X-ray single crystal and powder diffraction: possibilities and applications

In this article the main possibilities of single crystal and powder diffraction analysis using conventional laboratory x-ray sources are introduced. Several examples of applications with different solid samples and in different fields of applications are shown illustrating the multidisciplinary capabilities of both techniques.

De la bellesa ornamental a la bellesa comercial : De les relacions entre art i publicitat en l'obra cartellista d'Alphonse Mucha

En aquest treball s'investiga, a través de l'obra d'Alphonse Mucha com autor paradigmàtic de l'Art Nouveau en el context geogràfic del París de finals del segle XIX i principis del XX, la possible influència de la publicitat en la difusió i consolidació de les creences i valors dels grups socials més ben posicionats, i molt especialment en el cas de la dona, ja que l'obra de Mucha està centrada bàsicament en la figura femenina. Així mateix, també es busca esbrinar la intervenció d'aquests grups en la creació d'un camp artístic que alhora faria possible la contemplació estètica de l'anunci comercial, i que esdevindria un element més d'aquesta moderna cultura, capitalista i urbana, de grans transformacions i avenços tecnològics, i que des d'una òptica crítica com la de l'Escola de Frankfurt, estaria 'cosificant' l'individu en nom de la ciència i el progrés, des del moment en què aquest quedaria condemnat al consum il·limitat per tal de satisfer un desig insaciable: l'afany d'emulació de la classe ociosa, o dit d'altra manera, d'aquella que el domina.

X Jornada Tècnica de l'Arròs

L’èxit de les jornades tècniques de l’arròs ens posiciona com una plataforma de transferència referent en el sector arrosser, amb l’objectiu d’exposar i debatre les darreres innovacions tecnològiques. Benvinguts a aquesta trobada d’experts i professionals del sector arrosser.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and γ-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3σ γ-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the γ-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the γ-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for γ-ray emission from Cyg X-3.

Relation between plaque type, plaque thickness, blood shear stress, and plaque stress in coronary arteries assessed by X-ray Angiography and Intravascular Ultrasound

Purpose: Atheromatic plaque progression is affected, among others phenomena, by biomechanical, biochemical, and physiological factors. In this paper, the authors introduce a novel framework able to provide both morphological (vessel radius, plaque thickness, and type) and biomechanical (wall shear stress and Von Mises stress) indices of coronary arteries. Methods: First, the approach reconstructs the three-dimensional morphology of the vessel from intravascular ultrasound(IVUS) and Angiographic sequences, requiring minimal user interaction. Then, a computational pipeline allows to automatically assess fluid-dynamic and mechanical indices. Ten coronary arteries are analyzed illustrating the capabilities of the tool and confirming previous technical and clinical observations. Results: The relations between the arterial indices obtained by IVUS measurement and simulations have been quantitatively analyzed along the whole surface of the artery, extending the analysis of the coronary arteries shown in previous state of the art studies. Additionally, for the first time in the literature, the framework allows the computation of the membrane stresses using a simplified mechanical model of the arterial wall. Conclusions: Circumferentially (within a given frame), statistical analysis shows an inverse relation between the wall shear stress and the plaque thickness. At the global level (comparing a frame within the entire vessel), it is observed that heavy plaque accumulations are in general calcified and are located in the areas of the vessel having high wall shear stress. Finally, in their experiments the inverse proportionality between fluid and structural stresses is observed.

Teucrium x mailhoi Giraudias nothosubsp. orientalis nova, un nou híbrid del vessant meridional dels Pirineus.

Teucrium × mailhoi Giraudias nothosubsp. orientalis nova, un nou híbrid del vessant meridional dels Pirineus.- Donem notícia de l"observació d"una petita població de l"híbrid entre Teucrium aureum Schreb. subsp. aureum i T. pyrenaicum L. subsp. guarensis P. Monts. al vessant sud de la serra de Moixeró (Pirineus orientals), que proposem com a nova notosubespècie. Fem també una comparació morfològica entre l"híbrid i els dos presumptes parentals, i en presentem imatges de materials d"herbari i de la població natural.

Aplicación de la técnica de espectrometría de fluorescencia de rayos-X en el estudio de la dispersión de metales en áreas mineras

One critical factor for success in characterizing metals polluting mining environments so as to be able to eliminate them and subsequently recover these areas depends upon a speedy and correct response in the analysis of samples. Rapid, simultaneous, multi-element analysis can be undertaken using X-ray fluorescence spectrometry, a versatile, non-destructive analytical technique commonly employed to identify both major and minor elements in samples related to environmental studies. An additional advantage of this technique is the possibility of conducting the analysis directly on solid samples, which is extremely convenient when dealing with environmental samples that are difficult to dissolve, such as soils, sediments and mining wastes. Moreover, in recent years the development of spectrometers equipped with digital-signal processors combined with enlarged X-ray production, using better designs for excitation-detection, has contributed to an improvement in instrumental sensitivity, thus allowing us to detect important polluting elements such as Cd and Pb at trace levels. In this paper the authors describe, on the basis of their own experience, some interesting applications of XRF spectrometry for the analysis of several types of environmental samples related to the study of the dispersion of metals within mining environments: (A) analysis of mining wastes, soils and sediments; (B) analysis of samples of vegetation used as bioindicators or related to phytoremediation studies; and (C) analysis of water samples related to mining operations

Early diagnosis of osteoporosis by means of orthopantomograms and oral x-rays: a systematic review

Osteoporosis is a systemic bone disease that is characterized by a generalized reduction of the bone mass. It is the main cause of fractures in elderly women. Bone densitometry is used in the lumbar spine and hip in order to detect osteoporosis in its early stages. Different studies have observed a correlation between the bone mineral density of the jaw (BMD) and that of the lumbar spine and/or hip. On the other hand, there are studies that evaluate the findings in the orthopantomograms and perapical X-rays, correlating them with the early diagnosis of osteoporosis and highlighting the role of the dentist in the early diagnosis of this disease. Materials and methods: A search was carried out in the Medline-Pubmed database in order to identify those articles that deal with the association between the X-ray findings observed in the orthopantomograms and the diagnosis of the osteoporosis, as well as those that deal with the bone mineral density of the jaw. Results: There were 406 articles, and with the limits established, this number was reduced to 21. Almost all of the articles indicate that when examining oral X-rays, it is possible to detect signs indicative of osteoporosis. Discussion: The radiomorphometric indices use measurements in orthopantomograms and evaluate possible loss of bone mineral density. They can be analyzed alone or along with the visual indices. In the periapical X-rays, the photodensimetric analyses and the trabecular pattern appear to be the most useful. There are seven studies that analyze the densitometry of the jaw, but only three do so independently of the photodensitometric analysis. Conclusions: The combination of mandibular indices, along with surveys on the risk of fracture, can be useful as indicators of early diagnosis of osteoporosis. Visual and morphometric indices appear to be especially important in the orthopantomograms. Photodensitometry indices and the trabecular pattern are used in periapical X-rays. Studies on mandibular dual-energy X-ray absorptiometry are inconclusive

Análisis arqueomorfológico y dinámica territorial en el Vallés Oriental (Barcelona) de la Protohistoria s. VI-V a.C.) a la alta Edad Media (s. IX-X)

La investigación sobre el paisaje en zonas urbanas o periurbanas implica importantes limitaciones metodológicas. En el presente estudio, el trabajo se centra en un llano pre-litoral próximo a la ciudad de Barcelona, el Vallès Oriental, profundamente urbanizado en las últimas dos décadas, hecho que condiciona la recuperación de nuevos datos arqueológicos y la implementación de programas de prospección arqueológica. Asimismo, la particular topografía que presenta el llano, caracterizado por unos relieves suaves, ha obligado a adaptar la metodología del análisis arqueomorfológico a este contexto geográfico. El artículo presenta los resultados del análisis arqueomorfológico realizado, que han sido cruzados con la documentación histórica y arqueológica para caracterizar —desde una perspectiva diacrónica— la red viaria, la estructuración territorial y la evolución del poblamiento de esta área y, finalmente, determinar las dinámicas del paisaje en época romana. La investigación sobre la morfología del territorio se ha llevado a cabo a partir de un intenso trabajo de fotointerpretación y análisis de la cartografía histórica en entorno SIG, especialmente útil en un paisaje marcado por las importantes trasformaciones del medio rural. Igualmente, los datos generados en los últimos años por la investigación arqueológica han sido revisados de forma detallada, a fin de contribuir a la planificación de las prospecciones arqueológicas y arqueomorfológicas desarrolladas.

"Et hoc facimus propter necessitatem famis...". Possibilitats de les fonts documentals catalanes per a l'estudi de les crisis alimentàries dels segles X-XIII

European studies of famines before the thirteenth century have been based principally on chronicles and especially on information from monastic annals. These sources, which are especially numerous during the so-called Carolingian Cultural Renaissance, offer abundant evidence of a phenomenon scarcely mentioned in other types of sources, including archival sources: the frequency and gravity of crises of food supply in some regions of continental Europe during the central middle ages, an epoch which, being situated between the terrible famines of the carolingian period and the great panademics of the fourteenth century, has been considered a period “without famines.” The object of this article is to shed light on the limitations of medieval catalan chronicle sources for the reconstruction of food-supply crises which affected the catalan counties in the tenth through the thirteenth centuries and illustrate, in contrast, the multiple opportunities offered by sources from the lordly archives. A significant part of these archival sources are connected in a direct and indirect manner to the difficulties of the rural and urban populations during famines and therefore, in a broad sense, can be considered a consequence of these crises.

Análisis de modelos de perfil del fuste y estudio de la cilindricidad para tres clones de chopo (Populus x euramericana) en Navarra

El presente trabajo tiene por objetivo principal analizar tres funciones de perfil del fuste sobre tres clones de Populus x euramericana (Canadá Blanco, I-214 y MC) en la Comunidad Foral de Navarra para elaborar una tarifa de cubicación con clasificación de volumen. Para minimizar el efecto de la autocorrelación entre los residuos se emplea una estructura de error continua autorregresiva de orden 2 o de orden 3 en función del clon analizado. Por otra parte, se compara el coeficiente local de forma de cada uno de los clones estudiados mediante dos metodologías: el análisis de la varianza de la estimación individual de dicho coeficiente y el contraste del estadístico de máxima verosimilitud entre ajustes, resultando ser el clon Canadá el más cónico de los tres. Los datos utilizados provienen de 143 chopos de plantaciones coetáneas y con mismo marco de plantación (marco real de 4,5 × 4,5 m).

Spectroscopic ellipsometry study of the In1-x Gax Asy P1-y / InP Heterojunctions grown by metalorganic chemical-vapor deposition

The dielectric functions of InP, In0.53Ga0.47As, and In0.75Ga0.25As0.5P0.5 epitaxial layers have been measured using a polarization modulation spectroscopic ellipsometer in the 1.5 to 5.3 eV region. The oxide removal procedure has been carefully checked by comparing spectroscopic ellipsometry and x ray photoelectron spectroscopy measurements. These reference data have been used to investigate the structural nature of metalorganic chemical vapor deposition grown In0.53Ga0.47As/InP and In0.75Ga0.25As0.5P0.5/InP heterojunctions, currently used for photodiodes and laser diodes. The sharpness of the interfaces has been systematically compared for the two types of heterojunctions: In1 xGaxAsy/InP and InP/In1 xGaxAsyP1 y. The sharpest interface is obtained for InP growth on In0.75Ga0.25As0.5P0.5 where the interface region is estimated to be (10±10) Å thick. The importance of performing in situ SE measurements is emphasized.