Quantitative X-Ray Diffraction Measurements by Fast Scanning, HR-111

Two goals were pursued in this research: first, to evaluate statistically some effects of sample preparation and instrument geometry on reproducibility of X-ray diffraction intensity data; and second, to develop a procedure for finding minimum peak and background counting times for a desired level of accuracy. The ratio of calcite to dolomite in limestones was determined in trials. Ultra-fine wet grinding of the limestone in porcelain impact type ball mill gave most consistent X-ray results, but caused considerable line broadening, and peaks were best measured on an area count basis. Sample spinning reduced variance about one third, and a coarse beam-medium detector slit arrangement was found to be best. An equation is developed relating coefficient of variation of a count ratio to peak and background counts. By use of the equation or graphs the minimum coefficient of variation is predicted from one fast scan, and the number and optimum arrangement of additional counting periods to reduce variation to a desired limit may be obtained. The calculated coefficient is the maximum which may be attributed to the counting statistic but does not include experimental deviations.

Efectivitat dels diferents tipus de colpeig a pilota aturada en el futbol platja

El propòsit d’aquest estudi és analitzar quin és l’índex d’efectivitat en diferents situacions a pilota aturada (penals, faltes sense barrera i córners) en el futbol platja dins el context d’equips amateurs que participen en els tornejos de Blanes i Tossa de Mar. A l’hora de realitzar-lo he tingut en compte una sèrie de variables, com ara la precisió del colpeig, el tipus de colpeig, la superfície de contacte o la situació inicial de la pilota, és a dir, des d’on provenia la trajectòria inicial d’ aquesta, tot comprovant també com canvien els resultats en funció de la zona i del costat que es realitza el remat. Respecte els resultats, aquests demostren que l’índex d’efectivitat en aquest tipus d’accions és més baix en relació amb altres esports semblants com el futbol i el futbol sala.

Estudi de l'efectivitat del remat al primer toc dins la zona de finalització

L’objectiu principal d’aquest estudi ha estat comprovar quin nombre de contactes amb la pilota és més efectiu a l’hora d’executar l’acció del remat dins la zona de finalització. S’ha utilitzat la metodologia observacional, investigant en un context d’elit com són els partits realitzats per les quatre seleccions millor classificades a l’Eurocopa 2012. La investigació ha tingut en compte diferents variables del remat com el gol, el nombre de contactes amb la pilota abans del remat, l’orientació corporal del jugador que remata i la última acció abans que la pilota entri dins la zona de finalització per ser rematada. Els resultats obtinguts ens donen informació sobre com les seleccions de Portugal, Alemanya, Itàlia i Espanya finalitzaren les seves accions ofensives i permeten al lector fer-se una idea general de com hauria de realitzar-se un remat en la zona de finalització.

Anàlisi i quantificació de les accions i el temps de joc en l'hoquei sobre patins en equips de l'OK Lliga

Quantificar les variables temporal, les accions tècniques i els desplaçaments dels jugador al llarg de la competició proporciona una informació excel·lent per deduir les càrregues físiques i fisiològiques a les que estan sotmesos. Per aquest estudi es van visualitzar 4 partits de la Copa del Rei 2012. Es va enregistrà sistemàticament les dades en fulls de registre. Les principals dades analitzades van ser: temps total, temps real, temps de pausa, temps d’acció i relació entre el temps d’acció i el temps de pausa (densitat de treball). També es va analitzar: les incidències reglamentaries, les accions tècniques del jugador i els desplaçaments del jugador. El 45% de les accions es van produir entre 0 i 30s, i el promig d’interval de participació va ser 19:29s ±2:09. Més del 50% de les pauses es van produir entre 11s i 30s, i el promig d’interval de pausa va ser de 24:57s. Aquest va determinar que la densitat de treball era 1:1.3. Aproximadament el 70% de les incidències reglamentàries van ser faltes d’equip I tècniques. Van haver-hi 56 conduccions, 10 driblins, 12 remats, (3 xuts, 2 punxades/escopides, 5 remats de primeres i 2 arrossegades) i 80 passades. Finalment, en un partit el 42,23% dels desplaçaments van ser a baixa intensitat, el 27,02% van ser a intensitat mitjana i el 30,75% van ser a alta intensitat. A més a més, el 81,90% dels desplaçaments a alta intensitat van durar de 0s a 5s, el 54,56% a intensitat mitjana van durar de 6 a 10 s. I el 49,32% a intensitat baixa també van durar 6s a 10s. L’hoquei sobre patins és un esport en el que hi predominen els esforços intermitents a gran intensitat i de curta durada amb una important sol·licitació de la via anaeròbica alàctica. Analitzar la dimensió temporal, les accions tècniques i els desplaçaments dels jugador durant la competició permet estimar les exigències físiques i requeriments energètics, i aquest faciliten l’elaboració d’entrenaments més específics.

El joc d'esquena del davanter centre al futbol, és més eficaç jugant de cara o girant-se?

Segons Castelo (1999, 2009) i Ardá i Casal (2003) la fase ofensiva del futbol es divideix en la fase de progressió, en la qual es busca progressar a porteria, i en la fase de manteniment o emergència, en la qual s’assegura la possessió de la pilota. L’objectiu és analitzar si quan el davanter centre rep la pilota d’esquena a porteria, es manté amb més eficàcia la possessió jugant en progressió o en emergència durant els 5” posteriors a la recepció de la pilota per part del davanter. L’estudi és Descriptiu d’Observació Directa, en aquest s’observen i s’analitzen, a través de vídeos, 10 partits de la fase de grups de la fase final de la Eurocopa 2012, en concret els partits són dels grups A i B. Els resultats confirmen la hipòtesi inicial, ja que es manté amb més eficàcia la pilota quan aquesta es juga en emergència (71%) que no pas en progressió (54%).

Comparació del servei en curt i en llarg del porter dins de la fase ofensiva del joc

En el procés ofensiu de la majoria d’equips de futbol, es pot distingir una tendència a jugar en base a dos estils de joc. Un estil basat en un joc en curt, per tal de poder mantenir la possessió de la pilota, i estar durant més temps atacant la porteria contraria. I un altre estil que prefereix buscar la profunditat en les seves accions, anant d’una forma més directe cap a la porteria rival. En aquest treball es pretén analitzar quin dels dos estils és millor perquè un equip encadeni un total de 6 accions, tenint com a referència en l’inici de la jugada al porter. Per tal d’aconseguir-ho s’analitzaran els 24 partits de la fase de grups de l’Eurocopa 2012 a través d’una metodologia pròpia, que ens permetrà saber a través de quines situacions rep la pilota el porter abans de posar la pilota en joc, i a través de quines accions, l’equip no és capaç d’assolir el nombre d’encadenaments marcat.

Symmetric periodic orbits near a heteroclinic loop in R3 formed by two singular points, a semistable periodic orbit and their invariant manifolds

In this paper we consider C1 vector fields X in R3 having a “generalized heteroclinic loop” L which is topologically homeomorphic to the union of a 2–dimensional sphere S2 and a diameter connecting the north with the south pole. The north pole is an attractor on S2 and a repeller on . The equator of the sphere is a periodic orbit unstable in the north hemisphere and stable in the south one. The full space is topologically homeomorphic to the closed ball having as boundary the sphere S2. We also assume that the flow of X is invariant under a topological straight line symmetry on the equator plane of the ball. For each n ∈ N, by means of a convenient Poincar´e map, we prove the existence of infinitely many symmetric periodic orbits of X near L that gives n turns around L in a period. We also exhibit a class of polynomial vector fields of degree 4 in R3 satisfying this dynamics.

Understanding diffusion MR imaging techniques: from scalar diffusion-weighted imaging to diffusion tensor imaging and beyond.

The complex structural organization of the white matter of the brain can be depicted in vivo in great detail with advanced diffusion magnetic resonance (MR) imaging schemes. Diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique-the mapping of apparent diffusion coefficient values-to the more complex, such as diffusion tensor imaging, q-ball imaging, diffusion spectrum imaging, and tractography. The type of structural information obtained differs according to the technique used. To fully understand how diffusion MR imaging works, it is helpful to be familiar with the physical principles of water diffusion in the brain and the conceptual basis of each imaging technique. Knowledge of the technique-specific requirements with regard to hardware and acquisition time, as well as the advantages, limitations, and potential interpretation pitfalls of each technique, is especially useful.

Field Evaluation of Alternative Load Transfer Device Locations in Low Traffic Volume Pavements, TR-420, 2003

In jointed portland cement concrete pavements, dowel bars are typically used to transfer loads between adjacent slabs. A common practice is for designers to place dowel bars at a certain, consistent spacing such that a sufficient number of dowels are available to effectively transfer anticipated loads. In many cases, however, the standards developed today for new highway construction simply do not reflect the design needs of low traffic volume, rural roads. The objective of this research was to evaluate the impact of the number of dowel bars and dowel location on joint performance and ultimately on pavement performance. For this research, test sections were designed, constructed, and tested in actual field service pavement. Test sections were developed to include areas with load transfer assemblies having three and four dowels in the outer wheel path only, areas with no joint reinforcement whatsoever, and full lane dowel basket assemblies as the control. Two adjacent paving projects provided both rural and urban settings and differing base materials. This report documents the approach to implementing the study and provides discussion and suggestions based on the results of the research. The research results indicate that the use of single three or four dowel basket assemblies in the outer wheel path is acceptable for use in low truck volume roads. In the case of roadways with relatively stiff bases such as asphalt treated or stabilized bases, the use of the three dowel bar pattern in the outside wheel path is expected to provide adequate performance over the design life of the pavement. In the case of untreated or granular bases, the results indicate that the use of the three or four dowel bar basket in both wheel paths provides the best long-term solution to load transfer and faulting measurements.

Field Evaluation of Elliptical Steel Dowel Performance, 2006

Joints are always a concern in the construction and long-term performance of concrete pavements. Research has shown that we need some type of positive load transfer across transverse joints. The same research has directed pavement designers to use round dowels spaced at regular intervals across the transverse joint to distribute the vehicle loads both longitudinally and transversely across the joint. The goal is to reduce bearing stresses on the dowels and the two pavement slab edges and erosion of the underlying surface, hence improved long-term joint and pavement structure performance. Road salts cause metal corrosion in doweled joints, excessive bearing stresses hollow dowel ends, and construction processes are associated with cracking pavement at the end of dowels. Dowels are also a cost factor in the pavement costs when joint spacing is reduced to control curling and warping distress in pavements. Designers desire to place adequate numbers of dowels spaced at the proper locations to handle the anticipated loads and bearing stresses for the design life of the pavement. This interim report is the second of three reports on the evaluation of elliptical steel dowels. This report consists of an update on the testing and performance of the various shapes and sizes of dowels. It also documents the results of the first series of performance surveys and draws interim conclusions about the performance of various bar shapes, sizes, spacings, and basket configurations. In addition to the study of elliptical steel dowel performance, fiber reinforced polymers (FRP) are also tested as elliptical dowel material (in contrast to steel) on a section of the highway construction north of the elliptical steel test sections.

La representació fílmica de la intimitat

Aquest treball versa sobre la intimitat i el cinema. S'estructura entres actes. En el primer, explico la meva experiència com a directora d'unapel·lícula que protagonitzo i que vaig censurar per massa impúdica. En elsegon, reflexiono sobre les pel·lícules autobiogràfiques i el concepted'intimitat, per plantejar alguns dels dilemes sobre la seva representaciófílmica. Analitzo i comparo les imatges de pel·lícules de dos directors, NaomiKawase i Jonathan Caouette, qui també s'hi han encarat, buscant l'efectemirall. En el tercer, considero les motivacions, les compensacions, la reacciódels espectadors i les conseqüències d'arriscar-se a exposar la intimitat, lapròpia i la dels qui ens envolten.

Origin of needle fibre calcite (NFC) : a geochemical approach

ABSTRACTNeedle fibre calcite (NFC) is one of the most widespread habits of pedogenic calcite. It is a monocrystal of calcite, in the shape of a needle, with a diameter of one micron and a length between 4 and 103 times its width. NFC occurs in soils with different macroscopic and microscopic morphologies. Macroscopically, two main habits of NFC exist: "cotton ball'Mike clusters and as "powder" coating on pebbles inside the soil. It can also act as nucleation sites for precipitation of calcite cements of purely physicochemical origin (LCC - Late Calcitic Cement). Although many studies have been conducted on needle fibre calcite, its origin remains a subject of debate. The NFC having never been reproduced in the laboratory whatever the considered approach, the processes responsible for its precipitation as a so particular morphology remain unexplained. The shift between the length orientation of the needle crystal and the normal axis of calcite growth (c-axis) is also unresolved.Samples taken in two soils observed in quarries (Villiers and Savagnier) in the Swiss Jura Mountains are used to investigate the processes involved in the formation of these calcite crystals in pedogenic environments. Three groups of microscopic morphologies are distinguished: (i) simple needles (SN), (ii) simple needles with overgrowths (SNO), and (iii) simple needles with nanofibres (SNN), nanofibres being either organic or mineral in nature. These groups correspond to different stages in the formation and evolution of NFC.Comparison of carbon and oxygen isotope compositions of NFC with LCC, in relationship with the composition of the carbonate host rock (CHR), and the carbon isotope signature of dissolved inorganic carbon (DIC) from the soil waters, indicates that both NFC and LCC are precipitated in isotopic equilibrium with the soil solution. Similar Ô13C and Ô180 values of the elongated NFC and the rhombohedral calcite crystals of the LCC suggest that the precipitation of these different calcite habits is not due to changes in physicochemical conditions. The growth of NFC crystals inside an organic mould formed by the fungal hyphae could explain the formation of calcite ciystals in the shape of a needle in isotopic equilibrium with the local environment.Strontium and calcium isotope compositions of the three microscopic groups of NFC and LCC were also studied, in order to determine the origin of calcium (Ca2+) entrapped in the calcite lattice and to elucidate the processes responsible for the precipitation of NFC. The 87Sr/86Sr ratio of the SN is closer to the 87Sr/86Sr ratio of the carbonate host rock than the LCC, SNO, and SNN. This could be another clue for the formation of SN inside fungal hyphae, because fungi are known to dissolve the rocks to release and translocate through their hyphae nutrients necessary for their growth. SN and SNN are depleted in Sr and enriched in ^Ca compared to the LCC. In the context of Villiers quarry, where the two ciystal shapes precipitate at similar temperature (in a range of 0,6°C), such variations are the result of a slower precipitation rate of NFC, which is inconsistent with a purely physicochemically precipitated elongate crystal.Finally, NFC is enriched in major and trace elements (i.e. Fe, Zn, Cu, and Mo) compared to the LCC. This enrichment is ascribed to modification in precipitation processes between the NFC and LCC. Right now, it is not possible to preclude the influence of the particular shape of NFC or the biological influence. REEs are not fractionated in NFC, contrary to LCC. Thus, NFC does not precipitate from a percolation solution circulating downward the soil, which should lead to the fractionation of the REEs. As explained above, fungi, are able to dissolve and translocate nutrients. This kind of processes allows releasing elements in the soil solution without fractionation and could explain the particular chemical signature of NFC regarding the REEs.The geochemical approach to investigate the origin of NFC presented in this study does not allow providing direct clues to the fungal origin of NFC, but brings several new insights in the understanding of the formation of such a particular mineral, calcite needles, by precluding definitively their physicochemical origin.RESUMELa calcite en aiguilles (NFC) est l'une des formes les plus ubiquiste de calcite pédogénique. Il s'agit d'un monocrystal de calcite d'un diamètre d'un micron et d'une longueur 4 à 102 fois supérieure à sa largeur. A l'échelle macroscopique, la NFC a été observée sous deux principaux aspects : l'une « cotonneuse » et l'autre formant un mince croûte autour des graviers du sol. La NFC peut également servir de support à la nucléation de ciments secondaires précipités de manière purement physico-chimique (LCC). Malgré les nombreuses études menées sur la NFC, son origine demeure encore inconnue. A ce jour, aucune expérience en laboratoire n'a permis de créer de la calcite en aiguilles, et ce, quelque soit l'approche abordée. Par conséquent, les processus précis responsables de la précipitation calcite avec une telle morphologie restent inconnus. Le décalage existant entre l'axe d'allongement des aiguilles de calcite et l'axe normal de croissance de la calcite (axe c) reste inexpliqué.Des échantillons de NFC, LCC, roche mère, eau de pluie des différents horizons du sol ont été prélevés principalement au front de deux carrières de graviers, ainsi que dans un profil de sol adjacent à ces carrières, dans le but de mieux comprendre les processus à l'origine de la précipitation de calcite en forme d'aiguille. Trois micro-morphologies ont été distinguées: les aiguilles simples (SN), les aiguilles simples avec surcroissances calcitiques (SNO) et enfin les aiguilles simples avec nanofibres (SNN), celles-ci pouvant être de minérales ou organiques. Ces groupes, d'après nos résultats et les études antérieures pourraient correspondre à différentes étapes de formation de la calcite en aiguilles.Dans un premier temps, la comparaison des signatures isotopiques de la calcite en aiguilles, du LCC, de la roche mère et du carbone inorganique dissout dans la solution du sol (CID) indique que la NFC, tout comme le LCC, précipite en équilibre avec la solution du sol. Les valeurs similaires en Ô13C et δ180 de cristaux de calcite allongés (NFC) et rhombohédriques (LCC) formés dans un même milieu suggère que ces différences morphologiques ne peuvent pas être attribuées à des modifications purement physico-chimiques. La croissance de NFC à l'intérieur d'un moule organique comme les hyphes de champignons semble être la seule hypothèse plausible permettant d'expliquer la formation de monocrystaux allongés de calcite en équilibre avec leur environnement.La composition isotopique en strontium (Sr) et calcium (Ca) des LCC et des trois micro¬morphologies de la NFC ont été étudiées également, afin de déterminer l'origine du Ca2+ présent dans le réseau cristallin de la calcite en aiguilles, ainsi que les processus responsables de la formation de NFC. Les valeurs du rapport 87Sr/86$r de la forme SN sont les plus proches de celles de la roche mère par rapport aux formes SNN et SNO et du LCC. Ceci pourrait être un nouvel indice de l'implication des champignons dans la précipitation de calcite en aiguilles, puisqu'ils sont connus pour avoir la capacité de dissoudre les roches afin de libérer les nutriments nécessaires à leur croissance, ainsi que de les transloquer par leurs hyphes. De plus, les formes SN et SNN sont appauvries en Sr et enrichies en "Ca, comparativement au LCC. Dans le sol étudié, tous les carbonates de calcium précipitent à la même température, par conséquent, de telles variations sont dues à un taux de précipitation plus lent de SN et SNN, ce qui est contradictoire avec l'hypothèse physico-chimique. Pour finir, la NFC est enrichie en certains éléments majeurs et traces (i.e. Fe, Zn, Cu et Mo) par rapport au LCC. Ceci peut être attribué à différents processus de formation entre la NFC et le LCC. Pour le moment il est impossible d'exclure l'influence de la forme particulière de la NFC ou celle du champignon. Les terres rares (REEs) ne sont pas fractionnées dans la NFC, contrairement au LCC. Ceci peut être expliqué par le fait que la NFC précipite à partir d'une solution qui n'a pas percolé à travers le sol. Les champignons en dissolvant les roches mettent en solution éléments sans les fractionner. L'approche géochimique de l'étude de la calcite en aiguilles ne permets pas de produire des preuves directes sur sa potentielle origine fongique, mais permet de mieux comprendre comment un minéral aussi singulier que la NFC peut se former. D'autre pare cette étude permets d'exclure définitivement l'hypothèse physico-chimique de l'origine de la calcite en aiguilles

New horizons for black holes and branes

We initiate a systematic scan of the landscape of black holes in any spacetime dimension using the recently proposed blackfold effective worldvolume theory. We focus primarily on asymptotically flat stationary vacuum solutions, where we uncover large classes of new black holes. These include helical black strings and black rings, black odd-spheres, for which the horizon is a product of a large and a small sphere, and non-uniform black cylinders. More exotic possibilities are also outlined. The blackfold description recovers correctly the ultraspinning Myers-Perry black holes as ellipsoidal even-ball configurations where the velocity field approaches the speed of light at the boundary of the ball. Helical black ring solutions provide the first instance of asymptotically flat black holes in more than four dimensions with a single spatial U(1) isometry. They also imply infinite rational non-uniqueness in ultraspinning regimes, where they maximize the entropy among all stationary single-horizon solutions. Moreover, static blackfolds are possible with the geometry of minimal surfaces. The absence of compact embedded minimal surfaces in Euclidean space is consistent with the uniqueness theorem of static black holes

Seismic Wave Velocity as a Means of In-Place Density Measurement, Part 1, HR-114

Velocity-density tests conducted in the laboratory involved small 4-inch diameter by 4.58-inch-long compacted soil cylinders made up of 3 differing soil types and for varying degrees of density and moisture content, the latter being varied well beyond optimum moisture values. Seventeen specimens were tested, 9 with velocity determinations made along two elements of the cylinder, 180 degrees apart, and 8 along three elements, 120 degrees apart. Seismic energy was developed by blows of a small tack hammer on a 5/8-inch diameter steel ball placed at the center of the top of the cylinder, with the detector placed successively at four points spaced 1/2-inch apart on the side of the specimen involving wave travel paths varying from 3.36 inches to 4.66 inches in length. Time intervals were measured using a model 217 micro-seismic timer in both laboratory and field measurements. Forty blows of the hammer were required for each velocity determination, which amounted to 80 blows on 9 laboratory specimens and 120 blows on the remaining 8 cylinders. Thirty-five field tests were made over the three selected soil types, all fine-grained, using a 2-foot seismic line with hammer-impact points at 6-inch intervals. The small tack hammer and 5/8-inch steel ball was, again, used to develop seismic wave energy. Generally, the densities obtained from the velocity measurements were lower than those measured in the conventional field testing. Conclusions were reached that: (1) the method does not appear to be usable for measurement of density of essentially fine-grained soils when the moisture content greatly exceeds the optimum for compaction, and (2) due to a gradual reduction in velocity upon aging, apparently because of gradual absorption of pore water into the expandable interlayer region of the clay, the seismic test should be conducted immediately after soil compaction to obtain a meaningful velocity value.

Depression, migraine with aura and migraine without aura: their familiality and interrelatedness.

Migraine is frequently comorbid with depression. There appear to be common aetiological factors for both disorders, but the aetiology of migraine within depressed patients, in particular the significance of aura, has been little studied. A large sample of concordantly depressed sibling pairs [the Depression-Network (DeNT) sample] was assessed as having migraine with aura (MA), migraine without aura (MoA), probable migraine or no migraine according to International Headache Society guidelines. Correlations between siblings' migraine status were used to assess the nature of familial liability to migraine. A multiple threshold isocorrelational model fit best, in which different syndromes are conceptualized as different severities of one underlying dimension rather than as having separate aetiologies. Thus, MA and MoA were found to be different forms of the same disorder, with MA occupying the more extreme end of the spectrum of liability. Implications for our understanding of the relationship between migraine and depression are discussed.