Conductive Polymeric Composites Based on Multiwalled Carbon Nanotubes and Linseed Oil Functionalized and Cross-Linked with Diacetylenes from Propargyl Alcohol

Apoyo a Consolidadión de Cuerpos AcadémicosSe presenta la síntesis y saracterización de compuestos poliméricos a base de nanotubos de carbono con aceite de linaza epoxidadoPRODEP-SE

Proyecto de exportación de chompas de alpaca al mercado de los Estados Unidos

La empresa a crear estará dedicada al acopio y comercialización (exportación) de chompas de alpaca, productos que serán enviados a los estados Unidos con preferencia al Estado de Nueva York, el cual está localizado al noreste de dicho país.Tesi

Conductive Polymer Composites Synthesized from Diacetylene-Functionalized Linseed Oil and MWCNT: Gamma Irradiation and Organic Vapor Sensing

Beca de estancia de Posdoctorado del Dr. Alejandro Ramírez JiménezEpoxidized linseed oil (ELO) was synthesized and functionalized with propargylamine (PA) or 3-ethynylaniline (EA) and the products were crosslinked to obtain the diacetylene-functionalized epoxidized linseed oil polymers which were used as matrices in the preparation of the composites with multiwalled carbon nanotubes (MWCNTs). Electrical resistance at percentages between 4 and 20 wt/wt% of filler was measured and the percolation threshold was calculated, obtaining 1.2 and 1.7% for the composites with EA and PA respectively. Low critical concentration evidenced a good dispersion of the MWCNTs without necessity of any modification. The final products were used in the sensing of acetone, chloroform and ethanol. The electrical resistance changes were measured at different concentrations and the sensibility was calculated. In order to improve stability toward the vapors, composites were irradiated with gamma rays and new sensing was done and compared. The results showed differences in sensibility, selectivity and reproducibility.CONACy

Sensing parameters as a function of the chemical structure and thickness of two poly(styrene)-type based composites with carbon black

Sensing parameters of polymer composite layers were studied as a function of the polymer matrix structure and the initial resistance of the composite layers. Composites of Poly(styrene) and 4-Chloro-poly(styrene) at the same volume fraction of carbon black (8.7% V/V) were prepared by ultrasonic dispersion. Composite layers with different thicknesses and resistances were deposited by spin coating technique on flexible substrates from commercial cellulose acetate foils. Both kind of composite layers with initial resistances of 10, 50 and 100 kΩ were exposed to Acetone, Tetrahydrofuran, Chloroform and Toluene. Results evidenced that selectivity is very dependent on the chemical structure of the polymer matrix and sensitivity to the initial film electrical resistance. PS-based composite series were selective to Tetrahydrofuran whereas that 4ClPS-based composite series were selective to Acetone as expected due to their solubility parameters. For both composite series sensitivity increased for layers with less than 100 kΩ resistances. For all tested solvents 4ClPS-based composites showed higher sensitivities than PS-based composites. The response times for both series were into the range of 2 to 150 s and recovery times were in the range of 30 to 2000 s.SIEA-UAEM, 1025/2014RIF

Effect of thermal treatment on Zn nanodisks

Artículo asociado a tesis de Doctorado del estudiante Pedro Estanislao Acuña AvilaMetallic Zn nanodisks with hexagonal morphology were obtained onto glass sub- strate under vacuum thermal evaporation. A thermal characterization of Zn nanodiks showed a lower oxidation temperature than source powder Zn. Different thermal treatment on Zn nanodisks played an important role on the morphology, crystal size and surface vibrational modes of ZnO. The growth of ZnO nanoneedles started at the edge of metallic zinc hexagonal structures according with SEM images, the higher temperature the longer needles were grown. XRD diffractogram confirmed the wurtzite structure of ZnO with metallic nuclei. A wide band between 530 and 580 cm−1 of Raman scattering corresponded at surface vibrational modes not observed at higher temperatur

Physicochemical Properties of Grain and Starch from Kanihua (chenopodium Pallidicaule) Compared with Quinoa (chenopodium Quinoa) Originated from Peru

Kanihua and quinoa are closely related Andean grains that are unconventional starch sources. Starch was extracted from two kanihua and three quinoa genotypes and their physicochemical properties (proximate analysis, scanning electron microscopy, distribution and particle size, X-ray diffraction, FTIR, solubility, swelling power, pasting and thermal properties) were investigated. Kanihua and quinoa grains presented spherical shapes and regular sizes (1.05 - 1.30 mm). The starch granules show asymmetric monomodal distribution for all cases. Meanwhile, Sauter diameter values in kanihua were smaller (0.961 µm) than quinoa (1.099 µm). Regarding structure, all samples showed Type A polymorphism and similar FTIR spectra behavior. In addition, amilose content was around 11-14% and 8-12% for varieties of kanihua and quinoa respectively. Starch solubilities were less than 13%, and kanihua starches had less swelling power than quinoa starches. However, the maximum swelling power values were reached around 70 °C. The variety and type of grain influenced pasting properties, with an inverse relationship between the breakdown and setback values for the evaluated starches. Analyzing the thermal properties, gelatinization enthalpy and retrogradation were similar for all starches. Even though the kanihua and quinoa starches present similar structural characteristics, the pasting properties and swelling power were different. The insight into the morphological, thermal, and pasting properties of native Chenopodium starches could be helpful in the preparation and development of new food formulations

Brain Network Allostasis after Chronic Alcohol Drinking Is Characterized by Functional Dedifferentiation and Narrowing

Alcohol use disorder (AUD) causes complex alterations in the brain that are poorly understood. The heterogeneity of drinking patterns and the high incidence of comorbid factors compromise mechanistic investigations in AUD patients. Here we used male Marchigian Sardinian alcohol-preferring (msP) rats, a well established animal model of chronic alcohol drinking, and a combination of longitudinal resting-state fMRI and manganese-enhanced MRI to provide objective measurements of brain connectivity and activity, respectively. We found that 1 month of chronic alcohol drinking changed the correlation between resting-state networks. The change was not homogeneous, resulting in the reorganization of pairwise interactions and a shift in the equilibrium of functional connections. We identified two fundamentally different forms of network reorganization. First is functional dedifferentiation, which is defined as a regional increase in neuronal activity and overall correlation, with a concomitant decrease in preferential connectivity between specific networks. Through this mechanism, occipital cortical areas lost their specific interaction with sensory-insular cortex, striatal, and sensorimotor networks. Second is functional narrowing, which is defined as an increase in neuronal activity and preferential connectivity between specific brain networks. Functional narrowing strengthened the interaction between striatal and prefrontocortical networks, involving the anterior insular, cingulate, orbitofrontal, prelimbic, and infralimbic cortices. Importantly, these two types of alterations persisted after alcohol discontinuation, suggesting that dedifferentiation and functional narrowing rendered persistent network states. Our results support the idea that chronic alcohol drinking, albeit at moderate intoxicating levels, induces an allostatic change in the brain functional connectivity that propagates into early abstinence.Peer reviewe

¿Qué significa tener un deber jurídico?

Este trabajo investigativo está enfocado en resolver un gran interrogante ¿Qué es un deber jurídico?, para esto es importante resaltar que debemos de tener un punto de salida en la definición de los conceptos que se tratan en el cuestionamiento para así poder entender los temas que tratamos

Programa de internacionalización de los productos de Finca La Isla

Dentro del proyecto 3J04 “Inteligencia Cultural y Comercial para los Negocios Internacionales”, se realizó el programa de internacionalización de varios productos naturales de la empresa “Finca La Isla”. Estos van desde: Miel, Jengibre, Vainilla, Cúrcuma, Canela, entre otros. El proyecto se centró en la exportación de la miel en dos destinos: Alemania y Turquía, centrándose en las ferias Internacionales de la Anuga 2023, en Colonia, y Apimondia 2022 en Estambul. El proyecto nos llevó a crear un brochure, en donde se pueden encontrar diferentes aspectos económicos, culturales, sociales, políticos, y de mercado, para que el empresario tenga en cuenta todo antes de iniciar la inversión. Nos dividimos en dos equipos de trabajo, cada uno enfocado en un país.ITESO, A.C