5,782 research outputs found

    Investigation of the magnetic field from the AMS Luna-10

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    Magnitude and nature of lunar magnetic field observed from Lunik X prob

    Development of specific RAPD markers for identifying albino tea cultivars ‘Qiannianxue’ and ‘Xiaoxueya’

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    Albino tea cultivars grow white leaves at low temperature which are valuable materials for processing green tea, but they develop green leaves in summer and autumn seasons. It is difficult to discriminate albino tea cuttings from the normal tea cuttings by leaf colour and plant morphological characteristics.Specific RAPD markers for identifying albino tea cultivars ‘Qiannianxue’ and ‘Xiaoxueya’ were developed in the present paper and they can be used in the authentication of the two albino tea cultivars. An amplified fragment (about 1500 bp) from Primer (S 12 (Sangon Biological Engineering Technology and Services Co., Ltd.) was identified in the albino teas and not from the widely cultivated cultivar; Fudingdabai

    A Computationally Efficient Method for Estimating Multi-Model Process Sensitivity Index

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    Identification of important processes of a hydrologic system is critical for improving process-based hydrologic modeling. To identify important processes while jointly considering parametric and model uncertainty, Dai et al. (2017), https://doi.org/10.1002/2016WR019715, developed a multi-model process sensitivity index. Numerical evaluation of the index using a brute force Monte Carlo (MC) simulation is computationally expensive, because it requires a nested structure of parameter sampling and the number of model simulations is on the order of N-2 (N being the number of parameter samples). To reduce computational cost, we develop a new method (here denoted as quasi-MC for brevity) that uses triple sets of parameter samples (generated using quasi-MC sequence) to remove the nested structure of parameter sampling in a theoretically rigorous way. The quasi-MC method reduces the number of model simulations from the order of N-2 to 2N. The performance of the method is assessed against the brute force MC approach and the recent binning method developed by Dai et al. (2017), https://doi.org/10.1002/2016WR019715, through two synthetic cases of groundwater flow and solute transport modeling. Due to its rigorous theoretical foundation, the quasi-MC method overcomes the limitations imposed by the inherently empirical nature of the binning method. We find that the quasi-MC method outperforms both the brute force MC and the binning method in terms of computational requirements and theoretical aspects, thus strengthening its potential for the assessment of process sensitivity indices subject to various sources of uncertainty

    Voltage dependent conductance and shot noise in quantum microconstriction with single defects

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    The influence of the interference of electron waves, which are scattered by single impurities and by a barrier on nonlinear conductance and shot noise of metallic microconstriction is studied theoretically. It is shown that the these characteristics are nonmonotonic functions on the applied bias.Comment: 18 pages,5 figure

    Temperature and Salt Responsive Amphoteric Nanogels Based on N-Isopropylacrylamide, 2-Acrylamido-2-methyl-1-propanesulfonic Acid Sodium Salt and (3-Acrylamidopropyl) Trimethylammonium Chloride

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    Polyampholyte nanogels based on N-isopropylacrylamide (NIPAM), (3-acrylamidopropyl) trimethylammonium chloride (APTAC) and 2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt (AMPS) were synthesized via conventional redox-initiated free radical copolymerization. The resultant nanogels of various compositions, specifically [NIPAM]:[APTAC]:[AMPS] = 90:5:5; 90:7.5:2.5; 90:2.5:7.5 mol.%, herein abbreviated as NIPAM(90)-APTAC(5)-AMPS(5), NIPAM(90)-APTAC(7.5)-AMPS(2.5) and NIPAM(90)-APTAC(2.5)-AMPS(7.5), were characterized by a combination of H-1 NMR and FTIR spectroscopy, TGA, UV-Vis, DLS and zeta potential measurements. The temperature and salt-responsive properties of amphoteric nanogels were studied in aqueous and saline solutions in a temperature range from 25 to 60 degrees C and at ionic strengths (mu) of 10(-3) to 1M NaCl. Volume phase transition temperatures (VPTT) of the charge-balanced nanogel were found to reach a maximum upon the addition of salt, whereas the same parameter for the charge-imbalanced nanogels exhibited a sharp decrease at higher saline concentrations. A wide bimodal distribution of average hydrodynamic sizes of nanogel particles had a tendency to transform to a narrow monomodal peak at elevated temperatures and higher ionic strengths. According to the DLS results, increasing ionic strength results in the clumping of nanogel particles.Peer reviewe

    A Methodological Approach to the Selection of Priority Areas for the Export of Educational Services Based on the Analysis of Indicators of Foreign Trade

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    The article presents the key indicators reflecting the number of foreign students studying in Ukraine and the volume of demand for educational services in the countries that are their main suppliers. Furthermore, it justifies the procedure of ranking potential competitors of Ukraine in the world market of educational services as well as the selection of components of a comprehensive strategy for the state program to support the export potential of higher education institutions based on the grouping of priority export territories in view of the requirements of potential consumers, who have so far been choosing other countries to study abroad, to the infrastructure of national educational systems. It is proposed to use a combination of ranking methods, cluster and discriminant analysis when choosing priority geographic areas for the export of educational services and a list of measures aimed at improving the international competitiveness of the national education system and individual educational institutions, which together form a universal algorithm for determining the necessary set of measures at successive stages of developing a strategy for the country’s entry into the global market for educational services

    Polymorphism of the pig-implantation protein 3 (preis3) gene and its association with litter size traits

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    The pre-implantation protein 3 (prei3), which might play a role in pre-implantation embryogenesis, is one of the promising candidate genes for litter size traits in pigs. In this study, a single nucleotide polymorphism (SNP: T802G) in intron 6 of the pig prei3 gene was detected and a genotyping assay for this SNP was developed. An association study for this SNP with litter size was performed in two independent populations. One population consisted of crossbred sows derived from Landrace, Large White, Chinese Tongcheng and/or Chinese Meishan (Line DIV). The other population constituted of crossbred animals derived from Chinese Qingping and Duroc (QD). Statistical analysis demonstrated that, in first parity, 2.65 more piglets were born and 3.82 more piglets were born alive in sows in Line DIV with genotype TT than with genotype GG. For second and subsequent litters, in both the DIV and QD lines there were significant differences in the number of piglets born alive between TG and GG sows, with the TG sows producing more piglets born alive than the GG sows. These results suggest that the prei3 SNP is significantly associated with litter size in the two populations studied, and could be useful in selection for increasing litter size in pigs. Further investigations on more pig populations with large sample sizes are needed to confirm this. South African Journal of Animal Science Vol. 36(3) 2006: 209-21

    Prototyping of a concrete maturity sensor with a hermetically sealed housing made of two-component plastic

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    The construction industry, traditionally considered quite conservative, is now going through a marked change. With competition intensifying, companies have begun to gradually adopt various digital technologies to reduce construction costs, such as the wireless concrete monitoring sensors, which implement a temperature-strength monitoring method for concrete. Each device has its technological features, which are considered in the development of the concepts. Enclosure design is the most important stage of product development. An enclosure made in-house has many advantages and disadvantages. The most important part of the design of an electronic device enclosure is the preliminary research stage. This article presents features of wireless monitoring sensor enclosure design. A data acquisition station (DAS), also referred to in the network topology as a “gateway”, will be used to collect data from the wireless monitoring sensor over the selected protocol. The server application was created based on HTML, PHP, CSS, JavaScript. Testing of the wireless monitoring sensor, SDS, and the server application working together showed full functionality. A study is also given on the determination of concrete strength using the developed sensor according to the ASTM method and using the IPS MG 4.0 by GOST

    Morphological Changes in the Hepatic Tissue at the Impact of Industrial Copper-bearing Dust in the Experiment

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    BACKGROUND: It is known that an increased intake of copper (Cu) has an adverse effect, and above all leads to the defeat of parenchymal organs, including liver tissue. AIM: This study the morphological changes in the hepatic tissue at the impact of polymetallic Cu dust. METHODS: An experimental study was carried out on the outbred white male rats. Dust was injected once intratracheally at a dose of 50 mg. For dynamic observation, the animals were killed in 1, 3, and 6 months with the control group using instant decapitation. The Balkhash industrial polymetallic dust with a predominant Cu content (Cu-0.6%) was used for the study. Morphological changes were assessed using histological and morphometric methods. RESULTS: Morphometric examination of liver tissue at 30 days showed Vv necrosis increasing in 320 times in Group 2 (p < 0.001), Vv infiltrates – in 121 times (p < 0.001), Vv dystrophic altered hepatocytes – in 19.91 times (p < 0.001), Vv dual-core cells – in 23 times (p < 0.01), and Vv fibrosis – in 2.82 times (p < 0.001) in comparison with Group 1. Vv portal tracts are not reliably changed. In 90 days, there were also the following morphometric parameters increasing in comparison with the control group: Vv necrosis – in 522 times (p < 0.001), Vv infiltrates – in 395 times (p < 0.001), Vv dystrophic altered hepatocytes – in 26.7 times (p < 0.001), Vv dual-core cells – in 314 times (p < 0.01), and Vv fibrosis – in 13.27 times (p < 0.001). On the 180 day of the experiment, there was the increasing of Vv infiltrates in 421 times (p < 0.001), Vv dystrophic altered hepatocytes – in 34.09 times (p < 0.001), Vv dual-core cells – in 411 times (p < 0.001), and Vv fibrosis – in 54.09 times (p < 0.001) CONCLUSION: The impact of polymetallic dust with 0.6% Cu concentration at the early stages leads to the changes in the liver in the form of reactive hepatitis with the following transformation into portal-type hepatitis
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