Mechanical and optical properties of ultralarge flakes of a metal-organic framework with molecular thickness

The isolation of 2D-materials is already a success for graphene, graphene oxide, boron nitride and a few clays or metal chalcogenides, however despite the fact that some of them show very interesting physical properties, they lack useful functionalities. Metal-Organic Frameworks (MOFs) are multifunctional materials showing a wide range of physical and chemical properties that can be structurally designed by suitable selection of their building-blocks. This strategy may allow the production of layers with a variety of useful electronic and molecular recognition functionalities. Herein we isolate 2D-MOF flakes with areas of hundreds of square microns and an excellent control of the molecular thickness (from single up to ca. 50 layers). The samples exhibit such good photoluminescence and mechanical properties as to allow free-standing characterization of few layers' flakesThe authors acknowledge financial support from MICINN (MAT2013-46753-C2-1-P and MAT2013-46753-C2-2-P and Consolider CSD2010-00024

Carbon nanotube - Based cold cathodes: Field emission angular properties and temporal stability

The field emission (FE) properties of carbon nanotube (CNT)-based cathodes have been investigated on nanostructured surfaces grown by plasma enhanced chemical vapor deposition. The FE angular properties and temporal stability of the emergent electron beam have been determined using a dedicated apparatus for cathodes of various architectures and geometries, characterized by scanning electron microscopy and I-V measurements. The angular electron beam divergence and time instability at the extraction stage, which are crucial parameters in order to obtain high brilliance of FE-based-cathode electron sources, have been measured for electrons emitted by several regular architectures of vertically aligned arrays and critically compared to conventional disordered cathodes. The measured divergences strongly depend on the grid mesh. For regular arrays of individual CNT, divergences from 2° to 5° have been obtained; in this specific case, measurements together with ray-tracing simulations suggest that the maximum emission angle is of the order of ±30° about the tube main axis. Larger divergences have been measured for electron beams emitted from honeycomb-structured cathodes (6°) and significantly broader angle distributions (10°) from disordered CNT surfaces. Emission current instabilities of the order of 1% for temporal stability studies conducted across a medium time scale (hours) have been noted for all cathodes consisting of a high number (10$^{4}$ and larger) of aligned CNTs, with the degree of stability being largely independent of the architecture.The European AXIS project (FP7-SME-1-2007) is acknowledged for financial support

Light-induced reversible modification of the work function of a new perfluorinated biphenyl azobenzene chemisorbed on Au (111)

This work was financially supported by EC through the Marie-Curie ITN SUPERIOR (PITN-GA-2009-238177) and IEF MULTITUDES (PIEF-GA-2012-326666), the ERC project SUPRAFUNCTION (GA-257305), the Agence Nationale de la Recherche through the LabEx project Chemistry of Complex Systems (ANR-10-LABX-0026_CSC), and the International Center for Frontier Research in Chemistry (icFRC). The work in Mons is further supported by the Interuniversity Attraction Poles Programme (P7/05) initiated by the Belgian Science Policy Office, and by the Belgian National Fund for Scientific Research (FNRS). J.C. is an FNRS research director. The synthesis team in Switzerland acknowledges financial support by the Swiss National Science Foundation (SNF) and the Swiss Nanoscience Institute (SNI)

Electrical release of dopamine and levodopa mediated by amphiphilic \u3b2-cyclodextrins immobilized on polycrystalline gold

Vesicles of cationic amphiphilic \u3b2-cyclodextrins have been immobilized on polycrystalline gold by exploiting the chemical affinity between their amino groups and Au atoms. The presence of cyclodextrins has been widely investigated by means of AFM, XPS, kelvin probe and electrochemical measurements. This multi-functional coating confers distinct electrochemical features such as pH-dependent behavior and partial/total blocking properties towards electro-active species. The host-guest properties of \u3b2-cyclodextrins have been successfully exploited in order to trap drugs, like dopamine and levodopa. The further release of these drugs was successfully achieved by providing specific electrical stimuli. This proof-of-concept led us to fabricate an electronic device (i.e. an organic transistor) capable of dispensing both dopamine and levodopa in aqueous solution

Creating and Using Learning Objects in Qualitative Research Education

Based upon the lessons learned and the educational materials generated from a doctoral course on qualitative data analysis, a group of doctoral students, their professor, and a linguistics consultant launched an on- going project to create a series of reusable learning objects designed to help other groups of students and professors learn how to analyze qualitative data. The results of the first six months of this project are shared, as the team describes how they have begun to use instructional design and software applications to create a digital learning environment in the form of a series of activities engineered to help analysts learn how to master grounded theory open codin

Design development and assessment of a multi-interface IoT platform

LAUREA MAGISTRALEInternet of Things è la rete degli oggetti fisici che contengono tecnologia embedded utilizzata per comunicare, avvertire o interagire con i loro stati interni o con l'ambiente esterno. Tutti gli oggetti dunque possono potenzialmente acquisire un ruolo attivo grazie al collegamento alla Rete. Questo lavoro di tesi propone un prototipo di rete basato su Contiki e su 6LoWPAN che implementa un nodo border-router multi-interfaccia utilizzabile nel mondo dell'Internet of Things (IoT). Tale prototipo vuole aprire nuovi scenari di interoperabilità tra i nodi di una rete WSN, la quale sarebbe così svincolata dall'avere una sola interfaccia di comunicazione tra nodi. Possibili scenari di utilizzo comprendono la domotica e l'ambito industriale, nei quali il nodo border-router raccoglierebbe ed instraderebbe il traffico dati di diverse sottoreti, ognuna afferente una tecnologia di comunicazione differente. In questa tesi sono state studiate le differenti problematiche afferenti questo prototipo di rete, quali la configurazione dei nodi e i meccanismi di instradamento dei pacchetti. La soluzione proposta: - è stata implementata su Contiki, l'OS standard de-facto nel mondo dei dispositivi low-power/memory-constrained dell'IoT - è basata sul protocollo 6LoWPAN, lo standard IETF che introduce l'utilizzo dell'IPv6 nell'IoT - sfrutta e integra i protocolli di routing e le strutture dati già esistenti nell'OS - è scalabile: è possibile aggiungere al border-router un numero arbitrario di interfacce senza dover apportare modifiche al kernel - è stata testata in un caso reale di utilizzo, cioè in una rete che sfrutta due tecnologie di comunicazione: una radio sub-1 GHz RF ed un powerline modem - introduce un basso overhead sul footprint del programma - ha basso impatto sulle performance generali del sistemaThe Internet of Things is the network of physical objects that contain embedded technology to communicate and sense or interact with their internal states or the external environment. Any object can thus become interactive thanks to the internet. This master thesis project proposes a network prototype Contiki-based and 6LoWPAN-based that implements a multi-interface Border-Router that can be used in some Internet of Things (IoT) scenarios. This prototype wants to enable new interoperability scenarios among nodes belonging to a WSN, which would be allowed to utilize more than one communication interface. Possible scenarios include home automation and industrial field, where the border-router node would collect and route different subnets data traffic and where every subnets would utilize a different communication technology. This project analyzes the different issues that arises with this network prototype, such the nodes and network configuration and the packet routing. The proposed solution: - has been implemented in Contiki, the de-facto standard OS for low-power/memory-constrained IoT devices - is based on 6LoWPAN protocol, the IETF's standard that introduces IPv6 in the IoT - uses and integrates the already existing Operating System (OS)'s routing protocols and OS data structures - it's scalable: it's possible to add as many interfaces as needed to the border-router without having to modify the kernel - it has been tested in a real-case scenario, that is in a network based on two communication technologies: a sub-1 GHz RF radio channel and a power-line - introduces a low overhead on the application footprint - has low impact on system general performance

The Scope and Retroactivity of the Honoring American Veterans in Extreme Need “HAVEN” Act in Chapter 7 and Chapter 13 Bankruptcy Cases

(Excerpt) On August 23, 2019, President Donald J. Trump signed the Honoring American Veterans in Extreme Need Act (the “HAVEN Act”). Congress stated that the HAVEN Act’s purpose is to correct an “obvious inequity” in title 11 of the United States Code (the “Bankruptcy Code”) as it relates to veterans. The HAVEN Act is silent as to whether it applies retroactively. Certain courts, however, have explored the idea that it should apply to cases pending as of the HAVEN Act’s enactment. This memorandum analyzes whether the HAVEN Act can be applied retroactively or only to cases filed following its enactment. Part I examines the HAVEN Act itself, Part II examines the legislative history surrounding the HAVEN Act, and Part III examines the Landgraf test and its application to the HAVEN Act

Rheological and physical characterization of PEDOT: PSS/graphene oxide nanocomposites for perovskite solar cells

In this work, the influence of graphene oxide (GO) doped Poly(3,4 ethylenedioxythiophene):poly (styrenesulfonate)(PEDOT:PSS) thin nanocomposite on an indium–tin-oxide (ITO) anode, as hole transport layer (HTL) in perovskite solar cells, was investigated. Different concentrations of GO were added into the PEDOT:PSS in order to enhance its conductivity. In particular, the influence of GO content on the rheological and thermal properties of Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/GO nanocomposites was initially examined. The GO filler was prepared by using modified Hummers method and dispersed into PEDOT:PSS in different quantity (ranging from 0.05 to 0.25 %wt/wt). The obtained nanocomposite solutions were analyzed by rheological characterizations in order to evaluate the influence of the GO filler on the viscosity of the PEDOT:PSS matrix. The wettability of solutions was evaluated by Contact Angle (CA) measurements. The quality of GO dispersion into the polymer matrix was studied using Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Thermal characterizations (DSC and TGA) were, finally, applied on nanocomposite films in order to evaluate thermal stability of the films as well as to indirectly comprehend the GO influence on PEDOT:PSS-water links