Propuesta para la creación de una microempresa de confección y comercialización de prendas de vestir para hombres y mujeres, especialmente chompas de poliéster y plumón en la ciudad de Ibarra

Crea una microempresa dedicada a la confección y comercialización de chompas de poliéster con plumón (para la población económicamente activa de 18 a 50 años) ubicado en la cuidad de Ibarra, Provincia de Imbabura.El presente trabajo tiene como objetivo la propuesta para la creación de una microempresa de confección y comercialización de prendas de vestir para hombres y mujeres, con el fin de colaborar en el sector manufacturero con la producción de chompas con características similares a las provenientes de los países vecinos, además de reducir el contrabando de este tipo de prenda se pretende reducir al intermediario estos productos para que no se realcen los precios de venta. Para la realización del estudio se utilizó encuestas, entrevistas y fuentes bibliográficas. En el diagnostico situacional se identificó los aspectos demográficos, situación económica, fuerzas competitivas, factores legales y factores tecnológicos. En el cual se pudo identificar al número de habitantes, la población económicamente activa (80482 entre hombres y mujeres). En el marco teórico contienen las bases teóricas que fueron recopiladas de fuentes bibliográficas, que sustente los argumentos y análisis del presente estudio. Al realizar el estudio de mercado se identificó un 87% de aceptación de las prendas que se producirán; la demanda es de 720 chompas mensuales y el precio de producción por cada chompa es de $10.22 se determinó el precio de venta al por mayor de$17.50 y al por menor de $25 en donde se consideró los precios de la competencia. En lo referente al estudio técnico el mismo que permitió determinar la mejor ubicación del proyecto mediante un análisis de macro y micro localización, así también se determinó la inversión necesaria para poner en marcha el proyecto ($10554.88) el financiamiento se realizara por medio de la institución financiera BanEcuador. En cuanto al financiamiento se puedo determinar que la microempresa cuenta con los ingresos suficientes para solventar los costos y gastos y generar utilidades mediante la aplicación de índices financieros se confirmó la rentabilidad del proyecto. También se estableció la estructura organizacional con el nombre confecciones Rs y su respectivo eslogan estableciendo los manuales de funciones. Por último, se realizó un análisis de los posibles impactos que se generaran con la implementación del proyecto entre los cuales se consideró los impactos económicos y ambientales debido a su influencia tanto interna y externa en donde se determinó que el proyecto posee un impacto medio positivo.Ingenierí

Elastic tunneling charge transport mechanisms in silicon quantum dots / SiO2 thin films and superlattices

The role of different charge transport mechanisms in Si /SiO2 structures has been studied. A theoretical model based on the Transfer Hamiltonian Formalism has been developed to explain experimental current trends in terms of three different elastic tunneling processes: (1) trap assisted tunneling; (2) transport through an intermediate quantum dot; and (3) direct tunneling between leads. In general, at low fields carrier transport is dominated by the quantum dots whereas, for moderate and high fields, transport through deep traps inherent to the SiO 2 is the most relevant process. Besides, current trends in Si /SiO2 superlattice structure have been properly reproduced

Understanding the twist-bend nematic phase: the characterisation of 1-(4-cyanobiphenyl-4'-yloxy)-6-(4-cyanobiphenyl-4'--yl)hexane (CB6OCB) and comparison with CB7CB

The synthesis and characterisation of the nonsymmetric liquid crystal dimer, 1-(4-cyanobiphenyl-40-yloxy)-6- (4-cyanobiphenyl-40-yl)hexane (CB6OCB) is reported. An enantiotropic nematic (N)–twist-bend nematic (NTB) phase transition is observed at 109 1C and a nematic–isotropic phase transition at 153 1C. The NTB phase assignment has been confirmed using polarised light microscopy, freeze fracture transmission electron microscopy (FFTEM), 2H-NMR spectroscopy, and X-ray diffraction. The effective molecular length in both the NTB and N phases indicates a locally intercalated arrangement of the molecules, and the helicoidal pitch length in the NTB phase is estimated to be 8.9 nm. The surface anchoring properties of CB6OCB on a number of aligning layers is reported. A Landau model is applied to describe high-resolution heat capacity measurements in the vicinity of the NTB–N phase transition. Both the theory and heat capacity measurements agree with a very weak first-order phase transition. A complementary extended molecular field theory was found to be in suggestive accord with the 2H-NMR studies of CB6OCB-d2, and those already known for CB7CB-d4. These include the reduced transition temperature, TNTBN/TNI, the order parameter of the mesogenic arms in the N phase close to the NTB–N transition, and the order parameter with respect to the helix axis which is related to the conical angle for the NTB phase.Postprint (published version

A transfer Hamiltonian model for devices based on quantum dot arrays

We present a model of electron transport through a random distribution of interacting quantum dots embedded in a dielectric matrix to simulate realistic devices. The method underlying the model depends only on fundamental parameters of the system and it is based on the Transfer Hamiltonian approach. A set of noncoherent rate equations can be written and the interaction between the quantum dots and between the quantum dots and the electrodes is introduced by transition rates and capacitive couplings. A realistic modelization of the capacitive couplings, the transmission coefficients, the electron/hole tunneling currents, and the density of states of each quantum dot have been taken into account. The effects of the local potential are computed within the self-consistent field regime. While the description of the theoretical framework is kept as general as possible, two specific prototypical devices, an arbitrary array of quantum dots embedded in a matrix insulator and a transistor device based on quantum dots, are used to illustrate the kind of unique insight that numerical simulations based on the theory are able to provide

Transport in quantum dot stacks using the transfer Hamiltonian method in self-consistent field regime

The non-coherent rate equation approach to the electrical transport in a serial quantum dot system is presented. The charge density in each quantum dot is obtained using the transfer Hamiltonian formalism for the current expressions. The interactions between the quantum dots and between the quantum dots and the electrodes are introduced by transition rates and capacitive couplings. Within this framework analytical expressions for the current and the charge in each quantum dot are presented. The effects of the local potential are computed within the self-consistent field regime. Despite the simplicity of the model, well-known effects are satisfactorily explained and reproduced. We also show how this approach can be extended into a more general case

Conductive 3D printed PLA composites: On the interplay of mechanical, electrical and thermal behaviours

Additive manufacturing (AM) techniques represent a real challenge to manufacture novel composites with cou- pled multifunctional properties. This work focuses on the mechanical, electrical and thermal behaviours of 3D printed polymeric composites of polylactic acid (PLA) filled with carbon black (CB) conductive particles. The incorporation of conductive particles within the polymer matrix allows for programmable conduction paths via the printing process, whose electric properties are intimately coupled to thermo‐mechanical processes. In this study, samples were prepared using a fused deposition modelling (FDM) printer, controlling the filament ori- entation to manufacture three different types: longitudinal (0°); transverse (90°); oblique (±45°) printing ori- entations. Different types of multifunctional characterisation have been made: (i) electro‐thermal tests, evaluating the influence of electrical conductivity on the sample temperature due to Joule’s heating; (ii) thermo‐electrical tests, analysing the influence of temperature on the DC resistance of the samples; (iii) mechano‐electrical tests, analysing the effect of mechanical deformation on the specimens’ electric resistance. The results show a strong dependence of printing direction on the material properties of 3D printed conductive‐ PLA and identify strong thermo‐electro‐mechanical interplays. The results of this work will contribute to the AM progress in functional electro‐mechanical components with potential applications in biosensing devices, composite sensors, 3D electrodes and soft robotic industry.The authors acknowledge financial support from Ministerio de Ciencia, Innovación y Universidades, Spain, Agencia Estatal de Inves- tigación y Fondo Europeo de Desarrollo Regional, Spain, under Grant number RTI2018‐094318‐BI00. D.G.‐G., S.G.‐H. and A.A. acknowledge support from Programa de Apoyo a la Realización de Proyectos Inter- disciplinares de I + D para Jóvenes Investigadores de la Universidad Carlos III de Madrid (BIOMASKIN‐CM‐UC3M). D.G.‐G. acknowledges support from the Talent Attraction grant (CM 2018 ‐ 2018‐T2/ IND9992) from the Comunidad de Madrid, Spain. Some tests were made in the High Voltage Research and Test Laboratory (LINEALT) at UC3M

Broadband Dielectric Spectroscopy Study of Biobased Poly(alkylene 2,5-furanoate)s’ Molecular Dynamics

Abstract Poly(2,5-alkylene furanoate)s are bio-based, smart, and innovative polymers that are considered the most promising materials to replace oil-based plastics. These polymers can be synthesized using ecofriendly approaches, starting from renewable sources, and result into final products with properties comparable and even better than those presented by their terephthalic counterparts. In this work, we present the molecular dynamics of four 100% bio-based poly(alkylene 2,5-furanoate)s, using broadband dielectric spectroscopy measurements that covered a wide temperature and frequency range. We unveiled complex local relaxations, characterized by the simultaneous presence of two components, which were dependent on thermal treatment. The segmental relaxation showed relaxation times and strengths depending on the glycolic subunit length, which were furthermore confirmed by high-frequency experiments in the molten region of the polymers. Our results allowed determining structure–property relations that are able to provide further understanding about the excellent barrier properties of poly(alkylene 2,5-furanoate)s. In addition, we provide results of high industrial interest during polymer processing for possible industrial applications of poly(alkylene furanoate)s.This research was funded by the European Union: EUSMI, H2020-INFRAIA-2016-1, PROJECT 731019, via proposals E171100043 and E171100040. The APC was funded by EUSMI. B.R.-H. and A.A. acknowledge funding from Basque Government (IT-1175-19). D.E.M.-T. acknowledges financial support via the postdoctoral fellowship “Juan de la Cierva–Incorporación” grant (IJCI-2017-31600, MCIU–Spain). G.G., M.S. and N.L. and A.M. acknowledge financial support via the framework COST Action FUR4Sustain, CA18220, supported by COST (European Cooperation in Science and Technology)

A transfer Hamiltonian approach for an arbitrary quantum dot array in the self-consistent field regime

A transport methodology to study electron transport between quantum dot arrays based on the transfer Hamiltonian approach is presented. The interactions between the quantum dots and between the quantum dots and the electrodes are introduced via transition rates and capacitive couplings. The effects of the local potential are computed within the self-consistent field regime. The model has been developed and expressed in a matrix form in order to make it extendable to larger systems. Transport through several quantum dot configurations has been studied in order to validate the model. Despite the simplicity of the model, well-known effects are satisfactorily reproduced and explained. The results qualitatively agree with other results obtained using more complex theoretical approaches

Diseño y construcción de un prototipo de sistema para pasteurizar leche utilizando fluidos geotérmicos de baja entalpía

Se realizó el diseño y construcción de un prototipo de sistema pasteurizador de leche que aprovecha el calor proveniente de los fluidos geotérmicos de baja entalpía, para realizar dicho tratamiento térmico, que tiene como objetivo reducir la presencia de agentes patógenos que pueden estar presentes en la leche cruda, y de ésta manera obtener un producto que sea apto para el consumo humano, además de aumentar su vida útil en refrigeración, o que pueda ser destinada de manera segura al procesamiento lácteo, alternando lo menos posible su estructura física, sus componentes químicos y sus propiedades organolépticas. A partir de esto, se realizó selección de los materiales y elementos constituyentes del diseño del sistema pasteurizador de leche, aplicando lo referente al marco normativo que a esta aplicación específica concierne, por lo que fue necesario la recopilación de normas alimenticias teniendo en consideración el producto a manipular. Una vez construido el sistema prototipo, se realizaron pruebas en cuanto al funcionamiento del mismo, esto para garantizar que los parámetros establecidos en el proceso de diseño se alcanzara

Electronic transport in QD based structures: from basic parameters to opto-electronic device simulations

We present a theoretical model that explains the optoelectronic response of nanodevices based on large quantum dot (QD) arrays. The model is grounded on rate equations in the self-consistent field regime and it accurately describes the most important part of the system: the tunnel junctions. We demonstrate that the ratio between the optical terms and the transport rates determines the final device response. Furthermore, we showed that to obtain a net photocurrent the QD has to be asymmetrically coupled to the leads