Mechanical analysis of asphalt mixtures produced with waste plastic modified binders

This work compares the viscoelastic properties of an asphalt binder (70/100 pen) modified with different waste plastics and the mechanical properties of the resultant asphalt mixtures. Two different plastic wastes were used, namely recycled HDPE and EVA. Three different polymer modified binders were produced with these plastic wastes: i) 5% HDPE modified binder (P5); ii) 5% EVA modified binder (E5) and; iii) a modified binder with 4% of EVA and 2% HDPE (E4P2). Asphalt mixtures were produced with these modified binders, and their mechanical properties were analysed and compared with a conventional mixture produced with a 30/50 pen bitumen. It was possible to conclude that these recycled polymers are able to improve the mechanical performance of the asphalt mixtures used in road paving.

Study of the interaction between asphalt and plastic wastes in new polymer modified binders (PMB)

The aim of this study is evaluating the interaction between several base pen grade asphalt binders (35/50, 50/70, 70/100, 160/220) and two different plastic wastes (EVA and HDPE), for a set of new polymer modified binders produced with different amounts of both plastic wastes. After analysing the results obtained for the several polymer modified binders evaluated in this study, including a commercial modified binder, it can be concluded that the new PMBs produced with the base bitumen 70/100 and 5% of each plastic waste (HDPE or EVA) results in binders with very good performance, similar to that of the commercial modified binder.

Probing dispersion and re-agglomeration phenomena upon melt-mixing of polymer-functionalized graphite nanoplates

A one-step melt-mixing method is proposed to study dispersion and re-agglomeration phenomena of the as-received and functionalized graphite nanoplates in polypropylene melts. Graphite nanoplates were chemically modified via 1,3-dipolar cycloaddition of an azomethine ylide and then grafted with polypropylene-graft-maleic anhydride. The effect of surface functionalization on the dispersion kinetics, nanoparticle re-agglomeration and interface bonding with the polymer is investigated. Nanocomposites with 2 or 10 wt% of as-received and functionalized graphite nanoplates were prepared in a small-scale prototype mixer coupled to a capillary rheometer. Samples were collected along the flow axis and characterized by optical microscopy, scanning electron microscopy and electrical conductivity measurements. The as-received graphite nanoplates tend to re-agglomerate upon stress relaxation of the polymer melt. The covalent attachment of a polymer to the nanoparticle surface enhances the stability of dispersion, delaying the re-agglomeration. Surface modification also improves interfacial interactions and the resulting composites presented improved electrical conductivity.

Controlled aggregation of gold nanoparticles in a di-ureasilmatrix. Optical and micro indentation investigation

Nanocomposite materials with an organic-inorganic urea-silicate (di-ureasil) based matrix containing gold nanoparticles (NPs) were synthesized and characterized by optical (UV/Vis) spectroscopy and indentation measurement. The urea silicate gels were obtained by reaction between silicon alkoxyde modified by isocyanate group and polyethylene glycol oligomer with amine terminal groups in presence of catalyst. The latter ensures the successful incorporation of citrate-stabilized gold NPs in the matrix. It is shown that using a convenient destabilizing agent (AgNO3) and governing the preparative conditions, the aggregation degree of gold NPs can be controlled. The developed synthesis procedure significantly simplifies the preparative procedure of gold/urea silicate nanocomposites, compared to the procedure using gold NPs, preliminary covered with silica shells. Mechanical properties of the prepared sample were characterised using depth sensing indentation methods (DSI) and an idea about the type of aggregation structures was suggested.

Rheological characterization of EVA and HDPE polymer modified bitumens under large deformation at 20 º C

Large amplitude oscillatory shear (LAOS) coupled with Fourier transform rheology (FTR) was used for the first time to characterize the large deformation behavior of selected bituminous binders at 20 C. Two polymer modified bitumens (PMB) containing recycled EVA and HDPE and two unmodified bitumens were tested with LAOS-FTR. The LAOS-FTR response of all binders was compared at same frequency, at same Deborah number (by tuning the frequency to the relaxation time of each binder) and at same phase shift angle d (by tuning the frequency to the one corresponding to d = 50 in the SAOS response of each sample). In all the approaches, LAOS-FTR results allowed to differentiate between all the nonlinear mechanical characteristics of the tested binders. All binders show LAOS-FTR patterns reminiscent from colloidal dispersions and emulsions. EVA PMB was less prone to strain-induced microstructural changes when compared to HDPE PMB which showed larger values of nonlinear FTR parameters for the range of shear strains tested in LAOS.

On modified simple reacting spheres kinetic model for chemically reactive gases

Versão dos autores para esta publicação.

Diseño y desarrollo de superficies modificadas. Aplicaciones ambientales, biomédicas y farmacéuticas. Design and development of modified surfaces. Environmental, biomedical and pharmaceutical applications.

El objetivo general de este proyecto de investigación es diseñar, desarrollar y optimizar superficies con propiedades especificas para ser utilizadas como sensores y biosensores, materiales biocompatibles, columnas para separaciones por electroforesis capilar, matrices para la liberación controlada de fármacos y sorbentes para remediación ambiental. Para concretar este objetivo, se propone específicamente modificar superficies o particulas apuntando a optimizar un sistema concreto relevante en aplicaciones farmaceuticas, ambientales o biomedicas: 1. Modificacion de arcillas naturales o sinteticas para desarrollar matrices portadoras de farmacos o sorbentes para remediacion ambiental:1.1 Estudiar ilitas modificadas con Fe(III) para maximizar las propiedades adsortivas frente a aniones contaminantes como arsenico. 1.2 Sintetizar LDH de Al y Mg modificados con compuestos de interés farmacéutico para diseñar sistemas de liberación controlada.2. Modificación de canales de chips y electrodos para optimizar la separación, detección y cuantificación de compuestos farmacéutico: 2.1 Diseñar y construir microchips para la separación por EC de compuestos de base fenólica.2.2 Evaluar polímeros que mejoren la respuesta y/o estabilidad de electrodos de Carbono para ser usados como detectores amperométrico de compuestos de base fenólica en sistemas FIA y miniaturizados de análisis integrados.3. Modificación de superficies sólidas con biomoléculas para el desarrollo y optimización de superficies de bio-reconocimiento:3.1 Evaluar el comportamiento de superficies de titanio modificadas con TiO2 y depósitos inorgánicos frente a la interacción con proteínas plasmáticas (PP) para el análisis de la biocompatibilidad superficial.3.2 Diseñar y desarrollar superficies biofuncionales para el reconocimiento especifico de D-aminoácidos, anticuerpos en pacientes chagásicos y simple hebra de ADN. Las técnicas que se emplearán para llevar a cabo el proyecto dependen del tipo de sistema de estudio. En particular los estudios correspondientes al objetivo 1 se realizarán mediante análisis químicos, térmico, DXR, SEM, IR, BET así como mediante titulaciones ácido-base potenciométricas, movilidades electroforéticas, cinética e isotermas de adsorción.En general para desarrollar el objetivo 2 se utilizarán técnicas electroquímicas clásicas para la caracterización de los electrodos, los que luego se utilizarán como detectores en un sistema FIA amperométrico, mientras que los microchips se emplearán en electroforesis capilar para la separación de diferentes compuestos de interés farmacéutico.Finalmente, el objetivo 3 se llevará a cabo por un lado modificando electrodos de titanio con distintos depósitos (electroquímicas, sol-gel, térmicas) de TiO2 e hidroxiapatita y evaluando la interacción con proteínas plasmáticas para analizar la biocompatibilidad de los materiales preparados. Por otro lado, se estudiará el proceso de adsorción-desorción de D-aminoácido oxidasa, antígenos del T. Cruzi y ADN de simple hebra para optmizar la capacidad de bio-reconocimiento superficial de D-aminoácidos, anticuerpos de chagásicos y de cadena complementaria de ADN. Para concretar este objetivo se utilizarán técnicas electroquímicas, espectroscópicas y microscopias.Debido al carácter multidisciplinario del presente proyecto de investigación, su ejecución se llevara a cabo a través de la colaboración de investigadores pertenecientes a distintas áreas de la Química y permitirá continuar con la formación de recursos humanos mediante la realización de tesis doctorales y estadías postdoctorales.

Flow and transport in electrochromatography

Analyte retention, analyte transport, axial dispersion, adsorption, charge-selectivity, concentration polarization, confocal laser scanning microscopy, donnan-exclusion, electrical double layer; electrochromatography; electrohydrodynamics, electrokinetic instability, electroosmosis; electroosmotic flow; electroosmotic mobility, electroosmotic perfusion, electrophoresis, hierarchical porous media, hydrodynamic flow, induced-charge electroosmosis, ion-permselectivity, ion-permselective transport, monolith, nonequilibrium electrical double layer, nonequilibrium electrokinetic effects, nonlinear electroosmosis, plate height, plate number, porous media, pore-scale dispersion, refractive index matching, space charge effects, sphere packing, quantitative imaging, wall effect, zeta-potential

Characterization of the avian designer cells AGE1.CR and AGE1.CR.plX considering growth, metabolism and production of influenza virus and Modified Vaccinia Virus Ankara (MVA)

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2014

Consequences of the multipatient use of a single-patient capillary blood sampling device (CBSD)

Introduction/objectives: Multipatient use of a single-patient CBSD occurred inan outpatient clinic during 4 to 16 months before itsnotification. We looked for transmission of blood-bornepathogens among exposed patients.Methods: Exposed patients underwent serology testing for HBV,HCV and HIV. Patients with isolated anti-HBc receivedone dose of hepatitis B vaccine to look for a memoryimmune response. Possible transmissions were investigatedby mapping visits and sequencing of the viral genomeif needed.Results: Of 280 exposed patients, 9 had died without suspicionof blood-borne infection, 3 could not be tested, and 5declined investigations. Among the 263 (93%) testedpatients, 218 (83%) had negative results. We confirmeda known history of HCV infection in 6 patients (1 coinfectedby HIV), and also identified resolved HBVinfection in 37 patients, of whom 18 were alreadyknown. 2 patients were found to have a previouslyunknown HCV infection. According to the time elapsedfrom the closest previous visit of a HCV-infected potentialsource patient, we could rule out nosocomial transmissionin one case (14 weeks) but not in the other (1day). In the latter, however, transmission was deemedvery unlikely by 2 reference centers based on thesequences of the E1 and HVR1 regions of the virus.Conclusion: We did not identify any transmission of blood-bornepathogens in 263 patients exposed to a single-patientCBSD, despite the presence of potential source cases.Change of needle and disinfection of the device betweenpatients may have contributed to this outcome.Although we cannot exclude transmission of HBV, previousacquisition in endemic countries is a more likelyexplanation in this multi-national population.

Modified 'dumbbell' technique: a simple and intuitive method to position balloon-expandable stent valves.

Intraoperative cardiac imaging plays a key role during transcatheter aortic valve replacement. In recent years, new techniques and new tools for improved image quality and virtual navigation have been proposed, in order to simplify and standardize stent valve positioning and implantation. But routine performance of the new techniques may require major economic investments or specific knowledge and skills and, for this reason, they may not be accessible to the majority of cardiac centres involved in transcatheter valve replacement projects. Additionally, they still require injections of contrast medium to obtain computed images. Therefore, we have developed and describe here a very simple and intuitive method of positioning balloon-expandable stent valves, which represents the evolution of the 'dumbbell' technique for echocardiography-guided transcatheter valve replacement without angiography. This method, based on the partial inflation of the balloon catheter during positioning, traps the crimped valve in the aortic valve orifice and, consequently, very near to the ideal landing zone. It does not require specific echocardiographic knowledge; it does not require angiographies that increase the risk of postoperative kidney failure in elderly patients, and it can be also performed in centres not equipped with a hybrid operating room.

Solid-phase synthesis and NMR studies of modified oligonucleotides forming triplex helix and of oligonucleopeptides mimicking the topoisomerase I-DNA covalent complex

Report for the scientific sojourn carried out at the Institut de Biologia Molecular de Barcelona of the CSIC –state agency – from april until september 2007. Topoisomerase I is an essential nuclear enzyme that modulates the topological status of DNA, facilitating DNA helix unwinding during replication and transcription. We have prepared the oligonucleotide-peptide conjugate Ac-NLeu-Asn-Tyr(p-3’TTCAGAAGC5’)-LeuC-CONH-(CH2)6-OH as model compound for NMR studies of the Topoisomerase I- DNA complex. Special attention was made on the synthetic aspects for the preparation of this challenging compound especially solid supports and protecting groups. The desired peptide was obtained although we did not achieve the amount of the conjugate needed for NMR studies. Most probably the low yield is due to the intrinsic sensitive to hydrolysis of the phosphate bond between oligonucleotide and tyrosine. We have started the synthesis and the structural characterization of oligonucleotides carrying intercalating compounds. At the present state we have obtained model duplex and quadruplex sequences modified with acridine and NMR studies are underway. In addition to this project we have successfully resolved the structure of a fusion peptide derived from hepatitis C virus envelope synthesized by the group of Dr. Haro and we have synthesized and started the characterization of a modified G-quadruplex.