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Advances in Materials Physics and Chemistry 2011年第3期1卷 57-63页

作者： maría elena sánchez Juan Carlos Alonso Jerry Nathan Reider 不详

strong visible photoluminescence (PL) at room temperature is obtained from thermal-evaporated thin solid films of Metallophthalocyanine (M = Co, Fe, Pb) and double potassium salt from 1,8 dihydroxyan-thraquinone. The PL of all the investigated samples is observed with the naked eye in a bright background. The deconvolution of the normalized PL spectra shows that each PL spectrum is composed of four emission bands which peak at approximately the same energies of 2.1, 2.2 and 2.4 eV and whose intensities and widths depend upon the structure of the complexes. FTIR and ellipsometry are employed to investigate the structural differences among the films. The optical absorption of the films is also investigated to evaluate the changes in the electronic structure of these metal organic compounds, with respect to other metalphtalocya-nines thin films. Our results suggest that the visible PL comes from radiative transitions between energy lev-els associated to the double potassium salt coordination to the metallic ion in the phthalocyanine.

关键词： Thin Films Optical Properties Photoluminescence

Chemical Characterisation of the Industrial Residues of the Pineapple (Ananas comosus)

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Journal of Agricultural Chemistry and Environment 2014年第2期3卷 53-56页

作者： maría elena sánchez Pardo maría elena Ramos Cassellis Rosalva Mora Escobedo Epifanio Jiménez García Benemérita Universidad Autónoma de Puebla Av.San Claudio y 18 sur Edif.106 Ciudad Universitaria Puebla Pue.3ExHacienda san Juan Molino km 1.5 carretera Estatal Tecuexcomac-Tepetitla México Instituto Politécnico Nacional Escuela Nacional de Ciencias Biológicas Prolongación de Carpio y Plan de Ayala S/N Col. Sto. Tomás. C.P. 11340 México D.F. México

In Mexico pineapple processing produces industrial residues with a high concentration of dietary fibre. The aim of this study was to quantify the constituents of the fibrous residues from the industrial processing of ... 详细信息

关键词： Pineapple Total Dietary Fibre Hemicelluloses Cellulose Lignin Pectin

Conductive Behavior and Morphology of Axially Modified Gallium Phthalocyanine Thin Films onto Indium Tin Oxide substrates

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Advances in Materials Physics and Chemistry 2016年第7期6卷 211-219页

作者： margarita Rivera Brenda Reyes maría elena sánchez-Vergara Luis Humberto Mendoza-Huizar Instituto de Física Departamento de Materia Condensada Universidad Nacional Autónoma de México D.F. México México Facultad de Ingeniería Universidad Anáhuac México Norte Huixquilucan Estado de México México Centro de Investigaciones Químicas Mineral de la Reforma Universidad Autónoma del Estado de Hidalgo Hidalgo México

semiconductor molecular films based on a gallium phthalocyanine chloride (GaPcCl) and a bidentate amine were prepared by using vacuum thermal evaporation and electrochemical techniques in order to investigate the preferred conduction paths within the films. scanning Electron Microscopy (sEM) and Atomic Force Microscopy (AFM) were employed to characterize the morphology of the films. The conductivity measurements were performed with two different methods in order to investigate preferential conduction directions. The film transverse conductivity was obtained by using scanning tunneling spectroscopy (sTs) and the in-plane film conductivity was measured with a four-point probe system. From spectroscopy measurements, the tunneling conductance (dI/dV) was also obtained. From these results, it was found that the conductive nature of the films was strongly influenced by the deposition technique which in turn defined the morphological characteristics of the film. The evaporated method showed better conductivity response and provided semiconductor characteristics in the film transverse direction with an in-plane ohmic response. Finally, contact angle measurements were performed and showed hydrophobic characteristics in all cases.

关键词： Thin Films Phthalocyanines Electronic Properties Electrical Conductivity

Effect of Organic Dopants in Dimetallophthalocyanine Thin Films: Application to Optoelectronic Devices

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Advances in Materials Physics and Chemistry 2019年第4期9卷 71-88页

作者： maría elena sánchez-Vergara santiago Osorio-Lefler Pablo Osorio-Lefler José Ramón álvarez-Bada Universidad Anáhuac México Avenida Universidad Anáhuac 46 Col. Lomas Anáhuac Huixquilucan Estado de México México

semiconductor films of organic, doped dimetallophthalocyanine M2Pcs (M = Li, Na) on different substrates were prepared by synthesis and vacuum evaporation. Tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ) were used as dopants and the structure and morphology of the semiconductor films were studied using IR spectroscopy, X-ray diffraction (XRD), scanning Electron Microscopy (sEM) and Energy Dispersive X-Ray spectroscopy (EDs). The absorption spectra recorded in the ultraviolet-visible region for the deposited films showed the Q and soret bands related to the electronic π-π* transitions in M2Pc molecules. Optical characterization of the films indicates electronic transitions characteristic of amorphous thin films with optical bandgaps between 1.2 and 2.4 eV. Finally, glass/ITO/doped M2Pc/Ag thin-film devices were produced and their electrical behavior was evaluated by using the four-tip collinear method. The devices manufactured from Na2Pc have a small rectifying effect, regardless of the organic dopant used, while the device manufactured from Li2Pc-TCNQ presents ohmic-like behavior at low voltages, with an insulating threshold around 19 V. Parameters such as the hole mobility (μ), the concentration of thermally-generated holes (p0), the concentration of traps per unit of energy (P0) and the total trap concentration (Nt(e)) were also determined for the Li2Pc-TTF device.

关键词： Organic semiconductors Thin Films Optical Properties Electrical Properties Optoelectronic Devices

Hypolipidemic Activity of Microwave-Dehydrated Mango (Mangifera indicaL.) Powder in Mice Fed a Hypercholesterolemic Diet

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Journal of Biomedical science and Engineering 2014年第10期7卷 809-817页

作者： Obed Osorio-Esquivel Vianney Cortés-Viguri Leticia Garduñ o-siciliano Alicia Ortiz-Moreno maría elena sánchez-Pardo Department of Biochemical Engineering National School of Biological Sciences National Polytechnic Institute Mexico City Mexico Department of Physiology National School of Biological Sciences National Polytechnic Institute Mexico City Mexico

The effect of dietary supplementation with mango (Mangifera indica L.) powder obtained by microwave dehydration was studied in normal and hypercholesterolemic mice. The phenolic profiles in methanolic extracts and antioxidant activities were determined using high-performance liquid chromatography and DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTs (2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonic acid) assays, respectively. The total phenolic content of microwave-dehydrated mango powder was 1451.7 ± 26.7 μggallic acid equivalents/g dry weight. The main phenolic compounds identified were gallic acid, epicatechin, ferulic acid, and catechin. The anti-oxidant activity was 14.6% higher in microwave-dehydrated mango powder than in conventional mango powder. Mice were fed a hypercholesterolemic diet (1 g cholesterol/100g over 7 days). The hypercholesterolemic mice whose diets were supplemented with microwave-dehydrated mango powder showed a significant decrease (P ≤ 0.05) in total serum cholesterol compared to the hypercholesterolemic mice and the mice fed with conventional dehydrated mango powder. We observed a significant increase (P ≤ 0.05) in HDL-c levels in the microwave-dehydrated mango powder group mice (12.4 ± 1.3 mmol/L) compared to the hypercholesterolemic group (8.6 ± 1.4 mmol/L) and the conventional-dehydrated mango powder group (10.9 ± 1.3 mmol/L). The mice provided with microwave-dehydrated mango powder had significantly lower (P ≤ 0.05) levels of serum LDL-c (36.0%) and total cholesterol (43.3%) compared to the mice in hypercholesterolemic group. Notably, the atherogenic index was 72% lower in the microwave-dehydrated mango powder group compared to the hypercholesterolemic group. These results suggest that the biocompounds, such as polyphenols and dietary fiber, found in mango pulp might improve the lipid profile in mice fed a hypercholesterolemic diet.

关键词： Hypolipidemic Activity Microwave-Dehydrated Mango Powder Hypercholesterolemic Diet Phenolic Profiles

Microwave Dried Carrot Pomace as a source of Fiber and Carotenoids

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Food and Nutrition sciences 2013年第10期4卷 1037-1046页

作者： marcela Hernández-Ortega Guy Kissangou Hugo Necoechea-Mondragón maría elena sánchez-Pardo Alicia Ortiz-Moreno Coordinación de Cooperación Académica Edificio de la Secretaría Académica Instituto Politécnico Nacional México City México. Departamento de Ingeniería Bioquímica Escuela Nacional de Ciencias Biológicas Instituto Politécnico Nacional México City México

Carrot pomace is a major by-product obtained during the industrial juice extraction process, which is discarded contributing to environmental pollution. This residue is rich in fiber, and contains high amounts of carotenoids and phenolic compounds that could contribute to its application as functional ingredient, improving the quality of foods and helping to reduce the environmental problem. In this study, carrot pomace powders obtained by microwave or hot air drying were incorporated into cookies in order to improve their phytochemical content. Cookies were prepared using a traditional cookie recipe substituting 30% of the wheat flour for either of the carrot pomace powders. Fiber, carotenoids and phenolic compounds were determined;image analysis and acceptability of the cookies were also conducted. The substitution of 30% of wheat flour for carrot pomace powders increased 3.7 fold the total dietary fiber of cookies, from 7.13 g/100gto26.44 g/100g;accounting the 7.4% of fiber daily intake with the consumption of one cookie (7 g). A similar pattern was found in the content of carotenoids and phenolic compounds. Carrot pomace dried with microwaves had the highest amount of these bioactive compounds. β-carotene, epicatechin, gallic and ferulic acids were identified in cookies with microwave carrot pomace powder. The cookies incorporated with carrot pomace powders exhibited improved antioxidant properties because of the increase in the phytochemical content. Acceptable cookies with appealing orange color were obtained. The results indicated that the replacement of wheat flour for carrot pomace powders yielded dietary fiber enriched cookies with improved carotenoid content.

关键词： Carrot Pomace Microwave Drying Fiber Carotenoids Phenolic Compounds Antioxidant Activity Cookie

synthesis and Evaluation of the semiconductor Behavior in Vanadium Indanone Derivatives Thin Films

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Advances in Materials Physics and Chemistry 2017年第2期7卷 70-83页

作者： mariana Lozano-González maría elena sánchez-Vergara Isabel Alvarado-Beltrán mariel Leyva-Esqueda margarita Rivera Cecilio álvarez-Toledano Institute of Chemistry National Autonomous University of Mexico Mexico City Mexico Anahuac University Mexico City Mexico Institute of Physics National Autonomous University of Mexico Mexico City Mexico

In this work, we propose a method to synthesize vanadium (IV) 2-benzyli-dene-1-indanone derivatives, used to prepare film structures by thermal evaporation. The complexes possess high melting point allowing the using of vacuum deposition methods. All the samples were grown at room temperature (25℃) and low deposition rates (0.4 Å/s). The surface morphology and structure of the deposited films were studied by scanning electron microscopy (sEM) and spectroscopy dispersive energy (EDs). Optical absorption studies of the complex films were performed in the 200 - 1100 nm wavelength range. The Tauc band gap (Eg) of the thin films was determined from the (αhν)1/2 vs. hν plots for indirect transitions. The vanadium (IV) complex films show optical activation energies in the range of organic semiconductors. Multilayer nylon 11/vanadium indanone devices were fabricated using ITO and silver electrodes. The d.c. electrical properties of the device were also investigated. It was found that the temperature-dependent electric current in the structure showed a semiconductor behavior. At lower voltages below 7 V, the current density in the forward direction was found to obey an ohmic I-V relationship;for higher voltages above 7 V, the conduction was dominated by a space-charge-limited (sCLC) mechanism. The electrical activation energies (Ea) of the complexes were in the 2.17 - 2.31 eV range.

关键词： Chemical synthesis Thin Films Optical Properties Electrical Properties

Preparation of Hybrid Materials Containing M(II)Pc (M = Fe, Co, Ni)/Nylon films with Optical and Electrical Properties

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Advances in Materials Physics and Chemistry 2015年第7期5卷 271-280页

作者： maría elena sánchez Vergara mariana Huerta-Francos mariluz Menéndez-Huerta Mercedes Espinosa-Creel Oscar Amelines-sarria Jaime santoyo-salazar College of Engineering Universidad Anáhuac México Norte Huixquilucan México Physics Institute Department of Condensed Material Universidad Nacional Autónoma de México Coyoacán México Physics Department Research and Advanced Studies Center of the National Polythechnic Institute (CINVESTAV-IPN) Zacatenco México

Hybrid materials consisting of M(II)Pc (M = Fe, Co, Ni) particles dispersed in nylon 11 films have been prepared by using a thermal relaxation technique. The obtained films are characterized by AFM, sEM and TEM, and their structural composition is determined by IR spectroscopy and EDs. The M(II)Pc particles are homogeneously distributed in the nylon 11 matrix after heat treatment. Optical absorption studies of the hybrid films are performed in the 200 - 1150 nm wavelength range. The band-model theory is applied to determine the optical parameters for MPc/nylon 11 hybrid films. The optical band gap of the thin films is determined from the (αhν)1/2 vs. hν plots for indirectly allowing transitions and comparing with the as-deposited M(II)Pc thin films. The values of the optical band gap calculated from the absorption spectra, range between 1.07 and 2.7 eV. The electrical conductivity is measured in order to evaluate the conductivity behavior of these hybrid films.

关键词： Metallophthalocyanines Thermal Relaxation Polymer Film Optical Band Gap Electrical Properties

Developing Ontology systems as a Base of an Environmental Quality Management Model in México

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Journal of Environmental Protection 2015年第9期6卷 1084-1093页

作者： René Bernardo Elías Cabrera-Cruz Erika Alarcón-Ruiz Julio César Rolón-Aguilar salvador W. Nava-Díaz elena maría Otazo-sánchez Ricardo Pérez Aviléz Division of Postgraduate studies and Research Faculty of Engineering “Arturo Narro Siller” Autonomous University of Tamaulipas Tamaulipas Mexico Center for Chemical Research Autonomous University of Hidalgo State Hidalgo Mexico Institute of sciences Autonomous University of Puebla Puebla Mexico

The process of identifying the attributes and relationships considered in an ontology is a complex task because there are many factors involved in the deterioration of environmental quality, the diversity of sources and data dispersion. This work presents an ontology that integrates the data required by an Environmental Quality synoptic system (EQss), which to date scatters in different Internet sites and concentrates by different agencies for example INEGI, CONABIO, sEmarNAT, CNA, among others. The methodology process consists of the collection of environmental information in Mexico through the application of computational techniques resulting ontology with environmental knowledge that will be processed by the system EQss. Among the main advantages is than the selection and structure of information allow the automated generation of results in an environmental statement. The ontology proposal is based on knowledge of EQss system that is based on the architecture of expert systems and through this important information for decision-making in regard to environmental quality and interaction with Geographic Information system (GIs) is obtained.

关键词： Ontology software Knowledge Modeling Environmental Quality EIA

Morphological and Optical Properties of Dimetallo-Phthalocyanine-Complex Thin Films

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Advances in Materials Physics and Chemistry 2014年第2期4卷 20-28页

作者： maría elena sánchez-Vergara Jose R. álvarez-Bada Carlos O. Perez-Baeza Elías A. Loza-Neri Ricardo A. Torres-García Arturo Rodríguez-Gómez Juan C. Alonso-Huitron Facultad de Ingeniería Universidad Anáhuac (México Norte) Huixquilucan México Instituto de Física Universidad Nacional Autónoma de México México D.F. México Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de México México D. F. México

In this work, the synthesis of semiconducting molecular materials formed from metallo-phthalocyanines (MPcs) and bidentate amines is reported. Powder and thin-film samples of the synthesized materials, deposited by vacuum thermal evaporation, show the same intra-molecular bonds in IR-spectroscopy studies. The morphology of the deposited films was studied using scanning electron microscopy and atomic force microscopy. The optical parameters have been investigated using spectrophotometric measurements of transmittance in the wavelength range 200 - 1100 nm. The absorption spectra in the UV-Vis region for the deposited samples showed two bands, namely the Q and soret bands. The optical band gap values of the thin films were calculated from the absorption coefficient α in the absorption region and were found to be around 1.4 - 1.6 eV. The dependence of the Tauc and Cody optical gaps on the thickness of the film was also determined.

关键词： Phthalocyanines Organic semiconductors Thin Films Optical Gap