434 research outputs found
A Comparative Study of PMETAC-Modified Mesoporous Silica and Titania Thin Films for Molecular Transport Manipulation
The manipulation and understanding of molecular transport across functionalized nanopores will take us closer to mimicking biological membranes and thus to design high-performance permselective separation systems. In this work, Surface-initiated atom transfer radical polymerization (SI-ATRP) of (2-methacryloyloxy)-ethyltrimethylammonium chloride (METAC) was performed on both mesoporous silica and mesoporous titania thin films. Pores were proven to be filled using ellipsometry and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Furthermore, the employed method leads to a polymer overlayer, whose thickness could be discriminated using a double-layer ellipsometry model. Cyclic voltammetry experiments reveal that the transport of electrochemically active probes is affected by the PMETAC presence, both due to the polymer overlayer and the confined charge of the pore-tethered PMETAC. A more detailed study demonstrates that ion permeability depends on the combined role of the inorganic scaffoldsâ (titania and silica) surface chemistry and the steric and charge exclusion properties of the polyelectrolyte. Interestingly, highly charged negative walls with positively charged polymers may resemble zwitterionic polymer behavior in confined environments
ERP and Economic Influence on the Development of Business
The use of software in business has become very significant, thanks to this business have access to a progressive technological development, as a result you get great benefits in optimizing processes and information. This research work emphasizes on the ERP and its economic influence in business, an unknown subject for many people. The realization of this research will help understand how it has contributed ERP largely to the development of enterprises, through the creation of systems that are responsible for optimizing most processes within companies to obtain a gradual enterprise-level development. Through documentary research it has been able to gather information from scientific papers, journals, academic papers, among others, which will help to better understand the problem to find a solution. Of enterprises or industries. The result of this research shows that ERP applied in companies have largely improved the process optimization and cost reduction and improved management practices efficiency, therefore a constant business development is produced
Mesoporous Microspheres of Nickel-based Layered Hydroxides by Aerosol-Assisted Self-Assembly using Crystalline Nano-Building Blocks.
Structural control in micro- and nanometer scale is necessary to design highly functional materials. Crystalline mesoporous microspheres are expected to improve electrochemical, catalytic, and adsorption performances. In this study, we focused on the preparation of templated mesoporous microspheres of nickel-based layered hydroxides by using pre-crystallized nano-building blocks (NBBs). Layered nickel hydroxide nanoparticles were prepared through an epoxide-mediated alkalinization process and used as NBBs to construct microspheres. The spherical particles in micrometer scale were synthesized by an aerosol-assisted assembly of the NBBs dispersed in a solvent, in the presence of supramolecular templates. It was found that controlling the crystallization as well as the surface philicity permits to yield the NBB with an adequately small size and interparticle interactions that generate self-assembled mesoporous microspheres akin to those obtained in NBB-based mesoporous thin films. The preparation technique demonstrated here is highly versatile; templated mesoporous microspheres with various chemical compositions of nickel-based layered double hydroxides were successfully obtained.The present work was partially supported by JSPS KAKENHI, JSPS bilateral program, LNLS proposal SAXS1 18927, ANPCyT (PICT 2012-2087 and 2015-3526), UBACyT (20020130100610BA), Hitachi Metals Materials Science Foundation, The Sumitomo Foundation, and Izumi Science and Technology Foundation
Microparticles with hetero-nanointerfaces: controlled assembly of cobalt hydroxide and nickel hydroxide nanoclusters towards improved electrochemical functions
The ultimate control of the interfaces of nanocomposite materials is essential to tailor and improve their physical/chemical properties in applications such as catalysis, or energy storage or production. Fabrication and co-assembly of a variety of nanostructured colloids is a promising way to design the interface of materials in nano-scale toward high functionality. In this study, we demonstrate a synthesis of colloids of nanocluster-sized (~ 2 nm) cobalt and nickel hydroxides and their assembly into microparticles that present hetero-nanointerfaces. Electrochemical properties were investigated to elucidate the effect of the hetero-nanointerface. Microparticles with hetero nanostructures composed of cobalt and nickel hydroxide nanoclusters revealed improved mass specific capacity (91.4 mAh/g) compared with respective microparticles with homo-nanointerface (cobalt hydroxide; 15.8 mAh/g: nickel hydroxide; 64.4 mAh/g). Further investigation suggests that the introduced hetero-nanointerface leads to lower charge transfer resistance and to improved electrochemical properties. The synthetic concept demonstrated here is expected to create unique hetero-nanointerfaces for various materials with wide-range of chemical composition towards improved and novel functionalities.The present work is partially supported by JSPS KAKENHI, LNLS proposal SAXS1 18927, ANPCyT (PICT 2087), UBACyT (20020130100610BA), Izumi Science and Technology Foundation (H29-J-130) and the Foundation for the Promotion of Ion Engineering
Single-nanometer sized low-valence metal hydroxide crystals: synthesis via epoxide-mediated alkalinization and assembly towards functional mesoporous materials
The present work is partially supported by JSPS KAKENHI, LNLS proposal SAXS1 18927, ANPCyT (PICT 2087), UBACyT (20020130100610BA), and the Foundation for the Promotion of Ion Engineering
Highly Ordered Mesoporous Hydroxide Thin Films through Self-Assembly of Size-Tailored Nano-Building Blocks: A Theoretical- Experimental Approach
Mesoporous crystalline (hydr)oxides of low-valence metal ions (M(II) and M(III)) are highly demanded in the context of various applications. In this study, we demonstrate key factors to the successful formation of ordered mesoporous films through the Assembly of Nano-Building Block (ANBB) approach using a colloidal solution of crystalline M(OH)2 (M = Mn, Fe, Co, Ni, and Cu). The colloidal system of α-Ni(OH)2 is presented in-depth as a typical example. Crystal growth and aggregation kinetics of the NBB were tuned by synthetic parameters. Nanometer-sized NBBs of tailored size between oligomer scale to over 20 nm were obtained. The films prepared from α-Ni(OH)2 NBBs with a diameter of †7.5 nm showed ordered mesostructures through evaporation-induced self-assembly in the presence of supramolecular templates. Coarse-grained simulation suggests that there is a threshold diameter of NBB toward the formation of wellordered mesostructures. It was found that, as well as limiting the diameter of NBB, inhibition of an aggregation of NBBs by using coordinative additives or diluting the NBB colloidal solution were essential to control the assembly of NBBs and templates into the ordered mesostructures. The results obtained here open up the synthesis of ordered mesoporous materials with a crystalline wall of variety of chemical compositions containing low-valence metal elements.The present work was partially supported by JSPS KAKENHI, JSPS bilateral program, ABTLuS (LNLS proposal SAXS1 18927), ANPCyT (PICT 2014-3687 and 2015-3526), UBACyT (20020130100610BA), The Sumitomo Foundation, Izumi Science and Technology Foundation and Deutsche Forschungsgemeinschaft-CONICET under grant Mu1674/15-1
RecomendaçÔes técnicas para a reprodução do tambaqui.
Das espĂ©cies nativas brasileiras, o tambaqui (Colossoma macropomum) Ă© a mais produzida em cativeiro. Quase a totalidade da produção desse animal puro ocorre nos estados da regiĂŁo Norte do Brasil, com destaque para RondĂŽnia. No Mato Grosso, existe grande produção do hĂbrido tambacu (tambaqui x pacu-caranha, Piaractus mesopotamicus). Isso se deve Ă popularidade do pacu-caranha na bacia do rio Paraguai e do repasse de tecnologia, no inĂcio dos anos 1980, do Centro Nacional de Pesquisa e Conservação de Peixes Continentais (Cepta), que recomendava a produção do hĂbrido com o objetivo de explorar o potencial de crescimento do tambaqui associado Ă resistĂȘncia do pacu a temperaturas amenas. Atualmente, outro hĂbrido bastante produzido Ă© o tambatinga, cruzamento de duas espĂ©cies amazĂŽnicas (tambaqui x pirapitinga, Piaractus brachypomus) com caracterĂsticas produtivas parecidas com as do tambacu, mas com destaque para a cor prateada e o opĂ©rculo avermelhado, os quais chamam a atenção do consumidor. Desse modo, este manual vai tratar exclusivamente da tecnologia aplicada Ă reprodução do tambaqui, desenvolvida pela UFRGS, UEM e UFMT com apoio da Embrapa, por meio do Programa de Melhoramento GenĂ©tico de Organismos AquĂĄticos, no Ăąmbito do projeto AQUABRASIL.bitstream/item/83462/1/Doc-212-RecomendacoesTecnicasReproducaoTambaqui.pd
Impact of Routine Use of Drug-eluting Stents in Contemporary Interventional Cardiology at a Tertiary Center: One-decade Experience of the DESIRE Registry
ABSTRACTBackgroundDrug-eluting stents (DES) have changed contemporary interventional cardiology practice, enabling the approach of increasingly more complex clinical and angiographic scenarios. The objective of this study was to demonstrate the changes observed in the last 10 years in the indication and practice of percutaneous coronary intervention (PCI) at a tertiary private hospital in the State of São Paulo.MethodsDESIRE is a single-center prospective registry aiming at following the acute and late outcomes of consecutive patients treated by DES.ResultsFrom 2002 to 2011, 4,299 patients were included, with mean age of 64.3±11.2years, 23% were female and 30.5 were diabetic. The total number of lesions treated was 6,518 of which 61.5% were type B2/C. During the course of the study, DES were progressively more used, reaching a penetration of 88.4% in 2011. The complexity of PCIs has increased and in the past year 1.76 lesions per patient were treated with an average of 1.89 DES. The SYNTAX score increased from 12.3±4.4 (2002-2006) to 15.7±4.7 (2007-2011). Clinical follow-up was obtained in 98.2% of the patients, with a median of 5.2years, and during this period target-lesion revascularization rate was 5%, myocardial infarction was 6.7% and cardiovascular death was 4.1%. Stent thrombosis was observed in 2.4% of the cases.ConclusionsOur results showed a marked increment in the complexity profile of patients treated in the last 10 years and at the same time confirm the long-term effectiveness of DES, despite the clinical and angiographic profile of patients
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