43 research outputs found
Calidad, conocimiento e innovación de procesos de manufactura en Ciudad Juárez, México
Quality consists of the standardization of manufacturing processes, the establishment of controls in operations and continuous improvement, in turn,knowledge promotes process innovation, so the constant learning in companies allows them to stay competitive in the market. The objective of this research is to determine the relationship of significance between quality and knowledge in the innovation of production processes in the manufacturing industry in Ciudad Juarez, Mexico. The study was correlational, cross-sectional with a quantitative approach using the factor analysis method and the modeling ofstructural equations using the survey technique. The sample was 236 valid questionnaires applied in 30 industrial companies in the maquiladora sectorin the locality. The results of the convergent validity test showed that the variables are correlated and that according to the values of the average variance extracted the correlation is strong, likewise with the indicators of goodness-of-fit was obtained the degree to which the model predicts the correlations, in this case, what is observed in the data corresponds to some extent to what was proposed in the model. The relationship between quality, knowledge and innovations is positive and significant, so the research hypothesis is not rejected. Strategies implemented to improve quality and manage knowledge have a positive effect on the development of process innovations.La calidad consiste en la estandarización de los procesos de manufactura, el establecimiento de controles en las operacionesy la mejora continua, a su vez el conocimiento promueve la innovación en los procesos, por lo que el constante aprendizaje en las empresas les permite mantenerse competitivas en el mercado. El objetivo de esta investigación es determinar la relación de significancia entre la calidad y el conocimiento en la innovación de los procesos de producción en la industria de manufactura en Ciudad Juárez, México. El estudio fue de tipo correlacional, transversal con enfoquecuantitativo mediante el método de análisis factorial y el modelo de ecuaciones estructurales utilizando la técnica de encuesta. La muestra fue de 236 cuestionarios válidos aplicados en 30 empresas industriales del sector maquiladora en la localidad. Los resultados de la prueba de validez convergente mostraron que las variables están correlacionadas y queconforme los valores de la varianza media extraída la correlación es fuerte. Con los indicadores de bondad de ajustes se obtuvo que lo observado en los datos corresponde con lo que se propuso en el modelo. La relación entre calidad, conocimientoe innovaciones es positiva y significativa, por lo que la hipótesis de investigación no se rechaza. Las estrategias que se implementen para mejorar la calidad y gestionar el conocimiento pueden tener un efecto positivo en el desarrollo de las innovaciones de proceso
Calidad, conocimiento e innovación de procesos de manufactura en Ciudad Juárez, México
La calidad consiste en la estandarización de los procesos de manufactura, el establecimiento de controles en las operaciones
y la mejora continua, a su vez el conocimiento promueve la innovación en los procesos, por lo que el constante
aprendizaje en las empresas les permite mantenerse competitivas en el mercado. El objetivo de esta investigación es
determinar la relación de significancia entre la calidad y el conocimiento en la innovación de los procesos de producción
en la industria de manufactura en Ciudad Juárez, México. El estudio fue de tipo correlacional, transversal con enfoque
cuantitativo mediante el método de análisis factorial y el modelo de ecuaciones estructurales utilizando la técnica de
encuesta. La muestra fue de 236 cuestionarios válidos aplicados en 30 empresas industriales del sector maquiladora en
la localidad. Los resultados de la prueba de validez convergente mostraron que las variables están correlacionadas y que
conforme los valores de la varianza media extraída la correlación es fuerte. Con los indicadores de bondad de ajustes se
obtuvo que lo observado en los datos corresponde con lo que se propuso en el modelo. La relación entre calidad, conocimiento
e innovaciones es positiva y significativa, por lo que la hipótesis de investigación no se rechaza. Las estrategias
que se implementen para mejorar la calidad y gestionar el conocimiento pueden tener un efecto positivo en el desarrollo
de las innovaciones de proceso.//Quality consists of the standardization of manufacturing processes, the establishment of controls in operations and continuous improvement, in turn,
knowledge promotes process innovation, so the constant learning in companies allows them to stay competitive in the market. The objective of this research
is to determine the relationship of significance between quality and knowledge in the innovation of production processes in the manufacturing industry in
Ciudad Juarez, Mexico. The study was correlational, cross-sectional with a quantitative approach using the factor analysis method and the modeling of
structural equations using the survey technique. The sample was 236 valid questionnaires applied in 30 industrial companies in the maquiladora sector
in the locality. The results of the convergent validity test showed that the variables are correlated and that according to the values of the average variance
extracted the correlation is strong, likewise with the indicators of goodness-of-fit was obtained the degree to which the model predicts the correlations, in
this case, what is observed in the data corresponds to some extent to what was proposed in the model. The relationship between quality, knowledge and
innovations is positive and significant, so the research hypothesis is not rejected. Strategies implemented to improve quality and manage knowledge have a
positive effect on the development of process innovations
Copper Indium Sulfide Quantum Dots as Nanomanometers: Influence of Size and Composition
Mechanical forces control the function of organisms and mediate theinteraction between biological systems and their environments. Knowledge ofthese forces will increase the understanding of biological processes and cansupport the development of novel diagnostic and therapeutic procedures.Although techniques like atomic force microscopy and droplet insertionmethod allow measuring forces over a broad range of values, they are invasiveand lack versatility. A promising way to overcome these hurdles isluminescent nanomanometry. Quantum dots (QDs) specifically have opticalproperties that depend on their size because of the quantum confinement,which makes them responsive to applied forces. Yet, a fine understanding ofhow fundamental parameters affect the response to applied stress is requiredbefore a QD family can be credibly proposed as luminescentnanomanometers. Here, a thorough study is conducted on how size andstoichiometry affect the nanomanometry performance of CuInS2QDs. Thestudied QDs feature pressure-dependent photoluminescence in thered/near-infrared range, which can enable the measurement of mechanicalforces in the range of physiological relevance in a remote and minimallyinvasive way. It is shown that tuning size and stoichiometry cansimultaneously enhance the CuInS2QDs’ brightness and response to appliedpressure, thus providing guidelines for better luminescent nanomanometers
Optical Temperature Sensor Capabilities of the Green Upconverted Luminescence of Er3+ in La3NbO7 Ceramic Powders
We present a study of the Er3+ upconverted luminescence in erbium doped Lanthanum
Niobium Oxide, La3NbO7, ceramic powder, prepared by solid state reaction. This study focuses
on the analysis of the feasibility of this system as a temperature sensor. Efficient UC luminescence
was observed under the 975 nm excitation showing intense green, red and NIR (850 nm) emission
bands. The NIR luminescence centred at about 850 nm and lying on the first biological window is
mainly insensitive to the temperature. In contrast, the upconverted green bands, associated with
the (2H11/2,4S3/2) !4I15/2 transitions, showed a high sensibility to temperature. Their temperature
dependence was studied from RT up to 525 K, paying special attention to the physiological range of
temperature (303–318 K). The high thermal sensitivities obtained, in comparison with other Er3+ and
Er3+-Yb3+ based optical temperature sensors in such ranges, suggest the potential application of this
phosphor in thermal sensing, suitable for both biological systems and other industrial applications
requiring higher temperatures.This research has been partially supported by the Spanish Ministerio de Ciencia, Innovación
y Universidades (MICINN) through the Spanish projects RTI2018-101020-B-100 and PID2019-
106383GB-C44, by the Madrid Government (Comunidad de Madrid-Spain) under the Multiannual
Agreement with UC3Min the line of Excellence of University Professors (EPUC3MXX) and in the context
of the V PRICIT (Regional Programme of Research and Technological Innovation) by the Agencia
Canaria de Investigación, Innovación y Sociedad de la Información (ACIISI) (ProID2017010078).
M.A.H.-R. thanks MINECO for the FPI grant (BES-2014-068666). U.R.R.-M.
thanks Gobierno de Canarias and EU-FEDER for grant ProID2020010067
Accelerated and natural carbonation of concretes with internal curing and shrinkage/viscosity modifiers
Abstract In many parts of the world, corrosion of reinforcing steel in concrete induced by carbonation of the concrete continues to be a major durability concern. This paper investigates the accelerated and natural carbonation resistance of a set of seven concretes, specifically evaluating the effects of internal curing and/or shrinkage/viscosity modifiers on carbonation resistance. In addition to five different ordinary portland cement (OPC) concretes, two concretes containing 20 % of a Class F fly ash as replacement for cement on a mass basis are also evaluated. For all seven concrete mixtures, a good correlation between accelerated (lab) and natural (field) measured carbonation coefficients is observed. Conversely, there is less correlation observed between the specimens’ carbonation resistance and their respective 28 days compressive strengths, with the mixtures containing the shrinkage/viscosity modifier specifically exhibiting an anomalous behavior of higher carbonation resistance at lower strength levels. For both the accelerated and natural exposures, the lowest carbonation coefficients are obtained for two mixtures, one containing the shrinkage/viscosity modifier added in the mixing water and the other containing a solution of the same admixture used to pre-wet fine lightweight aggregate. Additionally, the fly ash mixtures exhibited a significantly higher carbonation coefficient in both exposures than their corresponding OPC concretes
High performance reinforced concrete, corrosion – resistant into aggressive industrial environments
Reinforced concrete structures exposed to aggressive industrial environments suffer different accelerated deterioration mechanisms. In chlor-alkali production plants, the industrial environment contains high concentrations of carbonates and chlorides, damaging the structures and causing constant stoppages and repair processes on the structure of reinforced concrete. In this study, the effect of using internal curing on high performance concrete with low water/binder ratios was
studied, implementing pumicite as internal curing agent, chemical additives and replacing Portland cement with pulverized fly ash. Durability measurements conducted were permeability of chloride ions, and carbonation depth under industrial andlaboratory conditions. Results showed that there is a reduction of the aggressive agents transport mechanisms when internal curing is applied. However, measurements at long ages must be done to evaluate the synergistic effect of the agents contained
in the industrial environment on the metal reinforcement
Optical nanothermometer based on the calibration of the Stokes and upconverted green emissions of Er3+ ions in Y3Ga5O12 nano-garnets
The temperature-dependent green luminescence of Y3Ga5O12 nano-garnets doped with different concentrations of Er3+ ions has been measured from 300 to 850 K and, in more detail, in the biological range from 292 to 335 K. The green emissions were obtained by excitation under 488 nm blue or 800 nm near-infrared laser radiations. Both excitations give rise to bright green luminescence that can be seen by the naked eye, and which can be associated either with Stokes processes, i.e. multiphonon relaxations followed by green spontaneous emission, in the former case or with infrared-to-visible upconversion processes in the latter. The temperature-induced changes in the Er3+ green emissions have been calibrated for both excitations and results point to a strong dependence on the concentration of optically active Er3+ ions. The maximum value of the thermal sensitivity, 64 × 10−4 K−1 at 547 K, has been obtained for the nano-garnets doped with the lowest concentration of Er3+ ions, which is one of the highest values found in the literature. These results allow to conclude that a relatively low concentration of optically active ions is advisable and the changes induced by temperature on the green emissions are independent of the laser excitation radiation used, which is necessary to calibrate the temperature of the immediate environment of the Er3+-doped Y3Ga5O12 nano-garnets.This work have been partially supported by Ministerio de
Economía y Competitividad de España (MINECO) under The
National Program of Materials (MAT2010-21270-C04-02/-03,
and MAT2013-46649-C4-3-P/-4-P), The Consolider-Ingenio
2010 Program (MALTA CSD2007-00045), and the Indo-
Spanish Joint Programme of Cooperation in Science and
Technology (PRI-PIBIN-2011-1153/DST-INT-Spain-P-38-11),
and by the EU-FEDER funds. V. Venkatramu is also grateful to
Council of Scientific and Industrial Research (CSIR), New
Delhi for the sanction of major research project (No.
03(1229)/12/EMR-II, dated: 16th April, 2012). V. Monteseguro
wishes to thank MICINN for the FPI grant (BES-2011-
044596)
Software de Aplicación Portable como herramienta comprobatoria de las medidas de dispersión para datos no agrupados en la Estadística Descriptiva
Dispersion measures indicate the variability of the data in a distribution, showing by means of a value, how spread are the data of a sample space. The understanding of dispersion measures allows us to know if the data are similar or have significant variations. This article intends to contribute to the realm of knowledge a portable application developed using the C/C++ programming language, in order to contribute with obtaining results for non-grouped data through Computational Science.Las medidas de dispersión indican la variación de los datos de una distribución, mostrando por medio de un valor, que tan alejados están los datos de un espacio muestral. Conocer las medidas de dispersión permite saber si los datos son parecidos o tienen variaciones significativas. Este artículo, pretende aportar al conocimiento un Software de Aplicación Portable desarrollado con Lenguaje C, a fin de que contribuya con la obtención de resultados para datos no agrupados a través de la Ciencia Computacional
2D Cu(I)‑I Coordination Polymer with Smart Optoelectronic Properties and Photocatalytic Activity as a Versatile Multifunctional Material
This work presents two isostructural Cu(I)-I 2-fluoropyrazine (Fpyz) luminescent
and semiconducting 2D coordination polymers (CPs). Hydrothermal synthesis allows the growth
of P-1 space group single crystals, whereas solvent-free synthesis produces polycrystals. Via
recrystallization in acetonitrile, P21 space group single crystals are obtained. Both show a reversible
luminescent response to temperature and pressure. Structure determination by single-crystal X-ray
diffraction at 200 and 100 K allows us to understand their response as a function of temperature.
Applying hydrostatic/uniaxial pressure or grinding also generates significant variations in their
emission. The high structural flexibility of the Cu(I)-I chain is significantly linked to the
corresponding alterations in structure. Remarkably, pressure can increase the conductivity by up to 3 orders of magnitude. Variations
in resistivity are consistent with changes in the band gap energy. The experimental results are in agreement with the DFT
calculations. These properties may allow the use of these CPs as optical pressure or temperature sensors. In addition, their behavior
as a heterogeneous photocatalyst of persistent organic dyes has also been investigatedThanks to Micro and Nanotechnology Institute CNM-CSIC
for SEM images. Thanks to the SCXRD laboratory of the
Interdepartmental Research Service and to Servicios Generales
de Apoyo a la Investigación (SEGAI) at La Laguna University.
This work has been supported by MCINN/AEI/ 10.13039/
5011000011033 under the National Program of Sciences and
Technological Materials, PID2019-108028GB-C22, PID2019-
106383GB-C41/C44, and TED2021-131132B-C22. Thanks to
Gobierno d e Canarias and EU-FEDER (grant:
ProID2020010067). This study forms part of the Advanced
Materials program and was supported by MCIN with funding
from European Union Next Generation EU (PRTR-C17.I1)
and by Generalitat Valenciana (grant MFA/2022/007 and
PROMETEO CIPROM/2021/075-GREENMAT). A.L.
(R.T.) and D.E. thank the Generalitat Valenciana for the
Ph.D. (Postdoctoral) Fellowship No. GRISOLIAP/2019/025
(CIAPOS/2021/20). J.C.G. and R. W. acknowledge the
support from the Spanish Ministry of Science and Innovation
(RTI2018-097508-B-I00, PID2021-128313OB-I00, TED2021-
131018B-C22) and the Regional Government of Madrid
through projects NMAT2D-CM (S2018/NMT-4511). J.C.G.
acknowledges support from the Regional Government of
Madrid through “Proyectos Sinérgicos de I + D” (grant
Y2018/NMT-5028 FULMATEN-CM) and NANOCOV-CM
(REACT-UE). IMDEA Nanociencia acknowledges support
from the Severo Ochoa Programme for Centres of Excellence
in R&D (MINECO, grant CEX2020-001039-S
Cunning defects: Emission control by structural point defects on Cu(i)I double chain coordination polymers
The following version is an accepted manuscript in Journal of Materials Chemistry C 8.4 (2020): 1448-1458 and may be found at ttps://doi.org/10.1039/C9TC05185FThe direct reaction between CuI and 3,5-dichloropyridine, in acetonitrile at room temperature, gives rise to [Cu(Cl2-py)I]n (Cl2-py = 3,5-dichloropyridine), which consists of a Cu(i)-I double chain based coordination polymer (CP) grafted with 3,5-dichloropyridine. In this simple one-pot process, the modulation of the reaction conditions, i.e. slight variations in the CuI and Cl2-py ratio caused by in situ disproportion, can, however, produce significant changes in the physical properties of the materials. For instance, the reaction carried out in a 1 : 1 ratio under ambient conditions leads to compound 1, while compound 1′ is obtained upon a solvothermal process of stoichiometric reaction mixture, Cl2-py and CuI, which produces partial disproportion (<0.5% in weight) of the initial Cu(i). Interestingly, compounds 1 and 1′ show an identical chemical composition and structure as determined by both single crystal and powder X-ray diffraction. However, they display remarkable differences in the luminescence behavior, featuring broad emission bands centered at 515 and 670 nm and associated to photoluminescence quantum yields of 12 and 5% for 1 and 1′, respectively. Density functional theory (DFT) calculations allowed us to rationalize the nature of this rare behavior. This is attributed to structural defects related to the weaker coordination bond present in these structures that provoke the strong red-shifted emissionThe authors thank financial support from the Spanish Ministerio de Economıa y Competitividad (MAT2016-77608-C3-1-P,
MAT2016-75883-C2-2-P, MAT2010-20843-C02-01, CTQ2016-75816-
C2-1P, MAT2016-75586-C4-4-P) and by EU-FEDER funds. JGP
thanks to Servicios Generales de Apoyo a la Investigacion (SEGAI)
at La Laguna University. J. I. M. acknowledges the financial support
by the ‘‘Ramo´n y Cajal’’ Program of MINECO (Grant RYC-2015-
17730) and the EU via the ERC-Synergy Program (Grant ERC-2013-
SYG-610256 NANOCOSMOS). J. C. E. acknowledges the financialsupport by the ‘‘FPI-MINECO’’ Program of MINECO (Grant BES2015-071534). R. D. C. acknowledges the program ‘‘Ayudas para la
atraccio´n de talento investigador—Modalidad 1 of the Consejerı´a de Educacio´n, Juventud y Deporte—Comunidad de
Madrid with the Reference No. 2016-T1/IND-1463.’’, Spanish
MINECO for the Ramo´n y Cajal program (RYC-2016-20891), the
Europa Excelencia program (ERC2019-092825), and HYNANOSC (RTI2018-099504-A-C22). R. D. C. also acknowledges the
2018 Leonardo Grant for Researchers and Cultural Creators
from BBVA Foundation and the FOTOART-CM project funded
by Madrid region under programm P2018/NMT-4367. J. F.-C.
acknowledges the Marie Skłodowska-Curie Individual Fellowships (H2020-MSCA-IF-2017). This paper is dedicated to Dmitri
Mendele´yev in honour of the 150th anniversary of the discovery
of the periodic tabl