Magnetoresistance through a single molecule

The use of single molecules to design electronic devices is an extremely challenging and fundamentally different approach to further downsizing electronic circuits. Two-terminal molecular devices such as diodes were first predicted [1] and, more recently, measured experimentally [2]. The addition of a gate then enabled the study of molecular transistors [3-5]. In general terms, in order to increase data processing capabilities, one may not only consider the electron's charge but also its spin [6,7]. This concept has been pioneered in giant magnetoresistance (GMR) junctions that consist of thin metallic films [8,9]. Spin transport across molecules, i.e. Molecular Spintronics remains, however, a challenging endeavor. As an important first step in this field, we have performed an experimental and theoretical study on spin transport across a molecular GMR junction consisting of two ferromagnetic electrodes bridged by a single hydrogen phthalocyanine (H2Pc) molecule. We observe that even though H2Pc in itself is nonmagnetic, incorporating it into a molecular junction can enhance the magnetoresistance by one order of magnitude to 52%.Comment: To appear in Nature Nanotechnology. Present version is the first submission to Nature Nanotechnology, from May 18th, 201

Modelling the course of anaerobic digestion process based on basic factors, which control the process

Fermentacja anaerobowa jest bardzo złożonym i rozbudowanym procesem składającym się z kilku zależnych od siebie etapów wymagającym znajomości biologii, chemii, fizyki. Niestety w dostępnej literaturze niewiele można znaleźć badań opisujących wpływ parametrów na przebieg rozwoju mikroorganizmów metanogennych w warunkach jakie panują w biogazowniach. Stąd też w artykule podjęto próbę wyznaczenia czynników, które mają największy wpływ na produkcje biogazu. Analizę przeprowadzono na podstawie danych zawartych w literaturze dotyczących produkcji biogazu czego efektem końcowym było wyznaczenie parametrów determinujących przebieg procesu fermentacji anaerobowej i opracowanie koncepcji modelu matematycznego opisującego proces. Umożliwi to dokładne scharakteryzowanie jak dane parametry wpływają na ten proces, a także pozwoli na napisanie równania matematycznego obliczającego potencjalną produkcję biogazu, możliwie najbliższą rzeczywistej wartości.Anaerobic digestion is a very complex and developed process consisting in few dependable stages, which require the knowledge of biology, chemistry and physics. Unfortunately, not much information on the research on influence of parameters on the course of methanogens microorganisms' development in the biogas works conditions can be found in the literature, which is accessible. That is why, the article tries to determine the factors, which influence biogas production in the highest degree. The analysis was carried out based on data included in the literature concerning biogas production, the result of which was determining parameters that influence the course of anaerobic digestion and compiling the idea of a mathematical model, which describes the process. It will allow for precise description on how the particular parameters influence the process, as well as for elaborating a mathematical equation, which would calculate potential biogas production, which would be the closest to the real value

Evapo application – a tool for determining evapotranspiration by FAO–Penman–Monteith method

W pracy zaprezentowano aplikację do wyznaczania wartości dobowych ewapotranspiracji wskaźnikowej (ET0), rozumianej jako wielkość parowania z powierzchni trawnika w pełni rozwoju, rosnącego na glebie, która zapewnia optymalne warunki wegetacji. Aplikacja ta umożliwia wyznaczenie wartości ET0 dla dowolnego miejsca zadanego współrzędnymi geograficznymi oraz wysokością nad poziomem morza na podstawie dobowych wartości temperatury powietrza, niedosytu wilgotności względnej, prędkości wiatru oraz usłonecznienia względnego. W zbiorze danych wejściowych znajdują się również zmienne o wartościach tabelarycznych, takie jak stała psychrometryczna zależna od wysokości nad po-ziomem morza i ciśnienia atmosferycznego, maksymalna prężność pary wodnej oraz tangens kąta nachylenia krzywej ciśnienia nasyconej pary wodnej zależne od temperatury, promieniowanie na górnej granicy atmosfery zależne od kolejnego numeru dnia w roku, które w aplikacji są wyznaczane automatycznie na podstawie zadanych informacji geograficznych. Aplikacja umożliwia przeprowadzenie analizy zmienności wartości ewapotranspiracji w latach, jak również w poszczególnych miesiącach. Na podstawie 30-letniego ciągu danych meteorologicznych wyznaczono wartości ewapotranspiracji dla Vancouver oraz Wrocławia - Swojca i wykonano przykładową analizę z zastosowaniem aplikacji Evapo.The paper presents an application to calculate the daily reference evapotranspiration values (ETo), understood as the amount of evaporation from the lawn surface fully developed, growing on the soil, which provides optimal growth conditions. The presented application allows to determine the ETo value for any location for given geographic coordinates and location above sea level on the basis of daily values of air temperature, saturation deficit, wind speed and relative sunshine. As the input data there are also variables such as psychometric constant dependent on the location above sea level and atmospheric pressure, the maximum vapor pressure and the slope vapor pressure deficit dependent on temperature, extraterrestrial radiation dependent on sequent day number of the year, which in Evapo application are determined automatically based on given geographical information. The application allows to analyze evapotranspiration variability during particular years and months. Basing on 30 years of meteorological data the values of evapotranspiration for the Vancouver and Wrocław – Swojec was calculated and exemplary analysis was performed using the presented application

The lifetime of carbon capture and storage as a climate-change mitigation technology

In carbon capture and storage (CCS), CO[subscript 2] is captured at power plants and then injected underground into reservoirs like deep saline aquifers for long-term storage. While CCS may be critical for the continued use of fossil fuels in a carbon-constrained world, the deployment of CCS has been hindered by uncertainty in geologic storage capacities and sustainable injection rates, which has contributed to the absence of concerted government policy. Here, we clarify the potential of CCS to mitigate emissions in the United States by developing a storage-capacity supply curve that, unlike current large-scale capacity estimates, is derived from the fluid mechanics of CO[subscript 2] injection and trapping and incorporates injection-rate constraints. We show that storage supply is a dynamic quantity that grows with the duration of CCS, and we interpret the lifetime of CCS as the time for which the storage supply curve exceeds the storage demand curve from CO[subscript 2] production. We show that in the United States, if CO[subscript 2] production from power generation continues to rise at recent rates, then CCS can store enough CO[subscript 2] to stabilize emissions at current levels for at least 100 y. This result suggests that the large-scale implementation of CCS is a geologically viable climate-change mitigation option in the United States over the next century.United States. Dept. of Energy (Grant DE-FE0002041)MIT Energy InitiativeReed Research FundMartin Family Society of Fellows for SustainabilityAtlantic Richfield Company (ARCO

Targeted matrisome analysis identifies thrombospondin-2 and tenascin-C in aligned collagen stroma from invasive breast carcinoma

Abstract Increasing evidence demonstrates an important role for the extracellular matrix (ECM) in breast cancer progression. Collagen type I, a core constituent of the fibrous ECM, undergoes a significant set of changes that accompany tumor progression, termed Tumor Associated Collagen Signatures (TACS). Late stages of this progression are characterized by the presence of bundled, straight collagen (TACS-2) that become oriented perpendicular to the tumor-stromal boundary (TACS-3). Importantly, the presence of TACS-3 collagen is an independent predictor of poor patient outcome. At present, it remains unclear whether reorganization of the collagen matrix is the consequence of mechanical or compositional tissue remodeling. Here, we identify compositional changes in ECM correlating to collagen fiber reorganization from nineteen normal and invasive ductal carcinoma (IDC) patient biopsies using matrisome-targeted proteomics. Twenty-seven ECM proteins were significantly altered in IDC samples compared to normal tissue. Further, a set of nineteen matrisome proteins positively correlate and five proteins inversely correlate with IDC tissues containing straightened collagen fibers. Tenascin-C and thrombospondin-2 significantly co-localized with aligned collagen fibers in IDC tissues. This study highlights the compositional change in matrisome proteins accompanying collagen re-organization during breast cancer progression and provides candidate proteins for investigation into cellular and structural influences on collagen alignment