Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds via a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials

Quantum measurement procedures via weak interactions

The general diagonal measurement A weak quantum measurement is a measurement for which any outcome does not disturb the quantum state more than a small amount ε. Weak measurements are universal: [OB05] showed one can construct a sequence of weak measurements that converge to any strong measurement using a random walk of weak measurement operators. Weak measurement walks via an interacting probe: We study possible realizations of a such a procedure when the weak measurement is effectuated via weak interaction of a probe with the system in question. Virtual measurements Given a desired measurement {M1, M2}, we construct a parametrized weak measurement {M±(x)} such that we achieve the desired measurement in the continuous limit lim δ→

Generation of Multigigahertz Soliton Pulse Train

NRC publication: Ye

Effect of medium modification on bio-catalytic properties of yeasts

Drożdże stanowią bogate źródło enzymów wykorzystywanych w procesach biotechnologicznych przemysłu spożywczego. Działanie enzymów polega na katalizowaniu reakcji chemicznych nie tylko w organizmach żywych, ale także i poza nimi, zatem drożdże mogą również spełniać ważną rolę w syntezach chemicznych. Z punktu widzenia przetwarzania produktów spożywczych szczególnie istotne są reakcje estryfikacji i hydrolizy estrów. Celem pracy było określenie wpływu składu pożywki na aktywność katalityczną trzech gatunków drożdży Rhodotorula glutinis, Pichia jadinii i Saccharomyces cerevisiae, na przykładzie reakcji modelowej, jaką jest hydroliza laurynianu fenylu. Badane gatunki drożdży, celem porównania, hodowano w standardowych warunkach (podłoże YPD) oraz na pożywkach wzbogacanych w różne źródła azotu oraz węgla. Najskuteczniejsze w hydrolizie estru, przy udziale w pożywce hodowlanej oliwy z oliwek, były drożdże z gatunku Pichia jadinii, (ok. 50 % przereagowania laurynianu fenylu po 10 h, w porównaniu z 8 % przereagowaniem przy standardowej pożywce YPD), natomiast gatunek Rhodotorula glutinis najskuteczniej hydrolizował badany ester podczas hodowli w obecności mocznika (powyżej 50 % po 5 h w porównaniu z 8 % przy zastosowaniu YPD). W przypadku Saccharomyces cerevisiae, hodowanego w obecności oliwy z oliwek, przereagowanie rzędu 50 % osiągnięto dopiero po 40 h. Można zatem wnioskować, że właściwe modyfikacje pożywki pozwalają na stymulowanie lipolitycznych zdolności poszczególnych gatunków drożdży.Yeasts constitute a rich source of enzymes used in biotechnological processes in food industry. The activity of enzymes consists in catalyzing chemical reactions not only in live organisms, but, also, outside those live organisms, thus, yeasts can also fulfil an important role in chemical syntheses. From the point of view of food products processing, the reactions of esterification and hydrolysis of esters are particularly essential. The objective of this paper was to determine the impact of medium composition on the catalytic activity of three kinds of yeasts: Pichia jadinii, Rhodotorula glutinis, and Saccharomyce cerevisiae exemplified by a model reaction of hydrolysis of phenyl laurate. The yeasts studied were cultured under the typical conditions (YDP medium) and on media enriched by various sources of nitrogen and carbon. The Pichia jadinii yeasts proved to be most efficient in the hydrolysis of esters with a medium containing olive oil (about 50 % of the conversion of phenyl laurate after 10 h compared to 8 % of conversion using a standard YPD medium). As for Rhodotorula glutinis, the ester studied hydrolyzed most efficiently while being culture with the participation of urea (more than 50 % after the 5 h compared with 8 % with the YPD medium applied). In the case of Saccharomyce cerevisiae, cultured in the presence of olive oil, a level of 50% of the conversion was reached as late as after 40 h. Therefore, it can be concluded that proper modifications of medium allow for the stimulation of lypolytic activity of individual kinds of yeasts

Utilization of waste from food and fuel industries by lipolytic yeast of Yarrowia lipolytica

Przemysł spożywczy i paliwowy wytwarzają znaczne ilości trudnych w utylizacji hydrofobowych odpadów, stąd istnieje potrzeba poszukiwania nowych metod ich zagospodarowania. Celem badań była ocena możliwości zastosowania wybranych hydrofobowych odpadów przemysłu spożywczego i paliwowego jako głównego źródła węgla oraz induktora syntezy enzymów lipolitycznych w hodowli szczepu drożdży Yarrowia lipolytica W29. Hodowle wstrząsane prowadzono przez 65 h w 28°C w zmodyfikowanym podłożu YPG, w którym glukoza została zastąpiona olejem po procesie wędzenia ryb, tłuszczem po procesie wędzenia wędlin wieprzowych, tłuszczem po pieczeniu kaczej tuszki, zjełczałym masłem klarowanym lub zużytym olejem silnikowym. Stwierdzono, że odpady te mogą być wykorzystywane jako źródło węgla w hodowli drożdży Y. lipolytica. Produkcję enzymów lipolitycznych zaobserwowano w podłożach zawierających tłuszczowe substraty, a aktywność enzymów korelowano ze składem kwasów tłuszczowych. Wykazano, że istnieje możliwość utylizacji zastosowanych substratów odpadowych w procesach mikrobiologicznych do syntezy enzymów o aktywności lipolitycznej.Waste disposal and by-product management in many branches of industry pose problems in the areas of environmental protection and sustainability. Hydrophobic waste substrates of food and fuel origin stands for one of the continuously gaining ground for waste management fields. The aim of the study was to evaluate the possibility to use food origin wastes and fuel industry waste as a carbon sources in the culture medium for Y. lipolytica W29 with their simultaneous valorization. Culture media contained 2% of waste substrates. In the study there were evaluated yeast biomass yield, number of yeast cells in 1 cm³ of medium and extracellular lipase activity after 65 h of yeast growth on a rotary shaker at 28°C. Five wastes were estimated: oily waste from duck roasting process, oily waste from sausages smoking process, rancid ghee, oily waste from fish smoking process and waste engine oil. Additionally fatty acid composition of lipid waste was analyzed using gas chromatography. It was shown the possibility of using these wastes in cultivation of yeast with their simultaneous valorization by obtaining valuable products, e.g. enzymes such as extracellular lipases as well as biomass intended for feed. Yeast biomass yielded from 19.77 g DM·dm⁻³ for oily waste from duck roasting process to 12.28 g DM·dm⁻³ for oily waste from fish smoking process. It has been found that waste substrates stimulate the synthesis of extracellular lipases with different efficiency. The highest activity was obtained in medium containing smoked fish oil (0.313 U·cm⁻³). Furthermore, in waste engine oil medium no lipase activity of Y. lipolytica yeast was observed, but cells did grow and formed a biofilm. The analysis of fatty acid compositions showed the highest oleic acid content in oily waste from duck roasting process (41.9%), slightly lower waste from sausages smoking process (37.8%) and two-fold lower in fish oil (17.3%). This is very important information, because some authors believe that lipolytic enzymes synthesized by the yeast Y. lipolytica show substrate specificity as compared to that oil. Furthermore, the waste oil from fish smoking process was characterized by the presence of polyunsaturated fatty acids containing more than 20 carbons in chain length (EPA and DHA). There was no correlation between lipolytic activity and oleic acid content in waste fat used as the carbon source in medium, but it can be concluded that Y. lipolytica yeast prefered unsaturated rather than saturated fatty acids in extracellular lipase production

Kolonialer Rassismus, eugenisches Denken und Geschlecht. Auguste Forel und Otto Stoll in der Debatte um die "allgemeine Natur des Menschen" um 1900

We present an analysis of Fourier-transform arrayed waveguide gratings in the Fresnel diffraction regime. We report a distinct spatial modulation of the interference pattern referred to as the Moire-Talbot effect. The effect and its influence in a FT AWG device is explained by deriving an original analytical expression for the modulated field, and is also confirmed by numerical simulations using the angular spectrum method to solve the Fresnel diffraction integral. We illustrate the retrieval of spectral information in a waveguide Fourier-transform spectrometer in the presence of the Moire-Talbot effect. The simulated device comprises two interleaved waveguide arrays each with 180 waveguides and the interference order of 40. It is designed with a Rayleigh spectral resolution of 0.1 nm and 8 nm bandwidth at wavelength λ~1.5 µm. We also demonstrate by numerical simulations that the spectrometer crosstalk is reduced from -20 dB to -40 dB by Gaussian apodization