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941.
Rapid decolourization and mineralization of the azo dye C.I. Acid Red 14 by heterogeneous Fenton reaction 总被引:2,自引:0,他引:2
Idel-aouad R Valiente M Yaacoubi A Tanouti B López-Mesas M 《Journal of hazardous materials》2011,186(1):745-750
The decolourization and mineralization of a solution of an azo dye using a catalyst based on Fe(II) supported on Y Zeolite (Fe(II)-Y Zeolite) and adding hydrogen peroxide (heterogeneous Fenton process) have been studied. The catalyst was prepared by ion exchange, starting from a commercial ultra-stable Y Zeolite. All experiments were performed on a laboratory scale set-up. The effects of different parameters such as initial concentration of the dye, initial pH of the solution of the dye, H(2)O(2) concentration, temperature and ratio of amount of catalyst by amount of solution on the decolourization efficiency of the process were investigated. A percentage of colour removal of 99.3±0.2% and a mineralization degree of 84±5% of the solution of the dye were achieved in only 6 min of contact time between the catalyst and the solution, under the following conditions: initial concentration of the dye of 50 ppm, pH 5.96, 8.7 mM of H(2)O(2), T of 80°C and catalyst concentration of 15 g/L. Moreover, the catalyst Fe(II)-Y Zeolite can be easily filtered from the solution, does not leach any iron into the solution (avoiding any secondary contamination due to the metal) and its effectivity can be reproduced after consecutive experiments. 相似文献
942.
Fàbrega C Andreu T Güell F Prades JD Estradé S Rebled JM Peiró F Morante JR 《Nanotechnology》2011,22(23):235403
Highly ordered TiO(2) nanohole layers were synthesized by anodic oxidation of titanium foils using ethylene glycol and ammonium fluoride as the electrolyte. The effectiveness of different methods, namely annealing at 500?°C in NH(3) and in H(2) diluted in N(2), to incorporate nitrogen into TiO(2) and thus extend its photoelectrochemical (PEC) activity to the visible range was studied. The intra-gap levels introduced by both processes were identified by means of XPS and PL measurements. Water splitting experiments demonstrated that annealing in H(2) improved the photocatalytic activity of pure TiO(2), while annealing in ammonia led to a decrease in the PEC performance. 相似文献
943.
Yangkun He Gerhard H. Fecher Chenguang Fu Yu Pan Kaustuv Manna Johannes Kroder Ajay Jha Xiao Wang Zhiwei Hu Stefano Agrestini Javier Herrero-Martín Manuel Valvidares Yurii Skourski Walter Schnelle Plamen Stamenov Horst Borrmann Liu Hao Tjeng Rudolf Schaefer Stuart S. P. Parkin John Michael D. Coey Claudia Felser 《Advanced materials (Deerfield Beach, Fla.)》2020,32(45):2004331
The development of high-density magnetic recording media is limited by superparamagnetism in very small ferromagnetic crystals. Hard magnetic materials with strong perpendicular anisotropy offer stability and high recording density. To overcome the difficulty of writing media with a large coercivity, heat-assisted magnetic recording was developed, rapidly heating the media to the Curie temperature Tc before writing, followed by rapid cooling. Requirements are a suitable Tc, coupled with anisotropic thermal conductivity and hard magnetic properties. Here, Rh2CoSb is introduced as a new hard magnet with potential for thin-film magnetic recording. A magnetocrystalline anisotropy of 3.6 MJ m−3 is combined with a saturation magnetization of μ0Ms = 0.52 T at 2 K (2.2 MJ m−3 and 0.44 T at room temperature). The magnetic hardness parameter of 3.7 at room temperature is the highest observed for any rare-earth-free hard magnet. The anisotropy is related to an unquenched orbital moment of 0.42 μB on Co, which is hybridized with neighboring Rh atoms with a large spin–orbit interaction. Moreover, the pronounced temperature dependence of the anisotropy that follows from its Tc of 450 K, together with a thermal conductivity of 20 W m−1 K−1, make Rh2CoSb a candidate for the development of heat-assisted writing with a recording density in excess of 10 Tb in.−2. 相似文献
944.
Garcia-Uribe A Kehtarnavaz N Marquez G Prieto V Duvic M Wang LV 《Applied optics》2004,43(13):2643-2650
Data obtained from 102 skin lesions in vivo by spectroscopic oblique-incidence reflectometry were analyzed. The participating physicians initially divided the skin lesions into two visually distinguishable groups based on the lesions' melanocytic conditions. Group 1 consisted of the following two cancerous and benign subgroups: (1) basal cell carcinomas and squamous cell carcinomas and (2) benign actinic keratoses, seborrheic keratoses, and warts. Group 2 consisted of (1) dysplastic nevi and (2) benign common nevi. For each group, a bootstrap-based Bayes classifier was designed to separate the benign from the dysplastic or cancerous tissues. A genetic algorithm was then used to obtain the most effective combination of spatiospectral features for each classifier. The classifiers, tested with prospective blind studies, reached statistical accuracies of 100% and 95% for groups 1 and 2, respectively. Properties that related to cell-nuclear size, to the concentration of oxyhemoglobin, and to the concentration of deoxyhemoglobin as well as the derived concentration of total hemoglobin and oxygen saturation were defined to explain the origins of the classification outcomes. 相似文献
945.
Optimal transportation meshfree method in geotechnical engineering problems under large deformation regime 下载免费PDF全文
Pedro Navas Susana López‐Querol Rena C. Yu Manuel Pastor 《International journal for numerical methods in engineering》2018,115(10):1217-1240
Meshfree methods have been demonstrated as suitable and strong alternatives to the more standard numerical schemes such as finite elements or finite differences. Moreover, when formulated in a Lagrangian approach, they are appropriate for capturing soil behavior under high‐strain levels. In this paper, the optimal transportation meshfree method has been applied for the first time to geotechnical problems undergoing large deformations. All the features employed in the current methodology (ie, F‐bar, explicit viscoplastic integration, and master‐slave contact) are described and validated separately. Finally, the model is applied to the particular case of shallow foundations by using von Mises and Drucker‐Prager yield criteria to find the load at failure in the. The presented methodology is demonstrated to be robust and accurate when solving this type of problems. 相似文献
946.
Nunes TG Polido M Amorim A Nunes SG Toledano M 《Journal of materials science. Materials in medicine》2007,18(10):2093-2099
This study presents evidence at molecular level for the chemical interaction between human dentin from different tooth regions
and a monomer with phosphate groups, incorporated in the formulation of a simplified adhesive system. Because dentin was observed
as a powder, previous verification was obtained for an eventual collagen denaturation due to the grinding process. The presence
of chemical bonds involving coronal (CD) or radicular dentin (RD) was investigated using multinuclear magnetic resonance (MR)
techniques. Narrow signals were identified in the carbon magic angle spinning (MAS) spectra of CD and RD treated with the
adhesive, which were assigned to methylenic groups in methacryloyloxydecyl dihydrogen phosphate (MDP) bound to hydroxyapatite
Ca2+; 1H spectra of the adhesive components and treated dentin, in ethanol, support this conclusion. 31P MAS spectra obtained from both dentin regions present additional shielding and broadening effects subsequent to application
and photopolymerization of the adhesive, which were higher for CD. Multinuclear MR studies provided evidence for the interaction
of the adhesive with dentin, which involves hydroxyapatite and is stronger for CD than for RD, but no direct proof was obtained
on bonding to collagen. 相似文献
947.
Do individual factors matter? A survey of scientists’ patenting in Portuguese public research organisations 总被引:1,自引:0,他引:1
Paula Susana Figueiredo Moutinho Margarida Fontes Manuel Mira Godinho 《Scientometrics》2007,70(2):355-377
This paper addresses scientists’ behaviour regarding the patenting of knowledge produced in universities and other public
sector research organisations (PSROs). Recent years have witnessed a rapid growth in patenting and licensing activities by
PSROs. We argue that the whole process depends to a certain extent on scientists’ willingness to disclose their inventions.
Given this assumption, we conduct research into individual behaviour in order to understand scientists’ views concerning the
patenting of their research results. Data from a questionnaire survey of Portuguese researchers from nine PSROs in life sciences
and biotechnology is presented and analysed and complemented with in-depth interviews. The results reveal that overall the
scientists surveyed show a low propensity to become involved in patenting and licensing activities, despite the fact that
the majority had no “ethical” objections to the disclosure of their inventions and the commercial exploitation of these. Perceptions
about the impacts of these activities on certain fundamental aspects of knowledge production and dissemination are however
divergent. This may account for the low participation levels. Furthermore, most scientists perceived the personal benefits
deriving from this type of activity to be low. Similarly, the majority also believed that there are many difficulties associated
with the patenting process and that they receive limited support from their organisations, which lack the proper competences
and structures to assist with patenting and licensing. 相似文献
948.
Liu J Rodriguez i Zubiri M Vigolo B Dossot M Humbert B Fort Y McRae E 《Journal of nanoscience and nanotechnology》2007,7(10):3519-3523
Single-wall carbon nanotubes (SWNTs) have been functionalized by a diazonium method through both a classical thermal reaction and a microwave-assisted reaction. The functionalized SWNTs have been characterized by nIR-Vis-UV absorption spectroscopy, Raman spectroscopy, and thermal gravimetric analysis. The results show that SWNTs are covalently functionalized through both reactions and that the microwave-assisted reaction is more rapid. Moreover, optimal choice of the reaction time can prevent the microwave irradiation from the adverse effect of subsequently removing the functional groups on the SWNT surface. 相似文献
949.
Tunnel junctions with multiferroic barriers 总被引:2,自引:0,他引:2
Gajek M Bibes M Fusil S Bouzehouane K Fontcuberta J Barthélémy A Fert A 《Nature materials》2007,6(4):296-302
Multiferroics are singular materials that can exhibit simultaneously electric and magnetic orders. Some are ferroelectric and ferromagnetic and provide the opportunity to encode information in electric polarization and magnetization to obtain four logic states. However, such materials are rare and schemes allowing a simple electrical readout of these states have not been demonstrated in the same device. Here, we show that films of La(0.1)Bi(0.9)MnO(3) (LBMO) are ferromagnetic and ferroelectric, and retain both ferroic properties down to a thickness of 2 nm. We have integrated such ultrathin multiferroic films as barriers in spin-filter-type tunnel junctions that exploit the magnetic and ferroelectric degrees of freedom of LBMO. Whereas ferromagnetism permits read operations reminiscent of magnetic random access memories (MRAM), the electrical switching evokes a ferroelectric RAM write operation. Significantly, our device does not require the destructive ferroelectric readout, and therefore represents an advance over the original four-state memory concept based on multiferroics. 相似文献
950.
Josefa Mula Francisco Campuzano-Bolarin Manuel Díaz-Madroñero Katerine M. Carpio 《国际生产研究杂志》2013,51(13):4087-4104
This article proposes a simulation approach based on system dynamics for operational procurement and transport planning in a two-level, multi-product and multi-period supply chain. This work uses the Vensim® simulation tool to highlight the potential of system dynamics for supply chain simulation. A real continuous simulation application is presented in an automobile supply chain. The effectiveness of the proposed model is validated through the comparison of the results provided by spreadsheet-based simulation, fuzzy multi-objective programming and system dynamics-based simulation models. The fundamental point of this paper is that the simulation model is the most effective approach in quantifying the trade-off between number of truck shipments and average inventory level. In this case, the number of truck shipments is to be minimised, resulting in a higher inventory level. If the average inventory level were minimised, then there would be more truck shipments. Here, it is shown the benefit of this type of simulation model in reducing inventory by about 10%. 相似文献