Results of experimental study of friction effect on mechanical properties of salt rocks

The purpose of the work is to study influence of friction between samples and press plates on mechanical parameters of salt rocks. The main source of information for determining values of mechanical parameters of salt rocks is laboratory tests of rock samples for compression. It is known that values of mechanical parameters determined from results of compression of samples essentially depend on magnitude of frictional force between fronts and plates of a press. Wherein, empirical coefficients of shape used in calculation of values of mechanical parameters corresponding to uniaxial compression do not take into account specific frontal conditions. This leads to a known inaccuracy in formulation of an experiment and interpretation of its results. Thus, relevant studies correspond to more detailed study of influence of friction between samples and press plates on mechanical properties of salt rocks. During experimental studies 75 samples of fine to medium grained rock salt from Verkhnekamsk deposit of potassium salts were tested. The paper presents results of experimental studies directed to determine coefficient of friction of salt rocks according to a scheme "shear with compression" over various surfaces. Studies were carried out on compression of samples of different heights under known contact conditions. The necessary friction value was modeled using manufactured gaskets placed between fronts of samples to be tested for compression and press plates. A full diagram of deformation was build from the compression results of each sample and a set of mechanical parameters was determined. Dependences that reflect an effect of frictional forces between fronts of samples and press plates under compression on values of strength limit, destructive deformation and specific energy consumption of rock salt deformation are determined. Results of the study are intended to improve a method of testing rocks for compression

Lipid Regulators during Atherogenesis : expression of LXR, PPAR, and SREBP mRNA in the Human Aorta

Transcription factors LXRs, PPARs, and SREBPs have been implicated in a multitude of physiological and pathological processes including atherogenesis. However, little is known about the regulation of these transcription factors at different stages of atherosclerosis progression. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to compare the contents of mRNAs in pairs intact-injured aorta fragments taken from the same donors. Only minor changes in LXR?, LXR?, PPAR?, PPAR?, SREBP1, and SREBP2 mRNA levels were found in initial lesions as compared with intact non-diseased tissue. The contents of all mRNAs but SREBP2 mRNA were found to be progressively up-regulated in fatty streaks and fibrous lipoid plaques. These changes were only partially reproduced in cultured macrophages upon lipid loading. Wave-shaped changes in abundance of correlations between given group of mRNAs and 28 atherosclerosis-related mRNA species in the course of atherogenesis were observed. The impact of specific mRNA correlations on the total correlations also significantly varied between different lesion types. The study suggests that the extent and forms of LXR/PPAR/SREBP participation in intima functions vary nonlinear in individual fashion in atherogenesis. We speculate that the observed changes in mRNAs expression and coupling reflect shifts in lipid ligands availability and cellular composition in the course of atherosclerosis progression

Prospects for the Development of the Oil and Gas Industry in the Regional and Global Economy

Problems of energy efficiency, along with increasing environmental safety of production and increasing social responsibility, are becoming a central object of research. Therefore, the main goal of the work is to analyze the prospects for the development of the oil and gas industry. It was established that innovative technologies play an important role in the development of energy. In the structure of public administration, the definition of the place in the close relationship with commodity-money relations, mediating its implementation. But refusal of oil resources will lead to negative consequences. It is established that the maximum production of conventional oil in the world in the amount of 4.5-4.8 billion tons per year will be achieved in 2020-2030. Major areas of conventional oil production in this period will be oil and gas basins of the Persian Gulf, Western and Eastern Siberia, the Caspian sea, the Atlantic shelves of Africa and South America. The achieved level of oil production can be maintained by large-scale involvement in the development of non-traditional sources (bitumen and shale oil). According to the raw material base, the leaders of unconventional oil production should be Venezuela, Canada, Russia and the United States. Keywords: environmental policy, oil production, forecast, coal-fired power plants, economic crisis. JEL Classifications: L100, Q400, Q430

How close can one approach the Dirac point in graphene experimentally?

The above question is frequently asked by theorists who are interested in graphene as a model system, especially in context of relativistic quantum physics. We offer an experimental answer by describing electron transport in suspended devices with carrier mobilities of several 10^6 cm^2V^-1s^-1 and with the onset of Landau quantization occurring in fields below 5 mT. The observed charge inhomogeneity is as low as \approx10^8 cm^-2, allowing a neutral state with a few charge carriers per entire micron-scale device. Above liquid helium temperatures, the electronic properties of such devices are intrinsic, being governed by thermal excitations only. This yields that the Dirac point can be approached within 1 meV, a limit currently set by the remaining charge inhomogeneity. No sign of an insulating state is observed down to 1 K, which establishes the upper limit on a possible bandgap

Efficient location strategy for airport surveillance using mode-s multilateration systems

© Cambridge University Press and the European Microwave Association, 2012[EN] In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér-Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. © Cambridge University Press and the European Microwave Association, 2012.Mr. Ivan A. Mantilla-Gaviria has been supported by a FPU scholarship (AP2008-03300) from the Spanish Ministry of Education. Moreover, the authors are grateful to Thales Italia S. p. A. (Dr. Ing. R. Scaroni) who supplied the geometry of the Multilateration system in Linate (Milan, Italy) airport.Mantilla Gaviria, IA.; Leonardi, M.; Galati, G.; Balbastre Tejedor, JV.; Reyes Davó, EDL. (2012). Efficient location strategy for airport surveillance using mode-s multilateration systems. International Journal of Microwave and Wireless Technologies. 1-8. https://doi.org/10.1017/S1759078712000104S18Bertero, M., Boccacci, P., Brakenhoff, G. J., Malfanti, F., & Voort, H. T. M. (1990). Three-dimensional image restoration and super-resolution in fluorescence confocal microscopy. Journal of Microscopy, 157(1), 3-20. doi:10.1111/j.1365-2818.1990.tb02942.xSchau, H., & Robinson, A. (1987). Passive source localization employing intersecting spherical surfaces from time-of-arrival differences. IEEE Transactions on Acoustics, Speech, and Signal Processing, 35(8), 1223-1225. doi:10.1109/tassp.1987.1165266Gfrerer, H. (1987). An a posteriori parameter choice for ordinary and iterated Tikhonov regularization of ill-posed problems leading to optimal convergence rates. Mathematics of Computation, 49(180), 507. doi:10.1090/s0025-5718-1987-0906185-4[6] Galati G. ; Leonardi M. ; Tosti M. : Multilateration (local and wide area) as a distributed sensor system: lower bounds of accuracy, in European Radar Conf., EuRAD, Amsterdam, 30–31 October 2008.[1]The European Organisation for the Safety of Air Navigation. The ATM surveillance strategy for ECAC, in European Air Traffic Management Programme, Eurocontrol, 2008.Torrieri, D. (1984). Statistical Theory of Passive Location Systems. IEEE Transactions on Aerospace and Electronic Systems, AES-20(2), 183-198. doi:10.1109/taes.1984.310439[12] Perl E. ; Gerry M.J. : Target localization using TDOA distributed antenna, US 2005/0035897 A1, USA, 17 February 2005.[2]The European Organisation for Civil Aviation Equipment. Ed-117, mops for mode s multilateration systems for use in advanced surface movement guidance and control systems (a-smgcs), in EUROCAE (Ed.), EUROCAE, November 2003.Leonardi, M., Mathias, A., & Galati, G. (2009). Two efficient localization algorithms for multilateration. International Journal of Microwave and Wireless Technologies, 1(3), 223-229. doi:10.1017/s1759078709000245Ho, K. C., & Chan, Y. T. (1993). Solution and performance analysis of geolocation by TDOA. IEEE Transactions on Aerospace and Electronic Systems, 29(4), 1311-1322. doi:10.1109/7.259534FOY, W. (1976). Position-Location Solutions by Taylor-Series Estimation. IEEE Transactions on Aerospace and Electronic Systems, AES-12(2), 187-194. doi:10.1109/taes.1976.308294Phillips, D. L. (1962). A Technique for the Numerical Solution of Certain Integral Equations of the First Kind. Journal of the ACM, 9(1), 84-97. doi:10.1145/321105.321114Hanke, M., & Raus, T. (1996). A General Heuristic for Choosing the Regularization Parameter in Ill-Posed Problems. SIAM Journal on Scientific Computing, 17(4), 956-972. doi:10.1137/0917062Golub, G. H., Heath, M., & Wahba, G. (1979). Generalized Cross-Validation as a Method for Choosing a Good Ridge Parameter. Technometrics, 21(2), 215-223. doi:10.1080/00401706.1979.10489751Harrington, R. F. (1993). Field Computation by Moment Methods. doi:10.1109/978047054463

Study of doubly strange systems using stored antiprotons

Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the P‾ANDA experiment at FAIR. For the first time, high resolution γ-spectroscopy of doubly strange ΛΛ-hypernuclei will be performed, thus complementing measurements of ground state decays of ΛΛ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Ξ−-atoms will be feasible and even the production of Ω−-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ω−-nucleus interaction. For the first time it will be possible to study the behavior of Ξ‾+ in nuclear systems under well controlled conditions

Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease

Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.