Search results for "photo"
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Vacuum Processed Narrow and Wide Bandgap Perovskites for Photovoltaic Applications
2021
El objetivo principal de la presente tesis fue el desarrollo de nuevos materiales que sirvan de ayuda en la actual emergencia climática. De este modo, se prepararon perovskitas de banda prohibida estrecha y ancha con la intención de integrarlas en tándems, que pueden aprovechar todo el espectro solar para generar energía, en el futuro. Las perovskitas fueron preparadas mediante la técnica de sublimación, o deposición a vacío. Además, se emplearon otras técnicas que no requieren del uso de disolventes, como la mecanoquímica. A lo largo de la tesis se preparan dos perovskitas de banda prohibida estrecha, siendo una de ellas la primera perovskita basada en plomo y estaño sintetizada mediante s…
Fotoutlenianie siarki w obecności wybranych diftalocyjanin lantanowców
2016
Zagadnienie odsiarczania jest problemem zarówno w przemyśle jak i w ochronie środowiska naturalnego, gdyż związki siarki stanowią zagrożenie dla organizmów żywych. Podjęto więc badania nad możliwością wykorzystania fotoaktywnych kompleksów ftalocyjaniny jako potencjalnych aktywatorów w procesie utleniania związków siarki. W pracy badano proces fotoutleniania siarki elementarnej w obecności NdPc2 oraz YbPc2 w roztworze DMF. Otrzymane wyniki wskazują, że jedynie kompleks z Yb efektywnie katalizował badaną reakcję, przy mniejszym natężeniu promieniowania UV. Okazało się, że największy wpływ na przebieg i wydajność procesu fotoutleniania ma intensywność naświetlania układu. Rodzaj użytego fotoa…
Appraisal of Combined Applications of Trichoderma virens and a Biopolymer-Based Biostimulant on Lettuce Agronomical, Physiological, and Qualitative P…
2020
The current research elucidated the agronomical, physiological, qualitative characteristics and mineral composition of lettuce (Lactuca sativa L. var. longifolia) after treatments with a beneficial fungus Trichoderma virens (TG41) alone or in combination with a vegetal biopolymer-based biostimulant (VBP
Photoinduced changes in phytochromes studied by means of low temperature UV-Vis spectroscopy
2018
Phytochromes are a major family of red-light-sensing kinases that control diverse cellular functions in plants, bacteria and fungi. These proteins must relay structural signals from the sensory site over large distances to regulatory output domains. To accomplish this function, they undergo rather large structural changes from one state to another. The general aim of this work was to study these structural changes and possible protonation states of the photosensory core of the bacteriophytochrome from Deinococcus radiodurans in the intermediate states of the photoreaction, which became possible to observe under low temperatures. Moreover, it was interesting to investigate the role Serine272…
Heat-sensitive UV-Vis measurements for Phytochrome
2016
Fytokromit ovat punaista valoa aistivia proteiineja, jotka säätelevät suurta joukkoa solun toimintoja kasvi-, bakteeri- ja sienisoluissa. Nämä valoaktiiviset proteiinit muuntavat konformaatiotaan palautuvasti aktiivisen (Pfr) ja inaktiivisen (Pr) tilan välillä. Fytokromien aminohappojen väliset heikot vuorovaikutukset - etenkin vetysidokset - vaikuttavat lopulta laskostumiseen ja proteiinin lämpöstabiiliuteen. Fytokromit esiintyvät homodimeerisinä rakenteina, joiden monomeerit koostuvat useista domeeneista. Nämä jakautuvat N- terminaaliseen valosensitiiviseen moduuliin (PSM) ja C-terminaaliseen OutPut moduliin (OPM). PSM koostuu kolmesta domeenista (PAS-GAF ja PHY). Tässä työssä tutkittiin …
The Interconnecting Hairpin Extension "Arm": An Essential Allosteric Element of Phytochrome Activity
2023
In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond t…
Ecological and social impacts of photovoltaic solar power plants and optimization of their locations in northern Chile
2017
Large scale photovoltaic (PV) solar power plants are gaining popularity in Chile. Solar energy potential in northern Chile is one of the best worldwide and true deserts are considered ideal environments for solar power plant projects. Atacama Desert is one of the driest places on earth. Nevertheless, northern Chile is home for many endemic species with 40 different vegetation types. The thesis presents studies of ecological effects (I-II) and location optimization of PV solar power plants in northern Chile (III). For ecological impacts two types of PV solar power plant technologies were studied: fixed mount solar plant and solar- tracking mounts. Study units were placed below the mounts or …
Structural and electronic elucidation of a N-heterocyclic silylene vanadocene adduct
2017
The solid and solution state structure of the vanadium(II) N‐ heterocyclic silylene (NHSi) complex, [(SiIPr)V(Cp)2] (1) is reported ( SiIPr: 1,3‐bis(2,6‐diisopropylphenyl)‐1,3‐diaza‐2‐silacyclopent‐4‐ en‐2‐ylidene). The electronic structure of 1 is probed using combination of magnetic measurements, EPR spectroscopy and computational studies. The V–Si bond strength and complex forming mechanism between vanadocene and NHSi ligand is elucidated using computational methods. peerReviewed
Pion photo- and electroproduction on nucleons in relativistic chiral perturbation theory
2022
En esta tesis, hemos estudiado la producción de piones mediante pruebas electromagnéticas en nucleones. Para cada uno de los estudios realizados aquí, nos enfocamos en la Teoría Quiral de Perturbaciones (ChPT) relativista para hadrones ligeros: nucleones, piones y los grados de libertad explícitos Delta. Para preservar la covariancia de la teoría, se implementó el método de renormalización en el esquema Extended On Mass Shell (EOMS). En este caso, las divergencias y los términos que violan el conteo de potencias se absorben en las constantes de baja energía (LECs) del Lagrangiano efectivo. El presente trabajo se desarrolló dentro de tres estudios principales relacionados con la producción d…
Comparison of 99mTc-Labeled Colloid SPECT/CT and Planar Lymphoscintigraphy in Sentinel Lymph Node Detection in Patients with Melanoma: A Meta-Analysis
2020
We compared the detection rate (DR) for sentinel lymph nodes (SLNS), the number of SLNs and the subjects with additional SLNs of single-photon emission computed tomography (SPECT/CT) and planar lymphoscintigraphy (PL) in patients with melanoma. Furthermore, we evaluated the impact of SPECT/CT on surgical plans. Articles containing head-to-head comparisons between SPECT/CT and PL were searched in Pubmed/MEDLINE and Scopus. The literature search was updated until December 31st, 2019. DR was calculated on a per-patient-based analysis; the studies were pooled by their odds ratios (ORs) with a random effects model to assess the significance of difference (p < 0.05). The number of additional S…