Parameter Optimisation of a Virtual Synchronous Machine in a Microgrid

Parameters of a virtual synchronous machine in a small microgrid are optimised. The dynamical behaviour of the system is simulated after a perturbation, where the system needs to return to its steady state. The cost functional evaluates the system behaviour for different parameters. This functional is minimised by Parallel Tempering. Two perturbation scenarios are investigated and the resulting optimal parameters agree with analytical predictions. Dependent on the focus of the optimisation different optima are obtained for each perturbation scenario. During the transient the system leaves the allowed voltage and frequency bands only for a short time if the perturbation is within a certain range.Comment: 17 pages, 5 figure

Photocatalytic degradation of diclofenac in wastewater using ironceramic composites

The photocatalytic degradation of diclofenac in model aqueous solution is investigated. The surface of composites were correlated with photocatalytic activity. Adsorption activity of the composites is related to the presence of surface active sites. The degradation under UV irradiation and photo-Fenton process using ironceramic composites is more effective than direct photolysis

Структура, механические свойства и особенности поведения при деформации пористой керамики на основе диоксида циркония

Пористая керамика находит широкое применение в качестве огнеупорного материала, фильтров и материалов медицинского назначения в качестве остеозамещающих элементов (эндопротезов). В полученном материале, с развитой поровой структурой, под нагрузкой происходит мартенситное превращение из тетрагональной в моноклинную фазу. Это должно способствовать повышению вязкости разрушения, а также надежности и долговечности пористой керамики, в условиях, например, мало- и многоцикловой усталости.The porous ceramics finds broad application as a refractory material, filters and medical materials as osteosubstaining elements (endoprostheses). In the received material, with the developed porous structure, under loading there is a martensitic transformation from tetragonal into a monoclinic phase. It has to promote increase in fracture toughness and also reliability and durability of porous ceramics, under conditions such as low and multi-cycle fatigue

A fast and sensitive method for the continuous in situ determination of dissolved methane and its d13C-isotope ratio in surface waters

A fast and sensitive method for the continuous determination of methane (CH4) and its stable carbon isotopic values (d13C-CH4) in surface waters was developed by applying a vacuum to a gas/liquid exchange membrane and measuring the extracted gases by a portable cavity ring-down spectroscopy analyser (M-CRDS). The M-CRDS was calibrated and characterized for CH4 concentration and d13C-CH4 with synthetic water standards. The detection limit of the M-CRDS for the simultaneous determination of CH4 and d13CCH4 is 3.6 nmol L21 CH4. A measurement precision of CH4 concentrations and d13C-CH4 in the range of 1.1%, respectively, 1.7& (1r) and accuracy (1.3%, respectively, 0.8& [1r]) was achieved for single measurements and averaging times of 10 min. The response time s of 5765 s allow determination of d13C-CH4 values more than twice as fast than other methods. The demonstrated M-CRDS method was applied and tested for Lake Stechlin (Germany) and compared with the headspace-gas chromatography and fast membrane CH4 concentration methods. Maximum CH4 concentrations (577 nmol L21) and lightest d13C-CH4 (235.2&) were found around the thermocline in depth profile measurements. The M-CRDS-method was in good agreement with other methods. Temporal variations in CH4 concentration and d13C-CH4 obtained in 24 h measurements indicate either local methane production/oxidation or physical variations in the thermocline. Therefore, these results illustrate the need of fast and sensitive analyses to achieve a better understanding of different mechanisms and pathways of CH4 formation in aquatic environments

Coeficientes de distribuição de elementos-traço em clinopiroxênio e plagioclásio de sills basálticos da Formação Serra Geral, Brasil

The use of an electron microprobe (EPMA) integrated with inductively coupled plasma mass spectrometer laser ablation (LA-ICP-MS) for the determination of major and trace elements in igneous minerals advances the knowledge of the distribution coefficients “D”in cores, intermediate portions and rims of crystals. Crystals of clinopyroxene and plagioclase of tholeiitic sills from the Serra Geral Formation, Paraná Basin, Brazil, display positive correlations between many major and trace elements. Plagioclase has core concentrations of SiO2 and Na2O wt.% which increase to the rim and Al2O3 and CaO wt.% decreasing from the core to the rim, corroborated by similar variations of distribution coefficients of Sr and Eu as a result of substitution of these compatible elements for Na in the structure of plagioclase. Clinopyroxene has the decreases in MgO, Al2O3 and CaO wt.% core to the rim and decreased D of Ni, Zn and V, and to increased concentration of FeOtotal wt.% core to the rim related increase in D of Sc, Y andHREE. This investigation is innovative because it presents the study of distribution coefficients oftrace elements with spatial control of the analyses, taking into account the effect of inclusions, fractures and compositional zoning.A utilização de técnicas de microanálise (microssonda eletrônica - EPMA e ablação a LASER em espectrômetro de massa com plasma indutivamente acoplado - LA-ICP-MS) de elementos maiores, traços e terras raras em minerais ígneos amplia o conhecimento do coeficiente de distribuição “D” em porções de núcleo, intermédio e borda do cristal. Cristais de clinopiroxênio e plagioclásio de sills toleíticos da Formação Serra Geral, Bacia do Paraná, Brasil, possuem correlações positivas entre muitos elementos maiores e traços. O plagioclásio possui em seu núcleo concentrações de SiO e Na O (peso %) 2 2 que aumentam para a borda e concentrações de Al O e CaO (peso %) que diminuem do núcleo para a 2 3 borda do cristal. Isto é corroborado pelas mesmas variações dos coeficientes de distribuição de Sr e Eu em decorrência de substituições destes elementos, nas posições estruturais do Na no plagioclásio. O clinopiroxênio mostra decréscimo nos conteúdos de MgO, Al O e CaO (peso %) do núcleo para a borda, 2 3 diminuição dos D de Ni, Zn e V e aumento das concentrações de FeO (peso %) do núcleo para a borda total relacionados com o aumento do D de Sc, Y e ETR pesados. Este trabalho é inovador, pois apresenta o estudo de coeficientes de distribuição de elementos traços com controle espacial das análises, controlando- se desta forma, a influência de inclusões, fraturas e zoneamentos composicionais

Opposite temperature effect on transport activity of KCC2/KCC4 and N(K)CCs in HEK-293 cells

<p>Abstract</p> <p>Background</p> <p>Cation chloride cotransporters play essential roles in many physiological processes such as volume regulation, transepithelial salt transport and setting the intracellular chloride concentration in neurons. They consist mainly of the inward transporters NCC, NKCC1, and NKCC2, and the outward transporters KCC1 to KCC4. To gain insight into regulatory and structure-function relationships, precise determination of their activity is required. Frequently, these analyses are performed in HEK-293 cells. Recently the activity of the inward transporters NKCC1 and NCC was shown to increase with temperature in these cells. However, the temperature effect on KCCs remains largely unknown.</p> <p>Findings</p> <p>Here, we determined the temperature effect on KCC2 and KCC4 transport activity in HEK-293 cells. Both transporters demonstrated significantly higher transport activity (2.5 fold for KCC2 and 3.3 fold for KCC4) after pre-incubation at room temperature compared to 37°C.</p> <p>Conclusions</p> <p>These data identify a reciprocal temperature dependence of cation chloride inward and outward cotransporters in HEK-293 cells. Thus, lower temperature should be used for functional characterization of KCC2 and KCC4 and higher temperatures for N(K)CCs in heterologous mammalian expression systems. Furthermore, if this reciprocal effect also applies to neurons, the action of inhibitory neurotransmitters might be more affected by changes in temperature than previously thought.</p

The selective phosphodiesterase 4 inhibitor roflumilast and phosphodiesterase 3/4 inhibitor pumafentrine reduce clinical score and TNF expression in experimental colitis in mice.

The specific inhibition of phosphodiesterase (PDE)4 and dual inhibition of PDE3 and PDE4 has been shown to decrease inflammation by suppression of pro-inflammatory cytokine synthesis. We examined the effect of roflumilast, a selective PDE4 inhibitor marketed for severe COPD, and the investigational compound pumafentrine, a dual PDE3/PDE4 inhibitor, in the preventive dextran sodium sulfate (DSS)-induced colitis model. The clinical score, colon length, histologic score and colon cytokine production from mice with DSS-induced colitis (3.5% DSS in drinking water for 11 days) receiving either roflumilast (1 or 5 mg/kg body weight/d p.o.) or pumafentrine (1.5 or 5 mg/kg/d p.o.) were determined and compared to vehicle treated control mice. In the pumafentrine-treated animals, splenocytes were analyzed for interferon-γ (IFNγ) production and CD69 expression. Roflumilast treatment resulted in dose-dependent improvements of clinical score (weight loss, stool consistency and bleeding), colon length, and local tumor necrosis factor-α (TNFα) production in the colonic tissue. These findings, however, were not associated with an improvement of the histologic score. Administration of pumafentrine at 5 mg/kg/d alleviated the clinical score, the colon length shortening, and local TNFα production. In vitro stimulated splenocytes after in vivo treatment with pumafentrine showed a significantly lower state of activation and production of IFNγ compared to no treatment in vivo. These series of experiments document the ameliorating effect of roflumilast and pumafentrine on the clinical score and TNF expression of experimental colitis in mice

Patient preference regarding assessment of clinical follow-up after percutaneous coronary intervention: the PAPAYA study

Aims: To keep patients in long-term clinical follow-up programmes after percutaneous coronary intervention (PCI), knowledge of the patient-preferred mode for follow-up assessment is crucial. We systematically assessed patient preference, and explored potential relationships with age and gender.Methods and results: In the prospective, observational PAPAYA study (ClinicalTrials.gov: NCT02189070), 2,566 patients, treated by PCI between June 2008 and May 2012, were invited to participate in a postal survey on the patient-preferred mode (postal questionnaire, telephone or e-mail consultation) and frequency of follow-up assessment. A total of 1,797 (70.0%) patients responded. The vast majority preferred completing postal questionnaires (1,248 [69.9%]) as compared to telephone (240 [13.4%]) or e-mail-based approaches (227 [12.7%]) (p<0.001). With increasing age, there was a gradual decline in preference for e-mail (p<0.001); the youngest patients (≤60 years) preferred e-mail-based follow-up more often than the oldest (21.1% vs. 3.1%). Nevertheless, 79.9% of the youngest preferred to be approached in ways other than by e-mail. Women more often preferred approaches other than e-mail (94.1% vs. 87.3%, p<0.001).Conclusions: Patients showed a distinct preference for completing postal questionnaires rather than being approached by telephone or e-mail. Younger patients accepted e-mail-based follow-up more often, but the majority of the youngest patients still preferred approaches other than by e-mail - See more at: http://www.pcronline.com/eurointervention/ahead-of-print/201510-06/patient-preference-regarding-assessment-of-clinical-follow-up-after-percutaneous-coronary-intervention-the-papaya-study

Forward K+ production in subthreshold pA collisions at 1.0 GeV

K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.Comment: 4 pages, 3 figure