Plan de manejo ambiental para mitigar los impactos generados por explotacion minera en el municipio de Nechí en el Bajo Cauca - Región de La Mojana

Trabajo de InvestigaciónEsta investigación propone un Plan de Manejo Ambiental enfocado a la explotación minera, especialmente dirigido al municipio de Nechí – Antioquia (Colombia), lo anterior debido a los problemas y fuertes impactos ambientales y sociales, que se han visto con el pasar del tiempo debido al mal manejo de los procesos necesarios para tal fin.INTRODUCCIÓN 1. ANTECEDENTES 2. PLANTEAMIENTO Y FORMULACION DEL PROBLEMA 3. OBJETIVOS 4. MARCO DE REFERECIA TEORICO 5. MARCO DE REFERECIA CONCEPTUAL 6. CARACTERIZACION DEL TERRITORIO 7. ESTUDIO DE IMPACTO AMBIENTAL E IDENTIFICACION DE PROBLEMAS GENERADOS POR LA EXPLOTACION MINERA 8. DISEÑO PLAN DE MANEJO AMBIENTAL 9. CONCLUSIONES Y RECOMENDACIONES 10. BIBLIOGRAFIAPregradoIngeniero Civi

Nanocellulose/Fullerene Hybrid Films Assembled at the Air/Water Interface as Promising Functional Materials for Photo-Electrocatalysis

Cellulose nanomaterials have been widely investigated in the last decade, unveiling attractive properties for emerging applications. The ability of sulfated cellulose nanocrystals (CNCs) to guide the supramolecular organization of amphiphilic fullerene derivatives at the air/water interface has been recently highlighted. Here, we further investigated the assembly of Langmuir hybrid films that are based on the electrostatic interaction between cationic fulleropyrrolidines deposited at the air/water interface and anionic CNCs dispersed in the subphase, assessing the influence of additional negatively charged species that are dissolved in the water phase. By means of isotherm acquisition and spectroscopic measurements, we demonstrated that a tetra-sulfonated porphyrin, which was introduced in the subphase as anionic competitor, strongly inhibited the binding of CNCs to the floating fullerene layer. Nevertheless, despite the strong inhibition by anionic molecules, the mutual interaction between fulleropyrrolidines at the interface and the CNCs led to the assembly of robust hybrid films, which could be efficiently transferred onto solid substrates. Interestingly, ITO-electrodes that were modified with five-layer hybrid films exhibited enhanced electrical capacitance and produced anodic photocurrents at 0.4 V vs Ag/AgCl, whose intensity (230 nA/cm2) proved to be four times higher than the one that was observed with the sole fullerene derivative (60 nA/cm2)

Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems

A model system for the electrochemical investigation of vectorial electron transfer in biological systems was designed, assembled and characterized. Gold electrodes, functionalized with a -OCH3 terminated, aromatic self-assembled monolayer, were used as a substrate for the adsorption of variants of copper- containing, redox metalloprotein azurin. The engineered azurin bears a polyhistidine tag at its C-terminus. Thanks to the presence of the solvent exposed tag, which chelates Cu2+ ions in solution, we introduced an exogenous redox centre. The different reduction potentials of the two redox centres and their positioning with respect to the surface are such that electron transfer from the exogenous copper centre and the electrode is mediated by the native azurin active site, closely paralleling electron transfer processes in naturally occurring multicentre metalloprotein

Recent Advances on Renewable and Biodegradable Cellulose Nanopaper Substrates for Transparent Light-Harvesting Devices: Interaction with Humid Environment

Cellulose nanopaper (CNP) has attracted much interest during the last decade as a new fascinating renewable and biodegradable substrate for printed electronics and solar cells. Its outstanding optical and mechanical properties make CNP the ideal substrate for the preparation of photovoltaic devices, since its high transparency and haze favour the absorption of light from the active layer of the solar cell. However, some advances need to be done in the direction of increasing CNP stability in humid environment without compromising its remarkable advantages. This review critically points at these aspects, presenting an overview of state-of-art solutions to enhance nanopaper stability in a humid environment

Nanocarta di cellulosa: proprietà e prospettive

Il rinnovato interesse nei confronti della cellulosa affonda le sue basi nella conoscenza approfondita oggi a disposizione sulla sua struttura cristallina e sulle sue proprietà. I film di cellulosa nanocristallina sono trasparenti e flessibili e prendono il nome di nanocarta. Essi potrebbero sostituire altri film plastici in molte applicazioni.The renewed interest towards cellulose comes from the deeper knowledge that is nowadays available about its crystalline structure and its properties. Films of nanocrystalline cellulose are transparent and flexible and are named nanopaper. They could replace other plastic materials films in many applications

Molecular and Supramolecular Architectures of Organic Semiconductors for Field Effect Transistor Devices and Sensors: a Synthetic Chemical Perspective

Organic field-effect transistors (OFETs) are key devices in organic electronics, and their performances largely depend on molecular structure and solid-state organization of the π-conjugated compounds used as semiconductors. This microreview reports several examples of materials for OFET devices and sensors, which have been selected to highlight the basic criteria of molecular design together with the synthetic logic driving the development of organic semiconductors. Versatile synthetic methodologies enable to optimize properties by tailoring molecular structures and functionalization, thus playing a key role in the progress of OFET technology, and more in general of organic electronics, which is emphasized in the discussion

Synthetic Routes to Thiol-Functionalized Organic Semiconductors for Molecular and Organic Electronics

Over the few last decades, the potential of using thiol functionalities to induce the self-assembly of various kinds of molecules on metal surfaces has been widely demonstrated. In particular, π-conjugated molecules can undergo self-assembly on metallic surfaces to create electroactive supramolecular layers, which have found important applications in organic and molecular electronics. For this reason, the synthesis of thiol-functionalized conjugated molecules has been the object of extensive research and many routes have been developed for their synthesis. This Focus Review provides an overview of the state-of-the-art methods for the syntheses of organic semiconductors that are decorated with pendant thiol groups for applications in self-assembly and molecular and organic electronics. Particular attention is given to synthetic strategies based on organometallic cross-coupling reactions for the preparation of compounds with extended conjugation

Impact of chirality on the aggregation modes of L-phenylalanine- and D-glucose-decorated phenylene-thiophene oligomers

The aggregation modes of three L-phenylalanine- or D-glucose-functionalized phenylene-thiophene oligomers have been investigated by UV-Vis absorption and electronic circular dichroism (ECD) spectroscopies in different conditions of solution aggregation and thin films. ECD measurements revealed superior capability to provide information about their first level of supramolecular organization and to detect the possible co-existence of multiple aggregation pathways, very difficult to identify by using only UV-Vis absorption. The impact on the (chiro)optical response of the nature of chiral pendant group, especially in terms of intermolecular hydrogen bonding and steric hindrance, as well as that of the oligothiophene π-conjugated length will be elucidated. The ability to recognize and control different aggregation modes could be very useful for the preparation of thin films of π-conjugated oligomers with highly tunable chiroptical features in view of optical sensing and other innovative opto-electronic application