hard diffractive processes: Topics by WorldWideScience.org

Sample records for hard diffractive processes

Hard diffraction and small-x

International Nuclear Information System (INIS)

Anon.

1995-01-01

In the United States, phrases such as ''small-x evolution'', ''the BFKL Pomeron'', ''deep-inelastic rapiditygap events'' and ''hard-diffraction'' do not generate the same intensity of discussion amongst high-energy physicists that they do in Europe. However, for three days in the fall such discussion filled the air at Fermilab. The ''2nd Workshop on Small-x and Diffractive Physics at the Tevatron'' was a review of the rapid theoretical and experimental progress taking place in this field. Although Quantum Chromo-dynamics (QCD) has been established as the theory of strong interactions for twenty years, as yet neither perturbative high-energy calculations nor low-energy non-perturbative techniques have been successfully extended to the mixture of high energy and low transverse momenta which characterize traditional ''soft'' diffractive processes. The simplest soft diffractive process is elastic scattering. In this case it is easiest to accept that there is an exchanged ''pomeron'', which can be pictured as a virtual entity with no electric charge or strong charge (colour), perhaps like an excitation of the vacuum. The same pomeron is expected to appear in all diffractive processes. Understanding the pomeron in QCD is a fundamental theoretical and experimental challenge. In the last two or three years the ''frontier'' in this challenging area of QCD has been pushed back significantly in both theory and experiment. Progress has been achieved by studying the evolution of hard collisions to relatively smaller constituent momenta (small x) and by studying ''hard'' diffractive collisions containing simultaneous signatures of diffraction and hard perturbative processes. The hard processes have included high transverse momentum jet production, deep inelastic lepton scattering, and (most recently) W
Hard diffraction and deep inelastic scattering

International Nuclear Information System (INIS)

Bjorken, J.D.

1994-04-01

Since the advent of hard-collision physics, the study of diffractive processes - shadow physics - has been less prominent than before. However, there is now a renewed interest in the subject, especially in that aspect which synthesizes the short-distance, hard-collision phenomena with the classical physics of large rapidity-gaps. This is especially stimulated by the recent data on deep-inelastic scattering from HERA, as well as the theoretical work which relates to it. The word diffraction is sometimes used by high-energy physicists in a loose way. The author defines this term to mean: A diffractive process occurs if and only if there is a large rapidity gap in the produced-particle phase space which is not exponentially suppressed. Here a rapidity gap means essentially no hadrons produced into the rapidity gap (which operates in the open-quotes legoclose quotes phase-space of pseudo-rapidity and azimuthal angle). And non-exponential suppression implies that the cross-section for creating a gap with width Δη does not have a power-law decrease with increasing subenergy s=e Δη , but behaves at most like some power of pseudorapidity Δη∼log(s). The term hard diffraction shall simply refer to those diffractive process which have jets in the final-state phase-space
Hard Diffraction - from Blois 1985 to 2005

Energy Technology Data Exchange (ETDEWEB)

Gunnar, Ingelman [Uppsala Univ., High Energy Physics (Sweden)

2005-07-01

The idea of diffractive processes with a hard scale involved, to resolve the underlying parton dynamics, was presented at the first Blois conference in 1985 and experimentally verified a few years later. Today hard diffraction is an attractive research field with high-quality data and new theoretical models. The trend from Regge-based pomeron models to QCD-based parton level models has given insights on QCD dynamics involving perturbative gluon exchange mechanisms. In the new QCD-based models, the pomeron is not part of the proton wave function, but diffraction is an effect of the scattering process. Models based on interactions with a colour background field provide an interesting approach which avoids conceptual problems of pomeron-based models, such as the pomeron flux, and provide a basis for common theoretical framework for all final states, diffractive gap events as well as non-diffractive events. Finally, the new process of gaps between jets provides strong evidence for the BFKL dynamics as predicted since long by QCD, but so far hard to establish experimentally.
Hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Brandt, A.

1995-09-01

The field of hard diffraction, which studies events with a rapidity gap and a hard scattering, has expanded dramatically recently. A review of new results from CDF, D OE, H1 and ZEUS will be given. These results include diffractive jet production, deep-inelastic scattering in large rapidity gap events, rapidity gaps between high transverse energy jets, and a search for diffractive W-boson production. The combination of these results gives new insight into the exchanged object, believed to be the pomeron. The results axe consistent with factorization and with a hard pomeron that contains both quarks and gluons. There is also evidence for the exchange of a strongly interacting color singlet in high momentum transfer (36 2 ) events
Hard scattering and a diffractive trigger

International Nuclear Information System (INIS)

Berger, E.L.; Collins, J.C.; Soper, D.E.; Sterman, G.

1986-02-01

Conclusions concerning the properties of hard scattering in diffractively produced systems are summarized. One motivation for studying diffractive hard scattering is to investigate the interface between Regge theory and perturbative QCD. Another is to see whether diffractive triggering can result in an improvement in the signal-to-background ratio of measurements of production of very heavy quarks. 5 refs
Theory of hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Del Duca, V.

1995-06-01

In this talk we review the models describing the hard diffractive production of jets or more generally high-mass states in presence of rapidity gaps in hadron-hadron and lepton-hadron collisions. By rapidity gaps we mean regions on the lego plot in (pseudo)-rapidity and azimuthal angle where no hadrons are produced, between the jet(s) and an elastically scattered hadron (single hard diffraction) or between two jets (double hard diffraction). (orig.)
Theory of hard diffraction and rapidity gaps

International Nuclear Information System (INIS)

Del Duca, V.

1996-01-01

In this talk we review the models describing the hard diffractive production of jets or more generally high-mass states in presence of rapidity gaps in hadron-hadron and lepton-hadron collisions. By rapidity gaps we mean regions on the lego plot in (pseudo)-rapidity and azimuthal angle where no hadrons are produced, between the jet(s) and an elastically scattered hadron (single hard diffraction) or between two jets (double hard diffraction). copyright 1996 American Institute of Physics
Factorization and non-factorization in diffractive hard scattering

International Nuclear Information System (INIS)

Berera, Arjun

1997-01-01

Factorization, in the sense defined for inclusive hard scattering, is discussed for diffractive hard scattering. A factorization theorem similar to its inclusive counterpart is presented for diffractive DIS. For hadron-hadron diffractive hard scattering, in contrast to its inclusive counterpart, the expected breakdown of factorization is discussed. Cross section estimates are given from a simple field theory model for non-factorizing double-pomeron-exchange (DPE) dijet production with and without account for Sudakov suppression
CMS results on hard diffraction

CERN Document Server

INSPIRE-00107098

2013-01-01

In these proceedings we present CMS results on hard diffraction. Diffractive dijet production in pp collisions at $\\sqrt{s}$=7 TeV is discussed. The cross section for dijet production is presented as a function of $\\tilde{\\xi}$, representing the fractional momentum loss of the scattered proton in single-diffractive events. The observation of W and Z boson production in events with a large pseudo-rapidity gap is also presented.
Novel Aspects of Hard Diffraction in QCD

International Nuclear Information System (INIS)

Brodsky, Stanley J.

2005-01-01

Initial- and final-state interactions from gluon-exchange, normally neglected in the parton model have a profound effect in QCD hard-scattering reactions, leading to leading-twist single-spin asymmetries, diffractive deep inelastic scattering, diffractive hard hadronic reactions, and nuclear shadowing and antishadowing--leading-twist physics not incorporated in the light-front wavefunctions of the target computed in isolation. I also discuss the use of diffraction to materialize the Fock states of a hadronic projectile and test QCD color transparency
Imaging the proton via hard exclusive production in diffractive pp scattering

International Nuclear Information System (INIS)

Charles Hyde; Leonid Frankfurt; Mark Strikman; Christian Weiss

2007-01-01

We discuss the prospects for probing Generalized Parton Distributions (GPDs) via exclusive production of a high-mass system (H = heavy quarkonium, di-photon, di-jet, Higgs boson) in diffractive pp scattering, pp -> p + H + p. In such processes the interplay of hard and soft interactions gives rise to a diffraction pattern in the final-state proton transverse momenta, which is sensitive to the transverse spatial distribution of partons in the colliding protons. We comment on the plans for diffractive pp measurements at RHIC and LHC. Such studies could complement future measurements of GPDs in hard exclusive ep scattering (JLab, COMPASS, EIC)
Diffractive hard scattering at ep and p antip colliders

International Nuclear Information System (INIS)

Bruni, P.; Ingelman, G.; Uppsala Univ.

1993-12-01

Models for diffractive scattering based on the exchange of a pomeron with a parton structure are analysed in terms of hard scattering processes and the resulting characteristics of the final state. Diffractive deep inelastic ep scattering is considered in connection with the recently observed rapidity gap events at HERA. Heavy flavour and W, Z production in p anti p interactions are interesting measures of the gluon and quark component, respectively, in the pomeron. (orig.)
A theoretical overview on single hard diffraction

International Nuclear Information System (INIS)

Wuesthoff, M.

1996-01-01

The concept of the Pomeron structure function and its application in Single Hard Diffraction at hadron colliders and in diffractive Deep Inelastic Scattering is critically reviewed. Some alternative approaches are briefly surveyed with a focus on QCD inspired models
Hard diffraction at HERA and Tevatron

International Nuclear Information System (INIS)

Kaidalov, A.B.

2001-01-01

A relation between hard diffraction at HERA and Tevatron is discussed. A model, which takes into account unitarity effects is developed for interaction of high-energy virtual photons with nucleons. It is shown that this model gives a good description of HERA data on both total γ* p total cross section and diffractive dissociation of virtual photons in a broad region of Q 2 . It is shown how to describe the CDF data on diffractive jet production at Tevatron using an information on distribution of partons in the Pomeron from HERA experiments
Hard single diffractive jet production at D0

International Nuclear Information System (INIS)

Abachi, S.; Abbott, B.; Abolins, M.

1996-08-01

Preliminary results from the D null experiment on jet production with forward rapidity gaps in p anti p collisions are presented. A class of dijet events with a forward rapidity gap is observed at center-of-mass energies √s = 1800 GeV and 630 GeV. The number of events with rapidity gaps at both center-of-mass energies is significantly greater than the expectation from multiplicity fluctuations and is consistent with a hard single diffractive process. A small class of events with two forward gaps and central dijets is also observed at 1800 GeV. This topology is consistent with hard double pomeron exchange
Diffractive hard photoproduction at HERA and evidence for the gluon content of the pomeron

International Nuclear Information System (INIS)

Derrick, M.; Krakauer, D.; Magill, S.

1995-01-01

Inclusive jet cross sections for events with a large rapidity gap with respect to the proton direction from the reaction ep→jet+X with quasi-real photons have been measured with the ZEUS detector. The cross sections refer to jets with transverse energies E T jet >8 GeV. The data show the characteristics of a diffractive process mediated by pomeron exchange. Assuming that the events are due to the exchange of a pomeron with partonic structure, the quark and gluon content of the pomeron is probed at a scale ∼(E T jet ) 2 . A comparison of the measurements with model predictions based on QCD plus Regge phenomenology requires a contribution of partons with a hard momentum density in the pomeron. A combined analysis of the jet cross sections and recent ZEUS measurements of the diffractive structure function in deep inelastic scattering gives the first experimental evidence for the gluon content of the pomeron in diffractive hard scattering processes. The data indicate that between 30% and 80% of the momentum of the pomeron carried by partons is due to hard gluons. (orig.)
Diffractive hard scattering and the SSC

International Nuclear Information System (INIS)

Berger, E.L.; Collins, J.C.; Soper, D.E.; Sterman, G.

1986-01-01

Events in high energy hadron collisions are discussed that contain a hard scattering, in the sense that very heavy quarks or high P/sub T/ jets are produced, yet are diffractive, in the sense that one of the incident hadrons is scattered with only a small energy loss. 12 refs., 6 figs
Diffractive Production of Jets and Weak Bosons, and Tests of Hard-Scattering Factorization

CERN Document Server

Alvero, L; Terrón, J; Whitmore, J; Alvero, Lyndon; Collins, John C.; Terron, Juan; Whitmore, Jim

1999-01-01

We extract diffractive parton densities from diffractive, deep inelastic (DIS) ep data from the ZEUS experiment. Then we use these fits to predict the diffractive production of jets and of W's and Z's in p\\bar p collisions at the Tevatron. Although the DIS data require a hard quark density in the pomeron, we find fairly low rates for the Tevatron processes (a few percent of the inclusive cross section). This results from the combined effects of Q^{2} evolution and of a normalization of the parton densities to the data. The calculated rates for W production are generally consistent with the preliminary data from the Tevatron. However, the jet data from CDF with a ``Roman pot'' trigger are substantially lower than the results of our calculations; if confirmed, this would signal a breakdown of hard-scattering factorization.
Crystallization and diffraction analysis of the serpin IRS-2 from the hard tick Ixodes ricinus

International Nuclear Information System (INIS)

Kovářová, Zuzana; Chmelař, Jindřich; Šanda, Miloslav; Brynda, Jiří; Mareš, Michael; Řezáčová, Pavlína

2010-01-01

Cleavage of the serpin IRS-2 from the hard tick I. ricinus by contaminating proteolytic activity mimicked the specific processing of the serpin by its target protease and resulted in a more stable form of the serpin which produced crystals that diffracted to 1.8 Å resolution. IRS-2 from the hard tick Ixodes ricinus belongs to the serpin family of protease inhibitors. It is produced in the salivary glands of the tick and its anti-inflammatory activity suggests that it plays a role in parasite–host interaction. Recombinant IRS-2 prepared by heterologous expression in a bacterial system was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to the primitive tetragonal space group P4 3 and diffracted to 1.8 Å resolution. Mass-spectrometric and electrophoretic analyses revealed that IRS-2 was cleaved by contaminating proteases during crystallization. This processing of IRS-2 mimicked the specific cleavage of the serpin by its target protease and resulted in a more stable form (the so-called relaxed conformation), which produced well diffracting crystals. Activity profiling with specific substrates and inhibitors demonstrated traces of serine and cysteine proteases in the protein stock solution
From HERA to the Tevatron: A scaling law in hard diffraction

International Nuclear Information System (INIS)

Goulianos, K.

1997-01-01

Results on hard diffraction from CDF are reviewed and compared with predictions based on the diffractive structure function of the proton measured in deep inelastic scattering at HERA. The predictions are generally larger than the measured rates by a factor of ∼ 6, suggesting a breakdown of conventional factorization. Correct predictions are obtained by scaling the rapidity gap probability distribution of the diffractive structure function to the total integrated gap probability. The scaling of the gap probability is traced back to the pomeron flux renormalization hypothesis, which was introduced to unitarize the soft diffraction amplitude

Wave packet autocorrelation functions for quantum hard-disk and hard-sphere billiards in the high-energy, diffraction regime.

Science.gov (United States)

Goussev, Arseni; Dorfman, J R

2006-07-01

We consider the time evolution of a wave packet representing a quantum particle moving in a geometrically open billiard that consists of a number of fixed hard-disk or hard-sphere scatterers. Using the technique of multiple collision expansions we provide a first-principle analytical calculation of the time-dependent autocorrelation function for the wave packet in the high-energy diffraction regime, in which the particle's de Broglie wavelength, while being small compared to the size of the scatterers, is large enough to prevent the formation of geometric shadow over distances of the order of the particle's free flight path. The hard-disk or hard-sphere scattering system must be sufficiently dilute in order for this high-energy diffraction regime to be achievable. Apart from the overall exponential decay, the autocorrelation function exhibits a generally complicated sequence of relatively strong peaks corresponding to partial revivals of the wave packet. Both the exponential decay (or escape) rate and the revival peak structure are predominantly determined by the underlying classical dynamics. A relation between the escape rate, and the Lyapunov exponents and Kolmogorov-Sinai entropy of the counterpart classical system, previously known for hard-disk billiards, is strengthened by generalization to three spatial dimensions. The results of the quantum mechanical calculation of the time-dependent autocorrelation function agree with predictions of the semiclassical periodic orbit theory.
Hard X-ray nanoimaging method using local diffraction from metal wire

Energy Technology Data Exchange (ETDEWEB)

Takano, Hidekazu, E-mail: htakano@sci.u-hyogo.ac.jp; Konishi, Shigeki; Shimomura, Sho; Azuma, Hiroaki; Tsusaka, Yoshiyuki; Kagoshima, Yasushi [Center for Novel Material Science under Multi-Extreme Conditions, Graduate School of Material Science, University of Hyogo, Kamigori, Hyogo 678-1297 (Japan)

2014-01-13

A simple hard X-ray imaging method achieving a high spatial resolution is proposed. Images are obtained by scanning a metal wire through the wave field to be measured and rotating the sample to collect data for back projection calculations; the local diffraction occurring at the edges of the metal wire operates as a narrow line probe. In-line holograms of a test sample were obtained with a spatial resolution of better than 100 nm. The potential high spatial resolution of this method is shown by calculations using diffraction theory.
Hard Distraction and Deep Inelastic Scattering

International Nuclear Information System (INIS)

BJORKEN, J.D.

1994-01-01

Since the advent of hard-collision physics, the study of diffractive processes- 'shadow physics' - has been less prominent than before. However, there is now a renewed interest in the subject, especially in that aspect which synthesizes the short-distance, hard-collision phenomena with the classical physics of large rapidity-gaps. This is especially stimulated by the recent data on deep-inelastic scattering from HERA, as well as the theoretical work which relates to it. The word 'diffraction' is sometimes used by high-energy physicists in a loose way. So I here begin by defining what I mean by the term: A diffractive process occurs if and only if there is a large rapidity gap in the produced-particle phase space which is not exponentially suppressed. Here a rapidity gap means essentially no hadrons produced into the rapidity gap (which operates in the 'lego' phase-space of pseudo-rapidity and azimuthal angle). And non-exponential suppression implies that the cross-section for creating a gap with width Δη does not have a power-law decrease with increasing sub energy Δη, but behaves at most like some power of pseudorapidity Δη∼ logs. The term 'hard diffraction' shall simply refer to those diffractive processes which have jets in the final-state phase-space. We may also distinguish, if desired, two subclasses, as suggested by Ingelman i) Diffractive hard processes have jets on only one side of the rapidity gap. ii) Hard diffractive processes have jets on both sides of the rapidity gap
Interplay of hard and soft physics in small x deep inelastic processes

International Nuclear Information System (INIS)

Abramowicz, H.

1995-01-01

Coherence phenomena, the increase with energy of coherence length and the nonuniversality of parton structure of the effective pomeron are explained. New hard phenomena directly calculable in QCD such as diffractive electroproduction of states with M 2 2 and the color transparency phenomenon as well as new options to measure the light-cone wave functions of various hadrons are considered. An analogue of Bjorken scaling is predicted for the diffractive electroproduction of ρ mesons at large momentum transfers and for the production of large rapidity gap events, as observed at HERA. A phenomenological QCD evolution equation is suggested to calculate the basic characteristics of the large rapidity gap events. The increase of parton densities at small x as well as new means to disentangle experimentally soft and hard physics are considered. We discuss constraints on the increase of deep inelastic amplitudes with Q 2 derived from the inconsistency of QCD predictions for inclusive and exclusive processes and from unitarity of the S matrix for collisions of wave packets. New ways to probe QCD physics of hard processes at large longitudinal distances and to answer the long standing problems on the origin of the pomeron are suggested. Unresolved problems and perspectives of small x physics are also outlined. (orig.)
Diffraction at TOTEM

OpenAIRE

Antchev, G.; Aspell, P.; Avati, V.; Bagliesi, M.G.; Berardi, V.; Berretti, M.; Bottigli, U.; Bozzo, M.; Brucken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Catanesi, M.G.; Catastini, P.L.; Cecchi, R.

2008-01-01

The TOTEM experiment at the LHC measures the total proton-proton cross section with the luminosity-independent method and the elastic proton-proton cross-section over a wide |t|-range. It also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral...
Diffraction at TOTEM

OpenAIRE

Giani, S; Niewiadomski, H; Antchev, G; Aspell, P; Avati, V; Bagliesi, M G; Berardi, V; Berretti, M; Besta, M; Bozzo, M; Brücken, E; Buzzo, A; Cafagna, F; Calicchio, M; Catanesi, M G

2010-01-01

The primary objective of the TOTEM experiment at the LHC is the measurement of the total proton-proton cross section with the luminosity-independent method and the study of elastic proton-proton cross-section over a wide |t|-range. In addition TOTEM also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage...
Hard X-ray diffraction enhanced imaging only using two crystals

Institute of Scientific and Technical Information of China (English)

LI Gang; WANG Nan; WU Ziyu

2004-01-01

Different configurations for the monochromator crystals and the analyzer crystals have been used in hard X-ray diffraction enhanced imaging (DEI) methods to overcome the complex task to adjust each of them to the ideal position. Here we present a very compact DEI configuration, and preliminary results of experiments performed at the Beijing Synchrotron Radiation Facility (BSRF) using only two crystals: the first one acting as monochromator and the second one as analyzer in the Bragg geometry. Refraction contrast images characterized by high contrast and spatial resolution are obtained and compared with absorption images. Differences among these images will be outlined and discussed emphasizing the potential capabilities of this very simple layout that guarantees a high transmission efficiency.
High-energy particle diffraction

International Nuclear Information System (INIS)

Barone, V.; Predazzi, E.

2002-01-01

This monograph gives a comprehensive and up-to-date overview of soft and hard diffraction processes in strong interaction physics. The first part covers the general formalism (the optical analogy, the eikonal picture, high-energy kinematics, S-matrix theory) and soft hadron-hadron scattering (including the Regge theory) in a complete and mature presentation. It can be used as a textbook in particle physics classes. The remainder of the book is devoted to the 'new diffraction': the pomeron in QCD, low-x physics, diffractive deep inelastic scattering and related processes, jet production etc. It presents recent results and experimental findings and their phenomenological interpretations. This part addresses graduate students as well as researchers. (orig.)
Observation of hard processes in rapidity gap events in {gamma}p interactions at HERA

Energy Technology Data Exchange (ETDEWEB)

Ahmed, T.; Aid, S.; Andreev, V.; Andrieu, B.; Appuhn, R.D.; Arpagaus, M.; Babaev, A.; Baehr, J.; Ban, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Barth, M.; Bassler, U.; Beck, H.P.; Behrend, H.J.; Belousov, A.; Berger, C.; Bergstein, H.; Bernardi, G.; Bernet, R.; Bertrand-Coremans, G.; Besancon, M.; Beyer, R.; Biddulph, P.; Bizot, J.C.; Blobel, V.; Borras, K.; Botterweck, F.; Boudry, V.; Braemer, A.; Brasse, F.; Braunschweig, W.; Brisson, V.; Bruncko, D.; Brune, C.; Buchholz, R.; Buengener, L.; Buerger, J.; Buesser, F.W.; Buniatian, A.; Burke, S.; Buschhorn, G.; Campbell, A.J.; Carli, T.; Charles, F.; Clarke, D.; Clegg, A.B.; Clerbaux, B.; Colombo, M.; Contreras, J.G.; Coughlan, J.A.; Courau, A.; Coutures, C.; Cozzika, G.; Criegee, L.; Cussans, D.G.; Cvach, J.; Dagoret, S.; Dainton, J.B.; Danilov, M.; Dau, W.D.; Daum, K.; David, M.; Deffur, E.; Delcourt, B.; Del Buono, L.; De Roeck, A.; De Wolf, E.A.; Di Nezza, P.; Dollfus, C.; Dowell, J.D.; Dreis, H.B.; Droutskoi, V.; Duboc, J.; Duellmann, D.; Duenger, O.; Duhm, H.; Ebert, J.; Ebert, T.R.; Eckerlin, G.; Efremenko, V.; Egli, S.; Ehrlichmann, H.; Eichenberger, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellison, R.J.; Elsen, E.; Erdmann, M.; Erdmann, W.; Evrard, E.; Favart, L.; Fedotov, A.; Feeken, D.; Felst, R.; Feltesse, J.; Ferencei, J.; Ferrarotto, F.; Flamm, K.; Fleischer, M.; Flieser, M.; Fluegge, G.; Fomenko, A.; Fominykh, B.; Forbush, M.; Formanek, J.; Foster, J.M.; Franke, G.; Fretwurst, E.; Gabathuler, E.; Gabathuler, K.; Gamerdinger, K.; Garvey, J.; Gayler, J.; Gebauer, M.; Gellrich, A.; Genzel, H.; Gerhards, R.; Goerlach, U.; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Goldner, D.; Gonzalez-Pineiro, B.; Goodall, A.M.; Gorelov, I.; Goritchev, P.; Grab, C.; Graessler, H.; Graessler, R.; Greenshaw, T.; Grindhammer, G.; Gruber, A.; Gruber, C.; Haack, J.; Haidt, D.; Hajduk, L.; Hamon, O.; Hampel, M.; Hanlon, E.M.; Hapke, M.; Haynes, W.J.; Heatherington, J.; Heinzelmann, G.; Henderson, R.C.W.; H1 Collaboration

1995-02-06

Events with no hadronic energy flow in a large interval of pseudo-rapidity in the proton direction are observed in photon-proton interactions at an average centre of mass energy left angle {radical}(s{sub {gamma}p}) right angle of 200 GeV. These events are interpreted as photon diffractive dissociation. Evidence for hard scattering in photon diffractive dissociation is demonstrated using inclusive single particle spectra, thrust as a function of transverse energy, and the observation of jet production. The data can be described by a Monte Carlo calculation including hard photon-pomeron scattering. ((orig.))
Hard exclusive QCD processes

Energy Technology Data Exchange (ETDEWEB)

Kugler, W.

2007-01-15

Hard exclusive processes in high energy electron proton scattering offer the opportunity to get access to a new generation of parton distributions, the so-called generalized parton distributions (GPDs). This functions provide more detailed informations about the structure of the nucleon than the usual PDFs obtained from DIS. In this work we present a detailed analysis of exclusive processes, especially of hard exclusive meson production. We investigated the influence of exclusive produced mesons on the semi-inclusive production of mesons at fixed target experiments like HERMES. Further we give a detailed analysis of higher order corrections (NLO) for the exclusive production of mesons in a very broad range of kinematics. (orig.)
Diffraction at TOTEM

CERN Document Server

Giani, S; Antchev, G; Aspell, P; Avati, V; Bagliesi, M G; Berardi, V; Berretti, M; Besta, M; Bozzo, M; Brücken, E; Buzzo, A; Cafagna, F; Calicchio, M; Catanesi, M G; Cecchi, R; Ciocci, M A; Dadel, P; Deile, M; Dimovasili, E; Eggert, K; Eremin, V; Ferro, F; Fiergolski, A; García, F; Greco, V; Grzanka, L; Heino, J; Hildén, T; Kaspar, J; Kopal, J; Kundrát, V; Kurvinen, K; Lami, S; Latino, G; Lauhakangas, R; Leszko, R; Lippmaa, E; Lokajícek, M; Lo Vetere, M; Lucas Rodriguez, F; Macrí, M; Magazzù, G; Meucci, M; Minutoli, S; Notarnicola, G; Oliveri, E; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Pedreschi, E; Petäjäjärvi, J; Prochazka, J; Quinto, M; Radermacher, E; Radicioni, E; Ravotti, F; Rella, G; Robutti, E; Ropelewski, L; Rostkowski, M; Ruggiero, G; Rummel, A; Saarikko, H; Sanguinetti, G; Santroni, A; Scribano, A; Sette, G; Snoeys, W; Spinella, F; Ster, A; Taylor, C; Trummal, A; Turini, N; Whitmore, J; Wu, J; Zalewski, M

2010-01-01

The primary objective of the TOTEM experiment at the LHC is the measurement of the total proton-proton cross section with the luminosity-independent method and the study of elastic proton-proton cross-section over a wide |t|-range. In addition TOTEM also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral particle detection and the large variety of trigger possibilities even at large luminosities. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximise its physics reach. This contribution describes the main features of the TOTEM diffractive physics programme including measurements to be made in the early LHC runs.
Twenty years of diffraction at the Tevatron

International Nuclear Information System (INIS)

Goulianos, K.; Rockefeller U.

2005-01-01

Results on diffractive particle interactions from the Fermilab Tevatron (bar p)p collider are placed in perspective through a QCD inspired phenomenological approach, which exploits scaling and factorization properties observed in data. The results discussed are those obtained by the CDF Collaboration from a comprehensive set of single, double, and multigap soft and hard diffraction processes studied during the twenty year period since 1985, when the CDF diffractive program was proposed and the first Blois Workshop was held
CONFERENCE: Elastic and diffractive scattering

Energy Technology Data Exchange (ETDEWEB)

White, Alan

1989-09-15

Elastic scattering, when particles appear to 'bounce' off each other, and the related phenomena of diffractive scattering are currently less fashionable than the study of hard scattering processes. However this could change rapidly if unexpected results from the UA4 experiment at the CERN Collider are confirmed and their implications tested. These questions were highlighted at the third 'Blois Workshop' on Elastic and Diffractive Scattering, held early in May on the Evanston campus of Northwestern University, near Chicago.
CONFERENCE: Elastic and diffractive scattering

International Nuclear Information System (INIS)

White, Alan

1989-01-01

Elastic scattering, when particles appear to 'bounce' off each other, and the related phenomena of diffractive scattering are currently less fashionable than the study of hard scattering processes. However this could change rapidly if unexpected results from the UA4 experiment at the CERN Collider are confirmed and their implications tested. These questions were highlighted at the third 'Blois Workshop' on Elastic and Diffractive Scattering, held early in May on the Evanston campus of Northwestern University, near Chicago
Diffraction at collider energies

International Nuclear Information System (INIS)

Frankfurt, L.L.

1992-01-01

Lessons with ''soft'' hadron physics to explain (a) feasibility to observe and to investigate color transparency, color opacity effects at colliders; (b) significant probability and specific features of hard diffractive processes; (c) feasibility to investigate components of parton wave functions of hadrons with minimal number of constituents. This new physics would be more important with increase of collision energy
Hard processes in hadronic interactions

International Nuclear Information System (INIS)

Satz, H.; Wang, X.N.

1995-01-01

Quantum chromodynamics is today accepted as the fundamental theory of strong interactions, even though most hadronic collisions lead to final states for which quantitative QCD predictions are still lacking. It therefore seems worthwhile to take stock of where we stand today and to what extent the presently available data on hard processes in hadronic collisions can be accounted for in terms of QCD. This is one reason for this work. The second reason - and in fact its original trigger - is the search for the quark-gluon plasma in high energy nuclear collisions. The hard processes to be considered here are the production of prompt photons, Drell-Yan dileptons, open charm, quarkonium states, and hard jets. For each of these, we discuss the present theoretical understanding, compare the resulting predictions to available data, and then show what behaviour it leads to at RHIC and LHC energies. All of these processes have the structure mentioned above: they contain a hard partonic interaction, calculable perturbatively, but also the non-perturbative parton distribution within a hadron. These parton distributions, however, can be studied theoretically in terms of counting rule arguments, and they can be checked independently by measurements of the parton structure functions in deep inelastic lepton-hadron scattering. The present volume is the work of Hard Probe Collaboration, a group of theorists who are interested in the problem and were willing to dedicate a considerable amount of their time and work on it. The necessary preparation, planning and coordination of the project were carried out in two workshops of two weeks' duration each, in February 1994 at CERn in Geneva andin July 1994 at LBL in Berkeley
Diffraction at TOTEM

CERN Document Server

Antchev, G.; Avati, V.; Bagliesi, M.G.; Berardi, V.; Berretti, M.; Bottigli, U.; Bozzo, M.; Brucken, E.; Buzzo, A.; Cafagna, F.; Calicchio, M.; Catanesi, M.G.; Catastini, P.L.; Cecchi, R.; Ciocci, M.A.; Deile, M.; Dimovasili, E.; Eggert, K.; Eremin, V.; Ferro, F.; Garcia, F.; Giani, S.; Greco, V.; Heino, J.; Hilden, T.; Kaspar, J.; Kopal, J.; Kundrat, V.; Kurvinen, K.; Lami, S.; Latino, G.; Lauhakangas, R.; Lippmaa, E.; Lokajicek, M.; Lo Vetere, M.; Lucas Rodriguez, F.; Macri, M.; Magazzu, G.; Meucci, M.; Minutoli, S.; Niewiadomski, H.; Noschis, E.; Notarnicola, G.; Oliveri, E.; Oljemark, F.; Orava, R.; Oriunno, M.; Osterberg, K.; Palazzi, P.; Pedreschi, E.; Petajajarvi, J.; Quinto, M.; Radermacher, E.; Radicioni, E.; Ravotti, F.; Rella, G.; Robutti, E.; Ropelewski, L.; Ruggiero, G.; Rummel, A.; Saarikko, H.; Sanguinetti, G.; Santroni, A.; Scribano, A.; Sette, G.; Snoeys, W.; Spinella, F.; Squillacioti, P.; Ster, A.; Taylor, C.; Trummal, A.; Turini, N.; Whitmore, J.; Wu, J.

2009-01-01

The TOTEM experiment at the LHC measures the total proton-proton cross section with the luminosity-independent method and the elastic proton-proton cross-section over a wide |t|-range. It also performs a comprehensive study of diffraction, spanning from cross-section measurements of individual diffractive processes to the analysis of their event topologies. Hard diffraction will be studied in collaboration with CMS taking advantage of the large common rapidity coverage for charged and neutral particle detection and the large variety of trigger possibilities even at large luminosities. TOTEM will take data under all LHC beam conditions including standard high luminosity runs to maximize its physics reach. This contribution describes the main features of the TOTEM physics programme including measurements to be made in the early LHC runs. In addition, a novel scheme to extend the diffractive proton acceptance for high luminosity runs by installing proton detectors at IP3 is described.
Generalized parton distributions and rapidity gap survival in exclusive diffractive pp scattering

Energy Technology Data Exchange (ETDEWEB)

Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman; Christian Weiss

2007-03-01

We propose a new approach to the problem of rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, heavy quarkonium, Higgs boson) in double-gap exclusive diffractive pp scattering, pp-->p + (gap) + H + (gap) + p. It is based on the idea that hard and soft interactions proceed over widely different time- and distance scales and are thus approximately independent. The high-mass system is produced in a hard scattering process with exchange of two gluons between the protons. Its amplitude is calculable in terms of the gluon generalized parton distributions (GPDs) in the protons, which can be measured in J= production in exclusive ep scattering. The hard scattering process is modified by soft spectator interactions, which we calculate in a model-independent way in terms of the pp elastic scattering amplitude. Contributions from inelastic intermediate states are suppressed. A simple geometric picture of the interplay of hard and soft interactions in diffraction is obtained. The onset of the black-disk limit in pp scattering at TeV energies strongly suppresses diffraction at small impact parameters and is the main factor in determining the RGS probability. Correlations between hard and soft interactions (e.g. due to scattering from the long-range pion field of the proton, or due to possible short-range transverse correlations between partons) further decrease the RGS probability. We also investigate the dependence of the diffractive cross section on the transverse momenta of the final-state protons (''diffraction pattern''). By measuring this dependence one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton. Such studies appear to be feasible with the planned forward detectors at the LHC.
Generalized parton distributions and rapidity gap survival in exclusive diffractive pp scattering

International Nuclear Information System (INIS)

Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman; Christian Weiss

2006-01-01

We propose a new approach to the problem of rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, heavy quarkonium, Higgs boson) in double-gap exclusive diffractive pp scattering, pp-->p + (gap) + H + (gap) + p. It is based on the idea that hard and soft interactions proceed over widely different time- and distance scales and are thus approximately independent. The high-mass system is produced in a hard scattering process with exchange of two gluons between the protons. Its amplitude is calculable in terms of the gluon generalized parton distributions (GPDs) in the protons, which can be measured in J= production in exclusive ep scattering. The hard scattering process is modified by soft spectator interactions, which we calculate in a model-independent way in terms of the pp elastic scattering amplitude. Contributions from inelastic intermediate states are suppressed. A simple geometric picture of the interplay of hard and soft interactions in diffraction is obtained. The onset of the black-disk limit in pp scattering at TeV energies strongly suppresses diffraction at small impact parameters and is the main factor in determining the RGS probability. Correlations between hard and soft interactions (e.g. due to scattering from the long-range pion field of the proton, or due to possible short-range transverse correlations between partons) further decrease the RGS probability. We also investigate the dependence of the diffractive cross section on the transverse momenta of the final-state protons (''diffraction pattern''). By measuring this dependence one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton. Such studies appear to be feasible with the planned forward detectors at the LHC
Diffractive corrections to the muon Bremsstrahlung

International Nuclear Information System (INIS)

Kel'ner, S.R.; Fedotov, A.M.

1999-01-01

The corrections to the muon Bremsstrahlung cross section due to diffraction of hard photons on nuclei are obtained. In this process the momentum is transmitted to a nucleus not by a charged particle but by the photon the interaction of which with the nucleus can be considered as diffraction on weakly absorbing ball. The amplitude of the process interferes with the usual Bremsstrahlung amplitude, therefore in the cross section together with the diffraction correction the interference term also appears, possessing different sings for μ + and μ - . The photon emission cross section also depends on the sing of muon charge and for muon energy about 10 TeV the difference between the cross section may reach 10%. The corrections to the radiation energy loss are also calculated [ru

Hard Electromagnetic Processes

International Nuclear Information System (INIS)

Richard, F.

1987-09-01

Among hard electromagnetic processes, I will use the most recent data and focus on quantitative test of QCD. More specifically, I will retain two items: - hadroproduction of direct photons, - Drell-Yan. In addition, I will briefly discuss a recent analysis of ISR data obtained with AFS (Axial Field Spectrometer) which sheds a new light on the e/π puzzle at low P T
Drell-Yan diffraction: breakdown of QCD factorization

International Nuclear Information System (INIS)

Pasechnik, R.S.; Kopeliovich, B.Z.

2011-01-01

We consider the diffractive Drell-Yan process in proton-(anti)proton collisions at high energies in the color dipole approach. The calculations are performed at forward rapidities of the leptonic pair. The effect of eikonalization of the universal ''bare'' dipole-target elastic amplitude in the saturation regime takes into account the principal part of the gap survival probability. We present predictions for the total and differential cross sections of the single-diffractive lepton-pair production at RHIC and LHC energies. We analyze implications of the QCD factorization breakdown in the diffractive Drell-Yan process, which is caused by a specific interplay of the soft and hard interactions, resulting in rather unusual properties of the corresponding observables. (orig.)
Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water

Directory of Open Access Journals (Sweden)

Nelson Saksono

2010-10-01

Full Text Available Magnetic treatment is applied as physical water treatment for scale prevention especially CaCO3, from hard water in piping equipment by reducing its hardness.Na2CO3 and CaCl2 solution sample was used in to investigate the magnetic fields influence on the formation of particle of CaCO3. By changing the strength of magnetic fields, exposure time and concentration of samples solution, this study presents quantitative results of total scale deposit, total precipitated CaCO3 and morphology of the deposit. This research was run by comparing magnetically and non-magnetically treated samples. The results showed an increase of deposits formation rate and total number of precipitated CaCO3 of magnetically treated samples. The increase of concentration solution sample will also raised the deposit under magnetic field. Microscope images showed a greater number but smaller size of CaCO3 deposits form in magnetically treated samples, and aggregation during the processes. X-ray diffraction (XRD analysis showed that magnetically samples were dominated by calcite. But, there was a significant decrease of calcite’s peak intensities from magnetized samples that indicated the decrease of the amount of calcite and an increase of total amorphous of deposits. This result showed that magnetization of hard water leaded to the decreasing of ion Ca2+ due to the increasing of total CaCO3 precipitation process.
Inclusive measurements on diffractive processes in ep collisions

International Nuclear Information System (INIS)

Janssen, Xavier

2007-01-01

Measurements from the H1 and ZEUS collaborations of the diffractive deep-inelastic scattering process, ep → eXY, where Y is a proton or a low mass proton excitation, are presented for photon virtualities in the range 2.2 2 2 and squared four-momentum transfer at the proton vertex satisfying | t | 2 . Diffractive parton distribution functions and their uncertainties are determined from a next-to-leading order DGLAP QCD analysis. Combining measurements of the inclusive diffractive deep-inelastic scattering process with an analysis of diffractive di jet production allows a very sensitive determination of both quark and gluon distributions. (author)
Double Diffractive Process Factorization from ηc and γ Associated Production at Tevatron and LHC

Institute of Scientific and Technical Information of China (English)

YANZhan-Yuan; LIZhi-Wen; DUANChun-Gui

2004-01-01

We present a study of associated ηc and γ double diffractive production in pp- collision based on Ingelman-Schlein model, and the framework of non-relativistic QOD factorization formalism for quarkonia production. The prediction of ηc and γ is more reliable than J/ψ production, because the associated ηc and γ production is a pure color-octet process, and the dominant contribution comes from color octet 1S0(8) subprocess, which is related to the color octet matrix element of 1S0(8) of J/ψ by the heavy quark spin symmetry and the large PT J/ψ production data. We find that the ratio of diffractive to inclusive cross sections is independent of the values of color octet matrix elements, but is sensitive to the gluon factor of the Pomeron and renormalized Pomeron flux factors. So experimental measurement of this ratio can give us more information of the nature of Pomeron and test the assumption of hard diffractive factorization in hadron-hadron collisions.
Multiorder nonlinear diffraction in frequency doubling processes

DEFF Research Database (Denmark)

Saltiel, Solomon M.; Neshev, Dragomir N.; Krolikowski, Wieslaw

2009-01-01

We analyze experimentally light scattering from 2 nonlinear gratings and observe two types of second-harmonic frequency-scattering processes. The first process is identified as Raman–Nath type nonlinear diffraction that is explained by applying only transverse phase-matching conditions. The angular...... position of this type of diffraction is defined by the ratio of the second-harmonic wavelength and the grating period. In contrast, the second type of nonlinear scattering process is explained by the longitudinal phase matching only, being insensitive to the nonlinear grating...
Hard and soft acids and bases: structure and process.

Science.gov (United States)

Reed, James L

2012-07-05

Under investigation is the structure and process that gives rise to hard-soft behavior in simple anionic atomic bases. That for simple atomic bases the chemical hardness is expected to be the only extrinsic component of acid-base strength, has been substantiated in the current study. A thermochemically based operational scale of chemical hardness was used to identify the structure within anionic atomic bases that is responsible for chemical hardness. The base's responding electrons have been identified as the structure, and the relaxation that occurs during charge transfer has been identified as the process giving rise to hard-soft behavior. This is in contrast the commonly accepted explanations that attribute hard-soft behavior to varying degrees of electrostatic and covalent contributions to the acid-base interaction. The ability of the atomic ion's responding electrons to cause hard-soft behavior has been assessed by examining the correlation of the estimated relaxation energies of the responding electrons with the operational chemical hardness. It has been demonstrated that the responding electrons are able to give rise to hard-soft behavior in simple anionic bases.
Diffractive DIS: Where are we?

International Nuclear Information System (INIS)

Nikolaev, N.N.

2001-01-01

A brief review of the modern QCD theory of diffractive DIS is given. The recent progress has been remarkably rapid, all the principal predictions from the color dipole approach to diffraction - the (Q 2 + m V 2 ) scaling, the pattern of SCHNC, shrinkage of the diffraction cone in hard diffractive DIS, the strong impact of longitudinal gluons in inclusive J/Ψ production at Tevatron - have been confirmed experimentally
Effects of carbon nanotube content and annealing temperature on the hardness of CNT reinforced aluminum nanocomposites processed by the high pressure torsion technique

Energy Technology Data Exchange (ETDEWEB)

Phuong, Doan Dinh, E-mail: phuongdd@ims.vast.ac.vn [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Str., Cau Giay Distr., Hanoi (Viet Nam); Trinh, Pham Van; An, Nguyen Van; Luan, Nguyen Van; Minh, Phan Ngoc [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Str., Cau Giay Distr., Hanoi (Viet Nam); Khisamov, Rinat Kh.; Nazarov, Konstantin S.; Zubairov, Linar R.; Mulyukov, Radik R.; Nazarov, Ayrat A. [Institute for Metals Superplasticity Problems, Russian Academy of Sciences 39, Stepan Khalturin Str., Ufa 450001 (Russian Federation)

2014-11-15

Highlights: • CNT/Al nanocomposites were consolidated by HIP and subsequently processed by the high pressure torsion technique. • High pressure torsion processing was unable to break apart or disperse the CNT agglomerates persisted in powder preparation. • HPT-processed CNT/Al nanocomposites exhibited secondary hardening during annealing at temperatures below 150 °C. - Abstract: In this paper, the microstructure and hardness of CNT reinforced aluminium (CNT/Al) nanocomposites prepared by the advanced powder metallurgy method and subsequently processed by the high pressure torsion (HPT) technique are studied. The effects of CNT content and annealing temperature on the hardness of the nanocomposites are investigated. The results show that annealing materials at temperatures below 150 °C leads to secondary hardening, while annealing at higher temperatures soften the nanocomposites. HPT-processed CNT/Al nanocomposites with 1.5 wt.% of CNTs are shown to have the highest hardness in comparison with other composites containing CNTs from 0 up to 2 wt.%. Microstructures, CNT distribution and the phase composition of CNT/Al nanocomposites are investigated by transmission and scanning electron microscopy and X-ray diffraction techniques.
Diffractive processes in pp collisions at 7 TeV measured with the CMS experiment

CERN Document Server

Brona, Grzegorz Konrad

2015-01-01

The differential diffractive cross section is measured as a function of $\\xi= M_X^2/s$ in the region dominated by single dissociation (SD) and double dissociation (DD), where $M_X$ is the mass of one of the two final-state hadronic systems separated by the largest rapidity gap in the event. The cross section is also measured as a function of the width of the central rapidity gap in the region dominated by DD, as well as for events with a forward gap over 8.4 units of pseudorapidity. The total SD and DD cross sections are extracted. Single diffraction is one of the main uncertainties both, experimentally and in theoretical calculations, of the particle-production cross section in proton-lead collisions as measured at the centre-of-mass energy per nucleon pair of 5.02 TeV. Furthermore, the observation of a hard color-singlet exchange process in events with a large rapidity gap between two leading jets (jet-gap-jet) is reported. The fraction of jet-gap-jet to all dijet events is measured as a function of the sec...
Rapidity gap survival in central exclusive diffraction: Dynamical mechanisms and uncertainties

International Nuclear Information System (INIS)

Strikman, Mark; Weiss, Christian

2009-01-01

We summarize our understanding of the dynamical mechanisms governing rapidity gap survival in central exclusive diffraction, pp -> p + H + p (H = high-mass system), and discuss the uncertainties in present estimates of the survival probability. The main suppression of diffractive scattering is due to inelastic soft spectator interactions at small pp impact parameters and can be described in a mean-field approximation (independent hard and soft interactions). Moderate extra suppression results from fluctuations of the partonic configurations of the colliding protons. At LHC energies absorptive interactions of hard spectator partons associated with the gg -> H process reach the black-disk regime and cause substantial additional suppression, pushing the survival probability below 0.01.
Diffraction and signal processing experiments with a liquid crystal microdisplay

International Nuclear Information System (INIS)

MartInez, Jose Luis; Moreno, Ignacio; Ahouzi, Esmail

2006-01-01

In this work, we show some diffraction experiments performed with a liquid crystal display (LCD) that shows how useful this device can be to teach and experience diffraction optics and signal processing experiments. The LCD acts as a programmable pixelated diffractive mask. The Fourier spectrum of the image displayed in the LCD is visualized through a simple free propagation diffraction experiment. This optical system allows easy testing of different diffractive elements. As a demonstration we include experimental results with well-known diffractive elements like diffraction gratings or Fresnel lenses, and with more complicated elements like computer-generated holograms
Diffraction and signal processing experiments with a liquid crystal microdisplay

Energy Technology Data Exchange (ETDEWEB)

MartInez, Jose Luis [Departamento de Ciencia y TecnologIa de Materiales, Universidad Miguel Hernandez de Elche, Alicante (Spain); Moreno, Ignacio [Departamento de Ciencia y TecnologIa de Materiales, Universidad Miguel Hernandez de Elche, Alicante (Spain); Ahouzi, Esmail [Institut National des Postes et Telecomunications (INTP), Madinat Al Irfane, Rabat (Morocco)

2006-09-01

In this work, we show some diffraction experiments performed with a liquid crystal display (LCD) that shows how useful this device can be to teach and experience diffraction optics and signal processing experiments. The LCD acts as a programmable pixelated diffractive mask. The Fourier spectrum of the image displayed in the LCD is visualized through a simple free propagation diffraction experiment. This optical system allows easy testing of different diffractive elements. As a demonstration we include experimental results with well-known diffractive elements like diffraction gratings or Fresnel lenses, and with more complicated elements like computer-generated holograms.
Soft and hard pomerons

International Nuclear Information System (INIS)

Maor, Uri; Tel Aviv Univ.

1995-09-01

The role of s-channel unitarity screening corrections, calculated in the eikonal approximation, is investigated for soft Pomeron exchange responsible for elastic and diffractive hadron scattering in the high energy limit. We examine the differences between our results and those obtained from the supercritical Pomeron-Regge model with no such corrections. It is shown that screening saturation is attained at different scales for different channels. We then proceed to discuss the new HERA data on hard (PQCD) Pomeron diffractive channels and discuss the relationship between the soft and hard Pomerons and the relevance of our analysis to this problem. (author). 18 refs, 9 figs, 1 tab
New focus for elastic and diffractive scattering

International Nuclear Information System (INIS)

Kwiecinski, J.

1995-01-01

A regular feature of the international physics calendar is the International Conference on Elastic and Diffractive Scattering, known also as the Blois Workshops, after their 1985 birthplace in France. The content of this year's meeting embraced a broad spectrum of problems ranging from the classical analysis of elastic scattering and total cross-sections to the ''hard'' or deep inelastic phenomena which test the underlying quark-gluon structure of hadrons. These meetings have traditionally concentrated on broad questions of elastic and diffractive scattering, however the shift of emphasis in physics is now reflected at Blois by interest in the wide range of 'soft' hadronic processes which dominate reaction cross-sections. On the traditional side, a substantial part of the conference was devoted to analysis of forward scattering parameters like total cross-sections, real parts etc, using dispersion relations and fundamental asymptotic theorems which bound the possible growth of those parameters with energy. The present experimental situation in this field was summarized by S. Pruss, followed by theoretical presentations by B. Nicolescu, A. Donnachie, T.T. Wu, A. Martin and others. The data for proton-proton and proton-antiproton scattering seem to support dominance of the 'crossing-even' part of the scattering amplitude (which contributes equally to both proton-proton and protonantiproton scattering), with little evidence for a substantial 'odderon' term which contributes with opposite sign in the two cases. The 'pomeron' physics of high energy behaviour was a central feature of the conference. The experimental data seem to suggest that behaviour with increasing energy depends on the magnitude of the scale which characterizes the process - i.e. whether the process is ''soft'' or ''hard''. Hard processes, in general, show a much more rapid increase with increasing
Transition from reversible to irreversible magnetic exchange-spring processes in antiferromagnetically exchange-coupled hard/soft/hard trilayer structures

International Nuclear Information System (INIS)

Wang Xiguang; Guo Guanghua; Zhang Guangfu

2011-01-01

The demagnetization processes of antiferromagnetically exchange-coupled hard/soft/hard trilayer structures have been studied based on the discrete one-dimensional atomic chain model and the linear partial domain-wall model. It is found that, when the magnetic anisotropy of soft layer is taken into account, the changes of the soft layer thickness and the interfacial exchange coupling strength may lead a transition of demagnetization process in soft layer from the reversible to the irreversible magnetic exchange-spring process. For the trilayer structures with very thin soft layer, the demagnetization process exhibits typical reversible exchange-spring behavior. However, as the thickness of soft layer is increased, there is a crossover point t c , after which the process becomes irreversible. Similarly, there is also a critical interfacial exchange coupling constant A sh c , above which the exchange-spring process is reversible. When A sh sh c , the irreversible exchange-spring process is achieved. The phase diagram of reversible and irreversible exchange-spring processes is mapped in the plane of the interfacial exchange coupling A sh and soft layer thickness N s . - Research highlights: → A differing magnetic exchange-spring process is found in antiferromagnetically exchange-coupled hard/soft/hard trilayers if the magnetic anisotropy of the soft layers is taken into account. → The change of the soft layer thickness may lead to a transition of demagnetization process in soft layer from the reversible to the irreversible exchange-spring process. → The change of the soft-hard interfacial exchange coupling strength may lead a transition of demagnetization process in soft layer from the reversible to the irreversible exchange-spring process. → The phase diagram of reversible and irreversible exchange-spring processes is mapped in the plane of the interfacial exchange coupling and soft layer thickness.
Encapsulation process for diffraction gratings.

Science.gov (United States)

Ratzsch, Stephan; Kley, Ernst-Bernhard; Tünnermann, Andreas; Szeghalmi, Adriana

2015-07-13

Encapsulation of grating structures facilitates an improvement of the optical functionality and/or adds mechanical stability to the fragile structure. Here, we introduce novel encapsulation process of nanoscale patterns based on atomic layer deposition and micro structuring. The overall size of the encapsulated structured surface area is only restricted by the size of the available microstructuring and coating devices; thus, overcoming inherent limitations of existing bonding processes concerning cleanliness, roughness, and curvature of the components. Finally, the process is demonstrated for a transmission grating. The encapsulated grating has 97.5% transmission efficiency in the -1st diffraction order for TM-polarized light, and is being limited by the experimental grating parameters as confirmed by rigorous coupled wave analysis.
Soft gluon contributions to hard processes

International Nuclear Information System (INIS)

Ciafaloni, M.

1981-10-01

The main concern of this paper is in trying to elucidate the origin of large QCD perturbative corrections and explain how to deal with them to all orders. They come essentially from the phase space regions close to the kinematical boundary of a hard process, in which one or many gluons become soft
Report of the Working Group on Diffractive Phenomena

International Nuclear Information System (INIS)

Bartel, W.; Bartels, J.W.

1994-01-01

Pomeron. The other contributions to the diffractive working group, which are included in the proceedings, refer to the coherent Pomeron and hard diffractive processes in QCD involving a coherent Pomeron by M. Strikman and L. Frankfurt, respectively. Furthermore N.N. Nikolaev introduced a dipole picture to describe deep inelastic processes, and J. Bartels presented a perturbative approach to diffraction dissociation
Diffractive processes at the LHC

CERN Document Server

Martin, A D; Ryskin, M G

2009-01-01

We present a model of high energy soft $pp$ interactions that has multi s- and t-channel components, which has been tuned to describe all the available data. The t-channel components allow matching of the soft to the hard (QCD) Pomeron. Absorptive effects are found to be large, and, for example, suppress the prediction of the total $pp$ cross section to about 90 mb at the LHC. We use the model to calculate the survival probability, S^2, of the rapidity gaps in the exclusive process pp \\to p+H+p, a process with great advantages for searching for the H \\to \\bb signal. We consider both eikonal and enhanced rescattering.

Hard processes in photon-photon interactions

International Nuclear Information System (INIS)

Duchovni, E.

1985-03-01

In this thesis, the existence of hard component in two-photon collisions is investigated. Due to the relative simplicity of the photon, such processes can be exactly calculated in QCD. Untagged (low Q 2 ) two-photon events are used. This leads to relatively high statistics, but to severe background problem due mainly to e + e - annihilation. The background contamination is reduced to a tolerable level using a special set of cuts. Moreover, the remaining contamination is shown to be calculable with a small systematic error. A large number of events of the hard ''γγ'' type is found. An attempt to explain these events using the simplest QCD diagram (the Born term) is done. This process is found to be capable of explaining only a 1/4 of the data. Other options like the constituent intercharge model, integer charged quarks, and higher order diagrams are therefore also discussed. The large cross-section for the production of ρ 0 ρ 0 pairs in ''γγ'' collisions has not been understood yet. Inorder to look at closely related processes, a search for φρ 0 and φφ was initiated. The cross-section for θπ + π - was found to be sizeable. Only upper limits for the production of φρ 0 and φφ are obtained
Soft color interactions and diffractive hard scattering at the Tevatron

International Nuclear Information System (INIS)

Enberg, R.; Timneanu, N.; Ingelman, G.; Uppsala Univ.

2001-06-01

An improved understanding of nonperturbative QCD can be obtained by the recently developed soft color interaction models. Their essence is the variation of color string-field topologies, giving a unified description of final states in high energy interactions, e.g., diffractive and nondiffractive events in ep and pp. Here we present a detailed study of such models (the soft color interaction model and the generalized area law model) applied to pp, considering also the general problem of the underlying event including beam particle remnants. With models turned to HERA ep data, we find a good description also of Tevatron data on production of W, bottom and jets in diffractive events defined either by leading antiprotons or by one or two rapidity gaps in the forward or backward regions. We also give predictions for diffractive J/ψ production where the soft exchange mechanism produces both a gap and a color singlet cc state in the same event. This soft color interaction approach is also compared with Pomeron-based models for diffraction, and some possibilities to experimentally discriminate between these different approaches are discussed. (orig.)
QCD and hard diffraction at the LHC

International Nuclear Information System (INIS)

Albrow, Michael G.; Fermilab

2005-01-01

As an introduction to QCD at the LHC I given an overview of QCD at the Tevatron, emphasizing the high Q 2 frontier which will be taken over by the LHC. After describing briefly the LHC detectors I discuss high mass diffraction, in particular central exclusive production of Higgs and vector boson pairs. I introduce the FP420 project to measure the scattered protons 420 m downstream of ATLAS and CMS
Relating hard QCD processes through universality of mass singularities

International Nuclear Information System (INIS)

Amati, D.; Petronzio, R.; Veneziano, G.

1978-01-01

Hard QCD processes involving final jets are studied and compared by means of a simple approach to mass singularities. This is based on the Lee-Nauenberg-Kinoshita theorem and on a rather subtle use of gauge invariance in hard collinear gluon bremsstrahlung. One-loop results are easily derived for processes involving any number of initial quarks and/or currents. The method greatly simplifies the computation of higher-order loops at the leading log level and the preliminary results allow one to conclude that the crucial features encountered at the one-loop level will persist. The authors are thus able to relate different hard processes and to show that suitable ratios of cross sections, being free from mass singularities, can be computed perturbatively, as usually assumed in QCD-inspired parton models. It is also possible to relate the universal leading mass singularities to leading scaling violations and to extend therefor the results of the operator product expansion method to processes outside the range of the light-cone analysis. Some delicate points caused by confinement-related singularities (e.g. narrow resonance poles) are also discussed. (Auth.)
Diffractive charm and jet production at HERA

International Nuclear Information System (INIS)

Savin, Alexander A.

2003-01-01

A new high precision inclusive measurement of the diffractive production of D* ± (2010) mesons in deep inelastic scattering (DIS) in the kinematic region Q 2 >1.5 GeV 2 , 0.02 IP 2 2 , 165 2 , χ IP < 0.03 are presented. Diffractive parton densities extracted using a NLO DGLAP QCD fit are used for comparisons with diffractive DIS and PHP dijet and open charm cross sections at HERA and the Tevatron, thus testing the factorization properties of hard diffraction
On Maximal Hard-Core Thinnings of Stationary Particle Processes

Science.gov (United States)

Hirsch, Christian; Last, Günter

2018-02-01

The present paper studies existence and distributional uniqueness of subclasses of stationary hard-core particle systems arising as thinnings of stationary particle processes. These subclasses are defined by natural maximality criteria. We investigate two specific criteria, one related to the intensity of the hard-core particle process, the other one being a local optimality criterion on the level of realizations. In fact, the criteria are equivalent under suitable moment conditions. We show that stationary hard-core thinnings satisfying such criteria exist and are frequently distributionally unique. More precisely, distributional uniqueness holds in subcritical and barely supercritical regimes of continuum percolation. Additionally, based on the analysis of a specific example, we argue that fluctuations in grain sizes can play an important role for establishing distributional uniqueness at high intensities. Finally, we provide a family of algorithmically constructible approximations whose volume fractions are arbitrarily close to the maximum.
Target costing as an element of the hard coal extraction cost planning process

Directory of Open Access Journals (Sweden)

Katarzyna Segeth-Boniecka

2017-09-01

Full Text Available Target costing as an element of the hard coal extraction cost planning process Striving for the efficiency of activities is of great significance in the management of hard coal extractive enterprises, which are constantly subjected to the process of restructuring. Effective cost management is an important condition of the increase in the efficiency of the researched business entities’ activity. One of the tools whose basic objective is conscious influencing cost levels is target costing. The aim of this article is to analyse the conditions of implementing target costing in the planning of hard coal extraction costs in hard coal mines in Poland. The subject area raises a topical and important problem of the scope of solutions concerning cost analysis in hard coal mines in Poland, which has not been thoroughly researched yet. To achieve the abovementioned aim, the theoretical works of the subject area have been referenced. The mine management process is difficult and requires the application of best suited and most modern tools, including those used in the planning process of hard coal extraction costs in order to support the economic efficiency of mining operations. The use of the target costing concept in the planning of hard coal mine operations aims to support the decision-making process, so as to achieve a specified level of economic efficiency of the operations carried out in a territorially designated site of hard coal extraction.
Inelastic diffraction nuclear processes with redistribution of particles

International Nuclear Information System (INIS)

Sitenko, A.G.; Goryachij, V.V.; Peresypkin, V.V.

1979-01-01

The inelastic nuclear processes at high energies with redistribution of particles are described within the framework of the diffraction approach. The capture processes (p,d) and (p,p'n) generated by the high energy nucleon collision with nuclei are considered. The angular distribution of 4 He(p,d) 3 He reaction is calculated and compared with experimental data
Strong Bisimilarity and Regularity of Basic Parallel Processes is PSPACE-Hard

DEFF Research Database (Denmark)

Srba, Jirí

2002-01-01

We show that the problem of checking whether two processes definable in the syntax of Basic Parallel Processes (BPP) are strongly bisimilar is PSPACE-hard. We also demonstrate that there is a polynomial time reduction from the strong bisimilarity checking problem of regular BPP to the strong...... regularity (finiteness) checking of BPP. This implies that strong regularity of BPP is also PSPACE-hard....
Process for altering the colour of hard stones

International Nuclear Information System (INIS)

Samoilovich, M.I.; Shaposhniko, A.A.; Turinge, A.P.; Vakhidov, S.A.; Nurullaev, Ergash.

1981-01-01

Process for altering the colour of hard stones and articles made with such stones, used in the jewellery trade, consisting in treating the hard stones in a neutron reactor and gamma particles accompanying them, whereby the treatment is performed with fast neutrons of at least 0.5 MeV, at integral doses of 5x10 15 to 1x10 18 neutrons/cm 2 , and gamma radiations, at integral doses of 5x10 6 to 1x10 9 R, at temperatures under 300 0 C [fr
Diffractive and non-diffractive wounded nucleons and final states in pA collisions

Energy Technology Data Exchange (ETDEWEB)

Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif [Department of Astronomy and Theoretical Physics,Sölvegatan 14A, S-223 62 Lund (Sweden)

2016-10-25

We review the state-of-the-art of Glauber-inspired models for estimating the distribution of the number of participating nucleons in pA and AA collisions. We argue that there is room for improvement in these model when it comes to the treatment of diffractive excitation processes, and present a new simple Glauber-like model where these processes are better taken into account. We also suggest a new way of using the number of participating, or wounded, nucleons to extrapolate event characteristics from pp collisions, and hence get an estimate of basic hadronic final-state properties in pA collisions, which may be used to extract possible nuclear effects. The new method is inspired by the Fritiof model, but based on the full, semi-hard multiparton interaction model of PYTHIA8.
Double Diffractive Process Factorization from ηc and γ Associated Production at Tevatron and LHC

Institute of Scientific and Technical Information of China (English)

YAN Zhan-Yuan; LI Zhi-Wen; DUAN Chun-Gui

2004-01-01

We present a study of associated ηc and γ double diffractive production in p-p collision based on Ingelman-Schlein model, and the framework of non-relativistic QCD factorization formalism for quarkonia production. The predic-tion of ηc and γ is more reliable than J/ψ production, because the associated ηc and γ production is a pure color-octetprocess, and the dominant contribution comes from color octet 1So(8) subprocess, which is related to the color octet matrixelement of 1So(8) of J/ψ by the heavy quark spin symmetry and the large PT J/ψ production data. We find that the ratioof diffractive to inclusive cross sections is independent of the values of color octet matrix elements, but is sensitive to thegluon factor of the Pomeron and renormalized Pomeron flux factors. So experimental measurement of this ratio can giveus more information of the nature of Pomeron and test the assumption of hard diffractive factorization in hadron-hadron collisions.
Implications of confining force field structures in hard hadronic processes

International Nuclear Information System (INIS)

Bengtsson, H.-U.

1983-04-01

This thesis is centered on the study of confining force field structures in hard scattering processes. Perturbative QCD provides the means of calculating any process on the parton level, but to be able accurately to describe the actual outcome of an event, one still needs a phenomenological model for how quarks and gluons transform into observable hadrons. One such model is based on the assumption that the particles are produced by the confining fields stretched between the partons. The actual particle distributions will then depend on the topology of the confining fields. We have developed a Monte Carlo program to simulate complete events in hard scattering, and we use this to study the properties of the confining field in different trigger situations. We further look at the amount of hard processes that can be expected in experiments that trigger on transverse energy sum (calorimeter experiments). Finally, we investigate charm production within our model. (author)
Transverse nucleon structure and diagnostics of hard parton-parton processes at LHC

Energy Technology Data Exchange (ETDEWEB)

L. Frankfurt, M. Strikman, C. Weiss

2011-03-01

We propose a new method to determine at what transverse momenta particle production in high-energy pp collisions is governed by hard parton-parton processes. Using information on the transverse spatial distribution of partons obtained from hard exclusive processes in ep/\\gamma p scattering, we evaluate the impact parameter distribution of pp collisions with a hard parton-parton process as a function of p_T of the produced parton (jet). We find that the average pp impact parameters in such events depend very weakly on p_T in the range 2 < p_T < few 100 GeV, while they are much smaller than those in minimum-bias inelastic collisions. The impact parameters in turn govern the observable transverse multiplicity in such events (in the direction perpendicular to the trigger particle or jet). Measuring the transverse multiplicity as a function of p_T thus provides an effective tool for determining the minimum p_T for which a given trigger particle originates from a hard parton-parton process.
Hard processes. Vol. 1

International Nuclear Information System (INIS)

Ioffe, B.L.; Khoze, V.A.; Lipatov, L.N.

1984-01-01

Deep inelastic (hard) processes are now at the epicenter of modern high-energy physics. These processes are governed by short-distance dynamics, which reveals the intrinsic structure of elementary particles. The theory of deep inelastic processes is now sufficiently well settled. The authors' aim was to give an effective tool to theoreticians and experimentalists who are engaged in high-energy physics. This book is intended primarily for physicists who are only beginning to study the field. To read the book, one should be acquainted with the Feynman diagram technique and with some particular topics from elementary particle theory (symmetries, dispersion relations, Regge pole theory, etc.). Theoretical consideration of deep inelastic processes is now based on quantum chromodynamics (QCD). At the same time, analysis of relevant physical phenomena demands a synthesis of QCD notions (quarks, gluons) with certain empirical characteristics. Therefore, the phenomenological approaches presented are a necessary stage in a study of this range of phenomena which should undoubtedly be followed by a detailed description based on QCD and electroweak theory. The authors were naturally unable to dwell on experimental data accumulated during the past decade of intensive investigations. Priority was given to results which allow a direct comparison with theoretical predictions. (Auth.)
Dispersion representations for hard exclusive processes. Beyond the born approximation

International Nuclear Information System (INIS)

Diehl, M.; Ivanov, D.Yu.

2007-07-01

Several hard exclusive scattering processes admit a description in terms of generalized parton distributions and perturbative hard-scattering kernels. Both the physical amplitude and the hard-scattering kernels fulfill dispersion relations. We give a detailed investigation of their consistency at all orders in perturbation theory. The results shed light on the information about generalized parton distributions that can be extracted from the real and imaginary parts of exclusive amplitudes. They also provide a practical consistency check for models of these distributions in which Lorentz invariance is not exactly satisfied. (orig.)
EFFECT OF ENDOSPERM HARDNESS ON AN ETHANOL PROCESS USING A GRANULAR STARCH HYDROLYZING ENZYME

Energy Technology Data Exchange (ETDEWEB)

Wang, P; W Liu, D B; Johnston, K D; Rausch, S J; Schmidt, M E; Tumbleson, V Singh

2010-01-01

Granular starch hydrolyzing enzymes (GSHE) can hydrolyze starch at low temperature (32°C). The dry grind process using GSHE (GSH process) has fewer unit operations and no changes in process conditions (pH 4.0 and 32°C) compared to the conventional process because it dispenses with the cooking and liquefaction step. In this study, the effects of endosperm hardness, protease, urea, and GSHE levels on GSH process were evaluated. Ground corn, soft endosperm, and hard endosperm were processed using two GSHE levels (0.1 and 0.4 mL per 100 g ground material) and four treatments of protease and urea addition. Soft and hard endosperm materials were obtained by grinding and sifting flaking grits from a dry milling pilot plant; classifications were confirmed using scanning electron microscopy. During 72 h of simultaneous granular starch hydrolysis and fermentation (GSHF), ethanol and glucose profiles were determined using HPLC. Soft endosperm resulted in higher final ethanol concentrations compared to ground corn or hard endosperm. Addition of urea increased final ethanol concentrations for soft and hard endosperm. Protease addition increased ethanol concentrations and fermentation rates for soft endosperm, hard endosperm, and ground corn. The effect of protease addition on ethanol concentrations and fermentation rates was most predominant for soft endosperm, less for hard endosperm, and least for ground corn. Samples (soft endosperm, hard endosperm, or corn) with protease resulted in higher (1.0% to 10.5% v/v) ethanol concentration compared to samples with urea. The GSH process with protease requires little or no urea addition. For fermentation of soft endosperm, GSHE dose can be reduced. Due to nutrients (lipids, minerals, and soluble proteins) present in corn that enhance yeast growth, ground corn fermented faster at the beginning than hard and soft endosperm.
CO II laser free-form processing of hard tissue

Science.gov (United States)

Werner, Martin; Klasing, Manfred; Ivanenko, Mikhail; Harbecke, Daniela; Steigerwald, Hendrik; Hering, Peter

2007-07-01

Drilling and surface processing of bone and tooth tissue belongs to standard medical procedures (bores and embeddings for implants, trepanation etc.). Small circular bores can be generally quickly produced with mechanical drills. However problems arise at angled drilling, the need to execute drilling procedures without damaging of sensitive soft tissue structures underneath the bone or the attempt to mill small non-circular cavities in hard tissue with high precision. We present investigations on laser hard tissue "milling", which can be advantageous for solving these problems. The processing of bone is done with a CO II laser (10.6 μm) with pulse durations of 50 - 100 μs, combined with a PC-controlled fast galvanic laser beam scanner and a fine water-spray, which helps keeping the ablation process effective and without thermal side-effects. Laser "milling" of non-circular cavities with 1 - 4 mm width and about 10 mm depth can be especially interesting for dental implantology. In ex-vivo investigations we found conditions for fast laser processing of these cavities without thermal damage and with minimised tapering. It included the exploration of different filling patterns (concentric rings, crosshatch, parallel lines, etc.), definition of maximal pulse duration, repetition rate and laser power, and optimal water spray position. The optimised results give evidence for the applicability of pulsed CO II lasers for biologically tolerable effective processing of deep cavities in hard tissue.
Single-diffractive production of charmed mesons at the LHC within the k{sub t}-factorization approach

Energy Technology Data Exchange (ETDEWEB)

Łuszczak, Marta [University of Rzeszów,PL-35-959 Rzeszów (Poland); Maciuła, Rafał; Szczurek, Antoni; Trzebiński, Maciej [Institute of Nuclear Physics PAN,PL-31-342 Cracow (Poland)

2017-02-16

We discuss the single-diffractive production of cc̄ pairs and charmed mesons at the LHC. For a first time we propose a k{sub t}-factorization approach to the diffractive processes. The transverse momentum dependent diffractive parton distributions are obtained from standard (collinear) diffractive parton distributions used in the literature. In this calculation the transverse momentum of the pomeron is neglected with respect to transverse momentum of partons entering the hard process. We also perform a first evaluation of the cross sections at the LHC using the diffractive transverse momentum dependent parton distributions. The results of the new approach are compared with those of the standard collinear one. Significantly larger cross sections are obtained in the k{sub t}-factorization approach in which some parts of higher-order effects is effectively included. The differences between corresponding differential distributions are discussed. Finally, we present a feasibility study of the process at the LHC using proton tagging technique. The analysis suggests that the measurement of single-diffractive charm production is possible using ATLAS and CMS/TOTEM detectors.
On a possible test of the hard-Pomeron theory

International Nuclear Information System (INIS)

Ioffe, B.L.

1992-01-01

In the last few years there have been discussions of the fact that the Pomeron-the Regge pole responsible for high-energy scattering-has in reality a double role: a soft Pomeron built of multiperipheral hadron exchange and a hard Pomeron described by gluon exchanges in QCD. Recently, Bjorken emphasized the need to distinguish these two forms of the Pomeron. The question arises of whether it is possible to distinguish the hard and soft Pomeron experimentally. According to the hard-Pomeron concept, the hadron-hadron total cross section is determined by the imaginary part of the forward scattering amplitude corresponding to two-gluon exchange with ladder corrections. This mechanism dominates in the case of scattering of particles built from heavy quarks (a good example is γγ scattering) and also in the case of virtual-particle scattering (for example, virtual photons, where quark pairs must also be included in the ladder). These processes are hard (γ virt γ virt scattering) or impossible (γγ scattering) to observe experimentally. Bjorken suggested another process whose cross section is determined by hard-Pomeron exchange - double diffractional hadron-hadron (e.g., pp) scattering at high energies with jet production in the projectile and target fragmentation regions. If the momentum transfer from the projectile to the target is in the intermediate region, |t|∼1 GeV, and events are selected with a rapidity gap in the rapidity distribution of produced particles between the two fragmentation regions, then, according to Bjorken, a process determined by the hard Pomeron will be observed. The author addresses this proposal

The logarithmic slope in diffractive DIS

International Nuclear Information System (INIS)

Gay Ducati, M.B.; Goncalves, V.P.; Machado, M.V.T.

2002-01-01

The logarithmic slope of diffractive structure function is a potential observable to separate the hard and soft contributions in diffraction, allowing to disentangle the QCD dynamics at small-x region. In this paper we extend our previous analyzes and calculate the diffractive logarithmic slope for three current approaches in the literature: (i) the Bartels-Wusthoff model, based on perturbative QCD, (ii) the CKMT model, based on Regge theory and (iii) the Golec-Biernat-Wusthoff model which assumes that the saturation phenomena is present in the HERA kinematic region. We analyze the transition region of small to large momentum transfer and verify that future experimental results on the diffractive logarithmic slope could discriminate between these approaches
A pipeline for comprehensive and automated processing of electron diffraction data in IPLT.

Science.gov (United States)

Schenk, Andreas D; Philippsen, Ansgar; Engel, Andreas; Walz, Thomas

2013-05-01

Electron crystallography of two-dimensional crystals allows the structural study of membrane proteins in their native environment, the lipid bilayer. Determining the structure of a membrane protein at near-atomic resolution by electron crystallography remains, however, a very labor-intense and time-consuming task. To simplify and accelerate the data processing aspect of electron crystallography, we implemented a pipeline for the processing of electron diffraction data using the Image Processing Library and Toolbox (IPLT), which provides a modular, flexible, integrated, and extendable cross-platform, open-source framework for image processing. The diffraction data processing pipeline is organized as several independent modules implemented in Python. The modules can be accessed either from a graphical user interface or through a command line interface, thus meeting the needs of both novice and expert users. The low-level image processing algorithms are implemented in C++ to achieve optimal processing performance, and their interface is exported to Python using a wrapper. For enhanced performance, the Python processing modules are complemented with a central data managing facility that provides a caching infrastructure. The validity of our data processing algorithms was verified by processing a set of aquaporin-0 diffraction patterns with the IPLT pipeline and comparing the resulting merged data set with that obtained by processing the same diffraction patterns with the classical set of MRC programs. Copyright © 2013 Elsevier Inc. All rights reserved.
Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

Science.gov (United States)

Umbrello, Domenico; Rizzuti, Stefania; Outeiro, José C.; Shivpuri, Rajiv

2007-04-01

In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.
Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

International Nuclear Information System (INIS)

Umbrello, Domenico; Rizzuti, Stefania; Outeiro, Jose C.; Shivpuri, Rajiv

2007-01-01

In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change
Takagi-Taupin description of x-ray dynamical diffraction from diffractive optics with large numerical aperture

International Nuclear Information System (INIS)

Yan Hanfei; Maser, Joerg; Macrander, Albert; Shen Qun; Vogt, Stefan; Stephenson, G. Brian; Kang, Hyon Chol

2007-01-01

We present a formalism of x-ray dynamical diffraction from volume diffractive optics with large numerical aperture and high aspect ratio, in an analogy to the Takagi-Taupin equations [Acta Crystallogr. 15, 1311 (1962); Bull. Soc. Fr. Mineral. Crystallogr. 87, 469 (1964)] for strained single crystals. We derive a set of basic equations for dynamical diffraction from volume diffractive optics, which enable us to study the focusing property of these optics with various grating profiles. We study volume diffractive optics that satisfy the Bragg condition to various degrees, namely, flat, tilted, and wedged geometries, and derive the curved geometries required for ultimate focusing. We show that the curved geometries satisfy both the Bragg condition everywhere and phase requirement for point focusing and effectively focus hard x rays to a scale close to the wavelength. Our calculations were made for an x-ray wavelength of 0.064 nm (19.5 keV)
Quark-antiquark production in DIS diffractive dissociation

International Nuclear Information System (INIS)

Bartels, J.; Lotter, H.; Wuesthoff, M.

1996-02-01

We calculate the cross section for the production of two jets with large transverse momenta k 2 in DIS diffractive dissociation for both transverse and longitudinally polarized photons. The scale which defines the hardness of the Pomeron is found to be k 2 (Q 2 +M 2 )/M 2 . We present analytic expressions and discuss numerical results relevant for the diffractive dissociation at HERA. (orig.)
D* Meson Production in Deep-Inelastic Diffractive Interactions at HERA

CERN Document Server

Adloff, C.; Andrieu, B.; Anthonis, T.; Arkadov, V.; Astvatsatourov, A.; Babaev, A.; Bahr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Bate, P.; Becker, J.; Beglarian, A.; Behnke, O.; Beier, C.; Belousov, A.; Benisch, T.; Berger, C.; Berndt, T.; Bizot, J.C.; Boehme, J.; Boudry, V.; Braunschweig, W.; Brisson, V.; Broker, H.B.; Brown, D.P.; Bruckner, W.; Bruncko, D.; Burger, J.; Busser, F.W.; Bunyatyan, A.; Burrage, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cao, Jun; Caron, S.; Cassol-Brunner, F.; Clarke, D.; Clerbaux, B.; Collard, C.; Contreras, J.G.; Coppens, Y.R.; Coughlan, J.A.; Cousinou, M.C.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Davidsson, M.; Delcourt, B.; Delerue, N.; Demirchyan, R.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dingfelder, J.; Dixon, P.; Dodonov, V.; Dowell, J.D.; Droutskoi, A.; Dubak, A.; Duprel, C.; Eckerlin, Guenter; Eckstein, D.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eisenhandler, E.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Ferron, S.; Fleischer, M.; Fleming, Y.H.; Flugge, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Gabathuler, E.; Gabathuler, K.; Garvey, J.; Gassner, J.; Gayler, Joerg; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Goerlich, L.; Gogitidze, N.; Goldberg, M.; Grab, C.; Grassler, H.; Greenshaw, T.; Grindhammer, Guenter; Hadig, T.; Haidt, D.; Hajduk, L.; Haller, J.; Haynes, W.J.; Heinemann, B.; Heinzelmann, G.; Henderson, R.C.W.; Hengstmann, S.; Henschel, H.; Heremans, R.; Herrera, G.; Herynek, I.; Hildebrandt, M.; Hilgers, M.; Hiller, K.H.; Hladky, J.; Hoting, P.; Hoffmann, D.; Horisberger, R.; Hurling, S.; Ibbotson, M.; Issever, C .; Jacquet, M.; Jaffre, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, C.; Johnson, D.P.; Jones, M.A.S.; Jung, H.; Kant, D.; Kapichine, M.; Karlsson, M.; Karschnick, O.; Keil, F.; Keller, N.; Kennedy, J.; Kenyon, I.R.; Kermiche, S.; Kiesling, Christian M.; Kjellberg, P.; Klein, M.; Kleinwort, C.; Kluge, T.; Knies, G.; Koblitz, B.; Kolya, S.D.; Korbel, V.; Kostka, P.; Kotelnikov, S.K.; Koutouev, R.; Koutov, A.; Krehbiel, H.; Kroseberg, J.; Kruger, K.; Kupper, A.; Kuhr, T.; Kurca, T.; Lahmann, R.; Lamb, D.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebailly, E.; Lebedev, A.; Leissner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindstroem, M.; List, B.; Lobodzinska, E.; Lobodzinski, B.; Loginov, A.; Loktionova, N.; Lubimov, V.; Luders, S.; Luke, D.; Lytkin, L.; Mahlke-Kruger, H.; Malden, N.; Malinovski, E.; Malinovski, I.; Maracek, R.; Marage, P.; Marks, J.; Marshall, R.; Martyn, H.U.; Martyniak, J.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Meyer, P.O.; Mikocki, S.; Milstead, D.; Mkrtchyan, T.; Mohr, R.; Mohrdieck, S.; Mondragon, M.N.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Murin, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, T.; Nellen, G.; Newman, Paul R.; Nicholls, T.C.; Niebergall, F.; Niebuhr, C.; Nix, O.; Nowak, G.; Olsson, J.E.; Ozerov, D.; Panassik, V.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Phillips, J.P.; Pitzl, D.; Poschl, R.; Potachnikova, I.; Povh, B.; Rabbertz, K.; Radel, G.; Rauschenberger, J.; Reimer, P.; Reisert, B.; Reyna, D.; Risler, C.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rusakov, S.; Rybicki, K.; Sankey, D.P.C.; Scheins, J.; Schilling, F.P.; Schleper, P.; Schmidt, D.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schoning, A.; Schorner, T.; Schroder, V.; Schultz-Coulon, H.C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Chekelian, V.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Straumann, U.; Swart, M.; Tasevsky, M.; Tchernyshov, V.; Tchetchelnitski, S.; Thompson, Graham; Thompson, P.D.; Tobien, N.; Traynor, D.; Truoel, Peter; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Turney, J.E.; Tzamariudaki, E.; Udluft, S.; Urban, Marcel; Usik, A.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vassiliev, S.; Vazdik, Y.; Vichnevski, A.; Wacker, K.; Wallny, R.; Waugh, B.; Weber, G.; Weber, M.; Wegener, D.; Werner, C.; Werner, M.; Werner, N.; White, G.; Wiesand, S.; Wilksen, T.; Winde, M.; Winter, G.G.; Wissing, C.; Wobisch, M.; Woehrling, E.E.; Wunsch, E.; Wyatt, A.C.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zomer, F.; Zsembery, J.; zur Nedden, M.

2001-01-01

A measurement is presented of the cross section for D* meson production in diffractive deep-inelastic scattering for the first time at HERA. The cross section is given for the process ep -> eXY, where the system X contains at least one D* meson and is separated by a large rapidity gap from a low mass proton remnant system Y. The cross section is presented in the diffractive deep-inelastic region defined by 2 2 GeV and |\\eta_D* | < 1.5. The cross section is found to be 246+-54+-56 pb and forms about 6% of the corresponding inclusive D* cross section. The cross section is presented as a function of various kinematic variables, including z_pom^obs which is an estimate of the fraction of the momentum of the diffractive exchange carried by the parton entering the hard-subprocess. The data show a large component of the cross section at low z_pom^obs where the contribution of the Boson-Gluon-Fusion process is expected to dominate. The data are compared with several QCD--based calculations.
Hardness and microstructure homogeneity of pure copper processed by accumulative back extrusion

International Nuclear Information System (INIS)

Bazaz, B.; Zarei-Hanzaki, A.; Fatemi-Varzaneh, S.M.

2013-01-01

The present work deals with the microstructure evolution of a pure copper processed by a new severe plastic deformation method. A set of pure copper (99.99%) work-pieces with coarse-grained microstructures was processed by accumulative back extrusion (ABE) method at room temperature. The optical and scanning electron microscopy (SEM) and hardness measurements were utilized to study the microstructural evolution and hardness homogeneity. The results indicated that ABE is a capable process to provide a homogenous grain refined microstructure in pure copper. The observed grain refinement was discussed relying on the occurrence of dynamic restoration processes. The analysis of microstructure and hardness showed outstanding homogeneity improvement throughout the work-pieces as the consecutive ABE passes were applied. The homogeneity improvement was attributed to the propagation of the shear bands and also the heavily deformed regions. A reversing route was also applied in the ABE processing to investigate its effect on the development of microstructural homogeneity. Comparing to the conventional route, the application of the reversing route was found to yield better homogeneity after less passes of the process.
Investigation of the near-surface structures of polar InN films by chemical-state-discriminated hard X-ray photoelectron diffraction

International Nuclear Information System (INIS)

Yang, A. L.; Yamashita, Y.; Kobata, M.; Yoshikawa, H.; Sakata, O.; Kobayashi, K.; Matsushita, T.; Píš, I.; Imura, M.; Yamaguchi, T.; Nanishi, Y.

2013-01-01

Near-surface structures of polar InN films were investigated by laboratory-based hard X-ray photoelectron diffraction (HXPD) with chemical-state-discrimination. HXPD patterns from In 3d 5/2 and N 1s core levels of the In-polar and N-polar InN films were different from each other and compared with the simulation results using a multiple-scattering cluster model. It was found that the near-surface structure of the In-polar InN film was close to the ideal wurtzite structure. On the other hand, on the N-polar InN film, defects-rich surface was formed. In addition, the existence of the In-polar domains was observed in the HXPD patterns.
Effect of raw materials and hardening process on hardness of manually forged knife

Science.gov (United States)

Balkhaya, Suwarno

2017-06-01

Knives are normally made by forging process either using a machine or traditional method by means of hammering process. This present work was conducted to study the effects of steel raw materials and hardening process on the hardness of manually forged knives. The knife samples were made by traditional hammering (forging) process done by local blacksmith. Afterward, the samples were heat treated with two different hardening procedures, the first was based on the blacksmith procedure and the second was systematically done at the laboratory. The forging was done in the temperature ranged between 900-950°C, while the final temperature ranged between 650-675°C. The results showed that knives made of spring steel and heat treated in simulated condition at the laboratory obtained higher level of hardness, i.e. 62 HRC. In general, knives heat treated by local blacksmith had lower level of hardness that those obtained from simulated condition. Therefore, we concluded that the traditional knife quality in term of hardness can be improved by optimizing the heat treatment schedule.
Synergy of modeling processes in the area of soft and hard modeling

Directory of Open Access Journals (Sweden)

Sika Robert

2017-01-01

Full Text Available High complexity of production processes results in more frequent use of computer systems for their modeling and simulation. Process modeling helps to find optimal solution, verify some assumptions before implementation and eliminate errors. In practice, modeling of production processes concerns two areas: hard modeling (based on differential equations of mathematical physics and soft (based on existing data. In the paper the possibility of synergistic connection of these two approaches was indicated: it means hard modeling support based on the tools used in soft modeling. It aims at significant reducing the time in order to obtain final results with the use of hard modeling. Some test were carried out in the Calibrate module of NovaFlow&Solid (NF&S simulation system in the frame of thermal analysis (ATAS-cup. The authors tested output values forecasting in NF&S system (solidification time on the basis of variable parameters of the thermal model (heat conduction, specific heat, density. Collected data was used as an input to prepare soft model with the use of MLP (Multi-Layer Perceptron neural network regression model. The approach described above enable to reduce the time of production process modeling with use of hard modeling and should encourage production companies to use it.
Hardness of basaltic glass-ceramics

DEFF Research Database (Denmark)

Jensen, Martin; Smedskjær, Morten Mattrup; Estrup, Maja

2009-01-01

The dependence of the hardness of basaltic glass-ceramics on their degree of crystallisation has been explored by means of differential scanning calorimetry, optical microscopy, x-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses were achieved...... by varying the temperature of heat treatment. The predominant crystalline phase in the glass was identified as augite. It was found that the hardness of the glass phase decreased slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreased....
Recent forward physics and diffraction results from CMS

CERN Document Server

AUTHOR|(CDS)2074117

2016-01-01

Recent CMS results on forward physics and diffraction are reviewed. The differential diffractive cross section is measured as a function of $\\xi= M_X^2/s$ in the region dominated by single dissociation (SD) and double dissociation (DD), where $M_X$ is the mass of one of the two final-state hadronic systems separated by the largest rapidity gap in the event. The total SD and DD cross sections are extracted. The observation of a hard color-singlet exchange process in events with a large rapidity gap between two leading jets (jet-gap-jet) is reported. The fraction of jet-gap-jet to all dijet events is measured as a function of the second leading jet transverse momentum and the size of the pseudorapidity gap. The measured fractions are compared with predictions as well as Tevatron data.
Tolerance analysis on diffraction efficiency and polychromatic integral diffraction efficiency for harmonic diffractive optics

Science.gov (United States)

Shan, Mao

2016-10-01

In this dissertation, the mathematical model of effect of manufacturing errors including microstructure relative height error and relative width error on diffraction efficiency for the harmonic diffractive optical elements (HDEs) is set up. According to the expression of the phase delay and diffraction efficiency of the HDEs, the expression of diffraction efficiency of refraction and diffractive optical element with the microstructure height and periodic width errors in fabrication process is presented in this paper. Furthermore, the effect of manufacturing errors on diffraction efficiency for the harmonic diffractive optical elements is studied, and diffraction efficiency change is analyzed as the relative microstructure height-error in the same and in the opposite sign as well as relative width-error in the same and in the opposite sign. Example including infrared wavelength with materials GE has been discussed in this paper. Two kinds of manufacturing errors applied in 3.7 4.3um middle infrared and 8.7-11.5um far infrared optical system which results in diffraction efficiency and PIDE of HDEs are studied. The analysis results can be used for manufacturing error control in micro-structure height and periodic width. Results can be used for HDEs processing.
Novel QCD Aspects of Hard Diffraction,Antishadowing, and Single-Spin Asymmetries

Energy Technology Data Exchange (ETDEWEB)

Brodsky, S.

2004-10-15

It is usually assumed--following the parton model--that the leading-twist structure functions measured in deep inelastic lepton-proton scattering are simply the probability distributions for finding quarks and gluons in the target nucleon. In fact, gluon exchange between the outgoing quarks and the target spectators effects the leading-twist structure functions in a profound way, leading to diffractive leptoproduction processes, shadowing and antishadowing of nuclear structure functions, and target spin asymmetries, physics not incorporated in the light-front wavefunctions of the target computed in isolation. In particular, final-state interactions from gluon exchange lead to single-spin asymmetries in semi-inclusive deep inelastic lepton-proton scattering which are not power-law suppressed in the Bjorken limit. The shadowing and antishadowing of nuclear structure functions in the Gribov-Glauber picture is due respectively to the destructive and constructive interference of amplitudes arising from the multiple-scattering of quarks in the nucleus. The effective quark-nucleon scattering amplitude includes Pomeron and Odderon contributions from multi-gluon exchange as well as Reggeon quark-exchange contributions. Part of the anomalous NuTeV result for sin{sup 2} {theta}{sub W} could be due to the non-universality of nuclear antishadowing for charged and neutral currents. Detailed measurements of the nuclear dependence of individual quark structure functions are thus needed to establish the distinctive phenomenology of shadowing and antishadowing and to make the NuTeV results definitive. I also discuss diffraction dissociation as a tool for resolving hadron substructure Fock state by Fock state and for producing leading heavy quark systems.
Dual constituent-exchange dynamics in soft and hard hadronic processes

International Nuclear Information System (INIS)

Akkelin, S.V.; Kobylinskij, N.A.; Martynov, E.S.; Shelest, V.P.

1987-01-01

A possibility to match the dual theory of soft hadronic processes to the dimensional counting rules for hard processes has been studied. This aim is shown to be attained within the framework of the dual analytical model under certain conditions on the shape and parameters of the Regge trajectories
Remarks on diffractive production of the Higgs boson

Energy Technology Data Exchange (ETDEWEB)

Peschanski, R. [CEA Saclay, Service de Physique Theorique, URA 2306, Unite de Recherche Associee au CNRS, 91 - Gif-sur-Yvette (France)

2005-07-01

Central diffractive production of the Higgs boson has recently received much attention as a potentially interesting production mode at the LHC (large hadron collider). While the standard production of Higgs boson via gluon-gluon fusion can reach high cross-sections, the study of the Higgs boson will be uneasy due to accompanying particles and background. The original guiding line for central diffractive production is to compensate the weak cross-sections by a cleaner signal, and precise production kinematics thanks to the tagging of diffracted protons. We shall review some of the wishes and realities encountered in this field. Theoretical open problems of diffractive dynamics are involved in making accurate predictions for the LHC, among which the most crucial is understanding factorization breaking in hard diffraction.
Hardness optimization of boride diffusion layer on Astm F-75 alloy using response surface methodology

Energy Technology Data Exchange (ETDEWEB)

Arguelles O, J. L.; Corona R, M. A. [Universidad Autonoma de San Luis Potosi, Doctorado Institucional en Ingenieria y Ciencia de Materiales, San Luis Potosi 78000, SLP (Mexico); Marquez H, A.; Saldana R, A. L.; Saldana R, A. [Universidad de Guanajuato, Ingenieria Mecanica Agricola DICIVA, Irapuato, Guanajuato 36500 (Mexico); Moreno P, J., E-mail: amarquez@ugto.mx [Universidad de Guanajuato, Departamento de Minas, Metalurgia y Geologia, Ex-Hacienda San Matias s/n, Guanajuato, Guanajuato 36020 (Mexico)

2017-11-01

In this study, the Response Surface Methodology (Rsm) and Central Composite Design (Ccd) were used to optimize the hardness of boride diffusion layer on Astm F-75 alloy (also called Haynes alloy). A boronizing thermochemical treatment was carried out at different temperatures and for different time periods. Hardness tests were conducted. The boride diffusion layer was verified by the X-ray diffraction (XRD) analysis indicating the formation of Co B, Co{sub 2}B, Cr B and Mo{sub 2}B phases. An optimal hardness of 3139.7 Hv was obtained for the samples subjected to the boriding process for a duration of 6.86 h at 802.4 degrees Celsius. (Author)
Diffractive production in deep inelastic scattering and hadronic interactions

International Nuclear Information System (INIS)

Kaidalow, A.

1996-01-01

Diffractive processes in hadronic interactions are considered and important role of multi-Pomeron exchanges is emphasized. It is argued that in deep inelastic scattering these contributions are much less important and energy behavior of structure functions at Q 2 ≥ 1 GeV 2 is determined mostly by bare Pomeron intercept. It is shown that the model based on these ideas is in a perfect agreement with recent results from HERA. Diffractive production in DIS is discussed and theoretical predictions for the structure function of the Pomeron are compared with experimental observations. It is emphasized that both quarks and gluons in the Pomeron have hard distributions. Shadowing corrections to structure function of a nucleon are calculated and found to small in the region of x > 10 -4 . A good agreement with experimental data on the shadowing of structure functions of nuclei is obtained. Energy dependence for the cross sections of the diffractive production of vector mesons by real and virtual photons is calculated in the same approach and is found to be in an excellent agreement with experiment. (author)
Hair treatment process providing dispersed colors by light diffraction

Science.gov (United States)

Sutton, Richard Matthew Charles; Lamartine, Bruce Carvell; Orler, E. Bruce; Song, Shuangqi

2015-12-22

A hair treatment process for providing dispersed colors by light diffraction including (a) coating the hair with a material comprising a polymer, (b) pressing the hair with a pressing device including one or more surfaces, and (c) forming a secondary nanostructured surface pattern on the hair that is complementary to the primary nanostructured surface pattern on the one or more surfaces of the pressing device. The secondary nanostructured surface pattern diffracts light into dispersed colors that are visible on the hair. The section of the hair is pressed with the pressing device for from about 1 to 55 seconds. The polymer has a glass transition temperature from about 55.degree. C. to about 90.degree. C. The one or more surfaces include a primary nanostructured surface pattern.

Kinetic neutron diffraction and SANS studies of phase formation in bioactive machinable glass ceramics

International Nuclear Information System (INIS)

Bentley, P M; Kilcoyne, S H; Bubb, N L; Ritter, C; Dewhurst, C D; Wood, D J

2007-01-01

Bioactive fluormica-fluorapatite glass-ceramic materials offer a very encouraging solution to the problem of efficient restoration and reconstruction of hard tissues. To produce material with the desired crystalline phases, a five-stage heat treatment must be performed. This thermal processing has a large impact on the microstructure and ultimately the final mechanical properties of the materials. We have examined the thermal processing of one of our most promising machinable biomaterials, using time-resolved small angle neutron scattering and neutron diffraction to study the nucleation and growth of crystallites. The processing route had already been optimized by studying the properties of quenched samples using x-ray diffraction, mechanical measurements and differential thermal analysis. However these results show that the heat treatment can be further optimized in terms of crystal nucleation, and we show that these techniques are the only methods by which a truly optimized thermal processing route may be obtained
100 years of discovery of X-ray diffraction

International Nuclear Information System (INIS)

Zhang Tao

2012-01-01

X-ray diffraction was discovered by Max von Laue a hundred years ago. Later, through the work of William H. Bragg and William L. Bragg, an experimental analysis method was developed to solve the structure of molecules at the atomic level. Over the past hundred years, science and technology has been dramatically changed by X-ray diffraction analysis, which has also undergone considerable development. The recent emergence of hard X-ray free electron lasers has provided a new dimension for X-ray diffraction analysis, promising even greater progress in the fields of physics, chemistry and biology. (author)
A Short Review of the Theory of Hard Exclusive Processes

International Nuclear Information System (INIS)

Wallon, S.

2012-01-01

We first present an introduction to the theory of hard exclusive processes. We then illustrate this theory by a few selected examples. The last part is devoted to the most recent developments in the asymptotical energy limit. (author)
Investigation of the effect of nanoclay and processing parameters on the tensile strength and hardness of injection molded Acrylonitrile Butadiene Styrene–organoclay nanocomposites

International Nuclear Information System (INIS)

Mamaghani Shishavan, Sajjad; Azdast, Taher; Rash Ahmadi, Samrand

2014-01-01

Highlights: • Development of polymer/clay nanocomposites. • Compatibility of ABS and montmorillonite nanoclay and composition capability of them. • Effect of nanoclay content and process parameters on the mechanical properties of nanocomposite. • Analyzing the distribution of nanoclay layers using XRD test. • Dependency of tensile strength and hardness to the nanoclay content and processing conditions. - Abstract: Polymer–clay nanocomposites have attracted considerable interest over recent years due to their dramatic improved mechanical properties. In the present study, compatibility of Acrylonitrile Butadiene Styrene (ABS) and organically modified montmorillonite nanoclay (Cloisite 30B) and composition capability of them are investigated. Polymethylmethacrylate (PMMA) in varying amount (0, 2, and 4 wt%) is used as the compatibilizer. In order to produce nanocomposite parts, the material is first compounded using a twin-screw extruder and then injected into a mold. The effect of the nanoclay percentage and processing parameters on the tensile strength and hardness of nanocomposite parts is also explored using Taguchi Design of Experiments method. Nanoclay content (in three levels: 0, 2 and 4 wt%), melt temperature (in three levels: 190, 200 and 210 °C), holding pressure (in three levels: 80, 105 and 130 MPa) and holding pressure time (in three levels: 1, 2.5 and 4 s) are considered as the variable parameters. Moreover, distribution of nanoclay layers is analyzed using Wide Angle X-ray Diffraction (XRD) test. XRD results displayed that with the presence of PMMA, nanoclay in ABS matrix is compounded in more exfoliated and less intercalated dispersion mode. Adding PMMA also leads to a remarkable increase in the fluidity of the melt during injection molding process. Results also illustrated that nanocomposites with medium loading level (i.e. 2%) of nanoclay have the highest tensile strength, while the highest hardness number belongs to nanocomposites with
Strong Bisimilarity and Regularity of Basic Parallel Processes is PSPACE-Hard

DEFF Research Database (Denmark)

Srba, Jirí

2002-01-01

We show that the problem of checking whether two processes definable in the syntax of Basic Parallel Processes (BPP) are strongly bisimilar is PSPACE-hard. We also demonstrate that there is a polynomial time reduction from the strong bisimilarity checking problem of regular BPP to the strong...
Shock Wave Diffraction Phenomena around Slotted Splitters

Directory of Open Access Journals (Sweden)

Francesca Gnani

2015-01-01

Full Text Available In the field of aerospace engineering, the study of the characteristics of vortical flows and their unsteady phenomena finds numerous engineering applications related to improvements in the design of tip devices, enhancement of combustor performance, and control of noise generation. A large amount of work has been carried out in the analysis of the shock wave diffraction around conventional geometries such as sharp and rounded corners, but the employment of splitters with lateral variation has hardly attracted the attention of researchers. The investigation of this phenomenon around two-dimensional wedges has allowed the understanding of the basic physical principles of the flow features. On the other hand, important aspects that appear in the third dimension due to the turbulent nature of the vortices are omitted. The lack of studies that use three-dimensional geometries has motivated the current work to experimentally investigate the evolution of the shock wave diffraction around two splitters with spike-shaped structures for Mach numbers of 1.31 and 1.59. Schlieren photography was used to obtain an insight into the sequential diffraction processes that take place in different planes. Interacting among them, these phenomena generate a complicated turbulent cloud with a vortical arrangement.
Hard Coat Layers by PE-CVD Process for the Top Surface of Touch Panel

International Nuclear Information System (INIS)

Okunishi, T; Sato, N; Yazawa, K

2013-01-01

In order to protect surface from damages, the high pencil hardness and the high abrasion resistance are required for the hard coat layers on polyethylene telephthalate (PET) films for the application of touch panel surface. We have already found that the UV-curing-hard-coat-polymer (UHP) coated PET films show the poor abrasion resistance, while they have the high pencil hardness. It reveals that the abrasion resistance of hard coat layers of the UHP is not simply dependent on the pencil hardness. In this work, we have studied to improve the abrasion resistance of SiOC films as hard coat layers, which were formed by PE-CVD process on UHP coated PET. The abrasion resistance was evaluated by Taber abrasion test. PE-CVD hard coat layers which formed on UHP coater PET films have showed the better abrasion resistance and have the possibility of substitution to the thin glass sheets for touch panel application.
Enhancing the Hardness of Sintered SS 17-4PH Using Nitriding Process for Bracket Orthodontic Application

Science.gov (United States)

Suharno, B.; Supriadi, S.; Ayuningtyas, S. T.; Widjaya, T.; Baek, E. R.

2018-01-01

Brackets orthodontic create teeth movement by applying force from wire to bracket then transferred to teeth. However, emergence of friction between brackets and wires reduces load for teeth movement towards desired area. In order to overcome these problem, surface treatment like nitriding chosen as a process which could escalate efficiency of transferred force by improving material hardness since hard materials have low friction levels. This work investigated nitriding treatment to form nitride layer which affecting hardness of sintered SS 17-4PH. The nitride layers produced after nitriding process at various temperature i.e. 470°C, 500°C, 530°C with 8hr holding time under 50% NH3 atmosphere. Optical metallography was conducted to compare microstructure of base and surface metal while the increasing of surface hardness then observed using vickers microhardness tester. Hardened surface layer was obtained after gaseous nitriding process because of nitride layer that contains Fe4N, CrN and Fe-αN formed. Hardness layers can achieved value 1051 HV associated with varies thickness from 53 to 119 μm. The presence of a precipitation process occurring in conjunction with nitriding process can lead to a decrease in hardness due to nitrogen content diminishing in solid solution phase. This problem causes weakening of nitrogen expansion in martensite lattice.
Dual dynamics of constituent interchange in soft and hard hadronic processes

International Nuclear Information System (INIS)

Akkelin, S.V.; Kobylinskii, N.A.; Martynov, E.S.; Shelest, V.P.

1987-01-01

The possibility of combining the dual theory of soft hadronic processes with the rules of dimensional counting for hard processes is investigated. It is shown that this is achieved in the framework of a dual analytic model with certain conditions on the form and parameters of the Regge trajectories
Study of QCD and Diffraction with the ATLAS detector at the LHC

CERN Document Server

Trzebinski, M; Royon, Christophe

The thesis is devoted to the study of diffractive physics with the ATLAS detector at the LHC. After a short introduction to diffractive physics including soft and hard diffraction, the Jet-Gap-Jet production at the LHC, which is particularly interesting for testing the BFKL theory, is discussed. Using the signal selection cuts and a gap definition based on tracks reconstructed in the ATLAS Inner Detector, a clear signal of Jet-Gap-Jet events in the data was observed. Starting from the half-gap size of 0.8 the data cannot be properly described using only the Non-Diffractive Jet sample. Furthermore, the DPE JGJ production, with both protons tagged in the AFP stations, was demonstrated to provide a significant test of the BFKL theory, once the 300~pb$^{-1}$ of integrated luminosity is collected. In the last part of the thesis, the processes of Central Exclusive Jet and Exclusive $\\pi^+\\pi^-$ production was discussed. After the postulated data selection, the signal to background ratio was found to be of about 5/9...
Nanocrystallite characterization of milled simulated dry process fuel powders by neutron diffraction

International Nuclear Information System (INIS)

Ryu, Ho Jin; Kang, Kwon Ho; Moon, Je Sun; Song, Kee Chan; Choi, Yong Nam

2003-01-01

The nano-scale crystallite sizes of simulated spent fuel powders were measured by the neutron diffraction line broadening method in order to analyze the sintering behavior of the dry process fuel. The mixed U0 2 and fission product oxide powders were dry-milled in an attritor for 30, 60, and 120 min. The diffraction patterns of the powders were obtained by using the high resolution powder diffractometer in the HANARO research reactor. Diffraction line broadening due to crystallite size was measured using various techniques such as the Stokes' deconvolution, profile fitting methods using Cauchy function, Gaussian function, and Voigt function, and the Warren-Averbach method. The r.m.s. strain, stacking fault, twin and dislocation density were measured using the information from the diffraction pattern. The realistic crystallite size can be obtained after separation of the contribution from the non-uniform strain, stacking fault and twin
Nanolaminated TiN/Mo2N hard multilayer coatings

International Nuclear Information System (INIS)

Martev, I N; Dechev, D A; Ivanov, N P; Uzunov, T S D; Kashchieva, E P

2010-01-01

The paper presents results on the synthesis of hard multilayer coatings consisting of titanium nitride and molybdenum nitride thin films with thickness of several nm. The TiN and Mo 2 N films were successively deposited by reactive DC magnetron sputtering. These multilayer structures were investigated by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), selected area electron diffraction (SAED), X-ray diffraction (XRD), cross-section scanning electron microscopy (CSSEM) and cross-section electron probe microanalysis (CSEPMA). The mechanical properties of the multilayer coatings, namely, hardness, Young's modulus and the coefficient of plastic deformation were measured. The adhesion was evaluated by the Rockwell-C-impact test. Coatings with different total thickness were examined with respect to adhesion to substrates of tool materials.
Processing and properties of mechanically alloyed sintered steels with hard inclusions

International Nuclear Information System (INIS)

Gutsfeld, C.

1991-10-01

The aim of this work was the development of mechanically alloyed sintered steels with inert hard inclusions and their characterisation concerning the mechanical properties and the sliding wear behaviour. For this material concept the hard materials NbC, TiC, TiN and Al 2 O 3 were chosen with volume contents upto 20%. Mechanical alloying of the raw powders is a necessary prerequisit for an extreme fine and homogeneous microstructure and good mechanical and wear properties. Through a connecting powder annealing a conventional powder metallurgical processing with cold pressing and sintering is possible. For the consolidation pressureless liquid phase sintering initiated through phosphorus contents of 0,6% is suitable. Because of the strong hampering of grain growth through the included hard particles sintering densities upto 99% TD are possible with extreme fine microstructures. The mechanical properties can be varied in wide ranges. So tensile strengths of 1150 MPa, elongations at fracture of 17%, hardness of over 800 HV and fatigue strengths of 370 MPa have been reached. Throughout HIP or sinter forging the mechanical properties can be improved furthermore. (orig.) [de
Analysis of hard inclusive processes in quantum chromodynamics

International Nuclear Information System (INIS)

Radyushkin, A.V.

1983-01-01

An approach to the investigation of hard processes in QCD based on a regular usage of α-representation analysis of Feynman diagram asymptotics is described. Analysis is examplified by two simplest inclusive processes: E + e - annihilation into hadrons and deep inelastic lepton-hadron scattering. The separation procedure of factorization of contributions stipulated by short- and long-range particle interactions is reported. The relation between expansion operators and methods based on direct analysis of diagrams as well as between theoretical field approaches and the parton model is discussed. Specific features of factorization of short- and long-range contributions in non-Abelian gauge theories are investigated
Dark-field imaging based on post-processed electron backscatter diffraction patterns of bulk crystalline materials in a scanning electron microscope.

Science.gov (United States)

Brodusch, Nicolas; Demers, Hendrix; Gauvin, Raynald

2015-01-01

Dark-field (DF) images were acquired in the scanning electron microscope with an offline procedure based on electron backscatter diffraction (EBSD) patterns (EBSPs). These EBSD-DF images were generated by selecting a particular reflection on the electron backscatter diffraction pattern and by reporting the intensity of one or several pixels around this point at each pixel of the EBSD-DF image. Unlike previous studies, the diffraction information of the sample is the basis of the final image contrast with a pixel scale resolution at the EBSP providing DF imaging in the scanning electron microscope. The offline facility of this technique permits the selection of any diffraction condition available in the diffraction pattern and displaying the corresponding image. The high number of diffraction-based images available allows a better monitoring of deformation structures compared to electron channeling contrast imaging (ECCI) which is generally limited to a few images of the same area. This technique was applied to steel and iron specimens and showed its high capability in describing more rigorously the deformation structures around micro-hardness indents. Due to the offline relation between the reference EBSP and the EBSD-DF images, this new technique will undoubtedly greatly improve our knowledge of deformation mechanism and help to improve our understanding of the ECCI contrast mechanisms. Copyright © 2014 Elsevier B.V. All rights reserved.
Eco-efficient and high performance hard chrome process

Energy Technology Data Exchange (ETDEWEB)

Negre, P. [Protection des Metaux, Montreuil (France)

2001-07-01

Clean manufacturing processes that can minimize effects on the environment are discussed using electrolytic hard chromium-plating as an example. The goal of the research proposal described in this paper is to develop processes from a new and non-toxic electrolytic solution that would allow for harder, thick coatings of chromium that is more resistant to corrosion than traditional coatings and without the carcinogenic effects of hexavalent chromium. The process, as envisaged, will combine the advantages of chromium plating processes based on non-toxic compounds already available, the result primarily of the chemical formulation of the solutions for chromium plating on which the microstructure and the capacity of the structural hardening of the coatings depend. The paper provides an overview of the project, estimates person year and time requirements (225 person-years and 3.5 years) and provides a list of participating partners.
Tomography for amplitudes of hard exclusive processes

International Nuclear Information System (INIS)

Polyakov, M.V.

2008-01-01

We discuss which part of information about hadron structure encoded in the Generalized Parton Distributions (GPDs) [part of total GPD image] can be restored from the known amplitude of a hard exclusive process. The physics content of this partial image is analyzed. Among other things, we show that this partial image contains direct information about how the target hadron responses to the (string) quark-antiquark operator of arbitrary spin J. Explicit equations relating physics content of the partial image of GPDs directly to the data are derived. Also some new results concerning the dual parametrization of GPDs are presented
Three-dimensional rotation electron diffraction: software RED for automated data collection and data processing.

Science.gov (United States)

Wan, Wei; Sun, Junliang; Su, Jie; Hovmöller, Sven; Zou, Xiaodong

2013-12-01

Implementation of a computer program package for automated collection and processing of rotation electron diffraction (RED) data is described. The software package contains two computer programs: RED data collection and RED data processing. The RED data collection program controls the transmission electron microscope and the camera. Electron beam tilts at a fine step (0.05-0.20°) are combined with goniometer tilts at a coarse step (2.0-3.0°) around a common tilt axis, which allows a fine relative tilt to be achieved between the electron beam and the crystal in a large tilt range. An electron diffraction (ED) frame is collected at each combination of beam tilt and goniometer tilt. The RED data processing program processes three-dimensional ED data generated by the RED data collection program or by other approaches. It includes shift correction of the ED frames, peak hunting for diffraction spots in individual ED frames and identification of these diffraction spots as reflections in three dimensions. Unit-cell parameters are determined from the positions of reflections in three-dimensional reciprocal space. All reflections are indexed, and finally a list with hkl indices and intensities is output. The data processing program also includes a visualizer to view and analyse three-dimensional reciprocal lattices reconstructed from the ED frames. Details of the implementation are described. Data collection and data processing with the software RED are demonstrated using a calcined zeolite sample, silicalite-1. The structure of the calcined silicalite-1, with 72 unique atoms, could be solved from the RED data by routine direct methods.
iMOSFLM: a new graphical interface for diffraction-image processing with MOSFLM

International Nuclear Information System (INIS)

Battye, T. Geoff G.; Kontogiannis, Luke; Johnson, Owen; Powell, Harold R.; Leslie, Andrew G. W.

2011-01-01

A new graphical user interface to the MOSFLM program has been developed to simplify the processing of macromolecular diffraction data. The interface, iMOSFLM, allows data processing via a series of clearly defined tasks and provides visual feedback on the progress of each stage. iMOSFLM is a graphical user interface to the diffraction data-integration program MOSFLM. It is designed to simplify data processing by dividing the process into a series of steps, which are normally carried out sequentially. Each step has its own display pane, allowing control over parameters that influence that step and providing graphical feedback to the user. Suitable values for integration parameters are set automatically, but additional menus provide a detailed level of control for experienced users. The image display and the interfaces to the different tasks (indexing, strategy calculation, cell refinement, integration and history) are described. The most important parameters for each step and the best way of assessing success or failure are discussed
Standard hardness conversion tables for metals relationship among brinell hardness, vickers hardness, rockwell hardness, superficial hardness, knoop hardness, and scleroscope hardness

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 Conversion Table 1 presents data in the Rockwell C hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.2 Conversion Table 2 presents data in the Rockwell B hardness range on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, Knoop hardness, and Scleroscope hardness of non-austenitic steels including carbon, alloy, and tool steels in the as-forged, annealed, normalized, and quenched and tempered conditions provided that they are homogeneous. 1.3 Conversion Table 3 presents data on the relationship among Brinell hardness, Vickers hardness, Rockwell hardness, Rockwell superficial hardness, and Knoop hardness of nickel and high-nickel alloys (nickel content o...

Optimizing a cleaning process for multilayer-dielectric- (MLD) diffraction gratings

Energy Technology Data Exchange (ETDEWEB)

Ashe, B. [Univ. of Rochester, NY (United States); Giacofei, C. [Univ. of Rochester, NY (United States); Myhre, G. [Univ. of Rochester, NY (United States); Schmid, A. W. [Univ. of Rochester, NY (United States)

2007-12-20

An essential component for the OMEGA EP short-pulse petawatt laser system is the grating compressor chamber (GCC). This large (12,375 ft³) vacuum chamber contains critical optics where laser-pulse compression is performed at the output of the system on two 40-cm-sq-aperture, IR (1054-nm) laser beams. Critical to this compression, within the GCC, are four sets of tiled multilayer-dielectric- (MLD) diffraction gratings that provide the capability for producing 2.6-kJ output IR energy per beam at 10 ps. The primary requirements for these large-aperture (43-cm × 47-cm) gratings are diffraction efficiencies greater than 95%, peak-to-valley wavefront quality of less than λ/10 waves, and laser-induced-damage thresholds greater than 2.7 J/cm² at 10-ps measured beam normal. Degradation of the grating laser-damage threshold due to adsorption of contaminants from the manufacturing process must be prevented to maintain system performance. In this paper we discuss an optimized cleaning process to achieve the OMEGA EP requirements. The fabrication of MLD gratings involves processes that utilize a wide variety of both organic materials (photoresist processes) and inorganic materials (metals and metal oxides) that can affect the final cleaning process. Finally, a number of these materials have significant optical absorbance; therefore, incomplete cleaning of these residues may result in the MLD gratings experiencing laser damage.
Optimization of a multilayer Laue lens system for a hard x-ray nanoprobe

International Nuclear Information System (INIS)

Jiang, Hui; Wang, Hua; Mao, Chengwen; Li, Aiguo; He, Yan; Dong, Zhaohui; Zheng, Yi

2014-01-01

Detailed designs of a multilayer Laue lens system for a hard x-ray nanoprobe, including flat and wedged types, are presented, to realize nanoscale point focus and high diffraction efficiency simultaneously. The difficulty of movement and alignment for lens, aperture and sample are considered in the optimization process. Considering the practical requirements of future experiments, the features of the beamline and the structural imperfections, the working energy range, the beam vibration and structural errors are estimated and discussed. (paper)
Double-diffractive processes in high-resolution missing-mass experiments at the Tevatron

International Nuclear Information System (INIS)

Khoze, V.A.; Martin, A.D.

2001-01-01

We evaluate, in a model-independent way, the signal-to-background ratio for Higgs→b anti b detection in exclusive double-diffractive events at the Tevatron and the LHC. For the missing-mass approach to be able to identify the Higgs boson, it will be necessary to use a central jet detector and to tag b quark jets. The signal is predicted to be very small at the Tevatron, but observable at the LHC. However we note that the background, that is double-diffractive dijet production, may serve as a unique gluon factory. We also give estimates for the double-diffractive production of χ c and χ b mesons at the Tevatron. We emphasize that a high-resolution missing-mass measurement, on its own, is insufficient to identify rare processes. (orig.)
Hardness and thermal stability of cubic silicon nitride

DEFF Research Database (Denmark)

Jiang, Jianzhong; Kragh, Flemming; Frost, D. J.

2001-01-01

The hardness and thermal stability of cubic spinel silicon nitride (c-Si3N4), synthesized under high-pressure and high-temperature conditions, have been studied by microindentation measurements, and x-ray powder diffraction and scanning electron microscopy, respectively The phase at ambient...
Measurement of the diffractive structure function in deep inelastic scattering hat HERA

International Nuclear Information System (INIS)

Derrick, M.; Krakauer, D.; Magill, S.

1995-05-01

This paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in ep interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of x IP , the momentum fraction lost by the proton, of β, the momentum fraction of the struck quark with respect to x IP , and of Q 2 . The x IP dependence is consistent with the form (1/x IP ) a where a=1.30-±0.80(stat) -0.14 +0.08 (sys) in all bins of βand Q 2 . In the measured Q 2 range, the diffractive structure function approximately scales with Q 2 at fixed β. In an Ingelman-Schlein type model, where commonly used pomeron flux factor normalisations are assumed, it is found that the quarks within the pomeron do not saturate the momentum sum rule. (orig.)
Diffractive dijet production in deep inelastic scattering at ZEUS

Energy Technology Data Exchange (ETDEWEB)

Bonato, A.

2008-03-15

This thesis presents a measurement of dijet production of diffractive deep inelastic scattering ep collisions. This type of process is specially relevant for the experimental validity of the perturbative QCD approach to diffractive physics. The measurement was based on an integrated luminosity of 61 pb{sup -1} collected at the HERA collider with the ZEUS experiment. The events were selected for virtualities of the photon, {gamma}*, 54 GeV. The jet with the highest transverse energy was required to have E{sub T} {sub jet}*>5 GeV. All jets were required to be in the pseudorapidity range -3.5<{eta}{sub jet}*<0 as measured in the {gamma}*p frame. The selection of diffractive events was carried out by requiring a large rapidity gap in the direction of the scattered proton. The value of the fraction of initial proton momentum entering in the hard process, x{sub P}, was required to be x{sub P}<0.03. The total cross section for the process was measured to be {sigma}{sub TOT}{sup D}(ep{yields}ep jet{sub 1}jet{sub 2} X')=9.15{+-}1.2 (stat.){sub 5.4}{sup 3.3} (syst.){sub -5.3}{sup +6.4} (corr.)pb. Single and double differential cross sections were extracted and compared to leading-order predictions and next-to-leading-order QCD calculations. The latter used several diffractive parton densities extracted from inclusive diffractive deep inelastic scattering data. The agreement with the leading and next-to-leading order predictions is good and no hints of factorisation breaking are observed. The double differential measurement can be a previous input for the extraction of more accurate diffractive parton densities. (orig.)
Diffraction in ALICE and trigger efficiencies

CERN Document Server

Navin, Sparsh; Lietava, Roman

ALICE is built to measure the properties of strongly interacting matter created in heavy-ion collisions. In addition, taking advantage of the low pT acceptance in the central barrel, ALICE is playing an important role in understanding pp collisions with minimum bias triggers at LHC energies. The work presented in this thesis is based on pp data simulated by the ALICE collaboration and early data collected at a center-of-mass energy of 7 TeV. A procedure to calculate trigger efficiencies and an estimate of the systematic uncertainty due to the limited acceptance of the detector are shown. A kinematic comparison between Monte Carlo event generators, PYTHIA 6, PYTHIA 8 and PHOJET is also presented. To improve the description of diffraction in PYTHIA, a hard diffractive component was added to PYTHIA 8 in 2009, which is described. Finally a trigger with a high efficiency for picking diffractive events is used to select a sample with an enhanced diffractive component from pp data. These data are compared to Monte ...
Transverse Imaging of the Proton in Exclusive Diffractive pp Scattering

International Nuclear Information System (INIS)

Christian Weiss; Leonid Frankfurt; Charles Hyde-Wright; Mark Strikman

2006-01-01

In a forthcoming paper we describe a new approach to rapidity gap survival (RGS) in the production of high-mass systems (H = dijet, Higgs, etc.) in exclusive double-gap diffractive pp scattering, pp -> p + H + p. It is based on the idea that hard and soft interactions are approximately independent (QCD factorization), and allows us to calculate the RGS probability in a model-independent way in terms of the gluon generalized parton distributions (GPDs) in the colliding protons and the pp elastic scattering amplitude. Here we focus on the transverse momentum dependence of the cross section. By measuring the ''diffraction pattern'', one can perform detailed tests of the interplay of hard and soft interactions, and even extract information about the gluon GPD in the proton from the data
Coherent hard x-ray focusing optics and applications

Energy Technology Data Exchange (ETDEWEB)

Yun, W.B.; Viccaro, P.J.; Chrzas, J.; Lai, B.

1991-01-01

Coherent hard x-ray beams with a flux exceeding 10{sup 9} photons/second with a bandwidth of 0.1% will be provided by the undulator at the third generation synchrotron radiation sources such as APS, ESRF, and Spring-8. The availability of such high flux coherent x-ray beams offers excellent opportunities for extending the coherence-based techniques developed in the visible and soft x-ray part of the electromagnetic spectrum to the hard x-rays. These x-ray techniques (e.g., diffraction limited microfocusing, holography, interferometry, phase contrast imaging and signal enhancement), may offer substantial advantages over non-coherence-based x-ray techniques currently used. For example, the signal enhancement technique may be used to enhance an anomalous x-ray or magnetic x-ray scattering signal by several orders of magnitude. Coherent x-rays can be focused to a very small (diffraction-limited) spot size, thus allowing high spatial resolution microprobes to be constructed. The paper will discuss the feasibility of the extension of some coherence-based techniques to the hard x-ray range and the significant progress that has been made in the development of diffraction-limited focusing optics. Specific experimental results for a transmission Fresnel phase zone plate that can focus 8.2 keV x-rays to a spot size of about 2 microns will be briefly discussed. The comparison of measured focusing efficiency of the zone plate with that calculated will be made. Some specific applications of zone plates as coherent x-ray optics will be discussed. 17 refs., 4 figs.
Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA

International Nuclear Information System (INIS)

Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

2014-01-01

The software suite SITENNO is developed for processing diffraction data collected in coherent X-ray diffraction imaging experiments of non-crystalline particles using an X-ray free-electron laser. Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the ‘diffraction before destruction’ scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles
Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

Research results of hard photon technology have been summarized as a part of novel technology development highly utilizing the quantum nature of photon. Hard photon technology refers to photon beam technologies which use photon in the 0.1 to 200 nm wavelength region. Hard photon has not been used in industry due to the lack of suitable photon sources and optical devices. However, hard photon in this wavelength region is expected to bring about innovations in such areas as ultrafine processing and material synthesis due to its atom selective reaction, inner shell excitation reaction, and spatially high resolution. Then, technological themes and possibility have been surveyed. Although there are principle proposes and their verification of individual technologies for the technologies of hard photon generation, regulation and utilization, they are still far from the practical applications. For the photon source technology, the laser diode pumped driver laser technology, laser plasma photon source technology, synchrotron radiation photon source technology, and vacuum ultraviolet photon source technology are presented. For the optical device technology, the multi-layer film technology for beam mirrors and the non-spherical lens processing technology are introduced. Also are described the reduction lithography technology, hard photon excitation process, and methods of analysis and measurement. 430 refs., 165 figs., 23 tabs.
Bragg concentrators for hard (> 10 keV) X-ray astronomy: Status report

Energy Technology Data Exchange (ETDEWEB)

Pareschi, G.; Pasqualini, G. [Ferrara, Univ. (Italy). Dipt. di Fisica; Frontera, F. [CNR, Bologna (Italy). Istituto di TESRE]|[Ferrara, Univ. (Italy). Dipt. di Fisica

1997-09-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. They present recent results obtained from their group regarding the possible use of Bragg-diffraction technique to design hard X-ray focusing telescopes.
Bragg concentrators for hard (> 10 keV) X-ray astronomy: Status report

International Nuclear Information System (INIS)

Pareschi, G.; Pasqualini, G.; Frontera, F.; Ferrara, Univ.

1997-01-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. They present recent results obtained from their group regarding the possible use of Bragg-diffraction technique to design hard X-ray focusing telescopes
Mechanical characterisation of surface layers by x-ray diffraction -application to tribology

International Nuclear Information System (INIS)

Farrahi, G.H.

1996-01-01

The results presented in this paper show that X-ray diffraction can be employed for the characterisation of surface layer damage through residual stresses and work hardening by some tribological actions such as fretting and dry sliding. X-ray diffraction technique can also be employed for a rapid and non-destructive measurement of hardness of hardened steel. The diffraction profile analysis can offer a good indication about the materials characteristics and the microstructural evolution caused by heat treatment or by mechanical loading
Diffractive heavy quark production in AA collisions at the LHC at NLO

Science.gov (United States)

Machado, M. M.; Ducati, M. B. Gay; Machado, M. V. T.

2011-07-01

The single and double diffractive cross sections for heavy quarks production are evaluated at NLO accuracy for hadronic and heavy ion collisions at the LHC. Diffractive charm and bottom production is the main subject of this work, providing predictions for CaCa, PbPb and pPb collisions. The hard diffraction formalism is considered using the Ingelman-Schlein model where a recent parametrization for the Pomeron structure function (DPDF) is applied. Absorptive corrections are taken into account as well. The diffractive ratios are estimated and theoretical uncertainties are discussed. Comparison with competing production channels is also presented.
Micromanufacturing Of Hard To Machine Materials By Physical And Chemical Ablation Processes

International Nuclear Information System (INIS)

Schubert, A.; Edelmann, J.; Gross, S.; Meichsner, G.; Wolf, N.; Schneider, J.; Zeidler, H.; Hackert, M.

2011-01-01

Miniaturization leads to high requirements to the applied manufacturing processes especially in respect to the used hard to machine materials and the aims of structure size and geometrical accuracy. Traditional manufacturing processes reach their limits here. One alternative for these provide thermal and chemical ablation processes. These processes are applied for the production of different microstructures in different materials like hardened steel, carbides and ceramics especially for medical engineering and tribological applications.
Elastic and Diffractive Scattering - Proceedings of the International Conference on Vth Blois Workshop

Science.gov (United States)

Kang, K.; Fried, H. M.; Tan, C.-I.

1994-02-01

Amplitude Analysis and a QCD-Inspired Analysis * Rapidity Gaps and Multiplicity Fluctuations * Branching Processes and Multi-Particle Production * High Energy Elastic Scattering and Nucleon as a Topological Soliton * The Behavior of Cross Sections at Very High Energies * The Pomeron and QCD with Many Light Quarks * Heterotic Pomeron: High Energy Hadronic Collisions in QCD * CDF Results on Electroweak Physics * DØ Results on Electroweak Physics * Search for the Top Quark and Other New Particles at DØ * Rapidity Gaps and Forward Physics at DØ * High Energy Asymptotics of Perturbative Multi-Color QCD * Rapidity Gaps in e+e- Collisions * Large Rapidity Gap, Jet Events at HERA: a PQCD Approach * High Energy Parton-Parton Elastic Scattering in QCD * Parton-Parton Elastic Scattering and Rapidity Gaps at Tevatron Energies * Hard Elastic Scattering * Hard Diffractive Processes * Three Successful Tests of Color Transparency and Nuclear Filtering * New KNO in QCD * A Chiral Condensate Search at the Tevatron * Cosmic Ray Evidences for Aligned High Energy Jets at Supertevatron Energy and Hard DDD * "New Hadronic State" Observed in Extremely High Energy Cosmic-Ray Interactions * Meson and Nucleon Form Factors in PQCD * Elastic Charge Form Factors for Pseudoscalar Mesons * The Ultimate Experiment * Search for Coherent Charm Production in 800 GeV/c Proton-Silicon Interactions * Chiral Quark Model and Hadron Scattering * Elastic Spin Experiments at UNK, Fermilab and SSC * Spin-Flip in Elastic and Diffractive Scattering * FNAL Polarized Beams and Spin Dependence at RHIC * Particle Tracking in the Close-to-Forward Region (η > 5.5) * Blois V: Experimental Summary * Blois V: Summary Talk * List of Participants
An introduction to three-dimensional X-ray diffraction microscopy

DEFF Research Database (Denmark)

Poulsen, Henning Friis

2012-01-01

Three-dimensional X-ray diffraction microscopy is a fast and nondestructive structural characterization technique aimed at studies of the individual crystalline elements (grains or subgrains) within millimetre-sized polycrystalline specimens. It is based on two principles: the use of highly...... penetrating hard X-rays from a synchrotron source and the application of tomographic reconstruction algorithms for the analysis of the diffraction data. In favourable cases, the position, morphology, phase and crystallographic orientation can be derived for up to 1000 elements simultaneously. For each grain...
Dijet production in diffractive deep-inelastic scattering in next-to-next-to-leading order QCD arXiv

CERN Document Server

Britzger, D.; Gehrmann, T.; Huss, A.; Niehues, J.; Žlebčík, R.

Hard processes in diffractive deep-inelastic scattering can be described by a factorisation into parton-level subprocesses and diffractive parton distributions. In this framework, cross sections for inclusive dijet production in diffractive deep-inelastic electron-proton scattering (DIS) are computed to next-to-next-to-leading order (NNLO) QCD accuracy and compared to a comprehensive selection of data. Predictions for the total cross sections, 39 single-differential and four double-differential distributions for six measurements at HERA by the H1 and ZEUS collaborations are calculated. In the studied kinematical range, the NNLO corrections are found to be sizeable and positive. The NNLO predictions typically exceed the data, while the kinematical shape of the data is described better at NNLO than at next-to-leading order (NLO). A significant reduction of the scale uncertainty is achieved in comparison to NLO predictions. Our results use the currently available NLO diffractive parton distributions, and the dis...
Crystallographic Analysis of Nucleation at Hardness Indentations in High-Purity Aluminum

DEFF Research Database (Denmark)

Xu, Chaoling; Zhang, Yubin; Lin, Fengxiang

2016-01-01

Nucleation at Vickers hardness indentations has been studied in high-purity aluminum cold-rolled 12 pct. Electron channeling contrast was used to measure the size of the indentations and to detect nuclei, while electron backscattering diffraction was used to determine crystallographic orientations....... It is found that indentations are preferential nucleation sites. The crystallographic orientations of the deformed grains affect the hardness and the nucleation potentials at the indentations. Higher hardness gives increased nucleation probabilities. Orientation relationships between nuclei developed...... they form. Finally, possible nucleation mechanisms are briefly discussed....

Self-standing quasi-mosaic crystals for focusing hard X-rays

International Nuclear Information System (INIS)

Camattari, Riccardo; Guidi, Vincenzo; Bellucci, Valerio; Neri, Ilaria; Frontera, Filippo; Jentschel, Michael

2013-01-01

A quasi mosaic bent crystal for high-resolution diffraction of X and γ rays has been realized. A net curvature was imprinted to the crystal thanks to a series of superficial grooves to keep the curvature without external devices. The crystal highlights very high diffraction efficiency due to quasi mosaic curvature. Quasi mosaic crystals of this kind are proposed for the realization of a high-resolution focusing Laue lens for hard X-rays.
Vector meson dominance and pointlike coupling of the photon in soft and hard processes

International Nuclear Information System (INIS)

Paul, E.

1990-05-01

Recent experimental results on photoproduction of hadrons probe the nature of the interacting photon over a wide kinematical range from soft to hard processes. Single inclusive spectra and energy flows of the final state charged particles are well described by assuming that photon production data are built up by an incoherent superposition of a soft Vector-Meson-Dominance component and a hard pointlike photon component. (orig.)
Research on Melt Degassing Processes of High Conductivity Hard Drawn Aluminum Wire

Science.gov (United States)

Xu, Xuexia; Feng, Yanting; Wang, Qing; Li, Wenbin; Fan, Hui; Wang, Yong; Li, Guowei; Zhang, Daoqian

2018-03-01

Degassing effects of ultrasonic and vacuum processes on high conductivity hard drawn aluminum melt were studied. Results showed that the degassing efficiency improved with the increase of ultrasonic power within certain range, stabilizing at 70% with 240W. For vacuum degassing process, hydrogen content of aluminum melt decreased with the loading time and was linear with logarithm of vacuum degree. Comparison of degassing effects of ultrasonic, vacuum, vacuum-ultrasonic degassing process showed that vacuum-ultrasonic process presented optimal effect.
Effect of Heat Treatment on the Hardness and Wear of Grinding Balls

Science.gov (United States)

Aissat, Sahraoui; Sadeddine, Abdelhamid; Bradai, Mohand Amokrane; Younes, Rassim; Bilek, Ali; Benabbas, Abderrahim

2017-09-01

The effect quenching and tempering by different regimes on Rockwell hardness and wear processes of grinding balls 50 and 70 mm in diameter made of two melts of chromium-molybdenum cast iron is studied. The heating temperature for quenching is 850, 950, and 1050°C; the tempering temperature is 250, 400, and 600°C. Iron is analyzed in an electron microscope. Diffraction patterns are obtained. A model of cast iron wear is suggested and compared to the Davis model and to experimental results. An optimum heat treatment regime is proposed.
Nanostructural Evolution of Hard Turning Layers in Carburized Steel

Science.gov (United States)

Bedekar, Vikram

The mechanisms of failure for components subjected to contact fatigue are sensitive to the structure and properties of the material surface. Although, the bulk material properties are determined by the steel making, forming and the heat treatment; the near surface material properties are altered during final material removal processes such as hard turning or grinding. Therefore, the ability to optimize, modulate and predict the near surface properties during final metal removal operations would be extremely useful in the enhancement of service life of a component. Hard machining is known to induce severely deformed layers causing dramatic microstructural transformations. These transformations occur via grain refinement or thermal phenomena depending upon cutting conditions. The aim of this work is to engineer the near surface nanoscale structure and properties during hard turning by altering strain, strain rate, temperature and incoming microstructure. The near surface material transformations due to hard turning were studied on carburized SAE 8620 bearing steel. Variations in parent material microstructures were introduced by altering the retained austenite content. The strain, strain rate and temperature achieved during final metal cutting were altered by varying insert geometry, insert wear and cutting speed. The subsurface evolution was quantified by a series of advanced characterization techniques such as transmission electron microscopy (TEM), glancing angle X-ray diffraction (GAXRD), X-ray stress evaluation and nanoindentation which were coupled with numerical modeling. Results showed that the grain size of the nanocrystalline near surface microstructure can be effectively controlled by altering the insert geometry, insert wear, cutting speed and the incoming microstructure. It was also evident that the near surface retained austenite decreased at lower cutting speed indicating transformation due to plastic deformation, while it increased at higher cutting
11. international conference on elastic and diffractive scattering: towards high energy frontiers

International Nuclear Information System (INIS)

2005-01-01

This conference is held every 2 years. Every time these conferences on elastic and diffractive scattering adapt their content to the most recent experimental and theoretical results concerning not only quantum chromodynamics (QCD) but also other fields of particle physics where diffractive physics is present. This year, besides classical themes such as: -) forward scattering, -) total cross-sections, -) real parts, and -) pomeron and odderon, the participants have addressed many other subjects such as: -) LHC physics, -) non-perturbative approaches to high-energy scattering, -) the dipole model, -) small-x evolution, -) hard diffraction in QCD, -) nuclear shadowing, -) diffractive Higgs studies, -) spin effects, -) 4-quarks and 5-quarks, or -) B-physics
11. international conference on elastic and diffractive scattering: towards high energy frontiers

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

This conference is held every 2 years. Every time these conferences on elastic and diffractive scattering adapt their content to the most recent experimental and theoretical results concerning not only quantum chromodynamics (QCD) but also other fields of particle physics where diffractive physics is present. This year, besides classical themes such as: -) forward scattering, -) total cross-sections, -) real parts, and -) pomeron and odderon, the participants have addressed many other subjects such as: -) LHC physics, -) non-perturbative approaches to high-energy scattering, -) the dipole model, -) small-x evolution, -) hard diffraction in QCD, -) nuclear shadowing, -) diffractive Higgs studies, -) spin effects, -) 4-quarks and 5-quarks, or -) B-physics.
Dijet Cross Sections and Parton Densities in Diffractive DIS at HERA

CERN Document Server

Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Roeck, A.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkiewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Jacquet, M.; Janssen, M.E.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Polifka, R.; Povh, B.; Preda, T.; Prideaux, P.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smiljanic, Ivan; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Staykova, Z.; Steder, M.; Stella, B.; Stiewe, J.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

2007-01-01

Differential dijet cross sections in diffractive deep-inelastic scattering are measured with the H1 detector at HERA using an integrated luminosity of 51.5 pb-1. The selected events are of the type ep --> eXY, where the system X contains at least two jets and is well separated in rapidity from the low mass proton dissociation system Y. The dijet data are compared with QCD predictions at next-to-leading order based on diffractive parton distribution functions previously extracted from measurements of inclusive diffractive deep-inelastic scattering. The prediction describes the dijet data well at low and intermediate zpom (the fraction of the momentum of the diffractive exchange carried by the parton entering the hard interaction) where the gluon density is well determined from the inclusive diffractive data, supporting QCD factorisation. A new set of diffractive parton distribution functions is obtained through a simultaneous fit to the diffractive inclusive and dijet cross sections. This allows for a precise ...
Exotic hybrid mesons in hard electroproduction

International Nuclear Information System (INIS)

Anikin, I.V.; Pire, B.; Szymanowski, L.; Teryaev, O.V.; Wallon, S.

2005-01-01

We estimate the sizeable cross section for deep exclusive electroproduction of an exotic J PC =1 -+ hybrid meson in the Bjorken regime. The production amplitude scales like the one for usual meson electroproduction, i.e., as 1/Q 2 . This is due to the nonvanishing leading twist distribution amplitude for the hybrid meson, which may be normalized thanks to its relation to the energy-momentum tensor and to the QCD sum rules technique. The hard amplitude is considered up to next-to-leading order in α S and we explore the consequences of fixing the renormalization scale ambiguity through the Brodsky-Lepage-Mackenzie (BLM) procedure. We study the particular case where the hybrid meson decays through a πη meson pair. We discuss the πη generalized distribution amplitude and then calculate the production amplitude for this process. We propose a forward-backward asymmetry in the production of π and η mesons as a signal for the hybrid meson production. We briefly comment on hybrid electroproduction at very high energy, in the diffractive limit where a QCD Odderon exchange mechanism should dominate. The conclusion of our study is that hard electroproduction is a promising way to study exotic hybrid mesons, in particular, at JLAB, HERA (HERMES), or CERN (Compass)
Effect of feed rate, workpiece hardness and cutting edge on subsurface residual stress in the hard turning of bearing steel using chamfer + hone cutting edge geometry

International Nuclear Information System (INIS)

Hua Jiang; Shivpuri, Rajiv; Cheng Xiaomin; Bedekar, Vikram; Matsumoto, Yoichi; Hashimoto, Fukuo; Watkins, Thomas R.

2005-01-01

Residual stress on the machined surface and the subsurface is known to influence the service quality of a component, such as fatigue life, tribological properties, and distortion. Therefore, it is essential to predict and control it for enhanced performance. In this paper, a newly proposed hardness based flow stress model is incorporated into an elastic-viscoplastic finite element model of hard turning to analyze process variables that affect the residual stress profile of the machined surface. The effects of cutting edge geometry and workpiece hardness as well as cutting conditions, such as feed rate and cutting speed, are investigated. Numerical analysis shows that hone edge plus chamfer cutting edge and aggressive feed rate help to increase both compressive residual stress and penetration depth. These predictions are validated by face turning experiments which were conducted using a chamfer with hone cutting edge for different material hardness and cutting parameters. The residual stresses under the machined surface are measured by X-ray diffraction/electropolishing method. A maximum circumferential residual stress of about 1700 MPa at a depth of 40 μm is reached for hardness of 62 HRc and feed rate of 0.56 mm/rev. This represents a significant increase from previously reported results in literatures. It is found from this analysis that using medium hone radius (0.02-0.05 mm) plus chamfer is good for keeping tool temperature and cutting force low, while obtaining desired residual stress profile
Coherent and noncoherent double diffractive production of QQ-bar pairs in heavy-ion collisions at high energies

International Nuclear Information System (INIS)

Agababyan, N.M.; Chatrchyan, S.A.; Galoyan, A.S.; Malakhov, A.I.; Melkumov, G.L.; Zarubin, P.I.; Jenkovszky, L.L.

1999-01-01

The coherent and noncoherent double diffractive production of heavy quark-antiquark pairs in ion scattering at the LHC energies has been considered. The total and differential cross sections for such processes featuring the production of cc-bar and bb-bar quark pairs in pp, CaCa, and PbPb collisions have been estimated. It has been shown that the fraction of heavy quark-antiquark pairs produced in double diffractive scattering amounts to a few percent of the number of QQ-bar pairs produced in hard QCD scattering; therefore, it is necessary to take into account such processes in detecting heavy quarks, in seeking Higgs bosons of intermediate mass, in investigating the suppression of heavy quarkonia in quark-gluon plasma, and so on. It has been demonstrated that the cross section for coherent scattering is so large that this process can be used to study collective effects in nuclei at high energies. Large values of the quark-antiquark invariant mass, M QQ-bar > or approx. 100 GeV, in association with a large rapidity gap between diffractive jets, Δη>5, exemplify manifestations of such nuclear interactions
Image processing for grazing incidence fast atom diffraction

Energy Technology Data Exchange (ETDEWEB)

Debiossac, Maxime; Roncin, Philippe, E-mail: philippe.roncin@u-psud.fr

2016-09-01

Grazing incidence fast atom diffraction (GIFAD, or FAD) has developed as a surface sensitive technique. Compared with thermal energies helium diffraction (TEAS or HAS), GIFAD is less sensitive to thermal decoherence but also more demanding in terms of surface coherence, the mean distance between defects. Such high quality surfaces can be obtained from freshly cleaved crystals or in a molecular beam epitaxy (MBE) chamber where a GIFAD setup has been installed allowing in situ operation. Based on recent publications by Atkinson et al. (2014) and Debiossac et al. (2014), the paper describes in detail the basic steps needed to measure the relative intensities of the diffraction spots. Care is taken to outline the underlying physical assumptions.
Study of caprine bones after moist and dry heat processes by X-ray diffraction

International Nuclear Information System (INIS)

Barbosa, Caroline M.; Azeredo, Soraia R.; Lopes, Ricardo T.; Souza, Sheila M.F.M de

2013-01-01

Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I rel ). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)
Study of caprine bones after moist and dry heat processes by X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Barbosa, Caroline M., E-mail: carolmattosb@yahoo.com.br [Instituto de Arqueologia Brasileira (IAB), Belford Roxo, RJ (Brazil); Azeredo, Soraia R.; Lopes, Ricardo T., E-mail: soraia@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/LIN/UFRJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Instrumentacao Nuclear; Souza, Sheila M.F.M de, E-mail: sferraz@ensp.fiocruz.br [Fundacao Oswaldo Cruz (ENSP/FIOCRUZ), Rio de Janeiro, RJ (Brazil). Escola Nacional de Saude Publica Sergio Arouca

2013-07-01

Bone tissue is a biological material composed of hydroxyapatite (HAp) and collagen matrix. The bone X-ray diffraction (XRD) pattern presents characteristics of the hydroxyapatite crystallography planes. This paper presents the characterization by X-ray diffraction of caprine bone powder pattern and the comparison of this pattern with moist or dry heat cooked bone patterns. The parameters chosen to characterize the X-ray diffraction peaks were: angular position (2θ), full width at half maximumt (FWHM), and relative intensity (I{sub rel}). The X-ray diffraction patterns were obtained with a Shimadzu XRD-6000 diffractometer. The caprine bone XRD pattern revealed a significant correlation of several crystallographic parameters (lattice data) with hydroxyapatite. The profiles of the three bone types analyzed presented differences. The study showed as small angular displacement (decrease of the 2θ angle) of some peaks was observed after moist and dry heat cooking processes. The characterization of bone tissue aimed to contribute to future analysis in the field of archeology. (author)
Interplay of soft and hard processes and hadron $p_{T}$ spectra in p A and AA collisions

CERN Document Server

Enke, Wang; 10.1103/PhysRevC.64.034901

2001-01-01

Motivated by a schematic model of multiple parton scattering within the Glauber formalism, the transverse momentum spectra in pA and AA collisions are analyzed in terms of a nuclear modification factor with respect to pp collisions. The existing data at the CERN Super Proton Synchrotron energies are shown to be consistent with the picture of Glauber multiple scattering in which the interplay between soft and hard processes and the effect of absorptive processes lead to nontrivial nuclear modification of the particle spectra. Relative to the additive model of incoherent hard scattering, the spectra are enhanced at large p/sub T/ (hard) by multiple scattering while suppressed at low p/sub T/ (soft) by absorptive correction with the transition occurring at around a scale p/sub 0/~1-2 GeV/c that separates soft and hard processes. Around the same scale, the p/sub T / spectra in pp collisions also change from an exponential form at low p/sub T/ to a power-law behavior at high p/sub T/. At very large p/sub T/>>p/sub...
Transverse energy circulation and the edge diffraction of an optical vortex beam.

Science.gov (United States)

Bekshaev, Aleksandr Ya; Mohammed, Kadhim A; Kurka, Ivan A

2014-04-01

Edge diffraction of a circular Laguerre-Gaussian beam represents an example of the optical vortex symmetry breakdown in which the hidden "vortex" energy circulation is partially transformed into the visible "asymmetry" form. The diffracted beam evolution is studied in terms of the irradiance moments and the moment-based parameters. In spite of the limited applicability of the moment-based formalism, we show that the "vortex" and "asymmetry" parts of the orbital angular momentum can still be reasonably defined for the hard-edge diffracted beams and retain their physical role of quantifying the corresponding forms of the transverse energy circulation.
Performance improvements of binary diffractive structures via optimization of the photolithography and dry etch processes

Science.gov (United States)

Welch, Kevin; Leonard, Jerry; Jones, Richard D.

2010-08-01

Increasingly stringent requirements on the performance of diffractive optical elements (DOEs) used in wafer scanner illumination systems are driving continuous improvements in their associated manufacturing processes. Specifically, these processes are designed to improve the output pattern uniformity of off-axis illumination systems to minimize degradation in the ultimate imaging performance of a lithographic tool. In this paper, we discuss performance improvements in both photolithographic patterning and RIE etching of fused silica diffractive optical structures. In summary, optimized photolithographic processes were developed to increase critical dimension uniformity and featuresize linearity across the substrate. The photoresist film thickness was also optimized for integration with an improved etch process. This etch process was itself optimized for pattern transfer fidelity, sidewall profile (wall angle, trench bottom flatness), and across-wafer etch depth uniformity. Improvements observed with these processes on idealized test structures (for ease of analysis) led to their implementation in product flows, with comparable increases in performance and yield on customer designs.
Soft and hard pomerons: Is there a distinction?

International Nuclear Information System (INIS)

Bjorken, J.D.

1991-07-01

One of the big unsolved problems of QCD remains the problem of the Pomeron: what is the relation of high energy elastic and diffractive phenomena to the underlying theory? This is not a subject in which I have actively worked. But my interest in it has in this year increased greatly. The reason has to do with ideas for experimentation at SSC/LHC which either directly address the problem or which require the understanding of strong-interaction diffractive phenomena as backgrounds for discovery-physics processes involving electroweak boson exchanges. I will in this talk omit these motivations, which can be found elsewhere, and instead concentrate on some personal veiwpoints regarding the Pomeron which may or may not be conventional. The main question has to do with the distinction between the original, old-fashioned ''soft'' Pomeron of the 1960s, built out of multiperipheral hadron-exchanges, and the more modern perturbative-QCD ''hard'' Pomeron, built out of multiperipheral gluon exchanges. The perspective I offer comes mainly from two sources: one is heavy-flavor physics, and the other is the Manohar-Georgi view of constituent quark physics. 27 refs., 5 figs
Effect of Crystallisation Degree on Hardness of Basaltic Glass-Ceramics

DEFF Research Database (Denmark)

Jensen, Martin; Smedskjær, Morten Mattrup; Yue, Yuanzheng

The dependence of hardness of basaltic glass-ceramics on their crystallisation degree has been explored by means of differential scanning calorimetry, optical microscopy, X-ray diffraction, and Vickers indentation. Different degrees of crystallisation in the basaltic glasses have been obtained...... by varying the temperature of heat treatment. The change of the relative degree of crystallisation with the heat treatment temperature can be described by an empirical model established in this work. The predominant crystalline phase in the glass has been identified as the pyroxene augite. The hardness...... principle calculations. It is found that the hardness of the glass phase decreases slightly with an increase in the degree of crystallisation, while that of the augite phase drastically decreases....
Unitarized model of inclusive and diffractive DIS with Q2 evolution

International Nuclear Information System (INIS)

Armesto, Nestor; Salgado, Carlos A.; Tywoniuk, Konrad; Kaidalov, Alexei B.

2010-01-01

We discuss the interplay of low-x physics and QCD scaling violations by extending the unified approach describing inclusive structure functions and diffractive production in γ*p interactions proposed in previous papers to large values of Q 2 . We describe the procedure of extracting, from the nonperturbative model, initial conditions for the QCD evolution that respect unitarity. Assuming Regge factorization of the diffractive structure function, a similar procedure is proposed for the calculation of hard diffraction. The results are in good agreement with experimental data on the proton structure function F 2 and the most recent data on the reduced diffractive cross section, x P σ r D(3) . Predictions for both F 2 and F L are presented in a wide kinematical range and compared to calculations within high-energy QCD.

Hardness of high-pressure high-temperature treated single-walled carbon nanotubes

International Nuclear Information System (INIS)

Kawasaki, S.; Nojima, Y.; Yokomae, T.; Okino, F.; Touhara, H.

2007-01-01

We have performed high-pressure high-temperature (HPHT) treatments of high quality single-walled carbon nanotubes (SWCNTs) over a wide pressure-temperature range up to 13 GPa-873 K and have investigated the hardness of the HPHT-treated SWCNTs using a nanoindentation technique. It was found that the hardness of the SWCNTs treated at pressures greater than 11 GPa and at temperatures higher than 773 K is about 10 times greater than that of the SWCNTs treated at low temperature. It was also found that the hardness change of the SWCNTs is related to the structural change by the HPHT treatments which was based on synchrotron X-ray diffraction measurements
Trapezoidal diffraction grating beam splitters in single crystal diamond

Science.gov (United States)

Kiss, Marcell; Graziosi, Teodoro; Quack, Niels

2018-02-01

Single Crystal Diamond has been recognized as a prime material for optical components in high power applications due to low absorption and high thermal conductivity. However, diamond microstructuring remains challenging. Here, we report on the fabrication and characterization of optical diffraction gratings exhibiting a symmetric trapezoidal profile etched into a single crystal diamond substrate. The optimized grating geometry diffracts the transmitted optical power into precisely defined proportions, performing as an effective beam splitter. We fabricate our gratings in commercially available single crystal CVD diamond plates (2.6mm x 2.6mm x 0.3mm). Using a sputter deposited hard mask and patterning by contact lithography, the diamond is etched in an inductively coupled oxygen plasma with zero platen power. The etch process effectively reveals the characteristic {111} diamond crystal planes, creating a precisely defined angled (54.7°) profile. SEM and AFM measurements of the fabricated gratings evidence the trapezoidal shape with a pitch of 3.82μm, depth of 170 nm and duty cycle of 35.5%. Optical characterization is performed in transmission using a 650nm laser source perpendicular to the sample. The recorded transmitted optical power as function of detector rotation angle shows a distribution of 21.1% in the 0th order and 23.6% in each +/-1st order (16.1% reflected, 16.6% in higher orders). To our knowledge, this is the first demonstration of diffraction gratings with trapezoidal profile in single crystal diamond. The fabrication process will enable beam splitter gratings of custom defined optical power distribution profiles, while antireflection coatings can increase the efficiency.
Bainitic transformation behavior studied by simultaneous neutron diffraction and dilatometric measurement

International Nuclear Information System (INIS)

Koo, Minseo; Xu, Pingguang; Tomota, Yo; Suzuki, Hiroshi

2009-01-01

Bainitic transformation behavior has firstly been observed using in situ neutron diffraction with an angular dispersive method for a hard bainite steel. The dilatometric measurement was carried out simultaneously with the neutron experiment where changes in (1 1 1) austenite and (1 1 0) ferrite diffraction profiles were monitored during heating, cooling and holding at a transformation temperature. The neutron experiments results agree with dilatometry results. They appear to have found that the austenite peak broadening occurs after the onset of bainitic transformation but not before.
Resummation of the QCD perturbative series for hard processes

International Nuclear Information System (INIS)

Catani, S.

1989-01-01

We study the region of inhibited radiation in hard hadronic processes, as for jet cross sections and heavy flavour production near threshold. The cases of deep inelastic scattering and Drell-Yan annihilation are explicitly considered. A general method to exponentiate leading and next-to-leading logarithms to all orders in perturbation theory is developed. A complete formula for the large N-moments is given and shown to agree with previous two-loop calculations. The resummation procedure suggests how to connect the perturbative and nonperturbative regions. The natural limit within the perturbative phase is shown to be the intrinsic transverse momentum. (orig.)
Diffractive optics for industrial and commercial applications

Energy Technology Data Exchange (ETDEWEB)

Turunen, J. [Joensuu Univ. (Finland); Wyrowski, F. [eds.] [Jena Univ. (Germany)

1997-12-31

The following topics were dealt with: diffractive optics, diffraction gratings, optical system design with diffractive optics, continuous-relief diffractive lenses and microlens arrays, diffractive bifocal intraocular lenses, diffractive laser resonators, diffractive optics for semiconductor lasers, diffractive elements for optical image processing, photorefractive crystals in optical measurement systems, subwavelenth-structured elements, security applications, diffractive optics for solar cells, holographic microlithography. 999 refs.
The radial hardness-profile and the microstructure of railroad car axle materials treated by surface rolling, determined by novel examination methods

International Nuclear Information System (INIS)

Berecz, Tibor; Balogh, Levente; Mészáros, István; Steinbach, Ágoston

2014-01-01

Surface rolling is a cold-working technique used for hardening the surface of steel and ductile cast iron components. This process increases the surface hardness and improves the fatigue properties of components, so it is commonly used to treat railroad car wheel axles. The present paper examines the influence of this surface strengthening technique on the microstructure of the railroad car wheel axle material by hardness tests, optical microscopy (OM), and other novel examination methods, such as scanning electron microscopy (SEM), X-ray line profile analysis (XLPA), non-destructive magnetic evaluation (NDE) and automated electron backscatter diffraction (EBSD). The results show that surface rolling causes an increase in hardness down to a depth of ∼10 mm. It is also shown, that the increase in hardness is not due to grain refinement or change in grain morphology; thus it is likely to be caused by an increase in dislocation density
The radial hardness-profile and the microstructure of railroad car axle materials treated by surface rolling, determined by novel examination methods

Energy Technology Data Exchange (ETDEWEB)

Berecz, Tibor, E-mail: berecz@eik.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary); Balogh, Levente, E-mail: levente@metal.elte.hu [Department of Materials Physics, Eötvös Loránd University, 1117 Budapest, Pázmány Péter sétány 1/a (Hungary); Mészáros, István, E-mail: meszaros@eik.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary); Steinbach, Ágoston, E-mail: sa984@hszk.bme.hu [Department of Materials Science and Engineering, Budapest University of Technology and Economics, 1111 Budapest, Bertalan Lajos utca 7 (Hungary)

2014-01-13

Surface rolling is a cold-working technique used for hardening the surface of steel and ductile cast iron components. This process increases the surface hardness and improves the fatigue properties of components, so it is commonly used to treat railroad car wheel axles. The present paper examines the influence of this surface strengthening technique on the microstructure of the railroad car wheel axle material by hardness tests, optical microscopy (OM), and other novel examination methods, such as scanning electron microscopy (SEM), X-ray line profile analysis (XLPA), non-destructive magnetic evaluation (NDE) and automated electron backscatter diffraction (EBSD). The results show that surface rolling causes an increase in hardness down to a depth of ∼10 mm. It is also shown, that the increase in hardness is not due to grain refinement or change in grain morphology; thus it is likely to be caused by an increase in dislocation density.
The underlying event in hard scattering processes

International Nuclear Information System (INIS)

Field, R.

2002-01-01

The authors study the behavior of the underlying event in hard scattering proton-antiproton collisions at 1.8 TeV and compare with the QCD Monte-Carlo models. The underlying event is everything except the two outgoing hard scattered jets and receives contributions from the beam-beam remnants plus initial and final-state radiation. The data indicate that neither ISAJET or HERWIG produce enough charged particles (with p T > 0.5 GeV/c) from the beam-beam remnant component and that ISAJET produces too many charged particles from initial-state radiation. PYTHIA which uses multiple parton scattering to enhance the underlying event does the best job describing the data
Studies of semi-inclusive and hard exclusive processes at Jlab

International Nuclear Information System (INIS)

Harutyun Avagyan

2008-01-01

The main goal of experiments proposed for the CLAS12 detector in conjunction with the 12-GeV CEBAF accelerator is the study of the nucleon through hard exclusive, semi-inclusive, and inclusive processes. This will provide new insights into nucleon dynamics at the elementary quark and gluon level. In this contribution we provide an overview of ongoing studies of the structure of nucleon in terms of quark and gluon degrees of freedom and future physics program planned with CLAS and CLAS12
Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel

Science.gov (United States)

Liu, Hanghang; Fu, Paixian; Liu, Hongwei; Li, Dianzhong

2018-01-01

The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron back-scattered diffraction (EBSD). The mechanical properties were compared by tensile, Charpy U-notch impact and hardness uniformity tests at room temperature. The results showed that the test steels after normalizing-quenching-tempering (N-QT) possessed the best strength-toughness combination and hardness uniformity compared with the conventional quenched-tempered (QT) steel. In addition, the test steel after austempering-tempering (A-T) demonstrated the worse hardness uniformity and lower yield strength while possessing relatively higher elongation (17%) compared with the samples after N-QT (14.5%) treatments. The better ductility of A-T steel mainly depended on the amount and morphology of retained austenite and thermal/deformation-induced twined martensite. This work elucidates the mechanisms of microstructure evolution during heat treatments and will highly improve the strength-toughness-hardness trade-off in large cross-section steels. PMID:29642642
Improvement of Strength-Toughness-Hardness Balance in Large Cross-Section 718H Pre-Hardened Mold Steel

Directory of Open Access Journals (Sweden)

Hanghang Liu

2018-04-01

Full Text Available The strength-toughness combination and hardness uniformity in large cross-section 718H pre-hardened mold steel from a 20 ton ingot were investigated with three different heat treatments for industrial applications. The different microstructures, including tempered martensite, lower bainite, and retained austenite, were obtained at equivalent hardness. The microstructures were characterized by using metallographic observations, scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and electron back-scattered diffraction (EBSD. The mechanical properties were compared by tensile, Charpy U-notch impact and hardness uniformity tests at room temperature. The results showed that the test steels after normalizing-quenching-tempering (N-QT possessed the best strength-toughness combination and hardness uniformity compared with the conventional quenched-tempered (QT steel. In addition, the test steel after austempering-tempering (A-T demonstrated the worse hardness uniformity and lower yield strength while possessing relatively higher elongation (17% compared with the samples after N-QT (14.5% treatments. The better ductility of A-T steel mainly depended on the amount and morphology of retained austenite and thermal/deformation-induced twined martensite. This work elucidates the mechanisms of microstructure evolution during heat treatments and will highly improve the strength-toughness-hardness trade-off in large cross-section steels.
IOTA: integration optimization, triage and analysis tool for the processing of XFEL diffraction images.

Science.gov (United States)

Lyubimov, Artem Y; Uervirojnangkoorn, Monarin; Zeldin, Oliver B; Brewster, Aaron S; Murray, Thomas D; Sauter, Nicholas K; Berger, James M; Weis, William I; Brunger, Axel T

2016-06-01

Serial femtosecond crystallography (SFX) uses an X-ray free-electron laser to extract diffraction data from crystals not amenable to conventional X-ray light sources owing to their small size or radiation sensitivity. However, a limitation of SFX is the high variability of the diffraction images that are obtained. As a result, it is often difficult to determine optimal indexing and integration parameters for the individual diffraction images. Presented here is a software package, called IOTA , which uses a grid-search technique to determine optimal spot-finding parameters that can in turn affect the success of indexing and the quality of integration on an image-by-image basis. Integration results can be filtered using a priori information about the Bravais lattice and unit-cell dimensions and analyzed for unit-cell isomorphism, facilitating an improvement in subsequent data-processing steps.
Parton saturation and $N_{part}$ scaling of semi-hard processes in QCD

CERN Document Server

Kharzeev, Dima E; McLerran, L; 10.1016/S0370-2693(03)00420-9

2003-01-01

We argue that the suppression of high p/sub t/ hadrons discovered recently in heavy ion collisions at RHIC may be a consequence of saturation in the color glass condensate. We qualitatively and semi- quantitatively describe the data, in particular, the dependence upon the number of nucleon participants. We show that if parton saturation sets in at sufficiently small energy, then in nucleus-nucleus collisions at RHIC and LHC energies the cross sections of semi-hard processes should scale approximately with the number of participants, N/sub part/. Our results provide a possible explanation of both the absence of apparent jet quenching at SPS energies and its presence at RHIC. Under the same assumption we predict that in semi-central and central pA (dA) collisions at collider energies the dependence of semi-hard processes on the number of participating nucleons of the nucleus will change to ~(N/sub part//sup A/)/sup 1/2/. The forthcoming data on dA collisions will provide a crucial test of this description. (61 ...
Diffraction efficiency enhancement of femtosecond laser-engraved diffraction gratings due to CO2 laser polishing

International Nuclear Information System (INIS)

Choi, Hun-Kook; Jung, Deok; Sohn, Ik-Bu; Noh, Young-Chul; Lee, Yong-Tak; Kim, Jin-Tae; Ahsan, Shamim

2014-01-01

This research demonstrates laser-assisted fabrication of high-efficiency diffraction gratings in fused-silica glass samples. Initially, femtosecond laser pulses are used to engrave diffraction gratings on the glass surfaces. Then, these micro-patterned glass samples undergo CO 2 laser polishing process. unpolished diffraction gratings encoded in the glass samples show an overall diffraction efficiency of 18.1%. diffraction gratings imprinted on the glass samples and then polished four times by using a CO 2 laser beam attain a diffraction efficiency of 32.7%. We also investigate the diffraction patterns of the diffraction gratings encoded on fused-silica glass surfaces. The proposed CO 2 laser polishing technique shows great potential in patterning high-efficiency diffraction gratings on the surfaces of various transparent materials.
Prediction of hardness for Al-Cu-Zn alloys in as-cast and quenching conditions

International Nuclear Information System (INIS)

Villegas-Cardenas, J. D.; Saucedo-Munoz, M. L.; Lopez-Hirata, V. M.; Dorantes Rosales, H. J.

2014-01-01

This work presents a new experimental and numerical methodology in order to predict the hardness in the as-cast, and solution treated and quenched Al-Cu-Zn alloys. Chemical composition of alloys is located inside two straight lines represented by two equations. Eight different compositions were selected from each line. All the alloys were characterized for light microscope, scanning electron microscope, X-ray diffraction and Rockwell B hardness test. The equilibrium phases were obtained at different temperatures by Thermo-Calc. The microstructure characterization and regression analysis enabled to determine the phase transformations and two equations of hardness assessment. The combination of hardness equations and composition line equations permitted to estimate the hardness of any alloy composition inside this zone. This was verified by calculating hardness with the information reported in other works, with an error lower than 7% in the estimated hardness. (Author)
Studies of diffraction with the ATLAS detector

International Nuclear Information System (INIS)

Trzebinski, Maciej

2013-01-01

The thesis is devoted to the study of diffractive physics with the ATLAS detector at the LHC. After a short introduction to diffractive physics including soft and hard diffraction, we discuss Jet-Gap-Jet production at the LHC which is particularly interesting for testing the Balitski Fadin Kuraev Lipatov QCD evolution equation. Using the signal selection requirements and a gap definition based on tracks reconstructed in the ATLAS Inner Detector, we observe a clear signal of Jet-Gap-Jet events in the data. Starting from the half-gap size of 0.8 the data cannot be properly described using only the Jet Monte Carlo sample without gaps. Furthermore, we demonstrated that DPE JGJ production, with both protons tagged in the AFP stations, should provide a significant test of the BFKL theory, once the 300 pb -1 of integrated luminosity is collected. In the last part of the thesis, we discussed the processes of Central Exclusive Jet and Exclusive π + π - production. After the data selection, the signal to background ratio is found to be of about 5/9 (1/13) for μ= 23 (46). For a collected integrated luminosity of 40(300) fb -1 (for pile-up of 23(46)) this measurement will deliver ten times better constraints on the theoretical models than the most recent ones. The additional measurement of exclusive pion production, relying on the use of the ALFA stations, allows to constrain further the exclusive models. We demonstrated that a data sample collected by the ALFA detectors should be sufficient to measure the cross section and to study various distributions, especially the invariant mass of the pion-pion system. (author) [fr
Studies of the process of an unsteady formation of hard nitride coatings in an arc plasma flow

International Nuclear Information System (INIS)

Zake, M.

1996-01-01

The kinetic studies of an unsteady formation of hard ZrN and TiN coatings on the surface of metallic (Zr, Ti) samples in an Ar-N plasma flow are carried out. The obtained result is that at the initial stage of an unsteady heating of titanium samples nitrogen atoms penetrate into metal lattice and form interstitial compounds of hard nitrogen solutions in α-phase of Ti. This process is followed by a growth of thin surface layers of titanium nitrides with subsequent changes of surface radiance of exposed samples. Unsteady formation of ZrN is a similar two-stage process which includes the ZrN film growth and formation of a α-hard solution with subsequent changes of total normal emissivity of the surface. (author). 1 ref., 1 fig
Grey signal processing and data reconstruction in the non-diffracting beam triangulation measurement system

Science.gov (United States)

Meng, Hao; Wang, Zhongyu; Fu, Jihua

2008-12-01

The non-diffracting beam triangulation measurement system possesses the advantages of longer measurement range, higher theoretical measurement accuracy and higher resolution over the traditional laser triangulation measurement system. Unfortunately the measurement accuracy of the system is greatly degraded due to the speckle noise, the CCD photoelectric noise and the background light noise in practical applications. Hence, some effective signal processing methods must be applied to improve the measurement accuracy. In this paper a novel effective method for removing the noises in the non-diffracting beam triangulation measurement system is proposed. In the method the grey system theory is used to process and reconstruct the measurement signal. Through implementing the grey dynamic filtering based on the dynamic GM(1,1), the noises can be effectively removed from the primary measurement data and the measurement accuracy of the system can be improved as a result.
A Demonstrator Analog Signal Processing Circuit in a Radiation Hard SOI-CMOS Technology

CERN Multimedia

2002-01-01

% RD-9 A Demonstrator Analog Signal Processing Circuit in a Radiation Hard SOI-CMOS Technology \\\\ \\\\Radiation hardened SOI-CMOS (Silicon-On-Insulator, Complementary Metal-Oxide- \\linebreak Semiconductor planar microelectronic circuit technology) was a likely candidate technology for mixed analog-digital signal processing electronics in experiments at the future high luminosity hadron colliders. We have studied the analog characteristics of circuit designs realized in the Thomson TCS radiation hard technologies HSOI3-HD. The feature size of this technology was 1.2 $\\mu$m. We have irradiated several devices up to 25~Mrad and 3.10$^{14}$ neutrons cm$^{-2}$. Gain, noise characteristics and speed have been measured. Irradiation introduces a degradation which in the interesting bandwidth of 0.01~MHz~-~1~MHz is less than 40\\%. \\\\ \\\\Some specific SOI phenomena have been studied in detail, like the influence on the noise spectrum of series resistence in the thin silicon film that constitutes the body of the transistor...
The impact of the manufacturing process on the hardness and sensory properties of milk chocolate

Directory of Open Access Journals (Sweden)

Zarić Danica B.

2012-01-01

Full Text Available The aim of this paper was to examine the impact of the manufacturing process on the textural characteristics and sensory properties of milk chocolate. The research was conducted on the samples of chocolate produced in a ball mill during 30, 60 and 90 minutes of refining, each of them being pre-crystallized at 26, 28 and 30°C. A chocolate mass of identical ingredient composition was also produced using a standard manufacturing process at the same pre-crystallization temperatures. Chocolate hardness was examined using a piece of equipment called Texture Analyser, measuring the stress intensity which leads to chocolate crushing. Sensory analysis was performed using the point scoring method. The new manufacturing process, i.e. the manufacturing of chocolate in a ball mill improves sensory properties and hardness of milk chocolate. [Projekat Ministarstva nauke Republike Srbije, br. TR 31014

Deformation processes in functional materials studied by in situ neutron diffraction and ultrasonic techniques

International Nuclear Information System (INIS)

Sittner, P.; Novak, V.; Landa, M.; Lukas, P.

2007-01-01

The unique thermomechanical functions of shape memory alloys (hysteretic stress-strain-temperature responses) not their structural properties (as strength, fatigue, corrosion resistance, etc.) are primarily utilized in engineering applications. In order to better understand and predict the functional behavior, we have recently employed two dedicated non-invasive in situ experimental methods capable to follow the deformation/transformation processes in thermomechanically loaded polycrystalline samples. The in situ neutron diffraction method takes advantage of the ability of thermal neutrons to penetrate bulk samples. As a diffraction technique sensitive to interplanar spacings in crystalline solids, it provides in situ information on the changes in crystal structure, phase composition, phase stress and texture in the transforming samples. The combined in situ ultrasonic and electric resistance method follows variations of the electric resistance as well as speed and attenuation of acoustic waves propagating through the transforming sample. The acoustic waves are mainly sensitive to changes of elastic properties accompanying the deformation/transformation processes. The latter method thus follows the changes in interatomic bonds rather than changes in the interplanar lattice spacings focused in the neutron diffraction method. The methods are thus complementary. They are briefly described and selected experimental results obtained recently on NiTi alloys are presented and discussed
Low energy positron diffraction from Cu(111): Importance of surface loss processes at large angles of incidence

International Nuclear Information System (INIS)

Lessor, D.L.; Duke, C.B.; Lippel, P.H.; Brandes, G.R.; Canter, K.F.; Horsky, T.N.

1990-10-01

Intensities of positrons specularly diffracted from Cu(111) were measured at the Brandeis positron beam facility and analyzed in the energy range 8eV i = 4eV. At lower energies strong energy dependences occur associated both with multiple elastic scattering phenomena within atomic layers of Cu parallel to the surface and with the thresholds of inelastic channels (e.g., plasmon creation). Use of the free electron calculation of V i shows that energy dependence of inelastic processes is necessary to obtain a satisfactory description of the absolute magnitude of the diffracted intensities below E = 50eV. Detailed comparison of the calculated and observed diffraction intensities reveals the necessity of incorporating surface loss processes explicitly into the model in order to achieve a quantitative description of the measured intensities for E 40 degree. 30 refs., 5 figs., 1 tab
Tuning hardness in calcite by incorporation of amino acids.

Science.gov (United States)

Kim, Yi-Yeoun; Carloni, Joseph D; Demarchi, Beatrice; Sparks, David; Reid, David G; Kunitake, Miki E; Tang, Chiu C; Duer, Melinda J; Freeman, Colin L; Pokroy, Boaz; Penkman, Kirsty; Harding, John H; Estroff, Lara A; Baker, Shefford P; Meldrum, Fiona C

2016-08-01

Structural biominerals are inorganic/organic composites that exhibit remarkable mechanical properties. However, the structure-property relationships of even the simplest building unit-mineral single crystals containing embedded macromolecules-remain poorly understood. Here, by means of a model biomineral made from calcite single crystals containing glycine (0-7 mol%) or aspartic acid (0-4 mol%), we elucidate the origin of the superior hardness of biogenic calcite. We analysed lattice distortions in these model crystals by using X-ray diffraction and molecular dynamics simulations, and by means of solid-state nuclear magnetic resonance show that the amino acids are incorporated as individual molecules. We also demonstrate that nanoindentation hardness increased with amino acid content, reaching values equivalent to their biogenic counterparts. A dislocation pinning model reveals that the enhanced hardness is determined by the force required to cut covalent bonds in the molecules.
The influence of milling-burnishing successive and simultaneous processes on the material hardness

Science.gov (United States)

Grigoraş, C. C.; Brabie, G.; Chirita, B.

2016-08-01

Recent developments in the field of bio-engineering allow the use of magnesium alloys as a substitute for medical implants. The issue with such alloys is the degradation rate witch has to be improved in order to provide the necessary support for the entire duration of the bone fraction healing. For improving the bone shielding heat treatment does not represent a solution, but chemical and/or mechanical do. One mechanical process that has excellent result is burnishing, but this process is difficult to be implemented on a milling machine. Therefore, it was necessary that a new tool and tool holder to be developed, that allow the simultaneous process to take place. A high-pressure hydraulic roller burnishing tool with a special tool holder was used on a CNC milling machine. The material used for this study is magnesium alloy AZ31B-F, and one of the main purposes was to improve the material hardness (HV). The milling-burnishing parameters that where varied are the speed and feed, burnishing pressure and depth, type of process (successive or simultaneous), machining direction and the material hardness after milling. The results were analyzed as percentage improvement between the milling and burnishing measured values.
Characterization of Transition Metal Carbide Layers Synthesized by Thermo-reactive Diffusion Processes

DEFF Research Database (Denmark)

Laursen, Mads Brink; Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin

2015-01-01

. In this study halide-activated pack cementation techniques were used on tool steel Vanadis 6 and martensitic stainless steel AISI 420 in order to produce hard layers of titanium carbide (TiC), vanadium carbide (V8C7) and chromium carbides (Cr23C6 and Cr7C3). Surface layers were characterized by scanning......Hard wear resistant surface layers of transition metal carbides can be produced by thermo-reactive diffusion processes where interstitial elements from a steel substrate together with external sources of transition metals (Ti, V, Cr etc.) form hard carbide and/or nitride layers at the steel surface...... electron microscopy, X-ray diffraction and Vickers hardness testing. The study shows that porosityfree, homogenous and very hard surface layers can be produced by thermo-reactive diffusion processes. The carbon availability of the substrate influences thickness of obtained layers, as Vanadis 6 tool steel...
Diffraction efficiency enhancement of femtosecond laser-engraved diffraction gratings due to CO{sub 2} laser polishing

Energy Technology Data Exchange (ETDEWEB)

Choi, Hun-Kook [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Chosun University, Gwangju (Korea, Republic of); Jung, Deok; Sohn, Ik-Bu; Noh, Young-Chul; Lee, Yong-Tak [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Kim, Jin-Tae [Chosun University, Gwangju (Korea, Republic of); Ahsan, Shamim [Khulna University, Khulna (Bangladesh)

2014-11-15

This research demonstrates laser-assisted fabrication of high-efficiency diffraction gratings in fused-silica glass samples. Initially, femtosecond laser pulses are used to engrave diffraction gratings on the glass surfaces. Then, these micro-patterned glass samples undergo CO{sub 2} laser polishing process. unpolished diffraction gratings encoded in the glass samples show an overall diffraction efficiency of 18.1%. diffraction gratings imprinted on the glass samples and then polished four times by using a CO{sub 2} laser beam attain a diffraction efficiency of 32.7%. We also investigate the diffraction patterns of the diffraction gratings encoded on fused-silica glass surfaces. The proposed CO{sub 2} laser polishing technique shows great potential in patterning high-efficiency diffraction gratings on the surfaces of various transparent materials.
Hard synchrotron radiation scattering from a nonideal surface grating from multilayer X-ray mirrors

International Nuclear Information System (INIS)

Punegov, V.I.; Nesterets, Ya.I.; Mytnichenko, S.V.; Kovalenko, N.V.; Chernov, V.A.

2003-01-01

The hard synchrotron radiation scattering from a multilayer surface grating is theoretically and experimentally investigated. The numerical calculations of angular distribution of scattering intensity from X-ray mirror Ni/C are executed with use of recurrence formulae and statistical dynamical theory of diffraction. It is shown, that the essential role in formation of a diffraction pattern plays a diffuse scattering caused by structure imperfection of a multilayer grating [ru
Hard and soft processes in small p/sub T/ inclusive reactions

Energy Technology Data Exchange (ETDEWEB)

Kanki, T [Osaka Univ., Toyonaka (Japan). Coll. of General Education; Okamoto, Y; Ryang, S

1977-12-01

Small p/sub T/ inclusive single-hadron spectra in high-energy hadron-hadron collisions are discussed in view of the two-component structure; each component corresponds to the contribution from the incoherent hard process or the coherent soft process among the partons. The clustered parton model, where each constituent quark is considered a cluster of the partons, gives the theoretical basis and certain regularities for both components. The various experimental spectra are shown to be well described by the two-component formula with these regularities. It is also argued that the CIM approach to small p sub(T) shows some disagreement with the data.
Status and Prospects of measurements of exclusive and diffractive processes with the ATLAS detector

CERN Document Server

Foster, Andrew Geoffrey; The ATLAS collaboration

2018-01-01

In the absence of forward proton tagging, exclusive processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been exploited to study the exclusive production of dilepton pairs in the data taken at centre-of-mass energies of 7 TeV and the exclusive production of W pairs in the 8 TeV data. We also present the latest results on exclusive dimuon production at 13 TeV. Moreover, the ATLAS collaboration has carried out a study of diffractive dijet production. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. The talk will conclude with prospects of the upcoming physics program with the Atlas Forward Proton detector. Recent results demonstrate its capabilities to distinguish single diffractive events via forward proton...
Apparatus and process for deposition of hard carbon films

Science.gov (United States)

Nyaiesh, Ali R.; Garwin, Edward L.

1989-01-03

A process and an apparatus for depositing thin, amorphous carbon films having extreme hardness on a substrate is described. An enclosed chamber maintained at less than atmospheric pressure houses the substrate and plasma producing elements. A first electrode is comprised of a cavity enclosed within an RF coil which excites the plasma. A substrate located on a second electrode is excited by radio frequency power applied to the substrate. A magnetic field confines the plasma produced by the first electrode to the area away from the walls of the chamber and focuses the plasma onto the substrate thereby yielding film deposits having higher purity and having more rapid buildup than other methods of the prior art.
Texture analysis of a friction stir processed 6061-T6 aluminum alloy using neutron diffraction

International Nuclear Information System (INIS)

Woo, W.; Choo, H.; Brown, D.W.; Vogel, S.C.; Liaw, P.K.; Feng, Z.

2006-01-01

Time-of-flight neutron diffraction was used to investigate the texture changes in friction stir-processed (FSP) 6061-T6 aluminum alloy plates. Two different specimens were prepared with the purpose of separating the effects of frictional heating and severe plastic deformation on the changes of the preferred orientation in the as-received rolled plates: a plate processed with both stirring pin and tool shoulder, i.e., a regular FSP plate subjected to both severe plastic deformation and frictional heating (Case 1); and a plate processed only with the tool shoulder, i.e., subjected mainly to frictional heating (Case 2). The diffraction peak intensities provide insights into the texture variations at various locations across the centerline and through the thickness of the FSP plates. Comparison of the texture variations between Cases 1 and 2 clearly shows that the severe plastic deformation from the stirring pin affects the preferred orientation during the FSP, while heating alone from the tool shoulder has little effect
A Radiation-Hard Analog Memory In The AVLSI-RA Process

International Nuclear Information System (INIS)

Britton, C.L. Jr.; Wintenberg, A.L.; Read, K.F.; Simpson, M.L.; Young, G.R.; Clonts, L.G.; Kennedy, E.J.; Smith, R.S.; Swann, B.K.; Musser, J.A.

1995-01-01

A radiation hardened analog memory for an Interpolating Pad Camber has been designed at Oak Ridge National Laboratory and fabricated by Harris Semiconductor in the AVLSI-RA CMOS process. The goal was to develop a rad-hard analog pipeline that would deliver approximately 9-bit performance, a readout settling time of 500ns following read enable, an input and output dynamic range of +/-2.25V, a corrected rms pedestal of approximately 5mV or less, and a power dissipation of less than 10mW/channel. The pre- and post-radiation measurements to 5MRad are presented
Production of hard hydrophilic Ni-B coatings on hydrophobic Ni-Ti and Ti-6Al-4V alloys by electroless deposition

Energy Technology Data Exchange (ETDEWEB)

Buelbuel, Ferhat; Karabudak, Filiz; Yesildal, Ruhi [Ataturk Univ., Erzurum (Turkey). Mechanical Engineering Dept.

2017-07-01

This paper is mainly focused on the wetting state of liquid droplets on Ni-Ti and Ti-6Al-4V hierarchical structured hydrophobic surfaces in micro/nanoscale. Electroless Ni-B deposition as a surface coating treatment has recently drawn considerable attention of researchers owing to remarkable advantages when compared with other techniques such as low price, conformal ability to coat substrates, good bath stability and relatively easier plating process control. The Ni-Ti and Ti-6Al-4V substrates were plated by electroless Ni-B plating process. The coated films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), hardness testing and static contact angle measurement. Results obtained from the analyses show that electroless Ni-B deposition may improve the hardness and wettability of the Ni-Ti and Ti-6Al-4V alloy surfaces.
Work Hardening, Dislocation Structure, and Load Partitioning in Lath Martensite Determined by In Situ Neutron Diffraction Line Profile Analysis

Science.gov (United States)

Harjo, Stefanus; Kawasaki, Takuro; Tomota, Yo; Gong, Wu; Aizawa, Kazuya; Tichy, Geza; Shi, Zengmin; Ungár, Tamas

2017-09-01

A lath martensite steel containing 0.22 mass pct carbon was analyzed in situ during tensile deformation by high-resolution time-of-flight neutron diffraction to clarify the large work-hardening behavior at the beginning of plastic deformation. The diffraction peaks in plastically deformed states exhibit asymmetries as the reflection of redistributions of the stress and dislocation densities/arrangements in two lath packets: soft packet, where the dislocation glides are favorable, and hard packet, where they are unfavorable. The dislocation density was as high as 1015 m-2 in the as-heat-treated state. During tensile straining, the load and dislocation density became different between the two lath packets. The dislocation character and arrangement varied in the hard packet but hardly changed in the soft packet. In the hard packet, dislocations that were mainly screw-type in the as-heat-treated state became primarily edge-type and rearranged towards a dipole character related to constructing cell walls. The hard packet played an important role in the work hardening in martensite, which could be understood by considering the increase in dislocation density along with the change in dislocation arrangement.
The automation of the "making safe" process in South African hard-rock underground mine

CSIR Research Space (South Africa)

Teleka, SR

2011-07-01

Full Text Available In South African hard-rock mines, best practice dictates that the hanging-walls be inspected after blasting. This process is known as ‘making safe’ and although intended to save lives, it is laborious and subjective. Pressure is placed on the barrer...
Structure changes in steels and hard metal induced by nanosecond and femtosecond laser processing

Science.gov (United States)

Dumitru, Gabriel; Romano, Valerio; Weber, Heinz P.; Haefke, Henry; Gerbig, Yvonne; Sentis, Marc L.; Hermann, Joerg; Bruneau, Sebastien

2003-11-01

Investigations on the occurrence of structure and hardness changes (for two sorts of steel and for a hard metal substrate) in the immediate vicinity of laser induced craters are presented in this work. Experiments with femtosecond pulses were performed in air with a Ti:sapphire laser (800 nm, 100 fs) at mean fluences of 2, 5 and 10 J/cm2. Series of microcraters were induced with 100 to 5,000 laser pulses per hole. Experiments with similar fluences, but 10 to 40 pules per hole, were performed on the same materials using a Nd:YAG delivering 100 ns pulese. After laser irradiation, cuts were made through the processed samples and the changes occurred in the crystalline structure of the target materials were evidenced by metallographical analysis of the resulting cross-sections. Hardness measurements were performed in points situated in the immediate vicinity of the laser-induced pores. Affected zones in the material surrounding laser induced pores were always found in the ns-regime, however with different properties for various laser parameters. In the fs-regime, zones of modified materials were also found and in such zones a significant hardness increasing was evidenced; the limit of the low fluences regime, where no structure changes occurred, was found to be slightly above 2 J/cm2.
Reliability evaluation of hard disk drive failures based on counting processes

International Nuclear Information System (INIS)

Ye, Zhi-Sheng; Xie, Min; Tang, Loon-Ching

2013-01-01

Reliability assessment for hard disk drives (HDDs) is important yet difficult for manufacturers. Motivated by the fact that the particle accumulation in the HDDs, which accounts for most HDD catastrophic failures, is contributed from the internal and external sources, a counting process with two arrival sources is proposed to model the particle cumulative process in HDDs. This model successfully explains the collapse of traditional ALT approaches for accelerated life test data. Parameter estimation and hypothesis tests for the model are developed and illustrated with real data from a HDD test. A simulation study is conducted to examine the accuracy of large sample normal approximations that are used to test existence of the internal and external sources.
Work Hard / Play Hard

OpenAIRE

Burrows, J.; Johnson, V.; Henckel, D.

2016-01-01

Work Hard / Play Hard was a participatory performance/workshop or CPD experience hosted by interdisciplinary arts atelier WeAreCodeX, in association with AntiUniversity.org. As a socially/economically engaged arts practice, Work Hard / Play Hard challenged employees/players to get playful, or go to work. 'The game changes you, you never change the game'. Employee PLAYER A 'The faster the better.' Employer PLAYER B
Tests of QCD factorisation in the diffractive production of dijets in deep-inelastic scattering and photoproduction at HERA

Science.gov (United States)

Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Beckingham, M.; Begzsuren, K.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cantun Avila, K. B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J. G.; Coughlan, J. A.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; de Roeck, A.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Eliseev, A.; Elsen, E.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Flucke, G.; Fomenko, A.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Habib, S.; Haidt, D.; Hansson, M.; Heinzelmann, G.; Helebrant, C.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Jacquet, M.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Landon, M. P. J.; Lange, W.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, L.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, T.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Plačakytė, R.; Povh, B.; Prideaux, P.; Rahmat, A. J.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauter, M.; Sauvan, E.; Schätzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smiljanic, I.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Stiewe, J.; Stoilov, A.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Toll, T.; Tomasz, F.; Traynor, D.; Trinh, T. N.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Usik, A.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wissing, C.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

2007-08-01

Measurements are presented of differential dijet cross sections in diffractive photoproduction (Q2<0.01 GeV2) and deep-inelastic scattering processes (DIS, 4diffractive parton densities previously obtained from a QCD analysis of inclusive diffractive DIS cross sections by H1. In DIS, the dijet data are well described, supporting the validity of QCD factorisation. The diffractive DIS dijet data are more sensitive to the diffractive gluon density at high fractional parton momentum than the measurements of inclusive diffractive DIS. In photoproduction, the predicted dijet cross section has to be multiplied by a factor of approximately 0.5 for both direct and resolved photon interactions to describe the measurements. The ratio of measured dijet cross section to NLO prediction in photoproduction is a factor 0.5±0.1 smaller than the same ratio in DIS. This suppression is the first clear observation of QCD hard scattering factorisation breaking at HERA. The measurements are also compared to the two soft colour neutralisation models SCI and GAL. The SCI model describes diffractive dijet production in DIS but not in photoproduction. The GAL model fails in both kinematic regions.
Non destructive evaluation of residual stresses in welding and hard-surfacing processes

International Nuclear Information System (INIS)

Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Aragon, B.; Merino, F.

1995-01-01

In this paper transversal and longitudinal stress profiles in welding and hard-surfacing by welding processes are presented. The stresses were measured by RMS of Barkhausen signal. In this work it is shown that in each case the level of stresses is strongly dependent on the number of weld beads of surfacing layers deposited. The subsequent deposition of new weld beads or surfacing layers produces a stress-relieving effect

CMOS optimization for radiation hardness

International Nuclear Information System (INIS)

Derbenwick, G.F.; Fossum, J.G.

1975-01-01

Several approaches to the attainment of radiation-hardened MOS circuits have been investigated in the last few years. These have included implanting the SiO 2 gate insulator with aluminum, using chrome-aluminum layered gate metallization, using Al 2 O 3 as the gate insulator, and optimizing the MOS fabrication process. Earlier process optimization studies were restricted primarily to p-channel devices operating with negative gate biases. Since knowledge of the hardness dependence upon processing and design parameters is essential in producing hardened integrated circuits, a comprehensive investigation of the effects of both process and design optimization on radiation-hardened CMOS integrated circuits was undertaken. The goals are to define and establish a radiation-hardened processing sequence for CMOS integrated circuits and to formulate quantitative relationships between process and design parameters and the radiation hardness. Using these equations, the basic CMOS design can then be optimized for radiation hardness and some understanding of the basic physics responsible for the radiation damage can be gained. Results are presented
Effect of Nb element content in U-Zr-Nb alloy on hardness, microstructure and phase formation

International Nuclear Information System (INIS)

Masrukan; M Husna Al Hasa; Jan Setiawan; Slamet Pribadi

2015-01-01

Experiments to determine the effect of Nb element in the U-Zr alloys on hardness, microstructure and phase formation has been done. The addition of Nb element would effect the hardness, microstructure and phase which formed. The U-Zr-Nb alloy was made with the variation of Nb 2%, 5% and 8% by melting in an electric arc melting furnace that equipped with water cooling and the argon atmosphere. The U-Zr-Nb alloy to be cut divided to some testing, such as hardness test, microstructure, and phase analysis. Hardness testing was done by Vickers hardness testing equipment, microstructure by an optical microscope, and diffraction pattern by XRD and phase analysis was done by GSAS. Hardness testing results showed that the addition of 2% to 5% Nb element in U-Zr alloys will increased in hardness, but the addition of Nb element over 5% the hardness was decreased. Observations the microstructure showed that the addition of 2% to 5% Nb element, grains were formed from fine into coarse. Phase analysis for diffraction pattern showed that the phase changed from αU and γU (Zr,Nb)at 2% Nb to be αU, γU (Zr,Nb) and δ1 (UZr_2) phase at 5% and 8% Nb. Phase changes was followed by changes in its compositions. The composition of αU at 2% Nb was 40% increased to 81% at 5% Nb and decreased to 3.9% at 8% Nb. The composition of γU decreased from 59,86% to 14,91% with increased Nb from 2% to 5% and further increased to 52,74% at 8% Nb. (author)
Undergraduate Experiment with Fractal Diffraction Gratings

Science.gov (United States)

Monsoriu, Juan A.; Furlan, Walter D.; Pons, Amparo; Barreiro, Juan C.; Gimenez, Marcos H.

2011-01-01

We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics…
Investigation of optimal manufacturing process for freeze-dried formulations: Observation of frozen solutions by low temperature X-ray diffraction measurements

International Nuclear Information System (INIS)

Egawa, Hiroaki; Yonemochi, Etsuo; Terada, Katsuhide

2005-01-01

Freeze-drying is used for the production of sterile injections in the pharmaceutical industry. However, most pharmaceutical compounds are obtained as less stable amorphous form. Freeze crystallization by annealing is an effective method for pharmaceutical compounds that fail to crystallize in the freeze-drying process. Crystallization occurs in the frozen solution during the thermal treatment. In order to establish suitable annealing conditions efficiently, it is important to observe the crystallization process directly in the frozen solution. Recently, low temperature X-ray diffraction has been used to observe frozen solutions. In order to investigate the crystallization process kinetically, the temperature of the low temperature X-ray diffraction instrument must be accurately controlled. We calibrated the temperature of X-ray diffraction instrument by measuring eutectic temperatures of solutions for a series of compounds. Each eutectic crystal was observed in frozen solution with ice crystal below the eutectic temperature. Eutectic temperatures were detected by the decrease in diffraction intensity associated with heating from below the eutectic temperature. Good correlation was obtained between values in the literature and experimental values
Bragg concentrators for hard (> 10keV) x-ray astronomy: Status report

DEFF Research Database (Denmark)

Pareschi, G.; Frontera, F.; Pasqualini, G.

1997-01-01

The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. We present recent results obtained from our group regarding the possible use of Bragg-diffraction tec......The use of focusing telescopes in hard X-ray (E > 10 keV) astronomy will provide better flux sensitivity and imaging performances with respect to the direct-viewing detectors, utilized until now. We present recent results obtained from our group regarding the possible use of Bragg...
Fabrication of 200 nanometer period centimeter area hard x-ray absorption gratings by multilayer deposition

Science.gov (United States)

Lynch, S K; Liu, C; Morgan, N Y; Xiao, X; Gomella, A A; Mazilu, D; Bennett, E E; Assoufid, L; de Carlo, F; Wen, H

2012-01-01

We describe the design and fabrication trials of x-ray absorption gratings of 200 nm period and up to 100:1 depth-to-period ratios for full-field hard x-ray imaging applications. Hard x-ray phase-contrast imaging relies on gratings of ultra-small periods and sufficient depth to achieve high sensitivity. Current grating designs utilize lithographic processes to produce periodic vertical structures, where grating periods below 2.0 μm are difficult due to the extreme aspect ratios of the structures. In our design, multiple bilayers of x-ray transparent and opaque materials are deposited on a staircase substrate, and mostly on the floor surfaces of the steps only. When illuminated by an x-ray beam horizontally, the multilayer stack on each step functions as a micro-grating whose grating period is the thickness of a bilayer. The array of micro-gratings over the length of the staircase works as a single grating over a large area when continuity conditions are met. Since the layers can be nanometers thick and many microns wide, this design allows sub-micron grating periods and sufficient grating depth to modulate hard x-rays. We present the details of the fabrication process and diffraction profiles and contact radiography images showing successful intensity modulation of a 25 keV x-ray beam. PMID:23066175
Rapid thermal processing chamber for in-situ x-ray diffraction

International Nuclear Information System (INIS)

Ahmad, Md. Imteyaz; Van Campen, Douglas G.; Yu, Jiafan; Pool, Vanessa L.; Van Hest, Maikel F. A. M.; Toney, Michael F.; Fields, Jeremy D.; Parilla, Philip A.; Ginley, David S.

2015-01-01

Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs −1 , and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi 2 O 3 -SiO 2 glass frit obtained during heating with ramp rates 5 °C s −1 and 100 °C s −1 , revealing numerous phase changes
Process and devices of detection of hard electromagnetic or particle radiations using a superconducting element

International Nuclear Information System (INIS)

Drukier, A.K.; Valette, Claude; Waysand, Georges.

1975-01-01

The invention relates to processes and systems for the detection of hard electromagnetic or particle radiations and the sensors fitted to these systems. 'Hard radiations' means those whose energy is greater than a variable threshold, depending on the applications, but always more than 5 keV. The use of these sensors and the associated systems can therefore be envisaged in radiography and also in emission gammagraphy in the biological, anatomic and medical fields. In these processes, in order to detect a photon or a radiation particle, use is made of the transition phenomenon of a homogeneous grain of superconducting material of the first kind, from the metastable superconducting state to the normal state, under the effect of a photoelectron ejected by the impact of the photon or of the particle on the grain of superconducting material [fr
Grain characterization and milling behaviour of near-isogenic lines differing by hardness.

Science.gov (United States)

Greffeuille, V; Abecassis, J; Rousset, M; Oury, F-X; Faye, A; L'Helgouac'h, C Bar; Lullien-Pellerin, V

2006-12-01

Wheat grain hardness is a major factor affecting the milling behaviour and end-product quality although its exact structural and biochemical basis is still not understood. This study describes the development of new near-isogenic lines selected on hardness. Hard and soft sister lines were characterised by near infrared reflectance (NIR) and particle size index (PSI) hardness index, grain protein content, thousand kernel weight and vitreousness. The milling behaviour of these wheat lines was evaluated on an instrumented micromill which also measures the grinding energy and flour particle size distribution was investigated by laser diffraction. Endosperm mechanical properties were measured using compression tests. Results pointed out the respective effect of hardness and vitreousness on those characteristics. Hardness was shown to influence both the mode of fracture and the mechanical properties of the whole grain and endosperm. Thus, this parameter also acts on milling behaviour. On the other hand, vitreousness was found to mainly play a role on the energy required to break the grain. This study allows us to distinguish between consequences of hardness and vitreousness. Hardness is suggested to influence the adhesion forces between starch granules and protein matrix whereas vitreousness would rather be related to the endosperm microstructure.
Hard coatings

International Nuclear Information System (INIS)

Dan, J.P.; Boving, H.J.; Hintermann, H.E.

1993-01-01

Hard, wear resistant and low friction coatings are presently produced on a world-wide basis, by different processes such as electrochemical or electroless methods, spray technologies, thermochemical, CVD and PVD. Some of the most advanced processes, especially those dedicated to thin film depositions, basically belong to CVD or PVD technologies, and will be looked at in more detail. The hard coatings mainly consist of oxides, nitrides, carbides, borides or carbon. Over the years, many processes have been developed which are variations and/or combinations of the basic CVD and PVD methods. The main difference between these two families of deposition techniques is that the CVD is an elevated temperature process (≥ 700 C), while the PVD on the contrary, is rather a low temperature process (≤ 500 C); this of course influences the choice of substrates and properties of the coating/substrate systems. Fundamental aspects of the vapor phase deposition techniques and some of their influences on coating properties will be discussed, as well as the very important interactions between deposit and substrate: diffusions, internal stress, etc. Advantages and limitations of CVD and PVD respectively will briefly be reviewed and examples of applications of the layers will be given. Parallel to the development and permanent updating of surface modification technologies, an effort was made to create novel characterisation methods. A close look will be given to the coating adherence control by means of the scratch test, at the coating hardness measurement by means of nanoindentation, at the coating wear resistance by means of a pin-on-disc tribometer, and at the surface quality evaluation by Atomic Force Microscopy (AFM). Finally, main important trends will be highlighted. (orig.)
On exact account of heavy quark thresholds in hard processes

International Nuclear Information System (INIS)

Dokshitzer, Yu. L.

1993-01-01

We study the problem to accurately account for the heavy quark threshold effects in hard processes. We employ the direction perturbative Feynman diagram analysis and the Stueckelberg-Bogoliubov massive renormalization group formalism to show that both methods results in the same prescription for the 'physical' mass-dependent QCD effective coupling as an argument of anomalous dimensions that determine the evolution of structure function (parton distributions). By considering the one-loop example, we demonstrate that an intrinsic ambiguity of the standard approach based on the notion of 'effective number of quark flavours' may affect the α s determination at the level of two-loop effects
Hard electronics; Hard electronics

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.
Gluon radiation in diffractive electroproduction

International Nuclear Information System (INIS)

Buchmueller, W.; McDermott, M.F.; Hebecker, A.

1996-07-01

Order α s -correlations to the diffractive structure functions F L D and F 2 D at large Q 2 and small x are evaluated in the semiclassical approach, where the initial proton is treated as a classical colour field. The diffractive final state contains a fast gluon in addition to a quark-antiquark pair. Two of these partons may have large transverse momentum. Our calculations lead to an intuitive picture of deep-inelastic diffractive processes which is very similar to Bjorken's aligned-jet model. Both diffractive structure functions contain leading twist contributions from high-p perpendicular to jets. (orig.)
Effect of ion nitridation process on hardness and the corrosion resistance of biomaterials

International Nuclear Information System (INIS)

Wirjoadi; Lely Susita; Bambang Siswanto; Sudjatmoko

2012-01-01

Ion nitriding process has been performed on metal biomaterials to improve their mechanical properties of materials, particularly to increase hardness and corrosion resistance. This metallic biomaterials used for artificial bone or a prosthetic graft and used as devices of orthopedic biomaterials are usually of 316L SS metal-type and Ti-6Al-4V alloy. The purpose of this study is to research the development and utilization of ion nitridation method in order to get iron and titanium nitride thin films on the metallic biomaterials for artificial bone that has wear resistance and corrosion resistance is better. Microhardness of the samples was measured using a microhardness tester, optimum hardness of SS 316L samples are about 582 VHN, this was obtained at the nitriding temperature of 500 °C, the nitriding time of 3 hours and the nitrogen gas pressure of 1.6 mbar, while optimum hardness of Ti-6Al-4V alloy is 764 VHN, this was obtained at the nitriding temperature of 500 °C, the nitriding time of 4 hours and the nitrogen gas pressure of 1.6 mbar. The hardness value of SS 316L sample and Ti-6Al-4V alloy increase to 143% and 153%, if compared with standard samples. The optimum corrosion resistance at temperature of 350 °C for SS 316L and Ti-6Al-4V are 260,12 and 110,49 μA/cm 2 or corrosion rate are 29,866 and 15,189 mpy, respectively. (author)
Possible connections between hard and soft processes

International Nuclear Information System (INIS)

Blankenbecler, R.

1977-10-01

Three topics in constituent hadron models are reviewed: the connection between fixed angle and Regge behavior, the validity of the hard scattering expansion and restrictions on the effects of the transverse momentum of constituents, and the x distribution in the fragmentation region at low transverse momentum. 6 figures
Nitride alloy layer formation of duplex stainless steel using nitriding process

Science.gov (United States)

Maleque, M. A.; Lailatul, P. H.; Fathaen, A. A.; Norinsan, K.; Haider, J.

2018-01-01

Duplex stainless steel (DSS) shows a good corrosion resistance as well as the mechanical properties. However, DSS performance decrease as it works under aggressive environment and at high temperature. At the mentioned environment, the DSS become susceptible to wear failure. Surface modification is the favourable technique to widen the application of duplex stainless steel and improve the wear resistance and its hardness properties. Therefore, the main aim of this work is to nitride alloy layer on the surface of duplex stainless steel by the nitriding process temperature of 400°C and 450°C at different time and ammonia composition using a horizontal tube furnace. The scanning electron microscopy and x-ray diffraction analyzer are used to analyse the morphology, composition and the nitrided alloy layer for treated DSS. The micro hardnesss Vickers tester was used to measure hardness on cross-sectional area of nitrided DSS. After nitriding, it was observed that the hardness performance increased until 1100 Hv0.5kgf compared to substrate material of 250 Hv0.5kgf. The thickness layer of nitride alloy also increased from 5μm until 100μm due to diffusion of nitrogen on the surface of DSS. The x-ray diffraction results showed that the nitride layer consists of iron nitride, expanded austenite and chromium nitride. It can be concluded that nitride alloy layer can be produced via nitriding process using tube furnace with significant improvement of microstructural and hardness properties.
Microstructure and hardness performance of AA6061 aluminium composite using friction stir processing

Science.gov (United States)

Marini, C. D.; Fatchurrohman, N.

2018-04-01

Rice husk ash (RHA) is an industrial waste that has become a potential reinforced material for aluminium matrix composite (AMCs) due to low cost and abundantly available resources. Friction stir processing (FSP) has been introduced as a method to modify surface properties of the metal and alloy including theirs composite as well. The present work reports the production and characterization of AA6061 and AA6061/5 vol% RHA using FSP using parameters rotation speed 1000 rpm and traversed speed 25 mm/min. The microstructure was studied using optical microscopy (OM). A homogenous dispersion of RHA particles was obtained in the composite. No agglomeration or segregation was observed. The produced composite exhibited a fine grain structure. An improvement in hardness profile was observed as AA6061/5 vol% RHA improves in hardness compared to FSPed of AA6061 without reinforcement.
Hard X-ray Microscopy with Elemental, Chemical and Structural Contrast

International Nuclear Information System (INIS)

Schroer, C.G.; Boye, P.; Feldkamp, J.P.

2010-01-01

We review hard X-ray microscopy techniques with a focus on scanning microscopy with synchrotron radiation. Its strength compared to other microscopies is the large penetration depth of hard x rays in matter that allows one to investigate the interior of an object without destructive sample preparation. In combination with tomography, local information from inside of a specimen can be obtained, even from inside special non-ambient sample environments. Different X-ray analytical techniques can be used to produce contrast, such as X-ray absorption, fluorescence, and diffraction, to yield chemical, elemental, and structural information about the sample, respectively. This makes X-ray microscopy attractive to many fields of science, ranging from physics and chemistry to materials, geo-, and environmental science, biomedicine, and nanotechnology. Our scanning microscope based on nanofocusing refractive X-ray lenses has a routine spatial resolution of about 100 nm and supports the contrast mechanisms mentioned above. In combination with coherent X-ray diffraction imaging, the spatial resolution can be improved to the 10 nm range. The current state-of-the-art of this technique is illustrated by several examples, and future prospects of the technique are given. (author)
An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

Science.gov (United States)

Calta, Nicholas P.; Wang, Jenny; Kiss, Andrew M.; Martin, Aiden A.; Depond, Philip J.; Guss, Gabriel M.; Thampy, Vivek; Fong, Anthony Y.; Weker, Johanna Nelson; Stone, Kevin H.; Tassone, Christopher J.; Kramer, Matthew J.; Toney, Michael F.; Van Buuren, Anthony; Matthews, Manyalibo J.

2018-05-01

In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ˜1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ˜50 × 100 μm area. We also discuss the utility of these measurements for model validation and process improvement.
Processing two-dimensional X-ray diffraction and small-angle scattering data in DAWN 2.

Science.gov (United States)

Filik, J; Ashton, A W; Chang, P C Y; Chater, P A; Day, S J; Drakopoulos, M; Gerring, M W; Hart, M L; Magdysyuk, O V; Michalik, S; Smith, A; Tang, C C; Terrill, N J; Wharmby, M T; Wilhelm, H

2017-06-01

A software package for the calibration and processing of powder X-ray diffraction and small-angle X-ray scattering data is presented. It provides a multitude of data processing and visualization tools as well as a command-line scripting interface for on-the-fly processing and the incorporation of complex data treatment tasks. Customizable processing chains permit the execution of many data processing steps to convert a single image or a batch of raw two-dimensional data into meaningful data and one-dimensional diffractograms. The processed data files contain the full data provenance of each process applied to the data. The calibration routines can run automatically even for high energies and also for large detector tilt angles. Some of the functionalities are highlighted by specific use cases.

Comparative of the Tribological Performance of Hydraulic Cylinders Coated by the Process of Thermal Spray HVOF and Hard Chrome Plating

Directory of Open Access Journals (Sweden)

R.M. Castro

2014-03-01

Full Text Available Due to the necessity of obtaining a surface that is resistant to wear and oxidation, hydraulic cylinders are typically coated with hard chrome through the process of electroplating process. However, this type of coating shows an increase of the area to support sealing elements, which interferes directly in the lubrication of the rod, causing damage to the seal components and bringing oil leakage. Another disadvantage in using the electroplated hard chromium process is the presence of high level hexavalent chromium Cr+6 which is not only carcinogenic, but also extremely contaminating to the environment. Currently, the alternative process of high-speed thermal spraying (HVOF - High Velocity Oxy-Fuel, uses composite materials (metal-ceramic possessing low wear rates. Research has shown that some mechanical properties are changed positively with the thermal spray process in industrial applications. It is evident that a coating based on WC has upper characteristics as: wear resistance, low friction coefficient, with respect to hard chrome coatings. These characteristics were analyzed by optical microscopy, roughness measurements and wear test.
Inelastic nucleon diffraction at high energy

International Nuclear Information System (INIS)

Goggi, G.

1975-01-01

Experiments carried out at ISR and at FNAL which have yielded a substantial amount of data on double diffraction processes, which were unambiguously indentified and measured and which provide new tools to study the dynamical properties shared by different classes of diffractive reactions are identified. In this review interest is focused on the experimental aspects of inclusive and exclusive results both on single and double diffraction and on the problems arising from their comparison. Problems covered include; inclusive and semi-inclusive diffraction, multiparticle inclusive studies, single-particle inclusive studies, resonance region, high mass region, exclusive single diffractive reactions, mass spectra, cross sections, t-dependence, decay angular properties, and double diffraction. (U.K.)
Diffraction dissociation

International Nuclear Information System (INIS)

Abarbanel, H.

1972-01-01

An attempt is made to analyse the present theoretical situation in the field of diffraction scattering. Two not yet fully answered questions related with a typical diffraction process AB→CD, namely: what is the structure of the transition matrix elements, and what is the structure of the exchange mechanism responsible for the scattering, are formulated and various proposals for answers are reviewed. Interesting general statement that the products (-1)sup(J)P, where J and P are respectively spin and parity, is conserved at each vertex has been discussed. The exchange mechanism in diffractive scattering has been considered using the language of the complex J-plane as the most appropriate. The known facts about the exchange mechanism are recalled and several routs to way out are proposed. The idea to consider the moving pole and associated branch points as like a particle and the associated two and many particle unitarity cuts is described in more details. (S.B.)
Thermal spray coatings replace hard chrome

International Nuclear Information System (INIS)

Schroeder, M.; Unger, R.

1997-01-01

Hard chrome plating provides good wear and erosion resistance, as well as good corrosion protection and fine surface finishes. Until a few years ago, it could also be applied at a reasonable cost. However, because of the many environmental and financial sanctions that have been imposed on the process over the past several years, cost has been on a consistent upward trend, and is projected to continue to escalate. Therefore, it is very important to find a coating or a process that offers the same characteristics as hard chrome plating, but without the consequent risks. This article lists the benefits and limitations of hard chrome plating, and describes the performance of two thermal spray coatings (tungsten carbide and chromium carbide) that compared favorably with hard chrome plating in a series of tests. It also lists three criteria to determine whether plasma spray or hard chrome plating should be selected
Undergraduate experiment with fractal diffraction gratings

International Nuclear Information System (INIS)

Monsoriu, Juan A; Furlan, Walter D; Pons, Amparo; Barreiro, Juan C; Gimenez, Marcos H

2011-01-01

We present a simple diffraction experiment with fractal gratings based on the triadic Cantor set. Diffraction by fractals is proposed as a motivating strategy for students of optics in the potential applications of optical processing. Fraunhofer diffraction patterns are obtained using standard equipment present in most undergraduate physics laboratories and compared with those obtained with conventional periodic gratings. It is shown that fractal gratings produce self-similar diffraction patterns which can be evaluated analytically. Good agreement is obtained between experimental and numerical results.
Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

Energy Technology Data Exchange (ETDEWEB)

Kocabas, Mustafa [Yildiz Technical Univ., Istanbul (Turkey). Metallurgical and Materials Engineering Dept.; Danisman, Murat [Gedik Univ., Istanbul (Turkey). Electrical and Electronic Engineering Dept.; Cansever, Nurhan [Yildiz Technical Univ., Istanbul (Turkey); Uelker, Suekrue [Afyon Kocatepe Univ. (Turkey). Dept. of Mechanical Engineering

2015-06-01

Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.
Effect of plasma nitriding time on surface properties of hard chromium electroplated AISI 1010 steel

International Nuclear Information System (INIS)

Kocabas, Mustafa; Uelker, Suekrue

2015-01-01

Properties of steel can be enhanced by surface treatments such as coating. In some cases, further treatments such as nitriding can also be used in order to get even better results. In order to investigate the properties of nitride layer on hard Cr coated AISI 1010 steel, substrates were electroplated to form hard Cr coatings. Then hard Cr coatings were plasma nitrided at 700 C for 3 h, 5 h and 7 h and nitride phases on the coatings were investigated by X-ray diffraction analysis. The layer thickness and surface properties of nitride films were investigated by scanning electron microscopy. The hardness and adhesion properties of Cr-N phases were examined using nano indentation and Daimler-Benz Rockwell C adhesion tests. The highest measured hardness was 24.1 GPa and all the three samples exhibited poor adhesion.
Mesoporous carbon prepared from carbohydrate as hard template for hierarchical zeolites

DEFF Research Database (Denmark)

Egeblad, Kresten; Christensen, Claus H.

2007-01-01

treatment of a mixture of sucrose and ammonia followed by carbonization of the mixture in N-2 at high temperatures. The porous carbon produced by this method was subsequently applied as a hard template in the synthesis of mesoporous silicalite-1 and removed by combustion after synthesis. X-ray diffraction......A mesoporous carbon prepared from sucrose was successfully employed as a hard template to produce hierarchical silicalite-1, thus providing a very simple and inexpensive route to desirable zeolite catalysts from widely available raw materials. The porous carbon was prepared by hydrothermal...... the porous carbon template as well as the mesoporous zeolite single-crystal material....
High throughput diffractive multi-beam femtosecond laser processing using a spatial light modulator

Energy Technology Data Exchange (ETDEWEB)

Kuang Zheng [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom)], E-mail: z.kuang@liv.ac.uk; Perrie, Walter [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom); Leach, Jonathan [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Sharp, Martin; Edwardson, Stuart P. [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom); Padgett, Miles [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Dearden, Geoff; Watkins, Ken G. [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom)

2008-12-30

High throughput femtosecond laser processing is demonstrated by creating multiple beams using a spatial light modulator (SLM). The diffractive multi-beam patterns are modulated in real time by computer generated holograms (CGHs), which can be calculated by appropriate algorithms. An interactive LabVIEW program is adopted to generate the relevant CGHs. Optical efficiency at this stage is shown to be {approx}50% into first order beams and real time processing has been carried out at 50 Hz refresh rate. Results obtained demonstrate high precision surface micro-structuring on silicon and Ti6Al4V with throughput gain >1 order of magnitude.
Diffraction and Total Cross-Section at the Tevatron and the LHC

CERN Document Server

Deile, M; Aurola, A; Avati, V; Berardi, V; Bottigli, U; Bozzo, M; Brucken, E; Buzzo, A; Calicchio, M; Capurro, F; Catanesi, M G; Ciocci, M A; Cuneo, S; Da Vià, C; Dimovasili, E; Eggert, K; Eraluoto, M; Ferro, F; Giachero, A; Guillaud, J P; Hasi, J; Haug, F; Heino, J; Hilden, T; Jarron, P; Kalliopuska, J; Kaspar, J; Kempa, J; Kenney, C; Kok, A; Kundrát, V; Kurvinen, K; Lami, S; Lamsa, J; Latino, G; Lauhakangas, R; Lippmaa, J; Lokajícek, M; Lo Vetere, M; Macina, D; Macri, M; Meucci, M; Minutoli, S; Morelli, A; Musico, P; Negri, M; Niewiadomski, H; Noschis, E; Ojala, J; Oljemark, F; Orava, R; Oriunno, M; Österberg, K; Paoletti, R; Parker, S; Perrot, Anne Laure; Radermacher, E; Radicioni, E; Robutti, E; Ropelewski, Leszek; Ruggiero, G; Saarikko, H; Sanguinetti, G; Santroni, A; Saramad, S; Sauli, Fabio; Scribano, A; Sette, G; Smotlacha, J; Snoeys, W; Taylor, C; Toppinen, A; Turini, N; Van Remortel, N; Verardo, L; Verdier, A; Watts, S; Whitmore, J

2006-01-01

At the Tevatron, the total p_bar-p cross-section has been measured by CDF at 546 GeV and 1.8 TeV, and by E710/E811 at 1.8 TeV. The two results at 1.8 TeV disagree by 2.6 standard deviations, introducing big uncertainties into extrapolations to higher energies. At the LHC, the TOTEM collaboration is preparing to resolve the ambiguity by measuring the total p-p cross-section with a precision of about 1 %. Like at the Tevatron experiments, the luminosity-independent method based on the Optical Theorem will be used. The Tevatron experiments have also performed a vast range of studies about soft and hard diffractive events, partly with antiproton tagging by Roman Pots, partly with rapidity gap tagging. At the LHC, the combined CMS/TOTEM experiments will carry out their diffractive programme with an unprecedented rapidity coverage and Roman Pot spectrometers on both sides of the interaction point. The physics menu comprises detailed studies of soft diffractive differential cross-sections, diffractive structure func...
The microstructure of mechanically alloyed Al-Mg determined by X-ray diffraction peak profile analysis

Energy Technology Data Exchange (ETDEWEB)

Gubicza, J.; Kassem, M.; Ribarik, G.; Ungar, T

2004-05-15

The effect of the nominal Mg content and the milling time on the microstructure and the hardness of mechanically alloyed Al-rich Al-Mg solid solutions is studied. The crystallite size distribution and the dislocation structure are characterized by X-ray diffraction (XRD) peak profile analysis and the hardness is obtained from depth-sensing indentation tests. Magnesium gradually goes into solid solution during ball milling and after 3 h an almost complete solid solution is attained. With increasing milling time, the Mg concentration in solid solution, the dislocation density and the hardness increase, whereas the crystallite size decreases. A similar tendency of these parameters is observed at a particular duration of ball milling with increasing nominal Mg content. After 3 h milling there are no changes in both the microstructure and the hardness.
Reggeon and pion contributions in exclusive diffractive processes at HERA

International Nuclear Information System (INIS)

Golec-Biernat, K.; Kwiecinski, J.; Szczurek, A.

1997-01-01

The contribution of subleading f 2 , ω, a 2 and ρ reggeons to the diffractive structure function F 2 D(3) (x P , β, Q 2 )are estimated. In addition we include the pion exchange which was recently found to be responsible for the violation of the Gottfried Sum Rule. The reggeon and pion contribution lead to a violation of the factorization of the diffractive structure function. The diffractive structure function is separated into the contributions with leading proton Δ (n) F 2 D /Δ (p) F 2 D as a function ox x P in the interval 10 -2 P -1 . The effect is due to the exchange of the isovector a 2 and ρ reggeons at smaller x P and the pion exchange at x P > 10 -2 . (author). 27 refs, 4 figs
Increasing reconstruction quality of diffractive optical elements displayed with LC SLM

Science.gov (United States)

Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

2015-03-01

Phase liquid crystal (LC) spatial light modulators (SLM) are actively used in various applications. However, majority of scientific applications require stable phase modulation which might be hard to achieve with commercially available SLM due to its consumer origin. The use of digital voltage addressing scheme leads to phase temporal fluctuations, which results in lower diffraction efficiency and reconstruction quality of displayed diffractive optical elements (DOE). Due to high periodicity of fluctuations it should be possible to use knowledge of these fluctuations during DOE synthesis to minimize negative effect. We synthesized DOE using accurately measured phase fluctuations of phase LC SLM "HoloEye PLUTO VIS" to minimize its negative impact on displayed DOE reconstruction. Synthesis was conducted with versatile direct search with random trajectory (DSRT) method in the following way. Before DOE synthesis begun, two-dimensional dependency of SLM phase shift on addressed signal level and time from frame start was obtained. Then synthesis begins. First, initial phase distribution is created. Second, random trajectory of consecutive processing of all DOE elements is generated. Then iterative process begins. Each DOE element sequentially has its value changed to one that provides better value of objective criterion, e.g. lower deviation of reconstructed image from original one. If current element value provides best objective criterion value then it left unchanged. After all elements are processed, iteration repeats until stagnation is reached. It is demonstrated that application of SLM phase fluctuations knowledge in DOE synthesis with DSRT method leads to noticeable increase of DOE reconstruction quality.
Determination of initial stages of recrystallization in aluminium alloys by X-ray diffraction

International Nuclear Information System (INIS)

Loew, Marjorie

2000-01-01

Aluminium is a metal with a wide variety of application, such as beer cans, pans, door and window borders, and others more advanced, such as airplane structure, car engines, nuclear reactors components, rocket propulsion components and so on. Most of aluminium application is in alloy form. Such alloys must present suitable mechanical and chemical properties that are obtained, not entirely, by microstructure development. In this work, the beginning of recrystallization processes of AA1050 and AA3003 aluminium alloys were studied using X-ray diffraction techniques, transmission electron microscopy and hardness test. For such a sample, an initial heat treatment was done in order to homogenize the samples microstructure, followed by cold rolling and submitted again to a heat treatment in different temperatures in a hot furnace. After that samples were analyzed to verify the beginning of the recrystallization. Vickers hardness test revealed that the beginning of recrystallization is between 150 and 300 deg C for 1050 aluminium alloy and 200 and 300 deg C for 3003 aluminium alloy. X-ray diffraction using transmission chamber showed that the beginning of recrystallization is 240 and 260 deg C for AA1050 and AA3003, respectively. These temperatures were determined as the diffraction patterns recorded in the photographic plates changes when the recrystallization takes place. In this way, the deformed sample shows continuous concentric lines and the beginning of recrystallization is characterized by the occurrence of defined spots in this pattern. The Pole Figures goniometric method revealed that the beginning of recrystallization takes place between 250 and 300 deg C for both alloys. In the same way, orientation distribution functions showed the same temperature range for the recrystallization. However, the analysis by α and β fiber figures, the recrystallization temperatures are 240 and 260 deg C for AA1050 and AA3003, respectively. Finally, after the analysis of all
Rapid thermal processing chamber for in-situ x-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Md. Imteyaz; Van Campen, Douglas G.; Yu, Jiafan; Pool, Vanessa L.; Van Hest, Maikel F. A. M.; Toney, Michael F., E-mail: mftoney@slac.stanford.edu [SSRL, SLAC National Accelerator Laboratory, 2575, Sand Hill Road, Menlo Park, California 94025 (United States); Fields, Jeremy D.; Parilla, Philip A.; Ginley, David S. [National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

2015-01-15

Rapid thermal processing (RTP) is widely used for processing a variety of materials, including electronics and photovoltaics. Presently, optimization of RTP is done primarily based on ex-situ studies. As a consequence, the precise reaction pathways and phase progression during the RTP remain unclear. More awareness of the reaction pathways would better enable process optimization and foster increased adoption of RTP, which offers numerous advantages for synthesis of a broad range of materials systems. To achieve this, we have designed and developed a RTP instrument that enables real-time collection of X-ray diffraction data with intervals as short as 100 ms, while heating with ramp rates up to 100 °Cs{sup −1}, and with a maximum operating temperature of 1200 °C. The system is portable and can be installed on a synchrotron beamline. The unique capabilities of this instrument are demonstrated with in-situ characterization of a Bi{sub 2}O{sub 3}-SiO{sub 2} glass frit obtained during heating with ramp rates 5 °C s{sup −1} and 100 °C s{sup −1}, revealing numerous phase changes.
Structure-properties relationships of novel poly(carbonate-co-amide) segmented copolymers with polyamide-6 as hard segments and polycarbonate as soft segments

Science.gov (United States)

Yang, Yunyun; Kong, Weibo; Yuan, Ye; Zhou, Changlin; Cai, Xufu

2018-04-01

Novel poly(carbonate-co-amide) (PCA) block copolymers are prepared with polycarbonate diol (PCD) as soft segments, polyamide-6 (PA6) as hard segments and 4,4'-diphenylmethane diisocyanate (MDI) as coupling agent through reactive processing. The reactive processing strategy is eco-friendly and resolve the incompatibility between polyamide segments and PCD segments in preparation processing. The chemical structure, crystalline properties, thermal properties, mechanical properties and water resistance were extensively studied by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Differential scanning calorimetry (DSC), Thermal gravity analysis (TGA), Dynamic mechanical analysis (DMA), tensile testing, water contact angle and water absorption, respectively. The as-prepared PCAs exhibit obvious microphase separation between the crystalline hard PA6 phase and amorphous PCD soft segments. Meanwhile, PCAs showed outstanding mechanical with the maximum tensile strength of 46.3 MPa and elongation at break of 909%. The contact angle and water absorption results indicate that PCAs demonstrate outstanding water resistance even though possess the hydrophilic surfaces. The TGA measurements prove that the thermal stability of PCA can satisfy the requirement of multiple-processing without decomposition.
Photon technology. Hard photon technology; Photon technology. Hard photon gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

For the application of photon to industrial technologies, in particular, a hard photon technology was surveyed which uses photon beams of 0.1-200nm in wavelength. Its features such as selective atom reaction, dense inner shell excitation and spacial high resolution by quantum energy are expected to provide innovative techniques for various field such as fine machining, material synthesis and advanced inspection technology. This wavelength region has been hardly utilized for industrial fields because of poor development of suitable photon sources and optical devices. The developmental meaning, usable time and issue of a hard photon reduction lithography were surveyed as lithography in ultra-fine region below 0.1{mu}m. On hard photon analysis/evaluation technology, the industrial use of analysis, measurement and evaluation technologies by micro-beam was viewed, and optimum photon sources and optical systems were surveyed. Prediction of surface and surface layer modification by inner shell excitation, the future trend of this process and development of a vacuum ultraviolet light source were also surveyed. 383 refs., 153 figs., 17 tabs.
Effect of cutting temperature on hardness of SiC and diamond in the nano-cutting process of monocrystalline silicon

Science.gov (United States)

Wang, Jiachun; Li, Yuntao; Liu, Xiaoxuan; Lv, Maoqiang

2016-10-01

In the process of cutting silicon by natural diamond tools, groove wear happens on the flank face of cutting tool frequently.Scholars believe that one of the wear reasons is mechanical scratching effect by hard particles like SiC. To reveal the mechanical scratching mechanism, it is essential to study changes in the mechanical properties of hard particles and diamond, especially the effect of cutting temperature on hardness of diamond and hard particles. Molecular dynamics (MD) model that contact-zone temperature between tool and workpiece was calculated by dividing zone while nano-cutting monocrystalline silicon was established, cutting temperature values in different regions were computed as the simulation was carried out.On this basis, the models of molecular dynamics simulation of SiC and diamond were established separately with setting the initial temperature to room temperature. The laws of length change of C-C bond and Si-C bond varing with increase of simulation temperature were studied. And drawing on predecessors' research on theoretical calculation of hardness of covalent crystals and the relationship between crystal valence electron density and bond length, the curves that the hardness of diamond and SiC varing with bond length were obtained. The effect of temperature on the hardness was calculated. Results show that, local cutting temperature can reach 1300K.The rise in cutting temperature leaded to a decrease in the diamond local atomic clusters hardness,SiC local atomic clusters hardness increased. As the cutting temperature was more than 1100K,diamond began to soften, the local clusters hardness was less than that of SiC.
X-ray diffraction microscopy based on refractive optics

DEFF Research Database (Denmark)

Poulsen, Henning Friis; Jakobsen, A. C.; Simons, Hugh

2017-01-01

A formalism is presented for dark‐field X‐ray microscopy using refractive optics. The new technique can produce three‐dimensional maps of lattice orientation and axial strain within millimetre‐sized sampling volumes and is particularly suited to in situ studies of materials at hard X‐ray energies....... An objective lens in the diffracted beam magnifies the image and acts as a very efficient filter in reciprocal space, enabling the imaging of individual domains of interest with a resolution of 100 nm. Analytical expressions for optical parameters such as numerical aperture, vignetting, and the resolution...
Nonlinear diffraction from a virtual beam

DEFF Research Database (Denmark)

Saltiel, Solomon M.; Neshev, Dragomir N.; Krolikowski, Wieslaw

2010-01-01

We observe experimentally a novel type of nonlinear diffraction in the process of two-wave mixing on a nonlinear quadratic grating.We demonstrate that when the nonlinear grating is illuminated simultaneously by two noncollinear beams, a second-harmonic diffraction pattern is generated by a virtual...... beam propagating along the bisector of the two pump beams. The observed iffraction phenomena is a purely nonlinear effect that has no analogue in linear diffraction...

A hard X-ray nanoprobe beamline for nanoscale microscopy

Energy Technology Data Exchange (ETDEWEB)

Winarski, Robert P., E-mail: winarski@anl.gov; Holt, Martin V. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Rose, Volker [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Fuesz, Peter; Carbaugh, Dean; Benson, Christa; Shu, Deming; Kline, David; Stephenson, G. Brian; McNulty, Ian [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States); Maser, Jörg [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60441 (United States)

2012-11-01

The Hard X-ray Nanoprobe Beamline is a precision platform for scanning probe and full-field microscopy with 3–30 keV X-rays. A combination of high-stability X-ray optics and precision motion sensing and control enables detailed studies of the internal features of samples with resolutions approaching 30 nm. The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals.
Coherent and non-coherent double diffractive production of QQ-bar-pairs in collisions of heavy ions at high energies

International Nuclear Information System (INIS)

Agababyan, N.M.; Galoyan, A.S.; Enkovskij, L.L.; Zarubin, P.I.; Malakhov, A.I.; Melkumov, G.L.; Chatrchyan, S.A.

1999-01-01

The double coherent and non-coherent diffractive production of heavy quark-antiquark pairs (QQ-bar) in heavy ion scattering at high energies (LHC) is considered. The total and differential cross sections of these processes with the formation of cc-bar and bb-bar pairs in pp, CaCa and PbPb collisions are evaluated. The contribution of the considered mechanisms is a few per cent of the number of heavy quark-antiquark pairs obtained in the processes of hard (QCD) scattering, and it will be taken into account in the registration of c, b quarks or, for instance, in the study of the heavy quarkonia suppression effect in Quark-Gluon Plasma, in the search got intermediate mass Higgs bosons and so on. It is shown that the cross section of the coherently scattering process is great enough. This makes it suitable for studying collective effects in nuclear interactions at high energies. An example of such effects is given: large values of the invariant mass of a QQ-bar pair, M QQ-bar ≥ 100 GeV, in association with a large rapidity gap between diffractive jets Δη >5 [ru
Coherent and non-coherent double diffractive production of QQ-bar - pairs in collisions of heavy ions at high energies

International Nuclear Information System (INIS)

Agababyan, N.M.; Chatrchyan, S.A.; Galoyan, A.S.; Malakhov, A.I.; Melkumov, G.L.; Zarubin, P.I.; Jenkovszky, L.L.

1998-01-01

The double coherent and non-coherent diffractive production of heavy quark-antiquark pair (QQ-bar) in heavy ion scattering at high energies (LHC) is considered. The total and differential cross sections of these processes with the formation of cc bar and bb bar pairs in pp, CaCa and PbPb collisions are evaluated. The contribution of the considered mechanisms is a few per cent of the number of heavy quark-antiquark pairs obtained in the processes of hard (QCD) scattering, and it will be taken into account in the registration of c, b quarks or, for instance, in the study of the heavy quarkonia suppression effects in quark-gluon plasma, in the search for intermediate mass Higgs bosons and so on. It is shown that the cross section of the coherent scattering process is great enough. This makes it suitable for studying collective effects in nuclear interactions at high energies. An example of such effects is given: large values of the invariant mass of a QQ- bar pair, M QQb ar ≥ 100 GeV, in association with a large rapidity gap between diffractive jets Δη>5
One-loop corrections to the process e+e-→tt including hard bremsstrahlung

International Nuclear Information System (INIS)

Fleischer, J.; Riemann, T.; Werthenbach, A.; Leike, A.

2002-03-01

Radiative corrections to the process e + e - → t anti t are calculated in one-loop approximation of the Standard Model. There exist results from several groups. This talk provides further comparisons of the complete electroweak contributions, including hard bremsstrahlung. The excellent final agreement of the different groups allows to continue by working on a code for an event generator for TESLA and an extension to e + e - → 6 fermions. (orig.)
Zirconium nitride hard coatings

International Nuclear Information System (INIS)

Roman, Daiane; Amorim, Cintia Lugnani Gomes de; Soares, Gabriel Vieira; Figueroa, Carlos Alejandro; Baumvol, Israel Jacob Rabin; Basso, Rodrigo Leonardo de Oliveira

2010-01-01

Zirconium nitride (ZrN) nanometric films were deposited onto different substrates, in order to study the surface crystalline microstructure and also to investigate the electrochemical behavior to obtain a better composition that minimizes corrosion reactions. The coatings were produced by physical vapor deposition (PVD). The influence of the nitrogen partial pressure, deposition time and temperature over the surface properties was studied. Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and corrosion experiments were performed to characterize the ZrN hard coatings. The ZrN films properties and microstructure changes according to the deposition parameters. The corrosion resistance increases with temperature used in the films deposition. Corrosion tests show that ZrN coating deposited by PVD onto titanium substrate can improve the corrosion resistance. (author)
Phase and Texture of Solution-Processed Copper Phthalocyanine Thin Films Investigated by Two-Dimensional Grazing Incidence X-Ray Diffraction

Directory of Open Access Journals (Sweden)

Lulu Deng

2011-07-01

Full Text Available The phase and texture of a newly developed solution-processed copper phthalocyanine (CuPc thin film have been investigated by two-dimensional grazing incidence X-ray diffraction. The results show that it has β phase crystalline structure, with crystallinity greater than 80%. The average size of the crystallites is found to be about 24 nm. There are two different arrangements of crystallites, with one dominating the diffraction pattern. Both of them have preferred orientation along the thin film normal. Based on the similarities to the vacuum deposited CuPc thin films, the new solution processing method is verified to offer a good alternative to vacuum process, for the fabrication of low cost small molecule based organic photovoltaics.
Time-resolved x-ray diffraction measurement of C60 under high pressure and temperature using synchrotron radiation

International Nuclear Information System (INIS)

Horikawa, T; Suito, K; Kobayashi, M; Onodera, A

2002-01-01

C 60 has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C 60 structure are presented and the relevance to the hardness of materials derived from C 60 is discussed
Processing of Bi-2212 and Nb$_3$Sn studied in situ by high energy synchrotron diffraction and micro-tomography

CERN Document Server

Kadar, Julian

Next generation superconducting wires have been studied to obtain more information on the evolution of phase growth, crystallite size and strain state during wire processing. The high energy scattering beam line ID15 at the European Synchrotron Radiation Facility provides a very high flux of high energy photons for very fast in situ X-ray diffraction and micro-tomography studies of Bi-2212/Ag and Nb$_3$S/Cu wire samples. The typical wire processing conditions could be imitated in the X-ray transparent furnace at ID15 for diffraction and tomography studies. Efficient data analysis is mandatory in order to handle the very fast data acquisition rate. For this purpose an Excel-VBA based program was developed that allows a semi-automated fitting and tracking of peaks with pre-set constraints. With this method, more than one thousand diffraction patterns have been analysed to extract d-spacing, peak intensity and peak width values. X ray absorption micro tomograms were recorded simultaneously with the X-ray diffrac...
High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector

Energy Technology Data Exchange (ETDEWEB)

Giewekemeyer, Klaus, E-mail: klaus.giewekemeyer@xfel.eu [European XFEL GmbH, Hamburg (Germany); Philipp, Hugh T. [Cornell University, Ithaca, NY (United States); Wilke, Robin N. [Georg-August-Universität Göttingen, Göttingen (Germany); Aquila, Andrew [European XFEL GmbH, Hamburg (Germany); Osterhoff, Markus [Georg-August-Universität Göttingen, Göttingen (Germany); Tate, Mark W.; Shanks, Katherine S. [Cornell University, Ithaca, NY (United States); Zozulya, Alexey V. [Deutsches Elektronen-Synchrotron DESY, Hamburg (Germany); Salditt, Tim [Georg-August-Universität Göttingen, Göttingen (Germany); Gruner, Sol M. [Cornell University, Ithaca, NY (United States); Cornell University, Ithaca, NY (United States); Kavli Institute of Cornell for Nanoscience, Ithaca, NY (United States); Mancuso, Adrian P. [European XFEL GmbH, Hamburg (Germany)

2014-08-07

The advantages of a novel wide dynamic range hard X-ray detector are demonstrated for (ptychographic) coherent X-ray diffractive imaging. Coherent (X-ray) diffractive imaging (CDI) is an increasingly popular form of X-ray microscopy, mainly due to its potential to produce high-resolution images and the lack of an objective lens between the sample and its corresponding imaging detector. One challenge, however, is that very high dynamic range diffraction data must be collected to produce both quantitative and high-resolution images. In this work, hard X-ray ptychographic coherent diffractive imaging has been performed at the P10 beamline of the PETRA III synchrotron to demonstrate the potential of a very wide dynamic range imaging X-ray detector (the Mixed-Mode Pixel Array Detector, or MM-PAD). The detector is capable of single photon detection, detecting fluxes exceeding 1 × 10{sup 8} 8-keV photons pixel{sup −1} s{sup −1}, and framing at 1 kHz. A ptychographic reconstruction was performed using a peak focal intensity on the order of 1 × 10{sup 10} photons µm{sup −2} s{sup −1} within an area of approximately 325 nm × 603 nm. This was done without need of a beam stop and with a very modest attenuation, while ‘still’ images of the empty beam far-field intensity were recorded without any attenuation. The treatment of the detector frames and CDI methodology for reconstruction of non-sensitive detector regions, partially also extending the active detector area, are described.
Hard coal; Steinkohle

Energy Technology Data Exchange (ETDEWEB)

Loo, Kai van de; Sitte, Andreas-Peter [Gesamtverband Steinkohle e.V., Herne (Germany)

2013-04-01

The year 2012 benefited from a growth of the consumption of hard coal at the national level as well as at the international level. Worldwide, the hard coal still is the number one energy source for power generation. This leads to an increasing demand for power plant coal. In this year, the conversion of hard coal into electricity also increases in this year. In contrast to this, the demand for coking coal as well as for coke of the steel industry is still declining depending on the market conditions. The enhanced utilization of coal for the domestic power generation is due to the reduction of the nuclear power from a relatively bad year for wind power as well as reduced import prices and low CO{sub 2} prices. Both justify a significant price advantage for coal in comparison to the utilisation of natural gas in power plants. This was mainly due to the price erosion of the inexpensive US coal which partly was replaced by the expansion of shale gas on the domestic market. As a result of this, the inexpensive US coal looked for an outlet for sales in Europe. The domestic hard coal has continued the process of adaptation and phase-out as scheduled. Two further hard coal mines were decommissioned in the year 2012. RAG Aktiengesellschaft (Herne, Federal Republic of Germany) running the hard coal mining in this country begins with the preparations for the activities after the time of mining.
Electron backscatter diffraction: Strategies for reliable data acquisition and processing

International Nuclear Information System (INIS)

Randle, Valerie

2009-01-01

In electron backscatter diffraction (EBSD) software packages there are many user choices both in data acquisition and in data processing and display. In order to extract maximum scientific value from an inquiry, it is helpful to have some guidelines for best practice in conducting an EBSD investigation. The purpose of this article therefore is to address selected topics of EBSD practice, in a tutorial manner. The topics covered are a brief summary on the principles of EBSD, specimen preparation, calibration of an EBSD system, experiment design, speed of data acquisition, data clean-up, microstructure characterisation (including grain size) and grain boundary characterisation. This list is not meant to cover exhaustively all areas where EBSD is used, but rather to provide a resource consisting of some useful strategies for novice EBSD users.
Sub-100 nm hard X-ray microbeam generation with Fresnel zone plate optics

CERN Document Server

Takano, H; Takeuchi, A

2003-01-01

A hard X-ray focusing test of a Fresnel zone plate has been performed with a synchrotron radiation source at the undulator beamline 20XU of SPring-8. Fresnel zone plate with a radius of 150 mu m, and an outermost zone width of 100 nm was used for the X-ray focusing device. The 248-m-long beamline provides fully coherent illumination for the focusing device. The focused beam evaluated by the knife-edge-scan method and scanning microscope test using test charts. Nearly diffraction- limited focusing with a size of 120 nm was achieved for the first-order diffraction at 10 keV X-ray. Evaluation for the third order diffraction was also performed at 8 keV X-ray, and a focal size of 50 m has been obtained. (author)
Diffractive dijet photoproduction in ep collisions at HERA

International Nuclear Information System (INIS)

Aaron, F.D.; Alexa, C.; Rotaru, M.; Stoicea, G.; Andreev, V.; Belousov, A.; Eliseev, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Loktionova, N.; Malinovski, E.; Rusakov, S.; Shtarkov, L.N.; Soloviev, Y.; Vazdik, Y.; Backovic, S.; Dubak, A.; Lastovicka-Medin, G.; Picuric, I.; Raicevic, N.; Baghdasaryan, A.; Zohrabyan, H.; Barrelet, E.; Bartel, W.; Brandt, G.; Campbell, A.J.; Cholewa, A.; Deak, M.; Eckerlin, G.; Elsen, E.; Felst, R.; Fischer, D.J.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Grebenyuk, A.; Grell, B.R.; Habib, S.; Haidt, D.; Helebrant, C.; Katzy, J.; Kleinwort, C.; Knutsson, A.; Kraemer, M.; Kutak, K.; Levonian, S.; Lipka, K.; List, J.; Marti, Ll.; Meyer, A.B.; Meyer, J.; Niebuhr, C.; Nikiforov, A.; Olsson, J.E.; Pahl, P.; Panagoulias, I.; Papadopoulou, T.; Petrukhin, A.; Piec, S.; Pitzl, D.; Placakyte, R.; Schmitt, S.; Sefkow, F.; Staykova, Z.; Steder, M.; Toll, T.; Vargas Trevino, A.; Driesch, M. von den; Wuensch, E.; Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B.; Bizot, J.C.; Brisson, V.; Delcourt, B.; Jacquet, M.; Pascaud, C.; Tran, T.H.; Zhang, Z.; Zomer, F.; Boudry, V.; Moreau, F.; Specka, A.; Bozovic-Jelisavcic, I.; Mudrinic, M.; Pandurovic, M.; Smiljanic, I.; Bracinik, J.; Kenyon, I.R.; Newman, P.R.; Shaw-West, R.N.; Thompson, P.D.; Brinkmann, M.; Dobre, M.; List, B.; Bruncko, D.; Cerny, V.; Ferencei, J.; Bunyatyan, A.; Buschhorn, G.; Chekelian, V.; Dossanov, A.; Grindhammer, G.; Kiesling, C.; Kogler, R.; Raspiareza, A.; Shushkevich, S.; Bystritskaya, L.; Efremenko, V.; Fedotov, A.; Kropivnitskaya, A.; Lubimov, V.; Ozerov, D.; Rostovtsev, A.; Zhokin, A.; Cantun Avila, K.B.; Contreras, J.G.; Ruiz Tabasco, J.E.; Cerny, K.; Pokorny, B.; Polifka, R.; Salek, D.; Valkarova, A.; Zacek, J.; Coughlan, J.A.; Morris, J.V.; Sankey, D.P.C.; Cvach, J.; Reimer, P.; Zalesak, J.; Dainton, J.B.; Gabathuler, E.; Greenshaw, T.; Klein, M.; Kluge, T.; Kretzschmar, J.; Laycock, P.; Maxfield, S.J.; Mehta, A.; Patel, G.D.; Daum, K.; Meyer, H.; Delvax, J.; Wolf, E.A. de; Favart, L.; Hreus, T.; Janssen, X.; Marage, P.; Mozer, M.U.; Roosen, R.; Sunar, D.; Sykora, T.; Mechelen, P. van; Diaconu, C.; Hoffmann, D.; Sauvan, E.; Vallee, C.; Dodonov, V.; Povh, B.; Egli, S.; Hildebrandt, M.; Horisberger, R.; Falkiewicz, A.; Goerlich, L.; Mikocki, S.; Milcewicz-Mika, I.; Nowak, G.; Sopicki, P.; Turnau, J.; Feltesse, J.; Perez, E.; Schoeffel, L.; Grab, C.; Henderson, R.C.W.; Sloan, T.; Hennekemper, E.; Herbst, M.; Jung, A.W.; Krueger, K.; Lendermann, V.; Schultz-Coulon, H.C.; Urban, K.; Henschel, H.; Hiller, K.H.; Kostka, P.; Lange, W.; Naumann, T.; Herrera, G.; Lopez-Fernandez, R.; Huber, F.; Pirumov, H.; Radescu, V.; Sauter, M.; Schoening, A.; Joensson, L.; Osman, S.; Jung, H.; DESY, Hamburg; Landon, M.P.J.; Rizvi, E.; Thompson, G.; Traynor, D.; Martyn, H.U.; Mueller, K.; Nowak, K.; Robmann, P.; Straumann, U.; Truoel, P.; South, D.; Wegener, D.; Stella, B.; INFN Roma 3, Rome

2010-01-01

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb -1 . The events are of the type ep→eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x γ of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models. (orig.)
Diffractive Dijet Photoproduction in ep Collisions at HERA

CERN Document Server

Aaron, F.D.; Andreev, V.; Backovic, S.; Baghdasaryan, A.; Barrelet, E.; Bartel, W.; Begzsuren, K.; Belousov, A.; Bizot, J.C.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; Delcourt, B.; Delvax, J.; De Wolf, E.A.; Diaconu, C.; Dobre, M.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Falkiewicz, A.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Fischer, D.J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, Samvel; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Helebrant, C.; Henderson, R.C.W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Jacquet, M.; Janssen, X.; Jonsson, L.; Jung, A.W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kluge, T.; Knutsson, A.; Kogler, R.; Kostka, P.; Kraemer, M.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kutak, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Lendermann, V.; Levonian, S.; Lipka, K.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.U.; Maxfield, S.J.; Mehta, A.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, M.U.; Mudrinic, M.; Muller, K.; Naumann, Th.; Newman, P.R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nowak, K.; Olsson, J.E.; Osman, S.; Ozerov, D.; Pahl, P.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pirumov, H.; Pitzl, D.; Placakyte, R.; Pokorny, B.; Polifka, R.; Povh, B.; Radescu, V.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Tabasco, J.E.Ruiz; Rusakov, S.; Salek, D.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.C.; Sefkow, F.; Shaw-West, R.N.; Shtarkov, L.N.; Shushkevich, S.; Sloan, T.; Smiljanic, Ivan; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stoicea, G.; Straumann, U.; Sunar, D.; Sykora, T.; Thompson, G.; Thompson, P.D.; Toll, T.; Tran, T.H.; Traynor, D.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Urban, K.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Trevino, A.Vargas; Vazdik, Y.; von den Driesch, M.; Wegener, D.; Wunsch, E.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zohrabyan, H.; Zomer, F.

2010-01-01

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb^-1. The events are of the type ep -> eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x_gamma of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models.
Borehole radar diffraction tomography

Energy Technology Data Exchange (ETDEWEB)

Cho, Seong Jun; Kim, Jung Ho; Yi, Myeong Jong; Chung, Seung Hwan; Lee, Hee Il [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

Tomography is widely used as imaging method for determining subsurface structure. Among the reconstruction algorithms for tomographic imaging, travel time tomography is almost applied to imaging subsurface. But isolated small body comparable with the wavelength could not be well recognized by travel time tomography. Other tomographic method are need to improve the imaging process. In the study of this year, diffraction tomography was investigated. The theory for diffraction tomography is based on the 1st-order Born approximation. Multisource holography, which is similar to Kirchihoff migration, is compared with diffraction tomography. To improve 1st-order Born diffraction tomography, two kinds of filter designed from multisource holography and 2-D green function, respectively, applied on the reconstructed image. The algorithm was tested for the numerical modeling data of which algorithm consists of the analytic computation of radar signal in transmitter and receiver regions and 2-D FDM scheme for the propagation of electromagnetic waves in media. The air-filled cavity model to show a typical diffraction pattern was applied to diffraction tomography imaging, and the result shows accurate location and area of cavity. But the calculated object function is not well matched the real object function, because the air-filled cavity model is not satisfied week scattered inhomogeneity for 1st born approximation, and the error term is included in estimating source wavelet from received signals. In spite of the object function error, the diffraction tomography assist for interpretation of subsurface as if conducted with travel time tomography. And the fracture model was tested, 1st born diffraction tomographic image is poor because of limited view angle coverage and violation of week scatter assumption, but the filtered image resolve the fracture somewhat better. The tested diffraction tomography image confirms effectiveness of filter for enhancing resolution. (author). 14
Effect of Anneal temperature and Time on Change of Texture and Hardness of Al-Cu-Mg

International Nuclear Information System (INIS)

Masrukan; Adolf Asih, S.

2000-01-01

Observation of the effect of annealing temperature to its texture and hardness of the Al-Cu-Mg has been done. In this experiments aluminium alloy powder and 5 pieces cubes of this alloy with size of 8 x 8 x 8 mm 3 were used. The powder was not annealed, 2 pieces cube were annealed for 20 hours at temperatures of 200 o C and 300 o respectively, finally 3 pieces cube were annealed at temperature of 400 o C. Texture measurement was done using x-ray diffraction with wave length of 1.78892 A using inverse pole figure method. The hardness testing results at constant temperature of 400 o C and various time indicated that the hardness values are decreased with increasing annealed time. Also, at hardness testing for constant time and various annealing temperatures indicated that the hardness values decreased with increasing annealing temperature
Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy

Science.gov (United States)

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J.; Jung, Il Woong; Walko, Donald A.; Dufresne, Eric M.; Jeong, Jaewoo; Samant, Mahesh G.; Parkin, Stuart S. P.; Freeland, John W.; Evans, Paul G.; Wen, Haidan

2016-02-01

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.
Study of hard processes in the ALICE experiment

CERN Document Server

Vajzer, Michal; Bielcikova, Jana

2015-01-01

Jets are collimated sprays of particles resulting from fragmentation of associated hard scattered partons. They are measured in different types of collisions at different energies to test perturbative quantum chromodynamic calculations and are used to study the hard scattering, fragmentation, hadronisation and other properties of partons. These properties studied in simple systems such as proton-proton collisions, serve as a baseline to investigate their modifications by hot and dense nuclear matter created in high energy heavy-ion collisions. This thesis presents analysis of data from minimum bias proton-proton collisions at centre of mass energy of 2.76 and 7 TeV collected using the ALICE detector system at the LHC is presented with jet transverse momenta in range from 20 GeV/c to 100 GeV/c. Reconstruction of the inclusive jet cross-section from charged tracks at midrapidity is done using standard modern anti-k$_T$ and k$_T$ algorithms with underlying event subtraction and correction for detector effects vi...
Advances in hard nucleus cataract surgery

Directory of Open Access Journals (Sweden)

Wei Cui

2013-11-01

Full Text Available Security and perfect vision and fewer complications are our goals in cataract surgery, and hard-nucleus cataract surgery is always a difficulty one. Many new studies indicate that micro-incision phacoemulsification in treating hard nucleus cataract is obviously effective. This article reviews the evolution process of hard nuclear cataract surgery, the new progress in the research of artificial intraocular lens for microincision, and analyse advantages and disadvantages of various surgical methods.
Structure-phase composition and nano hardness of chrome-fullerite-chrome films irradiated by boron ions

International Nuclear Information System (INIS)

Baran, L.V.

2015-01-01

By methods of atomic force microscopy, X-ray diffraction and nano indentation the research of change of structure phase composition and nano hardness of the chrome - fullerite - chrome films, subjected to implantation by B + ions (E = 80 keV, F = 5*10 17 ions/cm 2 ) are submitted. It is established, that as a result of Boron ion implantation of the chrome - fullerite - chrome films, chrome and fullerite inter fusion on sues, that is the solid-phase interaction and as a result of which forms the heterophase with increased nano hardness. (authors)

Effect of cure cycle on curing process and hardness for epoxy resin

Directory of Open Access Journals (Sweden)

2009-09-01

Full Text Available A 3-dimensional finite element model is developed to simulate and analyze the temperature and degree of cure field of epoxy casting part during cure process. The present model based on general finite element software ABAQUS is verified by literature example and experimental data. The numerical results show good agreement with literature example and measured data, and are even more accurate than the simulation of literature. After modeling successfully, the influence of temperature cure cycle ramps have on the temperature and degree of cure gradient is investigated. Moreover, the effect of non-uniform temperature and degree of cure field within epoxy casting part on hardness is demonstrated. The present model provides an accurate and novel method that allows further insight into the process of cure for epoxy resin.
Electron Beam Welding of IN792 DS: Effects of Pass Speed and PWHT on Microstructure and Hardness.

Science.gov (United States)

Angella, Giuliano; Barbieri, Giuseppe; Donnini, Riccardo; Montanari, Roberto; Richetta, Maria; Varone, Alessandra

2017-09-05

Electron Beam (EB) welding has been used to realize seams on 2 mm-thick plates of directionally solidified (DS) IN792 superalloy. The first part of this work evidenced the importance of pre-heating the workpiece to avoid the formation of long cracks in the seam. The comparison of different pre-heating temperatures (PHT) and pass speeds ( v ) allowed the identification of optimal process parameters, namely PHT = 300 °C and v = 2.5 m/min. The microstructural features of the melted zone (MZ); the heat affected zone (HAZ), and base material (BM) were investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), electron back-scattered diffraction (EBSD), X-ray diffraction (XRD), and micro-hardness tests. In the as-welded condition; the structure of directionally oriented grains was completely lost in MZ. The γ' phase in MZ consisted of small (20-40 nm) round shaped particles and its total amount depended on both PHT and welding pass speed, whereas in HAZ, it was the same BM. Even if the amount of γ' phase in MZ was lower than that of the as-received material, the nanometric size of the particles induced an increase in hardness. EDS examinations did not show relevant composition changes in the γ' and γ phases. Post-welding heat treatments (PWHT) at 700 and 750 °C for two hours were performed on the best samples. After PWHTs, the amount of the ordered phase increased, and the effect was more pronounced at 750 °C, while the size of γ' particles in MZ remained almost the same. The hardness profiles measured across the joints showed an upward shift, but peak-valley height was a little lower, indicating more homogeneous features in the different zones.
Effect of substitutional element in the microstructure and hardness of Ti-Zr system alloys used as biomaterials

International Nuclear Information System (INIS)

Correa, D.R.N.; Vicente, F.B.; Grandini, C.R.

2010-01-01

New titanium alloys had been developed with the aim of obtaining materials with improved properties for application as biomaterial, and alloys of the Ti-Zr system are among those most promising. The objective of this study is to analyze the influence of the zirconium concentration on microstructure and hardness of the Ti-5Zr, Ti-10Zr and Ti-15Zr alloys. After arc-melting melting, the samples were analyzed by chemical and gas composition, and characterized by density measurements, optical microscopy, x-ray diffraction and hardness. The results showed a microstructure formed by alpha phase (hexagonal close-packed structure) and increased of hardness. (author)
Current status of the hard x-ray nanoprobe beamline at the SSRF

Science.gov (United States)

Li, Aiguo; Jiang, Hui; Wang, Hua; Zhang, Zhaohong; He, Yan; Zhao, Gaofeng; Shu, Deming

2017-09-01

The hard X-ray nanoprobe beamline (HXN) designed at the Shanghai Synchrotron Radiation facility (SSRF) will be of capability to realize a focal spot size of 10 nm for hard X-rays to satisfy requirements in biology, environmental, material sciences and etc.. The beamline includes two modes of operation, high energy resolution mode and high flux mode respectively. High flux mode utilizes the multilayer KB system to obtain high-flux diffraction-limited focusing of 10nm. An ultra-high-precision figure fabrication for diffraction-limited focusing is required to meet the Rayleigh Criterion. An idea to overcome this problem is to introduce a phase compensator upstream of the KB system to compensate the wavefront errors in the beamline. At wavelength speckle-based method will be used to measure the wavefront error in the beamline and feedback to the phase compensator. Vibration measurements have been carried out at the secondary source and endstation hutch. The flexure hinge mechanisms and high-precision actuators ensure the KB system and sample manipulator working with high stability. The building of HXN has been designed and is under construction at present.
Effect of Solution Treatment Process on Hardness of Alumina Reinforced Al-9Zn Composite Produced by Squeeze Casting

Directory of Open Access Journals (Sweden)

Dwi Rahmalina

2014-10-01

Full Text Available Characteristics of aluminium matrix composites reinforced by alumina have been developed to improve mechanical properties. One of the determining factors in the development of this material is parameter of solution treatment process. This study discusses the performance of the composite matrix of Al-9Zn-6Mg-3Si reinforced by alumina powder of 5 % volume fraction. Composite are manufactured by squeeze casting process with the pressure of 20 Ton in the metal mould. To improve mechanical properties, the precipitation hardening process is conducted through variation of temperature of solution treatment of 450, 475 and 500 °C and holding time of solution treatment of 30, 60 and 90 minutes. Materials are characterized by hardness testing and microstructure observation. The results showed that the optimum condition of hardness was produced by solution treatment temperature of 500 °C and 90 minutes holding time of 86 HRB.
Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

Science.gov (United States)

Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

2016-03-01

Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization
The quark-recombination model and correlations between hard and soft hadronic processes

International Nuclear Information System (INIS)

Ranft, J.

1978-07-01

Proceeding from the fact that quark and gluon recombination models make definite predictions for correlations between hard and soft processes, the following experiments are briefly discussed: (i) correlations between deep inelastic antineutrino-proton scattering and particle production in the proton fragmentation region, (ii) correlations between massive lepton pairs and particles produced in the fragmentation regions, and (iii) correlations between large transverse momentum particles and leading protons. In order to present the large transverse momentum - leading proton correlation, a divided correlation function similar to that used for studying short-range correlations of low transverse momentum particles is defined
The Role of Diffusion Media in Nitriding Process on Surface Layers Characteristics of AISI 4140 with and without Hard Chrome Coatings

Directory of Open Access Journals (Sweden)

K.A. Widi

2016-09-01

Full Text Available The surface layer characteristics of the AISI 4140 tool steel treated by nitriding gas before and after hard chrome plating utilizing pure nitrogen diffusion media (fluidized bed reactor and the without gas (muffle reactor has been studied experimentally. The result shows that nitriding substrate with hard chrome layers has nitrogen atoms concentration almost twice greater than that without hard chrome layers. After being given a hard chrome plating, nitriding on AISI 4140 steel generally has a nitrogen concentration of up to 4 times more than the substrate without hard chrome coating. Almost the entire specimen showed the highest concentration of N atoms in the area below the surface (hardening depth of 200 to 450 µm. N atoms diffusion depth profile has a correlation with hardening depth profile, especially on the specimens layered with hard chromium. The substrate without hard chrome plating tends to have higher surface hardness than the sub-surface. The results show that the effectiveness and efficiency of the gas nitriding diffusion process can be produced without the use of gas in the muffle reactor but the specimens must be hard chromium coated first. This phenomenon can be explained by the role of the passive layer formation that works as a barrier to keeps the spreading of N atoms concentrated in sub-surface areas.
Influence of preferred orientation of minerals in the mineralogical identification process by X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Silva, Amanda Luzia da; Oliveira, Arno H. de [Universidade Federal de Minas Gerais (DEN/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Nuclear; Fernandes, Maria Lourdes Souza, E-mail: lourdesfernandes@ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Inst. de GeoCiencias. Centro de Pesquisa Professor Manoel Teixeira da Costa

2011-07-01

The X-ray diffraction corresponds to one of the main techniques for characterization of microstructures in crystalline materials, widely used in the identification of minerals in samples of geological materials. Some minerals have a property called preferred orientation which corresponds to the orientation tendency of the crystals of ground minerals to orient themselves in certain directions according to a preferred crystallographic plane. This property affects the analysis by X-ray diffraction and this fact can generates erroneous results in the characterization. The purpose of this study is to identify the negative influence of the preferred orientation of a mineral in the generation of diffraction patterns obtained in the X-ray diffraction analysis. For this, a sample of muscovite, a mineral of mica group, was prepared by two different methods: the frontal method and the back loading method. In the analysis using the frontal method there was displacement of the XRD pattern in the abscissa axis, where it was observed changes in interplanar distance and angle 2{theta} values, which are essential information for characterization and identification of a mineral. In the analysis using the back loading method, the generated XRD pattern showed no displacement in the axis of abscissas and showed interplanar distance and angle 2{theta} values closer to the real values for the muscovite. The results showed that one can only make improvements to the process of sample preparation minimizing the effect of preferred orientation in the analysis. There is no need to change conditions of diffractometer measurements. (author)
Influence of preferred orientation of minerals in the mineralogical identification process by X-ray diffraction

International Nuclear Information System (INIS)

Silva, Amanda Luzia da; Oliveira, Arno H. de; Fernandes, Maria Lourdes Souza

2011-01-01

The X-ray diffraction corresponds to one of the main techniques for characterization of microstructures in crystalline materials, widely used in the identification of minerals in samples of geological materials. Some minerals have a property called preferred orientation which corresponds to the orientation tendency of the crystals of ground minerals to orient themselves in certain directions according to a preferred crystallographic plane. This property affects the analysis by X-ray diffraction and this fact can generates erroneous results in the characterization. The purpose of this study is to identify the negative influence of the preferred orientation of a mineral in the generation of diffraction patterns obtained in the X-ray diffraction analysis. For this, a sample of muscovite, a mineral of mica group, was prepared by two different methods: the frontal method and the back loading method. In the analysis using the frontal method there was displacement of the XRD pattern in the abscissa axis, where it was observed changes in interplanar distance and angle 2θ values, which are essential information for characterization and identification of a mineral. In the analysis using the back loading method, the generated XRD pattern showed no displacement in the axis of abscissas and showed interplanar distance and angle 2θ values closer to the real values for the muscovite. The results showed that one can only make improvements to the process of sample preparation minimizing the effect of preferred orientation in the analysis. There is no need to change conditions of diffractometer measurements. (author)
Nanometer Linear Focusing of Hard X Rays by a Multilayer Laue Lens

International Nuclear Information System (INIS)

Kang, H.C.; Stephenson, G.B.; Maser, J.; Liu, C.; Conley, R.; Macrander, A.T.; Vogt, S.

2006-01-01

We report on a type of linear zone plate for nanometer-scale focusing of hard x rays, a multilayer Laue lens (MLL), produced by sectioning a multilayer and illuminating it in Laue diffraction geometry. Because of its large optical depth, a MLL spans the diffraction regimes applicable to a thin Fresnel zone plate and a crystal. Coupled wave theory calculations indicate that focusing to 5 nm or smaller with high efficiency should be possible. Partial MLL structures with outermost zone widths as small as 10 nm have been fabricated and tested with 19.5 keV synchrotron radiation. Focal sizes as small as 30 nm with efficiencies up to 44% are measured
In-situ studies of the recrystallization process of CuInS2 thin films by energy dispersive X-ray diffraction

International Nuclear Information System (INIS)

Thomas, D.; Mainz, R.; Rodriguez-Alvarez, H.; Marsen, B.; Abou-Ras, D.; Klaus, M.; Genzel, Ch.; Schock, H.-W.

2011-01-01

Recrystallization processes during the sulfurization of CuInS 2 (CIS) thin films have been studied in-situ using energy dispersive X-ray diffraction (EDXRD) with synchrotron radiation. In order to observe the recrystallization isolated from other reactions occurring during film growth, Cu-poor, small grained CIS layers covered with CuS on top were heated in a vacuum chamber equipped with windows for synchrotron radiation in order to analyze the grain growth mechanism within the CIS layer. In-situ monitoring of the grain size based on diffraction line profile analysis of the CIS-112 reflection was utilized to interrupt the recrystallization process at different points. Ex-situ studies by electron backscatter diffraction (EBSD) and energy dispersive X-ray spectroscopy (EDX) performed on samples of intermediate recrystallization states reveal that during the heat treatment Cu and In interdiffuse inside the layer indicating the importance of the mobility of these two elements during CuInS 2 grain growth.
Neutron diffraction for studying the influence of the relative humidity on the carbonation process of cement pastes

International Nuclear Information System (INIS)

Galan, I; Andrade, C; Castellote, M; Rebolledo, N; Sanchez, J; Toro, L; Puente, I; Campo, J; Fabelo, O

2011-01-01

The effect of humidity on hydrated cement carbonation has been studied by means of in-situ neutron diffraction measurements. The evolution of the main crystalline phases in the bulk of the sample, portlandite and calcite, has been monitored during the process. Data obtained from neutron diffraction allow the quantification of the phases involved. The results highlight the great influence of humidity on carbonation. At very low humidity there are almost no changes. Between 53 and 75% relative humidity, portlandite decrease and calcite increase data can be fitted to exponential decay functions. At very high humidity portlandite remains nearly constant while calcite increases slightly with time, almost linearly.
Hair treatment process providing dispersed colors by light diffraction

Science.gov (United States)

Lamartine, Bruce Carvell; Orler, E. Bruce; Sutton, Richard Matthew Charles; Song, Shuangqi

2013-12-17

Hair was coated with polymer-containing fluid and then hot pressed to form a composite of hair and a polymer film imprinted with a nanopattern. Polychromatic light incident on the nanopattern is diffracted into dispersed colored light.
Diffractive processes in antiproton-proton collision at √s = 1.96 TeV in the D0 experiment

Energy Technology Data Exchange (ETDEWEB)

Otec, Roman [Czech Technical Univ., Prague (Czech Republic)

2006-01-01

A first study of single diffractive central high-p_T dijet events in p$\\bar{p}$ collisions at center-of-mass energy √s = 1.96 TeV is presented, using data recorded by the D0 detector at the Tevatron during RunIIa in 2002-2004. The total integrated luminosity corresponding to the data sample is 398 pb^-1. A diffractive sample is selected using a rapidity gap approach. A precise definition of the rapidity gap constitutes the first part of the thesis. The rapidity gap is defined by means of two parts of the D0 detector--luminosity detectors and calorimeter. Luminosity detectors serve as a basic indicators of diffractive candidates and the calorimeter is used to confirm the low energy activity in the forward region (a rapidity gap). Presented studies of energy deposited in forward part of calorimeter by various types of events yield two rapidity gap definitions. Both of them use a fixed rapidity interval in calorimeter |η| ϵ [2.6,5.2] and introduce an upper limit on the energy deposited in this region. First definition, which corresponds to the lowest systematical errors, uses a limit of 10 GeV, an energy limit in the second definition is set to 3 GeV. This alternative definition corresponds to the lowest contamination of diffractive sample by non-diffractive events, on the other hand it is accompanied with rejection of high percentage of diffractive candidates. Using the gap definition dijet diffractive data are then selected and compared to inclusive dijet events in various distributions. The main focus is to measure the difference in azimuthal angles between two leading jets in events with at least two high p_t central jets. This variable is sensitive to the dynamics of the process. Indeed, the results show the different behavior of ΔΦ distributions between the inclusive and diffractive samples. It is also shown that this difference is bigger for lower p_T jets. Other distributions presented in the thesis show that most
Study on the microstructure of recycled zircaloy by X-ray diffraction line profile analysis

International Nuclear Information System (INIS)

Ichikawa, Rodrigo U.; Pereira, Luiz A.T.; Imakuma, Kengo; Martinez, Luis G.; Turrillas, Xavier

2013-01-01

In the fabrication of nuclear fuel elements parts, Zircaloy machining chips are generated and, as this material is high-valued and controlled, its recycling presents high interest not only in economic aspects but also for environmental reasons and due to its strategic role in nuclear technology. Two processes for the recovery of these Zircaloy chips are being studied at IPEN-CNEN/SP. One of the processes is by conventional remelting of the material in a VAR (Vacuum Arc Remelting) furnace for producing solid ingots. Concurrently it is being studied an alternative process, by powder metallurgy methods, by which the chips are hydrided in order to become brittle and be grinded. The resulting ground powder is then compacted and finally vacuum-dehydrided and sintered in one step to form solid pieces. The VAR-remelted samples were also submitted to heat treatments in order to refine their microstructures, resulting in three different samples named 'as cast', 'annealed' and 'tempered'. The microstructures resulting from both processes and also from heat treatments were studied by metallography and X-ray diffraction (XRD). In this work, results of a XRD study are presented applying X-ray diffraction Line Profile Analysis (XLPA) methods in order to determine the mean crystallite sizes and the RMS microstrains on these samples. Additionally, a study for verify the influence of different standard materials used for the correction of the instrumental breadth in the XLPA was developed. The XLPA results show the influence of the processes and also of heat treatments on mean crystallite sizes and microstrains of the samples and were compared to their metallographic study and hardness. (author)
Radiation hardness of CMOS monolithic active pixel sensors manufactured in a 0.18 μm CMOS process

Energy Technology Data Exchange (ETDEWEB)

Linnik, Benjamin [Goethe-Universitaet Frankfurt (Germany); Collaboration: CBM-MVD-Collaboration

2015-07-01

CMOS Monolithic Active Pixels Sensors (MAPS) are considered as the technology of choice for various vertex detectors in particle and heavy-ion physics including the STAR HFT, the upgrade of the ALICE ITS, the future ILC detectors and the CBM experiment at FAIR. To match the requirements of those detectors, their hardness to radiation is being improved, among others in a joined research activity of the Goethe University Frankfurt and the IPHC Strasbourg. It was assumed that combining an improved high resistivity (1-8 kΩcm) sensitive medium with the features of a 0.18 μm CMOS process, is suited to reach substantial improvements in terms of radiation hardness as compared to earlier sensor designs. This strategy was tested with a novel generation of sensor prototypes named MIMOSA-32 and MIMOSA-34. We show results on the radiation hardness of those sensors and discuss its impact on the design of future vertex detectors.
Time-resolved x-ray diffraction measurement of C{sub 60} under high pressure and temperature using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Horikawa, T [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Suito, K [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Kobayashi, M [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Onodera, A [Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan)

2002-11-11

C{sub 60} has been studied by means of time-resolved x-ray diffraction measurements using synchrotron radiation. Diffraction patterns were recorded at intervals of 1-10 min for samples under high pressure (12.5 and 14.3 GPa) and high temperature (up to 800 deg. C) for, at the longest, 3 h. Time, pressure, and temperature dependences of the C{sub 60} structure are presented and the relevance to the hardness of materials derived from C{sub 60} is discussed.
Determination of electronic and atomic properties of surface, bulk and buried interfaces: Simultaneous combination of hard X-ray photoelectron spectroscopy and X-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Rubio-Zuazo, J., E-mail: rubio@esrf.fr [SpLine, Spanish CRG BM25 Beamline at the ESRF, ESRF, B.P. 220, F-38043 Grenoble (France); Instituto de Ciencia de Materiales de Madrid, ICMM, CSIC, Cantoblanco, E-28049 Madrid (Spain); Castro, G.R. [SpLine, Spanish CRG BM25 Beamline at the ESRF, ESRF, B.P. 220, F-38043 Grenoble (France); Instituto de Ciencia de Materiales de Madrid, ICMM, CSIC, Cantoblanco, E-28049 Madrid (Spain)

2013-10-15

Highlights: •We have developed a novel and exceptional tool for non-destructive characterization of bulk and buried interfaces that combine XRD and HAXPES. •We studied the correlation between the atomic, electronic and transport properties of oxygen deficient manganite thin films. •The diffraction data showed a cooperative tilt of the MnO{sub 6} block along the out-of-plane direction. •We shown the absence of the conventional basal plane rotation for the oxygen deficient samples. -- Abstract: Hard X-ray photoelectron spectroscopy (HAXPES) is a powerful novel emerging technique for bulk compositional, chemical and electronic properties determination in a non-destructive way. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons enabling the study of bulk and buried interfaces up to several tens of nanometres depth. Its advantage over conventional XPS is based on the long mean free path of high kinetic energetic photoelectrons. Using the advantage of tuneable X-ray radiation provided by synchrotron sources the photoelectron kinetic energy, i.e. the information depth can be changed and consequently electronic and compositional depth profiles can be obtained. The combination of HAXPES with an atomic structure sensitive technique, as X-ray diffraction, opens a new research field with great potential for many systems in which their electronic properties are intimately linked to their crystallographic structure. At SpLine, the Spanish CRG Beamline at the European Synchrotron Radiation Facility (ESRF) we have developed a novel and exceptional set-up that combine grazing incidence X-ray diffraction (GIXRD) and HAXPES. Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a heavy 2S+3D diffractometer and UHV chamber equipped with an electrostatic analyzer. The UHV chamber has also MBE evaporation sources, an ion gun, a LEED optic, a sample heating and cooling
Phenomenology of the proton and the nucleus through hard processes in quantum chromodynamics

International Nuclear Information System (INIS)

Gousset, T.

2005-01-01

My scientific domain is the phenomenology of the non-perturbative quantum chromodynamics (QCD). In the introduction I quickly present the history of QCD since its establishing in the seventies. The first chapter is dedicated to the achievements of the last decade concerning first the hard electroproduction at low impulse transfer in electron-proton reactions and secondly the search for the quark-gluon plasma in ultra-relativistic heavy ion reactions with the help of hard probes. In the second chapter I detail the hard electroproduction reactions with the aim of explaining their factorization in a sub-process including partons and whose amplitude can be computed in the theory of perturbations. Generalized parton distributions, that describe the transition from hadrons to partons could be useful to get more information on hadronic wave functions. Experimental implications are reviewed. The third chapter is dedicated to the J/ψ production in proton-nucleus collisions. J/ψ and the quarkonium family offer, thanks to their easy identification a useful tool to shed light on different sides of QCD such as the production of heavy quarks or the existence of the quark-gluon plasma. In the last chapter I present my last works that concern first the nuclear effects that appear in proton-nucleus collisions when we want to describe the relationship between the production cross-section of a particle and the value of the transverse momentum of the particle, and secondly the observation through radio-detection of big showers due to the interaction with the atmosphere of an ultra-high energy cosmic ray [fr

Influence of diffractive interactions on cosmic ray air showers

International Nuclear Information System (INIS)

Luna, R.; Zepeda, A.; Garcia Canal, C.A.; Sciutto, S.J.

2004-01-01

A comparative study of commonly used hadronic collision simulation packages is presented. The characteristics of the products of hadron-nucleus collisions are analyzed from a general perspective, but focusing on their correlation with diffractive processes. One of the purposes of our work is to give quantitative estimations of the impact that different characteristics of the hadronic models have on air shower observables. Several sets of shower simulations using different settings for the parameters controlling the diffractive processes are used to analyze the correlations between diffractivity and shower observables. We find that the relative probability of diffractive processes during the shower development have a non-negligible influence over the longitudinal profile as well as the distribution of muons at ground level. The implications on experimental data analysis are discussed
Electrodeposited Ni-B coatings: Formation and evaluation of hardness and wear resistance

International Nuclear Information System (INIS)

Krishnaveni, K.; Sankara Narayanan, T.S.N.; Seshadri, S.K.

2006-01-01

The formation of electrodeposited Ni-B alloy coatings using a dimethylamine borane (DMAB) modified Watt's nickel bath and evaluation of their structural characteristics, hardness and wear resistance are discussed. The boron content in the electrodeposited Ni-B alloy coating is determined by the ratio of rate of reduction of nickel and rate of decomposition of DMAB. The boron content of the electrodeposited Ni-B coating decreases as the current density increased from 0.4 to 4 A dm -2 . XRD diffraction pattern of electrodeposited Ni-B coatings in their as-plated condition exhibits the presence of Ni (1 1 1) (2 0 0) and (2 2 0) reflections with (1 1 1) texture. Heat treatment at 400 deg. C for 1 h has resulted in the formation of nickel boride phases, which results in an increase in hardness and wear resistance. The mechanism of wear in electrodeposited Ni-B coatings is intensive plastic deformation of the coating due to the ploughing action of the hard counter disk
Tomography with energy dispersive diffraction

Science.gov (United States)

Stock, S. R.; Okasinski, J. S.; Woods, R.; Baldwin, J.; Madden, T.; Quaranta, O.; Rumaiz, A.; Kuczewski, T.; Mead, J.; Krings, T.; Siddons, P.; Miceli, A.; Almer, J. D.

2017-09-01

X-ray diffraction can be used as the signal for tomographic reconstruction and provides a cross-sectional map of the crystallographic phases and related quantities. Diffraction tomography has been developed over the last decade using monochromatic x-radiation and an area detector. This paper reports tomographic reconstruction with polychromatic radiation and an energy sensitive detector array. The energy dispersive diffraction (EDD) geometry, the instrumentation and the reconstruction process are described and related to the expected resolution. Results of EDD tomography are presented for two samples containing hydroxyapatite (hAp). The first is a 3D-printed sample with an elliptical crosssection and contains synthetic hAp. The second is a human second metacarpal bone from the Roman-era cemetery at Ancaster, UK and contains bio-hAp which may have been altered by diagenesis. Reconstructions with different diffraction peaks are compared. Prospects for future EDD tomography are also discussed.
Synthesis of mesoporous hydroxyapatite using a modified hard-templating route

International Nuclear Information System (INIS)

Xia Zhiguo; Liao Libing; Zhao Senlin

2009-01-01

Mesoporous polycrystals of hydroxyapatite-calcium are synthesized via a modified hard-templating route. The structure properties of hydroxyapatite-calcium are characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and N 2 adsorption-desorption isotherms. Wide-angle X-ray diffraction and Fourier transform infrared spectroscopy measurements reveal that the crystalline grains consist of highly crystalline pure hydroxyapatite phases. Transmission electron microscopy results show that rod-like hydroxyapatite-calcium grains with an average diameter of about 100 nm long and about 20 nm wide are uniformly distributed, which are also observed with an average pore size of 2-3 nm. Based on N 2 adsorption-desorption isotherms investigation, the pore size, surface area and pore volume of mesoporous hydroxyapatite-calcium are 2.73 nm, 42.43 m 2 g -1 and 0.12 cm 3 g -1 , respectively.
Effect of Tip Shape of Frictional Stir Burnishing Tool on Processed Layer’s Hardness, Residual Stress and Surface Roughness

Directory of Open Access Journals (Sweden)

Yoshimasa Takada

2018-01-01

Full Text Available Friction stir burnishing (FSB is a surface-enhancement method used after machining, without the need for an additional device. The FSB process is applied on a machine that uses rotation tools (e.g., machining center or multi-tasking machine. Therefore, the FSB process can be applied immediately after the cutting process using the same machine tool. Here, we apply the FSB to the shaft materials of 0.45% C steel using a multi-tasking machine. In the FSB process, the burnishing tool rotates at a high-revolution speed. The thin surface layer is rubbed and stirred as the temperature is increased and decreased. With the FSB process, high hardness or compressive residual stress can be obtained on the surface layer. However, when we applied the FSB process using a 3 mm diameter sphere tip shape tool, the surface roughness increased substantially (Ra = 20 µm. We therefore used four types of tip shape tools to examine the effect of burnishing tool tip radius on surface roughness, hardness, residual stress in the FSB process. Results indicated that the surface roughness was lowest (Ra = 10 µm when the tip radius tool diameter was large (30 mm.
Diffractive dijet photoproduction in ep collisions at HERA

Energy Technology Data Exchange (ETDEWEB)

Aaron, F.D. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Bucharest Univ. (Romania). Faculty of Physics; Alexa, C. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Andreev, V. [Lebedev Physical Institute, Moscow (RU)] (and others)

2010-03-15

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb{sup -1}. The events are of the type ep{yields}eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x{sub {gamma}} of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models. (orig.)
Diffractive dijet photoproduction in ep collisions at HERA

Energy Technology Data Exchange (ETDEWEB)

Aaron, F.D.; Alexa, C.; Rotaru, M.; Stoicea, G. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Andreev, V.; Belousov, A.; Eliseev, A.; Fomenko, A.; Gogitidze, N.; Lebedev, A.; Loktionova, N.; Malinovski, E.; Rusakov, S.; Shtarkov, L.N.; Soloviev, Y.; Vazdik, Y. [Lebedev Physical Inst., Moscow (Russian Federation); Backovic, S.; Dubak, A.; Lastovicka-Medin, G.; Picuric, I.; Raicevic, N. [Univ. of Montenegro, Faculty of Science, Podgorica (ME); Baghdasaryan, A.; Zohrabyan, H. [Yerevan Physics Inst. (Armenia); Barrelet, E. [CNRS/IN2P3, LPNHE, Univ. Pierre et Marie Curie Paris 6, Univ. Denis Diderot Paris 7, Paris (France); Bartel, W.; Brandt, G.; Campbell, A.J.; Cholewa, A.; Deak, M.; Eckerlin, G.; Elsen, E.; Felst, R.; Fischer, D.J.; Fleischer, M.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Gouzevitch, M.; Grebenyuk, A.; Grell, B.R.; Habib, S.; Haidt, D.; Helebrant, C.; Katzy, J.; Kleinwort, C.; Knutsson, A.; Kraemer, M.; Kutak, K.; Levonian, S.; Lipka, K.; List, J.; Marti, Ll.; Meyer, A.B.; Meyer, J.; Niebuhr, C.; Nikiforov, A.; Olsson, J.E.; Pahl, P.; Panagoulias, I.; Papadopoulou, T.; Petrukhin, A.; Piec, S.; Pitzl, D.; Placakyte, R.; Schmitt, S.; Sefkow, F.; Staykova, Z.; Steder, M.; Toll, T.; Vargas Trevino, A.; Driesch, M. von den; Wuensch, E. [DESY, Hamburg (Germany); Begzsuren, K.; Ravdandorj, T.; Tseepeldorj, B. [Inst. of Physics and Technology of the Mongolian Academy of Sciences, Ulaanbaatar (Mongolia); Bizot, J.C.; Brisson, V.; Delcourt, B.; Jacquet, M.; Pascaud, C.; Tran, T.H.; Zhang, Z.; Zomer, F. [CNRS/IN2P3, LAL, Univ. Paris-Sud, Orsay (France); Boudry, V.; Moreau, F.; Specka, A. [CNRS/IN2P3, LLR, Ecole Polytechnique, Palaiseau (France); Bozovic-Jelisavcic, I.; Mudrinic, M.; Pandurovic, M.; Smiljanic, I. [Vinca Inst. of Nuclear Sciences, Belgrade (RS); Bracinik, J.; Kenyon, I.R.; Newman, P.R.; Shaw-West, R.N.; Thompson, P.D. [Univ. of Birmingham (United Kingdom). School of Physics and Astronomy] (and others)

2010-11-15

Measurements are presented of single and double-differential dijet cross sections in diffractive photoproduction based on a data sample with an integrated luminosity of 47 pb{sup -1}. The events are of the type ep{yields}eXY, where the hadronic system X contains at least two jets and is separated by a large rapidity gap from the system Y, which consists of a leading proton or low-mass proton excitation. The dijet cross sections are compared with QCD calculations at next-to-leading order and with a Monte Carlo model based on leading order matrix elements with parton showers. The measured cross sections are smaller than those obtained from the next-to-leading order calculations by a factor of about 0.6. This suppression factor has no significant dependence on the fraction x{sub {gamma}} of the photon four-momentum entering the hard subprocess. Ratios of the diffractive to the inclusive dijet cross sections are measured for the first time and are compared with Monte Carlo models. (orig.)
Multi-order nonlinear diffraction in second harmonic generation

DEFF Research Database (Denmark)

Saltiel, S. M.; Neshev, D.; Krolikowski, Wieslaw

We analyze the emission patterns in the process of second harmonic (SH) generation in χ(2) nonlinear gratings and identify for the first time, to the best of our knowledge, the evidence of Raman-Nath type nonlinear diffraction in frequency doubling processes.......We analyze the emission patterns in the process of second harmonic (SH) generation in χ(2) nonlinear gratings and identify for the first time, to the best of our knowledge, the evidence of Raman-Nath type nonlinear diffraction in frequency doubling processes....
Visualization of electrolyte filling process and influence of vacuum during filling for hard case prismatic lithium ion cells by neutron imaging to optimize the production process

Science.gov (United States)

Weydanz, W. J.; Reisenweber, H.; Gottschalk, A.; Schulz, M.; Knoche, T.; Reinhart, G.; Masuch, M.; Franke, J.; Gilles, R.

2018-03-01

The process of filling electrolyte into lithium ion cells is time consuming and critical to the overall battery quality. However, this process is not well understood. This is partially due to the fact, that it is hard to observe it in situ. A powerful tool for visualization of the process is neutron imaging. The filling and wetting process of the electrode stack can be clearly visualized in situ without destruction of the actual cell. The wetting of certain areas inside the electrode stack can clearly be seen when using this technique. Results showed that wetting of the electrode stack takes place in a mostly isotropic manner from the outside towards a center point of the cell at very similar speed. When the electrolyte reaches the center point, the wetting process can be considered complete. The electrode wetting is a slow but rather steady process for hard case prismatic cells. It starts with a certain speed, which is reduced over the progress of the wetting. Vacuum can assist the process and accelerate it by about a factor of two as was experimentally shown. This gives a considerable time and cost advantage for designing the production process for large-scale battery cell production.
Daily Stress, Hearing-Specific Stress and Coping: Self-Reports from Deaf or Hard of Hearing Children and Children with Auditory Processing Disorder

Science.gov (United States)

Eschenbeck, Heike; Gillé, Vera; Heim-Dreger, Uwe; Schock, Alexandra; Schott, Andrea

2017-01-01

This study evaluated stressors and coping strategies in 70 children who are deaf or hard of hearing (D/HH) or with auditory processing disorder (APD) attending Grades 5 and 6 of a school for deaf and hard-of-hearing children. Everyday general stressors and more hearing-specific stressors were examined in a hearing-specific modified stress and…
New diffractive results from the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Gallinaro, Michele; /Rockefeller U.

2005-05-01

Experimental results in diffractive processes are summarized and a few notable characteristics described in terms of Quantum Chromodynamics. Exclusive dijet production is used to establish a benchmark for future experiments in the quest for diffractive Higgs production at the Large Hadron Collider. Using new data from the Tevatron and dedicated diffractive triggers, no excess over a smooth falling distribution for exclusive dijet events could be found. Stringent upper limits on the exclusive dijet production cross section are presented. The quark/gluon composition of dijet final states is used to provide additional hints on exclusive dijet production.
Femtosecond response of polyatomic molecules to ultra-intense hard X-rays.

Science.gov (United States)

Rudenko, A; Inhester, L; Hanasaki, K; Li, X; Robatjazi, S J; Erk, B; Boll, R; Toyota, K; Hao, Y; Vendrell, O; Bomme, C; Savelyev, E; Rudek, B; Foucar, L; Southworth, S H; Lehmann, C S; Kraessig, B; Marchenko, T; Simon, M; Ueda, K; Ferguson, K R; Bucher, M; Gorkhover, T; Carron, S; Alonso-Mori, R; Koglin, J E; Correa, J; Williams, G J; Boutet, S; Young, L; Bostedt, C; Son, S-K; Santra, R; Rolles, D

2017-06-01

X-ray free-electron lasers enable the investigation of the structure and dynamics of diverse systems, including atoms, molecules, nanocrystals and single bioparticles, under extreme conditions. Many imaging applications that target biological systems and complex materials use hard X-ray pulses with extremely high peak intensities (exceeding 10 20 watts per square centimetre). However, fundamental investigations have focused mainly on the individual response of atoms and small molecules using soft X-rays with much lower intensities. Studies with intense X-ray pulses have shown that irradiated atoms reach a very high degree of ionization, owing to multiphoton absorption, which in a heteronuclear molecular system occurs predominantly locally on a heavy atom (provided that the absorption cross-section of the heavy atom is considerably larger than those of its neighbours) and is followed by efficient redistribution of the induced charge. In serial femtosecond crystallography of biological objects-an application of X-ray free-electron lasers that greatly enhances our ability to determine protein structure-the ionization of heavy atoms increases the local radiation damage that is seen in the diffraction patterns of these objects and has been suggested as a way of phasing the diffraction data. On the basis of experiments using either soft or less-intense hard X-rays, it is thought that the induced charge and associated radiation damage of atoms in polyatomic molecules can be inferred from the charge that is induced in an isolated atom under otherwise comparable irradiation conditions. Here we show that the femtosecond response of small polyatomic molecules that contain one heavy atom to ultra-intense (with intensities approaching 10 20 watts per square centimetre), hard (with photon energies of 8.3 kiloelectronvolts) X-ray pulses is qualitatively different: our experimental and modelling results establish that, under these conditions, the ionization of a molecule is
Microstructure–hardness relationship in the fusion zone of TRIP steel welds

International Nuclear Information System (INIS)

Nayak, S.S.; Baltazar Hernandez, V.H.; Okita, Y.; Zhou, Y.

2012-01-01

Highlights: ► Fusion zone of TRIP steels in resistance spot welding was analyzed. ► Transmission electron microscopy (TEM) was used for characterizing microstructure. ► Fusion zone microstructure was found to depend on the chemistry. ► Hardness values were in accordance with the microstructural constituents in the fusion zone. - Abstract: Fusion zone of three TRIP steels, categorized as AT: C–Mn–Al, AST: C–Mn–Al–Si and ST: C–Mn–Si, in resistance spot welding was characterized with respect to microstructure, phase analysis, and hardness. The fusion zone microstructure was found to depend on chemistry: (i) AT steel contained ferrite phase surrounded by bainite and martensite regions, (ii) AST steel showed a bainite structures along with martensite laths and interlath retained austenite, whereas (iii) ST steel constituted single phase martensite laths with interlath austenite. X-ray diffraction study indicated that retained austenite fraction in the fusion zone increases with increase in Si content in it. The AST fusion zone hardness lies between those of the AT and ST steels; the ST fusion zone hardness was higher than that of AT steel because of the single phase martensite microstructure. Comparison of fusion zone microstructure and hardness to earlier study on laser welding of the TRIP steels with similar chemistries revealed that higher cooling rate in resistance spot welding led to higher fusion zone hardness compared to laser welding; which was attributed either to decrease in softer ferrite phase (AT steel) in the microstructure or refinement of martensite laths (ST steel).
Process of diffractive scattering and disintegration of complex particles by nonspherical deformed nuclei

International Nuclear Information System (INIS)

Evlanov, M.V.

1989-01-01

The differential and integral cross sections of diffractive elastic and inelastic scattering and of the disintegration of complex particles by axial and nonaxial deformed nuclei are investigated depending on the shape, deformability and diffuseness of nuclear boundary as well as on the structure of the incident particles and of the rescattering processes. It is shown that the complicated coincidence experiments and experimnts on inelastic scattering with excitation of the target nucleus collective states are satisfactorily described taking simultaneously into account all factors mentioned above and the final-state interaction between the disintegration products of the incident particle
Probing diffractive production of gauge bosons at forward rapidities

Energy Technology Data Exchange (ETDEWEB)

Basso, Eduardo; Rangel, Murilo S. [Universidade Federal do Rio de Janeiro, Instituto de Fisica, Caixa Postal 68528, Rio de Janeiro, RJ (Brazil); Goncalves, Victor P. [Universidade Federal de Pelotas, Instituto de Fisica e Matematica, Pelotas, RS (Brazil)

2016-12-15

Gauge boson production at forward rapidities in single diffractive events at the LHC is investigated considering pp collisions at √(s) = 8 and 13 TeV. The impact of gap survival effects is analysed using two different models for the soft rescattering contributions. We demonstrate that using the forward shower counter Project at LHCb-HERSCHEL, together with the Vertex Locator-VELO, it is possible to discriminate diffractive production of the gauge bosons W and Z from the non-diffractive processes and studies of the Pomeron structure and diffraction phenomenology are feasible. Moreover, we show that the analysis of this process can be useful to constrain the modelling of the gap survival effects. (orig.)
Neodymium as the main feature of permanent magnets from hard disk drives (HDDs).

Science.gov (United States)

München, Daniel Dotto; Veit, Hugo Marcelo

2017-03-01

As a way to manage neodymium-iron-boron (NdFeB) magnets wasted in end-of-life hard disk drives (HDDs), a waste characterization is needed prior to a recycling process. Due to their magnetic properties, NdFeB magnets are essential in technological applications nowadays, thus causing an increase in the industrial demand for rare earth metals. However, these metals have a short supply, since they are difficult to obtain from ores, creating a critical market. In this work, a study of the characterization of sintered neodymium-iron-boron magnets was undertaken by qualitatively and quantitatively uncovering the neodymium recovery potential from this type of electronic waste. From the collection and disassembly of hard disk drives, in which the magnet represents less than 3% of the total weight, an efficient demagnetization process was proceeded at 320°C. Then, the magnet was ground and screened for an X-ray diffraction (XRD) analysis, which showed the Nd 2 Fe 14 B tetragonal phase as the dominant constituent of the sample. An analysis was also carried out in a scanning electron microscope (SEM) and an inductively coupled plasma optical emission spectrometer (ICP-OES), where the magnet composition showed 21.5wt% of neodymium and 65.1wt% of iron, among other chemicals. This Nd content is higher than the one found in Nd ores, enhancing the recyclability and the importance of waste management. Copyright © 2017 Elsevier Ltd. All rights reserved.
Induction surface hardening of hard coated steels

DEFF Research Database (Denmark)

Pantleon, Karen; Kessler, Olaf; Hoffmann, Franz

1999-01-01

The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD-process is......The deposition of hard coatings with CVD-processes is commonly used to improve the wear resistance e.g. of tool steels in forming. The advantages of CVD are undisputed (high deposition rates with simple equipment, excellent coating properties). Nevertheless, the disadvantage of the CVD...
Diffraction efficiency calculations of polarization diffraction gratings with surface relief

Science.gov (United States)

Nazarova, D.; Sharlandjiev, P.; Berberova, N.; Blagoeva, B.; Stoykova, E.; Nedelchev, L.

2018-03-01

In this paper, we evaluate the optical response of a stack of two diffraction gratings of equal one-dimensional periodicity. The first one is a surface-relief grating structure; the second, a volume polarization grating. This model is based on our experimental results from polarization holographic recordings in azopolymer films. We used films of commercially available azopolymer (poly[1-[4-(3-carboxy-4-hydroxyphenylazo) benzenesulfonamido]-1,2-ethanediyl, sodium salt]), shortly denoted as PAZO. During the recording process, a polarization grating in the volume of the material and a relief grating on the film surface are formed simultaneously. In order to evaluate numerically the optical response of this “hybrid” diffraction structure, we used the rigorous coupled-wave approach (RCWA). It yields stable numerical solutions of Maxwell’s vector equations using the algebraic eigenvalue method.
About statistical process contribution to elastic diffraction scattering

International Nuclear Information System (INIS)

Ismanov, E.I.; Dzhuraev, Sh. Kh.; Paluanov, B.K.

1999-01-01

The experimental data on angular distribution show two basic properties. The first one is the presence of back and front peaks. The second one is the angular isotropic distribution near 90 degree, and has a big energy dependence. Different models for partial amplitudes a dl of the diffraction statistical scattering, particularly the model with Gaussian and exponential density distribution, were considered. The experimental data on pp-scattering were analyzed using the examined models
The microstructure and surface hardness of Ti6Al4V alloy implanted with nitrogen ions at an elevated temperature

Energy Technology Data Exchange (ETDEWEB)

Vlcak, Petr, E-mail: petr.vlcak@fs.cvut.cz [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague (Czech Republic); Cerny, Frantisek [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague (Czech Republic); Drahokoupil, Jan [Department of Metals, Institute of Physics, AS CR, v.v.i., Na Slovance 2, 182 21 Prague (Czech Republic); Sepitka, Josef [Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague (Czech Republic); Tolde, Zdenek [Department of Materials Engineering, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, 16607 Prague (Czech Republic)

2015-01-25

Highlights: • The Ti6Al4V samples were implanted with 90 keV nitrogen ions. • The samples were annealed at 500 °C during the ion implantation process. • An elevated temperature increases the mobility of the atoms and the quantity of TiN. • The hardness showed a significant increase compared to room temperature implantation. - Abstract: The effect of an elevated temperature during nitrogen ion implantation on the microstructure and on the surface hardness of Ti6Al4V titanium alloy was examined. The implantation process was carried out at fluences of 1 ⋅ 10{sup 17}, 2.7 ⋅ 10{sup 17} and 6 ⋅ 10{sup 17} cm{sup −2} and at ion energy 90 keV. The implanted samples were annealed at 500 °C during the implantation process. X-ray diffraction analysis was performed to obtain a phase characterization and a phase quantification in the implanted sample surface. The surface hardness was investigated by nanoindentation testing, and the nitrogen depth distribution was measured by Rutherford Backscattering Spectroscopy. Elevated temperature led to increased formation of a TiN compound. It was found that a mixture of TiN and an α-Ti(+N) solid solution had a predominant amount of TiN for samples with fluence of 2.7 ⋅ 10{sup 17} cm{sup −2} or higher. Elevated temperature during ion implantation caused an increase in surface hardening more towards the depth of the substrate in comparison with room temperature implantation. The hardness showed a remarkably significant increase at a fluence of 1 ⋅ 10{sup 17} and 2.7 ⋅ 10{sup 17} cm{sup −2} compared to samples implanted at the same fluences and at room temperature. There is a discussion of such mechanisms that explain the observed hardening more towards the depth of the substrate, and the increase in hardness.

Nano grained AZ31 alloy achieved by equal channel angular rolling process

International Nuclear Information System (INIS)

Hassani, F.Z.; Ketabchi, M.

2011-01-01

Equal channel angular rolling (ECAR) is a severe plastic deformation process which is carried out on large, thin sheets. The grain size could be significantly decreased by this process. The main purpose of this study is to investigate the possibility of grain refinement of AZ31 magnesium alloy sheet by this process to nanometer. The effect of the number of ECAR passes on texture evolution of AZ31 magnesium alloy was investigated. ECAR temperature was controlled to maximize the grain refinement efficiency along with preventing cracking. The initial microstructure of as-received AZ31 sheet showed an average grain size of about 21 μm. The amount of grain refinement increased with increasing the pass number. After 10 passes of the process, significant grain refinement occurred and the field emission scanning electron microscopic (FESEM) micrographs showed that the size of grains were decreased significantly to about 14-70 nm. These grains were formed at the grain boundaries and inside some of the previous larger micrometer grains. Observation of optical microstructures and X-ray diffraction patterns (XRD) showed the formation of twins after ECAR process. Micro-hardness of material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of ECAR process. At the 8th pass, hardness values increased by 53%. At final passes hardness reduced slightly, which was attributed to saturation of strain in high number of passes.
On the determination of double diffraction dissociation cross section at HERA

International Nuclear Information System (INIS)

Holtmann, H.; Nikolaev, N.N.; Speth, J.; Zakharov, B.G.

1996-01-01

The excitation of the proton into undetected multiparticle states (double diffraction dissociation) is an important background to single diffractive deep-inelastic processes ep→e'p'ρ 0 , e'p'J/Ψ, e'p'X at HERA. We present estimates of the admixture of the double diffraction dissociation events in all diffractive events. We find that in the J/Ψ photoproduction, electroproduction of the ρ 0 at large Q 2 and diffraction dissociation of real and virtual photons into high mass states X the contamination of the double diffraction dissociation can be as large as ∼30%, thus affecting substantially the experimental tests of the pomeron exchange in deep inelastic scattering at HERA. We discuss a possibility of tagging the double diffraction dissociation by neutrons observed in the forward neutron calorimeter. We present evaluations of the spectra of neutrons and efficiency of neutron tagging based on the experimental data for diffractive processes in the proton-proton collisions. (orig.)
Revisiting the definition of local hardness and hardness kernel.

Science.gov (United States)

Polanco-Ramírez, Carlos A; Franco-Pérez, Marco; Carmona-Espíndola, Javier; Gázquez, José L; Ayers, Paul W

2017-05-17

An analysis of the hardness kernel and local hardness is performed to propose new definitions for these quantities that follow a similar pattern to the one that characterizes the quantities associated with softness, that is, we have derived new definitions for which the integral of the hardness kernel over the whole space of one of the variables leads to local hardness, and the integral of local hardness over the whole space leads to global hardness. A basic aspect of the present approach is that global hardness keeps its identity as the second derivative of energy with respect to the number of electrons. Local hardness thus obtained depends on the first and second derivatives of energy and electron density with respect to the number of electrons. When these derivatives are approximated by a smooth quadratic interpolation of energy, the expression for local hardness reduces to the one intuitively proposed by Meneses, Tiznado, Contreras and Fuentealba. However, when one combines the first directional derivatives with smooth second derivatives one finds additional terms that allow one to differentiate local hardness for electrophilic attack from the one for nucleophilic attack. Numerical results related to electrophilic attacks on substituted pyridines, substituted benzenes and substituted ethenes are presented to show the overall performance of the new definition.
Effect of processing on the microstructure of finger millet by X-ray diffraction and scanning electron microscopy.

Science.gov (United States)

Dharmaraj, Usha; Parameswara, P; Somashekar, R; Malleshi, Nagappa G

2014-03-01

Finger millet is one of the important minor cereals, and carbohydrates form its major chemical constituent. Recently, the millet is processed to prepare hydrothermally treated (HM), decorticated (DM), expanded (EM) and popped (PM) products. The present research aims to study the changes in the microstructure of carbohydrates using X-ray diffraction and scanning electron microscopy. Processing the millet brought in significant changes in the carbohydrates. The native millet exhibited A-type pattern of X-ray diffraction with major peaks at 2θ values of 15.3, 17.86 and 23.15°, whereas, all other products showed V-type pattern with single major peak at 2θ values ranging from 19.39 to 19.81°. The corresponding lattice spacing and the number of unit cells in a particular direction of reflection also reduced revealing that crystallinity of starch has been decreased depending upon the processing conditions. Scanning electron microscopic studies also revealed that the orderly pattern of starch granules changed into a coherent mass due to hydrothermal treatment, while high temperature short time treatment rendered a honey-comb like structure to the product. However, the total carbohydrates and non-starch polysaccharide contents almost remained the same in all the products except for DM and EM, but the individual carbohydrate components changed significantly depending on the type of processing.
Opalescence of quartz: a study by high energy x-ray diffraction

Science.gov (United States)

Bastie, P.; Dolino, G.; Hamelin, B.

2003-05-01

The origin of the opalescence observed at the α-β transition of quartz remains an open question. This intense light scattering occurs during the coexistence, at the first order transition, of the α and incommensurate (inc) phases, in the vicinity of the phase interface. New hard x-ray diffraction experiment shows that the large angle light scattering is mainly in the α-phase region of the crystal and reveals the existence of an intermediate structure between the α-phase and the 3q inc phase.
Opalescence of quartz: a study by high energy x-ray diffraction

Energy Technology Data Exchange (ETDEWEB)

Bastie, P [Laboratoire de Spectrometrie Physique, Universite Joseph Fourier-Grenoble 1 - CNRS, UMR No 5588, BP 87, 38402 Saint Martin d' Heres Cedex (France); Dolino, G [Laboratoire de Spectrometrie Physique, Universite Joseph Fourier-Grenoble 1 - CNRS, UMR No 5588, BP 87, 38402 Saint Martin d' Heres Cedex (France); Hamelin, B [Institut Laue Langevin, BP 156X, 38042 Grenoble Cedex 9 (France)

2003-05-21

The origin of the opalescence observed at the {alpha}-{beta} transition of quartz remains an open question. This intense light scattering occurs during the coexistence, at the first order transition, of the {alpha} and incommensurate (inc) phases, in the vicinity of the phase interface. New hard x-ray diffraction experiment shows that the large angle light scattering is mainly in the {alpha}-phase region of the crystal and reveals the existence of an intermediate structure between the {alpha}-phase and the 3q inc phase.
Light-scattering theory of diffraction.

Science.gov (United States)

Guo, Wei

2010-03-01

Since diffraction is a scattering process in principle, light propagation through one aperture in a screen is discussed in the light-scattering theory. Through specific calculation, the expression of the electric field observed at an observation point is obtained and is used not only to explain why Kirchhoff's diffraction theory is a good approximation when the screen is both opaque and sufficiently thin but also to demonstrate that the mathematical and physical problems faced by Kirchhoff's theory are avoided in the light-scattering theory.
Measurement of diffractive and exclusive processes with the ATLAS detector

Directory of Open Access Journals (Sweden)

Gach Grzegorz

2016-01-01

Full Text Available The ATLAS Collaboration has carried out a study of diffractive dijet production in proton–proton collisions at a centre-of-mass energy of √s = 7 TeV at the LHC. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. Prospects for exclusive jet production studies with the forward proton tagging capability of the AFP sub-detector of ATLAS are also discussed. First results based on data taken jointly with the ATLAS and the LHCf detectors in a p+Pb run will also be shown. In addition, the measurement of the cross-section for the exclusive production of di-lepton pairs in pp collisions at √s = 7 TeV is discussed.
Hard X-ray studies on the Castor tokamak

International Nuclear Information System (INIS)

Mlynar, J.

1990-04-01

The electron runaway processes in tokamaks are discussed with regard to hard X radiation measurements. The origin and confinement of runaway electrons, their bremsstrahlung spectra and the influence of lower hybrid current drive on the distribution of high-energy electrons are analyzed for the case of the Castor tokamak. The hard X-ray spectrometer designed for the Castor tokamak is also described and preliminary qualitative results of hard X-ray measurements are presented. The first series of integral measurements made it possible to map the azimuthal dependence of the hard X radiation
Structure, hardness and fracture features of nanostructural materials

International Nuclear Information System (INIS)

Noskova, N.I.; Korznikov, A.V.; Idrisova, S.R.

2000-01-01

A study is made into nanocrystalline metals Cu and Mo, nanocrystalline intermetallic compound Ni 3 Al produced using severe plastic deformation; nanophase alloys Fe 73.5 Cu 1 Nb 3 Si 1.35 B 9 and Pd 81 Cu 7 Si 12 produced by crystallization from amorphous state as well as nanophase materials TiN and Al 2 O 3 produced by nano powder compacting in the temperature range of 273-573 K. Methods of transmission and scanning electron microscopy, X-ray diffraction analysis, mechanical testing and microhardness measurement are applied to study structure, internal elastic stress, phase composition, hardness, strength and plastic properties, surface fracture mode of nanostructural materials [ru
Visual inspection technology in the hard disc drive industry

CERN Document Server

Muneesawang, Paisarn

2015-01-01

A presentation of the use of computer vision systems to control manufacturing processes and product quality in the hard disk drive industry. Visual Inspection Technology in the Hard Disk Drive Industry is an application-oriented book borne out of collaborative research with the world's leading hard disk drive companies. It covers the latest developments and important topics in computer vision technology in hard disk drive manufacturing, as well as offering a glimpse of future technologies.
Effect of Polyelectrolyte and Fatty Acid Soap on the Formation of CaCO3 in the Bulk and the Deposit on Hard Surfaces.

Science.gov (United States)

Wang, Hao; Alfredsson, Viveka; Tropsch, Juergen; Ettl, Roland; Nylander, Tommy

2015-09-30

The effects of sodium polyacrylate (NaPAA) as well as potassium oleate on the nucleation and calcium carbonate crystal growth on hard surfaces, i.e., stainless steel and silica, have been investigated at different temperatures. The relation between the surface deposition and the corresponding bulk processes has been revealed by combining dynamic light scattering (DLS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and ellipsometry. The aim was to further our understanding of the crystal deposition/growth mechanism and how it can be controlled by the presence of polyelectrolytes (NaPAA) or soap (potassium oleate). The addition of polyelectrolytes (NaPAA) or soap (potassium oleate) decreases the size of CaCO3 particles in bulk solution and affects both crystal structure and morphology in the bulk as well as on hard surfaces. The amount of particles on hard surfaces decreases significantly in the presence of both potassium oleate and NaPAA. This was found to be a consequence of potassium oleate or NaPAA adsorption on the hard surface as well as on the CaCO3 crystal surfaces. Here, the polymer NaPAA exhibited a stronger inhibition effect on the formation and growth of CaCO3 particles than potassium oleate.
A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

Science.gov (United States)

2010-01-01

Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological
A comparative approach for the investigation of biological information processing: an examination of the structure and function of computer hard drives and DNA.

Science.gov (United States)

D'Onofrio, David J; An, Gary

2010-01-21

The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1) orthogonal uniqueness, (2) low level formatting, (3) high level formatting and (4) translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT) during high level formatting of the computer hard drive and the subsequent loading of an operating system (OS). Biological systems do not have an
A comparative approach for the investigation of biological information processing: An examination of the structure and function of computer hard drives and DNA

Directory of Open Access Journals (Sweden)

D'Onofrio David J

2010-01-01

Full Text Available Abstract Background The robust storage, updating and utilization of information are necessary for the maintenance and perpetuation of dynamic systems. These systems can exist as constructs of metal-oxide semiconductors and silicon, as in a digital computer, or in the "wetware" of organic compounds, proteins and nucleic acids that make up biological organisms. We propose that there are essential functional properties of centralized information-processing systems; for digital computers these properties reside in the computer's hard drive, and for eukaryotic cells they are manifest in the DNA and associated structures. Methods Presented herein is a descriptive framework that compares DNA and its associated proteins and sub-nuclear structure with the structure and function of the computer hard drive. We identify four essential properties of information for a centralized storage and processing system: (1 orthogonal uniqueness, (2 low level formatting, (3 high level formatting and (4 translation of stored to usable form. The corresponding aspects of the DNA complex and a computer hard drive are categorized using this classification. This is intended to demonstrate a functional equivalence between the components of the two systems, and thus the systems themselves. Results Both the DNA complex and the computer hard drive contain components that fulfill the essential properties of a centralized information storage and processing system. The functional equivalence of these components provides insight into both the design process of engineered systems and the evolved solutions addressing similar system requirements. However, there are points where the comparison breaks down, particularly when there are externally imposed information-organizing structures on the computer hard drive. A specific example of this is the imposition of the File Allocation Table (FAT during high level formatting of the computer hard drive and the subsequent loading of an operating
Diffraction contrast imaging using virtual apertures

International Nuclear Information System (INIS)

Gammer, Christoph; Burak Ozdol, V.; Liebscher, Christian H.; Minor, Andrew M.

2015-01-01

Two methods on how to obtain the full diffraction information from a sample region and the associated reconstruction of images or diffraction patterns using virtual apertures are demonstrated. In a STEM-based approach, diffraction patterns are recorded for each beam position using a small probe convergence angle. Similarly, a tilt series of TEM dark-field images is acquired. The resulting datasets allow the reconstruction of either electron diffraction patterns, or bright-, dark- or annular dark-field images using virtual apertures. The experimental procedures of both methods are presented in the paper and are applied to a precipitation strengthened and creep deformed ferritic alloy with a complex microstructure. The reconstructed virtual images are compared with conventional TEM images. The major advantage is that arbitrarily shaped virtual apertures generated with image processing software can be designed without facing any physical limitations. In addition, any virtual detector that is specifically designed according to the underlying crystal structure can be created to optimize image contrast. - Highlights: • A dataset containing all structural information of a given position is recorded. • The dataset allows reconstruction of virtual diffraction patterns or images. • Specific virtual apertures are designed to image precipitates in a complex alloy. • Virtual diffraction patterns from arbitrarily small regions can be established. • Using STEM diffraction to record the dataset is more efficient than TEM dark-field
Micro-computer cards for hard industrial environment

Energy Technology Data Exchange (ETDEWEB)

Breton, J M

1984-03-15

Approximately 60% of present or future distributed systems have, or will have, operational units installed in hard environments. In these applications, which include canalization and industrial motor control, robotics and process control, systems must be easily applied in environments not made for electronic use. The development of card systems in this hard industrial environment, which is found in petrochemical industry and mines is described. National semiconductor CIM card system CMOS technology allows the real time micro computer application to be efficient and functional in hard industrial environments.
Surface modification of EN-C35E steels by thermo-chemical boronizing process and its properties

International Nuclear Information System (INIS)

Yapar, U.; Arisoy, C.F.; Basman, G.; Yesilcubuk, S.A.; Sesen, M.K.

2004-01-01

Boronizing, which involves diffusion of boron atoms into steel substrate to form hard iron borides is well known diffusion coating technique. In this study, salt bath boronizing processes were performed on EN-C35E steel substrate in slurry salt bath containing borax, boric acid as boron sources and ferro-silicon as reductant. The process was performed at 850 and 950 C for 2, 4, 6 and 8 hours. Boride layers were examined by optical microscope (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). Hardness of borides formed on the steel substrate was measured by knoop indenter under load of 0.5N. Metallographic studies and XRD analysis revealed that single-type Fe 2 B layers were formed. Depending on boronizing time and temperature, it has found that the hardness of boride layer ranged from 1895-2143 HK 0.05 that is nearly 8 times higher than substrate hardness. The thickness of the layer ranged from 25 to 167 μm depending on boronizing time and temperature. (orig.)
Experimental studies of diffractive phenomena

International Nuclear Information System (INIS)

Cool, R.L.

1984-01-01

The coherent inelastic scattering process, usually called inclusive diffraction dissociation, is discussed. Topics include: t and M/sub x/ dependence, factorization, finite mass sum rule and charged particle multiplicities. 6 references, 14 figures
Diffractive Electroproduction of rho and phi Mesons at HERA

CERN Document Server

Aaron, F.D.; Alexa, C.; Andreev, V.; Antunovic, B.; Asmone, A.; Backovic, S.; Baghdasaryan, A.; Barrelet, E.; Bartel, W.; Begzsuren, K.; Belousov, A.; Bizot, J.C.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Bruncko, D.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Cholewa, A.; Contreras, J.G.; Coughlan, J.A.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Daum, K.; Deak, M.; de Boer, Y.; Delcourt, B.; Del Degan, M.; Delvax, J.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eliseev, A.; Elsen, E.; Falkiewicz, A.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Fischer, D.J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Greenshaw, T.; Grell, B.R.; Grindhammer, G.; Habib, S.; Haidt, D.; Helebrant, C.; Henderson, R.C.W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Jacquet, M.; Janssen, M.E.; Janssen, X.; Jonsson, L.; Jung, A.W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kluge, T.; Knutsson, A.; Kogler, R.; Kostka, P.; Kraemer, M.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kutak, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lytkin, L.; Makankine, A.; Malinovski, E.; Marage, P.; Marti, Ll.; Martyn, H.U.; Maxfield, S.J.; Mehta, A.; Meyer, A.B.; Meyer, H.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, M.U.; Mudrinic, M.; Muller, K.; Murin, P.; Naumann, Th.; Newman, P.R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nowak, K.; Nozicka, M.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Pandurovic, M.; Papadopoulou, Th.; Pascaud, C.; Patel, G.D.; Pejchal, O.; Perez, E.; Petrukhin, A.; Picuric, I.; Piec, S.; Pitzl, D.; Placakyte, R.; Pokorny, B.; Polifka, R.; Povh, B.; Preda, T.; Radescu, V.; Rahmat, A.J.; Raicevic, N.; Raspiareza, A.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J.E.; Rurikova, Z.; Rusakov, S.; Salek, D.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.C.; Sefkow, F.; Shaw-West, R.N.; Shtarkov, L.N.; Shushkevich, S.; Sloan, T.; Smiljanic, I.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stoicea, G.; Straumann, U.; Sunar, D.; Sykora, T.; Tchoulakov, V.; Thompson, G.; Thompson, P.D.; Toll, T.; Tomasz, F.; Tran, T.H.; Traynor, D.; Trinh, T.N.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Urban, K.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Vinokurova, S.; Volchinski, V.; von den Driesch, M.; Wegener, D.; Wissing, Ch.; Wunsch, E.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.; Zus, R.

2010-01-01

Diffractive electroproduction of rho and phi mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb^-1. About 10500 rho and 2000 phi events are analysed in the kinematic range of squared photon virtuality 2.5 < Q^2 < 60 GeV^2, photon-proton centre of mass energy 35 < W < 180 GeV and squared four-momentum transfer to the proton |t| < 3 GeV^2. The total, longitudinal and transverse cross sections are measured as a function of Q^2, W and |t|. The measurements show a transition to a dominantly "hard" behaviour, typical of high gluon densities and small q\\bar{q} dipoles, for Q^2 larger than 10 to 20 GeV^2. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (Q^2 + M_V^2)/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, t...

Diffraction theory

NARCIS (Netherlands)

Bouwkamp, C.J.

1954-01-01

A critical review is presented of recent progress in classical diffraction theory. Both scalar and electromagnetic problems are discussed. The report may serve as an introduction to general diffraction theory although the main emphasis is on diffraction by plane obstacles. Various modifications of
Jets and diffraction results from HERA

International Nuclear Information System (INIS)

Buniatyan, A.

2014-01-01

The latest results on precision measurements of jet and diffractive cross sections obtained by the H1 and ZEUS experiments at HERA are reported. The inclusive jet and multi-jet cross-sections are used in QCD calculations at next-to-leading order (NLO) to determine the strong coupling α s . The cross-section measurements for diffractive inclusive DIS processes with a leading proton in the final state are combined for the H1 and ZEUS experiments in order to improve the precision and extend the kinematic range. The di-jet cross sections are measured in diffractive DIS with a leading proton and compared with QCD predictions based on diffractive parton densities in the proton. The cross sections for exclusive heavy vector meson photoproduction are studied in terms of the momentum transfer at the proton vertex and of the photon-proton centre-of-mass energy. (author)
Interactive processing of x-ray diffraction maxima (exchange of experience)

International Nuclear Information System (INIS)

Zabolotnyi, V.A.; Moroz, E.M.

1993-01-01

A program package for primary processing of the curve of intensity of x-ray dispersion has been developed and tested within the framework of creating computer programs that are compatible with IBM/PC/XT/AT computers for calculation and modeling of randial distributions of atoms. The following calculations have been included in this package: determination of the positions of maxima; separation of the maxima; and calculation of the integral characteristics of components. This paper describes the main feature of the algorithm, which is the procedure for varying the form of components, each of which is represented as a sum of two Gaussians with differing half-width ad amplitude. Use of the described method of modeling of the x-ray diffraction maximum was found effective in most of the practically important cases. To illustrate the operation of the program the results of approximation of a pentaplet of quartz obtained in CuKα-radiation with 0.01 degrees scanning step and 20 sec build-up time (40 kV; 40 mA; HZG-4C) are presented. 3 refs., 2 figs., 1 tab
In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

Energy Technology Data Exchange (ETDEWEB)

Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

2007-06-29

We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.
Calculated efficiencies of three-material low stress coatings for diffractive x-ray transmission optics

International Nuclear Information System (INIS)

Kubec, Adam; Braun, Stefan; Gawlitza, Peter; Menzel, Maik; Leson, Andreas

2016-01-01

Diffractive X-ray optical elements made by thin film coating techniques such as multilayer Laue lenses (MLL) and multilayer zone plates (MZP) are promising approaches to achieve resolutions in hard X-ray microscopy applications of less than 10 nm. The challenge is to make a lens with a large numerical aperture on the one hand and a decent working distance on the other hand. One of the limiting factors with the coated structures is the internal stress in the films, which can lead to significant bending of the substrate and various types of unwanted diffraction effects. Several approaches have been discussed to overcome this challenge. One of these is a three-material combination such as Mo/MoSi_2/Si, where four single layers per period are deposited. Mo and Si represent the absorber and spacer in this case while MoSi_2 forms a diffusion barrier; in addition the thicknesses of absorber and spacer are chosen to minimize residual stress of the overall coating. Here the diffraction efficiency as well as the profile of the beam in the focal plane are discussed in order to find a tradeoff between lowest residual stress and best diffraction properties.
Investigation of biological microstructures by using diffraction-enhanced imaging computed tomography

International Nuclear Information System (INIS)

Shu Hang; Liu Bo; Zhu, Peiping; Gao Xin; Yin Hongxia; Yuan Qingxi; Wang Junyue; Huang Wanxia; Gao Xiulai; Luo Shuqian; Wu Ziyu; Fang Shouxian

2006-01-01

Diffraction-enhanced imaging computer tomography (DEI-CT) is a new method to provide the object's inner information. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here, we provide further evidence for the improved overall image quality and for the option to distinguish the inner microstructures of the guinea pig's cochlea. Data has shown the details of the cochlea's inner microstructure such as vestibular membrane which only have 6 μm. A better knowledge of these microstructures may be relevant to achieve progress in the otology of clinical anatomization
Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

International Nuclear Information System (INIS)

Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

2016-01-01

In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.
Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

Science.gov (United States)

Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

2016-07-01

In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.
Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

Energy Technology Data Exchange (ETDEWEB)

Ahmed, Sazzad Hossain; Mian, Ahsan, E-mail: ahsan.mian@wright.edu; Srinivasan, Raghavan [Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435 (United States)

2016-07-12

In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.
Effect of process time on structural and tribological properties of ferritic plasma nitrocarburized AISI 4140 steel

Energy Technology Data Exchange (ETDEWEB)

Karakan, Mehmet; Alsaran, Akguen; Celik, Ayhan

2004-06-15

AISI 4140 steel was plasma nitrocarburized at a gas mixture of 49%N{sub 2} + 49%H{sub 2} + 2%CO{sub 2}, for different process times (1, 2, 4, 8 and 12 h), at a temperature of 570 deg. C. The structural, mechanical and tribological properties of nitrocarburized steel were analyzed using a X-ray diffraction, microhardness tester, scanning electron microscopy, optical microscopy and pin-on-disk tribotester. The results have shown that the compound layer was composed of the {epsilon} and {gamma} iron carbonitrides. In addition, the compound layer included pores having a columnar structure. These pores are open to the surface. The nitrocarburizing process increases surface hardness, roughness and friction coefficient. The wear rate improves after plasma nitrocarburizing, and decreases with increasing surface hardness.
Effect of process time on structural and tribological properties of ferritic plasma nitrocarburized AISI 4140 steel

International Nuclear Information System (INIS)

Karakan, Mehmet; Alsaran, Akguen; Celik, Ayhan

2004-01-01

AISI 4140 steel was plasma nitrocarburized at a gas mixture of 49%N 2 + 49%H 2 + 2%CO 2 , for different process times (1, 2, 4, 8 and 12 h), at a temperature of 570 deg. C. The structural, mechanical and tribological properties of nitrocarburized steel were analyzed using a X-ray diffraction, microhardness tester, scanning electron microscopy, optical microscopy and pin-on-disk tribotester. The results have shown that the compound layer was composed of the ε and γ iron carbonitrides. In addition, the compound layer included pores having a columnar structure. These pores are open to the surface. The nitrocarburizing process increases surface hardness, roughness and friction coefficient. The wear rate improves after plasma nitrocarburizing, and decreases with increasing surface hardness
Investigation of composition and structure of spongy and hard bone tissue using FTIR spectroscopy, XRD and SEM

Science.gov (United States)

Al-Akhras, M.-Ali H.; Hasan Qaseer, M. K.; Albiss, B. A.; Alebrhim, M. Anwar; Gezawa, Umar S.

2018-02-01

Valuable structural and chemical features can be obtained for spongy and hard bone by infrared spectroscopy and X-ray diffraction. A better understanding of chemical and structural differences between spongy and hard bone is a very important contributor to bone quality. Our data according to IR data showed that the collagen cross-links occurred to be higher in spongy bone, and crystallinity was lower in spongy bone. Deconvolution of the infrared band near 870 cm-1 reveals evidence for A2-type carbonate substitution on hydroxyapatite of spongy bone in addition to the A and B type carbonate substitution that are also found in hard bone. IR and XRD data confirmed the results of each other since full width at half maximum of 002-apatite pattern of XRD showed that the crystallinity was lower in spongy bone. The microstructure was examined by using scanning electron microscope and the result showed that the lattice of thin threads in spongy bone and is less dense than hard bone.
Carbidosteels represents a new generation of hard alloys

International Nuclear Information System (INIS)

Narva, V.K.

2001-01-01

Different processes of production of carbidosteels and improvement of their properties after sintering have been studied. The carbidosteel coating applying processes onto steel basis by plasma sputtering, electric contact baking and diffusion welding under vacuum were studied. It is shown that the electric contact baking method achieves a sufficiently high hardness as well as coupling strength of the baking layer with the substrate. In the process of diffusion welding with an increase in titanium carbide content and with the growth of the alloying degree of steel-binder in carbidosteel, hardness rises [ru
A Study of Selected Properties and Applications of AlMgB₁₄ and Related Composites: Ultra-Hard Materials

Energy Technology Data Exchange (ETDEWEB)

Lewis, Theron L. [Iowa State Univ., Ames, IA (United States)

2001-01-01

This research presents a study of the hardness, electrical, and thermal properties AlMgB₁₄ containing Al₂MgO₄ spinel. This research also investigated how much Al₂MgO₄ spinel consistently forms with AlMgB₁₄, if AlMgB₁₄ materials can be produced by hot isostatic pressing (HIP), what effects TiC and TiB₂ have on this composite material, and the importance of mechanical alloying. Included also is a study of the variation in hardness measurements and how they relate to SI units. Heretofore, all ultra-hard materials (hardness > 40 GPA) have been found to be cubic in structure, electrical insulators, and expensive; the behavior of AlMgB₁₄, which in certain specimens and compositions can have hardness values greater than 40 GPa, is therefore quite unusual since it is non-cubic, conductive, and moderate in cost. This offers an opportunity to investigate the relationship between hardness, thermal, and electrical properties from a new perspective. The main purpose of this project was to characterize the different properties of the AlMgB₁₄ materials and to demonstrate that this material can be made in bulk. The technologies used for this study include microhardness measurement techniques, scanning electron microscopy, energy dispersive spectroscopy, x-ray diffraction spectroscopy, x-ray diffraction spectroscopy at different temperatures, optical microscopy, thermomechanical analysis, differential thermal analysis, 4-point probe resistivity, density techniques, Seebeck Effect, and Hall Effect. This research may lead to use of this material for applications where high abrasion resistance along with electrical conduction is needed. Also this research gave more information about a material that could have a great impact on industrial applications.
Twinning processes in Cu-Al-Ni martensite single crystals investigated by neutron single crystal diffraction method

International Nuclear Information System (INIS)

Molnar, P.; Sittner, P.; Novak, V.; Lukas, P.

2008-01-01

A neutron single crystal diffraction method for inspecting the quality of martensite single crystals is introduced. True interface-free martensite single crystals are indispensable for, e.g. measurement of elastic constants of phases by ultrasonic techniques. The neutron diffraction method was used to detect and distinguish the presence of individual lattice correspondence variants of the 2H orthorhombic martensite phase in Cu-Al-Ni as well as to follow the activity of twinning processes during the deformation test on the martensite variant single crystals. When preparing the martensite single variant prism-shaped crystals by compression deformation method, typically a small fraction of second unwanted martensitic variant (compound twin) remains in the prism samples. Due to the very low stress (∼1 MPa) for the compound twinning in many shape memory alloys, it is quite difficult not only to deplete the martensite prisms of all internal interfaces but mainly to keep them in the martensite single variant state for a long time needed for further investigations
Computational imaging using lightweight diffractive-refractive optics

KAUST Repository

Peng, Yifan

2015-11-23

Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.
Computational imaging using lightweight diffractive-refractive optics

KAUST Repository

Peng, Yifan; Fu, Qiang; Amata, Hadi; Su, Shuochen; Heide, Felix; Heidrich, Wolfgang

2015-01-01

Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.
Sputter deposition and characterisation of hard wear-resistant Ti/TiN multilayers

Energy Technology Data Exchange (ETDEWEB)

Simmonds, M.C.; Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1997-09-01

Multilayered Ti/TiN thin films have been synthesized by magnetron sputter deposition. Alternating layers of Ti and TiN with layer thickness in the 5-50 nm range are sequentially deposited. The structure of the films have been characterised by atomic force microscopy (AFM), X-ray diffraction and reflection and Auger depth profiling. The mechanical properties have been investigated using pin-on-disc wear rate testing, nanoindentation determination of hardness and micro scratch testing. (author) 1 fig., 3 refs.
Monitoring alloy formation during mechanical alloying process by x-ray diffraction techniques

International Nuclear Information System (INIS)

Abdul Kadir Masrom; Noraizam Md Diah; Mazli Mustapha

2002-01-01

Monitoring alloying (MA) is a novel processing technique that use high energy impact ball mill to produce alloys with enhanced properties and microscopically homogeneous materials starting from various powder mixtures. Mechanical alloying process was originally developed to produce oxide dispersion strengthened nickel superalloys. In principal, in high-energy ball milling process, alloy is formed by the result of repeated welding, fracturing and rewelding of powder particles in a high energy ball mill. In this process a powder mixture in a ball mill is subjected to high-energy collisions among balls. MA has been shown to be capable of synthesizing a variety of materials. It is known to be capable to prepare equilibrium and non-equilibrium phases starting from blended elemental or prealloyed powders. The process ability to produce highly metastable materials such as amorphous alloys and nanostructured materials has made this process attractive and it has been considered as a promising material processing technique that could be used to produce many advanced materials at low cost. The present study explores the conditions under which aluminum alloys formation occurs by ball milling of blended aluminum and its alloying elements powders. In this work, attempt was made in producing aluminum 2024 alloys by milling of blended elemental aluminum powder of 2024 composition in a stainless steel container under argon atmosphere for up to 210 minutes. X-ray diffraction together with thermal analysis techniques has been used to monitor phase changes in the milled powder. Results indicate that, using our predetermined milling parameters, alloys were formed after 120 minutes milling. The thermal analysis data was also presented in this report. (Author)
Soft gluon resummation formulae for hard proton processes in QCD

International Nuclear Information System (INIS)

Craigie, N.S.; Jones, H.F.

1980-01-01

We briefly review the treatment of leading logarithmic behaviour of the parton distributions in QCD within the Bethe-Salpeter framework by analysing directly parton hadron Green functions in the limit of parton four-momentum k 2 → - infinitely in a special light-like gauge involving a spectator vector. This technique allows us to derive the factorization of parton probabilities in leading logarithmic order in QCD in the various inclusive processes involving a single short-distance scale. The proof requires us to show that the use of planar gauges eta = psub(A) + psub(B) + ..., where psub(A), psub(B)... are the observed hadron momenta, reduces to choosing the appropriate light-like gauge for each hadron-parton BS channel, after demonstrating a Bloch-Nordsieck cancellation of the real and virtual soft left-over gluons. In the case where two large momentum scales appear, by restricting the transverse phase space into which the gluons are radiated, we derive the double logarithmic eikonal renormalization of the hard scattering formula of the type proposed recently by Parisi and Petronzio. (orig.)

Concurrent microstructural evolution of ferrite and austenite in a duplex stainless steel processed by high-pressure torsion

International Nuclear Information System (INIS)

Cao, Y.; Wang, Y.B.; An, X.H.; Liao, X.Z.; Kawasaki, M.; Ringer, S.P.; Langdon, T.G.; Zhu, Y.T.

2014-01-01

A duplex stainless steel with approximately equal volume fractions of ferrite and austenite was processed by high-pressure torsion. Nano-indentation, electron backscatter diffraction and transmission electron microscopy were used to investigate the hardness and microstructure evolutions of the steel. Despite the different strain-hardening rates of individual ferrite and austenite, the microstructures of the two phases evolved concurrently in such a way that the neighbouring two phases always maintained similar hardness. While the plastic deformation and grain refinement of ferrite occurred mainly via dislocation activities, the plastic deformation and grain refinement process of austenite were more complicated and included deformation twinning and de-twinning in coarse grains, grain refinement by twinning and dislocation–twin interactions, de-twinning in ultrafine grains and twin boundary subdivision
Unified Research on Network-Based Hard/Soft Information Fusion

Science.gov (United States)

2016-02-02

3.2.1 Hard +Soft Data Association Data gathered during various Counterinsurgency (or COIN) operations is in different formats . For example, the...characteristic, observation time, and related data. Figure 45: Sample snapshot frame from hard sensor data TML formats were developed and...160 Figure 54: Penn State components of overall hard and soft fusion process Summary of Year 1 Accomplishments • Team formation • Initial
Assessing accumulated hard-tissue debris using micro-computed tomography and free software for image processing and analysis.

Science.gov (United States)

De-Deus, Gustavo; Marins, Juliana; Neves, Aline de Almeida; Reis, Claudia; Fidel, Sandra; Versiani, Marco A; Alves, Haimon; Lopes, Ricardo Tadeu; Paciornik, Sidnei

2014-02-01

The accumulation of debris occurs after root canal preparation procedures specifically in fins, isthmus, irregularities, and ramifications. The aim of this study was to present a step-by-step description of a new method used to longitudinally identify, measure, and 3-dimensionally map the accumulation of hard-tissue debris inside the root canal after biomechanical preparation using free software for image processing and analysis. Three mandibular molars presenting the mesial root with a large isthmus width and a type II Vertucci's canal configuration were selected and scanned. The specimens were assigned to 1 of 3 experimental approaches: (1) 5.25% sodium hypochlorite + 17% EDTA, (2) bidistilled water, and (3) no irrigation. After root canal preparation, high-resolution scans of the teeth were accomplished, and free software packages were used to register and quantify the amount of accumulated hard-tissue debris in either canal space or isthmus areas. Canal preparation without irrigation resulted in 34.6% of its volume filled with hard-tissue debris, whereas the use of bidistilled water or NaOCl followed by EDTA showed a reduction in the percentage volume of debris to 16% and 11.3%, respectively. The closer the distance to the isthmus area was the larger the amount of accumulated debris regardless of the irrigating protocol used. Through the present method, it was possible to calculate the volume of hard-tissue debris in the isthmuses and in the root canal space. Free-software packages used for image reconstruction, registering, and analysis have shown to be promising for end-user application. Copyright © 2014. Published by Elsevier Inc.
Variation behavior of residual stress distribution by manufacturing processes in welded pipes of austenitic stainless steel

International Nuclear Information System (INIS)

Ihara, Ryohei; Hashimoto, Tadafumi; Mochizuki, Masahito

2012-01-01

Stress corrosion cracking (SCC) has been observed near heat affected zone (HAZ) of primary loop recirculation pipes made of low-carbon austenitic stainless steel type 316L in the nuclear power plants. For the non-sensitization material, residual stress is the important factor of SCC, and it is generated by machining and welding. In the actual plants, welding is conducted after machining as manufacturing processes of welded pipes. It could be considered that residual stress generated by machining is varied by welding as a posterior process. This paper presents residual stress variation due to manufacturing processes of pipes using X-ray diffraction method. Residual stress distribution due to welding after machining had a local maximum stress in HAZ. Moreover, this value was higher than residual stress generated by welding or machining. Vickers hardness also had a local maximum hardness in HAZ. In order to clarify hardness variation, crystal orientation analysis with EBSD method was performed. Recovery and recrystallization were occurred by welding heat near the weld metal. These lead hardness decrease. The local maximum region showed no microstructure evolution. In this region, machined layer was remained. Therefore, the local maximum hardness was generated at machined layer. The local maximum stress was caused by the superposition effect of residual stress distributions due to machining and welding. Moreover, these local maximum residual stress and hardness are exceeded critical value of SCC initiation. In order to clarify the effect of residual stress on SCC initiation, evaluation including manufacturing processes is important. (author)
X-ray beam splitting design for concurrent imaging at hard X-ray FELs and synchrotron facilities

Czech Academy of Sciences Publication Activity Database

Oberta, Peter; Mokso, R.

2013-01-01

Roč. 729, NOV (2013), s. 85-89 ISSN 0168-9002 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : diffractive-refractive optics * hard X-ray FEL * X-ray imaging Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013 http://www.sciencedirect.com/science/article/pii/S0168900213009613
Electron backscatter diffraction applied to lithium sheets prepared by broad ion beam milling.

Science.gov (United States)

Brodusch, Nicolas; Zaghib, Karim; Gauvin, Raynald

2015-01-01

Due to its very low hardness and atomic number, pure lithium cannot be prepared by conventional methods prior to scanning electron microscopy analysis. Here, we report on the characterization of pure lithium metallic sheets used as base electrodes in the lithium-ion battery technology using electron backscatter diffraction (EBSD) and X-ray microanalysis using energy dispersive spectroscopy (EDS) after the sheet surface was polished by broad argon ion milling (IM). No grinding and polishing were necessary to achieve the sufficiently damage free necessary for surface analysis. Based on EDS results the impurities could be characterized and EBSD revealed the microsctructure and microtexture of this material with accuracy. The beam damage and oxidation/hydration resulting from the intensive use of IM and the transfer of the sample into the microscope chamber was estimated to be effect on the surface temperature. However, a cryo-stage should be used if available during milling to guaranty a heating artefact free surface after the milling process. © 2014 Wiley Periodicals, Inc.
A method of analyzing the scaling violation of inclusive spectra in hard processes

International Nuclear Information System (INIS)

Furmanski, W.; Petronzio, R.

1982-01-01

The analytic solution of the evolution equations in QCD is given in the form of a series of Laguerre polynomials in the variable y = ln(1/x). The Laguerre series converges very quickly and it can be truncated after few terms with a reasonable accuracy. Also high precision calculations are possible since the coefficients of the series are given by simple recurrence formulae. The method works both for non-singlet and for singlet spectra and it can be applied to any hard process. The inclusion of higher order effects is immediate. The Laguerre technique provides a natural framework for extracting from the data the input quark and gluon distributions without any prejudices concerning their particular analytic form. (orig.)
Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

Science.gov (United States)

Kress, Bernard; Hejmadi, Vic

2010-05-01

When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.
Development and beyond: Strategy for long-term maintenance of an online laser diffraction particle size method in a spray drying manufacturing process.

Science.gov (United States)

Medendorp, Joseph; Bric, John; Connelly, Greg; Tolton, Kelly; Warman, Martin

2015-08-10

The purpose of this manuscript is to present the intended use and long-term maintenance strategy of an online laser diffraction particle size method used for process control in a spray drying process. A Malvern Insitec was used for online particle size measurements and a Malvern Mastersizer was used for offline particle size measurements. The two methods were developed in parallel with the Mastersizer serving as the reference method. Despite extensive method development across a range of particle sizes, the two instruments demonstrated different sensitivities to material and process changes over the product lifecycle. This paper will describe the procedure used to ensure consistent alignment of the two methods, thus allowing for continued use of online real-time laser diffraction as a surrogate for the offline system over the product lifecycle. Copyright © 2015 Elsevier B.V. All rights reserved.
Definition and measurement of the times-diffraction-limit number of high-power laser beams

Science.gov (United States)

Bollanti, Sarah; Di Lazzaro, Paolo; Murra, Daniele

1998-07-01

A novel definition of the times-diffraction-limit (TDL) number of a laser beam is given. A comparison is made with the commonly used beam-propagation parameter M2, which is unreliable for hard-edge beams, like those produced by unstable resonators with diffraction output coupling. The new suggested TDL number definition doesn't rely on the real beam comparison to a Gaussian beam, but on the comparison of the far-field performances of the real beam with respect to those of a uniphase beam with the same amplitude profile in the near field. A practical method is also given for the estimation of the TDL number of real beams. Finally, this procedure is applied to the high-peak-power laser beams generated by two excimer laser systems developed in ENEA.
A credit card verifier structure using diffraction and spectroscopy concepts

Science.gov (United States)

Sumriddetchkajorn, Sarun; Intaravanne, Yuttana

2008-04-01

We propose and experimentally demonstrate an angle-multiplexing based optical structure for verifying a credit card. Our key idea comes from the fact that the fine detail of the embossed hologram stamped on the credit card is hard to duplicate and therefore its key color features can be used for distinguishing between the real and counterfeit ones. As the embossed hologram is a diffractive optical element, we choose to shine one at a time a number of broadband lightsources, each at different incident angle, on the embossed hologram of the credit card in such a way that different color spectra per incident angle beam is diffracted and separated in space. In this way, the number of pixels of each color plane is investigated. Then we apply a feed forward back propagation neural network configuration to separate the counterfeit credit card from the real one. Our experimental demonstration using two off-the-shelf broadband white light emitting diodes, one digital camera, a 3-layer neural network, and a notebook computer can identify all 69 counterfeit credit cards from eight real credit cards.
Correlation between hardness and stress in Al-(Nb, Mo, Ta) thin films

Energy Technology Data Exchange (ETDEWEB)

Car, T., E-mail: car@irb.h [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Radic, N. [Rudjer Boskovic Institute, Division of Materials Science, Bijenicka cesta 54, 10000 Zagreb, P.O.B. 1016 (Croatia); Panjan, P.; Cekada, M. [Jozef Stefan Institute, Ljubljana (Slovenia); Tonejc, A. [Department of Physics, Bijenicka cesta 32, 10000 Zagreb, P.O.B. 331 (Croatia)

2009-06-30

The thin films of Al{sub x}Nb{sub 1-x} (95 {>=} x {>=} 20), Al{sub x}Mo{sub x} (90 {>=} x {>=} 20) and Al{sub x}Ta{sub 1-x} (95 {>=} x {>=} 20) were prepared by magnetron codeposition at room temperature. The average film thickness was from 325 to 400 nm, depending on the film composition. The structure of the as-deposited films was examined by the X-ray diffraction. The stress of the films was determined from the substrate deformation by the profilometer, and the microhardness (load 2 mN) was examined by the micro- and nano-hardness device. For the purpose of the examination of the hardness, the samples were deposited onto the sapphire wafers, while the examination of the film stress, was performed by using thin glass substrates. For all the Al-(Nb, Mo, Ta) alloy compositions, the microhardness is predominantly under the influence of the harder element, and monotonically decreases with the increase of the aluminum content. However, the microhardness of the amorphous AlTa films was higher than the bulk value of a harder element (Ta) in the alloy. A simple empirical linear relationship between the Vickers hardness, the bulk value hardness of the transition metal (harder element) and the elastic energy fraction of the identation deformation, was established. The elastic energy fraction in the microhardness is also linearly correlated with the stress in films.
Cost-effective large-scale fabrication of diffractive optical elements by using conventional semiconducting processes.

Science.gov (United States)

Yoo, Seunghwan; Song, Ho Young; Lee, Junghoon; Jang, Cheol-Yong; Jeong, Hakgeun

2012-11-20

In this article, we introduce a simple fabrication method for SiO(2)-based thin diffractive optical elements (DOEs) that uses the conventional processes widely used in the semiconductor industry. Photolithography and an inductively coupled plasma etching technique are easy and cost-effective methods for fabricating subnanometer-scale and thin DOEs with a refractive index of 1.45, based on SiO(2). After fabricating DOEs, we confirmed the shape of the output light emitted from the laser diode light source and applied to a light-emitting diode (LED) module. The results represent a new approach to mass-produce DOEs and realize a high-brightness LED module.
THE EFFICIENCY OF ELECTROCOAGULATION PROCESS USING ALUMINUM ELECTRODES IN REMOVAL OF HARDNESS FROM WATER

Directory of Open Access Journals (Sweden)

M. Malakootian ، N. Yousefi

2009-04-01

Full Text Available There are various techniques for removal of water hardness each with its own special advantages and disadvantages. Electrochemical or electrocoagulation method due to its simplicity has gained a great attention and is used for removal of various ions and organic matters. The aim of the present study was to investigate the efficiency of this technique in removal of water hardness under different conditions. This experimental study was performed using a pilot plant. The applied pilot was comprised of a reservoir containing aluminum sheet electrodes. The electrodes were connected as monopolar and a power supply was used for supplying direct electrical current. Drinking water of Kerman (southeast of Iran was used in the experiments. The efficiency of the system in three different pH, voltages and time intervals were determined. Results showed the efficiency of 95.6% for electrocoagulation technique in hardness removal. pH and electrical potential had direct effect on hardness removal in a way that the highest efficiency rate was obtained in pH=10.1, potential difference of 20 volt and detention time of 60 minutes. Considering the obtained efficiency in the present study, electrocoagulation technique may be suggested as an effective alternative technique in hardness removal.
Calorimeter triggers for hard collisions

International Nuclear Information System (INIS)

Landshoff, P.V.; Polkinghorne, J.C.

1978-01-01

We discuss the use of a forward calorimeter to trigger on hard hadron-hadron collisions. We give a derivation in the covariant parton model of the Ochs-Stodolsky scaling law for single-hard-scattering processes, and investigate the conditions when instead a multiple- scattering mechanism might dominate. With a proton beam, this mechanism results in six transverse jets, with a total average multiplicity about twice that seen in ordinary events. We estimate that its cross section is likely to be experimentally accessible at avalues of the beam energy in the region of 100 GeV/c
Design and fabrication of a diffractive beam splitter for dual-wavelength and concurrent irradiation of process points.

Science.gov (United States)

Amako, Jun; Shinozaki, Yu

2016-07-11

We report on a dual-wavelength diffractive beam splitter designed for use in parallel laser processing. This novel optical element generates two beam arrays of different wavelengths and allows their overlap at the process points on a workpiece. To design the deep surface-relief profile of a splitter using a simulated annealing algorithm, we introduce a heuristic but practical scheme to determine the maximum depth and the number of quantization levels. The designed corrugations were fabricated in a photoresist by maskless grayscale exposure using a high-resolution spatial light modulator. We characterized the photoresist splitter, thereby validating the proposed beam-splitting concept.
Hard scattering and gauge/string duality

International Nuclear Information System (INIS)

Polchinski, Joseph; Strassler, Matthew J.

2002-01-01

We consider high-energy fixed-angle scattering of glueballs in confining gauge theories that have supergravity duals. Although the effective description is in terms of the scattering of strings, we find that the amplitudes are hard (power law). This is a consequence of the warped geometry of the dual theory, which has the effect that in an inertial frame the string process is never in the soft regime. At small angle we find hard and Regge behaviors in different kinematic regions
Diffusion corrections to the hard pomeron

CERN Document Server

Ciafaloni, Marcello; Müller, A H; Ciafaloni, Marcello; Taiuti, Martina

2001-01-01

The high-energy behaviour of two-scale hard processes is investigated in the framework of small-x models with running coupling, having the Airy diffusion model as prototype. We show that, in some intermediate high-energy regime, the perturbative hard Pomeron exponent determines the energy dependence, and we prove that diffusion corrections have the form hinted at before in particular cases. We also discuss the breakdown of such regime at very large energies, and the onset of the non-perturbative Pomeron behaviour.
Investigation of hepatic fibrosis with synchrotron X-ray diffraction enhanced imaging

International Nuclear Information System (INIS)

Li Hui; Beijing Univ., Health Science Center, Beijing; Wang Xueyan; Zhao Tao; Hu Chunhong; Lu Weiyuan; Luo Shuqian; Wang Tailing; Wang Baoen; Zhao Xinyan; Zhu Peiping; Huang Wanxia; Yuan Qingxi; Wang Junyue

2008-01-01

In this paper, imaging investigation of hepatic fibrosis in rats induced by human albumin with hard X-ray diffraction enhanced imaging (DEI) is reported. The experiments were performed at 4W1A beamline of Beijing Synchrotron Radiation Facility (BSRF). The results show that great differences can be observed in DEI images between the normal and diseased rats in different stages of liver fibrosis. The difference can also be revealed by the profile curve and texture measurements on regions of interest. The results show that DEI may be a potential way for diagnosis of hepatic fibrosis. (authors)
Investigation of biological microstructures by using diffraction-enhanced imaging computed tomography

Energy Technology Data Exchange (ETDEWEB)

Shu Hang [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graudate School of the Chinese Academy of Sciences, 100864 Beijing (China); Liu Bo [Capital University of Medical Sciences (China); Zhu, Peiping [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China)]. E-mail: zhupp@ihep.ac.cn; Gao Xin [Capital University of Medical Sciences (China); Yin Hongxia [Capital University of Medical Sciences (China); Yuan Qingxi [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Wang Junyue [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Graudate School of the Chinese Academy of Sciences, 100864 Beijing (China); Huang Wanxia [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China); Gao Xiulai [Capital University of Medical Sciences (China); Luo Shuqian [Capital University of Medical Sciences (China); Wu Ziyu [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China) and National Center for NanoScience and Technology (China)]. E-mail: wuzy@mail.ihep.ac.cn; Fang Shouxian [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, CAS, Beijing (China)

2006-11-15

Diffraction-enhanced imaging computer tomography (DEI-CT) is a new method to provide the object's inner information. Previous reports demonstrated its applicability in soft and hard tissue imaging. Here, we provide further evidence for the improved overall image quality and for the option to distinguish the inner microstructures of the guinea pig's cochlea. Data has shown the details of the cochlea's inner microstructure such as vestibular membrane which only have 6 {mu}m. A better knowledge of these microstructures may be relevant to achieve progress in the otology of clinical anatomization.

Hardness and microstructural characteristics of rapidly solidified Al-8-16 wt.%Si alloys

International Nuclear Information System (INIS)

Uzun, O.; Karaaslan, T.; Gogebakan, M.; Keskin, M.

2004-01-01

Al-Si alloys with nominal composition of Al-8 wt.%Si, Al-12 wt.%Si, and Al-16 wt.%Si were rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The microstructures of the rapidly solidified ribbons and ingot samples were investigated by the optical microscopy, electron microscopy and X-ray diffraction (XRD) techniques. The results showed that the structures of all melt-spun ribbons were completely composed of finely dispersed α-Al and eutectic Si phase, and primary silicon was not observed. The XRD analysis indicated that the solubility of Si in the α-Al matrix was greatly increased with rapid solidification. Additionally, mechanical properties of both conventionally cast (ingot) and melt-spun ribbons were examined by using Vickers indenter for one applied load (0.098 N). The hardness values of the melt-spun ribbons were about three times higher than those of ingot counterparts. The high hardness of the rapidly solidified state can be attributed to the supersaturated solid solutions. Besides, hardness values with different applied loads were measured for melt-spun ribbons. The results indicated that Vickers hardness values (H v ) of the ribbons depended on the applied load. Applying the concept of Hays-Kendall, the load independent hardness values were calculated as 694.0, 982.8 and 1186.8 MN/m 2 for Al-8 wt.%Si, Al-12 wt.%Si and Al-16 wt.%Si, respectively
Diffractive optics and nanophotonics resolution below the diffraction limit

CERN Document Server

Minin, Igor

2016-01-01

In this book the authors present several examples of techniques used to overcome the Abby diffraction limit using flat and 3D diffractive optical elements, photonic crystal lenses, photonic jets, and surface plasmon diffractive optics. The structures discussed can be used in the microwave and THz range and also as scaled models for optical frequencies. Such nano-optical microlenses can be integrated, for example, into existing semiconductor heterostructure platforms for next-generation optoelectronic applications. Chapter 1 considers flat diffractive lenses and innovative 3D radiating structures including a conical millimeter-wave Fresnel zone plate (FZP) lens proposed for subwavelength focusing. In chapter 2 the subwavelength focusing properties of diffractive photonic crystal lenses are considered and it is shown that at least three different types of photonic crystal lens are possible. With the aim of achieving subwavelength focusing, in chapter 3 an alternative mechanism to produce photonic jets at Tera...
Characterization of hard nitride and carbide titanium and zirconium coatings on high-speed steel cutting tool inserts

International Nuclear Information System (INIS)

Fenske, G.; Kaufherr, N.; Albertson, C.; Mapalo, G.; Nielsen, R.; Kaminsky, M.

1986-01-01

Hard nitride and carbide coatings of titanium and zirconium deposited by reactive evaporation and reactive sputtering techniques were characterized by electron microscopy and Auger spectroscopy to determine the effect of coating process on coating composition and microstructure. Analysis of the chemical composition by Auger spectroscopy revealed the coatings were of high purity with slight differences in stoichiometry depending on the coating technique. Both techniques produced coatings with a columnar microstructure. However, the reactive sputtering technique produced coarser (shorter and wider) columnar grains than the reactive evaporation technique. Furthermore, selected area diffraction analysis of reactively sputtered ZrN coatings showed a two-phased zone (hcp Zr and fcc ZrN) near the substrate/coating interface, while TiC coatings deposited by reactive sputtering and evaporation only showed a single-phase region of fcc TiC
High Capacity of Hard Carbon Anode in Na-Ion Batteries Unlocked by PO _x Doping

Energy Technology Data Exchange (ETDEWEB)

Li, Zhifei; Ma, Lu; Surta, Todd Wesley; Bommier, Clement; Jian, Zelang; Xing, Zhenyu; Stickle, William F.; Dolgos, Michelle; Amine, Khalil; Lu, Jun; Wu, Tianpin; Ji, Xiulei

2016-08-12

The capacity of hard carbon anodes in Na-ion batteries 2.5 rarely reaches values beyond 300 mAh/g. We report that doping POx into local structures of hard carbon increases its reversible capacity from 283 to 359 mAh/g. We confirm that the doped POx is redox inactive by X-ray adsorption near edge structure measurements, thus not contributing to the higher capacity. We observe two significant changes of hard carbon's local structures caused by doping. First, the (002) d-spacing inside the turbostratic nanodomains is increased, revealed by both laboratory and synchrotron X-ray diffraction. Second, doping turns turbostratic nanodomains more defective along ab planes, indicated by neutron total scattering and the associated pair distribution function studies. The local structural changes of hard carbon are correlated to the higher capacity, where both the plateau and slope regions in the potential profiles are enhanced. Our study demonstrates that Na-ion storage in hard carbon heavily depends on carbon local structures, where such structures, despite being disordered, can be tuned toward unusually high capacities.
Residual stress characterization of welds using x-ray diffraction techniques

International Nuclear Information System (INIS)

Pineault, J.A.; Brauss, M.E.

1996-01-01

Neglect of residual stresses created during processes lead to stress corrosion cracking, distortion, fatigue cracking, premature failures in components, and instances of over design. Automated residual stress mapping and truly portable equipment have now made the characterization of residual stresses using x-ray diffraction (XRI) practical. The nondestructive nature of the x-ray diffraction technique has made the tile residual stress characterization of welds a useful tool for process optimization and failure analysis, particularly since components can be measured before and after welding and post welding processes. This paper illustrates the importance of residual stress characterization in welds and presents examples where x-ray diffraction techniques were applied in the characterization of various kinds of welds. arc welds, TIG welds, resistance welds, laser welds and electron beam welds. Numerous techniques are available to help manage potentially harmfull residual stresses created during the welding process thus, the effects of a few example post weld processes such as grinding, heat treating and shot peening are also addressed
Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Santiago, Denise Ester O. [Polymer Research Laboratory, Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City 1101 Philippines (Philippines); Department of Chemical Engineering, University of the Philippines, Los Baños, College, Laguna 4031 Philippines (Philippines); Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T. [Polymer Research Laboratory, Department of Chemical Engineering, University of the Philippines, Diliman, Quezon City 1101 Philippines (Philippines)

2016-05-18

The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.
Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

International Nuclear Information System (INIS)

Santiago, Denise Ester O.; Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T.

2016-01-01

The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.
Effect of bentonite modification on hardness and mechanical properties of natural rubber nanocomposites

Science.gov (United States)

Santiago, Denise Ester O.; Pajarito, Bryan B.; Mangaccat, Winna Faye F.; Tigue, Maelyn Rose M.; Tipton, Monica T.

2016-05-01

The effect of sodium activation, ion-exchange with tertiary amine salt, surface treatment with non-ionic surfactant, and wet grinding of bentonite on hardness and mechanical properties of natural rubber nanocomposites (NRN) was studied using full factorial design of experiment. Results of X-ray diffraction (XRD) show increase in basal spacing d of bentonite due to modification, while attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) confirm the organic modification of bentonite. Analysis of variance (ANOVA) shows that the main effect of surface treatment increases the hardness and decreases the tensile modulus of the NRN. The surface treatment and wet grinding of bentonite decrease the tensile stresses at 100, 200 and 300% strain of NRN. Sodium activation and ion-exchange negatively affect the compressive properties, while surface treatment significantly improves the compressive properties of NRN.
New photonic devices for ultrafast pulse processing operating on the basis of the diffraction-dispersion analogy

Energy Technology Data Exchange (ETDEWEB)

Torres-Company, Victor; Minguez-Vega, Gladys; Climent, Vicent; Lands, Jesus [GROC-UJI, Departament de Fisica, Universitat Jaume I, 12080 Castello (Spain); Andres, Pedro [Departament d' Optica, Universitat de Valencia, 46100 Burjassot (Spain)], E-mail: lancis@fca.uji.es

2008-11-01

The space-time analogy is a well-known topic within wave optics that brings together some results from beam diffraction and pulse dispersion. On the above basis, and taking as starting point some classical concepts in Optics, several photonic devices have been proposed during the last few years with application in rapidly evolving fields such as ultrafast (femtosecond) optics or RF and microwave signal processing. In this contribution, we briefly review the above ideas with particular emphasis in the generation of trains of ultrafast pulses from periodic modulation of the phase of a CW laser source. This is the temporal analogue of Fresnel diffraction by a pure phase grating. Finally, we extend the analogy to the partially coherent case, what enables us to design an original technique for wavelength-to-time mapping of the spectrum of a temporally stationary source. Results of laboratory experiments concerning the generation of user-defined radio-frequency waveforms and filtering of microwave signals will be shown. The devices are operated with low-cost incoherent sources.
Electrolytic plasma processing of steel surfaces

International Nuclear Information System (INIS)

Bejar, M.A; Araya, R.N; Baeza, B

2006-01-01

The thermo-chemical treatments of steels with plasma is normally carried out in low-pressure ionized gaseous atmospheres. Among the treatments used most often are: nitruration, carburization and boronized. A plasma can also generate at atmospheric pressure. One way to produce it is with an electrochemical cell that works at a relatively high inter-electrode voltage and under conditions of heavy gas generation. This type of plasma is known as electrolytic plasma. This work studies the feasibility of using electrolytic plasma for the surface processing of steels. Two processes were selected: boronized and nitruration., for the hardening of two types of steel: one with low carbon (1020) and one with low alloy (4140). In the case of the nitruration, the 1020 steel was first aluminized. The electrolytes were aqueous solutions of borax for the boronizing and urea for the nitruration. The electrolytic plasmas were classified qualitatively, in relation with their luminosity by low, medium and high intensity. The boronizing was carried out with low intensity plasmas for a period of one hour. The nitruration was performed with plasmas of different intensities and for period of a few minutes to half an hour. The test pieces processed by electrolytic plasma were characterized by micro-hardness tests and X-ray diffraction. The maximum surface hardnesses obtained for the 1020 and 4140 steels were the following: 300 and 700 HV for the boronizing, and 1650 and 1200 HV for the nitruration, respectively. The utilization of an electrolytic plasma permits the surface processing of steels, noticeably increasing their hardness. With this type of plasma some thermo-chemical surface treatments can be done very rapidly as well (CW)
Full Multilayer Laue Lens for Focusing Hard X-rays

International Nuclear Information System (INIS)

Liu Chian; Shi, B.; Qian, J.; Conley, R.; Yan, H.; Wieczorek, M.; Macrander, A. T.; Maser, J.; Stephenson, G. B.

2010-01-01

Multilayer Laue Lenses (MLLs) were developed by us using dynamic diffraction effects to efficiently focus hard x-rays to very small spots. Using a partial MLL we were able to focus 19.5-keV hard x-rays to a line focus of 16 nm with an efficiency of 31%. A full MLL is a complete linear MLL structure. It can be fabricated by bonding two partial MLL wafers, or by growing the full structure using magnetron sputtering without bonding. A 40-μm full MLL, with a total of 5166 layers of WSi 2 and Si, has been successfully grown by sputter deposition. The layer thicknesses gradually vary from 4 nm to ∼400 nm and then back to 4 nm. Two coating runs were used to grow the full structure, one for each half. It took over 56 h for each run. A 100-μm nearly-full MLL was constructed by bonding. Each 50-μm half-structure has 1788 WSi 2 and Si layers with 12-nm to ∼32-nm thicknesses and ∼32-μm total thickness, followed by a thick WSi 2 layer of ∼17 μm, and an AuSn layer of ∼1 μm. Both full MLL structures survived dicing and polishing. The primary results demonstrate the feasibility and potential of a full MLL with a doubled numerical aperture and large beam acceptance for hard x-rays.
In-situ structural investigations of ferroelasticity in soft and hard rhombohedral and tetragonal PZT

Energy Technology Data Exchange (ETDEWEB)

Morozov, Maxim I., E-mail: maximm@alumni.ntnu.no; Einarsrud, Mari-Ann; Tolchard, Julian R.; Grande, Tor [Department of Materials Science and Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Geiger, Philipp T.; Webber, Kyle G. [Department of Materials Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen (Germany); Damjanovic, Dragan [Ceramics Laboratory, Swiss Federal Institute of Technology in Lausanne-EPFL, 1015 Lausanne (Switzerland)

2015-10-28

Despite the technological importance of hard and soft PZT, Pb(Zr,Ti)O{sub 3}, ceramics, the mechanisms of ferroelectric hardening and softening remain widely discussed in the literature. The hardening and softening phenomena have traditionally been investigated in relation with dielectric manifestations such as aging of the dielectric susceptibility and constriction of the polarization-electric field hysteresis loop. Here, we present a systematic investigation of the ferroelectric and ferroelastic properties of soft and hard PZT in both the tetragonal and rhombohedral phases. A particular focus has been devoted to ferroelastic domain switching by characterizing the macroscopic mechanical constitutive behavior and in-situ synchrotron X-ray diffraction during compression. It is demonstrated that variation of the ordering state of point defects in PZT ceramics affects the switching behavior of both ferroelectric and ferroelastic domains under mechanical or electrical fields. Softening of the mechanical and electrical properties of originally hard PZT ceramics was conferred by quenching the materials from above the Curie temperature. The present findings are discussed with respect to the current understanding of hardening-softening transitions in ferroelectric materials.
Achromatic nested Kirkpatrick–Baez mirror optics for hard X-ray nanofocusing

International Nuclear Information System (INIS)

Liu, Wenjun; Ice, Gene E.; Assoufid, Lahsen; Liu, Chian; Shi, Bing; Khachatryan, Ruben; Qian, Jun; Zschack, Paul; Tischler, Jonathan Z.; Choi, J.-Y.

2011-01-01

A nested Kirkpatrick–Baez mirror pair has been designed, fabricated and tested for achromatic nanofocusing synchrotron hard X-rays. The prototype system achieved a FWHM focal spot of about 150 nm in both horizontal and vertical directions. The first test of nanoscale-focusing Kirkpatrick–Baez (KB) mirrors in the nested (or Montel) configuration used at a hard X-ray synchrotron beamline is reported. The two mirrors are both 40 mm long and coated with Pt to produce a focal length of 60 mm at 3 mrad incident angle, and collect up to a 120 µm by 120 µm incident X-ray beam with maximum angular acceptance of 2 mrad and a broad bandwidth of energies up to 30 keV. In an initial test a focal spot of about 150 nm in both horizontal and vertical directions was achieved with either polychromatic or monochromatic beam. The nested mirror geometry, with two mirrors mounted side-by-side and perpendicular to each other, is significantly more compact and provides higher demagnification than the traditional sequential KB mirror arrangement. Ultimately, nested mirrors can focus larger divergence to improve the diffraction limit of achromatic optics. A major challenge with the fabrication of the required mirrors is the need for near-perfect mirror surfaces near the edge of at least one of the mirrors. Special polishing procedures and surface profile coating were used to preserve the mirror surface quality at the reflecting edge. Further developments aimed at achieving diffraction-limited focusing below 50 nm are underway
Effects of laser shock processing on mechanical properties and micro-structure of ANSI 304 austenitic stainless steel

International Nuclear Information System (INIS)

Luo, K.Y.; Lu, J.Z.; Zhang, Y.K.; Zhou, J.Z.; Zhang, L.F.; Dai, F.Z.; Zhang, L.; Zhong, J.W.; Cui, C.Y.

2011-01-01

Highlights: → Effects of LSP on mechanical properties of stainless steel ANSI 304 are evaluated. → LSP can clearly enhance the values of mechanical properties in the shocked region. → Martensite transformation does not take place in the surface layer subjected to LSP. → Enhancement mechanisms of LSP on mechanical property of stainless steel are revealed. → The results can provide some insights on the surface modification of stainless steel. - Abstract: The aim of this article is to address the effects of a single laser shock processing (LSP) impact on the nano-hardness, elastic modulus, residual stress and phase transformation of ANSI 304 austenitic stainless steel. Residual stress distribution of the LSP-shocked region is determined by X-ray diffraction (XRD) with sin 2 ψ method, and the micro-structural features in the near-surface layer are characterized by using cross-sectional optical microscopy (OM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). By comparing with the untreated samples, LSP can clearly improve nano-hardness, elastic modulus, and residual stress in the LSP-shocked region. The underlying enhancement mechanisms of LSP on nano-hardness, elastic modulus and residual stress of stainless steel ANSI 304 are also revealed. These studies may provide some important insights into surface modification for metal materials.
Microstructural evolution and mechanical properties on an ARB processed IF steel studied by X-ray diffraction and EBSD

Energy Technology Data Exchange (ETDEWEB)

Cruz-Gandarilla, Francisco, E-mail: fcruz@ipn.mx [Instituto Politécnico Nacional, Escuela Superior de Física y Matemáticas, Edificio 9, U.P.A.L.M., Zacatenco, Del. G. A. Madero, México, D.F. C.P. 07738, México (Mexico); Salcedo-Garrido, Ana María, E-mail: salcedo_marya@yahoo.com.mx [Instituto Politécnico Nacional, Escuela Superior de Física y Matemáticas, Edificio 9, U.P.A.L.M., Zacatenco, Del. G. A. Madero, México, D.F. C.P. 07738, México (Mexico); Bolmaro, Raúl E., E-mail: bolmaro@ifir-conicet.gov.ar [Instituto de Física Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas-CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda, 2000 Rosario (Argentina); Baudin, Thierry, E-mail: thierry.baudin@u-psud.fr [CNRS, UMR 8182, ICMMO, Lab. de Synthèse, Propriétés et Modélisation des Matériaux, Université de Paris-Sud, Orsay F-91405 (France); De Vincentis, Natalia S., E-mail: devincentis@ifir-conicet.gov.ar [Instituto de Física Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas-CONICET, Universidad Nacional de Rosario, Ocampo y Esmeralda, 2000 Rosario (Argentina); and others

2016-08-15

Accumulative Roll Bonding (ARB) is one of the so-called severe plastic deformation (SPD) processes, allowing the production of metals and alloys with ultrafine (micro-nano) structures. Materials with ultrafine grains present attractive properties like the simultaneous increase in strength and ductility. Our interest in these materials is focused on their microstructural evolution during ARB processing, eventually responsible for the enhancement of those mechanical properties. In the current work we follow the evolution of the microstructure in an interstitial-free (IF) steel deformed by ARB after consecutive processing cycles, by means of Electron BackScatter Diffraction (EBSD) and X-ray diffraction (XRD). Particularly, we present results related to texture, grain (GS) and domain sizes, grain boundary character, density of Geometrically Necessary Dislocations (GND), Grain Orientation Spread (GOS), lattice parameters, microstrain, dislocation density and their spatial arrangement. After 5 ARB cycles the system shows a microstructure constituted mainly by submicrometric grains with high angle boundaries and low presence of dislocations inside the grains. - Highlights: •The evolution of microstructure is followed simultaneously by using GAM, GOS and GND (EBSD) and XRD. •LAGBs and subgrains disappear after few cycles SSDs and HAGBs persist at the end. •Dynamic recrystallization counterbalances dislocation arrays and diminishes hardening rate. •Grain size stabilization is revealed as a mechanism for increasing ductility after few ARB cycles.
Spatiotemporal optical pulse transformation by a resonant diffraction grating

Energy Technology Data Exchange (ETDEWEB)

Golovastikov, N. V.; Bykov, D. A., E-mail: bykovd@gmail.com; Doskolovich, L. L., E-mail: leonid@smr.ru; Soifer, V. A. [Russian Academy of Sciences, Image Processing Systems Institute (Russian Federation)

2015-11-15

The diffraction of a spatiotemporal optical pulse by a resonant diffraction grating is considered. The pulse diffraction is described in terms of the signal (the spatiotemporal incident pulse envelope) passage through a linear system. An analytic approximation in the form of a rational function of two variables corresponding to the angular and spatial frequencies has been obtained for the transfer function of the system. A hyperbolic partial differential equation describing the general form of the incident pulse envelope transformation upon diffraction by a resonant diffraction grating has been derived from the transfer function. A solution of this equation has been obtained for the case of normal incidence of a pulse with a central frequency lying near the guided-mode resonance of a diffraction structure. The presented results of numerical simulations of pulse diffraction by a resonant grating show profound changes in the pulse envelope shape that closely correspond to the proposed theoretical description. The results of the paper can be applied in creating new devices for optical pulse shape transformation, in optical information processing problems, and analog optical computations.
Diffractive interactions of hadrons at high energies

International Nuclear Information System (INIS)

Goulianos, K.

1982-01-01

Elastic scattering, inclusive single diffraction dissociation and total cross section results are reviewed, with emphasis on the inter-relationship among the parameters that characterize these processes
rf streak camera based ultrafast relativistic electron diffraction.

Science.gov (United States)

Musumeci, P; Moody, J T; Scoby, C M; Gutierrez, M S; Tran, T

2009-01-01

We theoretically and experimentally investigate the possibility of using a rf streak camera to time resolve in a single shot structural changes at the sub-100 fs time scale via relativistic electron diffraction. We experimentally tested this novel concept at the UCLA Pegasus rf photoinjector. Time-resolved diffraction patterns from thin Al foil are recorded. Averaging over 50 shots is required in order to get statistics sufficient to uncover a variation in time of the diffraction patterns. In the absence of an external pump laser, this is explained as due to the energy chirp on the beam out of the electron gun. With further improvements to the electron source, rf streak camera based ultrafast electron diffraction has the potential to yield truly single shot measurements of ultrafast processes.
Optical system storage design with diffractive optical elements

Science.gov (United States)

Kostuk, Raymond K.; Haggans, Charles W.

1993-01-01

Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.
Fundamentals of powder x-ray diffraction practice

International Nuclear Information System (INIS)

Raftery, T.

2002-01-01

Full text: The goal of powder Xray diffraction is to gain information about a specimen or sample. Key aspects of this goal are 1. the sample selection, preparation and presentation; 2. the data collection process and conditions; 3. the interaction between these and the interpretation of the data. The 'ideal' powder (or polycrystalline) xray diffraction sample is fine grained, randomly orientated, homogenous and representative. There exists standard sample selection and preparation techniques for powders - sometimes however, the required information must be gained by alternate sample selection and preparation techniques. While there are few variables in the data collection process, there are some significant ones such as matching diffractometer resolution and intensity to the data collection goal whether that is phase identity, quantitative analysis or structure refinement, etc. There are also options of optical arrangement (Bragg-Brintano versus parallel beam versus Debye-Scherrer). One important aspect of the collection process is the assessment of the data quality. Powder xray diffraction has many applications from the straight-forward confirmation of phase identity and purity to structural analysis. Some of these applications will be considered and the interaction between the goal of the application and aspects of sample selection. Copyright (2002) Australian X-ray Analytical Association Inc

Diffractive scattering of H atoms from the (001) surface of LiF at 78 K

International Nuclear Information System (INIS)

Caracciolo, G.; Iannotta, S.; Scoles, G.; Valbusa, U.

1980-01-01

We have built an apparatus for the measurement of high resolution diffractive scattering of hydrogen atoms from crystal surfaces. The apparatus comprises a hydrogen atom beam source, a hexapolar magnetic field velocity selector, a variable temperature UHV crystal manipulator, and a rotatable bolometer detector. The diffraction pattern of a beam of hydrogen atoms scattered by a (001) LiF surface at 78 K has been obtained for different angles of incidence and different orientations of the crystal. The Debye--Waller factor has been measured leading to a surface Debye temperature theta/sub S/=550 +- 38 K. The corrugated-hard-wall-with-a-well model of Garibaldi et al. [Surf. Sci. 48, 649 (1975)] has been used for the interpretation of the intensities of the diffracted peaks. By means of a best fit procedure we obtain a main ''corrugation'' parameter xi 0 =0.095 A. By comparison of the data with the theory of Cabrera et al. [Surf. Sci. 19, 70 (1967] at the first order, the strength parameters of a periodic Morse potential have been determined
Application of hard coatings for blanking and piercing tools

DEFF Research Database (Denmark)

Podgornik, B.; Zajec, B.; Bay, Niels

2011-01-01

The aim of the present investigation was to examine the possibility of reducing lubrication and replacing expensive tungsten carbide material in blanking/piercing through introduction of hard tool coatings. Results show that hard PVD coatings can be successfully used in blanking/piercing...... critical value under dry friction conditions and leads to tool failure. Therefore, at present oxidation and temperature resistant hard coatings can give improved wear resistance of stamping tools, but elimination of lubricants in blanking and piercing processes is still not feasible....
Diffractive interactions

International Nuclear Information System (INIS)

Del Duca, V.; Marage, P.

1996-08-01

The general framework of diffractive deep inelastic scattering is introduced and reports given in the session on diffractive interactions at the international workshop on deep-inelastic scattering and related phenomena, Rome, April 1996, are presented. (orig.)
Surface coatings of mixed hard alloy powder metals sintered-on in vacuo

International Nuclear Information System (INIS)

Knotek, O.; Reimann, H.

1980-01-01

No technological difficulties are to be encountered in the processing of pseudo hard alloys in the form of powder compounds of conventional nickel base hard alloys with carbides. There is a great alloy influence on the resulting structures of the surface layers. Under some processing conditions the tungsten carbide is completely dissolved from molten matrix alloy. Hard phases on chromium carbide basis resulted upon cooling. Induced chromium carbide Cr 3 C 2 retains its structure while absorbing large amounts of iron into its grid. It can be concluded that not only alloying properties, but also eminently structural criterions are decisive for the stability of the applied supplementary hard phases. (orig.) [de
Seismic signals hard clipping overcoming

Science.gov (United States)

Olszowa, Paula; Sokolowski, Jakub

2018-01-01

In signal processing the clipping is understand as the phenomenon of limiting the signal beyond certain threshold. It is often related to overloading of a sensor. Two particular types of clipping are being recognized: soft and hard. Beyond the limiting value soft clipping reduces the signal real gain while the hard clipping stiffly sets the signal values at the limit. In both cases certain amount of signal information is lost. Obviously if one possess the model which describes the considered signal and the threshold value (which might be slightly more difficult to obtain in the soft clipping case), the attempt of restoring the signal can be made. Commonly it is assumed that the seismic signals take form of an impulse response of some specific system. This may lead to belief that the sine wave may be the most appropriate to fit in the clipping period. However, this should be tested. In this paper the possibility of overcoming the hard clipping in seismic signals originating from a geoseismic station belonging to an underground mine is considered. A set of raw signals will be hard-clipped manually and then couple different functions will be fitted and compared in terms of least squares. The results will be then analysed.
Diffraction coherence in optics

CERN Document Server

Françon, M; Green, L L

2013-01-01

Diffraction: Coherence in Optics presents a detailed account of the course on Fraunhofer diffraction phenomena, studied at the Faculty of Science in Paris. The publication first elaborates on Huygens' principle and diffraction phenomena for a monochromatic point source and diffraction by an aperture of simple form. Discussions focus on diffraction at infinity and at a finite distance, simplified expressions for the field, calculation of the path difference, diffraction by a rectangular aperture, narrow slit, and circular aperture, and distribution of luminous flux in the airy spot. The book th
Diffractive electroproduction of {rho} and {phi} mesons at HERA

Energy Technology Data Exchange (ETDEWEB)

Aaron, F.D. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Bucharest Univ. (Romania). Faculty of Physics; Aldaya Martin, M. [DESY Hamburg (Germany); Alexa, C. [National Inst. for Physics and Nuclear Engineering (NIPNE), Bucharest (RO)] (and others)

2009-06-15

Diffractive electroproduction of {rho} and {phi} mesons is measured at HERA with the H1 detector in the elastic and proton dissociative channels. The data correspond to an integrated luminosity of 51 pb{sup -1}. About 10500 {rho} and 2000 {phi} events are analysed in the kinematic range of squared photon virtuality 2.5{<=}Q{sup 2}{<=}60 GeV{sup 2}, photon-proton centre of mass energy 35{<=}W{<=}180 GeV and squared four-momentum transfer to the proton vertical stroke 3 vertical stroke {<=} GeV{sup 2}. The total, longitudinal and transverse cross sections are measured as a function of Q{sup 2}, W and vertical stroke 3 vertical stroke. The measurements show a transition to a dominantly ''hard'' behaviour, typical of high gluon densities and small q anti q dipoles, for Q{sup 2} larger than 10 to 20 GeV{sup 2}. They support flavour independence of the diffractive exchange, expressed in terms of the scaling variable (Q{sup 2}+M{sub V}{sup 2})/4, and proton vertex factorisation. The spin density matrix elements are measured as a function of kinematic variables. The ratio of the longitudinal to transverse cross sections, the ratio of the helicity amplitudes and their relative phases are extracted. Several of these measurements have not been performed before and bring new information on the dynamics of diffraction in a QCD framework. The measurements are discussed in the context of models using generalised parton distributions or universal dipole cross sections. (orig.)
Fabrication of a metallic roll stamp with low internal stress and high hardness for large area display applications by a pulse reverse current electroforming process

International Nuclear Information System (INIS)

Kim, Joongeok; Han, Jungjin; Kim, Taekyung; Kang, Shinill

2014-01-01

With the increasing demand for large scale micro/nano components in the fields of display, energy and electrical devices, etc, the establishment of a roll imprinting process has become a priority. The fabrication of a roll stamp with high dimensional accuracy and uniformity is one of the key issues in the roll imprinting process, because the roll stamp determines the properties of the replicated micro/nano structures. In this study, a method to fabricate a metallic roll stamp with low internal stress, high flatness, and high hardness was proposed by a pulse reverse current (PRC) electroforming process. The effects of PRC electroforming processes on the internal stress, hardness, and grain size of the electroformed stamp were examined, and the optimum process conditions were suggested. As a practical example of the proposed method, various micro-patterns for electronic circuits were fabricated via the roll imprinting process using a PRC electroformed stamp. (paper)
Production of AA2124/MoSi{sub 2}/25p composites and effect of heat treatment on their microstructure, hardness and compression properties

Energy Technology Data Exchange (ETDEWEB)

Piyadeh, F.; Abdollah-Pour, H.; Lieblich, M.

2014-07-01

AA2124/25vol%MoSi{sub 2} composites were processed by two powder metallurgy routes: high energy ball milling of the reinforcement and alloy powder (B composite) and wet blending with cyclohexane (W composite), both followed by extrusion to achieve full consolidation. As-extruded and heat treated composite bars were studied microstructurally and mechanically (hardness and compression tests under quasistatic loading). Microstructure and fracture profiles were observed by scanning electron microscopy and the reaction products formed in the matrix were identified by energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. The results show that for both composites, the hardness of the specimens in solution and aged condition was higher than in the as-extruded condition. The hardness of the B composite was higher than that of the W composite whereas the age-harden ability of the B composite was significantly lower than that of the W composite. After heat treatments, small diffusion reaction phases appeared at the interface between matrix and reinforcements. Compressive yield strength and the ultimate strength of both composites improved considerably after the artificial ageing. The composite fracture surfaces exhibited microscopically a ductile appearance that consisted of dimples in the matrix and a fragile fracture of the MoS{sub i}2 particulates. (Author)
Prediction of hardness for Al-Cu-Zn alloys in as-cast and quenching conditions; Prediccion de la dureza de aleaciones Al-Cu-Zn en estado de colada y templado

Energy Technology Data Exchange (ETDEWEB)

Villegas-Cardenas, J. D.; Saucedo-Munoz, M. L.; Lopez-Hirata, V. M.; Dorantes Rosales, H. J.

2014-10-01

This work presents a new experimental and numerical methodology in order to predict the hardness in the as-cast, and solution treated and quenched Al-Cu-Zn alloys. Chemical composition of alloys is located inside two straight lines represented by two equations. Eight different compositions were selected from each line. All the alloys were characterized for light microscope, scanning electron microscope, X-ray diffraction and Rockwell B hardness test. The equilibrium phases were obtained at different temperatures by Thermo-Calc. The microstructure characterization and regression analysis enabled to determine the phase transformations and two equations of hardness assessment. The combination of hardness equations and composition line equations permitted to estimate the hardness of any alloy composition inside this zone. This was verified by calculating hardness with the information reported in other works, with an error lower than 7% in the estimated hardness. (Author)
Relationship Between Crystalline Structure and Hardness of Ti-Si-N-O Coatings Fabricated by dc Sputtering

Science.gov (United States)

García-González, Leandro; Hernández-Torres, Julián; Mendoza-Barrera, Claudia; Meléndez-Lira, Miguel; García-Ramírez, Pedro J.; Martínez-Castillo, Jaime; Sauceda, Ángel; Herrera-May, Agustin L.; Muñoz Saldaña, Juan; Espinoza-Beltrán, Francisco J.

2008-08-01

Ti-Si-N-O coatings were deposited on AISI D2 tool steel and silicon substrates by dc reactive magnetron co-sputtering using a target of Ti-Si with a constant area ratio of 0.2. The substrate temperature was 400 °C and reactive atmosphere of nitrogen and argon. For all samples, argon flow was maintained constant at 25 sccm, while the flow of the nitrogen was varied to analyze the structural changes related to chemical composition and resistivity. According to results obtained by x-ray diffraction and stoichiometry calculations by x-ray energy dispersive spectroscopy the Ti-Si-N-O coatings contain two solid solutions. The higher crystalline part corresponds to titanium oxynitrure. Hardness tests on the coatings were carried out using the indentation work model and the hardness value was determined. Finally, the values of hardness were corroborated by nanoindentation test, and values of Young’s modulus and elastic recovery were discussed. We concluded that F2TSN sample ( F Ar = 25 sccm, F N = 5 sccm, P = 200 W, and P W = 8.9 × 10-3 mbar) presented the greatest hardness and the lowest resistivity values, due to its preferential crystalline orientation.
Tool Wear and Formation Mechanism of White Layer When Hard Milling H13 Steel under Different Cooling/Lubrication Conditions

Directory of Open Access Journals (Sweden)

Song Zhang

2014-04-01

Full Text Available The present work aims at revealing the formation mechanism of white layer and understanding the effects of tool wear and cooling/lubrication condition on white layer when hard milling H13 steel with coated cutting tools. Hard milling experiments were carried out, and tool wear and its effect on formation of white layer were investigated. Compared to dry cutting condition, CMQL (cryogenic minimum quantity lubrication technique can obviously reduce tool wear and prolong tool life owing to its good cooling and lubrication properties. The optical images of the subsurface materials indicate that the formation of white layer is related to tool wear; moreover, the thickness of white layer increases with the increase of tool wear. SEM (scanning electron microscope images and XRD (X-ray diffraction analysis confirm that the formation of white layer is mainly due to the mechanical effect rather than the thermal effect. It also proves that white layer is partly decreased or can be totally eliminated by optimizing process parameters under CMQL cutting condition. CMQL technique has the potential to be used for achieving prolonged tool life and enhanced surface integrity.
Modification of WC-Co Hard Metal by Ion Implantation with Ti+, AI+, N+, C+ and B+

International Nuclear Information System (INIS)

Rassoul, El.M.A.; Saleh, Z.A.; Waheed, A.F.; Abdel- Samad, S.M.; EI- Awadi, G.A.

2010-01-01

WC/Co hard metal was implanted by Ti + , AI + , N + , C + , and B + ions at a dose of 5x 10 17 ions/cm 2 at different energies ranging from 50 keV to 200 keV. The implanted layers were investigated by means of nano indentation, calotte measurements, SEM, X-ray diffraction XRD, tribometer and EDX. The maximum implanted zone was about 0.13 μm. The hardness of WC-Co was increased by a factor of 140% after its implantation by Ti, AI, and N and increased by a factor of 170 % after implantation by Ti + , AI + , C + , N + and B + ions as compared to the original value. Also friction coefficient of WC/Co was improved after ion implantation.
Diffraction Techniques in Structural Biology

Science.gov (United States)

Egli, Martin

2016-01-01

A detailed understanding of chemical and biological function and the mechanisms underlying the molecular activities ultimately requires atomic-resolution structural data. Diffraction-based techniques such as single-crystal X-ray crystallography, electron microscopy, and neutron diffraction are well established and they have paved the road to the stunning successes of modern-day structural biology. The major advances achieved in the last 20 years in all aspects of structural research, including sample preparation, crystallization, the construction of synchrotron and spallation sources, phasing approaches, and high-speed computing and visualization, now provide specialists and nonspecialists alike with a steady flow of molecular images of unprecedented detail. The present unit combines a general overview of diffraction methods with a detailed description of the process of a single-crystal X-ray structure determination experiment, from chemical synthesis or expression to phasing and refinement, analysis, and quality control. For novices it may serve as a stepping-stone to more in-depth treatises of the individual topics. Readers relying on structural information for interpreting functional data may find it a useful consumer guide. PMID:27248784
Teaching Fraunhofer diffraction via experimental and simulated images in the laboratory

Science.gov (United States)

Peinado, Alba; Vidal, Josep; Escalera, Juan Carlos; Lizana, Angel; Campos, Juan; Yzuel, Maria

2012-10-01

Diffraction is an important phenomenon introduced to Physics university students in a subject of Fundamentals of Optics. In addition, in the Physics Degree syllabus of the Universitat Autònoma de Barcelona, there is an elective subject in Applied Optics. In this subject, diverse diffraction concepts are discussed in-depth from different points of view: theory, experiments in the laboratory and computing exercises. In this work, we have focused on the process of teaching Fraunhofer diffraction through laboratory training. Our approach involves students working in small groups. They visualize and acquire some important diffraction patterns with a CCD camera, such as those produced by a slit, a circular aperture or a grating. First, each group calibrates the CCD camera, that is to say, they obtain the relation between the distances in the diffraction plane in millimeters and in the computer screen in pixels. Afterwards, they measure the significant distances in the diffraction patterns and using the appropriate diffraction formalism, they calculate the size of the analyzed apertures. Concomitantly, students grasp the convolution theorem in the Fourier domain by analyzing the diffraction of 2-D gratings of elemental apertures. Finally, the learners use a specific software to simulate diffraction patterns of different apertures. They can control several parameters: shape, size and number of apertures, 1-D or 2-D gratings, wavelength, focal lens or pixel size.Therefore, the program allows them to reproduce the images obtained experimentally, and generate others by changingcertain parameters. This software has been created in our research group, and it is freely distributed to the students in order to help their learning of diffraction. We have observed that these hands on experiments help students to consolidate their theoretical knowledge of diffraction in a pedagogical and stimulating learning process.
Tests of hard and soft QCD with $e^{+}e^{-}$ Annihilation Data

CERN Document Server

Kluth, S

2002-01-01

Experimental tests of QCD predictions for event shape distributions combining contributions from hard and soft processes are discussed. The hard processes are predicted by perturbative QCD calculations. The soft processes cannot be calculated directly using perturbative QCD, they are treated by a power correction model based on the analysis of infrared renormalons. Furthermore, an analysis of the gauge structure of QCD is presented using fits of the colour factors within the same combined QCD predictions.
The Effect of Catalyst Type on The Microstructure and Magnetic Properties of Synthesized Hard Cobalt Ferrite Nanoparticles.

Directory of Open Access Journals (Sweden)

Shaima'a Jaber Kareem

2018-02-01

Full Text Available A sol-gel process prepared the nanoparticles of hard cobalt ferrite (CoFe2O4. Cobalt nitrate hexahydrate (Co (NO32⋅6H2O, iron nitrate nonahydrate (Fe (NO33⋅9H2O with using two catalysis acid (citric acid and alkaline (hydroxide ammonium were used as precursor materials. Crystallization behavior of the CoFe2O4 nanoparticles were studied by X-ray diffraction (XRD. Nanoparticles phases can change from amorphous to spinel ferrite crystalline depending on the calcinated temperature at 600°C, with using citric acid as a catalysis without finding forgone phase, while using hydroxide ammonium was shown second phase (α-Fe2O3 with CoFe2O4. Crystallite size was measured by Scherrer’s formula about (25.327 nm and (27.119 nm respectively. Structural properties were investigated by FTIR, which was appeared main bond of (Fe-O, (Co-O, (C-O, and (H-O. Scanning electron microscopy (FE- SEM was shown the microstructure observation of cobalt ferrite and the particle size at the range about (28.77-42.97 nm. Magnetization measurements were carried out on a vibrating sample magenometer (VSM that exhibited hard spinel ferrite.
Investigation of the exclusive light-ion disintegration processes on the basis of a diffraction model

International Nuclear Information System (INIS)

Evlanov, M.V.; Sokolov, A.M.

1986-01-01

A diffraction approach is developed for description of kinematically complete experiments on the disintegration on nuclei with diffuse edges of light, weakly bound ions consisting of one neutral and one charged cluster. The theoretical formalism is used to analyze exclusive experiments on deuteron disintegration in the region of intermediate energies and for a broad range of nuclear mass numbers with a view to studying the structural characteristics of the nuclei and the mechanisms underlying the disintegration process. The possibility of the occurrence of the Nemets effect in the case of the disintegration of other (not only deuterons) light, weakly bound ions on nuclei is discussed
Study of multiple hard-scatter processes from different p p interactions in the same ATLAS event

CERN Document Server

The ATLAS collaboration

2018-01-01

Given the large integrated luminosity and the large average pileup in the 2017 ATLAS dataset, the probability of having two leptonically decaying Z bosons originating from separate $pp$ interactions in the same LHC bunch crossing becomes non-negligible. Such events are searched for and the number observed compared with the expectation. These types of events (also for the case involving other hard scatter processes, such as W, photon or top quark production, in the same event) may cause additional backgrounds for particular physics analyses, and therefore this background must be accounted for when relevant.
Diffractive production of charm quark/antiquark pairs at RHIC and LHC

International Nuclear Information System (INIS)

Luszczak, Marta; Szczurek, Antoni

2013-01-01

We have discussed single and central diffractive production of c(bar sign)c pairs in the Ingelman-Schlein model. In these calculations we have included diffractive parton distributions obtained by the H1 collaboration at HERA and absorption effects neglected in some early calculations in the literature. The absorption effects which are responsible for the naive Regge factorization breaking cause that the cross section for diffractive processes is much smaller than that for the fully inclusive case, but could be measured at RHIC and LHC by imposing special condition on rapidity gaps. We discuss also different approaches to diffractive production of heavy quark/antiquark [1, 2, 3]. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the low-mass diffraction, or large β-region.

Diffractive production of charm quark/antiquark pairs at RHIC and LHC

Energy Technology Data Exchange (ETDEWEB)

Luszczak, Marta [University of Rzeszow, PL-35-959 Rzeszow (Poland); Szczurek, Antoni [Institute of Nuclear Physics PAN, PL-31-342 Cracow and University of Rzeszow, PL-35-959 Rzeszow (Poland)

2013-04-15

We have discussed single and central diffractive production of c(bar sign)c pairs in the Ingelman-Schlein model. In these calculations we have included diffractive parton distributions obtained by the H1 collaboration at HERA and absorption effects neglected in some early calculations in the literature. The absorption effects which are responsible for the naive Regge factorization breaking cause that the cross section for diffractive processes is much smaller than that for the fully inclusive case, but could be measured at RHIC and LHC by imposing special condition on rapidity gaps. We discuss also different approaches to diffractive production of heavy quark/antiquark [1, 2, 3]. The particular mechanism is similar to the diffractive dissociation of virtual photons into quarks, which drives diffractive deep inelastic production of charm in the low-mass diffraction, or large {beta}-region.
Towards automated diffraction tomography. Part II-Cell parameter determination

International Nuclear Information System (INIS)

Kolb, U.; Gorelik, T.; Otten, M.T.

2008-01-01

Automated diffraction tomography (ADT) allows the collection of three-dimensional (3d) diffraction data sets from crystals down to a size of only few nanometres. Imaging is done in STEM mode, and diffraction data are collected with quasi-parallel beam nanoelectron diffraction (NED). Here, we present a set of developed processing steps necessary for automatic unit-cell parameter determination from the collected 3d diffraction data. Cell parameter determination is done via extraction of peak positions from a recorded data set (called the data reduction path) followed by subsequent cluster analysis of difference vectors. The procedure of lattice parameter determination is presented in detail for a beam-sensitive organic material. Independently, we demonstrate a potential (called the full integration path) based on 3d reconstruction of the reciprocal space visualising special structural features of materials such as partial disorder. Furthermore, we describe new features implemented into the acquisition part
Hydration process for calcium-aluminate cement within EVA emulsion by SPring-8 synchrotron radiation x-ray diffraction method

International Nuclear Information System (INIS)

Kotera, Masaru; Matsuda, Ikuyo; Miyashita, Keiko; Adachi, Nobuyuki; Tamura, Hisayuki

2005-01-01

Polymer-modified mortars which consist of a polymer emulsion and cement materials have been widely developed in the construction materials fields. Forming process of the polymer-modified cement membrane simultaneously involves evaporation of water within the polymer emulsion and hydration of cement. It is important for the polymer-modified cement paste that the hydrate crystal of cement is generating by the hydration during the setting process under existence of the polymer emulsion. In this study, hydration process for calcium-aluminate cement under existence of poly (ethylene-vinyl acetate) (EVA) emulsion (polymer-cement ratio=100%) was investigated by X-ray diffraction method using synchrotron radiation (SPring-8). The diffraction peaks of calcium aluminate (CA) disappeared after the hardening, on the other hand, the peaks of hydrate crystals of calcium-aluminate cement (C 2 AH 8 and C 3 AH 6 ) could be observed. This polymer-modified cement paste hydrated using the water within the polymer emulsion. The hydration of C 2 AH 8 from CA started at around 300 min, and then C 3 AH 6 hydrate crystal increased after 700 min at ambient temperature. This implies that the conversion from C 2 AH 8 to C 3 AH 6 occurred to be more stable phase. The setting temperature affected the reaction rate. In case of hydration at 35degC, the start time of the hydration for calcium-aluminate cement was quicker than that in the ambient temperature four or more times. (author)
Finding an Optimal Thermo-Mechanical Processing Scheme for a Gum-Type Ti-Nb-Zr-Fe-O Alloy

Science.gov (United States)

Nocivin, Anna; Cojocaru, Vasile Danut; Raducanu, Doina; Cinca, Ion; Angelescu, Maria Lucia; Dan, Ioan; Serban, Nicolae; Cojocaru, Mirela

2017-09-01

A gum-type alloy was subjected to a thermo-mechanical processing scheme to establish a suitable process for obtaining superior structural and behavioural characteristics. Three processes were proposed: a homogenization treatment, a cold-rolling process and a solution treatment with three heating temperatures: 1073 K (800 °C), 1173 K (900 °C) and 1273 K (1000 °C). Results of all three proposed processes were analyzed using x-ray diffraction and scanning electron microscopy imaging, to establish and compare the structural modifications. The behavioural status was completed with micro-hardness and tensile strength tests. The optimal results were obtained for solution treatment at 1073 K.
Driven self-assembly of hard nanoplates on soft elastic shells

International Nuclear Information System (INIS)

Zhang Yao-Yang; Hua Yun-Feng; Deng Zhen-Yu

2015-01-01

The driven self-assembly behaviors of hard nanoplates on soft elastic shells are investigated by using molecular dynamics (MD) simulation method, and the driven self-assembly structures of adsorbed hard nanoplates depend on the shape of hard nanoplates and the bending energy of soft elastic shells. Three main structures for adsorbed hard nanoplates, including the ordered aggregation structures of hard nanoplates for elastic shells with a moderate bending energy, the collapsed structures for elastic shells with a low bending energy, and the disordered aggregation structures for hard shells, are observed. The self-assembly process of adsorbed hard nanoplates is driven by the surface tension of the elastic shell, and the shape of driven self-assembly structures is determined on the basis of the minimization of the second moment of mass distribution. Meanwhile, the deformations of elastic shells can be controlled by the number of adsorbed rods as well as the length of adsorbed rods. This investigation can help us understand the complexity of the driven self-assembly of hard nanoplates on elastic shells. (paper)
The design of macromolecular crystallography diffraction experiments

International Nuclear Information System (INIS)

Evans, Gwyndaf; Axford, Danny; Owen, Robin L.

2011-01-01

Thoughts about the decisions made in designing macromolecular X-ray crystallography experiments at synchrotron beamlines are presented. The measurement of X-ray diffraction data from macromolecular crystals for the purpose of structure determination is the convergence of two processes: the preparation of diffraction-quality crystal samples on the one hand and the construction and optimization of an X-ray beamline and end station on the other. Like sample preparation, a macromolecular crystallography beamline is geared to obtaining the best possible diffraction measurements from crystals provided by the synchrotron user. This paper describes the thoughts behind an experiment that fully exploits both the sample and the beamline and how these map into everyday decisions that users can and should make when visiting a beamline with their most precious crystals
Applications of a pnCCD detector coupled to columnar structure CsI(Tl) scintillator system in ultra high energy X-ray Laue diffraction

Science.gov (United States)

Shokr, M.; Schlosser, D.; Abboud, A.; Algashi, A.; Tosson, A.; Conka, T.; Hartmann, R.; Klaus, M.; Genzel, C.; Strüder, L.; Pietsch, U.

2017-12-01

Most charge coupled devices (CCDs) are made of silicon (Si) with typical active layer thicknesses of several microns. In case of a pnCCD detector the sensitive Si thickness is 450 μm. However, for silicon based detectors the quantum efficiency for hard X-rays drops significantly for photon energies above 10 keV . This drawback can be overcome by combining a pixelated silicon-based detector system with a columnar scintillator. Here we report on the characterization of a low noise, fully depleted 128×128 pixels pnCCD detector with 75×75 μm2 pixel size coupled to a 700 μm thick columnar CsI(Tl) scintillator in the photon range between 1 keV to 130 keV . The excellent performance of the detection system in the hard X-ray range is demonstrated in a Laue type X-ray diffraction experiment performed at EDDI beamline of the BESSY II synchrotron taken at a set of several GaAs single crystals irradiated by white synchrotron radiation. With the columnar structure of the scintillator, the position resolution of the whole system reaches a value of less than one pixel. Using the presented detector system and considering the functional relation between indirect and direct photon events Laue diffraction peaks with X-ray energies up to 120 keV were efficiently detected. As one of possible applications of the combined CsI-pnCCD system we demonstrate that the accuracy of X-ray structure factors extracted from Laue diffraction peaks can be significantly improved in hard X-ray range using the combined CsI(Tl)-pnCCD system compared to a bare pnCCD.
A Fabry-Perot interferometer for hard X-rays

International Nuclear Information System (INIS)

Caticha, A.; Caticha-Ellis, S.

1990-01-01

Reflection and transmission coefficients are calculated of a sequence of N thin parallel crystals diffracting close to normal incidence and separated by thin non-diffracting gaps. From the study of the particular case N=2 a new Fabry-Perot interferometer (FPI) is proposed for hard X-rays (wavelengths of the order of Angstroms). It is found that the FPI plates do not need to be carved from a single perfect crystal block but may be grown or cleaved by other methods. This interesting possibility is suggested by two facts. First, it is known that for incidence close to normal various features of dynamical diffraction are much less sensitive to crystal defects and crystal orientation. Second, the existence of a mismatch between the lattices of the two FPI plates may affect but does not qualitatively alter the performance of the FPI. It is shown that the optimal thickness of the plates is of the order of a few microns or less. The plates may be built from a wide variety of materials. The transmission of X-rays is studied as a function of the energy and direction of the incident photons for various values of the plate thickness, of the gap, of the lattice mismatch, and also for different materials in the gap. The transmission profile exhibits a peak which is spectrally very sharp (about 10 -3 eV for low order reflections and even less for higher ones) and which can be easily tuned by changing either the lattice mismatch or the temperature. FPI plates built of materials with low absorption such as graphite seem to be particularly convenient. Several possible applications are suggested. (author)
An amplitude and phase hybrid modulation Fresnel diffractive optical element

Science.gov (United States)

Li, Fei; Cheng, Jiangao; Wang, Mengyu; Jin, Xueying; Wang, Keyi

2018-04-01

An Amplitude and Phase Hybrid Modulation Fresnel Diffractive Optical Element (APHMFDOE) is proposed here. We have studied the theory of APHMFDOE and simulated the focusing properties of it along the optical axis, which show that the focus can be blazed to other positions with changing the quadratic phase factor. Moreover, we design a Composite Fresnel Diffraction Optical Element (CFDOE) based on the characteristics of APHMFDOE. It greatly increases the outermost zone width without changing the F-number, which brings a lot of benefits to the design and processing of diffraction device. More importantly, the diffraction efficiency of the CFDOE is almost unchanged compared with AFZP at the same focus.
Experimental coherent X-ray diffractive imaging: capabilities and limitations of the technique

International Nuclear Information System (INIS)

Schropp, Andreas

2008-08-01

The investigations pursued during this work were focused on the testing of the applicability of the coherent X-ray diffractive imaging(CXDI)-method in the hard X-ray regime and different measurements were carried out at photon energies between 7 keV and 10 keV. The samples investigated were lithographically prepared two-dimensional gold structures with a size ranging from 3 μm to 10 μm as well as a cluster of gold spheres with a lateral extension of about 3.5 μm. Continuous diffraction patterns were recorded in small angle scattering geometry. In some of the measurements a scattering signal up to the edge of the detector could be measured which corresponds to a lateral resolution of about 30 nm. For certain samples it was possible to reconstruct the object from the measured diffraction data. Since the scattered intensity of non-periodic objects is weak at large scattering angles, the available photon flux is finally the main limitation of the method with regard to the achievable resolution. The experimental data were used to get an estimate of photon flux required for sub-nanometer resolution. The ptychographic iterative phase retrieval algorithm proposed by J. M. Rodenburg et al. (2004) was implemented and tested on simulated diffraction data. Additionally, a genetic algorithm has been developed and implemented for phase retrieval. This algorithm is very different from state-of-the-art algorithms and allows to introduce further experimentally important parameters such as a certain illumination function and partial coherence of the X-ray light. (orig.)
Status and prospects of measurements of exclusive and diffractive processes with the ATLAS detector

CERN Document Server

Foster, Andrew Geoffrey; The ATLAS collaboration

2018-01-01

Fiducial and differential cross-sections are presented for the exclusive production of pairs of leptons and W bosons, measured across a range of centre-of-mass energies by the ATLAS Collaboration at the LHC. All measurements are compatible with Standard Model predictions. A measurement of the dijet production cross-section is presented differentially in variables which distinguish between diffractive and non-diffractive scattering. The first analysis utilising the new AFP detectors at ATLAS is detailed.
Workshop on industrial application of neutron diffraction. Stress measurement by neutron diffraction

CERN Document Server

Minakawa, N; Morii, Y; Oyama, Y

2002-01-01

This workshop was planned to make use of the neutron from the reactor and the pulse neutron source JSNS for the industrial world. Especially, this workshop focused on the stress measurement by the neutron diffraction and it was held on the Tokai JAERI from October 15 to 16, 2001. The participant total was 93 and 40 participated from the industrial world. The introduction of the residual stress development of measurement technique by the neutron diffraction method and a research of the measurement of the residual stress such as the nuclear reactor material, the ordinary structure material, the composite material, the quenching steel, the high strength material were presented and discussed in this workshop. Moreover, it was introduced for the industrial world that an internal stress measurement is important for development of new product or an improvement of a manufacturing process. The question from the industrial world about which can be measured the product form, the size, the measurement precision, the reso...
The effect of microstructure and texture evolution on mechanical properties of low-carbon steel processed by the continuous hybrid process

International Nuclear Information System (INIS)

Hwang, Sun Kwang; Baek, Hyun Moo; Son, Il-Heon; Im, Yong-Taek; Bae, Chul Min

2013-01-01

In this paper, the continuous hybrid process is newly designed and applied for producing grain-refined long and large cross-section wires of low-carbon steel at high speed at room temperature. The initial specimen, with a diameter of 13 mm, continuously passes through the rolls, equal channel angular pressing (ECAP) dies, and wire-drawing dies in sequence during the process. The specimens deformed by the continuous hybrid process without and with the wire-drawing dies were obtained to investigate the role in the deformation separately. Their microstructures, textures, and mechanical properties were investigated by optical microscopy (OM), electron backscattering diffraction (EBSD), X-ray diffraction (XRD), tension, and Vickers micro-hardness tests and were compared with those for the case processed by the conventional wire-drawing process. According to the present investigation, the continuous hybrid process can more efficiently manufacture fine-grained wires with a strong shear texture in a continuous way than the conventional wire-drawing process can. In addition, the ultimate tensile strength value of the specimen processed by the continuous hybrid process was 23.9% higher, although the elongation was slightly lower than the one produced by the conventional wire-drawing process. The plastic deformation was mainly imposed by the ECAP dies, and the wire-drawing dies improve the dimensional accuracy and increase the local strain homogeneity in the continuous hybrid process. It is demonstrated that the continuous hybrid process might be beneficial in commercializing a continuous application of the severe plastic deformation process for producing grain-refined wires for industrial applications
Using X-ray microbeam diffraction to study the long-range internal stresses in aluminum processed by ECAP

International Nuclear Information System (INIS)

Lee, I-Fang; Phan, Thien Q.; Levine, Lyle E.; Tischler, Jonathan Z.; Geantil, Peter T.; Huang, Yi; Langdon, Terence G.; Kassner, Michael E.

2013-01-01

Aluminum alloy 1050 was processed by equal-channel angular pressing (ECAP) using a single pass (equivalent uniaxial strain of about 0.88). Long-range internal stresses (LRISs) were assessed in the grain/subgrain interiors using X-ray microbeam diffraction to measure the spacing of {5 3 1} planes, with normals oriented approximately +27.3°, +4.9° and −17.5° off the pressing (axial) direction. The results are consistent with mechanical analysis that suggests the maximum tensile plastic-strain after one pass is expected for +22.5°, roughly zero along the pressing axis, and maximum compressive strain for the −67.5° direction. The magnitude of the measured maximum compressive long-range internal stress is about 0.13σ a (applied stress) in low-dislocation regions within the grain/subgrain interiors. This work is placed in the context of earlier work where convergent beam electron diffraction was used to analyze LRISs in close proximity to the deformation-induced boundaries. The results are complementary and the measured stresses are consistent with a composite model for long-range internal stresses
LAMBDA 2M GaAs—A multi-megapixel hard X-ray detector for synchrotrons

Science.gov (United States)

Pennicard, D.; Smoljanin, S.; Pithan, F.; Sarajlic, M.; Rothkirch, A.; Yu, Y.; Liermann, H. P.; Morgenroth, W.; Winkler, B.; Jenei, Z.; Stawitz, H.; Becker, J.; Graafsma, H.

2018-01-01

Synchrotrons can provide very intense and focused X-ray beams, which can be used to study the structure of matter down to the atomic scale. In many experiments, the quality of the results depends strongly on detector performance; in particular, experiments studying dynamics of samples require fast, sensitive X-ray detectors. "LAMBDA" is a photon-counting hybrid pixel detector system for experiments at synchrotrons, based on the Medipix3 readout chip. Its main features are a combination of comparatively small pixel size (55 μm), high readout speed at up to 2000 frames per second with no time gap between images, a large tileable module design, and compatibility with high-Z sensors for efficient detection of higher X-ray energies. A large LAMBDA system for hard X-ray detection has been built using Cr-compensated GaAs as a sensor material. The system is composed of 6 GaAs tiles, each of 768 by 512 pixels, giving a system with approximately 2 megapixels and an area of 8.5 by 8.5 cm2. While the sensor uniformity of GaAs is not as high as that of silicon, its behaviour is stable over time, and it is possible to correct nonuniformities effectively by postprocessing of images. By using multiple 10 Gigabit Ethernet data links, the system can be read out at the full speed of 2000 frames per second. The system has been used in hard X-ray diffraction experiments studying the structure of samples under extreme pressure in diamond anvil cells. These experiments can provide insight into geological processes. Thanks to the combination of high speed readout, large area and high sensitivity to hard X-rays, it is possible to obtain previously unattainable information in these experiments about atomic-scale structure on a millisecond timescale during rapid changes of pressure or temperature.
Diffractive heavy flavor production-including W/sup +-/ and Z/sup 0/

International Nuclear Information System (INIS)

White, A.R.

1986-01-01

It is shown that when the Pomeron has the semiperturbative origin in QCD, diffractive heavy quark production is independent from, and not suppressed relative to, the perturbative gluon fusion process. It is emphasized that anomalously large diffractive heavy flavor cross-sections could anticipate correspondingly large cross-sections for the diffractive production of W/sup +-/ and Z 0 -providing distinctive evidence for the dynamical nature of the electroweak Higgs sector
Electrospun PVA/HAp nanocomposite nanofibers: biomimetics of mineralized hard tissues at a lower level of complexity.

Science.gov (United States)

Kim, Gyeong-Man; Asran, Ashraf Sh; Michler, Georg H; Simon, Paul; Kim, Jeong-Sook

2008-12-01

Based on the biomimetic approaches the present work describes a straightforward technique to mimic not only the architecture (the morphology) but also the chemistry (the composition) of the lowest level of the hierarchical organization of bone. This technique uses an electrospinning (ES) process with polyvinyl alcohol (PVA) and hydroxyapatite (HAp) nanoparticles. To determine morphology, crystalline structures and thermal properties of the resulting electrospun fibers with the pure PVA and PVA/HAp nanocomposite (NC) before electrospinning various techniques were employed, including transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In addition, FT-IR spectroscopy was carried out to analyze the complex structural changes upon undergoing electrospinning as well as interactions between HAp and PVA. The morphological and crystallographic investigations revealed that the rod-like HAp nanoparticles exhibit a nanoporous morphology and are embedded within the electrospun fibers. A large number of HAp nanorods are preferentially oriented parallel to the longitudinal direction of the electrospun PVA fibers, which closely resemble the naturally mineralized hard tissues of bones. Due to abundant OH groups present in PVA and HAp nanorods, they strongly interact via hydrogen bonding within the electrospun PVA/HAp NC fibers, which results in improved thermal properties. The unique physiochemical features of the electrospun PVA/HAp NC nanofibers prepared by the ES process will open up a wide variety of future applications related to hard tissue replacement and regeneration (bone and dentin), not limited to coating implants.
Electrospun PVA/HAp nanocomposite nanofibers: biomimetics of mineralized hard tissues at a lower level of complexity

Energy Technology Data Exchange (ETDEWEB)

Kim, Gyeong-Man; Asran, Ashraf Sh; Michler, Georg H [Institute of Physics, Martin-Luther-University Halle-Wittenberg, D-06099 Halle/S (Germany); Simon, Paul [Max-Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden (Germany); Kim, Jeong-Sook [Department of Dental Technology, Daegu Health College, 702-722 Daegu (Korea, Republic of)], E-mail: gyeong.kim@physik.uni-halle.de

2008-12-01

Based on the biomimetic approaches the present work describes a straightforward technique to mimic not only the architecture (the morphology) but also the chemistry (the composition) of the lowest level of the hierarchical organization of bone. This technique uses an electrospinning (ES) process with polyvinyl alcohol (PVA) and hydroxyapatite (HAp) nanoparticles. To determine morphology, crystalline structures and thermal properties of the resulting electrospun fibers with the pure PVA and PVA/HAp nanocomposite (NC) before electrospinning various techniques were employed, including transmission electron microscopy (TEM), high-resolution TEM (HR-TEM), scanning electron microscopy (SEM), x-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). In addition, FT-IR spectroscopy was carried out to analyze the complex structural changes upon undergoing electrospinning as well as interactions between HAp and PVA. The morphological and crystallographic investigations revealed that the rod-like HAp nanoparticles exhibit a nanoporous morphology and are embedded within the electrospun fibers. A large number of HAp nanorods are preferentially oriented parallel to the longitudinal direction of the electrospun PVA fibers, which closely resemble the naturally mineralized hard tissues of bones. Due to abundant OH groups present in PVA and HAp nanorods, they strongly interact via hydrogen bonding within the electrospun PVA/HAp NC fibers, which results in improved thermal properties. The unique physiochemical features of the electrospun PVA/HAp NC nanofibers prepared by the ES process will open up a wide variety of future applications related to hard tissue replacement and regeneration (bone and dentin), not limited to coating implants.
Fabrication of amplitude-phase type diffractive optical elements in aluminium films

Science.gov (United States)

Fomchenkov, S. A.; Butt, M. A.

2017-11-01

In the course of studies have been conducted a method of forming the phase diffractive optical elements (DOEs) by direct laser writing in thin films of aluminum. The quality of the aluminum films were investigated depending on the parameters of magnetron sputtering process. Moreover, the parameters of the laser writing process in thin films of aluminum were optimized. The structure of phase diffractive optical elements was obtained by the proposed method.
failure analysis and shock protection of external hard disk drive

African Journals Online (AJOL)

user

model its structural responses to free fall drop-impact shock and vibration. Secondly, the hard ... Keywords: Free fall, impact force, Shock, Vibration, Stress, Reliability, Modeling, Simulation External Hard disk drive. 1. ..... on the disk, it could initiate process which could .... [19] Katta, P.: MATLAB Guide to Finite Elements - An.

Characterization and hardness of TiCu–Ti2Cu3 intermetallic material fabricated by mechanical alloying and subsequent annealing

International Nuclear Information System (INIS)

Akbarpour, Mohammad Reza; Hesari, Feridoun Alikhani

2016-01-01

In this research, the microstructural and phase evolutions during mechanical alloying (MA) and subsequent heat treatment of Cu–Ti powder mixture are investigated through x-ray diffraction, scanning electron microscopy, transmission electron microscopy and micro-hardness measurements. The obtained experimental results demonstrated that after an optimum MA time of 30 h, TiCu intermetallic compound was achieved with a mean grain size of ≈8 nm and a high micro-hardness value of ≈634 Hv. Annealing the milled powder at different temperatures resulted in formation of major TiCu and Ti 2 Cu 3 , and minor Ti 2 Cu and Cu 4 Ti nanocrystalline phases, release of internal strain, and coarsening of grains. The amount of TiCu phase and the grain size increased with increase of the annealing temperature. Micro-hardness value of ≈765 Hv was recorded when the milled TiCu powder was annealed at 850 °C. This superior high micro-hardness value can be attributed to formation of higher amount of TiCu phase. (paper)
The diffractive achromat full spectrum computational imaging with diffractive optics

KAUST Repository

Peng, Yifan

2016-07-11

Diffractive optical elements (DOEs) have recently drawn great attention in computational imaging because they can drastically reduce the size and weight of imaging devices compared to their refractive counterparts. However, the inherent strong dispersion is a tremendous obstacle that limits the use of DOEs in full spectrum imaging, causing unacceptable loss of color fidelity in the images. In particular, metamerism introduces a data dependency in the image blur, which has been neglected in computational imaging methods so far. We introduce both a diffractive achromat based on computational optimization, as well as a corresponding algorithm for correction of residual aberrations. Using this approach, we demonstrate high fidelity color diffractive-only imaging over the full visible spectrum. In the optical design, the height profile of a diffractive lens is optimized to balance the focusing contributions of different wavelengths for a specific focal length. The spectral point spread functions (PSFs) become nearly identical to each other, creating approximately spectrally invariant blur kernels. This property guarantees good color preservation in the captured image and facilitates the correction of residual aberrations in our fast two-step deconvolution without additional color priors. We demonstrate our design of diffractive achromat on a 0.5mm ultrathin substrate by photolithography techniques. Experimental results show that our achromatic diffractive lens produces high color fidelity and better image quality in the full visible spectrum. © 2016 ACM.
Restoration of diffracted far field at the output of circular diffraction waveplate

International Nuclear Information System (INIS)

Hovhannisyan, D; Margaryan, H; Abrahamyan, V; Hakobyan, N; Tabiryan, N

2014-01-01

The light propagation in an anisotropic periodic media, such us circular diffraction waveplate (CDW) by a finite-difference time-domain (FDTD) technique is studied. The FDTD numerical simulation and the subsequent Fourier transform of the diffracted electric near field was been used for study of ability of CDW to diffract a laser beam and simultaneously convert polarization state. The FDTD simulation results used to restore the diffracted electric far field at the CDW output. an abstract
Universality of transverse-momentum resummation and hard factors at the NNLO

Energy Technology Data Exchange (ETDEWEB)

Catani, Stefano [INFN, Sezione di Firenze and Dipartimento di Fisica e Astronomia, Università di Firenze, I-50019 Sesto Fiorentino, Florence (Italy); Cieri, Leandro [Dipartimento di Fisica, Università di Roma “La Sapienza” and INFN, Sezione di Roma, I-00185 Rome (Italy); Florian, Daniel de [Departamento de Física, FCEYN, Universidad de Buenos Aires, (1428) Pabellón 1 Ciudad Universitaria, Capital Federal (Argentina); Ferrera, Giancarlo [Dipartimento di Fisica, Università di Milano and INFN, Sezione di Milano, I-20133 Milan (Italy); Grazzini, Massimiliano [Institut für Theoretische Physik, Universität Zürich, CH-8057 Zürich (Switzerland)

2014-04-15

We consider QCD radiative corrections to the production of colorless high-mass systems in hadron collisions. The logarithmically-enhanced contributions at small transverse momentum are treated to all perturbative orders by a universal resummation formula that depends on a single process-dependent hard factor. We show that the hard factor is directly related to the all-order virtual amplitude of the corresponding partonic process. The direct relation is universal (process-independent), and it is expressed by an all-order factorization formula that we explicitly evaluate up to the next-to-next-to-leading order (NNLO) in QCD perturbation theory. Once the NNLO scattering amplitude is available, the corresponding hard factor is directly determined: it controls NNLO contributions in resummed calculations at full next-to-next-to-leading logarithmic accuracy, and it can be used in applications of the q{sub T} subtraction formalism to perform fully-exclusive perturbative calculations up to NNLO. The universality structure of the hard factor and its explicit NNLO form are also extended to the related formalism of threshold resummation.
Processed Apple Product Marketing Analysis: Hard Cider and Apple Wine

OpenAIRE

Rowles, Kristin

2000-01-01

Hard cider and apple wine offer new value-added marketing opportunities to the apple industry. Both products are situated in rapidly growing categories of the beverage industry. The development of effective marketing strategies for these products requires an understanding of the forces driving competition in these markets. This paper provides background information to support competitive analysis and strategy development. Development of these markets will be positive for the apple industry, b...
Bond-orientational analysis of hard-disk and hard-sphere structures.

Science.gov (United States)

Senthil Kumar, V; Kumaran, V

2006-05-28

We report the bond-orientational analysis results for the thermodynamic, random, and homogeneously sheared inelastic structures of hard-disks and hard-spheres. The thermodynamic structures show a sharp rise in the order across the freezing transition. The random structures show the absence of crystallization. The homogeneously sheared structures get ordered at a packing fraction higher than the thermodynamic freezing packing fraction, due to the suppression of crystal nucleation. On shear ordering, strings of close-packed hard-disks in two dimensions and close-packed layers of hard-spheres in three dimensions, oriented along the velocity direction, slide past each other. Such a flow creates a considerable amount of fourfold order in two dimensions and body-centered-tetragonal (bct) structure in three dimensions. These transitions are the flow analogs of the martensitic transformations occurring in metals due to the stresses induced by a rapid quench. In hard-disk structures, using the bond-orientational analysis we show the presence of fourfold order. In sheared inelastic hard-sphere structures, even though the global bond-orientational analysis shows that the system is highly ordered, a third-order rotational invariant analysis shows that only about 40% of the spheres have face-centered-cubic (fcc) order, even in the dense and near-elastic limits, clearly indicating the coexistence of multiple crystalline orders. When layers of close-packed spheres slide past each other, in addition to the bct structure, the hexagonal-close-packed (hcp) structure is formed due to the random stacking faults. Using the Honeycutt-Andersen pair analysis and an analysis based on the 14-faceted polyhedra having six quadrilateral and eight hexagonal faces, we show the presence of bct and hcp signatures in shear ordered inelastic hard-spheres. Thus, our analysis shows that the dense sheared inelastic hard-spheres have a mixture of fcc, bct, and hcp structures.
Boundary diffraction wave integrals for diffraction modeling of external occulters

OpenAIRE

Cady, E.

2012-01-01

An occulter is a large diffracting screen which may be flown in conjunction with a telescope to image extrasolar planets. The edge is shaped to minimize the diffracted light in a region beyond the occulter, and a telescope may be placed in this dark shadow to view an extrasolar system with the starlight removed. Errors in position, orientation, and shape of the occulter will diffract additional light into this region, and a challenge of modeling an occulter system is to accurately and quickly...
Economic Assessment for Recycling Critical Metals From Hard Disk Drives Using a Comprehensive Recovery Process

Science.gov (United States)

Nguyen, Ruby Thuy; Diaz, Luis A.; Imholte, D. Devin; Lister, Tedd E.

2017-09-01

Since the 2011 price spike of rare earth elements (REEs), research on permanent magnet recycling has blossomed globally in an attempt to reduce future REE criticality. Hard disk drives (HDDs) have emerged as one feasible feedstock for recovering valuable REEs such as praseodymium, neodymium, and dysprosium. Nevertheless, current processes for recycling electronic waste only focus on certain metals as a result of feedstock and metal price uncertainties. In addition, there is a perception that recycling REEs is unprofitable. To shed some light on the economic viability of REE recycling from U.S. HDDs, this article combines techno-economic information of an electro-hydrometallurgical process with end-of-life HDD availability in a simulation model. The results showed that adding REE recovery to an HDD base and precious metal recovery process was profitable given current prices. Recovered REEs from U.S. HDDs could meet up to 5.2% rest-of-world (excluding China) neodymium magnet demand. Feedstock, aluminum, and gold prices are key factors to recycling profitability. REEs contributed 13% to the co-recycling profit.
Study of lithium insertion in hard carbon made from cotton wool

Science.gov (United States)

Peled, Emanuel; Eshkenazi, Victor; Rosenberg, Yuri

Hard-carbon materials were made either by one-step or multi-step pyrolysis of cotton cloth between 700 and 1100°C. All carbons have been characterized by gas sorption, X-ray diffraction (XRD) and small-angle X-ray scattering (SAXS) techniques. Two types of carbons have been obtained. One, made by multi-step pyrolysis, has the highest lithium reversible capacity [about 600 (mA h)/g] and two distinct voltage regions: a sloping one between 1.5 and about 0.1 V, called the high-voltage region (HVR), and a horizontal one between 0.1 and 0 V, called the low-voltage plateau (LVP). The other carbons made by the one-step process have only the HVR and less capacity [up to 470 (mA h)/g]. The influence of the current density and temperature on the capacity and degradation rate in both LVP and HVR was checked. We suggest that there are two different modes of lithium insertion: intercalation-like (on both sides of single graphene sheets) at lower potentials and chemical binding to edge carbon atoms at higher potentials vs. lithium reference electrode. A schematic model for lithiated carbon is proposed.
Wheat Quality Council, Hard Spring Wheat Technical Committee, 2017 Crop

Science.gov (United States)

Nine experimental lines of hard spring wheat were grown at up to six locations in 2017 and evaluated for kernel, milling, and bread baking quality against the check variety Glenn. Wheat samples were submitted through the Wheat Quality Council and processed and milled at the USDA-ARS Hard Red Spring...
Ti-Al-Si-C-N hard coatings synthesized by hybrid arc enhanced magnetron sputtering

International Nuclear Information System (INIS)

Wu, Guizhi; Liu, Sitao; Ma, Shengli; Xu, Kewei; Vincent, Ji; Chu, Paul K.

2010-01-01

Ti-Al-Si-C-N coatings are deposited by hybrid arc-enhanced magnetic sputtering and characterized by various micro- and macro-tools. X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy reveal that the coatings are nanocomposites consisting of nanocrystallites and amorphous phases. They are generally in the form of nc-(Ti,Al)(C,N)/a-Si_3N_4/a-C depending on the composition of the coatings. With increasing Al concentrations, the X-ray diffraction peaks shift to a lower angle indicating compressive stress in the coatings. The measured hardness also diminishes implying reduced contributions from the self-organized stable nanostructure. The dry friction coefficients of the Ti-Al-Si-C-N coatings are found to be about 0.3 which is lower than that of conventional Ti-Si-N coatings. These coatings can find potential applications requiring high temperature with heavy contact loading. (author)
An investigation into the mechanical and tribological properties of plasma electrolytic oxidation and hard-anodized coatings on 6082 aluminum alloy

International Nuclear Information System (INIS)

Malayoglu, Ugur; Tekin, Kadir C.; Malayoglu, Ufuk; Shrestha, Suman

2011-01-01

Highlights: → Mechanical properties of PEO and anodised coatings were studied using ultra-micro hardness tester. → Elastic modulus and hardness of the PEO coating were found much higher than those of the anodised coating. → Improved sliding wear of PEO coating is due to presence of hard α and γ-Al 2 O 3 phases. - Abstract: A ceramic coating on AA6082 aluminum alloy prepared by plasma electrolytic oxidation (PEO) has been studied and compared against a sulphuric acid hard-anodized coating on the same alloy. Surface morphology and microstructures of the coatings have been examined by scanning electron microscopy. X-ray diffraction is used to determine the phase composition of the coatings. The adhesion strength of the coatings has been evaluated using a scratch test method. The coating's mechanical properties such elastic modulus and hardness data have been generated using a dynamic ultra-microhardness tester. Sliding wear tests with different loading rates are performed on the coatings in order to assess their wear resistance. Test results show that the PEO treated samples exhibit significantly better mechanical properties compared to hard anodized samples. The elastic modulus and hardness of the PEO coating are 2-3 times greater than of the hard anodized coating and subsequently, an improved wear resistance of the PEO coating has been achieved. The mechanical properties of the coatings and their relations to their tribological performance are discussed.
Neutron Diffraction and Inorganic Materials Discovery

International Nuclear Information System (INIS)

Rosseinsky, M.J.

2005-01-01

Full text: The discovery of complex inorganic materials is an important academic and technological challenge because of the opportunities these systems offer for observation of new phenomena, and the questions they pose for fundamental understanding. This presentation will illustrate the key role of neutron powder diffraction in enabling the discovery of new classes of materials, and in evaluating their properties and the conditions under which they need to be processed to optimise their behaviour in devices for applications. New chemistry is illustrated by the transition metal oxide hydrides, where both structure and ionic mobility required neutron scattering characterisation. The relationship between chemistry, structure and properties will be addressed by considering the difficulties in inducing superconductivity in analogues of magnesium diboride. The role of both neutron and X-ray diffraction in evaluating the processing of microwave dielectric ceramics will be highlighted, with the discovery of new phases shown to be a useful bonus in this type of in-situ study. (author)
In situ x-ray diffraction studies of three-dimensional C60 polymers

International Nuclear Information System (INIS)

Wood, R A; Lewis, M H; Bennington, S M; Cain, M G; Kitamura, N; Fukumi, A K

2002-01-01

In situ investigations into the P/T field of C 60 fullerene were performed using energy-dispersive x-ray diffraction techniques. Isobars were obtained at 11 and 9 GPa accompanied by isotherms at 750 and 800 K with pressure reaching 13 GPa. The P/T history and pressure isotropy were investigated with the aim of optimizing conditions for 3D polymer formation. Confirmation of the formation of 3D polymers was performed in situ; however, the reclaimed sample did not exhibit the expected high hardness value, due to depolymerization on pressure release. Isotropy in the pressure field promoted formation and retention of the face-centred-cubic structure
Hardness and electrochemical behavior of ceramic coatings on Inconel

Directory of Open Access Journals (Sweden)

C. SUJAYA

2012-03-01

Full Text Available Thin films of ceramic materials like alumina and silicon carbide are deposited on Inconel substrate by pulsed laser deposition technique using Q-switched Nd: YAG laser. Deposited films are characterized using UV-visible spectrophotometry and X-ray diffraction. Composite microhardness of ceramic coated Inconel system is measured using Knoop indenter and its film hardness is separated using a mathematical model based on area-law of mixture. It is then compared with values obtained using nanoindentation method. Film hardness of the ceramic coating is found to be high compared to the substrates. Corrosion behavior of substrates after ceramic coating is studied in 3.5% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The Nyquist and the Bode plots obtained from the EIS data are fitted by appropriate equivalent circuits. The pore resistance, the charge transfer resistance, the coating capacitance and the double layer capacitance of the coatings are obtained from the equivalent circuit. Experimental results show an increase in corrosion resistance of Inconel after ceramic coating. Alumina coated Inconel showed higher corrosion resistance than silicon carbide coated Inconel. After the corrosion testing, the surface topography of the uncoated and the coated systems are examined by scanning electron microscopy.
Phase behavior in diffraction

International Nuclear Information System (INIS)

Checon, A.

1983-01-01

Theoretical formulation of a straight edge diffraction shows a phase difference of π/2 between the incoming and diffracted waves. Experiments using two straight edges do not confirm the π/2 difference but suggest that the incoming wave is in phase with the wave diffracted into the shadowed region of the edge and out of phase by a factor of π with the wave diffracted into the illuminated region. (Author) [pt
Development of a hard nano-structured multi-component ceramic coating by laser cladding

International Nuclear Information System (INIS)

Masanta, Manoj; Ganesh, P.; Kaul, Rakesh; Nath, A.K.; Roy Choudhury, A.

2009-01-01

The present paper reports laser-assisted synthesis of a multi-component ceramic composite coating consisting of aluminum oxide, titanium di-boride and titanium carbide (Al 2 O 3 -TiB 2 -TiC). A pre-placed powder mixture of aluminum (Al), titanium oxide (TiO 2 ) and boron carbide (B 4 C) was made to undergo self-propagating high-temperature synthesis (SHS) by laser triggering. Laser subsequently effected cladding of the products of SHS on the substrate. The effect of laser scanning speed on the hardness, microstructure and phase composition of the composite coating was investigated. The coating exhibited an increase in hardness and a decrease in grain size with increase in laser scanning speed. A maximum micro-hardness of 2500 HV 0.025 was obtained. X-ray diffraction (XRD) of the top surface of the coating revealed the presence of aluminum oxide (Al 2 O 3 ), titanium di-boride (TiB 2 ) and titanium carbide (TiC) along with some non-stoichiometric products of the Ti-Al-B-C-O system. Field emission gun scanning electron microscopy (FESEM) and high-resolution transmission electron microscopic (HRTEM) analysis revealed some nano-structured TiB 2 and Al 2 O 3 , which are discussed in detail.
A Case Study of Engaging Hard-to-Reach Participants in the Research Process: Community Advisors on Research Design and Strategies (CARDS)®.

Science.gov (United States)

Kaiser, Betty L; Thomas, Gay R; Bowers, Barbara J

2017-02-01

Lack of diversity among study participants in clinical research limits progress in eliminating health disparities. The engagement of lay stakeholders, such as patient or community advisory boards (CABs), has the potential to increase recruitment and retention of underrepresented groups by providing a structure for gathering feedback on research plans and materials from this target population. However, many CABs intentionally recruit prominent stakeholders who are connected to or comfortable with research and academia and thus may not accurately represent the perspectives of underrepresented groups who have been labeled hard-to-reach, including racial minorities and low-income or low-literacy populations. We developed a partnership between the University of Wisconsin-Madison School of Nursing and two community centers to deliberately engage hard-to-reach people in two lay advisory groups, the Community Advisors on Research Design and Strategies (CARDS)®. Community center staff recruited the CARDS from center programs, including parenting and childcare programs, women's support groups, food pantries, and senior meal programs. The CARDS model differs from other CABs in its participants, processes, and outcomes. Since 2010, the CARDS have met monthly with nurses and other researchers, helping them understand how research processes and the language, tone, appearance, and organization of research materials can discourage people from enrolling in clinical studies. We have successfully used the CARDS model to bring hard-to-reach populations into the research process and have sustained their participation. The model represents a promising strategy for increasing the diversity of participants in clinical research. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Hard scattering processes in high energy γ-induced reactions

International Nuclear Information System (INIS)

D'Agostini, G.

1994-09-01

Recent results from photoproduction and γγ collisions are reviewed, with special focus on hard interactions, featuring the jets as the best evidence, as manifestation of parton-parton and photon-parton scattering. The experimental results are in good agreement with perturbative QCD expectations and the data are going to have the appropriate accuracy to discriminate between the available parameterizations of the photon structure functions. In particular, the combination of F 2 γ measured in γγ and the jet cross sections measured in γγ and γp will probably constrain in the near future the gluon content of the photon. (orig.)
Theory of time-resolved inelastic x-ray diffraction

DEFF Research Database (Denmark)

Lorenz, Ulf; Møller, Klaus Braagaard; Henriksen, Niels Engholm

2010-01-01

Starting from a general theory of time-resolved x-ray scattering, we derive a convenient expression for the diffraction signal based on a careful analysis of the relevant inelastic scattering processes. We demonstrate that the resulting inelastic limit applies to a wider variety of experimental...... conditions than similar, previously derived formulas, and it directly allows the application of selection rules when interpreting diffraction signals. Furthermore, we present a simple extension to systems simultaneously illuminated by x rays and a laser beam....

Evaluation of Treatments to Reduce Hardness of Agave americana Core

Directory of Open Access Journals (Sweden)

José A. Ramírez

2006-01-01

Full Text Available Agave americana contains inulin as storage carbohydrate. Therefore, agave is interesting to be used for the extraction of inulin by pressing. The yield of the process is low due to the high hardness of the core. The objective of this work was to evaluate pretreatments to reduce the hardness in the process of obtaining inulin by pressing. Treatments with water, sulphuric acid 1 % (by mass or sodium hydroxide 1 % (by mass were tested and optimized. The pretreatment of the core of A. americana with sulphuric acid 1 % allowed the reduction of hardness from 30 000 g to 2000 g of breaking force. The mathematical model obtained predicts an optimum processing at 84 °C during 75 min. The treatment with sulphuric acid 1 % also allows white core of A. americana to be obtained, while the other treatments provide yellow core. These results open a good alternative to obtain value added products from this resource.
Phase transformation and microstructural changes during ageing process of an Ag-Pd-Cu-Au alloy

Energy Technology Data Exchange (ETDEWEB)

Yu, Chin-Ho; Park, Mi-Gyoung; Kwon, Yong Hoon; Seol, Hyo-Joung [Department of Dental Materials, School of Dentistry and Medical Research Institute, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of); Kim, Hyung-Il [Department of Dental Materials, School of Dentistry and Medical Research Institute, Pusan National University, 1-10 Ami-dong, Seo-gu, Pusan 602-739 (Korea, Republic of)], E-mail: hilkim@pusan.ac.kr

2008-07-28

Age-hardening behaviour and the related phase transformation and microstructural changes during isothermal ageing process were studied to elucidate the age-hardening mechanism of an Ag-based dental casting alloy composed of Ag-Pd-Cu-Au-Zn, Ir and In by means of hardness test, X-ray diffraction (XRD), scanning electron microscopic (SEM) observations and energy dispersive spectroscopic microanalysis (EDS). In the hardness test at 350 and 400 deg. C, the hardness of the solution-treated specimen began to increase and reached a maximum value with increasing ageing time, and subsequently the hardness decreased gradually. By considering XRD results and SEM observations together, the solution-treated specimen consisted of three phases, the Ag-rich {alpha}{sub 1} phase as a matrix, the Cu-Pd {alpha}{sub 2} phase and the CuPd {beta} phase with a CsCl-type as particle-like structures. By ageing the solution-treated specimen, the Ag-rich {alpha}{sub 1} and Cu-Pd {alpha}{sub 2} phases were transformed into the Ag-rich {alpha}{sup '}{sub 1} and Cu{sub 3}Pd {alpha}{sup '}{sub 2} phases, respectively. The CuPd {beta} phase with a CsCl-type was not changed apparently during the ageing process. From the results of the hardness test, XRD study, SEM observations and EDS analysis, it could be derived that the hardness increased by the diffusion and precipitation of the Cu-rich phase from the Ag-rich matrix during the early stage of phase transformation of {alpha}{sub 1} into {alpha}{sup '}{sub 1} and that the progress of coarsening of the Cu-rich precipitates with an entanglement structure caused the hardness decrease during the later stage of phase transformation of {alpha}{sub 1} into {alpha}{sup '}{sub 1}. The particle-like structures composed of the Cu-Pd {alpha}{sub 2} and the CuPd {beta} phase with a CsCl-type contributed little to the hardness increase which occurred in the early stage of aging process.
Neutron diffraction study of carbontetrachloride, siliciumtetrachloride, titaniumtetrachloride, and tintetrachloride in the liquid state at 295 K

International Nuclear Information System (INIS)

Tricht, J.B. van

1977-01-01

Neutron diffraction data on the molecular liquids CCl 4 , SiCl 4 , TiCl 4 , and sSnCl 4 have been collected in an interval of the scattering parameter, kappa = 4πsintheta/lambda, extending from 0.4 A -1 to 13.3 A -1 . The neutron wavelength was 0.878 A. The statistical accuracy of the data was better than 0.25 percent, and for titanium and tin tetrachloride a factor of two better. The intermolecular contributions to the diffracted intensity is dealt with in two ways: first a comparison in kappa- and in r-space between the experimental scattering and the corresponding distribution calculated from a model of randomly oriented molecules consisting of hard spheres. Furthermore, the regions in kappa- and in r-space can be identified where positional and where orientational correlations are predominent
Exclusive diffractive processes at HERA within the dipole picture

International Nuclear Information System (INIS)

Kowalski, H.; Motkyka, L.; Uniwersytet Jagiellonski, Krakow; Watt, G.; Univ. College London

2006-08-01

We present a simultaneous analysis, within an impact parameter dependent saturated dipole model, of exclusive diffractive vector meson (J/ψ, φ and ρ) production, deeply virtual Compton scattering and the total γ * p cross section data measured at HERA. Various cross sections measured as a function of the kinematic variables Q 2 , W and t are well described, with little sensitivity to the details of the vector meson wave functions. We determine the properties of the gluon density in the proton in both longitudinal and transverse dimensions, including the impact parameter dependent saturation scale. The overall success of the description indicates universality of the emerging gluon distribution and proton shape. (orig.)
Comprehensive hard materials

CERN Document Server

2014-01-01

Comprehensive Hard Materials deals with the production, uses and properties of the carbides, nitrides and borides of these metals and those of titanium, as well as tools of ceramics, the superhard boron nitrides and diamond and related compounds. Articles include the technologies of powder production (including their precursor materials), milling, granulation, cold and hot compaction, sintering, hot isostatic pressing, hot-pressing, injection moulding, as well as on the coating technologies for refractory metals, hard metals and hard materials. The characterization, testing, quality assurance and applications are also covered. Comprehensive Hard Materials provides meaningful insights on materials at the leading edge of technology. It aids continued research and development of these materials and as such it is a critical information resource to academics and industry professionals facing the technological challenges of the future. Hard materials operate at the leading edge of technology, and continued res...
Erosion testing of hard materials and coatings

Energy Technology Data Exchange (ETDEWEB)

Hawk, Jeffrey A.

2005-04-29

Erosion is the process by which unconstrained particles, usually hard, impact a surface, creating damage that leads to material removal and component failure. These particles are usually very small and entrained in fluid of some type, typically air. The damage that occurs as a result of erosion depends on the size of the particles, their physical characteristics, the velocity of the particle/fluid stream, and their angle of impact on the surface of interest. This talk will discuss the basics of jet erosion testing of hard materials, composites and coatings. The standard test methods will be discussed as well as alternative approaches to determining the erosion rate of materials. The damage that occurs will be characterized in genera1 terms, and examples will be presented for the erosion behavior of hard materials and coatings (both thick and thin).
Materials and Manufacturing Processing; Special Issue on Hard Carbon Films

Science.gov (United States)

1993-01-01

AZ 85721 G. SMOLIK, P.O. Box 1625, Idaho National Engineering Laboratory, Idaho Falls, ID 83415 J.B. TERRELL, Reynolds Metals Company, P.O. Box 27003 ...18%Si alloy using inserts of ISO SPGN120308 and HEHN532FN. The damage to diamond films after cutting was examined by SEM and micro-laser Raman...uncoated cemented carbide insert corresponding to ISO K10 grade and sintered diamond insert were also used. Milling a hard carbon under dry condition The
Laser shock processing on microstructure and hardness of polycrystalline cubic boron nitride tools with and without nanodiamond powders

International Nuclear Information System (INIS)

Melookaran, Roslyn; Melaibari, Ammar; Deng, Cheng; Molian, Pal

2012-01-01

Highlights: ► Laser shock waves hardened polycrystalline cubic boron nitride tools by up to 15%. ► Laser shock waves can build layer-by-layer of nanodiamond to form micro-diamond tools. ► Multiple laser shocks induce significant phase transitions in cBN and nanodiamond. -- Abstract: High amplitude, short duration shock waves created by a 1064 nm, 10 ns Q-switched Nd:YAG laser were used to increase the hardness as well as build successive layers of nanodiamond on sintered polycrystalline cubic boron nitride (PcBN) tools. Multiple scans of laser shocking were applied. Scanning electron microscopy, Raman spectroscopy, Tukon microhardness tester, and optical surface profilometer were used to evaluate the microstructure, phase change, Vicker’s microhardness and surface roughness. Results indicated that laser shock processing of plain PcBN changed the binder concentration, caused phase transition from cubic to hexagonal form, increased the hardness, and almost unaffected surface roughness. Laser shock wave sintering of nanodiamond powders on PcBN resulted in deagglomeration and layer-by-layer build-up of nanoparticles for a thickness of 30 μm inferring that a novel solid freeform technique designated as “shock wave induced freeform technique (SWIFT)” is being discovered for making micro-tools. Depending on the number of multiple laser shocks, the hardness of nanodiamond compact was lower or higher than that of PcBN. It is hypothesized that nanodiamond particles could serve as crack deflectors, increasing the fracture toughness of PcBN.
Experimental Investigation of White Layer formation in Hard Turning

Science.gov (United States)

Umbrello, D.; Rotella, G.; Crea, F.

2011-05-01

Hard turning with super hard cutting tools, like PCBN or Ceramics inserts, represents an interesting advance in the manufacturing industry, regarding the finishing of hardened steels. This innovative machining technique is considered an attractive alternative to traditional finish grinding operations because of the high flexibility, the ability to achieve higher metal removal rates, the possibility to operate without the use of coolants, and the capability to achieve comparable workpiece quality. However, the surface integrity effects of hard machining need to be taken into account due to their influence on the life of machined components. In particular, the formation of a usually undesirable white layer at the surface needs further investigation. Three different mechanisms have been proposed as main responsible of the white layer genesis: (i) microstructural phase transformation due to a rapid heating and quenching, (ii) severe plastic deformation resulting in a homogenous structure and/or a very fine grain size microstructure; (iii) surface reaction with the environment. In this research, an experimental campaign was carried out and several experimental techniques were used in order to analyzed the machined surface and to understand which of the above mentioned theories is the main cause of the white layer formation when AISI 52100 hardened steel is machined by PCBN inserts. In particular, the topography characterization has obtained by means of optical and scanning electron microscope (SEM) while microstructural phase composition and chemical characterization have been respectively detected using X-ray Diffraction (XRD) and Energy-dispersive X-ray spectroscopy (EDS) techniques. The results prove that the white layer is the result of microstructural alteration, i.e. the generation of a martensitic structure.
Study of the microstructure and the hardness of PZT piezoelectric ceramics types I and III used in electro acoustic transducers; Estudo da microestrutura e da microdureza das ceramicas piezoeletricas tipos PZT I e III utilizadas em transdutores eletroacusticos

Energy Technology Data Exchange (ETDEWEB)

Cabral, Ricardo de Freitas; Itaboray, Lucas Mendes; Santos, Anna Paula de Oliveira [Centro Universitario de Volta Redonda (UNIFOA), Volta Redonda, RJ (Brazil)

2015-12-15

The field of electronic processing of the ceramic piezoelectric type imported powdered led to the production of ceramics with 97% of theoretical density, homogeneous microstructure with great potential for applications in piezoelectric devices such as electro acoustic transducers. However, the production of electronic ceramics National piezoelectric type is not yet able to have as raw material zirconate titanate Lead (PZT) 100% made in Brazil. Thus, this is used for supply of domestic production, the zirconium oxide. In this work, both post PZT types I and III, imported, were uniaxially pressed at 70 MPa and sintered at 1200 and 1250 deg C for 3 hours. Hardness measurements were performed by micro indentation, X-ray diffraction analysis and Scanning Electron Microscopy. The hardness of PZT I was 393 HV. (author)
Status of the Nanoscopium Scanning Hard X-ray Nanoprobe Beamline of Synchrotron Soleil

Science.gov (United States)

Somogyi, A.; Kewish, C. M.; Ribbens, M.; Moreno, T.; Polack, F.; Baranton, G.; Desjardins, K.; Samama, J. P.

2013-10-01

The Nanoscopium 155 m-long scanning hard X-ray nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal 2D/3D imaging. The beamline aims to reach down to 30 nm spatial resolution in the 5-20 keV energy range. Two experimental stations working in consecutive operation mode will be dedicated to coherent diffractive imaging and scanning X-ray nanoprobe techniques. The beamline is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this paper.
Status of the Nanoscopium Scanning Hard X-ray Nanoprobe Beamline of Synchrotron Soleil

International Nuclear Information System (INIS)

Somogyi, A; Kewish, C M; Ribbens, M; Moreno, T; Polack, F; Baranton, G; Desjardins, K; Samama, J P

2013-01-01

The Nanoscopium 155 m-long scanning hard X-ray nanoprobe beamline of Synchrotron Soleil (St Aubin, France) is dedicated to quantitative multi-modal 2D/3D imaging. The beamline aims to reach down to 30 nm spatial resolution in the 5–20 keV energy range. Two experimental stations working in consecutive operation mode will be dedicated to coherent diffractive imaging and scanning X-ray nanoprobe techniques. The beamline is in the construction phase, the first user experiments are expected in 2014. The main characteristics of the beamline and an overview of its status are given in this paper
Failure analysis and shock protection of external hard disk drive ...

African Journals Online (AJOL)

Technology for processing and storage of data in portable external storage hard disks has increasingly improved over the years. Currently, terabytes of data can be stored in one portable external storage hard disk drive. Storing such amount of data on a single disk on itself is a risk. Several instances of data lost by big ...
SPADE - software package to aid diffraction experiments

International Nuclear Information System (INIS)

Farren, J.; Giltrap, J.W.

1978-10-01

A software package is described which enables the DEC PDP-11/03 microcomputer to execute several different X-ray diffraction experiments and other similar experiments where stepper motors are driven and data is gathered and processed in real time. (author)
X-ray diffraction analysis of aluminium containing Al8Fe2Si processed by equal channel angular pressing

International Nuclear Information System (INIS)

Korchef, Atef; Champion, Yannick; Njah, Nabil

2007-01-01

A 99.1% aluminium with initial grain size of ∼85 μm was deformed by equal channel angular (ECA) pressing. The sample undergoes an effective strain of 1.07 N by N passes through the die. The material contains a low volume fraction of Al 8 Fe 2 Si precipitates located essentially at the grain boundaries. The analysis of the X-ray diffraction peaks showed a significant broadening, which was related to grain refinement and lattice distortions. The crystallite size, calculated using the Halder-Wagner method, reached 225 nm after two passes and did not subsequently change. A decrease of the lattice parameter was also observed after ECA pressing. This is due to a partial dissolution of the precipitates. The microstructure was stable up an annealing of 200 deg. C due to the precipitates which delay the diffusion process. The annealing of the ECA pressed samples up to 400 deg. C leads to a decrease in the X-ray diffraction peaks broadening and an increase of the lattice parameter. This is due to grain growth
Diffusion equations and hard collisions in multiple scattering of charged particles

International Nuclear Information System (INIS)

Papiez, Lech; Tulovsky, Vladimir

1998-01-01

The processes of angular-spatial evolution of multiple scattering of charged particles are described by the Lewis (special case of Boltzmann) integro-differential equation. The underlying stochastic process for this evolution is the compound Poisson process with transition densities satisfying the Lewis equation. In this paper we derive the Lewis equation from the compound Poisson process and show that the effective method of the solution of this equation can be based on the idea of decomposition of the compound Poisson process into processes of soft and hard collisions. Formulas for transition densities of soft and hard collision processes are provided in this paper together with the formula expressing the general solution of the Lewis equation in terms of those transition densities
Diffusion equations and hard collisions in multiple scattering of charged particles

Energy Technology Data Exchange (ETDEWEB)

Papiez, Lech [Department of Radiation Oncology, Indiana University, Indianapolis, IN (United States); Tulovsky, Vladimir [Department of Mathematics, St. John' s College, Staten Island, New York, NY (United States)

1998-09-01

The processes of angular-spatial evolution of multiple scattering of charged particles are described by the Lewis (special case of Boltzmann) integro-differential equation. The underlying stochastic process for this evolution is the compound Poisson process with transition densities satisfying the Lewis equation. In this paper we derive the Lewis equation from the compound Poisson process and show that the effective method of the solution of this equation can be based on the idea of decomposition of the compound Poisson process into processes of soft and hard collisions. Formulas for transition densities of soft and hard collision processes are provided in this paper together with the formula expressing the general solution of the Lewis equation in terms of those transition densities.
X-ray and Neutron Diffraction in the Study of Organic Crystalline Hydrates

Directory of Open Access Journals (Sweden)

Katharina Fucke

2010-07-01

Full Text Available A review. Diffraction methods are a powerful tool to investigate the crystal structure of organic compounds in general and their hydrates in particular. The laboratory standard technique of single crystal X-ray diffraction gives information about the molecular conformation, packing and hydrogen bonding in the crystal structure, while powder X-ray diffraction on bulk material can trace hydration/dehydration processes and phase transitions under non-ambient conditions. Neutron diffraction is a valuable complementary technique to X-ray diffraction and gives highly accurate hydrogen atom positions due to the interaction of the radiation with the atomic nuclei. Although not yet often applied to organic hydrates, neutron single crystal and neutron powder diffraction give precise structural data on hydrogen bonding networks which will help explain why hydrates form in the first place.
Diffraction by disordered polycrystalline fibers

International Nuclear Information System (INIS)

Stroud, W.J.; Millane, R.P.

1995-01-01

X-ray diffraction patterns from some polycrystalline fibers show that the constituent microcrystallites are disordered. The relationship between the crystal structure and the diffracted intensities is then quite complicated and depends on the precise kind and degree of disorder present. The effects of disorder on diffracted intensities must be included in structure determinations using diffraction data from such specimens. Theory and algorithms are developed here that allow the full diffraction pattern to be calculated for a disordered polycrystalline fiber made up of helical molecules. The model accommodates various kinds of disorder and includes the effects of finite crystallite size and cylindrical averaging of the diffracted intensities from a fiber. Simulations using these methods show how different kinds, or components, of disorder produce particular diffraction effects. General properties of disordered arrays of helical molecules and their effects on diffraction patterns are described. Implications for structure determination are discussed. (orig.)
High-Resolution Single-Grain Diffraction of Polycrystalline Materials

DEFF Research Database (Denmark)

Lienert, Ulrich; Ribárik, Gábor; Ungar, Tamas

2017-01-01

. The microstructure usually influences the materials properties critically. It has been demonstrated that, by using high-energy synchrotron radiation, diffraction peaks off individual grains can be recorded in-situ during processing. Important information such as the orientation, average strain, and size...... of individual grains can be obtained, even if the peak shapes are commonly not analyzed. However, it is also well-known that the shape of diffraction peaks, if observed with sufficient resolution, contains significant information about the microstructure. While the intensity distribution in reciprocal space...... of a perfect lattice consists of delta functions located at the reciprocal lattice points, defects induce characteristic peak broadening. In order to exploit the wealth of microstructural information contained in broadened diffraction peaks, the intensity distribution has to be characterized in all three...

Fabrication of Fe-Cr-Mo powder metallurgy steel via a mechanical-alloying process

Science.gov (United States)

Park, Jooyoung; Jeong, Gowoon; Kang, Singon; Lee, Seok-Jae; Choi, Hyunjoo

2015-11-01

In this study, we employed a mechanical-alloying process to manufacture low-alloy CrL and CrM steel powders that have similar specifications to their water-atomized counterparts. X-ray diffraction showed that Mo and Cr are alloyed in Fe after four cycles of planetary milling for 1 h at 150 RPM with 15-min pauses between the cycles (designated as P2C4 process). Furthermore, the measured powder size was found to be similar to that of the water-atomized counterparts according to both scanning electron microscope images and laser particle size analysis. The samples were sintered at 1120 °C, after which the P2C4-milled CrL showed similar hardness to that of water-atomized CrL, whereas the P2C4-milled CrM showed about 45% lower hardness than that of its water-atomized counterpart. Water-atomized CrM consists of a well-developed lathtype microstructure (bainite or martensite), while a higher fraction of polygonal ferrite is observed in P2C4-milled CrM. This phase difference causes the reduction of hardness in the P2C4-milled CrM, implying that the phase transformation behavior of specimens produced via powder metallurgy is influenced by the powder fabrication method.
Time-resolved diffraction studies of muscle using synchrotron radiation

International Nuclear Information System (INIS)

Harford, Jeffrey; Squire, John

1997-01-01

Muscle contraction is one of those biological phenomena that we can all appreciate in our everyday lives. Sometimes it is when we are resting quietly and are aware of our heartbeat. At other times it may be when we are exerting ourselves and become short of breath, or when we exercise for a long period and our muscles start to ache. The way in which muscles produce force has exercised the minds of philosophers and scientists at least since the days of Erasistratus in the third century BC. Nowadays, of course, we know a very great deal about muscle structure, physiology and biochemistry, but we still do not know exactly what the molecular process is that produces movement. An ideal way of probing this process would be to be able to obtain signals from the relevant molecules as they actually go through their normal force-generating routine in an active muscle. The spatial dimensions involved are in the region of 1-50 nm, thus precluding the use of light microscopy, and the time regime is microseconds to milliseconds. Techniques with the appropriate spatial resolution might be electron microscopy and x-ray diffraction, but electron microscopy cannot yet be carried out on living tissue. X-ray diffraction methods can clearly have the right sort of spatial resolution, but what about recording diffraction patterns in the very short times involved (say 1 ms)? It is here that the high flux from synchrotron storage rings comes into its own. Using synchrotron radiation from, say, the SRS at the CCLRC Daresbury Laboratory it is possible to record x-ray diffraction patterns from living muscles in the millisecond time regime and to follow how these diffraction patterns change as the muscles go through typical contraction cycles. Unfortunately, x-ray diffraction is not a direct imaging method; the observed distribution of diffracted intensity needs to be interpreted in some way to give useful information on the spatial relationships of the force-generating molecules. This review
Residual stresses generated in F-522 steel by different machining processes

International Nuclear Information System (INIS)

Gracia-Navas, V.; Ferreres, I.; Maranon, J. A.; Garcia-Rosales, C.; Gil-Sevillano, J.

2005-01-01

Machining operations induce plastic deformation and heat generation in the near surface area of the machined part, giving rise to residual stresses. Depending on their magnitude and sign, these stresses can be detrimental or beneficial to the service life of the part. The final stress state depends on the machining process applied, as well as on the machining parameters. Therefore, the establishment of adequate machining guidelines requires the measurement of the residual stresses generated both at the surface and inside the material. in this work, the residual stresses generated in F-522 steel by two hard turning (conventional and laser assisted) and two grinding (production and finishing) processes were measured by X-ray diffraction. Additionally, depth profiles of the volume fraction of retained austenite, microstructure and nano hardness were obtained in order to correlate those results with the residual stress state obtained for each machining process. It has been observed that turning generates tensile stresses in the surface while grinding causes compressive stresses. Below the surface grinding generates weak tensile or nearly null stresses whereas turning generates strong compressive stresses. These results show that the optimum mechanising process (disregarding economical considerations) implies the combination of turning plus elimination of a small thickness by final grinding. (Author) 19 refs
Developing very hard nanostructured bainitic steel

Energy Technology Data Exchange (ETDEWEB)

Amel-Farzad, H., E-mail: hh_amel@yahoo.com [Department of Materials Engineering and Metallurgy, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Department of Materials Engineering, Faculty of Engineering, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Faridi, H.R., E-mail: faridihr@yahoo.com [Department of Materials Engineering and Metallurgy, Hamedan University of Technology, Hamedan (Iran, Islamic Republic of); Rajabpour, F.; Abolhasani, A.; Kazemi, Sh.; Khaledzadeh, Y. [Department of Materials Engineering and Metallurgy, Faculty of Engineering, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of)

2013-01-01

Novel nanostructured high carbon high silicon, carbide-free bainitic steels with very high strength and good ductility have been developed in the recent decade. In this work, an alloy with a high carbon content and no manganese was designed and cast. The prepared samples were heat treated through an austempering process in the range 200-350 Degree-Sign C. Optical and scanning electron microscopes and XRD were used to analyze the microstructures precisely. Bainitic ferrite plates of just a few tens of nanometer thickness were obtained with the hardness of 697{+-}6 HV. It is reasonable to say that the unprecedented hardness values obtained in this work are mostly caused by the extraordinary carbon content of the alloy.
Hard-real-time resource management for autonomous spacecraft

Science.gov (United States)

Gat, E.

2000-01-01

This paper describes tickets, a computational mechanism for hard-real-time autonomous resource management. Autonomous spacecraftcontrol can be considered abstractly as a computational process whose outputs are spacecraft commands.
A new, bright and hard aluminum surface produced by anodization

Science.gov (United States)

Hou, Fengyan; Hu, Bo; Tay, See Leng; Wang, Yuxin; Xiong, Chao; Gao, Wei

2017-07-01

Anodized aluminum (Al) and Al alloys have a wide range of applications. However, certain anodized finishings have relatively low hardness, dull appearance and/or poor corrosion resistance, which limited their applications. In this research, Al was first electropolished in a phosphoric acid-based solution, then anodized in a sulfuric acid-based solution under controlled processing parameters. The anodized specimen was then sealed by two-step sealing method. A systematic study including microstructure, surface morphology, hardness and corrosion resistance of these anodized films has been conducted. Results show that the hardness of this new anodized film was increased by a factor of 10 compared with the pure Al metal. Salt spray corrosion testing also demonstrated the greatly improved corrosion resistance. Unlike the traditional hard anodized Al which presents a dull-colored surface, this newly developed anodized Al alloy possesses a very bright and shiny surface with good hardness and corrosion resistance.
Influence of skin hardness on dehydration kinetics of wine grapes.

Science.gov (United States)

Rolle, Luca; Caudana, Alberto; Giacosa, Simone; Gerbi, Vincenzo; Río Segade, Susana

2011-02-01

Knowledge of the influence of initial mechanical properties on the evolution of the weight loss of berries through the drying process is scarce. Therefore, the main purpose of this work was to investigate the effect of skin hardness at two different physiological stages of off-vine drying kinetics of grapes. Skin hardness was evaluated as the berry skin-break force parameter, measured by the texture analysis test. The decrease of berry weight as a function of the drying time was linear, indicating that the drying rates were constant within each cultivar studied (Moscato bianco and Erbaluce), and for each ripening stage and berry skin hardness. The drying rates decreased as berry skin hardness increased for the ripest grapes in the cultivars studied. The study allowed the assessment of the correlation between the skin hardness of fresh berries and the weight loss determined for different drying days. 2010 Society of Chemical Industry.
Holographic diffraction gratings as laser radiation protection filters

International Nuclear Information System (INIS)

Pantelic, D.; Pantelic, G.

2006-01-01

Holographic volume diffraction gratings are used as attenuation filters, due to their selective spectral transmission. They can be tailored to reflect or transmit narrow spectral ranges by adjusting spatial frequency of Bragg grating in carefully chosen photosensitive materials, like silver-halide emulsion or di-chromated gelatin layers. If properly recorded and chemically processed, resulting gratings can significantly attenuate light at wavelengths corresponding to various laser spectral lines. Thus, they can be used as filters in laser protection goggles. We analyze the characteristics of Bragg gratings necessary to obtain high attenuation coefficients. Also, their angular selectivity is taken into account and corresponding experimental conditions are investigated. Although di-chromated gelatin seems to be almost ideal material, due to its almost 100% diffraction efficiency, environmental stability is poor (degradation under humid environment), thus making its practical usage difficult. Thus, we have analyzed alternative materials like di-chromated pullulan, which is stable under normal environmental conditions (without drop in diffraction efficiency after prolonged exposure to humidity). Pullulan is polymer (polysaccharide) of biologic origin produced by certain bacteria. If doped with chromium ions it becomes photosensitive, enabling recording of diffraction gratings with spatial frequency of more than 3000 lines/mm. Material is chemically processed by mixture of isopropyl alcohol and water. Both thick and thin layers can be produced by gravity settling. Spectral properties of resulting gratings are analyzed, showing that they can significantly attenuate laser light of particular wavelength, depending of grating period and its slant angle. (authors)
Investigation of diffractive optical element femtosecond laser machining

Energy Technology Data Exchange (ETDEWEB)

Chabrol, Grégoire R., E-mail: g.chabrol@ecam-strasbourg.eu [ECAM Strasbourg-Europe, Espace Européen de l’entreprise, 2, rue de Madrid – 67300 SCHILTIGHEIM, CS. 20013, 67012 Strasbourg CEDEX (France); Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Ciceron, Adline [ECAM Strasbourg-Europe, Espace Européen de l’entreprise, 2, rue de Madrid – 67300 SCHILTIGHEIM, CS. 20013, 67012 Strasbourg CEDEX (France); Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Twardowski, Patrice; Pfeiffer, Pierre [Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Télécom Physique Strasbourg – Pôle API – 300 Bd Sébastien Brant – CS 10413, Illkirch Graffenstaden F 67400 (France); and others

2016-06-30

Highlights: • A method for rapid manufacturing of optical diffractive element in BK7 is proposed. • A binary grating in BK7 was successfully machined by femtosecond laser pulses. • Process relying on nonlinear absorption in the dielectric due to photoionization. • The binary grating was analysed by SEM and interferometric microscopy. • Simulations by Fourier modal method supported the measured diffractive efficiency. - Abstract: This paper presents an explorative study on the machining of diffractive optical elements (DOEs) in transparent materials using a femtosecond laser source. A simple form of DOE, a binary phase grating with a period of 20.85 μm (σ = 0.5 μm), a groove depth and width of 0.7 μm (σ = 0.2 μm) and 8.8 μm (σ = 0.5 μm) respectively, was successfully machined in BK7. The topographic characteristics were measured by white light interferometry and scanning electron microscopy (SEM). The processing was carried out on high precision stages with an ultrafast fibre laser (350 fs) emitting a 343 nm pulse focused onto the sample with a stationary microscope objective. A diffracted efficiency of 27%, obtained with a spectro goniometer, was corroborated by the theoretical results obtained by the Fourier modal method (FMM), taking into account the measured topographic values. These encouraging results demonstrate that high-speed femtosecond laser manufacturing of DOE in bulk glasses can be achieved, opening the way to rapid prototyping of multi-layered-DOEs.
Oxidation study of Cr-Ru hard coatings

Energy Technology Data Exchange (ETDEWEB)

Chen, Yung-I, E-mail: yichen@mail.ntou.edu.tw; Kuo, Yu-Chu; Chen, Sin-Min

2012-01-01

Cr-Ru alloy coatings with Cr content ranging from 47 to 83 at.% were deposited at 400 Degree-Sign C by direct current magnetron co-sputtering with a Ti interlayer on silicon substrates. With a total input power of 300 W, the Cr content in the Cr-Ru coatings increased linearly with the increasing input power of Cr. The intermetallic compound phase Cr{sub 2}Ru with columnar structure was identified for the as-deposited Cr{sub 56}Ru{sub 44} and Cr{sub 65}Ru{sub 35} coatings, resulting in an increase of hardness up to 15-16 GPa. To evaluate the performance of Cr-Ru coatings as a protective coating on glass molding dies, the annealing treatment was conducted at 600 Degree-Sign C in a 50 ppm O{sub 2}-N{sub 2} atmosphere. The outward diffusion and preferential oxidization of Cr in the Cr-Ru coatings resulted in the variations of the crystalline structure, chemical composition distribution, and surface hardness after annealing. X-ray diffraction and transmission electron microscopy (TEM) proved that an oxide scale consisting of Cr{sub 2}O{sub 3} formed on the free surface. Scanning electron microscopy and TEM observed the surface morphology and structural variation. The chemical composition depth profiles were analyzed by Auger electron microscopy, verifying the presence of a Cr-depleted zone beneath the oxide scale. The hardness of Cr{sub 56}Ru{sub 44} and Cr{sub 65}Ru{sub 35} coatings decreased to 11-12 GPa after annealing, accompanied by the replacement of the Cr{sub 2}Ru phase by the Ru phase. - Highlights: Black-Right-Pointing-Pointer We prepared crystalline Cr-Ru alloy coatings by direct current magnetron sputtering. Black-Right-Pointing-Pointer Cr-Ru coatings were annealed at 600 Degree-Sign C for 2 h in a 50 ppm O{sub 2}-N{sub 2} atmosphere. Black-Right-Pointing-Pointer Cr diffused outwardly and oxidized to form a stable and protective oxide scale. Black-Right-Pointing-Pointer The original columnar grains recrystallized to polycrystalline grains.
Application of modified analytical function for approximation and computer simulation of diffraction profile

International Nuclear Information System (INIS)

Marrero, S. I.; Turibus, S. N.; Assis, J. T. De; Monin, V. I.

2011-01-01

Data processing of the most of diffraction experiments is based on determination of diffraction line position and measurement of broadening of diffraction profile. High precision and digitalisation of these procedures can be resolved by approximation of experimental diffraction profiles by analytical functions. There are various functions for these purposes both simples, like Gauss function, but no suitable for wild range of experimental profiles and good approximating functions but complicated for practice using, like Vougt or PersonVII functions. Proposed analytical function is modified Cauchy function which uses two variable parameters allowing describing any experimental diffraction profile. In the presented paper modified function was applied for approximation of diffraction lines of steels after various physical and mechanical treatments and simulation of diffraction profiles applied for study of stress gradients and distortions of crystal structure. (Author)
Induction surface hardening of hard coated steels

Energy Technology Data Exchange (ETDEWEB)

Pantleon, K.; Kessler, O.; Hoffann, F.; Mayr, P. [Stiftung Inst. fuer Werkstofftechnik, Bremen (Germany)

1999-11-01

The properties of hard coatings deposited using CVD processes are usually excellent. However, high deposition temperatures negatively influence the substrate properties, especially in the case of low alloyed steels. Therefore, a subsequent heat treatment is necessary to restore the properties of steel substrates. Here, induction surface hardening is used as a method of heat treatment after the deposition of TiN hard coatings on AISI 4140 (DIN42CrMo4) substrates. The influences of the heat treatment on both the coating and the substrate properties are discussed in relation to the parameters of induction heating. Thereby, the heating time, heating atmosphere and the power input into the coating-substrate compounds are varied. As a result of induction surface hardening, the properties of the substrates are improved without losing good coating properties. High hardness values in the substrate near the interface allow the AISI 4140 substrates to support TiN hard coatings very well. Consequently, higher critical loads are measured in scratch tests after the heat treatment. Also, compressive residual stresses in the substrate are generated. In addition, only a very low distortion appears. (orig.)
Vectorial diffraction properties of THz vortex Bessel beams.

Science.gov (United States)

Wu, Zhen; Wang, Xinke; Sun, Wenfeng; Feng, Shengfei; Han, Peng; Ye, Jiasheng; Yu, Yue; Zhang, Yan

2018-01-22

A vortex Bessel beam combines the merits of an optical vortex and a Bessel beam, including a spiral wave front and a non-diffractive feature, which has immense application potentials in optical trapping, optical fabrication, optical communications, and so on. Here, linearly and circularly polarized vortex Bessel beams in the terahertz (THz) frequency range are generated by utilizing a THz quarter wave plate, a spiral phase plate, and Teflon axicons with different opening angles. Taking advantage of a THz focal-plane imaging system, vectorial diffraction properties of the THz vortex Bessel beams are comprehensively characterized and discussed, including the transverse (Ex, Ey) and longitudinal (Ez) polarization components. The experimental phenomena are accurately simulated by adopting the vectorial Rayleigh diffraction integral. By varying the opening angle of the axicon, the characteristic parameters of these THz vortex Bessel beams are exhibited and compared, including the light spot size, the diffraction-free range, and the phase evolution process. This work provides the precise experimental and theoretical bases for the comprehension and application of a THz vortex Bessel beam.
Remember Hard but Think Softly: Metaphorical Effects of Hardness/Softness on Cognitive Functions

Directory of Open Access Journals (Sweden)

Jiushu Xie

2016-09-01

Full Text Available Previous studies have found that bodily stimulation, such as hardness, biases social judgment and evaluation via metaphorical association; however, it remains unclear whether bodily stimulation also affects cognitive functions, such as memory and creativity. The current study used metaphorical associations between hard and rigid and between soft and flexible in Chinese, to investigate whether the experience of hardness affected cognitive functions requiring either rigidity (memory or flexibility (creativity. In Experiment 1, we found that Chinese-speaking participants performed better at recalling previously memorized words while sitting on a hard-surface stool (the hard condition than a cushioned one (the soft condition. In Experiment 2, participants sitting on a cushioned stool outperformed those sitting on a hard-surface stool on a Chinese riddle task, which required creative/flexible thinking, but not on an analogical reasoning task, which required both rigid and flexible thinking. The results suggest the hardness experience affects cognitive functions that are metaphorically associated with rigidity and flexibility. They support the embodiment proposition that cognitive functions and representations could be grounded via metaphorical association in bodily states.
Non-diffractive waves

CERN Document Server

Hernandez-Figueroa, Hugo E; Recami, Erasmo

2013-01-01

This continuation and extension of the successful book ""Localized Waves"" by the same editors brings together leading researchers in non-diffractive waves to cover the most important results in their field and as such is the first to present the current state.The well-balanced presentation of theory and experiments guides readers through the background of different types of non-diffractive waves, their generation, propagation, and possible applications. The authors include a historical account of the development of the field, and cover different types of non-diffractive waves, including Airy
Diffractive elements performance in chromatic confocal microscopy

International Nuclear Information System (INIS)

Garzon, J; Duque, D; Alean, A; Toledo, M; Meneses, J; Gharbi, T

2011-01-01

The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.
Modern trends in x-ray powder diffraction

International Nuclear Information System (INIS)

Goebel, H.E.; Snyder, R.L.

1985-01-01

The revival of interest in X-ray powder diffraction, being quoted as a metamorphosis from the 'ugly duckling' to a 'beautiful swan', can be attributed to a number of modern developments in instrumentation and evaluation software. They result in faster data collection, improved accuracy and resolution, and better detectability of minor phases. The ease of data evaluation on small computers coupled direct to the instrument allows convenient execution of previously tedious and time-consuming off-line tasks like qualitative and quantitative analysis, characterization of microcrystalline properties, indexing, and lattice-constant refinements, as well as structure refinements or even exploration of new crystal structures. Powder diffraction has also progressed from an isolated analytical laboratory method to an in situ technique for analysing solid-state reactions or for the on-stream control of industrial processes. The paper surveys these developments and their real and potential applications, and tries to emphasize new trends that are regarded as important steps for the further progress of X-ray powder diffraction
A hard-to-read font reduces the framing effect in a large sample.

Science.gov (United States)

Korn, Christoph W; Ries, Juliane; Schalk, Lennart; Oganian, Yulia; Saalbach, Henrik

2018-04-01

How can apparent decision biases, such as the framing effect, be reduced? Intriguing findings within recent years indicate that foreign language settings reduce framing effects, which has been explained in terms of deeper cognitive processing. Because hard-to-read fonts have been argued to trigger deeper cognitive processing, so-called cognitive disfluency, we tested whether hard-to-read fonts reduce framing effects. We found no reliable evidence for an effect of hard-to-read fonts on four framing scenarios in a laboratory (final N = 158) and an online study (N = 271). However, in a preregistered online study with a rather large sample (N = 732), a hard-to-read font reduced the framing effect in the classic "Asian disease" scenario (in a one-sided test). This suggests that hard-read-fonts can modulate decision biases-albeit with rather small effect sizes. Overall, our findings stress the importance of large samples for the reliability and replicability of modulations of decision biases.
On the extension of the Fermi-Watson Theorem to high energy diffraction

International Nuclear Information System (INIS)

Malecki, A.; Istituto Nazionale di Fisica Nucleare, Frascati

1995-12-01

The Fermi-Watson theorem, established for low energy reactions and then applied to high energy collision, is revisited. Its use for the processes of inelastic diffraction is discussed. The theorem turns out to be valid in the case inclusive cross-section of diffractive transition
Precipitation-Induced Changes in Microstrain and Its Relation with Hardness and Tempering Parameter in 17-4 PH Stainless Steel

Science.gov (United States)

Mahadevan, S.; Manojkumar, R.; Jayakumar, T.; Das, C. R.; Rao, B. P. C.

2016-06-01

17-4 PH (precipitation hardening) stainless steel is a soft martensitic stainless steel strengthened by aging at appropriate temperature for sufficient duration. Precipitation of copper particles in the martensitic matrix during aging causes coherency strains which improves the mechanical properties, namely hardness and strength of the matrix. The contributions to X-ray diffraction (XRD) profile broadening due to coherency strains caused by precipitation and crystallite size changes due to aging are separated and quantified using the modified Williamson-Hall approach. The estimated normalized mean square strain and crystallite size are used to explain the observed changes in hardness. Microstructural changes observed in secondary electron images are in qualitative agreement with crystallite size changes estimated from XRD profile analysis. The precipitation kinetics in the age-hardening regime and overaged regime are studied from hardness changes and they follow the Avrami kinetics and Wilson's model, respectively. In overaged condition, the hardness changes are linearly correlated to the tempering parameter (also known as Larson-Miller parameter). Similar linear variation is observed between the normalized mean square strain (determined from XRD line profile analysis) and the tempering parameter, in the incoherent regime which is beyond peak microstrain conditions.

A measurement of electron-wall interactions using transmission diffraction from nanofabricated gratings

International Nuclear Information System (INIS)

Barwick, Brett; Gronniger, Glen; Yuan, Lu; Liou, Sy-Hwang; Batelaan, Herman

2006-01-01

Electron diffraction from metal coated freestanding nanofabricated gratings is presented, with a quantitative path integral analysis of the electron-grating interactions. Electron diffraction out to the 20th order was observed indicating the high quality of our nanofabricated gratings. The electron beam is collimated to its diffraction limit with ion-milled material slits. Our path integral analysis is first tested against single slit electron diffraction, and then further expanded with the same theoretical approach to describe grating diffraction. Rotation of the grating with respect to the incident electron beam varies the effective distance between the electron and grating bars. This allows the measurement of the image charge potential between the electron and the grating bars. Image charge potentials that were about 15% of the value for that of a pure electron-metal wall interaction were found. We varied the electron energy from 50 to 900 eV. The interaction time is of the order of typical metal image charge response times and in principle allows the investigation of image charge formation. In addition to the image charge interaction there is a dephasing process reducing the transverse coherence length of the electron wave. The dephasing process causes broadening of the diffraction peaks and is consistent with a model that ascribes the dephasing process to microscopic contact potentials. Surface structures with length scales of about 200 nm observed with a scanning tunneling microscope, and dephasing interaction strength typical of contact potentials of 0.35 eV support this claim. Such a dephasing model motivated the investigation of different metallic coatings, in particular Ni, Ti, Al, and different thickness Au-Pd coatings. Improved quality of diffraction patterns was found for Ni. This coating made electron diffraction possible at energies as low as 50 eV. This energy was limited by our electron gun design. These results are particularly relevant for the
Deformation behaviors of aluminum alloys for automobile parts studied by neutron diffraction

International Nuclear Information System (INIS)

Katayanagi, Kazue; Morita, Kensuke; Tomota, Yo; Kamiyama, Takashi; Terakado, Katsuyoshi

2008-01-01

In situ time of flight neutron diffraction measurements during tension test were performed for three Al-Si alloys with different microstructures including hot-forged (AHS 2), T 6 heat-treated (AHS 2-T 6) and die-cast (ACD 12) specimens. Strength and work-hardening behaviors of these specimens are investigated by evaluating phase stresses, i.e., stress partitioning between Si and the Al matrix as well as intergranular stresses of [hkl] oriented family grains in the component phases. It is revealed that Si particles embedded in the Al matrix play a role of the hard second phase. The size and shape of the Si particles affect work hardening and fracture of the alloys. (author)
Diffraction gauging

International Nuclear Information System (INIS)

Wilkens, P.H.

1978-01-01

This system of gauging is now being designed to fit on an Excello NC lathe to measure the form, accuracy, and size of external contoured surfaces as they approach the finish machined size. A template profile of the finished workpiece, but 0.003 in. bigger on radius, will be aligned with the workpiece using a reference diameter and face on the machining fixture to leave a gap between the profile of the template and workpiece. A helium--neon laser beam will be projected through this gap using a rotating retroreflector and a fixed laser. The resulting diffraction pattern produced by the laser beam passing through the template to workpiece gap will be reflected and focused on a fixed diode array via a second retroreflector which moves and remains in optical alignment with the first. These retroreflectors will be rotated about a center that will enable the laser beam, which is shaped in a long slit, to scan the template workpiece gap from the pole to the equator of the workpiece. The characteristic diffraction pattern will be detected by the fixed diode array, and the signal levels from this array will be processed in a mini-computer programmed to produce a best fit through the two minima of the diode signals. The separation of the two minima will yield the size of the workpiece to template gap and this information will be presented to the machine tool operator
Rapidity gap survival in the black-disk regime

International Nuclear Information System (INIS)

Leonid Frankfurt; Charles Hyde; Mark Strikman; Christian Weiss

2007-01-01

We summarize how the approach to the black-disk regime (BDR) of strong interactions at TeV energies influences rapidity gap survival in exclusive hard diffraction pp -> p + H + p (H = dijet, Qbar Q, Higgs). Employing a recently developed partonic description of such processes, we discuss (a) the suppression of diffraction at small impact parameters by soft spectator interactions in the BDR; (b) further suppression by inelastic interactions of hard spectator partons in the BDR; (c) correlations between hard and soft interactions. Hard spectator interactions substantially reduce the rapidity gap survival probability at LHC energies compared to previously reported estimates
Development of strength-hardness relationships in additively manufactured titanium alloys

Energy Technology Data Exchange (ETDEWEB)

Keist, Jayme S., E-mail: keist@psu.edu; Palmer, Todd A., E-mail: tap103@psu.edu

2017-05-02

A major concern for additively manufactured (AM) Ti-6Al-4V components is how AM processing parameters and post-process heat treatments impact the resulting mechanical behavior. The applicability of using microhardness measurements as a predictive tool for yield and tensile strengths of AM Ti-6Al-4V would provide a rapid and useful screening mechanism for ensuring that properties meet requirements in complex geometries. However, microhardness measurements on Ti-6Al-4V exhibit high levels of data variability due to the orientational impact of the α phase. In order to overcome this variability in hardness measurements, a methodology for aggregating microhardness data in individual builds has been developed and validated. By compiling mean microhardness values from various AM components produced by electron beam based directed energy deposition (DED), laser based DED, and laser based powder bed fusion (PBF) processes in the as-deposited and post-process heat treated conditions, strong linear correlations between strength and hardness can be developed in AM materials having a lamellar α+β microstructure. With the addition of strain hardening and α phase orientation contributions to the mean microhardness measurement, the strength-hardness correlations of AM Ti-6Al-4V followed empirically derived models, opening the possibility of using these models to predict strengths from AM components regardless of the AM process or post-process state.
Co-electrodeposition of hard Ni-W/diamond nanocomposite coatings

Science.gov (United States)

Zhang, Xinyu; Qin, Jiaqian; Das, Malay Kumar; Hao, Ruru; Zhong, Hua; Thueploy, Adisak; Limpanart, Sarintorn; Boonyongmaneerat, Yuttanant; Ma, Mingzhen; Liu, Riping

2016-02-01

Electroplated hard chrome coating is widely used as a wear resistant coating to prolong the life of mechanical components. However, the electroplating process generates hexavalent chromium ion which is known carcinogen. Hence, there is a major effort throughout the electroplating industry to replace hard chrome coating. Composite coating has been identified as suitable materials for replacement of hard chrome coating, while deposition coating prepared using traditional co-deposition techniques have relatively low particles content, but the content of particles incorporated into a coating may fundamentally affect its properties. In the present work, Ni-W/diamond composite coatings were prepared by sediment co-electrodeposition from Ni-W plating bath, containing suspended diamond particles. This study indicates that higher diamond contents could be successfully co-deposited and uniformly distributed in the Ni-W alloy matrix. The maximum hardness of Ni-W/diamond composite coatings is found to be 2249 ± 23 Hv due to the highest diamond content of 64 wt.%. The hardness could be further enhanced up to 2647 ± 25 Hv with heat treatment at 873 K for 1 h in Ar gas, which is comparable to hard chrome coatings. Moreover, the addition of diamond particles could significantly enhance the wear resistance of the coatings.
Accessing the diffracted wavefield by coherent subtraction

Science.gov (United States)

Schwarz, Benjamin; Gajewski, Dirk

2017-10-01

Diffractions have unique properties which are still rarely exploited in common practice. Aside from containing subwavelength information on the scattering geometry or indicating small-scale structural complexity, they provide superior illumination compared to reflections. While diffraction occurs arguably on all scales and in most realistic media, the respective signatures typically have low amplitudes and are likely to be masked by more prominent wavefield components. It has been widely observed that automated stacking acts as a directional filter favouring the most coherent arrivals. In contrast to other works, which commonly aim at steering the summation operator towards fainter contributions, we utilize this directional selection to coherently approximate the most dominant arrivals and subtract them from the data. Supported by additional filter functions which can be derived from wave front attributes gained during the stacking procedure, this strategy allows for a fully data-driven recovery of faint diffractions and makes them accessible for further processing. A complex single-channel field data example recorded in the Aegean sea near Santorini illustrates that the diffracted background wavefield is surprisingly rich and despite the absence of a high channel count can still be detected and characterized, suggesting a variety of applications in industry and academia.
Scheduling of Fault-Tolerant Embedded Systems with Soft and Hard Timing Constraints

DEFF Research Database (Denmark)

Izosimov, Viacheslav; Pop, Paul; Eles, Petru

2008-01-01

In this paper we present an approach to the synthesis of fault-tolerant schedules for embedded applications with soft and hard real-time constraints. We are interested to guarantee the deadlines for the hard processes even in the case of faults, while maximizing the overall utility. We use time....../utility functions to capture the utility of soft processes. Process re-execution is employed to recover from multiple faults. A single static schedule computed off-line is not fault tolerant and is pessimistic in terms of utility, while a purely online approach, which computes a new schedule every time a process...
Optimization of process parameters for spark plasma sintering of nano structured SAF 2205 composite

Directory of Open Access Journals (Sweden)

Samuel Ranti Oke

2018-04-01

Full Text Available This research optimized spark plasma sintering (SPS process parameters in terms of sintering temperature, holding time and heating rate for the development of a nano-structured duplex stainless steel (SAF 2205 grade reinforced with titanium nitride (TiN. The mixed powders were sintered using an automated spark plasma sintering machine (model HHPD-25, FCT GmbH, Germany. Characterization was performed using X-ray diffraction and scanning electron microscopy. Density and hardness of the composites were investigated. The XRD result showed the formation of FeN0.068. SEM/EDS revealed the presence of nano ranged particles of TiN segregated at the grain boundaries of the duplex matrix. A decrease in hardness and densification was observed when sintering temperature and heating rate were 1200 °C and 150 °C/min respectively. The optimum properties were obtained in composites sintered at 1150 °C for 15 min and 100 °C/min. The composite grades irrespective of the process parameters exhibited similar shrinkage behavior, which is characterized by three distinctive peaks, which is an indication of good densification phenomena. Keywords: Spark plasma sintering, Duplex stainless steel (SAF 2205, Titanium nitride (TiN, Microstructure, Density, Hardness
Hardness measurements of silicon rubber and polyurethane rubber cured by ionizing radiation

International Nuclear Information System (INIS)

Basfar, A.A.

1995-01-01

This work investigates the hardness of both silicon rubber and polyurethane rubber cured by ionizing radiation. Shore A Hardness is used to characterize the subject elastomers in relation to the crosslinking process. Various formulations of both materials have been investigated in order to achieve the optimum cure conditions desired. A small amount of the curing agent has been incorporated in some formulations in order to reduce the required dose to achieve full cure conditions. Silicon rubber has shown improvements in hardness as absorbed dose is increased, whereas hardness remained constant over a range of absorbed doses for polyurethane rubber
Influence of high temperature annealing on the structure, hardness and tribological properties of diamond-like carbon and TiAlSiCN nanocomposite coatings

International Nuclear Information System (INIS)

Xie, Z.W.; Wang, L.P.; Wang, X.F.; Huang, L.; Lu, Y.; Yan, J.C.

2011-01-01

Diamond-like carbon (DLC) and TiAlSiCN nanocomposite coatings were synthesized and annealed at different temperatures in a vacuum environment. The microstructure, hardness and tribological properties of as-deposited and annealed DLC-TiAlSiCN nanocomposite coatings were characterized by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), Raman spectroscopy, nano-indentation and friction tests. The TEM results reveal that the as-deposited DLC-TiAlSiCN coating has a unique nanocomposite structure consisting of TiCN nanocrystals embedded in an amorphous matrix consisting of a-Si 3 N 4 , a-SiC, a-CN and DLC, and the structure changed little after annealing at 800 °C. However, XPS and Raman results show that an obvious graphitization of the DLC phase occurred during the annealing process and it worsened with annealing temperature. Because of the graphitization, the hardness of the DLC-TiAlSiCN coating after annealing at 800 °C decreased from 45 to 36 GPa. In addition, the DLC-TiAlSiCN coating after annealing at 800 °C has a similar friction coefficient to the as-deposited coating.
Custom Hardware Processor to Compute a Figure of Merit for the Fit of X-Ray Diffraction

International Nuclear Information System (INIS)

Gomez-Pulido, P.J.A.; Vega-Rodriguez, M.A.; Sanchez-Perez, J.M.; Sanchez-Bajo, F.; Santos, S.P.D.

2008-01-01

A custom processor based on re configurable hardware technology is proposed in order to compute the figure of merit used to measure the quality of the fit of X-ray diffraction peaks. As the experimental X-ray profiles can present many peaks severely overlapped, it is necessary to select the best model among a large set of reasonably good solutions. Determining the best solution is computationally intensive, because this is a hard combinatorial optimization problem. The proposed processors, working in parallel, increase the performance relative to a software implementation.
Development of a hard nano-structured multi-component ceramic coating by laser cladding

Energy Technology Data Exchange (ETDEWEB)

Masanta, Manoj [Department of Mechanical Engineering, IIT Kharagpur, West Bengal 721302 (India); Ganesh, P.; Kaul, Rakesh [Laser Material Processing Division, Raja Ramanna Centre for Advanced Technology, Indore (India); Nath, A.K. [Department of Mechanical Engineering, IIT Kharagpur, West Bengal 721302 (India); Roy Choudhury, A., E-mail: roychoudhuryasimava@gmail.com [Department of Mechanical Engineering, IIT Kharagpur, West Bengal 721302 (India)

2009-05-20

The present paper reports laser-assisted synthesis of a multi-component ceramic composite coating consisting of aluminum oxide, titanium di-boride and titanium carbide (Al{sub 2}O{sub 3}-TiB{sub 2}-TiC). A pre-placed powder mixture of aluminum (Al), titanium oxide (TiO{sub 2}) and boron carbide (B{sub 4}C) was made to undergo self-propagating high-temperature synthesis (SHS) by laser triggering. Laser subsequently effected cladding of the products of SHS on the substrate. The effect of laser scanning speed on the hardness, microstructure and phase composition of the composite coating was investigated. The coating exhibited an increase in hardness and a decrease in grain size with increase in laser scanning speed. A maximum micro-hardness of 2500 HV{sub 0.025} was obtained. X-ray diffraction (XRD) of the top surface of the coating revealed the presence of aluminum oxide (Al{sub 2}O{sub 3}), titanium di-boride (TiB{sub 2}) and titanium carbide (TiC) along with some non-stoichiometric products of the Ti-Al-B-C-O system. Field emission gun scanning electron microscopy (FESEM) and high-resolution transmission electron microscopic (HRTEM) analysis revealed some nano-structured TiB{sub 2} and Al{sub 2}O{sub 3}, which are discussed in detail.
Nanograined Ti–Nb microalloy steel achieved by Accumulative Roll Bonding (ARB) process

International Nuclear Information System (INIS)

Tohidi, A.A.; Ketabchi, M.; Hasannia, A.

2013-01-01

Over the last decade, nanocrystalline and ultra-fine grained (UFG) materials with grain size less than 1 μm have aroused considerable interest due to their superior mechanical properties compared to conventionally grained materials. In this work Ti–Nb microalloy steel was processed by the severe plastic deformation (SPD) technique called Accumulative Roll Bonding (ARB) in order to produce an ultra-fine grained microstructure and improve the mechanical properties. After initial preparation to achieve good sheet bonding, 8 cycles of ARB at 550 °C were successfully performed. Observation of optical microstructure, scanning electron microscopy (SEM) micrographs, and X-Ray Diffraction (XRD) peak broadening analysis were used for the characterization of grain structure of the ARB processed sample. The mechanical attributes after rolling and cooling were examined. It was calculated that metal's yield and tensile strength increased by 334% and 215% respectively, while the ductility dropped from as-received value of 34% to 2.9%. Microhardness of the material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of the ARB process. At the 8th pass, the hardness values increased by 230%. The rolling process was stopped at 8th cycle when cracking of the edge became pronounced
Hard x-ray monochromator with milli-electron volt bandwidth for high-resolution diffraction studies of diamond crystals

Energy Technology Data Exchange (ETDEWEB)

Stoupin, Stanislav; Shvyd' ko, Yuri; Shu Deming; Khachatryan, Ruben; Xiao, Xianghui; DeCarlo, Francesco; Goetze, Kurt; Roberts, Timothy; Roehrig, Christian; Deriy, Alexey [Advanced Photon Source, Argonne National Laboratory, Illinois 60439 (United States)

2012-02-15

We report on design and performance of a high-resolution x-ray monochromator with a spectral bandwidth of {Delta}E{sub X}{approx_equal} 1.5 meV, which operates at x-ray energies in the vicinity of the backscattering (Bragg) energy E{sub H} = 13.903 keV of the (008) reflection in diamond. The monochromator is utilized for high-energy-resolution diffraction characterization of diamond crystals as elements of advanced x-ray crystal optics for synchrotrons and x-ray free-electron lasers. The monochromator and the related controls are made portable such that they can be installed and operated at any appropriate synchrotron beamline equipped with a pre-monochromator.
QCD dipole prediction for dis and diffractive structure functions

International Nuclear Information System (INIS)

Royon, CH.

1996-01-01

The F 2 , F G , R = F L /F T proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function F 2 data in the low x, moderate Q 2 range. Without any additional parameter, the gluon density and the longitudinal structure functions are predicted. The diffractive dissociation processes are also discussed, and a new prediction for the proton diffractive structure function is obtained. (author)
30 CFR 75.1720-1 - Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps... STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color...
A Forging Hardness Dispersion Effect on the Energy Consumption of Machining

Directory of Open Access Journals (Sweden)

L. D. Mal'kova

2015-01-01

Full Text Available The aim of the work is to evaluate a hardness dispersion of forgings to be further machined, and analyse the impact of this dispersion on the resulting power consumption when cutting.The paper studies the hardness values of three kinds of parts for automotive manufacturing. Sample of each part was n = 100 pieces. Analysis of measurements showed that 46% - 93% of parts meet requirements for a range defined by the work-piece working drawing. It was found that hardness of one batch of forgings is under dispersion, which distribution is governed by the normal law.The work provides calculations for machining the external cylindrical surfaces of the considered parts. In the context of calculating are adopted parameters of the enterprise-processing rate. It is found that power consumption of machining because of the dispersion values of the work-piece hardness is a function of the random BH variable and it itself is a random variable. Two types of samples are considered, namely: the full sample and that of the values that meet requirements for hardness. The coefficient of variation for samples that meet the technical requirements for hardness is lower than for the full samples, so their average value is more reliable characteristic of a set. It was also found that to ensure a reliable prediction of power consumption in designing the manufacturing processes it is necessary to reduce a tolerance range of workpiece hardness to the limit.The work gives a comparative evaluation of electric power consumption per unit cylindrical surface of the parts under consideration. A relative change in the electric power consumed at the minimum and maximum levels of the hardness value was introduced as an evaluation criterion. It is found that with changing hardness of machined work-pieces within the tolerance, the change in power consumption in machining the unit surface reaches 16% while in the case its being out of the specified range it does 47%.
30 CFR 77.1710-1 - Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps... Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color from those worn by experienced miners shall be worn at...
Time-domain Brillouin scattering assisted by diffraction gratings

Science.gov (United States)

Matsuda, Osamu; Pezeril, Thomas; Chaban, Ievgeniia; Fujita, Kentaro; Gusev, Vitalyi

2018-02-01

Absorption of ultrashort laser pulses in a metallic grating deposited on a transparent sample launches coherent compression/dilatation acoustic pulses in directions of different orders of acoustic diffraction. Their propagation is detected by delayed laser pulses, which are also diffracted by the metallic grating, through the measurement of the transient intensity change of the first-order diffracted light. The obtained data contain multiple frequency components, which are interpreted by considering all possible angles for the Brillouin scattering of light achieved through multiplexing of the propagation directions of light and coherent sound by the metallic grating. The emitted acoustic field can be equivalently presented as a superposition of plane inhomogeneous acoustic waves, which constitute an acoustic diffraction grating for the probe light. Thus the obtained results can also be interpreted as a consequence of probe light diffraction by both metallic and acoustic gratings. The realized scheme of time-domain Brillouin scattering with metallic gratings operating in reflection mode provides access to wide range of acoustic frequencies from minimal to maximal possible values in a single experimental optical configuration for the directions of probe light incidence and scattered light detection. This is achieved by monitoring the backward and forward Brillouin scattering processes in parallel. Potential applications include measurements of the acoustic dispersion, simultaneous determination of sound velocity and optical refractive index, and evaluation of samples with a single direction of possible optical access.

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