3,542 research outputs found
CO2 storage properties of nanostructured carbons by a microwave plasma reactor
Nanostructured carbon was successfully produced by methane cracking in a relatively low-energy cold plasma reactor designed in-house. A followed thermal treatment was carried out to further enhance its porosity. The modified plasma carbon was then employed for CO2 adsorption at 25°C. The as-synthesized plasma carbon and the modified carbon were characterized by BET surface area/pore size analyzer, Raman spectra, and transmission electron microscopy (TEM). The results show thermal modification pronouncedly improves BET surface area and porosity of PC due to opening up of accessible micro-/mesopores in the graphitic structure and by the removal of amorphous carbons around the graphite surface. The modified PC displays a higher adsorption capacity at 25°C than that of the commercial activated carbon reported. The low hydrogen storage capacity of the modified PC indicates that it can be considered for CO2 removal in syngas
Marcela de Juan (黄玛赛): the Beginning of the Cultural Transfer between China and Spain in the Twentieth Century
En la comunicación entre China y España en el siglo xx, destaca la figura de Marcela de Juan. Autora de libros y artículos relacionados con la cultura china; traductora de poesía y cuentos chinos, intérprete de múltiples idiomas en conferencias internacionales y mediadora de culturas gracias a sus ciclos de conferencias para difundir la cultura china en Europa, Marcela de Juan tuvo un cargo permanente en la Oficina de Interpretación de lenguas del Ministerio de Asuntos Exteriores de España. Sin embargo, son escasas las investigaciones dedicadas tanto a su vida como a sus publicaciones. En este artículo evocamos a este personaje destacadísimo y presentamos una introducción a su vida y a sus publicaciones.Marcela de Juan is one of the most important translators from Chinese to Spanish in early 20th century’s Spain. She was a qualified interpreter and had a life-long job at the translation department of the Spanish government as well as experiences in numerous international conferences. She was also a mediator between Chinese and Spanish cultures and gave series of lectures on Chinese culture around Europe. She was a major translator of poetry and short stories from Chinese into Spanish. However, there has been little research on her life and works. In this article, we attempt to trace her life story and to introduce her activity and publications
CARBON STRUCTURES AND Mg-BASED MATERIALS FOR GAS SORPTION
Hydrogen is an alternative energy carrier for both mobile and stationary applications, which
can effectively alleviate greenhouse gas emissions and reduce dependence on fossil fuels.
The other promising approach in reducing greenhouse gas emissions is carbon capture. Mgbased
materials have been considered as a promising hydrogen storage system due to their
high hydrogen capacity (up to 7.6 wt.%), high abundance, low cost and lightweight. Different
carbon structures have also drawn considerable interests for hydrogen storage and carbon
capture.
In this research, the nanostructured carbon was produced in a cold plasma reactor designed
in-house as additives for improving hydrogen storage properties of Mg-based materials and
CO2 storage of MgO. The effects of the plasma reactor’s flow rate, temperature and power
were evaluated for the formation of the carbon structures. TEM shows that the carbon
consists of spherical particles of 40.8±8.7 nm in diameter and graphene sheets.
Further thermal treatment of the plasma carbon was carried out to enhance the surface area.
The treatment conditions were optimized through response surface methodology (RSM). The
effects of the treatment temperature, time and pressure on BET surface area and yield were
studied. The predicted BET surface area and yield by RSM were found to agree with the
experimental values. The optimum treatment conditions for the plasma carbon (PC) were
found to be: temperature = 950°C and time = 120 min, pressure = 100 kPaCO2 gas flow.
The optimized PC was mixed as an additive with 20h-milled MgH2/TiC for improvement of
hydrogen storage properties. RSM optimized the mixing time and the content of PC in the
(MgH2/TiC + PC) composite. The results demonstrated that both mixing time and the content
of plasma carbon (PC) significantly affected the hydrogen storage properties. The effects of
the PC, activated carbon (AC) and carbon nanotubes (CNTs) on hydrogen storage properties
of MgH2/TiC were studied. PC, AC and CNTs showed positive effects on reducing hydrogen
desorption temperature and improving the adsorption kinetics of the 20h-milled MgH2/TiC.
PC shows the best effect due to its unique structure. The mechanism of the effects of the three
carbon structures on hydrogen storage was discussed.
ABSTRACT
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The optimized PC was also mixed with MgO, both by ball milling and chemical coprecipitation
methods to form porous carbon supported MgO for CO2 storage and separation.
The results indicated that the chemically synthesized MgO+PC calcined at 800 °C (referred
to as MgO/PC-800) showed the most promising CO2 storage capacity up to 6.16 mmol/g at
25 °C and 1500 kPa CO2 pressure. The introduction of PC improves the CO2 adsorption
capacity of the chemical synthesized MgO due to improved surface area. The dual-site
Langmuir (DSL) model was employed to predict adsorption equilibria of CO2/H2 gas
mixtures, which well simulated the behaviors of pure CO2 adsorption and H2 adsorption, and
can be used to predict the binary CO2/H2 gas mixture separation
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Bank competition, information specialization and innovation
Complementary to rich existing evidence on bank competition and corporate innovation, this paper aims to investigate the impacts of bank competition on innovation efficiencies, in terms of both R&D input and output at firm level. By acknowledging the role played by information asymmetries in financing innovation, we also examine the moderating effects of information specialization at both industry and firm level on corporate innovation. Analyzing innovation and bank structure data from U.S. between 1992 and 2010, we show novel evidence that increased bank competition improves innovation efficiencies in terms of both R&D input (investment) and output (patents and profits generated by R&D). In addition, we find bank competition has a greater favorable effect on innovation for those firms with more specialized information, such as those operating in an industry with more dispersed productivity growth and those with more concentrated patent types. Overall, our findings support market power hypothesis and banking strategic theory where bank competition improves credit supply to corporate innovation
Laser-Scribing Technology for Wafer-Scale Graphene Devices
Graphene has attracted a lot of attention due to its amazing properties. A huge number of novel devices, covering the electric, acoustic, photonic, magnetic and mechanical domains, can be developed with graphene. Its ultrahigh mobility can enable ultra-fast transistors or photodetectors. However, the natural zero bandgap of graphene, with insufficient on/off ratio, limits its practical applications. In this chapter, we introduce laser-scribing technology that enables wafer-scale production of graphene devices. Moreover, such laser-scribed graphene (LSG) is, infact, semi-reduced graphene oxide with a finite bandgap, which is suitable for practical applications. We show five kinds of representative LSG devices and their integration. These devices are a resistive memory, an earphone, a strain sensor, a pressure sensor and a light-emitting device. These LSG devices are high-performance, flexible and low cost, which demonstrates the practical nature of laser-scribed graphene-based materials. Finally, an outlook is presented regarding how laser scribing, a serial patterning method, may lead to similar developments in various other serial lithography techniques, such as ion beam lithography
Efficient Algorithms for Fast Integration on Large Data Sets from Multiple Sources
Background
Recent large scale deployments of health information technology have created opportunities for the integration of patient medical records with disparate public health, human service, and educational databases to provide comprehensive information related to health and development. Data integration techniques, which identify records belonging to the same individual that reside in multiple data sets, are essential to these efforts. Several algorithms have been proposed in the literatures that are adept in integrating records from two different datasets. Our algorithms are aimed at integrating multiple (in particular more than two) datasets efficiently. Methods
Hierarchical clustering based solutions are used to integrate multiple (in particular more than two) datasets. Edit distance is used as the basic distance calculation, while distance calculation of common input errors is also studied. Several techniques have been applied to improve the algorithms in terms of both time and space: 1) Partial Construction of the Dendrogram (PCD) that ignores the level above the threshold; 2) Ignoring the Dendrogram Structure (IDS); 3) Faster Computation of the Edit Distance (FCED) that predicts the distance with the threshold by upper bounds on edit distance; and 4) A pre-processing blocking phase that limits dynamic computation within each block. Results
We have experimentally validated our algorithms on large simulated as well as real data. Accuracy and completeness are defined stringently to show the performance of our algorithms. In addition, we employ a four-category analysis. Comparison with FEBRL shows the robustness of our approach. Conclusions
In the experiments we conducted, the accuracy we observed exceeded 90% for the simulated data in most cases. 97.7% and 98.1% accuracy were achieved for the constant and proportional threshold, respectively, in a real dataset of 1,083,878 records
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