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Nonlinear Coefficient Determination of Au/Pd Bimetallic Nanoparticles Using Z-Scan

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Advances in Nanoparticles 2013年第3期2卷 223-228页

作者： José Luis Jiménez Pérez Rubén Gutiérrez-Fuentes José Francisco Sánchez Ramírez Omar Uriel García Vidal Daniel Erick Téllez-Sánchez Zormy Nacary Correa Pacheco Alfredo Cruz Orea Jesús Antonio Fuentes García Centro de Investigación en Ciencia Aplicada y tecnología Avanzada México D.F. México Departamento de Física Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional México D.F. México Unidad Profesional Interdisciplinaria en Ingeniería y Tecnologías Avanzadas del IPN México D.F. México

In this paper we present the nonlinear optical characterization of Au/Pd nanoparticles in order to obtain the nonlinear refractive indices using the Z-scan technique. The experiments were performed using a 514 nm laser beam Ar+, with 14 Hz of modulation frequency, as excitation source. By using a lens the excitation beam was focused to a small spot and the sample was moved across the focal region along the z-axis by a motorized translation stage. Seven samples with different concentration ratio of Au/Pd nanoparticles were prepared by simultaneous reduction of gold and palladium ions in presence of poly (N-vinyl-2-pirrolidone) (PVP) using ethanol as a reducing agent. In this work, we report the application of the Z-scan technique, to generate optical transmission of laser light as a function of the z position for solutions containing bimetallic nanoparticles of Au (core)/Pd (shell) with average sizes ranging from 3 to 5 nm. The magnitude of the obtained nonlinear refractive index was in the order of 10?8 cm2/W. Our results show that the nonlinear refractive index has a nonlinear behavior when the (Au/Pd) ratio was increased.

关键词： Nanofluids Nanoparticles Nonlinear Refractive Indices Z-Scan

Greenhouse Gas Emissions and Growth of Wheat Cultivated in Soil Amended with Digestate from Biogas Production

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Pedosphere 2017年第2期27卷 318-327页

作者： Liliana PAMPILLON-GONZALEZ Marco LUNA-GUIDO Victor Manuel RUIZ-VALDIVIEZO Olivia FRANCO-HERNANDEZ Fabign FERNANDEZ-LUQUenO Oetavio PAREDES-LOPEZ Gerardo HERNANDEZ Luc DenDOOVen PhD Program on Science Technology and Society Cinvestav IPN 2508 Mexico DF 07360 (Mexico) Laboratory of Soil Ecology Laboratorio de Matemdticas Aplicadas y Cdmputo de Alto Rendimiento Cinvestav-Edomex (ABACUS) Cinvestav IPN 2508 Mexico DF 07360 (Mexico) Department of Chemistry Unidad Profesional Interdisciplinaria de Biotecnologla-Instituto Politdcnico Nacional (UPIBI-IPN) Me- xico DF 07340 (Mexico) Sustainability of Natural Resources and energy Program Cinvestav-Saltillo 1062 Coahuila 25900 (Mexico) Department of Biotechnology and Biochemistry Cinvestav Irapuato 36821 (Mexico)

Digestate, the product obtained after anaerobic digestion of organic waste for biogas production, is rich in plant nutrients and might be used to fertilize crops. Wheat(Triticum spp. L.) was fertilized with digestate, urea, or left unfertilized and cultivated in the greenhouse for 120 d. Emissions of greenhouse gasses(carbon dioxide(CO_2), methane(CH_4), and nitrous oxide(N_2O)) were monitored and plant growth characteristics were determined at harvest. The digestate was characterized for heavy metals, pathogens, and C and N mineralization potential in an aerobic incubation experiment. No Salmonella spp., Shigella spp., or viable eggs of helminths were detected in the digested pig slurry, but the number of faecal coliforms was as high as 3.6 × 10~4colony-forming units(CFU) g-^(1)dry digestate. The concentrations of heavy metals did not surpass the upper limits established by US environmental Protection Agency(EPA). After 28 d, 17% of the organic C(436 g kg^(-1)dry digestate) and 8% of the organic N(6.92 g kg^(-1)dry digestate)were mineralized. Emissions of CO_2 and CH_4 were not significantly affected by fertilization in the wheat-cultivated soil, but digestate significantly increased the cumulative N_2O emission by 5 times compared to the urea-amended soil and 63 times compared to the uncultivated unfertilized soil. It could be concluded that digestate was nutrient rich and low in heavy metals and pathogens, and did not affect emissions of CH_4 and CO_2 when applied to a soil cultivated with wheat, but increased emission of N_2O.

关键词：温室气体排放土壤栽培小麦生长沼气肥修订重金属浓度美国环境保护局粪大肠菌群

Benzyl Amino Purine and Gibberellic Acid Coupled to Nitrogen-Limited Stress Induce Fatty Acids,Biomass Accumulation,and Gene Expression in Scenedesmus Obliquus

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Phyton-International Journal of Experimental Botany 2021年第2期90卷 515-531页

作者： Hans Christian Correa-Aguado Gloria Viviana Cerrillo-Rojas Alejandro Rocha-Uribe Ruth Elena Soria-Guerra JoséFrancisco Morales-Domínguez Departamento de Química Centro de Ciencias BásicasUniversidad Autónoma de AguascalientesAguascalientes20131México Facultad de Ciencias Químicas Universidad Autónoma de San Luis PotosíSan Luis Potosí78210México Instituto Politécnico Nacional Unidad Profesional Interdisciplinaria de Ingeniería Campus ZacatecasBlvd.del Bote 202Cerro del Gato Ejido La EscondidaCol.Ciudad AdministrativaZacatecasZAC 98160Mexico

The need for renewable energy sources makes microalgae an essential feedstock for biofuels production.The molecular aspects and the response to nitrogen(N)-limited conditions with a phytohormone stimulus in microalgae have been slightly explored.In this work,Scenedesmus obliquus was used as a study model to analyze the effect of benzyl amino purine(BAP)and gibberellic acid(GA)coupled to nitrogen limitation on cell growth,biomass and fatty acids.The selected 10^(-5)M BAP increased the biomass by 1.44-fold,and 10^(-6)M GA by 1.35-fold.The total lipids also increased by 2.8 and 1.11-fold,respectively.The 10^(-5)M BAP and 10^(-6)M GA addition to S.obliquus cultures at different initial nitrogen percentages(N-0,N-25,and N-50)showed a significant increase in cell growth and biomass productivity compared to the unstimulated cultures.BAP N-0 and GA N-0 produced the highest lipid yields with 55%and 50%,respectively.The lipid profile analysis revealed an increase,particularly in C18:1 and C16:0 fatty acids.Gene expression analysis showed an over-expression of acyl carrying protein(ACP),stearoyl-ACP desaturase(SAD),fatty acid acyl-ACP thioesterase(FATA),and diacylglycerol acyltransferase(DGAT)genes,which were mainly induced by nitrogen limitation.Furthermore,BAP and GA produced a significant over-expression on these genes in the N-replete cultures.This study shows that BAP and GA,coupled to N limitation stress,can be used to increase the biomass and lipid production in S.obliquus for sustainable biofuels.

关键词： Biodiesel gene expression lipids microalgae nitrogen deficiency phytohormones

Bacterial and archaeal communities in saline soils from a Los Negritos geothermal area in Mexico

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Pedosphere 2023年第2期33卷 312-320页

作者： Joseph GUEVARA-LUNA Mario HERNÁNDEZ-GUZMÁN Nina MONTOyA-CIRIACO Luc DenDOOVen Marina Olivia FRANCO-HERNÁNDEZ Paulina ESTRADA-DE LOS SANTOS María Soledad VÁSQUEZ-MURRIETA Escuela Nacional de Ciencias Biológicas Instituto Politécnico NacionalCiudad de México 11340(Mexico) Laboratory of Soil Ecology CinvestavMexico City 07360(Mexico) Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de Tlaxcala.Carretera Federal Tlaxcala-Puebla km.1.5Tlaxcala 90070(Mexico) unidad profesional interdisciplinaria de Biotecnología Instituto Politécnico NacionalCiudad de México 07340(Mexico)

In recent years,there has been a growing need to understand how salinity affects microbial communities in agricultural soils.Archaeal and bacterial community diversities and structures were investigated by high-throughput sequencing analysis of their 16S rRNA in two arable soils with low electrical conductivity(EC)(2.3 and 2.6 dS m^(-1))and a saline soil(EC=17.6 dS m^(-1)).The dominant bacterial phyla in the soils were Proteobacteria(relative abundance(RA)=46.2%),followed by Acidobacteria(RA=13.1%)and Actinobacteria(RA=10.0%),whereas Serratia(RA=6.0%)and Bacillus(RA=4.0%)were the dominant bacterial genera.Candidatus Nitrososphaera(53.5%)was the dominant archaeal phylotype in the arable soils,whereas Nitrosopumilus(RA=0.4%)dominated in the saline soil.The archaeal and bacterial community structures were different between the soils and significantly correlated with soil sand,arsenic,barium,and antimony contents,but not with soil salinity.

关键词： agricultural soil compositional approach microbial community mud volcano soil salinity soluble anion

Coherent States for the Two-Dimensional Dirac-Moshinsky Oscillator Coupled to an External Magnetic Field

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理论物理通讯：英文版 2015年第3期63卷 271-274页

作者： D.Ojeda-Guillen R.D.Mota V.D.Granados Escuela Superior de Física y Matemáticas Instituto Politécnico NacionalEd.9Unidad Profesional Adolfo López MateosC.P.07738México D.F.Mexico Escuela Superior de ingeniería Mecánica y Eléctrica Unidad CulhuacánInstituto Politécnico NacionalAv.Santa Ana No.1000Col.San Francisco CulhuacánDelegación CoyoacánC.P.04430Mexico D.F.Mexico

We show that the(2+l)-dimensional Dirac-Moshinsky oscillator coupled to an externa/ magnetic field can be treated algebraically with the SU(1,1) group theory and its group basis.We use the su(1,1) irreducible representation theory to find the energy spectrum and the eigenfunctions.Also,with the su(1,1) group basis we construct the relativistic coherent states in a closed form for this problem.

关键词：振荡器狄拉克相干态外部磁场连接二维本征函数表示理论

Disinfection of Primary Municipal Wastewater Effluents Using Continuous UV and Ozone Treatment

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Journal of Water Resource and Protection 2014年第1期6卷 16-21页

作者： yaneth Bustos Mabel Vaca Raymundo López Erick Bandala Luis Torres Neftalí Rojas-Valencia Departamento de energía Ciencias Básicas e Ingeniería Universidad Autónoma Metropolitana Azcapotzalco México Departamento de ingeniería Civil y Ambiental Universidad de las Américas Puebla. Sta. Catarina Mártir Cholula México unidad profesional interdisciplinaria de Biotecnología Instituto Politécnico Nacional México D. F. México Universidad Nacional Autónoma de México Instituto de Ingeniería Coordinación de Ingeniería Ambiental México D. F. México

UV radiation and ozonation were investigated as disinfection alternatives for the wastewater treatment plant. The inactivation of total and fecal coliforms using ozone and ultraviolet radiation as separate treatments was evaluated. Different ozone concentrations (3 to 40 mg O3/L) were applied and UV fluencies ranging from 8.5 to 12 mJ/cm2 at different pH values (from 5 to 9) were tested. Best results were obtained for ozone doses near 20 mg/min with removals of 72% and 78% of fecal and total coliforms, respectively. The ozone also was capable of oxidizing organic matter in the effluent measured as COD (the highest removal obtained was 36% for 20 mg O3/min). Maximum bacterial resistance was observed at pH 7 in both cases. The UV light offered a high bacterial inactivation (over 80%) and the lowest bacterial inactivation was observed at pH 7. Finally, we obtained the electric energy per order (EEO, kWh/m3/order), defined as the electric energy (kW-h) required to degrade a contaminant by one order of magnitude in a unit volume of contaminated water, being noteworthy that EEO values for the UV process resulted were lower than those determined for the process with ozone in all the water flow tested.

关键词： Disinfection Ozone Treatment UV Treatment Wastewater

Trehalose and Sucrose Osmolytes Accumulated by Algae as Potential Raw Material for Bioethanol

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Natural Resources 2011年第3期2卷 173-179页

作者： Ma.del Pilar Bremauntz Luis G.Torres-Bustillos Rosa-Olivia Canizares-Villanueva enrique Duran-Paramo Luis Fernández-Linares Laboratory of Bioprocesses Department of BioprocessesUnidad Profesional Interdisciplinaria de Biotecnologia UPIBI-Instituto Politecnico NacionalMexico CityMexico Departamento de Biotecnologia y Bioingenieria Centro de Investigacion y de Estudios Avanzados-IPNMexico CityMexico

Currently, obtaining sustainable fuels, such as biodiesel and bioethanol, from cheap and renewable materials is a challenge. In recent years, a new approach being developed consists of producing, sugars from algae by photosynthesis. Sugar accumulation can be increased under osmotic stress (osmoregulation). The aim of this study is to show the pro-duction of sugars from algae, isolated from natural sources, and the effect of osmotic stress on fermentable sugars ac-cumulation. Strain isolation, production of sugars from each alga and the effect of osmotic stress on growth and sugar production are described. Twelve algal strains were isolated, showing growths between 0.6 and 1.8 g of biomass dry weight /L, all with production of intracellular and extracellular sugars. The strain identified as Chlorella sp. showed an increase in sugar production from 23.64 to 421 mg of sugars/g of biomass dry weight after 24 h of osmotic stress with 0.4 M NaCl. Sucrose and trehalose, both fermentable sugars, were the compatible osmolytes accumulated in response to the osmotic stress. The isolated strains are potential producers of fermentable sugars, using the photosynthetic pathway and osmotic stress.

关键词： Algae Biofuels Osmoregulators Carbohydrates Bioethanol

Phase Transition in Superconducting Thin Films of Tl System Employing a One-Zone Furnace and Deposited by Spray Pyrolysis

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Materials Sciences and Applications 2013年第11期4卷 739-745页

作者： Jorge Luis Rosas-Mendoza L. Perez-Arrieta Miguel Aguilar-Frutis Ciro Falcony R. Vázquez-Arreguín Alejandro Miguel Rosas-Mendoza Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Instituto Politécnico Nacional México D.F. México Centro de Investigación en Ciencia Aplicada y tecnología Avanzada Instituto Politécnico Nacional México D.F. México unidad profesional interdisciplinaria de Biotecnología Instituto Politécnico Nacional México D.F. México Departamento de Física Centro de Investigación de Estudios Avanzados (CINVESTAV-IPN) México D.F. México unidad Académica de Física Universidad Autónoma de Zacatecas (UAZ) Zacatecas México

A study of the phase transitions in superconducting thin films of the Thallium-Barium-Calcium-Copper (TBCCO) system is carried out. In particular, it was got the Tl-1223 phase. For this purpose, and using the ultrasonic spray pyrolysis technique, Barium-Calcium-Copper precursor films were first obtained. Upon deposition of the precursor films, and as a second step, they were thallium (Tl) diffused in the one-zone furnace at 860°C. This methodology resulted in superconducting films that showed a phase transition as follows: Tl-2223 → Tl-2223 + Tl-2212 → Tl-2212 → Tl-1223, achieved between 2 and 7 hours of thallium diffusion. The evidence of the phase transitions was corroborated by the experimental results of X-ray diffraction, energy dispersive spectroscopy and resistance-temperature measurements.

关键词： Superconductors Thin Films Ultrasonic Spray Pyrolysis

Zinc and Lead Biosorption by delftia tsuruhatensis: A Bacterial Strain Resistant to Metals Isolated from Mine Tailings

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Journal of Water Resource and Protection 2012年第4期4卷 207-216页

作者： Dorian A. Bautista-Hernández Landy I. Ramírez-Burgos enrique Duran-Páramo Luis Fernández-Linares Faculty of Chemistry Programa de Ingeniería Química Ambiental y Química Ambiental PIQAyQA Universidad Nacional Autónoma de México México City México Laboratory of Bioprocesses Department of Bioprocesses Unidad Profesional Interdisciplinaria de Biotecnología UPIBI-Instituto Politécnico Nacional México City México Rearch Centre for environmental Quality Instituto Tecnológico de Estudios Superiores de Monterrey Campus Estado de México Atizapán de Zaragoza México

A bacterial strain capable of Zinc and Lead biosorption was isolated from mine tailings. This strain showed the highest minimum inhibitory concentrations (MIC) of metals among other isolates in metal-resistance tests. Sorption tests were conducted placing 0.015 g of dry biomass in 10 ml of metallic solution at fixed pH. Contact was analyzed at different times (kinetics) and different initial concentrations (isotherm). The biomass was separated by centrifugation and the concentration of non-absorbed metal was determined using atomic absorption spectroscopy. The strain was identified by 16S sequencing as delftia tsuruhatensis. The order of toxicity of the metals to the bacterium was Zn > Pb > Se > Ni > Cu = Al. Zinc and Lead absorption kinetics were adjusted to the pseudo second order equation (r2 = 0.99), showing that equilibrium was reached at 40 and 20 min, respectively. Maximal absorption of Pb and Zn was 0.216 and 0.207 mmol?g–1, respectively;which can be considered a median magnitude capacity when compared to other biosorbents described in the literature.

关键词： Biosorption Langmuir and Freundlich Isotherms delftia Tsuruhatensis Pb(II) Zn(II)