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Microstructural and photocatalytic characterization of cement-paste sol-gel synthesized titanium dioxide

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Frontiers of Structural and Civil Engineering 2016年第2期10卷 189-197页

作者： Elena CERRO-PRADA Miguel MANSO vicente torres Jesfs SORIANO Civil Engineering Department Universidad Politecnica de Madrid Alfonso XII 3 Madrid 28014 Spain Applied Physics Department Universidad Aut6noma de Madrid Ciudad Universitaria de Cantoblanco Madrid 28049 Spain Laboratory of Materials CEDEX Ministerio de Fomento de Espana Alfonso XIL Madrid 28014 Spain

ABSTRACT A routte for the in paste synthesis of TiO2 loaded cement is described. TiO2 sols are blended with fresh cement paste as an alternative process to add photocatalytic functionality to cement. The modification of cement paste structure after the addition ofTiO2 sols is analyzed by XRD, SEM and TGA. As a particular microstructural feature, TiO2 containing calcium silicate hydrate （C-H-S） particles are identified as networking centers ofa C-S-H gel fiber matrix. The increase of the TiO2 sol concentration induces a decrease of pore size and an increase in the specific surface area in the cement composites. The photocatalytic activity of the TiO2/cement system is evaluated from the degradation of Methylene Blue （MB） under UV irradiation, monitored through the absorbance at 665 nm. The results show that, although TiO2 phases reveal no long range order structure, the cement paste exothermal treatment in presence of hydrate products and alkaline conditions leads to a photocatalytic composite. Such new cement matrix may be twofold advantageous since it additionally promotes the formation of C-S-H gel, main determinant of cement mechanical properties.

关键词： cement composites photocatalytic TiO2 sol-gel C-S-H gel microstructure

A novel and stretchable carbon-nanotube/Ni@TiO_(2):W photocatalytic composite for the complete removal of diclofenac drug from the drinking water

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Journal of Environmental Sciences 2023年第4期126卷 575-589页

作者： Ernesto Valadez-Renteria Rafael Perez-Gonzalez Christian Gomez-Solis Luis Armando Diaz-torres Armando Encinas Jorge Oliva vicente Rodriguez-Gonzalez Consejo Nacional de Ciencia y Tecnología-División de Materiales Avanzados Instituto Potosino de Investigación Científica y TecnológicaSan Luis Potosí78216México División de Ciencias e Ingenierías Universidad de GuanajuatoLeón 37150México Grupo de Espectroscopia de Materiales Avanzados y Nanoestructurados(GEMANA) Centro de Investigaciones enópticaA.C.Lomas Del CampestreLeón 37150México

We present the structural,morphological and photocatalytic properties of stretchable composites made with carbon nanotubes (CNTs),silicon rubber and Ni@TiO_(2):W nanoparticles(TiWNi NPs) with average size of 37±2 *** images showed that the TiWNi NPs decorated the surface of the CNT fibers,which are oriented in a preferential *** NPs presented a mixture of anatase/rutile phases with cubic *** performance of the TiWNi powders and stretchable composites was evaluated for the photocatalytic degradation of diclofenac (DCF) anti-inflammatory drug under ultraviolet-visible *** results revealed that the maximum DCF degradation percentages were 34.6%,91.9%,97.1%,98.5%and 100%for the CNT composite (stretched at 0%),TiWNi powders,CNT+TiWNi(stretched at 0%),CNT+TiWNi (stretched at 50%) and CNT+TiWNi (stretched at 100%),***,stretching the CNT+TiWNi composites was a good strategy to enhance the DCF degradation percentage from 97.1%to 100%,since stretching created additional defects (oxygen vacancies) that acted as electron sink,delaying the electron-hole recombination,and favors the DCF ***/absorbance measurements confirmed the presence of such ***,the reactive oxygen species (ROS) were determined by the scavenger’s experiments and found that the main ROS were the·OH and O_(2)-radicals,which attacked the DCF molecules,causing their *** results of this investigation confirmed that the stretchable CNT/TiWNi-based composites are a viable alternative to remove pharmaceutical contaminants from water and can be manually separated from the decontaminated water,which is unviable using photocatalytic powders.

关键词： Diclofenac Pharmaceutical contaminant TiO_(2) Carbon nanotubes Stretchable composite Photocatalysis

Influence of fire on woody vegetation of savanna and forest formations in the Cerrado biome

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Journal of Forestry Research 2023年第5期34卷 1207-1216页

作者： Aline das Gracas Costa Fillipe Tamiozzo Pereira torres Gumercindo Souza Lima Fabiano Rodrigues de Melo Carlos Moreira Miquelino Eleto torres Bruno Leao Said Schettini vicente Paulo Santana Neto AndréLuiz Lopes de Faria Department of Forest Engineering Federal University of VicosaUFVVicosaMG 36570-900Brazil Department of Geography Federal University of VicosaUFVVicosaMG 36570-900Brazil

Wildfires have environmental,economic,and social impacts,and can shape the landscape and benefit ecosystems such as the *** study evaluated the diversity,similarity,and floristic and structural differences of woody savanna and forest formations of the Cerrado,when affected and not affected by ***-eight 25-400m2 plots were randomly allocated and divided into Burnt Cerrado and Unburnt Cerrado,Burnt Forest,and Unburnt Forest,and divided into three levels of inclusion according to diameter class(smaller than 2 cm,2-5 cm and larger than5 cm).Species were identified,DBH and height measured,and phyto sociological parameters such as volume,diversity,and floristic similarity *** Cerrado had lower diversity,density,and dominance at all inclusion levels compared to the Unburnt Cerrado,and showed similarities between treatments at the inclusion *** Forest had smaller differences in diversity,density,and dominance than Unburnt *** formation was similar at level 1 of inclusion and in the total ***,it was dissimilar at lower *** lower density and diversity of species at the lowest levels of inclusion was associated with mortality from fire.

关键词： Biodiversity Brazil Burning Floristic Phytosociology

Whole-rock geochemical, U-Pb and Sm-Nd isotope characteristics of the Dongueni Mont nepheline syenite intrusion, Mozambique

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Geoscience Frontiers 2017年第5期8卷 1063-1071页

作者： vicente Albino Manjate Instituto Nacional de Minas Av24 de Julho 1895 Maputo Mozambique

The Dongueni Mont nepheline syenite intrudes migmatitic paragneisses and siliciclastic metasediments of the Barue Complex, Mozambique. This study reports the whole-rock geochemical, U-Pb and Nd isotopic data of the nepheline syenite. The ferroan and alkalic geochemical characteristics are typical of alkaline rocks formed in a within-plate setting. The strong depletion in high field strength elements(HFSEs)(e.g. Ba, Nb, P,and Ti) and enrichment in large ion lithophile elements(LILEs)(e.g. Rb, Th, K, and Pb) are consistent with magmatism in a continental alkaline magmatic province associated with intracontinental rifting. Zircon U-Pb data yielded crystallization ages from 498 ± 19 to 562± 14 Ma,consistent with the Pan-African Orogeny and the inherited zircons yield an age of 1040 Ma, which supports the presence of a Mesoproterozoic crust. Theε_(Nd)(t) values from the nepheline syenite samples range from-15.1 to-16.1 and the T_(DM)values from 1.77 to 1.67 Ga, which indicate that the initial nepheline syenite magma formed from a tholeiitic or mantle source in a within-plate setting with crustal assimilation.

关键词： Orogeny Geochronology Model age Nepheline syenite Crystallization

Contribution of altered signal transduction associated to glutamate receptors in brain to the neurological alterations of hepatic encephalopathy

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World Journal of Gastroenterology 2006年第48期12卷 7737-7743页

作者： vicente Felipo Laboratory of Neurobiology Centro de Investigacion Principe Felipe Valencia Spain

Patients with liver disease may present hepatic enceph- alopathy (HE), a complex neuropsychiatric syndrome covering a wide range of neurological alterations, including cognitive and motor disturbances. HE reduces the quality of life of the patients and is associated with poor prognosis. In the worse cases HE may lead to coma or death. The mechanisms leading to HE which are not well known are being studied using animal models. The neurological alterations in HE are a consequence of impaired cerebral function mainly due to alterations in neurotransmission. We review here some studies indicating that alterations in neurotransmission associated to different types of glutamate receptors are responsible for some of the cognitive and motor alterations present in HE. These studies show that the function of the signal transduction pathway glutamate-nitric oxide-cGMP associated to the NMDA type of glutamate receptors is impaired in brain in vivo in HE animal models as well as in brain of patients died of HE. Activation of NMDA receptors in brain activates this pathway and increases cGMP. In animal models of HE this increase in cGMP induced by activation of NMDA receptors is reduced, which is responsible for the impairment in learning ability in these animal models. Increasing cGMP by pharmacological means restores learning ability in rats with HE and may be a new therapeutic approach to improve cognitive function in patients with HE. However, it is necessary to previously assess the possible secondary *** with HE may present psychomotor slowing, hypokinesia and bradykinesia. Animal models of HE also show hypolocomotion. It has been shown in rats with HE that hypolocomotion is due to excessive activation of metabotropic glutamate receptors (mGluRs) in substantia nigra pars reticulata. Blocking mGluR1 in this brain area normalizes motor activity in the rats, suggesting that a similar treatment for patients with HE could be useful to treat psychomotor slowing and hy

关键词： Hepatic encephalopathy Glutamate receptors Neurological alterations Cognitive function Motor func-tion NMDA receptors Metabotropic glutamate receptors Nitric oxide cGMP

Occult hepatitis C virus infection: A new form of hepatitis C

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World Journal of Gastroenterology 2006年第43期12卷 6922-6925页

作者： vicente Carreo Fundación para el Estudio de las Hepatitis Virales Madrid Spain

Occult hepatitis C virus (HCV) infection is a new recently characterized entity. This occult infection can be present in two different clinical situations: in anti-HCV negative, serum HCV-RNA negative patients with abnormal liver function tests and in anti-HCV positive subjects with normal values of liver enzymes and without serum HCV- RNA. This review describes recent studies of occult HCV infection in both kinds of patients.

关键词： Hepatitis C virus-RNA Liver Peripheral bloodmononuclear cells

Analysis of the impact of large scale seismic retrofitting strategies through the application of a vulnerability-based approach on traditional masonry buildings

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Earthquake Engineering and Engineering Vibration 2017年第2期16卷 329-348页

作者： Tiago Miguel Ferreira Rui Maio Romeu vicente ISISE Department of Civil EngineeringUniversity of MinhoCampus de Azurém RISCO Department of Civil EngineeringUniversity of AveiroCampus Universitário de Santiago

The buildings＇ capacity to maintain minimum structural safety levels during natural disasters, such as earthquakes, is recognisably one of the aspects that most influence urban resilience. Moreover, the public investment in risk mitigation strategies is fimdamental, not only to promote social and urban and resilience, but also to limit consequent material, human and environmental losses. Despite the growing awareness of this issue, there is still a vast number of traditional masonry buildings spread throughout many European old city centres that lacks of adequate seismic resistance, requiring therefore urgent retrofitting interventions in order to both reduce their seismic vulnerability and to cope with the increased seismic requirements of recent code standards. Thus, this paper aims at contributing to mitigate the social and economic impacts of earthquake damage scenarios through the development of vulnerability-based comparative analysis of some of the most popularretrofitting techniques applied after the 1998 Azores earthquake. The influence of each technique individually and globally studied resorting to a seismic vulnerability index methodology integrated into a GIS tool and damage and loss scenarios are constructed and critically discussed. Finally, the economic balance resulting from the implementation of that techniques are also examined.

关键词： urban resilience masonry buildings retrofitting strategies vulnerability-based approach loss estimation

Delayed Teleoperation with Force Feedback of a Humanoid Robot

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International Journal of Automation and computing 2021年第4期18卷 605-618页

作者： Viviana Moya Emanuel Slawinski vicente Mut Institute of Automation National University of San JuanSan Martin 5400Argentina

Teleoperation systems allow the extension of human capabilities to remote-control devices by providing the operator with conditions similar to those at the remote site through a communication channel that sends information from one site to the other. This article aims to present an analysis of the benefits of force feedback applied to the bilateral teleoperation of a humanoid robot with timevarying delay. As a control scheme, we link adaptive inverse dynamics compensation, balance control, and P+d like controllers. Finally,a test is performed where an operator simultaneously handles the locomotion(forward velocity and turn angle) and arm of a simulated 3D humanoid robot to do a pick-and-place task using two master devices with force feedback, where indexes such as time to complete the task, coordination errors, path tracking error, and percentage of successful tests are reported for different time-delays. We conclude with the results achieved.

关键词： Humanoid robot bilateral teleoperation time delay force feedback walking manipulation

Mapping fractional landscape soils and vegetation components from Hyperion satellite imagery using an unsupervised machinelearning workflow

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International Journal of Digital Earth 2018年第7期11卷 670-690页

作者： Michael J.Friedel Massimo Buscema Luiz Eduardo vicente Fabio Iwashita Andréa Koga-vicente Hydrogeology Department GNS ScienceLower HuttNew Zealand Mathematical&Statistical Sciences University of ColoradoDenverCOUSA Semeion Institute RomeItaly Satellite Monitoring Unit Brazilian Corporation of Agricultural Research-EMBRAPACampinasBrazil Earth Sciences Department University of FlorenceFlorenceItaly Center for Meteorological and Climatological Research in Agriculture University of CampinasCampinasBrazil

An unsupervised machine-learning workflow is proposed for estimating fractional landscape soils and vegetation components from remotely sensed hyperspectral *** workflow is applied to EO-1 Hyperion satellite imagery collected near Ibirací,Minas Gerais,*** proposed workflow includes subset feature selection,learning,and estimation *** training with landscape feature class realizations provide a hypersurface from which to estimate mixtures of soil(e.g.0.5 exceedance for pixels:75%clay-rich Nitisols,15%iron-rich Latosols,and 1%quartz-rich Arenosols)and vegetation(e.g.0.5 exceedance for pixels:4%Aspen-like trees,7%Blackberry-like trees,0%live grass,and 2%dead grass).The process correctly maps forests and iron-rich Latosols as being coincident with existing drainages,and correctly classifies the clay-rich Nitisols and grasses on the intervening *** classifications are independently corroborated visually(Google Earth)and quantitatively(random soil samples and crossplots of field spectra).Some mapping challenges are the underestimation of forest fractions and overestimation of soil fractions where steep valley shadows exist,and the under representation of classified grass in some dry areas of the Hyperion *** preliminary results provide impetus for future hyperspectral studies involving airborne and satellite sensors with higher signal-to-noise and smaller footprints.

关键词： Hyperspectral machine learning remote sensing soils and vegetation unsupervised workflow