196,113 research outputs found
Giant reed (Arundo donax L.) as a sustainable Energy crop for 2nd generation bio-ethanol production.
No full textThe production of new generation biofuels, made from lignocellulosic feedstock, is a fundamental and unavoidable step towards the achievement of the EU GHG emission reduction targets. Significantly less land is required per unit of product with 2nd gen. compared to traditional 1st gen. biofuels. Because massive import of low-density feedstock is not feasible, 2nd gen. biofuels will stimulate and activate EU internal production/recovery of biomass crops for energy, with minimal competition with food/feed production. An agro-industrial project, with an estimated output of 160,000 mT/y cellulosic bioethanol, is in progress at Crescentino (Piedmont – Italy), based on Chemtex cellulosic bioethanol technology Pro.E.SaTM. M&G Group and its subsidiary, Chemtex, have been conducting extensive multidisciplinary research to select and characterize a set of energy crop species. This work, to date, has demonstrated the economic viability of growing these crops for conversion to liquid transportation fuels and developed some of the specific data for designing and planning the supply chain system in a wide set of agronomic conditions and cropping schemes. Arundo donax L. (Adx) will represent the main input feedstock to the process, together with corn stalks and cereal straw, collected from nearby areas.
Adx has been indicated as one of the most promising lignocellulosic herbaceous energy crop in the Mediterranean area, due to its desirable traits: a geophytes and sinantropic, perennial C3 grass (high photosynthetic rates and little photoinhibition were observed), which showed a strong metal tolerance, making it suitable for ecoremediation purposes. Pure stands of improved strains exhibited a longevity of +10 years, with a high annual yield of biomass (35 t ha-1 DM). Reduced input requirements (tillage, fertilizers, agrochemicals) and favorable harvest logistics increase the energy production efficiency of this sub-cosmopolite species. Some agronomic and ecological aspects of Adx require further evaluation before spreading it on larger areas. A field trial was established to investigate the effect of irrigation and nitrogen fertilization on biomass yield and energy use efficiency in Adx production
Giant reed (Arundo donax L.) as a cellulosic bioethanol feedstock in Central Italy: the agronomist’s point of view
No full textArundo donax L. (Adx) is a geophytes and sinantropic species, native to the freshwaters regions of East Asia and widely cultivated for horticultural and medicinal uses since ancient times. Giant reed, an unusual C3 grass (high photosynthetic rates and little photoinhibition were observed), showed a strong metal tolerance, suitable for ecoremediation purposes. Pure stands of improved strains exhibited a longevity of +10 years, with a high annual yield of biomass (35 t ha-1 DM).Reduced input requirements (tillage, fertilizers, agrochemicals) and favorable harvest logistics increase the energy production efficiency of this perennial, sub-cosmopolite species. Due to desirable traits, it has been indicated as one of the most promising lignocellulosic herbaceous energy crop in the Mediterrean area. Recently Adx was investigated among potential feedstocks for cellulosic bioethanol in Southern Europe. Some agronomic and ecology aspects of Adx require further evaluation before spreading it on larger areas. In some countries, wild Adx is considered a noxious, invasive plant in riparian systems for its ease of spreading, dense stand, and suffocating canopy, uniquely through vegetative reproduction. Problems of rhizome dissemination, difficult soil and water reclamation of infested areas, reduced biodiversity and risks of fires are frequently claimed. However, none of the cited problems are related to Adx under controlled cultivation, where stripe planting, with alternate perennial and annual crops of native species, mitigate problems of reduced biodiversity, fire hazard, and dissemination.
An agro-industrial project, with an estimated output of 40,000 mT/y cellulosic bioethanol, is in progress in Tuscany (Central Italy), based on Chemtex cellulosic bioethanol technology PROESA. This project will exploit some lowland, marginal areas, where Adx has already been introduced over the last decade as an energy crop (CHP plant). Adx will represent 1⁄2 - 3⁄4 of the overall feedstock in input to the process, together with corn stalks and cereal straw, collected from nearby upland area
Tunneling transport of unitary fermions across the superfluid transition
No full textWe investigate the transport of a Fermi gas with unitarity-limited interactions across the superfluid phase transition, probing its response to a direct current (dc) drive through a tunnel junction. As the superfluid critical temperature is crossed from below, we observe the evolution from a highly nonlinear to an Ohmic conduction characteristic, associated with the critical breakdown of the Josephson dc current induced by pair condensate depletion. Moreover, we reveal a large and dominant anomalous contribution to resistive currents, which reaches its maximum at the lowest attained temperature, fostered by the tunnel coupling between the condensate and phononic Bogoliubov-Anderson excitations. Increasing the temperature, while the zeroing of supercurrents marks the transition to the normal phase, the conductance drops considerably but remains much larger than that of a normal, uncorrelated Fermi gas tunneling through the same junction. We attribute such enhanced transport to incoherent tunneling of sound modes, which remain weakly damped in the collisional hydrodynamic fluid of unpaired fermions at unitarity
Josephson effect in fermionic superfluids across the BEC-BCS crossove
No full textThe Josephson effect is a macroscopic quantum phenomenon that reveals the broken symmetry associated with any superfluid state. Here we report on the observation of the Josephson effect between two fermionic superfluids coupled through a thin tunneling barrier. We show that the relative population and phase are canonically conjugate dynamical variables throughout the crossover from the molecular Bose-Einstein condensate (BEC) to the Bardeen-Cooper-Schrieffer (BCS) superfluid regime. For larger initial excitations from equilibrium, the dynamics of the superfluids become dissipative, which we ascribe to the propagation of vortices through the superfluid bulk. Our results highlight the robust nature of resonant superfluids
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Strongly correlated superfluid order parameters from dc Josephson supercurrents
No full textThe direct-current (dc) Josephson effect provides a phase-sensitive tool for investigating superfluid order parameters. We report on the observation of dc Josephson supercurrents in strongly interacting fermionic superfluids across a tunneling barrier in the absence of any applied potential difference. For sufficiently strong barriers, we observed a sinusoidal current-phase relation, in agreement with Josephson's seminal prediction. We mapped out the zero-resistance state and its breakdown as a function of junction parameters, extracting the Josephson critical current behavior. By comparing our results with an analytic model, we determined the pair condensate fraction throughout the Bardeen-Cooper-Schrieffer-Bose-Einstein condensation crossover. Our work suggests that coherent Josephson transport may be used to pin down superfluid order parameters in diverse atomic systems, even in the presence of strong correlations
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
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