114 research outputs found
Innovative polycarbonates for lithium conducting polymer electrolytes
205 p.The highly qualified life, demanded by the society of the 21st century, requires constant scientific and technological developments. Energy is the essential ingredient for the economic and social development. In order to provide, clean energy, safe energy storage system has to be developed. The continuous research on polymer electrolytes will lead us into a promising energy storage system. Up to now, poly(ethylene oxide) (PEO) has been extensively explored polymer matrix in solid polymer electrolytes for lithium batteries. However, recently, polycarbonate-solid polymer electrolytes show considerable enhancements respect to PEO-solid polymer electrolytes, such as improved lithium conductivity and electrochemical stability. The main objective of this thesis is to evaluate and compare new polycarbonates¿ structures as SPEs in lithium batteries. For this purpose, the versatile and simple polycondensation technique was chosen as synthetic tool to develop polycarbonates. This synthetic method allowed to easily change the functionality of the diol and the properties of the polycarbonates, and therefore, to analyze the consequences in polymer electrolytes.Université de Pau et des Pays de l'Adour
Polymat
JPREM: Institut des sciences analytiques et de physics-chimie pour l'environnement et les matériau
Bizkar muineko lesioetan sorbaldako min muskulu- eskeletikoa; Mina tratatzeko eta saihesteko froga zientifikoan oinarritutako ariketa programa: errebisio bibliografikoa
[EUS] Euskaraz idatzitako errebisio bibliografikoan. Helburua bizkar muineko lesioetan sorbaldako min muskulu- eskeletikoa tratatzeko literaturan proposatutako ariketa programa ezberdinak konparatzea eta ondoren froga zientifikoan oinarritutako ariketa programa bat proposatzea izan zen
Diseño de de un proyecto de investigación: Evaluación de la eficacia del ácido tranexámico en fracturas extracapsulares de cadera en ancianos, tratadas con cirugía con clavo intramedular
La fractura de cadera es muy frecuente en pacientes ancianos, se asocia a una elevada comorbilidad, mortalidad y coste elevado. Debido a su elevada incidencia, potenciada por el progresivo envejecimiento de la población, constituye un problema socioeconómico importante en nuestro país. Este tipo de fracturas, especialmente las extracapsulares, producen un sangrado importante debido a la propia fractura y a la cirugía. Este sangrado supone un problema grave para los ancianos, ya que conlleva mucha morbilidad, complicaciones, alarga la estancia y eleva los costes y la mortalidad. Para minimizar el sangrado y sus consecuencias, se han desarrollado sistemas de ahorro de sangre denominadas Patient Blood Management. Una de estas técnicas, es el empleo de ácido tranexámico tópico, es un método muy barato con escasas contraindicaciones y complicaciones. Los estudios disponibles sobre el uso de este fármaco, son de artroplastias de cadera y rodilla, los cuales no llegan a un consenso ni a un protocolo de administración. Debido a que no hay estudios en fracturas extracapsulares de cadera tratadas con clavo intramedular en ancianos, se plantea este proyecto de investigación. Mediante un ensayo clínico experimental, longitudinal y prospectivo, evaluaremos la eficacia del ácido tranexámico para disminuir el sangrado de la fractura y reducir la tasa transfusional respecto a un placebo en ancianos.Grado en Enfermerí
Innovative polycarbonates for lithium conducting polymer electrolytes
205 p.The highly qualified life, demanded by the society of the 21st century, requires constant scientific and technological developments. Energy is the essential ingredient for the economic and social development. In order to provide, clean energy, safe energy storage system has to be developed. The continuous research on polymer electrolytes will lead us into a promising energy storage system. Up to now, poly(ethylene oxide) (PEO) has been extensively explored polymer matrix in solid polymer electrolytes for lithium batteries. However, recently, polycarbonate-solid polymer electrolytes show considerable enhancements respect to PEO-solid polymer electrolytes, such as improved lithium conductivity and electrochemical stability. The main objective of this thesis is to evaluate and compare new polycarbonates¿ structures as SPEs in lithium batteries. For this purpose, the versatile and simple polycondensation technique was chosen as synthetic tool to develop polycarbonates. This synthetic method allowed to easily change the functionality of the diol and the properties of the polycarbonates, and therefore, to analyze the consequences in polymer electrolytes.Université de Pau et des Pays de l'Adour
Polymat
JPREM: Institut des sciences analytiques et de physics-chimie pour l'environnement et les matériau
Tributuaren funtzio estrafiskala zuzenbidezko estatu sozial eta demokratikoan
[EUS]
Konstituzio Auzitegiak tributua bere xede tradizionaletik (fiskala) haratago erabiltzea onartu zutenetik, estrafiskalitateak garrantzi handia hartu du zerga-sisteman, herritar ororen portaeran eragiteko duen gaitasunaren bidez, eta Konstituzioaren helburuak betetzeko tresna eraginkorra dela erakutsiz. Gradu Amaierako Lan honen helburua politika fiskalek Konstituzio-mandatuak lortzeko duten garrantzia erakustea da, hau da, tributuaren funtzio estrafiskala analizatzea
Bizkar muineko lesioetan sorbaldako min muskulu- eskeletikoa; Mina tratatzeko eta saihesteko froga zientifikoan oinarritutako ariketa programa: errebisio bibliografikoa
[EUS] Euskaraz idatzitako errebisio bibliografikoan. Helburua bizkar muineko lesioetan sorbaldako min muskulu- eskeletikoa tratatzeko literaturan proposatutako ariketa programa ezberdinak konparatzea eta ondoren froga zientifikoan oinarritutako ariketa programa bat proposatzea izan zen
El contexto teórico del derecho moderno y las ideologías jurídicas
A partir de la noción de contexto teórico se examinan los presupuestos que informan al historicismo y al positivismo, considerados con orientaciones teóricas dominantes en la cultura jurídica moderna. Se sostiene al respecto que ambas orientaciones se fundan en creencias y valores sustantivos que se encubren, de modo ideológico, bajo la forma de presupuestos y principios no sometidos a debate. Y se vinculan ambas orientaciones con el desarrollo general de la cultura jurídica, desglosada en sus dos grandes etapas -el realismo clásico antiguo y medieval y el idealismo egocéntrico moderno-, en cuyo marco se destaca la transformación de la materia y el ámbito del derecho. Por último, se propone un punto de partida crítico que lleve aúna reformulación no ideológica de la teoría del derecho
Single-ion conducting poly(ethylene oxide carbonate) as solid polymer electrolyte for lithium batteries
Unformatted postprintSingle-ion conducting polymer electrolytes (SIPE) have attracted a lot of interest for application in high energy density lithium metal batteries. SIPEs possess lithium transport numbers close to unity, which does not provoke concentration gradients and holds the promise of limiting lithium dendrite formation. In this article, we have optimized a single-ion polymer incorporating the most successful chemical units in polymer electrolytes, such as ethylene oxide, carbonate and a lithium sulfonimide. This single-ion poly(ethylene oxide carbonate) copolymer was synthesized by polycondensation between polyethylene glycol, dimethyl carbonate and a functional diol including the pendant sulfonamide anionic group and the lithium counter-cation. By playing with the monomer stoichiometry, the crystallinity and ionic conductivity were optimized. The best copolymer showed high ionic conductivity values of 1.2·10-4 S.cm-1 at 70 °C. Lithium interactions and mobility were studied by lithium pulsed field gradient, lithium diffusion, NMR relaxation time measurements and FTIR-ATR analysis. High lithium mobility is observed which is due to the weakly coordinating chemical environment in the polymer and also that the sulfonamide in the SIPE adopts to a greater extent the cis conformation, which is known to promote lithium mobility. Finally, the performance of the singe-ion conducting poly(ethylene oxide carbonate) was compared in lithium symmetric cells versus an analogous conventional salt in polymer electrolyte, showing improved performance in lithium plating and stripping.We are grateful to the financial support of the European Research Council by the Starting Grant Innovative Polymers for Energy Storage (iPes) 306250 and IONBIKE (H2020-MSCA-RISE-2018-823989), and by the Basque Government through ETORTEK Energigune 2013 and IT 999-16. Leire Meabe thanks Spanish Ministry of Education, Culture and Sport for the predoctoral FPU fellowship received to carry out this work. The authors thank for the technical and human support provided by SGIker of UPV/EHU for the NMR facilities of Gipuzkoa campus. The authors thank also Dr. Jose Ignacio Miranda (SGIker) for useful and essential support. Authors would like to thank the human support of Dr. Haijin Zhu and Dr. Luke O’Dell
Effect of Chemical Structure and Salt Concentration on the Crystallization and Ionic Conductivity of Aliphatic Polyethers
Poly(ethylene oxide) (PEO) is the most widely used polymer in the field of solid polymer electrolytes for batteries. It is well known that the crystallinity of polymer electrolytes strongly affects the ionic conductivity and its electrochemical performance. Nowadays, alternatives to PEO are actively researched in the battery community, showing higher ionic conductivity, electrochemical window, or working temperature range. In this work, we investigated polymer electrolytes based on aliphatic polyethers with a number of methylene units ranging from 2 to 12. Thus, the effect of the lithium bis(trifluoromethanesulfone) imide (LiTFSI) concentration on the crystallization behavior of the new aliphatic polyethers and their ionic conductivity was investigated. In all the cases, the degree of crystallinity and the overall crystallization rate of the polymers decreased drastically with 30 wt % LiTFSI addition. The salt acted as a low molecular diluent to the polyethers according to the expectation of the Flory-Huggins theory for polymer-diluent mixtures. By fitting our results to this theory, the value of the interaction energy density (B) between the polyether and the LiTFSI was calculated, and we show that the value of B must be small to obtain high ionic conductivity electrolytes.We wish to thank the National Council of Science and Technology (CONACYT), Mexico for the grant awarded to Jorge L. Olmedo Martinez (471837). We are grateful to the financial support of the European Commission through the project SUSPOL-EJD 642671 and European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) 306250. Alejandro J. Muller acknowledges the support of MINECO through grant MAT2017-83014-C2-1-P. Leire Meabe thanks Spanish Ministry of Education, Culture and Sport for the predoctoral FPU
Solid–Solid Crystal Transitions (δ to α) in Poly(hexamethylene carbonate) and Poly(octamethylene carbonate)
Unformatted post-print version of the accepted articlePoly (hexamethylene carbonate) (PC6) and poly (octamethylene carbonate) (PC8) were studied under different crystallization conditions. Using differential scanning calorimetry (DSC), a new solid-solid transition, denoted α to δ transition, was detected at low temperatures (<RT) in both PC6 and PC8 samples. The α to δ transition was represented by exothermic (i.e., α to δ) (−6 °C (PC6) and −20 °C (PC8)) and endothermic peaks (i.e., δ to α) (15 °C (PC6) and 28 °C (PC8)), during cooling and heating DSC scans, respectively. Isothermal tests revealed that this solid-solid transition depends on the specific thermal history, since it is not observed at isothermal temperatures higher than room temperature. Still, it is detected in the subsequent cooling and heating scans. Wide-angle X-ray scattering (WAXS) and Fourier-transform infrared spectroscopy (FT-IR) experiments were performed at identical conditions to those by DSC. WAXS experiments showed lower d-spacings in the δ phase than in the α one, corresponding to a unit cell shrinkage, explained by a more efficient packing of the methylene groups in the δ phase. The δ phase is also characterized, according to FT-IR experiments, by more ordered conformation of the methylene groups (i.e., reflected in the appearance of a new absorption band) compared to the less ordered conformation in the α phase.This work is supported by the National Key R&D Program of China (2017YFE0117800) and the National Natural Science Foundation of China (51820105005, 21922308, and 52050410327). We would like to thank the financial support provided by the BIODEST project; this project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 778092. This work has also received funding from MINECO through project MAT2017-83014-C2-1-P and from Basque Government through grant IT1309-19. R.A.P.-C is supported by the China Postdoctoral Science Foundation (2020M670462). G.L. is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Y201908). We also thanks to the BSRF (beamline 1W2A)
- …