravitation

Microstructure-property relationships of rare-earth--zinc-oxide varistors

International Nuclear Information System (INIS)

Williams, P.; Krivanek, O.L.; Thomas, G.; Yodogawa, M.

1980-01-01

The microstructure and properties of ZnO varistors containing Ba, Co, and rare-earth--metal oxides, which give values of α [α=d(log I)/d(log V)] as high as 29, are examined. Mean ZnO grain size is 11 μm, and the grains are uniformly doped with Co. The barium and rare earth metals concentrate into 1.5-μm-wide particles embedded in a matrix of ZnO grains. Within the grains and at grain boundaries, the barium and rare-earth--metal concentration is below the detection limit of the energy-dispersive spectrometer technique (about 0.5%). No intergranular films, amorphous or crystalline, are detected, to within 10 A resolution. These results are shown to be consistent with the grain boundary charge depletion model for the voltage barrier formation and breakdown

Fluidization of spherocylindrical particles

Science.gov (United States)

Mahajan, Vinay V.; Nijssen, Tim M. J.; Fitzgerald, Barry W.; Hofman, Jeroen; Kuipers, Hans; Padding, Johan T.

2017-06-01

Multiphase (gas-solid) flows are encountered in numerous industrial applications such as pharmaceutical, food, agricultural processing and energy generation. A coupled computational fluid dynamics (CFD) and discrete element method (DEM) approach is a popular way to study such flows at a particle scale. However, most of these studies deal with spherical particles while in reality, the particles are rarely spherical. The particle shape can have significant effect on hydrodynamics in a fluidized bed. Moreover, most studies in literature use inaccurate drag laws because accurate laws are not readily available. The drag force acting on a non-spherical particle can vary considerably with particle shape, orientation with the flow, Reynolds number and packing fraction. In this work, the CFD-DEM approach is extended to model a laboratory scale fluidized bed of spherocylinder (rod-like) particles. These rod-like particles can be classified as Geldart D particles and have an aspect ratio of 4. Experiments are performed to study the particle flow behavior in a quasi-2D fluidized bed. Numerically obtained results for pressure drop and bed height are compared with experiments. The capability of CFD-DEM approach to efficiently describe the global bed dynamics for fluidized bed of rod-like particles is demonstrated.

Search for production of heavy particles decaying to top quarks and invisible particles in pp collisions at √s = 1.96  TeV.

Science.gov (United States)

Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, M; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Funakoshi, Y; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirby, M; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Rao, K; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rubbo, F; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stancari, M; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Ukegawa, F; Uozumi, S; Varganov, A; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S

2011-05-13

We present a search for a new particle T' decaying to top quark via T' → t + X, where X is an invisible particle. In a data sample with 4.8  fb(-1) of integrated luminosity collected by the CDF II detector at Fermilab in pp collisions with √s = 1.96  TeV, we search for pair production of T' in the lepton + jets channel, pp → tt + X + X → ℓνbqq'b + X + X. We interpret our results primarily in terms of a model where T' are exotic fourth generation quarks and X are dark matter particles. Current direct and indirect bounds on such exotic quarks restrict their masses to be between 300 and 600  GeV/c2, the dark matter particle mass being anywhere below m(T'). The data are consistent with standard model expectations, and we set 95% confidence level limits on the generic production of T'T' → tt + X + X. For the dark matter model we exclude T' at 95% confidence level up to m(T') = 360  GeV/c2 for m(X) ≤ 100  GeV/c2.

The electrorheological properties of nano-sized SiO2 particle materials doped with rare earths

International Nuclear Information System (INIS)

Liu Yang; Liao Fuhui; Li Junran; Zhang Shaohua; Chen Shumei; Wei Chenguan; Gao Song

2006-01-01

Electrorheological (ER) materials of pure SiO 2 and SiO 2 doped with rare earths (RE = Ce, Gd, Y) (non-metallic glasses (silicates)) were prepared using Na 2 SiO 3 and RECl 3 as starting materials. The electrorheological properties are not enhanced by all rare earth additions. The material doped with Ce exhibits the best ER performance

Quantum non-local charges and absence of particle production in the two-dimensional non-linear sigma-model

International Nuclear Information System (INIS)

Luescher, M.

1977-12-01

Conserved non-local charges are shown to exist in the quantum non-linear sigma-model by a non-perturbative method. They imply the absence of particle production and the 'factorization equations' for the two particle S-matrix, which can then be calculated explicitly. (Auth.)

Measurement of Particle Production and Inclusive Differential Cross Sections in p(bar p) Collisions at √s = 1.96 TeV

International Nuclear Information System (INIS)

2009-01-01

We report a set of measurements of particle production in inelastic p(bar p) collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a PYTHIA prediction at the hadron level is performed. The inclusive charged particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained

Impacts of Limestone Multi-particle Size on Production Performance, Egg Shell Quality, and Egg Quality in Laying Hens

Directory of Open Access Journals (Sweden)

X. Y. Guo

2012-06-01

Full Text Available This experiment was conducted to evaluate the effects of single or multi-particle size limestone on the egg shell quality, egg production, egg quality and feed intake in laying hens. A total of 280 laying hens (ISA brown were used in this 10-wk trial. Laying hens were randomly assigned to 4 treatments with 14 replications per treatment and 5 adjacent cages as a replication (hens were caged individually. The experimental treatments were: i L, basal diet+10% large particle limestone; ii LS1, basal diet+8% large particle limestone+2% small particle limestone; iii LS2, basal diet+6% large particle limestone+4% small particle limestone; iv S, basal diet+10% small particle limestone. The egg production was unaffected by dietary treatments. The egg weight in S treatment was lighter than other treatments (p<0.05. The egg specific gravity in S treatment was lower than other treatments (p<0.05. The eggshell strength and eggshell thickness in S treatment were decreased when compared with other dietary treatments (p<0.05. The laying hens in LS1 and LS2 treatment had a higher average feed intake than the other two treatments (p<0.05. Collectively, the dietary multi-particle size limestone supplementation could be as efficient as large particle size limestone.

The strange story of god particle

International Nuclear Information System (INIS)

Sengupta, Soumitra

2015-01-01

Discoveries of new fundamental particles are not new in the history of search of elementary structures of the material world around us. However the discovery of Higgs boson created sensation in the entire science community and is considered as a rare milestone among all scientific achievements. In this talk I shall try to explain why the moment of this discovery is so special in our understanding of this Universe and what is the God-like power associated with this very special particle Higgs boson - which popularly became famous as God Particle. I shall also describe the spectacular technological marvel which finally helped to discover this particle. (author)

Mean size among the particles of short-lived radon daughter products in the atmosphere

International Nuclear Information System (INIS)

Nakatani, S.

1980-01-01

The diffusion-battery method is used to classify the radioactive particles according to their sizes. The diffusion coefficient is determined from the fractional penetration of the particles through the battery. Particle radii are derived from the diffusion coefficients with the Stokes-Cunningham-Millikan formula. At the exit and entrance of the battery, individual concentrations of radon daughter products 218 Po, 214 Pb, 214 Bi are determined. Thus the mean sizes of individual radon daughters can be obtained from the fractional penetration of individual nuclides through the diffusion battery. Despite large statistical fluctuations the mean size of 214 Bi is always shifted toward the larger size region as compared with those of other radionuclides

Rare decays of B-mesons

International Nuclear Information System (INIS)

Ali, A.

1992-01-01

This article is dedicated to the memory of Andrei D. Sakharov, a great scientist and human rights activist. Sakharov was blessed with the rare gift of prophetic prediction in matters concerning both science and society. His paper in 1967 on the baryon asymmetry of the universe relating it to the baryon instability, CP-violation, and thermodynamic non-equilibrium, was a very long shot. In view of subsequent theoretical developments in grand unified theories of elementary particle physics and cosmology, where the Sakharov conditions can be accommodated, this paper represents indeed a very fine example of scientific genius and prophecy. His political judgement, exemplified by his visionary essay Progress, Coexistence, and Intellectual Freedom, written in 1968, was equally stunning. Among other topics Sakharov was also very much interested in physics of the heavy quarks. In this paper we review theoretical predictions about an interesting aspect of heavy quark physics, namely rare phenomena in the decays of B-meson involving flavor changing neutral current (FCNC) processes

Rare Earths and Clean Energy: analyzing China's upper hand

International Nuclear Information System (INIS)

Seaman, J.

2010-01-01

An ominous but avoidable resource crunch in the so-called 'rare earth elements' is now threatening the development of a number of key industries from energy to defense to consumer electronics. As key components in the latest generation of technologies, including specialized magnets for windmills and hybrid cars, lasers for range finders and 'smart' munitions, and phosphors for LCD screens, demand for these rare metals is expected to grow rapidly in the years to come. But decades of under-investment in the mining and separation of these elements across the globe has left the industry ill-prepared to meet thi s growing demand. Over the years, only China has recognized the strategic significance of these resources and has succeeded in gaining a near monopoly on production, currently churning out 97% of the world' s rare earth oxides. Faced with problems of its own, and eager to use its resource advantage to master higher levels of value-added production of rare earth-dependent products, China has increasingly limited the rest of the world's access to these raw materials. This only complicates what was already projected to be a problematic resource shortage. This issue demands a higher quality of public debate. Rare earth consuming countries outside of China have only recently become aware of their dependence and started to take stock of the risks. Time is of the essence. Bringing new supplies online to meet growing demand is a long, complicated and risky process but is nevertheless necessary to ensure the development of high tech industries, notably clean energy. Accessible reserves of rare earths do exist outside of China and mitigating the effects of the looming shortage requires opening up these reserves to production. Yet, as the Chinese experience attests, there are substantial risks to the environment associated with mining and separating rare earths. Care must be taken to ensure responsible mining practices across the globe. Longer-term solutions, such as

Rare K decays: Challenges and Perspectives

International Nuclear Information System (INIS)

Smith, C.

2014-09-01

At this stage of the LHC (Large Hadron Collider) program, the prospect for a new physics signal in the very rare K → Kνν-bar decays may be dented, but remains well alive thanks to their intrinsic qualities. First, these decays are among the cleanest observables in the quark flavor sector. When combined with their terrible suppression in the SM (Standard Model), they thus offer uniquely sensitive probes. Second, the LHC capabilities are not ideal for all kinds of new physics, even below the TeV scale. For example, rather elusive scenarios like natural-SUSY-like hierarchical spectrum, baryon number violation, or new very light but very weakly interacting particles may well induce deviations in rare K decays. Even though experimentalists should brace themselves for tiny deviations, these modes thus have a clear role to play in the LHC era. (author)

Signatures of energy flux in particle production: a black hole birth cry and death gasp

Energy Technology Data Exchange (ETDEWEB)

Good, Michael R.R. [Department of Physics, Nazarbayev University,53 Kabanbay Batyr Ave., Astana, Republic of (Kazakhstan); Ong, Yen Chin [Nordic Institute for Theoretical Physics, KTH Royal Institute of Technology Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden)

2015-07-27

It is recently argued that if the Hawking radiation process is unitary, then a black hole’s mass cannot be monotonically decreasing. We examine the time dependent particle count and negative energy flux in the non-trivial conformal vacuum via the moving mirror approach. A new, exactly unitary solution is presented which emits a characteristic above-thermal positive energy burst, a thermal plateau, and negative energy flux. It is found that the characteristic positive energy flare and thermal plateau is observed in the particle outflow. However, the results of time dependent particle production show no overt indication of negative energy flux. Therefore, a black hole’s birth cry is detectable by asymptotic observers via particle count, whereas its death gasp is not.

Hyperon and negative particle production at central rapidity in proton-beryllium interactions at 158 GeV/c

Czech Academy of Sciences Publication Activity Database

Antinori, F.; Bakke, H.; Beusch, W.; Staroba, Pavel; Závada, Petr

1999-01-01

Roč. 661, - (1999), 476c-480c ISSN 0375-9474 Institutional research plan: CEZ:AV0Z1010920 Keywords : CERN SPS * WA97 * proton-beryllium collisions * hyperon * negaive particle production Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.088, year: 1999

UCLA Particle and Nuclear Physics Research Group, 1993 progress report

International Nuclear Information System (INIS)

Nefkens, B.M.K.; Clajus, M.; Price, J.W.; Tippens, W.B.; White, D.B.

1993-09-01

The research programs of the UCLA Particle and Nuclear Physics Research Group, the research objectives, results of experiments, the continuing activities and new initiatives are presented. The primary goal of the research is to test the symmetries and invariances of particle/nuclear physics with special emphasis on investigating charge symmetry, isospin invariance, charge conjugation, and CP. Another important part of our work is baryon spectroscopy, which is the determination of the properties (mass, width, decay modes, etc.) of particles and resonances. We also measure some basic properties of light nuclei, for example the hadronic radii of 3 H and 3 He. Special attention is given to the eta meson, its production using photons, electrons, π ± , and protons, and its rare and not-so-rare decays. In Section 1, the physics motivation of our research is outlined. Section 2 provides a summary of the research projects. The status of each program is given in Section 3. We discuss the various experimental techniques used, the results obtained, and we outline the plans for the continuing and the new research. Details are presented of new research that is made possible by the use of the Crystal Ball Detector, a highly segmented NaI calorimeter and spectrometer with nearly 4π acceptance (it was built and used at SLAC and is to be moved to BNL). The appendix contains an update of the bibliography, conference participation, and group memos; it also indicates our share in the organization of conferences, and gives a listing of the colloquia and seminars presented by us

Cross Section Measurements In The Main Injector Particle Production (FNAL-E907) Experiment At 58 GEV Energy

International Nuclear Information System (INIS)

Gunaydin, Yusuf Oguzhan

2009-01-01

Cross-sections are presented for 58 GeV π, K, and p on a wide range of nuclear targets. These cross-sections are essential for determining the neutrino flux in measurements of neutrino cross-sections and oscillations. The E907 Main Injector Particle Production (MIPP) experiment at Fermilab is a fixed target experiment for measuring hadronic particle production using primary 120 GeV/c protons and secondary π, K, and p beams. The particle identification is made by dE/dx in a time projection chamber, and by time-of-flight, differential Cherenkov and ring imaging Cherenkov detectors, which together cover a wide range of momentum from 0.1 GeV/c up to 120 GeV/c. MIPP targets span the periodic table, from hydrogen to uranium, including beryllium and carbon. The MIPP has collected ∼ 0.26 x 10 6 events of 58 GeV/c secondary particles produced by protons from the main injector striking a carbon target.

Resonance particle production in inelastic N-N and π-N interactions

International Nuclear Information System (INIS)

Amelin, N.S.; Barashenkov, V.S.; Slavin, N.V.

1984-01-01

Using the considerations connected with the scaling hypothesis and the Regge pole model the phenomenological expressions are obtained for differential single-particle inclusive production cross sections (Δ + , Δ 0 , Δ ++ ) and (p +- , p 0 , ω) resonances in inelastic π-N and N-N collisions at high energies. These expressions describe the known experimental data in a wide region of kinematic variables from 10 to several thousand GeV

Structures of the particles of the condensed dispersed phase in solid fuel combustion products plasma

International Nuclear Information System (INIS)

Samaryan, A.A.; Chernyshev, A.V.; Nefedov, A.P.; Petrov, O.F.; Fortov, V.E.; Mikhailov, Yu.M.; Mintsev, V.B.

2000-01-01

The results of experimental investigations of a type of dusty plasma which has been least studied--the plasma of solid fuel combustion products--were presented. Experiments to determine the parameters of the plasma of the combustion products of synthetic solid fuels with various compositions together with simultaneous diagnostics of the degree of ordering of the structures of the particles of the dispersed condensed phase were performed. The measurements showed that the charge composition of the plasma of the solid fuels combustion products depends strongly on the easily ionized alkali-metal impurities which are always present in synthetic fuel in one or another amount. An ordered arrangement of the particles of a condensed dispersed phase in structures that form in a boundary region between the high-temperature and condensation zones was observed for samples of aluminum-coated solid fuels with a low content of alkali-metal impurities

Preparation of rare earth fluorides from apatite concentrate

International Nuclear Information System (INIS)

Mulyarchuk, I.F.; Voloshchenko, M.V.; Zen'kovich, E.G.; Sumenkova, V.V.; AN Ukrainskoj SSR, Kiev. Inst. Problem Lit'ya)

1980-01-01

The processes of preparation of the rare earths element sum from apatite concentrate of the Khibins, connected with preliminary extraction of rare earth phosphates from nitric acid extract using solvent extraction or direct precipitation from the extract by solution of potassium and ammonium fluorides. The sequence of the processes of the first variant is the following: solvent extraction of rare earths by tributylphosphate from clarified nitric acid extract of apatite with subsequent reextraction of rare earths with water and precipitation of rare earth phosphates from aqueous solution during neutralization by ammonia. In case of fluoride preparation from rare earth phosphate the main attention is paid to precipitation and filtration of fluorides. Technological scheme and cost price of industry for the production of 1800 t of rare earth trifluorides a year are calculated. When taking account of TBP losses according to its solubility the industry cost price is 1O times lower the modern cost of rare earth fluorides

Identified particle yield associated with a high-$p_T$ trigger particle at the LHC

CERN Document Server

Veldhoen, Misha; van Leeuwen, Marco

Identified particle production ratios are important observables, used to constrain models of particle production in heavy-ion collisions. Measurements of the inclusive particle ratio in central heavy-ion collisions showed an increase of the baryon-to-meson ratio compared to proton-proton collisions at intermediate pT, the so-called baryon anomaly. One possible explanation of the baryon anomaly is that partons from the thermalized deconfined QCD matter hadronize in a different way compared to hadrons produced in a vacuum jet. In this work we extend on previous measurements by measuring particle ratios in the yield associated with a high-pT trigger particle. These measurements can potentially further constrain the models of particle production since they are sensitive to the difference between particles from a jet and particles that are produced in the bulk. We start by developing a particle identification method that uses both the specific energy loss of a particle and the time of flight. From there, we presen...

Biosynthesis of rare hexoses using microorganisms and related enzymes

Science.gov (United States)

Li, Zijie; Gao, Yahui; Nakanishi, Hideki

2013-01-01

Summary Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to pharmaceutical and nutrition industry, or as starting materials for various natural products and drug candidates. Unfortunately, an important factor restricting the utilization of rare sugars is their limited availability, resulting from limited synthetic methods. Nowadays, microbial and enzymatic transformations have become a very powerful tool in this field. This article reviews the biosynthesis and enzymatic production of rare ketohexoses, aldohexoses and sugar alcohols (hexitols), including D-tagatose, D-psicose, D-sorbose, L-tagatose, L-fructose, 1-deoxy-L-fructose, D-allose, L-glucose, L-talose, D-gulose, L-galactose, L-fucose, allitol, D-talitol, and L-sorbitol. New systems and robust catalysts resulting from advancements in genomics and bioengineering are also discussed. PMID:24367410

Biosynthesis of rare hexoses using microorganisms and related enzymes

Directory of Open Access Journals (Sweden)

Zijie Li

2013-11-01

Full Text Available Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to pharmaceutical and nutrition industry, or as starting materials for various natural products and drug candidates. Unfortunately, an important factor restricting the utilization of rare sugars is their limited availability, resulting from limited synthetic methods. Nowadays, microbial and enzymatic transformations have become a very powerful tool in this field. This article reviews the biosynthesis and enzymatic production of rare ketohexoses, aldohexoses and sugar alcohols (hexitols, including D-tagatose, D-psicose, D-sorbose, L-tagatose, L-fructose, 1-deoxy-L-fructose, D-allose, L-glucose, L-talose, D-gulose, L-galactose, L-fucose, allitol, D-talitol, and L-sorbitol. New systems and robust catalysts resulting from advancements in genomics and bioengineering are also discussed.

Biosynthesis of rare hexoses using microorganisms and related enzymes.

Science.gov (United States)

Li, Zijie; Gao, Yahui; Nakanishi, Hideki; Gao, Xiaodong; Cai, Li

2013-11-12

Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to pharmaceutical and nutrition industry, or as starting materials for various natural products and drug candidates. Unfortunately, an important factor restricting the utilization of rare sugars is their limited availability, resulting from limited synthetic methods. Nowadays, microbial and enzymatic transformations have become a very powerful tool in this field. This article reviews the biosynthesis and enzymatic production of rare ketohexoses, aldohexoses and sugar alcohols (hexitols), including D-tagatose, D-psicose, D-sorbose, L-tagatose, L-fructose, 1-deoxy-L-fructose, D-allose, L-glucose, L-talose, D-gulose, L-galactose, L-fucose, allitol, D-talitol, and L-sorbitol. New systems and robust catalysts resulting from advancements in genomics and bioengineering are also discussed.

Production of zinc and manganese oxide particles by pyrolysis of alkaline and Zn-C battery waste.

Science.gov (United States)

Ebin, Burçak; Petranikova, Martina; Steenari, Britt-Marie; Ekberg, Christian

2016-05-01

Production of zinc and manganese oxide particles from alkaline and zinc-carbon battery black mass was studied by a pyrolysis process at 850-950°C with various residence times under 1L/minN2(g) flow rate conditions without using any additive. The particular and chemical properties of the battery waste were characterized to investigate the possible reactions and effects on the properties of the reaction products. The thermodynamics of the pyrolysis process were studied using the HSC Chemistry 5.11 software. The carbothermic reduction reaction of battery black mass takes place and makes it possible to produce fine zinc particles by a rapid condensation, after the evaporation of zinc from a pyrolysis batch. The amount of zinc that can be separated from the black mass is increased by both pyrolysis temperature and residence time. Zinc recovery of 97% was achieved at 950°C and 1h residence time using the proposed alkaline battery recycling process. The pyrolysis residue is mainly MnO powder with a low amount of zinc, iron and potassium impurities and has an average particle size of 2.9μm. The obtained zinc particles have an average particle size of about 860nm and consist of hexagonal crystals around 110nm in size. The morphology of the zinc particles changes from a hexagonal shape to s spherical morphology by elevating the pyrolysis temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Automated purification of Borrelia burgdorferi s.l. PCR products with KingFisherTM magnetic particle processor prior to genome sequencing

International Nuclear Information System (INIS)

Maekinen, Johanna; Marttila, Harri; Viljanen, Matti K.

2001-01-01

Borrelia burgdorferi sensu lato genospecies were differentiated by PCR-based sequencing of the borrelial flagellin gene. To evaluate the usefulness of KingFisher TM magnetic particle processor in PCR product purification, borrelia PCR products were purified with KingFisher TM magnetic particle processor prior to cycle sequencing and the quality of the sequence data received was analyzed. KingFisher was found to offer a rapid and reliable alternative for borrelial PCR product purification

Particle physics and cosmology

International Nuclear Information System (INIS)

Schramm, D.N.; Turner, M.S.

1982-06-01

work is described in these areas: cosmological baryon production; cosmological production of free quarks and other exotic particle species; the quark-hadron transition in the early universe; astrophysical and cosmological constraints on particle properties; massive neutrinos; phase transitions in the early universe; and astrophysical implications of an axion-like particle

Inclusive particle production and anomalous muons in e+e- collisions at SPEAR. Technical report No. 76-106

International Nuclear Information System (INIS)

Barnett, B.A.

1976-02-01

Results are presented on hadron and muon inclusive production in e + e - collisions at √s = 3.8 and 4.8 GeV. Anomalously large high momentum muon production is observed in noncoplanar two charged particle final states, but no anomalies are seen in multicharged particle final states. Arguments are presented that these extra muons do not come from charmed particles but could possibly come from heavy leptons. Results are also presented on a search for e + e - narrow resonances with 5.7 GeV less than M/sub ee/ less than 6.1 GeV. The UPSILON/sub ( 5 . 97 ) was not seen in this scan which means that GAMMA/sub ee/ less than 100 eV. if the UPSILON has decay modes similar to the PSI and PSI'

Multiple particles production for hadron-hadron reactions with finite hadronization time

International Nuclear Information System (INIS)

Arbex, N.

1991-01-01

Experimental data on multiple particle production for proton-proton reaction are analysed in the context of a very simple analytical model. The model exhibits the essential features of hydrodynamical calculations as, e.g., the formation of an intermediate object, which undergoes expansion. The simultaneous analysis of different types of data allows for the conclusion that such data reflect the dynamics of this intermediate object and have a very deem connection to the elementary processes. (author)

Theory and simulation of epitaxial rotation. Light particles adsorbed on graphite

DEFF Research Database (Denmark)

Vives, E.; Lindgård, P.-A.

1993-01-01

We present a theory and Monte Carlo simulations of adsorbed particles on a corrugated substrate. We have focused on the case of rare gases and light molecules, H-2 and D2, adsorbed on graphite. The competition between the particle-particle and particle-substrate interactions gives rise to frustra...... found a modulated 4 x 4 structure. Energy, structure-factor intensities, peak positions, and epitaxial rotation angles as a function of temperature and coverage have been determined from the simulations. Good agreement with theory and experimental data is found.......We present a theory and Monte Carlo simulations of adsorbed particles on a corrugated substrate. We have focused on the case of rare gases and light molecules, H-2 and D2, adsorbed on graphite. The competition between the particle-particle and particle-substrate interactions gives rise...... between the commensurate and incommensurate phase for the adsorbed systems. From our simulations and our theory, we are, able to understand the gamma phase of D2 as an ordered phase stabilized by disorder. It can be described as a 2q-modulated structure. In agreement with the experiments, we have also...

Particle production at energies available at the CERN Large Hadron Collider within an evolutionary model

Science.gov (United States)

Sinyukov, Yu. M.; Shapoval, V. M.

2018-06-01

The particle yields and particle number ratios in Pb+Pb collisions at the CERN Large Hadron Collider (LHC) energy √{sN N}=2.76 TeV are described within the integrated hydrokinetic model (iHKM) at two different equations of state (EoS) for quark-gluon matter and the two corresponding hadronization temperatures T =165 MeV and T =156 MeV. The role of particle interactions at the final afterburner stage of the collision in the particle production is investigated by means of comparison of the results of full iHKM simulations with those where the annihilation and other inelastic processes (except for resonance decays) are switched off after hadronization/particlization, similarly as in the thermal models. An analysis supports the picture of continuous chemical freeze-out in the sense that the corrections to the sudden chemical freeze-out results, which arise because of the inelastic reactions at the subsequent evolution times, are noticeable and improve the description of particle number ratios. An important observation is that, although the particle number ratios with switched-off inelastic reactions are quite different at different particlization temperatures which are adopted for different equations of state to reproduce experimental data, the complete iHKM calculations bring very close results in both cases.

Hydrogen Production by a Hyperthermophilic Membrane-Bound Hydrogenase in Soluble Nanolipoprotein Particles

Energy Technology Data Exchange (ETDEWEB)

Baker, S E; Hopkins, R C; Blanchette, C; Walsworth, V; Sumbad, R; Fischer, N; Kuhn, E; Coleman, M; Chromy, B; Letant, S; Hoeprich, P; Adams, M W; Henderson, P T

2008-10-22

Hydrogenases constitute a promising class of enzymes for ex vivo hydrogen production. Implementation of such applications is currently hindered by oxygen sensitivity and, in the case of membrane-bound hydrogenases (MBH), poor water solubility. Nanolipoprotein particles (NLPs), formed from apolipoproteins and phospholipids, offer a novel means to incorporate MBH into in a well-defined water-soluble matrix that maintains the enzymatic activity and is amenable to incorporation into more complex architectures. We report the synthesis, hydrogen-evolving activity and physical characterization of the first MBH-NLP assembly. This may ultimately lead to the development of biomimetic hydrogen production devices.

Search for pair production of strongly interacting particles decaying to pairs of jets in pp collisions at √s=1.96 TeV.

Science.gov (United States)

Aaltonen, T; Albin, E; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Bae, T; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Bland, K R; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brigliadori, L; Bromberg, C; Brucken, E; Budagov, J; Budd, H S; Burkett, K; Busetto, G; Bussey, P; Butti, P; Buzatu, A; Calamba, A; Camarda, S; Campanelli, M; Canelli, F; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Cho, K; Chokheli, D; Ciocci, M A; Clark, A; Clarke, C; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Cremonesi, M; Cruz, D; Cuevas, J; Culbertson, R; d'Ascenzo, N; Datta, M; De Barbaro, P; Demortier, L; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dorigo, M; Driutti, A; Ebina, K; Edgar, R; Elagin, A; Erbacher, R; Errede, S; Esham, B; Eusebi, R; Farrington, S; Fernández Ramos, J P; Field, R; Flanagan, G; Forrest, R; Franklin, M; Freeman, J C; Frisch, H; Funakoshi, Y; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González López, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gramellini, E; Grinstein, S; Grosso-Pilcher, C; Group, R C; Guimaraes da Costa, J; Hahn, S R; Han, J Y; Happacher, F; Hara, K; Hare, M; Harr, R F; Harrington-Taber, T; Hatakeyama, K; Hays, C; Heinrich, J; Herndon, M; Hocker, A; Hong, Z; Hopkins, W; Hou, S; Hughes, R E; Husemann, U; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jindariani, S; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kambeitz, M; Kamon, T; Karchin, P E; Kasmi, A; Kato, Y; Ketchum, W; Keung, J; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kim, Y J; Kimura, N; Kirby, M; Knoepfel, K; Kondo, K; Kong, D J; Konigsberg, J; Kotwal, A V; Kreps, M; Kroll, J; Kruse, M; Kuhr, T; Kurata, M; Laasanen, A T; Lammel, S; Lancaster, M; Lannon, K; Latino, G; Lee, H S; Lee, J S; Leo, S; Leone, S; Lewis, J D; Limosani, A; Lipeles, E; Liu, H; Liu, Q; Liu, T; Lockwitz, S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maestro, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, P; Martínez, M; Matera, K; Mattson, M E; Mazzacane, A; Mazzanti, P; McNulty, R; Mehta, A; Mehtala, P; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M J; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Nigmanov, T; Nodulman, L; Noh, S Y; Norniella, O; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagliarone, C; Palencia, E; Palni, P; Papadimitriou, V; Parker, W; Pauletta, G; Paulini, M; Paus, C; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Poprocki, S; Potamianos, K; Prokoshin, F; Pranko, A; Ptohos, F; Punzi, G; Ranjan, N; Redondo Fernández, I; Renton, P; Rescigno, M; Riddick, T; Rimondi, F; Ristori, L; Robson, A; Rodriguez, T; Rolli, S; Ronzani, M; Roser, R; Rosner, J L; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Sakurai, Y; Santi, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, E E; Schwarz, T; Scodellaro, L; Scuri, F; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shochet, M; Shreyber-Tecker, I; Simonenko, A; Sinervo, P; Sliwa, K; Smith, J R; Snider, F D; Sorin, V; Song, H; Stancari, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thomson, E; Thukral, V; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Ukegawa, F; Uozumi, S; Vázquez, F; Velev, G; Vellidis, C; Vernieri, C; Vidal, M; Vilar, R; Vizán, J; Vogel, M; Volpi, G; Wagner, P; Wallny, R; Wang, S M; Warburton, A; Waters, D; Wester, W C; Whiteson, D; Wicklund, A B; Wilbur, S; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamato, D; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Zanetti, A M; Zeng, Y; Zhou, C; Zucchelli, S

2013-07-19

We present a search for the pair production of a narrow nonstandard-model strongly interacting particle that decays to a pair of quarks or gluons, leading to a final state with four hadronic jets. We consider both nonresonant production via an intermediate gluon as well as resonant production via a distinct nonstandard-model intermediate strongly interacting particle. We use data collected by the CDF experiment in proton-antiproton collisions at √[s]=1.96 TeV corresponding to an integrated luminosity of 6.6 fb(-1). We find the data to be consistent with nonresonant production. We report limits on σ(pp[over ¯]→jjjj) as a function of the masses of the hypothetical intermediate particles. Upper limits on the production cross sections for nonstandard-model particles in several resonant and nonresonant processes are also derived.

Ultraviolet spectra of CeO2 nano-particles

International Nuclear Information System (INIS)

Tsunekawa, S.; Sivamohan, R.; Ohsuna, T.; Kasuya, A.; Takahashi, H.; Tohji, K.

1998-01-01

Full text: Quantum size effect is generally expected in nanometer size materials. The effect has been observed in many metal clusters and semiconducting nano-particles, but seldom in oxides, because the size control of crystalline oxides is generally difficult due to the ionic bond character. CeO 2 (ceria) is one of the rare-earth oxides and the size effect is worth studying from the viewpoint of an ultraviolet (u.v.) spectroscopy and applications. This report describes the first observation of a blue shift of u.v. spectra in ceria nano-particles of 2-5 nm in diameter with its deviation within 20%. A ceria aqueous sol (pH ≅ 2.5) having particle sizes under 6 nm in diameter was produced by ultrafiltration with a polyether sulfone membrane (SIP-1013, Asahi Chemical Industry Co.) from an original ceria aqueous sol (pH ≅ 1.5) having particle sizes extending over a wide range. Obtained sol contains a high concentration of Ce 3+ ions because of the high acidity. In order to separate ceria particles from Ce 3+ ions and fractionate the particle size, two kinds of anion-type surfactants were used in microemulsification process with toluene and water. One is sodium dodecylbenzene sulfonate (SD-BS) which is 2 nm in length and another is sodium octyl sulfonate (SOS) which is 1.2 nm in length. U.v. spectroscopic measurements and high resolution transmission electron microscopic (HRTEM) observations were performed for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t , where (SOS) t is a ceria suspension in toluene obtained by an emulsification with SOS surfactant, (SOS+SOS) t indicates the same product obtained by the further emulsification with SOS for an aqueous phase of the emulsion with SOS, and (SDBS+SOS+SDBS) t means that obtained by an additional emulsification with SDBS for an aqueous phase obtained by two successive emulsifications with SDBS and SOS. Optical density data for (SOS) t , (SOS+SOS) t , and (SDBS+SOS+SDBS) t show absorption edges at 4076 Angstroms, 3997

A large acceptance, high-resolution detector for rare K sup + -decay experiments

CERN Document Server

Appel, R; Bassalleck, B; Battiste, E; Bergman, D R; Boesiger, K; Brown, D N; Castillo, V; Cheung, N; Dhawan, S; Do, H; Egger, J; Eilerts, S W; Felder, C; Fischer, H; Gach, H M; Giles, R; Gninenko, S N; Herold, W D; Hotmer, J E; Issakov, V V; Karavichev, O V; Kaspar, H; Kraus, D E; Lazarus, D M; Lebedev, V A; Leipuner, L; Lichard, P; Lowe, J; Lozano, J; Lu, T; Ma, H; Magurno, B; Majid, W; Menzel, W; Miller, C S; Nickelson, M; Ober, I; Pile, P H; Pislak, S; Poblaguev, A A; Pomianowski, P A; Postoev, V E; Proskurjakov, A L; Rehak, P; Robmann, P; Schmid, B; Sher, A; Sher, A; Shunko, E; Steiner, S; Stever, T L; Stotzer, R W; Suhov, V V; Thompson, J A; Truöl, P; Valine, C M; Weyer, H; Wolfe, D M; Zeller, M E

2002-01-01

The detector of the E865-collaboration at the Brookhaven-AGS described here combines a magnetic spectrometer for the charged decay products of 6 GeV/c K sup + with excellent electromagnetic calorimetry and efficient particle identification for electrons and muons. Its high-resolution, large acceptance and high rate capability made it well suited for the study of extremely rare or forbidden decays with multi-leptonic final states such as K sup +-> pi sup +mu sup + e sup - , K sup +-> pi sup + l sup + l sup - , K sup +->l sup +nu sub l e sup - e sup + and K sup +-> pi sup +pi sup - e sup +nu sub e down to branching ratios below 10 sup - sup 1 sup 1 in an intense K sup + beam (approx 10 sup 8 per AGS spill).

A large acceptance, high-resolution detector for rare K{sup +}-decay experiments

Energy Technology Data Exchange (ETDEWEB)

Appel, R.; Atoyan, G.S.; Bassalleck, B.; Battiste, E.; Bergman, D.R.; Boesiger, K.; Brown, D.N.; Castillo, V.; Cheung, N.; Dhawan, S.; Do, H.; Egger, J.; Eilerts, S.W.; Felder, C.; Fischer, H.; Gach, H.M.; Giles, R.; Gninenko, S.N.; Herold, W.D.; Hotmer, J.E.; Issakov, V.V.; Karavichev, O.V.; Kaspar, H.; Kraus, D.E.; Lazarus, D.M. E-mail: lazarus@bnl.gov; Lebedev, V.A.; Leipuner, L.; Lichard, P.; Lowe, J.; Lozano, J.; Lu, T.; Ma, H.; Magurno, B.; Majid, W.; Menzel, W.; Miller, C.S.; Nickelson, M.; Ober, I.; Pile, P.H.; Pislak, S.; Poblaguev, A.A.; Pomianowski, P.; Postoev, V.E.; Proskurjakov, A.L.; Rehak, P.; Robmann, P.; Schmid, B.; Sher, A.; Sher, Aleksey; Shunko, E.; Steiner, S.; Stever, T.L.; Stotzer, R.W.; Suhov, V.V.; Thompson, J.A.; Truoel, P. E-mail: truoel@phyzik.unizh.ch; Valine, C.; Weyer, H.; Wolfe, D.M.; Zeller, M.E

2002-03-01

The detector of the E865-collaboration at the Brookhaven-AGS described here combines a magnetic spectrometer for the charged decay products of 6 GeV/c K{sup +} with excellent electromagnetic calorimetry and efficient particle identification for electrons and muons. Its high-resolution, large acceptance and high rate capability made it well suited for the study of extremely rare or forbidden decays with multi-leptonic final states such as K{sup +}{yields}{pi}{sup +}{mu}{sup +}e{sup -}, K{sup +}{yields}{pi}{sup +}l{sup +}l{sup -}, K{sup +}{yields}l{sup +}{nu}{sub l}e{sup -}e{sup +} and K{sup +}{yields}{pi}{sup +}{pi}{sup -}e{sup +}{nu}{sub e} down to branching ratios below 10{sup -11} in an intense K{sup +} beam ({approx}10{sup 8} per AGS spill)

Single particle analysis of TiO2 in candy products using triple quadrupole ICP-MS.

Science.gov (United States)

Candás-Zapico, S; Kutscher, D J; Montes-Bayón, M; Bettmer, J

2018-04-01

Titanium dioxide (TiO 2 ) belongs to the materials that have gained great importance in many applications. In its particulate form (micro- or nanoparticles), it has entered a huge number of consumer products and food-grade TiO 2 , better known as E171 within the European Union, represents an important food additive. Thus, there is an increasing need for analytical methods able to detect and quantify such particles. In this regard, inductively coupled-mass spectrometry (ICP-MS), in particular single particle ICP-MS (spICP-MS), has gained importance due to its simplicity and ease of use. Nevertheless, the number of applications for Ti nanoparticles is rather limited. In this study, we have applied the spICP-MS strategy by comparing different measuring modes available in triple quadrupole ICP-MS. First, single quadrupole mode using the collision/reaction cell system was selected for monitoring the isotope 47 Ti. Different cell gases like He, O 2 and NH 3 were tested under optimised conditions for its applicability in spICP-MS of standard suspensions of TiO 2 . The determined analytical figures of merit were compared to those obtained by triple quadrupole mode using the 47 Ti or 48 Ti reaction products using O 2 and NH 3 as reaction gases. This comparison demonstrated that the triple quadrupole mode (TQ mode) was superior in terms of sensitivity due to the more efficient removal of spectral interferences. Particle size detection limits down to 26nm were obtained using the best instrumental conditions for TiO 2 particles at a dwell time of 10ms. Finally, the different measuring modes were applied to the analysis of chewing gum samples after a simple extraction procedure using an ultrasonic bath. The obtained results showed a good agreement for the detected particle size range using the different TQ modes. The size range of TiO 2 particles was determined to be between approximately 30 and 200nm, whereas roughly 40% of the particles were smaller than 100nm. For the

Production of uranium-molybdenum particles by spark-erosion

International Nuclear Information System (INIS)

Cabanillas, E.D.; Lopez, M.; Pasqualini, E.E.; Cirilo Lombardo, D.J.

2004-01-01

With the spark-erosion method we have produced spheroidal particles of an uranium-molybdenum alloy using pure water as dielectric. The particles were characterized by optical metallography, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. Mostly spherical particles of UO 2 with a distinctive size distribution with peaks centered at 70 and 10 μm were obtained. The particles have central inclusions of U and Mo compounds

Production of uranium-molybdenum particles by spark-erosion

Energy Technology Data Exchange (ETDEWEB)

Cabanillas, E.D. E-mail: cabanill@cnea.gov.ar; Lopez, M.; Pasqualini, E.E.; Cirilo Lombardo, D.J

2004-01-01

With the spark-erosion method we have produced spheroidal particles of an uranium-molybdenum alloy using pure water as dielectric. The particles were characterized by optical metallography, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. Mostly spherical particles of UO{sub 2} with a distinctive size distribution with peaks centered at 70 and 10 {mu}m were obtained. The particles have central inclusions of U and Mo compounds.

Charged Particle, Photon Multiplicity, and Transverse Energy Production in High-Energy Heavy-Ion Collisions

Directory of Open Access Journals (Sweden)

Raghunath Sahoo

2015-01-01

Full Text Available We review the charged particle and photon multiplicities and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at different collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons, and the transverse energy measurement.

Neutral strange particle production at top SPS energy measured by the CERES experiment

International Nuclear Information System (INIS)

Radomski, S.

2006-01-01

Systematics of strange particle production in collisions of ultrarelativistic nuclei provides an insight into the properties of the strongly interacting matter. Hadrochemistry, the study of the relative yields, provides information about chemical freeze-out and the position of the system in the phase diagram. Strangeness production at Super Proton Synchrotron (SPS) energies is not fully explained by the thermal model of hadron gas. Data reported by one experiment show sharp structures as a function of energy which are interpreted as a signature for a phase transition, but due to discrepancies in the results between two different experiments, a conclusion can not be drawn. This thesis is part of an effort to build a database of the strangeness production at SPS energy. The particular subject of this work is a precise measurement of the production of K S 0 . The results are compared with two other experiments and the prediction of the thermal model. The high precision data shed light on the systematics of strangeness production and allow clarification of the experimental status. The study of transverse momentum spectra provides information about the temperature and the radial expansion of the system. Here, as in the case of particle yields, interesting structures are visible as a function of energy. A rapid increase in the number of degrees of freedom is visible in the SPS region. A large part of the strangeness is carried by the neutral strange baryon Λ. Here the experimental situation is even more complicated because the reconstruction of the Λ yield requires large extrapolation to low transverse momentum. In this work first results on Λ production will be presented. (orig.)

Applications of SCET to the pair production of supersymmetric particles at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Broggio, Alessandro

2013-02-04

In this thesis we investigate the phenomenology of supersymmetric particles at hadron colliders beyond next-to-leading order (NLO) in perturbation theory. We discuss the foundations of Soft-Collinear Effective Theory (SCET) and, in particular, we explicitly construct the SCET Lagrangian for QCD. As an example, we discuss factorization and resummation for the Drell-Yan process in SCET. We use techniques from SCET to improve existing calculations of the production cross sections for slepton-pair production and top-squark-pair production at hadron colliders. As a first application, we implement soft-gluon resummation at next-to-next-to-next-to-leading logarithmic order (NNNLL) for slepton-pair production in the minimal supersymmetric extension of the Standard Model (MSSM). This approach resums large logarithmic corrections arising from the dynamical enhancement of the partonic threshold region caused by steeply falling parton luminosities. We evaluate the resummed invariant-mass distribution and total cross section for slepton-pair production at the Tevatron and LHC and we match these results, in the threshold region, onto NLO fixed-order calculations. As a second application we present the most precise predictions available for top-squark-pair production total cross sections at the LHC. These results are based on approximate NNLO formulas in fixed-order perturbation theory, which completely determine the coefficients multiplying the singular plus distributions. The analysis of the threshold region is carried out in pair invariant mass (PIM) kinematics and in single-particle inclusive (1PI) kinematics. We then match our results in the threshold region onto the exact fixed-order NLO results and perform a detailed numerical analysis of the total cross section.

Neutral strange particle production at top SPS energy measured by the CERES experiment

Energy Technology Data Exchange (ETDEWEB)

Radomski, S.

2006-07-05

Systematics of strange particle production in collisions of ultrarelativistic nuclei provides an insight into the properties of the strongly interacting matter. Hadrochemistry, the study of the relative yields, provides information about chemical freeze-out and the position of the system in the phase diagram. Strangeness production at Super Proton Synchrotron (SPS) energies is not fully explained by the thermal model of hadron gas. Data reported by one experiment show sharp structures as a function of energy which are interpreted as a signature for a phase transition, but due to discrepancies in the results between two different experiments, a conclusion can not be drawn. This thesis is part of an effort to build a database of the strangeness production at SPS energy. The particular subject of this work is a precise measurement of the production of K{sub S}{sup 0}. The results are compared with two other experiments and the prediction of the thermal model. The high precision data shed light on the systematics of strangeness production and allow clarification of the experimental status. The study of transverse momentum spectra provides information about the temperature and the radial expansion of the system. Here, as in the case of particle yields, interesting structures are visible as a function of energy. A rapid increase in the number of degrees of freedom is visible in the SPS region. A large part of the strangeness is carried by the neutral strange baryon {lambda}. Here the experimental situation is even more complicated because the reconstruction of the {lambda} yield requires large extrapolation to low transverse momentum. In this work first results on {lambda} production will be presented. (orig.)

Fabrication of Superhydrophobic and Luminescent Rare Earth/Polymer complex Films.

Science.gov (United States)

Wang, Zefeng; Ye, Weiwei; Luo, Xinran; Wang, Zhonggang

2016-04-18

The motivation of this work is to create luminescent rare earth/polymer films with outstanding water-resistance and superhydrophobicity. Specifically, the emulsion polymerization of styrene leads to core particles. Then core-shell-structured polymer nanoparticles are synthesized by copolymerization of styrene and acrylic acid on the core surface. The coordination reaction between carboxylic groups and rare earth ions (Eu(3+) and Tb(3+)) generates uniform spherical rare earth/polymer nanoparticles, which are subsequently complexed with PTFE microparticles to obtain micro-/nano-scaled PTFE/rare earth films with hierarchical rough morphology. The films exhibit large water contact angle up to 161° and sliding angle of about 6°, and can emit strong red and green fluorescence under UV excitation. More surprisingly, it is found that the films maintain high fluorescence intensity after submersed in water and even in aqueous salt solution for two days because of the excellent water repellent ability of surfaces.

Separation of Rare Earths from Uranium and Thorium

International Nuclear Information System (INIS)

Krebs, Damien

2014-01-01

Greenland Minerals and Energy - Key Highlights – A unique world class mining project: 1. World-class, large scale development project: • Economically robust, proven technology, large-scale, long life production of rare earths concentrate and uranium; • Large JORC resource base to produce ~7kt HREO, 37kt LREO & 3Mlbs U_3O_8 per annum over 30 year mine life; • Ideally located near international airport, existing towns and potential hydro-electric power source. 2. Very attractive commodity portfolio: • Heavy rare earths and uranium are both recognised as strategically important commodities for the future; • Rare earths market characterised by limited capacity and increasing demand (particularly Dy, Nd, Tb, Eu and Y). 3. Strong management and technical team: • Experienced management team with proven track record; • Well-respected and knowledgeable technical/project team in place with exceptional local expertise. 4. Highly advantageous ore-type, makes for simple cost-effective processing, highly scalable production: • High upgrade through beneficiation brings optionality to Kvanefjeld project; • Leaching can be done in Greenland, or owing to the high-grade concentrate, can be shipped to other locations; • Allows to single concentrator in Greenland, multiple refineries/partners globally. 5. Globally significant, long life, low cost, multi-commodity asset: • Company to become one of the largest producers of rare earths globally and a significant U_3O_8 mine; • Potential to supply >20% of global critical (including heavy) rare earth element demand; • Company has low cost of production due to multiple by-product opportunities. 6. Low political risk: • Stable, low-risk operating environment with government looking to develop new industries and employment; • GME fully permitted to evaluate the project, exploration licence now includes radioactive elements; • Management and board have a solid working relationship with the government and are

Rare earth industries: Downstream business

International Nuclear Information System (INIS)

2011-01-01

The value chain of the rare earths business involves mining, extraction, processing, refining and the manufacture of an extensive range of downstream products which find wide applications in such industries including aerospace, consumer electronics, medical, military, automotive, renewable wind and solar energy and telecommunications. In fact the entire gamut of the high-tech industries depends on a sustainable supply of rare earths elements. The explosive demand in mobile phones is an excellent illustration of the massive potential that the rare earths business offers. In a matter of less than 20 years, the number of cell phones worldwide has reached a staggering 5 billion. Soon, going by the report of their growth in sales, the world demand for cell phones may even exceed the global population. Admittedly, the rare earths business does pose certain risks. Top among the risks are the health and safety risks. The mining, extraction and refining of rare earths produce residues and wastes which carry health and safety risks. The residues from the extraction and refining are radioactive, while their effluent waste streams do pose pollution risks to the receiving rivers and waterways. But, as clearly elaborated in a recent report by IAEA experts, there are technologies and systems available to efficiently mitigate such risks. The risks are Rare Earth manageable. However, it is crucial that the risk and waste management procedures are strictly followed and adhered to. This is where effective monitoring and surveillance throughout the life of all such rare earths facilities is crucial. Fortunately, Malaysia's regulatory standards on rare earths follow international standards. In some areas, Malaysia's regulatory regime is even more stringent than the international guidelines. (author)

Higgs particle production at LEP in multi-doublet scenarios with hierarchy of the vacuum expectation values

International Nuclear Information System (INIS)

Kalinowski, J.; Pokorski, S.

1989-01-01

We discuss the production at LEP of Higgs particles in multi-doublet scenarios with a hierarchy of the vacuum expectation values ν 2 /ν 1 ≅m t /m b . The cross sections are similar or larger than for the standard Higgs boson of the same mass but the signature is different. Events with four b-jets are the only important signature of such Higgs particles. (orig.)

Gravitational particle production in inflation. A fresh look

Science.gov (United States)

Yajnik, Urjit A.

1990-01-01

Gravitational production of energy density in the case of a minimally coupled scalar field is treated using quantum field theory in curved spacetime. We calculate 0> of the produced particles. The results for the massless case can be applied to gravitons, but an unphysically large contribution is found from wavelengths longer than the horizon size. Gravitons of wavelengths smaller that the horizon give rise to energy density ϱgrav~H4 (H being the Hubble constant during inflation). In the case of a light scalar of mass m≪H the long wavelengths contribute ϱm~H5/m, which too can become unphysically large for sufficiently small m. We also discuss how this energy density subsequently evolves. Address after August 1989: Physics Department, Indian Institute of Technology, Bombay 400 076, India.

Method of forming magnetostrictive rods from rare earth-iron alloys

Science.gov (United States)

McMasters, O. Dale

1986-09-02

Rods of magnetrostructive alloys of iron with rare earth elements are formed by flowing a body of rare earth-iron alloy in a crucible enclosed in a chamber maintained under an inert gas atmosphere, forcing such molten rare-earth-iron alloy into a hollow mold tube of refractory material positioned with its lower end portion within the molten body by means of a pressure differential between the chamber and mold tube and maintaining a portion of the molten alloy in the crucible extending to a level above the lower end of the mold tube so that solid particles of higher melting impurities present in the alloy collect at the surface of the molten body and remain within the crucible as the rod is formed in the mold tube.

Biosynthesis of rare hexoses using microorganisms and related enzymes

OpenAIRE

Li, Zijie; Gao, Yahui; Nakanishi, Hideki; Gao, Xiaodong; Cai, Li

2013-01-01

Summary Rare sugars, referred to as monosaccharides and their derivatives that rarely exist in nature, can be applied in many areas ranging from foodstuffs to pharmaceutical and nutrition industry, or as starting materials for various natural products and drug candidates. Unfortunately, an important factor restricting the utilization of rare sugars is their limited availability, resulting from limited synthetic methods. Nowadays, microbial and enzymatic transformations have become a very powe...

Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells

International Nuclear Information System (INIS)

Jantzen, Kim; Møller, Peter; Karottki, Dorina Gabriela; Olsen, Yulia; Bekö, Gabriel; Clausen, Geo; Hersoug, Lars-Georg; Loft, Steffen

2016-01-01

Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related to leukocyte-mediated oxidative stress. The study utilized a cross sectional design performed in 58 study participants from a larger cohort. Levels of circulating endothelial progenitor cells, defined as either late (CD34 + KDR + cells) or early (CD34 + CD133 + KDR + cells) subsets were measured using polychromatic flow cytometry. We additionally measured production of reactive oxygen species in leukocyte subsets (lymphocytes, monocytes and granulocytes) by flow cytometry using intracellular 2′,7′-dichlorofluoroscein. The measurements encompassed both basal levels of reactive oxygen species production and capacity for reactive oxygen species production for each leukocyte subset. We found that the late endothelial progenitor subset was negatively associated with levels of ultrafine particles measured within the participant residences and with reactive oxygen species production capacity in lymphocytes. Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate that exposure to fine and ultrafine particles derived from indoor sources may have adverse effects on human vascular health.

Lithium and Beryllium By-product Recovery from the Round Top Mountain, Texas, Peraluminous Rhyolite Heavy Rare Earth Deposit

Science.gov (United States)

Pingitore, N. E., Jr.; Clague, J. W.; Gorski, D.

2016-12-01

The technology metals Li and Be combine low mass and unique properties. Li batteries are critical in applications at scales from micro-electronics to automotive and grid storage. Low mass Be structural components are essential in aerospace/defense applications and in non-sparking BeCu alloy oilfield tools. Most Li is sourced from desert salarsin the "Lithium Triangle" of Argentina—Bolivia—Chile. In contrast, Materion Corp mines >80% of global Be at Spor Mountain, UT. The massive peraluminous rhyolite heavy rare earth deposit at Round Top Mountain, TX is also enriched in Li, 500 ppm, and Be, 50 ppm. 2016 prices of 7000/tonne Li2CO3 (19% Li) and 1000/kg Be metal suggest favorable economics to extract Li and Be as by-products of HREE mining. Li and some Be are hosted in annite biotite that comprises up to 5% of the rhyolite. Texas Mineral Resources Corp proposes to heap leach crushed rhyolite with dilute H2SO4to release the yttrofluorite-hosted HREEs. At bench scale the annite biotite dissolves, but not quartz and feldspars (>90% of the rock). A series of 40 high-yield laboratory tests at various acid strength, particle size, and exposure time released up to 350 ppm (70%) of the Li and 14 ppm (30%) of the Be. For a 20,000 tonne/day operation, these recoveries correspond to daily production of >3 tonnes Li and 250 kg Be. Higher Li and Be recoveries also increased yields of gangue elements, Fe & Al, into solution. This complicates subsequent separation of Li, Be, and HREEs from the pregnant leach solution. Recovery of target HREEs did not increase beyond 200 ppm Li and 8 ppm Be recovery. Greater Li and Be recoveries increased acid consumption. Thus the "sweet spot" economics for heap leach is likely under conditions of acid strength, grain size, and exposure time that do not maximize by-product Li and Be recoveries. Evolving market prices for the full target element suite and additional costs to recover and purify the Li and Be must also be considered.

A Local and Global Search Combine Particle Swarm Optimization Algorithm for Job-Shop Scheduling to Minimize Makespan

Directory of Open Access Journals (Sweden)

Zhigang Lian

2010-01-01

Full Text Available The Job-shop scheduling problem (JSSP is a branch of production scheduling, which is among the hardest combinatorial optimization problems. Many different approaches have been applied to optimize JSSP, but for some JSSP even with moderate size cannot be solved to guarantee optimality. The original particle swarm optimization algorithm (OPSOA, generally, is used to solve continuous problems, and rarely to optimize discrete problems such as JSSP. In OPSOA, through research I find that it has a tendency to get stuck in a near optimal solution especially for middle and large size problems. The local and global search combine particle swarm optimization algorithm (LGSCPSOA is used to solve JSSP, where particle-updating mechanism benefits from the searching experience of one particle itself, the best of all particles in the swarm, and the best of particles in neighborhood population. The new coding method is used in LGSCPSOA to optimize JSSP, and it gets all sequences are feasible solutions. Three representative instances are made computational experiment, and simulation shows that the LGSCPSOA is efficacious for JSSP to minimize makespan.

Dengue Virus Non-structural Protein 1 Modulates Infectious Particle Production via Interaction with the Structural Proteins.

Directory of Open Access Journals (Sweden)

Pietro Scaturro

Full Text Available Non-structural protein 1 (NS1 is one of the most enigmatic proteins of the Dengue virus (DENV, playing distinct functions in immune evasion, pathogenesis and viral replication. The recently reported crystal structure of DENV NS1 revealed its peculiar three-dimensional fold; however, detailed information on NS1 function at different steps of the viral replication cycle is still missing. By using the recently reported crystal structure, as well as amino acid sequence conservation, as a guide for a comprehensive site-directed mutagenesis study, we discovered that in addition to being essential for RNA replication, DENV NS1 is also critically required for the production of infectious virus particles. Taking advantage of a trans-complementation approach based on fully functional epitope-tagged NS1 variants, we identified previously unreported interactions between NS1 and the structural proteins Envelope (E and precursor Membrane (prM. Interestingly, coimmunoprecipitation revealed an additional association with capsid, arguing that NS1 interacts via the structural glycoproteins with DENV particles. Results obtained with mutations residing either in the NS1 Wing domain or in the β-ladder domain suggest that NS1 might have two distinct functions in the assembly of DENV particles. By using a trans-complementation approach with a C-terminally KDEL-tagged ER-resident NS1, we demonstrate that the secretion of NS1 is dispensable for both RNA replication and infectious particle production. In conclusion, our results provide an extensive genetic map of NS1 determinants essential for viral RNA replication and identify a novel role of NS1 in virion production that is mediated via interaction with the structural proteins. These studies extend the list of NS1 functions and argue for a central role in coordinating replication and assembly/release of infectious DENV particles.

Vacuum Potentials for the Two Only Permanent Free Particles, Proton and Electron. Pair Productions

International Nuclear Information System (INIS)

Zheng-Johansson, J X

2012-01-01

The two only species of isolatable, smallest, or unit charges +e and −e present in nature interact with the universal vacuum in a polarisable dielectric representation through two uniquely defined vacuum potential functions. All of the non-composite subatomic particles containing one-unit charges, +e or −e, are therefore formed in terms of the IED model of the respective charges, of zero rest masses, oscillating in either of the two unique vacuum potential fields, together with the radiation waves of their own charges. In this paper we give a first principles treatment of the dynamics of charge in a dielectric vacuum, based on which, combined with solutions for the radiation waves obtained previously, we subsequently derive the vacuum potential function for a given charge q, which we show to be quadratic and consist each of quantised potential levels, giving therefore rise to quantised characteristic oscillation frequencies of the charge and accordingly quantised, sharply-defined masses of the IED particles. By further combining with relevant experimental properties as input information, we determine the IED particles built from the charges +e, −e at their first excited states in the respective vacuum potential wells to be the proton and the electron, the observationally two only stable (permanently lived) and 'free' particles containing one-unit charges. Their antiparticles as produced in pair productions can be accordingly determined. The characteristics of all of the other more energetic single-charged non-composite subatomic particles can also be recognised. We finally discuss the energy condition for pair production, which requires two successive energy supplies to (1) first disintegrate the bound pair of vaculeon charges +e, −e composing a vacuuon of the vacuum and (2) impart masses to the disintegrated charges.

Particle production at very low transverse momenta in Au+Au collisions at √(sNN )=200 GeV

Science.gov (United States)

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steadman, S. G.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tang, J.-L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

2004-11-01

We present results on charged particle production at very low transverse momenta in the 15% most central Au+Au collisions at √(sNN )=200 GeV obtained with the PHOBOS detector at the Relativistic Heavy Ion Collider. The invariant yields were measured at midrapidity in the transverse momentum ranges from 30 to 50 MeV/c for charged pions, 90 to 130 MeV/c for charged kaons and 140 to 210 MeV/c for protons and antiprotons. No significant enhancement in low transverse momentum particle production is observed as compared to extrapolations of identified particle spectra measured at an intermediate pT range. The spectra tend to flatten at low pT , consistent with the expectations of transverse expansion of the system.

Izumoring: a novel and complete strategy for bioproduction of rare sugars.

Science.gov (United States)

Granström, Tom Birger; Takata, Goro; Tokuda, Masaaki; Izumori, Ken

2004-01-01

Starch, whey or hemicellulosic waste can be used as a raw material for the industrial production of rare sugars. D-glucose from starch, whey and hemicellulose, D-galactose from whey, and D-xylose from hemicellulose are the main starting monosaccharides for production of rare sugars. We can produce all monosaccharides; tetroses, pentoses and hexoses, from these raw materials. This is achieved by using D-tagatose 3-epimerase, aldose isomerase, aldose reductase, and oxidoreductase enzymes or whole cells as biocatalysts. Bioproduction strategies for all rare sugars are illustrated using ring form structures given the name Izumoring.

SCALP: Scintillating ionization chamber for ALPha particle production in neutron induced reactions

Science.gov (United States)

Galhaut, B.; Durand, D.; Lecolley, F. R.; Ledoux, X.; Lehaut, G.; Manduci, L.; Mary, P.

2017-09-01

The SCALP collaboration has the ambition to build a scintillating ionization chamber in order to study and measure the cross section of the α-particle production in neutron induced reactions. More specifically on 16O and 19F targets. Using the deposited energy (ionization) and the time of flight measurement (scintillation) with a great accuracy, all the nuclear reaction taking part on this project will be identify.

Rare-earth metal prices in the USA ca. 1960 to 1994

Science.gov (United States)

Hedrick, James B.

1997-01-01

Rare-earth metal prices were compiled from the late 1950s and early 1960s through 1994. Although commercial demand for rare-earth metals began in 1908, as the alloy mischmetal, commercial quantities of a wide range of individual rare-earth metals were not available until the late 1950s. The discovery of a large, high-grade rare-earth deposit at Mountain Pass. CA, USA, in 1949, was significant because it led to the production of commercial quantities or rare-earth elements that reduced prices and encouraged wider application of the materials. The availability of ore from Mountain Pass, and other large rare-earth deposits, especially those in Australia and China, has provided the world with abundant resources for rare-earth metal production. This availability, coupled with improved technology from Government and private-sector metallurgical research, has resulted in substantial decreases in rare-earth metal prices since the late 1950s and early 1960s. Price series for the individual rare-earth metals (except promethium) are quoted on a kilogram basis from the late 1950s and early 1960s through 1994. Prices are given in US dollars on an actual and constant dollar basis. Industrial and economic factors affecting prices during this time period are examined.

Particle Production in Hadron - Nuclear Matter in the Energy Range Between 50-GeV - 150-GeV

CERN Document Server

Braune, Kersten

1980-01-01

In an experiment at the CERN SPS the particle production in hadron-nucleus collisions in an energy range between 50 and 150 GeV was studied. The detector detects charged particles and separates them into two groups: fast particles, mainly produced pions, and slow particles, mainly recoil protons from the nucleus, whereby the boundary lies at a velocity v/c = 0.7. Multiplicity and angular respectively pseudo-rapidity distributions were measured. From the data analysis resulted that the slow particles are a measure for the number of collisions of the projectile in the nucleus. The properties of the fast particle were studied in dependence on . Thereby it was shown that at a description of the measured results using the variable the dependence on the projectile and on the mass number A of the target are extensively eliminated.

Rare B-meson decays in SU(2)LxSU(2)RxU(1) model

International Nuclear Information System (INIS)

Asatryan, H.M.; Ioannissian, A.N.

1989-01-01

Rare B-meson decays are investigated in the left-right synmmetric models. The scalar particle contribution to the amplitude of the b → s γ decay is calculated. It is shown that this contribution can be essential even for the scalar particles masses of about several TeV. The effects due to the left-right symmetry and scalar particles can be detected by measuring the photon polarization in the decay B → K * γ. 9 refs.; 1 fig.; 1 tab

Fission product behaviour - in particular Cs-137 - in HTR-TRISO-coated particle fuel

International Nuclear Information System (INIS)

Allelein, H.J.

1980-12-01

This work is performed between 1977 and 1979. The main task is to determine a temperature dependent diffusion coefficient of the fission product Cs-137 in the silicon carbide interlayer of HTR particles. The raw material is laso presented as the used measuring techniques and computer codes. The results are discussed in detail and some critical remarks are made about the efficiency of the silicon carbide interlayer to retent fission products including Ag-110m, Sr-90, and Ru-106, which temperature dependent diffusion coefficient is also been determined. (orig.) [de

Rare cancers are not so rare: The rare cancer burden in Europe

NARCIS (Netherlands)

Gatta, Gemma; van der Zwan, Jan Maarten; Casali, Paolo G.; Siesling, Sabine; Dei Tos, Angelo Paolo; Kunkler, Ian; Otter, Renee; Licitra, Lisa

2011-01-01

Purpose: Epidemiologic information on rare cancers is scarce. The project Surveillance of Rare Cancers in Europe (RARECARE) provides estimates of the incidence, prevalence and survival of rare cancers in Europe based on a new and comprehensive list of these diseases. Materials and methods: RARECARE

Life-Cycle Assessment of the Production of Rare-Earth Elements for Energy Applications: A Review

Energy Technology Data Exchange (ETDEWEB)

Navarro, Julio [School of Mechanical Engineering, Purdue University, West Lafayette, IN (United States); Zhao, Fu, E-mail: fzhao@purdue.edu [Division of Environmental and Ecological Engineering, School of Mechanical Engineering, Purdue University, West Lafayette, IN (United States)

2014-11-06

Rare-earth elements (REEs) are a group of 17 elements with similar chemical properties, including 15 in the lanthanide group, yttrium, and scandium. Due to their unique physical and chemical properties, REEs gain increasing importance in many new energy technologies and systems that contribute to reduce greenhouse gas emissions and fossil fuel depletion (e.g., wind turbine, electric vehicles, high efficiency lighting, batteries, and hydrogen storage). However, it is well known that production of REEs is far from environmentally sustainable as it requires significant material and energy consumption while generating large amounts of air/water emissions and solid waste. Although life-cycle assessment (LCA) has been accepted as the most comprehensive approach to quantify the environmental sustainability of a product or process, to date, there have been only very limited LCA studies on the production of REEs. With the continual growth of renewable energy and energy efficient technologies, global production of REEs will increase. Therefore, reducing environmental footprints of REE production becomes critical and identifying environmental hotspots based on a holistic and comprehensive assessment on environmental impacts serves as an important starting point. After providing an overview of LCA methodology and a high-level description of the major REE production routes used from 1990s to today, this paper reviews the published LCA studies on the production of REEs. To date, almost all the LCA studies are based on process information collected from the operation of Mountain Pass facility in U.S. in 1990s and the operation of facilities in Bayan Obo, China. Knowledge gaps are identified and future research efforts are suggested to advance understanding on environmental impacts of REE production from the life-cycle perspective.

Life-Cycle Assessment of the Production of Rare-Earth Elements for Energy Applications: A Review

International Nuclear Information System (INIS)

Navarro, Julio; Zhao, Fu

2014-01-01

Rare-earth elements (REEs) are a group of 17 elements with similar chemical properties, including 15 in the lanthanide group, yttrium, and scandium. Due to their unique physical and chemical properties, REEs gain increasing importance in many new energy technologies and systems that contribute to reduce greenhouse gas emissions and fossil fuel depletion (e.g., wind turbine, electric vehicles, high efficiency lighting, batteries, and hydrogen storage). However, it is well known that production of REEs is far from environmentally sustainable as it requires significant material and energy consumption while generating large amounts of air/water emissions and solid waste. Although life-cycle assessment (LCA) has been accepted as the most comprehensive approach to quantify the environmental sustainability of a product or process, to date, there have been only very limited LCA studies on the production of REEs. With the continual growth of renewable energy and energy efficient technologies, global production of REEs will increase. Therefore, reducing environmental footprints of REE production becomes critical and identifying environmental hotspots based on a holistic and comprehensive assessment on environmental impacts serves as an important starting point. After providing an overview of LCA methodology and a high-level description of the major REE production routes used from 1990s to today, this paper reviews the published LCA studies on the production of REEs. To date, almost all the LCA studies are based on process information collected from the operation of Mountain Pass facility in U.S. in 1990s and the operation of facilities in Bayan Obo, China. Knowledge gaps are identified and future research efforts are suggested to advance understanding on environmental impacts of REE production from the life-cycle perspective.

Productive interactions: heavy particles and non-Gaussianity

International Nuclear Information System (INIS)

Flauger, Raphael; Mirbabayi, Mehrdad; Senatore, Leonardo; Silverstein, Eva

2017-01-01

We analyze the shape and amplitude of oscillatory features in the primordial power spectrum and non-Gaussianity induced by periodic production of heavy degrees of freedom coupled to the inflaton φ. We find that non-adiabatic production of particles can contribute effects which are detectable or constrainable using cosmological data even if their time-dependent masses are always heavier than the scale φ̇ 1/2 , much larger than the Hubble scale. This provides a new role for UV completion, consistent with the criteria from effective field theory for when heavy fields cannot be integrated out. This analysis is motivated in part by the structure of axion monodromy, and leads to an additional oscillatory signature in a subset of its parameter space. At the level of a quantum field theory model that we analyze in detail, the effect arises consistently with radiative stability for an interesting window of couplings up to of order ∼< 1. The amplitude of the bispectrum and higher-point functions can be larger than that for Resonant Non-Gaussianity, and its signal/noise may be comparable to that of the corresponding oscillations in the power spectrum (and even somewhat larger within a controlled regime of parameters). Its shape is distinct from previously analyzed templates, but was partly motivated by the oscillatory equilateral searches performed recently by the Planck collaboration. We also make some general comments about the challenges involved in making a systematic study of primordial non-Gaussianity.

Productive interactions: heavy particles and non-Gaussianity

Energy Technology Data Exchange (ETDEWEB)

Flauger, Raphael [Department of Physics, The University of Texas at Austin, Austin, TX, 78712 (United States); Mirbabayi, Mehrdad [Institute for Advanced Study, Princeton, NJ 08540 (United States); Senatore, Leonardo; Silverstein, Eva, E-mail: flauger@physics.ucsd.edu, E-mail: mehrdadm@ias.edu, E-mail: senatore@stanford.edu, E-mail: evas@slac.stanford.edu [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States)

2017-10-01

We analyze the shape and amplitude of oscillatory features in the primordial power spectrum and non-Gaussianity induced by periodic production of heavy degrees of freedom coupled to the inflaton φ. We find that non-adiabatic production of particles can contribute effects which are detectable or constrainable using cosmological data even if their time-dependent masses are always heavier than the scale φ̇{sup 1/2}, much larger than the Hubble scale. This provides a new role for UV completion, consistent with the criteria from effective field theory for when heavy fields cannot be integrated out. This analysis is motivated in part by the structure of axion monodromy, and leads to an additional oscillatory signature in a subset of its parameter space. At the level of a quantum field theory model that we analyze in detail, the effect arises consistently with radiative stability for an interesting window of couplings up to of order ∼< 1. The amplitude of the bispectrum and higher-point functions can be larger than that for Resonant Non-Gaussianity, and its signal/noise may be comparable to that of the corresponding oscillations in the power spectrum (and even somewhat larger within a controlled regime of parameters). Its shape is distinct from previously analyzed templates, but was partly motivated by the oscillatory equilateral searches performed recently by the Planck collaboration. We also make some general comments about the challenges involved in making a systematic study of primordial non-Gaussianity.

Issues in leading particle and charm production in DIS at HERA

International Nuclear Information System (INIS)

Chekanov, S. V.

1999-01-01

A Monte Carlo simulation based on Ο(α s ) QCD matrix elements matched to parton showers shows that final-state hadrons in DIS can be used to tag events with a single (anti)quark recoiled against the proton. The method is particularly suited to study the mean charge of leading particles, which is sensitive to fragmentation and sea quark contribution to the proton structure function. They also discuss methods to study the charm production in DIS using the Breit frame

Experimental and theoretical investigations on diffusion process for rare earth ores

Energy Technology Data Exchange (ETDEWEB)

He, Ye; Li, Wenzhi Z. [Changchun Univ. (China)

2013-06-01

The diffusion reaction kinetics of weathered crust elution-deposited rare earth with mixed ammonium salts was studied. The influence of concentration of reagents and particle size of ore on diffusion rate was investigated. The results showed that the diffusion process and diffusion rate could be improved by increasing reagents concentration and decreasing diffusion flowing rate and particle size. The diffusion process could be explained with the shrinking core Model, which could be controlled by the diffusion rate of reacting reagents in porous solid layer.

Light hyper- and anti-nuclei production at the LHC measured with ALICE

CERN Multimedia

CERN. Geneva

2014-01-01

The high collision energies reached at the LHC lead to significant production yields of light (anti-) and hyper-nuclei in proton-proton, proton-lead and, in particular, lead-lead collisions. The excellent particle identification capabilities of the ALICE apparatus, based on the specific energy loss in the Time Projection Chamber and the velocity information obtained with the Time-Of-Flight detector, allow for the detection of these rarely produced particles. Furthermore, the Inner Tracking System gives the possibility to separate primary nuclei from those originating from the decay of hyper-nuclei. One example is the hypertriton which is reconstructed in the decay channel 3LambdaH -> 3H + pi. We present results on the production of stable nuclei and anti-nuclei in Pb--Pb and lighter collision systems. Hypernuclei production rates in Pb--Pb will also be shown. All results are compared with predictions for the production in thermal (statistical) models and alternatives which are based on coalescence mech...

EBIS/T charge breeding for intense rare isotope beams at MSU

CERN Document Server

Schwarz, S; Marrs, R E; Kittimanapun, K; Lapierre, A; Mendez, A J; Ames, F; Beene, J R; Lindroos, M; Ahle, L E; Stracener, D W; Kester, O; Wenander, F; Lopez-Urrutia, J R Crespo; Dilling, J; Bollen, G

2010-01-01

Experiments with reaccelerated beams are an essential component of the science program of existing and future rare isotope beam facilities. NSCL is currently constructing ReA3, a reaccelerator for rare isotopes that have been produced by projectile fragmentation and in-flight fission and that have been thermalized in a gas stopper. The resulting low-energy beam will be brought to an Electron Beam Ion Source/Trap (EBIS/T) in order to obtain highly charged ions at an energy of 12 keV/u. This charge breeder is followed by a compact linear accelerator with a maximum beam energy of 3MeV/u for U-238 and higher energies for lighter isotopes. Next-generation rare isotope beam facilities like the Facility for Rare Isotope Beams FRIB, but also existing Isotope Separator On-line (ISOL) facilities are expected to provide rare-isotope beam rates in the order of 10(11) particles per second for reacceleration. At present the most promising scheme to efficiently start the reacceleration of these intense beams is the use of a...

Spectroscopy of few-particle nuclei around magic 132Sn from fission product γ-ray studies

International Nuclear Information System (INIS)

Zhang, C. T.

1998-01-01

We are studying the yrast structure of very neutron-rich nuclei around doubly magic 132 Sn by analyzing fission product γ-ray data from a 248 Cm source at Eurogam II. Yrast cascades in several few-valence-particle nuclei have been identified through γγ cross coincidences with their complementary fission partners. Results for two-valence-particle nuclei 132 Sb, 134 Te, 134 Sb and 134 Sn provide empirical nucleon-nucleon interactions which, combined with single-particle energies already known in the one-particle nuclei, are essential for shell-model analysis in this region. Findings for the N = 82 nuclei 134 Te and 135 I have now been extended to the four-proton nucleus 136 Xe. Results for the two-neutron nucleus 134 Sn and the N = 83 isotones 134 Sb, 135 Te and 135 I open up the spectroscopy of nuclei in the northeast quadrant above 132 Sn

Production of strange particles in antineutrino interactions at the CERN PS

CERN Document Server

Erriquez, O; Bisi, V; Bonetti, S; Bonneaud, G; Bullock, F W; Cavalli, D; Escoubés, B; Fogli-Muciaccia, M T; Franzinetti, Carlo; Gamba, D; Guyonnet, J L; Halsteinslid, A; Huss, D; Jarlskog, C; Jones, T W; Marzari-Chiesa, A; Michette, A G; Myklebost, K; Natali, S; Nuzzo, S; Paty, M; Pullia, A; Racca, C; Riccati, L; Riester, J L; Rognebakke, A; Rollier, M; Romero, A; Sacco, R; Schäffer, M; Skjeggestad, O; Tvedt, B

1978-01-01

The authors have studied neutral strange particle production in the bubble chamber Gargamelle filled with propane and exposed to antineutrinos from the CERN PS. Cross sections are presented for Lambda , Sigma /sup 0/ and K/sup 0/ production. Associated production reactions ( Delta S=0) have been observed in the charged and the neutral current channels. From 45 candidates for the quasi-elastic reaction nu p to mu /sup +/ Lambda , on bound and free protons, estimates of the axial transition form factor M/sub A/ have been made using the total cross section and the t distribution. The weighted average from the two methods is M/sub A/=862+or-190 MeV. From a subsample of 15 candidates for nu interactions on free protons in propane, with (28+or-6)% background from nu interactions on bound protons, M/sub A/=883+or-243 MeV is obtained. The polarization of the Lambda hyperons has been studied for the quasi-elastic reaction. (11 refs).