Engineered Inks for Environment-Friendly Additive Manufacturing of Hierarchical Microstructures

Novel material synthesis and green engineering innovations in manufacturing are important enablers of new technologies. Here, a range of functional materials systems and their processing through additive manufacturing are investigated. The materials studied consist of Ag, ZnO and TiO2 based inks for additive manufacturing with potential application across multiple technological fields.;In particular, the synthesis of multi-functional emulsion inks, and their deposition through continuous-flow direct writing are investigated. Highlights of this work include the study of the curing/sintering conditions of such ink systems aiming for fundamental insights in their synthesis at low-temperatures (below 150°C), compatible with flexible polymeric substrates. Also, the investigation of texturing and microstructural control via ink composition, direct writing conditions and curing/sintering treatments is reported. In addition, the design and investigation of hybrid (organic/inorganic) multiphase composite ink systems for the realization of planar and 3D printable cellular structures, is discussed. Furthermore, the nucleation or decoration of the latter, via encapsulation of the decorative material and/or their precursors in one of the phases of the synthesized ink is investigated.;Special emphasis is placed on an environmentally-friendly approach for the realization of sustainable inks, aiming for industry-transferable developments. Such approach provides the potential to further additive manufacturing and its utilization in a plethora of technological applications; ranging from energy, to waste management and water cleaning, to biomedical

Tuning the Electrical and Thermal Conductivities of Thermoelectric Oxides through Impurity Doping

Waste heat and thermal gradients available at power plants can be harvested to power wireless networks and sensors by using thermoelectric (TE) generators that directly transform temperature differentials into electrical power. Oxide materials are promising for TE applications in harsh industrial environments for waste heat recovery at high temperatures in air, because they are lightweight, cheaply produced, highly efficient, and stable at high temperatures in air. Ca3Co4O9(CCO) with layered structure is a promising p-type thermoelectric oxide with extrapolated ZT value of 0.87 in single crystal form [1]. However the ZT values for the polycrystalline ceramics remain low of ∼0.1-0.3. In this research, nanostructure engineering approaches including doping and addition of nanoinclusions were applied to the polycrystalline CCO ceramic to improve the energy conversion efficiency.;Polycrystalline CCO samples with various Bi doping levels were prepared through the sol-gel chemical route synthesis of powders, pressing and sintering of the pellets. Microstructure features of Bi doped ceramic bulk samples such as porosity, development of crystal texture, grain boundary dislocations and segregation of Bi dopants at various grain boundaries are investigated from microns to atomic scale. The results of the present study show that the Bi-doping is affecting both the electrical conductivity and thermal conductivity simultaneously, and the optimum Bi doping level is strongly correlated with the microstructure and the processing conditions of the ceramic samples. At the optimum doping level and processing conditions of the ceramic samples, the Bi substitution of Ca results in the increase of the electrical conductivity, decrease of the thermal conductivity, and improvement of the crystal texture. The atomic resolution Scanning Transmission Electron Microscopy (STEM) Z-contrast imaging and the chemistry analysis also reveal the Bi-segregation at grain boundaries of CCO polycrystalline samples. In order to further decrease the thermal conductivity and increase the overall energy conversion efficiency of ceramic samples. The highest ZT value obtained is 0.32 at 973K for Ca and Co site Bi doping. The effect of the nanoinclusions on the performance and the microstructure of CCO were investigated as well

Estructuración de una empresa de consultoría en procesos organizacionales relacionados con la gestión del talento humano, enfocada a las empresas del sector público en Medellín

El problema en cuestión radicó en la importancia del papel que juega el capital humano en las empresas del sector público en Medellín; en consecuencia se aplicó una prueba piloto que permitió conocer algunas falencias en aspectos tan importantes como el clima y la cultura organizacional, la necesidad de conformar equipos de alto rendimiento, el papel de la información como un aspecto importante para generar un cambio dentro de la organización; por eso el objetivo de esta investigación es crear una sociedad que brinde asesoría y consultoría en procesos organizacionales relacionados con la Gestión del Talento Humano, en especial en aquellas falencias detectadas en las empresas del sector público en Medellín; para ello se implementó una metodología orientada a poner en práctica los pasos que permiten la creación de una sociedad; tomando en consideración las propuestas del Plan de Desarrollo Nacional en lo que tiene que ver con el emprendimiento y el empresarismo. Luego de constatar con la prueba piloto las necesidades de las entidades del sector público en Medellín; y considerando que la sociedad A&COPO (S.A.S.) debe aplicar conocimientos en todo lo pertinente al clima y la cultura organizacional, al desarrollo técnico administrativo, a los procesos y procedimientos que orientan la funcionalidad de la sociedad. De igual manera se tuvo en cuenta los resultados alcanzados en la investigación, se procedió a establecer unas conclusiones y recomendaciones.The problem in question lay in the importance of the role of human capital in the public sector enterprises in Medellín, in consequence-piloted yielded information on some weaknesses in key areas such as climate and organizational culture, the need to form high performance teams, the role of information as an important aspect to bring about change within the organization, hence the objective of this research is to create a company that provides consulting advice and related organizational processes Talent Management People, especially those shortcomings identified in the public sector enterprises in Medellín, for it was implemented a methodology aimed to implement the steps that allow the creation of a society, taking into account the proposals of the National Development Plan as it has to do with entrepreneurship and entrepreneurship. After verifying with the pilot the needs of public sector entities in Medellín, and considering that the company A & COPO (SAS) must apply knowledge in all relevant climate and organizational culture, technical development administrative processes and procedures functionality oriented society. Similarly, it took into account the results obtained in the investigation, proceeded to establish some conclusions and recommendations

Use of Transient Time Response as a Measure to Characterize Phononic Crystal Sensors

Phononic crystals are periodic composite structures with specific resonant features that are gaining popularity in the field as liquid sensors. The introduction of a structural defect in an otherwise periodic regular arrangement can generate a resonant mode, also called defect mode, inside the characteristic band gaps of phononic crystals. The morphology, as well as the frequency in which these defect modes appear, can give useful information on the composition and properties of an analyte. Currently, only gain and frequency measurements are performed using phononic crystal sensors. Other measurements like the transient response have been implemented in resonant sensors such as quartz microbalances showing great results and proving to be a great complimentary measure to the gain and frequency measurements. In the present paper, a study of the feasibility of using the transient response as a measure to acquire additional information about the analyte is presented. Theoretical studies using the transmission line model were realized to show the impact of variations in the concentration of an analyte, in this case, lithium carbonate solutions, in the transient time of the system. Experimental realizations were also performed showing that the proposed measurement scheme presents significant changes in the resulting data, indicating the potential use of this measure in phononic crystal sensors. This proposed measure could be implemented as a stand-alone measure or as a compliment to current sensing modalities

Acoustic spectrometer: Resonant sensing platform for measuring volumetric properties of liquid samples

A sensing platform for measuring volumetric properties of liquid samples using phononic crystals is presented in this paper. The proposed sensor concept is based on the transmission of elastic and acoustic waves through solids and liquids respectively to gather relevant information about the properties of the liquid under test. A major difference between this concept and the majority of current resonant sensors, like the well-known quartz crystal microbalance, is that the acoustic spectrometer proposed measures bulk properties and not interfacial properties of the liquid. The sensing platform uses a disposable analyte container to facilitate the measurement of hazardous substances and enable its use in biomedical applications. An electronic characterization system based on the acquisition of three mixed signals was developed to obtain the frequency response of the designed sensor. Finally, experimental and theoretical realizations were performed, using different analytes and showing characteristic transmission features that can be used as measures to determine the physical value speed of sound

Fully-disposable multilayered phononic crystal liquid sensor with symmetry reduction and a resonant cavity

Phononic crystals are artificial structures with unique capabilities to control the transmission of acoustic waves. These novel periodic composite structures bring new possibilities for developing a fundamentally new sensor principle that combines features of both ultrasonic and resonant sensors. This paper reports the design, fabrication and evaluation of a phononic crystal sensor for biomedical applications, especially for its implementation in point of care testing technologies. The key feature of the sensor system is a fully-disposable multi-layered phononic crystal liquid sensor element with symmetry reduction and a resonant cavity. The phononic crystal structure consists of eleven layers with high acoustic impedance mismatch. A defect mode was utilized in order to generate a well-defined transmission peak inside the bandgap that can be used as a measure. The design of the structures has been optimized with simulations using a transmission line model. Experimental realizations were performed to evaluate the frequency response of the designed sensor using different liquid analytes. The frequency of the characteristic transmission peaks showed to be dependent on the properties of the analytes used in the experiments. Multi-layered phononic crystal sensors can be used in applications, like point of care testing, where the on-line measurement of small liquid samples is required

Cavity Resonance Sensor with Disposable Analyte Container for Point of Care Testing

The use of phononic crystals and resonant structures as sensing platforms paves the way to the development of new biomedical technologies. An acoustic sensor with a resonant cavity and a disposable element was investigated in this paper. The sensor consists of seven layers with high acoustic impedance mismatch. The disposable element used was a glass spectrophotometry cuvette and, during the experimentation, it was filled with different liquid analytes showing characteristic transmission features that could be used as measures to differentiate and identify them. Experimental transmission curves were obtained using an electronic characterization system that uses a double sideband modulation technique to acquire valuable information about the structure being analyzed. Simulations using the 1-D transmission line method were performed to support the experimental realizations. The frequency of maximum transmission has been found to be strongly dependent on the speed of sound of the analyte under test

Valoración de mercado de la empresa Ladrillera El Ajizal S.A

Valorar una empresa es cuantificar el valor de mercado del patrimonio, teniendo en cuenta los flujos futuros fondos o flujos de caja libre, traídos al momento del análisis de valoración o al valor presente, con el fin que los dueños, accionistas y/o propietarios puedan realizar los siguientes propósitos: (realizar la compra o venta de una empresa, realizar una fusión o una escisión de una empresa, para medir la gestión administrativa y financiera de sus administradores, o tomar créditos, o cuando uno de los propietarios quiere adquirir una participación de otro quien vende, también es una herramienta de planeación estratégica que sirve para poder visionar la compañía y generar escenarios futuros de inversión, expansión, posicionamiento etc. Existen varios métodos de valoración que se clasifican en Métodos Contables y de Métodos de rentabilidad futura. Entre los métodos contables se pueden mencionar cinco: Valor en Libros, Valor con Ajuste de Activos netos, Valor de Reposición, Valor de liquidación y múltiplos, Estos métodos son relativamente fáciles de utilizar, pero presentan limitaciones. Los métodos asociados a la rentabilidad, a diferencia de los contables, tienen en cuenta la capacidad de la firma para generar riqueza, para producir valor en el futuro, se pueden mencionar: Valor en Bolsa, Flujo de Caja descontados y opciones reales. El método recomendado para hacer la aplicación práctica del modelo de valoración expuesto en este trabajo es el método de Flujo de Caja Libre descontado dado que la ladrillera el Ajizal S.A. es una Compañía en marcha permitiendo valorarla porque sus flujos de caja son el resultado de las entradas y salidas de dinero de la empresa que permiten la reposición del capital de trabajo y activos fijos, atención del servicio a la deuda y reparto de utilidades. El proceso de valoración incluye un análisis minucioso de la actividad macroeconómica del sector que para el año 2011 el cual vislumbra una dinámica positiva que redunda en las posibilidades de expansión y crecimiento de la empresa. Adicionalmente una análisis del proceso productivo actual que en comparación con otras ladrilleras esta medianamente tecnificado, y un análisis de la situación financiera.To appraise a company is to quantify the market value of the patrimony, considering the future cash flows or free cash flows, brought at the time of the analysis of valuation or to the present value, with the propose that the owners and/or shareholders can perform the following actions: (to perform the purchase or sale of a company, to perform a joint or a split of a company, to measure the administrative and financial management, to take credits, or when one of the proprietors wants to acquire a participation of another that sells, also is a tool of strategic planning that serves to be able to forecast and generate different scenes of future investment, expansion, positioning etc. Several valuation methods exist that are classified in Accounting Methods and future profitability Methods. Among the accounting methods five can be mentioned: Carrying Value, Value with Adjustment of Net worth, Value of Replacement, Value of liquidation and multiples. These methods are relatively easy to use, but they present limitations. The methods associated to the profitability, unlike the accounting methods, consider the capacity of the company to generate wealth, to produce future value, can be mentioned: Value in Stock market, discounted Cash Flow and real value. The recommended method to make the application practices of the model of valuation exhibited in this work is the method of Free Cash Flow discounted since the brick maker Ajizal S.A. is an ongoing Company allowing to appraise it because their cash flow is the result of the income and expense of the company that allow the replacement of the capital of work and fixed assets, attention of the service to the debt and distribution of utilities. The appraisal process includes a meticulous analysis of the macroeconomic activity of the sector until the year 2011 which glimpses a positive dynamic that results in expansion possibilities and growth of the company. Additionally, an analysis of the present productive process that in comparison with other brick makers is moderately advanced, and a financial standing analysis

Training on Emotional Intelligence for Caregivers of Patients with Acquired Brain Injury and Cognitive Impairment: A Quasi-Experimental Study

Background: Cognitive-behavioral alterations can occur after an acquired brain injury (ABI). Objectives: To develop and evaluate a synchronous online training program on emotional intelligence (EI) for the caregivers of adult patients with cognitive-behavioral impairment due to ABI. Methods: Quasi-experimental study. Ten caregivers attended a one-month virtual synchronous course about EI. The emotional status of the caregivers was registered one-month-previous and one-month-post program using comparative measures: The Trait Meta-Mood Scale (TMMS-24), the Positive and Negative Affect Schedule (PANAS), Caregiver Burden Interview, the 10-item Connor-Davidson Resilience Scale, and the Emotional Health Survey. Results: After the training course, the favorable changes related to emotional affect measured with the PANAS questionnaire were found; both positive (increase; Mdn = 39.5; effect size −12.79; adjusted variance 95.75) and negative (decrease; Mdn = 14.5; effect size 0.73; adjusted variance 95.50) presented a statistical significance of p < 0.05. The TMMS-24 post-test showed that 90% of the caregivers reported an adequate or excellent emotional repair (p < 0.05; effect size −0.68; adjusted variance 94.75). No other significant differences were found. Conclusions: After this training in EI, the caregivers had a more positive mood and improved aspects of their emotional intelligence, such as emotional regulation. More studies need to be conducted.Partial funding for open access charge: Universidad de Málag