32 research outputs found

    PEDOLOGICAL STUDY OF LAND SUITABILITY IN THE AREA OF MAVRODIN TELEORMAN COUNTY, REGARDING THE ARRANGEMENT OF IRRIGATION WITH WATER FROM ZOOTECHNICAL COMPLEXES

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    The studied area is located in the center of Teleorman County, belonging to the Mavrodin cadastral territory, currently used as an arable land. The pedological mapping was performed with the purpose of identifying the soil area, assessing its fertility as well as the suitability for irrigation with wastewater. In this regard, a soil profile was opened and several surveys were collected from soil samples in natural and modified settlements, for morphological, physical and chemical analyzes. The soil type identified is red preluvosol. Geomorphologically, the land is part of the Roman Plain, the subunit of Burnaz, between the Danube Lunca, the Vedea, Teleorman and Calniştei valleys, extended west to the Teleorman river and the eastern limit of the county. The ground level is maintained between 8-10 m, with small fluctuations depending on the terrain. The type of soil identified, is classified in the luvisoluri class, having the following sequence of horizons: Ao-AB-Bt-C. The criteria for classification into classes, subclasses and other subunits of land according to the suitability to irrigate with waste water are those mentioned in chap. 10 from MESP, vol II (ICPA, 1987) with some additions. According to Annex 11.1 of the MESP, vol II (ICPA, 1987), the following additional criteria intervene in the selection of lands that can be irrigated with wastewater (soil type, soil texture, soil volume, soil thickness, erosion, soil unevenness, groundwater depth, excess surface moisture, other restrictions

    RESEARCHES ON SOIL CONTAMINATION WITH HEAVY METALS AND THEIR REMANENCE IN VEGETABLES

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     The paper presents the results of experimental researches on soil contamination with heavy metals (copper, lead, zinc) in different concentration each (c1=1.5 %; c2=3.0 %; c3=4.5 %; c4=6.0 %). The contaminated soil was placed in pots, where spinach and radish seeds were planted. The vegetables were grown in a greenhouse until the end of the vegetation period, afterwards being harvested and the remanence of each heavy metal for each concentration was determined for each plant. The results obtained were compared with the blank sample where the soil was not contaminated.        The purpose of the study was to identify the levels of heavy metals (Cu, Zn and Pb) transfer/absorption from the soil into spinach leaves respectively radish roots

    CONSTRUCTION TYPES OF TECHNICAL EQUIPMENT FOR DOSING, WEIGHING, PACKAGING AND PROCEDURES USED IN MILLING UNITS

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    The paper presents several types of technical equipment for dosing, weighing, packaging and the procedures used in the milling units. The weighing systems take into account several important criteria for their design, namely: how the weight or mass of the load is offset and how the result is transferred

    The SKA Particle Array Prototype: The First Particle Detector at the Murchison Radio-astronomy Observatory

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    We report on the design, deployment, and first results from a scintillation detector deployed at the Murchison Radio-astronomy Observatory (MRO). The detector is a prototype for a larger array -- the Square Kilometre Array Particle Array (SKAPA) -- planned to allow the radio-detection of cosmic rays with the Murchison Widefield Array and the low-frequency component of the Square Kilometre Array. The prototype design has been driven by stringent limits on radio emissions at the MRO, and to ensure survivability in a desert environment. Using data taken from Nov.\ 2018 to Feb.\ 2019, we characterize the detector response while accounting for the effects of temperature fluctuations, and calibrate the sensitivity of the prototype detector to through-going muons. This verifies the feasibility of cosmic ray detection at the MRO. We then estimate the required parameters of a planned array of eight such detectors to be used to trigger radio observations by the Murchison Widefield Array.Comment: 17 pages, 14 figures, 3 table

    ASPECTS ON THE CONSTRUCTION AND OPERATION OF SPRAYING EQUIPMENT FOR REDUCING DRIFT IN FIELD CROPS

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    The paper presents innovative solutions on the construction si operation of spraying machines in the view of reducing drift in field crops: with innovative electrostatic spraying system, with special panels with static condenser, nozzle protection system, spraying devices provided with hoods, downward air curtain system and with shielded system with caps for controlling drop dispersion. The paper is important, on the one hand, for producers of spraying equipment for reducing drift and, on the other hand, for farmers in the view of efficiently applying treatments in field crops, but also for reducing environmental pollution

    Efficient Induction of Extrinsic Cell Death by Dandelion Root Extract in Human Chronic Myelomonocytic Leukemia (CMML) Cells

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    BACKGROUND: Chronic Myelomonocytic Leukemia (CMML) is a heterogeneous disease that is not only hard to diagnose and classify, but is also highly resistant to treatment. Available forms of therapy for this disease have not shown significant effects and patients rapidly develop resistance early on in therapy. These factors lead to the very poor prognosis observed with CMML patients, with median survival duration between 12 and 24 months after diagnosis. This study is therefore centered around evaluating the selective efficacy of a natural extract from dandelion roots, in inducing programmed cell death in aggressive and resistant CMML cell lines. METHODOLOGY/PRINCIPAL FINDINGS: To confirm the induction of programmed cell death in three human CMML cell lines, nuclear condensation and externalization of the phosphatidylserine, two main characteristics of apoptosis, were detected using Hoechst staining and annexin-V binding assay. The induction of another mode of cell death, autophagy, was determined using a monodansylcadaverine (MDC) stain, to detect the formation of autophagy vacuoles. The results from this study indicate that Dandelion Root Extract (DRE) is able to efficiently and selectively induce apoptosis and autophagy in these cell lines in a dose and time dependent manner, with no significant toxicity on non-cancerous peripheral blood mononuclear cells. More importantly, we observed early activation of initiator caspase-8, which led to mitochondrial destabilization and the induction of autophagy, suggesting that DRE acts through the extrinsic pathway of apoptosis. The inability of DRE to induce apoptosis in dominant-negative FADD cells, confirms the mechanism of action of DRE in in vitro models of CMML. CONCLUSION: The results from this study indicate that natural products, in particular Dandelion Root Extract, have great potential, as non-toxic and effective alternatives to conventional modes of chemotherapy available today

    A Gaussian-processes approach to fitting for time-variable spherical solar wind in pulsar timing data

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    Propagation effects are one of the main sources of noise in high-precision pulsar timing. For pulsars below an ecliptic latitude of 5°, the ionized plasma in the solar wind can introduce dispersive delays of order 100 µs around solar conjunction at an observing frequency of 300 MHz. A common approach to mitigate this assumes a spherical solar wind with a time-constant amplitude. However, this has been shown to be insufficient to describe the solar wind. We present a linear, Gaussian-process piecewise Bayesian approach to fit a spherical solar wind of time-variable amplitude, which has been implemented in the pulsar software RUN_ENTERPRISE. Through simulations, we find that the current EPTA+InPTA data combination is not sensitive to such variations; however, solar wind variations will become important in the near future with the addition of new InPTA data and data collected with the low-frequency LOFAR telescope. We also compare our results for different high-precision timing data sets (EPTA+InPTA, PPTA, and LOFAR) of 3 ms pulsars (J0030+0451, J1022+1001, J2145−0450), and find that the solar-wind amplitudes are generally consistent for any individual pulsar, but they can vary from pulsar to pulsar. Finally, we compare our results with those of an independent method on the same LOFAR data of the three millisecond pulsars. We find that differences between the results of the two methods can be mainly attributed to the modelling of dispersion variations in the interstellar medium, rather than the solar wind modelling

    Practical approaches to analyzing PTA data: Cosmic strings with six pulsars

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    We search for a stochastic gravitational wave background (SGWB) generated by a network of cosmic strings using six millisecond pulsars from Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA). We perform a Bayesian analysis considering two models for the network of cosmic string loops, and compare it to a simple power-law model which is expected from the population of supermassive black hole binaries. Our main strong assumption is that the previously reported common red noise process is a SGWB. We find that the one-parameter cosmic string model is slightly favored over a power-law model thanks to its simplicity. If we assume a two-component stochastic signal in the data (supermassive black hole binary population and the signal from cosmic strings), we get a 95%95\% upper limit on the string tension of log10(Gμ)<9.9\log_{10}(G\mu) < -9.9 (10.5-10.5) for the two cosmic string models we consider. In extended two-parameter string models, we were unable to constrain the number of kinks. We test two approximate and fast Bayesian data analysis methods against the most rigorous analysis and find consistent results. These two fast and efficient methods are applicable to all SGWBs, independent of their source, and will be crucial for analysis of extended data sets.Comment: 13 pages, 5 figure

    The second data release from the European Pulsar Timing Array I. The dataset and timing analysis

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    Pulsar timing arrays offer a probe of the low-frequency gravitational wave spectrum (1 - 100 nanohertz), which is intimately connected to a number of markers that can uniquely trace the formation and evolution of the Universe. We present the dataset and the results of the timing analysis from the second data release of the European Pulsar Timing Array (EPTA). The dataset contains high-precision pulsar timing data from 25 millisecond pulsars collected with the five largest radio telescopes in Europe, as well as the Large European Array for Pulsars. The dataset forms the foundation for the search for gravitational waves by the EPTA, presented in associated papers. We describe the dataset and present the results of the frequentist and Bayesian pulsar timing analysis for individual millisecond pulsars that have been observed over the last ~25 years. We discuss the improvements to the individual pulsar parameter estimates, as well as new measurements of the physical properties of these pulsars and their companions. This data release extends the dataset from EPTA Data Release 1 up to the beginning of 2021, with individual pulsar datasets with timespans ranging from 14 to 25 years. These lead to improved constraints on annual parallaxes, secular variation of the orbital period, and Shapiro delay for a number of sources. Based on these results, we derived astrophysical parameters that include distances, transverse velocities, binary pulsar masses, and annual orbital parallaxes.Comment: 29 pages, 9 figures, 13 tables, Astronomy & Astrophysics in pres
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