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2223
No full textLa ciencia ficción, desde sus inicios, ha superado las barreras de la ciencia mediante la exploración y el cuestionamiento de sus capacidades y límites en relación con la sociedad. 2223 es un punto de convergencia entre la ciencia ficción y las artes plásticas que tiene como resultado una experiencia inmersiva que sitúa al espectador en un fragmento de un futuro hipotético, y hará que se cuestione sobre lo que nos hace humanos, la percepción que tenemos de realidad, felicidad, necesidad y propósito, aparte de cuestionarse sobre las acciones de la humanidad frente a problemáticas actuales que pueden resultar en un replanteamiento de la estructura social y sobre cómo el desarrollo de ciertas tecnologías pueden tomar un papel fundamental dentro de esta.Science fiction, from its beginnings, has transcended scientific boundaries by exploring and questioning its capabilities and limits in relation to society. 2223 represents a convergence point between science fiction and the visual arts, resulting in an immersive experience that places the viewer within a fragment of a hypothetical future. It encourages reflection on what makes us human, our perception of reality, happiness, necessity, and purpose, as well as questioning humanity’s actions in the face of current issues that could lead to a rethinking of the social structure and the role certain technologies might play within it
Electrospinning synthesis of Bi-2223 superconducting nanowires
Get PDFThis paper presents the synthesis and characterization of Bi2Sr2Ca2Cu3O8+x superconducting nanowires. Bi2Sr2Ca2Cu3O8+x nanowires with Tc = 68 K were synthesized using the electrospinning process employing sol–gel precursors. A sol–gel methodology was used to obtain a homogeneous PVP solution containing Bi, Sr, Ca, and Cu oxalates. Samples were heat-treated at 120 °C to remove excess moisture, and then at 850 °C in box furnace. Bulk sample was also prepared using coprecipitation method for comparison. Based on XRD, the nanowire sample showed minimal Bi-2223 phases and apparent Bi-2212 phases. The morphology, microstructure, and crystal structure of these nanowires were examined using field emission scanning electron microscopy (FESEM) to reveal a rectangular morphology having typical wire thickness in the range of 150–1000 nm. Electrospun Bi-2223 were grinded and pressed at 0.9 GPa into pellets. DC measurements were conducted to investigate the critical transition temperature (Tc) of Bi-2223 nanowires and to compare their magnetic properties to those of coprecipitated Bi-2223 pellets. The Tc for the bulk sample is observed at 101 K and electrospun Bi-2223 at 68 K. Coprecipitated Bi-2223 was added with Pb whereas electrospun Bi-2223 does not employ Pb. These results point to the existence of utilizing of the substitution of Pb with Bi; Bi-2223 phases in pressed nanowire are less, and the potential of using electrospinning to synthesis functional Bi-2233 superconductors
Biological Carbon Sequestration and Carbon Trading Re-Visited
Get PDFUnder Kyoto, biological activities that sequester carbon can be used to create CO2 offset credits that could obviate the need for lifestyle-changing reductions in fossil fuel use. Credits are earned by storing carbon in terrestrial ecosystems and wood products, although CO2 emissions are also mitigated by delaying deforestation, which accounts for one-quarter of anthropogenic CO2 emissions. However, nonpermanent carbon offsets from biological activities are difficult to compare with each other and with emissions reduction because they differ in how long they prevent CO2 from entering the atmosphere. This is the duration problem; it results in uncertainty and makes it difficult to determine the legitimacy of biological activities in mitigating climate change. While there is not doubt that biological sink activities help mitigate climate change and should not be neglected, in this paper we demonstrate that these activities cannot be included in carbon trading schemes.carbon offset credits, climate change, duration of carbon sinks, Environmental Economics and Policy,
Gd-substituted Bi-2223 superconductor
No full textThe effects of gadolinium doping at calcium site on the
normal and superconducting properties of Bi-2223 system were studied.The Gd-doped (BiPb)-2223 series of specimens, namely Batch I, II and III were sintered at three different sintering temperatures 830, 850 and 895C respectively. The properties investigated are (1)the normal state resistivity with a view to study metal-to-insulator
transition, (2) the XRD patterns of the specimens with a view to study the relative composition of (BiPb)-2212 and (BiPb)-2223 phases and (3) the superconducting fluctuation behaviour (SFB) with a view to determine the effect of doping, if any, on the dimensionality of the fluctuation conductivity of the system. The normal state resistivity of Gd-substituted Bi-2223 specimens shows metallic, semiconducting and insulating behaviour. The T_{\rmc}(R=0) values indicate that (BiPb)-2223 phase is responsible for the observed superconducting transitions in Batch I and Batch II specimens with Gd concentrations . This observation is further confirmed in the analysis of XRD patterns of these specimens. Gadolinium, being a magnetic impurity, has pair breaking effect near
the Fermi level and decreases . The analysis of the superconducting fluctuation behaviour (SFB) shows a 2D dimensionality without any cross-over
COMP3211- Parallel Databases 2 - 2223
No full textCOMP3211- Parallel Databases 2 - 2223
Corrected Versio
Effect of SnO, MgO and Ag2O Mix-doping on the Formation and Superconducting Properties of Bi-2223 Ag/tapes
No full textAbstractThe Ag/tapes with the composition Bi1.8Pb0.4Sr1.9Ca2.1Cu3.5Oy + x wt% SnO + y wt% MgO + z wt% Ag2O (x = 0, 0.2, 0.4; y = 0, 0.2; z = 0, 0.2) were prepared by sintering at 835°C for 120h after partial-melting at 845°C for 1h. The individual SnO doping, SnO and Ag2O mix-doping, and SnO and MgO mix-doping all decrease the conversion of Bi-2212 phase to Bi-2223 phase. The tape with individual 0.4 wt% SnO doping shows the lowest conversion and the lowest critical current density. However, the SnO, MgO and Ag2O mix-doping increase the conversion of Bi-2212 phase to Bi-2223 phase. The tape with 0.2 wt% SnO, 0.2 wt% MgO and 0.2 wt%Ag2O mix-doping shows the highest proportion of Bi-2223 phase and the highest critical current density
Electrical properties and corrosion of Bi-2223 coatings on silver wires directly synthetized from a Bi-2223 precursor or from a Bi-2223/Bi-2212 mixture
No full textSuperconducting wires are prepared by coating of a silver substrate, by sintering of a slurry deposited onto the metal core and containing a grinded (Pb doped) Bi-2223 ceramic, a grinded Bi-2223/Bi-2212 mixed ceramic or a grinded mixture of the Bi-2223 precursors, and of 20% PbO in excess. The resistance-versus-temperature R(T) curves obtained for a 6 days sintering at 835°C presented only one drop, with Tc0 = 108K (107K when the slurry is a mixture of the Bi-2223 precursors). When the coating is obtained from a grinded Bi-2223/Bi-2212 mixed ceramic the R(T) curves are better (higher Tc and narrower ΔTc) than the R(T) curves obtained with the ceramic used for preparing the wires, for which Tc0 = 34K. The role of PbO in excess is discussed. These coatings hold rather well against corrosion by waper vapor at 90°C and the Bi-2223 phase is less corroded than the Bi-2212 phase
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Chicago & North Western (CNW) 2223
No full textA photograph print showing Chicago & Northwestern (CNW) 2223, 4-6-2 (class E-1), on passenger train
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