Search results for "I.7"
showing 10 items of 44 documents
Ultrafast excitation dynamics of low energy pigments in reconstituted peripheral light-harvesting complexes of photosystem I
2000
AbstractUltrafast dynamics of a reconstituted Lhca4 subunit from the peripheral LHCI-730 antenna of photosystem I of higher plants were probed by femtosecond absorption spectroscopy at 77 K. Intramonomeric energy transfer from chlorophyll (Chl) b to Chl a and energy equilibration between Chl a molecules observed on the subpicosecond time scale are largely similar to subpicosecond energy equilibration processes within LHCII monomers. However, a 5 ps equilibration process in Lhca4 involves unique low energy Chls in LHCI absorbing at 705 nm. These pigments localize the excitation both in the Lhca4 subunit and in LHCI-730 heterodimers. An additional 30–50 ps equilibration process involving red …
Confirmation of the topology of the Wendelstein 7-X magnetic field to better than 1:100,000
2016
Fusion energy research has in the past 40 years focused primarily on the tokamak concept, but recent advances in plasma theory and computational power have led to renewed interest in stellarators. The largest and most sophisticated stellarator in the world, Wendelstein 7-X (W7-X), has just started operation, with the aim to show that the earlier weaknesses of this concept have been addressed successfully, and that the intrinsic advantages of the concept persist, also at plasma parameters approaching those of a future fusion power plant. Here we show the first physics results, obtained before plasma operation: that the carefully tailored topology of nested magnetic surfaces needed for good c…
Mārketinga kompleksa elementu analīze un pilnveidošanas iespējas viesu namā "Stellas".
2018
Lai viesu nams veiksmīgi darbotos un atbilstu klientu prasībām, ir nepieciešams regulāri izvērtēt mārketinga kompleksa elementus un nepieciešamības gadījumā veikt to pilnveidi. Maģistra darba mērķis ir, pamatojoties uz teorētiskām atziņām par mārketinga kompleksu, interviju ar viesu nama vadību un Latvijas iedzīvotāju aptaujas rezultātiem, novērtēt viesu nama “Stellas” mārketinga kompleksa elementus, atklāt nepilnības un izstrādāt priekšlikumus mārketinga kompleksa elementu pilnveidošanai viesu namā “Stellas”. Pētījuma rezultātā tika noskaidrotas Latvijas iedzīvotāju prasības pret viesu nama pakalpojumiem, izdarīti secinājumi un izteikti priekšlikumi viesu nama “Stellas” mārketinga kompleks…
Étude des interconnexions dans les réseaux de régulation de Listeria monocytogenes en réponse aux conditions de l'environnement
2019
The facultative intracellular pathogen Listeria monocytogenes is a highly adaptable organism widely distributed in the environment. The ingestion of food contaminated with L. monocytogenes by at-risk individuals can ultimately lead to listeriosis, one of the leading causes of food-borne fatalities in developed countries. Regulatory networks are crucial for the adaptation and survival of this pathogen. The accessory gene regulator (Agr) system has been shown to be involved in virulence, biofilm formation, and survival of L. monocytogenes, affecting the transcription of over 700 genes. The alternative sigma factor Sigma B (σB) controls the general stress response in L. monocytogenes, regulati…
The σ B -dependent regulatory sRNA Rli47 represses isoleucine biosynthesis in Listeria monocytogenes through a direct interaction with the ilvA trans…
2019
International audience; The facultative intracellular pathogen Listeria monocytogenes can persist and grow in a diverse range of environmental conditions, both outside and within its mammalian host. The alternative sigma factor Sigma B (sigma(B)) plays an important role in this adaptability and is critical for the transition into the host. While some of the functions of the sigma(B) regulon in facilitating this transition are understood the role of sigma(B)-dependent small regulatory RNAs (sRNAs) remain poorly characterized. In this study, we focused on elucidating the function of Rli47, a sigma(B)-dependent sRNA that is highly induced in the intestine and in macrophages. Using a combinatio…
Vārdu mācīšanās paņēmienu izmantošana 7. klasē vācu valodas kā otrās svešvalodas apguves veicināšanai
2017
Diplomdarbā pētīta vārdu mācīšanās paņēmienu izmantošana vācu valodas kā otrās svešvalodas apguves veicināšanai 7. klasē, jo darba autore prakses ietvaros novēroja, ka skolēniem nav pilnīgas izpratnes par vārdu mācīšanās paņēmieniem. Lai sasniegtu darba mērķi – apzināt vārdu mācīšanās paņēmienu efektivitāti –, tika pētīta vācu valodas aktualitāte, kā arī tās apguve, mācoties vācu valodu kā otro svešvalodu pēc angļu valodas; uzsvars likts uz tiešo un netiešo vārdu mācīšanās paņēmienu izpēti. Tāpat tika aprakstītas smadzeņu darbības īpatnības un īslaicīgās un ilglaicīgās atmiņas nozīme mācīšanās procesā. Pētījuma ietvaros tika analizētas 3 skolās lietotas mācību grāmatas, kurās aplūkoti piedā…
Simulation of parasitic effects on Silicon Carbide devices for automotive electric traction
2020
Wide Band Gap (WBG) semiconductors are increasingly addressed towards Electric Vehicle (EV) applications, due to their significant advantages in terms of high-voltage and low-losses performances, suitable for high power applications. Nevertheless, the packaging in WBG devices represents a challenge for designers due to the notable impact that inductive and capacitive parasitic components can bring in high switching frequency regime in terms of noise and power losses. In this paper, a comparison between conventional Silicon (Si) and emerging Silicon-Carbide (SiC) power switching devices is presented. The effects of inductive parasitic effects and switching frequency are investigated in simul…
Energy Management and Smart Grids
2013
The paper outlines energy management concepts and the smart grid evolution. The necessity of considering energy management as a crucial innovation in load supplying to permit a more powerful penetration of renewable energy usage at the building and city level and to perform energy savings and CO2 emissions reduction is pointed out. The driving factors to enhance the current power distribution are presented, and the benefits concerning smart grids are underlined. In the paper, a specific energy management analysis is reported by considering all the electric value chain, and the demand-side management and distributed on site control actions are described. To verify the benefit of energy manag…
Le opere esposte da Maria Accascina alla Mostra d’Arte Sacra delle Madonie
2017
Il saggio espone i metodi e gli strumenti di ricerca utilizzati per la ricostruzione del catalogo della pioneristica Mostra D’Arte Sacra delle Madonie curata da Maria Accascina ed allestita nel 1937 presso il Convento dei PP. Riformati di Petralia Sottana, centro delle alte Madonie. Si tratta di più di quattrocento opere, tra gioielli, suppellettili liturgiche, oggetti preziosi di uso profano, coralli, paramenti sacri, tessuti, statue lignee, intagli, maioliche, tappeti, tele e tavole dipinte realizzate dal XI al XIX secolo. Le opere, alcune delle quali perdute, provengono dalle collezioni nobiliari, dall’allora Museo Nazionale di Palermo, ora Galleria Regionale della Sicilia, Palazzo Abate…
Design and Realization of a Bidirectional Full Bridge Converter with Improved Modulation Strategies
2020
In this paper a Full-Bridge Converter (FBC) for bidirectional power transfer is presented. The proposed FBC is an isolated DC-DC bidirectional converter, connected to a double voltage source&mdash