1,436 research outputs found

    Managing the Provenance of Crowdsourced Disruption Reports

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    A paid open access option is available for this journal. Authors own final version only can be archived Publisher's version/PDF cannot be used On author's website immediately On any open access repository after 12 months from publication Published source must be acknowledged Must link to publisher version Set phrase to accompany link to published version (see policy) Articles in some journals can be made Open Access on payment of additional chargePublisher PD

    The time and frequency comparisons via Loran-C and National TV Network in Yugoslavia

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    Time comparisons were made between cesium clocks in Yugoslavia and other cesium clocks in the country by the Laboratory of Federal Bureau of Measures and Precious Metals. Regional standard frequency and time signals dissemination is over National TV network by so called active TV system. International comparisons are performed via Loran-C system and by clock transportation. The method of calculation and approximation of the time signal propagation delays is given. Settled comparison results of the cesium clocks via TV network, Loran-C, and by clock transportation are also discussed in this paper

    Efikasno premeŔtanje push-pull 5-supstituisanih 4-oksotiazolidina indukovano piridinijum-hidrobromid-perbromidom pod homogenim reakcionim uslovima

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    Pyridinium hydrobromide perbromide (PHBP) is a highly efficient reagent for the conversion of 5-substituted-2-alkylidene-4-oxothiazolidine derivatives to the corresponding thiazolidines with two fully delocalized exocyclic double bonds at the C(2) and C(5) positions. This conversion as a two-step bromination-rearrangement process occurs in acetonitrile under homogeneous reaction conditions.Piridinijum-hidrobromid-perbromid (PHBP) je veoma efikasan reagens za konverziju 5-supstituisanih-2-alkiliden-4-oksotiazolidinskih derivata u odgovarajuće tiazolidine sa dve potpuno delokalizovane egzociklične dvogube veze u položajima C(2) i C(5). Ova konverzija je dvofazni proces bromovanja i premeÅ”tanja koji se odvija u acetonitrilu pod homogenim reakcionim uslovima

    Fast Frequency Control Scheme through Adaptive Virtual Inertia Emulation

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    This paper presents a novel virtual inertia controller for converters in power systems with high share of renewable resources. By combining the analytical study of system dynamics and a Linear-Quadratic Regulator (LQR)-based optimization technique, the optimal state feedback gain is determined, adapting the emulated inertia constant according to the frequency disturbance in the system. The optimality is achieved through trade-off between the critical frequency limits and the required control effort, i.e. utilization of the internal energy storage. The proposed controller is integrated into a state-of-the-art converter control scheme and verified through EMT simulations. The results show a significant improvement in the frequency response compared to an open-loop system, while also preserving drastically more DC-side energy than a non-adaptive controller

    Applications of Trajectory Data From the Perspective of a Road Transportation Agency: Literature Review and Maryland Case Study

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    Transportation agencies have an opportunity to leverage increasingly-available trajectory datasets to improve their analyses and decision-making processes. However, this data is typically purchased from vendors, which means agencies must understand its potential benefits beforehand in order to properly assess its value relative to the cost of acquisition. While the literature concerned with trajectory data is rich, it is naturally fragmented and focused on technical contributions in niche areas, which makes it difficult for government agencies to assess its value across different transportation domains. To overcome this issue, the current paper explores trajectory data from the perspective of a road transportation agency interested in acquiring trajectories to enhance its analyses. The paper provides a literature review illustrating applications of trajectory data in six areas of road transportation systems analysis: demand estimation, modeling human behavior, designing public transit, traffic performance measurement and prediction, environment and safety. In addition, it visually explores 20 million GPS traces in Maryland, illustrating existing and suggesting new applications of trajectory data

    Size distribution of alkyl amines in continental particulate matter and their online detection in the gas and particle phase

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    An ion chromatographic method is described for the quantification of the simple alkyl amines: methylamine (MA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA) and triethylamine (TEA), in the ambient atmosphere. Limits of detection (3Ļƒ) are in the tens of pmol range for all of these amines, and good resolution is achieved for all compounds except for TMA and DEA. The technique was applied to the analysis of time-integrated samples collected using a micro-orifice uniform deposition impactor (MOUDI) with ten stages for size resolution of particles with aerodynamic diameters between 56 nm and 18 Ī¼m. In eight samples from urban and rural continental airmasses, the mass loading of amines consistently maximized on the stage corresponding to particles with aerodynamic diameters between 320 and 560 nm. The molar ratio of amines to ammonium (R<sub>3</sub>NH<sup>+</sup>/NH<sub>4</sub><sup>+</sup>) in fine aerosol ranged between 0.005 and 0.2, and maximized for the smallest particle sizes. The size-dependence of the R<sub>3</sub>NH<sup>+</sup>/NH<sub>4</sub><sup>+</sup> ratio indicates differences in the relative importance of the processes leading to the incorporation of amines and ammonia into secondary particles. The technique was also used to make simultaneous hourly online measurements of amines in the gas phase and in fine particulate matter using an Ambient Ion Monitor Ion Chromatograph (AIM-IC). During a ten day campaign in downtown Toronto, DMA, TMA + DEA, and TEA were observed to range from below detection limit to 2.7 ppt in the gas phase. In the particle phase, MAH<sup>+</sup> and TMAH<sup>+</sup> + DEAH<sup>+</sup> were observed to range from below detection limit up to 15 ng m<sup>āˆ’3</sup>. The presence of detectable levels of amines in the particle phase corresponded to periods with higher relative humidity and higher mass loadings of nitrate. While the hourly measurements made using the AIM-IC provide data that can be used to evaluate the application of gas-particle partitioning models to amines, the strong size-dependence of the R<sub>3</sub>NH<sup>+</sup>/NH<sub>4</sub><sup>+</sup> ratio indicates that using bulk measurements may not be appropriate

    Feed Quantity Effect on Carp Juvenilesā€™ Plasma Protein and Immunoglobulin Levels

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    Plasma protein and immunoglobulin (Ig) levels in fish can be influenced by stress reaction, caused by some nutritional factors. This paper shows effects of different feed quantity on total protein and total Ig levels in blood of common carp (Cyprinus carpio) juveniles exposed to chronic stress conditions. The study was carried out in a recirculation aquaculture system (RAS) during 96 days. Carps (initial weight 6.43Ā±0.02 g) were distributed into four groups in three replicate tanks, 40 fish per tank. The groups were formed according to the feed quantity applied: 2, 3, 4 and 5% of commercial extruded mixture in relation to the ichthyomass (i.e. groups I, II, III and IV respectively). According to the results, the mean values of total plasma proteins and Ig were highest in group IV and the lowest in group II (p<0.05). Total protein levels were influenced by feed quantity (p<0.05), and sampling time (p<0.001). Total Ig levels were influenced by duration of the experiment i.e. sampling time (p<0.001). In all groups the mean values of plasma proteins after two month of the experiment was increased (p<0.01), and the mean values of Ig in less fed groups I and II (p<0.05 and p<0.01, respectively). Total plasma proteins and Ig were not significantly affected by water quality parameters only in the group fed 2% of feed (group I). Significant positive correlation between total proteins and Ig was determined in each experimental group (p<0.01). In terms of reducing stress and ensuring welfare in carp juveniles, applied feed amount should match to the length of fish growing in the fish tanks, stocking density and capacity of the system for efficient water purification

    Vodonična veza u push-pull 5-supstituisanim 2-alkiliden-4-oksotiazolidinima: 1H-NMR spektroskopsko proučavanje

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    Application of dynamic H-1-NMR spectroscopy added to the understanding of the hydrogen bonds existing in the structurally related 5-substituted-2-alklidene-4-oxothiazolidines in polar and apolar solvents. The equilibrated mixtures of these topical push-pull alkenes in CDCl3 consist of the intramolecularly H-bonded (E)-isomer and intermolecularly H-bonded (Z)-isomer in varying proportions which depend on the solvent polarity. For the representative of the series. (Z)-2-(5-ethoxycarbonylmethyl-4-oxothiazolidin-2-ylidene)-1-phenylethanone, a concentration effect on the degree of intermolecular hydrogen bonding in apolar CDCl3 has been studied.Primenom dinamičke 1H-NMR spektroskopije doÅ”lo se do boljeg razumevanja o vrsti vodoničnih veza koje postoje u strukturno sličnim 5-supstituisanim 2-alkiliden-4-oksotiazolidinima u polarnim i apolarnim rastvaračima. Uravnotežene smese ovih tipičnih push-pull alkena u CDCl3 sadrže (E)-izomer vezan intramolekulskom vodoničnom vezom kao i intermolekulski vodoničnom vezom vezan (Z)-izomer u različitim odnosima, koji zavise od polarnosti rastvarača. U slučaju tipičnog predstavnika serije (Z)-2-(5-etoksikarbonilmetil-4-oksotiazolidin- 2-iliden)-1-feniletanona uticaj koncentracije na stepen stvaranja intermolekulske vodonične veze u apolarnom CDCl3 je takođe proučavan

    PRODUCTIVE AND TECHNOLOGICAL CHARACTERISTICS OF TABLE VARIETIES GROWE IN THE CONDITIONS OF OPLENAC VINEYARDS

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    Investigations were carried out in vineyard of King Petar I Karadjordjevic Foundation of at Oplenac. In experiment were tested four table grapes varieties: Black Magic, Victoria, Michel palieri and Muscat Hamburg. Training system is characterized with height of 90 cm on which Guyot pruning is used. In research is studied vegetative potential, fertility, mechanical composition of grape and berries and sugar content and acidity. In red varieties is determined anthocyanins concentration. Michel palieri was with the largest vegetative potential expressed through shoot mass (0,590 kg/vine). The highest values of fertility parameters (number productive shoots, number of inflorescences on spur and arc, coefficients of fertility) had a variety Muscat Hamburg. The highest sugar content was determined in Muscat Hamburg must, a total acid in Victoria variety must. According to anthocyanins Mikele palieri content variety is dissociate (0.179 mg/g fresh weight)

    VARIATIONS OF CLIMATE PARAMETERS AND THEIR IMPACT ON CABERNET SAUVIGNON AND SAUVIGNON BLANC PHENOLOGY IN CONDITIONS OF CENTRAL SERBIA

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    Research carried out in vineyard of King Peter I Karadjordjevic-Royal Winery at Oplenac-Topola municipality, on Sauvignon blanc and Cabernet sauvignon. Vineyard planted with Sauvignon blanc is geographically positioned at GPS coordinates N 44Ā° 14' 4" and E 20Ā° 41' 15" and Cabernet sauvignon is geographically positioned at GPS coordinates N 44Ā° 14' 35" and E 20Ā° 41' 22". Climat parameters (series from 1982-2011 year) included following parameters: mean monthly, vegetation (april-october) and annual temperature, active and effective temperature, precipitation distribution (annual and vegetation) and wind direction. Phenological observation included beginning and end of following phenophases: bleeding, budbreakt, shoot growing, flowering, berry development and ripening. The greatest variation Sauvignon blanc manifested in duration of grape ripening which is in 2010. lasted 46 days while in 2011. lasted 34 days. Cabernet sauvignon in 2011. had a lower number of days that have passed from bleeding to full maturity (209 days) compared to 2010., when it passed 217 days
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