580 research outputs found

    Revisiting wetting, freezing, and evaporation mechanisms of water on copper

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    Wetting of metal surfaces plays an important role in fuel cells, corrosion science, and heat-transfer devices. It has been recently stipulated that Cu surface is hydrophobic. In order to address this issue we use high purity (1 1 1) Cu prepared without oxygen, and resistant to oxidation. Using the modern Fringe Projection Phase-Shifting method of surface roughness determination, together with a new cell allowing the vacuum and thermal desorption of samples, we define the relation between the copper surface roughness and water contact angle (WCA). Next by a simple extrapolation, we determine the WCA for the perfectly smooth copper surface (WCA = 34°). Additionally, the kinetics of airborne hydrocarbons adsorption on copper was measured. It is shown for the first time that the presence of surface hydrocarbons strongly affects not only WCA, but also water droplet evaporation and the temperature of water droplet freezing. The different behavior and features of the surfaces were observed once the atmosphere of the experiment was changed from argon to air. The evaporation results are well described by the theoretical framework proposed by Semenov, and the freezing process by the dynamic growth angle model

    System komunikacji alternatywnej i wspomagającej wraz ze stosowanymi znakami oraz wykorzystanie urządzenia sterowanego za pomocą oczu w Polsce

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    Patients who do not communicate verbally or speak in an understandable way are a serious problem in providing appropriate care to patients due to a lack of understanding of their needs. Therefore, it is important that nursing staff have the knowledge and skills of alternative and assistive communication to communicate with patients with speech disorders. The purpose of article is to present the current state of knowledge of the alternative and augmentative communication with special consideration the signs used in Poland with a practicular emphasis laid to the revelant description of the eye tracking device. The literature has been reviewed, including also in this relation topics: alternative and augmentative communication, examples of signs used in alternative communication in Poland and communication and eye tracking. Not everyone has the ability to communicate verbally with the environment. In relation to this problem the solution is the alternative and augmentative communication which uses signs and devices to enable the patient to communicate with other people. (JNNN 2020;9(1):39–45)Pacjenci nie komunikujący się werbalnie lub mówiący w sposób niezrozumiały stanowią istotny problem w zapewnieniu właściwej opieki chorych w wyniku braku zrozumienia ich potrzeb. Z tego względu istotne jest posiadanie przez personel pielęgniarski wiedzy i umiejętności w zakresie komunikacji alternatywnej i wspomagającej by porozumieć się z pacjentami z zaburzeniami mowy. Celem pracy jest przedstawienie dotychczasowego stanu wiedzy na temat systemu komunikacji alternatywnej i wspomagającej ze szczególnym uwzgędnieniem wykorzystywanych znaków w Polsce oraz opis urządzenia sterowanego za pomocą oczu. Dokonano przeglądu literatury w zakresie tematów: komunikacja alternatywna i wspomagająca, przykłady znaków stosowanych w komunikacji alternatywnej w Polsce oraz komunikacja za pomocą oczu. Nie każdy człowiek posiada zdolność do komunikowania się werbalnie z otoczeniem. W odniesieniu do tego problemu rozwiązaniem jest komunikacja alternatywna i wspomagająca, która stosuje między innymi znaki oraz urządzenia, dające pacjentowi możliwość komunikowania się z ludźmi. (PNN 2020;9(1):39–45

    Potential use of the organic fraction of municipal solid waste in anaerobic co-digestion with wastewater in submerged anaerobic membrane technology

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    Food waste was characterized for its potential use as substrate for anaerobic co-digestion in a submerged anaerobic membrane bioreactor pilot plant that treats urban wastewater (WW). 90% of the particles had sizes under 0.5 mm after grinding the food waste in a commercial food waste disposer. COD, nitrogen and phosphorus concentrations were 100, 2 and 20 times higher in food waste than their average concentrations in WW, but the relative flow contribution of both streams made COD the only pollutant that increased significantly when both substrates were mixed. As sulphate concentration in food waste was in the same range as WW, co-digestion of both substrates would increase the COD/SO4-S ratio and favour methanogenic activity in anaerobic treatments. The average methane potential of the food waste was 421 +/- 15 mL CH4 g(-1) VS, achieving 73% anaerobic biodegradability. The anaerobic co-digestion of food waste with WW is expected to increase methane production 2.9-fold. The settleable solids tests and the particle size distribution analyses confirmed that both treatment lines of a conventional WWTP (water and sludge lines) would be clearly impacted,by the incorporation of food waste into its influent. Anaerobic processes are therefore preferred over their aerobic counterparts due to their ability to valorise the high COD content to produce biogas (a renewable energy) instead of increasing the energetic costs associated with the aeration process for aerobic COD oxidation. (C) 2016 Elsevier Ltd. All rights reserved.This research work was possible thanks to financial support from the Generalitat Valenciana (project PROMETEO/2012/029) which is gratefully acknowledged.Moñino Amorós, P.; Jiménez Douglas, E.; Barat Baviera, R.; Aguado García, D.; Seco Torrecillas, A.; Ferrer, J. (2016). Potential use of the organic fraction of municipal solid waste in anaerobic co-digestion with wastewater in submerged anaerobic membrane technology. Waste Management. 56:158-165. https://doi.org/10.1016/j.wasman.2016.07.021S1581655

    Additive effects of the dopamine D2 receptor and dopamine transporter genes on the error-related negativity in young children

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    The error-related negativity (ERN) is a negative deflection in the event-related potential that occurs approximately 50ms following the commission of an error at fronto-central electrode sites. Previous models suggest dopamine plays a role in the generation of the ERN. We recorded event-related potentials (ERPs) while 279 children aged 5-7 years completed a simple Go/No-Go task; the ERN was examined in relation to the dopamine D2 receptor (DRD2) and dopamine transporter (DAT1) genes. Results suggest an additive effect of the DRD2 and DAT1 genotype on ERN magnitude such that children with at least one DRD2 A1 allele and children with at least one DAT1 9 allele have an increased (i.e. more negative) ERN. These results provide further support for the involvement of dopamine in the generation of the ERN. © 2012 Blackwell Publishing Ltd and International Behavioural and Neural Genetics Society

    SAMPLE TEMPERATURE DURING CORROSION REMOVAL BY LOW PRESSURE LOW-TEMPERATURE HYDROGEN RF PLASMA

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    Abstract. The plasma chemical reduction of corrosion layers from archaeological metallic objects is developing since the late 70 th . Contemporary, it is used in some museums, but the optimal treatment conditions are not fully known yet. Treated object temperature is one of the most critical points because metallographic changes can be initiated by elevated temperatures and thus the unique historical information can be lost. Temperature increases due to the direct inductive heating in the discharge as well as by the interaction of the surface with plasma active particles. In the case of samples prepared in acidic corrosion environment, the maximal temperature of the samples with the incrustation was lower than of samples without incrustation treated under the same conditions because the incrustation layers decrease the direct interaction of plasma active particles with the corrosion layers. In contrary, in the case of brass samples prepared in the ammonia atmosphere, the incrustation had an opposite effect due to intense heating of the sample during the reaction with oxygen presented in the outer corrosion layers. The maximal sample temperature was directly proportional to the linear size (or the third root of weight) of the treated sample

    Simple and efficient expression of Agaricus meleagris pyranose dehydrogenase in Pichia pastoris

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    Pyranose dehydrogenase (PDH) is a fungal flavin-dependent sugar oxidoreductase that is highly interesting for applications in organic synthesis or electrochemistry. The low expression levels of the filamentous fungus Agaricus meleagris as well as the demand for engineered PDH make heterologous expression necessary. Recently, Aspergillus species were described to efficiently secrete recombinant PDH. Here, we evaluate recombinant protein production with expression hosts more suitable for genetic engineering. Expression in Escherichia coli resulted in no soluble or active PDH. Heterologous expression in the methylotrophic yeast Pichia pastoris was investigated using two different signal sequences as well as a codon-optimized sequence. A 96-well plate activity screening for transformants of all constructs was established and the best expressing clone was used for large-scale production in 50-L scale, which gave a volumetric yield of 223 mg L−1 PDH or 1,330 U L−1 d−1 in space–time yield. Purification yielded 13.4 g of pure enzyme representing 95.8% of the initial activity. The hyperglycosylated recombinant enzyme had a 20% lower specific activity than the native enzyme; however, the kinetic properties were essentially identical. This study demonstrates the successful expression of PDH in the eukaryotic host organism P. pastoris paving the way for protein engineering. Additionally, the feasibility of large-scale production of the enzyme with this expression system together with a simplified purification scheme for easy high-yield purification is shown

    Use of electrospinning to develop antimicrobial biodegradable multilayer systems: encapsulation of cinnamaldehyde and their physicochemical characterization

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    In this work, three active bio-based multilayer structures, using a polyhydroxybutyrate-co-valerate film with a valerate content of 8 % (PHBV8) as support, were developed. To this end, a zein interlayer with or without cinnamaldehyde (CNMA) was directly electrospun onto one side of the PHBV8 film and the following systems were developed: (1) without an outer layer; (2) using a PHBV8 film as outer layer; and (3) using an alginate-based film as outer layer. These multilayer structures were characterized in terms of water vapour and oxygen permeabilities, transparency, intermolecular arrangement and thermal properties. The antimicrobial activity of the active bio-based multilayer systems and the release of CNMA in a food simulant were also evaluated. Results showed that the presence of different outer layers reduced the transport properties and transparency of the multilayer films. The active bio-based multilayer systems showed antibacterial activity against Listeria monocytogenes being the multilayer structure prepared with CNMA and PHBV outer layers (PHBV + zein/CNMA + PHBV) the one that showed the greater antibacterial activity. The release of CNMA depended on the multilayer structures, where both Fick's and Case II transport-polymer relaxation explained the release of CNMA from the multilayer systems.Acknowledgments: Miguel A. Cerqueira (SFRH/BPD/72753/2010) andAnaI.Bourbon(SFRH/BD/73178/2010)arerecipientofafellowship from the Fundação para a Ciência e Tecnologia (FCT, POPH-QREN and FSE Portugal). J.L. Castro-Mayorga is supported by the Administrative Department of Science, Technology and Innovation (Colciencias) of Colombian Government. M. J. Fabra is a recipient of a Ramon y Cajal contract (RyC-2014-158) from the Spanish Ministry of Economy and Competitiveness. This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and of the Project RECI/BBB-EBI/ 0179/2012 (FCOMP-01-0124-FEDER-027462). The support of EU Cost Action MP1206 is gratefully acknowledged

    Long-term land-cover/use change in a traditional farming landscape in Romania inferred from pollen data, historical maps and satellite images

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    Traditional farming landscapes in the temperate zone that have persisted for millennia can be exceptionally species-rich and are therefore key conservation targets. In contrast to Europe’s West, Eastern Europe harbours widespread traditional farming landscapes, but drastic socio-economic and political changes in the twentieth century are likely to have impacted these landscapes profoundly. We reconstructed long-term land-use/cover and biodiversity changes over the last 150 years in a traditional farming landscape of outstanding species diversity in Transylvania. We used the Regional Estimates of Vegetation Abundance from Large Sites model applied to a pollen record from the Transylvanian Plain and a suite of historical and satellite-based maps. We documented widespread changes in the extent and location of grassland and cropland, a loss of wood pastures as well as a gradual increase in forest extent. Land management in the socialist period (1947–1989) led to grassland expansion, but grassland diversity decreased due to intensive production. Land-use intensity has declined since the collapse of socialism in 1989, resulting in widespread cropland abandonment and conversion to grassland. However, these trends may be temporary due to both ongoing woody encroachment as well as grassland management intensification in productive areas. Remarkably, only 8% of all grasslands existed throughout the entire time period (1860–2010), highlighting the importance of land-use history when identifying target areas for conservation, given that old-growth grasslands are most valuable in terms of biodiversity. Combining datasets from different disciplines can yield important additional insights into dynamic landscape and biodiversity changes, informing conservation actions to maintain these species-rich landscapes in the longer term
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