1,270 research outputs found

    Drinkwater and Another v. Kimber

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    Tapered, tubular polyester fabric

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    A tapered tubular polyester sleeve is described to serve as the flexible foundation for a spacesuit limb covering. The tube has a large end and a small end with a length to be determined. The ratio of taper is also determined by scale factors. All the warp yarns extend to the large end. A requisite number of warp yarns extend the full length of the sleeve. Other warp yarns extend from the large end but are terminated along the length of the sleeve. It is then woven with a filling yarn which extends in a full circle along the full length of the sleeve to thereby define the tapered sleeve. The sleeve after fabrication is then placed on a mandrel, heated in an oven, and then attached to the arm or other limb of the spacesuit

    Classification of perovskite structural types with dynamical octahedral tilting.

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    Perovskites ABX3 with delocalized positions of the X atoms represent a distinct class of dynamically distorted structures with peculiar structural relations and physical properties. The delocalization originates from atoms crossing shallow barriers of the potential energy surface. Quantum mechanically, they can be treated similar to light atoms in diffusive states. Many of these perovskite structures are widely used functional materials thanks to their particular physical properties, such as superconductivity, ferroelectricity and photo-activity. A number of these properties are related to static or dynamic motion of octahedral units. Yet, a full understanding of the relationships between perovskite crystal structure, chemical bonding and physical properties is currently missing. Several studies indicate the existence of dynamic disorder generated by anharmonic motion of octahedral units, e.g. in halide perovskite structures. To simplify structural analysis of such systems we derive a set of space groups for simple perovskites ABX3 with dynamical octahedral tilting. The derived space groups extend the well established space group tables for static tiltings by Glazer [Acta Cryst. B (1972). 28, 3384-3392], Aleksandrov [Ferroelectrics (1976). 24, 801-805] and Howard & Stokes [Acta Cryst. B (1998). 54, 782-789]. Ubiquity of dynamical tilting is demonstrated by an analysis of the structural data for perovskites reported in recent scientific publications and the signature of dynamic tilting in the corresponding structures is discussed, which can be summarized as follows: (a) volume increase upon a lowering of temperature, (b) apparent distortion of octahedra (where Jahn-Teller distortions can be ruled out), (c) mismatch between observed instantaneous symmetry and average symmetry, (d) deviation of the experimental space group from the theoretically predicted structures for static tilting, (e) inconsistency of lattice parameters with those suggested by the theory of static tilts, and (f) large displacement parameters for atoms at the X and B sites. Finally, the possible influence of dynamic disorder on the physical properties of halide perovskites is discussed

    Possibilitats d'ampliar el ventall d'espècies de bolets cultivables: estudis sobre la múrgola

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    En el present estudi es mostra la importància i l'estat de la recerca sobre el cultiu de la múrgola (Morchella sp.) com a una de les possibilitats d'ampliar el ventall actual de les espècies de bolets cultivables. Es parteix d'una visió global sobre la importància de la fungicultura i el cultiu de bolets com a activitat dintre el sector agrícola. Seguidament, es fa una revisió de la informació publicada sobre la múrgola i el seu cultiu. També es mostren les diferents experiències dutes a terme a l'Escola Superior d'Agricultura de Barcelona (ESAB) en la línia de recerca iniciada sobre el cultiu de bolets. Finalment, es fa una anàlisi crítica sobre les expectatives que desperta la fungicultura, sobre la recerca realitzada a l'ESAB i sobre les possibilitats futures de desenvolupar-hi noves línies de recerca en fungicultura.The present study shows the importance and «state of the art» of research on the cultivation of morels (Morchella sp.) as one of the possibilities of enlarging the number of edible fungus species in current culture. After a general view on the importance of mushroom growing in agriculture, we review the publications on morels and their cultivation. We also show the different experiences carried out at the «Escola Superior d'Agricultura de Barcelona» (ESAB) on morel mushroom growing. Finally, we make a critical review on prospective fungiculture, on the research developed at the ESAB and on possibilities of new research unes on fungiculture in the mentioned University centre.En el presente estudio se muestra la importancia y el estado de los estudios sobre el cultivo de las colmenillas (Morchella sp.) como una de las posibilidades de ampliar la actual gama de especies de setas cultivables. Se parte de una visión global sobre la importancia del cultivo de setas como actividad dentro del sector agrícola, para seguir con una revisión de la información publicada sobre las colmenillas y su cultivo. Se exponen las distintas experiencias que se han llevado a cabo en la «Escola Superior d'Agricultura de Barcelona» (ESAB) en la línea de investigación iniciada sobre el cultivo de setas y finalmente, se hace un análisis crítico sobre las espectativas que despierta la fungicultura, sobre la investigación realizada en la ESAB y sobre las posibilidades futuras de desarrollar nuevas líneas de investigación

    Target-specific glioma therapy in an immunocompetent mouse model : meeting abstract

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    Objective: Establishment of an immunocompetent mouse model representing the typical progressive stages observed in malignant human gliomas for the in vivo evaluation of novel target-specific regimens. Methods: Isolated clones from tumours that arose spontaneously in GFAP-v-src transgenic mice were used to develop a transplantable brain tumour model in syngeneic B6C3F1 mice. STAT3 protein was knocked down by infection of tumour cells with replication-defective lentivirus encoding STAT3-siRNA. Apoptosis is designed to be induced by soluble recombinant TRAIL + chemical Bcl-2/Bcl-xL inhibitors. Results: Striatal implantation of 105 mouse tumour cells resulted in the robust development of microscopically (2 – 3 mm) infiltrating malignant gliomas. Immunohistochemically, the gliomas displayed the astroglial marker GFAP and the oncogenic form of STAT3 (Tyr-705-phosphorylated) which is found in many malignancies including gliomas. Phosphorylated STAT3 was particularly prominent in the nucleus but was also found at the plasma membrane of peripherally infiltrating glioma cells. To evaluate the role of STAT3 in tumour progression, we stably expressed siRNA against STAT3 in several murine glioma cell lines. The effect of STAT3 depletion on proliferation, invasion and survival will be first assessed in vitro and subsequently after transplantation in vivo. Upstream and downstream components of the STAT3 signalling pathway as well as possible non-specific side effects of STAT3-siRNA expression after lentiviral infection will be examined, too. Conclusions: Its high rate of engraftment, its similarity to the malignant glioma of origin, and its rapid locally invasive growth should make this murine model useful in testing novel therapies for malignant gliomas

    Fluxes of Copper-Complexing Ligands from Estuarine Sediments

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    Most studies of the organic complexation of Cu in natural waters have focused on distributions and processes in the water column, where a significant fraction of Cu-complexing ligands may be biologically produced. We present direct evidence for a flux of Cu-complexing ligands from estuarine sediments, demonstrating that sediments are a significant, yet previously unrecognized source of the ligands. Fluxes of Cu-complexing ligands from Chesapeake Bay sediments range from 300 to 1,200 nmol m-2 d-1, exceeding fluxes of total dissolved Cu by 3-\u3e40-fold, suggesting that any Cu fluxing from the sediments is likely to be organically complexed. Our results indicate that benthic fluxes may supply from 10 to 50% of the standing stock of Cu-complexing ligands in Chesapeake Bay and suggest that such fluxes may strongly influence the biogeochemistry of Cu in shallow water environments and potentially in the ocean as a whole

    From waste to high value utilization of spent bleaching clay in synthesizing high-performance calcium-based sorbent for CO 2 capture

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    A novel calcium looping (CaL) process integrated with a spent bleaching clay (SBC) treatment is proposed whereby fuels and/or heat from regeneration of SBC provide extra energy for the calcination process, in addition, the regenerated SBC can be used to synthesize enhanced CaO-based sorbents. Different kinds of composite samples were prepared with the regenerated SBC and/or aluminate cement at various doping ratios via a pelletization process. All pellets were subjected to thermogravimetic analyzer tests employing severe reaction conditions to determine the optimal doping ratios and regeneration method for the SBC based sorbents. These results demonstrate that pellets containing combustible components showed higher CO2 uptakes, due to the improved pore structure, which was verified by N2 adsorption measurements. The as-prepared sorbent “L-10PC” (90 wt.% CaO/10 wt.% pyrolytic SBC) achieved a final CO2 uptake of 0.164 g(CO2) g(calcined sorbent)−1 after 20 cycles, which was 67.3% higher than that of natural limestone particle. A new larnite (Ca2SiO4) phase was detected by X-ray diffraction analysis, however the weak diffraction peak associated with it indicated a low content of larnite in the pellets, which produced a smaller effect on performance compared to cement. A synergistic effect was achieved for a sample designated as “L-5PC-10CA” (85 wt.% CaO/5 wt.% pyrolytic SBC /10 wt.% cement), which resulted in the highest final uptake of 0.208 g(CO2) g(calcined sorbent)−1 after 20 cycles. Considering the simplicity of pyrolysis regeneration process and the excellent capture capability of pellets doped by pyrolytic SBC, the proposed system integrating CaL with SBC pyrolysis treatment appears to offer particular promise for further development

    L'Origine de la Loi Positive

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