Two-Dimensional Spectroscopy of Extended Molecular Systems: Applications to Energy Transport and Relaxation in an α-Helix

A simulation study of the coupled dynamics of amide I and amide II vibrations in an α-helix dissolved in water shows that two-dimensional (2D) infrared spectroscopy may be used to disentangle the energy transport along the helix through each of these modes from the energy relaxation between them. Time scales for both types of processes are obtained. Using polarization-dependent 2D spectroscopy is an important ingredient in the method we propose. The method may also be applied to other two-band systems, both in the infrared (collective vibrations) and the visible (excitons) parts of the spectrum.

Dynamic and spectral mixing in nanosystems

In the framework of simple spin-boson Hamiltonian we study an interplay between dynamic and spectral roots to stochastic-like behavior. The Hamiltonian describes an initial vibrational state coupled to discrete dense spectrum reservoir. The reservoir states are formed by three sequences with rationally independent periodicities typical for vibrational states in many nanosize systems. We show that quantum evolution of the system is determined by a dimensionless parameter which is characteristic number of the reservoir states relevant for the initial vibrational level dynamics. Our semi-quantitative analytic results are confirmed by numerical solution of the equation of motion. We anticipate that predicted in the paper both kinds of stochastic-like behavior (namely, due to spectral mixing and recurrence cycle dynamic mixing) can be observed by femtosecond spectroscopy methods in nanosystems.Comment: 6 pages, 4 figure

Rigorous Formulation of Duality in Gravitational Theories

In this paper we evince a rigorous formulation of duality in gravitational theories where an Einstein like equation is valid, by providing the conditions under which the Hodge duals (with respect to the metric tensor g) of T^a and R_b^a may be considered as the torsion and curvature 2-forms associated with a connection D', part of a Riemann-Cartan structure (M,g',D'), in the cases g = g' and g does not equal g', once T^a and R_b^a are the torsion and curvature 2-forms associated with a connection D part of a Riemann-Cartan structure (M,g,D). A new form for the Einstein equation involving the dual of the Riemann tensor of D is also provided, and the result is compared with others appearing in the literature.Comment: 15 page

Longitudinal Changes of Fixation Location and Stability Within 12 Months in Stargardt Disease: ProgStar Report No. 12

Purpose: To investigate the natural history of Stargardt disease (STGD1) using fixation location and fixation stability. // Design: Multicenter, international, prospective cohort study. // Methods: Fixation testing was performed using the Nidek MP-1 microperimeter as part of the prospective, multicenter, natural history study on the Progression of Stargardt disease (ProgStar). A total of 238 patients with ABCA4-related STGD1 were enrolled at baseline (bilateral enrollment in 86.6%) and underwent repeat testing at months 6 and 12. // Results: Outcome measures included the distance of the preferred retinal locus from the fovea (PRL) and the bivariate contour ellipse area (BCEA). After 12 months of follow-up, the change in the eccentricity of the PRL from the anatomic fovea was −0.0014 degrees (95% confidence interval [CI], −0.27 degrees, 0.27 degrees; P = .99). The deterioration in the stability of fixation as expressed by a larger BCEA encompassing 1 standard deviation of all fixation points was 1.21 degrees squared (deg2) (95% CI, −1.23 deg2, 3.65 deg2; P = .33). Eyes with increases and decreases in PRL eccentricity and/or BCEA values were observed. // Conclusions: Our observations point to the complexity of fixation parameters. The association of increasingly eccentric and unstable fixation with longer disease duration that is typically found in cross-sectional studies may be countered within individual patients by poorly understood processes like neuronal adaptation. Nevertheless, fixation parameters may serve as useful secondary outcome parameters in selected cases and for counseling patients to explain changes to their visual functionality

Ecological pellets from brown coal and biomass

Jedną z możliwości bezpiecznego wprowadzenie odnawialnych źródeł energii w Republice Czeskiej jest zastosowanie wybranych rodzajów biomasy jako dodatku do produkcji pelet z węgla brunatnego. Przed procesem peletyzacji biomasa jest poddawana wstępnej przeróbce (suszenie, kruszenie). Biomasa może być traktowana jako dodatek obniżający zawartość siarki w peletach. Możliwość wytwarzania pelet z węgla brunatnego z dodatkiem biomasy była weryfikowana w ciągu ubiegłych kilku lat. Zmieszanie węgla z odpowiednimi substancjami obniżającymi zawartość siarki i produkcja, na bazie węgla brunatnego, nowego rodzaju paliwa, spełniającego wymogi ograniczenia (w szczególności SO2) w trakcie spalania, w specjalnych kotłach, pozwala na optymalne wykorzystanie wartości energetycznej węgla brunatnego. Niektóre rodzaje materiału roślinnego (biomasy) mogą być komponentem paliwa produkowanego w procesie peletyzacji. Pelety wytworzone z węgla brunatnego pochodzącego z Kopalni Most (Mosteccka Uhelna Spolecnost) w Republice Czeskiej z dodatkiem masy drzewnej oraz odpadów drewnianych (na bazie trocin i wiórów) i z dodatkiem słomy gorczycowej) były badane w minionych latach. Doświadczenia, których celem była weryfikacja możliwości produkcji pelet z dodatkiem różnego rodzaju biomasy pokazały możliwość wyprodukowania ekologicznego paliwa z wykorzystaniem biomasy jako dodatku do węgla brunatnego. Paliwo takie może być konkurencyjne dla spalania czystego węgla.One of the possibilities for securing the development of exerting recoverable sources of energy in the Czech Republic is to breed suitable types of biomass, which may be added into a pelletizing mixture after treatment (drying, crushing) in order to produce coal pellets with the admixture of biomass and a desulphurizing additive. Possibilities to pelletize brown coal with the admixture of an additive and, if need be, biomass were being verified in the past years. By adding a suitable desulphurizing additive into a coal mixture and by its converting into the shape of pellets having suitable dimensions, there is being produced a new type of an additived brown-coal fuel, which may be combusted in specific combustion facilities under a lower production of injurants, especially SO2, provided that optimum conditions have been met. A certain share of a floral material, biomass, may be the next component of a fuel produced by the pelletization technology. Coal pellets made of the coal originating from the Most Brown-coal Mining District enriched with de-fibered wooden mass and wooden waste having (on a basis of sawdust with an admixture of shavings) and also with an addition of mustard straw) were being prepared in the past years. Tests executed in order to practically verify the production of pellets by using various types of biomass proved the reality of using biomass as a component of coal pellets and the fact that such pellets represented a new type of ecological fuel in comparison with the combustion of pure coal

Leaching of copper and tin from electronic waste using Acidithiobacillus ferrooxidans

Określono efekt ługowania metali z odpadów elektronicznych przy użyciu bakterii Acidithiobacillus ferrooxidans w warunkach statycznych. Zbadano ługowanie miedzi i cyny z płytki drukowanej układu elektronicznego i porównano do ługowania chemicznego. Całkowita ilość usuniętych metali była nieco mniejsza we wszystkich przypadkach. Dodatek bakterii ulepszył proces ługowania miedzi, jednak porównywalne rezultaty otrzymano poprzez dodanie mineralnej pożywki nie zawierającej bakterii. Ługowanie cyny przebiegało w inny sposób, a obecność bakterii nie polepszyła wydajności procesu.This contribution is focused on the leaching of metals from electronic waste using bacterium Acidithiobacillus ferrooxidans under static conditions. Leaching of copper and tin from circuit board using bacteria was verified and compared to chemical leaching. The overall amounts of leached metals were quite low in all variants. Addition of bacteria improved the leaching of copper; however comparable results were obtained by addition of the sole nutrient medium without bacteria. Leaching of the tin followed different pattern and was not improved by presence of bacteria

Potential energy recovery from waste pyrolytic treatment products

Piroliza jest procesem obecnie szeroko stosowanym. Jej główną zaletą jest powstawanie produktów, które mogą być wykorzystane. Celem artykułu jest porównanie wartości opałowej oleju pirolitycznego i kilku rodzajów odpadów. Olej pirolityczny był otrzymany podczas pirolizy opon w urządzeniu HOKS INDUSTRY TS500, a jego wartość opałowa mierzona była aparatem LECO AC350. Otrzymaną wartość opałową porównano z różnymi materiałami jak np. sortowane odpady komunalne, odpady drewna, paliwo samochodowe, paliwo stałe czy gaz ziemny.Pyrolysis is a much applied technology at present. The major advantage of pyrolysis is a formation of pyrolytic products which may be further used. The aim of the research is to compare the calorific value of pyrolytic oil and several kinds of waste. The pyrolytic oil is obtained pyrolyzing tyres in a HOKS INDUSTRY TS500 unit and its calorific value is determined using a LECO AC350 apparatus. Its calorific value is compared with the calorific value of various materials, such as sorted municipal waste, waste wood, car fuel, solid fuel and natural gas